JPH0724954B2 - Control method of forging press - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a forging press control method for performing highly accurate synchronous operation of the rams in a forging press device having a plurality of rams.

(Prior Art) For example, in a forging press having upper and lower rams, the forging end point, that is, the arrival time at the bottom dead center of the upper and lower rams needs to be synchronized with high accuracy in forming a forged product. As the control for this synchronization, for example, the control described in JP-A-63-37000 is known.

This conventional one is provided with a pair of upper and lower eccentric shafts which can be independently driven to rotate, and upper and lower rams are connected to the respective upper and lower eccentric shafts so that each ram can be moved up and down.
The average angular velocities of the upper and lower eccentric axes are calculated by
Moreover, the stop position of each vertical eccentric shaft is obtained, each arrival time from the stop position of each vertical eccentric shaft to each bottom dead center position is calculated based on the average angular velocity and the stop position, and each arrival time thereof is calculated. According to the above, the drive timings of the upper and lower eccentric shafts are adjusted so that the upper and lower rams reach the bottom dead center at the same time.

The upper and lower eccentric shafts are driven by connecting the eccentric shaft stopped at the stop position to the continuously rotating flywheel via a clutch. Therefore, adjusting the drive timing of the eccentric shaft means adjusting the clutch connection timing.

(Problems to be solved by the invention) In the synchronous control of the upper and lower rams, the arrival time from the stop position of the eccentric shaft to the bottom dead center greatly depends on the flywheel initial speed at the time of clutch engagement, but in the conventional method, Since the average angular velocity of the flywheel is obtained by N trials, the flywheel rotation speed will be significantly different from the previous average value due to a rapid change in the emitted energy (variation of the forging material, biting of foreign matter, etc.). However, there is a problem that the timing is greatly deviated, and that this data affects the subsequent timing adjustment.

Further, in manual forging such as trial, N times trial cannot be performed, so that there is a problem that the timing cannot be adjusted manually.

In addition, since the average angular velocity for performing the timing adjustment is obtained from 1 to N times, there is a problem that the timing adjustment cannot be performed during this period.

Therefore, an object of the present invention is to provide a method for controlling a forging press that solves the above problems.

(Means for Solving the Problems) In order to achieve the above object, the present invention has taken the following means.
That is, a feature of the present invention according to claim 1 is that a pair of flywheels, a pair of crank mechanisms connected to each flywheel via a clutch so as to be freely connected and disconnected, and each of the crank mechanisms are attached. A method of controlling a forging press, comprising: a pair of reciprocatingly movable rams arranged to face each other, and reciprocatingly moving the pair of rams synchronously to forge a forging object arranged between the rams. , The rotational speed W _U0 , W of each flywheel immediately before transmitting the rotation of the flywheel to the crank mechanism by the clutch
_L0 and crank angle CT from the stop position of each ram to the bottom dead center
_U, detects and CT _L, the rotational speed W _U0, W _L0 and the crank angle CT _U, and a CT _L, calculates the arrival time T _U, T _L up to the bottom dead center from the ram stop position, Further, the difference T _AD1 between the calculated arrival times T _U and T _L of the rams is calculated, and the timing of rotation transmission to the crank mechanism by the clutch is adjusted according to the difference T _AD1 .

A feature of the present invention according to claim 2 is that in the method for controlling a forging press according to claim 1, the arrival times T _U and T _L of the respective rams are calculated by the following formula T _U = CT _U / W _U0 T _L = CT _L / W _L0 .

A third aspect of the present invention is the method of controlling a forging press according to the first aspect, wherein the speed reduction amount Δ of each flywheel at the bottom dead center is Δ in advance.
W _U1 , ΔW _L1 and the time delay amounts Δt _U , Δt _L caused by clutch slippage and the like are calculated as constants, and the arrival times T _U , T _L of the respective rams are calculated by the following equation. There is a point to do by.

