JPH04238700A - Stop controller for power press - Google Patents

Abstract

PURPOSE:To always exactly stop a slide at a desired stop position without being affected by the air pressure of a slide balancer and a change in ambient temp., etc. CONSTITUTION:An actual speed V drops rapidly when a brake 20 is precedently applied in a prescribed position. Brake rereleasing control means 31, 32 release the brake 20 again and deceleration control means 31, 32, 39 decelerate a crank shaft while maintaining set deceleration rate VDRs by PWM voltage control when the actual speed V rises equal to the set speed Vs. Brake final application control means 31, 32, 39B finally and continuously apply the brake 20 upon arrival at the desired stop position Ps at a low speed. The slide 4 is, therefore, exactly stopped at the desired stop position Ps regardless of the fluctuations in external factors.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stop control device for a power press machine equipped with a clutch and brake. especially,
The braking force of the brake is controlled by PWM voltage control, and the brake is finally turned on at low speed and at the stop position.
It is characterized by

0002

2. Description of the Related Art FIG. 8 shows the general structure of a power press machine 1. In the same figure, 2 is the crankshaft, and its eccentric portion 2
A slide 4 is connected to e via a connecting rod 3. This slide 4 is provided with a pneumatic slide balancer to eliminate the so-called breathing phenomenon. Press rotation power is applied to the crankshaft 2 from a drive shaft 5 via a gear train 8. On the other hand, motor 7
The flywheel 6, which is rotationally driven, is coupled to and separated from the drive shaft 5 by a clutch 10.

Therefore, the rotational energy accumulated in the flywheel 6 is transmitted to the drive shaft 5 by engaging (ON) the clutch 10, and the rotational energy is transmitted to the drive shaft 5.
, the crankshaft 2 and the connecting rod 3 serve as a power source for moving the slide 4 up and down. In order to stop this slide 4 at a desired stop position such as top dead center, the clutch 1
It is well known that the brake 20 may be operated (ON) after separating (OFF) the brake 20.

[0004] Furthermore, when the clutch 10 is of a pneumatic type,
By turning on the switch 39C and energizing the solenoid 11S, the solenoid valve 11 is opened and a predetermined air pressure is sent from the pipe 12 into the clutch 10 to turn it on. That is, the clutch 10 is selected to transmit a rotational power corresponding to the maximum capacity of the power press machine through its engagement operation. Regarding this point, the same applies to clutches (10) of other types (for example, eddy current type). On the other hand, the brake 20 is activated by turning off the solenoid valve 21 by turning off the switch 39B and de-energizing the solenoid 21S.
is closed, the air pressure inside the brake 20 is released from the pipe 22, and the brake is turned on. Designed to provide safety protection.

By the way, in order to stop the slide 4 at a stop position Ps such as top dead center shown in FIG. 9, the timing of turning on the brake 20 is extremely important. Here, conventionally, the crankshaft angle equivalent to coasting from turning on the brake 20 until the slide 4 reaches the stop position is determined by taking into account the braking capacity, press speed, inertia of the slide 4, etc., and then setting the rotary cam switch, etc. When the detected crankshaft angle reaches the set angle, that is, when the slide reaches the predetermined position Po in FIG.
At the same time as the FF is turned on, the brake 20 is turned on.

[0006]

[Problems to be Solved by the Invention] However, in this conventional structure, the expected amount of coasting or sliding of the slide 4 is uniquely determined, so if the air pressure or ambient temperature of the slide balancer changes, for example, the amount of coasting or sliding of the slide 4 changes, Due to this influence, there is a problem in that the stop position (Ps) of the slide 4 is dislocated toward the front (Px) or overruns (Py). Moreover, in today's world where higher precision and greater variety are required, it has become difficult to tolerate such variations. However, adjusting the timing of turning on the brake 20 each time in response to changes in the air pressure of the slide balancer, etc. is complicated and time-consuming, and is practically impossible.

Although FIG. 8 shows a separate type, a so-called combination type in which the clutch and brake are integrated has similar problems.

