JP7452393B2 - electromagnetic brake device - Google Patents

Description

The present invention relates to an electromagnetic brake device.

For example, in a non-excitation operated electromagnetic brake device installed in an industrial vehicle such as a forklift, when the electromagnetic coil installed in the stator is not energized, the armature pressed against the spring works with the plate to brake the brake disc. By sandwiching the two, a braking force is generated on the rotating shaft. When the electromagnetic coil is energized, the electromagnetic coil is excited, so the armature is attracted to the electromagnetic coil against the urging force of the spring, and the brake disc is released, thereby releasing the braking of the rotating shaft.

In such an electromagnetic brake device, in a low-temperature environment, water droplets may adhere to the brake body including the armature, brake disc, and plate, and may enter between the armature and the brake disc. In this case, if the water droplets between the armature and the brake disc freeze, even if the electromagnetic coil is excited, the armature may not be attracted to the electromagnetic coil, and the brake disc may not be released.

For example, in Patent Document 1, when an electric motor is rotationally driven, the screw shaft of the ball screw mechanism rotates and the nut member moves in the brake activation direction, and the tension generated in the left and right Bowden wires connected to the nut member is It is described that by increasing the amount of water, the ice adhering to the brake force transmission system is crushed and defrozen.

Japanese Patent Application Publication No. 2002-317839

In the above-mentioned conventional technology, an ice crushing device is required to crush the ice existing between the armature and the brake disc. However, if there is no space for arranging the ice crushing device due to layout constraints or the like, even if the brake main body freezes, it is not possible to unfreeze it. Therefore, it is impossible to release the brake disc and release the brake on the rotating shaft.

An object of the present invention is to provide an electromagnetic brake device that can unfreeze a brake body even in a narrow space.

One aspect of the present invention is an electromagnetic brake device mounted on an industrial vehicle, including a brake body that brakes a rotary shaft that rotates a drive wheel of the industrial vehicle, and a brake body that is arranged in the axial direction of the rotary shaft with respect to the brake body. The brake body includes a stator, an electromagnetic coil provided on the stator, and a heat generating part that generates heat for heating the brake body. The heat generating part includes an annular plate disposed on the opposite side of the stator to the disc, and an annular armature disposed between the brake disc and the stator and working together with the plate to sandwich the brake disc. are arranged in an annular shape surrounding the outer peripheral surface of the rotating shaft.

In such an electromagnetic brake device, when the armature moves toward the brake disc, the brake disc is sandwiched between the armature and the plate, thereby generating a braking force on the rotating shaft. When the armature moves toward the stator, the armature separates from the brake disc, thereby releasing the brake on the rotating shaft. However, if the brake body freezes in a low-temperature environment, it becomes difficult for the armature to separate from the brake disc. Therefore, by generating heat by the heat generating part, the heat is transmitted from the heat generating part to the brake body, and the brake disc and armature are heated. Therefore, the ice attached to the brake disc and armature melts, and the armature separates from the brake disc. By providing the heat generating portion arranged in an annular manner so as to surround the outer circumferential surface of the rotating shaft in this manner, a large-scale ice crushing device is not required. This allows the brake body to be unfrozen even in a narrow space.

Two plates may be arranged side by side in the axial direction of the rotating shaft, and the heat generating part may be arranged between the two plates. With such a configuration, the structure of the heat generating portion is simplified, and there is no need to increase the radial dimension of the electromagnetic brake device.

The heat generating section is a cylindrical heat generating sheet having a structure in which a heat generating body is attached to a sheet, and the heat generating sheet may be wound around the outer peripheral surface of the brake main body. In such a configuration, since the heating element sheet is wound around the outer circumferential surface of the brake main body, there is no need to add a plate or the like. Therefore, there is no need to increase the axial dimension of the electromagnetic brake device.

The heating element sheet may be wrapped around the outer circumferential surface of the brake main body and the outer circumferential surface of the stator. With such a configuration, the heating element sheet is prevented from shifting in the axial direction as the armature moves in the axial direction. Therefore, the durability of the heating element sheet is improved.

