JP2019048489A - Suspension mechanism and seat structure - Google Patents

Abstract

To enhance vibration absorption property or impact shock absorption property due to impact resistance vibration further in comparison with conventional property.SOLUTION: A suspension mechanism 1A has a structure in which suspension parts 100, 300 with spring type damper comprising spring mechanisms 120, 320 and dampers 130, 330 are vertically stacked in the plural. Therefore, it is configured as a system in which the spring mechanisms 120, 320 are vertically connected in series, and the suspension parts with spring type damper can lower natural frequency in comparison with a single layer type system and can contribute to a positioning resonance point on low-frequency side. In addition, it is easy to cause phase difference by individual movement of each of the suspension parts 100, 300 with spring type damper accompanied by input vibration difference, and it can restrain vibration transmissibility of the resonance point efficiently.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a suspension mechanism suitable for supporting a seat of a vehicle, and to a seat structure provided with the suspension mechanism.

  Patent Documents 1 and 2 disclose a seat suspension in which an upper frame provided so as to be vertically movable with respect to a lower frame is elastically supported by a magnetic spring and a torsion bar. The characteristic that the restoring force in the same direction as the acting direction of the restoring force of the torsion bar increases with the increase of the displacement amount is the "positive spring characteristic (the spring constant at that time is" positive spring constant ")". If the characteristic in which the restoring force in the same direction as the acting direction of the restoring force decreases regardless of the increase in the displacement amount is “negative spring characteristic (the spring constant at that time is“ negative spring constant ”)”, the predetermined displacement By using the fact that the magnetic spring exhibits negative spring characteristics in the range, the load value for the displacement of the entire system in which both are superimposed in a predetermined displacement range is substantially constant by the combination with the torsion bar exhibiting positive spring characteristics. There is disclosed a suspension having the characteristics of a constant load area (an area in which a spring constant is substantially zero) which is

JP, 2010-179719, A JP, 2010-179720, A

  The suspension of Patent Documents 1 and 2 has a constant load region in which the spring constant obtained by superimposing both is approximately zero by the configuration using the above magnetic spring and the torsion bar for normal vibration of a predetermined frequency and amplitude. These vibrations are absorbed, and energy due to impact vibration is absorbed by a damper that is bridged between the upper and lower frames.

However, in the case of the driver's seat of an earthworking machine, there are many opportunities to travel on a road surface with large irregularities, so it is necessary to emphasize measures against impact vibration with greater amplitude and JIS A 8304 based on ISO 7096: 2000: Excitation is made according to the input spectrum class (ISO 10326-1) defined by the type of machine specified in 2001 "earthwork machine-operator seat vibration evaluation test", and each SEAT value (seat amplitude effective value The transmission factor (Seat Effective Amplitude Transmissibility factor) needs to be satisfied. For example, in the case of "a crawler type tractor dozer ザ 50,000 kg, a crawler loader and a crawler type irregular terrain vehicle", input spectrum class: EM6 (a dominant frequency of 7.6 Hz, a maximum value of PSD 0.34 (m / s ² ) SEAT value: Exceeding 0.7, it is necessary to excite by ² / Hz), and in the case of "compact loader", input spectrum class: EM8 (superior frequency 3.3 Hz, PSD maximum value 0.4 (m It is necessary to excite by / s ² ) ² / Hz) and to satisfy the SEAT value: less than 0.8. In addition, the vibration transmissibility at the resonance frequency in the vertical axis direction is required to be 1.5 or less for EM6 and 2.0 or less for EM8.

  However, for example, the vibration transmission rate of 1.5 or less required by EM6 can be achieved by adopting a structure that places importance on damping, but vibration at a high frequency band of 7.6 Hz of EM6's dominant frequency In order to lower the transmission rate, it is necessary to make the structure more resilient and to generate an antiphase. Similarly, the vibration transmission rate of 2.0 or less required by EM8 can be achieved by a structure with strong springiness originally, but the vibration transmission rate in the low frequency band of dominant frequency 3.3 Hz In order to lower it, it is also necessary to make the attenuation strong.

  As described above, in order to satisfy the SEAT value corresponding to the input spectrum class required by the earthworking machine and the standard of the vibration transmission rate, it is necessary to sufficiently consider the balance between the spring property and the damping property. However, it was difficult to achieve this with a single degree of freedom suspension incorporating a spring and a damper.

  The present invention has been made in view of the above-mentioned points, and can exhibit vibration absorption characteristics and shock absorption characteristics capable of coping with various input vibrations, and in particular, a suspension mechanism suitable for satisfying a standard required for earthworking machines and It is an object of the present invention to provide a seat structure provided with the suspension mechanism.

  In order to solve the above problems, a suspension mechanism of the present invention is a suspension mechanism disposed between a vehicle body structure and a seat, and includes a pair of upper and lower frame portions that move up and down relatively through a link mechanism, and A plurality of spring-dampered suspension units including a spring mechanism resiliently urging a pair of upper and lower frame portions and a damper for attenuating a force when the pair of upper and lower frame portions move up and down relatively Attenuation characteristics or spring characteristics of the spring-dampered suspension part of a part of the plurality of stacked spring-dampered suspension parts, which are laminated and configured, and damping of a spring-dampered suspension part of another layer To create a phase difference in the movement of each spring-dampered suspension by making it different from the characteristics or spring characteristics As a load-deflection characteristic that is set and measured so as to be at a neutral position when supporting a load mass of 50 to 120 kg, and characterized in that the hysteresis loss at loading and unloading is 150 N or less Do.

It is preferable that the phase difference of the movement between the respective spring-dampered suspension parts is 120 degrees or more in a frequency band including a resonance point with a frequency of 2 Hz or less.
It is preferable that the dampers of the spring-dampered suspension part of the partial layer have a damping force different from that of the dampers of the spring-dampered suspension part of the other layer.

The spring mechanism of the spring-dampered suspension portion of at least one layer among the plurality of stacked spring-dampered suspension portions has a variation in load value less than or equal to a predetermined value within a predetermined displacement range in load-deflection characteristics. A constant load spring mechanism having a load characteristic is adopted, and the constant load spring mechanism includes the linear spring showing the linear characteristic, the fixed magnet, and the relative vertical movement of the pair of upper and lower frame parts. A movable magnet whose relative position with respect to a fixed magnet is displaced, and a magnetic spring exhibiting a non-linear characteristic in which a spring constant changes according to the relative position of the fixed magnet and the movable magnet; It is preferable that the load-deflection characteristic obtained by combining with the spring has a characteristic such that the change amount of the load value becomes a constant load equal to or less than a predetermined value in a predetermined displacement range.
When the constant load spring mechanism is not adopted, when having a suspension portion with a spring and a damper, the spring mechanism of the suspension portion with a spring and a damper is configured to adopt a linear spring mechanism in which load-deflection characteristics change linearly. Is preferred.

  The spring-dampered suspension portion is composed of two layers, and the spring-dampered suspension portion disposed in the lower layer is configured to have the constant load spring mechanism, and the spring-dampered suspension portion disposed in the upper layer Is preferably configured to have the linear spring mechanism.

The spring-dampered suspension part is composed of two layers, and both the spring-dampered suspension part disposed in the lower layer and the spring-dampered suspension part disposed in the upper layer have the constant load spring mechanism. It is preferable that it is a structure.
In this case, one of the constant loads of the constant load spring mechanism of the spring-damper suspension part disposed in the lower layer and the constant load spring mechanism of the spring-damper suspension part disposed in the upper layer The magnetic spring constituting the spring mechanism is provided such that the movable magnet thereof is displaced in a substantially horizontal direction along with the vertical movement of the frame portion, and the magnetic spring constituting the other constant load spring mechanism is It is preferable that the movable magnet is provided so as to be vertically displaced as the frame portion moves up and down.

The stacked structure of the spring-dampered suspension part disposed in the lower layer and the stacked structure of the spring-dampered suspension part disposed in the upper layer is a load value in the load-deflection characteristics by the two constant load spring mechanisms. It is preferable to have the characteristic of exerting the characteristic that the amount of change of the constant load is a predetermined load or less at two different displacement positions.
In the load-deflection characteristics, the two regions showing the constant load characteristic are provided with a wedge showing a change in load value between the two, and there is a load difference between the two, but the load difference Is preferably within the range of hysteresis loss in the two constant load regions.

The spring-dampered suspension portion of each layer is provided with an elastic force adjusting member for adjusting the elastic force of the linear spring employed in each of the constant load spring mechanism or each linear spring mechanism, and two elastic forces are provided. Preferably, the adjusting member functions as a lifter that adjusts the seating position of the seat occupant.
It is preferable that the linear spring employ | adopted as said constant load spring mechanism or said each linear spring mechanism is a torsion bar.
Further, the suspension mechanism of the present invention is suitable for supporting a sheet of an earthworking machine.

