Mechanical stretching structure and seat unit

Abstract

The utility model relates to a mechanical stretching structure and a seat unit, and solves the problem that a seat cushion structure shakes to a certain extent relative to an armrest structure. The mechanical stretching structure comprises a base, a base and a leg component; the mechanical stretching structure has a sitting posture position and a lying posture position, the mechanical stretching structure further comprises at least one sitting posture supporting mechanism, the sitting posture supporting mechanism is fixedly connected with the base, and when the mechanical stretching structure is located at the sitting posture position, the sitting posture supporting mechanism supports the swing mechanism; when the mechanical stretching structure is in the lying posture position, the sitting posture supporting mechanism is separated from the swinging mechanism; the seat unit comprises an armrest structure, a backrest structure, a seat cushion structure, a leg placing structure and a mechanical stretching structure, the base is fixedly connected with the armrest structure, the backrest assembly is fixedly connected with the backrest structure, the leg placing structure is fixedly connected with the leg assembly, the seat cushion structure is fixedly connected with the base, and the backrest structure is provided with a ventilation structure and / or a heating structure.

Description

Technical Field

[0001] The utility model relates to a mechanical extension structure and a seat unit. Background Art

[0002] In the prior art, a variety of seat units are disclosed, which include a legrest structure, an armrest structure, a seat cushion structure and a mechanical extension structure. The user's buttocks can sit on the seat cushion structure, wherein the mechanical extension structure has a sitting position and a lying position. After the mechanical extension structure is changed from the sitting position to the lying position, the user's legs can be placed on the legrest structure.

[0003] The mechanical extension structure includes a swing mechanism, a leg assembly, a base and a pedestal. The base is fixedly connected to the armrest structure, the seat cushion structure is installed above the base, the leg rest structure is installed on the leg assembly, the leg assembly is rotatably connected to the pedestal, the pedestal is connected to the pedestal through a swing mechanism, and the pedestal supports the base through the swing mechanism, so that the base provides support for the user's buttocks through the seat cushion structure.

[0004] However, after the existing seat unit is used for a long time, the seat cushion structure may shake to a certain extent relative to the armrest structure. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a mechanical extension structure and a seat unit.

[0006] In order to solve the above technical problems, the utility model is solved by the following technical solutions:

[0007] The mechanical extension structure includes a base, two bases for mounting a cushion structure, two groups of leg assemblies for mounting a legrest structure, two groups of backrest assemblies for mounting a backrest structure, two groups of swing mechanisms and a driving device, wherein the driving device is arranged at the base, each group of leg assemblies is rotatably connected to a base, each base is movably connected to the base via a group of swing mechanisms, and each base is also connected to the base via a group of backrest assemblies;

[0008] The mechanical extension structure has a sitting position and a lying position. When the mechanical extension structure changes from the sitting position to the lying position, the driving device drives the base and the swing mechanism to move forward through the leg assembly, and the leg assembly is extended in front of the base; when the mechanical extension structure changes from the lying position to the sitting position, the driving device drives the base and the swing mechanism to move backward through the leg assembly, and the leg assembly is folded under the base. The mechanical extension structure also includes at least one sitting support mechanism, which is fixedly connected to the base. When the mechanical extension structure is in the sitting position, the sitting support mechanism supports the swing mechanism; when the mechanical extension structure is in the lying position, the sitting support mechanism is separated from the swing mechanism.

[0009] The base is fixedly connected to the armrest structure. In the prior art, the armrest structure does not move with the mechanical extension structure. Therefore, when the sitting support mechanism is fixedly connected to the base, the armrest structure prevents the sitting support mechanism from moving with the mechanical extension structure through the base.

[0010] When the sitting posture support mechanism is located below the swing mechanism and the sitting posture support mechanism abuts against the swing mechanism, the sitting posture support mechanism is used to support the swing mechanism; since the base is connected to the base through the swing mechanism, when the mechanical extension structure is in the sitting position and the sitting posture support mechanism is used to support the swing mechanism, the sitting posture support mechanism will support the base through the swing mechanism. When the user's buttocks sit on the seat cushion structure, the user's buttocks apply gravity to the base through the seat cushion structure; the sitting posture support mechanism will support the base through the swing mechanism, so that the base provides support force for the seat cushion structure. This structure prevents the seat cushion structure from moving relative to the armrest structure when the user sits on the seat cushion structure.

[0011] During the process of the mechanical extension structure changing from a sitting position to a lying position, the driving device drives the base and the swing mechanism to move forward through the leg assembly. Since the armrest structure prevents the sitting support mechanism from moving with the mechanical extension structure through the base, the sitting support mechanism is separated from the swing mechanism after the driving device drives the swing mechanism to move forward through the leg assembly.

[0012] Among them, "the driving device drives the base and the swing mechanism forward through the leg assembly" can mean that the driving device directly drives the swing mechanism forward through the leg assembly, and "the driving device drives the base and the swing mechanism forward through the leg assembly" can also mean that the driving device indirectly drives the swing mechanism forward through the leg assembly. For example, the driving device drives the base forward through the leg assembly, and the base drives the swing mechanism forward.

[0013] During the process of the mechanical extension structure changing from a lying position to a sitting position, the driving device drives the base and the swing mechanism to move backward through the leg assembly. Since the armrest structure prevents the sitting support mechanism from moving with the mechanical extension structure through the base, after the driving device drives the swing mechanism to move backward through the leg assembly, the sitting support mechanism can abut against the swing mechanism.

[0014] Preferably, the sitting posture support mechanism includes a sitting posture support rod, the hardness of the sitting posture support rod is different from that of the swinging mechanism, the sitting posture support rod is fixedly connected to the base, when the mechanical extension structure is in the sitting position, the sitting posture support rod is located below the swinging mechanism, and the sitting posture support rod abuts the swinging mechanism; when the mechanical extension structure is in the lying position, the sitting posture support rod is separated from the swinging mechanism.

[0015] When the sitting posture support rod abuts against the swing mechanism, and the hardness of the sitting posture support rod is different from that of the swing mechanism, one of the sitting posture support rod and the swing mechanism is deformed. This structure is used to reduce the probability of bending of the sitting posture support rod and the swing mechanism under the action of the squeezing force after the sitting posture support rod abuts against the swing mechanism.

[0016] Preferably, the sitting posture support mechanism includes a sitting posture support rod and a sitting posture support ring. The hardness of the sitting posture support ring is different from that of the swinging mechanism. The sitting posture support ring is sleeved on the sitting posture support rod. The sitting posture support rod is detachably provided on the base. When the mechanical extension structure is in the sitting position, the sitting posture support ring is located below the swinging mechanism, and the sitting posture support ring abuts against the swinging mechanism. When the mechanical extension structure is in the lying position, the sitting posture support ring is separated from the swinging mechanism.

[0017] When the sitting posture support ring abuts against the swing mechanism, and the hardness of the sitting posture support ring is different from that of the swing mechanism, one of the sitting posture support ring and the swing mechanism is deformed. This structure is used to reduce the probability of bending of the sitting posture support rod (the swing mechanism applies a squeezing force to the sitting posture support rod through the sitting posture support ring) and the swing mechanism under the action of the squeezing force after the sitting posture support ring abuts against the swing mechanism.

[0018] In addition, at least one component of the sitting posture support mechanism can be replaced by removing the sitting posture support rod from the base.

[0019] Preferably, the mechanical extension structure also includes at least one lying support mechanism, which is fixedly connected to the base. When the mechanical extension structure is in a sitting position, the lying support mechanism is separated from the swing mechanism; when the mechanical extension structure is in a lying position, the swing mechanism supports the lying support mechanism.

[0020] When the lying position support mechanism is located above the swing mechanism and the lying position support mechanism abuts against the swing mechanism, the swing mechanism is used to support the lying position support mechanism; since the lying position support mechanism is fixedly connected to the base, when the mechanical extension structure is in the lying position and the swing mechanism is used to support the lying position support mechanism, the swing mechanism supports the base through the lying position support mechanism. When the user sits on the seat cushion structure, the user's buttocks exert gravity on the base through the seat cushion structure; the swing mechanism supports the base through the lying position support mechanism, so that the base can provide support force for the seat cushion structure to prevent the seat cushion structure from moving relative to the armrest structure when the user sits on the seat cushion structure.

[0021] During the process of the mechanical extension structure changing from a sitting position to a lying position, the driving device drives the base and the swing mechanism to move forward through the leg assembly, wherein the base also moves downward relative to the swing mechanism. Therefore, after the driving device drives the swing mechanism to move forward through the leg assembly and the base also moves downward relative to the swing mechanism, the lying support mechanism abuts against the swing mechanism.

[0022] During the process of the mechanical extension structure changing from a lying position to a sitting position, the driving device drives the base and the swing mechanism to move backward through the leg assembly, wherein the base moves upward relative to the swing mechanism. Therefore, after the driving device drives the swing mechanism to move backward through the leg assembly and the base moves upward relative to the swing mechanism, the lying support mechanism is separated from the swing mechanism.

[0023] Preferably, the lying position support mechanism includes a lying position support rod, the hardness of the lying position support rod is different from that of the swinging mechanism, the lying position support rod is detachably arranged on the base, and when the mechanical extension structure is in the sitting position, the lying position support rod is separated from the swinging mechanism; when the mechanical extension structure is in the lying position, the lying position support rod is located above the swinging mechanism, and the lying position support rod abuts against the swinging mechanism.

[0024] When the lying posture support rod abuts against the swing mechanism, and the hardness of the lying posture support rod is different from that of the swing mechanism, one of the lying posture support rod and the swing mechanism is deformed. This structure is used to reduce the probability of bending of the lying posture support rod and the swing mechanism under the action of the squeezing force after the lying posture support rod abuts against the swing mechanism.

[0025] Preferably, the lying position support mechanism includes a lying position support rod and a lying position support ring. The hardness of the lying position support ring is different from that of the swinging mechanism. The lying position support ring is sleeved on the lying position support rod. The lying position support rod is detachably provided on the base. When the mechanical extension structure is in the sitting position, the lying position support ring is separated from the swinging mechanism; when the mechanical extension structure is in the lying position, the lying position support ring is located above the swinging mechanism, and the lying position support ring abuts against the swinging mechanism.

[0026] When the lying posture support ring abuts against the swing mechanism, and the hardness of the lying posture support ring is different from that of the swing mechanism, one of the lying posture support ring and the swing mechanism is deformed. This structure is used to reduce the probability of bending of the lying posture support rod (the swing mechanism applies a squeezing force to the lying posture support rod through the lying posture support ring) and the swing mechanism under the action of the squeezing force after the lying posture support ring abuts against the swing mechanism.

[0027] In addition, at least one component on the lying posture support mechanism can be replaced by removing the lying posture support rod from the base.

[0028] Preferably, the mechanical extension structure also has a TV posture position. When the mechanical extension structure is in the TV posture position, the leg assembly extends in front of the base, the sitting support mechanism is located below the swing mechanism, the sitting support mechanism abuts the swing mechanism, and the lying support mechanism is separated from the swing mechanism.

[0029] When the user's buttocks sit on the seat unit with the mechanical extension structure in the TV posture, the gravity of the user's buttocks is mainly applied to the base through the seat cushion structure; the sitting support mechanism will support the base through the swing mechanism to enable the base to provide supporting force for the seat cushion structure; this structure prevents the seat cushion structure from moving relative to the armrest structure when the user sits on the seat cushion structure.

[0030] Preferably, the mechanical extension structure also includes a tension spring, a hook is provided at the end of the tension spring, a flexible silencer is provided on the outer wall of the hook, the hardness of the flexible silencer is less than the hardness of the hook, one end of the tension spring is hung on the swing mechanism through the hook, and the other end of the tension spring is hung on the base through the hook. When one end of the tension spring is hung on the swing mechanism through the hook and the other end of the tension spring is hung on the base through the hook, a flexible silencer is clamped between the hook at one end of the tension spring and the swing mechanism, and a flexible silencer is clamped between the hook at the other end of the tension spring and the base.

