Leg support structure of pure connecting rod automobile seat

Abstract

The invention belongs to the technical field of automobile seats. The problems that in the prior art, a leg support is complex in structure and poor in use reliability are solved. The leg support structure of the pure connecting rod automobile seat comprises a push rod and a connecting shaft hinged to the push rod, the two ends of the connecting shaft are fixedly connected with connecting plates respectively, a first connecting rod and a fourth connecting rod are hinged to the connecting plates respectively, and the first connecting rod and the connecting plates are arranged in a crossed mode and hinged to a second connecting rod. The second connecting rod and the connecting plate are hinged to the seat basin, the first connecting rod and the fourth connecting rod are hinged to the first leg support, and the connecting plate, the first connecting rod, the second connecting rod, the seat basin, the connecting plate, the first connecting rod, the fourth connecting rod and the first leg support form a four-connecting-rod structure. The end, hinged to the first leg support, of the first connecting rod is further provided with an arc-shaped extension section, and the extension section is hinged to the second leg support and can drive the second leg support to slide relative to the first leg support. The leg support has the advantages that the leg support structure can be simplified, and the use reliability is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of automobile seats and relates to a leg support structure of a pure connecting rod automobile seat. Background Art

[0002] The car seat leg rest is an adjustable device located at the front end of the seat. It is used to help increase the passenger's leg support area, fill the entire knee bend, reduce the discomfort caused by hanging legs, and reduce the impact of sitting for a long time on blood circulation. It can reduce leg pressure and disperse body weight during long-distance driving, thereby improving riding comfort. At the same time, by adjusting the position and / or angle of the leg rest, it can meet the needs of users of different heights and body shapes.

[0003] For example, a Chinese patent document discloses a leg rest adjustment mechanism and a car seat (application number: 202421695313.9), comprising: a leg rest assembly; the leg rest assembly comprising: a first leg rest and a second leg rest, the second leg rest being slidably connected to the first leg rest; and the first leg rest and the second leg rest being connected to a telescopic drive assembly to drive the second leg rest to extend and retract relative to the first leg rest; wherein the telescopic drive assembly comprises a telescopic drive member and a telescopic transmission structure, the telescopic drive member being connected to the first leg rest, the telescopic transmission structure being connected to the first leg rest and the second leg rest and capable of amplifying the driving stroke of the telescopic drive member. The telescopic transmission structure comprises: a first connecting rod and a second connecting rod, arranged crosswise and hinged at an intersection; wherein the first connecting rod and the second connecting rod each have a power end and a resistance end, the distance between the power end and the intersection being smaller than the distance between the resistance end and the intersection; the telescopic drive member is capable of driving the two power ends toward and away from each other, and the approach and separation of the two resistance ends can drive the second leg rest to extend and retract relative to the first leg rest.

[0004] The above-mentioned leg rest adjustment mechanism has the following deficiencies during use: the expansion (or folding) of the leg rest assembly of the leg rest adjustment mechanism and the sliding of the second leg rest relative to the first leg rest require two motors to be driven respectively through the transmission structure. The structure is complex, which is not conducive to the lightweight design of the seat. In addition, the space under the car seat is small, resulting in difficulties in installation and maintenance. At the same time, the leg rest adjustment mechanism has high requirements on the coordination of the two motors. Once the two motors do not coordinate well, it is easy to cause mechanical interference and affect the normal use of the leg rest. Summary of the Invention