  Further, the seat structure of the present invention is a seat structure including the suspension mechanism and a seat supported by the suspension mechanism, wherein a vibration transmission rate at a resonance point is provided between the suspension mechanism and the seat cushion portion. A seat suspension unit for reducing the pressure is further interposed.

  The suspension mechanism according to the present invention has a structure in which a plurality of spring-dampered suspension sections including a spring mechanism and a damper are vertically stacked. Therefore, the spring mechanism is a system connected in series in the vertical direction, and the natural frequency can be lowered compared to a single-layer system in which the suspension unit with spring and damper has a single layer, and the resonance point is lower. It can contribute to the frequency side. Thereby, the vibration transmission rate in the frequency band higher than the resonance point can be efficiently reduced. In addition, the hysteresis loss is set to a small value of 150 N or less as the static load characteristic of the whole of the stacked spring-dampered suspension portion. As a result, the dynamic spring constant becomes smaller, causing the resonance point to appear in a lower frequency band, and having a characteristic that damping due to friction or the like is relatively small. Therefore, it is easy to produce the phase difference by the separate motion of each suspension part with a spring and a damper accompanying the input vibration difference, and can suppress the vibrational transmission rate of a resonance point efficiently. In particular, in the present invention, the phase difference in the frequency band of 2 Hz or less including the resonance point is preferably 120 degrees or more, more preferably in the opposite phase (phase difference 180 degrees), whereby Vibration transmission rate can be suppressed lower.

  Further, the damping characteristics or the spring characteristics of the spring-dampered suspension part of each layer can be variously adjusted by the damping force of the used damper or the spring force of the spring mechanism. Therefore, the suspension mechanism of the present invention, in which a plurality of them are stacked, can exhibit vibration absorption characteristics and shock absorption characteristics capable of coping with various input vibrations by adjusting various combinations of dampers and spring mechanisms used. . In particular, it is possible to have a structure corresponding to various input spectrum classes required by the earthworking machine. In addition, it is possible to satisfy the criteria required for different types of input spectrum classes with one suspension mechanism by selecting the number of stacked layers and the type of damper or spring mechanism to be used.

  In addition, it is preferable that a plurality of constant load spring mechanisms having characteristics such that the amount of change in the load value in the static load characteristics is a predetermined load or less as the suspension portion with springs and dampers be vertically stacked. . As a result, the phase difference of the motion between the spring-dampered suspension portions becomes more remarkable, and the vibration absorbing characteristics are improved. Moreover, while the area | region which shows the characteristic used as a constant load becomes two places, it has a wedge which shows the change which a load value becomes high between both, and while both have a load difference, the load difference becomes two constant. Since the characteristics fall within the range of the hysteresis loss in the load area, the range of the constant load area in which both are combined is wide, which contributes to the improvement of the vibration absorption characteristics.

FIG. 1 is a perspective view showing a suspension mechanism according to a first embodiment of the present invention. FIG. 2 is a plan view of FIG. FIG. 3 is a side view of FIG. FIG. 4 is a view on arrow AA of FIG. 2. FIG. 5 is a view for explaining the operation of the suspension mechanism according to the first embodiment. FIG. 6 is a perspective view showing a lower spring-dampered suspension part used in the suspension mechanism according to the first embodiment. 7 (a) is a perspective view showing the first damper removed to illustrate the configuration of the magnetic spring in the lower layer spring-dampered suspension portion shown in FIG. 6, and FIG. 7 (b) is a perspective view It is sectional drawing of Fig.7 (a). FIG. 8 is a view showing a seat structure (a seat structure according to the first embodiment) including the suspension mechanism according to the first embodiment and a seat supported by the suspension mechanism. FIG. 9 is a perspective view showing a seat suspension portion used in the seat structure of FIG. FIG. 10 shows an example of load-deflection characteristics of a torsion bar, a magnetic spring and a constant load spring mechanism including them, wherein (a) shows the characteristics when a vertically placed magnetic spring is adopted. And (b) show the characteristics when a transversely placed magnetic spring is adopted. FIG. 11 shows various dampers at a velocity of 0.3 m / s (symbols A-1, A-2, B-1, B-2, B-3, C-1, D-1 and D-2) It is the figure which showed the damping force of an oil damper and the code | symbol F-1 and F-2 are friction dampers. FIG. 12 is a view showing load-deflection characteristics of the seat cushion portion supported by the seat suspension portion in a state where the suspension mechanism of FIG. 8 is not included. FIG. 13 (a) shows the SEAT values for EM6 and EM8 of the subject A by measurement location, and FIG. 13 (b) shows the SEAT values for EM6 and EM8 of the subject B by measurement location. FIG. 14 is a view showing a sheet structure according to a second embodiment of the present invention. FIG. 15 is a view showing a seat structure (a seat structure according to a third embodiment) using a suspension mechanism according to a third embodiment of the present invention. FIG. 16 is a side view showing the suspension mechanism according to the third embodiment. FIG. 17 is a cross-sectional view showing the lower layer spring-dampered suspension part used in the suspension mechanism according to the third embodiment. FIG. 18 is a view showing load-deflection characteristics of the suspension mechanism according to the third embodiment, which was measured by setting the load mass at the neutral position as shown in the figure. FIG. 19 is a diagram in which the load-deflection characteristics of the load masses of 120 kg, 70 kg and 50 kg in the neutral position are extracted in FIG. 18 and compared with the load-deflection characteristics of the suspension mechanism according to the first embodiment. Fig.20 (a) is the A section enlarged view (characteristic of 120 kg of load mass) of FIG. 19, FIG.20 (b) is the B section enlarged view (characteristic of 70 kg of load mass) of FIG. FIG. 19 is an enlarged view of a portion C of FIG. 19 (characteristic of 50 kg load mass). FIG. 21 is a view showing load-deflection characteristics of the sheet structure according to the third embodiment shown in FIG. FIG. 22 is a view showing the measurement results of the vibration transmission rate of the suspension mechanism according to the third embodiment. Fig.23 (a) is the figure which showed the test result of the vibrational transmission rate regarding EM6 which made subjects A and B sit on the sheet | seat structure which concerns on 1st Embodiment, and FIG.23 (b) is a FIG. 23 is a diagram showing a test result of a vibration transfer rate regarding EM 7 performed by seating the test subjects A and B on the seat structure according to the third embodiment, and FIG. 23C shows the seat structure according to the first embodiment. It is the figure which showed the test result of the vibrational transmission rate regarding EM8 which made subjects A and B sit, and Drawing 23 (d) is rubber with a mass of 75 kg to each sheet structure concerning the 1st and 3rd embodiment. It is the figure which showed the vibrational transmission rate at the time of mounting weight and measuring regarding EM7. FIG. 24 is a view showing a vibration transmission rate when the subject C is seated on the seat structure according to the third embodiment and excitation is performed while changing the acceleration. FIG. 25 is a diagram showing, in time series, the displacement between the mounting table of the vibrator and the upper connecting portion of the upper-layer spring-dampered suspension portion in the vibration experiment of the seat structure according to the third embodiment. is there. FIG. 26 is a view showing the vibration transmission factor when each sheet structure according to the first and third embodiments and a sheet supported by the X link suspension are excited by the EM 7. FIG. 27 is a view showing measurement results of biological information of a subject seated on the seat structure according to the second embodiment and the seat of the reference example, wherein (a) and (b) show the heart rate, (c) And (d) shows LF / HF which is an index of sympathetic nerve, and (e) and (f) show HF which is an index of parasympathetic nerve.

Hereinafter, the present invention will be described in more detail based on the embodiments shown in the drawings.
First Embodiment
FIGS. 1 to 7 show a suspension mechanism 1A according to a first embodiment of the present invention. FIG. 8 shows the suspension mechanism 1A as a seat 1000 for vehicles such as passenger cars, trucks, buses, forklifts and the like. An example applied to the support of The seat 1000 incorporates a seat suspension portion 2000, and FIG. 9 is a perspective view of the seat suspension portion 2000. As shown in FIGS. 1 to 7, in the suspension mechanism 1 of the present embodiment, the lower-layer spring-damper suspension portion 100 and the upper-layer spring-damper suspension portion 300 have upper and lower two-layer spring-damper suspension portions. It is configured to have.

