JP3177618B2 - Releasing control device in feeder for press working - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a releasing control device for a material feeding device for press working.

[0002]

2. Description of the Related Art In general, in the case of press working, a product is rarely completed in one step, and a finished product is obtained through a plurality of steps. For example, in a press machine of a progressive press working type, press working in a plurality of steps can be performed simultaneously, and a material (for example, a plate material) intermittently fed by a feed device is processed in a process order.

Since an error occurs in the feed amount at the time of the intermittent feed, high-precision press working cannot be performed as it is, and it is necessary to correct the position of the material. That is, for the purpose of correcting the feeding error, the holding of the material is released (releasing) when the press is lowered, and the pilot pin is inserted into the pilot hole previously formed in the material, and the position error is corrected. Upon completion, the material is retained again.
Such an operation is performed based on an on / off signal from a cam switch linked to the crankshaft of the press machine, and is called a release operation.

By the way, since there is an operation delay time from when the feeder receives the signal for release until it actually releases the holding or re-holding, it is necessary to consider this operation delay. Without accurate measurement,
Since the operation point of the cam switch was determined by repeating the trial and error by operating the press machine many times, it was troublesome. Further, when the rotation speed of the press machine is changed, it is necessary to determine the operating point of the cam switch again by trial and error.

[0005] As an operation delay, there is a time delay from when the release operation output signal is output to the release solenoid valve or the release solenoid until the release device operates.

Accordingly, the applicant of the present invention has previously filed an application for solving such a problem (Japanese Patent Publication No. 2-3-3).
No. 6336). In this device, the release angle is set (release angle and re-hold angle), the operation delay time of the feeder is input, and the rotation speed of the drive shaft is further input to allow for the delay time, and the release An angle to issue a command and an angle to issue a re-hold command are calculated, and when the rotation angle of the drive shaft matches the calculated angle, a hold release command and a re-hold command are output to the feeder. . This allows
Even without mechanical adjustment by trial and error, the accuracy of the releasing control is improved.

[0007]

However, in the above-mentioned conventional releasing control apparatus of the applicant of the present invention, the angle at which the holding release command should be issued and the re-holding time should be taken in consideration of the operation delay time of the feeder. The angle at which the command is to be issued is calculated, and when the rotation angle of the drive shaft matches the calculated angle, the holding release command and the re-holding command are output to the feeder. Sometimes it is necessary to input shaft rotation angle detection means for detecting the angle of the crankshaft of the press. In practice, a rotary encoder has been used as the shaft rotation angle detection means. This rotary encoder is an extremely expensive device, and as a result, there is a problem that the cost of the device increases.

In the conventional apparatus, the output signal of the rotary encoder is used as shaft rotation angle detecting means, and the rotation speed of the drive shaft of the press machine is calculated by a microcomputer. A microcomputer capable of withstanding the burden was required, and the cost had risen from this aspect as well. Therefore,
It is preferable to simply use a small-scale processor used for the feeding device because the cost is reduced.

Further, when actually assembling and manufacturing a conventional device, a new circuit (for example, an arithmetic process in consideration of an input signal processing and an operation delay time) is used instead of using an existing circuit before that. , Counter 39 of the conventional device, etc.)
Was necessary, which led to an increase in cost.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a release control device for a press feeder capable of performing accurate release control without increasing costs.

[0011]

In order to achieve the above object, a releasing control device in a feeder for press working according to the present invention holds a plate material for press working by a feeder and sends it to a press machine for press working. At an appropriate time, the release command control means outputs a release operation command to release the holding of the plate by the feeder to correct the position, and after a predetermined time elapses, stops the output of the release command to stop the plate. In the feed device for press working, wherein the rotary cam switch is operated in conjunction with the crankshaft of the press machine, and the rotary cam switch outputs a release command. Including a switch and an early signal switch that operates at least before the release command switch The operation delay time of the feeder from when the release operation command is output to when the release operation is actually performed, and the return delay time of the feeder after the release operation command is stopped and the release operation is actually released are determined. A delay time setting means for setting, a first time from when the output signal of the early signal switch rises to when a release command which is an output signal of the release command switch rises, and when the output signal of the early signal switch rises And measuring means for measuring a second time until a release command, which is an output signal of the release command switch, falls, and the release command control means, when the output signal of the early signal switch rises, After a lapse of time obtained by subtracting the operation delay time from the first time, the release operation command is output, and the second operation After the time obtained by subtracting the return delay time from between, characterized in that so as to stop the output of the release actuation command.

