A seat with dynamically self-adapting lumbar support

Abstract

The utility model discloses a seat of dynamic self -adaptation adjustable waist support force, including base and the backrest of hinge connection with base, still include the elastic component for adjusting the included angle between base and backrest and for providing backrest support force and the waist support of hinge connection with backrest and can move up and down along backrest, wherein initial state, the included angle of base and backrest front is acute angle, and the elastic component exists initial pre -tightening force in initial state, along with backrest from initial angle counterclockwise rotation, the force of elastic component to human body gradually increases, and the increasing rate is first increase then decrease. The utility model dynamic self -adaptation provides a support force for human waist, thereby makes human body keep in comfortable and correct sitting posture, solves the problem that the existing seat can not dynamically provide support force for waist.

Description

Technical Field

[0001] This utility model relates to the field of chair technology, and in particular to a chair with dynamically adaptive lumbar support. Background Technology

[0002] Currently, office workers spend over 8 hours a day sitting (more than 60% of their day), and the prolonged use of chairs lacking ergonomic design leads to a high incidence of spinal diseases. Most office workers suffer from cervical spondylosis, lumbar disc herniation, or chest and back pain due to prolonged sitting, and the number of lumbar spine patients continues to rise. A healthy, ergonomically designed office chair can effectively reduce the probability of developing these diseases, making a healthy and comfortable office chair particularly important for office workers. However, most existing office chair backrests have a fixed shape and cannot dynamically adapt to changes in the curvature of the lumbar spine. When users lean forward or backward, the lumbar region is unsupported, causing pressure to concentrate on a single vertebral segment, accelerating intervertebral disc deformation. When a person sits in a chair, the center of rotation of the lumbar region and the center of rotation of the chair back around the base are not on the same axis of rotation. Therefore, the rotation and displacement of the back and the backrest do not coincide, resulting in relative slippage. This creates a "rubbing back" sensation when adjusting posture, and the friction between the backrest and the back forces muscles to compensate, exacerbating fatigue. Utility Model Content

[0003] Purpose of the utility model: The purpose of this utility model is to provide a seat that can dynamically and adaptively adjust the lumbar support force. Through the elastic component, it dynamically and adaptively provides a support force to the human lumbar region, thereby allowing the human body to maintain a comfortable and correct sitting posture, solving the problem that existing seats cannot dynamically provide lumbar support force.

[0004] Technical solution: To achieve the above objectives, this utility model discloses a seat with dynamically adaptive lumbar support force, including a base and a backrest hinged to the base, an elastic component for adjusting the angle between the base and the backrest and for providing backrest support force, and a lumbar support hinged to the backrest and movable up and down along the backrest. In the initial state, the angle between the base and the front of the backrest is an acute angle, and the elastic component has an initial preload in the initial state. As the backrest rotates counterclockwise from the initial angle, the force exerted by the elastic component on the human body gradually increases, and the rate of increase is first increased and then decreased.

[0005] Optionally, the upper end of the elastic component is hinged to the back of the backrest, and the lower end of the elastic component is hinged to the rear end of the base. The hinge point between the elastic component and the base is located behind the hinge point between the backrest and the base. The elastic component can extend and retract under the pressure of the backrest.

[0006] Optionally, the elastic component includes a telescopic cylinder hinged to the backrest via an upper connector and to the base via a lower connector, a threaded tube sleeved on the outside of the cylinder barrel of the telescopic cylinder, a nut threaded to the outer circumference of the threaded tube, a handle sleeve whose lower end is fixed to the outer circumference of the nut, a travel limiting sleeve whose lower end is sleeved to the upper end of the handle sleeve and whose upper end abuts against the lower surface of the upper connector, and a compression spring sleeved on the outside of the threaded tube, wherein one end of the compression spring abuts against the end face of the nut and the other end of the compression spring abuts against the stepped surface of the travel limiting sleeve; rotating the handle sleeve causes the nut to rotate, and the rotation adjusts the engagement position with the threaded tube, thereby adjusting the preload of the compression spring.

[0007] Optionally, the backrest includes a backrest base plate, a lumbar support adjustment assembly hinged to the lumbar support and used to adjust the up and down position of the lumbar support, and an elastic connection assembly for generating elasticity so that the lumbar support adaptively conforms to the waist.

[0008] Optionally, the lumbar support adjustment assembly includes two sets of guide rails parallel to each other on the backrest base plate, a matching slider hinged to the lumbar support and movable up and down along the guide rails, a matching nut embedded in the matching slider, a lead screw vertically inserted on the backrest base plate with its upper end passing through the matching nut and the matching slider, an adjustment knob located at the lower end of the lead screw, and a lower baffle for limiting the displacement stroke of the adjustment knob. Rotating the adjustment knob causes the lead screw to drive the matching slider to move up and down along the guide rails.

