KR102290869B1 - Drum type mr brake and auto door closer using the same - Google Patents

Abstract

The present invention relates to a drum-type MR brake, comprising: a rotor connected to the same axis of a rotary shaft; a housing installed on a circumference of the rotary shaft and accommodating the rotor; a stator installed on the housing to face the rotor; a fluid charging unit formed between the stator and the rotor and charged with a magneto rheological fluid (MR fluid); an electromagnet installed on the stator and forming a magnetic field continuously passing through the rotor, fluid charging unit, and stator; and a differential pressure forming unit protruding from the rotor to the fluid charging unit and forming a pressure difference between an upstream side and a downstream side in a rotating direction. The rotor includes: a first rotation unit placed on one side in an axial direction of the electromagnet; a second rotation unit placed on the same radial-directional extended line as that of the electromagnet; and a third rotation unit placed on the other side in the axial direction of the electromagnet. The differential pressure forming unit is formed on at least one side of the first rotation unit, the second rotation unit, and the third rotation unit. The present invention aims to provide a drum-type MR brake and an auto door closer using the same, which are able to realize a more excellent braking force.

Description

Drum type MR brake and automatic door closer using the same

The present invention relates to a drum-type MR brake and an auto door closer using the same, and more particularly, to a drum-type MR brake for improving the braking force that restricts the rotation of a rotating member, and an auto door closer using the same.

In general, MR fluid (Magneto Rheological fluid) refers to a fluid in which iron particles are distributed in silicone oil. It is applied to MR dampers or valves to control damping force or pressure, or applied to MR brakes or clutches for relative movement. It is used to transmit torque through control.

Existing MR brakes are manufactured and applied in a large size or have a complex structure in order to stably implement the braking force that restricts the rotation of the rotating member in rotational motion. is losing

On the other hand, an auto door closer system for automatically opening and closing a door for user convenience in opening and closing a vehicle door is applied. In the auto door closer system, not only the opening/closing operation that moves the door, but also the holding operation that stops or restricts the movement of the door for safety is treated as a major factor.

In the existing auto door closer system, opening and closing operation and holding of the door are performed by driving and stopping the motor. That is, the door is opened/closed and held depending only on the operation of the motor. However, the occurrence of a malfunction of the motor cannot be excluded, so preparation for this cannot be ruled out. Therefore, there is a need to improve it.

The background technology of the present invention is disclosed in Korean Patent Application Laid-Open No. 2019-0006197 (published on January 17, 2019, title of the invention: a control method of an automatic vehicle door opening and closing device).

the present invention An object of the present invention is to provide a drum-type MR brake capable of realizing excellent braking force with a smaller size and more stably holding the door movement when applied to an auto door closer and an auto door closer using the same.

The drum-type MR brake according to the present invention includes a rotating body connected on the same axis as a rotating shaft; a housing installed around the rotation shaft and accommodating the rotation body; a fixture installed in the housing and disposed to face the rotating body; a fluid filling part formed between the fixed body and the rotating body and filled with a magneto-rheological fluid (MR fluid, Magneto Rheological fluid); an electromagnet installed on the fixed body and configured to generate a magnetic field continuously passing through the rotating body, the fluid filling part, and the fixed body; and a differential pressure forming part which is formed to protrude from the rotation body to the fluid filling part, and forms a pressure difference between the upstream side and the downstream side in the rotational direction, wherein the rotation body is located on one side in the axial direction of the electromagnet a first rotation unit; a second rotating part positioned on the same radial extension line as the electromagnet; and a third rotating part positioned on the other side of the electromagnet in the axial direction, wherein the differential pressure forming part is formed on at least one side of the first rotating part, the second rotating part, and the third rotating part.

The electromagnet has the same inner diameter as the fixed body and is disposed at a distance of a first width from the rotating body, and the differential pressure forming part is on the first rotating part, the second rotating part, and the third rotating part, the first width It is characterized in that it is formed to protrude as much as possible.

The rotating body and the fixed body are disposed with a distance of a first width, the electromagnet has an inner diameter smaller than that of the fixed body by the first width, and the differential pressure forming part is, from the first rotating part toward the fixed body a first differential pressure forming part protrudingly formed; and a third differential pressure forming part formed to protrude from the third rotating part toward the fixed body.

The rotating body, the rotating center portion connected to the rotating body; and a rotating body part connected to the rotation center part and having a sector-shaped cross-sectional shape, wherein the differential pressure forming part is formed to protrude in a radial direction between both ends of the rotating body part in a circumferential direction.

The first differential pressure forming part and the third differential pressure forming part are formed to protrude toward the fixed body by a second width, and the differential pressure forming part may include the first width at the second width from the second rotating part toward the electromagnet. It characterized in that it further comprises; a second differential pressure forming portion formed to protrude by the third width minus the.

