JPH0671871B2 - Vehicle seat air suspension system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air suspension device for a vehicle seat, which mainly supports a vehicle seat such as an automobile using a link mechanism and an air spring.

[0002]

2. Description of the Related Art Generally, an air suspension device for a vehicle seat includes a lower frame fixed on the floor of the vehicle,
A link mechanism and an air spring are provided between the seat frame and the upper frame which is arranged above and supports the seat cushion, and the load generated in the seat cushion on the upper frame by the internal working pressure of the air spring is supported.

In this type of air suspension device, the seat cushion is maintained at a set reference height in a stationary state regardless of the weight of a seated person, and an appropriate suspension stroke is ensured according to vibration during traveling, which is optimum. The internal air pressure of the air spring is automatically controlled so as to obtain a good cushioning performance.

An example of such a typical vehicle seat air suspension device is shown in Japanese Patent Application Laid-Open No. 54-97924. This will be briefly described with reference to FIGS. 6 and 7. In the figure, reference numeral 1 is a frame-shaped lower frame fixed on the floor of the vehicle, and 2 is a frame-shaped upper frame which is arranged above the lower frame 1 and supports a seat cushion (not shown) of a vehicle seat. A link mechanism 3 that supports the upper frame 2 so as to be vertically movable is assembled between the upper frame 2 and the lower frame 1.

The link mechanism 3 pivotally mounts a pair of left and right link bars 3a and 3b in an X shape by means of pivot pins 3c, and connects the left and right connecting shafts to the upper and lower ends of the link bars 3a and 3b, respectively. 3d and 3e are provided, and both ends of the upper and lower connecting shafts 3d arranged in the front are rotatably connected to the front frames of the left and right frame members of the upper frame 2 and the lower frame 1, and the connecting shaft 3e arranged in the rear. Both ends of the upper frame 2 and the lower frame 1 are slidably moved toward the rear ends of the left and right frame portions so as to be movable back and forth via rolling rollers 3f.

An air spring 5 is provided between the lower frame 1 and the upper frame 2, and the internal working pressure of the air spring 5 causes the seat cushion to move from the upper frame 2 to the upper frame 2.
It supports the load on.

A valve body 6 having a supply / exhaust valve for supplying air to the air spring 5 from an air supply source (not shown) such as a compressor or exhausting the air inside the air spring 5 is the lower frame. 1 is attached and fixed in a substantially frontward state via a bracket 9 protruding upward from 1. As shown in FIG. 7, the valve body 6 has a structure in which a normally closed air supply valve and an exhaust valve are built in a single casing, and the valve rods 7 and 8 of the air supply valve and the exhaust valve have predetermined intervals. Existing in parallel with each other on the same surface side, and the valve rods 7 and 8 are individually pushed in to open the air supply valve and the exhaust valve. When the pushing force is released, the built-in valve spring is attached. Each valve automatically returns to its closed state.

One cam 10 is provided as a valve switching mechanism for opening and closing the supply / exhaust valve of the valve body 6. As shown in FIG. 7, the cam 10 has a substantially fan-shaped plate shape,
The slope 11 is provided on the upper and lower parts of the rear end opposite to the front end apex.
The cam surfaces 11 and 12 are raised through a and 12a. The cam 10 is rotatably fitted to and attached to the connecting shaft 3d at the lower end of one of the link bars 3a of the link mechanism 3 with the front end apex angled. Further, an arc-shaped elongated hole 13 centered on the shaft 3d is provided in the middle of the cam 10, and a pin 14 which is a connecting member protruding from the link bar 3a is loosely fitted in the elongated hole 13. The pin 14 moves up and down together with the link bar 3a, and when the pin 14 passes the idling distance x in the elongated hole 13, the cam 10 interlocks and rotates up and down.