[0005] The purpose of the present invention is to solve the above problems in the existing technology and propose a leg support structure for a pure connecting rod car seat. The technical problem to be solved by the present invention is how to simplify the leg support structure of the car seat and improve its reliability.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A leg support structure for a pure connecting rod car seat, the car seat includes a seat basin and a leg support assembly, the leg support assembly includes a first leg support and a second leg support slidably connected to the first leg support, characterized in that the leg support structure includes a push rod arranged along the front-to-back direction of the car seat and capable of moving forward and backward relative to the car seat, a connecting shaft hinged to the push rod is arranged between the seat basin and the leg support assembly along the left-right direction of the car seat, the two ends of the connecting shaft are respectively fixedly connected with a connecting plate, the connecting plates are respectively hinged with a first connecting rod and a fourth connecting rod, the first connecting rod and the connecting plate are cross-arranged and hinged with a fourth connecting rod Two connecting rods, and the second connecting rod and the connecting plate are both hinged to the seat basin at their ends facing the seat basin, the connecting plate, the first connecting rod, the second connecting rod and the seat basin form a four-link structure, the first connecting rod and the fourth connecting rod are both hinged to the first leg support at their ends facing the first leg support, the connecting plate, the first connecting rod, the fourth connecting rod and the first leg support also form a four-link structure, the end of the first connecting rod hinged to the first leg support also has an arc-shaped extension section, the extension section is hinged to the second leg support and can drive the second leg support to slide relative to the first leg support.

[0008] The leg support structure of this pure-link car seat only needs one push rod to move forward and backward along its axis when expanding and contracting. Specifically, when the leg support structure needs to be expanded, the push rod moves forward along its axis, and the push rod drives the double four-link structure forming a "scissor fork" to extend by pushing the connecting shaft. At the same time, when the first link is extended, its extended section can drive the second leg support to move synchronously, so as to realize the upward rotation of the leg support assembly as a whole relative to the seat basin and the forward sliding of the second leg support relative to the first leg support. When the leg support structure needs to be contracted, the push rod moves backward along its axis, and the push rod drives the double four-link structure forming a "scissor fork" to contract by dragging the connecting shaft. At the same time, when the first link is contracted, its extended section can drive the second leg support to move synchronously, so as to realize the leg support assembly The downward rotation of the entire component relative to the seat basin and the backward sliding of the second leg support relative to the first leg support, coupled with the fact that the push rod is arranged along the front and rear direction of the car seat and can move front and rear relative to the car seat, the distance the push rod moves back and forth is longer. On the one hand, it can realize the maximum expansion or contraction of the leg support assembly in the front and rear direction. On the other hand, the double four-link structure forming a "scissors fork" can realize the minimum distance change of the leg support assembly in the up and down directions. At the same time, the leg support structure adopts a single push rod and a pure connecting rod structure for transmission, and the structure is simple. At the same time, the connecting rod structure can withstand large impact loads and continuous loads. The wear after long-term use is mainly concentrated at the hinge of the rod. The replacement and maintenance are simple and convenient, and the reliability is high, thereby simplifying the leg support structure of the car seat and improving the reliability of use.

[0009] In the above-mentioned pure-link car seat leg support structure, the front ends of the two connecting plates are respectively hinged to the two first connecting brackets on the seat basin, the rear ends of the two connecting plates are respectively hinged to the two second connecting brackets on the first leg support via a fourth connecting rod, the upper ends of the two connecting plates are respectively hinged to the first connecting rod on the same side, the connecting plate, the first connecting rod, the second connecting rod, and the first connecting bracket are hinged to form a four-bar structure, the connecting plate, the first connecting rod, the fourth connecting rod, and the second connecting bracket are hinged to form a four-bar structure, and the extensions of the two first connecting rods are respectively hinged to the two third connecting brackets on the second leg support via a third connecting rod. By hingedly forming a "scissor fork" double four-bar structure with the connecting plate, the first connecting rod, the second connecting rod, and the first connecting bracket, and the connecting plate, the first connecting rod, the fourth connecting rod, and the second connecting bracket, the accuracy of the rotation of the leg support assembly as a whole relative to the seat basin and the sliding motion trajectory of the second leg support relative to the first leg support, as well as the reliability of the leg support structure, can be further improved.

[0010] In the aforementioned pure-link car seat leg rest structure, the first leg rest is in an inverted L-shaped configuration, with L-shaped mounting plates connected to both sides of the first leg rest. The second leg rest is located between the mounting plates and the first leg rest and is connected to an upper rail, which is connected to a lower rail. The upper rail is slidably mounted on the lower rail, thereby achieving an integrated design for the seat pan and leg rest assembly cover.

