CN103549787B - A kind of seat and backrest installation structure thereof - Google Patents

Abstract

The invention discloses a seat and a backrest installation structure thereof. The backrest installation structure comprises a seat cushion connecting frame, a backrest connecting frame, a connecting piece I, a connecting piece J, a connecting piece K, a connecting piece L and a connecting piece arranged in pairs on the left and right. M; the backrest connecting frame, the cushion connecting frame, the connecting piece I and the connecting piece J form a four-bar linkage mechanism, one end of the connecting piece K is hinged to the rear of the intermediate connecting frame, the other end of the connecting piece K is hinged to the lower end of the connecting piece L, The middle of the connecting piece L is hinged to the rear of the cushion connecting frame, the upper end of the connecting piece L is hinged to the lower end of the connecting piece M, and the upper end of the connecting piece M is hinged to the middle of the connecting piece I or connecting piece J; two backrests arranged opposite to each other The upper end of the connector is fixedly installed with a back seat, and the back seat is fixedly installed with a backrest, and the seat cushion connecting frame is driven by a driving device to move back and forth. The technical scheme is stable in action, comfortable in use, reasonable in structure and saves space.

Description

Seat and its backrest installation structure

technical field

The invention belongs to the field of furniture, in particular to a seat such as a recliner, a sofa, etc., and in particular to a backrest installation structure used therein.

Background technique

Traditionally, furniture such as lounge chairs, sofas, etc. will be installed with an actuating mechanism - a functional frame, on which a chair frame composed of a backrest, a seat cushion, and a leg rest is installed, and the functional frame is used to realize the movement of the chair frame and the motionless The interconnection between the base components. The functional frame is usually a combination of various mechanical linkages that are operable to provide various comfort features, such as independent reclining movement of the seat assembly, and actuation of the extendable leg rest assembly and associated tipping of the chair frame. While many conventional recliners operate satisfactorily, furniture manufacturers are continually pursuing improved chair frames and functional frames that reduce system complexity, improve smooth operation, and occupant comfort. In addition, there is a continuing desire to develop improved manufacturing and assembly techniques that will result in cost reductions while promoting increased efficiency and improved product quality.

Contents of the invention

In order to solve the above technical problems, one of the objects of the present invention is to provide a backrest installation structure, which improves the mechanical linkage structure, so as to reduce the complexity of the system, improve the stability of operation and the comfort of use.

The second object of the present invention is to provide a seat, including the above-mentioned backrest installation structure.

In order to achieve the above-mentioned purpose, the present invention has adopted following technical scheme:

A backrest installation structure, comprising left and right paired seat cushion connectors, backrest connectors, connectors I, connectors J, connectors K, connectors L and connectors M; the middle and connectors of the backrest connectors The upper end of I is hinged, the lower end of connector I is hinged with the rear part of the cushion connecting frame, the lower end of the backrest connecting frame is hinged with the upper end of connector J, and the lower end of connector J is hinged with the rear part of the cushion connecting frame. The connecting frame, the connecting piece I and the connecting piece J form a four-bar linkage mechanism, one end of the connecting piece K is hinged to the rear of the intermediate connecting frame, the other end of the connecting piece K is hinged to the lower end of the connecting piece L, and the middle of the connecting piece L is hinged. Hinged with the rear of the cushion connecting frame, the upper end of the connecting piece L is hinged with the lower end of the connecting piece M, and the upper end of the connecting piece M is hinged with the middle of the connecting piece I or connecting piece J; the two backrest connecting pieces arranged opposite to each other The upper end of the back seat is fixedly installed with a backrest, and the backrest is fixedly installed with a backrest, and the cushion connecting frame is driven by a driving device to move back and forth.

The above-mentioned drive device may be any power mechanism capable of directly or indirectly driving the connecting member C to rotate back and forth, such as a cylinder, a motor, and the like. As a preference, a connector C is installed at the front of the cushion connecting frame, and the two connectors C oppositely arranged on the left and right are fixedly connected through the left and right connecting rods. The moving slider of the rod motor is hinged with one end of the push rod, and the other end of the push rod is hinged with the left and right connecting rods.