In the vehicle seat air suspension device having such a structure, when a seated person with a heavy weight sits down or the seat cushion is lowered from a preset reference height by the load caused by the traveling vibration of the automobile, From the state shown in the drawing, the link bar 3a rotates downward together with the pin 14, and when the pin 14 exceeds the idling distance x in the elongated hole 13, the cam 10 is interlocked and pushed down for the first time. As a result, the valve rod 7 of the air supply valve of the valve body 6 is provided with the slope portion 11 of the upper portion of the cam 10.
The air supply valve is opened by being pushed in by the cam surface 11 through a, supplies compressed air from the air supply source to the air spring 5, and pushes up the upper frame 2 by increasing the internal working pressure of the air spring 5. Raise the seat cushion. During this ascent, the valve rod 7 remains pressed into the cam surface 11, the air supply valve does not close immediately, and the pin 14 together with the link bar 3a passes the idling distance x in the slot 13, that is, When the seat cushion returns to the set reference height, the cam 10 rotates upward, the valve rod 7 projects from the upper cam surface 11 via the inclined surface portion 11a, and the air valve closes. The user stops feeling and the seat cushion is returned to and held at the set reference height.

Contrary to the above, when the seat cushion rises from the set reference height due to the occupant leaving the seat or the traveling vibration of the automobile, the link bar 3a and the pin are removed from the state shown in FIG. When the cam 10 interlocks with 14 and rotates upward by an angle equal to or more than the idling distance x,
The valve rod 8 of the exhaust valve of the valve body 6 has a sloped portion 12 below the cam 10.
The exhaust valve is opened by being pushed in by the cam surface 12 via a, and the compressed air in the air spring 5 is discharged. As a result, the internal working pressure of the air spring 5 is reduced and the upper frame 2 is lowered together with the seat cushion. During this descent, the valve rod 8
Remains pressed into the cam surface 12, the exhaust valve does not close immediately, and the pin 14 together with the link bar 3a passes the idling distance x in the elongated hole 13, that is, the seat cushion returns to the set reference height. In the vicinity, the cam 10 pivots downward, the valve rod 8 projects from the lower cam surface 12 via the slope portion 12a and protrudes, the exhaust valve closes, the exhaust from the air spring 5 stops, and the seat cushion reaches the set reference height. Will be held back.

That is, in this vehicle seat air suspension device, when the seat cushion is lowered or raised from the set reference height, the pin 14 is moved up and down via the link bar 3a of the link mechanism 3, and the pin 14 is moved up and down. When the idling distance x in the oblong hole 13 of the cam 10 passes, the cam 10 interlocks with the pin 14 and the supply / exhaust valve 6 of the air spring 5
This is a configuration for operating the. Conversely speaking, even if the seat cushion moves up and down within a range corresponding to the above-mentioned idle travel distance x from the set reference height, the air spring 5 is set as a so-called dead zone where it is not controlled, and in the dead zones above and below that, the suspension is set. The cushioning operation, which is the original function of the apparatus, is performed, and when the seat cushion exceeds the upper and lower dead zones, the air spring 5 is controlled to perform the adjusting operation to return the seat cushion to the set reference height.

[0012]

In the conventional vehicle seat air suspension apparatus having the above-described structure, when the seat cushion moves upward and downward from the set reference height over a predetermined dead zone, The cam 14 starts moving after the pin 14 interlocked with moves past the idling distance x, but at the beginning of the movement of the cam 10, the valve rod 7 of the valve body 6 is moved.
Alternatively, 8 is gradually pushed in by the inclined surface portion 12a or 13a of the cam 10 to slowly open the valve, and when the vehicle 8 rides on the cam surface 12 or 13, it is in the fully opened state. In other words, even if the seat cushion exceeds the predetermined dead zone from the set reference height, it does not open immediately but opens slowly, so even if there is some compressed air flow in the process, the seat cushion is set. However, there is a problem that the response is slow and the seat cushion moves up and down greatly beyond the dead zone to cause an uncomfortable feeling such as bottom bumping.

Further, the internal working pressure of the air spring 5 is adjusted by the valve open state, and the pin 14 passes the idling distance x near the position where the seat cushion returns to the set reference height.
When 0 is moved, the valve spring built in the valve rod 7 or 8 urges the cam surface 12 or 13 down the slope 12a or 13a at once, and the valve is immediately closed. Therefore, there is a disadvantage that the valve body is fully closed before the seat cushion is completely returned to the set reference height, and the set reference height is changed.

