JP7465566B2 - Air suspension device for vehicle seats - Google Patents

Description

The present invention relates to an air suspension device for a vehicle seat that can be automatically adjusted to a reference height position that is set in accordance with the occupant's body type, etc., and more particularly to a multi-functional air suspension device for a vehicle seat that improves operability as well as convenience for the occupant.

In order to drive a vehicle comfortably and safely, an air suspension device is used in vehicle seats, which allows the height of the vehicle seat to be set to a desired position that suits the occupant's body type and accurately dampens and absorbs shocks, vibrations, etc. This air suspension device has the function of adjusting and maintaining a predetermined set height reference position regardless of the weight of the occupant by supplying air from the outside to the air spring or exhausting air from the air spring to the outside through valve control according to the change in the height of the vehicle seat.

Many air suspension devices that have the function of adjusting and maintaining this type of height position involve complex device configurations and control operations, which not only increase costs but also make them difficult to use and lack speed and convenience. In order to solve these issues, the applicant has applied for a patent for an air suspension device with simplified control operations that is easy to use (see Patent Document 1).

JP 2010-241270 A

JP 2014-162397 A

The air suspension device described above has an auto-leveling function (a function for maintaining a reference height position), a function for changing a reference height position, and a function for lowering the seat. However, in order to perform each function, an air supply and exhaust control valve is required for each function, so there are two or more supply and exhaust control valves (air valves). In addition, an air tube that serves as an air passage connected from an air supply source such as a compressor must be split into two via connectors and connected to each air valve, and further, the air tubes connected from each air valve must be joined together via a connector and connected to the air spring.

This increases the number of parts, such as air valves, connectors, and tubes, and the number of assembly points, resulting in increased costs and a greater risk of air leakage at connection points, etc.

Furthermore, the auto-leveling function (reference height position maintaining function) is required to be able to stably maintain the reference height, the reference height position changing function is required to be able to quickly set the reference height, and the seat lowering function is required to be able to quickly lower the seat.

In order to achieve the above object, the present invention provides
A lower frame installed on a floor surface side of the vehicle;
an upper frame disposed on an upper portion of the lower frame and provided under a vehicle seat of the vehicle;
a pair of X links, which are members intersecting in an X shape and are disposed on left and right side surfaces between the lower frame and the upper frame, connected to the lower frame and the upper frame to support the upper frame so as to be vertically movable, and which are pivotally mounted on shafts connecting the mutual intersecting portions of the X shape;
an air spring that moves the upper frame up and down by pressure changes caused by air supply from a compressed air supply source and exhaust to the outside;
a passage having one end connected to the supply source and the other end connected to the air spring, through which air can pass, an exhaust passage connected to the passage and capable of exhausting the air within the passage to the outside, an air supply valve for opening and closing the passage and an exhaust valve for opening and closing the exhaust passage, a diameter of a portion of the passage up to the supply valve and a diameter of a portion of the exhaust passage from the exhaust valve to the outside being different, and an air supply and exhaust valve body portion provided on one of the link members forming an X link on either the left or right side surface;
an intake control cam that is provided on one of the link members and controls the opening and closing of the intake valve, and an exhaust control cam that controls the opening and closing of the exhaust valve;
a cam member that is pivotally mounted on the shaft and tensioned on another link member that intersects with the one link member so as to rotate together with the other link member;
an arm member pivotally mounted on the shaft so as to be rotatable integrally with the cam member, and which rotates the intake control cam or the exhaust control cam in accordance with the direction of rotation of the X link to open or close the intake valve or the exhaust valve;
a reference height position maintaining mechanism for maintaining the upper frame at a preset reference height position;
a reference height position changing mechanism that can change the reference height position;
a height position lowering mechanism that lowers the upper frame from the reference height position to a lower limit height position,
the reference height position changing mechanism has a height position changing operation unit that pulls or sends out a first wire member connected to the cam member that is integral with the arm member in order to rotate the arm member,
the height position change operation unit includes a fixed plate having a through hole, a first gear plate having a through hole of substantially the same diameter as the through hole and aligned with the through hole of the fixed plate, and having a concave-convex shape formed along a circumference of a certain radius centered on the through hole, and fixed to the fixed plate; a shaft passing through both through holes; a second gear plate facing the first gear plate and having concave-convex shapes that detachably mesh with the concave-convex shapes of the gear plate, and fixed to the shaft and connected to the first wire member; and a spring that is disposed around one end of the shaft and applies a force to the shaft in the axial direction of the shaft so that the concave-convex shapes of the first gear plate mesh with the concave-convex shapes of the second gear plate, while the concave-convex shapes of the gears that were meshed with each other due to the rotation of the shaft shift to the adjacent positions and mesh with each other again;
The cross-sectional shape of the projections and recesses of the first and second gear plates is substantially trapezoidal,
the shaft of the height position change operation unit is rotated against the force of the spring to rotate the second gear plate, and the first wire member connected to the second gear plate is pulled or sent out to rotate the arm member through the cam member, thereby rotating the intake control cam or the exhaust control cam to open and close the intake valve or the exhaust valve, and the upper frame is moved upward or downward by the pressure change of the air spring to set a new specified position as the reference height,
the reference height position maintaining mechanism is a mechanism in which, when the upper frame is at a position previously set as a reference height, the arm member is in a neutral position in which it does not act on either the air intake control cam or the exhaust control cam, and when the upper frame descends a predetermined distance or more from the reference height, the X-link rotates in association with the descent, causing the arm member to rotate the air intake control cam to open the air intake valve and increase the pressure of the air spring to return the upper frame to the reference height, and when the upper frame rises a predetermined distance or more from the reference height, the X-link rotates in association with the ascent, causing the arm member to rotate the exhaust control cam to open the exhaust valve and reduce the pressure of the air spring to return the upper frame to the reference height,
This is an air suspension device for a vehicle seat, characterized in that the height position lowering mechanism is a mechanism that opens the air intake valve by abutting it against the air intake control cam when a second wire member connected to the air intake and exhaust valve body is pulled, thereby reducing the pressure of the air spring and lowering the upper frame to a lower limit height position.

According to the above configuration, the second gear plate rotates by rotating the shaft of the height position changing operation unit against the force of the spring, and the arm member rotates through the cam member by pulling or sending out the first wire member connected to the second gear plate. The rotation of the arm member rotates the intake control cam or the exhaust control cam to open or close the intake valve or the exhaust valve, and the upper frame moves upward or downward due to a pressure change in the air spring, so that a new predetermined position can be set as the reference height, and therefore the reference height can be set according to the physique of the occupant, etc.

The concaves and convexes of the first gear plate of the shaft of the height position changing operation unit and the concaves and convexes of the second gear plate that mesh with them have a substantially trapezoidal cross-sectional shape, so that the angle (angle of one rotation) at which each plate sequentially meshes with the adjacent concaves and convexes can be made large, and the length of pulling and feeding the wire member can be made large (long). Therefore, the number of sequential rotations for meshing can be reduced to set the reference height position.

The vehicle also has a height lowering mechanism for lowering the upper frame from the reference height position to a lower limit height position, i.e., a mechanism for rotating the supply and exhaust valve body by pulling a second wire member connected to the supply and exhaust valve body, causing the exhaust valve to come into contact with the exhaust control cam and open, thereby reducing the pressure of the air spring and lowering the upper frame to the lower limit height position. The height lowering mechanism allows a sufficient distance to be maintained between the occupant and the handlebars, making it easy for the occupant to get on and off the vehicle.

In the supply and exhaust valve body, the diameter of the passage portion up to the supply valve is different from the diameter of the exhaust passage portion from the exhaust valve to the outside. For example, if the diameter of the passage portion up to the supply valve is made smaller (thinner) than the diameter of the exhaust passage portion from the exhaust valve to the outside, the reference height can be set quickly by the height position change operation unit, but the supply speed (amount of air supplied per hour) from the compressed air supply source to the air spring decreases, and the sudden rise of the upper frame can be suppressed. On the other hand, when the height position lowering mechanism lowers the pressure of the air spring to lower the upper frame to the lower limit height position, the diameter of the exhaust passage portion from the exhaust valve to the outside is large (thick), so the exhaust speed of air from the air spring (amount of air exhausted per hour) is faster, and therefore the upper frame can be quickly lowered to the lower limit height position and the upper frame can be quickly lowered to the position when not in use.

