JP6820010B2 - Rotating damper - Google Patents

Description

The present invention relates to a rotary damper capable of on / off control of damping force using a functional fluid such as a magnetic fluid or a magnetic viscous fluid.

As a conventional rotary damper, for example, as in Patent Document 1, a magnetic viscous fluid is enclosed in a magnetic case, a magnetic rotating plate is housed in a relative rotatable manner, and an electromagnetic coil is provided in the case. There is something.

This rotary damper obtains a damping force due to the shear resistance of the ferrofluid between the case and the rotary plate by energizing the electromagnetic coil.

Therefore, it is possible to control the on / off of the damping force by controlling the energization of the electromagnetic coil, but the wiring structure is complicated. In addition, the heat generated by the electromagnetic coil is difficult to dissipate to the outside of the case, which causes a problem of impairing durability.

Japanese Unexamined Patent Publication No. 2014-20539

The problem to be solved is that if the damping force can be controlled on and off, the structure is complicated and the durability is impaired by heat generation.

In the present invention, in order to simplify the structure and improve durability while enabling on / off control of the damping force of the rotating damper, a damping force is generated by passing a magnetic flux between the relatively rotatable inner rotating member and the outer rotating member. A damping force generating portion interposed with a functional fluid to be generated, a permanent magnet having at least a pair of magnetic poles for generating the magnetic flux across the damping force generating portion, and the damping force generating portion and the permanent magnet. A non-damping state in which the magnetic flux is shorted to the damping force generating portion and the magnetic flux is short-circuited without passing to the damping force generating portion by changing the relative position with respect to the permanent magnet. A switching portion for switching between a force generating state is provided, and the switching portion comprises a magnetic blocking portion made of a non-magnetic material and a magnetic path forming portion made of at least a pair of magnetic materials arranged so as to sandwich the magnetic blocking portion. In the non-damping force generating state, the magnetic blocking portion faces between the pair of magnetic poles, and the pair of magnetic path forming portions face each of the pair of magnetic poles. The most main feature of the rotating damper is that one of the pair of magnetic path forming portions faces both of the pair of magnetic poles.

The rotary damper of the present invention can control the damping force by the functional fluid on and off only by changing the relative position of the switching part with respect to the permanent magnet, has a simple structure, does not have problems such as heat generation, and has durability. Can be improved.

It is a top view of the rotary damper (Example 1). It is sectional drawing which concerns on line II-II of FIG. 1 (Example 1). It is sectional drawing which concerns on line III-III of FIG. 2 (Example 1). FIG. 3 is an enlarged cross-sectional view of a main part of FIG. 3 (Example 1). It is sectional drawing of the rotary damper (Example 2). It is a top view which shows the permanent magnet of the rotary damper of FIG. 5 (Example 2). It is a top view which shows the switching part of the rotary damper of FIG. 5 (Example 2).

The purpose of simplifying the structure and improving durability while enabling on / off control of the damping force of the rotary damper was realized by a rotary damper with a switching part that enables the damping force to be turned on / off by changing the relative position with respect to the permanent magnet. ..

That is, the rotary damper extends over the damping force generating portion and the damping force generating portion in which the functional fluid that generates the damping force by passing the magnetic flux between the relative rotatable inner rotating member and the outer rotating member is interposed. A permanent magnet having at least a pair of magnetic poles for generating magnetic flux is arranged between the damping force generating portion and the permanent magnet, and the magnetic flux is transferred to the damping force generating portion by changing the relative position with respect to the permanent magnet. It is provided with a switching unit for switching between a crossing damping force generation state and a non-damping force generation state in which the magnetic flux is short-circuited without crossing the damping force generation portion.

The switching portion has a magnetic blocking portion made of a non-magnetic material and a magnetic path forming portion made of at least a pair of magnetic materials arranged so as to sandwich the magnetic blocking portion, and the magnetic blocking portion is in a state where a damping force is generated. The pair of magnetic path forming portions face each other between the pair of magnetic poles, and the pair of magnetic path forming portions face each of the pair of magnetic poles. In the non-damping force generation state, either one of the pair of magnetic path forming portions faces both of the pair of magnetic poles. ..

As the configuration of the permanent magnet and the switching portion, an appropriate one can be adopted, and one of them may operate so that the relative position with respect to the other can be changed.

