JP4529114B2 - Air gap type electromagnetic braking device - Google Patents

Description

  The present invention relates to a gap type electromagnetic braking device such as a powder brake or a hysteresis brake, and more particularly to a gap type electromagnetic braking device provided with a torque detection device.

  Conventionally, a constant tension take-up device or a constant tension feeding device for a line material such as a thread, a magnet wire, an electrode wire of an electric discharge machine, or a strip material such as a tape or a film, An air gap type electromagnetic braking device (hereinafter referred to as an electromagnetic braking device) for applying tension, and tension applied to the wire material or strip material, which is disposed in the travel path of the wire material or strip material. A detector for detection is provided. In addition, such a device is provided with a control device that controls the excitation current supplied to the excitation coil of the electromagnetic braking device in accordance with a command from the detector, and the control device performs torque control of the electromagnetic braking device. Yes.

  In addition, when the structure is such that a torque detector is provided separately from the electromagnetic braking device in the travel path of the wire rod or strip material, as in the conventional constant tension winding device and constant tension feeding device, winding or feeding is performed. The configuration of the apparatus becomes complicated and the cost cannot be reduced. As an electromagnetic braking device that can solve such a problem, for example, in Japanese Utility Model Publication No. 4-39434 (Patent Document 1), an electromagnetic braking device capable of detecting torque is proposed.

  4 and 5 of Patent Literature 1 includes a rotating shaft, a cylindrical member connected to the rotating shaft, a field core disposed outside the cylindrical member, and a cylindrical member. A magnetic powder filled in an annular gap formed between the rotating member disposed inside and the inner peripheral surface of the cylindrical portion of the cylindrical member and the outer peripheral surface of the rotating member is provided. The electromagnetic braking device is provided with a lock bar and a torque arm fixed to the rotating member. Further, the tip of the lock bar is interposed between a pair of stoppers formed at intervals on the side of the field core, each side is pressed by a spring, and the tip of the torque arm is fixed to the field core. It extends to the (position detection sensor) side. In the electromagnetic braking device having such a configuration, when the rotational displacement between the field core and the rotating member occurs against the pressing force of the spring, the torque arm is also rotationally displaced and the output of the detector changes, so that the torque is increased. It can be measured. Further, the electromagnetic braking device can control the torque by controlling the exciting current supplied to the exciting coil.

Japanese Utility Model Publication No. 4-39434

  The electromagnetic brake device of Patent Document 1 includes a cylindrical member connected to a rotation shaft, a field core disposed outside the cylindrical member, a rotating member disposed inside the cylindrical member, and a cylinder of the cylindrical member. This is a structure in which a magnetic powder filled in an annular gap formed between the inner peripheral surface of the part and the outer peripheral surface of the rotating member is provided, and a lock bar and torque arm are connected to the rotating member. The apparatus becomes large and the cost of the apparatus cannot be reduced. An object of the present invention is to provide a lightweight, compact and inexpensive air gap type electromagnetic braking device.

In order to achieve such an object, an electromagnetic braking device of the present invention includes a support base, a rotary shaft that is rotatably supported by the support base, and a rotary member that is rotatably attached to the rotary shaft. The field core is rotatably supported on the rotating shaft, the exciting coil is accommodated in the field core, the rotation preventing means for limiting the rotation amount of the field core, and the field core is operated by the rotational displacement. A torque detecting device that rotates together with the field core, a base end portion fixed to the support base, and a free end abutting against the pressing member, and the field detecting device. a plate spring for elastically deformed in rotational displacement direction of the core, a permanent magnet fixed to the free end of the leaf spring, the support base of the side wall portion facing the side and the axis direction of the field core Fixed, characterized by being constituted by said Hall sensor facing the non-contact state and the permanent magnet.

The electromagnetic braking device of the present invention is characterized in that the pressing member is composed of a roller rotatably supported by the field core.

  In the electromagnetic braking device according to the present invention, the field core is rotatably supported on the rotating shaft on which the rotating member is mounted, and the field core is rotated against the elastic force of the elastic member by the reaction force of the braking torque. Since the torque detection device is activated, there is no need to form a cylindrical member between the outer peripheral surface of the rotating member and the inner peripheral surface of the field core unlike the electromagnetic braking device of Patent Document 1, and it is lightweight, small and inexpensive. An electromagnetic braking device can be provided.

In the electromagnetic braking device according to the present invention, the torque arm is constituted by a leaf spring that is elastically deformed in the direction of rotation of the field core. Can be adjusted. In the electromagnetic braking device of the present invention, the pressing member is composed of a roller rotatably supported by the field core, so that the frictional resistance acting between the elastic member and the roller is reduced, and the elastic member is slightly vibrated. Thus, it is possible to prevent problems such as deterioration in torque detection accuracy.

  1 to 4 show an electromagnetic braking device according to an embodiment of the present invention. 1 is a plan view, and FIG. 2 is a front view with a partial cross section. 3 is a right side view, and FIG. 4 is a cross-sectional view taken along line AA of FIG. In these drawings, reference numeral 1 denotes a powder brake as an electromagnetic braking device, which is supported by a support base 2 provided with opposing side wall portions 2a and 2b. Further, the powder brake 1 has a rotating shaft 4 whose both ends are rotatably supported on the side wall portions 2a and 2b of the support base 2 via a bearing 3, and a rotating member 5 mounted on the rotating shaft 4 so as to be integrally rotatable. And a field core 6 fitted with a predetermined gap on the outer side in the radial direction of the rotating member 5.