[0012]

In the present invention, the operation delay time and the return delay time of the feeder are determined in advance by experiments and the like, and are input to the release command control means (for example, realized by a microcomputer) and set (for example, stored). You. And
The first time and the second time are measured, and when the output signal of the early signal switch rises, after a lapse of a time obtained by subtracting the operation delay time from the first time, a release operation command is sent to the feeding device (for example, , A release solenoid valve or a release solenoid), the holding of the plate material is released, and the position is corrected. Thereafter, after a lapse of a time obtained by subtracting the return delay time from the second time, the output of the release operation command is stopped, and the plate is held again.

Therefore, the release operation command is output to the release solenoid valve or the release solenoid earlier than the output signal of the release command switch, and the release operation command is similarly stopped earlier.
The so-called release command input matches the actual release operation position of the feeder, and the releasing control is performed accurately.

In this case, there is no need to use a rotary encoder for detecting the angle of the crankshaft of the press machine, and there is no need to calculate the rotational speed of the crankshaft by a microcomputer using the output signal of the rotary encoder. Therefore, a microcomputer that can withstand a large calculation load is not required, and a small-scale processor used for the feeder can be simply used. Therefore, the cost is reduced.

Further, the existing circuit of the conventional device can be used, and a new circuit is not required for processing input signals from the respective switches and arithmetic processing in consideration of the operation delay time. Even lower costs.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 to FIG. 4 are views showing an embodiment of a releasing control device in a press feed device according to the present invention. FIG.
FIG. 3 is a diagram showing a hardware configuration of the present apparatus. In FIG. 1, reference numeral 1 denotes a microcomputer, which includes a CPU, a memory (for example, a ROM and a RAM), and an I / O port.

The microcomputer 1 also realizes a function other than the releasing control of the feeder (for example, a normal feed control).
In order to realize the functions of the present invention, it means that the configuration utilizes a part of the functions of the microcomputer 1 used in the conventional device. Microcomputer 1
Has a function as a release command control unit and a measurement unit.

Reference numeral 2 denotes a crankshaft of the press machine. The crankshaft 2 is connected to a sprocket 4 via a chain 3. The sprocket 4 is fixed to a shaft 6 of a rotary cam switch 5, and the rotary cam switch 5 includes two cams 11 and 12 and an early signal switch 1 described later.
3. It has a release command switch 14. Therefore, the shaft 6 of the rotary cam switch 5 rotates in conjunction with the crankshaft 2.

The cams 11 and 12 are provided with limit switch type early signal switches 13 and release command switches 14, respectively. The early signal switch 13 outputs an ON signal which becomes “H” level at the timing when the cam 11 rotates by a predetermined angle in conjunction with the rotation of the crankshaft 2. Is stopped (that is, the level of the ON signal becomes “L”). This ON signal is called an early signal.

The ON signal in this embodiment is a signal in an active state. Therefore, in this case, the "H" level is active and the "L" level is non-active. On the other hand, it is also possible to use the “L” level as an active state, in which case,
It is so-called low active. Thus, the form of the ON signal is not limited to the method of the present embodiment.

In the claims, "the output signal rises" means an active state, and "the output signal falls" means a non-active state.

The early signal is output at an early timing when executing the releasing control, and serves as a reference for executing the release instruction. FIG. 2 is a timing chart of the releasing control, and FIG. 2 shows a period in which the early signal is at the “H” level. In FIG. 2, the early signal becomes "H" at timing a and "L" at timing f.

In this embodiment, the early signal switch 13 is configured to share a normal feed command switch. That is, the feed command is usually supplied by an input device such as a rotary cam switch that operates in conjunction with the crankshaft 2 of the press.

Specifically, when a switch on the operation panel is depressed and a start signal is sent from the start switch to the input device, a feed command signal is output from the input device and the process proceeds to the sheet feeding process. A feed command switch that outputs such a feed command is used as the early signal switch 13. Therefore, when the feed command input is used as the early signal input, the return point f (see FIG. 2) of the early signal input is the starting point of the feed operation.

