JP4631495B2 - Anti-vibration bed - Google Patents

Description

  The present invention relates to an anti-vibration bed that supports, for example, a stretcher.

  Conventionally, an anti-vibration bed is provided in the rear room of an ambulance.

  This anti-vibration bed is configured to be able to support the transported stretcher in a mounted state, and the upper frame that supports the mounting portion of the stretcher is supported by air suspension at four corners. Thereby, it is comprised so that the transmission to the said stretcher of the vibration at the time of driving | running | working can be suppressed.

  However, in such a conventional anti-vibration bed, since the upper frame is supported by the air suspension, when a load is input, air is taken in and out of the air suspension and the stretcher on the upper frame is moved up and down. I was going to match.

  For this reason, it takes time to raise and lower the stretcher. In particular, when descending the stretcher, it is necessary to rely on exhaust from the air suspension, and the descending speed depends on the load.

  This invention is made | formed in view of such a conventional subject, and it aims at providing the anti-vibration bed which can control raising / lowering.

In order to solve the above-mentioned problem, in the vibration isolating bed according to claim 1 of the present invention, the upper frame constituting the placement portion side is supported by the lower frame constituting the floor side via a four-bar link so as to be movable up and down. A vibration isolation bed, wherein the four-bar link is provided with an upper link provided in the upper frame and extending in the front-rear direction, and an upper link side rotation provided on a front end side and a rear end side of the upper link. A pair of front and rear rotation links and a front rotation link for connecting the moving support point to the lower frame side rotation center point provided on the front end side and the rear end side on the lower frame side, and front portions thereof constituted by a connecting link for connecting between the pivot link and the rear pivot link, provided a coil spring that extends in a spiral shape along the vertical direction on the front end portion of the vibration isolation bed, the lower end of the coil spring The lower cover is supported by the cover and is rotatably supported on the lower frame side at the tilt center so that the coil spring can be tilted in the front-rear direction around the tilt center, and the coil spring is tilted A guide that guides the upper end portion of the coil spring in the front-rear direction when tilting in the front-rear direction around the center is the rotation between the lower frame side rotation center point and the upper link side rotation support point in the front-rear direction. Provided at the site of the dynamic link,
The guide is formed in an arc shape with the tilt center as a center, and the guide is disposed along the front-rear direction on the side of the coil spring to change the tilt angle of the coil spring with respect to the vertical direction. Was provided.

That is, the upper frame that constitutes the placement portion side is supported by the lower frame via the four-bar link so as to be movable up and down, and is provided between the rotating link and the lower frame that constitute the four-bar link. A force for moving the upper frame upward is applied by the coil spring. For this reason, the direct transmission of the vibration input from the lower frame to the upper frame is suppressed, and an anti-vibration effect can be obtained.

When the load is input to the upper frame, the upper frame is lowered according to the magnitude of the load. At this time, the support point of the coil spring to the rotation link is configured to be movable, and by moving the support point, from the rotation center point of the rotation link to the support point of the spring. The lever ratio determined by the separation distance can be changed.

Therefore, by changing this lever ratio, the amount of deformation of the spring with respect to the amount of lowering of the upper frame is changed. Thereby, the reaction force from the coil spring with respect to the lowering amount of the upper frame is varied.

Moreover, even when changing the supporting point of said coil spring by changing the inclination angle of the coil spring to the pivot link, the influence of the spring length is eliminated.

As described above, in the vibration-proof bed according to the first aspect of the present invention, the support point where the upper end portion of the coil spring engages with the guide moves along the guide , whereby the lowering amount of the upper frame is reduced. the reaction force from the Koirusu pulling can be variable.

Therefore, when the upper frame with the load input is lowered, by which the support point guide and the upper end portion of the coil spring is engaged to move to increase the reaction force from the Koirusu pulling, the The upper frame can be raised.

  Therefore, compared with the conventional case where the upper frame has to be moved up and down by adjusting the flow of air into and out of the air suspension that supports the upper frame, the lifting speed of the upper frame is changed, the lifting amount is changed, etc. Elevation control can be performed.