[0009] Optionally, the elastic connection assembly includes a connecting spring sleeved on the lead screw, a fastening nut located at the upper end of the connecting spring and sleeved on the lead screw that can move with the lead screw, and the lower end of the connecting spring abutting against the inner surface of the lower baffle; under the action of external force, the waist support pushes the matching slider to move downward along the guide rail, and the lead screw and the fastening nut move downward together to compress the connecting spring.

[0010] Optionally, the sum of the adjustment stroke S1 of the adjustment knob and the compression stroke S2 ​​of the connecting spring is not greater than the stroke S3 of the guide rail.

[0011] Optionally, the base includes a base, a breathable cushion on the upper surface of the base, and a friction element on the lower surface of the base, wherein the base includes a hollow annular structure and a mesh fabric fixed to the hollow annular structure.

[0012] Optionally, the elastic component includes a torsion spring pivot for hinged backrest and base, a double torsion spring sleeved on the torsion spring pivot, and a torsion spring limiting member located at the bottom of the backrest. A torsion spring pad that fits against the backrest surface is provided at the position where the middle torsion arm of the double torsion spring contacts the back of the backrest. The two torsion arms of the double torsion spring pass through the base and are fixed to the base. In the initial state, the double torsion spring is compressed, generating an initial preload force, which pushes the backrest to rotate forward, and the torsion spring limiting member abuts against the base.

[0013] Optionally, the lumbar support includes an arc-shaped support hinged to the backrest via a backrest connector and a flexible pad located on the front side of the arc-shaped support.

[0014] Beneficial Effects: Compared with existing technologies, this utility model has the following advantages: This utility model achieves real-time position adjustment of the lumbar support component through elastic components, adapting to changes in human sitting posture and actively conforming to the lumbar curve; it provides dynamic adaptive support to the lumbar region through elastic components, thus maintaining a comfortable and correct sitting posture, solving the problem that current lumbar support cushions and chairs cannot dynamically provide lumbar support; the backrest of this utility model has an elastic connection mechanism, which can prevent relative displacement between the lumbar support and the back when the backrest moves back and forth, eliminating the rubbing sensation caused by relative displacement friction between the back and the lumbar support; this utility model allows for easy adjustment of the lumbar support position, suitable for users of different heights and body types, and the base adopts a rigid-flexible coupling design, making it more compatible with chairs and sofas of different curvatures and textures; this utility model can be easily folded and stored, reducing logistics and warehousing costs. Attached Figure Description

[0015] Figure 1 This is a simplified schematic diagram of the principle of this utility model;

[0016] Figure 2 This is an axonometric view of the present invention;

[0017] Figure 3 This is a side view of the present invention;

[0018] Figure 4 This is a detailed axial side view of the present invention;

[0019] Figure 5 This is a diagram illustrating the folded state of this utility model;

[0020] Figure 6 This is a detailed view of the backrest of this utility model;

[0021] Figure 7 This is a detailed drawing of the base plate of this utility model;

[0022] Figure 8 Here are detailed drawings of the elastic component of this utility model;

[0023] Figure 9 This is a schematic diagram illustrating the force exerted on the human back by the lumbar support of this utility model.

[0024] Figure 10 This is a force analysis diagram of the human body according to the present invention;

[0025] Figure 11 This is a schematic diagram of Embodiment 2 of the present invention;

[0026] Figure 12 Axial view of Embodiment 2 of this utility model Figure 1 ;

[0027] Figure 13 Axial view of Embodiment 2 of this utility model Figure 2 ;

[0028] Figure 14 Axial view of Embodiment 2 of this utility model Figure 3 ;

[0029] In the diagram: Base 1, Base 101, Hollow Ring Structure 1011, Mesh Fabric 1012, Breathable Seat Cushion 102, Friction Component 103, Backrest Hinge Shaft 104, Elastic Component Hinge Shaft 105; Backrest 2, Backrest Base Plate 201, Guide Rail 202, Matching Slider 203, Matching Nut 204, Lead Screw 205, Adjustment Knob 206, Lower Baffle 207, Connecting Spring 208, Fastening Nut 209, Rear Rotary Shaft Hole 210, Bottom Rotary Shaft Hole 211, Groove 2 12. Cover plate 213; Elastic component 3, upper connector 301, lower connector 302, telescopic cylinder 303, screw tube 304, nut 305, handle sleeve 306, stroke limit sleeve 307, compression spring 308, appearance cover 309, torsion spring shaft 310, double torsion spring 311, torsion spring limit component 312, torsion spring pad 313, torsion spring fixing plate 314, torsion spring fixing component 315; Lumbar support 4, backrest connector 401, arc-shaped support component 402, flexible pad 403. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the scope of the present utility model.

