JP4330456B2 - Seat suspension and control device therefor - Google Patents

Description

  The present invention relates to a seat suspension for a vehicle such as an automobile and a control device therefor.

  Patent Document 1 discloses the following seat suspension. In other words, an upper frame provided to be movable up and down with respect to a lower frame attached to a vehicle body floor is elastically supported by a magnetic spring and a torsion bar, and the magnetic spring has a negative spring constant in a predetermined displacement range. By combining the torsion bar having a positive spring constant, the overall spring constant is extremely small, preferably the overall spring constant is substantially zero, and vibration is absorbed. .

In such a seat suspension, in order to effectively use a region where the spring constant of the magnetic spring is negative, that is, in order to ensure as large a vibration absorption region where the overall spring constant is substantially zero, the magnetic spring It is preferable that the two magnet parts that make up and move away from each other are supported in a neutral position while supporting a load (human body). For this reason, in Patent Document 1, the vertical displacement of the upper frame when load mass is applied to the upper frame is detected, the torsion bar is twisted by a predetermined amount, the pre-tension of the torsion bar is adjusted, and the upper frame is moved up and down. And a control device that sets the relative position of the two magnet portions of the magnetic spring to the neutral position is disclosed.
JP 2003-320884 A

  However, the control device disclosed in Patent Document 1 adjusts the position of the upper frame in accordance with the load mass (human weight) as described above, but when the parking brake is used or the shift lever is in the parking range. The control circuit is set to be turned on only when it is input. Therefore, when the load mass fluctuates due to a change in posture during traveling, the magnetic spring cannot be maintained in the neutral position. On the other hand, in order to be able to always secure a neutral position according to the posture change, it is conceivable in Patent Document 1 to set the control circuit to be ON even during traveling. However, in this case, even if it becomes possible to secure the neutral position according to the posture change, it is intended to return to the neutral position even when there is an external vibration input that does not necessarily need to be adjusted in position. To do. That is, even though the neutral position corresponding to the load mass is already maintained, the position is not adjusted to the neutral position corresponding to the load mass by the external vibration input. With this, the vibration absorbing mechanism cannot effectively exhibit its vibration isolation function.

  The present invention has been made in view of the above, and can more reliably hold the neutral position according to the load mass of the vibration absorption mechanism, and more effectively exhibit the vibration isolation function of the vibration absorption mechanism. It is an object of the present invention to provide a seat suspension and a control device used for the seat suspension.

In order to solve the above-mentioned problem, in the invention according to claim 1, the lower frame attached to the vehicle body floor, the upper frame attached to the lower frame through the link so as to be movable up and down, and supporting the seat, the upper frame And a vibration absorption mechanism having a vibration absorption region in a predetermined displacement range with a neutral position as a center,
Detecting means for detecting the vertical position of the upper frame that is displaced according to the load mass;
Position adjusting means for adjusting the vibration absorbing mechanism to a neutral position in a state where a load mass is supported on the upper frame in accordance with an output from the detecting means;
When the upper frame moves up and down due to the input of vibration , and the displacement of the upper frame in the opposite direction is detected within a predetermined time range by the detection unit, the position adjustment unit is operated. A seat suspension comprising a control device including a cancel mechanism for canceling is provided.
In the invention according to claim 2 , the vibration absorbing mechanism comprises a combination of a magnetic spring having a negative spring constant in a predetermined displacement range and an elastic member having a positive spring constant,
The magnetic spring includes a first magnet portion and a second magnet portion that move relative to and away from each other, one of which is fixed to the upper frame side and the other is fixed to the lower frame side. And
2. The seat suspension according to claim 1, wherein the elastic member is provided with elasticity that urges the upper frame in the upward direction in a normal state.
In the invention according to claim 3 , the position adjusting means sets the relative position between the first magnet part and the second magnet part of the magnetic spring to a neutral position by adjusting the tension of the elastic member. The seat suspension according to claim 2 , wherein the seat suspension is configured.
According to a fourth aspect of the present invention, there is further provided an auxiliary spring member that elastically supports the upper frame with respect to the lower frame, wherein the position adjusting means adjusts the tension of the auxiliary spring member, and 3. The seat suspension according to claim 2 , wherein the relative position between the first magnet part and the second magnet part is set to a neutral position.
According to the fifth aspect of the present invention, the lower frame attached to the vehicle body floor, the upper frame attached to the lower frame so as to be movable up and down via a link, and the upper frame supporting the seat, the upper frame is elastic with respect to the lower frame. And a vibration suspension mechanism having a vibration absorption region with a predetermined displacement range centered on a neutral position, and a seat suspension control device comprising:
Detecting means for detecting the vertical position of the upper frame that is displaced according to the load mass;
Position adjusting means for adjusting the vibration absorbing mechanism to a neutral position in a state where a load mass is supported on the upper frame in accordance with an output from the detecting means;
When the upper frame moves up and down due to the input of vibration, and the displacement of the upper frame in the opposite direction is detected within a predetermined time range by the detection unit, the position adjustment unit is operated. Canceling mechanism to cancel and
A control device for a seat suspension is provided.

