JPH0249075Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a seat suspension device on which a vehicle seat is placed and which prevents vibrations from being transmitted to the seat.

[Prior Art] When the cushioning properties of a vehicle seat are increased, depending on the weight of the occupant, the vehicle seat may sink into the seat excessively, resulting in worse riding comfort, and may impair visibility and operability during driving. Therefore, instead of increasing the cushioning properties of a vehicle seat, there is a vehicle seat in which the entire seat is elastically supported on the vehicle floor by a suspension device.

Such seat suspension devices are usually provided with a shock absorber to quickly damp large amplitude vibrations. Generally, this is a so-called liquid-filled piston-cylinder type in which damping force is generated by flowing liquid sealed in the cylinder through a throttle hole provided in the piston, and the damping force is uniquely determined by the diameter of the throttle hole. Ru.

By the way, it is desirable that the suspension device reduce the damping force to absorb the high-frequency, small-amplitude vibrations that are input thereto.
Here, in the suspension device using the conventional shock absorber described above, if the damping force is set high to effectively damp large amplitude vibrations, the absorption of minute vibrations cannot be achieved well. In some cases, a problem arises in that large-amplitude vibrations are not sufficiently damped.

Therefore, the inventor first proposed a seat suspension device that could generate an optimal damping force according to the vibration amplitude by particularly improving the structure of the shock absorber (Utility Application No. 60-034864).
issue).

An outline of the above proposed device will be explained below.

The device has a lower frame 1 (FIG. 4) fixed to the vehicle floor, and an upper frame 2 elastically supported on the lower frame 1 by a parallel link 3 provided with a torsion bar 31. A vehicle seat is placed on the Atsupah frame 2. Both frames 1 and 2 are connected by a shock absorber 4. That is, in the shock absorber 4, the lower end of the cylinder 41 is connected to a support shaft 111 provided on the lower frame 1, and the upper end of the piston rod 42 is connected to a support shaft 21 provided on the upper frame 2.

A piston 43 is provided in the cylinder 41 (FIG. 5), and the piston 43 has a throttle hole 431.
(Fig. 6) is formed. The piston 43 is provided with a rotary plate 44 that rotates in sliding contact with the piston surface, and the rotary plate 44 is formed with a liquid flow hole 441 corresponding to the throttle hole 431. Therefore, when the rotary plate 44 rotates, the liquid flow hole 441
is shifted from the aperture hole 431, and the opening area of the aperture hole 431 becomes smaller. The piston rod 42 has a cylindrical shape, and a shaft 45 for rotating the rotary plate 44 is inserted into the cylinder. A pin member 451' projects from the shaft 45, and the pin member 451' is inserted into the cam hole 5 of the cam plate 5' (FIG. 7).
1'. The cam plate 5' has one end rotatably connected to the support shaft 21 and the other end connected to the support shaft 111 via the link plate 6, and is operated in accordance with the vertical movement of the Atsupah frame 2. The pin member 451' is rotated around the axis of the shaft 45. With the above structure, when a large-amplitude vibration is input and the Atsupah frame 2 moves significantly downward, the rotary plate 44 is rotated greatly and the damping force of the device is increased, and when a small-amplitude vibration is input, the rotary plate 44 is Since the amount of rotation is small, the damping force can be kept small.

[Problems to be solved by the invention] By the way, in the proposed device, when the Atsupah frame 2 vibrates upward from the neutral position, the rotary plate 44 is forcibly returned to its original position by the cam plate 5' and rotated. It's forcing me. Normally, upward rebound vibration is relatively small, so there is no problem even if the rotary plate 44 is completely rotated to the original position as described above to reduce the damping force. However, depending on the application, rebound vibration may be It is desirable to be able to exert sufficient damping force.

In view of these demands, the present invention is a further improvement of the suspension device previously proposed by the inventor, and the object is to provide a seat suspension device that can effectively suppress the rebound vibration of the seat. shall be.

[Means for Solving the Problems] The device of the present invention, as shown in FIG.
A pin member 451 is provided protruding from the upper frame 2 (FIG. 4), and a cam plate 5 is provided which engages with the pin member 451 and rotates the shaft 45 when the upper frame 2 (FIG. 4) moves downward. Furthermore, the pin member 451 is provided with a return mechanism that gradually rotates the pin member 451 in the return direction when the cam plate 5 is not engaged with the pin member 451, and the return mechanism includes a spring that urges the pin member 451 in the return direction. It consists of a member 9 and a damper 8 that generates resistance in the biasing direction of the spring member 9.