According to a fourth aspect of the present invention, there is provided a pair of flywheels, a pair of crank mechanisms connected to each flywheel via clutches so as to be freely connected and disconnected, and a pair of crank mechanisms attached to and opposed to each other. In a method of controlling a forging press, which has a pair of reciprocatingly movable rams arranged, and reciprocally moves the pair of rams synchronously to forge a forging object arranged between the rams, The rotation speed (W _U0 , W _L0 ) of each flywheel immediately before transmitting the rotation of the flywheel to the crank mechanism by the clutch, and the crank angle (CT _U , CT _L ) from the stop position of each ram to the bottom dead center In addition to detecting the crank angle, set a break point between each ram's stop position and bottom dead center, and determine the crank angle (CT _U1 , CT _L1 ) from each ram's stop position to the break point and the bottom dead center. crank angle up (CT _U2, CT _L2) Computes, the rotational speeds of both the flywheel _{(W U0, W L0) (} W
_UC , W _LC ), the crank angle (CT _U1 , CT _L1 ) from the stop position of each ram to the break point, and the crank angle (CT _U2 , CT _L2 ) from the break point to the bottom dead center in advance. Amount of decrease in speed of each flywheel (ΔW _UC ,
ΔW _LC ) and the amount of speed reduction of each flywheel at the bottom dead center (ΔW _U1 , ΔW _L1 ) and the amount of time delay caused by the clutch slippage (Δt _U , Δt _L ) from the stop position of each ram to the bottom dead center. The arrival time (T _U , T _L ) is calculated by the following formula, Furthermore, the difference (T _AD1 ) between the calculated arrival times (T _U , T _L ) of each ram is calculated, and the rotation transmission timing by the clutch to the crank mechanism is adjusted according to this difference (T _AD1 ). .

Further, the feature of the present invention according to claim 5 is that the time difference T _{AD1 according} to claim 1 is added with a predetermined timing error time Δtab, and T _AD2 is calculated by the following equation T _AD2 = T _AD1 + Δtab , T _AD2 is used to adjust the rotation transmission timing of the clutch to the crank mechanism.

Further, the feature of the present invention according to claim 6 is that the timing error time (Δtab) according to claim 5 is However, Δtab ₍ n ₎ is the current timing error correction time Δtab ₍ n ₊₁₎ , the next timing error correction time Δt _ER is the actual timing error actual measurement time N, and is corrected by an integer 1 ≦ N. There is a point to be.

Further, the feature of the present invention according to claim 7 is that the speed reduction amount (ΔW _U1 , ΔW _L1 ) of the flywheel at the bottom dead center according to claim 3 or 4 is: However, ΔW _{U1 (} n ₎ , ΔW _{L1 (} n ₎ are corrected by the current flywheel speed reduction amount ΔW _{U1 (} n ₊₁₎ , ΔW _{L1 (} n ₊₁₎ are corrected by the next flywheel speed reduction amount In point.

Further, according to a feature of the present invention described in claim 8, the time delay amounts (Δt _U , Δt _L ) described in claim 3 or 4 are: However, Δt _{U (} n ₎ , Δt _{L (} n ₎ is the time delay amount of this time Δt _{U (} n ₊₁₎ , Δt _{L (} n ₊₁₎ is corrected by the next time delay amount of.

Further, the feature of the present invention according to claim 9 is that the speed reduction amount (Δ of the flywheel at the break point according to claim 4).
W _UC , ΔW _LC ) However, ΔW _{UC (} n ₎ , ΔW _{LC (} n ₎ are corrected by the flywheel speed reduction amount this time ΔW _{UC (} n ₊₁₎ , ΔW _{LC (} n ₊₁₎ are corrected by the next flywheel speed reduction amount In point.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

Fig. 1 is a schematic view of the press. 1,2 are upper / lower motors, 3,4 are upper / lower flywheels driven by upper / lower motors 1 and 2, 5 and 6 are upper / lower rotations. Axes 7, 7 are upper and lower flywheels 3, 4 and pneumatic upper and lower clutches interposed between upper and lower rotating shafts 5 and 6, 9 and 10 are upper and lower rotating shafts 5 Pneumatic upper and lower brakes for braking 6 and 6, 11 and 12 for upper and lower rotating shafts 5 and 6, respectively.
Is provided eccentrically with respect to its rotation axis O ₁ , O ₂ .
Lower eccentric shaft part, 13 and 14 are upper and lower rams that move up and down, 15 and 16 are upper and lower connecting rods that connect the upper and lower eccentric shaft parts 11 and 12 to the upper and lower rams 13 and 14, respectively. 17,18 are the upper and lower detectors for detecting the positions of the upper and lower eccentric shaft parts 11,12, and 19,20 are the upper and lower detectors for detecting the rotational angular velocity of the upper and lower flywheels 3,4. The lower detector, 21 is a forged material.