As a form of moving the permanent magnet, for example, the inner rotating member is a rotating body made of a magnetic material, the outer rotating member is a case having a switching portion integrally, and the permanent magnet is outside the case with respect to the case. The switching portion may be provided so as to be movable, and the switching portion may be configured so that the relative position with respect to the permanent magnet can be changed by moving the permanent magnet.

In this case, the case is formed by alternately arranging magnetic blocking portions and magnetic path forming portions in the circumferential direction, and the permanent magnets are rotatably fitted to the outside of the case by arranging different magnetic poles alternately in the circumferential direction. It has a ring shape, and may be configured to switch between a damping force generating state and a non-damping force generating state according to the rotation position of the permanent magnet.

On the other hand, as a form for moving the switching portion, it has a rotating shaft rotatably housed in the case, the inner rotating member is an inner plate made of a magnetic material fixed to the rotating shaft, and the outer rotating member is. It is an outer plate that is fixed to the case and can rotate relative to the inner plate, the permanent magnet is fixed to the case, and the switching part is provided so that it can be moved with respect to the case, and the position relative to the permanent magnet can be changed. It may be configured as.

In this case, a shaft portion is provided so as to project to the outside of the case, and the switching portion constitutes a magnetic path forming portion on a holding plate made of a non-magnetic material which constitutes a magnetic blocking portion rotatably supported around the shaft portion. The magnetic piece is held, and the permanent magnet holds the magnet piece having the opposite polarity on the non-magnetic switching plate fixed around the shaft, and the damping force is generated according to the rotation position of the switching part. It may be configured to switch between the non-damping force generation state and the non-damping force generation state.

[Structure of rotating damper]
1 is a plan view of a rotary damper according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1, and FIG. 3 is a cross-sectional view taken along the line III-III of FIG. It is a figure, (A) is a damping force generation state, (B) is a non-damping force generation state, and FIG. 4 is an enlarged sectional view of a main part of FIG. In the following, the "axis direction" means the direction of the rotation axis of the rotation damper (hereinafter, simply referred to as "rotation damper") 1. Further, the "radial direction" means the radial direction of rotation of the rotary damper 1. Further, in FIGS. 3 and 4, the permanent magnet 9, the magnetic path forming portion 19 of the case body 13, and the rotating body 5 are not hatched from the viewpoint of clarity, but all show cross sections.

The rotary damper 1 of the present embodiment generates a damping force with respect to a movable side such as a sliding door (not shown), and has a damping force generation state (on state) that generates a damping force and a non-damping force generation state that does not generate a damping force. It is possible to switch between (off state).

As shown in FIGS. 1 to 4, the rotating damper 1 includes a case 3 which is an outer rotating member, a rotating body 5 which is an inner rotating member, a damping force generating portion 7, and a permanent magnet 9.

Case 3 of this embodiment has a configuration in which a switching portion is integrally provided. That is, the case 3 has a base portion 11 made of a non-magnetic material and a case main body 13 constituting a switching portion on the base portion 11.

The base portion 11 of this embodiment is made of a non-magnetic material, and is made of, for example, a resin. As the non-magnetic material, for example, a non-magnetic metal other than resin, ceramic, or the like can be used. Examples of the non-magnetic metal include copper, aluminum, stainless steel and the like.

The base portion 11 has a plate shape and is fixed to the fixed side or the like via holes 11a provided at both ends. A case body 13 is projected from the central portion between the ends of the base portion 11. Further, the base portion 11 is integrally provided with a shaft 11b at the axial center portion. The shaft 11b projects from the base portion 11 into the case body 13.

The case body 13 is formed in a cylindrical shape and includes a peripheral wall portion 15 integrated with the base portion 11.

As shown in FIGS. 3 and 4, the peripheral wall portion 15 is provided with recesses 17 on the inner circumference, which are thinned at predetermined intervals in the circumferential direction. A wall-shaped magnetic path forming portion 19 made of a magnetic material is housed in the recess 17. The magnetic material of this embodiment is a ferromagnet. Instead of the recess 17, a through hole penetrating the inside and outside of the peripheral wall portion 15 may be provided to hold the magnetic path forming portion 19.

