JP2003290997A - Safety device for electric servo press - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To furthermore improve safety by setting up a stronger brake in addition to a conventional brake. <P>SOLUTION: A brake device using an electromagnet is arranged between a servo motor for driving an electric servo press and a frame of a mechanical press. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a safety device for an electric servo press. Electric servomotor means a mechanical press driven by a servomotor.
The safety device is a device that protects a worker by interlocking with another device to suddenly stop the mechanical press or prevent an unexpected start.

[0002]

2. Description of the Related Art Conventionally, an electric servo press has been braked by a servo brake or a dynamic brake. That is, the regular braking is performed by a program, and when abnormal, the braking is performed by the reverse excitation or the reverse starting current.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a stronger braking device in addition to the conventional braking device to further improve safety.

[0004]

A braking device using an electromagnet is interposed between a servo motor for driving an electric servo press and a frame of a mechanical press. More specifically, in the invention of claim 1, a brake is interposed between a case of a servo motor for driving the electric servo press and a frame of the electric servo press, and the brake uses an electromagnet. The friction plate engaged with the shaft of the motor is pressed by the fixed plate and the movable plate.

According to a second aspect of the present invention, in addition to the structure of the first aspect, the electromagnet has a structure in which a loop-shaped coil is provided so as to surround the shaft so that magnetic force lines do not interfere with the shaft. According to a third aspect of the present invention, in addition to the configuration of the second aspect, the electric servo press has a pinion shaft connected to a motor shaft of the drive servomotor, and a crankshaft that meshes with a pinion provided on the pinion shaft. It was a one-stage reduction type press having a main gear fixed to.

[0006]

1 shows a vertical section of an electric servo press. The longitudinal section is a section taken along the center line running before and after the electric servo press. Therefore,
Shows a state in which the internal structure of the electric servo press is viewed from the side. The electric servo press in this embodiment is
This is a so-called C-frame type mechanical press. The present invention is not limited to the C frame type, but may be a straight side type, a C type
It can be applied to the child of the frame type and the straight side type.

A crankshaft 3 is rotatably provided on a frame 2 of the electric servo press 1, and a large diameter portion of a connecting rod 4 is engaged with an eccentric portion of the crankshaft 3. The lower end of the connecting rod 4 is connected to the slide 5. A crank mechanism is constituted by the crank shaft 3 and the connecting rod 4, and the slide 5 is vertically guided by the frame 2,
As the crankshaft 3 rotates, it moves up and down.

A bolster 7 is fixed to the bed 6 of the frame 2 so as to face the slide 5. The upper die is fixed to the lower surface of the slide 5, and the lower die is fixed to the upper surface of the bolster 7. The material supplied between the upper mold and the lower mold is pressed by the vertical movement of the slide 5 to become a product.

At the end of the crankshaft 3, the main gear 1
0 is provided. The taper hole of the main gear 10 is engaged with the taper shaft of the crankshaft 3, and the main gear 10 is
It is fixed to the crankshaft 3. The main gear 10 is
It meshes with a pinion of a pinion shaft 9 which is rotatably provided. The pinion and the main gear 10 constitute a speed reducer. This is commonly referred to as single stage deceleration.

The servo motor 8 is incorporated in the frame 2. A motor shaft 13 which is an output shaft of the servo motor 8 is connected to the pinion shaft 9. The spline formed at the tip of the motor shaft 13 is engaged with the spline hole formed in the pinion shaft 9. Both shafts are integrated by a spline, and rotational force is transmitted to each other. A brake 35 is interposed between the servo motor 8 and the frame 2.

In FIG. 2, the case 1 of the servomotor 8
2, a motor shaft 13 is rotatably provided. The motor shaft 13 is supported by bearings 14 and 18. A rotor 15 is provided on the motor shaft 13. On the circumference of the rotor 15, the magnet 3
4 is fixed. A stator 16 is provided outside the rotor 15. The stator 16 is a coil 17. The structures of the rotor 15 and the stator 16 are the same as those of a normal servomotor.

An encoder 19 is provided at the end of the motor shaft 13. The encoder 19 detects the amount of rotation of the servo motor 8 and
Used to control the.

In FIGS. 1 and 2, the case 12 and the bearing 11 of the servo motor 8 are tightened by stud bolts 25 to be integrated. The bearing 11 is fixed to the frame 2 of the electric servo press 1 and rotatably supports one end of the pinion shaft 9 via the bearing fitted in the hole.