The field core 6 includes magnetic path members 7 and 8 that face each other in the axial direction, and an inner peripheral surface that is integrally fitted to the outer peripheral surfaces of the magnetic path members 7 and 8, and an annular flange portion on the outer peripheral surface. A cylindrical outer magnetic path member 9 formed with 9a is provided, and an excitation coil 10 wound around a coil bobbin is accommodated in an annular space surrounded by the magnetic path members 7, 8, and 9. Reference numeral 11 denotes an annular non-magnetic member that is sandwiched between the magnetic path member 7 and the inner peripheral surface side of the magnetic path member 8. Magnetic flux generated by energizing the excitation coil 10 is generated from one of the magnetic path members 7. The rotary member 5 is bypassed and flows to the other magnetic path member 8.

The field core 6 is fitted between a pair of bearings 12 fitted to the rotary shaft 4 and the outer ring of the bearing 12 and the inner peripheral surfaces of the magnetic path members 7 and 8 and faces the side surface of the rotary member 5. The rotating shaft 4 is supported by a pair of nonmagnetic support members . Reference numeral 13 is configured so that magnetic powder (not shown) filled in an annular gap formed between the inner peripheral surface of the field core 6 and the outer peripheral surface of the rotating member 5 does not leak to the rotating shaft 4 side. It is a pair of made seals. Reference numeral 14 denotes a heat radiating plate for releasing frictional heat generated by operating the powder brake 6.

Next, the torque detection device 15 will be described. The torque detector 15 includes a roller 18 as a pressing member rotatably supported on the flange portion 9a of the field core 6 by a bolt 16 and a collar 17 and a nut (not shown) screwed to the tip of the bolt 16. A leaf spring 19 as a torque arm whose base end is fixed with a screw to a mounting base 2 c fixed to the bottom of the support base 2 and whose free end abuts on the roller 18, and the free end of the leaf spring 19 A permanent magnet 20 fixed on the side opposite to the roller 18 and a hall sensor 21 facing the permanent magnet 20 in a non-contact state are provided.

Further, the torque detection means 15 is fixed to the flange portion 9a of the field core 6 and has a non-rotating pin as an engaging member inserted into a through hole 2d drilled in a mounting base 2c as a locking member. 25, and the rotation prevention pin 25 abuts against the wall portion of the through hole 2d of the mounting base 2c to limit the amount of rotation of the field core 6. The Hall sensor 21 is attached to a support plate 24 having four corners fixed to the side wall 2a with screws 23 with a collar 22 interposed. A pulley (not shown) is attached to the shaft end of the rotating shaft 4, and a wire material (not shown) wound or sent out by an electric motor is wound around the pulley 360 degrees.

  In the powder brake 1 having such a structure, when the exciting coil 10 is energized, the magnetic flux flows around the field core 6 to the rotating member 5, so that the magnetic powder filled in the gap is magnetized and linked in a chain shape. When the wire rod travels on the pulley in such a state, the rotating shaft 4 and the rotating member 5 rotate while shearing the magnetization connection of the magnetic powder, so that a certain tension is applied to the wire rod. The field core 6 receives the reaction force of the braking force of the wire rod, but its rotation is limited by the elastic force of the leaf spring 19. Further, when the reaction force of the braking force of the wire rod is increased and the leaf spring 19 is bent, the permanent magnet 20 is displaced and the output of the Hall sensor 21 is also changed, so that the excitation coil 10 is supplied based on the output change. By adjusting the excitation current, the tension applied to the wire rod can be adjusted.

  In the above embodiment, the powder brake has been described as the gap type electromagnetic braking device. However, the gap type electromagnetic braking device according to the present invention is described in, for example, Japanese Patent Application Laid-Open Nos. 9-14119 and 10-304649. Applied hysteresis brakes can be applied.

It is a top view of the electromagnetic brake concerning this invention. It is the front view which made a part of electromagnetic brake of Drawing 1 a section. It is a right view of FIG. It is the sectional view on the AA line of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Powder brake, 2 ... Support stand, 5 ... Rotating member, 6 ... Field core, 10 ... Excitation coil, 15 ... Torque detection apparatus, 18 ... Roller, 19 ... Leaf spring, 20 ... Permanent magnet, 21 ... Hall sensor, 25: Non-rotating pin.

Claims (2)

A support base, a rotary shaft rotatably supported on the support base, a rotary member mounted on the rotary shaft so as to rotate integrally therewith, a field core rotatably supported on the rotary shaft, and the field An excitation coil housed in the core, a rotation preventing means for limiting the amount of rotation of the field core, and a torque detection device that operates by the rotational displacement of the field core,
The torque detection device includes a pressing member that rotates integrally with the field core, a base end portion fixed to the support base, and a free end abutting on the pressing member, and a rotational displacement direction of the field core. A leaf spring that is elastically deformed, a permanent magnet that is fixed to the free end of the leaf spring , and a side wall portion of the support that faces the side surface of the field core in the axial direction, and is not in contact with the permanent magnet An air gap type electromagnetic braking device comprising a hall sensor facing a state. 2. The air gap type electromagnetic braking device according to claim 1 , wherein the pressing member is composed of a roller rotatably supported by the field core.

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