The present invention has been made in view of the above circumstances, and an object thereof is to immediately release an exhaust valve or an air supply valve of a valve body when a seat cushion moves above or below a predetermined dead zone from a set reference height. Can be fully opened and the seat cushion can be returned to the set reference height with a quick response, and when the seat cushion returns to the set reference height by the adjustment operation, the exhaust valve or the air supply valve can be gradually opened. An object of the present invention is to provide an air suspension device for a vehicle seat, which is capable of reliably returning and holding the seat cushion at a set reference height by closing the valve.

[0015]

In order to achieve the above object, an air suspension device for a vehicle seat of the present invention supports a lower frame and a seat cushion of the vehicle seat disposed above the lower frame. An upper frame, a link mechanism that supports the upper frame so that the upper frame can move up and down with respect to the lower frame, an air spring that supports a load generated in the upper frame, and an air spring for supplying air from an air supply source or inside the air spring. A valve body having a normally closed supply / exhaust valve for exhausting air from the valve, and a valve opening / closing mechanism for selectively opening / closing the supply / exhaust valve of the valve body in conjunction with the vertical movement of the seat cushion. With a configuration in which the seat cushion is returned to the set reference height by controlling the air spring internal pressure by opening / closing the valve supply / exhaust valve by the valve opening / closing mechanism,

A support shaft is fixedly provided on one of the two members that are displaced relative to each other as the seat cushion moves up and down, and the valve body and the valve opening / closing mechanism are supported by the support shaft. Are arranged to face each other on the neutral axis line that crosses the center of the shaft, and the valve body and the valve opening / closing mechanism are provided with rotation fulcrums at two positions displaced from the center of the support shaft in a direction orthogonal to the neutral axis line. A tension spring is provided on both sides of the valve body and the valve opening / closing mechanism opposite to each other so as to hold the valve body and the valve opening / closing mechanism on the neutral axis, and the valve opening / closing mechanism is provided with the seat cushion. A connecting member that rotates in conjunction with the other of the two members that undergo relative displacement with the vertical movement of the valve, and a stopper that restricts the rotation of the valve element within a predetermined range,

When the valve opening / closing mechanism is rotated from the neutral axis above the dead point of the tension spring via the connecting member as the seat cushion moves up and down, the valve element is instantly attracted to the valve opening / closing mechanism by the tension spring. When the valve body is moved, either the supply / exhaust valve of the valve element is opened, and when the valve opening / closing mechanism is returned from its open state, the valve element is held by the stopper and the valve element is gradually closed. When the valve opening / closing mechanism returns to the initial neutral axis by turning, the valve body is fully closed and the tension spring causes the valve to return to the initial neutral axis.

[0018]

According to the vehicle seat air suspension apparatus having the above structure, when the upper frame moves up and down together with the seat cushion via the link mechanism, the valve opening / closing mechanism interlocks with this movement via the connecting member and resists the tension spring. Rotate from the neutral axis. At this time, if the vertical movement of the seat cushion is within a certain range from the set reference height, that is, if the valve opening / closing mechanism does not rotate more than one angle on the neutral axis from the neutral axis, the tension spring sets the dead point. In that range, the supply / exhaust valve of the valve body remains closed without opening and closing, and the air spring is not supplied / exhausted at all, which is a so-called dead zone, and the air spring causes vertical vibration of the seat cushion. Buffer.

Here, when the seat cushion rises from the set reference height beyond the above-mentioned dead zone, the valve opening / closing mechanism is rotated via the connecting member by a certain angle or more from one side on the neutral axis and pulled. The spring exceeds the dead point, and the valve body is instantly pulled toward the valve opening / closing mechanism to rotate the valve body, so that the exhaust valve of the valve body is immediately fully opened. With this, the seat cushion is adjusted to return to the set reference height with a quick response, that is, the compressed air in the air spring is discharged, the internal working pressure of this air spring is reduced, and the seat cushion is returned downward with the upper frame. To do.

