JP4841198B2 - Servo motor for press drive with brake mechanism - Google Patents

Description

  The present invention relates to a servo motor for press drive with a brake mechanism.

As a servo motor for press drive, there is known a press drive servo motor with a brake mechanism that is used by providing an electromagnetic brake on the front side of the servo motor and attaching the servo motor to the press body via a fixed plate of the electromagnetic brake ( For example, Patent Document 1).
Japanese Patent Laid-Open No. 2003-290997

  The electromagnetic brake in the press drive servomotor with the brake mechanism described in Patent Document 1 described above obtains a braking force by a spring force that presses and urges the brake disc against the fixed plate via the movable plate during braking. Release of braking by a spring force is performed by attracting the movable plate in a direction away from the friction plate by passing a current through an exciting coil of an electromagnet that attracts the movable plate.

  In the servo motor for press drive with a brake mechanism described in Patent Document 1, a servo brake (dynamic brake) is used to stop the slide during normal operation. Therefore, when the press is suddenly stopped for safety, or The electromagnetic brake is in an OFF state except when the servo motor is out of control. That is, the electromagnetic brake is constantly supplied with a large current to release the electromagnetic brake, and thus the electromagnetic brake generates heat and consumes more power.

  Since the servo motor for press drive with a brake mechanism described above is attached to the press main body via a fixed plate of the electromagnetic brake, heat generated in the electromagnetic brake portion is transferred to the press main body, and heat distortion occurs in the press main body. There is a problem that the processing accuracy is adversely affected.

  Further, since the brake disk is structured to be spline-engaged with the motor shaft in order to be able to slide on the motor shaft together with the movable plate, there is a problem in durability of the spline engaging portion. Also, in order to increase the rigidity of the spline section, it is necessary to increase the axial length. As a result, the mass of the brake disk increases, the inertia of the brake disk increases, and the brake stop time is delayed. There are also problems such as becoming.

  In addition, since the encoder, which is a precision component, is provided at the rear part of the servo motor, there is a problem that the accuracy of the encoder may be affected.

  SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and it is an object of the present invention to generate a brake that has low heat generation, low power consumption, low thermal influence on the press body, low inertia, and high durability. It is providing the servomotor for a press drive with a brake mechanism provided with.

The press drive servomotor with a brake mechanism according to claim 1 as means for solving the above-mentioned problems is provided in the press drive servomotor with a brake mechanism provided with a motor mounting portion on the front side of the servomotor. Provided with a pneumatically operated disk brake on the rear side of the motor, an encoder for detecting the rotation of the servomotor via the disk brake, and an output shaft of the servomotor in which the disk brake protrudes rearward of the servomotor A brake disc integrally fixed to the rear end portion, an annular press disc provided behind the brake disc so as not to be rotatable and movable only in the direction of the output shaft, and provided facing the press disc An annular fixed disk and the outer periphery of the pressing disk are always pressed against the brake disk. And a brake release means for moving the pressing disk away from the brake disk. The brake release means is provided with a cylinder body via a plurality of guide members provided on the fixed disk. An annular cylinder opened rearward is provided, and an annular piston operated by air pressure is slidably fitted to the annular cylinder, and the annular piston and the pressing disk are connected via a plurality of guide members, The annular cylinder and the pressing disk are provided so as to be integrally movable, the brake disk is made of an elastically bendable material, and a central portion of the brake disk is fixed to the output shaft. The main point is not to move in the direction .

  According to the servo motor for press drive with a brake mechanism of the present invention, heat generation due to friction with the friction plate hardly occurs, so that the press working accuracy is not adversely affected. Furthermore, since the power required for operating the pneumatic brake is only the control unit such as the pneumatic valve, the power consumption can be greatly reduced.

  In addition, since the encoder that detects the rotation of the servo motor via the disc brake is provided, the influence of heat generated by the servo motor on the encoder, which is a precision component, can be reduced, and the deterioration of the slide positioning accuracy can be suppressed. .

  In addition, the brake disc is made of an elastically bendable material, and the central portion of the brake disc is fixed to the output shaft so that it does not move in the axial direction. The brake disc can be manufactured, the inertia of the brake disc is reduced, and the brake performance can be improved by shortening the brake stop time.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a cross-sectional view of the servo press 1 along the crankshaft 3 extending in the front-rear direction (left-right direction in FIG. 1). Devices other than the slide 5 and the press drive servomotor 7 with a brake mechanism are shown in FIG. It is omitted.