[0031] Preferably, the mechanical extension structure also includes a tension spring, a hook is provided at the end of the tension spring, a flexible silencer is provided on the outer wall of the hook, the hardness of the flexible silencer is less than the hardness of the hook, one end of the tension spring is hung on the swing mechanism through the hook, and the other end of the tension spring is hung on the backrest assembly through the hook. When one end of the tension spring is hung on the swing mechanism through the hook and the other end of the tension spring is hung on the backrest assembly through the hook, a flexible silencer is clamped between the hook at one end of the tension spring and the swing mechanism, and a flexible silencer is clamped between the hook at the other end of the tension spring and the backrest assembly.

[0032] Preferably, when the mechanical extension structure is in a sitting position, the tension spring undergoes elastic deformation and is in a stretched state; when the mechanical extension structure is in a lying position, the tension spring undergoes elastic deformation and is in a stretched state; the axial length of the tension spring in the lying position is greater than the axial length of the tension spring in the sitting position.

[0033] The tension spring applies a force to the swing mechanism to increase the stability of the swing mechanism when the mechanical extension structure is in a sitting position or a lying position; when the mechanical extension structure is in a lying position, the user places his legs on the leg rest structure. At this time, the leg rest structure transfers more gravity to the swing mechanism through the leg assembly. Therefore, the axial length of the tension spring in the lying position is greater than the axial length of the tension spring in the sitting position, so that the tension spring maintains the stability of the swing mechanism through its own greater tension.

[0034] Preferably, when the mechanical extension structure is in the TV posture, the tension spring does not undergo elastic deformation; the axial length of the tension spring in the lying position is greater than the axial length of the tension spring in the sitting position and greater than the axial length of the tension spring in the TV posture.

[0035] Since the sitting position is the most commonly used posture of the mechanical extension structure of the seat unit, when the mechanical extension structure is in the sitting position and the tension spring undergoes elastic deformation and is in a stretched state, the tension spring can maintain the stability of the swing mechanism for a long time through its own tension, thereby preventing the seat cushion structure from moving relative to the armrest structure when the user sits on the seat cushion structure.

[0036] Preferably, the swing mechanism includes a main connecting rod, a secondary connecting rod, an intermediate connecting rod, a front main swing rod, a front secondary swing rod, a rear main swing rod, a rear secondary swing rod, a front support rod and a rear support rod, one end of the front support rod and one end of the rear support rod are rotatably connected to the base respectively, the other end of the front support rod and the other end of the rear support rod are rotatably connected to the intermediate connecting rod respectively, the other end of the front main swing rod and the other end of the rear main swing rod are rotatably connected to the base respectively, the other end of the front secondary swing rod and the other end of the rear secondary swing rod are rotatably connected to the intermediate connecting rod respectively, one end of the front secondary swing rod is rotatably connected to the front main swing rod, one end of the rear secondary swing rod is rotatably connected to the rear main swing rod, one end of the main connecting rod is rotatably connected to one end of the front main swing rod, the other end of the main connecting rod is rotatably connected to the rear main swing rod, one end of the secondary connecting rod is rotatably connected to the main connecting rod, and the other end of the secondary connecting rod is rotatably connected to the rear secondary swing rod.

[0037] When the mechanical extension structure is in the sitting position, since one end of the front auxiliary swing bar is rotatably connected to the front main swing bar and the other end of the front main swing bar is located in front of the other end of the front auxiliary swing bar, the front auxiliary swing bar and the front main swing bar form a support structure shaped like a "human" character; similarly, since one end of the rear auxiliary swing bar is rotatably connected to the rear main swing bar and the other end of the rear main swing bar is located in front of the other end of the rear auxiliary swing bar, the rear auxiliary swing bar and the rear main swing bar also form a support structure shaped like a "human" character. The "human"-shaped support structure has a relatively stable supporting function.

[0038] In addition, when the mechanical extension structure is in a lying position, the other end of the front main swing rod is located behind the other end of the front auxiliary swing rod, and the other end of the rear main swing rod is located behind the other end of the rear auxiliary swing rod; when the mechanical extension structure is transformed from a sitting position to a lying position, the other end of the front auxiliary swing rod moves from the rear of the other end of the front main swing rod to the front of the other end of the front main swing rod, and the other end of the rear auxiliary swing rod moves from the rear of the other end of the rear main swing rod to the front of the other end of the rear main swing rod; when the mechanical extension structure is transformed from a lying position to a sitting position, the other end of the front auxiliary swing rod moves from the front of the other end of the front main swing rod to the rear of the other end of the front main swing rod, and the other end of the rear auxiliary swing rod moves from the front of the other end of the rear main swing rod to the rear of the other end of the rear main swing rod. In this structure, the front main swing rod cooperates with the front auxiliary swing rod, and the rear main swing rod cooperates with the rear auxiliary swing rod to control the forward movement distance of the intermediate connecting rod, and the intermediate connecting rod controls the forward movement distance of the base through the front support rod and the rear support rod.

[0039] Since the other end of the front auxiliary sway bar and the other end of the rear auxiliary sway bar are respectively rotatably connected to the intermediate link, one end of the main link is rotatably connected to one end of the front main sway bar, one end of the front auxiliary sway bar is rotatably connected to the front main sway bar, the other end of the main link is rotatably connected to the rear main sway bar, and one end of the rear auxiliary sway bar is rotatably connected to the rear main sway bar, the intermediate link, the front auxiliary sway bar, the rear auxiliary sway bar and the main link form a motion structure similar to a quadrilateral; as is well known, the quadrilateral structure has the disadvantage of uncertain motion posture, and therefore, the swing mechanism controls the motion posture of the rear main sway bar and the rear auxiliary sway bar through the auxiliary link (one end of the auxiliary link is rotatably connected to the main link, and the other end of the auxiliary link is rotatably connected to the rear auxiliary sway bar), thereby controlling the motion posture of the front main sway bar and the front auxiliary sway bar; wherein, the other end of the auxiliary link is mainly used to control the motion posture of the rear auxiliary sway bar, and the other end of the main link is mainly used to control the motion posture of the rear main sway bar.

[0040] In addition, the secondary link can also increase the deformation resistance of the rear secondary sway bar.

[0041] Preferably, the swing mechanism includes a main connecting rod, a secondary connecting rod, an intermediate connecting rod, a front main swing rod, a front secondary swing rod, a rear main swing rod, a rear secondary swing rod, a front support rod and a rear support rod, one end of the front support rod and one end of the rear support rod are rotatably connected to the base respectively, the other end of the front support rod and the other end of the rear support rod are rotatably connected to the intermediate connecting rod respectively, the other end of the front main swing rod and the other end of the rear main swing rod are rotatably connected to the base respectively, the other end of the front secondary swing rod and the other end of the rear secondary swing rod are rotatably connected to the intermediate connecting rod respectively, one end of the front secondary swing rod is rotatably connected to the front main swing rod, one end of the rear secondary swing rod is rotatably connected to the rear main swing rod, the other end of the main connecting rod is rotatably connected to the rear secondary swing rod, one end of the main connecting rod is rotatably connected to one end of the front main swing rod, the other end of the secondary connecting rod is rotatably connected to the main connecting rod, and one end of the secondary connecting rod is rotatably connected to the front secondary swing rod.

[0042] Since the other end of the front auxiliary sway bar and the other end of the rear auxiliary sway bar are respectively rotationally connected to the intermediate link, the other end of the main link is rotationally connected to the rear auxiliary sway bar, one end of the main link is rotationally connected to one end of the front main sway bar, and one end of the front auxiliary sway bar is rotationally connected to the front main sway bar, the intermediate link, the front auxiliary sway bar, the rear auxiliary sway bar and the main link form a motion structure similar to a quadrilateral; as is well known, the quadrilateral structure has the disadvantage of uncertain motion posture, and therefore, the swing mechanism controls the motion posture of the front main sway bar and the front auxiliary sway bar through the auxiliary link (the other end of the auxiliary link is rotationally connected to the main link, and one end of the auxiliary link is rotationally connected to the front auxiliary sway bar), and then controls the motion posture of the rear main sway bar and the rear auxiliary sway bar; wherein, one end of the auxiliary link mainly controls the motion posture of the front auxiliary sway bar, and one end of the main link mainly controls the motion posture of the front main sway bar.

[0043] The secondary link is used to increase the deformation resistance of the front secondary sway bar.

[0044] When the auxiliary link is set on the front auxiliary sway bar, in order to avoid interference between the auxiliary link and the main link and the front main sway bar, the front main sway bar needs to be lengthened to achieve a rotational connection between one end of the auxiliary link and the middle position of the front auxiliary sway bar.

[0045] When the mechanical extension structure changes from the lying position to the sitting position, the seat cushion structure moves forward and upward, and the serpentine spring of the seat cushion structure bends upward. Therefore, the seat cushion structure has enough space for the front main swing rod to be lengthened. In other words, one end of the secondary connecting rod is rotatably connected to the middle position of the front secondary swing rod, which can avoid interference between the swing mechanism and the seat cushion structure.

[0046] Preferably, the mechanical extension structure also includes two sitting posture support mechanisms. When the mechanical extension structure is in a sitting position, the other end of the front main rocker arm is located in front of the other end of the front auxiliary rocker arm, and the other end of the rear main rocker arm is located in front of the other end of the rear auxiliary rocker arm. One of the sitting posture support mechanisms is located below the front main rocker arm and the sitting posture support mechanism abuts against the front main rocker arm, and the other sitting posture support mechanism is located below the rear main rocker arm and the sitting posture support mechanism abuts against the rear main rocker arm. When the mechanical extension structure is in a lying position, the other end of the front main rocker arm is located behind the other end of the front auxiliary rocker arm, and the other end of the rear main rocker arm is located behind the other end of the rear auxiliary rocker arm, and the front main rocker arm and the rear main rocker arm are both separated from their respective corresponding sitting posture support mechanisms.

[0047] The user usually adjusts the mechanical extension structure of the seat unit to a lying position during recreational time, while the seat unit is in a sitting position most of the time. Therefore, the mechanical extension structure can provide more stable support for the swing mechanism through the two sitting support mechanisms.

[0048] Preferably, an inwardly recessed sitting posture limit groove is provided on the front main rocker arm and / or the rear main rocker arm, and when the mechanical extension structure is in the sitting posture position, the sitting posture support mechanism is inserted into the sitting posture limit groove and abuts against the groove wall of the sitting posture limit groove.

[0049] After the swing mechanism is damaged, the sitting position limit groove prevents the swing mechanism from collapsing relative to the base by limiting the movement of the sitting position support mechanism. Therefore, the provision of the sitting position limit groove is equivalent to providing an anti-deformation "stuck" structure for the swing mechanism to a certain extent, so as to further prevent the seat cushion structure from moving relative to the armrest structure when the user sits on the seat cushion structure.

[0050] Preferably, the mechanical extension structure further comprises a sitting posture support mechanism, when the mechanical extension structure is in the sitting position, the other end of the front main swing link is located in front of the other end of the front auxiliary swing link, the other end of the rear main swing link is located in front of the other end of the rear auxiliary swing link, the sitting posture support mechanism is located below the front main swing link and the sitting posture support mechanism abuts against the front main swing link; when the mechanical extension structure is in the lying position, the other end of the front main swing link is located behind the other end of the front auxiliary swing link, the other end of the rear main swing link is located behind the other end of the rear auxiliary swing link, and the sitting posture support mechanism is separated from the front main swing link;

[0051] Or, when the mechanical extension structure is in the sitting position, the other end of the front main swing rod is located in front of the other end of the front auxiliary swing rod, the other end of the rear main swing rod is located in front of the other end of the rear auxiliary swing rod, the sitting posture support mechanism is located below the rear main swing rod, and the sitting posture support mechanism abuts against the rear main swing rod; when the mechanical extension structure is in the lying position, the other end of the front main swing rod is located behind the other end of the front auxiliary swing rod, the other end of the rear main swing rod is located behind the other end of the rear auxiliary swing rod, and the sitting posture support mechanism is separated from the rear main swing rod;

[0052] Or, when the mechanical extension structure is in the sitting position, the other end of the front main swing rod is located in front of the other end of the front auxiliary swing rod, the other end of the rear main swing rod is located in front of the other end of the rear auxiliary swing rod, the sitting posture support mechanism is located below the main connecting rod, and the sitting posture support mechanism abuts against the main connecting rod; when the mechanical extension structure is in the lying position, the other end of the front main swing rod is located behind the other end of the front auxiliary swing rod, the other end of the rear main swing rod is located behind the other end of the rear auxiliary swing rod, and the sitting posture support mechanism is separated from the main connecting rod;

[0053] Or, when the mechanical extension structure is in a sitting position, the other end of the front main rocker arm is located in front of the other end of the front auxiliary rocker arm, the other end of the rear main rocker arm is located in front of the other end of the rear auxiliary rocker arm, the sitting posture support mechanism is located below the main connecting rod and the sitting posture support mechanism abuts against the auxiliary connecting rod; when the mechanical extension structure is in a lying position, the other end of the front main rocker arm is located behind the other end of the front auxiliary rocker arm, the other end of the rear main rocker arm is located behind the other end of the rear auxiliary rocker arm, and the sitting posture support mechanism is separated from the auxiliary connecting rod.