  According to the present invention, the control device detects the vertical position of the upper frame that is displaced according to the load mass, and the load mass is supported by the upper frame according to the output from the detection unit, Position adjusting means for adjusting the vibration absorbing mechanism to a neutral position, and a cancel mechanism for canceling the operation of the position adjusting means when the upper frame moves up and down due to vibration input. When a load is applied, for example, when a person is seated on the upper frame, or when the posture is changed, the position adjusting means operates to adjust the vibration absorbing mechanism to the neutral position according to the load mass. For this reason, even if the load mass fluctuates due to a change in posture or the like, the vibration absorption mechanism is ensured to the maximum with the vertical displacement range (vibration absorption region) that exhibits the vibration isolation function hardly changing. Further, when the vertical movement of the upper frame is caused by vibration input, the operation of the position adjusting means is canceled by the cancel mechanism. For this reason, since the position adjusting means does not operate depending on the vibration input, the neutral position of the vibration absorbing mechanism does not substantially change even though the load mass does not fluctuate. Function can be demonstrated.

  Hereinafter, the present invention will be described in more detail based on embodiments shown in the drawings. FIG. 1 is a perspective view showing a structure of a seat suspension 1 according to an embodiment of the present invention, and FIG. 2 is a side view thereof. FIG. 3 is a perspective view with the upper frame removed, and FIG. 4 is a partial exploded perspective view thereof.

  As shown in these drawings, the seat suspension 1 of the present embodiment includes an upper frame 10 and a lower frame 20 that are substantially rectangular and are connected via a pair of X links 30 and 40. A vehicle seat (not shown) is supported on the upper frame 10, and the lower frame 20 is fixed to a vehicle body floor (not shown). The pair of X links 30 and 40 are provided in the vicinity of the side portions of the upper frame 10 and the lower frame 20, respectively, and support the upper frame 10 so as to be movable up and down with respect to the lower frame 20.

  In this embodiment, the vibration absorbing mechanism is composed of a combination of a magnetic spring 50 having a negative spring constant in a predetermined displacement range and torsion bars 61 and 62 which are elastic members having a positive spring constant. . As illustrated in FIG. 2, the magnetic spring 50 includes an outer magnet portion 51 that is a first magnet portion and an inner magnet portion 52 that is a second magnet portion. The outer magnet portion 51 is composed of a pair of two members that are arranged to face each other with a predetermined distance therebetween, and two permanent magnets 51a and 51b are held with two different poles adjacent to each other. The inner magnet portion 52 has a permanent magnet held substantially at the center, and is provided to be slidable in the vertical direction between a pair of two members constituting the outer magnet portion 51. Then, when the outer magnet portion 51 and the inner magnet portion 52 are relatively displaced, a negative spring characteristic is exhibited in which the load decreases with an increase in the displacement amount within a predetermined displacement range. As such a magnetic spring 50, what was disclosed by Unexamined-Japanese-Patent No. 2002-206594 can be used, for example.