A magnetic blocking portion 21 made of a non-magnetic material is arranged between the magnetic path forming portions 19. The magnetic blocking portion 21 is composed of a relatively thick portion of the peripheral wall portion 15 which is not thinned. With this configuration, the case body 13 (case 3) of the present embodiment is formed by alternately arranging the magnetic blocking portions 21 and the magnetic path forming portions 19 in the circumferential direction, and a pair of adjacent magnetic path forming portions. Reference numeral 19 denotes a configuration arranged with the magnetic blocking portion 21 interposed therebetween.

In this embodiment, the magnetic blocking portion 21 and the magnetic path forming portion 19 of the case body 13 are formed over the entire circumferential direction, but they may be provided only in a part of the circumferential direction. In this case, for example, it is possible to have a configuration having only one magnetic blocking portion 21 and a pair of magnetic blocking portions 21 arranged so as to sandwich the magnetic blocking portion 21.

As shown in FIGS. 1 and 2, the case body 13 is opened on one side in the axial direction, and the lid portion 23 is integrally attached to the end opening by adhesion, welding, or the like. A through hole 23a is formed in the axial center portion of the lid portion 23.

The rotating body 5 is made of a magnetic material, for example, a ferromagnet, and is formed in a columnar shape. The rotating body 5 is arranged so as to be relatively rotatable in the case body 13 of the case 3. A gap is secured between the rotating body 5 and the case 3. The functional fluid F is interposed in the gap to form the damping force generating unit 7.

A fitting hole 5a is formed in the axial center portion of the rotating body 5 corresponding to the shaft 11a of the case 3. Therefore, the rotating body 5 is rotatably fitted to the shaft 11a of the case 3 in the fitting hole 5a. Further, a rotating shaft 25 that rotates integrally with the rotating body 5 is projected from the axial center portion of the rotating body 5. The rotating shaft 25 projects from the through hole 23a of the lid portion 23 to the outside of the case 3.

A seal member 23b is supported in the through hole 23a of the lid portion 23, and the seal member 23b is in close contact with the rotating shaft 25. For the seal member 23b, for example, an O-ring or an X-ring is used.

A gear (not shown) is attached to the outer end of the rotating shaft 25, and torque is input from the movable side via the gear.

The damping force generating unit 7 has a functional fluid F that generates a damping force by passing the magnetic flux loop R between the case 3 and the rotating body 5 which are the relative rotatable inner rotating member and the outer rotating member. It is a thing. The damping force generating portion 7 of this embodiment is interposed in the gap between the rotating body 5 and the case 3 as described above. The gap between the rotating body 5 and the case 3 includes both a radial gap and an axial gap.

As the functional fluid F, a magnetic fluid (Magnetic Fluid) in which iron powder or the like is dispersed or a magnetic viscous fluid (Magneto Rheological Fluid) called an MR fluid is used. The functional fluid F forms a cluster of iron powder or the like by passing a magnetic flux loop R described later between the case 3 and the rotating body 5, and generates a damping force due to shear resistance between the case 3 and the rotating body 5. Let me.

The permanent magnet 9 is made of an alnico magnet, a ferrite magnet, a neodymium magnet, or the like. The permanent magnet 9 of this embodiment is formed in a ring shape in which different magnetic poles 27a and 27b in FIGS. 1, 3 and 4 are alternately arranged in the circumferential direction. The permanent magnet 9 has four magnetic poles 27a and 27b in the circumferential direction, for a total of eight poles, but the number of magnetic poles 27a and 27b can be changed as appropriate.

In the permanent magnet 9, the fitting hole 9a on the inner circumference is rotatably fitted to the case body 13 from the outside. As a result, the permanent magnet 9 can be moved in the circumferential direction with respect to the case 3 outside the case 3, and the case body 13 as a switching portion changes its relative position with respect to the permanent magnet 9 by moving the permanent magnet 9. Make it possible.

Specifically, the permanent magnet 9 rotates with respect to the case body 13, whereby the rotation position with respect to the case body 13 can be changed. By changing the rotation position, the relative position of the case body 13 with respect to the permanent magnet 9 is changed in the circumferential direction.

With this change in the rotational position, the damping force generation state and the non-damping force generation state can be switched.

