JP5818135B2 - Ambulance anti-vibration stand - Google Patents

Description

  The present invention relates to an anti-vibration stand for an ambulance that is provided in an ambulance, supports a stretcher on which a patient is placed, and absorbs vibrations and shocks applied to the patient during transportation.

  As an anti-vibration stand for ambulances, for example, the one shown in Patent Document 1 proposed by the present applicant is known. An upper frame that swings through a link mechanism with respect to the lower frame, and a vertical vibration during traveling of an ambulance by the repulsive force of a first permanent magnet that makes the repulsive magnetic pole attached to the lower frame and the upper frame face each other. It is the structure which suppresses. Also, when forward acceleration due to sudden braking is input, the front side of the upper frame (the victim's head side) is lifted and the rear side (the victim's foot side) is lowered to advance forward. Is suppressed.

JP 2000-126233 A

  The vibration isolator for ambulances of Patent Literature 1 can improve riding comfort by absorbing vibration and suppress nose dives by reducing forward acceleration. However, the technique of Patent Document 1 has a structure in which a vibration absorbing mechanism that mainly performs a vibration suppressing function in the vertical direction and a vibration absorbing mechanism that mainly performs a vibration suppressing function in the front-rear direction are provided separately, and both are complicated. The one with a simple structure is used, which causes an increase in weight.

  The present invention has been made in view of the above, and devised the link mechanism and provided with a vibration absorbing mechanism that can reduce the longitudinal vibration and the vertical vibration with a simple structure, thereby simplifying the structure and reducing the weight as compared with the conventional structure. An object is to provide an anti-vibration stand for an ambulance.

  In order to solve the above problems, an anti-vibration stand for an ambulance according to the present invention is attached to a base frame via a link mechanism and a vibration absorbing mechanism, and can swing up and down and back and forth with respect to the base frame. An ambulance anti-vibration stand that supports a stretcher on the upper frame, wherein the link mechanism includes a front link mechanism positioned on each front side of the base frame and the upper frame, and A rear link mechanism located on the rear side, and by the link mechanism, at the bottom dead center, the upper frame has an inclined posture in which the front side is located above the rear side, and at the top dead center, The upper frame can swing along the movement trajectory of the four-joint rotation chain mechanism that assumes a substantially horizontal posture, and the tilted posture at the bottom dead center is low. Is set to be position, wherein the vertical or the input vibration around a structure that absorbs and converts into pieces pendulum motion along the motion trajectory the 4-bar linkage mechanism.

It is preferable that the centload of the four-node rotation chain mechanism is set so as to substantially coincide with an imaginary line passing through the center of gravity of the upper frame from the top dead center to the bottom dead center. It is preferable that the inclined posture at the bottom dead center is set so that the front side is inclined upward in the range of 3 to 8 degrees with respect to the horizontal. The front link mechanism protrudes upward from a base-side front bracket projecting upward from the base frame, and projects downward from the upper frame to a position lower than the top of the base-side front bracket. A front link member that is pivotally supported between the lower bracket of the upper side front bracket, and the rear link mechanism has a lower end pivotally supported by the base frame and an upper end pivoted by the upper frame. Preferably, the rear link member is supported.
A permanent magnet connected to one of the base frame or the upper frame and arranged at a predetermined interval and a movable permanent magnet slidable between the permanent magnets and connected to the other of the base frame or the upper frame It is preferable to have a magnetic spring comprising:
The vibration absorbing mechanism includes the following dampers a) to c):
a) a permanent magnet connected to one of the base frame or the upper frame and arranged at a predetermined interval; a conductor slidable between the permanent magnets and connected to the other of the base frame or the upper frame; An interlinkage magnetic damper comprising:
b) a cylinder connected to one of the base frame or the upper frame, and a piston inserted in the cylinder so as to be reciprocable in the axial direction and connected to the other of the base frame or the upper frame, The cylinder includes a cylindrical conductor and a yoke that covers the outer peripheral surface of the conductor, and the piston is a plurality of permanent magnets arranged with the same poles facing each other along the axial direction of the cylinder. And a magnetic flux focusing type magnetic damper comprising a yoke disposed between the adjacent permanent magnets, or
c) Oil comprising a cylinder connected to one of the base frame or the upper frame, and a piston inserted in the cylinder so as to reciprocate in the axial direction and connected to the other of the base frame or the upper frame. It is preferable to have at least one of the dampers.
The vibration absorbing mechanism is connected to one of the base frame or the upper frame, and is slidable between a permanent magnet disposed at a predetermined interval and the permanent magnet, and is connected to the other of the base frame or the upper frame. An interlinkage magnetic damper comprising a conductor, a cylinder connected to one of the base frame or the upper frame, and the base frame or the upper part inserted into the cylinder so as to reciprocate in the axial direction. A piston connected to the other of the frame, and the cylinder includes a cylindrical conductor and a yoke that covers an outer peripheral surface of the conductor, and the piston extends along an axial direction of the cylinder. A magnetic flux concentrating magnetic damper comprising a plurality of permanent magnets arranged with the same poles facing each other, and a yoke disposed between the adjacent permanent magnets. It is preferable that the have one.
The vibration absorbing mechanism is connected to one of the base frame or the upper frame, and is slidable between a permanent magnet disposed at a predetermined interval and the permanent magnet, and is connected to the other of the base frame or the upper frame. An interlinkage magnetic damper comprising a conductor, a cylinder connected to one of the base frame or the upper frame, and the base frame or the upper part inserted into the cylinder so as to reciprocate in the axial direction. It is preferable to have both the oil dampers provided with the piston connected with the other of the flame | frame.
A vibration absorption mechanism that mainly performs a vibration suppression function in the vertical direction and a vibration absorption mechanism that mainly performs a vibration suppression function in the front-rear direction by absorbing and converting to a single pendulum movement along the movement trajectory of the four-bar chain mechanism Compared to those provided separately, it is preferable that the vibration transmission rate of the resonance point with respect to the input vibration is reduced by at least 40%, and the tension is easily maintained and maintained.