[0054] Preferably, the mechanical extension structure further comprises a lying support mechanism, which is fixedly connected to the base. When the mechanical extension structure is in the lying position, the lying support mechanism is located above the front support rod and abuts against the front support rod; when the mechanical extension structure is in the sitting position, the lying support mechanism is separated from the front support rod;

[0055] Or, when the mechanical extension structure is in the lying position, the lying support mechanism is located above the rear support rod and the lying support mechanism abuts against the rear support rod; when the mechanical extension structure is in the sitting position, the lying support mechanism is separated from the rear support rod.

[0056] Preferably, the rotational connection between the other end of the front support rod and the middle link is located above the rotational connection between the other end of the front auxiliary swing rod and the middle link, the rotational connection between the other end of the rear support rod and the middle link is located above the rotational connection between the other end of the rear auxiliary swing rod and the middle link, and the rotational connection between the other end of the front support rod and the middle link is located above the rotational connection between the other end of the rear support rod and the middle link.

[0057] When the user's buttocks sit on the seat cushion structure and the mechanical extension structure is in the sitting position, the seat cushion structure provides a downward force to the front support rod through the base. Since the rotation connection between the other end of the front support rod and the middle link is located above the rotation connection between the other end of the front secondary swing rod and the middle link, the "rotation connection between the other end of the front support rod and the middle link" applies a downward thrust to the "rotation connection between the other end of the front secondary swing rod and the middle link" to achieve the front secondary swing rod pulling the front main swing rod downward to abut against the sitting support mechanism. This structure further improves the reliability of the sitting support mechanism supporting the swing mechanism.

[0058] When the user's buttocks sit on the seat cushion structure and the mechanical extension structure is in the sitting position, the seat cushion structure provides a downward force to the rear support rod through the base. Since the rotation connection between the other end of the rear support rod and the middle link is located above the rotation connection between the other end of the rear auxiliary swing rod and the middle link, the "rotation connection between the other end of the rear support rod and the middle link" applies a downward thrust to the "rotation connection between the other end of the rear auxiliary swing rod and the middle link" to achieve the rear auxiliary swing rod pulling the rear main swing rod downward to abut against the sitting support mechanism. This structure further improves the reliability of the sitting support mechanism supporting the swing mechanism.

[0059] In this embodiment, the rotation connection between the other end of the front support rod and the middle connecting rod is located above the rotation connection between the other end of the rear support rod and the middle connecting rod. The "rotation connection between the other end of the front support rod and the middle connecting rod" is slightly higher than the "rotation connection between the other end of the rear support rod and the middle connecting rod". Therefore, the swing mechanism slightly raises the height of the front side of the base, that is, raises the height of the user's legs, so that the user has a feeling that his buttocks sink into the seat unit and he himself leans back slightly.

[0060] Preferably, a first reinforcing rib is provided on the front auxiliary sway bar; and / or a second reinforcing rib is provided on the rear auxiliary sway bar.

[0061] The middle link provides a downward pulling force to the front main swing arm through the front auxiliary swing arm, therefore, the first reinforcing rib is used to increase the deformation resistance of the front auxiliary swing arm; the middle link provides a downward pulling force to the rear main swing arm through the rear auxiliary swing arm, therefore, the second reinforcing rib is used to increase the deformation resistance of the rear auxiliary swing arm.

[0062] Preferably, when the front auxiliary rocker arm is provided with a first reinforcing rib, the sitting posture support mechanism is located on one side of the front auxiliary rocker arm, and the first reinforcing rib is located on the other side of the front auxiliary rocker arm; when the rear auxiliary rocker arm is provided with a second reinforcing rib, the sitting posture support mechanism is located on one side of the rear auxiliary rocker arm, and the first reinforcing rib is located on the other side of the rear auxiliary rocker arm.

[0063] When the sitting posture support mechanism is located on one side of the front auxiliary rocker arm and the first reinforcement rib is located on the other side of the front auxiliary rocker arm, the first reinforcement rib will not interfere with the sitting posture support mechanism during the movement of the front auxiliary rocker arm; when the sitting posture support mechanism is located on one side of the rear auxiliary rocker arm and the first reinforcement rib is located on the other side of the rear auxiliary rocker arm, the second reinforcement rib will not interfere with the sitting posture support mechanism during the movement of the rear auxiliary rocker arm.

[0064] Preferably, a third reinforcing rib is provided on the base, and the third reinforcing rib is located between a rotation connection between one end of the front support rod and the base and a rotation connection between the rear support rod and the base.

[0065] The front support rod and the rear support rod need to provide support force for the base for a long time. Therefore, adding a third reinforcing rib between the two can effectively increase the service life of the base.

[0066] Preferably, a fourth reinforcing rib is provided on the front main rocker arm; and / or a fifth reinforcing rib is provided on the rear main rocker arm.

[0067] When the mechanical extension structure is in the sitting position, the sitting support mechanism abuts against the front main rocker; therefore, providing the fourth reinforcing rib on the front main rocker can increase the deformation resistance of the front main rocker, so as to increase the service life of the seat unit.

[0068] When the mechanical extension structure is in the sitting position, the sitting support mechanism abuts against the rear main swing arm; therefore, providing the fifth reinforcing rib on the rear main swing arm can increase the deformation resistance of the rear main swing arm, so as to increase the service life of the seat unit.

[0069] Preferably, the swing mechanism comprises a front support rod and a rear support rod, one end of the front support rod and one end of the rear support rod are respectively rotatably connected to the base, and the other end of the front support rod and the other end of the rear support rod are respectively rotatably connected to the base;

[0070] The mechanical extension structure also includes at least one sitting support mechanism. When the mechanical extension structure is in a sitting position, the sitting support mechanism is located below the front support rod and abuts against the front support rod; and / or the sitting support mechanism is located below the rear support rod and abuts against the rear support rod; when the mechanical extension structure is in a lying position, the sitting support mechanism is separated from the front support rod and the rear support rod.

[0071] When one of the sitting posture support mechanisms is located below the front support rod and abuts against the front support rod, one of the sitting posture support mechanisms provides support force for the base through the front support rod; when the other sitting posture support mechanism is located below the rear support rod and abuts against the rear support rod, the other sitting posture support mechanism provides support force for the base through the rear support rod. When the front support rod cannot rotate relative to the base and the rear support rod cannot rotate relative to the base, the position of the base is also fixed, which will prevent the seat cushion structure from moving relative to the armrest structure when the user sits on the seat cushion structure.

[0072] When the swing mechanism includes the front support rod and the rear support rod, the seat unit can reduce the manufacturing cost of the seat unit by simplifying the number of parts of the swing mechanism.

[0073] Preferably, the backrest assembly comprises a backrest plate, a front backrest bracket, a backrest bracket and a backrest driving rod, one end of the front backrest bracket is rotatably connected to the backrest plate, the other end of the front backrest bracket is rotatably connected to the base, one end of the backrest bracket is rotatably connected to the backrest plate, the backrest bracket is rotatably connected to the base, one end of the backrest driving rod is rotatably connected to the other end of the backrest bracket, and the other end of the backrest driving rod is rotatably connected to the base;

[0074] During the mechanical extension from the sitting position to the lying position, the backrest moves forward.

[0075] Preferably, the backrest assembly comprises a backrest plate, a front backrest bracket, a backrest bracket and a backrest driving rod, one end of the front backrest bracket is rotatably connected to the backrest plate, the other end of the front backrest bracket is fixedly connected to the base, one end of the backrest bracket is rotatably connected to the backrest plate, the backrest bracket is rotatably connected to the base, one end of the backrest driving rod is rotatably connected to the other end of the backrest bracket, and the other end of the backrest driving rod is rotatably connected to the base;

[0076] During the mechanical extension from the sitting position to the lying position, the backrest moves forward.

[0077] Preferably, the backrest assembly comprises a backrest plate, a front backrest bracket, a backrest rear bracket, a backrest connecting bracket and a backrest driving rod, one end of the front backrest bracket is rotatably connected to the backrest plate, the other end of the front backrest bracket is fixedly connected to the base, one end of the backrest bracket is rotatably connected to the backrest plate, the other end of the backrest bracket is rotatably connected to one end of the backrest connecting bracket, the backrest connecting bracket is rotatably connected to the base, one end of the backrest driving rod is rotatably connected to the other end of the backrest connecting bracket, and the other end of the backrest driving rod is rotatably connected to the base;

[0078] During the mechanical extension from the sitting position to the lying position, the backrest moves forward.

[0079] Preferably, the driving device includes a driver, a screw and a push block, the driver is fixedly connected to the base, the driver is provided with a driving rod fixedly connected to the screw, the push block is threadedly connected to the screw, and the leg assembly is directly or indirectly rotatably connected to the push block; or, the driving device includes a driver, the driver is provided with a driving rod, the driver is rotatably connected to the base, and the leg assembly is rotatably connected to the driving rod.

[0080] The seat unit comprises an armrest structure, a backrest structure, a seat cushion structure, a legrest structure and a mechanical extension structure, wherein the mechanical extension structure comprises the mechanical extension structure described in any one of the above technical solutions, the base is fixedly connected to the armrest structure, the backrest assembly is fixedly connected to the backrest structure, the legrest structure is fixedly connected to the leg assembly, and the seat cushion structure is fixedly connected to the base;

[0081] Wherein, a ventilation structure and / or a heating structure is provided on the backrest structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0082] Figure 1 It is a front view of the seat unit in the utility model (the mechanical extension structure is in the sitting position);

[0083] Figure 2 It is a three-dimensional diagram of a part of the mechanical extension structure of the utility model;

[0084] Figure 3 It is a three-dimensional diagram of a part of the swing mechanism (first structure) in the utility model;

[0085] Figure 4 It is a three-dimensional diagram of the swing mechanism (first structure) in the utility model;

[0086] Figure 5 It is a three-dimensional diagram of the swing mechanism (second structure) in the utility model;

[0087] Figure 6 It is a front view of the mechanical extension structure of the utility model in a lying position;

[0088] Figure 7 It is a three-dimensional diagram of the backrest assembly in the utility model. DETAILED DESCRIPTION

[0089] The present invention is further described in detail below through specific implementation examples and in conjunction with the accompanying drawings:

[0090] exist Figure 1 and Figure 2The utility model discloses a mechanical extension structure 100 including a base 3, two bases 1 for installing a cushion structure 300, two groups of leg assemblies 5 for installing a legrest structure, two groups of backrest assemblies 2 for installing a backrest structure 200, two groups of swing mechanisms 4 and a driving device 6, the driving device 6 is arranged on the base 3, each group of leg assemblies 5 is rotatably connected to a base 1, each base 1 is movably connected to the base 3 through a group of swing mechanisms 4, and each base 1 is also connected to the base 3 through a group of backrest assemblies 2;

[0091] The mechanical extension structure 100 has a sitting position and a lying position. When the mechanical extension structure 100 changes from the sitting position to the lying position, the driving device 6 drives the base 1 and the swing mechanism 4 to move forward through the leg assembly 5, and extends the leg assembly 5 in front of the base 1; when the mechanical extension structure 100 changes from the lying position to the sitting position, the driving device 6 drives the base 1 and the swing mechanism 4 to move backward through the leg assembly 5, and retracts the leg assembly 5 under the base 1. The mechanical extension structure 100 also includes at least one sitting support mechanism 311, which is fixedly connected to the base 3. When the mechanical extension structure 100 is in the sitting position, the sitting support mechanism 311 supports the swing mechanism 4; when the mechanical extension structure 100 is in the lying position, the sitting support mechanism 311 is separated from the swing mechanism 4.