[0031] It should be understood that this invention can be implemented in various forms and should not be construed as being limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of this invention to those skilled in the art. In the drawings, for clarity, the dimensions and relative dimensions of the components may be exaggerated. The same reference numerals denote the same components throughout.

[0032] Example 1: As Figure 1 , Figure 2 and Figure 3As shown, a dynamically adaptive adjustable lumbar support seat according to this embodiment includes a base 1, a backrest 2, an elastic component 3, and a lumbar support 4. The backrest 2 is hinged to the base 1. The elastic component 3 is used to adjust the angle between the base 1 and the backrest 2, and also to provide support force to the backrest 2. The lumbar support 4 is hinged to the backrest 2 and can move up and down along the backrest 2. In the initial state, the angle between the front of the base 1 and the backrest 2 is an acute angle, and the elastic component has an initial preload. As the backrest rotates counterclockwise from the initial angle, the force exerted by the elastic component 3 on the human body gradually increases, with the rate of increase first increasing and then decreasing. When a person sits in a chair, there is usually a certain distance between them and the backrest. If the person does not actively lean back, that is, if the angle between the waist and thigh is less than 90 degrees, a force that pushes the waist cannot be generated. In this invention, the angle between the front of the base 1 and the backrest 2 is set to an acute angle so that the waist can generate a forward pushing force as long as it remains in an upright position. Moreover, even if the waist makes small adjustments and movements, the backrest and lumbar support can still follow the body's adjustments and continuously provide a force to support the waist, thereby achieving the best effect.

[0033] The base 1 and backrest 2 are connected via a rotating joint. An elastic component 3 is connected to both the base 1 and backrest 2 via rotating joints. The rotating joint connecting the base 1 and backrest 2 is located in the rear half of the base, while the rotating joint connecting the base 1 and elastic component 3 is located at the rear edge of the base. In the absence of external force, the elastic component 3 forms an acute angle with the base 1. The backrest 2 can rotate around its hinge point with the seat cushion 1. When the backrest 2 rotates, the spring component 3 deforms. When a person leans back against the lumbar support 4, they exert a backward force on the backrest 2. As the backrest 2 rotates counterclockwise under this force, the elastic force of the elastic component 3 gradually increases, and the angle between the elastic component 3 and the base 1 increases. At this time, the back of the person also experiences a forward force on the lumbar spine from the backrest 4. This ensures that the backrest 2 consistently provides support, creating a chafing sensation and reducing pressure on the lumbar spine. This invention can improve posture problems, ensuring an optimal sitting position and alleviating lumbar spine issues caused by improper posture. The lumbar support 4 can be adjusted up and down on the backrest 2 to accommodate people of different heights and needs. The connection between the lumbar support 4 and the backrest 2 is flexible. When the lumbar support 4 is subjected to the force of the user's back, the user's back and the lumbar support 4 remain relatively fixed, while the flexible connection between the lumbar support 4 and the backrest 2 undergoes a certain deformation. This prevents the back from shifting relative to the lumbar support 4 during forward and backward movement, thus avoiding a rubbing sensation that would affect the user experience. The elastic component 3 has an initial preload when in its initial position, and the stiffness and initial preload of the elastic component 3 can be adjusted.

