JPH0567453B2 - - Google Patents

Description

Detailed Description of the Invention: a. Field of Industrial Application The present invention relates to a forward overturning device for a reversible seat for a vehicle, which folds the seat forward as necessary to temporarily expand the rear floor space. Related.

b. Conventional technology and its problems For example, forward-folding seats have been widely used in tour buses as guide seats next to the driver's seat and passenger seats in front of the emergency exit door, and the seats can only be used when passing behind the seat. Each of these is designed to be tilted forward, but in conventional known examples, the support legs of the seat are designed with a simple rigid structure for both the front and rear legs, and the lower end of the front leg is rotatably pivoted to the base frame. When the seat falls forward, the lower ends of the rear legs lift upward from the floor and the height of the upper end of the backrest rises above the floor, which has the disadvantage of reducing forward visibility in cars equipped with guide seats. Ta. In addition, as a means of fixing the seat posture during normal operation, in order to simplify handling, the lower ends of the rear legs are elastically supported by springs, or the seat posture is stabilized by using the weight of the seated person. Therefore, when a collision occurs, a large forward acceleration force causes the seated occupant and the seat to fall forward, resulting in a large degree of unsafety. Therefore, if you want to attach a safety belt to this type of seat, the only option is to install the safety belt anchor on the floor or other structural part of the car body. Nakatsuta. Furthermore, if the clamp structure at the lower end of the rear legs were to be improved to withstand strong collision loads, the operation may become complicated and become an obstacle during emergency evacuation, so this improvement also applies to front-folding seats. remained as an unresolved problem.

c. Purpose of the present invention The present invention provides a system for attaching a safety belt directly to the seat side of a front-folding seat that is often used in vehicles, etc. by providing support legs that are easy to roll over and can withstand strong collision loads. The purpose of this invention is to reduce the height of the upper end of the backrest above the floor as much as possible in the event of a forward fall. A joint is provided at the lower end of the seat and at the middle of the front leg, and the folding structure is such that the front leg is extended straight to fix the seat posture during normal operation, and when the front leg falls forward, the front leg is bent and the entire supporting leg is folded compactly. Furthermore, the front legs are engaged with or connected to the energy storage springs so that the front legs maintain mechanical stability only in the extreme postures of straight extension and V-shaped bending.

d Structure of the present invention The structure of the present invention is a front-folding type seat in which the supporting legs are composed of front legs and rear legs, and the upper end of the rear leg is integrally connected to the seat frame, and the lower end is connected to the base frame. The front legs are rotatably connected at the upper end to the seat frame and the lower end to the base frame, and a joint is provided in the middle, and the bending direction is set so that the joint protrudes rearward. The front legs are equipped with a movement restriction mechanism that is integrated with or separate from the front legs to limit the range of movement of the front legs so that the front legs do not bend forward from the straight extension state. The energy storage spring is engaged or connected, and the repulsive force of the energy storage spring constantly applies a forward pressing force to the joints of the front legs.Furthermore, the pedal or handle for starting operation is connected to the front legs. The front legs stably maintain a straight posture, and the seat posture is fixed using the truss principle. When the seat falls forward, the seat posture is elastically fixed by the repulsive force of the energy storage spring.

e-1 First Embodiment Fig. 1 is a right side view showing the first embodiment of the present invention, Fig. 2 is a view showing the seat in Fig. 1 tipped forward, and Fig. 3 is a right side view showing the first embodiment of the present invention. 1 is a front view showing only a portion of the device in FIG. 1, 1 is a seat frame made by combining a plurality of irregularly shaped members in a mouth shape, 2 is a base frame forming the base of the seat, and the upper surface of the base frame is Bearing portions 2a, 2 for connecting the support legs are provided in the
b and 2c are each integrally attached.

Reference numerals 3a and 3b denote a pair of left and right rear legs, the upper ends of which are integrally connected to the seat frame 1, the lower ends of which are rotatably pivoted to the bearings 2a and 2b of the base frame 2, respectively. The entire seat can then tip forward with the lower ends of the rear legs 3a, 3b as the center of rotation. 4a and 4b are reinforcing members that diagonally connect the rear legs 3a and 3b to the seat frame 1, respectively.

5a and 5b are rotating struts each having a shaft fitting portion at both upper and lower ends and rotatably connected to each other via a pin 6, and the front leg is constituted by the rotating strut and the pin 6. and rotation struts 5a and 5b.
The shaft fitting portions and the pin 6 constitute a joint at the intermediate portion of the front leg. The upper end of the front leg is attached to the seat frame 1
In addition, the lower ends are rotatably connected to the base frame 2, and the joint at the middle part is set in a bending direction so as to protrude rearward.