While the seat cushion is returning to the descending position,
The valve body and the valve opening / closing mechanism keep the exhaust valve open while being pulled and rotated by the tension spring, and the valve opening / closing mechanism makes the valve body follow the valve body to return and rotate in the neutral axis direction. Meanwhile, the exhaust in the air spring is continued. Then, when the seat cushion descends to near the set reference height due to the pressure reduction of the air spring, the valve opening / closing mechanism returns and rotates to the vicinity of the neutral axis, and at this point, the valve body hits the stopper and further valve The follow-up rotation to the opening / closing mechanism is blocked, and after that, only the valve opening / closing mechanism makes a return rotation, so that the valve body and the valve opening / closing mechanism separate from each other against the tension spring, and the exhaust valve of the valve body When the seat cushion is gradually closed and finally returned to the set reference height, the valve opening / closing mechanism just returns to the original neutral axis, and the exhaust valve of the valve body is fully closed. Exhaust from the air spring stops, the seat cushion is reliably returned to the original set reference height and held, and the tension spring causes the valve body to rotate back to the original neutral axis beyond the dead point.

On the contrary, when the seat cushion descends from the set reference height beyond the dead zone, the valve opening / closing mechanism is rotated by a connecting member from the neutral axis to an angle greater than the other angle and pulled. The spring crosses the dead point,
The valve body is instantly pulled toward the valve opening / closing mechanism and rotated to fully open the air supply valve of the valve body immediately. With this, the adjustment action to return the seat cushion to the set reference height with a quick response is performed, that is, the compressed air from the air supply source is supplied to the air spring, the internal working pressure of this air spring increases, and the upper frame is pushed up. , Lift the seat cushion back up.

Even when the seat cushion is returned to the raised position, the valve body and the valve opening / closing mechanism keep the open state of the air supply valve while being pulled and rotated by the tension spring, and the valve opening / closing mechanism causes the valve body to follow. While doing so, it returns and rotates in the direction of the neutral axis. Meanwhile, the compressed air is continuously supplied to the air spring from the air supply source. Then, when the seat cushion is pushed up by the air spring and rises close to the set reference height, the valve opening / closing mechanism makes a return rotation near the neutral axis, and at this point the valve disc strikes the stopper and further The follow-up rotation to the valve opening / closing mechanism is blocked, and after that, only the valve opening / closing mechanism returns and rotates, so that the valve body and the valve opening / closing mechanism are separated from each other against the tension spring. The valve gradually closes, and when the seat cushion finally rises to the set reference height and returns, the valve opening / closing mechanism just returns to the original neutral axis, and the air supply valve of the valve body is completely restored. When closed, the supply of compressed air to the air spring is stopped, the seat cushion is reliably returned to the original reference height and held, and the tension spring rotates beyond the dead point to rotate the valve element to the original neutral axis. I'll return.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. The same components as those shown in FIGS. 6 and 7 are designated by the same reference numerals to simplify the description.

First, FIG. 5 is a side view showing a partial cross-section of an air suspension device for a vehicle seat. The lower frame 1 is fixed to the floor A of the vehicle and the upper portion of the lower frame 1 is arranged in the same manner as in the conventional case. The upper frame 2 that supports a seat cushion (not shown) of a vehicle seat, the X-link mechanism 3 that supports the upper frame 2 so that the upper frame 2 can move up and down with respect to the lower frame 1, and the load generated on the upper frame 2 A supporting air spring 5, and a valve body 20 having a supply / exhaust valve for supplying air to the air spring 5 from an air supply source (not shown) such as a compressor or exhausting the air inside the air spring 5. When the seat cushion moves up and down from the set reference height and exceeds a predetermined dead zone, the valve body 20
And a valve switching mechanism 30 for returning the seat cushion to the set reference height by selectively opening the supply / exhaust valve to control the internal pressure of the air spring 5. In addition,
In this air suspension device, a shock absorber 15 is provided between the lower frame 1 and the upper frame 2.

