JP2009248798A - Suspension unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a suspension unit achieving weight saving and cost reduction by using only one magnetic spring unit. <P>SOLUTION: This suspension unit having a lower frame 2 and an upper frame vertically movably attached to the lower frame 2 through a link mechanism is provided with: a plurality of torsion bars and the magnetic spring unit 94 elastically supporting the upper frame with respect to the lower frame 2; and a static characteristic increasing mechanism increasing static characteristics around the equilibrium position of the magnetic spring unit 94. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a suspension unit having a magnetic spring unit.

  In recent years, various types of suspension units using magnetic springs have been proposed as permanent magnets having high holding force and high residual magnetic flux density have been put into practical use.

  Some conventional suspension units that use magnetic springs are a combination of a magnetic spring unit with a negative spring constant and a metal spring with a positive spring constant. In some cases, the stroke of the magnetic spring unit is made smaller than that of the suspension unit, thereby ensuring a large stroke and miniaturization (see, for example, Patent Document 1).

JP 2004-353770 A

  However, in the suspension unit described in Patent Document 1, two magnetic spring units are arranged in parallel and used in order to make the operation amount of the magnetic spring unit smaller than the operation amount of the metal spring. The weight was increasing.

  The present invention has been made in view of the above-described problems of the prior art, and provides a suspension unit that achieves weight reduction and cost reduction by using only one magnetic spring unit. It is an object.

  To achieve the above object, the invention according to claim 1 of the present invention is a suspension unit comprising a lower frame and an upper frame attached to the lower frame through a link mechanism so as to be movable up and down. A plurality of torsion bars that elastically support the upper frame with respect to the lower frame and a magnetic spring unit, and a static characteristic expansion mechanism that expands a static characteristic around an equilibrium point of the magnetic spring unit. It is characterized by that.

  According to a second aspect of the present invention, the magnetic spring unit includes a fixed magnet unit fixed to the lower frame and a movable magnet unit movable up and down with respect to the fixed magnet unit. The magnifying mechanism is connected to the movable magnet unit.

  Furthermore, the invention according to claim 3 is characterized in that the static characteristic enlarging mechanism has a lever having one end connected to the movable magnet unit and a gear connected to the other end of the lever. A rotation shaft that is rotatably attached, and a sector gear having one end fixed to the rotation shaft are provided, and the gear is engaged with a tooth portion formed at the other end of the sector gear. The effective lever length of the lever is set large.

  According to a fourth aspect of the present invention, there is provided a swinging member that is swingably attached to the lower frame, the movable magnet unit is attached to the swinging member, and the lever of the lever is interposed via the swinging member. One end is connected to the movable magnet unit.

  According to the present invention, a plurality of torsion bars that elastically support the upper frame with respect to the lower frame and the magnetic spring unit are provided, and a static characteristic expansion mechanism that expands the static characteristics around the equilibrium point of the magnetic spring unit is provided. Therefore, when the enlargement ratio is set to 2, for example, only one magnetic spring unit, which is conventionally required, is required, and weight reduction and cost reduction can be achieved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 and 2 show a suspension unit S according to the present invention. The suspension unit S is used, for example, as a vehicle seat suspension, and includes a substantially rectangular lower frame 2 attached to a vehicle body floor, and a substantially rectangular upper frame 4 attached to the lower frame 2 so as to be movable up and down. The vehicle seat (not shown) is placed on and attached to the upper frame 4.

  The lower frame 2 includes a pair of left and right lower side frames 6 extending in the front-rear direction, a cylindrical front connecting shaft 8 having both ends joined to the front ends of the pair of lower side frames 6, and a pair of lower side frames. 6 and a cylindrical rear connecting shaft 10 having both end portions joined to the rear end portion. Further, a cylindrical front rotating shaft 12 extending in parallel with the front connecting shaft 8 is provided behind the front connecting shaft 8, and both ends of the front rotating shaft 12 are connected to the pair of lower side frames 6. The front end is pivotally attached. Further, a cylindrical rear rotating shaft 14 extending in parallel with the rear connecting shaft 10 is provided in front of the rear connecting shaft 10, and both ends of the rear rotating shaft 14 are connected to the rear end portions of the pair of lower side frames 6. It is pivotally attached.

