A multi-directional adjustment mechanism for a lumbar support of a sofa seat

Abstract

The application discloses a multi-direction adjusting mechanism for a lumbar support of a sofa seat and belongs to the technical field of furniture. The mechanism comprises a backrest frame, a support frame, a linear driving mechanism for driving the support frame to lift, and a sliding assembly for guiding the lifting of the support frame. Two support rods are further included, the upper ends of the two support rods being hingedly connected to the front side of the support frame. A synchronous rod is fixedly connected to the middle parts of the two support rods at both ends, so that the two support rods form a linkage structure. A second sliding rail is fixedly installed on the support frame. A second sliding block is slidingly arranged in the second sliding rail. A connecting rod is hingedly connected to the second sliding block at one end and to the middle part of the synchronous rod at the other end. The linear driving device drives the second sliding block to move and drive the linkage of the connecting rod and the synchronous rod. The linear driving mechanism realizes the front-back and up-down bidirectional adjustment of the lumbar support. The problems that the traditional lumbar support cannot dynamically adapt to the body shape of a user and the change of a sitting posture are solved. The mechanism has the advantages of wide adjusting range, convenient operation, stable and reliable structure.

Description

Technical Field

[0001] This utility model belongs to the field of furniture technology, and specifically relates to a multi-directional adjustment mechanism for lumbar support of sofa seats. Background Technology

[0002] In modern home life, sofas, as important pieces of furniture for relaxation, directly impact the user experience with their comfort. Currently, most sofas on the market use a fixed lumbar support design, creating a lumbar support structure by filling the seat cushion with materials such as sponge or foam. This traditional design has significant functional defects: firstly, the fixed height of the lumbar support cannot adapt to the different lumbar curves of users of different body types, leading to problems such as shorter users having their lower back unsupported or taller users experiencing excessive pressure on their lower back; secondly, the single thickness of the lumbar support cannot dynamically adjust according to changes in the user's sitting posture, and maintaining the same support level for a long time can easily cause lower back muscle fatigue. More importantly, current technology lacks the ability to coordinate the adjustment of the lumbar support angle and height, failing to achieve a dynamic support effect that conforms to ergonomics. This structural defect not only reduces user comfort but may also have adverse effects on the user's lumbar spine health with long-term use. Although adjustable height lumbar support products have appeared on the market, they generally suffer from limited adjustment range, inconvenient operation, and poor structural stability, failing to meet users' diverse needs for sofa comfort. Utility Model Content

[0003] The purpose of this application is to provide a multi-directional lumbar support adjustment mechanism for sofa seats, which improves the adjustment range and stability of the lumbar support and adapts to the lumbar curve and dynamic changes in sitting posture of users of different body types.

[0004] This application provides a multi-directional adjustment mechanism for lumbar support in a sofa seat. The technical solution is as follows: it includes a backrest frame, a support frame, a linear drive mechanism for driving the support frame to rise and fall, and a sliding assembly for guiding the rise and fall of the support frame; it also includes two symmetrically distributed support rods, the upper ends of which are hinged to the front side of the support frame; the lower ends of the two support rods are connected to the lumbar support; a synchronizing rod, the two ends of which are respectively fixedly connected to the middle of the two support rods, so that the two support rods form a linkage structure; a second slide rail, which is fixedly installed on the support frame and extends along the length direction of the backrest frame; a second slider, which is slidably disposed in the second slide rail; a connecting rod, one end of which is hinged to the second slider and the other end of which is hinged to the middle of the synchronizing rod; a linear drive device, the fixed end of which is installed on the support frame and the output end of which is connected to the second slider; the linear drive device is used to drive the second slider to move along the second slide rail, and the second slider drives the connecting rod to swing, and the connecting rod drives the synchronizing rod and the two support rods to swing synchronously, so as to realize the front and back adjustment of the lumbar support; the linear drive mechanism operates to drive the support frame and the support rods on it to rise and fall along the backrest frame, so as to realize the up and down adjustment of the lumbar support.

[0005] Furthermore, this application also proposes that the linear drive mechanism includes a motor, a lead screw, and a nut sleeve, wherein the lead screw is mounted on the backrest frame; the motor is fixedly mounted on the back of the backrest frame; the lead screw is connected to the output shaft of the motor, and the motor is used to drive the lead screw to rotate; the nut sleeve is adapted to be mounted on the lead screw and fixedly connected to the support frame; when the motor drives the lead screw to rotate, the support frame is driven to move up and down along the axial direction of the lead screw through the nut sleeve.