The heating element may be attached to a region of the sheet corresponding to the brake main body. With such a configuration, the heating element is efficiently placed only in the area to be heated in the electromagnetic brake device. Therefore, the amount of heating elements used is suppressed, and wasteful energy consumption due to heat generation in areas that do not require heating is suppressed.

The heating element sheet may be removably wrapped around the outer peripheral surface of the brake main body. In such a configuration, by removing the heating element sheet from the brake main body, it is possible to check the degree of wear of the brake disc.

One end of the sheet may be provided with a locking portion for locking both ends of the sheet, and the other end of the sheet may be provided with a locking receiving portion that engages with the locking portion. good. In such a configuration, the heat generating sheet is fixed to the brake main body by engaging the locking portion and the lock receiving portion while the heat generating sheet is wrapped around the outer peripheral surface of the brake main body. Furthermore, by disengaging the locking portion and the locking receiving portion, the heating element sheet is removed from the brake body. Therefore, the heating element sheet can be easily attached and detached from the brake main body.

According to the present invention, an armature and a brake disc can be thawed even in a narrow space.

1 is a schematic configuration diagram showing a drive device including an electromagnetic brake device according to an embodiment of the present invention. FIG. 1 is an exploded perspective view showing an electromagnetic brake device according to a first embodiment of the present invention together with a travel motor. 3 is a sectional view of the electromagnetic brake device shown in FIG. 2. FIG. It is an exploded perspective view showing an electromagnetic brake device concerning a 2nd embodiment of the present invention together with a travel motor. 5 is a sectional view of the electromagnetic brake device shown in FIG. 4. FIG. FIG. 5 is a plan view showing a developed state in which the heating element sheet shown in FIG. 4 is not wrapped around the outer peripheral surface of the brake main body.

Embodiments of the present invention will be described in detail below with reference to the drawings. In the figures, the same or equivalent elements are denoted by the same reference numerals, and redundant explanations will be omitted.

FIG. 1 is a schematic configuration diagram showing a drive device including an electromagnetic brake device according to an embodiment of the present invention. In FIG. 1, a drive device 1 is mounted on an industrial vehicle 2 such as an electric forklift.

The drive device 1 includes two travel motors 4 that rotatably drive left and right drive wheels 3, two speed reducers 5 disposed between the travel motors 4 and the drive wheels 3, and a motor between the two travel motors 4. It is equipped with two electromagnetic brake devices 6 disposed at.

As shown in FIG. 2, the travel motor 4 includes a motor body 8 having a rotating shaft 7 for rotating the drive wheel 3, and motor cases 9A and 9B that respectively cover both ends of the motor body 8 in the axial direction. ing. The rotating shaft 7 protrudes from both sides of the motor body 8 in the axial direction. The rotating shaft 7 is connected to the drive wheels 3 via a reduction gear 5. The motor case 9A is arranged on the reducer 5 side. The motor case 9B is arranged on the electromagnetic brake device 6 side.

FIG. 2 is an exploded perspective view showing the electromagnetic brake device according to the first embodiment of the present invention together with a travel motor. FIG. 3 is a sectional view of the electromagnetic brake device shown in FIG. 2. In FIGS. 2 and 3, the electromagnetic brake device 6 of this embodiment is used, for example, as a parking brake for an industrial vehicle 2. The electromagnetic brake device 6 is a non-excitation-operated electromagnetic brake that brakes the rotating shaft 7 when not energized and releases the braking of the rotating shaft 7 when energized.

The electromagnetic brake device 6 includes a brake main body 20 that brakes a rotating shaft 7, a stator 11 arranged in line with the brake main body in the axial direction of the rotating shaft 7, and a brake main body 20 and a stator 11. It includes a plurality of coil springs 15 disposed between them, an electromagnetic coil 16 provided on the stator 11, and a heating element 17 (heat generating section) that generates heat for heating the brake main body 20.