  On the other hand, the upper frame 4 includes a pair of left and right upper side frames 16 extending in the front-rear direction, a cylindrical front connecting shaft 18 having both ends joined to the front end portions of the pair of upper side frames 16, and a pair of upper portions. A cylindrical rear connecting shaft 20 having both ends joined to the rear end of the side frame 16 is configured. A cylindrical front rotating shaft 22 extending in parallel with the front connecting shaft 18 is provided behind the front connecting shaft 18, and both ends of the front rotating shaft 22 are connected to the pair of upper side frames 16. The front end is pivotally attached. Further, a cylindrical rear rotating shaft 24 extending in parallel with the rear connecting shaft 20 is provided in front of the rear connecting shaft 20, and both ends of the rear rotating shaft 24 are connected to the rear end portions of the pair of upper side frames 16. It is pivotally attached.

  Further, the upper frame 4 is attached to the lower frame 2 via a left and right link mechanism so as to be movable up and down.

  The link mechanism includes a front link 26 whose lower end is joined to the front rotary shaft 12 of the lower frame 2, a rear link 28 whose lower end is joined to the rear rotary shaft 14 of the lower frame 2, and a front link 26. A link link 30 in which both end portions (front and rear end portions) are rotatably connected to the upper end portion of the rear link 28 and the upper end portion of the rear link 28, and a front portion in which the upper end portion is joined to the front rotary shaft 22 of the upper frame 4. A link 32 and a rear link 34 having an upper end joined to the rear rotating shaft 24 of the lower upper frame 4 are provided.

  An intermediate portion of the front link 32 is rotatably connected to an upper end portion of the front link 26 positioned below the front link 32, and a lower end portion of the front link 32 is freely rotatable to a lower end portion of the intermediate link 36. The upper end of the intermediate link 36 is pivotally attached to the upper end of a bracket 37 whose lower end is joined to the lower side frame 6. Further, the lower end portion of the rear link 34 is rotatably connected to the upper end portion of the rear link 28 positioned below the rear link 34.

  A torsion bar 38 is loosely inserted inside the cylindrical front rotary shaft 12 of the lower frame 2, and one end of the torsion bar 38 is fixed to the front rotary shaft 12 and a pair of lower side frames 6. The other end of the torsion bar 38 is fixed to the other of the pair of lower side frames 6 via a fixing member 42. Similarly, a torsion bar 44 is loosely inserted inside the cylindrical rear rotating shaft 14 of the lower frame 2, and one end of the torsion bar 44 is fixed to the rear rotating shaft 14 and a pair of lower side frames. The other end of the torsion bar 44 is fixed to the other of the pair of lower side frames 6 via a fixing member 48.

  A torsion bar (not shown) is loosely inserted inside the cylindrical front rotary shaft 22 of the upper frame 4, and one end of the torsion bar is fixed to one of the pair of upper side frames 16. The other end of the torsion bar is fixed to the front rotary shaft 22 and is rotatably attached to a holding member 54 fixed to the other of the pair of upper side frames 16. Similarly, a torsion bar 56 is loosely inserted inside the cylindrical rear rotating shaft 24 of the upper frame 4, and one end of the torsion bar 56 is connected to one of the pair of upper side frames 16 via a fixing member 58. The other end of the torsion bar 56 is fixed to the rear rotating shaft 24 and is rotatably attached to a holding member 60 fixed to the other of the pair of upper side frames 16.

  When assembling the suspension unit S, the torsion bar 38 is twisted through the front link 26 by twisting the opposite end of the torsion bar 38 in the direction of arrow A in FIG. The lifting force of the upper frame 4 is generated. The same applies to the torsion bar 44. In addition, the torsion bar loosely inserted into the front rotating shaft 22 is twisted in the direction of arrow B in FIG. The lifting force of the upper frame 4 is generated via 32. The same applies to the torsion bar 56.

  Furthermore, a U-shaped bracket 62 in front view is joined to the front connecting shaft 18 of the upper frame 4, and a rotating shaft 64 is attached to the lower end portion of the U-shaped bracket 62. Lower end portions of two levers 66 extending in parallel are fixed to the rotating shaft 64, and both end portions of the load adjusting shaft 68 are rotatably attached to upper end portions of the two levers 66. The load adjusting shaft 68 is formed with a female screw, and this female screw is screwed with a male screw formed on the operation shaft 70. A front end portion of the operation shaft 70 is a knob attached to the U-shaped bracket 62. The opening of the mounting plate 71 is penetrated. A knob 72 is rotatably attached to the knob mounting plate 71, and the knob 72 is fixed to the front end portion of the operation shaft 70.