When a passenger sits on the vehicle seat, the load causes the upper frame to descend, but the X-link rotates in association with this descent, causing the arm member to rotate the air intake control cam to open the air intake valve, thereby increasing the pressure in the air spring and returning the upper frame to the reference height.

In addition, when the upper frame rises due to a reduction in load caused by the occupant standing up, the X-link rotates in conjunction with the rise, causing the arm member to rotate the exhaust control cam to open the exhaust valve, thereby reducing the pressure in the air spring and returning the upper frame to the reference height, so that the upper frame can be maintained at the preset reference height position regardless of the weight of the occupant.

In addition, a height position rise limiting mechanism that limits the rise of the upper frame from the reference height position to a predetermined height or more includes a plate member that is rotatably provided on one of the link members and is biased by an elastic member so that a guide roller at an end of the plate member rolls on the sloped portion of the cam member, a first gear member that rotates integrally with the plate member, and a second gear member that is provided on the other link member, and when the upper frame rises from the reference height position to a predetermined height position, the guide roller descends to a wall portion formed on the end of the sloped portion of the cam member, causing the first gear member and the second gear member to engage with each other to stop the rise of the upper frame. This prevents the upper frame from rising above a predetermined height, thereby ensuring a constant gap between the handlebars and the occupant and preventing interference with the handlebars when disembarking.

In addition, the intake control cam and the exhaust control cam are plate-shaped members having curved portions, and the intake control cam and the exhaust control cam are pivotally mounted on one of the link members in an arrangement in which the curved portions are symmetrical so that a recess is formed between them, and a rotatable roller member is provided at the tip of the arm member, and when the X-link rotates as the upper frame descends, the intake control cam presses and slides against the curved portion to rotate the intake control cam and open the intake valve, and when the X-link rotates as the upper frame rises, the exhaust control cam presses and slides against the curved portion to rotate the exhaust control cam and open the exhaust valve, and when the upper frame is at the reference height, the roller member is positioned in the overlapping recess and is in the neutral position.

In addition, either the one link member or the other link member is pivoted to the upper frame, and the other is pivoted so as to be movable back and forth via a roller member that can slide or rotate on a running path within the upper frame, and a collar member that ensures a clearance for the roller member to run is inserted between the upper and lower walls of the running path via a plate-shaped reinforcing member provided on the upper frame.

By inserting the collar member, the distance between the top and bottom walls of the running path inside the upper frame can be kept constant, and the roller members can continue to run smoothly. Furthermore, by providing a plate-shaped reinforcing member, deformation of the upper frame can be suppressed, and the roller members can be prevented from falling off and rattling can be suppressed.

Since the plate member and the first gear member are detachably provided on one link member, and the second gear member is detachably provided on the other link member, a height position rise limiting mechanism can be easily added.
The arm member and the arm member may be integrally formed.

According to the present invention, an air suspension device equipped with an auto-leveling function, that is, a height position maintaining mechanism, a reference height position changing mechanism, and a seat lowering mechanism, can be provided as a device with a simple structure and good usability, and further, the device can be provided as a device that can quickly set the reference height and adjust the up and down speed of the upper frame.

FIG. 1(a) is a perspective view of an air suspension device for a vehicle seat, and FIG. 1(b) is a plan view of the same air suspension device.

2(a) is a view (front view) taken along line AA in FIG. 1(b), and FIG. 2(b) is a view taken along line BB in FIG. 1(b).

3(a) is a view (front view) taken along the line CC in FIG. 1(b), and FIG. 3(b) is a view taken along the line DD in FIG. 1(b).

4(a) is a view (front view) taken along line EE in FIG. 1(b), and FIG. 4(b) is a view taken along line FF in FIG. 1(b).

Figure 5(a) is a front view of the intake control cam, Figure 5(b) is a perspective view of the intake control cam, Figure 5(c) is a front view of the exhaust control cam, Figure 5(d) is a perspective view of the exhaust control cam, and Figure 5(e) is a front view of the intake control cam and the exhaust control cam in an engaged state.

Figure 6(a) is a front view of the air valve, Figure 6(b) is a perspective view of the air valve, Figure 6(c) is a front view of the valve plate, Figure 6(d) is a perspective view of the valve plate, Figure 6(e) is a front view of the valve bracket, Figure 6(f) is a perspective view of the valve bracket, Figure 6(g) is a front view of the bracket, and Figure 6(h) is a perspective view of the bracket.

7A is a plan view of the air valve, valve plate, valve bracket and bracket in an assembled state, FIG. 7A is a front view of the assembled state, and FIG. 7A is a perspective view of the assembled state.

Figure 7B(a) is a cross-sectional view of the air valve showing the internal structure, Figure 7B(b) shows the state when the exhaust operating rod is pressed, causing compressed air from the air spring to be exhausted through the exhaust valve, and Figure 7B(c) shows the state when the air supply operating rod is pressed, causing compressed air to be supplied to the air spring through the air supply valve.

8(a) is a front view of the cam member, FIG. 8(b) is a perspective view of the cam member, FIG. 8(c) is a front view of the arm member, and FIG. 8(d) is a perspective view of the arm member.

Figure 9A(a) is a plan view of the height position changing operating part (with the dial removed), Figure 9A(b) is a partial cross-sectional view of the height position changing operating part (with the dial removed), and Figure 9A(c) is a front view of the dial before it is attached.

FIG. 9B(a) is an oblique view of the height position changing operation part (with the dial removed), FIG. 9B(b) is an oblique view of each gear plate, and FIG. 9B(c) shows a cross section along the circumferential direction of the gear plates meshed with each other.

FIG. 10(a) is a front view of the descending device, and FIG. 10(b) is a front view of the descending device during operation.

FIG. 11 is a schematic diagram of the ducts that supply and exhaust air to and from the air spring.

Figure 12 is a schematic diagram of the device explaining the operation of the reference height position maintaining mechanism, where Figure 12(a) is a schematic diagram of the device in a state where the upper frame is at the reference height position, Figure 12(b) is a schematic diagram of the device in a state where it has been lowered from the reference height position, and Figure 12(c) is a schematic diagram of the device in a state where it has been raised from the reference height position.

Figure 13 is a schematic diagram of the device explaining the operation of the reference height position changing mechanism, where Figure 13(a) is a schematic diagram of the device when the upper frame is at the reference height position, Figure 13(b) is a schematic diagram of the device when it has been lowered from the reference height position, and Figure 13(c) is a schematic diagram of the device when it has been raised from the reference height position.

Figure 14 is a schematic diagram of the device explaining the operation of the height position lowering mechanism, where Figure 14(a) is a schematic diagram of the device in a state where the upper frame is at the reference height position before lowering, Figure 14(b) is a schematic diagram of the device in a state where the lowering device has been activated and the device has been lowered, and Figure 14(c) is a schematic diagram of the device in a state where the operation of the lowering device has been released.

FIG. 15 is a schematic diagram of the device in a state where the height position rise limiting mechanism is in operation.

A preferred embodiment of an air suspension device for a vehicle seat according to the present invention will now be described with reference to the accompanying drawings. First, the configuration of the air suspension device for a vehicle seat will be described with reference to Figures 1 to 11, and then the operation of the device will be described with reference to Figures 12 to 15.

<Overall Schematic Configuration of Air Suspension Device>
As shown in FIGS. 1 to 11 , an air suspension device 11 for a vehicle seat (hereinafter referred to as "air suspension device 11" as appropriate) includes a lower frame 12 that is installed on a floor surface of a vehicle or on a slide rail on the floor surface, an upper frame 13 that is arranged on an upper portion of the lower frame 12 and provided under a vehicle seat (not shown) of the vehicle, and a pair of X links 15 a, 15 b that intersect in an X shape and are arranged on the left and right sides between the lower frame 12 and the upper frame 13, connected to the lower frame 12 and the upper frame 13, and supporting the upper frame 13 so as to be vertically movable.