The guide In the anti-vibration bed claim 1, a coil spring for imparting an urging force to the upper frame is tilted rotatably supported by the lower frame, for supporting movably the coil spring, the It is formed in an arc shape with the tilt center as the center.

  At this time, the influence on the spring length according to the tilt of the spring can be eliminated. Thereby, a stable spring force can be obtained in the entire region where the spring is tilted.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a view showing an anti-vibration bed 1 according to the present embodiment. The anti-vibration bed 1 is provided in a rear chamber of an ambulance and can be supported in a state where a loaded stretcher is placed. It is configured.

  The anti-vibration bed 1 includes a lower frame 12 fixed to a floor 11, an upper frame 13 supported so as to be movable up and down with respect to the lower frame 12, and a buffer for supporting the upper frame 13 on the lower frame 12. As shown in FIG. 2, a placement portion 15 on which a stretcher is placed is provided on the upper frame 13.

  As shown in FIG. 1, the buffer mechanism 14 is configured around four-bar links 21 and 21 provided on the left side and the right side of the vibration-isolating bed 1. It has the same structure. The four-bar link 21 includes an upper link 22 formed by a side member of the upper frame 13, and a front portion rotatably supported by a front support portion 23 of the upper link 22 via a front bracket 24. A moving link 25, a rear rotating link 28 rotatably supported by a rear support portion 26 of the upper link 22 via a rear bracket 27, and a connecting link 29 connecting both the rotating links 28, 28. It consists of

As shown in FIG. 2, the rear rotation link 28 is formed in an L shape by a plate material, and a lower frame side rotation center point 31 (hereinafter simply referred to as “ rotation ”) is formed at a corner portion which is an intermediate portion. (Referred to as “moving center point 31”) . As shown in FIG. 1, a shaft portion 32 protrudes from the rotation center point 31, and the shaft portion 32 is attached to a bracket 34 erected on the lower frame 12 via a bearing 33. It is supported rotatably. The rear turning link 28 constituting the left four-link 21 and the rear turning link 28 constituting the right four-joint link 21 have short pieces 35 and 35 and long pieces 36 and 36 connected in series. Bars 37 and 37 are connected to each other, and rear pivot links 28 and 28 of both four-joint links 21 and 21 are configured to be interlocked.

A rear end portion of the connecting link 29 is rotatably supported on a free end portion of the rear rotating link 28 on the short piece 35 side, and a free end portion of the rear rotating link 28 on the long piece 36 side is supported. The bush portion 38 (the upper link side rotation center) of the rear bracket 27 is fixed.

As shown in FIG. 2, the front rotation link 25 is also formed of a plate material. A lower frame side rotation center point 41 (hereinafter simply referred to as “ (Described as “rotation center point 41”) . As shown in FIG. 1, a shaft portion 42 protrudes from the rotation center point 41, and the shaft portion 42 is attached to a bracket 44 erected on the lower frame 12 via a bearing 43. It is supported rotatably. The front rotation link 25 that constitutes the four-joint link 21 on the left side and the front rotation link 25 that constitutes the four-joint link 21 on the right side are connected at the front end by a front cross member 45, and thereafter The ends are connected by a rear cross member 46. Thereby, the front part rotation links 25 and 25 of both the four-bar links 21 and 21 are configured to be interlocked by being connected by the cross members 45 and 46.

As shown in FIG. 2, the front rotation link 25 is provided with a downward extension 51 extending downward from the rotation center point 41, and the downward extension 51 A front end portion of the connecting link 29 is rotatably supported on the free end portion. As shown in FIG. 1, the front end portion of the front rotation link 25 is fixed with a bush portion 52 (upper link side rotation support point) of the front bracket 24.