The rotation struts 5a, 5b are provided with stoppers 7a, 7 that are integrally or separately configured as a movement limiting mechanism.
b, respectively, to unilaterally limit the range of joint movement so that the front legs do not bend forward from the straight extended state. Furthermore, stepped portions 8a and 8b are formed on the rotating support column 5a, and when the seat is tilted forward, the stepped portions 8a and 8b are formed as shown in FIG.
b comes into contact with the front edge of the rotation strut 5b to limit the range of bending during joint movement. The front legs and rear legs 3a and 3b described above constitute the support legs in this embodiment.

Next, reference numeral 9 denotes a connecting shaft interposed between the rotation support 5b and the bearing portion 2c, and 10 denotes a power storage spring fitted into the connection shaft 9. The power storage spring always carries a set load. It is mounted with an appropriate deformation so as to function, and one end is engaged with the rotation support 5b and the other end is engaged with the base frame 2. Reference numeral 11 denotes a pedal for starting operation, and this pedal is integrally connected to the rotation support column 5b via a suitable member. Note that 12 and 13 are a cushion and a back rest fixed to the seat frame 1.

There is no problem in changing the settings of the pedal 11 as long as it meets the purpose of starting operation, and in this embodiment, the pedal 11 is connected to the rotation support 5.
b, but depending on design considerations, it may be changed to a separate type. For example, a horizontally oriented pivot shaft is provided above the base frame 2, and the pedal 11 is attached to one end of the pivot shaft. , it is also possible to configure the device by attaching one lever to the other end and connecting the pivoting end of the lever and the pivoting post 5b with a link, and in place of the pedal 11. The device of the present invention can also be configured by attaching a vertically elongated arm and using the upper end of the arm as a handle to change the operation method from a foot-operated type to a manual type.

Note that the stoppers 7a and 7b are an example of a means for limiting the range of joint motion of the front legs, and there is no problem in changing the design structure to an appropriate one as long as it meets the purpose of limiting the range of motion. 1
The stoppers 7a and 7b shown in the figure are abolished, and another stopper is installed on the upper front edge of the rotational support 5a or on the rotational support 5.
The stopper is attached to the lower front edge of seat frame 1.
Alternatively, it may be brought into contact with the base frame 2, or the device of the present invention may be constructed by replacing it with a movement limiting mechanism which will be described later in the second embodiment shown in FIG.

Next, the operation of the first embodiment will be explained.
In the steady state, that is, in the state in which the user is able to sit as shown in FIG. In other words, a forward pressing force is always applied to the joints of the front legs, but when the front legs are in a straight extension position, the stoppers 7a and 7b are in contact with each other, so that the joints This prevents it from moving forward, and keeps the front legs in a stable upright position. In this state, the entire support leg constitutes a truss, so the posture of the seat is firmly fixed.

When attaching the safety belt directly to the seat, the anchor of the safety belt is attached near the rear end of the seat frame 1, as in the case of general passenger seats, so in the event of a collision, the forward acceleration force acting on the human body will cause the seat frame to 1 is subjected to a huge collision load in the direction of travel. Therefore, in the event of a collision, a huge compressive load will be applied to the front legs and a huge tensile load will be applied to the rear legs, but since the front legs maintain an upright posture, the joints will bend backwards due to the compressive load. No component force is generated, and the seat can continue to maintain the posture shown in FIG. 1.

Next, when folding the seat forward, while stepping on the pedal 11, move the upper end of the backrest 13 forward, i.e. in the direction indicated by the arrow.
By manually pushing in the direction of , it can be turned over to the position shown in Figure 2. The pressing force applied to the pedal 11 in the process of falling is sufficient to offset the repulsive force of the energy storage spring 10, and the pressing force applied to the backrest 13 is similar to that of the known example since the range of elevation of the center of gravity of the seat is narrow. The burden is lighter compared to other models, and it provides an excellent function of being able to change posture with extremely light operating force.

In the state after the seat is tilted forward, that is, in the state shown in Figure 2, the front legs are in the ultimate V-shaped flexion position, but due to the repulsive force of the energy storage spring 10, the joints of the front legs are pushed in the direction of arrow P. If pressure is constantly applied and the V-shaped posture of the front legs is stably maintained, in other words, if the entire seat is elastically fixed in the posture shown in Figure 2, the seat will become uncomfortable due to the vertical vibration of the vehicle. There is no risk of causing any upset.

In addition, since the front legs are provided with joints and the entire supporting legs are folded compactly when the seat falls forward, the height of the backrest 13 above the floor when the seat falls forward is lower than that of the known example, and the front of the vehicle This also provides the advantage of improved visibility.