As preferably, it also includes connecting piece E, connecting piece F, connecting piece G, connecting piece H and intermediate connecting frame arranged in pairs on the left and right, the front part of the cushion connecting frame is hinged with one end of connecting piece H, and the other side of connecting piece H is hinged. One end is hinged to the front part of the intermediate connecting frame, the rear part of the cushion connecting frame is hinged to one end of the connecting piece G, and the other end of the connecting piece G is hinged to the rear part of the intermediate connecting frame, so that the cushion connecting frame, the connecting piece H, the intermediate connecting frame It forms a four-bar linkage mechanism with the connecting piece G, the front part of the intermediate connecting frame is hinged with the upper end of the connecting piece E, the lower end of the connecting piece E is hinged with the front part of the base, and the rear part of the intermediate connecting frame is hinged with the upper end of the connecting piece F , the lower end of the connecting piece F is hinged to the rear of the base, so that the intermediate connecting frame, the connecting piece E, the connecting piece F and the base form a four-bar linkage mechanism; wherein, the base or the intermediate connecting frame is provided with a limiting connecting piece E and a connecting A limiting structure B for the range of movement of the piece F, and a limiting structure C for limiting the range of movement of the connecting piece G and the connecting piece H is provided on the intermediate connecting frame or the cushion connecting frame.

The above-mentioned limiting structure B can be any structure that can directly or indirectly limit the movable range of the connector E and the connector F, such as a limiting column, a stopper, etc. As a preference, the limiting structure B is fixed on the base or connected in the middle The limit column on the frame makes the direct limit simple and convenient, and the structure is stable. In addition, the limiting structure B is not limited to a rigid limiting structure, and may also be an elastic limiting structure, such as a tension spring.

The above-mentioned limiting structure C can be any structure that can directly or indirectly limit the movable range of the connecting piece G and the connecting piece H, such as a limiting column, a stopper, etc. As a preference, the limiting structure C is fixed on the intermediate connecting frame Or the limit column on the cushion connecting frame, so that the direct limit is simple and convenient, and the structure is stable. In addition, the limiting structure B is not limited to a rigid limiting structure, and may also be an elastic limiting structure, such as a tension spring.

Preferably, a tension spring is installed between the cushion connecting frame and the base. In this way, the instability of the link mechanism can be reduced as much as possible, and the action stability, reliability, support strength and use comfort of the functional frame can be improved.

As preferably, the hinge point of the connecting piece J and the cushion connecting frame is located in front of the hinge point of the connecting piece L and the cushion connecting frame, and the hinge point of the connecting piece L and the cushion connecting frame is located at the hinge point of the connecting piece I and the cushion connecting frame in front of. In this way, the structural design is more reasonable, simpler and more reliable.

As a preference, near the hinge point of the backrest connecting frame and the connecting piece J, a backrest board capable of pushing the rear end of the seat cushion is installed, and the two ends of the backrest board are respectively fixedly connected to the two backrest connecting frames or the connecting piece J arranged opposite to the left and right. . A top waist plate is set on the jacking part of the four-bar linkage mechanism of the backrest, so that it can push up the rear end of the seat cushion when the backrest is lying down, so that the sponge at the rear end of the seat cushion is lifted appropriately, which greatly improves the use of the seat. comfort.

Preferably, the cushion connecting frame is provided with an elastic potential energy mechanism that always gives the backrest connecting frame a tendency to approach the seat cushion connecting frame. In this way, the instability of the link mechanism can be reduced as much as possible, and the action stability, reliability, support strength and use comfort of the functional frame can be improved. The elastic potential energy mechanism can be an extension spring or other elastic components, preferably an extension spring, and the extension spring has multiple arrangements, for example, an extension spring is installed between the connector I and the connector L.

A seat includes the above-mentioned backrest installation structure.

The present invention adopts the above technical scheme, improves the structure of the mechanical linkage, reduces the complexity of the system, improves the stability of the movement, and improves the comfort of use, and is convenient to use, reasonable in structure, and saves space.

Description of drawings

Fig. 1 is the structural representation (sitting state) of embodiment 1 seat;

Fig. 2 is a perspective view (sitting state) of the functional frame of Embodiment 1;

Fig. 3 is a schematic diagram of the action of the functional frame of Embodiment 1 (sitting state);

Fig. 4 is a schematic diagram of the action of the functional frame of Embodiment 1 (the cushion connecting frame moves forward);

Fig. 5 is a schematic diagram of the action of the functional frame of Embodiment 1 (the leg rest is lifted);

Fig. 6 is a schematic diagram of the action of the functional frame of Embodiment 1 (lying state);

Fig. 7 is a perspective view of the functional frame of Embodiment 2.

detailed description

The specific implementation manner of the present invention will be described in detail below in conjunction with the accompanying drawings.