On the other hand, the release command switch 14 outputs a command for executing the releasing control, and is set to the "H" level at a later timing than the earlier signal switch 13. The release command switch 14 outputs an ON signal that goes to an “H” level at the timing when the cam 12 rotates by a predetermined angle in conjunction with the rotation of the crankshaft 2. Thereafter, when the cam 12 further rotates by a certain angle, the ON signal is output. The output is stopped (that is, the level of the ON signal becomes “L”). This ON signal is called a release command signal.

FIG. 2 shows a period in which the release command signal is at "H" level. In FIG. 2, the release command signal becomes “H” at timing b and “L” at timing c.
Becomes Therefore, the early signal switch 13 is turned on earlier than the release command switch 14.

Signals from the early signal switch 13 and the release command switch 14 are input to the microcomputer 1. The microcomputer 1 also receives numerical data from the numerical value setting device 20.

On the other hand, 30 is a known feeding device, and the feeding device 30 has two rollers 31 and 32 arranged vertically. The lower roller 31 is fixed to a shaft (not shown), and this shaft is connected to a motor (not shown) and is driven to rotate at a fixed position. The upper roller 32 is moved up and down by a release operation cylinder 41 using air.

The cylinder part 4 of the release operation cylinder 41
2 is disposed below the lower roller 31, and a rod 44 that projects upward from the cylinder portion 42 is connected to a piston portion 43 that slides in the cylinder portion 42. The release operation cylinder 41 is operated by the compressed air pressure of the compressed air source 52 under the control of the electromagnetic valve 51.

In the feed device 30, the upper roller 32 is urged toward the lower roller 31 by the release operation cylinder 41, and a coil-shaped plate (not shown in the figure: corresponding to a plate for pressing) is urged between the rollers 31 and 32. Hold in between. In this holding state, the lower roller 31 is driven to rotate for a predetermined time to feed the plate material to the press. In the press machine, when the upper die moves up and down due to the rotation of the crankshaft 2 and the coil material is stopped, press working is performed by repeating the pressing of each step by a punch (not shown).

Further, when performing the press working as described above,
At an appropriate time, the microcomputer 1 outputs a release operation command 61 to the electromagnetic valve 51 to operate the release operation cylinder 41 to release the holding of the plate material by the feeder 30 and correct the position. ,
The output of the release operation command 61 is stopped, and the plate material is held again.

In FIG. 2, the release operation command 61 is "H".
Indicates the level period. The release operation command 61 becomes “H” at timing d and becomes “L” at timing e. Therefore, the release operation command 61 is output earlier than the release command switch 14.

In the above description, the release operation cylinder 41
Is controlled by a releasing control device 60 which is a feature of the present invention. The releasing control device 60 includes the microcomputer 1, the rotary cam switch 5, and the numerical value setting device 20 described above. The numerical value setter (delay time setting means) 20 is an operation delay time T1 of the feeder 30 from when the microcomputer 1 outputs the release operation command 61 to when the microcomputer 1 actually performs the release operation.
(See FIG. 2) and a return delay time T2 (see FIG. 2) of the feeder 30 from when the release operation command 61 is stopped to when the release operation is actually released. It is composed of numeric keys.

Here, the operation delay time T1 and the return delay time T2 are both determined in advance by experiments or the like from the operation state of the feeder 30 in the press. For example, each of the delay times T1 and T2 is constant depending on the type of the press machine, and once obtained, the values can be used until the influence of a change with time or the like becomes remarkable thereafter. The obtained value is input and set by the operator from the numerical value setting device 20.

The microcomputer 1 has a C
CPU including PU, memory, I / O port
Executes arithmetic processing required for the releasing control according to a program stored in the memory, and the memory stores programs and data, temporarily stores necessary data, and the like.

Specifically, the microcomputer 1 comprises:
A first time S1 (see FIG. 2) from when the output signal of the early signal switch 13 rises to when a release command signal which is an output signal of the release command switch 14 rises;
A second time S2 (see FIG. 2) from the rise of the output signal of the early signal switch 13 to the fall of the release command signal, which is the output signal of the release command switch 14, is measured, and the output of the early signal switch 13 is measured. When the signal rises, after a lapse of time obtained by subtracting the operation delay time T1 from the first time S1, a release operation command 61 is issued.
Is output to the electromagnetic valve 51, and after the lapse of a time obtained by subtracting the return delay time T2 from the second time S2, the output of the release operation command 61 to the electromagnetic valve 51 is stopped.