  The lower-layer spring-dampering suspension unit 100 can move up and down via the first link mechanism 110, the constant load spring mechanism 120, and the first damper 130 with respect to the fixed unit 101 integrally fixed to the vehicle body floor. It comprises a movable support 140 supported. The first link mechanism 110 includes a pair of left and right front links 111 and 111 and a pair of left and right rear links 112 and 112. The lower portions 111a and 111a of the front links 111 and 111 are rotatably supported at the front of the side edge portion 101a of the fixed portion 101, and the upper portions 111b and 111b are movable support portions 140 having a substantially square plate shape. Is connected to the front frame 141 of the The rear links 112, 112 have their lower portions 112a, 112a rotatably supported at the rear of the side edge 101a of the fixed portion 101, and the upper portions 112b, 112b are connected to the rear frame 142 of the movable support 140 It is done. Thereby, the movable support portion 140 can move up and down relative to the fixed portion 101, and more precisely, the parallel link in which the first link mechanism 110 includes the front links 111 and 111 and the rear links 112 and 112. Because of the structure, it moves up and down along the rotation path of the front links 111, 111 and the rear links 112, 112. That is, along the rotation direction of the front links 111 and 111 and the rear links 112 and 112 with the lower portions 111a, 111a, 112a and 112a as rotation centers, that is, the front links 111 and 111 and the rear links 112 and 112 It falls forward and returns along the direction toward the lower limit position and back, and is displaced along the direction toward the upper limit position, and the movable support portion 140 moves up and down. Therefore, in the lower layer spring-dampered suspension portion 100, the fixed portion 101 and the movable support portion 140 constitute "a pair of upper and lower frame portions relatively moved up and down through the link mechanism" defined in the claims.

  The front frame 141 and the rear frame 142 are both formed of a pipe material in the present embodiment, and the torsion bars 121 and 121 are respectively inserted (see FIGS. 4 and 8). In the present embodiment, the torsion bars 121, 121 are linear springs that exhibit a linear characteristic that changes almost linearly in load-deflection characteristics (see FIG. 10), and together with a magnetic spring 122 described later, a constant load spring mechanism 120. Configure One end of the torsion bars 121, 121 is provided so as not to rotate relative to the front frame 141 and the rear frame 142, respectively, and the torsion bars 121, 121 make the movable support portion 140 relative to the fixed portion 101. It is set so as to exert an elastic force for biasing in the direction of separation, that is, upward. The other ends of the torsion bars 121 and 121 are connected to the plate members 125c and 125d of the elastic force adjustment member 125, respectively (see FIGS. 2, 6 and 7).

  When the adjustment dial 125 b is rotated, the elastic force adjustment member 125 rotates the adjustment shaft 125 a, and the plate member 125 c connected to the torsion bar 121 on the front link 111, 111 side is rotated by the rotation. Furthermore, the plate member 125d connected to the torsion bar 121 on the rear link 112, 112 side connected to the plate member 125c via the connection plate 125e is rotated. Therefore, when the adjustment dial 125 b is rotated, the torsion bars 121, 121 are twisted in either direction, the initial elastic force of the torsion bars 121, 121 is adjusted, and the movable support portion 140 is adjusted regardless of the weight of the seated person. Can be adjusted to a predetermined position (for example, a neutral position). Moreover, as a linear spring which urges | moves the movable support part 140 in the direction which mutually spaces apart with respect to the fixing | fixed part 101, a torsion bar 121,121 is preferable.

  The torsion bars 121 and 121 themselves become centers of the rotation axis and are twisted to exert a predetermined spring force, but when a coil spring or the like is used, friction occurs at a portion where the coil spring is suspended and supported . As a result, the friction damping in the lower layer spring-dampered suspension portion 100 becomes high, which causes the hysteresis loss in the load-deflection characteristics (static load characteristics) to be increased. Here, the lower layer spring-damper suspension part 100 and the upper layer spring-damper suspension part 300 described later have a lower layer spring-damper suspension part 100 and an upper layer spring in order to cause a phase difference in movement between them. -Hysteresis loss at the time of loading and unloading when the load load at the neutral position is set in the range of 50 to 120 kg is adjusted to be 150 N or less as the whole laminated structure combining the suspension portion 300 with a damper Is preferred. More preferably, it is 120 N or less, still more preferably 100 N or less. The lower limit value of the hysteresis loss is not particularly limited, but is usually in the range of 10 to 30N.

  The magnetic spring 122 includes a fixed magnet unit 1220 and a movable magnet unit 1221 as shown in FIG. The fixed magnet unit 1220 has two fixed side support frames 1220 a and 1220 a which are disposed at predetermined intervals along the substantially vertical direction of the lower layer spring-dampered suspension portion 100. The fixed side support frames 1220a and 1220a are fixed to the fixed portion 101, and fixed magnets 1220b and 1220b are attached to the fixed side support frames 1220a and 1220a, respectively. The fixed magnets 1220b and 1220b facing each other at a predetermined interval use two-pole magnets, and different poles are adjacent to each other, and each fixed side support frame 1220a and 1220a has an attitude that the same poles face each other at a predetermined interval. It is attached.

  The movable magnet unit 1221 is provided with a movable magnet 1221 b disposed in the gap between the fixed magnets 1220 b and 1220 b which are disposed opposite to each other at a predetermined interval. The rear end of the movable magnet 1221 b is supported by the tip of the movable magnet support link plate 1221 c pivotally supported by the movable support portion 140, and the gap between the fixed magnets 1220 b and 1220 b along with the vertical movement of the movable support portion 140. Is moved substantially horizontally back and forth. The movable magnet 1221b is magnetized along the longitudinal direction.

  In the magnetic spring 122, the spring characteristic exerted by the movement of the movable magnet 1221b between the fixed magnets 1220b and 1220b changes depending on the relative position of the movable magnet 1221b and the fixed magnets 1220b and 1220b. Specifically, as shown in FIG. 10 (b), in the load-deflection characteristic of the magnetic spring 122, the action direction of the elastic force (restoring force) of the torsion bars 121 and 121 which are linear springs, that is, the movable support portion When a characteristic in which the restoring force increases in a direction in which 140 is separated from the fixed portion 101 is a positive spring characteristic, a negative spring characteristic in which the restoring force in the direction decreases in a predetermined displacement amount range is exhibited. . That is, in a predetermined range (in the example of FIG. 10B, in the range of about -11 mm to about +10 mm) near the position crossing the boundaries of the N and S poles of two fixed magnets 1220b and 1220b where different poles are adjacent to each other. Demonstrates negative spring characteristics.

  As a result, in the constant load spring mechanism 120 of the present embodiment comprising the magnetic spring 122 and the above-described torsion bars 121, 121, the negative spring characteristic of the magnetic spring 122 functions (example of FIG. 10B) Then, in the range of about -11 mm to about +10 mm), the spring constant (positive spring constant) of the positive spring characteristic of the torsion bar 121, 121 and the spring constant (negative spring) of the negative spring characteristic range of the magnetic spring 122 By adjusting the constant load spring mechanism 120 in which both are superimposed by adjusting so as to be substantially the same as the constant), a constant load region in which the amount of change in load value becomes smaller than a predetermined value even if the amount of displacement increases Will have a region where it is approximately zero (preferably, the spring constant is in the range of about -10 N / mm to about 10 N / mm). In order to make effective use of the region where the spring constant becomes substantially zero as much as possible, at the neutral position of the vertical stroke of the movable support portion 140, the central position of the movable magnet 1221b of the movable magnet unit 1221 is different. It is preferable that the poles be set so as to substantially coincide with the boundary between two adjacent fixed magnets 1220 b and 1220 b.

  In the present embodiment, the magnetic spring 122 is installed in a posture (horizontally placed) in which the movable magnet 1221b moves in a substantially horizontal direction between the fixed magnets 1220b and 1220b. In the case of horizontal placement, the space in the vertical direction when the magnetic spring 122 is disposed can be smaller than that in the case of vertical placement, and it is easy to make the suspension mechanism 1 thinner. On the other hand, a link mechanism is required to convert the vertical movement of the movable support portion 140 into the substantially horizontal movement of the movable magnet 1221b, and when operating the movable magnet 1221b, the efficiency associated with the movement of the link mechanism Change and friction damping occur. Therefore, the spring constant (negative spring constant) of the negative spring characteristic range of the magnetic spring 122 changes slightly non-linearly as shown in FIG. 10 (b). In the example of FIG. 10 (b), when the spring constant from about -11 mm to 0 mm and the spring constant from 0 mm to about +10 mm are compared, the former is a spring constant with a larger absolute value, and the torsion bar 121 , 121, the range of about -11 mm to 0 mm is lower than the range of 0 mm to about +10 mm.