According to the present invention, at the bottom dead center, the upper frame has an inclined posture in which the front side is located above the rear side, and at the top dead center, the upper frame has a substantially horizontal posture. It can swing along the movement trajectory, and the tilting posture at the bottom dead center is stable, that is, the balance of spring force, damping force and mass is optimized at the bottom dead center, and minute vibration is generated by vibration input from the floor. Is set to occur. As a result, the vertical vibration or the front / rear input vibration input during traveling is converted into a single pendulum motion along the motion trajectory of the four-bar rotation chain mechanism and absorbed. That is, since a rotational motion is generated by using a vibration in the front-rear direction given by acceleration / deceleration during traveling as a trigger, the vibration input in the vertical direction is also converted into a rotational motion by this rotational motion, and is effectively reduced. In the present invention, it is preferable that the centload of the four-node rotation chain mechanism substantially coincides with an imaginary line passing through the center of gravity of the upper frame from the top dead center to the bottom dead center. The more the points, the less the rotational motion that combines the longitudinal motion and the vertical motion is less likely to occur. Therefore, the four-joint rotation chain mechanism is less likely to move as it moves in the direction of the bottom dead center, thereby being able to exert a damping force. That is, usually bottoming occurs at the bottom dead center, and impact vibration is input to the human side. However, according to the present invention, the bottom dead center is more stable at the spring force, damping force, and mass as described above. In addition, since the damping action associated with the lowering of the link operating efficiency functions, it is possible to suppress bottoming and to have a characteristic close to a rigid body at the bottom dead center.
Since the present invention is configured to absorb by converting to a single pendulum motion along the motion trajectory of the four-bar rotation chain mechanism in this way, it becomes a characteristic close to a rigid body with respect to vertical vibration, and the characteristic is Compared with the vibration absorption mechanism that mainly performs the vibration suppression function in the vertical direction and the vibration absorption mechanism that mainly performs the vibration suppression function in the front-rear direction, respectively, the resonance point for the vertical and front-rear input vibrations Can be reduced by at least 40%. This is preferably achieved by taking a stable posture at the bottom dead center and repeating minute vibrations at the bottom dead center, so that a phase lag (for example, a phase lag of about 90 degrees) that does not become an antiphase caused by structural damping is preferably obtained. Can be converted into a phase delay of 160 to 180 degrees to create an antiphase in a low frequency band, and can be achieved by increasing the return speed at an unstable top dead center that is substantially horizontal. In recent years, the unsprung mass has increased along with the increase in the diameter and width of vehicle tires, the loading weight has increased, and the suspension has been made with a firm spring. Reduce ride comfort. For this reason, it is necessary to adjust the vibration riding comfort with the damper, but it is difficult to match the suspension of the vehicle and the suspension mechanism of the vibration isolator. However, according to the present invention, due to the characteristics of the rigid body, the vibration transmissibility of the resonance point in the vertical direction becomes small (the resonance region becomes narrow), and it becomes easy to match the two. On the other hand, the vibration energy generated by the vertical direction input is converted into the vertical direction by converting the place where the vibration transmissibility is 1 in the characteristic of the rigid body into the front-rear direction in the equilibrium state near the bottom dead center where micro vibrations are repeated. The vibration transmissibility falls below 1 and becomes an attenuation region, and the vibration energy in the vertical direction is attenuated. In addition, since the head is lifted up is the reference position, vibration can be attenuated using the weight of the person, and because it constantly tries to return to a stable state, the feeling of rocking of the head is reduced. It is a structure. That is, in the present invention, the frequency band in which resonance with the human body is caused by the above-described minute vibration and the longitudinal movement due to acceleration / deceleration of the vehicle is also changed to the attenuation region, and the vibration absorption performance according to the input is improved.

  Further, by using a configuration in which a linkage magnetic flux type magnetic damper, a magnetic focusing type magnetic damper and a magnetic spring are used in combination as the vibration absorption mechanism, higher vibration absorption characteristics can be exhibited. In particular, in the present invention, a cylindrical magnetic flux concentrating magnetic damper having a repulsive magnet arrangement and a conductor disposed around a permanent magnet is used, so that a high damping force can be exhibited.

FIG. 1 is a perspective view showing a skeleton of an ambulance vibration isolator according to an embodiment of the present invention. FIG. 2 is a plan view of FIG. FIG. 3 is a side view of FIG. 4A and 4B are views showing the first vibration absorbing mechanism, in which FIG. 4A is a bottom view, FIG. 4B is a side view, and FIG. 4C is a front view. FIG. 5 is a diagram for explaining a magnetic damper constituting the second vibration absorbing mechanism. 6A and 6B are diagrams showing a cent load of the upper frame and the link mechanism, where FIG. 6A shows a stable state at the bottom dead center, and FIG. 6B shows a top dead center. (C) is the figure which combined and showed the state of the top dead center and the bottom dead center. FIG. 7A is an analysis diagram showing a magnetic flux distribution of an interlinkage flux type magnetic damper, and FIG. 7B is a magnetic flux distribution of a flux-concentration type magnetic damper. FIG. FIG. 8 is a diagram showing a BH curve of the yoke used in the analysis of FIG. FIG. 9 shows an electromagnetic force corresponding to the speed generated in each linkage magnetic field type and magnetic flux focusing type damper when the moving speed of copper is 0.05 m / s, 0.1 m / s, and 0.3 m / s. It is the figure which showed the analysis result. FIG. 10A is a diagram showing load-displacement characteristics of an interlinkage flux type magnetic damper, and FIG. 10B is a load of a flux-concentration type magnetic damper. -It is the figure which showed the displacement characteristic. FIG. 11A is a diagram showing the load-speed characteristics of an interlinkage flux type magnetic damper, and FIG. 11B is the load of a flux-concentration type magnetic damper. -It is the figure which showed the speed characteristic. FIG. 12 is a diagram showing analysis values and experimental values of the attenuation coefficient of each model used in the experimental example. FIG. 13 is a diagram illustrating vibration transmission characteristics in the front-rear direction of the head with respect to vibrations in the front-rear direction of the floor of the vehicle. FIG. 14 is a diagram illustrating the vibration transmissibility of the head in the vertical direction with respect to the floor with respect to the vertical input when the front-rear input is not applied. FIG. 15 is a diagram illustrating the vibration transmissibility in the vertical direction of the head relative to the floor with respect to the vertical direction input in a state where the longitudinal direction input is applied. FIG. 16 is a diagram showing a vibration transmissibility when a running test is performed on a one-box car equipped with the vibration isolator (new magnetic damper model) of the first embodiment, and (a) is a vibration transmission in the vertical direction. (B) is the figure which each showed the vibration transmissibility of the front-back direction. FIG. 17 shows the vibration transmissibility in the vertical direction when a running test was conducted with a subject in his twenties lying on his back on the anti-vibration mount of the first embodiment mounted on a one-box car. (B) is a test result obtained by locking the vertical suspension of the conventional model, and (c) is a test result of the vibration isolator of the embodiment (new magnetic damper). It is the figure which showed the test result in a model. FIG. 18 shows the vibration transmission rate in the vertical direction when another subject in his twenties is laid on his / her back on the anti-vibration mount of the first embodiment mounted on a one-box car and a running test is performed. (B) is a test result obtained by locking the vertical suspension of the conventional model, and (c) is a test result of the embodiment (new model). It is the figure which showed the test result in a magnetic damper model. FIG. 19 is a diagram showing the vibration reach rate in the vertical direction of the upper frame with respect to the base frame of the anti-vibration mount base of the second embodiment installed on the 6-axis shaker in the vibration isolation performance test 2. FIG. 20 is a diagram showing the vertical frame vibration transmissibility and the vertical acceleration PSD of the upper frame with respect to the base frame of the vibration isolating frame of the second embodiment during vehicle running in the vibration isolation performance test 2. is there. FIG. 21 is a diagram illustrating the vibration transmissibility in the longitudinal direction of the upper frame and the PSD of the longitudinal acceleration on the upper frame with respect to the base frame of the vibration isolating frame according to the second embodiment during vehicle running in the vibration isolation performance test 2. It is. FIG. 22 is a diagram illustrating a biological signal detection device used in a test related to physiological evaluation. FIG. 23 is a diagram showing the results of Test 1 regarding physiological evaluation. FIG. 24 shows a time-series waveform of the power spectrum of LF / HF, which is an index of sympathetic nerve, and a time-series waveform of the power spectrum of HF, which is an index of parasympathetic nerve, in Test 1 relating to physiological evaluation. (A) is a figure about a conventional model, (b) is a figure about the anti-vibration stand (new magnetic damper model) of 1st Embodiment. FIG. 25 is a waveform obtained by performing absolute value processing on the frequency gradient time-series waveform obtained by the zero cross method and the peak detection method for the heart part oscillating wave in Test 1 for physiological evaluation. It is a figure about a conventional model, (b) is a figure about the anti-vibration stand (new magnetic damper model) of 1st Embodiment. FIG. 26 shows a time-series waveform of the power spectrum of LF / HF, which is an index of sympathetic nerve, and a time-series waveform of the power spectrum of HF, which is an index of parasympathetic nerve, in Test 2 relating to physiological evaluation. (A) is a figure about a conventional model, (b) is a figure about the vibration isolator (development model) of 2nd Embodiment. FIG. 27 is a waveform obtained by performing absolute value processing on a frequency gradient time-series waveform obtained by the zero cross method and the peak detection method for the heart part oscillating wave in Test 2 for physiological evaluation. It is a figure about a conventional model, (b) is a figure about the antivibration stand (development model) of 2nd Embodiment. FIG. 28 shows a power spectrum obtained by frequency analysis of a time-sequential waveform of a frequency obtained from a frequency time-series waveform by the zero cross method, and (a) and (b) are analysis results of the conventional model. , (C), (d) are the analysis results of the anti-vibration vibration isolator 1 (development model) of the second embodiment.