Next, the operation of the present apparatus will be described. 3 and 4 are flowcharts showing a subroutine program of the releasing control. The releasing control is executed as a part of the processing performed by the microcomputer 1, and this is executed in the timer interrupt processing every 0.01 seconds. Therefore, the processing routine is a subroutine.

The processing for setting the operation delay time T1 and the return delay time T2 of the feed device 30 is executed in other parameter setting functions in the microcomputer 1, and therefore, the description of the release processing subroutine is omitted. I have. That is, since the operation delay time T1 and the return delay time T2 of the feeder 30 are substantially constant depending on the structure of the feeder 30, they are measured in advance, and
And stores it in the memory of the microcomputer 1.

In this case, an operation delay time T1 from the output of the release operation command 61 to the actual execution of the release operation by the feeder 30 is obtained as a numerical value T1 with a timer interrupt time interval of 0.01 second as a unit. . Further, a return delay time T2 from when the output of the release operation command 61 is stopped to when the release operation is returned is obtained as a numerical value T2 in units of a timer interrupt time interval of 0.01 second.

Next, the flags and memories used in the release processing subroutine will be described as follows. Early signal flag: Stores that an early signal is input and release processing is being executed. S1 memory: Measures the time from input of an early signal to input of a release command. S1 flag: Set when the measurement of the time from the input of the early signal to the input of the release command is completed,
The fact that the measurement is completed is stored.

S2 memory: Measures the time from the input of the early signal until the release command is no longer input. S2 flag: Set when the measurement of the time from the input of the early signal to the end of the release command input ends, and stores the end of the measurement.

T1 memory: A value in which a delay time from when the release operation command is output to when the release operation is actually performed is set as a parameter is stored. T2 memory: stores a value set as a parameter of a delay time from when the release operation command is stopped to when the release operation is actually returned.

D1 memory: Used to control the time from when an early signal is input to when a release operation command is output. When the early signal flag is set, the result of S1-T1 is stored. D2 memory: Used to control the time from when the early signal is input to when the release operation command is stopped.
When the early signal flag is set, S2-T2
Is stored.

When the release processing subroutine starts, first, an early signal is determined in step S1, and an early signal flag is determined in step S2. As described above, since the early signal switch 13 is also used as a feed command input switch, the feed command input is used as the early signal input, and the return point f of the early signal input (FIG. 2) Is the starting point of the feed operation. If there is no early signal and no early signal flag, the routine returns without executing the release processing.

On the other hand, if there is an early signal input and there is no early signal flag (step S3), the flow advances to step S4 to set the early signal flag and store the result of [S1-T1] in the D1 memory. Then, the result of [S2-T2] is stored in the D2 memory.

The calculation of S1 and S2 will be described below, as described above. That is, the first time S1 is the time a when the rising edge of the output signal of the early signal switch 13 is input for each of the above timer interrupts.
, The number of interrupts up to the point b at which the rising edge of the output signal of the release command switch 14 is input is counted, and the counted number of interrupts is set as S1.

The second time S2 starts from the time point a at which the rising edge of the output signal of the early signal switch 13 is input for each of the above-described timer interrupts, and starts from the release command switch 14.
Is calculated by counting the number of interrupts up to the time point c when the falling edge of the output signal is input, and setting the counted number of interrupts as S2.

In this manner, the time from the input of the rising edge of the output signal of the early signal switch 13 to the input of the rising edge of the output signal of the release command switch 14 is measured by the following equation: S1 × 0.01 second You. On the other hand, early signal switch 1
The time from the input of the rising edge of the output signal of No. 3 to the input of the falling edge of the output signal of the release command switch 14 is measured by the following equation: S2 × 0.01 seconds.

By the processing in step S4, the time from when the early signal is input to the time when the release operation command is output and the time when the release operation command is stopped are D1 and D2.
2 are stored. Further, [0] is stored in S1 and S2, and measurement of the time until the release command input is input and the time until the input is no longer started are started.

The relationship between D1 and D2 is shown in FIG. If there is no early signal (step S1) and there is an early signal flag (step S2), the process jumps to step S5. Similarly, when there is an early signal flag in step S3, the process jumps to step S5.

