JP5147753B2 - Electromagnetic brake - Google Patents

Description

  The present invention relates to an electromagnetic brake that applies braking by pressing a braking piece with a braking spring and releases braking with an electromagnet, and particularly relates to a coil arrangement and excitation method of an electromagnet composed of two electromagnetic coils or coil portions.

  Conventionally, an electromagnetic brake in which one electromagnet is constituted by two electromagnetic coils has been disclosed (see, for example, Patent Document 1). In addition, a method in which one electromagnet is composed of two coils and each electromagnetic coil is excited by an individual power source (see, for example, Patent Document 2), a method in which two electromagnetic coils are excited by one power source (for example, , See Patent Document 3), and a method of switching and exciting two electromagnetic coils with one power source (for example, see Patent Document 4) is disclosed.

Japanese Patent Laid-Open No. 04-203628 JP 2008-120469 A Japanese Patent Publication No. 47-26547 Japanese Utility Model Publication No. 63-147937

  Generally, in an electromagnetic brake, it is necessary to reduce the temperature rise of an electromagnetic coil that constitutes an electromagnet. That is, when a current is passed through the electromagnetic coil, heat is generated by the self-resistance and the self-resistance value is increased, so that a power source that generates a high additional voltage for flowing the required current is required. Therefore, it is necessary to reduce the temperature rise of the electromagnetic coil.

  However, the electromagnet of the electromagnetic brake proposed in Patent Document 1 is composed of two electromagnets in one electromagnet, one is a main coil that is always used, and the other is an auxiliary coil that is used in an emergency. As an arrangement of the two electromagnetic coils, a case is disclosed in which they are arranged in the radial direction on the yoke side, arranged in the axial direction, or one on the yoke side and the movable iron piece side. The conventional method of Patent Document 1 is an arrangement of a regular main coil and an emergency auxiliary coil, and is not a case where two electromagnetic coils are always used. Furthermore, there is no disclosure about a specific excitation method of two electromagnetic coils and a reduction in temperature rise of the coils for the brake releasing operation.

  Further, the elevator hoisting machine brake control device proposed in Patent Document 2 uses two electromagnetic coils for one electromagnet, and one electromagnetic coil is arranged on the bottom side of the coil housing portion and is used as a coil current. A method is disclosed in which a current is fed back by a current control circuit that feeds back the current, and the other electromagnetic coil is placed on the opening side of the coil housing portion, and the current is passed by connecting and disconnecting contacts in a resistance-controlled circuit (Patent Literature). 2 to FIG. 22 to FIG. 26). However, the conventional method of Patent Document 2 does not disclose the case of forming two coil portions in which the winding direction of the coils is reversed to form one electromagnetic coil and the reduction in the temperature rise of the coil.

  The electromagnetic clutch or brake proposed in Patent Document 3 uses two electromagnetic coils for one electromagnet, and one electromagnetic coil is arranged as a holding coil on the bottom side of the coil housing portion and is always excited by a power source. The other electromagnetic coil is disposed as a suction coil on the magnetic pole surface side of the coil housing portion, and is also excited by a transistor with the power source only during suction. However, as in the case of Patent Document 2, there is no disclosure of a case in which two coil portions are formed by reversing the winding direction of the coil to form one electromagnetic coil, and a reduction in the temperature rise of the coil.

  The electromagnetic clutch and brake proposed in Patent Document 4 includes an armature suction coil and a holding coil that are movable iron pieces, and the arrangement of these two electromagnetic coils is the same as that of Patent Document 3, The energization to the two coils is switched according to the attracting state of the armature which is a movable iron piece by a power source (see FIGS. 1 and 2 of Patent Document 4). For this reason, as in the case of Patent Documents 2 and 3, the case where two coil portions are formed by reversing the winding direction of the coil to form one electromagnetic coil and the reduction in temperature rise of the coil are not disclosed.

  An object of the present invention is to provide an electromagnetic brake capable of reducing a rise in coil temperature when two electromagnetic coils or coil portions are arranged in one electromagnet and each coil is excited by an individual power source.

