JP2897658B2 - Toggle punch press abnormality detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an abnormality detecting apparatus for a toggle type punch press such as a turret punch press using a servomotor as a drive source.

[0002]

2. Description of the Related Art A conventional mechanical punch press transmits the rotation of a flywheel, which rotates at a constant speed, to a crank mechanism via a clutch brake and converts the rotation into a ram elevating operation. Therefore, the speed cannot be changed during the stroke. The speed change during the stroke is strongly demanded to simultaneously prevent noise and enable high-speed machining, and is realized by a hydraulic punch press. However, the hydraulic type press is costly due to a hydraulic system. Therefore, the applicant of the present invention has proposed a device that uses a servomotor as a drive source and raises and lowers a ram via a toggle mechanism (for example, Japanese Patent Application No. 6-157971). According to this, it is possible to change the speed in the middle of a stroke while using a mechanical punch press.

However, since a servo motor is used as a drive source, there is a possibility that various advanced functions can be added, and it is desired to further increase the commercial value by adding the functions. On the other hand, in conventional turret punch presses, etc., to check that the life of a punch tool is approaching due to wear,
The punch tool is removed from the turret and inspected visually, which requires time and effort for maintenance work. Therefore, automation of tool life determination is desired.

An object of the present invention is to provide a toggle punch press abnormality detecting apparatus which can easily detect an abnormality such as tool wear.

[0005]

The structure of the present invention will be described with reference to FIG. 1 corresponding to an embodiment. The abnormality detecting device according to the present invention includes a servo motor (12) via a toggle mechanism (8).
To detect the abnormality of the punch press that drives the ram (6). An abnormal value storage means (45) is provided in which an abnormal judgment value (τ _L ) of the torque value of the servo motor (12) for a predetermined ram elevating position is set.
Always read the load torque from the ammeter of the servo motor (12).
A torque monitoring means (48) for monitoring the time is provided, and when the monitored torque value of the means (48) exceeds the abnormality determination value (τ _L ) at the predetermined ram elevating position, an abnormality warning signal (a)
Is provided. The abnormal value storage means (45) may set an abnormal determination value (τ _L ) of a torque value with respect to a ram elevating position while the punch tool (4) punches a workpiece. In that case, the abnormality determining means (47) is replaced with the torque monitoring means (4).
If the monitored torque value according to 8) exceeds the abnormality determination value (τ _L ) at the ram elevating position during punching of the work, the abnormality warning signal (a) is output. Further, an abnormality determination value (τ _L ) set in the abnormal value storage means (45)
Is preferably set for each type of punch tool (4). In this case, the abnormality determination means (47) is configured to input the predetermined tool selection signal (b) to the abnormal value storage means (4).
Abnormality judgment value of tool type selected from 5) (τ _L1 ~
τ _Ln ) and the monitored torque value to compare with the abnormal warning signal (a)
Is output.

[0006]

[Action] According to this configuration, the torque value of the servo motor (12) is monitored by the torque monitoring means (48), when monitoring the torque value exceeds the abnormality determination value with a predetermined ram lifting position (tau _L), abnormal warning signal (A) is output to prompt the worker or the like to perform maintenance or the like. When a plurality of the same punch holes are sequentially processed, the load torque of the servo motor (12) with respect to the ram elevating position in each ram elevating operation becomes substantially the same value. Therefore, the abnormality can be detected by comparing the torque values at the predetermined ram elevating position as described above.
When the abnormality determination is performed based on the torque value at the time of punching out the work, it is understood that the tool life of the punch tool (4) is approaching due to wear or the like. Normally, the punching torque is not so large when the punch tool (4) is new and sharp, and when the sharpness is poor due to wear, the output of the motor (12) is required accordingly,
The torque value also increases. Therefore, by comparing the torque values at the time of punching, abnormalities such as tool life can be known in advance. When the abnormality determination value (τ _L ) is set for each type of punch tool (4), even if the model uses a plurality of punch tools (4), such as a turret punch press, the punch tool (4) is used. Regarding (4), it is possible to accurately determine that the tool life is approaching.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. First, the configuration of a toggle punch press to which the abnormality detection device is applied will be described. FIG. 2 is a vertical sectional side view of the toggle punch press, and FIG. 3 is a partially broken plan view and a partially broken front view thereof. The press frame 1 is formed to have a C-shaped side surface, and the upper turret 2 and the lower turret 3 are provided on the upper frame portion 1a and the lower frame portion 1b.
Are installed coaxially with each other. Upper and lower turrets 2, 3
Is a tool in which a plurality of punch tools 4 and die tools 5 are arranged side by side in the circumferential direction. It is turned out. When each punch tool 4 is indexed to the punch position P, the ram 6
And is driven up and down. The ram 6 includes a guide member 7
The upper frame portion 1a is supported by the upper frame portion 1a via a vertical movement, and is driven up and down by a toggle mechanism 8 that bends. The plate-shaped work is sent to the punch position P back and forth and right and left on the table 18 by a work feeding mechanism (not shown).

