JPH08131480A - Magnetic damper for vibration proof and on-vehicle vibration proof head using magnetic damper - Google Patents

Abstract

PURPOSE: To offer comfortable utilizeability without the uncomfortable feel on a lying person by providing the piston in a cylinder and the side wall of the cylinder facing this piston with magnetic materials in such a manner that repulsive forces against each other are generated, thereby well absorbing vibration and rapidly attenuating the vibration. CONSTITUTION: This magnetic damper 4 has the cylinder 41, the piston 42 fitted into the cylinder 41 and a piston rod 43 disposed through the central part of the piston 42. An air chamber 4a is formed upper than the piston 42 in the cylinder 41. The upper part of the cylinder 41 is bored with small holes 41d to allow the air to flow. A disk-shaped magnet 44 is disposed on the inside surface in the bottom of the cylinder 41. The disk-shaped magnet 44 and the piston 42 consisting of the magnet are so arranged that the same poles opposite to each other. The piston 42 is formed of a disk-shaped permanent magnet and is bored with a mounting hole 42a in the central part. On the other hand, an external screw thread part 43b is formed forward of the collar part 43a at the base end of the piston rod 42.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping magnetic damper having an excellent vibration absorbing function, and a vehicle-mounted vibration damping bed equipped with the magnetic damper mounted on a vehicle such as an ambulance.

[0002]

2. Description of the Related Art Conventionally, an anti-vibration bed for a vehicle as shown in FIG. 6 has been known. The anti-vibration bed B includes a pair of front and rear support rods R rotatably provided on a floor F of a vehicle around a support shaft, and a bed body pivotally supported by the support shaft at the tip ends of the support rods R. It is basically composed of B1 and B1. Then, the pair of front and rear support rods R,
A parallelogrammatic link structure is formed by the bed body B1 and the floor F, and the bed body B1 can move up and down while being restricted by this link structure.

Magnets M having the same poles facing each other are provided on the bottom surface of the bed body B1 and the floor F.
The bed body B1 is magnetically levitated on the floor F in a state where the repulsive force of the magnet M and the weight of the bed body B1 are balanced. Therefore, when, for example, a stretcher S on which a patient is placed is placed on such a bed body B1, the bed body B1 is magnetized on the floor F by the repulsive force of the magnet M while the weights thereof are also added. Surface.

Since the repulsive force of the magnet M has a cushioning action, the vibration of the running vehicle is absorbed and is not directly transmitted to the patient lying on the stretcher S, so that the lying state is stable. . Since such a magnetic levitation type vibration isolation structure is superior in vibration absorption efficiency to the spring type and has a simple structure, many vibration proof structures will replace the magnetic levitation type in the future. Is in a situation where

[0005]

In the conventional magnetic levitation type vibration isolation structure as described above, the bed body B1 is once absorbed by the vehicle vibration due to the characteristics of the magnet and then reverberated. It was common that the vibration of the machine continued and that it took time for the vibration to damp. That is, in the conventional magnetic levitation type vibration damping structure in which the same poles of the magnet M are simply opposed to each other, the initial vibration is efficiently absorbed, but thereafter, the vibration continues for a long time. . Moreover, at the time of resonance in which the natural frequency of the bed body B1 and the frequency of the facing magnet M match, the vibration of the bed body B1 lasts for a very long time.

Therefore, if such a lingering vibration continues for a long time, there is a problem that a person lying on the bed body B1 feels very uncomfortable.

The present invention has been made in order to solve the above-mentioned problems, and the vibration is favorably absorbed and the vibration is promptly damped. As a result,
Can be used comfortably without causing discomfort to lying people,
It is an object of the present invention to provide a magnetic damper for vibration isolation utilizing magnetic repulsive force and an in-vehicle vibration isolation bed using the magnetic damper.

[0008]

According to a first aspect of the present invention, there is provided a vibration damping magnetic damper comprising: a cylindrical cylinder; a piston provided in the cylinder; and a piston provided in the piston and external from the cylinder. A vibration-damping magnetic damper comprising a piston rod projecting from the cylinder, and a small hole through which the internal fluid flows in and out of the cylinder.
A magnetic body is provided on the piston and a side wall of the cylinder facing the piston so that a repulsive force is generated between the piston and the side wall.