  Hereinafter, the present invention will be described in more detail based on the embodiments shown in the drawings. FIGS. 1-3 is the figure which showed the vibration isolator 1 for ambulances which concerns on one Embodiment of this invention. As shown in these drawings, the ambulance vibration isolator 1 according to this embodiment includes a base frame 10 and an upper frame 20.

  The base frame 10 has an outer frame member 11 formed in a substantially rectangular shape in plan view. The outer frame member 11 has a base-side front bracket 12 that protrudes upward on the front side of the side frame 11a (the head side of a person riding on a stretcher). A base-side rear bracket 13 having a height lower than that of the base-side front bracket 12 is provided on the rear side of the side frame 11a (the foot side of the person riding on the stretcher).

  The upper frame 20 has an outer frame member 21 formed in a substantially rectangular shape in plan view, and an upper side front bracket 22 that protrudes downward is provided on the front side of the side frame 21a. The base-side front bracket 12 and the upper-side front bracket 22 are provided at a protruding height such that the upper part of the base-side front bracket 12 is positioned above the lower part of the upper-side front bracket 22. In addition, a guide portion 21c that is curved downward toward the rear end side is formed on the rear side of the upper frame 20 so that the stretcher can be easily carried in.

  The link mechanism includes a front link mechanism 30 located on each front side of the base frame 10 and the upper frame 20 and a rear link mechanism 40 located on each rear side. The front link mechanism 30 includes a front link member 31 whose upper end is pivotally supported on the upper part of the base side front bracket 12 and whose lower end is pivotally supported on the lower part of the upper side front bracket 22. The rear link mechanism 40 includes a shaft member 42 that is pivotally supported between a pair of base-side rear brackets 13 facing in the width direction, and a lower end fixed to the shaft member 42 by welding or the like. And a rear link member 41 that is pivotally supported by the upper side rear bracket 23 provided.

  In the present embodiment, the vibration absorption mechanism includes a first vibration absorption mechanism 50 and a second vibration absorption mechanism 60. The first vibration absorbing mechanism 50 is a mechanism including a magnetic damper portion 510 and a magnetic spring portion 520. As shown in FIGS. 1 and 4 (a) to 4 (c), the mountain-shaped frame 15 provided in a substantially mountain-shaped manner in the vicinity of the center in the longitudinal direction of the base frame 10 includes the first, second, second, The three permanent magnets 51a, 51b, 51c are opposed to each other with a predetermined interval, and a magnet unit 51 of an attracting system in which the different poles are adjacent to each other is supported. A conductor 52a such as copper and a movable permanent magnet 52b are supported on the central bracket 25 provided on the upper frame 20 at a position corresponding to the angle frame 15. The conductor 52a is provided, for example, between the first and second permanent magnets 51a, 51b, and the movable side permanent magnet 52b is provided, for example, between the second and third permanent magnets 51b, 51c. . Thereby, the magnetic damper portion 510 is formed by the first and second permanent magnets 51a and 51b and the conductor 52a, and the magnetic spring portion 520 is formed by the second and third permanent scales 51b and 51c and the movable-side permanent magnet 52b. .

  Therefore, when the upper frame 20 moves back and forth relative to the base frame 10, a predetermined damping ratio is obtained by the damping coefficient of the magnetic damper portion 510 and the spring constant of the magnetic spring portion 520.

  As shown in FIGS. 1 to 3, the second vibration absorbing mechanism 60 includes a cylinder 61 and a flux-concentration type magnetic damper including a piston 62 that slides in the cylinder 61. The bottom of 61 is pivotally supported by the cylinder bracket 16 of the base frame 10, and the projecting end of the piston rod 63 to which the piston 62 is connected is pivotally supported by the piston bracket 26 of the upper frame 20, mainly in the vertical direction. Absorbs vibration.

  Specifically, as shown in FIG. 5, the cylinder 61 includes a conductor 61a such as copper formed in a cylindrical shape, preferably a cylindrical shape, and a cylindrical, preferably cylindrical iron yoke that covers the outer peripheral surface thereof. (Cylinder side yoke) It is formed with a double cylinder structure with 61b.

  In this embodiment, the piston 62 includes a plurality of annular permanent magnets 62a and an annular iron yoke (piston side yoke) 62b. The permanent magnet 62a and the piston side yoke 62b are supported by inserting the tip end side of the piston rod 63 made of a nonmagnetic material such as nonmagnetic stainless steel.

  In the flux-concentration type magnetic damper, the permanent magnets 62a are arranged adjacent to each other with the same poles facing each other. In the example of FIG. 5, the two permanent magnets 62a and 62a have the N poles opposed to each other. And piston side yoke 62b is arrange | positioned between each of the permanent magnets 62a and 62a arrange | positioned adjacently. Moreover, it is preferable that the piston side yoke 62b is laminated | stacked also on the outer side edge part (opposite surface opposite side) of each permanent magnet 62a, 62a. A sliding member 62c for reducing sliding resistance is provided on the outer side of the piston side yoke 62b.