[0008] Here, an object of the present invention is to
To provide a stop control device for a power press machine that can always accurately stop a slide at a desired stop position by automatically adjusting the braking force of a brake by controlling the M voltage.

[0009]

[Means for Solving the Problems] The present invention is designed to prevent the slide from stopping as expected by simply turning on the brake in advance, since there are many factors that affect the braking force in a power press machine with a complex structure. Based on the empirical rule that it is impossible to stop the vehicle without variation in position, the braking force is actively automatically adjusted using PWM voltage control, and after decelerating while controlling the actual deceleration rate, the vehicle comes to a stop position at low speed. When the vehicle stops, the final brake is applied to accurately stop the vehicle at the desired stop position.

That is, the invention of claim 1 includes a clutch that transmits the rotational energy of a flywheel rotationally driven by a motor to the crankshaft, and a brake that is operated in reverse to this clutch and applies braking force to the crankshaft. In a stop control device for a power press machine configured to turn off a clutch and turn on a brake to stop the machine when the slide reaches a predetermined position, the actual speed of the crankshaft is lower than or equal to a preset speed. The brake that was turned on at the predetermined position is then turned off again
and a brake re-off control means that causes the brake to be re-off.
After F is applied until the slide reaches the stop position, a PWM voltage signal is applied to the brake operation solenoid valve while comparing the actual deceleration rate obtained from the actual speed of the crankshaft with the preset deceleration rate. In addition, turn on the brakes intermittently.
The present invention is characterized by comprising a deceleration control means for controlling the actual deceleration rate within a predetermined range, and a brake final ON control means for finally turning on the brake when the slide reaches the stop position.

[0011] Furthermore, the invention according to claim 2 includes a clutch that transmits the rotational energy of a flywheel rotationally driven by a motor to the crankshaft, and a brake that is operated in reverse to this clutch and applies braking force to the crankshaft. , a stop control device for a power press machine configured to turn off a clutch and turn on a brake to stop the slide when the slide reaches a predetermined position; Until the stop position is reached, a PWM voltage signal is applied to the brake operation solenoid valve intermittently while comparing the actual deceleration rate determined from the actual speed of the crankshaft with a preset deceleration rate. The present invention is characterized by comprising a deceleration control means for turning off the brake and controlling the actual deceleration rate within a predetermined range, and a brake final ON control means for finally turning on the brake when the slide reaches the stop position.

0012

[Operation] In the invention of claim 1, when the slide reaches the predetermined position, the clutch is turned off and the brake is turned off in advance.
N is given. Therefore, the slide freely decelerates while coasting. Here, if the actual speed of the slide, that is, the crankshaft, becomes lower than the preset speed, the brake will be reactivated.
The F control means operates to turn off the brake again. Subsequently, the deceleration control means controls the brake braking force by intermittently turning on the brake by PWM voltage control while comparing the actual deceleration rate and the set deceleration rate. Therefore, the actual deceleration rate is automatically adjusted as accurately as possible within a predetermined range,
The crankshaft decelerates slowly. Therefore, when the slide reaches the desired stop position, the final brake ON control means finally and continuously turns on the brake. Therefore, since the speed is low, the slide can always be accurately stopped at the desired stop position. This is particularly effective when a change in the air pressure of the slide balancer or the like increases the coasting force and causes the stop position to be overrun.

In the second aspect of the invention, when the slide reaches a predetermined position, the clutch is turned off and the brake is turned on. The slide coasts, but decelerates freely and rapidly along with the crankshaft. Then, the deceleration control means compares the actual deceleration rate and the set deceleration rate, and intermittently turns off the brake by PWM voltage control, and automatically adjusts the brake braking force to achieve the set deceleration rate. Here, the final brake ON control means finally and continuously turns on the brake when the slide reaches the stop position. Therefore, since the speed is low, the slide can be accurately stopped at the desired stop position. This is particularly effective when the air pressure of the slide balancer has a large effect on the slide, causing it to stop before the stop position.

