JPH10226256A - Seat suspension device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize forward and backward movement of a seat frame without losing cushioning action of a tension spring. SOLUTION: The rear end of a tension spring 24 is connected to a base frame 11 through a movable member 22 and the front end thereof is connected to a link 13 through a reinforcement member 18 which is arranged so that it may be positioned practically right above a shaft 15 connecting the link 13 to the base frame 11 in a rotatably movable manner when a user is seated on a short cushion (not on the drawing).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension device suitable for use in a vehicle seat, in particular, a seat of a construction machine or the like.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional seat suspension apparatus. This suspension device includes a base frame 1 fixed to a frame of a vehicle (not shown), and a seat frame 2 disposed above the base frame 1, and a seat cushion 3 is provided on the seat frame 2. The seat cushion 4 is mounted and fixed, and a seat back 4 is connected and fixed to the seat cushion 3.

The above-mentioned base frame 1 and seat frame 2
, Two pairs of links 5 and 6 are provided on the left and right sides, respectively. The links 5 and 5, together with the base frame 1 and the seat frame 2, constitute a parallel link mechanism. Therefore, the seat frame 2 moves in parallel with the rotation of the links 5 and 6. The seat frame 2 is positioned between the base frame 1 and the seat frame 2 such that the links 5 and 6 are raised from the inclined state.
A tension spring (biasing means) 7 for urging the seat cushion 3 rearward is provided, and the occupant sitting on the seat cushion 3 is supported by the tension spring 7.

[0004]

In the suspension device having the above structure, when the seat frame 2 moves vertically with respect to the base frame 1 due to the vibration of the vehicle or the like, the seat frame 2 also moves greatly in the front-rear direction. There was a problem that it would. Therefore, there is a problem that it is difficult to drive the vehicle.

Of course, if the inclination angle θ of the links 5 and 6 is reduced, the movement of the seat frame 2 in the front-rear direction due to the vertical movement can be reduced. However, if it does so, the amount of expansion and contraction of the extension spring 7 accompanying the up-and-down movement of the seat frame 2 will also become small. As a result, there is a problem that the cushioning effect of the extension spring 7 against the vertical movement of the seat frame 2 is lost.

[0006]

According to a first aspect of the present invention, there is provided a base frame, a seat frame disposed above the base frame, and
At least one pair of links respectively disposed between a front portion and a rear portion of the base frame and the seat frame, so as to constitute a parallel link mechanism with the base frame and the seat frame, and each link, the base frame and the seat. A urging means for urging the seat frame so that a line connecting each connection point with the frame approaches a vertical state from an inclined state, wherein the urging means rotates the link. One end of the urging means is connected to the base frame so as to expand and contract in the front-rear direction, and the other end is an upper portion of a connection point of one of the pair of links to the base frame. It is characterized by being connected to. In this case, a pair of the links is provided on each of the left and right sides of the base frame and the seat frame, and the links disposed on the front side and the links disposed on the rear side are connected to each other by a reinforcing member, and one of the reinforcements is provided. It is desirable to connect the other end of the biasing means to the member. Further, it is desirable that the reinforcing members be connected to each other by connecting members that are rotatably connected to each other. Further, it is desirable to use a tension spring as the urging means.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG.
FIG. 2 is a side view showing a suspension device A for a seat according to the present invention, and FIG. 2 is a perspective view of a main part thereof. As shown in these drawings, the suspension device A is provided with a base frame 11 fixed to a vehicle body (not shown), and is disposed above the base frame 11, and a seat cushion (not shown) is placed thereon. And a seat frame 12.

[0008] Base frame 11 and seat frame 12
A pair of links 13 and 14 are provided on each of the left and right sides of the pair, which are disposed apart in the front-rear direction. The front link 13 has a substantially equilateral triangular shape, and the lower corner of the three corners is rotatably connected to the base frame 11 via a horizontal shaft 15. The shaft 16 and the bracket 1 whose corners are positioned diagonally upward and forward with respect to the horizontal
7 and rotatably connected to the seat frame 12. The rear link 14 is the same as the front link 13 and is rotatably connected to the base frame 11 via a shaft 15 and rotatably connected to the seat frame 12 via a shaft 16 and a bracket 17. I have.

Here, a line connecting the shafts 15, 15 and the shafts 16,
16 are parallel to each other, and the line connecting the shafts 15 and 16 connected to the link 13 and the line connecting the shafts 15 and 16 connected to the link 14 are parallel to each other. Therefore, the base frame 11, the seat frame 12, and the links 13, 13 constitute a parallel link mechanism, and the seat frame 12 moves parallel to the base frame 11.

The remaining corners of the three corners of the link 13 are located diagonally above and behind the corners connected to the base frame 12, and there is a reinforcement made of pipe material having a circular cross section. One end of each member 18 is fixed.
The other end of the reinforcing member 18 extends horizontally in the left-right direction, and is fixed to the same corner of the link 13 disposed on the other side of the base frame 11. Similarly, a reinforcing member 19 is provided on the links 14, 14 arranged on the rear side. The front end and the rear end of the connecting member 20 are rotatably connected to the reinforcing members 18 and 19, respectively. Thereby, the reinforcing members 18 and 19 are connected, and the four links 13 and 14 are connected to each other. Therefore, even if there is some backlash between each of the links 13 and 14 and the base frame 11 and the seat frame 12, all the links 13 and 14 are rotated at the same angle to each other, and the seat frame 12 is securely parallelized. Can be moved.

