JPH0867193A - Vehicle seat with air suspension system - Google Patents

Abstract

(57) [Summary] [Purpose] The seat cushion can be maintained at the set standard height,
Moreover, the main purpose is to maintain the seat height when the seat back is tilted backward. A supply / exhaust valve 16 is provided between an air spring 14 for supporting a load applied to a seat cushion and an air supply source 15. The air supply / exhaust valve 16 is controlled by the valve switching mechanism 30 to supply compressed air sent from the air supply source 15 to the air spring 14 when the seat cushion falls below a predetermined height so that the seat cushion rises above a predetermined height. When it becomes, air is discharged from the air spring 14. An on-off valve 51 is provided between the air spring 14 and the air supply / exhaust valve 16. The drive member 5 is attached to the valve body operating portion 65 of the open / close valve 51.
One end side of 2 is connected. The other end side of the drive member 52 is connected to a part of the seat back, and moves the valve body operating part 65 to the position of the valve closing mode only when the seat back is tilted backward by a predetermined angle or more. There is.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle seat provided with an air suspension device for supporting a seat cushion of a vehicle seat such as an automobile using a link mechanism and an air spring.

[0002]

2. Description of the Related Art An air suspension device for a vehicle seat used in a cab of a large vehicle such as a truck includes a lower frame fixed on the floor of the vehicle, an upper frame arranged above the lower frame, and an upper frame. A link mechanism arranged between the lower frame and the upper frame, an air spring, and the like are provided, and the load applied to the seat cushion on the upper frame is supported by the pressure of the air spring.

In this type of air suspension device, as disclosed in, for example, Japanese Unexamined Patent Publication No. 5-42849, the seat cushion is maintained at a set reference height in a stationary state regardless of the weight of a seated person. In addition, there has been proposed a system in which the internal pressure of the air spring is automatically controlled so as to secure an appropriate suspension stroke against vibration during traveling and obtain optimum cushioning performance.

As shown in part in FIG. 5, the above-mentioned prior art has a lower frame a fixed on the floor of a vehicle, an upper frame arranged above the lower frame a, and an upper frame with respect to the lower frame a. From the air supply source d when the upper frame is below a predetermined height, an air spring c that supports the load applied to the upper frame, an air supply source d, and an air supply source d. A supply / exhaust valve e that supplies compressed air to be sent to the air spring c and discharges air from the air spring c when the height of the upper frame exceeds a predetermined height, and a supply / exhaust valve depending on the height of the upper frame. The seat cushion is configured by including a valve switching mechanism f that operates e, and controls the internal pressure of the air spring c by switching the air supply / exhaust valve e to the air supply mode or the exhaust mode by the valve switching mechanism f. So as to maintain the reference height.

The valve switching mechanism f of the prior art described above is interlocked with a guide shaft h, a cam i provided on the guide shaft h so as to be reciprocally movable and rotatable in the vertical direction, and with the vertical movement of the seat cushion. And a connecting member j for reciprocating the cam i along the guide shaft h. A first convex portion k and a second convex portion n are provided below the cam i.

In this type of valve switching mechanism f, when the seat cushion descends from the reference height, the cam i moves from the neutral position to the left along the guide axis h via the connecting member j, and the cam i moves over a certain distance. When moved, the bottom surface of cam i is first
By riding on the convex portion k and rotating the cam i upward, the air supply valve rod p of the air supply / exhaust valve e is pushed and the air supply / exhaust valve e enters the air supply mode. In the air supply mode, the compressed air sent from the air supply source d is supplied to the air spring c via the air supply / exhaust valve e, so that the internal pressure of the air spring c increases, the seat cushion rises, and the reference height increases. Return to.

When the seat cushion rises above the reference height, the cam i moves from the neutral position to the right in the figure, and when the cam i moves a certain distance or more, the lower surface of the cam i moves to the second position.
By riding on the convex portion n and rotating the cam i upward, the exhaust valve rod r of the supply / exhaust valve e is pushed and the supply / exhaust valve e enters the exhaust mode. In the exhaust mode, the air inside the air spring c is discharged through the air supply / exhaust valve e, so that the air spring c
The seat cushion lowers and returns to the standard height due to the lower internal pressure.