  On the other hand, the magnetic spring 322 employed in the suspension unit 300 with upper layer spring and damper of the third embodiment described later has a structure in which the movable magnet 1221 b is vertically displaced between the fixed magnets 1220 b and 1220 b )I have to. In the case of vertical mounting, the movable magnet 1221b can be supported simply by fixing it to the upper connecting portion 340 which is a frame portion displaced up and down, and there is no need to provide a link mechanism for converting the operation direction. And no effect of friction damping. Therefore, as shown in FIG. 10 (a), for example, the magnetic spring 322 exhibits negative spring characteristics in the range of about -9 mm to about +10 mm, as shown in FIG. 10 (a). More linear than in the case. Therefore, when superimposed on the spring constant of the torsion bars 321 and 321, a constant load area is formed in a range from about -9 mm to +10 mm, which has a smaller change than in the case of FIG. As apparent from this, depending on whether the magnetic springs 122 and 322 are vertically or horizontally used, the spring characteristics of the spring-dampered suspension portions 100 and 300 change.

  Next, the first damper 130 used in the lower layer spring-damper suspension unit 100 will be described. The first damper 130 is a telescopic damper having a piston rod 131 and a cylinder 132 in which a piston attached to the piston rod 131 reciprocates. The end 131 a of the piston rod 131 is pivotally supported by a mounting bracket 131 b attached to a rear frame 142 which is stretched in the width direction toward the rear of the movable support 140. The end 132a of the cylinder 132 is pivotally supported by a mounting bracket 132b provided on the fixed portion 101 (see FIG. 4). Accordingly, when the movable support portion 140 moves up and down with respect to the fixed portion 101, the first damper 130 also expands and contracts.

  Further, as shown in FIG. 4, the projecting direction of the mounting bracket 131 b attached to the rear frame 142 supporting the end of the piston rod 131 of the first damper 130 is provided so as to project substantially forward. In the present embodiment, the mounting angle of the first damper 130 is set to about 10 degrees with respect to the horizontal plane. The mounting angle of the first damper 130 can be adjusted to, for example, 20 degrees by setting the projecting direction of the mounting bracket 131 b to, for example, obliquely upward. Therefore, it is also possible to adjust the damping characteristic by the mounting angle of the damper.

  As the first damper 130, for supporting the driver's seat of the earthworking machine, the damping force on the extension side (speed: 0.3 m / s) in order to be able to cope with the impact to the large amplitude input received by the earthworking machine. Is preferably more than 500 N and has a characteristic that the damping force on the expansion side is 1.5 or more times the damping force on the contraction side. More preferably, the damping force on the extension side is in the range of 800 to 1,500 N at a velocity of 0.3 m / s. For example, in FIG. 11, the damper of the symbol of "A-1", "A-2", "B-1", and "B-2" corresponds. By using the first damper 130 having such characteristics, more impact energy is absorbed at the time of the upward movement of the movable support portion 140, and as a result, the force generated at the time of the downward movement becomes smaller. I can suppress the bottom feeling of time. For example, when a damping force of 1000 N or more is employed as the first damper 130 disposed in the lower layer in order to absorb a large impact force (for example, a damper of “D-1” in FIG. 11) Is not preferable because the bottoming feeling is increased. However, by adopting the first damper 130 under the above conditions, the damping force is small at the time of the downward operation, and the elastic force of the constant load spring mechanism 120 can alleviate the impact and suppress the bottoming feeling. The first damper 130 is preferably an oil damper, but may be a friction damper or the like as long as the above conditions are satisfied. However, since the oil damper has speed dependency, it contributes not only to absorption of impact energy but also to phase control particularly in a low frequency band.

  The upper-layer spring-dampered suspension unit 300 has a configuration in which the magnetic spring is removed from the lower-layer spring-dampered suspension unit 100, and as a spring mechanism, not a constant load spring mechanism but a linear spring composed only of a torsion bar 321 A mechanism 320 is employed.

  In the upper-layer spring-dampered suspension unit 300, the lower connecting portion 301 is connected on the movable support portion 140 of the lower-layer spring-dampered suspension unit 100, and on the upper connecting portion 340, a slider 343 is mounted. The lower rail 251 of 250 is fixed, and the slider 250 moves up and down together with the upper connecting portion 340.

  The upper connecting portion 340 is supported by the lower connecting portion 301 via the second link mechanism 310. Like the first link mechanism 110, the second link mechanism 310 has a pair of left and right front links 311, 311 and a pair of left and right rear links 312, 312. A front frame 301a is disposed in front of the lower connecting portion 301 along the width direction, and a rear frame 301b is disposed rearward in the width direction. Each of the front frame 301a and the rear frame 301b is formed of a pipe material, and the torsion bars 321 and 321 that constitute the linear spring mechanism 320 are disposed therein. One end of the torsion bars 321 and 321 is provided so as not to rotate relative to the front frame 301a and the rear frame 301b, and the other end is connected to plate members 325c and 325c of an elastic force adjustment member 325 described later.

  The lower portions 311 a and 311 a of the front links 311 and 311 are connected to the front frame 301 a of the lower connecting portion 301, and the upper portions 311 b and 311 b are rotatably supported by the upper connecting portion 340. The lower portions 312 a and 312 a of the rear links 312 and 312 are connected to the rear frame 301 b of the lower connecting portion 301, and the upper portions 312 b and 312 b are rotatably supported on the upper connecting portion 340. The rotation direction of the front links 311 and 311 and the rotation direction of the rear links 312 and 312 are both reverse to the rotation directions of the front links 111 and 111 and the rear links 112 and 112 of the first link mechanism 110. Is set to be That is, the movable support portion 140 of the suspension portion 100 with the lower layer spring and damper is moved forward by the first link mechanism 110 from the uppermost end position of FIG. 5A to the lowermost position of FIG. 5C. The upper-layer spring-dampered suspension unit 300 is provided so as to be displaced downward while being displaced rearward while being displaced downward and moving downward. Therefore, in the state where the lower layer spring-damper suspension part 100 and the upper layer spring-damper suspension part 300 are stacked, the upper connecting part 340 moves up and down in a substantially vertical direction. As a result, the seating position of the seated person is stabilized by reducing the longitudinal displacement even with the vertical movement. In the upper-layer spring-dampered suspension unit 300, the lower connecting portion 301 and the upper connecting portion 340 constitute "a pair of upper and lower frame portions relatively moved up and down through the link mechanism" defined in the claims.

  Here, the elastic force adjustment member 325 to which the other ends of the torsion bars 321 and 321 are connected has exactly the same configuration as the elastic force adjustment member 125 in the lower layer spring-damper suspension portion 100, and operates the adjustment dial 325b. By doing this, the twisting amount of the torsion bars 321 and 321 can be adjusted. In the present embodiment, the elastic force adjustment member 125 in the lower layer spring-damper suspension unit 100 has the magnetic spring 122 of the constant load spring mechanism 120 in a neutral position (back and forth between the fixed magnets 1220b and 1220b) according to the weight of the seat occupant. In order to support the seat occupant at a predetermined equilibrium position, the center of the movable magnet 1221b is set to be at the middle position in the direction so as to be the position where the longitudinal central portions thereof are aligned. Of course, this also adjusts the height of the seating person's eyes. Further, the elastic force adjustment member 325 of the suspension unit 300 with the upper layer spring and damper is used mainly to adjust the eye height of the seated person by adjusting the twist amount of the torsion bars 321 and 321. According to the present embodiment, two sets of elastic force adjustment members 125, 325 are provided, and the torsion bars 121, 121 of the lower layer spring-damper with suspension portion 100 and the torsion bars 321, 321 of the upper layer spring-damper with suspension portion 300. The initial elastic force of the both can be adjusted respectively, and the adjustment range of the line-of-sight height of the seated person is large, and this can also function as a lifter.

  The second damper 330 used in the upper-layer spring-dampered suspension portion 300 has an end portion of the cylinder 332 pivotally supported by a mounting bracket 332 b provided to project downward from the rear frame 301 b of the lower connection portion 301, The end of the piston rod 331 is pivotally mounted on a mounting bracket 331 b provided so as to project rearward from the front frame 341 of the upper connecting portion 340. The second damper 330 is the same as the first damper 130 because the upper spring-dampered suspension unit 300 adopts the linear spring mechanism 320 as in the present embodiment, because the second damper 330 has high resilience against downward force. It is preferable that the damping force on the extension side (speed 0.3 m / s) exceeds 500 N and the damping force on the extension side is 1.5 times or more of the damping force on the compression side. More preferably, the damping force on the extension side is in the range of 800 to 1500 N at a velocity of 0.3 m / s, and the same one as the first damper 130 can be used.