[0092] The base 3 can be fixedly connected to the armrest structure (not marked). In the prior art, the armrest structure does not move with the mechanical extension structure 100. Therefore, when the sitting support mechanism 311 is fixedly connected to the base 3, the armrest structure prevents the sitting support mechanism 311 from moving with the mechanical extension structure 100 through the base 3.

[0093] Of course, some existing seat units are armless structures. The seat units without armrest structures are provided with four flexible support rods under the base, that is, the support function of the armrest structure for the seat unit is replaced by the flexible support rods.

[0094] When the sitting posture support mechanism 311 is located below the swing mechanism 4 and the sitting posture support mechanism 311 abuts against the swing mechanism 4, the upper part of the sitting posture support mechanism 311 supports the swing mechanism 4; since the base 1 is connected to the base 3 through the swing mechanism 4, when the mechanical extension structure 100 is in the sitting position and the sitting posture support mechanism 311 is used to support the swing mechanism 4, the sitting posture support mechanism 311 will support the base 1 through the swing mechanism 4. When the user sits on the seat cushion structure 300, the user's buttocks apply gravity to the base 1 through the seat cushion structure 300; the sitting posture support mechanism 311 will support the base 1 through the swing mechanism 4, so that the base 1 provides support force for the seat cushion structure 300; this structure prevents the seat cushion structure 300 from moving relative to the armrest structure when the user sits on the seat cushion structure 300.

[0095] During the process of the mechanical extension structure 100 changing from a sitting position to a lying position, the driving device 6 drives the base 1 and the swing mechanism 4 to move forward through the leg assembly 5. Since the armrest structure prevents the sitting support mechanism 311 from moving with the mechanical extension structure 100 through the base 3, after the driving device 6 drives the swing mechanism 4 to move forward through the leg assembly 5, the sitting support mechanism 311 is separated from the swing mechanism 4.

[0096] Among them, "the driving device 6 drives the base 1 and the swing mechanism 4 to move forward through the leg assembly 5" can be that the driving device 6 directly drives the swing mechanism 4 to move forward through the leg assembly 5, and "the driving device 6 drives the base 1 and the swing mechanism 4 to move forward through the leg assembly 5" can also be that the driving device 6 indirectly drives the swing mechanism 4 to move forward through the leg assembly 5. For example, the driving device 6 drives the base 1 to move forward through the leg assembly 5, and the base 1 drives the swing mechanism 4 to move forward.

[0097] During the process of the mechanical extension structure 100 changing from a lying position to a sitting position, the driving device 6 drives the base 1 and the swing mechanism 4 to move backward through the leg assembly 5. Since the armrest structure prevents the sitting support mechanism 311 from moving with the mechanical extension structure 100 through the base 3, after the driving device 6 drives the swing mechanism 4 to move backward through the leg assembly 5, the sitting support mechanism 311 can abut against the swing mechanism 4.

[0098] like Figure 3 As shown, the sitting posture support mechanism 311 includes a sitting posture support rod, the hardness of the sitting posture support rod is different from that of the swing mechanism 4, the sitting posture support rod is fixedly connected to the base 3, when the mechanical extension structure 100 is in the sitting position, the sitting posture support rod is located below the swing mechanism 4, and the sitting posture support rod abuts against the swing mechanism 4; when the mechanical extension structure 100 is in the lying position, the sitting posture support rod is separated from the swing mechanism 4.

[0099] When the sitting posture support rod abuts against the swing mechanism 4, and the hardness of the sitting posture support rod is different from that of the swing mechanism 4, one of the sitting posture support rod and the swing mechanism 4 is deformed. This structure is used to reduce the probability of bending of the sitting posture support rod and the swing mechanism 4 under the action of the extrusion force after the sitting posture support rod abuts against the swing mechanism 4; in addition, the base 3 includes two armrest plates 31, and the sitting posture support mechanism 311 is fixedly connected to the armrest plates 31. Since the base 3 includes two armrest plates 31 and the sitting posture support mechanism 311 is fixedly connected to the armrest plates 31, when the sitting posture support mechanism 311 includes the sitting posture support rod and the sitting posture support rod abuts against the swing mechanism 4, the single sitting posture support rod increases its position accuracy on the armrest plate 31, so that the sitting posture support rods on the left and right sides can abut against their respective swing mechanisms 4, respectively, thereby extending the service life of all sitting posture support rods.

[0100] Preferably, the hardness of the sitting posture support rod is lower than the hardness of the swing mechanism 4. When the sitting posture support rod abuts against the swing mechanism 4 and the hardness of the sitting posture support rod is lower than that of the swing mechanism 4, the sitting posture support rod is deformed.

[0101] Of course, in other embodiments, the sitting posture support mechanism includes a sitting posture support rod and a sitting posture support ring, the hardness of the sitting posture support ring is different from that of the swing mechanism, the sitting posture support ring is sleeved on the sitting posture support rod, and the sitting posture support rod is detachably arranged on the base, when the mechanical extension structure is in the sitting position, the sitting posture support ring is located below the swing mechanism, and the sitting posture support ring abuts the swing mechanism; when the mechanical extension structure is in the lying position, the sitting posture support ring is separated from the swing mechanism. When the sitting posture support ring abuts the swing mechanism, and the hardness of the sitting posture support ring is different from that of the swing mechanism, one of the sitting posture support ring and the swing mechanism is deformed. This structure is used to reduce the probability of bending of the sitting posture support rod (the swing mechanism applies a squeezing force to the sitting posture support rod through the sitting posture support ring) and the swing mechanism under the action of the squeezing force after the sitting posture support ring abuts the swing mechanism. In addition, the sitting posture support rod can be removed from the base to replace at least one component on the sitting posture support mechanism.

[0102] In this embodiment, the mechanical extension structure 100 also includes at least one lying position support mechanism 12, which is fixedly connected to the base 1. When the mechanical extension structure 100 is in a sitting position, the lying position support mechanism 12 is separated from the swing mechanism 4; when the mechanical extension structure 100 is in a lying position, the swing mechanism 4 supports the lying position support mechanism 12.

[0103] When the lying position support mechanism 12 is located above the swing mechanism 4 and the lying position support mechanism 12 abuts against the swing mechanism 4, the swing mechanism 4 supports the lower part of the lying position support mechanism 12; since the lying position support mechanism 12 is fixedly connected to the base 1, when the mechanical extension structure 100 is in the lying position and the swing mechanism 4 is used to support the lying position support mechanism 12, the swing mechanism 4 supports the base 1 through the lying position support mechanism 12. When the user's buttocks sit on the cushion structure 300, the user's buttocks apply gravity to the base 1 through the cushion structure 300; the swing mechanism 4 supports the base 1 through the lying position support mechanism 12, so that the base 1 provides support force for the cushion structure 300; this structure prevents the cushion structure 300 from moving relative to the armrest structure when the user sits on the cushion structure 300.

[0104] When the mechanical extension structure 100 is transformed from the sitting position to the lying position, the driving device 6 drives the base 1 and the swing mechanism 4 to move forward through the leg assembly 5, wherein the base 1 moves downward relative to the swing mechanism 4. Therefore, after the driving device 6 drives the swing mechanism 4 to move forward through the leg assembly 5 and the base 1 moves downward relative to the swing mechanism 4, the lying support mechanism 12 abuts against the swing mechanism 4. This structure reduces the height of the base 1 relative to the swing mechanism 4, thereby shortening the time required for the lying support mechanism 12 to abut against the swing mechanism 4 and improving the reliability of the abutment between the two.

[0105] When the mechanical extension structure 100 is transformed from the lying position to the sitting position, the driving device 6 drives the base 1 and the swing mechanism 4 to move backward through the leg assembly 5, wherein the base 1 moves upward relative to the swing mechanism 4. Therefore, after the driving device 6 drives the swing mechanism 4 to move backward through the leg assembly 5 and the base 1 moves upward relative to the swing mechanism 4, the lying support mechanism 12 is separated from the swing mechanism 4. This structure increases the time required for the lying support mechanism 12 to separate from the swing mechanism 4 and improves the reliability of the separation of the two by raising the height of the base 1 relative to the swing mechanism 4.

[0106] like Figure 2 As shown, the lying position support mechanism 12 includes a lying position support rod, the hardness of the lying position support rod is different from that of the swing mechanism 4, the lying position support rod is fixedly connected to the base 1, and when the mechanical extension structure 100 is in the sitting position, the lying position support rod is separated from the swing mechanism 4; when the mechanical extension structure 100 is in the lying position, the lying position support rod is located above the swing mechanism, and the lying position support rod abuts against the swing mechanism 4.

[0107] When the lying position support rod abuts against the swing mechanism 4, and the hardness of the lying position support rod is different from that of the swing mechanism 4, one of the lying position support rod and the swing mechanism 4 is deformed. This structure is used to reduce the probability of bending of the lying position support rod and the swing mechanism 4 under the action of the extrusion force after the lying position support rod abuts against the swing mechanism 4; in addition, the mechanical extension structure 100 includes two bases 1, and the lying position support rod is fixedly connected to the base 1. Since the mechanical extension structure 100 includes two bases 1 and the lying position support rod is fixedly connected to the base 1, when the lying position support mechanism 12 includes the lying position support rod and the lying position support rod abuts against the swing mechanism 4, the single lying position support rod increases its position accuracy on the base 1, so that the lying position support rods on the left and right sides can abut against their respective swing mechanisms respectively, thereby extending the service life of all lying position support rods.

[0108] Preferably, the hardness of the lying position support rod is lower than the hardness of the swing mechanism 4. When the lying position support rod abuts against the swing mechanism 4 and the hardness of the lying position support rod is lower than that of the swing mechanism 4, the lying position support rod is deformed.

[0109] Of course, in other embodiments, the lying position support mechanism includes a lying position support rod and a lying position support ring, the hardness of the lying position support ring is different from that of the swing mechanism, the lying position support ring is sleeved on the lying position support rod, and the lying position support rod is detachably arranged on the base, and when the mechanical extension structure is in the sitting position, the lying position support ring is separated from the swing mechanism; when the mechanical extension structure is in the lying position, the lying position support ring is located above the swing mechanism, and the lying position support ring abuts the swing mechanism. When the lying position support ring abuts the swing mechanism, and the hardness of the lying position support ring is different from that of the swing mechanism, one of the lying position support ring and the swing mechanism is deformed. This structure is used to reduce the probability of bending of the lying position support rod (the swing mechanism applies an extrusion force to the lying position support rod through the lying position support ring) and the swing mechanism under the action of the extrusion force after the lying position support ring abuts the swing mechanism. In addition, the lying position support rod is removed from the base, and at least one component on the lying position support mechanism can be replaced.

[0110] In this embodiment, the mechanical extension structure also has a TV posture position. When the mechanical extension structure is in the TV posture position, the leg assembly 5 extends in front of the base 1, the sitting support mechanism 311 is located below the swing mechanism 4, the sitting support mechanism 311 abuts against the swing mechanism 4, and the lying support mechanism 12 is separated from the swing mechanism 4.

[0111] When the user's buttocks sit on the seat unit with the mechanical extension structure 100 in the TV posture position, the gravity of the user's buttocks is mainly applied to the base 1 through the seat cushion structure 300; the sitting support mechanism 311 will support the base 1 through the swing mechanism 4 to enable the base to provide support force for the seat cushion structure 300; this structure prevents the seat cushion structure 300 from moving relative to the armrest structure when the user sits on the seat cushion structure 300.

[0112] In this embodiment, the mechanical extension structure 100 also includes a tension spring (unmarked), a hook (unmarked) is provided at the end of the tension spring, and a flexible silencer (unmarked) is provided on the outer wall of the hook, the hardness of the flexible silencer is less than the hardness of the hook, one end of the tension spring is hung on the swing mechanism 4 through the hook, and the other end of the tension spring is hung on the backrest assembly 2 through the hook, when one end of the tension spring is hung on the swing mechanism 4 through the hook and the other end of the tension spring is hung on the backrest assembly 2 through the hook, a flexible silencer is clamped between the hook at one end of the tension spring and the swing mechanism 4, and a flexible silencer is clamped between the hook at the other end of the tension spring and the backrest assembly 2.