As shown in FIGS. 3A and 4A, in the damping force generation state, the magnetic poles 27a and 27b are respectively located between the adjacent magnetic blocking portions 21 of the case body 13 in the circumferential direction. That is, each magnetic blocking portion 21 is radially opposed between a pair of adjacent magnetic poles 27a and 27b, and the magnetic path forming portion 19 is radially opposed to only one magnetic pole.

As a result, the adjacent magnetic poles 27a and 27b can generate a magnetic flux loop R that extends to the damping force generating portion 7 via the magnetic path forming portion 19 and the rotating body 5 of the case body 13 that face each other. In response to the magnetic flux loop R, the functional fluid F forms a cluster in the damping force generation unit 7 to generate a damping force.

Therefore, the torque input to the rotating body 5 from the movable side of the sliding door or the like is damped by the damping force of the rotating damper 1.

On the other hand, as shown in FIGS. 3B and 4B, in the non-damping force generation state, the magnetic poles 27a and 27b are located between the pair of magnetic path forming portions 19 adjacent to each other across the magnetic blocking portion 21 in the circumferential direction. Located across. That is, the magnetic poles 27a and 27b are radially opposed to a single magnetic path forming portion 19 at the end, and each magnetic path forming portion 19 is radially opposed to both of a pair of adjacent magnetic paths 27a and 27b. It will be.

As a result, the adjacent magnetic poles 27a and 27b form a magnetic flux loop R'via the magnetic path forming portion 19 whose ends face each other. That is, the magnetic flux loop R'is short-circuited without reaching the damping force generating unit 7, does not affect the functional fluid F, and does not generate a damping force.

Therefore, it is possible to leave the movable side of the sliding door or the like in a free state.

[Effect of Example 1]
The rotary damper 1 of the present embodiment includes a damping force generating portion 7 intervening with a functional fluid F that generates a damping force by passing a magnetic flux loop R between a rotating body 5 that is relatively rotatable and a case 3, and damping. A permanent magnet 9 having at least a pair of magnetic poles 27a and 27b for generating a magnetic flux loop R over the force generating portion 7 is arranged between the damping force generating portion 7 and the permanent magnet 9, and is arranged with respect to the permanent magnet 9. By changing the relative position, the magnetic flux loop R switches between the damping force generation state in which the damping force generation unit 7 is generated and the non-damping force generation state in which the magnetic flux loop R'is shorted without passing through the damping force generation unit 7. It includes a case body 13 as a part.

The case body 13 has a magnetic blocking portion 21 made of a non-magnetic material and a magnetic path forming portion 19 made of at least a pair of magnetic materials arranged so as to sandwich the magnetic blocking portion 21, and is magnetic in a damping force generation state. When the blocking portion 21 faces the pair of magnetic poles 27a and 27b and the pair of magnetic path forming portions 19 face the pair of magnetic poles 27a and 27b, respectively, and the non-damping force is generated, the pair of magnetic path forming portions 19 One of them faces both of the pair of magnetic poles 27a and 27b.

Therefore, in this embodiment, the damping force due to the functional fluid F can be controlled on / off only by changing the relative position of the case body 13 which is the switching portion with respect to the permanent magnet 9, the structure is simple, heat generation, etc. There is no problem and the durability can be improved.

Further, in this embodiment, the case 3 has a switching portion integrally, the permanent magnet 9 is provided so as to be movable with respect to the case 3 outside the case 3, and the case body 13 as the switching portion moves the permanent magnet 9. Allows the relative position of the permanent magnet 9 to be changed.

Therefore, in the present embodiment, the damping force can be more easily controlled on and off only by moving the permanent magnet 9 with respect to the case 3.

In particular, in this embodiment, the case 3 is formed by alternately arranging the magnetic blocking portions 21 and the magnetic path forming portions 19 in the circumferential direction, and the magnetic poles 27a and 27b having different permanent magnets 9 are alternately arranged in the circumferential direction. , It has a ring shape that rotatably fits on the outside of the case 3, and controls the damping force on and off according to the rotation position of the permanent magnet 9.

Therefore, in this embodiment, the on / off control of the damping force can be performed extremely easily by using the permanent magnet 9 as a switching dial only by rotating the permanent magnet 9 with respect to the case 3.