[0011] In the aforementioned pure-link car seat leg support structure, the second leg support further includes a clearance hole into which the hinged portions of the first and third links extend. The rear sides of both the first and second leg supports are curved downward. This prevents the hinged portions of the first and third links from interfering with the second leg support when the leg support structure is folded. Furthermore, the downwardly curved rear sides of both the first and second leg supports prevent wrinkles on the surface of the leg support assembly, thereby achieving a more visually seamless effect.

[0012] In the aforementioned pure-link car seat leg rest structure, the second leg rest is in an inverted L-shaped configuration, with L-shaped mounting plates connected to either side. The first leg rest is located between the mounting plates and the second leg rest and is connected to an upper rail, which is connected to a lower rail. The upper rail is slidably mounted on the lower rail. This allows for a split design (a seam effect is required between the seat cushion and leg rest components).

[0013] In the aforementioned pure-link car seat leg support structure, a mounting tube is fixedly connected between the two first connecting brackets. A motor for driving the push rod to move forward and backward relative to the car seat is mounted on the mounting tube. The hinge points of the connecting plate and the second connecting rod on the same side with the first connecting bracket are located on either side of the mounting tube. The mounting tube not only facilitates the installation and fixation of the motor but also enhances the structural strength of the leg support structure. The hinge points of the connecting plate and the second connecting rod with the first connecting bracket are located on either side of the mounting tube, preventing the mounting tube from interfering with the movement of the connecting plate and the second connecting rod, thereby better achieving maximum expansion or contraction of the leg support assembly in the fore-and-aft direction.

[0014] In the aforementioned pure-link car seat leg support structure, a curved plate is fixedly attached to the connecting shaft, with the concave side of the curved plate facing the motor. The end of the push rod near the leg support assembly is hingedly connected to the curved plate. The provision of the curved plate allows the push rod to better push the connecting shaft and the connecting plate fixed to the connecting shaft to swing up and down, thereby better achieving maximum expansion or contraction of the leg support assembly in the fore-and-aft direction.

[0015] In the above-mentioned leg support structure of a pure connecting rod car seat, a support tube is fixedly connected between the two third connecting brackets, a front transverse tube is also fixedly connected to the seat basin, the middle portion of the second connecting rod has an arc-shaped groove for the side portion of the front transverse tube to be embedded in, and the support tube, connecting shaft, mounting tube and front transverse tube are arranged in parallel with each other. This makes the movement synchronization of the first connecting rod, the second connecting rod, the third connecting rod and the fourth connecting rod on both sides of the connecting rod assembly better. At the same time, the support tube and the front transverse tube can further enhance the structural strength of the leg support structure, making the leg support structure more stable to expand and fold. In the folded state, the side portion of the front transverse tube can be embedded in the arc-shaped groove of the second connecting rod, thereby further improving the stability of the folded leg support structure. At the same time, the support tube, connecting shaft, mounting tube and front transverse tube are arranged in parallel with each other, which can achieve the maximum expansion or folding of the leg support assembly in the front-to-back direction and avoid mutual interference.

[0016] Compared with the existing technology, the advantages of the leg support structure of the pure connecting rod car seat are: when expanding and folding, the leg support structure of the pure connecting rod car seat only needs a push rod to move forward and backward along its axis and push or drag the connecting shaft to drive the double four-link structure forming a "scissor fork" to extend and retract. In addition, the push rod is arranged along the front and rear directions of the car seat and can move forward and backward relative to the car seat. On the one hand, it can realize the maximum expansion or retraction of the leg support assembly in the front and rear directions, and on the other hand, it can realize the minimum distance change of the leg support assembly in the up and down directions. At the same time, the leg support structure adopts a single push rod and a pure connecting rod structure for transmission, and the structure is simple. At the same time, the connecting rod structure can withstand large impact loads and continuous loads. The wear after long-term use is mainly concentrated at the hinge of the rod. Replacement and maintenance are simple and convenient, and the reliability is high, thereby simplifying the leg support structure of the car seat and improving the reliability of use. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the three-dimensional structure of the leg support structure of the pure connecting rod car seat in the folded state in the first embodiment.