The brake body 20 includes a brake disc 10, plates 12 and 13, and an armature 14. The brake disc 10 is integrated with the rotating shaft 7 via a fixed part 18. The brake disc 10 rotates together with the rotating shaft 7.

The plates 12 and 13 are arranged on the opposite side of the stator 11 with respect to the brake disc 10. The plates 12 and 13 are arranged side by side at intervals in the axial direction of the rotating shaft 7. The plate 12 is arranged closer to the brake disc 10 than the plate 13 is. The plates 12 and 13 are shaped like perforated disks. That is, the plates 12 and 13 have an annular shape. The plates 12 and 13 are fixed to the stator 11 with a plurality of screws (not shown). The diameters of the plates 12 and 13 are larger than the diameter of the brake disc 10.

Armature 14 is arranged between brake disc 10 and stator 11. The shape of the armature 14 is a perforated disc. In other words, the armature 14 has an annular shape. The armature 14 is movable in the axial direction of the rotating shaft 7. The armature 14 cooperates with the plate 12 to sandwich the brake disc 10 in the axial direction of the rotating shaft 7. The diameter of the armature 14 is larger than the diameter of the brake disc 10.

The stator 11 is attached to the motor case 9A of the travel motor 4. The stator 11 is arranged to face the brake disc 10 with the armature 14 in between. The stator 11 is provided with a through hole 11b through which the rotating shaft 7 passes. The diameter of the stator 11 is equivalent to the diameters of the plates 12 and 13 and the armature 14.

Coil spring 15 is arranged between stator 11 and armature 14. Specifically, one end of the coil spring 15 is in contact with a bottom 19a of a spring housing hole 19 provided in the stator 11. The other end of the coil spring 15 is in contact with the armature 14. The coil spring 15 is a biasing member that biases the armature 14 in a direction to press it against the brake disc 10.

The electromagnetic coil 16 is arranged in an annular shape inside the stator 11. The electromagnetic coil 16 is connected to a power source (not shown).

When no current flows through the electromagnetic coil 16, the armature 14 is pushed toward the brake disc 10 by the biasing force of the coil spring 15, so the armature 14 pinches the brake disc 10 with the plate 12, and a braking force is generated on the rotating shaft 7. do.

When a current flows through the electromagnetic coil 16, the electromagnetic coil 16 is excited, so that the armature 14 is attracted to the electromagnetic coil 16 against the biasing force of the coil spring 15. Therefore, since the armature 14 moves toward the stator 11 and separates from the brake disc 10, the braking of the rotating shaft 7 is released.

The heating element 17 is arranged between the two plates 12 and 13. In other words, the heating element 17 is arranged so as to be sandwiched between the plates 12 and 13 in the axial direction of the rotating shaft 7. The heating elements 17 are continuously arranged in an annular shape so as to surround the outer circumferential surface 7a of the rotating shaft 7. The heating element 17 is composed of a heating wire. The heating element 17 is connected to a power source (not shown).

When a current flows through the heating element 17 while a braking force is being generated on the rotating shaft 7, the heating element 17 generates heat. The heat generated by the heating element 17 is transferred to the plate 12, brake disc 10, and armature 14. At this time, since the heating elements 17 are continuously arranged in an annular shape, heat is generated evenly in the circumferential direction of the brake body 20.

In the electromagnetic brake device 6 as described above, when the electromagnetic coil 16 is not energized, the armature 14 is pushed toward the brake disc 10 by the biasing force of the coil spring 15. Therefore, the rotary shaft 7 is braked by the brake disc 10 being sandwiched between the armature 14 and the plate 12.

When the industrial vehicle 2 is traveling, the electromagnetic coil 16 is energized by a power source (not shown). When the electromagnetic coil 16 is energized, the electromagnetic coil 16 is excited, so that the armature 14 is attracted to the electromagnetic coil 16. Therefore, the armature 14 moves toward the stator 11 against the biasing force of the coil spring 15, and the armature 14 separates from the brake disc 10, thereby releasing the braking of the rotating shaft 7.