[0113] In other embodiments, the mechanical extension structure also includes a tension spring, a hook is provided at the end of the tension spring, a flexible silencer is provided on the outer wall of the hook, the hardness of the flexible silencer is less than the hardness of the hook, one end of the tension spring is hung on the swing mechanism through the hook, and the other end of the tension spring is hung on the base through the hook. When one end of the tension spring is hung on the swing mechanism through the hook and the other end of the tension spring is hung on the base through the hook, a flexible silencer is clamped between the hook at one end of the tension spring and the swing mechanism, and a flexible silencer is clamped between the hook at the other end of the tension spring and the base.

[0114] Preferably, when the mechanical extension structure 100 is in a sitting position, the tension spring undergoes elastic deformation and is in a stretched state; when the mechanical extension structure 100 is in a lying position, the tension spring undergoes elastic deformation and is in a stretched state; the axial length of the tension spring in the lying position is greater than the axial length of the tension spring in the sitting position.

[0115] The tension spring applies a force to the swing mechanism 4 to increase the stability of the swing mechanism 4 when the mechanical extension structure 100 is in a sitting position or a lying position; when the mechanical extension structure 100 is in a lying position, the user places his legs on the leg rest structure. At this time, the leg rest structure transfers more gravity to the swing mechanism 4 through the leg assembly 5. Therefore, the axial length of the tension spring in the lying position is greater than the axial length of the tension spring in the sitting position, so that the tension spring maintains the stability of the swing mechanism 4 through its own greater tension.

[0116] More preferably, when the mechanical extension structure 100 is in the TV posture, the tension spring does not undergo elastic deformation; the axial length of the tension spring in the lying position is greater than the axial length of the tension spring in the sitting position and greater than the axial length of the tension spring in the TV posture.

[0117] Since the sitting position is the most commonly used posture of the mechanical extension structure of the seat unit, when the mechanical extension structure is in the sitting position and the tension spring undergoes elastic deformation and is in a stretched state, the tension spring can maintain the stability of the swing mechanism 4 for a long time through its own tension, so as to avoid the seat cushion structure 300 from moving relative to the armrest structure when the user sits on the seat cushion structure 300.

[0118] like Figure 3 and Figure 4As shown, the first structure of the swing mechanism 4 includes a main connecting rod 41, a secondary connecting rod 42, an intermediate connecting rod 43, a front main swing rod 45, a front secondary swing rod 44, a rear main swing rod 47, a rear secondary swing rod 46, a front support rod 48 and a rear support rod 49, one end of the front support rod 48 and one end of the rear support rod 49 are respectively rotatably connected to the base 1, the other end of the front support rod 48 and the other end of the rear support rod 49 are respectively rotatably connected to the intermediate connecting rod 43, and the other end of the front main swing rod 45 and the other end of the rear main swing rod 47 are respectively connected to the bottom The seat 3 is rotatably connected, the other end of the front auxiliary sway bar 44 and the other end of the rear auxiliary sway bar 46 are rotatably connected to the intermediate link 43 respectively, one end of the front auxiliary sway bar 44 is rotatably connected to the front main sway bar 45, one end of the rear auxiliary sway bar 46 is rotatably connected to the rear main sway bar 47, one end of the main link 41 is rotatably connected to one end of the front main sway bar 45, the other end of the main link 41 is rotatably connected to the rear main sway bar 47, one end of the auxiliary link 42 is rotatably connected to the main link 41, and the other end of the auxiliary link 42 is rotatably connected to the rear auxiliary sway bar 46.

[0119] When the mechanical extension structure 100 is in the sitting position, since one end of the front auxiliary swing link 44 is rotatably connected to the front main swing link 45 and the other end of the front main swing link 45 is located in front of the other end of the front auxiliary swing link 44, the front auxiliary swing link 44 and the front main swing link 45 form a support structure shaped like a "human" character; similarly, since one end of the rear auxiliary swing link 46 is rotatably connected to the rear main swing link 47 and the other end of the rear main swing link 47 is located in front of the other end of the rear auxiliary swing link 46, the rear auxiliary swing link 46 and the rear main swing link 47 also form a support structure shaped like a "human" character. The "human"-shaped support structure has a relatively stable supporting function.

[0120] In addition, when the mechanical extension structure 100 is in the lying position, the other end of the front main rocker 45 is located behind the other end of the front auxiliary rocker 44, and the other end of the rear main rocker 47 is located behind the other end of the rear auxiliary rocker 46; when the mechanical extension structure 100 is transformed from the sitting position to the lying position, the other end of the front auxiliary rocker 44 moves from the rear of the other end of the front main rocker 45 to the front of the other end of the front main rocker 45, and the other end of the rear auxiliary rocker 46 moves from the rear of the other end of the rear main rocker 47 to the front of the other end of the rear main rocker 47; when the mechanical extension structure 100 is transformed from the lying position to the sitting position, the other end of the front auxiliary rocker 44 moves from the front of the other end of the front main rocker 45 to the rear of the other end of the front main rocker 45, and the other end of the rear auxiliary rocker 46 moves from the front of the other end of the rear main rocker 47 to the rear of the other end of the rear main rocker 47. In this structure, the front main rocker arm 45 cooperates with the front auxiliary rocker arm 44, and the rear main rocker arm 47 cooperates with the rear auxiliary rocker arm 46 to control the forward movement distance of the intermediate link 43. The intermediate link 43 controls the forward movement distance of the base 1 through the front support rod 48 and the rear support rod 49.

[0121] Since the other ends of the front auxiliary sway bar 44 and the other ends of the rear auxiliary sway bar 46 are rotatably connected to the intermediate link 43 respectively, one end of the main link 41 is rotatably connected to one end of the front main sway bar 45, one end of the front auxiliary sway bar 44 is rotatably connected to the front main sway bar 45, the other end of the main link 41 is rotatably connected to the rear main sway bar 47, and one end of the rear auxiliary sway bar 46 is rotatably connected to the rear main sway bar 47, the intermediate link 43, the front auxiliary sway bar 44, the rear auxiliary sway bar 46 and the main link 41 form a kinematic structure similar to a quadrilateral; as is well known, a quadrilateral The polygonal structure has the disadvantage of uncertain motion posture. Therefore, the swing mechanism 4 controls the motion posture of the rear main swing arm 47 and the rear auxiliary swing arm 46 through the auxiliary connecting rod 42 (one end of the auxiliary connecting rod 42 is rotationally connected to the main connecting rod 41, and the other end of the auxiliary connecting rod 42 is rotationally connected to the rear auxiliary swing arm 46), and then controls the motion posture of the front main swing arm 45 and the front auxiliary swing arm 44; wherein, the other end of the auxiliary connecting rod 42 is mainly used to control the motion posture of the rear auxiliary swing arm 46, and the other end of the main connecting rod 41 is mainly used to control the motion posture of the rear main swing arm 47.

[0122] In addition, the secondary link 42 can also increase the deformation resistance of the rear secondary sway bar 46 .

[0123] like Figure 5As shown, the second structure of the swing mechanism 4 includes a main connecting rod 41, a secondary connecting rod 42, an intermediate connecting rod 43, a front main swing rod 45, a front secondary swing rod 44, a rear main swing rod 47, a rear secondary swing rod 46, a front support rod 48 and a rear support rod 49, one end of the front support rod 48 and one end of the rear support rod 49 are respectively rotatably connected to the base 1, the other end of the front support rod 48 and the other end of the rear support rod 49 are respectively rotatably connected to the intermediate connecting rod 43, and the other end of the front main swing rod 45 and the other end of the rear main swing rod 47 are respectively connected to the bottom The seat 3 is rotatably connected, the other end of the front auxiliary sway bar 44 and the other end of the rear auxiliary sway bar 46 are rotatably connected to the intermediate link 43 respectively, one end of the front auxiliary sway bar 44 is rotatably connected to the front main sway bar 45, one end of the rear auxiliary sway bar 46 is rotatably connected to the rear main sway bar 47, the other end of the main link 41 is rotatably connected to the rear auxiliary sway bar 46, one end of the main link 41 is rotatably connected to one end of the front main sway bar 45, the other end of the auxiliary link 42 is rotatably connected to the main link 41, and one end of the auxiliary link 42 is rotatably connected to the front auxiliary sway bar 44. Since the other ends of the front auxiliary sway bar 44 and the other ends of the rear auxiliary sway bar 46 are respectively rotatably connected to the intermediate link 43, the other end of the main link 41 is rotatably connected to the rear auxiliary sway bar 46, one end of the main link 41 is rotatably connected to one end of the front main sway bar 45, and one end of the front auxiliary sway bar 44 is rotatably connected to the front main sway bar 45, the intermediate link 43, the front auxiliary sway bar 44, the rear auxiliary sway bar 46 and the main link 41 form a kinematic structure similar to a quadrilateral; as is well known, the quadrilateral structure has a kinematic structure. The disadvantage of uncertain posture, therefore, the swing mechanism 4 controls the movement posture of the front main swing bar 45 and the front auxiliary swing bar 44 through the auxiliary link 42 (the other end of the auxiliary link 42 is rotatably connected to the main link 41, and one end of the auxiliary link 42 is rotatably connected to the front auxiliary swing bar 44), and then controls the movement posture of the rear main swing bar 47 and the rear auxiliary swing bar 46; wherein, one end of the auxiliary link 42 mainly controls the movement posture of the front auxiliary swing bar 44, and one end of the main link 41 mainly controls the movement posture of the front main swing bar 45. The auxiliary link 42 is used to increase the deformation resistance of the front auxiliary swing bar 44. When the auxiliary link 42 is set at the front auxiliary swing bar 44, in order to avoid interference between the auxiliary link 42 and the main link 41 and the front main swing bar 45, the front main swing bar 45 needs to be lengthened to realize the rotation connection of one end of the auxiliary link 42 with the middle upper position of the front auxiliary swing bar 44. When the mechanical extension structure 100 is transformed from the lying position to the sitting position, the seat cushion structure 300 moves forward and upward, and the serpentine spring of the seat cushion structure 300 bends upward. Therefore, the seat cushion structure 300 has enough space for the front main swing rod 45 to be lengthened. In other words, one end of the secondary connecting rod 42 is rotatably connected to the middle upper position of the front secondary swing rod, which can avoid interference between the swing mechanism 4 and the seat cushion structure 300.

[0124] like Figure 3As shown, when the first swing mechanism 4 is adopted, the mechanical extension structure 100 also includes two sitting posture supporting mechanisms 311. When the mechanical extension structure 100 is in the sitting position, the other end of the front main swing arm 45 is located in front of the other end of the front auxiliary swing arm 44, and the other end of the rear main swing arm 47 is located in front of the other end of the rear auxiliary swing arm 46. One of the sitting posture supporting mechanisms 311 is located below the front main swing arm 45 and abuts against the front main swing arm 45, and the other sitting posture supporting mechanism 311 is located below the rear main swing arm 47 and abuts against the rear main swing arm 47; when the mechanical extension structure 100 is in the lying position, the other end of the front main swing arm 45 is located behind the other end of the front auxiliary swing arm 44, and the other end of the rear main swing arm 47 is located behind the other end of the rear auxiliary swing arm 46, and the front main swing arm 45 and the rear main swing arm 47 are separated from their respective corresponding sitting posture supporting mechanisms 311.

[0125] When the mechanical extension structure 100 is in a lying position, the other end of the front main rocker arm 45 is located behind the other end of the front auxiliary rocker arm 44, and the other end of the rear main rocker arm 47 is located behind the other end of the rear auxiliary rocker arm 46. One of the sitting support mechanisms 311 is separated from the front main rocker arm 45, and the other sitting support mechanism 311 is separated from the rear main rocker arm 47.

[0126] The user usually adjusts the mechanical extension structure 100 of the seat unit to a lying position during recreation time, and the seat unit is in a sitting position most of the time. Therefore, the mechanical extension structure 100 can provide more stable support for the swing mechanism 4 through the two sitting support mechanisms 311.

[0127] like Figure 3 As shown, the front main rocker arm 45 is provided with a front sitting posture limit groove 451 which is recessed inwardly, and the rear main rocker arm 47 is provided with a rear sitting posture limit groove 471 which is recessed inwardly. When the mechanical extension structure 100 is in the sitting position, one of the sitting posture support mechanisms 311 is inserted into the front sitting posture limit groove 451 and abuts against the groove wall of the front sitting posture limit groove 451; the other sitting posture support mechanism 311 is inserted into the rear sitting posture limit groove 471 and abuts against the groove wall of the rear sitting posture limit groove 471.