[0014]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First Embodiment) As shown in FIG. 1, this stop control device turns off the clutch 10 and turns off the brake 20 in advance when the slide 4 in FIG. 8 reaches the predetermined position Po in FIG. Fixed position brake control means (31, 32, 39B) that is turned ON to stop the slide 4 at the stop position Ps
and brake re-off control means (31, 32,
39B), deceleration control means (31, 32, 39), and brake final ON control means (31, 32, 39B),
The brake re-OFF control means turns off the brake 20 once turned on at a predetermined position Po, and then, after the actual speed V of the crankshaft 2 becomes equal to the set speed Vs, the brake 20 is controlled by PWM voltage by the deceleration control means. Turns on intermittently. This controls the braking force so that the actual deceleration rate is maintained within a certain range. Then, when the slide 4 reaches the stop position Ps, the brake final ON control means continuously and finally turns on the brake 20 to move the slide 4 to the intended stop position Ps.
It is designed to ensure that it stops.

[0016] Regarding the power press machine (1),
In the case of this embodiment, the structure is the same as that of the conventional example shown in FIG. 8, so the explanation thereof will be omitted or simplified.

In FIG. 1, reference numeral 30 denotes a CPU 31 which controls calculations, judgments, executions, etc., and an RO in which various programs are stored.
This is a drive control device consisting of an M32, a RAM 33 for temporarily storing various data, a keyboard 34, and input/output ports 35 and 36, and controls the drive of the entire press machine. In this embodiment, these components 31, 32, 33, and 34 and some of their functions are also used to provide speed setting means, deceleration rate setting means, deceleration rate calculation means, fixed position brake control means, Brake re-OFF control means, deceleration control means,
It constitutes brake final ON control means. Here, these means can be implemented as other configurations, such as logic circuits or the like.

Now, when the slide 4 reaches the predetermined position Po shown in FIG. 3, the fixed position brake control means outputs the signal S1 shown in FIG. 1 to turn off the clutch 10, and also outputs the signal S2. A means for controlling the slide 4 to stop at the stop position Ps in FIG. 3 by turning on the brake 20,
In this embodiment, it is formed of the CPU 31, ROM 32, and switches 39B and 39C. The ROM 32 stores programs shown in FIG. 2 [step (ST) 11, etc.]. Furthermore, before checking the predetermined position Po, it is also checked whether the restart prevention point has been passed (ST10).
. Incidentally, this fixed position brake control means has the same function as a conventional stop control device.

In this embodiment, the predetermined position Po is determined by detecting the rotation angle of the crankshaft 2 from the fixed position switch 42 of the rotary cam switch 40 shown in FIG. The same applies to restart prevention (41) and stop position (43). However, these may be formed so as to directly engage with the slide 4 for detection, for example.

The speed setting means is means for setting the set speed Vs shown in ST13 in FIG. 2 and FIG. 3, and is formed of the keyboard 34 shown in FIG. The set speed Vs is temporarily stored in the RAM 33. However, it may also be stored in the ROM 32 as a fixed value. This set speed Vs is the speed of the slide 4 to the crankshaft 2. Note that the actual speed V is determined by the tachogenerator 3 connected to the motor 7 via a speed reducer as necessary, as shown in FIG.
8 or a rotary encoder.

The deceleration rate setting means is also formed from a keyboard 34, and is used to set a suitable deceleration rate (VDRs in FIG. 2) for decelerating from the set speed Vs to an appropriate low speed at the stop position Ps. It is something to set. On the other hand, the deceleration rate calculation means is a means for calculating the actual deceleration rate (VDR of ST18 in FIG. 2) from the previous value and current value of the actual speed V detected from the tachogenerator 38, and is It is formed. In other words, the rotational speed detected by the tacho generator 38 and R
The CPU 31 calculates the actual deceleration rate VDR based on the calculation formula stored in the OM 32. Calculated actual deceleration rate VD
R is also stored in the RAM 33, and its value is updated from time to time. Note that 37 in FIG. 1 is a driver for controlling the rotation of the motor 7.

The brake re-off control means is controlled by the CPU 31.
, ROM 32, and switch 39B, and the condition is that the actual speed V is lower than the set speed Vs (ST in Fig. 2).
13), the brake 20 is turned on at a predetermined position Po.
This is a means for turning off (ST14) again as shown in FIG. That is, according to the conventional stop control device that keeps the brake ON in advance, the vehicle will stop before the stop position Ps, but this brake re-OFF control means eliminates this problem.