There is an early signal flag (step S
2) If there is no S1 flag (step S5), the process proceeds to step S6, where S1 and S2 for measuring the time from the early signal input to the release command input are incremented.

Next, in step S7, a release command input is determined. There is an early signal flag (step S
2) When there is no S1 flag (step S5), and when there is a release command input (step S7), since the measurement of the time from the input of the early signal to the input of the release command is completed, step S8 is performed. To set the S1 flag to store that the measurement of the S1 time has been completed.

Next, in step S9, it is determined whether or not D1 = 0, and if D1 is not 0, the release operation command 61 (the sign of the release operation command 61 is not changed) when there is a release command input. Is omitted), the process proceeds to step S10, and the storage of D1 is changed to [0].
To output the release operation command. This is to prevent malfunction. If there is no release command input in step S7, the process jumps to step S11, and if D1 = 0 in step S9, the process jumps to step S11.

Thereafter, it is determined again in step S11 whether D1 = 0. If D1 is not 0, D1 is decremented in step S12. When D1 becomes 0 as a result of the decrement (step S13), a release operation command is output (output at point d in FIG. 2) in step S14. Thereby, from the previous measurement time S1 from the input of the early signal to the input of the release command,
The release operation command is output earlier by the release operation delay time T1. By the processing in step S14, a release operation command is output to the electromagnetic valve 51, the release operation cylinder 41 is operated, the holding of the plate material by the feed device 30 is released, and the position is corrected.

In this case, after the processing as in the present embodiment, it is possible to output the release operation command earlier by the release operation delay time T1 than the measurement time from the input of the early signal to the input of the release command signal. it can. Therefore, the timing at which the release command signal, which is the output signal of the release command switch 14, rises (the operation position of the release command switch 14) can be made to coincide with the actual release operation position of the feeder 30, and accurate releasing control can be performed. It can be performed.

That is, the timing for outputting the release operation command can be extremely accurately executed. Next, in step S15, it is determined whether or not D2 = 0. When D1 = 0 (step S11) and when D1
If 1 is not 0 (step S13), step S1
Go to 5.

When D2 is not 0 in step S15,
Proceeding to step S16, D2 is decremented. When D2 becomes 0 as a result of the decrement (step S17), the output of the release operation command is stopped in step S18 (the output is stopped at point e in FIG. 2).

Thus, the output of the release operation command is stopped earlier by the release operation return delay time T2 than the previous measurement time S2 from the input of the early signal to the return of the release command input. That is, the output of the release operation command to the electromagnetic valve 51 is stopped, the operation of the release operation cylinder 41 is stopped, and the plate material is held again by the feed device 30.

In this case, after the processing as in the present embodiment, the output of the release operation command 61 is stopped earlier by the release return delay time T2 than the measurement time from when the early signal is input to the release command return. be able to.
Therefore, the timing at which the release command signal, which is the output signal of the release command switch 14, falls (the operating position of the release command switch 14) and the actual feed device 30
Can be made to coincide with the release return position, and accurate releasing control can be performed. In other words,
The timing for stopping the output of the release operation command can be executed extremely accurately.

After step S18, the process returns.
When D2 = 0 (step S15) and when D2 is not 0 (step S17), the process returns.

On the other hand, if there is an S1 flag in step S5, the process proceeds to step S19 in FIG.
1 flag is determined. There is an S1 flag (step S
5) If there is no S2 flag (step S19), S2 is incremented in step S22. Then, in step S23, a release command input is determined. If there is a release command input, the process returns to step S15 via R1, and if there is no release command input, the process proceeds to step S24 to set the S2 flag and release operation command. Is stopped, and D2 is set to [0].

Since there is an S1 flag (step S
5), since the release command input has disappeared after the release command input, D2 is decremented before that, so that D2 becomes [0] and the output of the release operation command should be stopped. However, the output of the release operation command is stopped just in case, and [0] is stored in D2. This is to prevent malfunction.

On the other hand, there is an S1 flag (step S
5) If there is also an S2 flag (step S1)
9), an early signal input is determined in step S20, and if there is an early signal input, the process returns. If there is no early signal input, in step S21, an early signal flag, S1 flag, S1
Reset both flags and return. By resetting each flag, the release processing ends and the routine returns.