  The front rotating link 25 is provided with a front extending portion 61 extending forward, and the front cross member 45 is fixed to the front extending portion 61 as shown in FIG. Has been. The front cross member 45 is configured to move up and down within a stopper bracket 62 provided on the lower frame 12, and an upper stopper 63 is provided on the top surface of the stopper bracket 62. The bottom bracket 64 to which the stopper bracket 62 is fixed is provided with a lower stopper 65, and the front rotation link 25 is connected to the front stopper 63 or the lower stopper 65. By abutting, the moving range is restricted.

  A spring support bracket 71 is erected at the center of the front rotation links 25, 25, and a lower cover 72 is pivotally supported on the spring support bracket 71. A coil spring 73 is held on the lower cover 72, and the coil spring 73 can be tilted back and forth about a tilt center 74 that pivotally supports the lower cover 72. An upper cover 75 is provided at the upper end of the coil spring 73, and center cross members 76 and 76 extend from both sides of the upper cover 75 as shown in FIG.

  As shown in FIG. 3, a plate-like guide 81 that movably supports the upper end of the coil spring 73 is provided on the inner side surface of the front rotation link 25, and the guide 81 is The coil spring 73 is formed in an arc shape centered on the tilt center 74. An upper roller 82 provided on the end surface of the center cross member 76 is configured to roll on the upper surface of the guide 81, and a lower roller provided on the end surface of the center cross member 76 on the lower surface of the guide 81. 83 and 83 are configured to roll.

  Thus, the upper end portion of the coil spring 73 is supported by the front rotation link 25 via the rollers 82, 83, 83 and the guide 81, and the rotation of the front rotation link 25 is performed. The coil spring 73 is disposed between a portion on the upper frame 13 side from the moving center point 41 and the lower frame 12, and the urging force from the coil spring 73 is a force that moves the upper frame 13 upward. It is comprised so that it may be given as. Further, when the rollers 82, 83, 83 roll along the guide 81, the support point 85 to the front rotation link 25 by the coil spring 73 is configured to move back and forth. The lever ratio determined by the separation distance from the pivot center point 41 of the front pivot link 25 to the support point 85 can be changed.

As shown in FIG. 1, a drive unit support member 91 is swingably supported on the upper part of the rear cross member 46, and the drive unit support member 91. Is provided with a drive unit 92 for changing the tilt angle of the coil spring 73 with respect to the vertical direction . The drive unit 92 is configured around a drive motor 93 provided on the drive unit support member 91, and a ball screw 95, 95 is connected to a rotation shaft of the drive motor 93 via a gear box 94, 94. It is connected. As shown in FIG. 3, the ball screw 95 extends forward. The ball screw 95 is screwed into screw portions 96 and 96 supported by the center cross member 76 in a swingable manner. ing.

  Thus, when the drive motor 93 is operated and the coil spring 73 is tilted forward along the guide 81, the lever ratio can be increased. When tilted backward along 81, the lever ratio can be reduced.

  A baffle plate 101 extending downward is provided on the front wall surface of the front cross member 45, and a height sensor for detecting the height position of the baffle plate 101 is provided on the stopper bracket 62. (Not shown).

  Thereby, when the stretcher is placed on the placement unit 15 and the upper frame 13 is lowered by the weight of the patient carried by the stretcher, by operating an auto level switch (not shown), By controlling the drive motor 93 based on an input from a height sensor and changing the lever ratio, the tilt angle of the front rotation link 25 is always controlled to be the same angle. The height position of the upper frame 13 supported by the front rotation link 25 is always maintained at the same height.

  And the recessed part 111 is provided in the front-end part of the said mounting part 15, The wheel stopper which regulates the front and upward movement of the axial part 113 of the wheel 112 of a stretcher at the front-end | tip of this recessed part 111. 114 is provided. A wheel sensor for detecting the wheel 112 is attached to the wheel stopper 114 (not shown). Thus, when the wheel sensor does not detect the wheel 112, the rear end of the mounting portion 15 is lowered before the stretcher is inserted.