By the way, in a low-temperature environment such as a freezer, water droplets may adhere to the armature 14, the brake disc 10, and the plates 12, 13, and may enter between the armature 14 and the brake disc 10. If the water droplets between the armature 14 and the brake disc 10 freeze, the armature 14 will not be attracted to the electromagnetic coil 16 even if the electromagnetic coil 16 is energized.

Therefore, under such a situation, the electromagnetic coil 16 is energized and the heating element 17 is energized. When the heating element 17 is energized, heat is generated from the heating element 17, and the heat is transmitted from the heating element 17 to the brake body 20, thereby heating the brake disc 10 and the armature 14. Therefore, the ice attached to the brake disc 10 and armature 14 melts. Therefore, since the armature 14 is attracted to the electromagnetic coil 16, the armature 14 is separated from the brake disc 10.

As described above, according to the present embodiment, by providing the heating element 17 arranged in an annular shape so as to surround the outer circumferential surface 7a of the rotating shaft 7, a large-scale ice crushing device is not required. As a result, the brake main body 20 is unfrozen even in a narrow space. As a result, the braking of the rotating shaft 7 can be released even in a low temperature environment while reducing costs.

Furthermore, in this embodiment, since the heating element 17 is arranged between the plates 12 and 13, the structure of the heating element 17 is simplified and the radial dimension of the electromagnetic brake device 6 does not need to be increased.

Note that the heating element 17 may be arranged in a rectangular ring shape so as to surround the outer circumferential surface 7a of the rotating shaft 7. Furthermore, the diameters of the stator 11, plates 12, 13, and armature 14 may be different. Further, the diameter of the brake disc 10 may be equal to the diameter of the stator 11.

FIG. 4 is an exploded perspective view showing an electromagnetic brake device according to a second embodiment of the present invention together with a travel motor. FIG. 5 is a sectional view of the electromagnetic brake device shown in FIG. 4. In FIGS. 4 and 5, the electromagnetic brake device 6 of this embodiment is a non-excitation-operated electromagnetic brake, similar to the first embodiment described above.

The electromagnetic brake device 6 includes a brake main body portion 25, the stator 11, the coil spring 15, and the electromagnetic coil 16 described above, and a cylindrical heat generating sheet 30 (heat generating portion).

The brake body 25 includes the brake disc 10, plate 12, and armature 14 described above. The brake body 25 does not have the plate 13 described above. The diameters of the plate 12 and armature 14 are equivalent to the diameter of the stator 11. The diameter of the brake disc 10 is smaller than the diameter of the stator 11.

The heating element sheet 30 is removably wrapped around the outer circumferential surface 25a of the brake body 25. Specifically, the heating element sheet 30 is removably wound around the outer peripheral surface 12a of the plate 12, the outer peripheral surface 14a of the armature 14, and the outer peripheral surface 11a of the stator 11. That is, the heating element sheet 30 is arranged in an annular shape so as to surround the outer circumferential surface 7a of the rotating shaft 7.

As shown in FIG. 6, the heating element sheet 30 has a structure in which a heating element 31, which is a heating wire, is attached to a substantially rectangular sheet 32. Note that FIG. 6 is a plan view showing a developed state in which the heat generating sheet 30 is not wrapped around the outer circumferential surface 25a of the brake main body portion 25. The material of the sheet 32 is, for example, heat-resistant rubber or flexible metal such as aluminum.

The heating element 31 is attached, for example, to one main surface of the sheet 32 in a wavy manner so as to be folded back multiple times near both ends of the sheet 32 in the longitudinal direction. Note that the longitudinal direction of the sheet 32 is the direction in which the heat generating sheet 30 extends in the unfolded state in which it is not wrapped around the outer peripheral surface 25a of the brake main body 25, and the heating sheet 30 extends along the outer peripheral surface 25a of the brake main body 25. This corresponds to the circumferential direction when it is wrapped around the

The heating element 31 is attached to an inner region 32a of the seat 32 that corresponds to the brake body 25. The heating element 31 is not attached to the outer region 32b of the sheet 32 corresponding to the stator 11. The heating element 31 is connected to a power source (not shown).