As shown in FIG. 2, the toggle mechanism 8 comprises a short upper toggle link 8a and a long lower toggle link 8b, which are flexibly connected by a pin 9. Is driven to bend. A lower end of the lower toggle link 8 b of the toggle mechanism 8 is rotatably pin-connected to an upper end of the ram 6. Upper toggle link 8a
Is supported by the upper frame portion 1a via a fulcrum support member 21 so as to be rotatable around the pivot shaft 23 at the upper end. The forward / backward lever 10 is driven forward / backward by a servo motor 12 via a crank mechanism 13 which is a conversion mechanism between rotation and reciprocating linear motion. The forward / backward lever 10 and the crank mechanism 13
Thus, the transmission mechanism 11 is configured.

The reciprocating lever 10 includes a reciprocating lever body 10b.
The swing lever 10c is vertically rotatably connected to the tip of the swing lever 10c. The forked end (FIG. 3A) of the swing lever 10c is connected to the pin 9 of the bent portion of the toggle mechanism 8. Are connected to be vertically rotatable. By the vertical swing of the swing lever 10c, the vertical displacement of the bent portion accompanying the bending operation of the toggle mechanism 8 is absorbed. The advance / retreat lever body 10b is supported by two guide rails 19, 19 vertically arranged in parallel on a support 25 in the upper frame portion 1a via a guide member 10a composed of a linear motion bearing or the like so as to be able to advance / retreat freely. I have. Support stand 25
3B, as shown in FIG. 3 (B), comprises a horizontal plate 25a and a vertical plate 25b integrally joined to the lower surface of the horizontal plate 25a. On both sides, both sides of the horizontal plate 25a are fixed.

As shown in FIG. 2, the crank mechanism 13
The disk-shaped crank 13a is provided above the throat portion 1c of the frame 1 so that the axis thereof is in a horizontal posture perpendicular to the side surface of the frame.
One end of the connecting rod 14 is rotatably connected to the eccentric position. The other end of the connecting rod 14 is rotatably connected to the base end of the advance / retreat lever body 10b. The rotating shaft of the disc-shaped crank 13a is rotatably supported by a mounting plate 33 mounted on an opening of one of the side plates of the throat portion 1c via a bearing (not shown). The servo motor 12 is mounted on a mounting plate 33 immediately below the bearing of the disc-shaped crank 13a. The servo motor 12 is provided with a speed reducer (not shown).
Is engaged with the input gear 16 of the disc-shaped crank 13a to be transmitted to the disc-shaped crank 13a.

Next, the configuration of a control system including an abnormality detection device will be described with reference to FIG. The control device 40 is a means for controlling the entire punch press, and includes a computer-based numerical control device, a programmable controller, and a servo controller for each axis. By a part of the control device 40,
A main control unit 41, a ram axis servo controller 42, an abnormal value storage unit 45, a friction torque storage unit 46, an abnormality determination unit 47, and a torque monitoring unit 48 are configured. The main control means 41 is means for decoding a machining program and outputting a sequence control command such as a drive command for each axis or a turret indexing command. In response to a punch command from the main control means 41, a drive current is supplied to the servomotor 12 via the ram axis servo controller 42 and the amplifier 43. The ram axis servo controller 42 uses a detection value of a position detector 44 such as an encoder provided for the servomotor 12 to
Performs closed-loop position control.

The abnormal value storage means 45 stores an abnormal judgment value τ of the torque value of the servo motor 12 with respect to a predetermined ram elevating position.
_In this embodiment, the abnormality determination value τ _L (τ _L1
To τ _Ln ) is set for each tool type in association with the tool number.