In order to achieve the above object, according to a first aspect of the present invention, there is provided a braking application means for applying a braking force by applying a pressing force to a braking piece facing a braked body by a braking spring, an electromagnetic coil and a yoke. The electromagnetic coil is composed of two cylindrical coil parts and is arranged to overlap in the radial direction. Winding with one winding and winding continuously from the middle in the reverse direction to form two coil parts with different winding directions and arranged in the same coil housing part of the yoke, the coil part one is located outside a radial direction of the coil receiving portion of the yoke as holding coil, the other of said coil portions is disposed radially inward of the holding coil as a promoter coil and the holding coil DC By adjusting the current in the power supply of the variable voltage, with flowing a current to brake the addition from the brake releasing operation started, the accelerator coil is characterized in that it flows through the current promotion period the brake releasing operation started.

  With this configuration, when two electromagnetic coils are arranged in a radial direction on one electromagnet, an electromagnetic brake that can reduce the temperature rise of the coil is obtained.

According to a second aspect of the present invention, the braking force is applied by a braking application means for applying a braking force by applying a pressing force to the braking piece facing the braked body by a braking spring, and an electromagnet comprising an electromagnetic coil and a yoke. The electromagnetic coil is composed of two cylindrical coil parts and is arranged so as to overlap the cylindrical axial direction. Winding in the middle of winding and winding continuously with the winding direction reversed, forming two coil parts with different winding directions and arranged in the same coil storage part of the yoke, one of the coil parts The holding coil is disposed at the bottom of the yoke coil housing portion on the side opposite to the magnetic pole surface, the other coil portion is disposed as an acceleration coil on the yoke coil housing portion magnetic pole surface side , and the holding coil is DC variable voltage Adjust the current source, with flowing a current to brake the addition from the brake releasing operation started, the accelerator coil is characterized in that flows through the current promotion period brake release operation start

  With this configuration, when two electromagnetic coils are arranged on one electromagnet in the axial direction, an electromagnetic brake capable of reducing the temperature rise of the coil can be obtained.

  According to the present invention, when two electromagnetic coils or coil portions are arranged in one electromagnet and each coil is excited by an individual power source, an electromagnetic brake that can reduce the temperature rise of the coil can be obtained.

It is the whole structure of the electromagnetic brake at the time of applying to the hoist of an elevator which becomes one Example of this invention, for example. FIG. 2 is a side view showing one side (left side in FIG. 1) of a pair of electromagnets in FIG. 1, which is an electromagnet formed by overlapping two cylindrical electromagnetic coils in the radial direction. It is an AA view in the front view of FIG. It is an excitation circuit of the electromagnetic coil of FIG. It is a timing diagram which shows operation | movement of a brake, and excitation of an electromagnetic coil. FIG. 3 is a view corresponding to FIG. 2 and comprising a holding coil and an accelerating coil of two coil portions having different winding directions in one electromagnetic coil in a second embodiment of the present invention. FIG. 6 is a diagram equivalent to FIG. 4 in the excitation circuit of the electromagnetic coil 30a of FIG. FIG. 5 is a side view showing one side (left side in FIG. 1) of a pair of electromagnets in FIG. 1, which is an electromagnet formed by overlapping two cylindrical electromagnetic coils according to a third embodiment of the present invention in the axial direction. It is a BB view in the front view of FIG.

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

  One embodiment of the electromagnetic brake of the present invention will be described with reference to FIGS.

  In FIG. 1, reference numeral 1 denotes a drive sheave of an elevator hoisting machine. A car 3 is suspended on one side of a main rope 2 wound around the drive sheave 1 and a counterweight 4 is suspended on the other side. The driving sheave 1 is driven by the hoisting motor 5 and the car 3 and the counterweight 4 are moved up and down. Reference numeral 6 denotes a brake drum as a braked body, which is installed on a shaft 5 a that connects the hoisting motor 5 and the drive sheave 1. A pair of braking pieces 7 abut on the braking surface 6 a of the brake drum 6. Reference numeral 8 denotes a pair of braking arms. The braking piece 7 is provided in the intermediate portion 8c, and the one end portion 8a is rotatably supported. Reference numeral 9 denotes a pair of braking springs, which are arranged on the other end portion 8b of the braking arm 8 so that the braking piece 7 applies a pressing force to the braking surface 6a.