  The C-shaped main body frame 9 of the servo press 1 is rotatably supported by bearing portions 3j before and after the crankshaft 3. An engaging hole 11 h in the upper part of the connecting rod 11 is engaged with the eccentric portion 3 h of the crankshaft 3. The lower end of the connecting rod 11 is slidably connected to the slide 5 via a ball bearing (not shown).

  The crankshaft 3 and the connecting rod 11 constitute a crank mechanism, and the slide 5 is vertically guided by a slide guide (not shown) provided on the main body frame 9 and moves up and down by the rotation of the crankshaft 3. It is configured as follows.

  A bolster 15 is replaceably mounted on the bed 13 of the main body frame 9 so as to face the slide 5. An upper die (not shown) is attached to the lower surface of the slide 5, and a lower die (not shown) is attached to the upper surface of the bolster 15. The material (not shown) supplied between the upper mold and the lower mold is subjected to press work by the up and down movement of the slide 5 to become a product.

  A taper is formed at the right end portion of the crankshaft 3. A taper hole of the main gear 17 is engaged with the taper portion of the crankshaft 3, and the main gear 17 is connected to the crankshaft 3 by a fixing member 19 and a bolt (not shown). It is fixed to.

  An output shaft 21 of the servo motor 7, that is, an output shaft 21 of the rotor 25 protrudes from the front side (left side in FIGS. 1 and 2) of the press drive servomotor 7 with the brake mechanism. A pinion gear 23 is attached to the tip. The casing of the servo motor 7 includes a central stator casing 25C, a front casing 25F on the front side of the stator casing 25C, and a rear rear casing 25R. The front casing 25F includes a front part. A stepped portion 29 having a cylindrical boss 27 slightly smaller in diameter than the casing 25F is formed.

  The body frame 9 of the servo press 1 is integrally provided with a mounting plate 9M for fixing the servo motor 7. The mounting plate 9M is provided with a mounting hole 31 that fits into the cylindrical boss 27 of the servomotor 7. The servo motor 7 is fixed to a predetermined position of the main body frame 9 of the servo press 1 with bolts (not shown) through the mounting holes 31.

  The tip of the output shaft 21 is rotatably supported by a bearing portion 9j provided on the main body frame 9, and is arranged so that the pinion gear 23 provided on the output shaft 21 and the main gear 17 are engaged. .

  Therefore, the slide 5 can be moved up and down via the crank mechanism by appropriately rotating and driving the pinion gear 23 by the servo motor 7.

  As shown in FIG. 2, the output shaft 21 is rotatably supported by a bearing 33 comprising a self-aligning roller bearing provided in the front casing 25F and a bearing 35 comprising a deep groove ball bearing provided in the rear casing 25R. Has been. The bearing 33 is fixed to the output shaft 21 by an annular bearing retainer 38 and a nut 40.

  A magnet 37 is attached to the circumferential portion of the rotor 25, and a stator 41 having an exciting coil 39 is provided on the circumferential portion of the rotor 25 with a small gap.

  The rear casing 25R of the servo motor 7 is provided with a pneumatically operated disc brake 43.

  The disc brake 43 has a structure in which an annular fixed disk 45 is provided in the rear casing 25R, and a plurality of guide members 47 such as shoulder bolts arranged at appropriate intervals in the circumferential direction on the outer peripheral portion of the annular fixed disk 45. The cylinder main body 49 is integrally fixed to the threaded portion of the rear shaft end of the plurality of guide members 47 by a nut 50 so as to extend rearward in parallel with the output shaft 21. The guide member 47 is provided so that the distance between the cylinder body 49 and the fixed disk 45 is constant.

  The cylinder body 49 is provided with an annular cylinder 51 that opens rearward coaxially with the output shaft 21, and an annular piston 53 that is operated by air pressure is movably fitted to the annular cylinder 51. . The cylinder body 49 is provided with an air pressure supply port 85 for supplying air pressure to the annular cylinder 51, and air pressure is supplied from the air pressure supply port 85 to the annular cylinder 51 through the flow path 86. The

  An annular pressing disk 55 is held on the guide member 47 between the cylinder body 49 and the fixed disk 45 so as not to rotate and to move only in the output shaft direction.