The base frame 11 is provided with an adjustment shaft 21 extending in the front-rear direction at the center in the left-right direction so as to be immovable in the front-rear direction and rotatable. A movable member 22 is screwed to the adjustment shaft 21. The movable member 22 is connected to the base frame 11 so as to be movable in the front-rear direction and non-rotatably. Therefore, the movable member 22 moves in the front-back direction when the adjustment shaft 21 is rotated by the handle 23 provided at the front end thereof.

The rear ends of two tension springs (biasing means) 24 are hooked to the movable member 22. The front end of each tension spring 24, 24
Each is hooked on the front reinforcing member 18. Therefore, the tension spring 24 is set so that the line connecting the shafts 15 and 16 approaches the vertical state from the inclined state (inclination angle θ).
The front link 13 is urged to rotate about the shaft 15 in the direction of the arrow. The urging force of the tension spring 24 can be adjusted by moving the movable member 20 in the front-rear direction. Further, when the links 13, 13 abut against a stopper 25 provided on the base frame 11, they cannot rotate further in the direction of the arrow in FIG. 1.

In the suspension device A having the above-described structure, when the occupant sits on the seat cushion, the tension spring 24 is extended by the weight of the occupant, and the link 13 rotates in the direction opposite to the arrow. And weight and tension spring 2
4 stops at the position where the biasing forces are balanced. In this case, the urging force of the tension spring 24 is adjusted in advance so that the reinforcing member 18 which is a connection point of the tension spring 24 to the link 13 is located almost directly above the shaft 15.

In the above state, it is assumed that the seat frame 12 has now moved vertically with respect to the base frame 11. At this time, the seat frame 12
Although the suspension device A moves in the front-rear direction with the vertical movement, in the suspension device A, the movement in the front-rear direction with the vertical movement of the seat frame 12 can be reduced.

That is, since the tension spring 24 is connected to the reinforcing member 18 located almost directly above the shaft 15,
When the link 13 rotates with the vertical movement of the seat frame 12, the tension spring 24 always expands and contracts regardless of the magnitude of the inclination angle θ. Therefore, even if the angle θ between the line connecting the shafts 15 and 16 and the horizontal line is reduced, the cushioning effect of the extension spring 24 is not lost. In other words, the angle θ can be reduced without losing the cushioning effect of the extension spring 24. Therefore, the forward / backward movement caused by the vertical movement of the seat frame 12 can be reduced.

The present invention is not limited to the above embodiment, but can be changed as appropriate. For example, in the above suspension device A, the link 1 is connected so that the line connecting the shafts 15 and 16 approaches the vertical state from the inclined state.
Other urging means may be used as long as the urging means 3 is energized. Further, although the tension spring 24 is disposed between the seat frame 11 and the reinforcing member 18, it may be disposed between the seat frame 11 and the reinforcing member 19. In this case, however, the shaft 16 is disposed behind the shaft 15 and the connecting members 18 and 19 are connected.
Is arranged in front of the shaft 16. And the tension spring 24
Thereby, the connecting member 19 is urged forward.

[0017]

As described above, according to the first to fourth aspects of the present invention, the longitudinal movement of the seat frame caused by the vertical movement can be suppressed, and the cushioning function of the urging means is lost. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of the present invention.

FIG. 2 is a perspective view showing a main part of the embodiment.

FIG. 3 is a side view showing an example of a conventional suspension device.

[Description of Signs] A Suspension device for seat 11 Base frame 12 Seat frame 13 Link 14 Link 18 Reinforcement member 19 Reinforcement member 20 Connecting member 24 Tension spring (biasing means)

Claims (4)

[Claims] 1. A base frame, a seat frame disposed above the base frame, and a front portion between the base frame and the seat frame so as to form a parallel link mechanism with the base frame and the seat frame. And at least one pair of links respectively arranged between the rear portions, and urging the seat frame so that a line connecting each link and each connecting portion of the base frame and the seat frame approaches a vertical state from an inclined state. A seat suspension device provided with a biasing means, wherein one end of the biasing means is connected to the base frame so that the biasing means expands and contracts in the front-rear direction with the rotation of the link; Is connected to an upper portion of a connection point of one of the pair of links with the base frame. Characteristic seat suspension device. 2. A pair of links are provided on each of the left and right sides of the base frame and the seat frame, and the links arranged on the front side and the links arranged on the rear side are connected to each other by a reinforcing member. 2. The seat suspension device according to claim 1, wherein the other end of the urging means is connected to one of the reinforcing members. 3. The suspension device for a seat according to claim 2, wherein the reinforcing members are connected to each other by connecting members rotatably connected to each other. 4. The suspension system for a seat according to claim 1, wherein said urging means is a tension spring.