  A pair of fixed electromagnets 10a and 10b are provided in the vicinity of the other end portion 8b of the braking arm 8 so as to release the pressing force of the braking spring 9. The electromagnets 10a and 10b are respectively composed of a holding coil 11a1 having two coil portions and an electromagnetic coil 11a and a yoke 12a made up of an accelerating coil 11a2, and an electromagnetic coil 11b and a yoke made up of a holding coil 11b1 made of two coils and an accelerating coil 11b2. The electromagnets 10a and 10b have magnetic pole surfaces 13a and 13b, and movable pieces 14a and 14b are arranged to face the magnetic pole surfaces 13a and 13b. The movable pieces 14a and 14b are coupled to one ends of the shafts 15a and 15b. The other ends of the shafts 15a and 15b are connected to the other end portion 8b of the braking arm 8 to drive the braking arm 8 and to the braking piece 7. The shafts 15a and 15b are slidably supported at the central portions of the yokes 12a and 12b. That is, the left electromagnet 10a, the braking spring 9, and the braking piece 7 system and the right electromagnet 10b, the braking spring 9, and the braking piece 7 system are configured in two sets that function independently.

  Reference numeral 16 denotes a coil excitation power source that controls the current by energizing the electromagnetic coils 11a and 11b of the pair of electromagnets 10a and 10b. Reference numeral 17 denotes a contact of an electromagnetic contactor that energizes and interrupts the electromagnetic coils 11a and 10b of the pair of electromagnets 10a and 10b.

  2 and 3, since the pair of electromagnets 10a and 10b in FIG. 1 have the same structure and the same configuration, the left electromagnet 10a will be described. The electromagnetic coil 11a is cylindrical and includes a holding coil 11a1 and a promotion coil 11a2. That is, the brake release holding coil 11a1 having a large diameter on one side of the coil, and the brake release promoting coil 11a2 having a small diameter on the other side and having a small diameter on the inner side in the radial direction of the holding coil 11a1, and the yoke 12a It is arrange | positioned at the coil accommodating part 12c of a recessed part. The holding coil 11a1 and the exciting coil 11a2 are excited by the holding power source 18 for releasing the brake and the promoting power source 19 for releasing the brake, respectively, and are excited so that the directions of the magnetic fluxes 18a and 19a generated in the yoke 12a are the same. . As described above, the movable piece 14a is supported by the shaft 15a, and this shaft 15a is slidably supported by the bearing 21 provided in the hole 20 in the central portion of the yoke 12a.

  4, the holding coil 11a1 of the left electromagnetic coil 11a in FIG. 1 and the holding coil 11b1 of the right electromagnetic coil 11b are connected in parallel and excited by the holding power supply 18 through the contact 17a. At this time, the holding power source 18 is controlled so that the current i 1 flowing through the holding coils 11 a 1 and 11 b 1 is detected by the current detection means 22 and fed back to obtain a constant current output commanded by the current command value 23. The holding power source 18 generates a DC variable voltage by a switching element, for example, and adjusts the current. Similarly, the promotion coils 11a2 and 11b2 are connected in parallel and excited by the promotion power source 19 via the contact point 17b. Reference numerals 24 and 25 denote current limiting resistors, which are inserted into the holding power supply 18 and the accelerating power supply 19 as necessary for current adjustment. Reference numerals 26 and 27 are normally closed contacts that are opened in an emergency such as an emergency stop of the elevator. A diode 28 and a resistor 29 connected in series are connected in parallel to the holding coils 11a1, 11b1 and the promotion coils 11a2, 11b2, respectively, and when the contacts 26, 27 are opened, the holding coils 11a1, 11b1 and the promotion coil 11a2, 11b2 reflux current is consumed.

  Next, referring to FIG. 4 and based on FIG. 5, the operation from the release of braking to the addition of braking according to this embodiment, that is, the operation from time T1 to time T4 will be described.