[0018] Figure 2 It is a structural schematic diagram of the side view of the leg support structure of the pure connecting rod car seat in the folded state in the first embodiment.

[0019] Figure 3 It is a schematic diagram of the three-dimensional structure of the leg support structure of the pure connecting rod automobile seat in the first embodiment when viewed from above in the folded state.

[0020] Figure 4 It is a schematic diagram of the three-dimensional structure of the leg support structure of the pure connecting rod automobile seat in the first embodiment in the unfolded state.

[0021] Figure 5 This is a structural schematic diagram of the side view of the leg support structure of the pure connecting rod automobile seat in the first embodiment in the unfolded state.

[0022] Figure 6 It is a schematic diagram of the three-dimensional structure of the leg support structure of the pure connecting rod automobile seat in the first embodiment when viewed from above in the unfolded state.

[0023] Figure 7 This is a schematic diagram of the rotation and deployment principle of the leg support structure of the pure connecting rod car seat in the first embodiment.

[0024] Figure 8 The present invention is a schematic diagram of the three-dimensional structure of the first connecting rod of the leg support structure of the pure connecting rod car seat.

[0025] Figure 9 The utility model is a three-dimensional structural diagram of the leg support structure connecting rod assembly of the pure connecting rod car seat.

[0026] Figure 10It is a schematic diagram of the three-dimensional structure of the leg support structure of the pure connecting rod automobile seat in the second embodiment when viewed from above in the folded state.

[0027] Figure 11 It is a structural schematic diagram of the side view of the leg support structure of the pure connecting rod automobile seat in the second embodiment in the unfolded state.

[0028] Figure 12 It is a schematic diagram of the three-dimensional structure of the leg support structure of the pure connecting rod automobile seat in the second embodiment when viewed from above in the unfolded state.

[0029] In the figure, 1. seat basin; 2. leg rest assembly; 2a. first leg rest; 2b. second leg rest; 2b1. clearance hole; 3. motor; 4. push rod; 5. connecting rod assembly; 6. connecting shaft; 7. front cross tube; 8. connecting plate; 9. first connecting rod; 9a. extension section; 10. second connecting rod; 10a. arc groove; 11. first connecting bracket; 12. third connecting rod; 13. second connecting bracket; 14. fourth connecting rod; 15. third connecting bracket; 16. mounting plate; 17. upper slide rail; 18. lower slide rail; 19. arc plate; 20. mounting tube; 21. support tube. DETAILED DESCRIPTION

[0030] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

[0031] Example 1

[0032] A leg support structure of a pure connecting rod car seat, referring to Figure 1-9, a leg support structure of a pure connecting rod car seat, the car seat includes a seat basin 1 and a leg support assembly 2, the leg support assembly 2 includes a first leg support 2a and a second leg support 2b slidably connected to the first leg support 2a, the leg support structure includes a push rod 4 arranged along the front and rear direction of the car seat and capable of moving forward and backward relative to the car seat, a connecting shaft 6 hinged to the push rod 4 is arranged between the seat basin 1 and the leg support assembly 2 along the left and right direction of the car seat, the two ends of the connecting shaft 6 are respectively fixed with a connecting plate 8, the connecting plate 8 is respectively hinged with a first connecting rod 9 and a fourth connecting rod 14, the first connecting rod 9 and the connecting plate 8 are cross-arranged and hinged with a second connecting rod 10, and the second The ends of the connecting rod 10 and the connecting plate 8 facing the seat basin 1 are respectively hinged to the seat basin 1, and the connecting plate 8, the first connecting rod 9, the second connecting rod 10 and the seat basin 1 form a four-bar structure. The ends of the first connecting rod 9 and the fourth connecting rod 14 facing the first leg support 2a are respectively hinged to the first leg support 2a, and the connecting plate 8, the first connecting rod 9, the fourth connecting rod 14 and the first leg support 2a also form a four-bar structure. The end of the first connecting rod 9 hinged to the first leg support 2a also has an arc-shaped extension section 9a, and the extension section 9a is hinged to the second leg support 2b and can drive the second leg support 2b to slide relative to the first leg support 2a.