  When a vertical vibration is input to the magnetic damper constituting the second vibration absorbing mechanism 60, for example, the piston 62b reciprocates along the axial direction in the cylinder 61. At this time, the magnetic flux of the permanent magnet 62a is focused by the piston side yoke 62b and most of the magnetic flux passes through the conductor 61a, and the penetrating magnetic flux further passes through the cylinder side yoke 61b, so that there is very little magnetic flux leaking outward. Therefore, a high damping force works with the reciprocation. Note that an oil damper may be used as the second vibration absorbing mechanism 60 in place of the magnetic flux concentrating type magnetic damper. Details of this point will be described later.

  In the present embodiment, the adjustment of the spring constant and damping coefficient of the magnetic damper portion 510 and magnetic spring portion 520 of the first vibration absorbing mechanism 50 and the adjustment of the weight of the guide portion 21c of the upper frame 20 are shown in FIG. At the bottom dead center shown, it is set so that the front side becomes an inclined posture located above the rear side and becomes a stable posture, and the substantially horizontal posture of the top dead center shown in FIG. Set to a stable state. For example, at the top dead center, the movable permanent magnet 52b of the magnetic spring portion 520 is set to be in a neutral state.

  When trying to place a stretcher on which a person rides on the upper frame 20, the rear side is positioned below, and therefore it is easier to carry in compared to a case where the stretcher is level in a stable posture. When the stretcher is carried in, the front side (head side) descends due to the load of the stretcher and the person. At this time, as indicated by an arrow in FIG. 6A, the lower end of the front link member 31 of the front link mechanism 30 is displaced forward, and the upper end of the rear link member 41 of the rear link mechanism 40 is oblique. It is displaced upward and approaches the substantially horizontal posture of the top dead center shown in FIG.

  Since the substantially horizontal posture shown in FIG. 6B is an unstable state, when the ambulance starts to travel, the movable permanent magnet 52b of the magnetic spring portion 520 tries to move to a stable position due to the acceleration in the backward direction. The upper frame 20 is displaced from the substantially horizontal posture shown in FIG. 6B to the inclined posture shown in FIG. When front / rear or vertical vibrations are input, the front link mechanism 30 and the rear link mechanism 40 follow the motion trajectory of the four-bar rotation chain mechanism between the inclined posture and the substantially horizontal posture. Swing. As shown in FIG. 6A, the centload is set so as to substantially coincide with the center of gravity of the upper frame 20, and the structure is less likely to move back and forth as it approaches the inclined position of the bottom dead center. For this reason, a damping force is exhibited when moving from the top dead center side to the bottom dead center side. The input vibration is absorbed by the damping force of the four-bar rotation chain mechanism itself, and is also absorbed by the damping forces of the first vibration absorbing mechanism 50 and the second vibration absorbing mechanism 60. Further, in FIG. 6A, the centload between the top dead center and the bottom dead center is set so as to substantially coincide with a virtual line passing through the center of gravity of the upper frame 20, so that the center of gravity of the stretcher and the person is also assumed to be virtual. It becomes on the line and can improve a person's sense of stability.

  Therefore, the vehicle is basically inclined as shown in FIG. 6A during traveling, and the abbreviation shown in FIG. 6B is applied even when forward acceleration is input by sudden braking. Since it only becomes a horizontal posture, the descent of the head is reduced. Since the head-side descent at the time of sudden braking is usually about 5 degrees, the inclination angle in the inclined posture shown in FIG. 6A is preferably set in the range of 3 to 8 degrees with respect to the horizontal, More preferably, it is set in the range of 4 to 6 degrees.

・ Experimental example (damping force of magnetic damper)
Like an interlinkage flux type magnetic damper in which permanent magnets are attracted and arranged in the operating direction like the magnetic damper portion 510 of the first vibration absorbing mechanism 50 and a magnetic damper of the second vibration absorbing mechanism 60 The magnetic flux distribution was analyzed for a flux-concentration type magnetic damper arranged in a repulsive magnetic field and shown in FIGS. 7 (a) and 7 (b). The analysis conditions were a residual magnetic flux density of 1.26 T and a copper electrical conductivity of 56 × 10 ⁶ S / m. FIG. 8 shows the BH curve of the yoke. The non-linear analysis using the Newton-Raphson method was performed from the magnetic field 0 to A in the figure, and the magnetic flux density was saturated thereafter. FIG. 9 shows the electromagnetic force corresponding to the speed generated in each of the linkage magnetic field type and magnetic flux focusing type dampers when the moving speed of copper is 0.05 m / s, 0.1 m / s, and 0.3 m / s. The analysis results are shown, and it can be seen that the magnetic focusing magnetic damper has a damping force about three times that of the interlinkage magnetic damper.

  In order to confirm the damping force obtained by magnetic field analysis by experiment, the damping force was measured using a servo pulsar manufactured by Shimadzu Corporation. Waveforms input to the server pulser are 1 to 4 Hz and a sine wave with a single amplitude of 10 mm is given in increments of 1 Hz under constant amplitude conditions to determine the load-displacement characteristics of each magnetic damper. FIGS. 10 (a) and 10 (b) It was shown to. FIG. 11 shows the load-speed characteristics of each magnetic damper, and FIG. 12 shows the analytical values and experimental values of the attenuation coefficient of each model. The error between the analytical value and the experimental value was 10% or less. From FIG. 12, it can be seen that the flux-concentration type magnetic damper can obtain a damping force of about 2.9 times as an experimental value compared to the interlinkage flux type magnetic damper. The linkage magnetic field type magnetic damper is a magnet arrangement of an attraction system, and an eddy current is generated in a loop shape around the direction between the magnets of the attraction system, so that an electromagnetic force in a direction not contributing to the damping force is generated. On the other hand, the magnetic flux focusing type magnetic damper generates an eddy current in a loop shape around the axial direction, which is the direction of motion, and therefore generates a large amount of electromagnetic force in a direction effective as a damping force. Further, from the magnetic flux distribution of FIG. 7, in the magnetic flux focusing type magnetic damper, the magnetic flux is focused on the magnet gap portion by the repulsive magnet arrangement, and further, the axial center portion by the yoke arrangement between the magnets, both ends of the magnet, and the outside of the conductor. The magnetic flux passing through is decreasing. Moreover, since it is an object of the axis, the magnetic flux deviating from the conductor is greatly reduced as compared with the interlinkage magnetic damper, and it is considered that the damping coefficient has increased.

・ Vibration isolation test 1
(Test on the anti-vibration stand 1 for an ambulance according to the first embodiment of the present invention using the magnetic flux focusing magnetic damper disposed in the repulsive magnetic field shown in FIG. 5 as the second vibration absorbing mechanism 60)
The anti-vibration stand 1 for the ambulance of the above-described embodiment on the uniaxial vertical vibration exciter (using the magnetic flux focusing type magnetic damper arranged in the repulsive magnetic field shown in FIG. 5 as the second vibration absorbing mechanism 60) , With an 80 kg body weight test subject in their 40s lying on their back, attach an acceleration pickup to the subject's head, perform vertical sine wave excitation, and generate vertical and longitudinal accelerations generated on the head Was measured.
The measurement during running of the vehicle is carried out by installing the magnetic flux focusing type magnetic damper arranged in the repulsive magnetic field shown in FIG. 5 as the second vibration absorbing mechanism 60 at the rear part of the one-box car. The test course of the paved road surface (conditions exposed to whole body vibration without impact vibration (vibration with a crest factor of 2 to 3 or more)) while accelerating / decelerating assuming actual driving conditions Ran. Then, the vertical and longitudinal accelerations of the floor and the vertical and longitudinal accelerations generated on the head of a subject weighing 80 kg were measured.