The upper and lower rotary shafts 5 and 6, the upper and lower eccentric shaft portions 11 and 12, and the upper and lower
Upper and lower crank mechanisms are configured by the lower connecting rods 15 and 16.

FIG. 2 is an explanatory diagram showing the positions of the upper and lower eccentric shaft portions 11 and 12, and in FIG. 2, P _U1 and P _U2 are the upper and lower dead points of the upper ram 13 on the upper eccentric shaft portion 11. Top and bottom dead center position corresponding to P
_U3 is the stop position of the upper eccentric shaft portion 11. CT _U is the angle (degree) measured in the rotational direction from the stop position P _U3 of the upper eccentric shaft portion 11 to the bottom dead center P _U2 .

P _L1 and P _L2 are upper and lower dead center positions corresponding to the upper and lower dead centers of the lower ram 14 in the lower eccentric shaft portion 12, and P _L3 is a stop position of the lower eccentric shaft portion 12. CT _L is an angle (degree) measured in the rotational direction from the stop position P _L3 of the lower eccentric shaft portion 12 to the bottom dead center P _L2 .

For W _U0 and W _L0 , upper and lower flywheels 3 and 4 have upper and lower rams 13,
It is the initial speed (degrees / second) when driving 14.

In the forging press having the above-mentioned structure, upper and lower flywheels
The motors 3 and 4 are rotationally driven by the motors 1 and 2 at constant angular speeds W _U0 and W _L0 .

The upper and lower clutches 7 and 8 are disconnected, the upper and lower brakes 9 and 10 are connected, and the vertical eccentric shaft parts 11 and 12 of the crank mechanism are connected.
_Are stopped at stop positions P _U3 and P _L3 , respectively.

In this state, a connection signal is output to the upper and lower clutches 7 and 8 and an open signal is output to the upper and lower brakes 9 and 10, so that the upper and lower flywheels 3 and 4 and the rotating shafts 5 and 6 are rotated.
, The crank mechanism is driven, and the upper and lower rams 13, 1
4 approach each other, compress the forging material 21 at its bottom dead center, then the upper and lower rams 13, 14 are separated from each other, when the upper and lower eccentric shaft portions 11, 12 reach near the stop position P _U3 , P _L3 , The clutches 7 and 8 are disengaged, the brakes 9 and 10 are connected, the upper and lower eccentric shaft portions 11 and 12 stop at the stop positions P _U3 and P _L3 , and one forging cycle ends.

In the forging, the forging end point, that is, the arrival time at the bottom dead center of the upper and lower rams 13 and 14 must be synchronized with high accuracy in forming the forged product.

Therefore, the timing adjustment of the upper and lower rams 13 and 14 will be described below. (In the following description, P _U2 and P _L2 are referred to as bottom dead centers of the upper and lower rams 13 and 14, and P _U3 and P _L3 are referred to as upper and lower rams.
Sometimes it's 13,14 stopping points. ) Now, the upper and lower eccentric shaft parts 11 and 12 can be driven independently, and the time T _U and T _L from the stop points P _U3 and P _{L3 of the} upper and lower rams 13 and 14 to the bottom dead center P _U2 and P _L2 are If it can be estimated, the drive signals of the upper and lower rams 13 and 14 (upper and lower clutches 7 and 8 connection signals) are timing-corrected by T _AD1 expressed by the following equation (1) to obtain the upper and lower rams.
The arrival times at the bottom dead centers P _U2 and P _{L2 of} 13, 14 can be accurately synchronized.

T _AD1 = T _U −T _L (1) However, even if the timing of T _AD1 is corrected, the synchronization error Δt at the bottom dead center due to the difference in the forging energy, the error in the estimation formula of T _U , T _L , etc. _ER is expected to occur constantly,
This can be measured with a timer, and if the drive signal is adjusted in timing by the sum T _AD2 with the previous T _AD1 , it can be synchronized with higher accuracy.

T _AD2 = T _AD1 + Δt _ER (2) The control according to the above equations (1) and (2) is hereinafter referred to as “instantaneous control”.