The lower frame 12 consists of a frame body assembled into a square shape by plate-shaped members at the front and rear, with the left and right side sides made of U-shaped cross-section members, and the opening of the U-shaped cross-section members faces the inside of the air suspension device 11.

The upper frame 13 consists of side frames 13a, 13b, which are U-shaped in cross section on the left and right side sides, and cylindrical connecting frames 13c, 13d, which are members that join these together and are located on the front and rear sides, respectively, assembled into a rectangular frame body, with the openings of the side frames 13a, 13b facing toward the inside of the air suspension device 11.

The X links 15a, 15b are disposed on the left and right side surfaces of the air suspension device 11, respectively, between the lower frame 12 and the upper frame 13. The X link 15a has an outer link member 16a and an inner link member 16b that intersect in an X shape at approximately the middle position (see FIGS. 1 and 4(a)). Similarly, the X link 15b has an outer link member 16c and an inner link member 16d that intersect in an X shape at approximately the middle position (see FIGS. 1 and 2(a)). The intersecting portions are each pivotally mounted on a cylindrical rotating shaft 20.

As the height position of the upper frame 13 changes up and down, one of the two link members (16a, 16b) and (16c, 16d) that constitute the X-links 15a, 15b, which serve as support members for the upper frame 13, rotates clockwise and the other rotates counterclockwise, thereby changing the intersection angle.

Between the lower frame 12 and the upper frame 13, an air spring 18 that moves the upper frame 13 up and down by adjusting the pressure by supplying and exhausting air into a container is placed on an air spring lower support member 19a installed on the floor. An air spring upper support member 19b that is suspended between X-links 15a and 15b is attached to the upper part of the air spring 18, and the air spring upper support member 19b moves up and down due to pressure fluctuations of the air spring 18, rotating the X-links 15a and 15b, and moving the upper frame 13 up and down.

The rear end of the outer link member 16a of the X-link 15a and the rear end of the outer link member 16c of the X-link 15b are each connected to a connecting shaft body 21b pivotally mounted to the upper frame 13, and are pivotally mounted to the upper frame 13 by passing through each end and each rear end of the connecting shaft body 21b.

The front end of the outer link member 16a and the front end of the outer link member 16c are each connected to a connecting shaft 23a that is pivotally mounted on the lower frame 12 so as to be movable back and forth (see Figures 1 and 4). Each end of the connecting shaft 23a penetrates the respective front end portions and is movably stored in the lower frame 12.

In addition, a rear end of the inner link member 16b of the X link 15a and a rear end of the inner link member 16d of the X link 15b are each connected to a connecting shaft body 21a pivoted to the lower frame 12, and each end of the connecting shaft 21a passes through each rear end and is pivoted to the lower frame 12.

The front end portion of the inner link member 16b and the front end portion of the inner link member 16d are each connected to a connecting shaft body 23b that is pivotally mounted on the upper frame 13 so as to be movable back and forth (see Figures 1 and 4). Each end portion of the connecting shaft body 23b passes through each front end portion and is movably stored in the upper frame 13.

A roller member 25 is attached to each end of connecting shaft body 23a, which is pivoted to the lower frame 12 so as to be movable back and forth, and to each end of connecting shaft body 23b, which is pivoted to the upper frame 13 so as to be movable back and forth. This roller member 25 rolls or slides along the running path of the U-shaped cross-sectional portion of the side frame 13a that constitutes the lower frame 12 and the upper frame 13, thereby enabling connecting shaft bodies 23a, 23b to move back and forth.
Conversely, the connecting shaft bodies 21a, 21b may be pivoted to move forward and backward, and the connecting shaft bodies 23a, 23b may be pivoted.

In addition, between the upper and lower walls of the side frame 13a constituting the upper frame 13 that forms the running path of the roller member 25, cylindrical collar members 26 are attached with bolts and nuts at the front and rear positions of the running path via plate-shaped reinforcing members 27 arranged on the upper outer part in order to ensure a constant distance between the upper and lower walls (see FIG. 4(b)). By keeping the distance between the upper and lower walls constant, it is possible to prevent the roller member 25 from swinging up and down as it rolls along the running path between the upper and lower walls of the upper frame 13. That is, by attaching and assembling the collar members between the upper and lower walls of the upper frame 13, it is possible to increase the accuracy of the dimensions between the upper and lower walls, and further to suppress deformation of the frame due to welding or the like, and also to suppress the vertical wobbling of the roller member 25. The collar members 26 may be made of either resin or metal.

The reinforcing plate 27 is placed on the upper part of the upper frame 13 and is attached with the bolts and nuts that attach the collar member 26 as described above. By providing the plate-shaped reinforcing member 27, deformation of the upper frame can be further suppressed, and the roller members can be prevented from falling off and the occurrence of rattling can be suppressed.

Further, shock absorbers 29 are attached to the X-links 15a, 15b to damp the rotational movement of the X-links 15a, 15b and the vertical movement of the upper frame 13 (see FIG. 1(b)).

As shown in FIG. 1A, a height position changing operation unit 32 including a dial member 31 for operating a reference height position changing mechanism of the upper frame is attached to the side of the lower frame 12.

Furthermore, a lowering operation unit 35 including a lever member 33 for operating a height lowering mechanism that lowers the upper frame 13 is attached to the end of the connecting frame 13 c that constitutes the upper frame 13 .

Of the two link members constituting the X link 15a, an air valve 43, which is an air supply/exhaust valve body that houses an exhaust valve 41 and an air supply valve 42 for exhausting air from and supplying air to the air spring 18, is provided on the outer link member 16a, which is one of the two link members, between the rotating shaft 20 and the connecting shaft 23a, together with a valve plate 61, which is a fastening member, a valve bracket 62 to which the valve plate 61 is pivoted, and a valve bracket 62 to which the valve plate 61 is pivoted (see FIGS. 2(b), 3(a), and 7A). The details of the attachment of the air valve 43 to the outer link member 16a will be described later.

The air valve 43 is provided with an exhaust valve actuating rod 51 that actuates the exhaust valve 41 and an air intake valve actuating rod 52 that actuates the air intake valve 42 , which protrude from the air valve 43 in the direction of the rotating shaft 20 .

Furthermore, an exhaust control cam 55 is pivotally attached to the outer link member 16a, which presses the exhaust valve operating rod 51 when rotated to open the exhaust valve 41, and an intake control cam 56 is pivotally attached to the outer link member 16a, which presses the intake valve operating rod 52 when rotated to open the intake valve 42 (see Figures 2(b) and 3(a)).

<Air intake control cam, exhaust control cam>
The shapes of the exhaust control cam 55 and the intake control cam 56 and their combination will be described with reference to FIG.

As shown in Figure 5(a), which is a front view of the exhaust control cam 55, and Figure 5(b), which is an oblique view of the same, the exhaust control cam 55 is a plate-shaped member including a curved portion 55a along which a roller member at the tip of an arm member described later moves when pressed, a pivot shaft hole portion 55b into which a pivot shaft that rotates when the roller member moves when pressed, and a pressing portion 55c that presses the exhaust valve operating rod 51 when rotated to open the exhaust valve 41.

As shown in Figure 5(c), which is a front view of the air intake control cam 56, and Figure 5(d), which is an oblique view of the same, the air intake control cam 56, like the exhaust control cam 55, is a plate-shaped member having a curved portion 56a, a pivot shaft hole portion 56b, and a pressing portion 56c.

As shown in Fig. 5(e), the exhaust control cam 55 and the air intake control cam 56 are integrated and rotatably engaged by overlapping the pivot hole portions 55b, 56b for inserting the pivot shaft (see Fig. 3(a)). When integrated, a recess 58 is formed between the curved portion 55a of the exhaust control cam 55 and the curved portion 56a of the air intake control cam 56, which serves as a gap between the two cams. As will be described later, when the roller member located at the tip of the arm member is at a reference height position, which is a neutral position where it does not act on either the exhaust control cam 55 or the air intake control cam 56, the roller member is located in this recess 58.