  The contacts 17a and 17b of the magnetic contactor supplied with power supply are connected at time T1, a constant current i1 flows from the holding power supply 18 according to a step-like current command, and the currents ia1 and ib1 flow to the holding coils 11a1 and 11b1 according to the time constant of the circuit. Current i2 flows from the accelerating power source 19, and currents ia2 and ib2 flow through the accelerating coils 11a2 and 11b2 according to the circuit time constant. At time T2, the contact point 17b is cut off, and the currents ia2 and ib2 from the accelerating power source 19 to the accelerating coils 11a2 and 11b2 are cut off. The current decreases and becomes zero according to the time constant of the circuit, and the current flowing through the electromagnetic coils 11a and 11b is maintained. Only the currents ia1 and ib1 of the coils 11a1 and 11b1 are obtained. At time T3, the current command of the holding coils 11a1 and 11b1 is cut off, and the contact 17a is cut off to cut off the currents ia1 and ib1 from the holding power supply 18 to the holding coils 11a1 and 11b1, and the current decreases according to the time constant of the circuit. It disappears at that point.

  That is, the period from T1 to T3 is a braking release operation, and the period from T1 to T2 is a braking release promotion period, and both the holding power source 18 and the acceleration power source 19 are made effective in order to speed up the braking release operation. As a result, magnetic fluxes generated by the currents ia1 and ib1 of the holding power supply 18 and the currents ia2 and ib2 of the accelerating power supply 19 are added, so that a large electromagnetic attraction force is generated in the electromagnet 10a shown in FIG. To speed up the brake release operation. The time from T1 to T2 is about several seconds when the elevator starts running.

  The period from T2 to T3 is a braking release holding period, and only the holding power source 18 is effective and holds the braking release state. That is, if the movable piece 14a is attracted, the gap is reduced and the magnetic resistance of the magnetic circuit is reduced. Therefore, even if the current is reduced, the movable piece 14a can be kept attracted. The time from T2 to T3 is until the elevator runs at a substantially constant speed and stops. The acceleration period of the brake release is about several seconds, which is very short compared with the brake release holding period, and is almost negligible in the entire period of brake release.

  After the time T3, the braking application operation is performed and the currents ia1 and ib1 of the holding power supply 11a1 and 11b1 on the holding power supply 18 side disappear, and the pressing force of the braking piece 7 is restored by the braking spring 9 of FIG. Become.

  The holding coils 11a1 and 11b1 are controlled at a constant current because the voltage fluctuation of the power supply drawn into the building, particularly the voltage drop, and as will be described later, when the coil is energized, heat is generated and the self-resistance value increases and the current value decreases. As a result, the release of braking cannot be maintained, the braking piece 7 is in a half-open state and rotates by rubbing against the brake drum 6, and the braking piece 7 is worn and the braking performance is deteriorated. For this reason, it is necessary to reliably maintain the brake release during the traveling of the elevator.

  In short, the holding power supply 18 continuously controls the current value to be the commanded current value from T1 to T3 by one-step wide pulse current command, and causes the coil currents ia1 and ib1 to flow through the holding coils 11a1 and 11b1. The accelerating power source 19 supplies currents ia2 and ib2 to the accelerating coils 11a2 and 11b2 for a short time from T1 to T2 at the initial stage of braking release. Then, both the holding power source 18 and the accelerating power source 19 are set to a coil current that speeds up the brake release, and the holding power source 18 is set to a current that holds the brake release.

By the way, the temperature rise of the electromagnetic coil is determined by heat generation (coil current) ² × coil resistance × time and heat dissipation state of heat dissipation. If the temperature rise is large, a highly heat-resistant insulation type winding and peripheral parts are required, resulting in an expensive problem. Comparing the temperature rises of the holding coil 11a1 and the accelerating coil 11a2, as described above, there is a difference in coil current and coil resistance, but the holding coil 11a1 excited by the holding power source 18 is overwhelmingly passed for a long time. Therefore, the temperature rises greatly. Therefore, in order to reduce the temperature rise, it is preferable to dispose the holding coil 11a1 having a large diameter, a large heat radiation area and a good heat radiation effect, and the holding coil 11a1 having a large temperature rise. There is no need to use a heat-resistant insulator.