[0033] Reference Figure 2 、 Figure 3 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8 and Figure 9 Specifically, the front ends of the two connecting plates 8 are respectively hinged to the two first connecting brackets 11 on the seat basin 1, and the rear ends of the two connecting plates 8 are respectively hinged to the two second connecting brackets 13 on the first leg support 2a through the fourth connecting rod 14. The upper ends of the two connecting plates 8 are respectively hinged to the first connecting rod 9 on the same side. The connecting plate 8, the first connecting rod 9, the second connecting rod 10 and the first connecting bracket 11 are hinged to form a four-bar structure. The connecting plate 8, the first connecting rod 9, the fourth connecting rod 14 and the second connecting bracket 13 are hinged to form a four-bar structure. The two extended sections 9a of the first connecting rod 9 are respectively hinged to the two third connecting brackets 15 on the second leg support 2b through the third connecting rod 12.

[0034] Reference Figure 2 、 Figure 3 、 Figure 5 and Figure 6More specifically, the first leg support 2a is in an inverted L-shape, and L-shaped mounting plates 16 are connected to both sides of the first leg support 2a. The second leg support 2b is located between the mounting plate 16 and the first leg support 2a and is connected to an upper slide rail 17. A lower slide rail 18 is connected to the mounting plate 16, and the upper slide rail 17 is slidably installed on the lower slide rail 18.

[0035] In this embodiment, the second leg support 2b preferably further has a clearance hole 2b1 for the hinged parts of the first connecting rod 9 and the third connecting rod 12 to extend into, and the rear sides of the first leg support 2a and the second leg support 2b are both in a downward curved arc.

[0036] Reference Figure 2 、 Figure 3 、 Figure 5 and Figure 6 To be more specific, a mounting tube 20 is fixedly connected between the two first connecting brackets 11, and a motor 3 for driving the push rod 4 to move forward and backward relative to the car seat is installed on the mounting tube 20. The hinge points of the connecting plate 8 and the second connecting rod 10 on the same side and the first connecting bracket 11 are respectively located on both sides of the mounting tube 20; an arc-shaped plate 19 is fixedly connected to the connecting shaft 6, and the concave side of the arc-shaped plate 19 is arranged toward the motor 3, and the end of the push rod 4 close to the leg support assembly 2 is hinged on the arc-shaped plate 19; a support tube 21 is fixedly connected between the two third connecting brackets 15, and a front cross tube 7 is also fixedly connected to the seat basin 1, and the middle part of the second connecting rod 10 has an arc-shaped groove 10a for the side of the front cross tube 7 to be embedded, and the support tube 21, connecting shaft 6, mounting tube 20 and front cross tube 7 are arranged parallel to each other.

[0037] The following describes the working principle of the leg support structure of this pure connecting rod car seat:

[0038] When the leg support structure of the pure connecting rod car seat needs to be unfolded, the motor 3 drives the push rod 4 to move forward along the axial direction of the push rod 4, and the push rod 4 pushes the connecting shaft 6 and the connecting plate 8 fixed on the connecting shaft 6 to swing upward through the arc plate 19, and then the connecting plate 8 drags the first connecting rod 9 and the fourth connecting rod 14 hinged thereto to swing together around the hinge axis of the connecting plate 8 and the first connecting bracket 11. At the same time, the first connecting rod 9 and the fourth connecting rod 14 rotate around their respective hinge points respectively. Since the distance from the hinge point of the connecting plate 8 and the fourth connecting rod 14 to the hinge point of the connecting plate 8 and the first connecting bracket 11 is greater than the distance from the hinge point of the connecting plate 8 and the first connecting rod 9 to the hinge point of the connecting plate 8 and the first connecting bracket The distance between the hinge points of the bracket 11 is large, so the linear velocity of the fourth link 14 is greater than the linear velocity of the first link 9, and the first link 9 and the fourth link 14 are respectively hinged to the second connecting bracket 13, so that the linear velocity of the hinge between the fourth link 14 and the second connecting bracket 13 is greater than the linear velocity of the hinge between the first link 9 and the second connecting bracket 13, so that the second connecting bracket 13 will rotate around the hinge axis between it and the fourth link 14 and drive the first leg support 2a to rotate synchronously. At the same time, the second leg support 2b slidingly connected to the first leg support 2a can move synchronously with the first leg support 2a, so that the first leg support 2a and the second leg support 2b can swing synchronously at the same angle.