  A proximal end portion of the pointer 74 and a lower end portion of the lever 76 are adjacently fixed to the outer end portion of the rotating shaft 64. A bracket 78 is fixed to one front end portion of the pair of upper side frames 16, and the tip end portion of the pointer 74 faces the load scale plate 80 formed at the front portion of the bracket 78.

  Further, one end of the connecting shaft 82 is attached to the upper end portion of the lever 76, the connecting shaft 82 is loosely inserted into the opening 78 a of the bracket 78, and the first connecting link is connected to the other end of the connecting shaft 82. The front end portion of 84 is connected. Further, the rear end portion of the first connection link 84 is connected to the front end portion of the second connection link 86, and the lower end portions of the two levers 88 and 90 that are spaced apart from each other rotate on the second connection link 86. It is attached freely. The upper end portion of the lever 88 is fixed to the end portion of the torsion bar fixed to the front rotating shaft 22, and the upper end portion of the lever 90 is similarly fixed to the end portion of the torsion bar 56 fixed to the rear rotating shaft 24. Has been.

  Further, a front end portion of a damper 92 is rotatably attached to the front rotating shaft 12, and a rear end portion of the damper 92 is rotatably attached to the rear rotating shaft 24.

  Further, a magnetic spring unit 94 that elastically supports the upper frame 4 is provided adjacent to the damper 92, and the magnetic spring unit 94 is movable up and down with respect to the fixed magnet unit 96. A movable magnet unit 98 is included.

  As shown in FIG. 3, the fixed magnet unit 96 has an upper magnet pair 96a and a lower magnet pair 96b facing the same magnetic pole at a predetermined interval, and upper and lower permanent magnets arranged on the same side. Are joined to each other so that different magnetic poles face in the same direction (inward or outward). On the other hand, the movable magnet unit 98 has a permanent magnet inserted into the internal space of the fixed magnet unit 96, and the permanent magnet is formed with magnetic poles in the vertical direction, and the upper magnetic pole is the upper magnet pair of the fixed magnet unit 96. The same magnetic pole as 96a faces, while the lower magnetic pole is set so that the same magnetic pole as the lower magnet pair 96b of the fixed magnet unit 96 faces. As shown in FIG. 3B, a predetermined clearance is provided between the fixed magnet unit 96 and the movable magnet unit 98.

  As shown in FIGS. 4 to 9, the fixed magnet unit 96 is attached to the inner surface of the side wall of the metal frame 100, and the metal frame 100 is fixed to the attachment plate 102 attached to the lower frame 2. Yes. On the other hand, the movable magnet unit 98 inserted into the internal space of the fixed magnet unit 96 is connected to the front end portion of the movable magnet unit mounting swing member 106 via the mounting members 104 provided at both ends (front and rear end portions). Each is fixed near the rear end. Further, the rear end portion of the movable magnet unit mounting swing member 106 is swingably mounted on a bracket 108 joined to the rear connecting shaft 10 of the lower frame 2.

  The movable magnet unit mounting swing member 106 has a U-shaped cross section in the width direction, and a long hole 106a that is long in the front-rear direction is formed in the vertical wall surface. A roller 112 rotatably attached to the first shaft 110 is loosely inserted into the long hole 106 a, and the first shaft 110 is fixed to one end of the lever 114. A second shaft 116 is fixed to the other end of the lever 114 so as to protrude in a direction opposite to the first shaft 110, and the second shaft 116 is attached to a bracket 118 fixed to the mounting plate 102. A gear 120 is attached to a tip end portion thereof.

  The gear 120 meshes with a tooth portion 122 a formed at the rear end portion of the sector gear 122, and the front end portion of the sector gear 122 is fixed to the front rotary shaft 12 of the lower frame 2.

  The ratio (lever ratio) between the pitch circle radius of the gear 120 and the distance between the centers of the first shaft 110 and the second shaft 116 is set to, for example, 1: 2.