An in-vehicle anti-vibration bed using a magnetic damper according to claim 2 of the present invention is an anti-vibration bed provided in a vehicle compartment of a vehicle, wherein the bed main body and the bed main body supporting the bed main body are supported. The above-mentioned bed body is supported by the piston rod.

An in-vehicle anti-vibration bed using the magnetic damper according to claim 3 of the present invention is the in-vehicle anti-vibration bed using the magnetic damper according to claim 2, wherein the magnetic damper has the piston rod suspended. In this state, it is provided on the ceiling of the vehicle, and the bed main body is hung on the tip of this piston rod.

According to a fourth aspect of the present invention, there is provided an in-vehicle anti-vibration bed using the magnetic damper according to the second aspect of the present invention, wherein the magnetic damper projects the piston rod upward. It is characterized in that it is provided on the floor of the vehicle in such a state that the bed body is supported by the tip of this piston rod.

According to a fifth aspect of the present invention, there is provided an in-vehicle anti-vibration bed using the magnetic damper according to any one of the first to fourth aspects, wherein the cylinder has the small size. It is characterized in that it is connected to a fluid storage container through a hole.

[0013]

According to the vibration damping magnetic damper of the first aspect, the magnetic body is provided so that the piston in the cylinder and the side wall of the cylinder facing the piston are repulsive to each other. If the vibrating body is connected to either the piston rod or the cylinder and the vibrating body is connected to the other so that the vibrating body and the vibrating body are in the same vibration direction, the vibration of the vibrating body will repel the magnetic field. The piston reciprocates in the cylinder by being transmitted to the vibrating body via force, but the elastic force of the repulsive force acting between these magnetic bodies causes the vibration transmitted to the vibrating body to vibrate. Will be relaxed. Therefore, such a magnetic damper can be applied to various places as a cushion member.

Since the cylinder has a small hole through which the internal fluid flows in and out, a fluid such as air moves through the small hole by the relative reciprocal movement of the piston with respect to the cylinder caused by the absorption of vibration. However, during this movement, resistance to fluid movement occurs, and this resistance suppresses relative movement of the piston with respect to the cylinder. Therefore, after the vibration of the vibrating body is stopped, the vibration of the vibrated body is quickly attenuated by suppressing the relative movement.

According to the vehicle-mounted anti-vibration bed using the magnetic damper of the second aspect, when the bed main body is supported by the magnetic damper in a state where there is no vibration in the vehicle, the piston in the cylinder and the side wall of the cylinder. The mutual repulsive force of the pair of magnetic bodies provided and the weight of the bed body are balanced with each other, and the bed body is magnetically levitated.
Then, when the vehicle travels and vertical vibration is applied to the vehicle-mounted bed, the balance between the repulsive force between the magnetic bodies and the weight of the bed body is lost, and a force in the bed body direction is applied to the magnetic damper. Mutual repulsive elastic force of the magnetic materials plays a role of a cushion, and the vibration of the bed body is moderated.

Since a small hole is formed in the cylinder, when the piston vibrates in the cylinder due to the imbalance, the fluid in the cylinder passes through the small hole and goes in and out of the cylinder. However, the resistance generated at this time quickly damps the vibration of the piston.

According to the vehicle-mounted anti-vibration bed using the magnetic damper of the third aspect, the magnetic damper is provided on the ceiling portion of the vehicle with the piston rod being hung, and the tip end portion of the piston rod is provided. Since the bed body is suspended, when the vehicle turns a curve, the bed body tilts in the direction of the combined force of centrifugal force and gravity, and as a result, the position of the recumbent on the bed body in the direction of centrifugal force. The gap is effectively suppressed.

According to the vehicle-mounted anti-vibration bed using the magnetic damper of the fourth aspect, the magnetic damper is provided on the floor of the vehicle with the piston rod protruding upward.
Since the bed body is supported by the tip portion of the piston rod, the bed body is stably supported.

According to the vehicle-mounted vibration isolation bed using the magnetic damper of the fifth aspect, since the cylinder is connected to the fluid storage container through the small hole, a liquid can be used as the fluid. .