An auto door closer using a drum-type MR brake according to the present invention includes: an actuator installed on a door; a rotating shaft rotated in association with the actuator; a vehicle body connection part connecting the rotation shaft and the vehicle body, and varying a position of the door with respect to the vehicle body according to the rotation of the rotation shaft; a rotating body coaxially connected to the rotating shaft; a housing installed around the rotation shaft and accommodating the rotation body; a fixture installed in the housing and disposed to face the rotating body; a fluid filling part formed between the fixed body and the rotating body and filled with a magneto-rheological fluid (MR fluid, Magneto Rheological fluid); an electromagnet installed on the fixed body and configured to generate a magnetic field continuously passing through the rotating body, the fluid filling part, and the fixed body; and a differential pressure forming part which is formed to protrude from the rotating body toward the fluid filling part and forms a pressure difference between the upstream side and the downstream side in the rotational direction.

The vehicle body connection unit may include: a first link bar disposed inside the door and rotatable in association with the rotation shaft; and a second link bar having one end connected to the first link bar, the other end connected to the vehicle body, and rotating in conjunction with the first link bar to change a relative angle with the first link bar. do it with

In the drum type MR brake and the auto door closer using the same according to the present invention, by forming the differential pressure forming part, the flow mode braking force in addition to the shear mode braking force of the magnetostrictive fluid acts as a braking force that further restricts the rotation of the rotating body. , compared to the embodiment using only one side of the shear mode braking force or the flow mode braking force, or the embodiment having a disk structure, it is possible to implement a superior braking force, and to realize the same braking force, a smaller size is possible.

In addition, according to the present invention, when the electromagnet is disposed in a section of the fluid-filled part that is not affected by the magnetic field, the entire fluid-filled part can be effectively utilized to generate shear force and braking force, and the amount of the magnetostrictive fluid can be adjusted to that of the electromagnet. Since it can be reduced by the amount of protrusion, it is possible to further reduce the burden of cost due to the application of an expensive magnetostrictive fluid, and to realize further miniaturization. And, when implemented with the same size, it is possible to more stably secure the winding space of the electromagnet, so that the magnetic field and braking force can be increased by further increasing the number of windings of the coil.

In addition, according to the present invention, when the area of the differential pressure forming part is further increased while minimizing the decrease in the effective circumference length of the fluid filling part, the flow mode braking force can be maximized at the same size, and the size can be further reduced in implementing the same braking force. .

In addition, when the present invention is applied to an auto door closer of a vehicle, it is possible to open and close the door while moving the door in conjunction with the rotation of the rotation shaft, and when necessary, the magnetostrictive fluid provided in the MR brake to increase the movement resistance to the rotation shaft. By changing the state, it is possible to stably hold the movement of the door.

1 is a cross-sectional perspective view schematically showing a drum type MR brake according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view of a main part of FIG. 1 .
3 is a cross-sectional view taken along line A-A' of FIG. 2 .
FIG. 4 is an enlarged view of part B of FIG. 2 .
5 is a cross-sectional perspective view schematically showing a drum type MR brake according to a second embodiment of the present invention.
6 is a cross-sectional view taken along line C-C' of FIG. 5 .
7 is a cross-sectional perspective view schematically showing a drum type MR brake according to a third embodiment of the present invention.
FIG. 8 is a cross-sectional view of a main part of FIG. 7 .
9 is a cross-sectional view taken along line D-D' of FIG. 8 .
10 is a cross-sectional view schematically showing a drum type MR brake according to a fourth embodiment of the present invention.
11 is a conceptual diagram illustrating an auto door closer using a drum type MR brake according to an embodiment of the present invention.

Hereinafter, an embodiment of a drum type MR brake and an auto door closer using the same according to the present invention will be described with reference to the accompanying drawings. In this process, the thickness of the lines or the size of the components shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, the terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to intentions or customs of users and operators. Therefore, definitions of these terms should be made based on the content throughout this specification.

1 is a cross-sectional perspective view schematically showing a drum-type MR brake according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view of the main part of FIG. 1, and FIG. 4 is an enlarged view of part B of FIG. 2 .

1 to 3, the drum type MR brake 2 according to the first embodiment of the present invention includes a rotating body 20, a housing 30, a fixed body 40, a fluid filling part 50, and an electromagnet. (60), and a differential pressure forming unit (70).

The rotating body 20 is connected coaxially with the rotating shaft 10 . The rotating shaft 10 is a rotating member that rotates in association with the actuator 4, and the rotation is restricted by the drum-type MR brake 2 according to the present invention, that is, it becomes an object to be braked. The rotating body 20 has a column shape and is integrally coupled to the circumference of the rotating shaft 10 , and is rotated at the same angular displacement and angular velocity as the rotating shaft 10 .

Here, having a columnar shape may presuppose that an axial length parallel to the rotation shaft 10 has a relatively longer shape than a radial length centered on the rotation shaft 10 .