Example 1:

A kind of back installation structure as shown in Figure 1, comprises the seat cushion connecting frame 13 that is arranged in pairs on the left and right, backrest connecting frame 21, connecting piece I19, connecting piece J23, connecting piece K14, connecting piece L18 and connecting piece M20; The middle of the backrest connecting frame 21 is hinged to the upper end of the connecting piece I19, the lower end of the connecting piece I19 is hinged to the rear of the cushion connecting frame 13, the lower end of the backrest connecting frame 21 is hinged to the upper end of the connecting piece J23, and the lower end of the connecting piece J23 is connected to the seat cushion Frame 13 rear parts are hinged, and backrest connecting frame 21, cushion connecting frame 13, connecting piece I19 and connecting piece J23 constitute four-bar linkage like this, and one end of described connecting piece K14 is hinged with intermediate connecting frame 24 rear parts, and connecting piece K14 The other end is hinged to the lower end of the connecting piece L18, the middle of the connecting piece L18 is hinged to the rear of the cushion connecting frame 13, the upper end of the connecting piece L18 is hinged to the lower end of the connecting piece M20, and the upper end of the connecting piece M20 is connected to the connecting piece I19 or the connecting piece J23 The middle is hinged; the upper ends of the two backrest connectors 21 oppositely arranged on the left and right are fixedly installed with the backrest 3, and the backrest 4 is fixedly installed on the backrest 3, and the cushion connecting frame 12 is driven by the driving device to move back and forth.

A functional frame of a seat as shown in Fig. 2 to Fig. 6 includes a base 16, and the left and right sides of the base 16 are respectively equipped with left and right paired legrest connecting frames 6, connectors A7, connectors B8, Connector C9, Connector D10, Intermediate Connector 24, Seat Cushion Connector 13, Connector E11, Connector F17, Connector G22, Connector H25, Backrest Connector 21, Connector I19, Connector J23, Connector K14 , connector L18 and connector M20; one end of the legrest connecting frame 6 is hinged with one end of the connector A7, the other end of the connector A7 is hinged with one end of the connector C9, and the other end of the connector C9 is connected with the cushion The upper front part of the frame 13 is hinged, the other end of the legrest connecting frame 6 is hinged with one end of the connecting piece B8, the other end of the connecting piece B8 is hinged with one end of the connecting piece D10, and the other end of the connecting piece D10 is connected with the cushion connecting frame 13 The upper front part of the hinge is hinged, and the connecting piece B8 and the connecting piece C9 cross each other and are hinged at the cross position. In this way, the leg rest connecting frame 6, the connecting piece A7, the connecting piece B8 and the connecting piece C9 form a four-bar linkage mechanism, and the connecting piece B8 , connecting piece C9, connecting piece D10 and cushion connecting frame 13 constitute a four-bar linkage mechanism, and the two connecting pieces C9 arranged opposite to each other are fixedly connected to rotate synchronously through the left and right connecting rods 26, and a driving device drives the connecting piece C9 to rotate back and forth; The front portion of the cushion connecting frame 13 is hinged with one end of the connecting piece H25, the other end of the connecting piece H25 is hinged with the front portion of the intermediate connecting frame 24, the rear portion of the cushion connecting frame 13 is hinged with one end of the connecting piece G22, and the other end of the connecting piece G22 is hinged. One end is hinged with the rear portion of the intermediate connecting frame 24, such that the cushion connecting frame 13, the connecting piece H25, the intermediate connecting frame 24 and the connecting piece G22 form a four-bar linkage mechanism, and the front portion of the intermediate connecting frame 24 is hinged with the upper end of the connecting piece E11, The lower end of the connecting piece E11 is hinged with the front portion of the base 16, the rear portion of the intermediate connecting frame 24 is hinged with the upper end of the connecting piece F17, and the lower end of the connecting piece F17 is hinged with the rear portion of the base 16, so that the intermediate connecting frame 24, the connecting piece E11, The connecting piece F17 and the base 16 constitute a four-bar linkage; the middle of the backrest connecting frame 21 is hinged with the upper end of the connecting piece I19, the lower end of the connecting piece I19 is hinged with the rear part of the cushion connecting frame 13, and the lower end of the backrest connecting frame 21 is connected with the The upper end of the piece J23 is hinged, and the lower end of the connecting piece J23 is hinged with the rear part of the cushion connecting frame 13, so that the backrest connecting frame 21, the cushion connecting frame 13, the connecting piece I19 and the connecting piece J23 constitute a four-bar linkage mechanism, and the connecting piece K14 One end is hinged to the rear of the intermediate connecting frame 24, the other end of the connecting piece K14 is hinged to the lower end of the connecting piece L18, the middle of the connecting piece L18 is hinged to the rear of the cushion connecting frame 13, and the upper end of the connecting piece L18 is hinged to the lower end of the connecting piece M20 , the upper end of the connecting piece M20 is hinged with the middle of the connecting piece I19, like this, the connecting piece L18, the connecting piece M20, the connecting piece I19 and the cushion connecting frame 13 constitute a four-bar linkage mechanism. Wherein, a limiting structure A that limits the forward rotation range of the connecting piece D10 is provided between the cushion connecting frame 13 and the connecting piece D10, and the base 16 or the intermediate connecting frame 24 is provided with a limiting connecting piece E11 and a connecting piece F17 The limiting structure B of the movable range, the intermediate connecting frame 24 or the cushion connecting frame 13 is provided with a limiting structure C that limits the movable range of the connecting piece G22 and the connecting piece H25.