[0034] like Figure 7As shown, the base 1 includes a base 101, a breathable seat cushion 102, a friction element 103, a backrest hinge shaft 104, and an elastic component hinge shaft 105. The base 1 is hinged to the backrest 2 via the backrest hinge shaft 104, which is located in the rear half of the base 101 and is used for hinged connection with the backrest 2. The lower end of the elastic component is hinged to the base 1 via the elastic component hinge shaft 105, which is located at the rear edge of the base 1 and is used for hinged connection with the elastic component 3. The breathable seat cushion 102 is provided on the upper surface of the base 101, and the friction element 103 is provided on the lower surface of the base 101. The base 101 is made of engineering plastics such as PP, possessing good resistance to deformation and toughness. The breathable seat cushion 102 is fixed to the base 101, and the specific fixing method can be quick-release structures such as glue, magnetic adsorption, clips, or Velcro. The breathable seat cushion 102 is integrally molded from a 30% open-cell polyurethane mesh, or alternatively, from a honeycomb TPE material. The breathable seat cushion 102 is elastic and breathable, providing excellent support for the buttocks and improving seating comfort. The upper front edge of the breathable seat cushion 102 is 4cm above the base 101 at a height H1=4cm, and the upper rear edge is 2cm above the base 101 at a height H2=2cm, forming an angle α=5°. A friction element 103 is located at the bottom of the base 101, effectively preventing the chair from sliding. The friction element 103 is an embedded 3mm thick silicone pad with a friction coefficient μ≥0.8, or it can be a textured feature on the bottom of the base 101, or an anti-slip structure such as rubber anti-slip dots. The base 101 includes a hollow ring structure 1011 and a mesh fabric 1012 fixed to the hollow ring structure 1011. The base 101 adopts a rigid-flexible coupling design, resulting in better compatibility with chairs and sofas of different materials. The mesh fabric 1012 is fixed to the hollow ring structure 1011 using ultrasonic welding or adhesive methods. The hollow ring structure 1011 is made of PP plastic and, due to the absence of structural components in the center, possesses good toughness, allowing it to conform well to various non-flat surfaces such as ergonomic chairs, sofas, and other similar objects. The mesh fabric 1012 can be a mesh-shaped polymer material, a fabric with some elasticity, or a thinner plastic component. When a person sits on the mesh fabric 1012, it will slightly concave and deform, better conforming to the buttocks. When the base 101 is placed on a flexible ergonomic chair, the mesh fabric 1012 can retain the original flexibility of the ergonomic chair as much as possible. The structure of the base 101 provides better comfort and breathability.

[0035] The backrest 2 includes a backrest base plate 201, a lumbar support adjustment assembly, and an elastic connection assembly. The lumbar support adjustment assembly is hinged to the lumbar support 4 and is used to adjust the vertical position of the lumbar support. The elastic connection assembly generates elasticity to allow the lumbar support to adaptively conform to the waist. The backrest base 201 is hinged to the elastic assembly 3 through a rear pivot hole 210, and the backrest base 201 is hinged to the backrest hinge shaft 104 of the base 1 through a bottom pivot hole 211. The backrest has a certain arc shape. When not fixedly connected to the elastic assembly, the backrest can rotate clockwise, allowing the entire backrest and lumbar support to fold and fit snugly against the base; this reduces its packaging volume, facilitates transportation, and lowers transportation costs.

[0036] like Figure 6 As shown, the lumbar support adjustment assembly includes a guide rail 202, a matching slider 203, a matching nut 204, a lead screw 205, an adjustment knob 206, and a lower baffle 207. Two sets of guide rails 202 are arranged parallel to each other on the backrest base plate 201. The matching slider 203 is hinged to the lumbar support 4 and can move up and down along the guide rail 202. The matching nut 204 is embedded in the matching slider 203. A groove 212 is provided on the backrest base plate 201. The lead screw 205 is vertically inserted into the groove of the backrest base plate 201. The upper end of the lead screw 205 passes through the matching nut 204 and the matching slider 203. The adjustment knob 206 is located at the lower end of the lead screw 205. The lower bottom surface of the backrest base plate 201 forms a lower baffle 207 to limit the displacement stroke of the adjustment knob. By rotating the adjustment knob 206, the lead screw 205 can drive the matching slider 203 to move up and down along the guide rail 202. The backrest base plate 201 is made of PP material and is hinged to the base 1 through the bottom pivot hole 211. The pivot diameter is Ø4mm. Two sets of parallel guide rails 202 are spaced 8cm apart. Matching nuts 204 are embedded in matching sliders 203. The matching sliders 203 are adjusted vertically via a lead screw 205 and matching nuts 204, with a travel range of 8~12cm. An adjustment knob 206 limits the upper limit of the lumbar support movement on the backrest base plate 201. The lumbar support adjustment assembly 205 can also be adjusted via other adjustable mechanisms such as gears and racks or limiting holes.

[0037] The lumbar support 4 is hinged to the matching slider 203. The elastic connection component has elasticity. When the human back moves back and forth, the back will not be displaced relative to the lumbar support 4. The lumbar support 4 and the back move synchronously to avoid relative friction and not affect the human user experience.

[0038] The elastic connection assembly includes a connecting spring 208, a fastening nut 209, and a cover plate 213 that mates with the groove 212. The connecting spring 208 is sleeved on the lead screw 205, and the fastening nut 209 is located at the upper end of the connecting spring 208. The fastening nut 209 is sleeved on the lead screw 205 and can move with the lead screw. The lower end of the connecting spring 208 abuts against the inner surface of the lower baffle 207, that is, the lower end of the connecting spring 208 abuts against the bottom of the groove 212. Under the action of external force, the waist support pushes the matching slider 203 to move downward along the guide rail 202. The lead screw 205 and the fastening nut 209 move downward together to compress the connecting spring 208. The sum of the adjustment stroke S1 of the adjustment knob 206 and the compression stroke S2 ​​of the connecting spring is not greater than the stroke S3 of the guide rail.