The rotating body 20 according to the first embodiment of the present invention includes a first rotating unit 21 , a second rotating unit 22 , and a third rotating unit 23 . The first rotating part 21 is located on one side in the axial direction of the electromagnet 60 . The second rotating part 22 is positioned on the same radial extension line as the electromagnet 60 . The third rotating part 23 is located on the other side of the electromagnet 60 in the axial direction.

The rotating body 20 according to the first embodiment of the present invention is coupled to the circumference of the rotating body 20 in a cylindrical shape. Here, the circumferential shape may be assumed to have the same or relatively long column shape as compared to the axial length rather than the radial length centered on the rotation axis 10 , that is, the radius. In addition, it means that the edge portion of the rotating body 20 has a circular cross-sectional shape as a whole.

The housing 30 has a drum shape that can accommodate the rotating body 20 , the differential pressure forming unit 70 , the fixed body 40 and the electromagnet 60 , and is installed around the rotating shaft 10 . The housing 30 is applied to the drum type MR brake 2 according to the present invention so as to maintain a stopped state even when the rotating body 20 coupled to the rotating shaft 10 and the differential pressure forming unit 70 are rotated together. The installation is made on the target object (eg, the door 3 of the vehicle, etc.).

The housing 30 is disposed to extend in a circular shape along the circumference of the rotation shaft 10 and has a 'C' cross-sectional shape. The housing 30 forms the exterior of the drum type MR brake 2 according to the present invention, serves as a cover to protect internal components, and supports the fixture 40 and the electromagnet 60 in place. Provide possible frameworks.

The fixture 40 and the electromagnet 60 are maintained in a fixedly installed state at the set position on the housing 30 . Between the housing 30 , the fixed body 40 and the electromagnet 60 , and the rotating body 20 and the vehicle body forming part 70 , a fluid filling part that can be filled with a magneto-rheological fluid (MR fluid, Magneto Rheological fluid) (50) is formed.

The fixture 40 has a cylindrical shape having an inner diameter and a diameter, and is installed in the housing 30 . The fixed body 40 is disposed to face the rotating body 20 on the radially outer side of the rotating body 20 . Between the outer diameter portion of the rotating body 20 and the inner diameter portion of the fixed body 40, a spacing of the first width (d1) is formed.

The fluid filling part 50 is a space part filled with the magnetostrictive fluid, and is formed between the fixed body 40 and the rotating body 20 . As a gap of the first width d1 is formed between the outer diameter of the rotating body 20 and the inner diameter of the fixed body 40, the fluid filling part 50 is formed between the rotating body 20 and the fixed body ( 40) in the first width d1.

The electromagnet 60 is installed to face the rotating body 20 in the inner diameter part of the fixed body 40, and continuously connects the rotating body 20, the fluid filling part 50, and the fixed body 40 by supplying current. To form a magnetic field (MF) to pass through to adjust the viscosity of the viscous variable fluid portion (26). When a current is supplied to the electromagnet 60 , a magnetic field MF is formed around the electromagnet 60 to continuously extend in a closed loop form along the circumference of the electromagnet 60 as shown in FIG. 3 .

At one side and the other side in the axial direction of the electromagnet 60 , the magnetic field MF proceeds in a radial or reverse radial direction, and the magnetic field MF at the radial direction and the reverse radial direction of the electromagnet 60 proceeds in the axial direction. The fluid filling part 50 is positioned on a path in which the magnetic field MF proceeds in a radial direction or a reverse radial direction.

When a current is supplied to the electromagnet 60, as shown in FIG. 4, the particles of the magnetostrictive fluid are solidified and crystallized while being arranged in the radial direction under the influence of the magnetic field MF. While varying the viscosity of the magnetostrictive fluid filled in the fluid filling unit 50 by the action of the electromagnet 60 , the resistance to the relative movement of the rotating body 20 with respect to the fixed body 40 is increased or decreased. can

The rotating body 20 and the fixed body 40 are made of a material having a lower resistance to the magnetic field MF than that of a magnetostrictive fluid. In addition, the electromagnet 60 is installed in the axial direction intermediate portion of the fixed body (40). Accordingly, the rotating body 20 and the fixed body 40 are not only arranged with a set thickness on one side and the other side in the radial direction with respect to the electromagnet 60 as a reference, but also on one side and the other side in the axial direction of the fixed body 40 . The side portions are respectively disposed on one side and the other side in the axial direction of the electromagnet 60 with a set thickness.

Therefore, even if the fluid filling part 50 is disposed between the fixed body 40 and the rotating body 20, the path passing through the fluid filling part 50 in the radial and reverse radial directions as shown in FIG. 3 . It is possible to stably form a magnetic field MF having The electromagnet 60 includes a magnetic field forming unit 61 for forming a magnetic field MF by supply of current, and an electromagnet bobbin 62 supporting the magnetic field forming unit 61 .