FIG. 13 shows the vibration transmission characteristics in the front-rear direction of the head relative to the front-rear direction vibration of the vehicle floor. For the front-rear input, there is resonance at 2 Hz to 4 Hz, but the gain is small. In other words, the vibration characteristics of the ambulance anti-vibration stand using the single pendulum motion are considered to have the same resonance peak on the floor and the anti-vibration stand for the longitudinal input. It can be said that the relative acceleration with respect to the floor surface is small, and it becomes difficult for humans to perceive the acceleration. So-called vibration characteristics close to a rigid body.

  FIG. 14 shows the vibration transmission rate in the vertical direction of the head relative to the floor with respect to the vertical direction input on the single-axis vertical direction vibration exciter on which the longitudinal direction input does not act. Here, a large resonance peak is observed at 4 to 6 Hz, and it can be seen that the human head is well splashed on a stretcher installed on a vibration isolator having vibration absorption performance close to a rigid body. On the other hand, FIG. 15 shows the measurement results when the vehicle is running, and shows that the vertical transmission characteristic is improved by the movement of the resonance peak of FIG. 14 with the longitudinal input. That is, it can be seen that the vibration transmission rate of the head is reduced by converting the vertical direction input into the longitudinal motion.

  FIG. 16 shows the one mounted with the ambulance anti-vibration stand 1 of the above embodiment (using the magnetic flux focusing type magnetic damper arranged in the repulsive magnetic field shown in FIG. 5 as the second vibration absorbing mechanism 60). It is the figure which showed the vibration transmissibility at the time of running test of the box car on the test course (paved road surface) (in the figure, “new magnetic damper model”). 16A shows the vibration transmissibility in the vertical direction, and FIG. 16B shows the vibration transmissibility in the front-rear direction. In either case, the vibration isolator 1 (new magnetic damper model) of the embodiment includes a conventional anti-vibration stand (conventional model (vertical vibration absorbing mechanism and front-rear vibration absorbing mechanism for absorbing the nose dive), respectively. Separately provided: Delta Touring Co., Ltd. (registered trademark “MEDIC MASTER” Model NA-3)) has a reduced vibration transmissibility. The vibration transmissibility at the resonance point of the vibration isolator 1 of the embodiment (new magnetic damper model) is about 1.15 in the vertical direction and about 1.2 in the front-rear direction, and the vibration transmissibility is very small. The vibration transmissibility at the resonance point of the mold model was reduced by about 60% or more. This transfer characteristic with respect to the longitudinal vibration input in the lying posture reduces fluffy feeling, leopard feeling and visceral resonance.

  FIGS. 17 and 18 show the anti-vibration frame 1 for the ambulance according to the above-described embodiment in which subjects A and B in their 20s are mounted on the one-box car (the repulsion shown in FIG. 5 as the second vibration absorbing mechanism 60). Lay on its back on a magnetic field-focused magnetic damper (exposed to a magnetic field) and exposed to whole body vibration with impact vibration (crest factor of 2 or more). The vibration transmissibility when a running test is performed under (Condition). (A) of each figure is a test result by the vibration isolator of the conventional model, (b) is a test result obtained by locking the vertical suspension of the conventional model, and (c) The test result in the vibration isolator stand 1 (new magnetic damper model) of embodiment is shown. As described above, the vibration isolator 1 (new magnetic damper model) of the present embodiment has a very low vibration transmissibility at the resonance point (about 1.5 in FIG. 17C and FIG. 18C). Then about 1.6). On the other hand, (b) in each figure locks the vertical suspension of the conventional model and approaches the characteristics of the rigid body, but the vibration transmissibility at the resonance point is the conventional model in (a) of each figure. It is not so small as compared with (Fig. 17B, about 4 and Fig. 18B, about 2.5). However, since the vibration isolator 1 of the present embodiment is close to a rigid body and converts the vertical vibration into the front-rear direction by the single pendulum motion along the motion trajectory of the four-bar rotation chain mechanism, the vibration at the resonance point It can be seen that the transmissibility (particularly the vibration transmissibility at a resonance point of 10 Hz or less) can be greatly reduced. The vibration transmissibility of the resonance point (particularly the resonance point of 10 Hz or less) is at least 40 compared to the conventional type (about 3.2 in FIG. 17A and about 3.4 in FIG. 18A). % Reduction is preferred. Although it depends on input conditions, it is preferable to set the vibration transmissibility at a resonance point of 10 Hz or less to be 1.8 or less. More preferably, it is 1.5 or less, More preferably, it is 1.2 or less.

・ Vibration isolation test 2
(Test on the vibration isolator 1 for an ambulance according to the second embodiment of the present invention using an oil damper as the second vibration absorbing mechanism 60)
The vibration isolation performance test 2 shows test results for an embodiment in which an oil damper filled with oil in a cylinder is used as the second vibration absorbing mechanism 60 in the ambulance vibration isolation frame 1 of the above embodiment. In addition, the other structure of the vibration isolator for ambulances is the same as that of the vibration isolator for ambulances 1 of the above embodiment.

  First, a vibration test was conducted by attaching an anti-vibration frame for an ambulance using an oil damper to a 6-axis shaker. The load weight was 130 kg corresponding to the combined weight of the stretcher and the 80 kg test subject. The input waveform to the exciter reproduces the acceleration data in the vertical and longitudinal directions of the vehicle floor measured by running the vehicle, and the longitudinal acceleration is 0%, 20%, 50%, 80%, 100 when the vehicle is running. The vibration was performed while changing to%. Then, the vertical and longitudinal accelerations of the base frame of the ambulance anti-vibration stand and the vertical and longitudinal accelerations generated in the upper frame were measured.

  The measurement during running of the vehicle is the same as in the case of the vibration isolation performance test 1, and an anti-vibration stand for an ambulance using the oil damper according to the second embodiment is attached to the rear part of the one-box car, and the stretcher and weight An 80 kg test subject was placed and ran on a test course (a stretched road surface) while performing acceleration / deceleration assuming actual driving conditions. Then, the vertical and longitudinal accelerations of the base frame of the ambulance vibration isolation frame according to the second embodiment and the vertical and longitudinal accelerations generated in the upper frame were measured. In order to compare with the anti-vibration function of an ambulance anti-vibration stand of the conventional type (registered trademark “MEDIC MASTER” Model NA-3 manufactured by Delta Touring Co., Ltd.), the same measurement was performed on the anti-vibration stand for the conventional ambulance. .