Here, in comparison with a conventional device (see Japanese Patent Publication No. 2-36336) filed by the applicant of the present invention, the conventional device detects the rotation angle of the drive shaft of a press machine, and Since the release control is performed by changing the time to the time, a process of shifting from the rotation angle to the time is necessary, which is complicated and troublesome, and the cost is increased. However, in the case of the present invention, attention is paid to time. Since the time processing is immediately performed, there is an effect that the processing is simple and the cost can be reduced.

Then, after performing the accurate releasing control as described above, the plate material is pressed. Since the operation delay time T1 of the release operation and the return delay time T2 are similar, the processing may be performed by setting only T1. In this case, the return delay time T
The setting of 2 can be omitted.

Further, the present invention is not limited to the example using a microcomputer as in the above embodiment, but can be realized by an electronic circuit.

[0067]

As described above, according to the present invention,
Since the release operation command is output to the feeder earlier than the output signal of the release command switch, the output of the release operation command is also stopped earlier, so that the so-called release command input and the actual release operation of the feeder are performed. The position can be matched, and the release control can be performed accurately.

In executing this accurate releasing control, there is no need to use a rotary encoder for detecting the angle of the crankshaft of the press machine, and the microcomputer uses the output signal of the rotary encoder to rotate the crankshaft by a microcomputer. There is no need to calculate speed. Therefore, there is no need for a microcomputer capable of withstanding a large calculation load, and it is sufficient to use only a small-scale processor used for the feeder and use only a part of its functions, thereby reducing costs. Further, the operation position of the release command switch can be easily set.

Also, the output signal from the conventional feed command switch or the feed command switch can be used as the early signal switch or the early signal output, and almost all costs required for implementing the present invention are shared with the conventional device. Without doing so, costs can be reduced. Furthermore, the existing circuit of the conventional device can be used for processing of input signals from other switches and arithmetic processing in consideration of the operation delay time, and a new circuit is not required. Cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a releasing control device in a press-feeding device according to the present invention.

FIG. 2 is a timing chart for explaining the operation of the embodiment.

FIG. 3 is a flowchart showing a part of a program for the releasing control of the embodiment.

FIG. 4 is a flowchart showing a part of a program for the releasing control of the embodiment.

FIG. 5 is a flowchart showing a part of a program for the releasing control of the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Microcomputer (release command control means, measuring means) 2 Crankshaft 3 Chain 4 Sprocket 5 Rotary cam switch 6 Shaft 11, 12 Cam 13 Early signal switch 14 Release command switch 20 Numerical value setting device (Delay time setting means) 30 Feeding device 31, 32 roller 41 release operation cylinder 42 cylinder part 43 piston part 44 rod 51 solenoid valve 52 compressed air source 60 releasing control device 61 release operation command

Claims (3)

(57) [Claims] 1. When a plate material for press working is held by a feeder and sent to a press machine for press working, a release operation control unit outputs a release operation command at an appropriate time to release the holding of the plate material by the feeder. After a predetermined time has elapsed after the position correction, the output of the release operation command is stopped, and a releasing control device in the press feed device for holding the plate material again is provided. A rotary cam switch that operates in conjunction with the rotary cam switch, the rotary cam switch including a release command switch that outputs a release command, and an early signal switch that operates at least earlier than the release command switch; The operation delay time of the feeder from when the command is output to when the release Delay time setting means for setting a return delay time of the feeder from when the movement command is stopped to when the release operation is actually released, and an output signal of the release command switch after an output signal of the early signal switch rises. And a second time from when the output signal of the early signal switch rises to when the release command, which is the output signal of the release command switch, falls. The release command control means, when the output signal of the early signal switch rises, outputs the release operation command after a lapse of time obtained by subtracting the operation delay time from the first time, The output of the release operation command is stopped after a lapse of a time obtained by subtracting the return delay time from the second time. Releasing the control device in a press machining feed apparatus characterized. 2. The method according to claim 1, wherein the release command control means and the measuring means are realized by using a part of a function of a microcomputer which realizes a feeding function of the feeding device. Item 4. A releasing control device in the feed device for press working according to Item 1. 3. The releasing control in the press feed device according to claim 1, wherein the early signal switch shares a feed command switch used for a feed operation of the feed device. apparatus.