[0006] Furthermore, this application also proposes that the sliding assembly includes a first slide rail and a first slider; the first slide rail is fixed to the backrest frame in a vertical direction, the first slider is fixed to the support frame, and the first slider is slidably connected to the first slide rail to form a guide structure for the lifting and lowering movement of the support frame.

[0007] Furthermore, this application also proposes that the first slider is fixed to the back of the support frame.

[0008] Furthermore, this application also proposes that a first limiting block is fixedly provided inside the first slide rail above the first slider.

[0009] Furthermore, this application also proposes that the first limiting block has a first buffer protrusion integrally formed on the side facing the first slider. The first buffer protrusion is made of elastic material and is used to limit the upward limit position of the first slider and buffer the collision force.

[0010] Furthermore, this application also proposes that a second limiting block is fixedly provided inside the second slide rail above the second slider.

[0011] Furthermore, this application also proposes that the second limiting block has a second buffer protrusion integrally formed on the side facing the second slider. The second buffer protrusion is made of elastic material and is used to limit the upward limit position of the second slider and buffer the collision force.

[0012] Furthermore, this application also proposes that the linear drive device is an electric push rod; the fixed end of the electric push rod is installed on the backrest frame, and its telescopic end is connected to the second slider, providing power to drive the support rod to swing through telescopic movement.

[0013] Furthermore, this application also proposes that it includes two support seats fixed to the backrest frame, with the upper and lower ends of the lead screw rotatably connected to the two support seats respectively.

[0014] As can be seen from the above, the lumbar support multi-directional adjustment mechanism for sofa seats provided in this application drives the second slider to move through a linear drive device, thereby driving the connecting rod and the synchronous rod to move in conjunction. Combined with the linear drive mechanism, the lumbar support can be adjusted in both directions, both forward and backward and up and down. This solves the problem that traditional lumbar supports cannot dynamically adapt to changes in the user's body shape and sitting posture. It has the advantages of wide adjustment range, convenient operation, and stable and reliable structure. Attached Figure Description

[0015] Figure 1 This is a front view of the lumbar support multi-directional adjustment mechanism provided in the embodiments of this application.

[0016] Figure 2 This is a front view of the lumbar support multi-directional adjustment mechanism provided in an embodiment of this application.

[0017] Figure 3 This is a side view of the lumbar support multi-directional adjustment mechanism provided in an embodiment of this application.

[0018] Figure 4 This is a schematic diagram of the back of the lumbar support multi-directional adjustment mechanism provided in the embodiments of this application.

[0019] Labeling Explanation: 10. Backrest Frame; 20. Support Frame; 31. First Slide Rail; 32. First Slider; 33. First Limiting Block; 34. First Buffer Protrusion; 41. Lead Screw; 42. Nut Sleeve; 43. Motor; 44. Support Base; 51. Second Slide Rail; 52. Second Slider; 53. Second Limiting Block; 54. Second Buffer Protrusion; 60. Linear Drive Device; 71. Support Rod; 72. Synchronizing Rod; 73. Connecting Rod; 74. Lumbar Support. Detailed Implementation

[0020] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The components of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. It should be noted that similar reference numerals and letters in the following drawings indicate similar items; therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0021] In existing technologies, the lumbar support structure of sofas and chairs typically uses a fixed design, which cannot be adjusted according to different user body shapes and usage needs. The lack of an adjustable mechanism between the existing lumbar support and the seat body leads to user fatigue after prolonged use and fails to meet personalized support needs. In scenarios requiring adaptation to different heights or sitting postures, a fixed-height lumbar support is insufficient to provide effective support, affecting user comfort.

[0022] To address the aforementioned issues, the core contradiction of existing lumbar supports, with their single-position adjustment, was first recognized. Analysis of ergonomic principles revealed that lumbar support requires dual adjustment capabilities in both vertical height and forward / backward depth. Based on this, a combination of a lifting mechanism and a swing mechanism was considered, using independent drive units to control movement in both dimensions. Further research into motion transmission methods led to the use of a linkage 73 mechanism to convert linear motion into rotational motion, while a synchronization structure was designed to ensure consistent movement of the support rods 71 ​​on both sides. Ultimately, a technical solution achieving multi-directional adjustment through linear drive was developed.

[0023] Therefore, this application proposes a multi-directional adjustment mechanism for lumbar support in a sofa seat, including an adjustment mechanism for a backrest frame 10 and a support frame 20. The support frame 20 achieves lifting and lowering movement through a linear drive mechanism, and a sliding component guides the vertical movement of the support frame 20. Two symmetrically distributed support rods 71 ​​are hinged at their upper ends to the front side of the support frame 20, and their lower ends are connected to the lumbar support 74. A synchronizing rod 72 connects the middle of the two support rods 71 ​​to form a linkage structure. A second slide rail 51 is fixed on the support frame 20, and a second slider 52 slides within the slide rail. The two ends of a connecting rod 73 are respectively hinged to the slider and the synchronizing rod 72. A linear drive device 60 drives the second slider 52 to move, and through the connecting rod 73, drives the synchronizing rod 72 to swing, causing the support rod 71 to change its angle, thereby achieving the front-to-back adjustment of the lumbar support 74.