Next, the deceleration control means compares the actual deceleration rate VDR and the set deceleration rate VDRs as shown in ST18, and determines whether the actual deceleration rate VDR is within a predetermined range (ideally equal to the set deceleration rate VDRs). ), the braking force of the brake 20 is automatically adjusted (ST15-21), and the CPU
31, ROM 32, and PWM voltage signal generating means 39. That is, as shown in FIG. 4, this PWM voltage signal generation means 39 applies a pulse signal (PWM) with a set voltage and a different time width to the solenoid 21S, and the set voltage value and time width can be set variably. P of
It may be formed from a WM circuit. Here, the CPU 31 and ROM 32 forming the deceleration control means compare the set deceleration rate VDRs read from the RAM 33 and the actual deceleration rate VDR, and calculate the PWM voltage signal outputted from the PWM voltage signal generation means 39.
Control signal C for controlling the voltage signal mode
NT is input to the means 39.

In this embodiment, the PWM voltage signal generating means 39 is configured to generate a PWM voltage signal with a width of 1 ms, as shown in ST17 of FIG.
The control signal CNT is configured to output a voltage signal, and the control signal CNT is
The mode is controlled by specifying the number of pulses. That is, while the actual deceleration rate VDR is greater than or equal to the set deceleration rate VDRs (YES in ST18), the control signal CNT specifies "N+1" PWM signals (ST19), and midway through, VDR<VDRs. (NO judgment in ST18), “N-1” (ST
21) is formed to cut off the signal PWM. Therefore, in practice, if an appropriate maximum deceleration rate is set on the keyboard 34, the actual speed V can be set to the minimum when the stop position Ps is reached.

Incidentally, in FIG. 4, the actual speed V becomes very small as the stop position Ps is approached, so if the actual deceleration rate VDR is small and the brake is kept on,
In order to prevent the slide 4 from stopping before the stop position Ps, the relationship is shown in which the brake ON time is decreased in steps ST18, 20, 21, and 17.

Thus, when the actual speed V becomes low and reaches the stop position Ps, the brake final ON control means (C
The PU 31, ROM 32, and switch 39B) operate, and the brake 20 is continuously turned on. Here, the slide 4 is reliably and accurately stopped at the desired stop position Ps.

Next, the operation of this embodiment will be explained. The set speed Vs and the set deceleration rate VDRs are set on the keyboard 34 (speed setting means, deceleration rate setting means). Vs and VDRs are stored in the RAM 33. When a command to stop the slide 4 at a predetermined position Ps such as top dead center is input, the CPU 31 of the drive control device 30 automatically activates the restart prevention switch 41 and the fixed position switch 42 of the rotary cam switch 40. (ST1 in Figure 2)
0,11). Then, the CPU 31 as a fixed position brake control means outputs the signal S1 and the signal S2 to the switches 39C and 39B to turn off the clutch 10 and turn on the brake 20 (ST12). Therefore, the actual speed V of the crankshaft 2 suddenly decreases as shown in FIG.

After that, when the actual speed V decreases below the set speed Vs, the CPU as the brake re-OFF control means
31 turns off the brake 20 (ST14). That is, the fixed position brake control means operates the brake 20 as before.
If the switch is left ON, the slide 4 may stop short of the stop position Ps, but this can be avoided in the present invention by turning the switch OFF again. On the other hand, if the brake 20 is left off again, the slide 4 will greatly exceed the stop position Ps.