[Operations and Effects] When large-amplitude vibration is input downward, the pin member 451 engages with the cam hole 51 of the cam plate 5 and is rotated around the piston rod 42. This increases the damping force of the shock absorber 4 and suppresses vibrations. When upward vibration is input due to rebound, the cam hole 51 and pin member 45
1 is released. And pin member 451
is rotated in the return direction by the spring force of the spring member 9, but due to the constant resistance generated by the damper 8, the rotation is gradually performed. Therefore, even during rebound vibration, the shock absorber 4
The damping force of is maintained relatively large to suppress vibration.

[Example] Fig. 1 shows a perspective view of the main parts of the present invention, and Fig. 2 shows a view taken along arrow A in Fig. 1. The other configurations are the same as the previously proposed device.

In the figure, the shock absorber 4 has a piston with a throttle hole provided in the cylinder 41, as described above, and the tip of the piston rod 42 is connected to the support shaft 21 through the eyelet 7. A shaft for driving a rotary plate that changes the opening area of the aperture hole is installed inside the cylindrical rod 42, and a pin member 451 extending through the shaft extends along the length of both side walls of the eyelet 7. It protrudes from the hole 71 (only one is shown).

The pin member 451 is formed into an L-shape, and one end thereof is inserted into the cam hole 51 of the cam plate 5. One end of the cam plate 5 is rotatably connected to the support shaft 21, and the other end is connected to the support shaft 111 via the link plate 6. The cam hole 51 has a U-shape with an open bottom end.

There is a bracket 82 on the bottom surface of the seat S (Fig. 2).
The damper 8 is fixed thereto, and the tip of a piston rod 81 protruding from the damper 8 is connected to the other end 451b of the pin member 451. The damper 8 is configured to generate almost no resistance in the retracting direction of the piston rod 81, and to generate a constant resistance in the retracting direction. A coil spring 9 is disposed on the outer periphery of the piston rod 81 to bias it in the advancing direction.

Now, when a large amplitude downward vibration is input to the suspension device having the above configuration, the cam plate 5
It is rotated around the support shaft 21 as shown by the arrow. The pin member 451 engages with the cam hole 51 and rotates around the piston rod 42 (arrow b in the figure). As a result, the rotary plate provided in contact with the piston provided in the cylinder is rotated, the area of the throttle hole of the piston is reduced, and the device produces a large damping force (region x in FIG. 3). At this time, the piston rod 81 of the damper 8 connected to the other end 451b of the pin member 451 is moved in the retracting direction without resistance as the pin member 451 rotates (c in the figure).
arrow).

During the subsequent upward rebound vibration, the cam plate 5
rotates in the opposite direction to the above, and the engagement with the pin member 451 is released. Here, the pin member 451
As the piston rod 81 is moved in the advancing direction by the spring force of the spring 9, it is rotated in the returning direction opposite to the above. Incidentally, the advancing movement of the piston rod 81 is carried out gradually over a predetermined period of time due to the action of resistance.
Therefore, the damping force of the device in this case gradually decreases at a constant slope, as shown by region y in FIG. As a result, a relatively large damping force is maintained even during rebound vibrations, so vibrations are effectively suppressed.

When large amplitude vibrations are not input, the pin member 451 is completely rotated to the return position, and the damping force of the device becomes small.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the main parts of the present invention, Fig. 2 is a view taken from arrow A in Fig. 1, Fig. 3 is a diagram showing changes in damping force of the device due to vibration input, and Figs. 4 to 7. The figures show a conventional example: Fig. 4 is an overall side view of the device, Fig. 5 is an overall sectional view of the shock absorber, Fig. 6 is a view taken in the direction of arrow B in Fig. 5, and Fig. 7 is a perspective view of the main parts. be. 1...Lower frame, 2...Atsupa frame,
3...Parallel link, 31...Torsion bar, 4
...Shock absorber, 42... Piston rod, 43... Piston, 44... Rotating plate, 45...
...Shaft, 451... Pin member, 5... Cam plate, 8... Damper, 9... Spring member.

Claims (1)

[Claims for Utility Model Registration] (1) An atsupa frame on which a seat cushion is mounted is supported by a lower frame fixed to the vehicle floor via an elastic member, and these frames are
A seat suspension device that is connected to a liquid-filled piston-cylinder type shock absorber that has a restrictor hole that allows liquid to flow through the piston. In the seat suspension device, a rotary plate is provided to reduce the opening area of the aperture hole, the piston rod is formed into a cylindrical shape, and a shaft for rotating the rotary plate is inserted into the cylinder.
The shaft is provided with a protruding pin member, and is also provided with a cam plate that is connected to the Atsupah frame and engages with the pin member during downward movement to rotate the shaft. A seat suspension device comprising a return mechanism that gradually rotates the pin member in the return direction when the plates are not engaged. (2) The seat suspension device according to claim 1, wherein the return mechanism includes a spring member that biases in the return direction and a damper that creates resistance in the bias direction of the spring member.