As shown in Fig. 5(e), the exhaust control cam 55 and the intake control cam 56 are integrated into one cam, which acts on the exhaust valve actuating rod 51 or the intake valve actuating rod 52 depending on the direction of rotation as described later (see Fig. 3(a)). The relative positions of the exhaust control cam 55 and the intake control cam 56 can be adjusted by loosening the engagement between the exhaust control cam 55 and the intake control cam 56. This is to adjust the timing with the rotation of the X-links 15a, 15b to switch between exhaust and intake, as described later.

<Air valve>
The attachment of the air valve 43 to the outer link member 16a will be described with reference to Figures 3(a) and 3(b). Also, the attachment parts used to attach the air valve 43 to the outer link member 16a will be described with reference to Figures 6 and 7A.

As shown in Figures 6(a) and 6(b), the air valve 43 is fixed to a valve plate 61 so that the exhaust operating rod 51 is located at the top and the air intake valve operating rod 52 is located at the bottom (see Figures 7A(b) and 7A(c)).

6(c) and 6(d), the valve plate 61 is a plate-like member to which the air valve 43 is fixed, and is pivoted relative to the valve bracket 62. A rotation shaft portion 63a (see FIG. 2(b)) fixed to the valve bracket 62 is provided in the rotation shaft hole portion 61a, and the valve plate 61 is rotatable relative to this rotation shaft portion 63a.

The valve plate 61 is formed with a valve pin hole 61b (see FIG. 6(c)) into which a valve pin 64 (shown by a dotted line) is inserted to limit the rotation, and further formed with a wall portion 61c which limits the rotation of a bracket 65 which will be described later.

As shown in Fig. 6(e) which is a front view and Fig. 6(f) which is a perspective view, the valve bracket 62 fixed to the outer link member 16a is formed so that walls 62a, 62b against which a valve pin 64 attached to the valve plate 61 abuts are opposed at a predetermined distance in order to limit the rotation range of the valve plate 61. Furthermore, a tension spring 66a is hooked between a hole 61d of the valve plate 61 and a protrusion 62c of the valve bracket 62 (see Figs. 2(b) and 7A(b)), and the elastic force of the spring 66a causes the valve pin 64 to abut against the wall 62b of the valve bracket 62 (see Fig. 7A(c)), thereby limiting the rotation of the valve plate 61.

A shaft-shaped pin member 62d is further fixed to the valve bracket 62 so as to be positioned in a recess 58 between the exhaust control cam 55 and the intake control cam 56, thereby restricting the rotation of the exhaust control cam 55 and the intake control cam 56, as described below (see Figure 3(a)).

6(g) and 6(h), the bracket 65 is a bent plate-like member, and is provided with a pivot hole 65a for inserting the pivot shaft 63b (see FIG. 2(b)) at its approximate center, a hole 65b for engaging a tension spring 66b, and a protrusion 65c for engaging one end of a spring 66c (see FIG. 2(b) and FIG. 3(a)). The other end of the spring 66c is connected to a wire member 68a (second wire member) that connects the lever member 33 of the lowering operation unit 35 (see FIG. 3(a)).

FIG. 7A(a) is a plan view of the air valve 43, the valve plate 61, the valve bracket 62 and the bracket 65 in an assembled state, FIG. 7A(b) is a front view of the same, and FIG. 7A(c) is a perspective view of the same.

The air valve 43 is fixed to a valve plate 61, which is pivotally mounted on a valve bracket 62 via a rotary shaft 63a. As described above, the valve plate 61 is pulled by a spring 66a hooked between the valve plate 61 and the valve bracket 62, and the valve pin 64 abuts against a wall portion 62b to prevent rotation.

The bracket 65 is pivotally mounted on the valve plate 61 at a pivot shaft 63b, and both ends are pulled and tensioned by springs 66b and 66c, respectively. By operating the lever member 33 of the lowering operation unit 35 to which the wire member 68a to which the spring 66c is connected is connected, the bracket 65 rotates, and the valve plate 61 rotates, so that the exhaust valve operating rod 51 of the air valve 43 is pressed by the pressing portion 55c of the exhaust control cam 55, thereby opening the exhaust valve 41 (see FIG. 3(a), details of which will be described later).

It is also possible to connect the wire member 68a directly to the valve plate 61, but in this case, variations in the length of the wire member 68a can cause problems with the lowering operation, so the bracket 65 and springs 66b and 66c are provided for adjustment. That is, when the wire member 68a is directly connected to the valve plate 61, if the wire member 58a is short, the valve plate 61 will be pulled counterclockwise, causing the lowering device to be constantly in the ON state, and if the wire member 68a is too long, it will sag, causing more play than necessary in the lever portion 35a of the lowering operation portion 35.

The basic structure of the air valve 43 having the exhaust valve 51 and the intake valve 52 is the same as that of a conventional air valve as shown in Figure 7B, so details will be omitted, but the air valve 43 used in the present invention further incorporates an orifice 42' for reducing the flow rate in the passage on the intake valve 42 side (Figure 7B). The orifice 42' has an inner through hole 42" that is narrower than the passage.

As shown in FIG. 11, a pipe 44b is connected between a connection part 45d of the air spring 18 and a connection part 45c on the exhaust valve 42 side, and a pipe 44a from the air spring 18 is connected between a connection part 45a to which a compressor (not shown) is connected and a connection part 45b on the intake valve 42 side.

In the air valve 43, as shown in Fig. 7B, there is a passage through which air can pass between the connection parts 45b and 45c. An exhaust passage is connected to this passage and allows the air in the passage to be exhausted to the outside. An intake valve 42 that opens and closes the passage, and an exhaust valve 41 that opens and closes the exhaust passage are provided. When the intake operating rod 52 is pressed, the intake valve 42 opens, and the compressed air that has flowed from the compressor through the pipe 44a flows through the passage through the intake valve 42, but when the exhaust valve 41 is closed, it flows into the pipe 44b and is supplied to the air spring 18.

When the air intake operating rod 52 is not pressed, as shown in Fig. 7B(a), the air intake valve 42 is closed and compressed air is not supplied to the air spring 18. In this state, when the exhaust operating rod 51 is pressed, as shown in Fig. 7B(b), the exhaust valve 41 opens and air from the air spring 18 is exhausted to the outside through the exhaust passage.

<Down operation unit>
The lowering operation unit 35 of the height lowering mechanism is provided at an end of the connecting frame 13c that constitutes the upper frame 13 (see FIG. 1(a)). Front views of the lowering operation unit 35 are shown in FIG. 10(a) and FIG. 10(b).

10A is a front view of the lowering operation part 35 when the lowering operation is OFF, and the lever part 35a for operation is in a downward state. When the lever part 35 is rotated in the R direction so that the tip of the lever part 35 is positioned directly above (see FIG. 10B), the wire member 68a is wound around the disk-shaped winding part 35b, and the bracket 65 is rotated counterclockwise via the spring 66c to which the wire member 68a is connected, and comes into contact with the wall part 61c of the valve plate 61.

When the bracket 65 rotates, the bracket 65 rotates the valve plate 61 counterclockwise around the rotation shaft 63a via the spring 66b. When the valve plate 61 rotates counterclockwise, the air valve 43 provided on the valve plate 61 also rotates counterclockwise, and the exhaust valve actuating rod 51 of the exhaust valve 41 presses the pressing portion 55c of the exhaust control cam, but since the exhaust control cam 55 is prevented from rotating counterclockwise by the pin member 62d, the exhaust valve actuating rod 51 is pressed. This opens the exhaust valve 41, reduces the pressure of the air spring 18, and the upper frame 13 descends, turning the lowering device ON.

As the upper frame 13 descends, the arm member 72 rotates clockwise and the roller member 71a at the tip of the arm member 72 rotates the air intake control cam 56 counterclockwise. However, as the air valve 43 rotates counterclockwise as described above, a certain gap is created between the air intake control cam 56 and the air intake valve operating rod 52, so the air intake valve 42 cannot be opened and it descends to the lowest end.