Here, the torque value of the servo motor 12 in each punching operation will be described. Servo motor 1
When the punch tool 4 is driven via the crank mechanism 13 and the toggle mechanism 8 by the second rotation, the punch tool 4 is displaced up and down as shown in FIG. At this time, in the case of a normal operation, a substantially uniform friction torque τ ₁ is applied to the punch tool 4 over the entire stroke of the ascending and descending as shown by oblique lines in FIG. An acceleration torque τ ₂ is applied to the end portion of the operation as shown by hatching in FIG. At the moment when the workpiece W is punched, a punching torque τ ₃ is applied as shown by hatching in FIG. Therefore, the total torque τ _all applied to the servo motor 12 in the entire lifting / lowering process is as shown by the hatched lines in FIG. In each of FIGS. 4A and 4B, the horizontal axis indicates the rotational position θ of the servo motor 12. This rotation position θ is
Although it has a non-linear relationship with the ram elevating position H, it has a unique positional relationship. Therefore, in FIGS. 4B to 4E, the horizontal axis can be seen as the ram elevating position.

The abnormality determination value τ _L set in the abnormal value storage means 45 is set to be slightly larger than the normal value τ _3n of the punching torque τ ₃ shown in FIG. For example,
Set to about 1.2 times. Naturally, the abnormality determination value τ _L is
The torque value is set to be smaller than a damage value τ _B which is a torque value just before the damage. Since the normal value τ _3n of the punching torque τ ₃ differs for each tool type, the abnormality determination value τ _L1 to
Set τ _Ln .

The friction torque storage means 46 shown in FIG.
This is storage means for setting the value of the friction torque τ _{1 in} (B). The set value of the friction torque storage means 46 is made variable by an operation of a manual input means or the like so as to cope with a case where the machine becomes old. The torque monitoring means 48 includes the servo motor 12
This embodiment is a calculating means for monitoring the current value of the ammeter 50 for detecting the supply current of the servomotor 12 and converting the current value into a torque value.

The abnormality determining means 47 includes a torque monitoring means 48
The monitored torque value of the abnormal value storage means 4
5 is a means for judging whether or not an abnormality judgment value τ _L is exceeded, and outputting an abnormality warning signal a when the judgment is made. Upon determination of the monitoring torque values, so as to compare the value obtained by subtracting the friction torque value tau ₁ set in the friction torque storage means 46 and the abnormality determination value tau _L. The predetermined ram elevating position is set in advance in the abnormality judging means 47, and the abnormality judging means 47 monitors the detection value of the position detector 44 of the servomotor 12, and monitors the monitored torque value only during the predetermined ram elevating position. Is continued. Further, when the turret index signal b, which is a tool selection signal, is output from the main control unit 41, the abnormality determination unit 47 determines the abnormality determination value τ _L corresponding to the tool number of the selected tool in the abnormal value storage unit 45. It shall be selected for the above determination. The warning unit 49 is a unit that issues a warning in response to the abnormality warning signal a of the abnormality determination unit 47, and includes a display such as a CRT, a buzzer, a lamp, and the like.

The operation of the above configuration will be described. When the disk-shaped crank 13a is rotated once by the servo motor 12, the forward / backward lever 10 performs one reciprocating forward / backward operation. In this one reciprocating operation, while the advance / retreat lever 10 reaches the center position of the advance / retreat stroke S from the right end position in FIG. 1A, the toggle mechanism 8 changes its bent portion from the right bent state to the extended state. Accordingly, the ram 6 descends from the top dead center to the bottom dead center. While the forward / backward lever 10 reaches the left end position from the center position of the forward / backward stroke S, the toggle mechanism 8 changes its bent portion from the extended state to the leftward bent state, and the ram 6 moves from the bottom dead center accordingly. Ascend to top dead center. When the forward / backward lever 10 returns from the left end position to the right end position, the ram 6 moves up and down as described above. In this way, while the reciprocating lever 10 performs one reciprocating reciprocating operation, the ram 6 repeats the elevating operation twice, and the punching operation by the punch tool 4 is performed two times.
Is done many times.

In each punching operation, abnormality determination is performed by the abnormality determining means 47. In this case, the torque monitoring means 48 constantly monitors the load torque from the ammeter 50 of the servomotor 12, and when the ram elevating position obtained from the position detector 44 becomes the work punching position, the abnormality determining means 47 From the monitored torque value to the friction torque value τ
A comparison is made between the value obtained by subtracting ₁ and the abnormality determination value τ _L. The abnormality determination value τ _L is an abnormality determination value τ _{L1 to} τ _Ln of the currently determined tool. As a result of the determination, the abnormality determination value τ
If it does not exceed _L , processing is continued without any processing. If the result of the determination is that the abnormality determination value τ _L is exceeded, an abnormality warning signal a is output, and a warning is issued to the warning means 49. This warning may be displayed by a mark or a character corresponding to the tool number on the display in addition to the buzzer or the like as described above. When there is the abnormality warning signal a, the machine may be stopped in response to the signal a, and the machine operation may be continued normally.