The magnetic field forming unit 61 has a structure of a winding coil (not shown) capable of forming a magnetic field MF by supplying current. The electromagnet bobbin 62 has a shape of a shaft that can accommodate the magnetic field forming unit 61 , and is coupled to the inner diameter of the fixture 40 . The electromagnet bobbin 62 has a circular ring shape as a whole, and has a 'C'-shaped cross-sectional shape capable of supporting the inner diameter part and both ends of the axial direction of the magnetic field forming part 61). A portion of the electromagnet 60 in contact with the fluid filling part 50 , the rotating body 20 , and the differential pressure forming part 70 is covered by the electromagnet bobbin 62 .

The differential pressure forming part 70 is formed to protrude from the rotating body 20 onto the fluid filling part 50 . When the rotating body 20 rotates, the differential pressure forming unit 70 is continuously moved in a circular path along the extending direction of the fluid filling unit 50 on the fluid filling unit 50 . The magnetostrictive fluid may flow in the circumferential direction on the fluid filling part 50 by the movement of the differential pressure forming part 70 .

As described above, when a current is applied to the electromagnet 60 while the rotating body 20 and the differential pressure forming unit 70 are moving, the magnetic field MF is generated in a direction perpendicular to the flow direction (circumferential direction) of the magnetostrictive fluid (radial direction). ), and in particular, a pressure difference is clearly generated between the upstream side and the downstream side of the rotational direction with respect to the differential pressure forming unit 70 as a reference.

Referring to FIG. 4 , when the rotating body 20 rotates clockwise, in particular, in the state in which the magnetic field MF is formed as described above, it is located on the clockwise side (upstream side) with respect to the differential pressure forming unit 70 . The pressure (P ₁ ) of the fluid filling part 50 to be, and the pressure (P ₂ ) of the fluid filling part 50 located in the counterclockwise direction (downstream side) will have a clear difference.

_{More specifically, the pressure P 1} of the fluid filling part 50 acting on the upstream surface 74 of the differential pressure forming part 70 is the pressure of the fluid filling part 50 acting on the downstream surface 75 ( P ₂ ) has a relatively high pressure compared to that. In the description of the present invention, one end of the differential pressure forming unit 70 in contact with the upstream fluid filling part 50 is referred to as the upstream surface 74 for convenience of explanation, and the downstream fluid filling part 50 of the differential pressure forming part 70 is referred to as an upstream side fluid filling part 50. ) and the other end in contact with the downstream surface (75).

Accordingly, the braking force by the fluid filling part 50 is the braking force F according to the change of the state so that the particles are regularly arranged under the influence of the magnetic field MF and approach the solid state, in other words, the viscosity increases. ₁ ) (hereinafter referred to as 'shear mode braking force (F _{1 )'), in addition to the braking force F 2} due to the differential pressure between the upstream and downstream of the differential pressure forming unit 70 (hereinafter referred to as 'flow mode braking force (F ₂ )') ) will be added.

The shear mode braking force F ₁ acts on the outer peripheral surface of the rotating body 20, which is proportional to the 'shear force of the magnetostrictive fluid' and the 'distance from the rotation center point to the shear force action point'. According to the drum-type structure as in the first embodiment of the present invention, compared to the disk-type structure having the same diameter size, that is, the rotating body 20 has a flat disk-shaped disk shape and is magnetic on the upper and lower surfaces thereof. Compared to the structure in which the denaturing fluid is arranged, it is possible to implement a clearly increased braking force.

More specifically, as in the first embodiment of the present invention, the fixed body 40 or housing 30 having a drum shape is disposed on the radially outer side of the rotating body 20 having a columnar or column shape, and the rotating body ( According to the drum-type structure in which the magnetostrictive fluid is arranged in a cylindrical shape between the 20) and the fixed body 40, the 'distance from the center of rotation to the shear force action point' becomes the radius (r) of the rotating body 20, Compared with the disc-type structure in which the 'distance from the rotational center point to the shear force action point' is substantially r/2, which is the average of the radius r of the rotating body 20, it is possible to implement a clearly superior braking force.

The differential pressure forming unit 70 according to the present invention is formed on at least one side of the first rotating unit 21 , the second rotating unit 22 , and the third rotating unit 23 . In the description of the present invention, a portion of the differential pressure forming part 70 that is formed to protrude from the first rotating part 21 toward the fixed body 40 is formed by the first differential pressure forming part 71 and the second rotating part 22 from the fixed body. A portion that is formed to protrude toward 40 is referred to as a second differential pressure forming part 72 and a third differential pressure forming part 73 formed to protrude from the third rotating part 23 toward the fixed body 40 .

The electromagnet 60 according to the first embodiment of the present invention has the same inner diameter as the fixed body 40 and is disposed with a gap between the rotating body 20 and the first width d1. The differential pressure forming unit 70 is formed to protrude by the first width d1 on the first rotating unit 21, the second rotating unit 22, and the third rotating unit 23. That is, the first embodiment of the present invention The differential pressure forming unit 70 according to FIG. 1 has a shape in which the first differential pressure forming unit 71 , the second pressure forming unit 72 , and the third pressure forming unit 73 are continuously extended in a direction parallel to the axial direction.