As shown in FIGS. 1 to 3, the valve body 20 has a construction in which a normally closed air supply valve and an exhaust valve are built in one casing 21 as described above. The valve rods 22 and 23 of the air supply valve and the exhaust valve are projected in parallel on one side surface of the casing 21 at equal intervals from the center to both sides, and the valve rods 22 and 23 are individually pushed. As a result, the air supply valve and the exhaust valve are opened, and when the pushing force is released, they are automatically returned to the closed state by the urging of the valve spring.

Two connection ports 24a and 24b are provided on the other end side surface of the casing 21 of the valve body 20, and one of the connection ports 24a communicates with an air supply source (not shown) such as a compressor. The pipe 25a is connected to the other connection port 2
A pipe 25b communicating with the air spring 5 is connected to 4b. Although not shown, it has an exhaust port.

Further, a half sleeve sleeve-shaped bearing portion 26 having upper and lower flanges, which is located at an intermediate position between the valve rods 22 and 23, is provided on the one end side surface of the casing 21 of the valve body 20 so as to vertically project. ing. On the contrary, a nose 27 is projectingly provided on the other side surface of the casing 21, and a spring receiving pin 28 is provided upright on the upper end of the nose 27. Also the casing 21
A base end portion is adhered to the center of the lower surface of the casing 21, and a substantially U-shaped floating prevention bar 29 is provided extending from the lower side of the casing 21 to one end.

On the other hand, the valve opening / closing mechanism 30 includes the valve body 2
By controlling the supply / exhaust valve of 0 to increase / decrease the internal working pressure of the air spring 5, the reference height Y of the seat cushion is set as shown in FIG. 5, and the dead zone above the set reference height Y is set. M and the lower dead zone N are set respectively.

As shown in FIGS. 1 to 3, the valve opening / closing mechanism 30 is composed of a horizontally long arm portion 31 and valve rod pressing portions 32 and 33 projecting from one end thereof to both sides, and has a generally T-shaped sideways shape. A half-sleeve-shaped bearing portion 34 having upper and lower flanges is vertically provided on one end side of the arm portion 31, and a connecting hole 35 is vertically formed on the other end portion of the arm portion 31. Is pierced through.

The valve body 20 and the valve opening / closing mechanism 30 are opposed to each other with a support shaft 40 fixedly provided on one of two members that are displaced relative to each other as the seat cushion moves up and down. It is arranged and provided.

That is, as shown in FIG. 5, a flat plate-shaped mounting base 42 is horizontally mounted and fixed to the rear portion of the lower frame 1 via a pair of front and rear brackets 41.
As shown in FIGS. 1 to 3, the support shaft 40 is vertically erected at a portion near one end of the center of the upper surface of 2. The support shaft 40 has a structure in which flange portions 40a and 40b such as blades are vertically projected on the front and rear portions of the peripheral surface of a round bar. The valve body 20 and the valve opening / closing mechanism 30 join the respective half-sleeve sleeve-shaped bearing portions 26 and 34 on both sides of the support shaft 40 so that the neutral axis O crosses the center of the support shaft 40. It is arranged opposite to.

The valve body 20 and the valve opening / closing mechanism 30 are joined to the respective side surfaces of the support shaft 40 with the collar portions 40a and 40b by the respective half-sleeve-shaped bearing portions 26 and 34, so that FIG. As shown in the figure, there are rotation fulcrums A, B and C, D at two positions displaced from the center of the support shaft 40 in the direction orthogonal to the neutral axis O (front-back direction).

The valve body 20 and the valve opening / closing mechanism 30 are provided with tension springs 43 on both sides opposite to each other by hooking both ends. The valve body 20 and the valve opening / closing mechanism 30 are constantly attracted to each other by the tension spring 43 so that the valve body 20 and the valve opening / closing mechanism 30 are constantly pressed against the support shaft 40 at the front and rear rotation fulcrums A, B and C, D. It is designed to be held at. In addition, one end of the tension spring 43 is connected to the valve body 2
0 of the casing 21 is hooked on the spring receiving pin 28 at the tip of the nose 27 on the other end, and the other end is hooked on the upper end of the connecting member 44 which penetrates the connecting hole 35 at the other end of the arm 31 of the valve opening / closing mechanism 30. It has been stopped.