Continue to sequentially modify the Delta] t _ER in order to correct the setting error of the initial value of Delta] t _ER change and Delta] t _ER by further temperature change.

Hereinafter, this is referred to as "learning correction".

The above is a brief description, but the details will be described below.

First, an estimation formula of the bottom dead center arrival times T _U and T _L will be described.

In an ideal case, that is, assuming that the vertical eccentric shafts 11 and 12 operate at a constant speed over the entire stroke, the bottom dead center arrival time T _{U of the} upper ram 13 and the bottom dead center arrival time T _L of the lower ram 14 are It is expressed by the following equation.

However, in actual operation, there are the following factors that deviate from the above formula.

(A) Dead time from the output of the clutch 7,8on signal to the start of the rams 13,14 (b) Sliding time of the clutch 7,8 (c) Reduction in the speed of the flywheels 3, 4 due to energy loss (a) (b) ) Is a factor that delays by a certain period of time Δt _U , Δt _L , and (c) shows that loss linearly occurs, and the amount of decrease in the flywheel speed from the start of driving until reaching bottom dead center P _U2 , P _L2. Is ΔW _U1 and ΔW _L1 , T _U , T _L is Becomes Δt _U is the offset of the bottom dead center arrival time of the upper ram 13, ΔW _U1 is the speed decrease amount of the upper flywheel 3, Δt _L is the offset of the bottom dead center arrival time of the lower ram, ΔW _L1 is the speed of the lower flywheel 4 It is the amount of decrease.

Since Δt _U , Δt _L and ΔW _U1 , ΔW _L1 are constant values under the same electrical and mechanical conditions, they can be obtained in advance during no-load operation. If this value is taken as a constant, if CT _U , CT _L and W _U0 , W _L0 immediately before the start of forging are detected by the detectors 17, 18, 19, 20 then T _U , T _L can be calculated. it can.

Incidentally, FIG. 3 is a graph of the expressions 3A, 3B, 4A and 4B.

The constant values (parameters) of Δt _U , Δt _L and ΔW _U1 , ΔW _L1 are determined as follows.

Upper ram 13 performs no-load operation under ram 14 singly, T _U, and measured the _{T L, CT U, CT L} , the W _U0, W _L0 and vertical flywheel 3 and 4 at the bottom dead center Speed W _U1 〔deg / sec〕, W _L1 〔deg / s
ec] is detected by the detectors 17, 18, 19, 20. From these values, the flywheel speed reduction amount ΔW
_U1 and ΔW _L1 are calculated, and the bottom dead center arrival time offsets Δt _U and Δt _L are calculated using these values.

ΔW _U1 ＝ W _U0 −W _U1 …… (5A) ΔW _L1 ＝ W _L0 −W _L1 …… (5B) In this way, the calculated ΔW _U1 , ΔW _L1 and Δt _U , Δt _L include many probabilistic errors if they are calculated once, so they are averaged several times. The number of times of performing this averaging is called the average number of times.

Next, the "instantaneous control" will be described in more detail.

First, the upper and lower ram stop angles CT _U , CT _L and the upper and lower flywheel initial speed immediately before starting forging in the above formulas (4A) and (4B)
The bottom dead center arrival times T _U and T _L of the upper and lower rams 13 and 14 are estimated by detecting and substituting W _U0 and W _L0 . Then, the bottom dead center arrival time difference T _AD1 of each ram 13,14 is calculated by the following formula, and the upper and lower rams 13,14 are
Drive timing adjustment.

T _AD1 = T _U −T _L (7) Even if the timing of the upper and lower rams 13 and 14 is adjusted using this T _AD1 , if there is a synchronization error that occurs steadily, the error Δt _ER (upper ram) Assuming that 13 is delayed from the lower ram 14 as positive, the sum of T _{AD1 in} equation (7) and the value Δtad close to the manually input Δt _ER is taken, and this is taken as the bottom dead center arrival time difference T _AD2 .

That is, T _AD2 is expressed by the following equation.

T _AD2 = T _AD1 + Δtad (8) Here, the difference between the equations (2) and (8) will be explained.
The expression (2) is a theoretical expression using the actual error Δt _ER , while the expression (8) is a practical expression using the input value Δtad set based on the Δt _ER .