The differential pressure forming part 70 according to the first embodiment of the present invention has a shape continuously extending in a straight line as described above, and has a length L as a whole. In this case, the flow mode braking force (F ₂ ) may be defined as the product of the cross-sectional area (A) of the differential pressure forming part (70) and the pressure difference (P ₁ -P _{2 ) between the upstream and downstream (F 2} =(P ₁ -P) ₂ )×A). In addition, the cross-sectional area A of the differential pressure forming part 70 is the product of the first width d1 and the axial length L of the differential pressure forming part 70 (A=d1×L).

_{And, the pressure difference (P 1} -P ₂ ) between upstream and downstream based on the differential pressure forming part 70 is inversely proportional to the radial width (t, d1) of the fluid filling part 50, It is proportional to the effective circumferential length, that is, the length R (=2πr) of the section in which the braking force by the magnetostrictive fluid is substantially realized, the pressure drop coefficient of the fluid (c, for example 2.07), and the yield stress τ _{y of the fluid (} P ₁ -P ₂ ∝ 2πr·c·τ _y / d1). The yield stress (yield stress) is the point at which the deformation starts when a force is applied to the fluid, expressed ^{as a force (dyne/cm 2 ).}

According to the drum type MR brake (2) according to the present invention, the shear mode braking force (F ₁ ) and the flow mode braking force (F ₂ ) of the magnetostrictive fluid act together as a braking force to restrict the rotation of the rotating body 20, Compared to the embodiment using only one side of the shear mode braking force or the flow mode braking force, or the embodiment having a disk structure, a better braking force may be implemented, and a smaller size may be realized in implementing the same braking force.

5 is a cross-sectional perspective view schematically showing a drum type MR brake according to a second embodiment of the present invention, and FIG. 6 is a cross-sectional view taken along line C-C' of FIG.

5 and 6, the drum-type MR brake 2 according to the second embodiment of the present invention includes the drum-type MR brake 2 according to the first embodiment of the present invention shown in FIGS. 1 to 4 and In comparison, the electromagnet 60 has an inner diameter smaller than that of the fixed body 40 by the first width d1 and has a structure disposed in the axial middle portion of the fluid filling part 50 .

As the rotating body 20 and the fixed body 40 are disposed with an interval of a first width d1, and the electromagnet 60 has an inner diameter smaller than the fixed body 40 by the first width d1, The fluid filling part 50 is divided into both sides in the axial direction with respect to the electromagnet 60 . More specifically, the fluid filling part 50 is divided into a first fluid filling part 51 positioned on one side in the axial direction of the electromagnet 60 and a second fluid filling part 52 positioned on the other side in the axial direction.

In describing the drum type MR brake 2 according to the second embodiment of the present invention, the same, similar or corresponding to the drum type MR brake 2 according to the first embodiment of the present invention shown in FIGS. About the part, redundancy of the description is abbreviate|omitted.

According to the first embodiment of the present invention, the portion of the fluid filling part 50 in contact with the electromagnet 60 is not affected by the magnetic field MF (see FIG. 3 ). According to the second embodiment of the present invention, By disposing the electromagnet 60 in a section of the fluid filling part 50 that is not affected by the magnetic field MF, the entire fluid filling part 50 can be effectively utilized to generate shear and braking forces.

Since the amount of the magnetostrictive fluid can be reduced by the amount of protrusion of the electromagnet 60, it is possible to further reduce the burden of cost due to the application of the expensive magnetostrictive fluid, and to realize further miniaturization. In implementing the same size, it is possible to more stably secure the winding space of the electromagnet 60, so that the magnetic field and braking force can be increased by further increasing the number of windings of the coil.

At this time, the differential pressure forming part 70 is not interfered with the electromagnet 60, without the second differential pressure forming part 72, from the first rotating part 21 toward the fixed body 40 by a first width (d1) The first differential pressure forming part 71 is formed to protrude, and the third differential pressure forming part 73 is formed to protrude from the third rotating part 23 toward the fixed body 40 by the first width d1. have a structure

7 is a cross-sectional perspective view schematically showing a drum-type MR brake according to a third embodiment of the present invention, FIG. 8 is a cross-sectional view of the main part of FIG. 7, and FIG. 10 is a cross-sectional view schematically showing a drum type MR brake according to a fourth embodiment of the present invention.

7 to 9, the drum-type MR brake 2 according to the third embodiment of the present invention, the first embodiment shown in FIGS. 1 to 4, and the second embodiment shown in FIGS. 5 and 6 Compared with the example, the rotating body 20 has a shape in which a part of the cylindrical shape is cut out, not in a cylindrical shape.