  In the present embodiment, the outer magnet portion 51 of the magnetic spring 50 is fixed to the lower surface of the upper frame 10, and the inner magnet portion 52 is disposed on the right side of the X link 30 in FIG. 2. The first link member 31 is supported via a bracket 31a. Thereby, when the upper frame 10 is displaced relative to the lower frame 20, the outer magnet portion 51 and the inner magnet portion 52 are relatively displaced.

  In addition, although not shown in figure, the magnetic spring 50 is arrange | positioned also at the other X link 40 side by the same structure. Of course, the number of magnetic springs 50 is not limited, and the displacement stroke amount of the upper frame 10 and the lower frame 20, the displacement stroke amount that generates a negative spring constant, and the size and strength of the permanent magnet provided on the magnetic spring 50 are not limited. It is possible to set arbitrarily. Further, the outer magnet portion 51 and the inner magnet portion 52 are vertically moved together with any member (upper frame 10 side) that moves up and down with the upper frame 10 and the lower frame 20 so as to be relatively displaced together with the upper frame 10 and the lower frame 20. For example, the inner magnet portion 52 may be directly attached to the lower frame 20 instead of the first link member 31 of one X link 30. It can also be supported via a connected bracket (not shown). However, in order to secure a displacement stroke amount that is smaller and has a negative spring constant as much as possible, it is preferable to support the link 30 or 40 via a bracket at an appropriate position as in this embodiment.

  One torsion bar 61, which is an elastic member having a positive spring constant, has an upper end portion of the first link member 31 in one X link 30 and the second X link 40 in the other X link 40 disposed opposite thereto. 1 between the upper end portions of one link member 41. Specifically, one end of the torsion bar 61 is fixed to the upper end of the first link member 31 of one X link 40 by a bush 61a, and the other end is the other end. The X link 40 is attached to the upper end portion of the first link member 41, and the upper surface is connected to a bracket 61 b fixed to the upper frame 10. Due to the torsional torque of the torsion bar 61, the lower frame 20 fixed to the vehicle body floor is urged so that the lower ends of the first link members 31, 41 are pressed downward with the torsion bar 61 as a fulcrum. On the other hand, the upper frame 10 is biased relatively upward. The other torsion bar 62 has a lower end portion of the second link member 32 that intersects the first link member 31 in one X link 30 and the second X link 40 disposed opposite to the second link member 32. Between the two link members 42 and the lower end portion thereof, one end portion is provided as a fixed end, and the torsional torque biases the upper end portions of the second link members 32 and 42 upward. Then, together with one torsion bar 61, the upper frame 10 is biased relatively upward.

  In the displacement region where the spring constant of the magnetic spring 50 is negative by superimposing the spring characteristics of the magnetic spring 50 on the positive spring constant of the torsion bars 61 and 62, the overall spring constant is Both cancel each other and become extremely small, preferably substantially zero, so that vibration can be absorbed. The torsion bars 61 and 62 may be arranged so as to urge the upper frame 10 in a direction away from the lower frame 20, and the arrangement positions thereof are not limited to the mode shown in the drawing. Of course. Further, any elastic member having a positive spring constant may be used, and another metal spring such as a coil spring may be used instead of or together with the torsion bar.

  The above-described vibration absorbing mechanism reduces the overall spring constant by combining the magnetic spring 50 and the torsion bars 61 and 62, and preferably absorbs vibration by making it zero (hereinafter referred to as “spring zero”). . However, in order to make maximum use of this spring zero region (that is, the vibration absorption region), a seat is attached to the upper frame 10 and a person is seated, i.e., a load is applied. Most preferably, the positional relationship between the magnet unit 51 and the inner magnet unit 52 is set to a neutral position in a displacement region where the spring constant is negative. However, even if the weight of the seat is constant, there are individual differences in human weight. Further, the load mass applied to the upper frame 10 also changes due to the posture change.

  Therefore, in order to set the vibration absorbing mechanism in the neutral position in the seated state, that is, in order to set the positional relationship between the outer magnet portion 51 and the inner magnet portion 52 of the magnetic spring 50 to the neutral position, in the present embodiment, Detection means 70 and position adjustment means 80 are provided.

