Sofa seat frame, sofa base assembly, sofa and sofa production and assembly process

The invention discloses a sofa seat frame, a sofa base assembly, a sofa and a sofa production and assembly process, the sofa seat frame comprises two cross beams arranged at intervals and two longitudinal beams connecting the two cross beams, wherein a plurality of supporting elastic pieces are arranged between the two cross beams; and each longitudinal beam comprises a first supporting plate for supporting a seat cushion and a first side plate arranged at one side of the lower part of the first supporting plate and used for being detachably connected with sofa fabric on the seat cushion. In the sofa seat frame provided by the invention, when the seat cushion is placed on the supporting elastic pieces, the first supporting plates can give a certain supporting force to the seat cushion, so as to improve the sitting comfort of users.

FIELD OF THE INVENTION

The invention relates to the technical field of furniture, in particular to a sofa seat frame, a sofa base assembly, a sofa and a sofa production and assembly process.

BACKGROUND OF THE INVENTION

As we all know, the furniture industry has always been a labor-intensive traditional industry, especially the sofa industry. Its production process requires a lot of manual labor and production materials. For the sofa, the bearing capacity of the sofa determines the service life of the sofa, while the sofa base assembly determines the bearing capacity of the sofa to a large extent. At present, the sofa base assembly is generally composed of a rack and a sofa seat frame detachably connected to the rack.

Among them, sofa seat frames made of solid wood are the most common. When a wooden seat frame is made, a framework is first set up with solid wood in a wood factory, and hooks for connecting supporting elastic pieces are installed on the wooden framework, and the hooks are fixed on the wooden framework by means of rivets or screws, etc. After the wooden framework is made, the framework is transported to a sofa assembly workshop. In the sofa assembly workshop, the supporting elastic pieces are installed on the wooden framework to obtain the wooden seat frame. Subsequently, the wooden seat frame and the wooden or iron rack are assembled to obtain a sofa base assembly; then the seat cushion is placed on the supporting elastic pieces and is wrapped with sofa fabric, and the fabric is fixed to the wooden seat frame by rivets, thus completing the assembly of the seat cushion part. Therefore, the sofa seat frame made of a solid wood material is not only light in weight but also easy to process, since the sofa can be assembled by a traditional manual production line, the sofa seat frame made of the solid wood material is suitable for sofa production technology in traditional furniture industry.

However, the sofa seat frame made of the solid wood material has the following defects: first, the supporting strength of the wooden seat frame is not enough, so that the wooden seat frame is easy to damage after being used for a period of time and has a short service life; second, due to the material reason, the wood needs to be tested in import and export trade, and when single pieces that do not meet the requirements are found during sampling inspection, the whole batch needs to be stranded or repatriated, which is not conducive to international trade; third, the connection process between the wooden seat frame and the iron rack is complicated and the connection stability is poor; fourth, due to the different materials of the wooden seat frame and the iron rack, they need to be produced in different workshops, which not only has a higher cost, but also increases the transportation distance, resulting in low installation efficiency; fifth, rivets are usually used to connect the seat cushion fabric and the wooden frame, so that the fault tolerance rate is low, if there is an assembly error, it is difficult to rework, thus causing waste of a large amount of materials; and sixth, there are many manual manufacturing processes for the wooden seat frame, which is not conducive to standardized production and has difficulty in maintaining the unity of sofa quality.

In view of various defects of the wooden seat frame, some powerful furniture enterprises have begun to try to use metal materials to make the sofa seat frame. Compared with the wooden seat frame, a sofa seat frame made of a metal material has higher supporting strength and a longer service life. However, at present, the metal seat frame on the market still has the problems of complex structure, many parts and troublesome assembly. As disclosed in a Comparative Document 1 (Publication Number: CN110101245A), the frame comprises two symmetrically arranged longitudinal beams and two cross beams for connecting the two longitudinal beams. The cross section of the longitudinal beam is L-shaped and comprises a vertical plate and a transverse plate, wherein the vertical plate and the transverse plate define a containing cavity, and the two cross beams are symmetrically arranged on the folded edges at two ends of the longitudinal beam and are located in the containing cavity. In addition, the frame also comprises at least one supporting beam which connects the two cross beams. Although the sofa seat frame in the Comparative Document 1 reduces the manufacturing materials and weight, it has more parts and is troublesome to assemble. At the same time, the longitudinal beam with the L-shaped cross section not only has low supporting strength, but also is prone to deformation. In addition, since a containing cavity is defined by the vertical plate and the horizontal plate on the longitudinal beam, when the seat cushion is placed on the sofa seat frame, the two sides of the seat cushion are not supported correspondingly. When the seat cushion is squeezed, the two sides are easy to collapse, so it is also necessary to process the sponges on the two sides of the seat cushion, which not only wastes materials but also increases the processing procedures. Finally, the seat cushion fabric cannot be directly connected with the metal seat frame by riveting with rivets, which is more troublesome.