More specifically, the rotating body 20 according to the third embodiment of the present invention has a shape in which a portion is cut and cut symmetrically in the circumferential direction with respect to the radial extension line. The rotation body 20 according to the third embodiment of the present invention includes a rotation center portion 24 and a rotation body portion 25 . The rotation center 24 is integrally connected to rotate at the same angular displacement and angular velocity as the rotating body 20 . The rotating body part 25 is connected to the rotation center part 24 and has a sector-shaped cross-sectional shape.

The differential pressure forming part 70 has a structure formed to protrude in a radial direction between the circumferential direction both ends 26 and 27 of the rotating body part 25 . One end of the differential pressure forming unit 70 in the radial direction is in contact with the rotation center portion 24 , and the other end in the radial direction is in contact with the fixed body 40 and the electromagnet 60 . In addition, the upstream surface 74 and the downstream surface 75 of the differential pressure forming part 70 are respectively disposed to face one end 26 in the circumferential direction and the other end 27 in the circumferential direction of the rotating body 25 .

The first differential pressure forming unit 71 and the third pressure forming unit 73 hold the fixed body 40 by a second width (d2>d1) corresponding to the distance from the rotation center 24 to the fixed body 40 . formed to protrude toward the The second differential pressure forming part 72 is formed to protrude from the second rotating part 22 toward the electromagnet 60 , and subtracting the first width d1 from the second width d2 so as not to interfere with the electromagnet 60 . It is formed to protrude by a third width (d3=d2-d1).

A first fluid filled part 51 formed on one side of the axial direction of the electromagnet 60 is formed, and the other side of the electromagnet 60 in the axial direction is partitioned from the first fluid filled part 51 by the electromagnet 60 . The second fluid filling part 52 is formed, and between the circumferential direction both ends 26 and 27 of the rotating body part 25 in which the differential pressure forming part 70 is disposed, the third fluid filling part 53 is the first fluid The filling part 51 and the second fluid filling part 52 are formed to communicate with each other.

In the description of the first embodiment of the present invention, the flow mode braking force (F ₂ ) is defined as the product of the cross-sectional area (A) of the differential pressure forming unit (70) and the pressure difference (P ₁ -P _{2 ) between the upstream and downstream (P 1 -P 2 )} (F ₂ =(P ₁ -P _{2 )×A), and the pressure difference (P 1} -P ₂ ) between upstream and downstream based on the differential pressure forming unit 70 is the radial width of the fluid filling unit 50 . (t, d1) inversely proportional to the effective circumferential length R (=2πr) of the fluid filled part 50 having a radial width (t), the pressure drop coefficient of the fluid (c, for example 2.07), the yield of the fluid It has been explained that it is proportional to the stress τ _{y (P 1} -P ₂ ∝ 2πr·c·τ _{y / d1).}

Since the cross-sectional area A of the differential pressure forming part 70 according to the first embodiment of the present invention is the product of the first width d1 and the axial length L of the differential pressure forming part 70 (A=d1×L) ), the flow mode, the braking force (F ₂ according to the first embodiment of the present invention) is finally 2πr · c · τ _y · is proportional to _{L (F 2 α 2πr · c} · τ y · L).

In comparison, the cross-sectional area (A) of the differential pressure forming part 70 according to the third embodiment of the present invention is approximately the product of the second width (d2 > d1) and the axial length (L) of the gap forming part 70 . _{, the flow mode braking force (F 2} ) according to the third embodiment of the present invention is finally proportional to R·c·τ _y ·L ·d2/d1 (F ₂ ∝ R·c·τ _y ·L ·d2 /d1).

At this time, in the third embodiment of the present invention, d2 corresponds to approximately r+d1, so the element corresponding to (d2/d1) is approximately {(r+d1)/d1}, which has a value of 1 in the first embodiment. It can be clearly increased compared to, but the effective circumferential length (R) of the fluid filling part 50 is reduced compared to R (= 2πr) of the first embodiment of the present invention.

Therefore, if the length R of the fluid filling part 50 is formed longer as in the fourth embodiment of the present invention shown in FIG. If the forming unit 70 has only a gap sufficient to allow the inflow of the magnetostrictive fluid, it is possible to compensate for the decrease in the effective circumferential length R of the fluid filling unit 50 according to the third embodiment, and the differential pressure forming unit The cross-sectional area of (70) can be extended and applied regardless of the radial width (t, d1) of the fluid filling part (50). Accordingly, the flow mode braking force F ₂ can be maximized according to F ₂ ∝ 2πr·c·τ _{y ·L ·d2/d1 .}

In describing the drum-type MR brakes 2 according to the third and fourth embodiments of the present invention, the drum-type MR brakes according to the first and second embodiments of the present invention shown in FIGS. 1 to 6 are described. For parts that are the same as, similar to, or corresponding to (2), redundancy of the description will be omitted.

11 is a conceptual diagram illustrating an auto door closer using a drum type MR brake according to an embodiment of the present invention.