2 and 3, an iron core 20 is fixed to the case 12 of the servomotor 8. Iron core 20
A coil 21 is wound around the convex portion 20a in a loop shape. When a current is applied to the coil 21, the iron core 20 becomes magnetized. That is, the iron core 20 and the coil 21 form an electromagnet. Since the magnetic lines of force of the electromagnet run parallel to the motor shaft 13, there is no risk of adversely affecting the motor shaft 13 and its peripheral members.

In FIG. 2, a spline 22 is formed on the motor shaft 13. The spline 22 and the spline formed in the hole of the brake disk 28 are engaged with each other. The brake disk 28 is the motor shaft 1
On the other hand, it cannot rotate but can move in the axial direction. The brake disc 28 is provided with a lining 29. The lining 29 is fixed to the brake disc 28 with screws 29a. The brake disk 28 and the lining 29 form a friction plate 36.

In FIGS. 2 and 4, the movable plate 23 is provided adjacent to the iron core 20, and the spring 30 and the bolt 33 are provided.
Is connected to the fixed plate 24 with the friction plate 36 interposed therebetween. That is, the spring case 31 is embedded in the fixed plate 24.
The spring 30 and the spring plate 32 are housed in the spring case 31, and the bolt 33 is screwed into the movable plate 23 through the spring case 31 and the spring plate 32. The spring 30 includes a spring plate 32 and a bolt 33.
Are stored in the spring case 31 in a compressed state.

The case 12, the iron core 20 and the fixing plate 24 of the servo motor 8 are fastened with the stat bolt 25 as described above with the spacer 27 interposed. Therefore, the fixed plate 24 is always fixed to the iron core 20 at a constant distance. In this state, the side surface of the iron core 20 and the movable plate 2
A gap of about 0.5 mm is provided between the side surface and the side surface of No. 3.

A guide 26 is fitted around the outer periphery of the spacer 27. The movable plate 23 is guided by a guide 26 so as to be movable back and forth in the longitudinal direction of the motor shaft 13.
That is, the guide 26 is engaged with the notch provided in the outer diameter portion of the movable plate 23.

When a current is passed through the coil 21, the iron core 20 serves as a magnet to attract the movable plate 23, the spring 30 contracts, and the gap disappears so that both are attracted. Then, the friction plate 36 is released from the fixed plate 24 and the movable plate 23, and the motor shaft 1
3 becomes rotatable. The electric servo press is operated in this state.

[0020]

The servomotor can be stopped arbitrarily, and the stop can be held by a brake having a large braking force in addition to the conventional servo brake or dynamic brake, which is safer.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an electric servo press.

FIG. 2 is a vertical sectional view of a servo motor unit

3 is a sectional view taken along line AA in FIG.

4 is a sectional view taken along line BB in FIG.

[Explanation of symbols]

1 is an electric servo press, 2 is a frame, 3 is a crankshaft, 4 is a connecting rod, 5 is a slide, 6 is a bed, 7 is a bolster, 8 is a servomotor, 9 is a pinion shaft, 10 is a main gear, 11 is a bearing, 12 Is a case, 13 is a motor shaft, 14 is a bearing, 15 is a rotor, 16 is a stator, 17 is a coil, 18 is a bearing, 19 is an encoder, 20 is an iron core, 20a is a convex portion, 21 is a coil, 2
2 is a spline, 23 is a movable plate, 24 is a fixed plate, 25 is a stud bolt, 26 is a guide, 27 is a spacer, 28
Is a brake disk, 29 is a lining, 29a is a screw, 30 is a spring, 31 is a spring case, 32 is a spring plate, 33 is a bolt, 34 is a magnet, 35 is a brake, and 36 is a friction plate.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Satoshi Nishida             Gunma Prefecture Fujioka 696 Fujinogo F term (reference) 3J058 AA48 AA53 AA57 AA69 AA78                       AA88 BA13 CC07 CC72 CC77                       DD10 FA31 FA42                 4E089 AA03 BA03                 4E090 AA01 AB01 BA02 BB01 CC01

Claims (3)

[Claims] 1. A brake is interposed between a case of a servo motor for driving an electric servo press and a frame of the electric servo press, and the brake is an electromagnet, and is engaged with a shaft of the servo motor. A safety device for an electric servo press having a structure in which a friction plate is pressed by a fixed plate and a movable plate. 2. The safety device for an electric servo press according to claim 1, wherein the electromagnet has a loop-shaped coil surrounding the shaft so that magnetic lines of force do not interfere with the shaft. 3. The electric servo press includes a pinion shaft connected to a motor shaft of the driving servo motor,
A safety device for an electric servo press, which is a one-stage reduction type press having a pinion provided on the pinion shaft and a main gear fixed to an interlocking crankshaft.