In addition, the connection mode between the metal seat frame and the rack currently on the market also has the problems of insufficient supporting strength and the like. As disclosed in a Comparative Document 2 (Publication Number: CN101879014A), a sofa frame convenient for disassembly and assembly and small in transportation volume is disclosed, wherein a seat frame in the sofa frame is provided with a connecting slot, and a first rack body and a second rack body in the sofa frame are respectively provided with positioning clamping slots. In addition, the sofa frame also comprises a clamping and fixing unit, and the two ends of the clamping and fixing unit are respectively clamped in the positioning clamping slots of the first rack body and the second rack body and the connecting slot of the seat frame so as to realize the connection of the seat frame with the first rack body and the second rack body. Although the sofa frame in the Comparative Document 2 does not adopt threaded or complicated connection structures, and can be easily assembled and disassembled without any assembly tools with relatively high efficiency, the buckling clamping method is adopted, the force bearing mode between the seat frame and the rack is point-to-point or line-to-line, and the acting force at the joint is relatively large. At the same time, the supporting strength given by the rack body to the seat frame is also low, and damage is easy to occur.

To sum up, there are still many problems in the sofa seat frames made of metal materials on the market. Therefore, in order to adapt to the globalized furniture market, it is necessary to adjust the sofa industry chain and improve the structure and technology of the sofa seat frame, the sofa base assembly and the sofa so as to control the quality and production cost of the sofa and realize the standardized and automatic production of the sofa.

SUMMARY OF INVENTION

In order to overcome the at least one defect in the prior art, the invention provides a sofa seat frame, a sofa base assembly, a sofa and a sofa production and assembly process.

The technical solution adopted by the invention to solve the above problem is as follows:

a first aspect of the invention provides a sofa seat frame which comprises two cross beams arranged at intervals and two longitudinal beams connecting the two cross beams, wherein:

a plurality of supporting elastic pieces are arranged between the two cross beams; and

each longitudinal beam comprises a first supporting plate for supporting a seat cushion and a first side plate arranged at one side of the lower part of the first supporting plate and used for being detachably connected with sofa fabric on a seat cushion.

According to the sofa seat frame provided in the first aspect of the invention, a supporting structure for supporting the seat cushion can be formed by the plurality of supporting elastic pieces arranged between the two cross beams. As each longitudinal beam is provided with the first supporting plate, when the seat cushion is placed on the supporting structure, the first supporting plates can also give a certain supporting force to the seat cushion, thus improving the sitting comfort of users. In addition, when the sofa fabric is assembled, it is only necessary to install a clamping strip at the edge of the sofa fabric, and then clamp the clamping strip with the lower edges of the first side plates of the longitudinal beams to fix the sofa fabric on the seat cushion to the sofa seat frame. The process is simple and convenient, not only improves the installation efficiency, but also facilitates disassembly, has a high fault tolerance rate and cannot cause material waste.

Further, each longitudinal beam is a metal piece and comprises the first side plate, a second side plate arranged at a distance from the first side plate and located on the other side of the lower part of the first supporting plate, and the first supporting plate connecting the first side plate with the second side plate from the top of the first side plate and the top of the second side plate.

Therefore, by arranging the second side plates, not only is the overall structure of the longitudinal beams stabler, but also the firmness of the connection with the cross beams and a bottom rack is improved, thus improving the overall stability of the sofa seat frame and increasing the supporting strength of the sofa seat frame.

Further, the sofa seat frame also comprises first connecting pieces for connecting a sofa rack, each first connecting piece comprising two fifth side plates arranged at intervals and a third supporting plate connecting the bottoms of the two fifth side plates, wherein:

the third supporting plate is connected with the sofa rack; and

one fifth side plate is connected to the first side plate of the longitudinal beam, and the other fifth side plate is connected to the second side plate of the longitudinal beam.

Therefore, by arranging the plurality of first connecting pieces on the sofa seat frame, the installation efficiency between the sofa seat frame and the sofa rack can be improved. In addition, as each first connecting piece is provided with the third supporting plate, the supporting area of the joint between the sofa seat frame and the sofa rack is increased, the supporting strength of the sofa rack to the sofa seat frame is further improved, and the sofa seat frame is stabler and firmer.