Two locking pins 33 (locking portions) for locking both ends of the sheet 32 in the longitudinal direction are provided at one end of the sheet 32 in the longitudinal direction. Two pin holes 34 (locking receiving portions) that engage with the locking pin 33 are provided at the other end of the sheet 32 in the longitudinal direction.

With the heating element sheet 30 wrapped around the outer peripheral surface 12a of the plate 12, the outer peripheral surface 14a of the armature 14, and the outer peripheral surface 11a of the stator 11 so that the heating element 31 is exposed on the outer peripheral side, the locking pin 33 is inserted into the pin hole. 34, both ends of the heating element sheet 30 are locked together. As a result, the heating element sheet 30 is fixed to the brake main body 25 and the stator 11.

In this embodiment, by providing the heating element sheet 30 arranged in an annular shape so as to surround the outer circumferential surface 7a of the rotating shaft 7, a large-scale ice crushing device is not required. Thereby, even in a narrow space, the brake main body portion 25 is unfrozen.

Further, in this embodiment, since the heating element sheet 30 is wound around the outer circumferential surface 25a of the brake main body 25, it is not necessary to add the plate 13 and the like as described above. Therefore, there is no need to increase the axial dimension of the electromagnetic brake device 6.

Further, in the present embodiment, the heating element sheet 30 is wrapped around the outer circumferential surface 25a of the brake main body 25 and the outer circumferential surface 11a of the stator 11. Therefore, the heating element sheet 30 is prevented from shifting in the axial direction as the armature 14 moves. Therefore, the durability of the heating element sheet 30 is improved.

Further, in this embodiment, the heating element 31 is attached to an inner region 32a of the seat 32 corresponding to the brake body 25. Therefore, the heating element 31 is efficiently placed only in the area of the electromagnetic brake device 6 that is desired to be heated. Therefore, the amount of heat generating element 31 used is suppressed, and wasteful energy consumption due to heat generation in areas that do not require heating is suppressed.

Further, in this embodiment, the heat generating sheet 30 is removably wound around the outer circumferential surface 25a of the brake body 25. Therefore, by removing the heating element sheet 30 from the brake main body 25, it is possible to check the degree of wear of the brake disc 10, etc.

Furthermore, in this embodiment, the heating element sheet 30 is wrapped around the outer circumferential surface 25a of the brake main body part 25, and the locking pin 33 and the pin hole 34 are engaged, so that the heating element sheet 30 is wrapped around the outer circumferential surface 25a of the brake main body part 25. Fixed. Moreover, by releasing the engagement between the locking pin 33 and the pin hole 34, the heating element sheet 30 is removed from the brake main body portion 25. Therefore, the heat generating sheet 30 can be easily attached to and detached from the brake body 25.

Note that in the heating element sheet 30, the heating element 31 may be attached to the entire surface of the sheet 32. Further, the heating element 31 may be attached to both main surfaces of the sheet 32.

Further, the heating element sheet 30 may be wrapped only around the outer circumferential surface 25a of the brake main body portion 25. Further, the diameter of the brake disc 10 may be equal to the diameter of the armature 14. In this case, the heating element sheet 30 will also be wrapped around the outer peripheral surface 10a of the brake disc 10.

Furthermore, the sheet 32 of the heating element sheet 30 may be provided with a hook or the like for hanging instead of the locking pin 33. Further, the heating element sheet 30 may be wound around the outer peripheral surface 25a of the brake body 25 and fixed to the brake body 25 excluding the armature 14 with screws, adhesive, or the like.

Although several embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. For example, in the embodiment described above, the heating element 17 or the heating element sheet 30 is continuously arranged in an annular shape so as to surround the outer circumferential surface 7a of the rotating shaft 7, but the heating element 17 or the heating element sheet 30 is not particularly limited to such a form. The heating element 17 or the heating element sheet 30 may be arranged intermittently in an annular manner so as to surround the outer circumferential surface 7a of the rotating shaft 7.