Here, the CPU 31 as deceleration control means
sets “N=1” in ST15 and outputs the control signal CNT to set the PWM voltage signal generating means 39 to “1”.
A PWM voltage signal with a width of ms is generated (ST17). Therefore, the actual deceleration rate VDR is still the set deceleration rate VDRs.
(YES in ST18), ST1
9 and outputs a PWM voltage signal with a width of 2 ms and brake O.
Take a longer N time. This procedure (ST17, 18, 19)
By repeating, VDR<VDRs (NO in ST18)
judgment). In this case, in ST20 and ST21, the PWM voltage signal is made narrower than the previous width. Therefore, since the braking force of the brake 20 is controlled in a half-brake state by PWM voltage control, the actual deceleration rate VD
R is almost equal to the set deceleration rate VDRs, and the actual speed V
is decelerated as shown in FIG. 3, and continues to rotate at a low speed even when approaching the stop position Ps.

Thus, when the switch 43 operates at the stop position Ps, the CP as the brake final ON control means is activated.
U31 finally and continuously turns on brake 20 in response to signal S2. In this case, the PWM voltage signal generating means 3
9 is turned off. However, instead of switch 39B, PW
An infinite length PWM voltage signal may be generated from the M voltage signal generating means 39. Here, since the actual speed V is very small, the slide 4 can be accurately stopped at the predetermined position PS by turning on the final brake. The effects of the slide balancer and ambient temperature become irrelevant.

According to this embodiment, the brake re-OFF control means, the deceleration control means, and the brake final ON control means are provided, and when the actual speed V becomes equal to the set speed Vs, the fixed position brake control means is provided. The brake 20 that was previously turned on is turned off again, the actual deceleration rate VDR is decelerated to be equal to the set deceleration rate VDRs until the stop position Ps, and the brake is finally turned on at the low speed stop position Ps. Therefore, the slide 4 can always be accurately stopped at the desired stop position Ps without being affected by air pressure fluctuations of the slide balancer or ambient temperature.

Furthermore, since the brake re-OFF control means is configured to reversely operate only the brake function of the fixed position brake control means, the operation is reliable and simple. The same applies to the final brake ON control means.

The deceleration control means also includes a PWM voltage signal generation means 39, and changes the actual deceleration rate VDR to the set deceleration rate VDR.
Since the brake braking force is controlled so that the pulse width of the PWM voltage signal is changed and the setting of the pulse width of the PWM voltage signal can be changed, it can be applied to any power press machine.

Furthermore, since the deceleration control means and the final brake ON control means are designed to maintain a low speed at the stop position Ps and finally turn on the brake at the stop position Ps, the slide balancer When the prior brake is turned on by the conventional stop control device, the air pressure and ambient temperature of the stop control device change either before the stop position Ps or when the stop position Ps is overrun, and there is no effect at all.

Furthermore, since the deceleration control means is designed to operate at a speed lower than the set speed Vs, the press stop time does not become long.

Furthermore, the setting speed means and the deceleration rate setting means have wide applicability because the values of the speed Vs and deceleration rate VDRs can be set and changed.

Furthermore, a brake re-off control means,
Since the deceleration control means, the brake final ON control means, etc. are configured to share the same functions as the CPU 31, ROM 32, etc. of the drive control device 30, the reliability is high and the response is fast.

(Second Embodiment) In this second embodiment, the PWM voltage control at speeds below the set speed Vs in the first embodiment determines the ON time ( 4), the OFF time (FIG. 7) in which the brake 20, which was previously turned ON by the fixed position brake control means, is intermittently turned OFF below the set speed Vs is adjusted. It is made up of things. Therefore, compared to the first embodiment,
Brake re-OFF control means is not included, but deceleration control means (
As shown in ST37 in FIG.
It is formed to output a WM voltage signal.

Therefore, in the case of this second embodiment, S in FIG.
T30-35 and ST38, 40, 42 are ST10-15 and ST18, 20, 22 in FIG. 2 of the first embodiment.
, but ST37, 39, and 41 act like S in Figure 2.
Unlike T17, 19, and 21, adjust the brake OFF time. Therefore, as shown in FIG. 6, the actual speed V rapidly decreases from the predetermined position Po, and is gradually decelerated below the set speed Vs.

According to this second embodiment, the first
In addition to producing the same effects as in the first embodiment, the brake braking force is controlled while intermittently turning off the brake 20 that was previously turned on, so the set speed Vs is set lower than in the first embodiment. As a result, overall downtime can be shortened.