Using this T _AD2 , the timing of driving signals for the upper and lower rams 13 and 14 is adjusted as follows.

(1) When T _AD2 > 0 The upper ram 13 is driven first, and the lower ram 14 is driven after T _AD2 [sec].

(2) When T _AD2 <0 Drive the lower ram 14 first, and drive the upper ram 13 after T _AD2 [sec].

(3) When T _AD2 = 0 The upper and lower rams 13 and 14 are driven simultaneously without correction.

Next, the "learning correction" will be described.

By adjusting the timing shown in the instantaneous control, the upper and lower rams
The synchronization errors of 13 and 14 are expected to approach 0 sufficiently, but Δtad is sequentially corrected to eliminate the Δt _ER change due to temperature change and the Δtad setting error, and the synchronization error is always kept close to 0. Of.

That is, the upper and lower ram timing deviations that have been adjusted by T _{AD2 in the} equation (8) and are still present are Δt _ER .
Then, assuming that the setting error at that time is Δtad ₍ n ₎ , the next setting error Δtad ₍ n ₊₁₎ is obtained by the following equation.

The next Δtad ₍ n ₊₁₎ is corrected using the equation (9).

Here, N is an integer of 1 ≦ N ... (10) 1 / N is a small constant, and N is a constant of about 10.

By using Δtad ₍ n ₊₁₎ newly calculated by the equation (9) to adjust the timing by the method shown by the instantaneous control, the synchronization error can be always kept close to zero.

Further, not only the correction of the timing error time Δtad but also the learning correction of correcting the parameters ΔW _U1 , ΔW _L1 and Δt _U , Δt _L by the following equations can be performed to perform more accurate timing adjustment.

In the expressions (11A) to (12B), the subscript (n) term is the parameter used this time, the subscript (n + 1) term is the parameter used next time, and the term without the subscript is the actual measurement value this time. This also applies to the subscript (9).

Furthermore, by determining the parameters as described below, it is possible to perform control with higher accuracy.

That is, the above formulas (4A) and (4B) are linear approximations that are calculated by assuming that the flywheel speed decreases uniformly from the stop point to the bottom dead center, but in order to further improve the accuracy, as shown in FIG. Using the flywheel speed measurement point as a break point, add one point from the stop position of each ram to the bottom dead center, the initial speed W _U0 , W _L0 at the stop point, and the speed W _U2 , W at the bottom dead center. _In addition to _L2 , the parameters are calculated from the bottom dead center arrival time T _U , T _{L which} is the velocity W _U1 , W _L1 at three angles CT _U1 , CT _L1 at the bottom dead center is there.

Estimation formula However, ΔW _UC = W _U0 −W _UC : Break point speed decrease amount ΔW _U1 = W _U0 −W _U2 : Bottom dead center speed decrease amount ΔW _L1 = W _U0 −W _L1 : Break point speed decrease amount ΔW _L1 = W _U0 − W _L2 : Bottom dead center speed decrease amount * indicates parameters, and others indicate measured values.

Parameter determination formula However, ΔW _U1 = ▲ W ^☆ _U0 ▼-▲ W ^☆ _U1 ▼: Breaking point speed decrease amount ΔW _U2 = ▲ W ^☆ _U2 ▼-▲ W ^☆ _U2 ▼: Bottom dead center speed decrease amount ΔW _L1 = ▲ W ^☆ _U0 ▼ -▲ W ^☆ _L1 ▼: Breaking point speed decrease amount ΔW _L2 = ▲ W ^☆ _U2 ▼ − ▲ W ^☆ _L2 ▼: Bottom dead center speed decrease amount ☆ indicates the measured value.

The parameters obtained from the above (11A) (11B) (12
It is possible to successively learn and correct this parameter by calculating and averaging for each forging according to A) and (12B).

In addition, the amount of decrease in flywheel speed ΔW _UC ,
If ΔW _LC is successively learned and corrected by the following equation, higher precision control becomes possible.

FIG. 5 is a block diagram of a control device for performing the timing adjustment. In the figure, the upper and lower flywheel speed detectors 19 and 20 are composed of tacho generators, and the flywheel velocities (angular velocities) W _U and W _L detected by the detectors 19 and 20 are the arithmetic processing unit 23 of the controller 22.
Entered in. In addition, the vertical eccentric shaft position detectors 17, 18
Is a pulse generator, and the positions (angles) CT _U and CT _{L of} the vertical eccentric portions 11 and 12 detected by the detectors 17 and 18 are also input to the arithmetic processing unit 23.