According to this abnormality detecting device, it is automatically determined that the life of the punch tool 4 is nearing its end due to wear or the like, and the operator is notified. This prevents the punch tool 6 from being damaged during machining.

[0020] In the above embodiment has been previously subtracted value friction torque tau ₁ from the monitoring torque values as compared with the abnormality determination value tau _L, includes pre friction torque tau ₁ abnormality determination value tau _L It is also possible to set the monitoring torque value as it is and compare it with the abnormality determination value τ _L.
In the above-described embodiment, the torque value during punching of the workpiece W is determined. May be determined. In this case, the tool life cannot be determined, but a machine abnormality such as poor acceleration or an increase in friction can be automatically determined and a warning can be issued.

[0021]

Effects of the Invention abnormality detecting device of a toggle-type punch press of the present invention includes means for setting the abnormality determination value of the torque value of the servo motor for a given ram vertical position, the load torque from the ammeter of the servo motor at all times Means for monitoring ;
A means for outputting an abnormality warning signal when the monitored torque value of this means exceeds the abnormality determination value at the predetermined ram elevating position is provided, so that a mechanical abnormality can be automatically detected with a simple configuration. In the case of the invention of claim 2, in the above configuration, the abnormality determination is performed based on the torque value at the time of punching the workpiece, so that it is known in advance that the punch tool is about to reach the tool life due to wear or the like. Therefore, breakage of the tool during machining can be prevented. In the case of the third aspect of the present invention, since the abnormality determination value is set for each type of punch tool, even when a plurality of punch tools are indexed and used, such as a turret punch press, the tool life is determined for each punch tool. , Etc. can be accurately determined.

[Brief description of the drawings]

FIG. 1A is an explanatory diagram of a conceptual configuration of a toggle punch press abnormality detecting device according to an embodiment of the present invention;
(B) is an explanatory diagram of a load torque, and (C) is an explanatory diagram of an abnormality determination value.

FIG. 2 is a cutaway side view of the toggle punch press.

FIG. 3A is a partially broken plan view of the punch press,
(B) is a fracture front view of the same part.

FIG. 4 is an explanatory diagram of various load torques acting on a toggle mechanism.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Press frame, 2, 3 ... Turret, 4 ... Punch tool, 8 ... Toggle mechanism, 8a ... Upper toggle link, 8b ...
Lower toggle link, 10 forward / backward lever, 11 transmission mechanism, 12 servo motor, 13 crank mechanism, 13a
... Crank, 40 ... Control device, 41 ... Main control means, 44
... Position detector, 45 ... Abnormal value storage means, 46 ... Friction torque value storage means, 47 ... Abnormality determination means, 48 ... Torque monitoring means, 49 ... Warning means, 50 ... Ammeter, a ... Abnormality warning signal, b ... Turret indexing signal (tool selection signal), τ _L … abnormal judgment value

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-64-71541 (JP, A) JP-A-2-30400 (JP, A) JP-A-55-61400 (JP, A) 95125 (JP, U) Japanese Utility Model Showa 47-13776 (JP, U) JP-B 64-9120 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) B30B 15/28 B21D 28 / 00 B21D 28/34 B30B 1/14 B30B 15/00

Claims (3)

(57) [Claims] 1. A punch press abnormality detecting device for driving a ram by a servo motor via a toggle mechanism,
An abnormal value storage means for setting an abnormal judgment value of the torque value of the servo motor with respect to a predetermined ram elevating position; a torque monitoring means for constantly monitoring a load torque from an ammeter of the servo motor ; and a monitoring torque value of this means. An abnormality detection device for a toggle-type punch press, comprising: an abnormality determination unit that outputs an abnormality warning signal when the abnormality determination value is exceeded at the predetermined ram elevating position. 2. The abnormal value storage means according to claim 1, wherein an abnormal determination value of a torque value with respect to a ram elevating position during punching of a workpiece by a punch tool is set. 2. An abnormality warning signal is output when a value exceeds the abnormality determination value at a ram elevating position during punching of the workpiece.
The toggle-type punch press described above. 3. An abnormality determination value set in said abnormal value storage means is set for each type of punch tool, and said abnormality determination means selects a tool selected from said abnormal value storage means by inputting a predetermined tool selection signal. 3. The toggle punch press abnormality detection device according to claim 2, wherein an abnormality warning signal is output by comparing the type of abnormality determination value with the monitoring torque value.