11, the auto door closer 1 using the drum type MR brake 2 according to an embodiment of the present invention has an actuator 4, a rotating shaft 10, an MR brake 2, and a vehicle body connection part 5. includes

The actuator 4 is fixedly installed inside the door 3 . The actuator 4 may be a motor, and may further include a speed reducer for adjusting the rotation speed and torque of the output shaft of the motor.

The rotating shaft 10 is rotated at a fixed position in association with the driving of the actuator (4). One end of the rotating shaft 10 is connected to the actuator 4 , and the other end of the rotating shaft 10 is connected to the vehicle body connection unit 5 via a gear unit 7 having a reduction gear structure. The MR brake (2) is installed in the middle of the rotating shaft (10).

The MR brake 2 according to the present invention has a structure according to the first to fourth embodiments of the present invention as shown in FIGS. 1 to 10 , and is installed on the rotating shaft 10 . The MR brake 2 according to the present invention includes a rotating body 20 , a housing 30 , a fixed body 40 , a fluid filling part 50 , an electromagnet 60 , and a differential pressure forming part 70 . 1 to 10 for the rotating body 20, the housing 30, the fixed body 40, the fluid filling part 50, the electromagnet 60, and the differential pressure forming part 70 according to the present invention Since the brake 2 has been previously described, a detailed description thereof will be omitted.

The vehicle body connection part 5 connects the rotating shaft 10 and the vehicle body 9 , and changes the position of the door 3 with respect to the vehicle body 9 according to the rotation of the rotating shaft 10 . For example, when the rotation shaft 10 rotates in the forward direction, the door 3 rotates in one direction with respect to the vehicle body 9, and when the rotation shaft 10 rotates in the reverse direction, the door 3 rotates with respect to the vehicle body 9 in the opposite direction. The vehicle body 9 and the rotating shaft 10 are connected to be rotated. The vehicle body connection part 5 according to an embodiment of the present invention includes a first link bar 6 and a second link bar 8 .

The first link bar 6 is disposed inside the door 3 and rotates in association with the rotation shaft 10 . In connecting one end of the first link bar 6 with the rotary shaft 10, it can be freely disposed at a position spaced apart from the rotary shaft 10 through the gear portion 7 having a reduction gear structure as a medium. At this time, one end of the first link bar 6 may be key-coupled or spline-coupled to rotate at the same angular velocity and angular displacement as the output shaft (not shown) of the driven gear of the gear part 7 .

One end of the second link bar 8 is hinge-connected to the other end of the first link bar 6 , and the other end is hinge-connected to the vehicle body 9 . The second link bar 8 is linked to the first link bar 6 and rotates about the connection part (the other end) with the vehicle body 9, so that the relative angle with the first link bar 6 is changed. When the rotation shaft 10 rotates in the forward and reverse directions, the relative angle between the first link bar 6 and the second link bar 8 is changed as described above and at the same time the relative angle between the vehicle body 9 and the door 3 is changed. , the door 3 can be opened and closed.

And, when a situation in which it is necessary to stop the movement of the door 3 through a sensor (not shown) or the like is detected while the door 3 is being opened and closed, by supplying a current to the electromagnet 60, _{The rotation of the rotary shaft 10 is stopped by the shear mode braking force F 1} and the flow mode braking force F ₂ of the magnetostrictive fluid filled in the fluid filling part 50, that is, the operation state of the door 3 is stopped as it is, can be held

According to the drum type MR brake 2 and the auto door closer 1 using the same according to the present invention having the above configuration, by forming the differential pressure forming part 70, the shear mode braking force F _{1 of the magnetostrictive fluid} In addition to ), the fluid mode braking force (F ₂ ) additionally acts as a braking force constraining the rotation of the rotating body 20, so an embodiment using only one side of the shear mode braking force or the fluid mode braking force, or an embodiment having a disk structure, In comparison, it is possible to implement a better braking force, and to achieve the same braking force, it is possible to further reduce the size.

In addition, according to the present invention, when the electromagnet 60 is disposed in a section of the fluid filling part 50 that is not affected by the magnetic field MF, the entire fluid filling part 50 is effectively used for shearing and braking force generation. It can be utilized, and the amount of the magnetostrictive fluid can be reduced by the amount of protrusion of the electromagnet 60, so that it is possible to further reduce the burden of cost due to the application of the expensive magnetostrictive fluid, and to realize more compactness. And, when implemented with the same size, the winding space of the electromagnet 60 can be more stably secured, so that the magnetic field and braking force can be increased by further increasing the number of windings of the coil.

In addition, according to the present invention, when the area of the differential pressure forming part 70 is further increased while minimizing the decrease in the effective circumferential length R of the fluid filling part 50, the flow mode braking force F ₂ is maximized at the same size. It can be done, and more compactness is possible in realizing the same braking force.