  FIG. 19 shows the acceleration transmission rate in the vertical direction of the upper frame with respect to the base frame of the vibration isolator on the 6-axis shaker. When the acceleration in the front-rear direction increases, the vibration transmissibility decreases around 7-9 Hz. In other words, the vertical transmission characteristics are improved by the motion accompanied by the longitudinal input. In particular, according to the present embodiment, the vibration transfer characteristics change as the longitudinal acceleration increases from 0% to 100%, and the head gain decreases as the forward / backward swing increases. Recognize. It can also be seen that the resonance frequency is different from the conventional transfer characteristics shown in the figure. The difference in natural frequency is a difference in design specifications of the spring constant due to the difference in vibration isolation direction. In the conventional type, the suspension in the vertical direction is a front and rear suspension that absorbs the nose dive, and in the present embodiment, the function of the front and rear suspension is the second purpose, with the first purpose being to absorb the nose dive, Vibration isolation in the vertical direction is performed during these steps. The front / rear suspension generates an impact force at the front / rear ends due to the inertial force generated in the front / rear direction, so that the damping performance is increased to alleviate the impact force.

  For this reason, in the anti-vibration stand 1 for ambulances of the said embodiment, a spring constant can be enlarged and it can set to 0.35 vicinity which is an ideal damping ratio. Specifically, the vibration isolator for ambulance 1 used in this test has a spring constant k = 108600 N / m, a damping coefficient c = 2600 N · s / m, and a damping ratio of 0.35. k = 46000 N / m, damping coefficient c = 2000 N · s / m, damping ratio 0.409. Therefore, the vibration isolator for ambulance 1 according to the second embodiment has a higher natural frequency. In addition, anti-vibration performance in a low frequency band is improved by assuming acceleration / deceleration that occurs during general travel of an ambulance. The coulomb friction force is designed to be small so that the front and rear suspensions can operate sensitively even during acceleration and deceleration at high speeds. Therefore, we decided to absorb the vibration isolation performance in the vertical direction around 6 Hz or above 6 Hz with a stretcher. The structural features of the stretcher are the hammock structure and the rubber tires. It was decided to make the rubber tires generate a slight movement in the front-rear direction to help the absorption performance in the vertical direction.

  FIG. 20 shows the vertical vibration transmission rate of the upper frame and the vertical acceleration PSD of the upper frame relative to the base frame of the anti-vibration frame during vehicle travel. When the vehicle is running, the effect of improving the performance is recognized in the vertical vibration characteristics in the vicinity of 2 to 4 Hz as compared with the conventional vibration isolator. When compared at a resonance point of 10 Hz or less, the vibration transmissibility of the conventional type is about 3.1, whereas that of the embodiment is about 1.7, which is reduced by about 40%. FIG. 21 shows the PSD of the longitudinal frame transmissibility of the upper frame relative to the base frame of the anti-vibration mount and the longitudinal acceleration PSD on the upper frame when the vehicle is traveling. As for the vibration characteristics in the front-rear direction, an effect of improving the performance in the vicinity of 2 Hz and in the vicinity of 4 to 6 Hz is recognized as compared with the conventional vibration isolator.

  However, the data of FIGS. 20A and 21A according to the second embodiment using this oil damper and FIG. 16A according to the first embodiment using the magnetic flux focusing type magnetic damper are shown. , (B), the effect of reducing the vibration transmissibility with respect to the vibration in the vertical direction is large, but the vibration transmissibility with respect to the vibration in the front-rear direction is the first using a magnetic flux focusing type magnetic damper. The vibration isolator 1 according to the embodiment was far superior. This is because the oil damper has a large damping force and has a hard characteristic in the low speed region, whereas the magnetic flux focusing type magnetic damper has a small damping force at the beginning of movement, and the damping force increases as the speed increases. This is because it has the property of increasing. Therefore, the vibration isolator 1 that employs a magnetic flux concentrating magnetic damper as the second vibration absorbing mechanism 60 is preferable to one that employs an oil damper. However, by using an oil damper having a damping force smaller than that used here, the vibration transmissibility with respect to the vibration in the front-rear direction can be made closer to that using a magnetic flux focusing type magnetic damper.

  Moreover, when the weight of the vibration isolator for ambulance 1 of the second embodiment using the oil damper and the conventional anti-vibration rack is compared, the conventional one is about 120 kg due to the simplification of the vibration absorbing mechanism. On the other hand, the vibration isolator for ambulance 1 of the above embodiment is about 50 kg, and can be significantly reduced in weight. Therefore, the ambulance anti-vibration stand 1 of the above embodiment contributes to saving the fuel consumption and saving energy of the ambulance. In the anti-vibration stand 1 for the ambulance used in the experiment, the base frame 10 is 26 kg, and the upper frame 20 is 32 kg including the guide portion 21c (6 kg), both of which are lighter than the mass of the stretcher (usually 47 kg). That is, since the unsprung mass of the stretcher is lighter than the mass of the stretcher, stable pendulum movement is likely to occur, and the reaction force acting on the person due to input vibration is reduced. Many of the vibration reduction effects are caused by the presence or absence of minute vibrations at the bottom dead center.

・ Test 1 for physiological evaluation
(Test on the anti-vibration stand 1 for an ambulance according to the first embodiment of the present invention using the magnetic flux focusing magnetic damper disposed in the repulsive magnetic field shown in FIG. 5 as the second vibration absorbing mechanism 60)
As in the above tests, the test course was performed with the ambulance anti-vibration stand 1 of the first embodiment using a magnetic flux focusing type magnetic damper attached to the rear of the one-box car, and performing acceleration / deceleration assuming actual driving conditions. Ran. A 40-year-old male subject lay on his back on the vibration isolator for ambulance 1, and the back pressure wave (heart rocking wave: APW) and fingertip volume pulse wave were measured. In order to compare with the anti-vibration function of an ambulance anti-vibration stand of the conventional type (registered trademark “MEDIC MASTER” Model NA-3 manufactured by Delta Touring Co., Ltd.), the same measurement was performed on the anti-vibration stand for the conventional ambulance. .

  The back pressure wave (heart rocking wave) was measured by placing on the ambulance anti-vibration stand 1 so that the biological signal detection device abuts on the back of the subject. The biological signal detection device 200 used here is the one proposed by the present applicant as Japanese Patent Application No. 2010-14870. As shown in FIG. 22, the plate-like bead foam 215 is cut into two rectangles, for example. The three-dimensional three-dimensional knitted fabric 210 is loaded into the hollowed holes 215a and 215a, the front and back sides of the three-dimensional three-dimensional knitted fabric 210 are respectively covered with the film 216, and further, a plate-like bead foam is formed on the outer side of each film 216. 220 and 221 are laminated. A sensing unit 230a of a vibration sensor (preferably a condenser microphone sensor) 230 is fixed to the surface of the three-dimensional solid knitted fabric 210 sandwiched between the two films 216 and 216. When this biological signal detection device 200 is brought into contact with the back of the subject, microvibrations on the body surface due to biological signals (hereinafter referred to as “heart swinging waves”) due to swinging of the atrium, ventricle and aorta are caused by the bead foam and Propagated as film vibration of the film and string vibration of the yarn of the three-dimensional solid knitted fabric, there is an advantage that the biological signal can be accurately detected as compared with the conventional air pack sensor.