  The detection means 70 detects the vertical position of the upper frame 10 that is displaced according to the load mass. An arbitrary part of the upper frame 10 may be directly detected, or an arbitrary part of a member whose vertical position varies with the upper frame 10 such as the X links 30 and 40 connected to the upper frame 10 may be detected. There may be. Further, the type of sensor is not limited as long as the detection means 70 fulfills such a function.

  In the present embodiment, two brackets 20a and 20b are attached to the lower frame 20 at positions corresponding to the first link members 31 and 41 of the X links 30 and 40, and detection means is attached to the brackets 20a and 20b. 70, there are provided Hall ICs 71 and 72, which are magnetic sensors, and a detection magnet 73 (a detection magnet facing the Hall IC 71 is not shown) disposed opposite to the Hall ICs 71 and 72 at a predetermined distance from each other. Yes. When each of the first link members 31 and 41 of the X links 30 and 40 moves up and down together with the upper frame 10 via a bracket, one Hall IC 71 and one detection magnet are moved. Plate members 74 and 75 made of iron plates that pass between the other Hall IC 72 and the other detection magnet 73 and shield the magnetic field are provided. The Hall ICs 71 and 72 are attached at the same height, but the plate members 74 and 75 are attached at different heights. As a result, when the upper frame 10 moves up and down, the plate members 74 and 75 have different positions for blocking the magnetic field. Therefore, the upper frame 10 is designed to be in a neutral position (at this position, the outer portion of the vibration absorbing mechanism). While the magnet unit 51 and the inner magnet unit 52 are in a neutral position), different signals can be output depending on whether the magnet unit 51 and the inner magnet unit 52 are positioned on the upper side or the lower side, while the difference in height (length) is present. Is an acceptable range to be regarded as a neutral position.

  The position adjusting means 80 moves the upper frame 10 up and down relative to the lower frame 20 in accordance with the output signal from the detecting means 70 described above and adjusts it to the neutral position. In the present embodiment, a motor 81 whose output shaft is rotated forward or reverse by an output signal from the detection means 70 is connected to the output shaft of the motor 81 via a gear mechanism 81a composed of a worm and a worm wheel, A trapezoidal screw 82 arranged and rotated in a direction orthogonal to the output shaft of the motor 81 and a female screw portion screwed into the trapezoidal screw 82 are provided, and arranged in a direction orthogonal to the trapezoidal screw 82. An adjustment shaft 83, an adjustment bracket 84 having an upper end 84a connected to the adjustment shaft 83, and an engagement welded to the adjustment bracket 84 and one end of a plurality of coil springs 85 engaged. A shaft 86 is provided. The other end of the coil spring 85 is engaged with a support shaft 10 a provided on a bracket attached to the lower surface of the upper frame 10. The coil spring 85 is an auxiliary spring member that elastically supports the upper frame 10 with respect to the lower frame 20.

  These are formed by bending a plate-like member into a substantially U-shape, spanned between the upper portions of the second link members 32 and 42 of the X links 30 and 40, and are supported by the U-shaped links. Supported by the member 87. Specifically, the U-shaped link member 87 is welded with a supporting pipe member 87a along the width direction, and is fixed by an outer mounting plate 87b fixed so as to protrude outside the supporting pipe member 87a. The motor 81 and the trapezoidal screw 82 are supported via the gear mechanism 81a, and the lower end portion 84b of the adjustment bracket 84 is pivotally supported by the inner mounting plate 87c fixed so as to protrude inside the supporting pipe member 87a. Is done. Accordingly, when the rotational force of the motor 81 is transmitted through the trapezoidal screw 82 and the adjustment shaft 83, the adjustment bracket 84 rotates about the lower end portion 84b (see FIGS. 5 and 6).

  The position adjusting means 80 adjusts the upper frame 10 (the positional relationship between the outer magnet portion 51 and the inner magnet portion 52 of the magnetic spring 50 of the vibration absorbing mechanism) to the neutral position according to the output signal from the detecting means 70. However, when vibration is input, in order to perform vibration isolation using the spring zero function of the vibration absorbing mechanism, the present embodiment includes a cancel mechanism that cancels the operation of the position adjusting means 80. Yes. The cancel mechanism in the present embodiment includes a cancel circuit that cancels the output signal from the detection means 70 to the position adjustment means 80 under certain conditions. Then, next, the control circuit 90 of this embodiment that includes this cancel circuit and controls the position adjusting means 80 that operates in response to the detection signal of the detecting means 70 will be described with reference to FIG.