  The annular pressing disk 55 has a plurality of guide members 59 such as shoulder bolts that slidably pass through guide holes 57 provided at appropriate intervals in the circumferential direction on the outer periphery of the cylinder body 49. The annular piston 53 is integrally fixed by a nut 61 to the shoulder portion of the rear end portion of the guide member 59.

  Between the annular fixed disk 45 and the annular pressing disk 55, for example, a thin disc-like brake disk 63 that is elastically bent with a material such as spring steel is disposed. A pressing plate 65 and bolts 67 are integrally fixed to the rear end portion of the output shaft 21. An annular friction material 69 is bonded to both surfaces of the outer periphery of the brake disc 63.

  In the outer peripheral portion of the cylinder body 49, a plurality of spring mounting holes 73 for accommodating springs 71 as pressing urging members for constantly urging the pressing disk 55 against the brake disk 63 are appropriately provided in the circumferential direction. It is provided at a certain interval.

  Further, a hole 75 penetrating in the front-rear direction is provided in an inner wall portion 49i of an annular cylinder formed in the center of the cylinder body 49. An encoder 79 such as a pulse encoder is attached via an annular mounting base 77 attached to the rear end portion of the inner wall portion 49i of the cylinder.

  The pressing plate 65 is integrally provided with an encoder shaft 81 for transmitting the rotation of the output shaft 21 of the servomotor 7 to the encoder 79. The encoder 79 has an encoder cover 83 attached thereto.

  The operation of the press drive servomotor 7 with the brake mechanism configured as described above will be described with reference to FIGS.

  FIGS. 3A and 3B are views showing a state in which the pneumatically operated disc brake 43 is released, and an air pressure switching valve (not shown) is operated to flow from the air pressure supply port 85 to the flow path 86. If high-pressure air is supplied into the annular cylinder 51 via, the annular piston 53 moves to the right against the urging force of the spring 71.

  Since the annular piston 53 and the pressing disk 55 are integrally connected by the guide member 59, the pressing disk 55 moves to the right simultaneously with the annular piston 53, and the pressing biasing force to the brake disk 63 is released. The brake disk 63 that is pressed and held between the fixed disk 45 and the pressing disk 55 is free to rotate, and the disk brake 43 is released.

  As shown in FIG. 3B, a limit switch 85 for detecting the operating state of the disc brake 43 is provided at an appropriate position of the cylinder body 49. A dog 87 facing the limit switch 85 is attached to the annular piston 53 with a bolt 89. In the state in which the disc brake 43 is released, a slight gap d is set between the limit switch 85 and the dog 87.

  Next, a case where the pneumatic brake is operated will be described with reference to FIG. In the case of operating the pneumatic brake, if the pneumatic switching valve (not shown) is operated and the high-pressure air in the annular cylinder 51 is exhausted from the pneumatic supply port 85 via the flow path 86, The pressing disk 55 is moved to the left together with the annular piston 53 by the urging force of the spring 71, and the brake disk 63 is pressed and held between the fixed disk 45 and the pressing disk 55, and the brake is applied. At this time, the central portion of the disc-shaped brake disc 63 is fixed to the output shaft 21 and cannot move in the axial direction, but the brake disc 63 can be elastically bent with a material such as spring steel. Since it is made of a material, the peripheral edge of the brake disk 63 is bent to the left, and is pressed and held between the fixed disk 45 and the pressing disk 55.

  In the state where the pneumatic brake is activated, the limit switch 85 is in contact with the dog 87 as shown in FIG. 4B, and it is detected that the pneumatic brake is activated.

  When driving the press using the servo motor with the above configuration, the servo brake (dynamic brake) is mainly used to stop the slide when the press is operating normally, and the pneumatic brake is used during power outages. It is used after applying the servo brake (dynamic brake) for safety such as preventing the slide from falling by its own weight.

  In this case, the pneumatic brake is only a static operation, and hardly generates heat due to friction with the friction plate. Therefore, although there is some heat generation from the servo motor, it is not so much that heat is conducted to the press body and heat distortion is generated, and the press working accuracy is not adversely affected. Note that power consumption is greatly reduced because only the control unit such as a pneumatic valve is required for operating the pneumatic brake.