[0008]

The above-described air suspension device of the prior art is an excellent device that can maintain the seat cushion at the reference height regardless of the weight of the seated person and can secure an appropriate suspension stroke. However, there was room for improvement as described below.

Engines of large vehicles such as trucks in recent years tend to be equipped with turbochargers, intercoolers and the like for high output and high horsepower, so that the engine room tends to be large. Due to the increase in the size of the engine room, the bed installed in the engine room has become higher than the conventional one as shown in FIG. Therefore, when an occupant of a truck or the like collapses the seat back and tries to take a necessary rest or nap, the following problems may occur.

In the above-mentioned air suspension device, when the seated person lifts his / her waist to tilt the seat back, the seating load on the seat cushion is reduced. Moreover, when the seat back is tilted down, the center of gravity of the seated person and the seat back moves rearward, so that the seating load on the seat cushion is further reduced. When the seating load decreases in this way, the seat cushion rises due to the reaction force of the air spring. Then, as the seat cushion rises, the air supply / exhaust valve e described above enters the exhaust mode, and the seat cushion and the seat back begin to descend. As a result, the seat back comes into contact with the edge of the bed and crushes the bed.

Even when the seat back comes into contact with the bed as described above, the air supply / exhaust valve e remains in the exhaust mode until the seat cushion reaches the neutral position (reference height). The part will be plastically deformed. Further, the series of operations described above causes the seat itself to be in a front-lowering state, which makes it difficult for the seated person to take a comfortable posture. In addition, the bed may be deformed or the entire sheet may be distorted.

As an improvement plan for solving the above problem, the second convex portion n in the valve switching mechanism f is configured to be capable of projecting and retracting, and the second convex portion n is reclined through a wire cable or the like. It was thought to be linked to the movement of. That is, when the seat back is tilted backward by a predetermined angle or more, the convex portion n is retracted by pulling the cable so that the air supply / exhaust valve e is not in the exhaust mode when the seat back is tilted. .

However, in the above improvement plan, since a long cable must be routed from the reclining mechanism to the valve switching mechanism f, special consideration must be given to the cable routing so as not to obstruct the cable. . Further, it is difficult to set the length and tension of the cable because it is necessary to pull the cable by an accurate amount when the rearward tilt angle of the seat back reaches a predetermined value.

Therefore, an object of the present invention is to avoid the above-mentioned problems by preventing the air suspension device from operating in the direction in which the seat descends when the seat back is tilted rearward at rest, and Reliable operation,
An object is to provide a vehicle seat equipped with an air suspension device that can be easily adjusted.

[0015]

A vehicle seat of the present invention developed to achieve the above object comprises a lower frame provided on the floor side of a vehicle and a seat cushion arranged above the lower frame. An upper frame to support,
A seat back that is provided at the rear of the seat cushion and that can change the inclination angle in the front-rear direction, a link mechanism that supports the upper frame to move up and down with respect to the lower frame, and the upper frame from above. An air spring that supports a load to be applied, an air supply source that supplies compressed air to the air spring, and the upper frame that is provided between the air supply source and the air spring and has a predetermined height or less. When the temperature rises, compressed air sent from the air supply source is supplied to the air spring, and when the upper frame is at a predetermined height or higher, air is discharged from the air spring. An exhaust valve, a valve switching mechanism that operates the supply / exhaust valve in the supply mode or the exhaust mode according to the height of the upper frame, the air spring, and the supply valve. A valve provided between the air valve and operable in a valve opening mode capable of discharging the air in the air spring to the supply / exhaust valve side and a valve closing mode in which the air in the air spring is shut off undischargeable. The valve body operating portion is connected only to the opening / closing valve having a body operating portion, the seat back side member and the valve body operating portion of the opening / closing valve, and only when the seat back is tilted backward by a predetermined angle or more. And a drive member for moving to the valve closing mode.

[0016]

When the seat cushion falls below a predetermined height when the seating load is large, the air supply / exhaust valve enters the air supply mode, and the compressed air sent from the air supply source is supplied to the air spring. The internal pressure of the vehicle rises and the seat cushion rises to the standard height. Conversely, when the seat cushion is above a certain height, such as when the seating load is light, the air supply / exhaust valve switches to the exhaust mode, air is discharged from the air spring, and the internal pressure of the air spring drops, and the seat cushion To descend.