To return the overturned seat to its normal position, that is, the position shown in Figure 1, press the backrest 1 while stepping on the pedal 11.
If you pull the top end of 3 backwards, that is in the direction of arrow S, by hand,
As in the case of a forward fall, the seat position can be changed with extremely light operating force.

e-2 Second Embodiment Fig. 4 is a right side view of the device of the second embodiment of the present invention. 15b is a rotating support with the stopper 7b of the rotating support 5b replaced with a bearing 17b; 18 is a supporter having a guide hole at the upper end and fixed to the base frame 2; Reference numeral 19 denotes a sliding shaft having a flange 20 near the end thereof; the end portion of the sliding shaft near the flange 20 is connected to the bearing portion 17b via a connecting pin 21, and the other end portion is connected to the supporter 18. A stopper 22 is attached at a position that is inserted into the guide hole and passes through the guide hole. In addition, a compression-type accumulating spring 23, which should replace the accumulating spring 10, is fitted in the middle part of the sliding shaft 19, and the repulsive force of the accumulating spring causes a gap between the flange 20 and the supporter 18. The device of this embodiment is configured such that a relative pressing force is always applied to the . The mounting position of the stopper 22 with respect to the sliding shaft 19 is set at a position where the front leg can maintain a correct straight extension posture.

Next, the operation of this embodiment will be explained.
In the steady state shown in the figure, the repulsive force of the energy storage spring 23 constantly acts on the joints of the front legs to move them forward, that is, in the direction of arrow P. Since the forward movement of the sliding shaft 19 is prevented by contacting with the front leg, the front leg maintains dynamic stability in the straight extension posture.

When folding the seat forward, it can be activated by the operation exactly the same as in the first embodiment. During the process of overturning the seat, the sliding shaft 19 temporarily moves rearward, but after the overturning is complete, it returns to the same position as or close to the position shown in Fig. 4, and is dynamically in the second position.
The posture of the entire supporting leg is maintained stably by the same principle as that shown in the figure.

Since the following explanation is the same as that of the first embodiment, the description will be omitted.

f Effects of the present invention According to the present invention, it is possible to provide a front-folding seat for a vehicle with support legs that can withstand a strong collision load without impairing the ease of the folding operation. The excellent effect of making it possible and easy to attach the safety belt to the seat body side, which has been impossible, can be obtained.

In addition, since the entire support leg has a structure that can be folded compactly, the height of the upper end of the backrest above the floor in the event of a forward fall is reduced compared to known examples, and forward visibility from the passenger compartment is improved for guide seats. You can also obtain the following effects. Particularly in the case of the deluxe model, the backrest is long and thick, making it impossible to use a folding structure for the backrest itself, so reducing the height of the upper end of the backrest above the floor in the event of a forward fall is extremely effective.

[Brief explanation of the drawing]

Fig. 1 is a right side view showing the first embodiment of the present invention, Fig. 2 is a view showing the seat in Fig. 1 in a tilted forward state, and Fig. 3 shows only the device part in Fig. 1. The front view shown in FIG. 4 is a right side view showing only a portion of the apparatus according to the second embodiment of the present invention. 1... Seat frame, 2... Base frame, 2a, 2
b, 2c...bearing part, 3a, 3b...rear leg, 5
a, 5b... Rotating column, 6... Pin, 7a, 7b
... Stopper, 8a, 8b ... Stepped portion, 9 ... Connection shaft, 10 ... Accumulation spring, 11 ... Pedal, 15
a, 15b...Rotating strut, 17b...Bearing part, 1
8...Supporter, 19...Sliding shaft, 21...Connection pin, 22...Stopper, 23...Storage spring.

Claims (1)

[Claims] 1. In a forward-tipping type seat in which the supporting legs are composed of front legs and rear legs, the upper end of the rear leg is integrally connected to the seat frame, the lower end is rotatably attached to the base frame, and the front leg is The upper end is rotatably connected to the seat frame and the lower end to the base frame, and a joint is provided in the middle part, and the bending direction is set so that the joint protrudes rearward, and the front leg is attached to the front leg either integrally with the front leg or separately. A motion restriction mechanism configured in the form of is attached to limit the range of motion of the front legs so that the front legs do not bend forward from the straight extension state, and a storage spring is engaged or connected to the front legs, A forward pressing force is constantly applied to the joint of the front leg by the repulsive force of the energy storage spring, and a pedal or handle for starting operation is connected to the front leg, so that the front leg stably maintains a straight extension posture during normal operation.
A forward overturning device for a vehicle seat, characterized in that the posture of the seat is fixed by the principle of a truss, and when the seat overturns forward, the posture of the seat is elastically fixed by the repulsive force of a storage spring.