  However, the lower-layer spring-dampered suspension portion 100 and the upper-layer spring-dampered suspension portion 300 have different damping characteristics or spring characteristics. In the present embodiment, the constant load spring mechanism 120 including the magnetic spring 122 is employed in the lower layer spring-damper suspension unit 100, and the constant load spring mechanism is not employed in the upper layer spring and damper suspension unit 300. Therefore, since a difference arises in a spring characteristic by the difference, the 1st damper 130 and the 2nd damper 330 may use the thing which has an equivalent characteristic. However, it is preferable to adopt a structure in which the damping characteristics are also different by adopting different damping forces as the two dampers 130 and 330 or making the mounting angles different. With such a configuration, a difference occurs in the position, that is, the phase of the period of the vibration waveform of each of the spring-dampered suspension units 100 and 300 that vibrates up and down by the input vibration. The larger the phase difference is, that is, the closer to the opposite phase, the more preferable because the vibration absorption characteristics are excellent. Preferably, the frequency band of the resonance point when excited by the input spectrum class (EM6, EM7, EM8, EM9) defined in JIS A 8304: 2001 based on ISO 7096: 2000 is 2 Hz or less, and this resonance point In the frequency band of 2 Hz or less, which includes the above, the phase difference of the vibration waveform between each of the spring-dampered suspension units 100 and 300 is 120 degrees or more. More preferably, the vibration waveforms are in opposite phase.

  In order to improve the vibration absorption characteristics more remarkably by the phase difference between the spring-dampered suspension portions 100 and 300, it is preferable that the hysteresis loss at the time of loading and unloading in the load-deflection characteristics of the suspension mechanism 1A be smaller. As a result, the dynamic spring constant can be kept low, the resonance point can be made to appear in a lower frequency band, and the phase difference due to the individual movement of each of the spring-dampered suspension units 100 and 300 due to the input vibration difference can be easily generated. . The hysteresis loss in the load-deflection characteristics of the suspension mechanism 1A is preferably 150 N or less when the load applied at the neutral position is set in the range of 50 to 120 kg. Moreover, it is more preferable that it is the range of 20-150N.

  As shown in FIG. 8, the seat suspension portion 2000 is via the seat suspension portion link mechanism 2100, the linear spring mechanism 2200, and the seat suspension portion damper 2300 with respect to the upper connection portion 340 of the upper layer spring-damper suspension portion 300. The seat support unit 2400 is supported so as to be vertically movable.

  In the present embodiment, a cushion frame for supporting the seat cushion portion 1100 of the seat 1000 constitutes the seat support portion 2400, and includes side frames 2410 and 2410, a front edge frame 2420, a rear edge frame 2430 and the like. The seat support portion 2400 formed of a cushion frame is supported by the upper rail 2520 of the slider 2500. The lower rail 2510 is fixed to the upper connecting portion 340 via the mounting base 343, and the slider 250 moves up and down together with the upper connecting portion 340. Note that, for example, a three-dimensional three-dimensional knitted fabric as a cushion member is stretched on the side frames 2410 and 2410, the front edge frame 2420, and the rear edge frame 2430.

  The seat support portion 2400 is supported by the upper rail 2520 via the seat suspension portion link mechanism 2100 as shown in FIGS. 8 and 9. The seat suspension link mechanism 2100 includes a pair of left and right front links 2110 and 2110, a pair of left and right rear links 2120 and 2120, and a connecting link 2130 and 2130 for connecting the front link 2110 and the rear link 2120 on the left and right, respectively. And.

  The front links 2110 and 2110 are formed in a substantially trapezoidal shape (see FIG. 9), and the upper portion near the front end is pivotally supported by the front bracket 2520a of the upper rail 2520 by the shaft member 2110a, and the upper portion near the rear end is seat supporting Between the side frames 2410 and 2410 of the part 2400, as shown in FIG. 9, it is relatively rotatably connected to a front side reinforcing pipe 2440 which is stretched backward from the shaft member 2110a in a plan view.

  The rear links 2120 and 2120 are formed in a substantially triangular shape with the top at the bottom as shown in FIG. 9, and the upper part near the front end is pivotally supported by the rear bracket 2520b of the upper rail 2520 by the shaft member 2120a. An upper portion in the vicinity is connected between the side frames 2410 and 2410 of the seat support portion 2400 so as to be relatively rotatable with a rear side reinforcing pipe 2450 that is stretched rearward from the shaft member 2120a in plan view. Therefore, the front links 2110 and 2110 and the rear links 2120 and 2120 of the seat suspension link mechanism 2100 rotate about the shaft members 2110a and 2120a, respectively, and the seat support part 2400 moves along its rotation path to the upper limit position. Move up and down between the and the lower limit position.

  The linear spring mechanism 2200 of the seat suspension portion 2000 is configured to include only a linear spring that exhibits a linear characteristic that changes almost linearly in the load-deflection characteristic. Specifically, it is configured to have torsion bars 2210 and 2210 as linear springs respectively inserted into the front side reinforcing pipe 2440 and the rear side reinforcing pipe 2450 (see FIGS. 8 and 9). Each of the torsion bars 2210 and 2210 has one end fixed to one side frame 2410 and the other end passing through the other side frame 2410 to form a free end so as to bias the sheet support portion 240 upward 0. Will be placed on As a result, when the seat support portion 2400 is relatively displaced downward while a person is seated, a spring force is exerted to return to the seating position.

  The seat suspension part damper 2300 engages the tip of the piston rod 2310 with the front reinforcement pipe 2440 and engages with the lower rear pipe 2530 which spans the bottom of the cylinder 2320 between the upper rails 2520 and 2520 of the slider 2500. They are arranged as shown in FIG. 8 and FIG. 9 etc.

  It is preferable to use a seat suspension part damper 2300 whose damping force is equal to or less than that of the first damper 130 and the second damper 330. The seat suspension portion 2000 is provided between the suspension mechanism 1A consisting of the two-layered suspension portions 100 and 300 and the seat cushion portion 1100. The suspension mechanism 1A is provided for the purpose of suppressing the vibration transmissibility at the resonance point lower than when the seat 1000 is directly supported by the suspension mechanism 1A, but is sufficiently damped by the suspension mechanism 1A and also dampens the seat cushion portion 1100. In the seat suspension portion 2000, one having a smaller damping force than the first damper 130 and the second damper 230 is employed. For example, the oil damper of "B-3" of FIG. 11 can be used. The load-deflection characteristics including the seat suspension portion 2000 and the seat cushion portion 1100 (including a cushion material such as a three-dimensional solid knitted fabric) have a hysteresis loss larger than that of the suspension mechanism 1A, as shown in FIG. The hysteresis loss is 200N or more.

  Here, it is preferable to set the lower-layer spring-damper suspension portion 100, the upper-layer spring-damper suspension portion 300, and the seat suspension portion 2000 so that their vertical strokes become substantially the same. Thereby, the position of the hip point of the person sitting on the seat 1000 is stabilized. In addition, adjustment of the up and down stroke is adjustment of the length of the first link mechanism 110, the link mechanism 310 and the seat suspension link mechanism 2100, adjustment of the length and expansion amount of the dampers 130, 330, 2300, adjustment of the attachment angle. And so on.

  According to the present embodiment, the constant load spring mechanism 120 is adopted in the lower-layer spring-damper suspension part 100, and the linear spring mechanisms 310 not provided in the upper-layer spring-damper suspension part 300 are adopted individually. The dampers 130 and 330 are attached. Therefore, each of the spring-damper suspension units 100 and 300 has a difference in damping characteristics or spring characteristics with respect to input vibration, and the vibration waveform of the lower layer spring-damper suspension unit 100 to input vibration and the upper-layer spring-damper suspension unit 300 There is a phase difference with the vibration waveform of. Because of the laminated structure, having a predetermined stroke can exhibit a high damping effect against impact vibration with a large amplitude. Therefore, it is particularly suitable as a suspension mechanism for the driver's seat of an earthworking machine.

(Experiment on Vibration Characteristics of Suspension Mechanism 1A)
In the case where the subject A (height 173 cm, weight 54.8 kg) and the subject B (height 179 cm, weight 99 kg) are seated on the seat 1000 supported by the suspension mechanism 1A of the present embodiment, JIS A 8304: 2001 (ISO 7096) The SEAT value was determined on the basis of: 2000). Vibration experiments were performed using input spectrum classes EM6, EM7, EM8 and EM9.

In addition, input spectrum class EM6 is a standard for "a crawler type tractor dozer of 50,000 kg or less", and it excites by the highest value of 0.34 (m / s ² ) ² / Hz of dominant frequency 7.6Hz and PSD. The SEAT value is less than 0.7, and the transmissibility at the resonance frequency in the vertical axis direction is less than 1.5. The input spectrum class EM7 is a standard for “compact dampers” and excites with a dominant frequency of 3.24 Hz and a PSD maximum value of 5.56 (m / s ² ) ² / Hz, and a SEAT value of less than 0.6, The vibration transmissibility at the resonance frequency in the vertical axis direction is required to be less than 2.0. The input spectrum class EM8 is a standard for “a compact loader of 4,500 kg or less”, which excites with a dominant frequency of 3.3 Hz, a maximum PSD value of 0.4 (m / s ² ) ² / Hz, and a SEAT value The vibration transmissibility at the resonance frequency in the vertical axis direction less than 0.8 is required to be less than 2.0. The input spectrum class EM9 is a standard for the "compact loader (skipped steer type)", and it excites with a dominant frequency of 4.0 Hz, a maximum value of PSD of 0.78 (m / s2) 2 / Hz, and a SEAT value The vibration transmissibility at the resonance frequency in the vertical axis direction less than 0.9 is required to be less than 2.0. The vibration transmissibility was measured by placing a 75 kg rubber weight on the seat cushion portion 1100 of the seat 1000.