The connecting member 44 is a single rod-like member bent in an L-shape, and the tip rising portion 44a penetrates through the connecting hole 35 at the other end of the arm portion 31 of the valve opening / closing mechanism 30 from below to above. The other end of the tension spring 43 is hooked to the upper end portion of the pull spring 43 so as to prevent it from coming off by caulking. A loop portion 44b is formed on the base end side of the connecting member 44 as shown in FIG. A rear connecting shaft 3 that can move back and forth at the lower end of the link bar 3b of the link mechanism 3.
It is fitted and engaged with e. As a result, the valve opening / closing mechanism 30 can be rotated in the front-rear direction in cooperation with the connecting shaft 3e of the X-link mechanism 3 that operates as the seat cushion moves up and down.

The spindle 4 is mounted on the upper surface of the mounting base 42.
A pair of stoppers 45 spaced apart from each other in the front-rear direction about 0,
46 are erected. Front and rear stoppers 45, 46
Is for regulating the rotation of the valve body 20 within a predetermined range,
When the casing 21 of the valve body 20 rotates more than a predetermined amount, it will stop.

A substantially U-shaped floating prevention bar 29 extending from the center of the lower surface of the casing 21 of the valve body 20.
Is designed to prevent the valve body 20 from rotating in the vertical (up and down) direction by inserting and engaging the tip from below into a hole 42a bored in the approximate center of the mounting base 42.
Reference numerals 47 and 48 in the figure denote the valve body 20 and the valve opening / closing mechanism 30.
With a spring pin that prevents vertical movement of the valve body 20
And the valve opening / closing mechanism 30.
It is provided so that the upper and lower parts may be wrapped around the upper and lower parts.

According to the above-described vehicle seat air suspension device, when the seat cushion moves up and down together with the upper frame 2 through the link mechanism 3 due to traveling vibration of the automobile, as shown in FIG. The connecting shaft 3e on the lower rear side of the link mechanism 3 has a lower frame 1
To move back and forth. The valve opening / closing mechanism 30 is interlocked with the forward / backward movement of the connecting shaft 3e via the connecting member 44, and the valve opening / closing mechanism 30 rotates front and rear fulcrums A of the support shaft 40 by an angle corresponding to the vertical movement of the seat cushion. It reciprocates in the front-rear direction from the neutral axis O against the tension spring 43 about B. At this time, if the vertical movement of the seat cushion is within the range of the vertical dead zones M and N from the set reference height Y, that is, if the valve opening / closing mechanism 30 does not rotate more than a certain angle forward or backward from the neutral axis O. As shown in FIG. 4 (b), the tension spring 43 does not exceed the dead point, the valve rods 22 and 23 of the valve body 20 are not pushed in that range, and the supply / exhaust valve remains closed, so Air is not supplied or exhausted at all, forming a so-called dead zone, and the air spring cushions the vertical vibration of the seat cushion.

Here, for example, when the seat cushion rises from the set reference height Y over the dead zone M described above, the valve opening / closing mechanism 30 via the connecting member 44 causes the neutral axis O about the rotation fulcrum A as a center. As shown in FIG. 4 (c), the tension spring 43 moves forward from the top by a certain angle or more, and the tension spring 43 goes over the dead point, so that the valve body 20 moves forward with respect to the valve opening / closing mechanism 30 about the rotation fulcrum C. The valve rod 23 is instantly pulled and rotated, and the valve rod pressing portion 33 on the front side of the valve opening / closing mechanism 30 pushes the valve rod 23 of the valve body 20 at once to immediately fully open the exhaust valve. This starts the adjusting operation for returning the seat cushion to the set reference height with a quick response. At this time, as shown in FIG. 4D, the valve opening / closing mechanism 30 temporarily rotates further forward to push back the valve body 20, but the compressed air in the air spring 5 is discharged, and the air spring 5 is discharged. Since the internal working pressure of the seat cushion decreases, the seat cushion descends and returns together with the upper frame 2.