[0020]

1 is a perspective view showing an example of an on-vehicle vibration-proof bed to which a magnetic damper according to the present invention is applied. As shown in this figure, a vehicle-mounted vibration-damping bed 1 includes a flat-bed bed body 2 and a pair of front and rear inverted U's that suspend the bed body 2.
It is composed of a V-shaped member 3 and a magnetic damper 4 connected to the tops of the pair of inverted U-shaped members 3. The above-mentioned magnetic damper 4 is suspended from a pair of suspension members 5 in the vehicle width direction that are suspended from a vehicle ceiling portion (not shown), so that the vehicle-mounted anti-vibration bed 1 is suspended from the vehicle ceiling.

A projecting piece 21 is provided in a diagonally horizontal direction at a corner of the bed body 2, and the tip of the inverted U-shaped member 3 is joined to the projecting piece 21. Also, the bed body 2
A pair of wheel guide grooves 22 in the vehicle width direction for guiding the wheels S1 of the stretcher S mounted thereon are recessed on the surface of the wheel, and the wheel S1 is fitted into the wheel guide grooves 22. The stretcher S is moved in and out of the bed body 2.

The pair of suspension members 5 are provided with concentric support shafts 51 extending in the front-rear direction, respectively. A bracket 41 a protruding from the upper surface of each magnetic damper 4 is fitted onto these support shafts 51. In this state, the magnetic damper 4 is rotatable around the support shaft 51 in the vehicle width direction. A pair of piston rods 43 hang from the lower part of each magnetic damper 4. The lower ends of these piston rods 43 and the pair of inverted U-shaped members 3
Are coupled to each other by a pair of concentric coupling shafts 31, which are rotatable relative to each other around the coupling shaft 31. It should be noted that the piston rod 43 and the reverse U
The character-shaped member 3 is not limited to being coupled to the coupling shaft 31 so as to be relatively rotatable, and the piston rod 4
3 and the inverted U-shaped member 3 may be integrally fixed.

FIG. 2 is a cross sectional view showing a first embodiment of the support member. As shown in this figure, the magnetic damper 4 includes a cylinder 41, a piston 42 mounted in the cylinder 41, and a piston rod 43 penetrating the central portion of the piston 42. On the upper end surface of the cylinder 41, a bracket 41a having a support hole 41b is provided so as to project upward. The support shaft 51 of the suspension member 5 is inserted into the support hole 41b.

The piston 42 is made of a disk-shaped permanent magnet and has a mounting hole 42a at its center. On the other hand, the base end portion of the piston rod 43 has a collar portion 43a.
Is provided, and a male screw portion 43b is formed on the front side of the collar portion 43a. Then, the nut 43c is fastened by the nut 43c and the flange portion 43a by fastening the nut 43c with the base end portion of the piston rod 43 penetrating into the mounting hole 42a of the piston 42. 43 and the piston 42 are integrally connected.

Further, the insertion hole 41 is provided at the bottom of the cylinder 41.
c is perforated, and a portion of the piston rod 43 below the flange portion 43a is slidably penetrated through the insertion hole 41c. Further, an air chamber 4a is formed above the piston 42 in the cylinder 41, and a small hole 41d for allowing an appropriate number of air to flow is formed in the upper portion of the cylinder 41. Therefore, the piston 42
When the cylinder moves up and down in the cylinder 41, the air in the air chamber 4a moves in and out through the small hole 41d.

On the inner surface of the bottom of the cylinder 41,
The disk-shaped magnet 44 is provided, and the disk-shaped magnet 44 is provided.
And the piston 42 composed of the magnet are arranged so that the same poles face each other. An insertion hole 44a corresponding to the insertion hole 41c of the cylinder 41 through which the piston rod 43 is inserted is formed in the central portion of the disc magnet 44, and the piston rod 43 is inserted into the cylinder 41 through the insertion holes 44a and 41c. It projects from the inside to the outside.

A support hole 43e is formed in the lower end of the piston rod 43, and the support shaft 43e is inserted in the support shaft 43e (FIG. 1) to form an inverted U-shape with the piston rod 43. The member 3 is connected.

Further, an inverted U is formed on the lower portion of the piston rod 43.
In a state where the character-shaped member 3 is coupled and the weight of the bed body 2 is applied to the piston 42, the piston 42 and the disk-shaped magnet 44
The piston 42 and the disk-shaped magnet 44 are separated from each other by the repulsive force acting between the bed body 2 and the bed body 2 in a magnetically levitated state in which the bed body 2 is lifted from the floor F.