[0024] The linear drive mechanism refers to the device that drives the support frame 20 to rise and fall through linear motion. Specifically, it can be implemented using a motor 43 in conjunction with a lead screw 41 and nut mechanism. The rotation of the motor 43 drives the lead screw 41 to rotate, causing the nut sleeve 42 to move axially along the lead screw 41, thereby pushing the support frame 20 to rise and fall. The support rod 71 is a rigid rod connecting the support frame 20 and the lumbar support 74. Specifically, it can be implemented using a metal connecting rod 73, with its upper end hinged to the support frame 20 and its lower end fixed to the lumbar support 74. The synchronizing rod 72 is a transverse connecting piece connecting the two support rods 71. Specifically, it can be implemented using a steel pipe or alloy rod, ensuring synchronous swinging of the two support rods 71 ​​through a rigid connection. The second slide rail 51 is a linear guide structure fixed to the support frame 20. Specifically, it can be implemented using U-shaped channel steel or a guide rail, extending along the length of the backrest frame 10. The second slider 52 is a moving component that slides along the second slide rail 51. Specifically, it can be a metal block with a low-friction coating, hinged to the connecting rod 73 to form a motion transmission node. Link 73 refers to the transmission component connecting the slider and the synchronizing rod 72. Specifically, it can be implemented using an adjustable-length metal rod, which converts linear motion into rotational motion through hinges at both ends. Linear drive device 60 refers to the actuator that generates linear driving force. Its fixed end is mounted on the support frame 20, and its output end is connected to the second slider 52.

[0025] Specifically, when the support frame 20 moves vertically along the backrest frame 10 via a linear drive mechanism, it causes the support rod 71 to rise and fall as a whole, thereby changing the vertical position of the lumbar support 74. When it is necessary to adjust the front and back position of the lumbar support 74, the linear drive device 60 pushes the second slider 52 to move along the second slide rail 51. The second slider 52 drives the connecting rod 73 to swing, and at the same time, the connecting rod 73 drives the synchronizing rod 72 to rotate around the hinge point of the support frame 20. The rotation of the synchronizing rod 72 forces the two support rods 71 ​​to change their tilt angle synchronously, causing the lumbar support 74 to move back and forth. The lifting and lowering motion and the front and back adjustment are decoupled through independent drive mechanisms, and their coordinated work allows the lumbar support 74 to form a composite motion trajectory in space.

[0026] Compared to existing technologies, traditional lumbar supports 74 are fixedly installed and can only provide a single support position. This solution, through a combination of a linear drive mechanism and a linkage mechanism, achieves dual-degree-of-freedom adjustment of the lumbar support 74 in both vertical and horizontal directions for the first time. Existing technologies lack a rigid connection structure for synchronously controlling the support rods 71 ​​on both sides, which can easily lead to asymmetrical support. The introduction of the synchronizing rod 72 ensures consistent movement on both sides. Compared to adjustment mechanisms using complex gear transmissions, this solution achieves motion conversion through a simple combination of slide rails and connecting rods 73, resulting in a more compact structure and lower manufacturing costs.

[0027] Through the above technical solution, this application can precisely adjust the spatial position of the lumbar support 74 according to the user's body shape and usage habits, providing personalized lumbar support. The vertical adjustment range can cover the lumbar spine position needs of users of different heights, and the forward and backward adjustment can change the support depth to adapt to changes in sitting posture. The linkage structure ensures the symmetrical distribution of support force during adjustment, avoiding mechanism jamming caused by unilateral force. The independent drive design allows up-and-down and forward / backward adjustments to be performed individually or simultaneously, significantly improving operational flexibility.

[0028] This application further proposes a linear drive mechanism including a motor 43, a lead screw 41, and a nut sleeve 42. The lead screw 41 is mounted on the backrest frame 10, the motor 43 is fixedly mounted on the back of the backrest frame 10, the lead screw 41 is connected to the output shaft of the motor 43, and the nut sleeve 42 is adapted to be mounted on the lead screw 41 and fixedly connected to the support frame 20. When the motor 43 drives the lead screw 41 to rotate, the support frame 20 is driven to move up and down along the axial direction of the lead screw 41 through the nut sleeve 42.