  In the control circuit 90, the first NOT circuit 91 is connected to one Hall IC 71 corresponding to the long plate member 74 of the detection means 70, and the first AND circuit 92 is connected to the subsequent stage. Has been. Further, an exclusive OR (EX-OR) circuit 93 is connected to one Hall IC 71 and the other Hall IC, and its output is input to the second NOT circuit 94. Then, the output of the first NOT circuit 91 and the output of the second NOT circuit 94 are input to the first AND circuit 92, and the output of one Hall IC 71 and the output of the second NOT circuit 94 are the second AND circuit. Input to the circuit 95. The outputs of the first AND circuit 92 and the second AND circuit 95 are input to the motor drive circuit 98 through the motor protection circuit 96 and the cancel circuit 97. The motor drive circuit 98 includes a first relay (weight adjustment minimum (min) side) 98a and a second relay 98b (weight adjustment maximum (max) side), and is disposed in front of the relays 98a and 98b. Transistors 98c and 98d. The output from the first AND circuit 92 is charged in one capacitor 97c of the cancel circuit 97, and then a current flows through the transistor 98c in the subsequent stage to turn on the first relay 98a and to turn the motor 81 in one direction. The output from the second AND circuit 95 is charged in the other capacitor 97d of the cancel circuit 97, and then a current flows through the subsequent transistor 98d to turn on the second relay 98b, and the motor 81 Is rotated in the reverse direction.

  The motor protection circuit 96 includes two limit switches 96a and 96b, and the output of one limit switch 96a is input to a third AND circuit 96c connected to the first AND circuit 92, and the other limit switch 96b. Are input to a fourth AND circuit 96d connected to the second AND circuit 95. As a result, when any of the limit switches 96a and 96b is activated, the circuit is disconnected and the supply of current to the motor 81 is cut off. As shown in FIGS. 2 and 4, one limit switch 96a contacts the inner mounting plate 87c when the adjustment bracket 84 is rotated downward (clockwise in FIG. 6) by the motor 81. The other limit switch 96b is positioned on the outer mounting plate 87b and the adjustment bracket 84 is moved upward by the motor 81 (counterclockwise in FIG. 5). The switch lever is attached so as to come into contact with the adjustment bracket 84, and the upper rotation position of the adjustment bracket 84 is restricted.

  The cancel circuit 97 includes transistors 97a and 97b and capacitors 97c and 97d on the first AND circuit 92 side and the second AND circuit 95 side, respectively, and connects one transistor 97a and the other capacitor 97d. The other transistor 97b and one capacitor 97c are connected. Thus, when a current flows through one transistor 97a, the other capacitor 97d is discharged, and when a current flows through the other transistor 97b, one capacitor 97c is discharged. Therefore, before supplying current to the motor drive circuit 98, the capacitors 97c and 97d are discharged when current flows through the corresponding transistors 97a and 97b, respectively. Therefore, the relay 98a of the motor drive circuit 98 is discharged. , 98b are not turned ON. That is, the electrical signal from one Hall IC 71 and the electrical signal from the other Hall IC 72 are the same, and “H (High)” and “L (Law)” are alternately detected within a predetermined time interval. In such a case, the vibration is caused and the operation of the motor drive circuit 98 is cancelled. This time interval can be arbitrarily set depending on the capacitance of the capacitors 97c and 97d and the circuit configuration. For example, when the detection interval of each Hall IC 71 and 72, that is, when the vibration frequency is 1 to 2 Hz or more, the cancel circuit 97 is activated. Set to

  Next, the operation of this embodiment will be described. When a person is seated on the seat in a predetermined posture and a load mass is applied to the upper frame 10, it is detected that the position of the upper frame 10 detected by the detection means 70 matches the neutral position. At that time, the position adjusting means 80 does not operate. On the other hand, the upper frame 10 moves from the neutral position when the seated person bends forward, for example, and thus moves upward from the neutral position. When the leg is lifted, the load mass increases. Also move down. When such a state is detected, the position adjusting means 80 is operated via the control circuit 90 by the electric signal from the detecting means 70 so that the upper frame 10 is adjusted to the neutral position. Specifically, it is as follows. Strictly speaking, the neutral position is one point according to the load mass applied to the upper frame 10 (which changes depending on the body weight and posture). However, in the present invention, as in the above embodiment, the plate member for detection is used. If the lengths 74 and 75 are different from each other and are located within an allowable range (for example, 10 mm) corresponding to the different lengths, the neutral positions are set.