  Further, a metal belt holding member 124 is attached to the rear connecting shaft 10 of the lower frame 2, and an intermediate portion of the stroke regulating belt 126 held at both ends by the belt holding member 124 is an upper frame 4. It is wound around the rear connecting shaft 20.

The operation of the suspension unit S according to the present invention having the above configuration will be described below.
When sitting on the seat placed on the upper frame 4, the upper frame 4 is lowered according to the load (weight of the seated person). When the upper frame 4 is lowered, four torsion bars 38, 44, and 56 (one is not shown) are twisted, and a lifting force of the upper frame 4 corresponding to the amount of lowering of the upper frame 4 is generated. The magnetic spring unit 94 is a negative spring until a load of a predetermined value or more is applied to the upper frame 4 and the upper frame 4 is lowered by a predetermined value (for example, 20 mm from the equilibrium point of the magnetic spring unit 94) or more. When the upper frame 4 is further lowered from the predetermined value, a positive spring constant is indicated, and thereafter the lifting force of the upper frame 4 corresponding to the amount of lowering is gradually generated.

  The torsion bars 38, 44, and 56 have a linear spring constant regardless of the displacement (stroke), whereas the magnetic spring unit 94 has a predetermined range (for example, an equilibrium position shown in FIG. 3B). A negative spring constant is indicated for a displacement of about ± 20 mm from the center, and a positive spring constant is indicated outside this range.

  In addition, if the magnetic spring unit 94 in the seated state is not set to the equilibrium position regardless of the load, the original cushion performance of the suspension unit S is impaired, so it is necessary to adjust the load (weight). The adjustment will be described.

  The knob 72 is attached to the front end portion of the operation shaft 70. Since the male screw formed on the operation shaft 70 and the female screw formed on the load adjustment shaft 68 are screwed together, by rotating the knob 72, The interval between the knob 72 and the load adjustment shaft 68 changes. When the load adjustment shaft 68 approaches the knob 72 by the rotation of the knob 72, the lever 66 is inclined forward and the rotation shaft 64 rotates in the direction of arrow C in FIG. As a result, the lever 76 is inclined forward, and the first and second connecting links 84 and 86 are moved forward, and the torsion bar accommodated in the front rotating shaft 22 of the upper frame 4 via the lever 88 is an arrow. While rotating in the B direction, the torsion bar 56 accommodated in the rear rotating shaft 24 of the upper frame 4 rotates in the same direction via the lever 90. The rotation of the two torsion bars (one of which is 56) increases the amount of torsion of the torsion bar 56 and increases the lifting force of the upper frame 4. Therefore, the seat is seated from the assumed average load at the time of the design of the suspension unit S. The above operation is performed when the person is heavy.

  On the other hand, when the weight of the seated person is lighter than the assumed average load, the amount of twist of the torsion bar 56 is reduced by rotating the knob 72 in the direction opposite to the above operation, and the lifting force of the upper frame 4 is reduced. To do.

  This load adjustment can be performed while observing the scale of the load scale plate 80 indicated by the pointer 74, and can be adjusted, for example, in a load range of 50 to 130 kg.

  When vibration is input to a body frame (not shown), the vibration is absorbed by the elastic force of the torsion bars 38, 44, 56 and the magnetic spring unit 94. In the case of the magnetic spring unit 94, the vibration from the body frame is absorbed. The vibration is input to the magnetic spring unit 94 through the meshing of the sector gear 122 and the gear 120, the lever 114, the movable magnet unit mounting swing member 106, and the like.

  As described above, the ratio between the pitch circle radius of the gear 120 and the distance between the centers of the first shaft 110 and the second shaft 116 (effective lever length of the lever 114) is set to, for example, 1: 2. Therefore, of the loads applied to the upper frame 4, except for the loads supported by the four torsion bars 38, 44, 56, the magnetic spring unit 94 supports half the load applied to the gear 120 via the sector gear 122. You can do it. That is, the sector gear 122, the gear 120, the lever 114, and the like constitute a static characteristic enlarging mechanism of the magnetic spring unit 94. When the lever ratio is 1: 2, the enlargement ratio is doubled, and the lever ratio is increased. By appropriately setting (the effective lever length of the lever 114 is set larger than the pitch circle radius of the gear 120), an arbitrary enlargement ratio can be obtained.