[0039] At the same time, the first connecting rod 9 is connected to the first connecting bracket 11 through the second connecting rod 10, and the first connecting rod 9 is connected to the third connecting bracket 15 through the third connecting rod 12. The distance between the hinge point between the first connecting rod 9 and the third connecting rod 12 and the hinge point between the second connecting rod 10 and the first connecting bracket 11 is much greater than the distance between the hinge point between the fourth connecting rod 14 and the second connecting bracket 13 and the hinge point between the connecting plate 8 and the first connecting bracket 11. Therefore, when swinging, the linear velocity of the hinge point between the first connecting rod 9 and the third connecting rod 12 is greater than the linear velocity of the hinge point between the second connecting bracket 13 and the fourth connecting rod 14. This will cause a speed difference between the upper slide rail 17 and the lower slide rail 18, thereby achieving the effect of the second leg support 2b sliding forward relative to the first leg support 2a. When the leg support structure of this pure connecting rod car seat needs to be folded, the motor 3 drives the push rod 4 to move backward in the opposite direction along the axial direction of the push rod 4. The leg support structure of the pure connecting rod car seat, the overall rotation of the leg support assembly 2 relative to the seat basin 1 and the sliding of the second leg support 2b relative to the first leg support 2a occur simultaneously, which can avoid the obvious friction between the leg support assembly 2 and the user's legs caused by the successive movement of the two, and the user experience is more comfortable. At the same time, the leg support structure of the pure connecting rod car seat can meet the requirement that the size of the surface cover of the connection part between the first leg support 2a and the seat cushion is ≤10mm when the leg support structure of the pure connecting rod car seat changes from the folded state to the unfolded state. Within this length change scale, a visually seamless effect can be achieved, that is, the surface cover covering the surface of the leg support assembly 2 will not produce wrinkles during movement.

[0040] Example 2

[0041] The structure and principle of this embodiment are basically the same as those of the first embodiment, except that: Figure 8-12 The second leg rest 2b is in an inverted L-shaped configuration, with L-shaped mounting plates 16 connected to either side of the second leg rest 2b. The first leg rest 2a is located between the mounting plates 16 and the second leg rest 2b and is connected to an upper rail 17. A lower rail 18 is connected to the mounting plates 16, and the upper rail 17 is slidably mounted on the lower rail 18. The placement of the first and second leg rests 2a, 2b in this embodiment is exactly opposite to that of the first and second leg rests 2a, 2b in the first embodiment, achieving a split design (a seam effect is required between the seat cushion and leg rest components).

[0042] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope of the appended claims.

Claims

1. A leg support structure for a pure connecting rod automobile seat, the automobile seat comprising a seat basin (1) and a leg support assembly (2), the leg support assembly (2) comprising a first leg support (2a) and a second leg support (2b) slidably connected to the first leg support (2a), characterized in that: The leg support structure includes a push rod (4) arranged along the front-back direction of the car seat and capable of moving forward and backward relative to the car seat, a connecting shaft (6) hinged to the push rod (4) is arranged between the seat basin (1) and the leg support assembly (2) along the left-right direction of the car seat, and the two ends of the connecting shaft (6) are respectively fixed with connecting plates (8), and the connecting plates (8) are respectively hinged with a first connecting rod (9) and a fourth connecting rod (14), the first connecting rod (9) and the connecting plate (8) are cross-arranged and hinged with a second connecting rod (10), and the second connecting rod (10) and the connecting plate (8) are respectively hinged to the seat basin (1) at their ends facing the seat basin (1), and the connecting plates (8), the first connecting rod (9), the second connecting rod (10) and the seat basin (1) form a four-link structure, the first connecting rod (9) and the fourth connecting rod (14) are respectively hinged to the first leg support (2a) at their ends facing the first leg support (2a), and the connecting plate (8), the first connecting rod (9), the fourth connecting rod (14) and the first leg support (2a) also form a four-link structure, the end of the first connecting rod (9) hinged to the first leg support (2a) also has an arc-shaped extension section (9a), the extension section (9a) is hinged to the second leg support (2b) and can drive the second leg support (2b) to slide relative to the first leg support (2a).