In this embodiment, the drive device is a push rod motor 15, and the push rod motor 15 is installed on the base 16. The moving slider of the push rod motor 15 is hinged to one end of the push rod 12, and the other end of the push rod 12 is connected to the left and right sides. The rod 26 is hinged. The limiting structure A is a limiting column fixed on the cushion connecting frame 13 or the connecting piece D10. The limiting structure B is a limiting column fixed on the base 16 or the intermediate connecting frame 24 . The limiting structure C is a limiting post fixed on the intermediate connecting frame 24 or the cushion connecting frame 13 . The hinge point between the connecting piece C9 and the cushion connecting frame 13 is located in front of the hinge point between the connecting piece D10 and the cushion connecting frame 13 . The hinge point of the connecting piece J23 and the cushion connecting frame 13 is located in front of the hinge point of the connecting piece L18 and the cushion connecting frame 13, and the hinge point of the connecting piece L18 and the cushion connecting frame 13 is located at the hinge of the connecting piece I19 and the cushion connecting frame 13. point ahead. A tension spring is installed between the cushion connecting frame 13 and the base 16 . Near the hinge point of the backrest connecting frame 21 and the connecting piece J23, a top waist board (not shown in the figure) capable of pushing the rear end of the seat cushion 2 is installed. 21 or the connector J23 is fixedly connected. The cushion connecting frame 13 is provided with an elastic potential energy mechanism that always gives the backrest connecting frame 21 a tendency to approach the seat cushion connecting frame 13 . A tension spring is installed between the connecting piece I19 and the connecting piece L18. The two connecting parts J23 arranged opposite to each other move synchronously through the fixed connection of the left and right connecting rods, the two connecting parts E11 arranged opposite to the left and right move synchronously through the fixed connection of the left and right connecting rods, Two intermediate connecting frames 24 are fixedly connected to move synchronously by the left and right connecting rods.

A kind of seat as shown in Figure 1, comprises the above-mentioned functional frame, described two seat cushion connecting frames 13 that are arranged opposite to each other are fixedly installed cushion seat 1, and seat cushion 2 is fixedly installed on cushion seat 1, described The upper ends of the two backrest connectors 21 that are arranged opposite to each other are fixedly installed with a backrest 3, and the backrest 4 is fixedly installed on the backrest 3, and the legrest 5 is fixedly installed on the two left and right oppositely arranged legrest connectors 6. .