When lever portion 35a is rotated in the L direction so that the tip of lever portion 35a shown in Fig. 10(b) is positioned directly below (see Fig. 10(a)), wire member 68a is sent out towards bracket 65. This sending out of wire member 68a causes the valve plate, which has been rotating counterclockwise through bracket 65, to rotate clockwise until the valve pin 64 (Fig. 6(d)) reaches a position where it abuts against wall portion 62b (Fig. 6(f)) of valve bracket 62.

The exhaust control cam is released from the exhaust valve actuating rod 51, and the exhaust valve closes. At this time, the exhaust valve is lower than the reference height position, so the roller member 72a of the arm member 72 is in a position to press the intake control cam 56 (FIGS. 12(b) and 14(b)). This opens the intake valve 42, and the pressure of the air spring 18 increases, causing the upper frame 13 to rise toward the reference height position.

<Cam Member and Arm Member>
The shapes and arrangement of the cam member 71 and the arm member 72 will be described with reference to FIGS.

A front view of the cam member 71 is shown in Figure 8(a) and a perspective view thereof is shown in Figure 8(b), a front view of the arm member 72 is shown in Figure 8(c) and a perspective view thereof is shown in Figure 8(d). The arrangement of the cam member 71 and the arm member 72 in the suspension device 11 is shown in Figures 2(b), 3(a) and 3(b).

The cam member 71 is a member rotatably inserted into the rotating shaft 20, and a tension spring 66d attached to the inner link member 16b is hooked into a hole 71a formed at one end (FIG. 3B), and a wire member 68b (first wire member) connecting to the dial member 31 of the height position changing operation unit 32 is hooked into a hole 71b formed at the other end (see FIG. 9A). The cam member 71 is in a state of being tensioned on the inner link member 16b because tensile forces act on the holes 71a and 71b in directions opposite to the rotation direction, and it rotates at the same angle as the inner link member 16b.

The cam member 71 is formed on the upper frame 13 side with a curved inclined surface portion 71c and a wall portion 71d that slopes down from the end of the inclined surface portion 71c toward the rotating shaft body 20 side.

As shown in FIG. 2B, a plate 70, which is a plate-shaped member, is pivotally mounted to the outer link member 16a by a pivot shaft 70a and is biased toward the cam member 71 by a leaf spring 66f, so that a roller member 70b at the tip of the plate 70 is pressed against the inclined portion 71c.

When the upper frame 13 rises and the outer link member 16a rotates clockwise, the roller member 70b rolls on the inclined portion 71c, and when the upper frame 13 reaches a predetermined height, the roller member 70b rolling on the inclined portion 71c falls down the wall portion 71d due to the action of the biasing force of the spring 66f.

As shown in FIG. 4(a), a plate-shaped gear member 73 which rotates integrally with the plate 70 is provided between the plate 70 and the outer link member 16a. When the roller member 70b falls toward the rotating shaft 20 at the wall portion 71d, the gear member 73 also falls toward the rotating shaft 20, and the mutual gear portions mesh with a gear member 74 provided on the inner link member 16b, limiting further rise of the upper frame 13 (height position rise limit).

The arm member 72 shown in Figures 8(c) and 8(d) is structured to rotate the rotating shaft 20 together with the above-mentioned cam member 71, and a cylindrical roller member 72a is rotatably inserted into the tip of the cam member.

In this embodiment, the cam member 71 and the arm member 72 are configured as separate members, but since they rotate the rotating shaft body 20 as a unit, they may be configured as a single member.

As the arm member 72 rotates, the roller member 72 rolls while pressing against the curved portion 55a of the exhaust control cam 55 and the curved portion 56a of the intake control cam 56, and is structured to press against the exhaust valve operating rod 51 and the intake valve operating rod 52 of the air valve 43 to open the exhaust valve 41 and the intake valve 42 (see Figures 3(a) and 11).

When the upper frame 13 rises from the reference height position, the outer link member 16a rotates clockwise and the inner link member 16b rotates counterclockwise, causing the roller member 72a of the arm member 72 to rotate the exhaust control cam 55 and press the exhaust valve operating rod 51 to open the exhaust valve 41, and then return to the reference height position.

Conversely, when the upper frame 13 descends from the standard height position, the outer link member 16a rotates counterclockwise and the inner link member 16b rotates clockwise, causing the roller member 72a of the arm member 72 to rotate the air intake control cam 56 and press the air intake valve operating rod 52 to open the air intake valve 42, and then return to the standard height position.

When the upper frame 13 is at the reference height position, the roller member 72a is located in the recess 58, which is a neutral position where it presses neither the exhaust control cam 55 nor the intake control cam 56 (see FIG. 5(e)).

<Height position change operation section>
As shown in FIG. 1A, a height position changing operation unit 32 having a dial member 31 for changing the reference height position of the upper frame 13 by a rotational operation is provided on the lower frame on the X-link 15b side.

9A and 9B show the height changing operation unit 32. By rotating the dial member 31 of the height changing operation unit 32 in the L direction or the R direction, the wire member 68c connected to the wire member 68b can be pulled or advanced.

By rotating the dial member 31, the cam member 71 to which the wire member 68b is connected and the arm member 71 which rotates integrally with the cam member 71 are rotated, thereby opening the exhaust valve 41 or the intake valve 42 of the air valve 43 through the rotation of the exhaust control cam 55 or the intake control cam 56, thereby moving the upper frame 13 up and down.

9A and 9B, the height position changing operation unit 32 is attached to the lower frame 12, includes a fixing plate 36b having a through hole 36a, and includes a first gear plate 36c having a through hole of the same diameter as and aligned with the through hole 36a and fixed to the fixing plate 36b. The first gear plate 36c has irregularities 36d (see FIG. 9B(b)) along a circumference of a certain radius centered on the through hole. The irregularities 36d have a substantially continuous trapezoidal cross section along the circumference (see FIG. 9B(c)).

A shaft 36e is provided to pass through these through holes, and a second gear plate 37c is fixed to the shaft 36e. The second gear plate 37c faces the first gear plate 36c and has projections and recesses 37d that can be fitted and meshed with the projections and recesses 36d of the first gear plate 36c. The projections and recesses 37d also have a substantially trapezoidal cross section along the circumference that continues in a continuous manner.

A spring 36f is provided between the end of the shaft 36e and the fixed plate 36b. The spring 36f exerts a force on the shaft 36e to press the second gear plate 37c fixed to the shaft 36e against the first gear plate 37c so that the projections 37d mesh with the projections 36d, while the rotation of the shaft 36e disengages the meshed projections and recesses, shifts to the adjacent projections, and meshes with each other again.

Therefore, when the dial 31 is used to rotate the shaft 36c, the concaves and convexes of the gear plates mesh with each other in stages, and the wire member 68c (wire member 36b attached thereto) attached to the bracket 37b provided on the second gear plate 37c is pulled or sent out.

The cross section of each projection and recess is approximately trapezoidal because, as shown in Figure 9B (c), when it engages with an adjacent projection and recess, the wire member can be pulled or sent out by a greater amount than if the cross section were triangular, and the contact area when engaging is large, preventing "step jumps."

As shown in FIG. 9B(b), stoppers 36s and 37s are provided on the outer periphery of each of the first gear plate 36c and the second gear plate 37c, preventing the second gear plate 37c from rotating beyond a predetermined limit.

As shown in FIG. 9A , when the dial member 31 is rotated in the L direction, the arm member 72 is rotated counterclockwise to rotate the exhaust control cam 55 through the winding of the wire member 68 (68b), which opens the exhaust valve 41. Also, when the dial member 31 is rotated in the R direction, the arm member 72 is rotated clockwise to rotate the air intake control cam 56 through the winding of the wire member 68c (68b), which opens the air intake valve 42. This controls the pressure of the air spring 18 to move the upper frame 13 upward or downward, and the height position after the movement becomes the new reference height position due to the action of the reference height maintenance mechanism.