  In addition, since the encoder that detects the rotation of the servo motor via the disc brake is provided, the influence of the heat generated by the servo motor on the encoder, which is a precision component, can be reduced, and the decrease in slide positioning accuracy can be suppressed. be able to.

  In addition, the brake disc in the servo motor having the above configuration is made of an elastically bendable material, and the central portion of the brake disc is fixed to the output shaft and does not move in the axial direction. This makes it possible to manufacture with a thin plate that can be flexibly bent, and to reduce the inertia of the brake disc. As a result, it was possible to improve brake performance, such as shortening the brake stop time.

  FIG. 5 shows a second embodiment, which is characterized in that the pneumatic brake 43 in the press drive servomotor 7 with the brake mechanism described above is arranged on the front side of the servomotor 7. is there. Therefore, when the servo motor for press driving with a brake mechanism according to the second embodiment is fixed to the main body frame 9 of the servo press 1, heat conduction of the heat generated by the servo motor portion to the main body frame 9 is further suppressed, and the press No heat distortion occurs in the main body, improving the accuracy of press working.

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing (longitudinal cross section) of the servo press equipped with the press drive servomotor with a brake mechanism based on this invention. FIG. 2 is an enlarged explanatory view (partially sectional view) of details of a servo motor unit in FIG. FIG. 3A is an explanatory view of a press drive servomotor with a brake mechanism according to the present invention, FIG. 3A is an explanatory view of a state where a disc brake is released, and FIG. 3B is a position of a limit switch in a brake OFF state. FIG. FIG. 4A is an explanatory view of the press drive servomotor with a brake mechanism according to the present invention, FIG. 4A is an explanatory view of a state where the disc brake is operated, and FIG. 4B is a position of the limit switch in the brake ON state. FIG. Explanatory drawing of the servo press provided with the servomotor for press drive with a brake mechanism of 2nd Embodiment which concerns on this invention (the longitudinal cross-sectional view which fractured | ruptured one part).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Servo press 3 Crankshaft 3j Bearing part 5 Slide 7 Press drive servomotor with brake mechanism 9 Main body frame 9j Bearing part 9M Mounting plate 11 Connecting rod 11h Engagement hole 13 Bed 15 Bolster 17 Main gear 19 Fixing member 21 Output shaft 23 Pinion gear 25 Rotor 25C Stator casing 25F Front casing 25R Rear casing 27 Boss 29 Step 31 Mounting hole 33, 35 Bearing 37 Magnet 38 Bearing retainer 39 Excitation coil 40 Nut 41 Stator 43 Disc brake 45 Fixed disk 47 Guide member 49 Cylinder body 49i Inner wall portion 51 Annular cylinder 53 Annular piston 55 Pressing disc 57 Guide hole 59 Guide member 61 Nut 63 Brake disc 65 Holding plate 6 Bolt 69 Friction material 71 spring 73 spring mounting hole 75 hole 77 annular mount 79 encoder 81 of encoder shaft 83 encoder cover 85 air pressure supply port 86 passage 87 Dog 89 volts

Claims (1)

In a press drive servomotor with a brake mechanism having a motor mounting portion on the front side of the servomotor, a pneumatically operated disc brake is provided on the rear side of the servomotor, and the servomotor An encoder for detecting rotation; a brake disc integrally fixed to a rear end portion of the output shaft of the servo motor, wherein the disc brake protrudes rearward of the servo motor; and a non-rotatable rear portion of the brake disc; An annular pressing disk provided so as to be movable only in the output shaft direction, an annular fixed disk provided opposite to the pressing disk, and an outer peripheral portion of the pressing disk are always pressed against the brake disk. Brake release hand that moves the spring and the pressing disc away from the brake disc The brake release means is provided with a cylinder main body via a plurality of guide members provided on the fixed disk, an annular cylinder opened rearward is provided in the cylinder main body, and the annular cylinder is operated with air pressure. An annular piston is slidably fitted, and the annular piston and the pressing disk are connected via a plurality of guide members, and the annular cylinder and the pressing disk are provided so as to be integrally movable, A press drive servomotor with a brake mechanism, wherein the brake disk is made of an elastically bendable material, and a central portion of the brake disk is fixed to the output shaft and does not move in the axial direction .

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