(When upper frame 10 is in neutral position)
In the present embodiment, as described above, one plate member 74 and the other plate member 75 are formed so as to have a difference in length. If one plate member 74 is longer than the other plate member 75 and both of them are not detected by the Hall ICs 71 and 72, the upper frame 10 is positioned above the neutral position (min side), and the plate members 74, When both 75 are detected by the Hall ICs 71 and 72, they are positioned below the neutral position (max side). Therefore, for example, when one plate member 74 is longer than the other plate member 75, only one plate member 74 is detected by one Hall IC 71 and the other plate member 75 is not detected in the neutral position. .

  As shown in FIG. 8, when the upper frame 10 is in the neutral position, the Hall IC 71 corresponding to one plate member 74 becomes “H (High)” and the output signal “H” of the Hall IC 72 corresponding to the other plate member 75 is “ L (Law) ". Each signal passes through an exclusive OR (EX-OR) circuit 93 and a second NOT circuit 94, and the inputs of the first AND circuit 92 and the second AND circuit 95 are set to "L". For this reason, there is no output from any of the first and second AND circuits 92 and 95, both the relays 98a and 98b are turned off, and the position adjusting means 80 is not activated.

(When the upper frame 10 is below the neutral position)
For example, when the seated person lifts the leg and the load mass becomes heavy and the upper frame 10 moves to the lower position, the one plate member 74 and the other plate member 75 are both holed. It is detected by the ICs 71 and 72, that is, the magnetic fields between the Hall ICs 71 and 72 and the corresponding magnets 73 are blocked. In this case, as shown in FIG. 8, the output signals of the Hall ICs 71 and 72 are both “H”, and after passing through the exclusive OR (EX-OR) circuit 93 and the second NOT circuit 94, The inputs of the first AND circuit 92 and the second AND circuit 95 are set to “H”. The output signal of the Hall IC 71 passes through the first NOT circuit 91 to set the input of the first AND circuit 92 to “L” and the input of the second AND circuit 95 to “H”. Only the output of the AND circuit 95 becomes “H”. For this reason, the second relay 98b is turned ON, and the output shaft of the motor 81 rotates in a predetermined direction (max side) by the output. The drive of the motor 81 is transmitted to the trapezoidal screw 82, and the adjustment shaft 83 screwed to the trapezoidal screw 82 is moved forward from the state of FIG. 6 as shown in FIG. 5, and the adjustment bracket 84 is rotated counterclockwise. Rotate to When the adjustment bracket 84 rotates counterclockwise, one end of the coil spring 85 follows and rotates upward. Since the other end of the coil spring 85 is connected to the support shaft 10a of the upper frame 10, when the coil spring 85 is pulled, a force for raising the second link members 32 and 42 is increased. As a result, the force to lift the upper frame 10 becomes stronger with respect to the lower frame 20, and the upper frame 10 is raised and balanced at the neutral position. When the neutral position is reached, the operation of the position adjusting means 80 is turned off as described above.