<Pipe line to air spring>
A schematic diagram of the piping for supplying air to and discharging air from the air spring is shown in Figure 11. As shown in Figure 11, a pipe 44b is connected between a connection 45d of the air spring 18 and a connection 45c on the exhaust valve 41 side, and a pipe 44a from the air spring 18 is connected between a connection 45a to which a compressor (not shown) is connected and a connection 45b on the intake valve 42 side.

The air spring 18 is a container that expands and contracts vertically. When compressed air flows into the container through pipe 44a, air intake valve 42, and pipe 44b, it expands upward, pushing up the air spring upper tray 19b, and when compressed air is discharged from the container through pipe 44b and exhaust valve 41, it contracts downward, lowering the air spring upper tray 19b.

The pipeline to the air spring 18 in this embodiment has a simple structure consisting of one air valve 43, two pipes 44a, 44b, and four connection parts 45a, 45b, 45c, and 45d. Compared with conventional pipelines, the number of devices, the number of pipes, and the connection parts are all minimized, thereby reducing costs and the risk of air leakage.

Next, the operation of the air suspension device 11 for a vehicle seat according to the present invention will be described mainly with reference to FIGS.

<Reference height position maintaining mechanism>
Figure 12 is a schematic diagram of the device explaining the operation of the reference height position maintaining mechanism, Figure 12(a) is a schematic diagram of the device in a state where the upper frame is at the reference height position, Figure 12(b) is a schematic diagram of the device in a state where it has been lowered from the reference height position, and Figure 12(c) is a schematic diagram of the device in a state where it has been raised from the reference height position.

As shown in Figure 12(a), in the reference height position maintaining mechanism that exhibits an auto-leveling function for maintaining the reference height of the vehicle seat, when the upper frame 13 is at the reference height position, the roller member 72a at the tip of the arm member 72 is located in a recess 58 formed between the curved portion 55a of the exhaust control cam 55 and the curved portion 56a of the intake control cam 56, which is a neutral position in which it does not press against either the exhaust control cam 55 or the intake control cam 56 (see Figures 3(a) and 5).

Therefore, neither the exhaust valve nor the intake valve of the air valve 43 is open, and the pressure inside the air spring 18 does not fluctuate.

12(b), when a passenger sits on the vehicle seat (not shown), the upper frame 13 receives the load of the passenger and descends from the reference height position to a lower predetermined height position. This descent of the upper frame 13 causes the outer link member 16a to rotate counterclockwise around the rotating shaft 20, and the inner link member 16b to rotate clockwise.

As link member 16b rotates, arm member 72 rotates clockwise, and as link member 16a rotates, the exhaust control cam 55 and the intake control cam 56 rotate counterclockwise, so that roller member 72a located at the tip of arm member 72 rotates clockwise from the neutral position of recess 58, pressing against curved portion 56b of the intake control cam 56 and rotating the intake control cam 56 counterclockwise around pivot axis 63 (see Figures 3(a) and 5).

Counterclockwise rotation of air intake control cam 56 presses air intake valve operating rod 52 of air valve 43, opening air intake valve 52, causing compressed air to flow into air spring 18 and increasing the pressure. Air spring 18 lifts air spring upper tray 19b, thereby lifting the upper frame toward the reference height position.

At this time, since the amount of compressed air flowing into the air spring 18 is restricted by the orifice 42' on the intake valve 52 side of the air valve 43, the upper frame rises gently.

When the upper frame 13 returns to the reference height position, the outer link member 16a rotates clockwise and the inner link member 16b rotates counterclockwise, causing the arm member 72 to rotate counterclockwise, the exhaust control cam 55 and the intake control cam 56 to rotate clockwise, and when the roller member 72a reaches the recess 58, which is the neutral position, the intake control valve 42 closes and the rise of the upper frame 13 stops at the reference height position.

12(c), when the occupant stands up from the vehicle seat (not shown), the load of the occupant is reduced and the upper frame 13 rises from the reference height position to a predetermined height position due to the reaction force of the air spring 18. This rise of the upper frame 13 causes the outer link member 16a to rotate clockwise around the rotating shaft 20 and the inner link member 16b to rotate counterclockwise.

As a result of the above-mentioned rotation of link member 16b, arm member 72 rotates counterclockwise, and as a result of the above-mentioned rotation of link member 16a, the exhaust control cam 55 and the air supply control cam 56 rotate clockwise, so that roller member 72a located at the tip of arm member 72 rotates counterclockwise from the recess 58, which is the neutral position, and presses against curved portion 55b of the exhaust control cam 55, causing the exhaust control cam 55 to rotate clockwise around pivot axis 63 (see Figures 3(a) and 5).

The clockwise rotation of the exhaust control cam 55 presses the exhaust valve operating rod 51 of the air valve 43, opening the exhaust valve 51, causing the compressed air to flow out of the air spring 18 and reducing the pressure (see FIG. 3(a)). The air spring 18 lowers the air spring upper tray 19b, lowering the upper frame toward the reference height position.

Here, since the exhaust valve 51 of the air valve 43 does not have a flow rate restriction such as the orifice 42', the compressed air from the air spring 18 is quickly exhausted and the upper frame quickly descends.

When the upper frame 13 returns to the reference height position, the outer link member 16a rotates counterclockwise and the inner link member 16b rotates clockwise, causing the arm member 72 to rotate clockwise, the exhaust control cam 55 and the intake control cam 56 to rotate counterclockwise, and when the roller member 72a reaches the recess 58, which is the neutral position, the exhaust control valve 41 closes and the descent of the upper frame 13 stops at the reference height position.

In this way, the height position maintaining mechanism always returns the vehicle seat to the standard height position in response to changes in the height of the vehicle seat caused by load changes due to the occupant sitting on or standing up from the vehicle seat, thereby maintaining the height position at the standard position. This height position maintaining mechanism can always maintain the vehicle seat at the standard position regardless of the weight of the occupant.

<Reference height position changing mechanism>
Figure 13 is a schematic diagram of the device explaining the operation of the reference height position changing mechanism, where Figure 13(a) is a schematic diagram of the device when the upper frame is at the reference height position, Figure 13(b) is a schematic diagram of the device when it has been lowered from the reference height position, and Figure 13(c) is a schematic diagram of the device when it has been raised from the reference height position.

As shown in Figure 13(a), when the upper frame 13 is at the reference height position, the roller member 72a located at the tip of the arm member 72 is located in a recess 58 formed between the curved portion of the exhaust control cam and the curved portion of the intake control cam, which is a neutral position where it does not press against either the exhaust control cam 55 or the intake control cam 56 (see Figures 3(a) and 5).

The cam member 71, which rotates integrally with the arm member 72, has a hole 71a at one end connected to a tension spring 66d provided on the inner link member 16b, and is pulled in the direction of the spring 66d, and a hole 71b at the other end connected to a wire member 68b (see FIG. 8). Therefore, the cam member 71 is in a tensioned state on the inner link member 16b.

The wire member 68 b has one end connected to the hole 71 b and the other end connected to a wire member 68 c connected to the height position changing operation unit 32 .

9A and 9B, the height position changing operation unit 32 constitutes a means for pulling or feeding the wire member 68c (wire member 68b) by rotation of the dial member 31. When the dial member 31 is rotated in the L direction, the wire member 68b is wound around the bracket 36a and pulled in the direction of the dial member 31. Since the dial member 31 is rotated in stages, the wire member 68b is pulled by a length corresponding to the stage.

When the wire member 68b is pulled by the dial member 31, the cam member 71 and the arm member 72 are rotated clockwise, and the roller member 72a at the tip of the arm member 72 moves from the recessed portion 58 in the neutral position to a position where it presses the curved portion 56a of the air intake control cam 56. Pressed by the roller member 72a, the air intake control cam 56 rotates counterclockwise and presses the air intake operating rod 52 of the air valve 43 to open the air intake valve 42, causing compressed air to flow into the air spring 18 and increasing the pressure (see Figures 3(a) and 11). The air spring 18 raises the air spring upper receiver 19b, which raises the upper frame 13.