  In addition, the experiment was conducted at the research facility of Delta Industrial Co., Ltd. (Aichi-gun, Fuchu-cho, Shinchi No. 1-14, Hiroshima Prefecture), which is one of the applicants, and the Institute for Agricultural and Earthmoving Machinery (IMAMOTER) In two places.

  In the research facility of Delta Industrial Co., Ltd., experiments on EM6, EM8 and EM9 were carried out using an electrodynamic 3-axis shaker (IMV Corp. 3-axis shaker TAS-1000-5, maximum excitation stroke 60 mm). Conducted an experiment on EM6, EM7, EM8 and EM9 at the IMAMOTER research facility using a single-axis shaker.

  The maximum stroke amounts in the vertical direction of the lower layer spring-damper suspension part 100 and the upper layer spring-damper suspension part 300 constituting the suspension mechanism 1A used in this experiment were respectively 40 mm, for a total of 80 mm. Further, the maximum stroke amount in the vertical direction of the seat suspension portion 2000 was also 40 mm, and the maximum excitation stroke obtained by combining the suspension mechanism 1A and the seat suspension portion 2000 was 120 mm. Although FIG. 5 shows the movement of the suspension mechanism 1A consisting of the combination of the lower layer spring-suspension suspension portion 100 and the upper layer spring-damper suspension portion 300, the dimensions when the respective maximum stroke amounts are 40 mm are shown. An example of the change of is also shown.

  The first damper 130 incorporated in the lower-layer spring-dampered suspension unit 100 adopts the oil damper of “A-1” shown in FIG. 11 (elongation side damping force 1370 N, compression side damping force 380 N), and the upper layer The second damper 330 incorporated in the spring-dampered suspension unit 300 adopts the oil damper (elongation side damping force 1370 N, compression side damping force 760 N) of “B-1” shown in FIG. The seat suspension portion damper 2300 incorporated in the seat suspension portion 2000 adopts the oil damper (elongation side damping force 400 N, contraction side damping force 200 N) of “B-3” shown in FIG.

The results of the vibration experiments were as shown in the following table.

  As apparent from Table 1 and FIG. 13, the experiments conducted at any of the research facilities met the conditions required by EM6, EM8 and EM9.

Second Embodiment
In the present embodiment, as shown in FIG. 14, the suspension unit 1A according to the first embodiment has the seat suspension unit 2000 of the first embodiment with the seat suspension unit 2300 removed, as shown in FIG. , "Spring suspension part") 2000A is adopted. That is, the spring mechanism consists only of the linear spring mechanism 2200 having only the torsion bars 2210 and 2210.

  A subject with a weight of 54 kg, a weight of 57 kg and a weight of 99 kg was seated on the seat 1000 of the second embodiment, and an experiment regarding EM6 and EM8 was performed. The results are shown in the following table.

  From Table 2, even in the second embodiment, the criteria for the SEAT values of EM6 and EM8 were satisfied. However, although the vibration transmissibility at the resonance point was 1.593 and the EM8 standard was satisfied, the EM6 standard was slightly higher.

  From the above results, in both the first embodiment and the second embodiment, the resonance frequency is as low as 2 Hz or less, and the vibration transmission rate is also suppressed low, and in the frequency band of 2 Hz or less It can be seen that there is a phase difference between the damper suspension 100 and the upper layer spring-damper suspension 300.

  Note that, for comparison, in the seat suspension portion 2000, the oil damper of "A-1" instead of the oil damper (elongation side damping force 400N, contraction side damping force 200N) of "B-3" of the first embodiment The experiment regarding EM6 and EM8 was conducted on a subject with a body weight of 54 kg, a body weight of 57 kg, and a body weight of 99 kg for the configuration adopting (stretching side damping force 1370 N, contraction side damping force 380 N).

  As a result, for EM6, the SEAT values were 0.60, 0.59, and 0.42, respectively, which satisfied the standard, but not for EM8. Moreover, in the case of either EM6 or EM8, the standard of the vibrational transmission rate could not be satisfied. From this, it can be said that, in the seat suspension portion 2000, it is preferable to adopt a damping force of 1000 N or less, preferably 500 N or less, more preferably 300 to 500 N as described above.

Third Embodiment
Next, a suspension mechanism 1C according to a third embodiment of the present invention will be described based on FIGS. The suspension mechanism 1C according to the third embodiment is different from the suspension mechanism 1A according to the first embodiment in the configuration of the upper-layer spring-dampered suspension portion 300A. In the present embodiment, the suspension unit 300A with upper layer spring and damper also has a constant load spring mechanism 320A, similarly to the suspension unit 100 with lower layer spring and damper. That is, a magnetic spring 322A exhibiting negative spring characteristics in a predetermined displacement range is disposed, and combined with the torsion bars 321 and 321 exhibiting linear spring characteristics, the constant load spring mechanism 320A is configured.

  However, as in the first embodiment, the fixed springs 1220 b and 1220 b are installed in a substantially horizontal posture (horizontally placed), as in the first embodiment, of the magnetic spring 122 constituting the constant load spring mechanism 120 of the lower layer spring-dampered suspension unit 100. The movable magnet 1221b is configured to move in a substantially horizontal direction, but in the suspension unit 300A with the upper layer spring and damper, in the magnetic spring 322A constituting the constant load spring mechanism 320A, the movable magnet 322A11 of the movable magnet unit 322A1 is a fixed magnet unit The fixed magnets 322A21 of the 322A2 are installed in a posture (vertically placed) moving in the vertical direction. In addition, when comparing the vertical installation and the horizontal installation, in the vertical installation, as in the horizontal installation, the vertical movement of the upper connecting portion 340 which is the movable support is converted into the substantially horizontal movement of the movable magnet 322A11. Since the link mechanism of the above is not required, the friction damping is small, and has the characteristics shown in FIG. This point is as described above.

The other configuration is the same as that of the first embodiment, including the configuration of the seat suspension portion 2000, and the same members are denoted by the same reference numerals. However, the mounting angles of the first damper 130 disposed in the lower layer spring-damper suspension portion 100 and the second damper 330 disposed in the upper layer spring-damper suspension portion 300A are all relative to the horizontal plane. It was about 10 degrees. Thereby, as compared with the case where the mounting angle is set to about 20 degrees, the spring characteristics of the magnetic spring and the torsion bar relatively strongly act on the damping force of each damper 130, 330. This is the input spectrum class of "compact damper" in JIS A 8304: 2001 "earthwork machine-operator's seat vibration evaluation test": Like EM7, superior frequency 3.24 Hz, PSD maximum value 5.56 ( This is to provide a structure corresponding to a larger input energy than other standards such as EM6, such as m / s ² ) ² / Hz. In addition, the SEAT value of EM 7 needs to satisfy less than 0.7, and the vibration transmissibility at the resonance frequency in the vertical axis direction is required to be 2.0 or less.

(Vibration characteristics)
FIG. 18 is a diagram showing static load characteristics obtained by measuring the load mass at the neutral position (displacement 40 mm) differently for the suspension mechanism 1C according to the third embodiment, and among them, the load masses 50 kg and 70 kg. The data measured by setting the neutral position when supporting 120 kg is the curve shown by the symbol "S-VSUM, B" in FIG. In FIG. 19, in the suspension mechanism 1A according to the first embodiment, data measured and set to be in the neutral position when the load masses 50 kg, 70 kg, and 120 kg are supported is denoted by symbol S-VSUM, A ”. It shows together as. FIG. 20 is an enlarged view of a portion A, a portion B and a portion C of a curve indicated by a symbol “S-VSUM, B” in FIG. FIG. 21 shows a static load characteristic measured by supporting the seat 1000 incorporating the seat suspension unit 2000 having the characteristics shown in FIG. 12 in the suspension mechanism 1C according to the third embodiment, wherein the load at the neutral position It is data in the case of mass 20 kg, 30 kg, 50 kg, 70 kg and 90 kg.