Then, in the arithmetic processing unit 23, the parameters ΔW _U1 , ΔW _L1 ,
Δt _U and Δt _L are calculated and CT _L1 and CT _U1 are input.

Reference numerals 24 and 25 are comparators, which emit a signal when the rotational positions of the vertical eccentric shaft portions 11 and 12 reach predetermined break points CT _U1 , CT _L1 and bottom dead centers CT _U2 , CT _L2, and flywheels at that time. Angular velocity W _U1 , W _L1 , W
_UC and _WLC are stored in the arithmetic processing unit 23.

The arithmetic processing unit 23 uses the parameters and the measured values.
T _U , T _L and T _AD are calculated, and the operation timings of the clutches 7, 8 and the brakes 9, 10 are controlled based on the T _AD .

FIG. 6 is a flow chart of the timing adjustment using the controller 22. In the figure, it is judged in the step whether or not the forging is started, and if the forging is started, in the step, the position detector 17 for the vertical eccentric shaft portion, From 18, the stop angle CT _U , at the stop positions P _U3 , P _L3 of the vertical eccentric shaft parts 11, 12
The CT _L is input to the arithmetic processing unit 23. At the same time, in steps, the upper and lower flywheel speed detectors 19 and 20 input the angular velocities W _U0 and W _L0 of the upper and lower flywheels 3 and 4, respectively. Then, in the step, T _U , T _L , and T _AD are calculated, and in the step, the vertical timing control is output.

Then, the upper and lower rams 13 and 14 are driven with timing adjustment, and forging is performed.

At this time, in step, bottom dead center arrival time T _U , T
Flywheel speeds W _U1 and W _{L1 at L} and bottom dead center are measured and input.

Then, the parameter is calculated in the step, the parameter used in the next step is corrected in the step, and one control cycle is completed.

The invention is not limited to the above embodiment.

According to the present invention, the vertical flywheel speed immediately before the output of the vertical ram drive signal is detected, and the next timing T _AD is detected _.
Therefore, the timing can be adjusted corresponding to the change in the speed of the flywheel due to the change in the energy released last time.

Further, since it is not a method of taking the average of N times, the timing can be adjusted even during the manual forging once to several times, and further, the timing can be adjusted from the first time even during the continuous automatic forging.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a forging press used in the method of the present invention, FIG. 2 is an explanatory diagram showing the positions of the vertical eccentric shaft portion, and the like.
The figure is a graph showing the formulas (3A) (3B) and (4A) (4B),
FIG. 4 is an explanatory view showing the position of the eccentric shaft portion at the time of controlling the break point, FIG. 5 is a block diagram of the timing adjustment control device, and FIG. 6 is a flowchart of the method of the present invention. 3,4 …… Upper and lower flywheel, 7,8 …… Upper and lower clutch, 1
0,11 …… Vertical eccentric shaft (part of crank mechanism), 12,13
...... Upper and lower rams, 17,18 …… Position detectors, 19,20 …… Speed detectors, 21 …… Forging materials.

Claims (9)