[0128] After the swing mechanism 4 is damaged, the front sitting position limiting groove 451 limits the movement of one of the sitting position supporting mechanisms 311, and the rear sitting position limiting groove 471 limits the movement of the other sitting position supporting mechanism 311, thereby preventing the swing mechanism 4 from collapsing relative to the base 3. Therefore, the provision of the front sitting position limiting groove 451 and the rear sitting position limiting groove 471 is equivalent to providing an anti-deformation "stuck" structure for the swing mechanism 4 to a certain extent, so as to further prevent the seat cushion structure 300 from moving relative to the armrest structure when the user sits on the seat cushion structure 300.

[0129] In other embodiments, the first swing mechanism is adopted, and the mechanical extension structure further includes a sitting posture support mechanism. When the mechanical extension structure is in the sitting position, the other end of the front main swing rod is located in front of the other end of the front auxiliary swing rod, the other end of the rear main swing rod is located in front of the other end of the rear auxiliary swing rod, and the sitting posture support mechanism is located below the front main swing rod and abuts against the front main swing rod; when the mechanical extension structure is in the lying position, the other end of the front main swing rod is located behind the other end of the front auxiliary swing rod, the other end of the rear main swing rod is located behind the other end of the rear auxiliary swing rod, and the sitting posture support mechanism is separated from the front main swing rod;

[0130] Or, when the mechanical extension structure is in a sitting position, the other end of the front main rocker arm is located in front of the other end of the front auxiliary rocker arm, the other end of the rear main rocker arm is located in front of the other end of the rear auxiliary rocker arm, and the sitting posture support mechanism is located below the rear main rocker arm and abuts against the rear main rocker arm; when the mechanical extension structure is in a lying position, the other end of the front main rocker arm is located behind the other end of the front auxiliary rocker arm, the other end of the rear main rocker arm is located behind the other end of the rear auxiliary rocker arm, and the sitting posture support mechanism is separated from the rear main rocker arm.

[0131] like Figure 5 As shown, when the second swing mechanism 4 is adopted, the mechanical extension structure 100 also includes a sitting posture supporting mechanism 311. When the mechanical extension structure 100 is in the sitting position, the other end of the front main swing arm 45 is located in front of the other end of the front auxiliary swing arm 44, the other end of the rear main swing arm 47 is located in front of the other end of the rear auxiliary swing arm 46, and the sitting posture supporting mechanism 311 is located below the main connecting rod 41 and abuts against the auxiliary connecting rod 42; when the mechanical extension structure 100 is in the lying position, the other end of the front main swing arm 45 is located behind the other end of the front auxiliary swing arm 44, the other end of the rear main swing arm 47 is located behind the other end of the rear auxiliary swing arm 46, and the sitting posture supporting mechanism 311 is separated from the auxiliary connecting rod 42.

[0132] In other embodiments, a second swing mechanism is adopted, and the mechanical extension structure also includes a sitting posture support mechanism. When the mechanical extension structure is in a sitting position, the other end of the front main swing arm is located in front of the other end of the front auxiliary swing arm, the other end of the rear main swing arm is located in front of the other end of the rear auxiliary swing arm, and the sitting posture support mechanism is located below the main connecting rod and abuts against the main connecting rod; when the mechanical extension structure is in a lying position, the other end of the front main swing arm is located behind the other end of the front auxiliary swing arm, the other end of the rear main swing arm is located behind the other end of the rear auxiliary swing arm, and the sitting posture support mechanism is separated from the main connecting rod.

[0133] like Figure 2As shown, the mechanical extension structure 100 also includes a lying position support mechanism 12, which is fixedly connected to the base 1. When the mechanical extension structure 100 is in a lying position, the lying position support mechanism 12 is located above the rear support rod 49 and the lying position support mechanism 12 abuts against the rear support rod 49; when the mechanical extension structure 100 is in a sitting position, the lying position support mechanism 12 is separated from the rear support rod 49.

[0134] In other embodiments, the mechanical extension structure includes a lying position support mechanism, when the mechanical extension structure is in the lying position, the lying position support mechanism is located above the front support rod and the lying position support mechanism abuts the front support rod; when the mechanical extension structure is in the sitting position, the lying position support mechanism is separated from the front support rod; or, the mechanical extension structure includes two lying position support mechanisms, the two lying position support mechanisms are fixedly connected to the base, when the mechanical extension structure is in the lying position, one of the lying position support mechanisms is located above the front support rod and the lying position support mechanism abuts the front support rod, and the other lying position support mechanism is located above the rear support rod and the lying position support mechanism abuts the rear support rod; when the mechanical extension structure is in the sitting position, one of the lying position support mechanisms is separated from the front support rod, and the other lying position support mechanism is separated from the rear support rod; the swing mechanism supports the base through the two lying position support mechanisms to reduce the probability of the base shaking.

[0135] like Figure 4 As shown, taking the upper end surface of the base 1 as the reference plane, the rotation connection between the other end of the front support rod 48 and the intermediate link 43 is located above the rotation connection between the other end of the front auxiliary rocker arm 44 and the intermediate link 43, the rotation connection between the other end of the rear support rod 49 and the intermediate link 43 is located above the rotation connection between the other end of the rear auxiliary rocker arm 46 and the intermediate link 43, and the rotation connection between the other end of the front support rod 48 and the intermediate link 43 is located above the rotation connection between the other end of the rear support rod 49 and the intermediate link 43.

[0136] When the user's buttocks sit on the seat cushion structure 300 and the mechanical extension structure 100 is in a sitting position, the seat cushion structure 300 provides a downward force to the front support rod 48 through the base 1. Since the rotation connection between the other end of the front support rod 48 and the middle link 43 is located above the rotation connection between the other end of the front auxiliary swing rod 44 and the middle link 43, the "rotation connection between the other end of the front support rod 48 and the middle link 43" applies a downward thrust to the "rotation connection between the other end of the front auxiliary swing rod 44 and the middle link 43" to achieve the front auxiliary swing rod 44 pulling the front main swing rod 45 downward to abut against the sitting support mechanism 311. This structure further improves the reliability of the sitting support mechanism 311 supporting the swing mechanism 4.

[0137] When the user's buttocks sit on the seat cushion structure 300 and the mechanical extension structure 100 is in a sitting position, the seat cushion structure 300 provides a downward force to the rear support rod 49 through the base 1. Since the rotation connection between the other end of the rear support rod 49 and the middle link 43 is located above the rotation connection between the other end of the rear auxiliary swing rod 46 and the middle link 43, the "rotation connection between the other end of the rear support rod 49 and the middle link 43" applies a downward thrust to the "rotation connection between the other end of the rear auxiliary swing rod 46 and the middle link 43" to achieve the rear auxiliary swing rod 46 pulling the rear main swing rod 47 downward to abut against the sitting support mechanism 311. This structure further improves the reliability of the sitting support mechanism 311 supporting the swing mechanism 4.

[0138] In this embodiment, the rotation connection between the other end of the front support rod 48 and the intermediate connecting rod 43 is located above the rotation connection between the other end of the rear support rod 49 and the intermediate connecting rod 43. Figure 4 As shown, "the rotation connection between the other end of the front support rod 48 and the middle connecting rod 43" is slightly higher than "the rotation connection between the other end of the rear support rod 49 and the middle connecting rod 43". Therefore, the swing mechanism 4 slightly raises the height of the front side of the base 1, that is, raises the height of the user's legs, so that the user has a feeling of his buttocks sinking into the seat unit and leaning back slightly.

[0139] Preferably, a first reinforcing rib (not marked) is provided on the front auxiliary sway bar 44 ; and / or a second reinforcing rib (not marked) is provided on the rear auxiliary sway bar 46 .

[0140] The middle link 43 provides a downward pulling force for the front main rocker 45 through the front secondary rocker 44, therefore, the first reinforcing rib is used to increase the deformation resistance of the front secondary rocker 44; the middle link 43 provides a downward pulling force for the rear main rocker 47 through the rear secondary rocker 46, therefore, the second reinforcing rib is used to increase the deformation resistance of the rear secondary rocker 46.

[0141] More preferably, when the front auxiliary rocker arm 44 is provided with a first reinforcing rib, the sitting posture support mechanism 311 is located on one side of the front auxiliary rocker arm 44, and the first reinforcing rib is located on the other side of the front auxiliary rocker arm 44; when the rear auxiliary rocker arm 46 is provided with a second reinforcing rib, the sitting posture support mechanism 311 is located on one side of the rear auxiliary rocker arm 46, and the first reinforcing rib is located on the other side of the rear auxiliary rocker arm 46.

[0142] When the sitting posture support mechanism 311 is located on one side of the front auxiliary rocker arm 44 and the first reinforcement rib is located on the other side of the front auxiliary rocker arm 44, the first reinforcement rib will not interfere with the sitting posture support mechanism 311 during the movement of the front auxiliary rocker arm 44; when the sitting posture support mechanism 311 is located on one side of the rear auxiliary rocker arm 46 and the first reinforcement rib is located on the other side of the rear auxiliary rocker arm 46, the second reinforcement rib will not interfere with the sitting posture support mechanism 311 during the movement of the rear auxiliary rocker arm 46.

[0143] like Figure 2 As shown, the base 1 is provided with a third reinforcing rib 13 , which is located between a rotation connection between one end of the front support rod 48 and the base 1 and a rotation connection between the rear support rod 49 and the base 1 .

[0144] The front support rod 48 and the rear support rod 49 need to provide tension for the base 1 for a long time, therefore, adding a third reinforcing rib 13 between the two can effectively increase the service life of the base 1.

[0145] Preferably, a fourth reinforcing rib (not marked) is provided on the front main swing arm 45 ; and / or, a fifth reinforcing rib (not marked) is provided on the rear main swing arm 47 .

[0146] When the mechanical extension structure 100 is in the sitting position, the sitting support mechanism 311 abuts against the front main swing arm 45; therefore, providing the fourth reinforcing rib on the front main swing arm 45 can increase the deformation resistance of the front main swing arm 45 to increase the service life of the seat unit.

[0147] When the mechanical extension structure 100 is in the sitting position, the sitting support mechanism 311 abuts against the rear main swing arm 47; therefore, providing the fifth reinforcing rib on the rear main swing arm 47 can increase the deformation resistance of the rear main swing arm 47 to increase the service life of the seat unit.

[0148] In this embodiment, the third structure of the swing mechanism 4 includes a front support rod 48 and a rear support rod 49, one end of the front support rod 48 and one end of the rear support rod 49 are respectively rotatably connected to the base 1, and the other end of the front support rod 48 and the other end of the rear support rod 49 are respectively rotatably connected to the base 3;

[0149] The mechanical extension structure 100 also includes at least one sitting support mechanism 311. When the mechanical extension structure 100 is in a sitting position, the sitting support mechanism 311 is located below the front support rod 48 and abuts against the front support rod 48; and / or the sitting support mechanism 311 is located below the rear support rod 49 and abuts against the rear support rod 49; when the mechanical extension structure 100 is in a lying position, the sitting support mechanism 311 is separated from the front support rod 48 and the rear support rod 49.

[0150] Preferably, when the third swing mechanism 4 is adopted, the mechanical extension structure 100 includes two sitting posture support mechanisms 311. When one of the sitting posture support mechanisms 311 is located below the front support rod 48 and the sitting posture support mechanism 311 abuts against the front support rod 48, one of the sitting posture support mechanisms 311 provides support force for the base 1 through the front support rod 48; when the other sitting posture support mechanism 311 is located below the rear support rod 49 and the sitting posture support mechanism 311 abuts against the rear support rod 49, the other sitting posture support mechanism 311 provides support force for the base 1 through the rear support rod 49. When the front support rod 48 cannot rotate relative to the base 3 and the rear support rod 49 cannot rotate relative to the base 3, the position of the base 1 is also fixed, which will prevent the seat cushion structure 300 from moving relative to the armrest structure when the user sits on the seat cushion structure 300.