As shown in Figure 3, the functional frame is in the sitting state; when the push rod motor 15 pushes the two connecting pieces C9 forward through the left and right connecting rods 26, the cushion connecting frame 13 and the middle connecting frame 24 move forward, as shown in Figure 4 ; The two four-bar linkages of the leg rest act until the leg rest reaches the lifted state, as shown in Figure 5; then, the connecting piece D10 is limited by the limit post so that it is connected with the cushion connecting frame 13 as a whole , the forward driving force of the push rod motor 15 is just directly applied on the cushion connecting frame 13 to drive the cushion connecting frame 13 to move forward, and a four-bar linkage mechanism is formed between the cushion connecting frame 13 and the base 16, so that the cushion connecting frame 13 And the upper cushion is in a forward and upward swing lifting process. At the same time, because the connecting piece M20 hinged with the connecting piece I19 is connected to the intermediate connecting frame 24 through the connecting piece L18 and the connecting piece K14, and the middle of the connecting piece L18 is connected to the cushion connecting frame 13 rear parts are hinged, so, in the process of moving forward of the cushion connecting frame 13, the four-bar linkage mechanism for installing the backrest at the rear portion of the cushion connecting frame 13 also changes, impelling the backrest to move forward and gradually topple until the lying state, As shown in Figure 6. On the contrary, in the reset process of push rod motor 15, the cushion connecting frame 13 moves successively, and the backrest is erected gradually, and then the leg rest board is put down.

Example 2:

A backrest installation structure as shown in Figure 7, the only difference from Embodiment 1 is that one end of the connecting piece K14 is hinged to the rear of the intermediate connecting frame 24, and the other end of the connecting piece K14 is hinged to the lower end of the connecting piece L18 , the middle of the connecting piece L18 is hinged with the rear part of the cushion connecting frame 13, the upper end of the connecting piece L18 is hinged with the lower end of the connecting piece M20, and the upper end of the connecting piece M20 is hinged with the middle of the connecting piece J23. Like this, the connecting piece L18, the connecting piece M20 , the connector J23 and the cushion connecting frame 13 constitute a four-bar linkage. Others are the same as in Example 1. Its action principle and process are also similar to Embodiment 1.

In the present invention, there is only one driving device providing power, and the leg rest is installed on two interconnected four-bar linkages, and the two four-bar linkages are driven by the power driving device to realize the leg rest in the lifted state. During the conversion process, the distance between the leg rest and the seat cushion changes very little, which prevents the leg rest from rubbing and pulling the trouser legs, and improves the comfort of use. The middle connecting frame structure capable of moving back and forth can promote the forward movement of the seat cushion connecting frame before or at the same time when the leg rest is lifted, which improves the rationality of the linkage between the leg rest and the seat cushion and the comfort of the user. When the leg rest is in the lifted state, the two four-bar linkages of the leg rest are connected to the cushion connecting frame through the limiting structure A, so that the forward driving force of the driving device is applied to the seat cushion connecting frame, Drive the cushion connecting frame to move forward, a four-bar linkage mechanism is formed between the cushion connecting frame and the intermediate connecting frame, and a four-bar linkage mechanism is formed between the intermediate connecting frame and the base, so that the cushion connecting frame and its upper cushion swing forward and upward During the lifting process, at the same time, because the connecting piece M hinged with the connecting piece I or the connecting piece J is connected to the intermediate connecting frame through the connecting piece L, the connecting piece K, and the middle of the connecting piece L is hinged with the cushion connecting frame, so when the cushion is connected During the forward lifting process of the frame, the four-bar linkage mechanism at the rear of the seat cushion connecting frame to install the backrest also changes, prompting the backrest to move forward and gradually tilt down, realizing the linkage between the seat cushion and the backrest, avoiding the rubbing and pulling of the waist clothes, The comfort of use is improved, and the structure of the present invention also realizes leaning against the wall, that is, when the seat is sitting upright, even if the seat is leaning against the wall, it can still directly realize the action of lying down, while in the prior art, the seat is required There is a distance between the backrest and the wall to implement the lying down action, so the structure of this program is more convenient to use and saves space.

It should be emphasized that: the above are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention are valid. Still belong to the scope of the technical solution of the present invention.