  That is, when two electromagnetic coil portions are arranged in a radial direction on one electromagnet, in this embodiment, the holding coil of the coil portion with the larger amount of heat generation is used as a radius with a large heat radiation area of the yoke coil housing portion. It arrange | positions on the outer side of a direction, and the other promotion coil of the said coil part is arrange | positioned at the radial inside of the said holding coil. With this configuration, it is possible to reduce the temperature rise of the holding coil of the coil portion where the heat generation amount of the electromagnetic coil is large, and an effect that an insulating component having low heat resistance can be used is obtained.

  Although the acceleration power source 19 has been described without current control, current may be fed back in the same manner as the holding power source 18 so that a constant current flows during the braking release acceleration period from T1 to T2 in FIG.

  Next, a second embodiment is shown in FIGS. This embodiment is different from the first embodiment in that it is wound with one winding and continuously wound with the winding direction reversed in the middle to form two coil portions with different winding directions. This is a case where an electromagnetic coil is used.

  6, description will be made with the electromagnet 10a on the left side of FIG. 1 as in FIG. The electromagnetic coil 30a has a cylindrical shape, and a winding coil is wound by one electromagnetic coil 30a, for example, a left-handed reverse rotation of the acceleration coil 30a2 having a small right-handed diameter and a large diameter, and is superposed on the outer diameter side of the acceleration coil 30a2. It is continuously wound with one winding so as to be two coil portions with 30a1, and is formed as one electromagnetic coil 30a. Excitation to the holding coil 30a1 and the promotion coil 30a2 is performed by the holding power source 18 and the promotion power source 19, respectively. If the current direction of the accelerating coil 30a2 is reversed with respect to the holding coil 30a1, the directions of the magnetic fluxes 31a1 and 31a2 generated in the holding coil 30a1 and the accelerating coil 30a2 are the same, and the addition of the magnetic flux results in the electromagnetic of the electromagnet 10a. The suction power increases.

  In FIG. 7, as in FIG. 4, the holding coil 30a1 of the electromagnetic coil 30a and the holding coil 30b1 of the electromagnetic coil 30b are connected in parallel and excited by the holding power supply 18 via the contact 17a. At this time, the holding power supply 18 is controlled such that the current i1 flowing through the holding coils 30a1 and 30b1 is detected by the current detection means 22 and fed back, so that a constant current output of the current command value 23 is obtained. Similarly, the promotion coils 30a2 and 30b2 are connected in parallel and excited by the promotion power source 19 via the contact point 17b. The intermediate points 32a and 32b where the winding directions of the electromagnetic coils 30a and 30b are reversed are connected so that the holding power source 18 and the accelerating power source 19 have the same polarity. The current i1 flows through the holding coils 30a1 and 30b1, the currents ia1 and ib1, respectively, and the current i2 flows through the promotion coils 30a2 and 30b2, respectively. As a result, magnetic flux due to currents ia1 and ia2 is generated in the electromagnetic coil 30a, and magnetic flux due to currents ib1 and ib2 is generated in the electromagnetic coil 30b.

  The time course of excitation of the holding coils 30a1 and 30b1 and the promotion coils 30a2 and 30b2 is the same as that in FIG. 5 and corresponds to the holding coils 11a1 and 11b1 and the promotion coils 11a2 and 11b2, respectively. Moreover, you may carry out electric current control of the promotion power supply 19 similarly to 1st Embodiment.

  The effect of this embodiment is the same as that of the first embodiment, and it is possible to form one electromagnetic coil by winding with one coil without using two individual coils. The effect that can be reduced is obtained.

  Next, a third embodiment is shown in FIGS. This embodiment is different from the first and second embodiments when two electromagnetic coils or coil portions are overlapped in the axial direction to form one electromagnetic coil.