2. The leg support structure of a pure connecting rod car seat according to claim 1, characterized in that: The front ends of the two connecting plates (8) are respectively hinged to the two first connecting brackets (11) on the seat basin (1), and the rear ends of the two connecting plates (8) are respectively hinged to the two second connecting brackets (13) on the first leg support (2a) through the fourth connecting rod (14). The upper ends of the two connecting plates (8) are respectively hinged to the first connecting rod (9) on the same side. The connecting plate (8), the first connecting rod (9), the second connecting rod (10) and the first connecting bracket (11) are hinged to form a four-bar structure. The connecting plate (8), the first connecting rod (9), the fourth connecting rod (14) and the second connecting bracket (13) are hinged to form a four-bar structure. The extended sections (9a) of the two first connecting rods (9) are respectively hinged to the two third connecting brackets (15) on the second leg support (2b) through the third connecting rod (12).

3. The leg support structure of a pure connecting rod car seat according to claim 2, characterized in that: The first leg support (2a) is in an inverted shape, and L-shaped mounting plates (16) are connected to both sides of the first leg support (2a). The second leg support (2b) is located between the mounting plate (16) and the first leg support (2a) and is connected to an upper slide rail (17). A lower slide rail (18) is connected to the mounting plate (16), and the upper slide rail (17) is slidably mounted on the lower slide rail (18).

4. The leg support structure of a pure connecting rod car seat according to claim 3, characterized in that: The second leg support (2b) also has a clearance hole (2b1) for the hinged parts of the first connecting rod (9) and the third connecting rod (12) to extend into, and the rear sides of the first leg support (2a) and the second leg support (2b) are both in a downward curved arc shape.

5. The leg support structure of a pure connecting rod car seat according to claim 2, characterized in that: The second leg support (2b) is in an inverted shape, and L-shaped mounting plates (16) are connected to both sides of the second leg support (2b). The first leg support (2a) is located between the mounting plate (16) and the second leg support (2b) and is connected to an upper slide rail (17). A lower slide rail (18) is connected to the mounting plate (16), and the upper slide rail (17) is slidably mounted on the lower slide rail (18).

6. A leg support structure for a pure connecting rod vehicle seat according to any one of claims 2 to 5, characterized in that: A mounting tube (20) is fixedly connected between the two first connecting brackets (11), and a motor (3) is mounted on the mounting tube (20) for driving the push rod (4) to move forward and backward relative to the car seat. The hinge points of the connecting plate (8) and the second connecting rod (10) located on the same side and the first connecting bracket (11) are respectively located on both sides of the mounting tube (20).

7. The leg support structure of a pure connecting rod automobile seat according to claim 6, characterized in that: An arc-shaped plate (19) is fixedly connected to the connecting shaft (6), the concave side of the arc-shaped plate (19) is arranged toward the motor (3), and the end of the push rod (4) close to the leg support assembly (2) is hinged on the arc-shaped plate (19).

8. The leg support structure of a pure connecting rod automobile seat according to claim 6, characterized in that: A support tube (21) is fixedly connected between the two third connecting brackets (15), and a front transverse tube (7) is also fixedly connected to the seat basin (1). The middle portion of the second connecting rod (10) has an arc-shaped groove (10a) for the side portion of the front transverse tube (7) to be embedded. The support tube (21), the connecting shaft (6), the mounting tube (20) and the front transverse tube (7) are arranged parallel to each other.

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