[0029] Among them, motor 43 refers to the power source that converts electrical energy into mechanical energy. Specifically, it can be implemented using a DC servo motor 43 with a reducer. The reducer can reduce the speed and increase the output torque, ensuring that the lead screw 41 receives sufficient driving force. Lead screw 41 refers to a transmission component with external threads. Specifically, it can be implemented using a trapezoidal thread lead screw 41. The thread structure can convert rotary motion into linear motion. Nut sleeve 42 refers to a sleeve component that threads with the lead screw 41. Specifically, it can be implemented using a self-lubricating nut made of copper alloy. The threaded fit can ensure the accuracy of motion conversion while reducing friction loss.

[0030] Specifically, the motor 43 drives the lead screw 41 to rotate via its output shaft. The threaded engagement between the nut sleeve 42 and the lead screw 41 converts the rotational motion into linear motion. The fixed connection between the nut sleeve 42 and the support frame 20 allows the linear motion to be directly transmitted to the support frame 20, thereby driving the support rod 71 and the lumbar support 74 to rise and fall. The rigid mounting of the lead screw 41 avoids radial offset during transmission. The motor 43's placement on the back of the backrest frame 10 reduces space occupation and avoids interference with other adjustment mechanisms. The self-locking characteristic of the threaded drive prevents the support frame 20 from shifting due to external forces in the non-drive state, thus maintaining the stability of the lumbar support 74's height.

[0031] Compared to existing technologies, traditional sofas and chairs mostly use manual adjustment or simple gas spring structures to achieve height adjustment, which suffers from low adjustment accuracy and is prone to accidental displacement. By adopting a lead screw 41 transmission structure, rotational motion is converted into linear displacement, and the mechanical characteristics of the threaded engagement are used to achieve millimeter-level precision in height control. At the same time, the programmable control of the motor 43 enables multi-level height adjustment, which can adapt to the different needs of users of different body types for lumbar support height.

[0032] Through the above technical solution, this application can drive the lead screw 41 through the motor 43 to generate a stable linear displacement, thereby driving the support frame 20 and the lumbar support 74 to perform precise lifting and lowering movements. This solves the problems of insufficient height adjustment accuracy and easy positional deviation of the lumbar support 74 in traditional sofas and chairs, allowing users to adjust the lumbar support height according to their own needs and improve the comfort of use.

[0033] This application further proposes a sliding assembly including a first slide rail 31 and a first slider 32. The first slide rail 31 is fixed to the backrest frame 10 in the vertical direction, and the first slider 32 is fixed to the support frame 20. The first slider 32 is slidably connected to the first slide rail 31 to form a guide structure for the lifting and lowering movement of the support frame 20.

[0034] The first slide rail 31 refers to a rigid track structure arranged along the length of the backrest frame 10. It can be made of metal profile or high-strength engineering plastic, and its cross-sectional shape is designed as a guide groove that cooperates with the slider to limit the linear movement trajectory of the support frame 20. The first slider 32 refers to a moving part that forms a sliding pair with the first slide rail 31. It can be a metal block with a low-friction coating, which achieves sliding contact by being embedded in the slide rail groove. It is used to transfer the load of the support frame 20 to the slide rail and limit its lateral displacement.

[0035] Specifically, the first slide rail 31 is vertically fixed to the backrest frame 10 frame by bolts or welding, and its axis is parallel to the lifting direction of the support frame 20. The first slider 32 is rigidly connected to the back of the support frame 20 by fasteners, and its sliding surface maintains surface contact with the inner wall of the slide rail groove. When the support frame 20 is subjected to lifting motion by the linear drive mechanism, the first slider 32 slides along the inner wall of the slide rail groove. The geometric constraint of the slide rail groove eliminates the horizontal displacement degree of freedom of the support frame 20, retaining only the single degree of freedom of vertical motion. The contact surface between the first slide rail 31 and the first slider 32 is made of low-friction material or lubricated to reduce sliding resistance. At the same time, the lateral constraint of the groove wall on the slider prevents the support frame 20 from tilting or swaying during lifting.

[0036] Compared to existing technologies, traditional sofa lumbar support adjustment mechanisms typically employ a non-guided linear drive structure, with the support frame 20 relying solely on a single-point drive rod for support. This makes it prone to swaying or shifting under load changes or motion inertia. This solution, through a rigid guide structure of the slide rail and slider, expands the force-bearing point of the support frame 20 from a single-point drive to a continuous contact surface distributed along the slide rail. This effectively disperses the motion load and suppresses lateral displacement, thereby improving the stability of the lifting process.