[0039] like Figure 10 As shown, in a regular chair, when a person leans back and applies force, because the lumbar joint A of the human body and the seat joint B do not coincide, a relative displacement occurs between the waist and the lumbar support when the person rotates backward. At this time, the lumbar support will move upward relative to the human body, and the person will exert a downward force on the lumbar support. Because the lumbar support is fixed, a relative displacement occurs between the lumbar support and the human body, causing the human body to experience a back-rubbing sensation.

[0040] With the addition of the elastic connection component, when a person leans back and applies force, the person will exert a positive pressure F on the lumbar support. N Furthermore, due to the relative downward displacement tendency, a downward static friction force F will be generated. h The elastic connection component provides an upward force F to the lumbar support. s Because of the force F of the spring s The static friction force F between the human body and the lumbar support is relatively small. h The limit value is large, when F h Greater than F s When the body moves backward, the body and the lumbar support remain relatively stationary, while the lumbar support moves downward relative to the backrest base. Once the movement stops, the lumbar support is in equilibrium, at which point the static friction force F... h =Spring force F s At this time, the human body is only subjected to static friction equivalent to the elastic force of a spring, and there is no great back-rubbing sensation.

[0041] When the body is removed from the lumbar support, due to the positive pressure F N The static friction force F between the person and the lumbar support disappears. H The lumbar support disappears, and then returns to its highest point under the action of the spring. The next time the body sits down and touches the lumbar support, the above process will be repeated to ensure that there is no relative displacement between the lumbar support and the body each time the body sits down and leans back.

[0042] like Figure 5As shown, the backrest 2 has a certain arc. When not hinged to the elastic component 3, the backrest 2 can rotate clockwise, causing the entire backrest 2 and lumbar support 4 to fold and fit snugly against the base 1. This reduces its packaging volume, facilitates transportation, and lowers transportation costs. Folding parameters: Folded thickness 12~18cm, unfolded structural safety factor ≥2.5.

[0043] like Figure 4 As shown, the upper end of the elastic component 3 is hinged to the back of the backrest 2, and the lower end of the elastic component 3 is hinged to the rear end of the base 1. The hinge point between the elastic component 3 and the base 1 is located behind the hinge point between the backrest 2 and the base 1. The elastic component 3 can extend and retract under the pressure of the backrest 2.

[0044] like Figure 8 As shown, the elastic component 3 includes an upper connector 301, a lower connector 302, a telescopic cylinder 303, a screw tube 304, a nut 305, a handle sleeve 306, a stroke limit sleeve 307, a compression spring 308, and an appearance shield 309. The lower end of the telescopic cylinder 303 is hinged to the elastic component hinge shaft 105 of the base 1 via the lower connector 302, and the upper end of the telescopic cylinder 303 is hinged to the pin in the rear rotating shaft hole 210 of the backrest 2 via the upper connector 301. The screw tube 304 is sleeved on the outside of the cylinder barrel of the telescopic cylinder 303, and the screw tube 304 is interference-fitted with the cylinder barrel. A nut 305 is threaded onto the outer circumference of the screw tube 304. The lower end of the handle sleeve 306 is fixedly connected to the outer circumference of the nut 305. The lower end of the travel limit sleeve 307 is sleeved onto the upper end of the handle sleeve 306, and the upper end of the travel limit sleeve 307 abuts against the lower surface of the upper connector 301. A compression spring 308 is sleeved on the outside of the screw tube 304, with one end of the compression spring 308 abutting against the end face of the nut 305 and the other end abutting against the stepped surface of the travel limit sleeve 307. Rotating the handle sleeve 306 causes the nut 305 to rotate, adjusting the engagement position with the screw tube 304 and adjusting the preload of the compression spring 308. An appearance shield 309 is fixed to the travel limit sleeve 307 by magnetic attraction or a snap fastener to cover the appearance of the upper connector 301.

[0045] The handle sleeve 306 can control the initial preload of the elastic component 3 by adjusting the pre-deformation of the compression spring 308. The compression spring 308 and the telescopic cylinder 303 are compressible; when the backrest 2 rotates counterclockwise, the compression spring 308 and the telescopic cylinder 303 are compressed, and the entire elastic component 3 shortens. The function of the elastic component 3 is to provide a clockwise rotational force to the backrest 2, ensuring an initial force when the human body contacts the backrest.