In the rotary damper 1, the lid 23 and the base portion 11 of the case 3 may be provided with marks indicating that the damping force is generated and the non-damping force is generated.

5A and 5B are cross-sectional views of the rotary damper according to the second embodiment, where FIG. 5A shows a damping force generation state and FIG. 5B shows a non-damping force generation state. Note that FIG. 5 corresponds to the cross section taken along the line III-III of FIG. Further, in the second embodiment, the components corresponding to the first embodiment are designated by the same reference numerals, and duplicate description will be omitted.

In the rotary damper 1 of this embodiment, the switching portion 29 is provided separately from the case 3, and the switching portion 29 is moved with respect to the case 3. Further, in the present embodiment, a rotating plate set 31 is provided between the case 3 and the rotating shaft 25, and the inner plate 33 and the outer plate 35 constituting the rotating plate set 31 are provided as relative rotatable inner / outer rotating members. ing.

The case 3 includes a hollow cylindrical case body 13 made of a non-magnetic material, and the case body 13 is closed by a lid portion 23 on one side in the axial direction and a partition plate 37 made of a magnetic material on the other side in the axial direction. Is closed by.

The partition plate 37 is a plate-like body, and a recess 37a is formed in the axial center portion on one side in the axial center direction, and a shaft portion 37b is projected outside the case 3 in the axial center portion on the other side in the axial center direction. ing.

In the partition plate 37 of this embodiment, a magnetic division portion 39a is interposed in the middle portion of the inner and outer circumferences. The magnetic dividing portion 39a magnetically divides the inner peripheral portion and the outer peripheral portion of the partition plate 37. In this embodiment, the magnetic division portion 39a is made of a non-magnetic material. The magnetic dividing portion 39a may be a hole (space portion) or the like as long as the inner peripheral portion and the outer peripheral portion of the partition plate 37 can be magnetically divided.

The rotating shaft 25 is made of a non-magnetic material and is formed in a columnar shape extending in the axial direction. The inner end of the rotating shaft 25 is supported in the recess 37a of the partition plate 37 inside the case 3, and the rotating shaft 25 is rotatable relative to the case 3 by inserting the through hole 23a of the lid portion 23. A rotating plate set 31 is provided between the rotating shaft 25 and the case 3.

The rotating plate set 31 is configured by arranging a plurality of inner plates 33 made of a magnetic material and a plurality of outer plates 35 made of a magnetic material alternately in the axial direction. A gap is provided between the adjacent inner plate 33 and the outer plate 35. A functional fluid F is interposed in this gap, and a damping force generating portion 7 is formed.

The inner plate 33 and the outer plate 35 are integrally rotatably fixed to the rotating shaft 25 and the case 3, respectively. Specifically, the inner peripheral portion of the inner plate 33 is fixed to the outer circumference of the rotating shaft 25, and the outer peripheral portion of the outer plate 35 is supported by the inner circumference of the case 3.

The inner plate 33 and the outer plate 35 are each provided with a magnetic division portion 39b. The magnetically divided portions 39b are provided in the intermediate portions of the inner peripheral portion and the outer peripheral portion of the inner plate 33 and the outer plate 35, and are aligned along the axial direction as a whole. The magnetic dividing portions 39b may not be aligned along the axial direction, and may be slightly displaced in the radial direction as long as there is no short circuit in the magnetic circuit in the rotating plate set 31.

The magnetic dividing portion 39b is made of a non-magnetic material like the magnetic dividing portion 39a, but may be a hole (space portion) or the like.

An end member 41 and a permanent magnet 9 are arranged on the end side of the rotating plate set 31, respectively.

The end member 41 is a plate-like body made of a magnetic material, and is arranged on one end side of the rotating plate set 31. The end member 41 secures a gap for interposing the functional fluid F with the inner plate 33 located at one end of the rotary plate set 31. The end member 41 extends so as to extend over the inner peripheral portion and the outer peripheral portion of the inner plate 33 at one end of the rotating plate set 31 in the radial direction.

The end member 41 is not limited to a plate-like body as long as it extends over the inner peripheral portion and the outer peripheral portion of the inner plate 33 at one end of the rotary plate set 31. Further, although the inner plate 33 is located at one end of the rotary plate set 31 in this embodiment, the outer plate 35 may be located depending on the characteristics of the rotary damper 1 depending on the specifications, so that the rotary plate set 31 is located. It may be extended so as to extend over the inner peripheral portion and the outer peripheral portion of the inner plate 33 or the outer plate 35 located at one end of the above.