Since the vehicle-mounted anti-vibration bed using the magnetic damper of the present invention is constructed as described above, when the stretcher S with a lying person is placed on the bed body 2, the bed body 2 and the stretcher S are placed. And the weight of the lying person is added to the piston 42 magnetically levitated in the cylinder 41, and the piston 4 is moved to a position where the above weight and the repulsive force of the magnet are antagonized.
2 descends. The bed main body 2 is in a magnetically levitated state at the position where they are in opposition.

When the vehicle vibrates, this vibration is transmitted to the bed body 2 via the repulsive magnetic force between the piston 42 and the disc magnet 44. The magnetic force acts as a cushion to cause the vibration. It is absorbed and the vibration of the bed body 2 is reduced. Moreover, when absorbing the vibration, the piston 42 moves vertically in the cylinder 41.
However, since the air in the air chamber 4a moves in and out of the small hole 41d due to this relative vibration, the vibration of the piston 42 is quickly attenuated by the resistance of the air at this time, and the vibration is continued for a long time. It is surely prevented from continuing, and does not give an uncomfortable feeling to a lying person lying on the bed body 2 via the stretcher S.

When the vehicle turns a curve, the bed body 2 turns about the support shaft 51 along the resultant force of centrifugal force and gravity, and the side portion farther from the turning center of the vehicle. It tilts so as to rise, and as a result, displacement of the lying person in the direction of centrifugal force on the lying surface is effectively suppressed.

FIG. 3 is a cross sectional view showing a second embodiment of the supporting member. In the case of this example, a fluid storage container 6 is provided above the magnetic damper 4X, and a partition wall 61 is provided between the fluid storage container 6 and the fluid chamber 4a 'of the cylinder 41. Then, an appropriate number of small holes 61a are bored in the partition wall 61, and the storage chamber 6a in the fluid storage container 6 and the cylinder 41 are formed.
The inner fluid chamber 4a 'is in communication with the small hole 61a.

An air hole 6 is provided at the top of the fluid storage container 6.
2 is provided, and a bracket 63 corresponding to the bracket 41a of the magnetic damper 4 is provided. Others are the same as the magnetic damper 4 of the first embodiment.

In the case of this embodiment, a liquid such as oil having a predetermined viscosity is stored in the storage chamber 6a and the fluid chamber 4a '. Therefore, the piston 42 is
When vibrating in a, the liquid such as oil reciprocates between the inside of the air chamber 4a and the inside of the storage chamber 6a through the small hole 61a, but the vibration of the piston 42 rapidly due to the small hole passage resistance of the liquid at this time. Decays to.

As described above, in this embodiment, the fluid such as oil is enclosed in the fluid chamber 4a 'of the magnetic damper 4,
The vibration of the piston 42 is damped by the resistance when the liquid passes through the small hole 61a. Since the resistance due to the liquid is greater than the resistance due to the air, vibration damping of the piston 42 is promptly performed accordingly.

FIG. 4 is a perspective view showing another example of the on-vehicle vibration-proof bed 1a to which the magnetic damper according to the present invention is applied.
In the case of this example, four support members 7 of the third embodiment described later are arranged on the floor F of the vehicle, and the flat plate-shaped bed body 2a is provided on the top of the piston rod 73 protruding from the upper portion of the support member 7. Is supported. On the upper surface of the bed body 2a, a pair of wheel guide grooves 72 in the vehicle width direction similar to the previous example.
Is provided.

FIG. 5 is a cross sectional view showing a third embodiment of the support member. As shown in this figure, the supporting member 7 includes a cylinder 71, a piston 72 made of a permanent magnet mounted in the cylinder 71, and a piston rod 73 provided on the piston 72. . A flange portion 71a is provided at the bottom of the cylinder 71,
The support member 7 is fixed on the floor F in a state where the flange portion 71 a is bolted to the floor F.

A disk-shaped magnet 74 is arranged at the bottom of the cylinder 71. The disk-shaped magnet 74 and the magnet of the piston 72 have the same poles facing each other, and the piston 72 is magnetically levitated in the cylinder 71 due to the repulsive force of each other. A mounting hole 72a is formed in the center of the piston 72 as described above.
The base end portion of the piston rod 73 is inserted into the. A flange portion 73a is provided at a lower portion of the piston rod 73, and the flange portion 73a is abutted against the peripheral portion of the mounting hole 72a to prevent the piston rod 73 from falling downward.