[0046] The telescopic cylinder 303 and the compression spring 308 can only deform axially and will not bend due to external forces. The telescopic cylinder 303 has a pneumatic pressure of 100N, an outer diameter of 15mm, and a length of 220mm. The compression spring 308 has a length of 100mm. The telescopic cylinder 303 provides some elastic force and also acts as a radial limiter. The compression spring supplements the elastic force and allows for easy adjustment of the preload by changing the initial compression distance.

[0047] Because of the travel limitation, the telescopic cylinder 303 and the travel limit sleeve 307 allow for forward and backward limits on the rotation of the backrest 2. By selecting appropriate travel for the telescopic cylinder 303 and the travel limit sleeve 307, or by adjusting the fixed position of the connector 302, the optimal maximum and minimum angles between the backrest 2 and the base 1 can be obtained. In this specific embodiment, the maximum and minimum angles are 80° and 150°, respectively. The minimum angle range limitation ensures that, under the initial preload of the spring, the angle between the backrest and the base still conforms to the most comfortable angle for a person sitting on it. The maximum angle range limitation prevents the backrest from being excessively pressed backward, causing the elastic element to exceed its travel range and undergo plastic deformation and failure. It also ensures that heavy individuals will not completely press down on the backrest, thus preventing the risk of falls or injury.

[0048] The lumbar support 4 includes a backrest connector 401, an arc-shaped support 402, and a flexible pad 403. The arc-shaped support 402 is hinged to the backrest via the backrest connector 401, and the flexible pad 403 is located at the front of the arc-shaped support 402. The arc-shaped support 402 is made of PP or ABS material. The rear of the arc-shaped support 402 is flexibly connected to the backrest 2 via the backrest connector 401, and the front is fixed to the flexible pad 403. The fixing method can be a non-removable method such as rivets and glue, or a detachable method such as Velcro. The arc-shaped support 402 is similar to the curve of the human waist, so it can fit the human waist as closely as possible. The arc-shaped support 402 has a porous structure for easy ventilation. The arc-shaped support 402 is height-adjustable via a lumbar support adjustment component, with an adjustment range suitable for people with heights of 150-190cm, better adapting to people of different heights. The flexible pad 403 is a memory foam with an open area of ​​40%, a pore size of Ø2mm, and a thickness of 3cm. Its deformation recovery rate is ≥95%, and it is similar to the curve of the human waist, so it can fit the human waist as closely as possible.

[0049] like Figure 9 As shown, assuming the seat is in its initial state, the initial elastic force of the elastic component 3 on the backrest 2 is... The distance between the hinge point between the backrest and the base and the hinge point between the elastic component and the backrest is The distance between the hinge point between the backrest and the elastic component and the hinge point between the backrest and the base is The distance between the hinge point of the elastic component and the backrest and the hinge point of the elastic component and the base is The initial angle between the backrest 2 and the base 1 is... The initial angle between the elastic component 3 and the base 1 is When the human body applies a backward force to the backrest 2, the backrest 2 rotates counterclockwise. Angle becomes , Angle becomes , and remain unchanged. shortened to .

[0050] In the initial state: After deformation: The force F1 of the elastic component 3 changes as follows after deformation: The force of elastic component 3 after deformation: The force exerted by the elastic component on the human body in the forward direction: As the backrest rotates counterclockwise from its initial angle, the force exerted on the human body by the elastic component 3 gradually increases, with the rate of increase first increasing and then decreasing.

[0051] Example 2: The structure of Example 2 is the same as that of Example 1, except that: Figure 11 As shown, the elastic component 3 adopts a torsion spring structure, connected to both the base 1 and the backrest 2. The rotation center of the torsion spring and the revolute joint of the backrest 2 are on the same straight line. The backrest 2 can rotate around its hinge point with the base 1, and the spring component 3 deforms when the backrest 2 rotates. When a person leans back against the lumbar support 4, the person exerts a backward force on the backrest 2. When the backrest 2 rotates counterclockwise under this force, the elastic component 3 is compressed, and the elastic force gradually increases. Figure 12 , Figure 13 and Figure 14 As shown, the elastic component 3 includes a torsion spring shaft 310, a double torsion spring 311, a torsion spring limiting member 312, a torsion spring pad 313, and a torsion spring fixing plate 314. The torsion spring shaft 310 is used to hinge the backrest 2 and the base 1. The torsion spring shaft 310 is also the hinge shaft between the backrest 2 and the base 1. The double torsion spring 311 is sleeved on the torsion spring shaft 310. The torsion spring limiting member 312 is provided at the bottom front of the backrest. The torsion spring pad 313 is provided at the position where the middle torsion arm of the double torsion spring 311 contacts the back of the backrest, and is in contact with the back surface of the backrest. The two torsion arms of the double torsion spring pass through the base and are fixed to the base. In the initial state, the double torsion spring is compressed, generating an initial preload force, which pushes the backrest 2 to rotate forward, and the torsion spring limiting member 312 abuts against the base.