During the descending return of the seat cushion,
Although the valve opening / closing mechanism 30 is returned and rotated in the neutral axis direction by being pulled back by the connecting member 44, the valve body 20 is rotated so as to follow the valve opening / closing mechanism 30 by the pulling of the tension spring 43, and thus the valve rod. Keep 23 open and keep the exhaust valve open. Therefore, during that time, the exhaust of the air spring 5 is continued. Then, when the seat cushion is lowered to near the set reference height by the pressure reduction of the air spring, the valve opening / closing mechanism 30 is returned and rotated to near the neutral axis 0 as shown in FIG. It stops at the stopper 45 to prevent further follow-up rotation to the valve opening / closing mechanism 30, and thereafter, only the valve opening / closing mechanism 30 is returned and rotated,
As a result, the valve body 20 and the valve opening / closing mechanism 30 are separated from each other against the tension spring 43, and the valve rod 23 of the valve body 20 is gradually projected by the valve spring to slowly close the exhaust valve. Finally, when the seat cushion returns to the set reference height Y, the valve opening / closing mechanism 30 just returns to the original neutral axis O as shown in FIG. Stick 2
3 protrudes to the original state, the exhaust valve is fully closed, the exhaust from the air spring 5 is stopped, the seat cushion is surely returned to the original set reference height Y and held, and the tension spring 43 is at the dead point. 4A, the valve body 20 is pivoted back to the original neutral axis O to return to the state of FIG.

On the contrary, the seat cushion is set standard height Y
When it descends beyond the dead zone N below from the above, the valve opening / closing mechanism 30 is located rearward from the neutral axis O about the pivot fulcrum B by the connecting member 44, although the operation is the same as the previous one. When the tension spring 43 is rotated beyond the angle and exceeds the dead point, the valve body 20 is instantly drawn and rotated with respect to the valve opening / closing mechanism 30, and the valve rod 22 of the valve body 20 is pushed all at once to supply the air supply valve. Instantly fully open. With this, an adjusting operation for returning the seat cushion to the set reference height Y with a quick response is performed, that is, compressed air from the air supply source is supplied to the air spring 5, and the internal working pressure of the air spring 5 is increased to increase the upper pressure. Push up the frame 2 to raise and restore the seat cushion.

Even when the seat cushion is returned to the raised position, the valve body 20 and the valve opening / closing mechanism 30 are kept pulled open by the tension spring 43 and the air supply valve is kept open. The body 20 is caused to return and rotate in the direction of the neutral axis O line while following the body 20. Meanwhile, the compressed air is continuously supplied to the air spring 5 from the air supply source. Then, when the seat cushion is pushed up by the air spring 5 and rises to the vicinity of the set reference height Y, the valve opening / closing mechanism 30 pivots so as to return to the vicinity of the neutral axis O, and at this time, the valve body 20 stops at the stopper 46. Then, further follow-up rotation to the valve opening / closing mechanism 30 is blocked, and thereafter, only the valve opening / closing mechanism 30 makes a return rotation, whereby the valve body 20 and the valve opening / closing mechanism 30 resist the tension spring 43. When the seat cushion is released, the air supply valve of the valve body 20 is gradually closed, and when the seat cushion finally rises and returns to the set reference height Y, the valve opening / closing mechanism 30 is just opened.
Returns to the original neutral axis O, whereby the air supply valve of the valve body 20 is fully closed, the supply of compressed air to the air spring 5 is stopped, and the seat cushion is returned to the original set reference height Y. The return spring is positively held and the tension spring 43 moves beyond the dead point to rotate the valve body 20 back to the original neutral axis O.