[0037] Through the above technical solution, this application solves the problem of motion jamming or trajectory deviation caused by the lack of a guiding structure in the support frame 20. By forming a forced guiding constraint through the geometric cooperation of the slide rail and the slider, it ensures that the support frame 20 moves smoothly only along a preset path. This structure can eliminate motion interference caused by assembly errors or uneven loads, making the up-and-down adjustment of the lumbar support 74 more reliable and avoiding positional deviation of the lumbar support 74 or overload damage to the drive mechanism caused by the offset of the support frame 20.

[0038] This application further proposes that the first slider 32 is fixed to the back of the support frame 20.

[0039] The back side of the support frame 20 refers to the side of the support frame 20 away from the waist support 74 adjustment mechanism. This can be achieved through welding or bolting, ensuring a rigid connection between the first slider 32 and the main body of the support frame 20. The first slider 32 is a sliding component that cooperates with the first slide rail 31, used to guide the vertical movement of the support frame 20.

[0040] Specifically, when the first slider 32 is fixed to the back of the support frame 20, its sliding contact surface is in the same vertical plane as the guide surface of the first slide rail 31, so that the lateral force on the support frame 20 during lifting is evenly transmitted to the slide rail structure. Since the back area of ​​the support frame 20 is far from the hinge point of the front support rod 71 and the load center of the waist support 74, this layout avoids slider offset caused by torque imbalance during lifting. The back fixing method also provides space for the symmetrical installation of the linear drive mechanism, so that the transmission axis of the nut sleeve 42 and the lead screw 41 remains parallel to the sliding direction of the first slider 32, reducing the risk of jamming during the lifting of the support frame 20.

[0041] Compared to existing technologies, the sliders of existing sliding components are usually located on the side or front of the support frame 20. This makes the contact surface between the slider and the slide rail susceptible to interference from the lateral force generated by the adjustment of the waist support 74, affecting the guiding accuracy. In contrast, this solution uses a back-mounting method to ensure that the force direction of the slider is consistent with the extension direction of the slide rail, eliminating the problem of increased frictional resistance caused by unreasonable spatial layout.

[0042] Through the above technical solution, this application effectively improves the linearity and stability of the lifting movement of the support frame 20, and avoids wear or deformation of the slider caused by uneven force. This layout also optimizes the internal space utilization of the support frame 20, provides installation positions for other adjustment mechanisms, and ensures the coordinated operation of multi-directional adjustment functions.

[0043] This application further proposes that a first limiting block 33 is fixedly provided inside the first slide rail 31 above the first slider 32.

[0044] The first limiting block 33 is a blocking component that is fixedly installed at the upper end of the first slide rail 31. Specifically, it can be fixed by bolts. Its position corresponds to the upper limit position of the first slider 32 and is used to limit the movement range of the slider through physical contact.

[0045] Specifically, when the support frame 20 is driven to rise and fall by the linear drive mechanism, the first slider 32 fixed to the support frame 20 slides vertically along the first slide rail 31. The first limiting block 33 is pre-fixed at the upper end of the movement path of the first slider 32 within the first slide rail 31. When the support frame 20 rises to the set height, the first slider 32 contacts the first limiting block 33, at which point the first limiting block 33 acts as a block, preventing the slider from continuing to rise. Through this mechanical limiting method, the lifting stroke of the support frame 20 is strictly limited within a safe range, avoiding the slider from disengaging from the slide rail or colliding with the backrest frame 10 due to overload of the drive mechanism, thereby protecting the mechanical structural integrity of the adjustment mechanism.

[0046] Compared to existing technologies, the lumbar support adjustment mechanism of traditional sofa seats typically relies on the travel control of the drive unit itself or electronic sensors to achieve limit movement, which carries the risk of damage to mechanical components due to overtravel caused by control system failure. This solution, however, by setting a fixed limit block within the first slide rail 31, directly constrains the slider movement mechanically, eliminating the need for an external control system and significantly improving limit reliability.

[0047] Through the above technical solution, this application effectively prevents mechanical collisions or structural deformation caused by the slider exceeding the safe stroke during the lifting and lowering process of the support frame 20, ensuring that the up and down adjustment of the lumbar support 74 is always within the controllable range and extending the service life of the adjustment mechanism.

[0048] This application further proposes that the first limiting block 33 has a first buffer protrusion 34 integrally formed on the side facing the first slider 32. The first buffer protrusion 34 is made of elastic material and is used to limit the upward limit position of the first slider 32 and buffer the collision force.

[0049] The first buffer protrusion 34 can be hemispherical. This structure absorbs impact energy through elastic deformation, avoiding rigid contact. The elastic material refers to a material with high resilience and compressive deformation capacity, specifically rubber, silicone, or thermoplastic polyurethane. This material disperses collision stress through its own deformation, reducing wear on the contact surface.