FIG. 6 is a plan view showing the permanent magnet 9.

As shown in FIGS. 5 and 6, the permanent magnet 9 holds magnet pieces 45a and 45b having opposite polarities in a magnet holding plate 43 made of a non-magnetic material fixed around the shaft portion 37b in an embedded state. ing. A plurality of pairs of magnet pieces 45a and 45b are provided in the circumferential direction.

In this embodiment, four pairs of magnet pieces 45a and 45b are provided every 90 degrees in the circumferential direction. The number of magnet pieces 45a and 45b can be set arbitrarily.

In the permanent magnet 9, the magnet pieces 45a and 45b face the inner peripheral portion and the outer peripheral portion of the rotating plate set 31 via the inner peripheral portion and the outer peripheral portion of the switching portion 29 and the partition plate 37, respectively.

Therefore, the permanent magnet 9 has magnet pieces 45a and 45b via the switching portion 29, the partition plate 37, the rotating plate set 31, and the end member 41 on one side in the axial direction according to the rotation position of the switching portion 29. A magnetic circuit is formed between them.

On the other side in the axial direction, the permanent magnet 9 is supported by a support plate 47 made of a magnetic material. The support plate 47 is formed in a plate shape and extends between the magnet pieces 45a and 45b of the permanent magnet 9 in the radial direction.

Therefore, in the permanent magnet 9, a magnetic circuit extending between the magnet pieces 45a and 45b is formed by the support plate 47 on the other side in the axial direction.

The permanent magnet 9 and the support plate 47 are attached to the case 3 via the attachment frame 49. The mounting frame 49 has a circumferential wall 51a and 51b that are formed in a circular shape and project from the inner and outer circumferences in the axial direction. A storage recess 53 for accommodating the permanent magnet 9 and the support plate 47 is provided between the peripheral walls 51a and 51b.

The inner peripheral wall 51a has a support hole 55 defined on the inner circumference thereof, and a shaft portion 37b of the partition plate 37 is inserted through the support hole 55 and fastened to the partition plate 37. The tip of the circumferential wall 51a is abutted against the stepped portion 37c of the shaft portion 37b. A switching portion 29 is rotatably fitted to the outer periphery of the step portion 37c.

FIG. 7 is a plan view showing the switching unit 29.

As shown in FIGS. 5 and 7, the switching portion 29 is a magnetic material forming a magnetic path forming portion on a switching plate 57 made of a non-magnetic material forming a magnetic blocking portion rotatably supported around the shaft portion 37b. The piece 59 is held in an embedded state. The magnetic material piece 59 is composed of a peripheral portion 59a, a radiating portion 59b, and an island-shaped portion 59c.

The peripheral portion 59a is formed in a circumferential shape and always faces the magnet piece 45a on the inner peripheral side of the permanent magnet 9. The radiating portion 59b protrudes radially from the circling portion 59a and extends between the magnet pieces 45a and 45b of the permanent magnet 9 together with the circling portion 59a in a non-damping force generation state. Therefore, four radiating portions 59b correspond to the magnet pieces 45a and 45b and are provided every 90 degrees in the circumferential direction.

The island-shaped portion 59c is magnetically separated from the peripheral portion 59a and the radiating portion 59b, and faces the magnet piece 45b on the outer peripheral side in the damping force generation state. Therefore, in the damping force generation state, the circumferential portion 59a and the island-shaped portion 59c of the switching portion 29 face the magnet pieces 45a and 45b of the permanent magnet 9, respectively, and the magnet pieces 45a and 45b of the permanent magnet 9 and the partition plate 37 are included. Magnetically connect between the peripheral part and the outer peripheral part.

As a result, the magnetic flux loop R of the permanent magnet 9 is folded back at the end member 41 from one of the magnet pieces 45a and 45b through the rotating plate set 31 on one side in the axial direction, and the rotating plate set 31 is taken to take the magnet. It reaches the other side of the pieces 45a and 45b, and extends between the magnet pieces 45a and 45b via the support plate 47 on the other side in the axial direction. Therefore, the magnetic flux loop R is formed over the damping force generating portion 7.