When the seat back is greatly tilted rearward at rest or the like, the load applied to the seat cushion from above is smaller than that when seated normally, so that the seat rises due to the internal pressure of the air spring. Thus, when the seat back is tilted backward by a predetermined angle or more, the valve body operating portion of the on-off valve is driven in the valve closing mode direction via the drive member, and the on-off valve is closed. Therefore, even if the intake / exhaust valve is in the exhaust mode by the valve switching mechanism as the seat rises, the air is prevented from being discharged from the air spring.

Therefore, the seat cushion is prevented from being lowered while the seat back is tilted backward, and the height of the seat is maintained. When the seat back is raised to the angle of normal use, the movement of the seat back is transmitted to the valve body operation part of the opening / closing valve via the drive member, and this opening / closing valve switches to the opening mode, so that air from the air spring is released. It will be ready to be discharged, and the normal height adjustment function will be exerted.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.
Will be described with reference to. The vehicle seat 1 shown in FIGS. 2 and 4 has an air suspension device 2 located on the lower side in the figure and a tilt mechanism portion 3 mounted on the air suspension device 2, and the tilt mechanism portion A seat cushion 4 is provided on the upper frame 3a of the seat 3. The tilt mechanism section 3 can adjust the inclination of the upper frame 3a with respect to the horizontal plane, and can also adjust the position in the front-back direction by the seat slide mechanism 5.

A seat back 6 is provided at the rear of the seat cushion 4. As shown in FIG. 3, hinge brackets 7a and 7b are provided below the seat back frame 6a. The seat back 6 is rotatable in the front-rear direction with respect to the seat cushion 4 and can be tilted at a desired angle by a known reclining mechanism (not shown) provided on the one hinge bracket 7b side. .

The air suspension device 2 includes a lower frame 11 fixed on the floor of a vehicle, an upper frame 12 arranged above the lower frame 11, and a lower frame 1.
1, a link mechanism 13 that supports the upper frame 12 so as to be movable up and down, an air spring 14 (shown in FIG. 1) that supports a load applied to the upper frame 12 from above, and an air supply source 15 such as an air compressor. An air supply / exhaust valve 16 for supplying or exhausting air supplied from the air spring 14 is provided. The air spring 14 is provided between the lower frame 11 and the upper frame 12.

As shown in FIG. 4 etc., the link mechanism 13
Is a pair of left and right link bars 13a and 13b, respectively.
Is pivotally supported in an X shape by a pivot pin 13c, and link shafts 13e (partly shown in FIG. 1) extending left and right are provided at the upper and lower ends of the link bars 13a and 13b, respectively. Both ends of the upper and lower connecting shafts 13e arranged frontward are rotatably connected to the front ends of the left and right frame members 11a of the lower frame 11 and the upper frame 12, and both ends of the connecting shaft 13e arranged rearward are lower. The frame 11 and the upper frame 12 are supported near the rear ends of the left and right frame members 11a so as to be movable back and forth via rolling rollers 13f.

As shown in FIG. 1, the air supply / exhaust valve 16 is provided with a normally closed air supply valve and an exhaust valve inside one casing, and has a valve rod 17 for the air supply valve and an exhaust valve. Valve stem 18
Are projected in parallel on the same side face with a predetermined interval. When the valve rod 17 for the air supply valve is pushed in, the air supply valve opens to enter the air supply mode, and when the valve rod 18 for the exhaust valve is pushed in, the exhaust valve opens to cause exhaust gas. I'm trying to get into mode. Valve rod 17,18
When the pushing force is released, the air supply valve and the exhaust valve are each returned to the closed state by the urging force of a built-in valve spring (not shown).

The supply / exhaust valve 16 is attached to one of two members that are displaced relative to each other as the seat cushion moves up and down. For example, as shown in FIG. 1, it is horizontally fixed to the rear portion of the lower frame 11 via a mounting base 20. An air pipe 22 communicating with the air supply source 15 is connected to one connection port 16a of the air supply / exhaust valve 16. An air pipe 23 communicating with the air spring 14 is connected to the other connection port 16b of the supply / exhaust valve 16 via an on-off valve 51 described later.