In the above embodiments, a separate type in which the clutch 10 and brake 20 are separated is disclosed, but the present invention is of course applicable to a combination type in which both 10 and 20 are integrated.

[0042]

[Effect of the invention] As described above, according to the invention of claim 1,
A brake re-OFF control means, a PWM voltage control type deceleration control means, and a brake final ON control means are provided to intermittently turn on the brake that has been turned off again when the speed is below a set speed.
The system is configured to decelerate at the set deceleration rate and finally turn on the brake at the low speed stop position, so there is no premature stop or overrun due to changes in the air pressure or ambient temperature of the slide balancer, and the desired stop position is achieved. can be stopped accurately at all times. Further, according to the invention of claim 2, a PWM voltage control system deceleration control means and a brake final ON control means are provided, and when the speed is below a set speed, the brake that has been previously turned on at a predetermined position is intermittently turned off to decelerate. In addition, since the brake is finally turned on at a low speed stop position, the same effect as in claim 1 can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining the configurations of first and second embodiments of the present invention.

FIG. 2 is a flowchart for explaining the operation of the first embodiment.

FIG. 3 is a timing chart for explaining the operation of the first embodiment.

FIG. 4 is a diagram for explaining PWM voltage control in the first embodiment.

FIG. 5 is a flowchart for explaining the operation of the second embodiment.

FIG. 6 is a timing chart for explaining the operation of the second embodiment.

FIG. 7 is a diagram for explaining PWM voltage control in a second embodiment.

FIG. 8 is a diagram for explaining the configuration of a power press machine according to a conventional example and the present invention.

FIG. 9 is a timing chart for explaining problems with a conventional stop control device.

[Explanation of symbols]

1 Power press machine 2 Crankshaft 4 Slide 5 Drive shaft 6 Flywheel 7 Motor 10 Clutch 11 Solenoid valve for clutch actuation 11S Solenoid 20 Brake 21 Solenoid valve for brake actuation 30 Drive control device 31 CPU (fixed position brake control means, brake re-controller) OFF control means, deceleration control means, brake final ON control means) 32 ROM (fixed position brake control means, brake re-OFF control means, deceleration control means, brake final ON control means) 33 RAM 34 Keyboard (speed setting means, deceleration rate Setting method)
37 Driver 38 Tacho generator (speed detection means) 39 P
WM voltage signal generation means (deceleration control means) 39B Switch (fixed position brake control means) 39C Switch (
Fixed position brake control means) 40 Position detection means 41 Restart prevention switch 42 Fixed position switch 43 Stop position switch

Claims (2)

[Claims] [Claim 1] A clutch that transmits the rotational energy of a flywheel rotationally driven by a motor to a crankshaft, and a brake that operates in reverse to this clutch and applies braking force to the crankshaft, so that the slide is in a predetermined position. In a stop control device for a power press machine configured to turn off a clutch and turn on a brake to stop the machine when , ON at the predetermined position
and a brake re-off control means for turning off the brake that has been turned off again, and an actual deceleration rate determined from the actual speed of the crankshaft and a preset setting between when the brake is turned off again and until the slide reaches the stop position. A deceleration control means applies a PWM voltage signal to a solenoid valve for brake operation while comparing the deceleration rate and turns on the brake intermittently to control the actual deceleration rate within a predetermined range, and when the slide reaches the stop position. A stop control device for a power press machine, comprising: brake final ON control means for finally turning on the brake. [Claim 2] A clutch that transmits the rotational energy of a flywheel rotationally driven by a motor to a crankshaft, and a brake that operates in reverse to this clutch and applies braking force to the crankshaft, so that the slide is in a predetermined position. In a stop control device for a power press machine configured to turn off a clutch and turn on a brake to stop the machine when While comparing the actual deceleration rate determined from the actual speed of the crankshaft with a preset deceleration rate, a PWM voltage signal is applied to the brake operating solenoid valve to intermittently turn off the brake and determine the actual deceleration rate. a deceleration control means for controlling within a predetermined range;
A stop control device for a power press machine, comprising: brake final ON control means for finally turning on the brake when the slide reaches the stop position.