In addition, according to the present invention, when applied to the auto door closer 1 of a vehicle, it is possible to open and close the door 3 while moving the door 3 in association with the rotation of the rotation shaft 10 , and when necessary, resistance to movement with respect to the rotation shaft 10 . By varying the state of the magnetostrictive fluid provided in the MR brake 2 to increase this, it is possible to stably hold the movement of the door 3 .

Up to now, the present invention has been looked at mainly with respect to the embodiments. Those of ordinary skill in the art to which the present invention pertains will understand that the present invention can be implemented in a modified form without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments are to be considered in an illustrative rather than a restrictive sense. The scope of the present invention is indicated in the claims rather than the foregoing description, and all differences within the scope equivalent thereto should be construed as being included in the present invention.

1: Auto door closer 2: MR brake
3: Door 4: Actuator
5: body connection part 6: first link bar
7: gear part 8: second link bar
9: body 10: rotation shaft
20: rotating body 21: first rotating part
22: second rotation part 23: third rotation part
24: rotation center portion 25: rotation body portion
26: one end in the circumferential direction 27: the other end in the circumferential direction
30: housing 40: fixed body
50: fluid filling part 51: first fluid filling part
52: second fluid filling part 53: third fluid filling part
60: electromagnet 61: magnetic field forming part
62: electromagnet bobbin 70: differential pressure forming part
71: first differential pressure forming part 72: second differential pressure forming part
73: third differential pressure forming part 74: upstream surface
75: downstream side

Claims (7)

a rotating body connected on the same axis as the rotating shaft;
a housing installed around the rotation shaft and accommodating the rotation body;
a fixture installed in the housing and disposed to face the rotating body;
a fluid filling part formed between the fixed body and the rotating body and filled with a magneto-rheological fluid (MR fluid, Magneto Rheological fluid);
an electromagnet installed on the fixed body and configured to generate a magnetic field continuously passing through the rotating body, the fluid filling part, and the fixed body; and
and a differential pressure forming part which is formed to protrude from the rotating body to the fluid filling part and forms a pressure difference between the upstream side and the downstream side in the rotational direction;
The rotating body is
a first rotating part located on one side in the axial direction of the electromagnet;
a second rotating part positioned on the same radial extension line as the electromagnet; and
and a third rotating part located on the other side of the electromagnet in the axial direction.
The rotating body and the fixed body are disposed with an interval of a first width,
The electromagnet has an inner diameter smaller than the first width by the first width,
The differential pressure forming unit,
a first differential pressure forming part formed to protrude from the first rotating part toward the fixed body; and
and a third differential pressure forming part formed to protrude from the third rotating part toward the fixed body.
delete delete According to claim 1,
The rotating body is
a rotation center connected to the rotation body; and
It includes a; is connected to the rotation center portion, the rotating body having a sector-shaped cross-sectional shape;
The differential pressure forming unit,
A drum type MR brake, characterized in that it is formed to protrude in a radial direction between both ends of the rotating body in the circumferential direction.
5. The method of claim 4,
The first differential pressure forming part and the third differential pressure forming part are formed to protrude toward the fixture by a second width,
The differential pressure forming unit,
The drum type MR brake further comprising a; a second differential pressure forming part formed to protrude from the second rotating part toward the electromagnet by a third width obtained by subtracting the first width from the second width.
actuators installed on the door;
a rotating shaft rotated in association with the actuator;
a vehicle body connection part connecting the rotation shaft and the vehicle body, and varying a position of the door with respect to the vehicle body according to the rotation of the rotation shaft;
a rotating body coaxially connected to the rotating shaft;
a housing installed around the rotation shaft and accommodating the rotation body;
a fixture installed in the housing and disposed to face the rotating body;
a fluid filling part formed between the fixed body and the rotating body and filled with a magneto-rheological fluid (MR fluid, Magneto Rheological fluid);
an electromagnet installed on the fixed body and configured to generate a magnetic field continuously passing through the rotating body, the fluid filling part, and the fixed body; and
and a differential pressure forming part which is formed to protrude from the rotating body toward the fluid filling part and forms a pressure difference between the upstream side and the downstream side in the rotational direction;
The rotating body is
a first rotating part located on one side in the axial direction of the electromagnet;
a second rotating part positioned on the same radial extension line as the electromagnet; and
and a third rotating part located on the other side of the electromagnet in the axial direction.
The rotating body and the fixed body are disposed with an interval of a first width,
The electromagnet has an inner diameter smaller than the first width by the first width,
The differential pressure forming unit,
a first differential pressure forming part formed to protrude from the first rotating part toward the fixed body; and
and a third differential pressure forming part formed to protrude from the third rotating part toward the fixture.
7. The method of claim 6,
The vehicle body connection part,
a first link bar disposed inside the door and rotatable in association with the rotation shaft; and
and a second link bar having one end connected to the first link bar, the other end connected to the vehicle body, and the relative angle with the first link bar being variable while being rotated in conjunction with the first link bar. Automatic door closer using drum type MR brake.

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