  8 and 9, since the pair of electromagnets 10a and 10b in FIG. 1 have the same structure and the same configuration, the left electromagnet 10a will be described. The electromagnetic coil 33a is cylindrical and includes a holding coil 33a1 and a promotion coil 33a2. That is, the brake release promoting coil 33a2 disposed on the magnetic pole surface 13a side of the coil housing portion 12c of the concave portion of the yoke 12a on the other side coil, and the opposite side of the magnetic pole surface 13a on the coil housing portion 12c on the one side coil. This is a braking release holding coil 33a1 arranged at the bottom of the side. That is, the holding coil 33a1 having a large temperature rise is brought into contact with the bottom surface, the inner diameter, and the outer diameter side surface of the coil housing portion 12c. Thereby, since a contact area becomes large, a temperature rise can be reduced. The holding coil 33a1 and the accelerating coil 33a2 are excited by the brake releasing holding power source 18 and the brake releasing promoting power source 19, respectively, so that the directions of the magnetic fluxes 34a1 and 34a2 generated in the yoke 12a are the same. Is done.

  2 and 6, the electromagnetic coil 33a has a holding coil 33a1 and an accelerating coil 33a2 as two electromagnetic coils whose winding directions are opposite to each other. The electromagnetic coil 33a is formed, or is wound continuously by one winding so as to form two coil portions, for example, a left-handed promotion coil 33a2 opposite to the right-handed holding coil 33a1. Rotate to form one electromagnetic coil 33a. Excitation to the holding coil 33a1 and the promotion coil 33a2 is performed by the holding power source 18 and the promotion power source 19, respectively, and is performed in the same manner as described in FIG. 4 or FIG. The time course of excitation of the holding coil 33a1 and the accelerating coil 32a2 is the same as in FIG. As in the first and second embodiments, the accelerating power source 19 may be current controlled.

  The effect of this embodiment is the same as that of the first or second embodiment.

7 Braking piece 9 Braking spring 10a, 10b Electromagnet 11a, 11b Electromagnetic coil 11a1, 11b1 Holding coil 11a2, 11b2 Promoting coil 12a, 12b yoke 12c Coil storage part 13a, 13b Magnetic pole surface 23 Current command value 30a, 30b, 33a Electromagnetic coil 30a1, 30b1, 33a1 Holding coil 30a2, 30b2, 33a2 Promoting coil

Claims (2)

The brake adding unit applies a braking force by applying a pressing force to the braking piece facing the brake target with a braking spring, and the brake releasing unit releases the braking force with an electromagnet including an electromagnetic coil and a yoke. In the electromagnetic brake, the electromagnetic coil is composed of two cylindrical coil portions and is arranged to overlap in the radial direction.
The coil portion is wound with a single winding and continuously wound with the winding direction reversed in the middle to form two coil portions with different winding directions and disposed in the same coil housing portion of the yoke One of the coil parts is disposed as a holding coil on the radially outer side of the coil coil receiving portion, the other coil part is disposed as an accelerating coil on the radially inner side of the holding coil , and The holding coil adjusts the current with a DC variable voltage power source to pass current from the start of braking release operation to the addition of braking, and the accelerating coil passes current during the acceleration period at the start of braking release operation. Features an electromagnetic brake. The brake adding unit applies a braking force by applying a pressing force to the braking piece facing the brake target with a braking spring, and the brake releasing unit releases the braking force with an electromagnet including an electromagnetic coil and a yoke. In the electromagnetic brake, the electromagnetic coil is composed of two cylindrical coil portions and is arranged so as to overlap the cylindrical axial direction.
The coil portion is wound with a single winding and continuously wound with the winding direction reversed in the middle to form two coil portions with different winding directions and disposed in the same coil housing portion of the yoke One of the coil portions is disposed as a holding coil on the bottom side of the yoke coil housing portion on the side opposite to the magnetic pole surface, and the other coil portion is disposed on the magnetic pole surface side of the yoke coil housing portion as an accelerating coil. The holding coil adjusts the current with a DC variable voltage power source to pass the current from the start of the braking release operation to the braking addition, and the acceleration coil supplies the current during the acceleration period at the start of the braking release operation. Electromagnetic brake characterized by flowing through.

Images