The supply / exhaust valve 16 is supplied or exhausted by the valve switching mechanism 30. The valve switching mechanism 30 sets the reference height Y of the seat cushion as shown in FIG. 4 by controlling the supply / exhaust valve 16 to increase / decrease the internal pressure of the air spring 14, and at the same time, set the reference height Y.
The upper dead zone B and the lower dead zone C are set respectively.

That is, as shown in FIG. 1, the valve switching mechanism 30 has a horizontally extending round rod-shaped guide shaft 31 supported by bearing pieces 20c and 20d of the mounting base 20.
And a cam 32 provided on the guide shaft 31 so as to be reciprocally movable and vertically rotatable, and a connecting member 33 for reciprocating the cam 32 along the guide shaft 31 in conjunction with the vertical movement of the seat cushion. And the first to rotate and raise the cam 32
And the second convex portion 35.

The cam 32 has a rectangular parallelepiped shape and has a round hole 32a at its base end which penetrates in the front-rear direction. The round hole 32a is inserted into the guide shaft 31 to face the supply / exhaust valve 16. In this state, the guide shaft 31 can be reciprocally moved in the front-rear direction and can be rotated in the vertical direction.

The cam 32 integrally has at its tip a head portion 32b having a width substantially equal to the mutual distance between the valve rods 17 and 18 of the supply / exhaust valve 16. This head portion 32b is
Even if the cam 32 moves back and forth along the guide shaft 31 in the horizontal state, it does not come into contact with the valve rods 17 and 18 of the supply / exhaust valve 16. Moreover, the head portion 32b is provided on the cam 3
When the 2 rotates upward around the guide shaft 31, either one of the valve rods 17 and 18 of the supply / exhaust valve 16 can be pushed in. Then, once the head portion 32b pushes the valve rods 17 and 18, the head portion 32b is stretched by the urging force of the built-in springs of the valve rods 17 and 18 to prevent the cam 32 from returning to the downward rotation. Thus, the pushed state of the valve rods 17 and 18 is maintained.

As shown in FIG. 1, the connecting member 33 includes one connecting rod 33b having a U-shaped member 33a at the rear end, and a connecting lever 33c fastened in a state orthogonal to the front end of the connecting rod 33b. Is equipped with. The tip of the connecting lever 33c is inserted into a slit 32i formed at the base end of the cam 32 so that it can move in the front-rear direction with the cam 32 with respect to the guide shaft 31. The U-shaped member 33a at the rear end of the connecting rod 33b is the connecting shaft 1 of the link mechanism 13.
3e is engaged.

The first convex portion 34 and the second convex portion 35 are
It is projected between the air supply / exhaust valve 16 and the guide shaft 31 like a hemispherical ridge. The first convex portion 34 pivotally raises the cam 32 when the cam 32 moves rearward from the neutral position along the guide shaft 31 by a predetermined distance or more. The second convex portion 35 is set at a position where the cam 32 is rotated and raised when the cam 32 moves forward along the guide shaft 31 from the neutral position by a predetermined distance or more.

An on-off valve unit 50 is provided at the rear of the seat cushion 4. This on-off valve unit 50 is
An on-off valve 51 of an angle controllable type and a drive member 52 are provided. The above-mentioned air piping 2 is connected to the first port 55 of the opening / closing valve 51.
3 is connected. The other end of the air pipe 23 is connected to the connection port 16b of the air supply / exhaust valve 16. On-off valve 5
The other end of the air pipe 23 a connected to the first second port 56 is connected to the air supply / exhaust port of the air spring 14. The air pipes 23 and 23a are covered with bellows-shaped protection tubes 58 and 59, respectively.

Inside the on-off valve 51, the first port 5
5 has a built-in valve body for connecting and disconnecting the second port 56. The valve element is driven by a valve element operating unit 65 that rotates about a shaft 64 in a valve opening mode and a valve closing mode. In valve open mode, air spring 1
The air inside 4 can be discharged to the air supply / exhaust valve 16. In the valve closing mode, the air of the air spring 14 is shut off so that it cannot be discharged.