[0151] like Figure 2 As shown, the base 3 includes two armrest plates 31 and a crossbeam tube 32, and the two armrest plates 31 are directly or indirectly connected as a whole through the crossbeam tube 32; the first rocker mechanism 4, the second rocker structure 4: the front main rocker 45 and the rear main rocker 47 are rotatably connected to the armrest plates 31 respectively, and the armrest plates 31 are fixedly connected to the armrest structure; the third rocker structure 4: the other end of the support rod 48 and the other end of the rear support rod 49 are rotatably connected to the armrest plates 31 respectively.

[0152] In other embodiments, the base includes a metal frame, such as a concave metal frame, an I-shaped metal frame, a quadrilateral metal frame, an elliptical metal frame, a hexagonal metal frame, etc.; the first rocker arm mechanism, the second rocker arm structure: the front main rocker arm and the rear main rocker arm are respectively rotatably connected to the annular metal frame, and the annular metal frame is fixedly connected to the armrest structure; the third rocker arm structure: the other end of the support rod and the other end of the rear support rod are respectively rotatably connected to the annular metal frame.

[0153] like Figure 6 As shown, the first structure of the backrest assembly 2 includes a backrest plate 21, a backrest front bracket 22, a backrest rear bracket 23 and a backrest driving rod 24, one end of the backrest front bracket 22 is rotatably connected to the backrest plate 21, the other end of the backrest front bracket 22 is rotatably connected to the base 1, one end of the backrest rear bracket 23 is rotatably connected to the backrest plate 21, the backrest rear bracket 23 is rotatably connected to the base 1, one end of the backrest driving rod 24 is rotatably connected to the other end of the backrest rear bracket 23, and the other end of the backrest driving rod 24 is rotatably connected to the base 3;

[0154] During the transformation of the mechanical extension structure 100 from the sitting position to the lying position, the backrest plate 21 moves forward.

[0155] In this embodiment, the second structure of the backrest assembly 2 includes a backrest plate 21, a front backrest bracket 22, a backrest bracket 23 and a backrest driving rod 24, one end of the front backrest bracket 22 is rotatably connected to the backrest plate 21, the other end of the front backrest bracket 22 is fixedly connected to the base 1, one end of the backrest bracket 23 is rotatably connected to the backrest plate 21, the backrest bracket 23 is rotatably connected to the base 1, one end of the backrest driving rod 24 is rotatably connected to the other end of the backrest bracket 23, and the other end of the backrest driving rod 24 is rotatably connected to the base 3;

[0156] During the transformation of the mechanical extension structure 100 from the sitting position to the lying position, the backrest plate 21 moves forward.

[0157] like Figure 7 As shown, the third structure of the backrest assembly 2 includes a backrest plate 21, a backrest front bracket 22, a backrest back bracket 23, a backrest connecting bracket 25 and a backrest driving rod 24, one end of the backrest front bracket 22 is rotatably connected to the backrest plate 21, the other end of the backrest front bracket 22 is fixedly connected to the base 1, one end of the backrest back bracket 23 is rotatably connected to the backrest plate 21, the other end of the backrest back bracket 23 is rotatably connected to one end of the backrest connecting bracket 25, the backrest connecting bracket 25 is rotatably connected to the base 1, one end of the backrest driving rod 24 is rotatably connected to the other end of the backrest connecting bracket 25, and the other end of the backrest driving rod 24 is rotatably connected to the base 3;

[0158] During the transformation of the mechanical extension structure 100 from the sitting position to the lying position, the backrest plate 21 moves forward.

[0159] Three types of backrest components 2 are used for different seat units: the first type of backrest component 2 is mainly used for seat units with zero wall leaning and zero back rubbing (in the process of the mechanical extension structure 100 changing from a sitting position to a lying position, the front backrest bracket 22 drives the backrest structure 200 to move relative to the seat cushion structure 300 through the backrest plate 21, so as to reduce the displacement difference between the backrest structure 200 and the user's back); the second type of backrest component 2 is mainly used to increase the reclining range of the backrest structure 200; the third type of backrest component 2 mainly slows down the reclining speed of the backrest structure 200 through the rear backrest bracket 23.

[0160] like Figure 2 As shown, the driving device 6 includes a driver 61, a driving rod 62 is provided on the driver 61, the driver 61 is rotatably connected to the base 3, and the leg assembly 5 is rotatably connected to the driving rod 62. In other embodiments, the driving device includes a driver, a screw and a push block, the driver is fixedly connected to the base, the driver is provided with a driving rod fixedly connected to the screw, the push block is threadedly connected to the screw, and the leg assembly is directly or indirectly rotatably connected to the push block.

[0161] The seat unit comprises an armrest structure, a backrest structure 200, a seat cushion structure 300, a leg rest structure (not marked) and a mechanical extension structure 100, wherein the mechanical extension structure 100 comprises the mechanical extension structure described in this embodiment, the base 3 is fixedly connected to the armrest structure, the backrest assembly 2 is fixedly connected to the backrest structure 200, the leg rest structure is fixedly connected to the leg assembly 5, and the seat cushion structure 300 is fixedly connected to the base 1;

[0162] The backrest structure 200 is provided with a ventilation structure and / or a heating structure.

[0163] like Figure 1 As shown, the backrest structure 200 includes a backrest frame 2001, a backrest filler 2003, a backrest decorative cover 2004, and a backrest elastic member 2002. A backrest cavity (not marked) is provided on the backrest frame 2001. A mounting member (not marked) is provided on the wall of the backrest cavity of the backrest frame 2001. The backrest elastic member 2002 is provided on the backrest frame 2001. The backrest filler 2003 is provided on the backrest decorative cover 2004. The backrest decorative cover 2004 is provided on the backrest frame 2001. When the backrest decorative cover 2004 is provided on the backrest frame 2001, the backrest elastic member 2002 abuts against the backrest filler 2003 and / or the backrest decorative cover 2004, and provides elastic support force for the backrest filler 2003.

[0164] like Figure 1 As shown, the seat cushion structure 300 includes a seat cushion frame 3001, a seat cushion filler 3003, a seat cushion decorative cover 3004, and a seat cushion elastic member 3002. The seat cushion elastic member 3002 is arranged on the seat cushion frame 3001, the seat cushion filler 3003 is arranged on the seat cushion decorative cover 3004, and the seat cushion decorative cover 3004 is arranged on the seat cushion frame 3001. When the seat cushion decorative cover 3004 is arranged on the seat cushion frame 3001, the seat cushion elastic member 3002 abuts against the seat cushion filler 3003 and / or the seat cushion decorative cover 3004, and provides elastic supporting force for the seat cushion filler 3003.

[0165] In this embodiment, the ventilation structure is used to supply air to the user's back, and the heating structure is used to heat the user's back; since the utility model does not improve the ventilation structure and the heating structure, the ventilation structure and the heating structure will not be described in detail.

[0166] Preferably, the seat cushion structure 300 is also provided with a ventilation structure and / or a heating structure.

[0167] In this embodiment, the upper, lower, front and rear positions of the seat unit are Figure 1 The direction indicated by the arrow is the standard.

[0168] The above is only an explanation of the best embodiment of the utility model, which cannot be understood as a limitation of the claims. The utility model is not limited to the above embodiments, and all changes made within the protection scope of the independent claims of the utility model are within the protection scope of the utility model.

Claims

1. A mechanical extension structure, comprising a base, two bases for mounting a cushion structure, two groups of leg assemblies for mounting a legrest structure, two groups of backrest assemblies for mounting a backrest structure, two groups of swing mechanisms and a driving device, wherein the driving device is arranged at the base, each group of leg assemblies is rotatably connected to a base, each base is movably connected to the base via a group of swing mechanisms, and each base is also connected to the base via a group of backrest assemblies; The mechanical extension structure has a sitting position and a lying position. When the mechanical extension structure changes from the sitting position to the lying position, the driving device drives the base and the swing mechanism to move forward through the leg assembly, and the leg assembly is extended in front of the base; when the mechanical extension structure changes from the lying position to the sitting position, the driving device drives the base and the swing mechanism to move backward through the leg assembly, and the leg assembly is folded under the base, characterized in that: The mechanical extension structure further comprises at least one sitting support mechanism, the sitting support mechanism being fixedly connected to the base, and the sitting support mechanism supporting the swing mechanism when the mechanical extension structure is in the sitting position; When the mechanical extension structure is in the lying position, the sitting support mechanism is separated from the swing mechanism.

2. The mechanical extension structure according to claim 1, characterized in that: The sitting posture support mechanism includes a sitting posture support rod. The hardness of the sitting posture support rod is different from that of the swinging mechanism. The sitting posture support rod is fixedly connected to the base. When the mechanical extension structure is in the sitting position, the sitting posture support rod is located below the swinging mechanism, and the sitting posture support rod abuts against the swinging mechanism. When the mechanical extension structure is in the lying position, the sitting posture support rod is separated from the swinging mechanism.

3. The mechanical extension structure according to claim 1, characterized in that: The sitting posture support mechanism includes a sitting posture support rod and a sitting posture support ring. The hardness of the sitting posture support ring is different from that of the swinging mechanism. The sitting posture support ring is sleeved on the sitting posture support rod. The sitting posture support rod is detachably arranged on the base. When the mechanical extension structure is in the sitting position, the sitting posture support ring is located below the swinging mechanism, and the sitting posture support ring abuts against the swinging mechanism. When the mechanical extension structure is in the lying position, the sitting posture support ring is separated from the swinging mechanism.

4. The mechanical extension structure according to claim 1, characterized in that: The mechanical extension structure also includes at least one lying support mechanism, which is fixedly connected to the base. When the mechanical extension structure is in a sitting position, the lying support mechanism is separated from the swing mechanism; when the mechanical extension structure is in a lying position, the swing mechanism supports the lying support mechanism.

5. The mechanical extension structure according to claim 4, characterized in that: The lying position support mechanism includes a lying position support rod. The hardness of the lying position support rod is different from that of the swinging mechanism. The lying position support rod is fixedly connected to the base. When the mechanical extension structure is in the sitting position, the lying position support rod is separated from the swinging mechanism; when the mechanical extension structure is in the lying position, the lying position support rod is located above the swinging mechanism, and the lying position support rod abuts against the swinging mechanism.

6. The mechanical expansion structure according to claim 4, characterized in that: The lying posture support mechanism includes a lying posture support rod and a lying posture support ring. The hardness of the lying posture support ring is different from that of the swinging mechanism. The lying posture support ring is sleeved on the lying posture support rod. The lying posture support rod is detachably arranged on the base. When the mechanical extension structure is in the sitting position, the lying posture support ring is separated from the swinging mechanism; when the mechanical extension structure is in the lying position, the lying posture support ring is located above the swinging mechanism, and the lying posture support ring abuts against the swinging mechanism.

7. The mechanical expansion structure according to claim 4, characterized in that: The mechanical extension structure also has a TV posture position. When the mechanical extension structure is in the TV posture position, the leg assembly extends in front of the base, the sitting support mechanism is located below the swing mechanism, the sitting support mechanism abuts the swing mechanism, and the lying support mechanism is separated from the swing mechanism.

8. The mechanical expansion structure according to claim 7, characterized in that: The mechanical extension structure also includes a tension spring, a hook is provided at the end of the tension spring, and a flexible silencer is provided on the outer wall of the hook. The hardness of the flexible silencer is less than the hardness of the hook. One end of the tension spring is hung on the swing mechanism through the hook, and the other end of the tension spring is hung on the base through the hook. When one end of the tension spring is hung on the swing mechanism through the hook and the other end of the tension spring is hung on the base through the hook, a flexible silencer is clamped between the hook at one end of the tension spring and the swing mechanism, and a flexible silencer is clamped between the hook at the other end of the tension spring and the base.

9. The mechanical expansion structure according to claim 7, characterized in that: The mechanical extension structure also includes a tension spring, a hook is provided at the end of the tension spring, and a flexible silencer is provided on the outer wall of the hook. The hardness of the flexible silencer is less than the hardness of the hook. One end of the tension spring is hung on the swing mechanism through the hook, and the other end of the tension spring is hung on the backrest assembly through the hook. When one end of the tension spring is hung on the swing mechanism through the hook and the other end of the tension spring is hung on the backrest assembly through the hook, a flexible silencer is clamped between the hook at one end of the tension spring and the swing mechanism, and a flexible silencer is clamped between the hook at the other end of the tension spring and the backrest assembly.