  When vibration is input to the body frame (not shown), the damper 92 is actuated to attenuate the vibration. For example, when the impact force is input and the lower frame 2 approaches the upper frame 4 abnormally, the rear connection The shaft 20 abuts against a cushion member (not shown) and absorbs an impact (bottom butt). Further, when the lower frame 2 is abnormally separated from the upper frame 4, tension is applied to the stroke regulating belt 126, and the stroke of the upper frame 4 with respect to the lower frame 2 is restricted.

  The above embodiment has been described by taking a seat suspension to which a vehicle seat is attached as an example, but the present invention is not limited to the seat suspension, and a device other than the vehicle seat is placed to dampen vibrations from the outside. It is also used as a damping unit that attenuates.

  Since the suspension unit according to the present invention can achieve weight reduction and cost reduction by using only one magnetic spring unit, it is useful as a suspension unit for a vehicle seat or the like that requires weight reduction.

1 is a perspective view of a suspension unit according to the present invention. It is a disassembled perspective view of the suspension unit of FIG. The schematic structure of the magnetic spring unit provided in the suspension unit of FIG. 1 is shown, (a) is a perspective view, (b) is a front view. FIG. 2 is a partial perspective view of the suspension unit of FIG. 1. It is another partial perspective view of the suspension unit of FIG. FIG. 2 is a partially exploded perspective view of the suspension unit of FIG. 1. FIG. 2 is a plan view with a part of the suspension unit of FIG. 1 removed. It is a side view of the static characteristic expansion mechanism which expands the static characteristic of a magnetic spring unit. It is a principal part side view of the static characteristic expansion mechanism of FIG.

Explanation of symbols

2 Lower frame, 4 Upper frame, 6 Lower side frame,
8 front connecting shaft, 10 rear connecting shaft, 12 front rotating shaft, 14 rear rotating shaft,
16 upper side frame, 18 front connecting shaft, 20 rear connecting shaft,
22 front rotating shaft, 24 rear rotating shaft, 26 front link, 28 rear link,
30 connecting links, 32 front links, 34 rear links, 36 intermediate links,
37 bracket, 38 torsion bar, 40 holding member, 42 fixing member,
44 torsion bar, 46 holding member, 48 fixing member, 52 fixing member,
54 holding members, 56 torsion bars, 58 fixing members, 60 holding members,
62 U-shaped bracket, 64 rotating shaft, 66 lever, 68 load adjusting shaft,
70 operation shaft, 71 knob mounting plate, 72 knob, 74 pointer,
76 lever, 78 bracket, 80 load scale plate, 82 connecting shaft,
84 first connecting link, 86 second connecting link, 88,90 lever,
92 damper, 94 magnetic spring unit, 96 fixed magnet unit,
98 movable magnet unit, 100 metal frame, 102 mounting plate,
104 mounting member, 106 swinging member for moving magnet unit mounting, 106a long hole,
108 brackets, 110 first shaft, 112 rollers, 114 levers,
116 second shaft, 118 bracket, 120 gear, 122 sector gear,
122a tooth portion, 124 belt holding member, 126 stroke regulating belt,
S Suspension unit.

Claims (4)

A suspension unit comprising a lower frame and an upper frame attached to the lower frame via a link mechanism so as to be movable up and down,
A plurality of torsion bars that elastically support the upper frame with respect to the lower frame and a magnetic spring unit are provided, and a static characteristic enlarging mechanism that expands the static characteristics around the equilibrium point of the magnetic spring unit is provided. Suspension unit. The magnetic spring unit is composed of a fixed magnet unit fixed to the lower frame and a movable magnet unit movable up and down with respect to the fixed magnet unit, and the static characteristic expansion mechanism is connected to the movable magnet unit. The suspension unit according to claim 1. The static characteristic enlarging mechanism has a lever having one end connected to the movable magnet unit and a gear connected to the other end of the lever, and a rotating shaft rotatably attached to the lower frame; A sector gear having one end fixed to the rotating shaft is provided, the gear is engaged with a tooth portion formed at the other end of the sector gear, and the effective lever length of the lever is set larger than the pitch circle radius of the gear. The suspension unit according to claim 2. A swing member attached to the lower frame so as to be swingable is provided, the movable magnet unit is attached to the swing member, and one end of the lever is connected to the movable magnet unit via the swing member. The suspension unit according to claim 2 or 3, characterized in that

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