As shown in FIG. 4, in the on-off valve 51, the valve body operating portion 65 has a neutral position N (angle α _{0 with} respect to the horizontal plane).
From the variation allowable range α ₁ of about 10 ° to the backward tilt angle range α ₂ in the full reclining direction, the valve body and the valve body operating unit 65 are set so as to be in the valve closing mode.
The relationship with is set. The opening / closing valve 51 is in the valve opening mode when the valve body operating portion 65 falls forward from the neutral position N.

When the valve body operating portion 65 is in the neutral position N, the other end 52b of the drive member 52 is in the seat back design reference position (angle θ ₀ ). This reference angle θ ₀ is about 60 ° with respect to the horizontal plane. Then, when the seat back is tilted in the full reclining direction, when it reaches the range of the angle θ _{2 in} the full reclining direction beyond the variation allowable angle θ _{1 of} about 10 °, the valve body operating portion 65 is passed through the drive member 52. Is displaced to the angle range α ₂ where is the valve closing mode.

Further, by making the turning radius R ₂ of the valve body operating portion 65 larger than the turning radius R _{1 of} the drive member 52 on the seat back side, the on-off valve 51 is not burdened at the time of tilting forward and at the time of full reclining. I am trying. Reference symbol C in the drawing is the center of rotation of the seat back 6.

As shown in FIG. 3, the opening / closing valve 51 is
On the positioning bracket 70 welded to the frame 3a,
It is fixed by the nut 71. The on-off valve 51 is prevented from rotating by a detent bracket 72.

The valve body operating portion 65 of the opening / closing valve 51 is operated by the drive member 52 in the valve opening mode and the valve closing mode. One end 52a of the driving member 52
Is connected to the valve body operating portion 65 by a pin 75 and is rotatable about a horizontal axis. The other end 5 of the drive member 52
2b is connected to a pin 76 provided on the hinge bracket 7a of the seat back frame 6a and is rotatable about a horizontal axis. A protective cover 80 for covering the rear portion of the drive member 52 and the like is provided on the frame 3a with screws 81 and the like.

Next, the operation of the vehicle seat 1 provided with the opening / closing valve unit 50 having the above structure will be described. When the seat cushion 4 moves up and down together with the upper frame 12 via the link mechanism 13 due to traveling vibration of the automobile,
The connecting shaft 13e of the link mechanism 13 is the lower frame 1
Move back and forth with respect to 1. Since the connecting member 33 of the valve switching mechanism 30 moves in the same direction in conjunction with the movement of the connecting shaft 13e, and the connecting member 33 also interlocks, the cam 32 moves the guide shaft by a distance corresponding to the vertical movement of the seat cushion 4. It reciprocates back and forth along 31.

At this time, if the vertical movement of the seat cushion 4 is within the dead zones B and C above and below the set reference height Y shown in FIG. 4, the cam 32 moves from the neutral position along the guide shaft 31. Do not move more than a certain distance in the front-back direction.
Therefore, since the cam 32 does not touch the first convex portion 34 or the second convex portion 35, the cam 32 does not rotate upward. That is, the cam 32 remains horizontal and the tip head portion 32 is
b is not in contact with the valve rods 17 and 18 of the supply / exhaust valve 16 but escapes to the lower side thereof, and the supply / exhaust valve 16 is kept closed.

Therefore, even if the seat cushion 4 moves up and down from the set reference height Y, the air supply / exhaust valve 16 remains closed and the air supply / exhaust air is supplied to the air spring 14 within the upper and lower dead zones B and C. The air spring 14 cushions the vertical vibration of the seat cushion 4 without any operation.