[0052] The double torsion spring 311 is made of spring steel and has an axially symmetrical shape. Both the left and right sides of the torsion spring can provide torsional force. The left and right sides of the torsion spring are fitted onto the torsion spring shaft 310 of the base 1. The torsion arms at both ends of the double torsion spring are fixed to the base 1, and the middle torsion arm is fixed to the backrest 2.

[0053] The diameter of the torsion spring shaft is slightly smaller than the inner diameter of the torsion spring. This serves two purposes: firstly, it prevents the torsion spring from wobbling excessively; secondly, during the compression of the torsion spring, the inner diameter of the torsion spring will decrease, and being slightly smaller prevents the torsion spring from locking the shaft with slight compression. By setting an appropriate size difference, when the backrest reaches its maximum rotation angle, the inner diameter of the torsion spring shrinks to match the diameter of the torsion spring shaft, causing it to lock and preventing the shaft from continuing to rotate backward, thus achieving the purpose of rear limit.

[0054] When a torsion spring rotates around its axis, especially in the "tightening" direction (the direction that increases the number of coils), its internal coils tighten, resulting in a decrease in the effective inner diameter, which is: D. min =(D0*N) / (N+(θ / 360°)), where: D min D0 is the minimum inner diameter of the torsion spring after a certain angle of twist, in mm; D0 is the initial inner diameter of the torsion spring, i.e., the inner diameter of the torsion spring in its free state, in mm; N is the effective number of coils of the torsion spring; θ is the torsion angle of the torsion spring, in degrees, assuming the chair can rotate a maximum of 90°; the outer diameter of the torsion spring's pivot must be less than the minimum inner diameter D calculated above. min To avoid suffocation, it is necessary to... min A safety clearance C is provided between the outer diameter of the torsion spring shaft and the outer diameter D of the torsion spring shaft. sleeve_max =D min -C, if the safety clearance is too small, friction or even jamming may occur due to machining tolerances, surface roughness, fine dust, or insufficient lubrication. If the safety clearance is too large, the torsion spring will shift its center and wobble during rotation, affecting motion accuracy and stability, and may even produce abnormal noise and additional wear. The recommended safety clearance C range is: C = (0.003~0.006) * D0.

[0055] The backrest 2 has a torsion spring limiting component 312 at its bottom. In the initial state, the backrest and the base form an acute angle of approximately 90 degrees. At this time, the double torsion springs are compressed, and the torsion springs have preload, which will cause the backrest to rotate forward. At this point, the torsion spring limiting component 312 will interfere with the base, thus limiting the maximum forward position that the backrest can reach in the initial state. The torsion spring limiting component 312 can also be other adjustment mechanisms, such as using a ratchet to achieve an adjustable initial position of the backrest.

[0056] To prevent excessive stress concentration at the contact points between the torsion spring and the backrest and base, which could damage the plastic parts, a torsion spring pad 313 is installed at the contact point between the torsion spring and the backrest. The torsion spring pad 313 is flush with the curved surface of the backrest and is fixed to the backrest. The torsion spring pad 313 contacts the torsion spring, and the torsion spring transmits force to the torsion spring pad 313, which then distributes the force to the backrest. The two ends of the torsion spring pass through the base, and a torsion spring fixing plate 314 is installed at the contact point with the bottom of the base. The torsion spring fixing plate 314 is fixed to the base, and the two ends of the torsion spring are fixed to the torsion spring fixing plate 314 by torsion spring fixing parts 315 to prevent the torsion spring from shifting back and forth. There are two double torsion springs, symmetrically distributed, which apply force to both ends of the backrest.

[0057] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A seat with dynamically adaptive lumbar support, comprising a base (1) and a backrest (2) hinged to the base (1), characterized in that: It also includes an elastic component (3) for adjusting the angle between the base (1) and the backrest (2) and for providing support for the backrest (2), and a lumbar support (4) that is hinged to the backrest (2) and can move up and down along the backrest (2). In the initial state, the angle between the front of the base (1) and the backrest (2) is an acute angle, and the elastic component has an initial preload in the initial state. As the backrest (2) rotates counterclockwise from the initial angle, the force exerted by the elastic component (3) on the human body gradually increases, and the rate of increase is first increased and then decreased.