  As the first damper 130 in the lower layer, the oil damper (elongation damping force 900 N, compression damping force 250 N) of “A-2” shown in FIG. 11 is used, and as the second damper 330 in the upper layer The oil damper (elongation side damping force 446N, compression side damping force 820N) of D-2 "is used. Further, as the seat suspension part damper 230, an oil damper of “B-3” (elongation side damping force 400N, compression side damping force 200N) is used. As measured by various dampers, this combination satisfied the criteria of EM 7 described later, in which both the body weight 54.8 kg and the body weight 99 kg. Among them, the second damper 330 (D-2) in the upper layer is different from the other embodiments in that a damper whose contraction side damping force is larger than the expansion side damping force is employed. This is because the constant load spring mechanism 320A is adopted also in the upper-layer spring-damper suspension part 300A in this embodiment, and when the contraction side damping force is small, the upper-layer spring-damper attachment suspension part is obtained by the input of large amplitude. Since the displacement of 300 A tends to be large, in order to suppress it, a high compression side damping force is adopted. In addition, by using the oil dampers “A-2” and “D-2” adopted in the present embodiment, which have a large difference in damping force, the lower layer spring-damper suspension portion 100 and the upper layer spring-damper The phase difference of the suspension unit 300A can be made larger and closer to the opposite phase, and the vibration absorption characteristics and the shock absorption characteristics can be improved.

  As shown in FIG. 18 to FIG. 20, the suspension mechanism 1C of the present embodiment provided with a constant load spring mechanism of upper and lower two layers of the lower layer spring-damper suspension part 100 and the upper layer spring-damper suspension part 300A is neutral. The characteristic which shows a constant load area | region in two places of the both sides area | region which pinched | interposed the part which becomes the wedge which the amount of spring constants of the displacement amount of position 40 mm increased slightly is shown. The action of the constant load spring mechanism 120 of the lower layer spring-dampered suspension unit 100 in which the magnetic spring is placed horizontally functions relatively largely at a displacement of around 30 mm to around 40 mm, and a magnetic spring from around 40 mm to around 50 mm The function of the constant load spring mechanism 320A of the upper layer spring-dampered suspension portion 300A, which is vertically disposed, functions relatively largely. Moreover, although there is a load difference of about 20 to 50 N in the two constant load regions due to the wrinkled portion around 40 mm, they fall within the range of hysteresis loss, and the two constant load regions The constant load area (dead zone) of 20 mm to 25 mm is substantially ensured.

  Therefore, when the equilibrium point when a person is seated is adjusted to near the neutral position of 40 mm, the vibration with small amplitude exhibits the vibration isolation function in the constant load region near 40 to 50 mm, and the amplitude becomes large and upward Even in the case of displacement, vibration isolation is performed with the characteristics of a constant load area of about 30 to 40 mm. It can be seen that the structure provided with these two upper and lower constant load spring mechanisms contributes to the improvement of the vibration absorption characteristics.

(Test on EM7)
Next, on the seat 1000 supported by the suspension mechanism 1C according to the third embodiment, subject A (height 173 cm, weight 54.8 kg) and subject B (height 179 cm, weight 99 kg) as in the first embodiment. ) Was seated and an experiment on EM7 was conducted. The results are shown in the following table. In Table 3, the vibration transfer rate at the resonance point is 75 kg of load mass mounted on the suspension mechanism 1C according to the third embodiment installed on the exciter, peak-to-peak amplitude of 48 mm, and sine wave sweep waveform It is a value at the time of vibration and was adopted from the data shown in FIG. The measurement was carried out using a 6-axis shaker (manufactured by Delta Tooling Co., Ltd .; maximum excitation stroke: 1000 mm) installed at a research facility of Delta Industrial Co., Ltd.

  From Table 3, according to the configuration of the third embodiment, the standard of the SEAT value of EM 7 was satisfied. Further, from Table 3 and FIG. 22, the vibration transfer coefficient at the resonance point was 1.33, and the reference of EM7 was satisfied.

  In the graph of FIG. 22, inflection points appear near 0.9 Hz, 1.2 Hz, and 1.5 Hz. For example, the lower layer spring-damper suspension part 100 and the upper layer spring-damper as in this embodiment. In the case of a seat suspension that uses one X link generally adopted, not a structure in which the suspension portion 300A is stacked, such an inflection point does not appear, and the vicinity of 0.9 Hz to around 1.5 Hz Until it becomes a mountain-shaped curve which becomes a top part approximately at the middle of them, the vibrational transmission rate of a resonance point becomes higher. However, in the present embodiment, the laminated structure of the lower-layer spring-dampered suspension portion 100 and the upper-layer spring-dampered suspension portion 300A has different A damping characteristics and spring characteristics of the respective suspension portions 100 and 300. Acts independently of each other, causing a phase difference in the movement of the two. This phase difference contributes to the reduction of the vibration transmission rate in the frequency band of 2 Hz or less where the resonance point appears. This action is the same as in the suspension mechanisms 1A and 1B according to the first and second embodiments. The larger the phase difference, that is, the closer to the opposite phase, the better for reducing the vibration transmission rate. It is preferable to adjust the damping characteristics and the spring characteristics so that a phase difference of 120 degrees or more is produced with an input vibration of 2 Hz or less even when the phases are not reversed.

  It should be noted that in the vicinity of 0.9 Hz in FIG. 22, both the constant load spring mechanism 120 of the lower layer spring-damper suspension part 100 and the constant load spring mechanism 320 A of the upper layer spring damper suspension part 300 work to remove vibration In the vicinity of 2 Hz, the action of the constant load spring mechanism 320A of the suspension unit 300 with the upper layer spring-damper in which the magnetic spring is vertically placed functions largely to isolate the vibration, and in the vicinity of 1.5 Hz, the magnetic spring It is considered that the action of the constant load spring mechanism 120 of the lower layer spring-damper-attached suspension unit 100, in which the wheel is placed horizontally, functions relatively largely to isolate the vibration.

  Here, in FIGS. 23 (a) and 23 (c), the suspension mechanism 1A (S-VSUM, A) according to the first embodiment supports the seat 1000 incorporating the seat suspension portion 2000, and the seat 1000 is used. The vibration transmission rate at the time of sitting test subjects A and B and performing a test about EM6 and EM8 is shown. In FIG. 23B, the suspension mechanism 1C (S-VSUM, B) according to the third embodiment supports the seat 1000 incorporating the seat suspension unit 2000, and the subjects A and B are seated on the seat 1000. Vibration transfer rate when the test on EM7 is performed. Further, FIG. 23 (d) shows the suspension mechanism 1A (S-VSUM, A) according to the first embodiment and the suspension mechanism 1C (S-VSUM, B) according to the third embodiment, respectively. A sheet 1000 incorporating the portion 2000 is supported, and a rubber weight having a weight of 75 kg is placed on the sheet 1000 to indicate a vibration transfer rate when measured with respect to the EM 7.

  From FIG. 23D, the suspension mechanism 1A (S-VSUM, A) according to the first embodiment has a resonance frequency of 1.7 Hz, but the suspension mechanism 1C (S-VSUM according to the third embodiment) VSUM, B) has a resonance frequency of 1.5 Hz, and a vibration transmission rate of 3.24 Hz is 0.53 for the suspension mechanism 1A (S-VSUM, A) according to the first embodiment. On the other hand, it is understood that the suspension mechanism 1C (S-VSUM, B) according to the third embodiment is 0.43 which is lower. This point is considered to be a major factor for the SEAT value of the suspension mechanism 1C according to the third embodiment to be better than the SEAT value of the suspension mechanism 1A according to the first embodiment regarding EM7.

  Next, a subject C with a height of 171 cm and a weight of 63 kg is seated on the seat 1000 supported by the suspension mechanism 1C according to the third embodiment installed on the vibrator, and a sine sweep waveform with constant acceleration ± The vibration transmissibility when excited at 0.015 G, ± 0.025 G, ± 0.05 G is shown in FIG. From FIG. 24, it can be seen that the resonance peak changes in accordance with the input acceleration, but the vibration transfer rates are all extremely low. This is because the suspension mechanism 1C has a dead zone as shown in FIG. 20, so that a phase difference is easily generated in the movement of the two suspension units 100 and 300A, whereby the vibration is absorbed. In particular, for an input of ± 0.025 G, the resonance peak disappears, and it shows a characteristic like a rigid body, because the movements of the two suspension units 100 and 300 A are almost in antiphase. is there.

  FIG. 25 is a vibration test in which the subject C was seated on the seat 1000 supported by the suspension mechanism 1C (S-VSUM, B) according to the third embodiment installed on the vibration exciter. It is the figure which showed the displacement between the mounting base of the machine, and the upper connection part 340 of the suspension part 300A with an upper layer spring-damper in a time series. The measurement of displacement used the laser displacement meter. For comparison, while having a natural frequency and resonance characteristics substantially equal to those of the suspension mechanism 1A according to the first embodiment, the same measurement is performed also in the case of using a single suspension of the X link structure generally used. went. In addition, in the figure, since the part shown by the arrow exceeded the measurement range of the laser displacement meter, it has a flat waveform.