[0050] Specifically, when the support frame 20 drives the first slider 32 to slide upward along the first slide rail 31 to its limit position, the first slider 32 comes into contact with the first buffer protrusion 34. The elastic material deforms under pressure, converting the mechanical impact into elastic potential energy, which is then released through material recovery. The one-piece molding design makes the buffer structure and the limiting block a single unit, preventing the buffer components from detaching due to long-term impact.

[0051] Compared to existing technologies, traditional limiting devices typically employ split-type buffer pads or rigid limiting blocks. Split-type buffer pads suffer from complex installation and are prone to detachment, while rigid limiting blocks generate noise and component deformation upon direct impact. This solution utilizes a one-piece molded elastic buffer structure to absorb impact energy while maintaining the limiting function, thus resolving the noise and wear problems caused by rigid collisions.

[0052] Through the above technical solution, this application achieves silent buffering when the first slider 32 contacts the limit block during the lifting process of the support frame 20, reduces the wear of mechanical parts caused by frequent collisions, extends the service life of the sliding components, and improves the operational stability of the waist support 74 adjustment mechanism.

[0053] This application further proposes that a second limiting block 53 is fixedly provided inside the second slide rail 51 above the second slider 52.

[0054] The second limiting block 53 is a blocking component fixed inside the second slide rail 51 and above the movement path of the second slider 52. It can be made of plastic and is used to limit the maximum upward sliding stroke of the second slider 52 along the second slide rail 51. The position inside the second slide rail 51 refers to the fixed structure formed by the second limiting block 53 and the second slide rail 51 connected by bolts. Its installation position is preset according to the movement range of the second slider 52 to ensure that the slider is blocked when it moves to the predetermined position.

[0055] Specifically, when the linear drive device 60 pushes the second slider 52 to move along the second slide rail 51, the second slider 52 slides upward until it contacts the second limiting block 53 and then stops moving. At this time, the second limiting block 53 restricts the slider from continuing to move upward through rigid blocking, thereby preventing the slider from exceeding the preset stroke range. This blocking process directly cuts off the overtravel path of the slider, preventing excessive torque from being applied to the hinge point of the connecting rod 73 and the synchronous rod 72 due to excessive movement, thereby preventing deformation of the support rod 71 or overload of the drive device.

[0056] Compared to existing technologies, the movement range of the slider in the traditional lumbar support 74 adjustment mechanism relies solely on the stroke control of the drive device itself, which carries the risk of mechanical error accumulation or sensor failure leading to slider malfunction. This solution, however, adds a physical limiting structure inside the slide rail, forming a dual protection mechanism. Even if the drive device fails, the second limiting block 53 can still mechanically restrict the slider position, significantly reducing the probability of structural damage.

[0057] Through the above technical solution, this application effectively solves the problem of uncontrolled slider movement range during the front and rear adjustment of the lumbar support 74. By combining rigid limit and physical blocking, it ensures that the slider movement trajectory is always within a safe range, thereby maintaining the stable operation of the lumbar support 74 adjustment mechanism and extending its service life.

[0058] This application further proposes that the second limiting block 53 has a second buffer protrusion 54 integrally formed on the side facing the second slider 52. The second buffer protrusion 54 is made of elastic material and is used to limit the upward limit position of the second slider 52 and buffer the collision force.

[0059] The second buffer protrusion 54 refers to an elastic protrusion structure provided on the contact surface of the second limiting block 53. It can be made of polyurethane or rubber material, which absorbs mechanical impact energy through the elastic deformation of the material. The integral molding means that the second buffer protrusion 54 and the second limiting block 53 are formed into an integral structure through injection molding or compression molding, avoiding assembly gaps between the buffer component and the limiting block.

[0060] Specifically, when the second slider 52 moves upward along the second slide rail 51 to its limit position, the second buffer protrusion 54 absorbs the kinetic energy of the slider through the compression deformation of the elastic material, transforming rigid contact into flexible buffering. During this process, the deformation of the second buffer protrusion 54 is positively correlated with the impact force, and the stretching and rebound of the molecular chains within the material dissipates energy. Due to the integrated structural design of the second buffer protrusion 54 and the second limiting block 53, it will not detach or shift under repeated impacts, ensuring the long-lasting effectiveness of the limiting function.

[0061] Compared to existing technologies, traditional limit blocks use metal for direct positioning, resulting in metal-on-metal collision noise and surface wear when the slider contacts the block. This solution replaces rigid contact with an elastic buffer structure, eliminating mechanical collision noise and reducing impact stress on the contact surface between the slider and the guide rail while maintaining the stroke limiting function.