Here, when the seat cushion 4 descends from the set reference height Y over the above-mentioned lower dead zone C due to a heavy person sitting, the link mechanism 1 is accompanied by this.
The cam 32 moves rearward from the neutral position along the guide shaft 31 by a predetermined distance or more together with the third connecting shaft 13e via the connecting member 33 of the valve switching mechanism 30. Therefore, the cam 32 touches the first convex portion 34 so as to ride up and pivots upward around the guide shaft 31, and the head portion 32b of the cam 32 rises to be used for the air supply valve of the air supply / exhaust valve 16. Valve stem 17
Push in and open the air supply valve to enter the air supply mode. As a result, the compressed air from the air supply source 15 is supplied to the air spring 14, the internal pressure of the air spring 14 increases, the upper frame 12 is pushed up, and the seat cushion 4 is raised.

While the seat cushion 4 is rising, the cam 3
Since the valve rod 17 once pushes the valve rod 17, the valve rod 17 is stretched by the urging force of the spring of the valve rod 17 to prevent the downward rotation return regardless of the presence or absence of the first convex portion 34. With this, the cam 32 slides in contact with the valve rod 17 pushed in, and returns to the front along the guide shaft 31 in conjunction with the rise of the seat cushion 4. During that time, since the supply / exhaust valve 16 is in the supply mode,
The compressed air is continuously supplied to the air spring 14 from the air supply source 15.

The seat cushion 4 is the air spring 1
When it is pushed up by 4 and rises to the position just before the set reference height Y, the cam 32 interlocks via the connecting member 33 and returns to the vicinity of the neutral position. Therefore, the oblique side surface of the head portion 32b is joined to one of the valve rods 17 and 18 of the supply / exhaust valve 16,
The cam 32 is forcibly returned to rotate downward by the biasing force of the valve rods 17, 18. Simultaneously with the downward return of rotation of the cam 32, the valve rod 17 projects by the urging force of the built-in spring to close the air supply valve of the air supply / exhaust valve 16, and the supply of compressed air to the air spring 14 is stopped to stop the seat cushion 4 Is held at the original set reference height Y.

On the other hand, when the seat cushion 4 rises from the set reference height Y over the dead zone, the cam 32 extends along the guide shaft 31 via the connecting member 33 from the neutral position forward by a predetermined distance or more. Moving. Therefore, the cam 32 comes into contact with the second convex portion 35 and rotates upward so as to ride up, push the valve rod 18 to open the exhaust valve of the supply / exhaust valve 16, and the exhaust mode is set. Thus the air spring 14
The compressed air inside is discharged, the internal pressure of the air spring 14 decreases, and the seat cushion 4 returns to the reference height together with the upper frame 12.

Even in the exhaust mode, the cam 32 keeps the valve rod 1
By the urging force of the built-in spring of 8, the cam 32 maintains the state of being rotated upward regardless of the presence or absence of the second convex portion 35, and
8 is pushed in, that is, in the exhaust mode, it moves backward along the guide shaft 31 in conjunction with the connecting member 33, and the exhaust in the air spring 14 is continued during that time.

When the seat cushion 4 is lowered to the position just before the set reference height Y, the cam 32 returns to the vicinity of the neutral position, so that the oblique side surface of the head portion 32b causes the valve rod 1 to move.
The cam 32 comes into contact with any one of 7 and 18, and the cam 32 is forcibly returned to rotate downward by the urging force of the valve rods 17 and 18. When the cam 32 returns to the downward rotation, the valve rod 18 projects due to the urging force of the built-in spring to close the exhaust valve of the air supply / exhaust valve 16, the exhaust from the air spring 14 stops, and the seat cushion 4 returns to the original setting reference. Return to height Y.

When the seat back 6 is tilted rearward at rest or the like, the load applied to the seat cushion 4 is smaller than that when seated normally, so that the seat cushion 4 rises due to the internal pressure of the air spring 14. In this case, as the seat back 6 is tilted backward by a predetermined angle or more, the driving member 5
The valve body operating portion 65 of the on-off valve 51 is driven in the direction of the valve closing mode via 2 to close the on-off valve 51.

Therefore, even if the valve switching mechanism 30 switches the supply / exhaust valve 16 to the exhaust mode as the seat rises, air is prevented from being discharged from the air spring 14. Therefore, the seat cushion 4 and the seat back 6 are held in the raised position. When the seat back 6 is raised up to the normal angle, the opening / closing valve 51 is switched to the valve opening mode via the drive member 52 interlocking with the seat back 6.
Since the air can be discharged from the air spring 14, the above-described automatic height adjusting function can be exerted.