  That is, FIG. 25 has a dead zone and a suspension mechanism 1C (S-VSUM, B) of the third embodiment having a dead zone and a resonance point in the range of 1.0 to 1.5 Hz, and a dead zone. It does not show the difference in behavior around the resonance point with the X link suspension where the resonance point is near 1.0 Hz. The displacement amount of the suspension mechanism 1C (S-VSUM, B) of the third embodiment was 50 mm and the displacement transfer ratio was about 1.5 from 50 mm / 32 mm with respect to the excitation amplitude of ± 16 mm. On the other hand, in the case of the X link suspension, the displacement transfer ratio was about 2.1 from 70 mm / 32 mm. Therefore, it is difficult to meet the standard of EM7 in the commonly used X-link suspension pen.

  26 shows a suspension mechanism 1A (S-VSUM, A) according to the first embodiment, a suspension mechanism 1C (S-VSUM, B) according to the third embodiment, and a seat supported by the X link suspension described above. The vibration transmission rate at the time of sitting the test subject C to 1000 and exciting with EM7 is shown. It can be seen that the behavior around the resonance point matches the displacement transfer ratio of FIG. 25 and is almost the same. The suspension mechanism 1A (S-VSUM, A) according to the first embodiment and the suspension mechanism 1C (S-VSUM, B) according to the third embodiment are both passively controlled in comparison with the X link suspension. It can be seen that the vibration transmission rate at the resonance point is reduced, and the phase difference of the movement of the suspension part of the laminated structure contributes significantly.

  As described above, according to the present invention, by making the damping characteristics or the spring characteristics of the stacked suspension parts different, the suspension parts acting mainly according to the input will be different, causing a phase difference, and various inputs It is possible to provide a suspension mechanism that can cope with vibration and impact.

  Here, FIG. 27 shows a seat 1000 according to the second embodiment (a seat 1000 supported by the seat suspension portion 2000A having a structure in which the suspension mechanism 1A and the seat suspension portion damper 2300 are removed) and a seat according to a reference example. In a dynamic state in which the subject was seated and vibrated with a waveform according to the EM8 standard for 15 minutes, heart rate (HR), sympathetic index LF / HF, and parasympathetic index HF were determined. It is a thing. The seat of the reference example has a structure in which the upper-layer spring-damper suspension 300 is removed from the seat according to the first embodiment, that is, a linear spring directly on the lower-layer spring-damper suspension 100 including the magnetic spring 122. It is a seat supporting a mechanism consisting of a seat suspension unit 200 provided with a mechanism 220.

  As for the heart rate in FIGS. 27A and 27B, the heart rate is lower in the sheet 1000 of the second embodiment, and the change is also smaller and the convergence tendency tends to be stable. In the indices of sympathetic nerve activity in FIGS. 27C and 27D, the sheet of the reference example has a large value and a large amount of change, while the sheet 1000 of the second embodiment is stable. In each index of the parasympathetic nerve activity in FIGS. 27E and 27F, the sheet 1000 of the second embodiment has a larger value and tends to be stable.

  From these results, the seat 1000 of the second embodiment supported by the suspension mechanism 1A provided with the suspension part of the laminated structure leads to a state in which a person is in a resting state, that is, a stress-less pressure sense and relaxing. It has high tendency characteristics.

DESCRIPTION OF SYMBOLS 1A, 1C Suspension mechanism 100 Lower layer spring-suspension part with damper 101 Fixed part 110 Link mechanism 111 Front link 112 Rear link 120 Constant load spring mechanism 121 Torsion bar 122 Magnetic spring 130 1st damper 140 Movable support part 2000, 2000A sheet Suspension part 2100 Link mechanism 2110 Front link 2120 Rear link 2200 Linear spring mechanism 2210 Torsion bar 2300 Seat suspension part damper 2400 Seat support part 300, 300A Upper layer spring-suspension suspension part 310 Second link mechanism 320 Linear spring mechanism 321 Torsion Bar 330 second damper 320A constant load spring mechanism 322A magnetic spring

Claims (14)

A suspension mechanism disposed between the vehicle body structure and the seat,
A pair of upper and lower frame parts relatively moved up and down through the link mechanism,
A spring mechanism resiliently urging the pair of upper and lower frame parts;
A plurality of spring-dampered suspension units including a damper for damping the force when the pair of upper and lower frame portions move up and down relatively are stacked vertically.
The damping characteristics or spring characteristics of the spring-dampered suspension portion of one layer among the plurality of stacked spring-dampered suspension portions and the damping characteristics or spring characteristics of the spring-dampered suspension portion of the other layer By making them different, it is possible to cause a phase difference in the movement of each spring-dampered suspension part, and
What is claimed is: 1. A suspension mechanism characterized by having a hysteresis loss of 150 N or less at the time of loading and unloading as load-deflection characteristics measured to be in a neutral position when supporting a load mass of 50 to 120 kg and measured.   The suspension mechanism according to claim 1, wherein the phase difference between the motions of the respective spring-dampered suspension portions is 120 degrees or more in a frequency band including a resonance point having a frequency of 2 Hz or less.   The said damper of the suspension part with a spring-damper of the said one part layer has a damping force different from the said damper of the suspension part with a spring-damper of the said other layer. Suspension mechanism. Of the plurality of stacked suspension-spring-damper units,
The spring mechanism of the spring-dampered suspension portion of at least one layer employs a constant load spring mechanism having a characteristic that the amount of change in load value becomes a predetermined load or less within a predetermined displacement range in the load-deflection characteristics. And
The constant load spring mechanism is
A linear spring showing linear characteristics,
A fixed magnet, and a movable magnet whose relative position with the fixed magnet is displaced in accordance with relative vertical movement of the pair of upper and lower frame parts, and a spring constant according to the relative position of the fixed magnet and the movable magnet And a magnetic spring that exhibits non-linear characteristics that vary
The load-deflection characteristic which united the above-mentioned linear spring and the above-mentioned magnetic spring is the composition provided with the characteristic used as the fixed load whose change amount of load value is less than a predetermined within the predetermined displacement range. The suspension mechanism described in 1.   In the case where the constant load spring mechanism is not adopted, in the case of having a spring-dampered suspension part, the spring mechanism of the spring-dampered suspension part adopts a linear spring mechanism in which load-deflection characteristics change linearly. Suspension mechanism described. The spring-dampered suspension part consists of two layers,
The spring-dampered suspension part disposed in the lower layer is configured to have the constant load spring mechanism,
The suspension mechanism according to claim 5, wherein the spring-dampered suspension portion disposed in the upper layer has the linear spring mechanism. The spring-dampered suspension part consists of two layers,
5. The suspension mechanism according to claim 4, wherein both the suspension part with spring and damper disposed in the lower layer and the suspension part with spring and damper disposed in the upper layer have the constant load spring mechanism.   One of the constant load spring mechanisms of the constant load spring mechanism of the spring-damper suspension part disposed in the lower layer and the constant load spring mechanism of the spring-damper suspension part disposed in the upper layer The movable magnet is provided such that the movable magnet is displaced in a substantially horizontal direction along with the vertical movement of the frame portion, and the magnetic spring constituting the other constant load spring mechanism is the movable magnet. The suspension mechanism according to claim 7, wherein the frame portion is vertically displaced as the frame portion moves up and down.   The stacked structure of the spring-dampered suspension part disposed in the lower layer and the stacked structure of the spring-dampered suspension part disposed in the upper layer is a load value in the load-deflection characteristics by the two constant load spring mechanisms. 9. The suspension mechanism according to claim 8, having a characteristic of exerting a characteristic that a constant load below a predetermined value is exerted at two different displacement positions.   In the load-deflection characteristics, the two regions showing the constant load characteristic are provided with a wedge showing a change in load value between the two, and there is a load difference between the two, but the load difference The suspension mechanism according to claim 9, wherein is within the range of hysteresis loss of two constant load areas.   The spring-dampered suspension portion of each layer is provided with an elastic force adjusting member for adjusting the elastic force of the linear spring employed in each of the constant load spring mechanism or each linear spring mechanism, and two elastic forces are provided. The suspension mechanism according to any one of claims 4 to 10, wherein the adjustment member functions as a lifter that adjusts the seating position of the seat occupant.   The suspension mechanism according to any one of claims 4 to 11, wherein the linear spring employed in the constant load spring mechanism or each linear spring mechanism is a torsion bar.   The suspension mechanism according to any one of claims 1 to 12, which is used for supporting a sheet of an earthworking machine. A seat structure comprising the suspension mechanism according to any one of claims 1 to 13 and a seat supported by the suspension mechanism,
A seat structure characterized in that a seat suspension portion for reducing a vibration transmission rate at a resonance point is further interposed between the suspension mechanism and the seat cushion portion.