Claims (10)

1. a backrest mounting structure, is characterized in that, comprises the seat cushion connecting frame (13) that is arranged in pairs, backrest connecting frame (21), connector I (19), connector J (23), connector K ( 14), connector L (18) and connector M (20); the middle of the backrest connector (21) is hinged with the upper end of the connector I (19), and the lower end of the connector I (19) is connected with the cushion connector (13) the rear portion is hinged, the lower end of the backrest connecting frame (21) is hinged with the upper end of the connecting piece J (23), and the lower end of the connecting piece J (23) is hinged with the rear portion of the cushion connecting frame (13), so that the backrest connecting frame ( 21), cushion connecting frame (13), connecting piece I (19) and connecting piece J (23) constitute four-bar linkage, and one end of described connecting piece K (14) is hinged with the middle connecting frame (24) rear portion, The other end of the connector K (14) is hinged with the lower end of the connector L (18), the middle of the connector L (18) is hinged with the rear of the cushion connecting frame (13), and the upper end of the connector L (18) is hinged with the connector The lower end of M (20) is hinged, and the upper end of connector M (20) is hinged with the middle of connector I (19) or connector J (23); The back seat (3) is fixedly installed on the upper end, and the backrest (4) is fixedly installed on the back seat (3), and the cushion connecting frame (13) is driven to move forward and backward by a driving device. 2. A backrest installation structure according to claim 1, characterized in that, a connector C (9) is installed at the front of the cushion connecting frame (13), and two connectors C (9) arranged opposite to each other on the left and right Fixedly connected by the left and right connecting rods (26), the drive unit is a push rod motor (15), and the push rod motor (15) is installed on the base (16), and the moving slide block of the push rod motor (15) and the push rod ( 12) is hinged at one end, and the other end of the push rod (12) is hinged with the left and right connecting rods (26). 3. A backrest installation structure according to claim 1, characterized in that it also includes connecting pieces E (11), connecting pieces F (17), connecting pieces G (22), connecting pieces H arranged in pairs on the left and right (25) and the intermediate connecting frame (24), the front portion of the cushion connecting frame (13) is hinged with one end of the connecting piece H (25), and the other end of the connecting piece H (25) is connected with the intermediate connecting frame (24) front portion Hinged, the rear portion of the cushion connecting frame (13) is hinged with one end of the connecting piece G (22), and the other end of the connecting piece G (22) is hinged with the rear portion of the intermediate connecting frame (24), so that the cushion connecting frame (13) , connecting piece H (25), intermediate connecting frame (24) and connecting piece G (22) constitute four-bar linkage mechanism, described intermediate connecting frame (24) front portion is hinged with the upper end of connecting piece E (11), connecting piece The lower end of E (11) is hinged with the front of the base (16), the rear of the intermediate connecting frame (24) is hinged with the upper end of the connecting piece F (17), and the lower end of the connecting piece F (17) is hinged with the rear of the base (16). The part is hinged, so that the intermediate connecting frame (24), the connecting piece E (11), the connecting piece F (17) and the base (16) constitute a four-bar linkage mechanism; wherein, the base (16) or the intermediate connecting frame (24) A limiting structure B that limits the movable range of the connecting piece E (11) and the connecting piece F (17) is provided on the top, and the intermediate connecting frame (24) or the cushion connecting frame (13) is provided with a limiting connecting piece G (22) And the limiting structure C of the movable range of the connector H (25). 4. The backrest installation structure according to claim 3, characterized in that, the limiting structure B is a limiting column fixed on the base (16) or the intermediate connecting frame (24). 5. The backrest installation structure according to claim 3, characterized in that, the limiting structure C is a limiting column fixed on the intermediate connecting frame (24) or the cushion connecting frame (13). 6. The backrest installation structure according to claim 3, characterized in that, a tension spring is installed between the cushion connecting frame (13) and the base (16). 7. A backrest installation structure according to claim 1, characterized in that, the hinge point between the connecting piece J (23) and the cushion connecting frame (13) is located between the connecting piece L (18) and the cushion connecting frame (13). ), the hinge point of connector L (18) and cushion connector (13) is positioned at the front of the hinge of connector I (19) and cushion connector (13). 8. A backrest installation structure according to claim 1, characterized in that, near the hinge point of the backrest connecting frame (21) and the connecting piece J (23), a top that can push the rear end of the seat cushion (2) is installed. As for the waist board, the two ends of the top waist board are respectively fixedly connected with two backrest connecting frames (21) or connectors J (23) arranged opposite to each other on the left and right sides. 9. A backrest installation structure according to claim 1, characterized in that, the cushion connecting frame (13) is provided with an elastic potential energy mechanism that always gives the backrest connecting frame (21) a tendency to approach the cushion connecting frame (13) . 10. A seat, comprising a backrest installation structure according to any one of claims 1 to 9.