A piston rod 73 is inserted through the top wall 71d of the cylinder 71 in a sliding contact with an insertion hole 71c. Further, a plurality of small holes 71b are bored in appropriate places on the upper surface wall 71d, and when the piston 72 moves up and down, the air in the air chamber 7a comes in and out through the small holes 71b. . An upper collar portion 73b is provided on the upper portion of the piston rod 73, and the upper collar portion 73b is provided.
The bed main body 2a is magnetically levitated in a state in which the protruding portion of the piston rod 73 above b is fitted into the support hole 23 provided on the back surface of the bed main body 2a.

Therefore, when the floor F vibrates in the vertical direction due to the vibration of the vehicle, the vibration causes the piston 72, the piston rod 73 and the bed body 2a to float.
The vibration is absorbed by the cushioning effect of the magnetic levitation, and the vibration of the piston 72 is quickly attenuated by the air resistance caused by the air flowing in and out of the air chamber 7a through the small hole 71b.

A fluid storage container as used in the second embodiment is provided above the cylinder 71 of the support member 7 of the third embodiment, and oil or the like is loaded into the fluid storage container.
This liquid may be circulated in the cylinder 71 and the fluid storage container through the small holes. With this configuration, similarly to the second embodiment, the vibration of the bed body 2a is damped more quickly due to the resistance larger than the air generated when the liquid passes through the small holes.

In the above embodiment, the magnetic damper 4,
7 is an example applied to support the vehicle-mounted beds 1, 1a, but the magnetic dampers 4, 7 of the present invention are not limited to being used for the vehicle-mounted beds 1, 1a, and vibration It is also possible to use it as a base member for a structure which needs to be excluded, for example, various mechanical equipments and structures such as houses and buildings.

[0043]

As described in detail above, the first aspect of the present invention
The vibration-damping magnetic damper described above is composed of a cylindrical cylinder, a piston incorporated in the cylinder, and a piston rod that is provided in the piston and protrudes from the cylinder to the outside. A vibration damping magnetic damper having a small hole through which an internal fluid flows in and out, wherein a magnetic body is provided on the piston and a cylinder side wall facing the piston so that repulsive force is generated between them. It will be.

Therefore, if the vibrating body is connected to either the piston rod or the cylinder and the vibrating body is connected to the other so that the vibrating body and the vibrating body are in the same vibration direction, the vibrating body The vibration is transmitted to the vibrated body via magnetic repulsion, and the piston reciprocates in the cylinder.The vibration transmitted to the vibrated body vibrates due to the elastic function of the repulsive force acting between these magnetic bodies. It becomes relaxed against the vibration of the body. Therefore, such a magnetic damper can be applied to various places as a cushion member.

Since the cylinder has a small hole through which the internal fluid flows in and out, a fluid such as air moves through the small hole by the relative reciprocating motion of the piston with respect to the cylinder caused by the absorption of vibration. However, during this movement, resistance to fluid movement occurs, and this resistance suppresses relative movement of the piston with respect to the cylinder. Therefore, after the vibration of the vibrating body is stopped, the vibration of the vibrated body is quickly attenuated by suppressing the relative movement.

As described above, the magnetic damper of the present invention is such that the magnetic material is housed in the cylinder to obtain the vibration-proof function by the repulsive elastic force of the magnet, and the elastic member such as the coil spring is provided in the cylinder. This is effective in reducing the number of parts and the number of manufacturing steps as compared with the conventional vibration damping damper mounted in, and is effective in reducing the manufacturing cost.

An in-vehicle anti-vibration bed using a magnetic damper according to a second aspect of the present invention is an in-vehicle anti-vibration bed using a magnetic damper provided in a vehicle interior of a vehicle, the bed main body comprising:
The vibration damping magnetic damper according to claim 1 supports the bed body, and the bed body is supported by the piston rod.

Therefore, when the bed body is supported by the support member in a state where the vehicle is not vibrating, the mutual repulsive force between the piston in the cylinder and the magnetic body provided on the cylinder side wall and the weight of the bed body. And are in balance with each other. Then, when the vehicle travels and vibration is applied to the in-vehicle anti-vibration bed, the balance between the repulsive force between the magnetic bodies and the weight of the bed body is lost, and the force toward the bed body is applied to the magnetic damper. Mutual impact resilience of the body plays the role of a cushioning material, and the vibration of the bed body is alleviated.