[0062] Through the above technical solution, this application effectively reduces the noise level generated by the upward movement of the second slider 52, reduces the wear depth of the inner wall of the second slide rail 51, and extends the service life of the adjustment mechanism. The collision energy is gradually absorbed through the deformation process of the elastic material, avoiding the negative impact of instantaneous impact on the slider's sliding accuracy and ensuring the smoothness of the front-to-back adjustment of the waist support 74.

[0063] This application further proposes that the linear drive device 60 is an electric push rod; the fixed end of the electric push rod is installed on the support frame 20, and its telescopic end is connected to the second slider 52, providing power to drive the support rod 71 to swing through telescopic movement.

[0064] The electric actuator is a power device that converts electrical energy into linear reciprocating motion. Specifically, it can be implemented using a structure with a built-in motor 43 driving a lead screw, with its extension end outputting linear displacement. The fixed end being mounted on the support frame 20 means that the housing of the electric actuator is rigidly connected to the support frame 20 via bolts or welding. This can be achieved using a mounting bracket and fasteners, thereby ensuring the stability of the power output.

[0065] Specifically, the fixed end of the electric actuator forms a rigid constraint with the support frame 20, and its telescopic end applies a pushing or pulling force to the second slider 52 through the hinge point. When the electric actuator is energized and extends or retracts, the linear motion of its output end is converted into the rotational motion of the synchronizing rod 72 through the hinge point, thereby driving the two support rods 71 ​​to deflect synchronously around the hinge point. Since the synchronizing rod 72 is fixedly connected to the middle of the two support rods 71, the swing angle of the two support rods 71 ​​remains consistent, making the displacement of the waist support 74 symmetrically distributed in the front-back direction. The linear drive path of the electric actuator and the extension direction of the second slide rail 51 form a spatial matching relationship to avoid motion interference.

[0066] Compared to existing technologies, traditional lumbar support 74 adjustment mechanisms often employ gear and rack systems or manual knobs, resulting in long transmission chains and low synchronization accuracy. This solution, however, directly drives the linkage components via an electric actuator, shortening the power transmission path to a single drive source and a linear-rotational motion conversion between the synchronizer 72, eliminating the error accumulation caused by multi-stage transmissions. Furthermore, the electric actuator offers higher stroke control accuracy than traditional mechanical transmissions, enabling stepless adjustment of the lumbar support 74 position.

[0067] Through the above technical solution, this application solves the matching problem between the linear drive device 60 and the linkage structure. By directly driving the synchronous rod 72 or the slider through the linear output of the electric push rod, the swing angles of the two support rods 71 ​​are strictly synchronized. This design simplifies the power transmission path, avoids motion lag caused by multiple rod connections, and improves the response speed and positioning accuracy of the lumbar support 74 in front and behind adjustment.

[0068] This application further proposes a backrest frame 10 with two support seats 44 fixed thereto, and the upper and lower ends of the lead screw 41 are rotatably connected to the two support seats 44 respectively.

[0069] The support base 44 refers to a rigid mounting structure fixed to the backrest frame 10. Specifically, it can be a metal base fixed to the backrest frame 10 with bolts, providing a stable rotational support foundation for the lead screw 41. The rotary connection refers to a connection method that allows the lead screw 41 to rotate around its own axis. Specifically, it can be implemented using rolling bearings or sliding bushings, used to constrain the radial displacement of the lead screw 41 and transmit axial loads.

[0070] Specifically, the upper and lower ends of the lead screw 41 are mounted on two support seats 44 via bearing assemblies, forming a double-end fixed support structure. When the motor 43 drives the lead screw 41 to rotate, the upper and lower ends of the lead screw 41 maintain stable rotational freedom within the support seats 44, avoiding radial sway caused by single-sided cantilever support. The double support seats 44 distribute the axial load of the lead screw 41 to the upper and lower areas of the backrest frame 10, reducing bending deformation of the lead screw 41 due to its own weight or load. At the same time, axial constraints ensure the thread engagement accuracy between the nut sleeve 42 and the lead screw 41, thereby improving transmission efficiency.

[0071] Compared with existing technologies, traditional lead screw 41 lifting mechanisms typically employ a single-end support structure. The free end of the lead screw 41 is prone to radial vibration during movement, leading to swaying of the support frame 20 and wear of the threaded joint. This solution uses double support seats 44 to form a fully constrained support, eliminating the cantilever effect of the lead screw 41, reducing vibration amplitude, and simultaneously reducing local stress concentration by distributing the load, thus extending the service life of the lead screw 41.