The present invention is not limited to the above-described embodiment. For example, a member for mounting the mounting base 42 of the support shaft 40 and a member for interlocking the valve switching mechanism 30 via the connecting member 44 are seats. Any two members such as the upper frame 2, the lower frame 1, and the link bar of the link mechanism 3 that undergo relative displacement as the cushion moves up and down can be appropriately selected. In addition, various modifications can be made without departing from the scope of the present invention.

[0043]

Since the air suspension device for a vehicle seat according to the present invention is constructed as described above, when the seat cushion moves above or below a predetermined dead zone from the set reference height, the valve body is immediately exhausted. The valve or the air supply valve can be fully opened, and an adjusting operation for returning the seat cushion to the set reference height with a quick response can be executed, and when the seat cushion returns to the set reference height by the adjusting operation, the exhaust valve or The air supply valve gradually closes, and the seat cushion can be reliably returned to and held at the set reference height, resulting in extremely high performance and improved reliability.

[Brief description of drawings]

FIG. 1 is a plan view of a main part of a valve body and a valve switching mechanism showing an embodiment of an air suspension device for a vehicle seat of the present invention.

FIG. 2 is a side view in which a part of a main part of the same is cut away.

FIG. 3 is an exploded perspective view of a main part of the same.

FIG. 4A to FIG. 4F are diagrams for explaining the operation of the main part of the same as above.

FIG. 5 is a sectional view of the entire air suspension device of the above embodiment.

FIG. 6 is a perspective view of an air suspension device for a vehicle seat showing a conventional example.

FIG. 7 is an enlarged side view showing the relationship between the valve element and the valve switching mechanism in the conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Lower frame, 2 ... Upper frame, 3 ... Link mechanism, 3e ... Connection shaft, 5 ... Air spring, 20 ... Valve body, 22,23 ... Valve rod, 30 ... Valve switching mechanism, 40 ... Support shaft, 43 ... Extension spring, 44 ... Connection member, 45, 46
... Stopper, A, B, C, D ... Rotation fulcrum, O ... Neutral axis, M, N ... Dead zone, Y ... Seat cushion setting reference height.

Claims (1)

[Claims] 1. A lower frame, an upper frame which is arranged above the lower frame and supports a seat cushion of a vehicle seat, a link mechanism which supports the upper frame so as to be vertically movable with respect to the lower frame, and the upper frame. An air spring for supporting a load generated in the frame, a valve body having a normally closed supply / exhaust valve for causing the air spring to supply air from an air supply source and exhausting air from the inside of the air spring, and vertical movement of the seat cushion. And a valve opening / closing mechanism for selectively opening / closing the supply / exhaust valve of the valve body, and controlling the inner pressure of the air spring by opening / closing the supply / exhaust valve of the valve body by the valve opening / closing mechanism. In a vehicle seat air suspension device for returning a cushion to a set reference height, relative displacement is generated as the seat cushion moves up and down. A support shaft is fixedly provided on one of the members, and the valve body and the valve opening / closing mechanism are arranged to face each other on a neutral axis line that crosses the center of the support shaft, with the support shaft being sandwiched between the valve body and the valve body. The valve opening / closing mechanism is provided with rotation fulcrums at two positions displaced from the center of the support shaft in a direction orthogonal to the neutral axis,
Further, a tension spring is provided which hooks both ends of the valve body and the valve opening / closing mechanism on opposite sides to each other and holds the valve body and the valve opening / closing mechanism on the neutral axis. The seat cushion is provided with a stopper that restricts the rotation of the valve body within a predetermined range, as well as a connecting member that rotates in conjunction with the other of the two members that undergo relative displacement as the seat cushion moves up and down. When the valve opening / closing mechanism rotates from above the neutral axis to the dead point of the tension spring or more through the connecting member due to the movement, the valve body is instantly attracted and rotated by the tension spring to the valve opening / closing mechanism. When either the supply / exhaust valve of the body is opened and the valve opening / closing mechanism returns from its opened state, the valve body is held by the stopper and the valve body is gradually closed. Rotate on vertical axis An air suspension device for a vehicle seat, characterized in that, when returned, the valve body is brought into a fully closed state and is returned to rotate on an initial neutral axis by a tension spring.