The present invention is not limited to the above-described embodiments, but specific aspects of the supply / exhaust valve 16, the valve switching mechanism 30 and the on-off valve 51, the shape of the driving member 52, the mounting position, and the like are not limited. However, various modifications can be made without departing from the scope of the present invention. Further, the present invention can of course be applied to a vehicle seat device that does not include the tilt mechanism section 3.

[0050]

According to the present invention, the seat cushion can be constantly maintained at the set reference height regardless of the weight of the seated person, and when the seatback is tilted rearward at rest or the like, the load on the seat cushion is reduced. Even if the number of seats decreases, it is possible to prevent the seat from descending and maintain the seat height. Therefore, it is possible to avoid various problems due to the seat being lowered while the seat back is tilted. For example, problems such as the bed being crushed by the seat back, the entire seat being lowered forward, and the seat being distorted can be avoided.

Since the on-off valve is directly moved to the valve closing mode by the driving member in accordance with the backward tilting movement of the seat back, it is not necessary to install a long wire cable and there is no risk of malfunction. Further, it is also easy to adjust the position of the valve body operating portion of the on-off valve in relation to the inclination angle of the seat back.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of a vehicle seat showing an embodiment of the present invention.

2 is a perspective view of the entire vehicle seat shown in FIG. 1. FIG.

FIG. 3 is an exploded perspective view of a part of a frame of the vehicle seat shown in FIG. 1 and an opening / closing valve mechanism.

FIG. 4 is a side view of a portion of the vehicle seat shown in FIG.

FIG. 5 is a perspective view of a part of a vehicle seat showing a prior art.

FIG. 6 is a conceptual diagram showing a relationship between a seat provided with an air suspension device and peripheral members.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Vehicle seat 2 ... Air suspension device 4 ... Seat cushion 6 ... Seat back 11 ... Lower frame 12 ... Upper frame 13 ... Link mechanism 14 ... Air spring 15 ... Air supply source 16 ... Air supply / exhaust valve 30 ... Valve switching mechanism 50 On-off valve unit 51 ... On-off valve 52 ... Drive member 65 ... Valve body operation unit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Murakami 1-3-1 Shimotsuruma, Yamato-shi, Kanagawa Isuzu Motors Ltd. Yamato factory (72) Inventor Nobuyuki Tashiro 1-3-1 Shimotsuruma, Yamato-shi, Kanagawa Isuzu Motors Co., Ltd. Yamato Factory

Claims (2)

[Claims] 1. A lower frame provided on a floor side of a vehicle, an upper frame disposed above the lower frame to support a seat cushion, and a rear frame provided at a rear portion of the seat cushion and changing a tilt angle in a front-rear direction. A seat back that can be moved, a link mechanism that vertically moves the upper frame relative to the lower frame, an air spring that supports a load applied to the upper frame from above, and compressed air in the air spring. Is provided between the air supply source and the air spring, and the compressed air sent from the air supply source when the upper frame is below a predetermined height is supplied to the air spring. To the air supply mode for supplying air to the air frame and to the exhaust mode for discharging air from the air spring when the upper frame becomes higher than a predetermined height. An exhaust valve, a valve switching mechanism that operates the supply / exhaust valve in the supply mode or the exhaust mode according to the height of the upper frame, and is provided between the air spring and the supply / exhaust valve. An on-off valve having a valve body operating section operable in a valve opening mode capable of discharging the air in the spring to the air supply / exhaust valve side and a valve closing mode in which the air in the air spring is shut off so that the air cannot be discharged; A drive member connected to the member on the back side and the valve body operating portion of the on-off valve, and moving the valve body operating portion to the valve closing mode only when the seat back is tilted backward by a predetermined angle or more. A vehicle seat provided with an air suspension device comprising: 2. The opening / closing valve is an angle controllable valve having a swingable valve body operating portion, wherein one end of the drive member is connected to the valve body operating portion of the opening / closing valve, and the drive member The vehicle seat provided with the air suspension device according to claim 1, wherein the other end is connected to the member on the seat back side so as to be rotatable about a horizontal axis.