When the upper frame 13 rises to a height corresponding to the number of steps to which the dial member 31 has been rotated, the roller member 72a leaves the position pressing the air supply control cam 56 and returns to the position of the recess 58, stopping the supply of air to the air spring 18 and stopping the rise of the upper frame 13. The height position of the upper frame 13 at this time becomes the new reference height position determined by operating the reference height position changing mechanism.

9(b), when the dial member 31 is rotated in the R direction, the wire member 68b is pushed out toward the cam member 71. The rotation of the dial member 31 is performed in stages, so that the wire member 68b is pushed out by a length corresponding to each stage.

When the wire member 68b is pushed out toward the cam member 71, the cam member 71 and the arm member 72 are rotated counterclockwise, and the roller member 72a at the tip of the arm member 72 moves from the recessed portion 58 in the neutral position to a position where it presses the curved portion 55a of the exhaust control cam 55. Pressed by the roller member 72a, the exhaust control cam 55 rotates clockwise and presses the exhaust operating rod 51 of the air valve 43 to open the exhaust valve 41, causing compressed air to flow out of the air spring 18 and reducing the pressure. The air spring 18 contracts downward, lowering the air spring upper receiver 19b and further lowering the upper frame 13.

When the upper frame 13 descends to a height corresponding to the number of steps to which the dial member 31 has been rotated, the roller member 72a leaves the position pressing the exhaust control cam 55 and returns to the position of the recess 58, causing exhaust from the air spring 18 to stop and the descent of the upper frame 13 to stop. The height position of the upper frame 13 at this time becomes the new reference height position determined by operating the reference height position changing mechanism.

In this way, according to the reference height position changing mechanism, by rotating the dial member 31 of the height position changing operating unit 32 in stages, the upper frame 13 can be raised or lowered to a height position corresponding to the number of steps to establish a new reference height position.

<Height position lowering mechanism>
Figure 14 is a schematic diagram of the device explaining the operation of the height position lowering mechanism, where Figure 14(a) is a schematic diagram of the device in a state where the upper frame is at the reference height position before lowering, Figure 14(b) is a schematic diagram of the device in a state where the lowering device has been activated and the device has been lowered, and Figure 14(c) is a schematic diagram of the device in a state where the operation of the lowering device has been released.

The height lowering mechanism is a mechanism for forcibly moving the upper frame 13 downward to ensure a sufficient distance between the seat (not shown) and the handlebars (not shown) in order to facilitate the passenger's dismounting motion when dismounting. Also, by ensuring a sufficient distance between the seat and the handlebars, the passenger's motion when getting on the vehicle is also smooth.

As shown in Fig. 10, the height lowering mechanism can be activated and deactivated by rotating the lever portion 35a of the lowering operation unit 35. When the tip of the lever portion 35a shown in Fig. 10(a) is rotated in the R direction to position the tip of the lever portion 35a directly above as shown in Fig. 10(b), the wire member 68a is wound up by the winding portion 35b, and the wire member 68a is pulled toward the lowering operation unit 35.

14(a), 6(h) and 7(b), the wire member 68a is connected to a protrusion 65c of the bracket 65 via a tension spring 66c provided midway. Also, a hole 65b of the bracket 65 is connected to a hole 61e of the valve plate 61 by a tension spring 66b. When the wire member 68a is pulled, the bracket 65 rotates counterclockwise about the rotation shaft 63b, but since the protrusion 65c abuts against a wall portion 61c of the valve plate 61, the valve plate 61 is rotated counterclockwise about the rotation shaft 63a.

Due to the elastic force of the tension spring 66c, which is joined to the protrusion 62c of the valve bracket 62 and the hole 61d of the valve plate 61, the valve plate 61 rotates counterclockwise from a position in which the valve pin 64 of the valve plate 61 presses against the wall portion 62b of the valve bracket 62 to a position in which the valve pin 64 presses against the wall portion 62a of the valve bracket 62.

Counterclockwise rotation of the valve plate 61 causes the exhaust valve actuating rod 51 of the air valve 43 to come into contact with the pressing portion 55c of the exhaust cam 55. At this time, the exhaust cam 55 comes into contact with the pin member 62d of the valve bracket 62 and is prevented from rotating counterclockwise, so that the exhaust valve actuating rod 51 is pushed into the air valve 43 and the exhaust valve 41 is opened (see Figures 5, 6, 11, and 14(a)).

The exhaust valve 41 opens, and as shown in Fig. 14(b), the pressure of the air spring 18 decreases, causing the upper frame 13 to descend. As the upper frame 13 descends, the roller member 72a rotates clockwise and presses the curved portion 56a of the air intake control cam 56, causing the air intake control cam 56 to rotate counterclockwise (see Fig. 5). However, because the valve plate 61 is in a counterclockwise rotation state as described above, even if the air intake control cam 56 rotates counterclockwise, there is a predetermined gap between the air intake valve actuating rod 52 of the air valve 43 and the cam 72a, so the air intake control cam 56 cannot press the curved portion 56a. Therefore, the exhaust valve 41 remains open, and the upper frame descends to the lowest end.

As shown in Figure 10(b), when the lever portion 35 with its tip facing upward is rotated in the L direction so that the tip is directed downward (see Figure 10(a)), the wire member 68a is pushed out from the winding portion 35b, and the action is released by the height position lowering mechanism.

As the wire member 68a is pushed out, the bracket 65 is released from pressure against the wall portion 61d of the valve plate 61 and rotates clockwise. The valve plate 61 is then pulled by the spring 66c, and the valve pin 64 rotates to a position where it presses against the wall portion 62b of the valve bracket 62.

As a result of the clockwise rotation of the valve plate 61, the pressure applied to the exhaust valve operating rod 51 by the exhaust control cam 55 is released, and the intake valve operating rod 52 is pushed in by the pressing portion 56c of the intake control cam 56 which has rotated counterclockwise, thereby opening the intake valve 42.

When the intake valve 42 is opened, compressed air flows into the air spring 18, pushing the upper frame 13 upward and returning it to the set reference height position. Note that even if the operation of the height lowering mechanism is stopped midway through the descent, the upper frame 13 will still return to the set reference height position.

<Height position rise limiting mechanism>
The height position rise limiting mechanism is a mechanism that limits the distance of rise from the standard height position when the vehicle seat is at a standard height position and the load on the suspension device is reduced, such as when an occupant stands up, causing the upper frame 13 to rise due to the reaction force of the air spring, in order to maintain a specified distance between the vehicle seat and the handlebars.

FIG. 15 is a schematic diagram of the device when the height position rise limiting mechanism is activated, and the shapes and arrangements of the main components of this mechanism, that is, cam member 71, plate 70, gear members 73, 74 and spring 66f, are shown in FIGS. 3(a), 3(b), 4(a), 8(a) and 8(b).

As shown in Figure 15, plate 70, a plate-shaped member located on the upper part of cam member 71, is pivoted to the outer link member 16a at a rotating shaft 70a, and an elastic force is applied toward the cam member 71 by leaf spring 66f, so that roller member 70b abuts against the cam member 71 while pressing it.

Furthermore, a gear member 73 that rotates integrally with the plate 70 is provided between the plate 70 and the outer link member 16a (see FIG. 4(a)).

15, when the upper frame 13 (not shown) rises from the reference height position due to the rider standing up or the like, the roller member 70a starts to press the inclined surface 71c of the cam member 71 toward the wall portion 71d due to the rotation of the X links 15a, 15b (see FIGS. 8(a) and 8(b)). When the upper frame 13 rises from the reference height position to a predetermined height, the roller member 70a falls from the inclined surface 71c to the wall portion 71, and the plate 70 rotates clockwise around the rotation shaft 70a.

At this time, the gear member 73, which rotates integrally with the plate 70, also rotates clockwise (see FIG. 4(a)), and the gear portions of the gear member 73 and the gear member 74 provided in an arc shape around the rotating shaft 20 of the inner link member 16 mesh with each other, so that the rotation of the X link 15a stops and the lifting of the upper frame 13 also stops.