(When the upper frame 10 is above the neutral position)
For example, when the load mass is reduced due to forward bending, the upper frame 10 is positioned above the neutral position. In this case, the plate members 74 and 75 are not detected by the Hall ICs 71 and 72, that is, the magnetic fields between the Hall ICs 71 and 72 and the magnets 73 and 74 corresponding thereto are not blocked. As shown in FIG. 8, the output signals 72 are all “L”. The inputs of the first AND circuit 92 and the second AND circuit 95 are set to “H” via the exclusive OR (EX-OR) circuit 93 and the second NOT circuit 94. The output signal of the Hall IC 71 passes through the first NOT circuit 91 and the input of the first AND circuit 92 is set to “H” and the input of the second AND circuit 95 is set to “L”. Only the output of the AND circuit 95 becomes “H”. As a result, the first relay 98a is turned on, and its output is input to the motor 81. The output shaft of the motor 81 rotates in the reverse direction (min side). The drive of the motor 81 is transmitted to the trapezoidal screw 82, the adjustment shaft 83 screwed to the trapezoidal screw 82 is moved rearward as shown in FIGS. 5 to 6, and the adjustment bracket 84 is rotated clockwise. . Thereby, compared with the case where the tension of the coil spring 85 is adjusted to the max side, the force for raising the second link members 32 and 42 is weakened. Accordingly, the force to lift the upper frame 10 with respect to the lower frame 10 is weakened, and the upper frame 10 is lowered by the load mass and balanced at the neutral position. When the neutral position is reached, the operation of the position adjusting means 80 is turned off.

  If the posture is changed or a person with a different weight is newly seated to cause a substantial change in the load mass and the upper frame 10 moves up and down, the above adjustment is repeated.

(For vibration input)
On the other hand, when a change in load mass occurs due to input of vibration, the upper frame 10 vibrates up and down within a predetermined time interval (for example, a vibration frequency of 1 to 2 Hz or more). In this case, for example, when the upper frame 10 moves upward, the outputs of the two Hall ICs 71 and 72 both become “L” and the output of the first AND circuit 92 becomes “H”. In order to move downward at short time intervals, the outputs of the two Hall ICs 71 and 72 are both switched to “H”, and the output of the second AND circuit 95 is set to “H”. In order to repeat this at short time intervals, before the current flows through the relays 98a and 98b, the one capacitor 97d of the cancel circuit 97 discharges the other capacitor 97d, and the other transistor 97b discharges the one capacitor 97c. As a result, both the relays 98a and 98b of the motor drive circuit 98 are not turned on by external vibration.

  As a result, the external vibration is efficiently absorbed by making the maximum use of the spring zero region (vibration absorption region) of the vibration absorption mechanism comprising the combination of the magnetic spring 50 incorporated in the suspension unit 1 and the torsion bars 61 and 62. The 2 is a damper disposed between the upper frame 10 and the lower frame 20, and a large impact vibration is also absorbed by the action of the damper 15.

  However, in order to absorb the impact vibration more efficiently, when the impact vibration is detected, the position adjusting means 80 is activated again or another impact absorbing mechanism (not shown) is activated. It is preferable to do. Whether or not it is impact vibration, for example, when the detecting means 70 is Hall ICs 71 and 72, it is determined from the ON-OFF time interval or the like, or another sensor such as a rotary encoder is arranged to provide impact vibration. It is determined whether or not the shock absorbing mechanism is activated.

  The present invention is not limited to the embodiment described above. In the above embodiment, the X links 30 and 40 are used as the links connecting the upper frame 10 and the lower frame 20, but other links may be used. The vibration absorbing mechanism is not limited to the combination of the magnetic spring 50 and the torsion bars 61 and 62 described above, and any other vibration absorbing mechanism may be used as long as it has a vibration absorbing region due to a zero spring action. . The position adjusting means 80 is not limited to the above-described configuration, and may be configured to adjust the pretension of any torsion bar as disclosed in, for example, Japanese Patent Laid-Open No. 2003-320884. it can. The above configuration of the control circuit 90 is only an example, and other circuit configurations may be used, or a programmed microcomputer may be used.

  Further, in the above-described embodiment, by adjusting the vertical position of the upper frame 10 with respect to the lower frame 20, the outer magnet portion 51 constituting the magnetic spring 50 is moved up and down to adjust the position with respect to the inner magnet portion 52, so that the neutral position is neutral. Set to position. However, in the present invention, the vibration absorbing mechanism is set to the neutral position, that is, the positional relationship between the outer magnet portion 51 and the inner magnet portion 52 is set to the neutral position in order to make maximum use of the spring zero region. . Therefore, as the position adjusting means 80, in the above embodiment, the position of the outer magnet portion 51 is adjusted by adjusting the height of the upper frame 10, but conversely, the vertical position of the inner magnet portion 52 of the magnetic spring 50 is A mechanism that adjusts the amount of displacement according to the load mass can also be used. This is the same even when the outer magnet portion 51 and the inner magnet portion 52 are attached in the reverse positional relationship.