Further, in the non-damping force generation state, the peripheral portion 59a and the radiating portion 59b of the switching portion 29 magnetically connect the magnet pieces 45a and 45b of the permanent magnet 9.

As a result, the magnetic flux loop R'of the permanent magnet 9 is short-circuited between the magnet pieces 45a and 45b of the permanent magnet 9 via the magnetic material piece 59 of the switching portion 29 on one side in the axial direction, and is in the axial direction. On the other side, it extends between the magnet pieces 45a and 45b via the support plate 47. Therefore, the magnetic flux loop R'does not reach the damping force generating unit 7 and does not affect the functional fluid F.

Therefore, in the present embodiment, the damping force due to the functional fluid F can be controlled on and off as in the first embodiment by simply rotating the switching unit 29 in the circumferential direction with respect to the case 3, and the structure is configured. It is simple, has no problems such as heat generation, and can improve durability.

1 Rotating damper 3 Case (outer rotating member)
5 Rotating body (inner rotating member)
7 Damping force generating part 9 Permanent magnet 13 Case body (switching part)
19 Magnetic path forming part 21 Magnetic blocking part 29 Switching part 33 Inner plate (inner rotating member)
35 Outer plate (outer rotating member)
43 Magnet holding plate 45a, 45b Magnet piece 57 Switching plate (magnetic blocking part)
59 Magnetic material piece (magnetic path forming part)

Claims (5)

A damping force generating part with a functional fluid that generates a damping force by passing magnetic flux between the relative rotatable inner rotating member and the outer rotating member,
A permanent magnet having at least a pair of magnetic poles for generating the magnetic flux over the damping force generating portion,
It is arranged between the damping force generating portion and the permanent magnet, and by changing the relative position with respect to the permanent magnet, the damping force generation state in which the magnetic flux extends to the damping force generating portion and the magnetic flux are attenuated. It is equipped with a switching unit that switches between a non-damping force generation state that shorts without crossing the force generation unit.
The switching portion has a magnetic blocking portion made of a non-magnetic material and a magnetic path forming portion made of at least a pair of magnetic materials arranged so as to sandwich the magnetic blocking portion.
In the damping force generation state, the magnetic blocking portion faces the pair of magnetic poles, and the pair of magnetic path forming portions face the pair of magnetic poles.
In the non-damping force generation state, any one of the pair of magnetic path forming portions faces both of the pair of magnetic poles.
A rotating damper that features that. The rotary damper according to claim 1.
The inner rotating member is a rotating body made of a magnetic material.
The outer rotating member is a case having the switching portion integrally.
The permanent magnet is provided so as to be movable with respect to the case outside the case.
The switching unit makes it possible to change the position relative to the permanent magnet by moving the permanent magnet.
A rotating damper that features that. The rotary damper according to claim 2.
The case is formed by alternately arranging the magnetic blocking portion and the magnetic path forming portion in the circumferential direction.
The permanent magnet has a ring shape in which different magnetic poles are alternately arranged in the circumferential direction and rotatably fitted to the outside of the case.
Switching between the damping force generation state and the non-damping force generation state according to the rotation position of the permanent magnet.
A rotating damper that features that. The rotary damper according to claim 1.
It has a rotating shaft that is rotatably housed in the case.
The inner rotating member is an inner plate made of a magnetic material fixed to the rotating shaft.
The outer rotating member is an outer plate that is fixed to the case and can rotate relative to the inner plate.
The permanent magnet is fixed to the case and
The switching portion is provided so as to be movable with respect to the case, and enables the relative position of the permanent magnet to be changed.
A rotating damper that features that. The rotary damper according to claim 4.
With a shaft portion protruding outside the case,
The switching portion holds the magnetic material piece constituting the magnetic path forming portion on a switching plate made of a non-magnetic material constituting the magnetic blocking portion rotatably supported around the shaft portion.
The permanent magnet holds a magnet piece having the opposite polarity on a magnet holding plate made of a non-magnetic material fixed around the shaft portion.
Switching between the damping force generation state and the non-damping force generation state according to the rotation position of the switching unit.
A rotating damper that features that.

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