Since the cylinder has a small hole for letting in and out the internal fluid, when the piston vibrates in the cylinder due to the imbalance, the fluid in the cylinder passes through the small hole. The vibrations of the piston are quickly attenuated by the resistance generated at this time through the passage through the cylinder.

As described above, the vibration of the vehicle is absorbed by the support member and transmitted to the bed main body in a relaxed state, and the vibration is quickly attenuated, so that the vibration of the bed main body is surely suppressed. This is convenient because the bed body is comfortable to lie on and the adverse effects of vibration on the emergency patient can be minimized, especially when the vehicle is for emergency use.

According to the vehicle-mounted anti-vibration bed using the magnetic damper of the third aspect of the present invention, the support member is provided on the ceiling portion of the vehicle with the piston rod suspended, and the tip of the piston rod is provided. Since the bed main body is suspended in the section, when the vehicle turns a curve, the bed main body tilts so that the side part in the direction where centrifugal force is applied rises, and as a result, the direction of centrifugal force of a recumbent on the recumbent surface. Is effectively suppressed.

According to the vehicle-mounted anti-vibration bed using the magnetic damper of the fourth aspect of the present invention, the support member is provided on the floor of the vehicle with the piston rod protruding upward. Since the bed body is supported at the tip of the bed, the support of the bed body is stable.

According to the vehicle-mounted anti-vibration bed using the magnetic damper of the fifth aspect of the present invention, since the cylinder is connected to the fluid storage container through the small hole, liquid is used as the fluid. This is advantageous because the resistance value between the liquid and the small holes is larger than the resistance value between the gas and the small holes, so that a good vibration suppressing action can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of an in-vehicle anti-vibration bed to which a magnetic damper according to the present invention is applied.

FIG. 2 is a cross-sectional view showing a first embodiment of the support member.

FIG. 3 is a cross-sectional view showing a second embodiment of the support member.

FIG. 4 is a perspective view showing another example of an on-vehicle vibration-proof bed to which the magnetic damper according to the present invention is applied.

FIG. 5 is a cross-sectional view showing a third embodiment of the support member.

FIG. 6 is an explanatory diagram illustrating a conventional magnetic levitation type vehicle-mounted anti-vibration bed.

[Explanation of symbols]

 1, 1a In-vehicle anti-vibration bed 2, 2a Bed body 21 Projection piece 22 Wheel guide groove 23 Support hole 3 Reverse U-shaped member 31 Coupling shaft 4,7 Magnetic damper 4a, 7a Air chamber 4a 'Fluid chamber 41,71 Cylinder 41a Bracket 41b Support hole 41c Insertion hole 41d, 71b Small hole 42, 72 Piston (disk magnet) 42a Mounting hole 43, 73 Piston rod 43a Collar part 43b Screw part 43c Nut 43e Support hole 44, 74 Disk magnet 5 Suspending member 6 fluid storage container 61 partition wall 61a small hole 62 air hole

Claims (5)

[Claims] 1. A cylindrical cylinder, a piston mounted in the cylinder, and a piston rod provided on the piston and projecting outward from the cylinder, wherein fluid inside the cylinder enters and exits the cylinder. A magnetic damper for vibration isolation having small holes formed therein, wherein a magnetic body is provided so that repulsive force is generated between the piston and a side wall of a cylinder facing the piston. Anti-vibration magnetic damper. 2. An in-vehicle anti-vibration bed using a magnetic damper provided in a vehicle compartment of a vehicle, comprising a bed body and the anti-vibration magnetic damper according to claim 1. The bed main body is supported by the piston rod, and the in-vehicle vibration-damping bed uses a magnetic damper. 3. The magnetic damper is provided on a ceiling portion of a vehicle with the piston rod hung, and a bed body is hung on a tip portion of the piston rod. In-vehicle anti-vibration bed using the described magnetic damper. 4. The magnetic damper is provided on a floor of a vehicle with the piston rod protruding upward, and a bed body is supported by a tip end portion of the piston rod. In-vehicle anti-vibration bed using the magnetic damper described in 2. 5. The vehicle-mounted vibration-damping bed using the magnetic damper according to claim 1, wherein the cylinder is connected to the fluid storage container through the small hole.