[Claims] 1. A pair of flywheels, a pair of crank mechanisms connected to each flywheel via clutches so as to be freely connected and disconnected, and a pair of reciprocating rams attached to and opposed to each crank mechanism. And a method of controlling a forging press forging a workpiece to be forged disposed between the rams by synchronously reciprocating the pair of rams, wherein the clutch rotates the flywheel by a crank mechanism. The rotation speed (W _U0 , W _L0 ) of each flywheel immediately before transmission and the crank angle (CT _U , CT _L ) from the stop position of each ram to the bottom dead center are detected, and the rotation speed (W _U0 , W _L0 ) and the crank angle (CT _U , CT _L ), the arrival time (T _U , T _L ) from the stop position of each ram to the bottom dead center is calculated, and the calculated arrival time of each ram is calculated. (T _U, T _L) calculates the difference (T _AD1), the difference The method of forging press, characterized by adjusting the rotation transmission timing to the crank mechanism by the clutch in response to T _AD1). 2. The method for controlling a forging press according to claim 1, wherein the arrival time (T _U , T _L ) of each ram is calculated by the following equation T _U = CT _U / W _U0 T _L = CT _A method for controlling a forging press, which is characterized by performing _L / W _L0 . 3. The method for controlling a forging press according to claim 1, wherein the speed reduction amount (ΔW _U1 , ΔW _L1 ) of each flywheel at the bottom dead center and the amount of time delay caused by clutch slippage or the like. (Δt _U , Δt _L ) is calculated as a constant, and the arrival time (T _U , T _L ) of each ram is calculated by the following equation. A method for controlling a forging press, which is characterized in that: 4. A pair of flywheels, a pair of crank mechanisms connected to each flywheel via clutches so as to be freely connected and disconnected, and a pair of reciprocating rams attached to and opposed to each crank mechanism. And a method of controlling a forging press forging a workpiece to be forged disposed between the rams by synchronously reciprocating the pair of rams, wherein the clutch rotates the flywheel by a crank mechanism. The rotation speed of each flywheel (W _U0 , W _L0 ) immediately before transmission and the crank angle (CT _U , CT _L ) from the stop position of each ram to the bottom dead center are detected, and the stop position of each ram is detected. And the bottom angle to the bottom dead center are set, and the crank angle (CT _U1 , CT _L1 ) from the stop position of each ram and the crank angle (CT _U2 , CT _L2 ) from the break point to the bottom dead center. ) And calculate the above flywheels The speed of rotation _{(W U0, W L0) (} W
_UC , W _LC ), the crank angle (CT _U1 , CT _L1 ) from the stop position of each ram to the break point, and the crank angle (CT _U2 , CT _L2 ) from the break point to the bottom dead center in advance. Amount of decrease in speed of each flywheel (ΔW _UC ,
ΔW _LC ) and the amount of speed reduction of each flywheel at the bottom dead center (ΔW _U1 , ΔW _L1 ) and the amount of time delay caused by the clutch slippage (Δt _U , Δt _L ) from the stop position of each ram to the bottom dead center. The arrival time (T _U , T _L ) is calculated by the following formula, Further, the difference (T _AD1 ) between the calculated arrival times (T _U , T _L ) of each ram is calculated, and the rotation transmission timing by the clutch to the crank mechanism is adjusted according to this difference (T _AD1 ). Control method for forging press. 5. The time difference (T _AD1 ) according to claim 1 or 4.
, In addition predetermined timing error time the (Δtad), obtains a T _AD2 by the following equation T _AD2 = T _AD1 + Δtad, using this T _AD2, adjusting the rotation transmission timing to the crank mechanism by the clutch Characteristic forging press control method. 6. The timing error time (Δta according to claim 5,
b) However, Δtad ₍ n ₎ is the current timing error correction time Δtad ₍ n ₊₁₎ , the next timing error correction time Δt _ER is the actual timing error actual measurement time N, and is corrected by an integer of 1 ≦ N. A method for controlling a forging press, which comprises: 7. The speed reduction amount (ΔW _U1 , ΔW _L1 ) of the flywheel at the bottom dead center according to claim 3 or 4, However, ΔW _{U1 (} n ₎ , ΔW _{L1 (} n ₎ are corrected by the current flywheel speed reduction amount ΔW _{U1 (} n ₊₁₎ , ΔW _{L1 (} n ₊₁₎ are corrected by the next flywheel speed reduction amount A method for controlling a forging press, which is characterized in that 8. The amount of time delay (Δ) according to claim 3 or 4.
t _U , Δt _L ) is However, Δt _{U (} n ₎ , Δt _{L (} n ₎ is the time delay amount of this time Δt _{U (} n ₊₁₎ , Δt _{L (} n ₊₁₎ is corrected by the next time delay amount Press control method. 9. The flywheel speed reduction amount (ΔW _UC , ΔW _LC ) at the break point according to claim 4, However, ΔW _{UC (} n ₎ , ΔW _{LC (} n ₎ are corrected by this time's flywheel speed reduction amount ΔW _{UC (} n ₊₁₎ , ΔW _{LC (} n ₊₁₎ are corrected by this flywheel speed reduction amount A method for controlling a forging press, which is characterized in that