FIG. 1 is a perspective view showing a schematic configuration of a seat suspension according to an embodiment of the present invention. FIG. 2 is a side view of FIG. FIG. 3 is a perspective view showing a state in which the upper frame is removed. 4 is an exploded perspective view of a part of FIG. FIG. 5 is a diagram for explaining a state in which the position adjusting means is on the weight adjustment maximum (max) side and the lifting force of the upper frame by the coil spring is the highest. FIG. 6 is a diagram for explaining a state in which the position adjusting means is on the weight adjustment minimum (max) side and the lifting force of the upper frame by the coil spring is the lowest. FIG. 7 is a diagram for explaining a control circuit including the cancel circuit used in the embodiment. FIG. 8 is a table for explaining the operation of the control circuit of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Seat suspension 10 Upper frame 20 Lower frame 30, 40 X link 50 Magnetic spring 61, 62 Torsion bar 70 Detection means 71, 72 Hall IC
73 Magnet for detection 74, 75 Plate member for detection 80 Position adjustment means 81 Motor 82 Trapezoid screw 83 Adjustment shaft 84 Adjustment bracket 85 Coil spring 90 Control circuit 96 Motor protection circuit 97 Cancellation circuit 98 Motor drive circuit 98a, 98b Relay

Claims (5)

A lower frame attached to the vehicle floor, an upper frame that is attached to the lower frame so as to be movable up and down via a link, elastically supports the upper frame with respect to the lower frame, and is in a neutral position And a vibration absorption mechanism having a vibration absorption region in a predetermined displacement range with a center as a center,
Detecting means for detecting the vertical position of the upper frame that is displaced according to the load mass;
Position adjusting means for adjusting the vibration absorbing mechanism to a neutral position in a state where a load mass is supported on the upper frame in accordance with an output from the detecting means;
When the upper frame moves up and down due to the input of vibration , and the displacement of the upper frame in the opposite direction is detected within a predetermined time range by the detection unit, the position adjustment unit is operated. A seat suspension comprising a control device including a cancel mechanism for canceling. The vibration absorbing mechanism comprises a combination of a magnetic spring having a negative spring constant in a predetermined displacement range and an elastic member having a positive spring constant,
The magnetic spring includes a first magnet portion and a second magnet portion that move relative to and away from each other, one of which is fixed to the upper frame side and the other is fixed to the lower frame side. And
The seat suspension according to claim 1, wherein the elastic member has elasticity that urges the upper frame in the upward direction in a normal state. The position adjusting means is configured to set a relative position between the first magnet portion and the second magnet portion of the magnetic spring to a neutral position by adjusting a tension of the elastic member. The seat suspension according to claim 2 . An auxiliary spring member that elastically supports the upper frame with respect to the lower frame is further provided, and the position adjusting means adjusts the tension of the auxiliary spring member, and the first magnet portion and the second magnet spring of the magnetic spring are adjusted. The seat suspension according to claim 2 , wherein the seat suspension is configured to set the relative position to the magnet portion to a neutral position. A lower frame attached to the vehicle floor, an upper frame that is attached to the lower frame so as to be movable up and down via a link, elastically supports the upper frame with respect to the lower frame, and is in a neutral position A suspension control device comprising a vibration absorption mechanism having a vibration absorption region in a predetermined displacement range centered on
Detecting means for detecting the vertical position of the upper frame that is displaced according to the load mass;
Position adjusting means for adjusting the vibration absorbing mechanism to a neutral position in a state where a load mass is supported on the upper frame in accordance with an output from the detecting means;
When the upper frame moves up and down due to the input of vibration, and the displacement of the upper frame in the opposite direction is detected within a predetermined time range by the detection unit, the position adjustment unit is operated. Canceling mechanism to cancel and
A control device for a seat suspension, comprising:

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