Further, the electromagnetic brake device 6 of the above embodiment is a non-excitation-operated electromagnetic brake that brakes the rotating shaft 7 when not energized and releases the braking of the rotating shaft 7 when energized. It is also applicable to an excitation-activated electromagnetic brake that brakes the shaft 7 and releases the brake on the rotary shaft 7 when power is not applied.

Further, in the embodiment described above, the drive device 1 includes two electromagnetic brake devices 6 corresponding to the two travel motors 4, but the present invention is applicable even if the number of travel motors 4 used is one. For example, it is also applicable to a drive device in which the number of electromagnetic brake devices 6 is one.

Moreover, although the electromagnetic brake device 6 of the above embodiment is mounted on an industrial vehicle 2 such as an electric forklift, the present invention is also applicable to an engine-type industrial vehicle.

2... Industrial vehicle, 3... Driving wheel, 6... Electromagnetic brake device, 7... Rotating shaft, 7a... Outer circumferential surface, 10... Brake disc, 11... Stator, 11a... Outer circumferential surface, 12... Plate, 13... Plate, 14... Armature, 15... Coil spring (biasing member), 16... Electromagnetic coil, 17... Heat generating element (heat generating part), 20... Brake main body, 25... Brake main body, 25a... Outer peripheral surface, 30... Heat generating element sheet (heat generating part) ), 31... Heat generating element, 32... Sheet, 32a... Inner region, 33... Locking pin (locking part), 34... Pin hole (locking receiving part).

Claims (6)

In electromagnetic brake devices installed in industrial vehicles,
a brake main body that brakes a rotating shaft that rotates a drive wheel of the industrial vehicle;
a stator arranged in an axial direction of the rotating shaft with respect to the brake main body;
an electromagnetic coil provided in the stator;
and a heat generating part that generates heat for heating the brake main body,
The brake main body portion includes a brake disc integrated with the rotating shaft, an annular plate located on the opposite side of the stator with respect to the brake disc, and located between the brake disc and the stator. and an annular armature that cooperates with the plate to sandwich the brake disc,
Two of the plates are arranged side by side in the axial direction of the rotating shaft,
In the electromagnetic brake device, the heat generating portion is arranged in an annular shape between the two plates so as to surround the outer peripheral surface of the rotating shaft. In electromagnetic brake devices installed in industrial vehicles,
a brake main body that brakes a rotating shaft that rotates a drive wheel of the industrial vehicle;
a stator arranged in an axial direction of the rotating shaft with respect to the brake main body;
an electromagnetic coil provided in the stator;
and a heat generating part that generates heat for heating the brake main body,
The brake main body portion includes a brake disc integrated with the rotating shaft, an annular plate located on the opposite side of the stator with respect to the brake disc, and located between the brake disc and the stator. and an annular armature that cooperates with the plate to sandwich the brake disc,
The heat generating part is a cylindrical heat generating sheet arranged in an annular manner so as to surround the outer peripheral surface of the rotating shaft, and having a structure in which a heat generating body is attached to the sheet,
In the electromagnetic brake device, the heating element sheet is wrapped around the outer peripheral surface of the brake main body. The electromagnetic brake device according to claim 2 , wherein the heating element sheet is wrapped around an outer circumferential surface of the brake main body and an outer circumferential surface of the stator. The electromagnetic brake device according to claim 3 , wherein the heating element is attached to a region of the sheet corresponding to the brake body. The electromagnetic brake device according to any one of claims 2 to 4 , wherein the heating element sheet is removably wrapped around the outer peripheral surface of the brake main body. A locking portion for locking both ends of the sheet is provided at one end of the sheet,
6. The electromagnetic brake device according to claim 5 , wherein the other end of the seat is provided with a lock receiving portion that engages with the locking portion.

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