  In the present embodiment according to the above configuration, the upper frame 13 provided with the mounting portion 15 is supported by the lower frame 12 via the four-bar links 21 and 21 constituting the buffer mechanism 14 so as to be movable up and down. A force can be applied to the upper frame 13 in the upward direction by a coil spring 73 provided between the front rotating link 25 and the lower frame 12 constituting the four-bar link 21. For this reason, the direct transmission of the vibration input from the lower frame 12 to the upper frame 13 can be suppressed, and an anti-vibration effect can be obtained.

  Next, the support point 85 of the coil spring 73 to the front rotation link 25 is configured to be movable, and the rotation center of the front rotation link 25 is moved by moving the support point 85. The lever ratio determined by the separation distance from the point 41 to the support point 85 of the coil spring 73 can be changed. Therefore, by changing this lever ratio, the deformation amount of the coil spring 73 with respect to the lowering amount of the upper frame 13 can be changed, and the reaction force from the coil spring 73 with respect to the lowering amount of the upper frame 13 Can be varied.

  For this reason, when the upper frame 13 descends with load input, the upper frame 13 can be raised by changing the lever ratio and increasing the reaction force from the coil spring 73. .

  Therefore, compared with the conventional case where the upper frame has to be moved up and down by adjusting the flow of air to and from the air suspension that supports the upper frame, the lifting speed of the upper frame 13 is changed, the lifting amount is changed, and the like. Can be controlled.

  In addition, the coil spring 73 that applies a biasing force to the upper frame 13 is supported by the lower frame 12 so as to be tiltable, and a guide 81 that supports a support point 85 of the coil spring 73 is movable. The coil spring 73 is formed in an arc shape centered on the tilt center 74.

  Therefore, by rotating the ball screw 95 by the drive motor 94 of the drive unit 92, the tilt angle of the coil spring 73 is changed to change the support point 85 of the coil spring 73 to the precursor rotation link 25. Accordingly, the lever ratio determined by the separation distance from the rotation center point 41 of the front rotation link 25 to the support point 85 of the coil spring 73 can be changed.

  At this time, the guide 81 is formed in an arc shape with the tilt center 74 of the coil spring 73 as the center. For this reason, the coil spring 73 can be tilted without expanding or contracting the coil spring 73. Thereby, a stable spring force can be obtained in the entire region where the coil spring 73 is tilted.

It is a disassembled perspective view which shows one embodiment of this invention. It is sectional drawing of the same embodiment. It is sectional drawing which shows the principal part of the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Anti-vibration bed 12 Lower frame 13 Upper frame 15 Mounting part 21 Four-bar link 25 Front part rotation link 28 Rear part rotation link 29 Connection link 41 Rotation center point 73 Coil spring 74 Inclination center 81 Guide 85 Support point 92 Drive Part

Claims (1)

The upper frame that constitutes the placement unit side is a vibration isolation bed that is supported by the lower frame that constitutes the floor side via a four-bar link so as to be movable up and down,
The four-bar link includes an upper link provided in the upper frame and extending in the front-rear direction, upper link side rotation support points provided on the front end side and the rear end side of the upper link, and a lower frame side A pair of front and rear pivot links for connecting the lower frame side pivot center provided on the front end side and the rear end side, respectively, and the front pivot link and the rear pivot link. And connecting links to connect
A coil spring that extends in a spiral shape along the vertical direction is provided at the front end of the vibration-proof bed, and the lower end of the coil spring is held by the lower cover, and the lower cover is rotatable to the lower frame side at the tilt center. By being supported, the coil spring is configured to be tiltable in the front-rear direction around the tilt center,
A guide that guides the upper end of the coil spring in the front-rear direction when the coil spring is tilted in the front-rear direction about the tilt center, and a front-rear position between the lower frame side rotation center point and the upper link side rotation support point Provided in the part of the rotation link between the directions,
A drive unit configured to change the tilt angle of the spring with respect to the vertical direction by forming the guide in an arc shape centered on the tilt center and arranging the guide along a front-rear direction on a side of the coil spring ; Anti-vibration bed characterized by the provision.

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