10. The mechanical expansion structure according to claim 8 or 9, characterized in that: When the mechanical extension structure is in a sitting position, the tension spring undergoes elastic deformation and is in a stretched state; when the mechanical extension structure is in a lying position, the tension spring undergoes elastic deformation and is in a stretched state; the axial length of the tension spring in the lying position is greater than the axial length of the tension spring in the sitting position.

11. The mechanical expansion structure according to claim 10, characterized in that: When the mechanical extension structure is in the TV posture position, the tension spring does not undergo elastic deformation; the axial length of the tension spring in the lying position is greater than the axial length of the tension spring in the sitting position and greater than the axial length of the tension spring in the TV posture position.

12. The mechanical expansion structure according to claim 1, characterized in that: The swing mechanism includes a main connecting rod, a secondary connecting rod, an intermediate connecting rod, a front main swing rod, a front secondary swing rod, a rear main swing rod, a rear secondary swing rod, a front supporting rod and a rear supporting rod, one end of the front supporting rod and one end of the rear supporting rod are rotatably connected to the base respectively, the other end of the front supporting rod and the other end of the rear supporting rod are rotatably connected to the intermediate connecting rod respectively, the other end of the front main swing rod and the other end of the rear main swing rod are rotatably connected to the base respectively, the other end of the front secondary swing rod and the other end of the rear secondary swing rod are rotatably connected to the intermediate connecting rod respectively, one end of the front secondary swing rod is rotatably connected to the front main swing rod, one end of the rear secondary swing rod is rotatably connected to the rear main swing rod, one end of the main connecting rod is rotatably connected to one end of the front main swing rod, the other end of the main connecting rod is rotatably connected to the rear main swing rod, one end of the secondary connecting rod is rotatably connected to the main connecting rod, and the other end of the secondary connecting rod is rotatably connected to the rear secondary swing rod.

13. The mechanical expansion structure according to claim 1, characterized in that: The swing mechanism includes a main connecting rod, a secondary connecting rod, an intermediate connecting rod, a front main swing rod, a front secondary swing rod, a rear main swing rod, a rear secondary swing rod, a front supporting rod and a rear supporting rod, one end of the front supporting rod and one end of the rear supporting rod are rotatably connected to the base respectively, the other end of the front supporting rod and the other end of the rear supporting rod are rotatably connected to the intermediate connecting rod respectively, the other end of the front main swing rod and the other end of the rear main swing rod are rotatably connected to the base respectively, the other end of the front secondary swing rod and the other end of the rear secondary swing rod are rotatably connected to the intermediate connecting rod respectively, one end of the front secondary swing rod is rotatably connected to the front main swing rod, one end of the rear secondary swing rod is rotatably connected to the rear main swing rod, the other end of the main connecting rod is rotatably connected to the rear secondary swing rod, one end of the main connecting rod is rotatably connected to one end of the front main swing rod, the other end of the secondary connecting rod is rotatably connected to the main connecting rod, and one end of the secondary connecting rod is rotatably connected to the front secondary swing rod.

14. The mechanical expansion structure according to claim 12 or 13, characterized in that: The mechanical extension structure also includes two sitting posture support mechanisms. When the mechanical extension structure is in a sitting position, the other end of the front main rocker arm is located in front of the other end of the front auxiliary rocker arm, and the other end of the rear main rocker arm is located in front of the other end of the rear auxiliary rocker arm. One of the sitting posture support mechanisms is located below the front main rocker arm and the sitting posture support mechanism abuts against the front main rocker arm, and the other sitting posture support mechanism is located below the rear main rocker arm and the sitting posture support mechanism abuts against the rear main rocker arm. When the mechanical extension structure is in a lying position, the other end of the front main rocker arm is located behind the other end of the front auxiliary rocker arm, and the other end of the rear main rocker arm is located behind the other end of the rear auxiliary rocker arm. The front main rocker arm and the rear main rocker arm are both separated from their corresponding sitting posture support mechanisms.

15. The mechanical expansion structure according to claim 14, characterized in that: An inwardly recessed sitting posture limiting groove is provided on the front main swing arm and / or the rear main swing arm. When the mechanical extension structure is in the sitting posture position, the sitting posture supporting mechanism is inserted into the sitting posture limiting groove and abuts against the groove wall of the sitting posture limiting groove.

16. The mechanical expansion structure according to claim 12 or 13, characterized in that: The mechanical extension structure also includes a sitting posture support mechanism. When the mechanical extension structure is in the sitting position, the other end of the front main swing rod is located in front of the other end of the front auxiliary swing rod, the other end of the rear main swing rod is located in front of the other end of the rear auxiliary swing rod, and the sitting posture support mechanism is located below the front main swing rod and abuts against the front main swing rod; when the mechanical extension structure is in the lying position, the other end of the front main swing rod is located behind the other end of the front auxiliary swing rod, the other end of the rear main swing rod is located behind the other end of the rear auxiliary swing rod, and the sitting posture support mechanism is separated from the front main swing rod; Or, when the mechanical extension structure is in the sitting position, the other end of the front main swing rod is located in front of the other end of the front auxiliary swing rod, the other end of the rear main swing rod is located in front of the other end of the rear auxiliary swing rod, the sitting posture support mechanism is located below the rear main swing rod, and the sitting posture support mechanism abuts against the rear main swing rod; when the mechanical extension structure is in the lying position, the other end of the front main swing rod is located behind the other end of the front auxiliary swing rod, the other end of the rear main swing rod is located behind the other end of the rear auxiliary swing rod, and the sitting posture support mechanism is separated from the rear main swing rod; Or, when the mechanical extension structure is in the sitting position, the other end of the front main swing rod is located in front of the other end of the front auxiliary swing rod, the other end of the rear main swing rod is located in front of the other end of the rear auxiliary swing rod, the sitting posture support mechanism is located below the main connecting rod, and the sitting posture support mechanism abuts against the main connecting rod; when the mechanical extension structure is in the lying position, the other end of the front main swing rod is located behind the other end of the front auxiliary swing rod, the other end of the rear main swing rod is located behind the other end of the rear auxiliary swing rod, and the sitting posture support mechanism is separated from the main connecting rod; Or, when the mechanical extension structure is in a sitting position, the other end of the front main rocker arm is located in front of the other end of the front auxiliary rocker arm, the other end of the rear main rocker arm is located in front of the other end of the rear auxiliary rocker arm, the sitting posture support mechanism is located below the main connecting rod and the sitting posture support mechanism abuts against the auxiliary connecting rod; when the mechanical extension structure is in a lying position, the other end of the front main rocker arm is located behind the other end of the front auxiliary rocker arm, the other end of the rear main rocker arm is located behind the other end of the rear auxiliary rocker arm, and the sitting posture support mechanism is separated from the auxiliary connecting rod.

17. The mechanical expansion structure according to claim 12 or 13, characterized in that: The mechanical extension structure also includes a lying support mechanism, which is fixedly connected to the base. When the mechanical extension structure is in a lying position, the lying support mechanism is located above the front support rod and abuts against the front support rod; when the mechanical extension structure is in a sitting position, the lying support mechanism is separated from the front support rod; Or, when the mechanical extension structure is in the lying position, the lying support mechanism is located above the rear support rod and the lying support mechanism abuts against the rear support rod; when the mechanical extension structure is in the sitting position, the lying support mechanism is separated from the rear support rod.

18. The mechanical expansion structure according to claim 12 or 13, characterized in that: The rotation connection between the other end of the front support rod and the middle link is located above the rotation connection between the other end of the front auxiliary swing rod and the middle link, the rotation connection between the other end of the rear support rod and the middle link is located above the rotation connection between the other end of the rear auxiliary swing rod and the middle link, and the rotation connection between the other end of the front support rod and the middle link is located above the rotation connection between the other end of the rear support rod and the middle link.

19. The mechanical expansion structure according to claim 18, characterized in that The front auxiliary swing arm is provided with a first reinforcing rib; and / or the rear auxiliary swing arm is provided with a second reinforcing rib.

20. The mechanical expansion structure according to claim 19, characterized in that When the first reinforcing rib is provided on the front auxiliary sway bar, the sitting posture support mechanism is located on one side of the front auxiliary sway bar, and the first reinforcing rib is located on the other side of the front auxiliary sway bar; when the second reinforcing rib is provided on the rear auxiliary sway bar, the sitting posture support mechanism is located on one side of the rear auxiliary sway bar, and the first reinforcing rib is located on the other side of the rear auxiliary sway bar.

21. The mechanical expansion structure according to claim 18, characterized in that The base is provided with a third reinforcing rib, and the third reinforcing rib is located between a rotation connection between one end of the front support rod and the base and a rotation connection between the rear support rod and the base.

22. The mechanical expansion structure according to claim 18, characterized in that A fourth reinforcing rib is provided on the front main swing arm; and / or a fifth reinforcing rib is provided on the rear main swing arm.

23. The mechanical expansion structure according to claim 1, characterized in that The swing mechanism includes a front support rod and a rear support rod, one end of the front support rod and one end of the rear support rod are respectively rotatably connected to the base, and the other end of the front support rod and the other end of the rear support rod are respectively rotatably connected to the base; The mechanical extension structure also includes at least one sitting support mechanism. When the mechanical extension structure is in a sitting position, the sitting support mechanism is located below the front support rod and abuts against the front support rod; and / or the sitting support mechanism is located below the rear support rod and abuts against the rear support rod; when the mechanical extension structure is in a lying position, the sitting support mechanism is separated from the front support rod and the rear support rod.

24. The mechanical expansion structure according to claim 1, characterized in that The backrest assembly includes a backrest plate, a front backrest bracket, a backrest bracket and a backrest driving rod, one end of the front backrest bracket is rotatably connected to the backrest plate, the other end of the front backrest bracket is rotatably connected to the base, one end of the backrest bracket is rotatably connected to the backrest plate, the backrest bracket is rotatably connected to the base, one end of the backrest driving rod is rotatably connected to the other end of the backrest bracket, and the other end of the backrest driving rod is rotatably connected to the base; During the mechanical extension from the sitting position to the lying position, the backrest moves forward.

25. The mechanical expansion structure according to claim 1, characterized in that The backrest assembly includes a backrest plate, a front backrest bracket, a backrest bracket and a backrest driving rod, one end of the front backrest bracket is rotatably connected to the backrest plate, the other end of the front backrest bracket is fixedly connected to the base, one end of the backrest bracket is rotatably connected to the backrest plate, the backrest bracket is rotatably connected to the base, one end of the backrest driving rod is rotatably connected to the other end of the backrest bracket, and the other end of the backrest driving rod is rotatably connected to the base; During the mechanical extension from the sitting position to the lying position, the backrest moves forward.

26. The mechanical expansion structure according to claim 1, characterized in that The backrest assembly includes a backrest plate, a backrest front bracket, a backrest rear bracket, a backrest connecting bracket and a backrest driving rod, one end of the backrest front bracket is rotatably connected to the backrest plate, the other end of the backrest front bracket is fixedly connected to the base, one end of the backrest rear bracket is rotatably connected to the backrest plate, the other end of the backrest rear bracket is rotatably connected to one end of the backrest connecting bracket, the backrest connecting bracket is rotatably connected to the base, one end of the backrest driving rod is rotatably connected to the other end of the backrest connecting bracket, and the other end of the backrest driving rod is rotatably connected to the base; During the mechanical extension from the sitting position to the lying position, the backrest moves forward.

27. The mechanical expansion structure according to claim 1, characterized in that The driving device includes a driver, a screw and a push block. The driver is fixedly connected to the base, the driver is provided with a driving rod fixedly connected to the screw, the push block is threadedly connected to the screw, and the leg assembly is directly or indirectly connected to the push block; or, the driving device includes a driver, the driver is provided with a driving rod, the driver is connected to the base, and the leg assembly is connected to the driving rod.

28. A seat unit comprising an armrest structure, a backrest structure, a seat cushion structure, a leg rest structure and a mechanical extension structure, characterized in that: The mechanical extension structure includes the mechanical extension structure described in any one of claims 1-27, the base is fixedly connected to the armrest structure, the backrest assembly is fixedly connected to the backrest structure, the footrest structure is fixedly connected to the leg assembly, the seat cushion structure is fixedly connected to the base, and the backrest structure is provided with a ventilation structure and / or a heating structure.

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