After the upper frame 13 has stopped rising, as shown in FIG. 15, it has risen above the reference height position, and therefore the roller member 72a of the arm member 72 is in a position to press the exhaust control cam 55, and therefore the reference height position maintaining mechanism operates to open the exhaust valve and return the upper frame 13 to the set reference height position.

The height position rise limiting mechanism maintains the same height limit distance from the reference height even if the reference height is changed by the reference height position changing mechanism. The mechanism applies a rise limit when the height rises a specified distance from the set reference height. The limited height distance can be changed by changing the shape and size of the slope 71c and wall 71d of the cam member 71.

The height position rise limiting mechanism described above has a function of preventing the seat from rising more than necessary, and can prevent a passenger from being pinched between the handlebars and the seat during an emergency exit.

Furthermore, the gear members, plates, etc., which are the main components of the height position rise limiting mechanism, are detachable parts and do not need to be installed in suspension devices that do not require a height position rise limiting mechanism, which can contribute to reducing costs.

REFERENCE SIGNS LIST 11 Air suspension device for vehicle seat 12 Lower frame 13 Upper frame 15a, 15b X-link 16a, 16c Outer link member 18 Air spring 20 Rotating shaft body 21a, 21b Connecting shaft body 23a, 23b Connecting shaft body 31 Dial member 32 Height position change operation unit 35 Lowering operation unit 35a Lever portion 41 Exhaust valve 42 Intake valve 42' Orifice 43 Air valve 51 Exhaust valve operating rod 52 Intake valve operating rod 55 Exhaust control cam 56 Intake control cam 68a Wire member (second wire member)
68b Wire member (first wire member)
71 Cam member 72 Arm member 72a Roller member 61 Valve plate 62 Valve bracket 65 Bracket

Claims (7)

A lower frame installed on a floor surface side of the vehicle;
an upper frame disposed on an upper portion of the lower frame and provided under a vehicle seat of the vehicle;
a pair of X links, which are members intersecting in an X shape and are disposed on left and right side surfaces between the lower frame and the upper frame, connected to the lower frame and the upper frame to support the upper frame so as to be vertically movable, and which are pivotally mounted on shafts connecting the mutual intersecting portions of the X shape;
an air spring that moves the upper frame up and down by pressure changes caused by air supply from a compressed air supply source and exhaust to the outside;
a passage having one end connected to the supply source and the other end connected to the air spring, through which air can pass, an exhaust passage connected to the passage and capable of discharging air within the passage to the outside, an air intake valve for opening and closing the passage and an exhaust valve for opening and closing the exhaust passage, a diameter of a portion of the passage up to the air intake valve and a diameter of a portion of the exhaust passage from the exhaust valve to the outside being different, and an intake and exhaust valve body portion provided on one of the link members forming an X link on either the left or right side surface;
an intake control cam provided on one of the link members for controlling opening and closing of the intake valve;
an exhaust control cam that controls the opening and closing of the exhaust valve;
a cam member that is pivotally mounted on the shaft and tensioned on another link member that intersects with the one link member so as to rotate together with the other link member;
an arm member pivotally mounted on the shaft so as to be rotatable integrally with the cam member, and which rotates the intake control cam or the exhaust control cam in accordance with the direction of rotation of the X link to open or close the intake valve or the exhaust valve;
a reference height position maintaining mechanism for maintaining the upper frame at a preset reference height position;
a reference height position changing mechanism that can change the reference height position;
a height position lowering mechanism that lowers the upper frame from the reference height position to a lower limit height position,
the reference height position changing mechanism has a height position changing operation unit that pulls or sends out a first wire member connected to the cam member that is integral with the arm member in order to rotate the arm member,
the height position changing operation unit includes a fixed plate having a through hole, a first gear plate having a through hole of substantially the same diameter as the through hole and aligned with the through hole of the fixed plate, and having projections and recesses formed along a circumference of a certain radius centered on the through hole, and fixed to the fixed plate; a shaft passing through both through holes ; a second gear plate facing the first gear plate and having projections and recesses that detachably mesh with the projections and recesses of the gear plate, and fixed to the shaft and connected to the first wire member; and a spring that is disposed around one end of the shaft and applies a force to the shaft in the axial direction of the shaft so that the projections and recesses of the first gear plate mesh with the projections and recesses of the second gear plate, while the projections and recesses of the gears that were meshed with each other due to rotation of the shaft shift to the adjacent positions and mesh with each other again;
The cross-sectional shape of the projections and recesses of the first and second gear plates is substantially trapezoidal,
the shaft of the height position change operation unit is rotated against the force of the spring to rotate the second gear plate, and the first wire member connected to the second gear plate is pulled or sent out to rotate the arm member through the cam member, thereby rotating the intake control cam or the exhaust control cam to open and close the intake valve or the exhaust valve, and the upper frame is moved upward or downward due to a pressure change in the air spring, so that a new specified position becomes the reference height;
the reference height position maintaining mechanism is a mechanism in which, when the upper frame is at a position previously set as a reference height, the arm member is in a neutral position in which it does not act on either the air intake control cam or the exhaust control cam, and when the upper frame descends a predetermined distance or more from the reference height, the X-link rotates in association with the descent, causing the arm member to rotate the air intake control cam to open the air intake valve and increase the pressure of the air spring to return the upper frame to the reference height, and when the upper frame rises a predetermined distance or more from the reference height, the X-link rotates in association with the ascent, causing the arm member to rotate the exhaust control cam to open the exhaust valve and reduce the pressure of the air spring to return the upper frame to the reference height,
an intake valve for lowering a vehicle seat that is in a position where the intake valve is in contact with the intake control cam and opens when a second wire member connected to the intake and exhaust valve body is pulled, thereby reducing the pressure of the air spring and lowering the upper frame to a lower limit height position; a height position rise limiting mechanism that limits the rise of the upper frame from the reference height position to a predetermined height or more;
the height position rise limiting mechanism includes a plate member rotatably provided on the one link member and biased by an elastic member so that a guide roller at an end of the plate member rolls on the inclined surface of the cam member, a first gear member that rotates integrally with the plate member, and a second gear member that is provided on the other link member;
When the upper frame is raised from a reference height position to a predetermined height position,
2. The air suspension device for a vehicle seat according to claim 1, characterized in that when the guide roller descends to a wall portion formed at the end of the inclined portion of the cam member, a first gear member and a second gear member engage with each other to stop the rise of the upper frame. 3. An air suspension device for a vehicle seat as described in claim 2, characterized in that the second wire member is connected to a lowering operating part provided on the lower frame or the upper frame, and the supply and exhaust valve body part is rotated by pulling the second wire member when a lever member of the lowering operating part is rotated. the intake control cam and the exhaust control cam are plate-like members having curved portions, and the intake control cam and the exhaust control cam are pivotally mounted on the one of the link members in such an arrangement that the curved portions are symmetrical to each other so that a recess is formed between the intake control cam and the exhaust control cam;
2. The air suspension device for a vehicle seat according to claim 1, wherein a rotatable roller member is provided at a tip of the arm member, and when the X-link rotates as the upper frame descends, the air intake control cam presses and slides against a curved portion to rotate the air intake control cam and open the air intake valve, and when the X-link rotates as the upper frame rises, the exhaust control cam presses and slides against a curved portion to rotate the exhaust control cam and open the exhaust valve, and when the upper frame is at the reference height, the roller member is located in the overlapping recess and is in the neutral position. 2. An air suspension device for a vehicle seat as described in claim 1, characterized in that either the one link member or the other link member is pivotally mounted to the upper frame, and the other is pivotally mounted so as to be movable back and forth via a roller member that can slide or rotate on a running path within the upper frame, and a collar member that ensures a spacing for the roller member to run is inserted between the upper and lower walls of the running path via a plate-shaped reinforcing member provided on the upper frame. 4. The air suspension device for a vehicle seat according to claim 3, wherein the plate member and the first gear member are detachably mounted on one link member, and the second gear member is detachably mounted on the other link member. 2. The air suspension for a vehicle seat according to claim 1, wherein said cam member and said arm member are integrally formed.

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