Further, the third supporting plate and the two fifth side plates are integrally formed by bending, and are U-shaped.

Therefore, the first connecting piece integrally formed by bending has higher supporting strength and is convenient to process. In addition, the first connecting piece is arranged in a U shape, which not only makes the structure of the first connecting piece stabler, but also has higher connection stability with the sofa rack due to the flat bottom, thus further improving the supporting strength of the sofa rack to the sofa seat frame.

Further, the first side plate, the second side plate and the first supporting plate are integrally formed by bending, and are inverted U-shaped.

Therefore, the longitudinal beam integrally formed by bending has higher supporting strength and is convenient to process. In addition, the longitudinal beam is arranged in an inverted U shape, so that the structure of the longitudinal beam is stabler and the supporting strength is higher, thus improving the overall supporting strength of the sofa seat frame.

Further, the first supporting plate is provided with a reinforcing rib.

Therefore, the arranged reinforcing rib can enhance the strength of the longitudinal beam and make the structure of the longitudinal beam stabler.

Further, the two cross beams are each provided with a plurality of hooks integrally formed by stamping; one ends of the supporting elastic pieces are connected to the hooks on one cross beam, and the other ends of the supporting elastic pieces are connected to the corresponding hooks on the other cross beam.

Therefore, the hooks formed by stamping have higher strength than the existing hooks welded or connected to a cross beam through other forms, and are less likely to be damaged under the pulling action of the supporting elastic pieces, thus prolonging the service life of the sofa seat frame, simplifying the assembly process and omitting the step of welding the hooks.

Further, each hook is provided with a protrusion for preventing unhooking of the supporting elastic piece.

Therefore, the protrusion can not only prevent the supporting elastic piece from being separated from the hook in the use process, but also avoid bending the end of the supporting elastic piece to reinforce the connection with the hook when the supporting elastic piece is hooked, thus reducing the assembly steps and improving the assembly efficiency.

Specifically, the supporting elastic piece is a serpentine spring.

Further, each cross beam is a metal piece and comprises a second supporting plate, a third side plate arranged on the outer side of the lower part of the second supporting plate and used for being detachably connected with the sofa fabric on the seat cushion, and a fourth side plate arranged on the inner side of the lower part of the second supporting plate, wherein:

a plurality of hooks on each cross beam are formed by stamping the second supporting plate and the fourth side plate.

Therefore, when the sofa fabric is assembled, it is only necessary to install the clamping strip at the edge of the sofa fabric, and then clamp the clamping strip with the lower edges of the third side plates on the two cross beams, so that the sofa fabric on the seat cushion can be fixed to the sofa seat frame. The process is simple and convenient, not only improves the installation efficiency, but also facilitates disassembly, has a high fault tolerance rate, and cannot cause material waste.

Further, the third side plate, the fourth side plate and the second supporting plate are integrally formed by bending, and are inverted U-shaped.

Therefore, the cross beam formed by integral bending has higher supporting strength and is convenient to process. In addition, each cross beam is arranged in an inverted U shape, so that the structure of the cross beam is stabler and the supporting strength is higher, thus improving the overall supporting strength of the sofa seat frame.

Further, the two ends of each cross beam are also provided with reinforcing plates, and the reinforcing plates are connected with the third side plates and the fourth side plates.

Therefore, by arranging the reinforcing plates at two ends of each cross beam, the structure of the cross beam is stabler and the supporting strength of the cross beam is further improved.

In addition, a second aspect of the invention also provides a sofa base assembly which comprises a rack and the sofa seat frame which is detachably connected with the rack and is provided by the first aspect of the invention, wherein:

the rack comprises two metal supporting legs arranged opposite to each other; and

third supporting plates of the sofa seat frame are detachably connected to the supporting legs.

Therefore, by arranging the third supporting plates to be connected with the supporting legs, the supporting area at the joint between the sofa seat frame and the rack can be improved, thus improving the overall supporting strength of the rack to the sofa seat frame and making the sofa seat frame stabler and firmer. In addition, the supporting legs made of a metal material are adopted for replacing the existing wooden frame structure, not only have a simple structure, but also have higher supporting strength and improve the overall stability of the sofa base assembly.