  The heart rocking wave detected by the biological signal detection device was processed based on the technique of Japanese Patent Application No. 2009-237802 previously proposed by the present applicant, and the result is shown in FIG. Specifically, positive / negative of the first frequency gradient time series waveform using the zero cross method, positive / negative of the integrated waveform obtained by integrating the first frequency gradient time series waveform, and the first frequency gradient time series waveform and peak detection using the zero cross method. Comparison of absolute values of frequency gradient time series waveforms obtained by processing absolute values of the second frequency gradient time series waveforms using the method, and superimposing the first frequency gradient time series waveform and the first frequency fluctuation time series waveform FIG. 6 is a graph that displays a comprehensive determination result of a person's state performed in combination with the appearance of an opposite phase (an appearance of the opposite phase indicates a sleep onset sign) or the like. Note that the time-series waveform of the frequency gradient is obtained by processing the time-series waveform of the output signal obtained from the vibration sensor by the zero cross method or the peak detection method to obtain the time-series waveform of the frequency, and further, the least square method for each predetermined time window. This is a time series waveform obtained by sliding calculation of a frequency gradient time series waveform. The zero-cross method is a method for obtaining a time-series waveform of frequency using a point (zero-cross point) that switches from positive to negative in the time-series waveform of the output signal obtained from the vibration sensor, and the peak detection method is obtained from the vibration sensor. In this method, the time series waveform of the output signal is smoothed and differentiated to obtain the time series waveform of the frequency using the maximum value (peak).

  FIG. 23 shows that the upper side of the vertical axis indicates a relaxed state (energy state), and the lower side shows that the degree of fatigue (fatigue state) increases. This is the positive / negative of the positive / negative integrated waveform of the frequency gradient time series waveform. The comparison of absolute values, etc. is set in accordance with the sensory evaluation of a large number of subjects, under which conditions, for example, whether they feel fatigued or relaxed.

  From FIG. 23, the vibration isolator for ambulance 1 (hereinafter referred to as “new magnetic damper model” in some cases) of the first embodiment is a conventional ambulance vibration isolator for ambulance (hereinafter sometimes referred to as “conventional model”). The difference occurs after 15 minutes. That is, in the new magnetic damper model, after 15 minutes, the fatigue stage 1 (the healthy state) and the fatigue stages 3 to 4 (the state in which the sympathetic compensation action is applied) are repeated in a short cycle. It shows a good condition. Therefore, although fatigue is gradually progressing in the conventional model, it can be said that in the new magnetic damper model, the progress of fatigue is controlled by the autonomic nervous system and the feeling of fatigue is not felt.

  FIG. 24 shows the time series waveform of the power spectrum of LF / HF, which is an index of sympathetic nerve, obtained from the finger plethysmogram and the time series waveform of the power spectrum of HF, which is an index of parasympathetic nerve. This is processed by the technique disclosed in Japanese Patent Application Laid-Open No. 2008-264138 by the present applicant. FIG. 24 shows that the conventional model is induced in a state in which the parasympathetic nerve is dominant and sleepiness occurs after 15 minutes, suggesting the possibility of falling asleep. On the other hand, it is suggested that the new magnetic damper model is in a sympathetic nerve dominant state for 15 to 20 minutes, and a state of reducing fatigue due to the compensatory action of the sympathetic nerve.

  FIG. 25 shows a time series waveform of the frequency of the center part oscillating wave by the zero cross method and the peak detection method, and slide calculation of the frequency slope time series waveform by the least square method every predetermined time window. Is a waveform obtained by performing absolute value processing on the obtained frequency gradient time series waveform (based on the technique of the above-mentioned Japanese Patent Application No. 2009-237802 previously proposed by the present applicant). The zero cross method waveform approximates the LF / HF waveform, and the peak detection method waveform approximates the HF waveform. From FIG. 25, in the conventional model, the sympathetic function tends to decrease with time, and the parasympathetic nerve tends to increase. In contrast, the new magnetic damper model has a sympathetic compensation function and reduces fatigue.

  From these results, the determination result of FIG. 23 is similar in tendency to the determination results of FIG. 24 and FIG. 25, and the effect of the new magnetic damper model to reduce fatigue by sympathetic nerve compensation than the conventional model. Is high.

・ Test 2 for physiological evaluation
(Test on the vibration isolator 1 for an ambulance according to the second embodiment of the present invention using an oil damper as the second vibration absorbing mechanism 60)
Similar to Test 1 related to the physiological evaluation described above, the ambulance vibration isolator 1 of the second embodiment using an oil damper is attached to the rear part of the one-box car, and the test is performed while performing acceleration / deceleration assuming the actual driving situation. I ran the course. A 20-year-old male subject was laid on his back on the vibration isolator for ambulance 1, and the back pressure wave (heart rocking wave: APW) and the fingertip volume pulse wave were measured.

  FIG. 26 shows the time-series waveform of the power spectrum of LF / HF, which is an index of sympathetic nerve, obtained from the fingertip volume pulse wave, and the time-series waveform of the power spectrum of HF, which is an index of parasympathetic nerve. As shown in FIG. 26 (a), the conventional model is guided to a parasympathetic dominant state, whereas the ambulance vibration isolator 1 (development model) of the second embodiment is shown in FIG. It can be seen from (b) that the sympathetic nerve is dominant.

  FIG. 27 shows the time-series waveform of the frequency of the center oscillating wave by the zero-cross method and the peak detection method, and the slide calculation of the frequency-gradient time-series waveform by the least square method every predetermined time window. This is a waveform obtained by performing absolute value processing on the obtained frequency gradient time series waveform. As shown in FIG. 27A, in the conventional model, the sympathetic function tends to decrease with time and the parasympathetic nerve tends to become dominant. In contrast, the ambulance anti-vibration stand 1 (development model) of the second embodiment is found to be in a state in which the sympathetic nerve is enhanced as compared with the conventional model.

  FIG. 28 shows a power spectrum obtained by frequency analysis of a time-sequential waveform of a frequency obtained from a frequency time-series waveform by the zero cross method, and (a) and (b) are analysis results of the conventional model. , (C), (d) are the analysis results of the anti-vibration vibration isolator 1 (development model) of the second embodiment. Further, “first half of experiment” in (a) and (c) shows an initial state immediately after lying on the anti-vibration stand, and “second half of experiment” in (b) and (d) shows a state just before the end of the experiment. . In the conventional model, the fluctuation slope of the power spectrum is closer to 1 / f in the latter half of the experiment than in the first half of the experiment. This indicates a tendency to relax. On the other hand, the ambulance stand 1 for ambulances of the second embodiment (development model) is closer to 1 / f in the latter half of the experiment than in the first half of the experiment, but more 1 in comparison with the conventional model of (b). Close to / f. Therefore, in the case of the ambulance anti-vibration stand 1 (development model) of the second embodiment, it can be determined that the user is guided to a higher concentration state even when relaxed.