2. The seat with dynamically adaptive lumbar support force according to claim 1, characterized in that: The upper end of the elastic component (3) is hinged to the back of the backrest (2), and the lower end of the elastic component (3) is hinged to the rear end of the base (1). The hinge point between the elastic component (3) and the base (1) is located behind the hinge point between the backrest (2) and the base (1). The elastic component (3) can extend and retract under the pressure of the backrest (2).

3. A seat with dynamically adaptive lumbar support force according to claim 2, characterized in that: The elastic component (3) includes a telescopic cylinder (303) hinged to the backrest (2) via an upper connector (301) and hinged to the base (1) via a lower connector (302), a threaded tube (304) sleeved on the outside of the cylinder barrel of the telescopic cylinder (303), a nut (305) threaded to the outer circumference of the threaded tube (304), a handle sleeve (306) whose lower end is fixed to the outer circumference of the nut, and a handle sleeve (306) whose lower end is sleeved to the upper end of the handle sleeve (306) and whose upper end abuts against the upper connector (304). 301) The travel limit sleeve (307) on the lower surface and the compression spring (308) sleeved on the outside of the screw tube (304), wherein one end of the compression spring (308) abuts against the end face of the nut (305) and the other end of the compression spring (308) abuts against the stepped surface of the travel limit sleeve (307); rotate the handle sleeve (306), the handle sleeve (306) drives the nut (305) to rotate, rotate to adjust the engagement position with the screw tube (304), and adjust the preload of the compression spring (308).

4. A seat with dynamically adaptive lumbar support force according to claim 1, characterized in that: The backrest (2) includes a backrest base plate (201), a lumbar support adjustment assembly hinged to the lumbar support (4) for adjusting the up and down position of the lumbar support, and an elastic connection assembly for generating elastic force so that the lumbar support adapts to fit the waist.

5. A seat with dynamically adaptive lumbar support force according to claim 4, characterized in that: The lumbar support adjustment assembly includes two sets of guide rails (202) arranged parallel to each other on the backrest base plate (201), a matching slider (203) hinged to the lumbar support (4) and movable up and down along the guide rails (202), a matching nut (204) embedded in the matching slider (203), a lead screw (205) vertically inserted on the backrest base plate (201) with its upper end passing through the matching nut (204) and the matching slider (203), an adjustment knob (206) located at the lower end of the lead screw (205), and a lower baffle (207) for limiting the displacement stroke of the adjustment knob. When the adjustment knob (206) is rotated, the lead screw (205) can drive the matching slider (203) to move up and down along the guide rails (202).

6. A seat with dynamically adaptive lumbar support force according to claim 5, characterized in that: The elastic connection assembly includes a connecting spring (208) sleeved on the lead screw (205) and a fastening nut (209) located at the upper end of the connecting spring (208) and sleeved on the lead screw (205) and movable with the lead screw. The lower end of the connecting spring (208) abuts against the inner surface of the lower baffle (207). Under the action of external force, the waist support pushes the matching slider (203) to move downward along the guide rail (202), and the lead screw (205) and the fastening nut (209) move downward together to compress the connecting spring (208).

7. A seat with dynamically adaptive lumbar support force according to claim 6, characterized in that: The sum of the adjustment stroke S1 of the adjustment knob (206) and the compression stroke S2 ​​of the connecting spring (208) is not greater than the stroke S3 of the guide rail (202).

8. A seat with dynamically adaptive lumbar support force according to claim 1, characterized in that: The base (1) includes a base (101), a breathable seat cushion (102) located on the upper surface of the base (101), and a friction element (103) located on the lower surface of the base (101). The base (101) includes a hollow annular structure (1011) and a mesh fabric (1012) fixed on the hollow annular structure (1011).

9. A seat with dynamically adaptive lumbar support force according to claim 1, characterized in that: The elastic component (3) includes a torsion spring shaft (310) for hinged backrest (2) and base (1), a double torsion spring (311) sleeved on the torsion spring shaft (310), and a torsion spring limiting member (312) located at the bottom of backrest (2). A torsion spring pad (313) that fits against the surface of backrest (2) is provided at the position where the middle torsion arm of the double torsion spring (311) contacts the back of backrest (2). The two torsion arms of the double torsion spring (311) pass through the base (1) and are fixed to the base (1). In the initial state, the double torsion spring (311) is compressed, generating an initial preload force, pushing the backrest (2) to rotate forward, and the torsion spring limiting member (312) abuts against the base.

10. A seat with dynamically adaptive lumbar support force according to claim 1, characterized in that: The lumbar support (4) includes an arc-shaped support (402) hinged to the backrest (2) via a backrest connector (401) and a flexible pad (403) located on the front side of the arc-shaped support (402).

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