[0072] Through the above technical solution, this application effectively suppresses the radial deflection and vibration of the lead screw 41 during the lifting process, enhances the rigidity of the linear drive mechanism, and reduces the risk of abnormal wear of the threaded pair, thereby ensuring the smoothness of the lifting motion of the support frame 20 and the transmission accuracy.

[0073] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A multi-directional lumbar support adjustment mechanism for a sofa seat, comprising a backrest frame (10), a support frame (20), a linear drive mechanism for driving the support frame (20) to rise and fall, and a sliding assembly for guiding the support frame (20) to rise and fall; Its features are: It also includes two symmetrically distributed support rods (71), the upper ends of which are hinged to the front side of the support frame (20); the lower ends of the two support rods (71) are connected to a waist support (74); Synchronous rod (72), with its two ends fixedly connected to the middle of the two support rods (71), so that the two support rods (71) form a linkage structure; The second slide rail (51) is fixedly installed on the support frame (20) and extends along the length of the backrest frame (10); The second slider (52) is slidably disposed within the second slide rail (51); The connecting rod (73) has one end hinged to the second slider (52) and the other end hinged to the middle of the synchronizing rod (72); A linear drive device (60) has its fixed end mounted on the support frame (20) and its output end connected to the second slider (52); The linear drive device (60) is used to drive the second slider (52) to move along the second slide rail (51). The second slider (52) drives the connecting rod (73) to swing. The connecting rod (73) drives the synchronous rod (72) and the two support rods (71) to swing synchronously, thereby realizing the front and back adjustment of the lumbar support (74). When the linear drive mechanism is running, it drives the support frame (20) and the support rods (71) on it to rise and fall along the backrest frame (10), thereby realizing the up and down adjustment of the lumbar support (74).

2. The multi-directional lumbar support adjustment mechanism for a sofa seat according to claim 1, characterized in that: The linear drive mechanism includes a motor (43), a lead screw (41), and a nut sleeve (42). The lead screw (41) is mounted on the backrest frame (10). The motor (43) is fixedly mounted on the back of the backrest frame (10). The lead screw (41) is connected to the output shaft of the motor (43), and the motor (43) is used to drive the lead screw (41) to rotate. The nut sleeve (42) is adapted to be mounted on the lead screw (41) and fixedly connected to the support frame (20). When the motor (43) drives the lead screw (41) to rotate, the nut sleeve (42) drives the support frame (20) to move up and down along the axial direction of the lead screw (41).

3. The multi-directional lumbar support adjustment mechanism for a sofa seat according to claim 1, characterized in that: The sliding assembly includes a first slide rail (31) and a first slider (32); the first slide rail (31) is fixed to the backrest frame (10) in the vertical direction, the first slider (32) is fixed to the support frame (20), and the first slider (32) is slidably connected to the first slide rail (31) to form a guide structure for the lifting and lowering movement of the support frame (20).

4. A multi-directional lumbar support adjustment mechanism for a sofa seat according to claim 3, characterized in that: The first slider (32) is fixed to the back of the support frame (20).

5. A multi-directional lumbar support adjustment mechanism for a sofa seat according to claim 3, characterized in that: A first limiting block (33) is fixedly provided inside the first slide rail (31) above the first slider (32).

6. A multi-directional lumbar support adjustment mechanism for a sofa seat according to claim 5, characterized in that: The first limiting block (33) has a first buffer protrusion (34) integrally formed on the side facing the first slider (32). The first buffer protrusion (34) is made of elastic material and is used to limit the upward limit position of the first slider (32) and buffer the collision force.

7. A multi-directional lumbar support adjustment mechanism for a sofa seat according to claim 1, characterized in that: A second limiting block (53) is fixedly provided inside the second slide rail (51) above the second slider (52).

8. A multi-directional lumbar support adjustment mechanism for a sofa seat according to claim 7, characterized in that: The second limiting block (53) has a second buffer protrusion (54) integrally formed on the side facing the second slider (52). The second buffer protrusion (54) is made of elastic material and is used to limit the upward limit position of the second slider (52) and buffer the collision force.

9. A multi-directional lumbar support adjustment mechanism for a sofa seat according to claim 1, characterized in that: The linear drive device (60) is an electric push rod; the fixed end of the electric push rod is installed on the support frame (20), and its telescopic end is hinged to the second slider (52), providing power to drive the support rod (71) to swing through telescopic movement.

10. A multi-directional lumbar support adjustment mechanism for a sofa seat according to claim 2, characterized in that: It also includes two support seats (44) fixed to the backrest frame (10), and the upper and lower ends of the lead screw (41) are rotatably connected to the two support seats (44).

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