  From the tests 1 and 2 relating to the physiological evaluation, the conventional model has a tendency that the function of the sympathetic nervous system decreases with time and the parasympathetic nerve is enhanced and relaxed. It was found that the anti-vibration stand 1 for ambulances according to the second embodiment tends to maintain a sense of tension in all cases, with the function of the sympathetic nervous system being enhanced. Therefore, the anti-vibration stand 1 for an ambulance according to the present invention can easily maintain the cardiovascular homeostasis by controlling the sympathetic nervous system, and can maintain and maintain a sense of tension in a good sense for the patient until transported to the hospital. It can be said that it is easy to be configured.

As described above, the vibration absorbing mechanism is most preferably a type in which the magnetic spring portion 520 is combined with the magnetic damper portion (linkage magnetic field type magnetic damper) 510 and the magnetic flux focusing type magnetic damper. A type in which an oil damper is combined with a mold magnetic damper is preferable, but the following dampers a) to c) are added to the magnetic spring portion 520:
a) a permanent magnet connected to one of the base frame or the upper frame and arranged at a predetermined interval; a conductor slidable between the permanent magnets and connected to the other of the base frame or the upper frame; An interlinkage magnetic damper comprising:
b) a cylinder connected to one of the base frame or the upper frame, and a piston inserted in the cylinder so as to be reciprocable in the axial direction and connected to the other of the base frame or the upper frame, The cylinder includes a cylindrical conductor and a yoke that covers the outer peripheral surface of the conductor, and the piston is a plurality of permanent magnets arranged with the same poles facing each other along the axial direction of the cylinder. And a magnetic flux focusing type magnetic damper comprising a yoke disposed between the adjacent permanent magnets, or
c) Oil comprising a cylinder connected to one of the base frame or the upper frame, and a piston inserted in the cylinder so as to reciprocate in the axial direction and connected to the other of the base frame or the upper frame. The structure which has any one damper among dampers, or the structure which has a combination of two or more of these may be sufficient.

DESCRIPTION OF SYMBOLS 1 Ambulance anti-vibration stand 10 Base frame 12 Base side front bracket 13 Base side rear bracket 20 Upper frame 22 Upper side front bracket 30 Front link mechanism 31 Front link member 40 Rear link mechanism 41 Rear link member 42 Shaft member DESCRIPTION OF SYMBOLS 50 1st vibration absorption mechanism 510 Magnetic damper part 520 Magnetic spring part 60 2nd vibration absorption mechanism 61 Cylinder 62 Piston

Claims (8)

An ambulance that includes a base frame and an upper frame that is attached to the base frame via a link mechanism and a vibration absorption mechanism and that can swing up and down and back and forth with respect to the base frame, and supports a stretcher on the upper frame Anti-vibration stand for
The link mechanism comprises a front link mechanism located on each front side of the base frame and the upper frame, and a rear link mechanism located on each rear side,
Due to the link mechanism, at the bottom dead center, the upper frame is in an inclined posture in which the front side is positioned higher than the rear side, and at the top dead center, the four-bar rotation chain mechanism in which the upper frame is in a substantially horizontal posture. Is set so that the tilt posture at the bottom dead center becomes a stable posture.
Vertical or input vibration before and after, Ri configured der absorbs and converts into pieces pendulum motion along the motion trajectory the 4-bar linkage mechanism, and,
An ambulance anti-vibration stand for an ambulance, characterized in that the cent load of the four-joint rotation chain mechanism is set to substantially coincide with a virtual line passing through the center of gravity of the upper frame from top dead center to bottom dead center . Inclined attitude in the bottom dead center, to the horizontal, the front side of the vibration-proof table for ambulances as claimed in claim 1, wherein it is set such that the tilt angle which is inclined upwardly in the range of 3-8 degrees. The front link mechanism protrudes upward from a base-side front bracket projecting upward from the base frame, and projects downward from the upper frame to a position lower than the top of the base-side front bracket. A front link member that is pivotally supported between the lower bracket of the upper side front bracket,
The vibration isolator for an ambulance according to claim 1 or 2 , wherein the rear link mechanism includes a rear link member having a lower end pivotally supported by the base frame and an upper end pivotally supported by the upper frame. A permanent magnet connected to one of the base frame or the upper frame and arranged at a predetermined interval and a movable permanent magnet slidable between the permanent magnets and connected to the other of the base frame or the upper frame An anti-vibration stand for an ambulance according to claim 3, comprising a magnetic spring comprising: The vibration absorbing mechanism includes the following dampers a) to c):
a) a permanent magnet connected to one of the base frame or the upper frame and arranged at a predetermined interval; a conductor slidable between the permanent magnets and connected to the other of the base frame or the upper frame; An interlinkage magnetic damper comprising:
b) a cylinder connected to one of the base frame or the upper frame, and a piston inserted in the cylinder so as to be reciprocable in the axial direction and connected to the other of the base frame or the upper frame, The cylinder includes a cylindrical conductor and a yoke that covers the outer peripheral surface of the conductor, and the piston is a plurality of permanent magnets arranged with the same poles facing each other along the axial direction of the cylinder. And a magnetic flux focusing type magnetic damper comprising a yoke disposed between the adjacent permanent magnets, or
c) Oil comprising a cylinder connected to one of the base frame or the upper frame, and a piston inserted in the cylinder so as to reciprocate in the axial direction and connected to the other of the base frame or the upper frame. The vibration isolator for ambulances according to any one of claims 1 to 4 , comprising at least one of the dampers. The vibration absorbing mechanism is
A permanent magnet connected to one of the base frame and the upper frame and arranged at a predetermined interval; and a conductor slidable between the permanent magnets and connected to the other of the base frame or the upper frame. A linkage magnetic field type magnetic damper,
A cylinder connected to one of the base frame or the upper frame, and a piston inserted in the cylinder so as to be reciprocally movable in the axial direction and connected to the other of the base frame or the upper frame. Is provided with a cylindrical conductor and a yoke that covers the outer peripheral surface of the conductor, and the piston has a plurality of permanent magnets arranged with the same poles facing each other along the axial direction of the cylinder, The vibration isolator for an ambulance according to any one of claims 1 to 4 , comprising both a magnetic flux focusing type magnetic damper including a yoke disposed between the adjacent permanent magnets. The vibration absorbing mechanism is
A permanent magnet connected to one of the base frame and the upper frame and arranged at a predetermined interval; and a conductor slidable between the permanent magnets and connected to the other of the base frame or the upper frame. A linkage magnetic field type magnetic damper,
An oil damper comprising: a cylinder connected to one of the base frame or the upper frame; and a piston inserted in the cylinder so as to be reciprocable in the axial direction and connected to the other of the base frame or the upper frame. The anti-vibration stand for ambulances according to any one of claims 1 to 4 . A vibration absorption mechanism that mainly performs a vibration suppression function in the vertical direction and a vibration absorption mechanism that mainly performs a vibration suppression function in the front-rear direction by absorbing and converting to a single pendulum movement along the movement trajectory of the four-bar chain mechanism There compared to those provided separately from each other, the vibration transmissibility of the resonance point with respect to the input vibration is reduced by at least 40%, according to any one of claims 1 to 7 tension is continued, sustained easy configuration Anti-shake stand for ambulances.