Besides, a third aspect of the invention further provides a functional sofa base assembly which comprises a functional rack and the sofa seat frame which is detachably connected to the functional rack and is provided by the first aspect of the invention, wherein:

the functional rack comprises a first base and two telescopic brackets arranged on the first base at intervals, each telescopic bracket comprising a seat frame mounting plate and a first mounting plate arranged on the seat frame mounting plate; and

the third supporting plates of the sofa seat frame are detachably connected to the first mounting plates.

Therefore, by arranging the third supporting plates to be connected with the first mounting plates, the supporting area of the joint between the sofa seat frame and the functional rack can be improved, thus improving the overall supporting strength of the functional rack to the sofa seat frame and making the sofa seat frame stabler and firmer.

Further, the first mounting plate is formed by bending the seat frame mounting plate.

Therefore, the supporting strength of the first mounting plate formed by bending the seat frame mounting plate is higher.

Further, the first mounting plate is arranged at a middle position in the height direction of the seat frame mounting plate.

Therefore, by arranging the first mounting plate at the middle position in the height direction of the seat frame mounting plate, the height of the first mounting piece is lowered, thereby lowering the mounting height of the sofa seat frame, and further improving the sitting comfort of users.

Further, third side plates of the cross beams close to a sofa backrest are provided with an extension plate used for being detachably connected with the sofa fabric on the seat cushion.

Therefore, the extension plate is arranged to be connected with the sofa fabric, so that a motor at the bottom of the sofa can be sealed to prevent articles or dust from falling into the motor to affect the motor at the bottom of the sofa.

Further, the extension plate is provided with a positioning hole.

Therefore, the positioning hole can be used for fixing a power plug of the motor at the bottom of the sofa.

In addition, a fourth aspect of the invention further provides a sofa, which comprises the sofa base assembly provided by the second aspect of the invention, a seat cushion and sofa fabric wrapping the seat cushion, sofa armrests, a sofa backrest and a sofa foot pad plate, wherein the sofa fabric, the sofa armrests and the sofa backrest are all detachably connected with the sofa seat frame, and the sofa foot pad plate is detachably connected with the supporting legs.

Further, the edge of the sofa fabric is provided with a clamping strip, and the sofa fabric is clamped with the lower edges of the first side plates of the two longitudinal beams through the clamping strip.

Further, the sofa also comprises fourth connecting pieces, wherein each fourth connecting piece comprises a first member connected to the first side plate of the longitudinal beam and a second member connected to the sofa armrest, and the first member and the second member are in sliding insertion fit;

or, the first member is connected to the sofa armrest, the second member is connected to the first side plate of the longitudinal beam, and the first member and the second member are in sliding insertion fit.

Further, the first member comprises a first substrate, two guide rails arranged at intervals on the first substrate, and a stopper arranged on the first substrate and located under the two guide rails; the second member comprises a second substrate and two guide bars arranged at intervals on the second substrate, and the two guide bars are respectively in sliding insertion fit with the two guide rails.

In addition, a fifth aspect of the invention further provides a functional sofa which comprises the functional sofa base assembly provided by the third aspect of the invention, the seat cushion and the sofa fabric wrapping the seat cushion, the sofa armrests, the sofa backrest and the sofa foot pad plate, wherein the sofa fabric and the sofa armrests are detachably connected with the sofa seat frame; and the sofa backrest and the sofa foot pad plate are detachably connected with the telescopic brackets.

Further, the edge of the sofa fabric is provided with a clamping strip, and the sofa fabric is clamped with the lower edges of the first side plates of the two longitudinal beams through the clamping strip.

Further, the functional sofa also comprises fourth connecting pieces, wherein each fourth connecting piece comprises a first member connected to the first side plate of the longitudinal beam and a second member connected to the sofa armrest, and the first member and the second member are in sliding insertion fit;

or, the first member is connected to the sofa armrest, the second member is connected to the first side plate of the longitudinal beam, and the first member and the second member are in sliding insertion fit.

Further, the first member comprises a first substrate, two guide rails arranged at intervals on the first substrate, and a stopper arranged on the first substrate and located under the two guide rails; the second member comprises a second substrate and two guide bars arranged at intervals on the second substrate, and the two guide bars are respectively in sliding insertion fit with the two guide rails.

In addition, a sixth aspect of the invention also provides a sofa production and assembly process, comprising the following steps:producing cross beams and longitudinal beams according to defined dimensions, and assembling the two cross beams and the two longitudinal beams to form a sofa seat frame;installing a plurality of serpentine springs between the two cross beams of the sofa seat frame to form a seat cushion supporting structure;producing a plurality of first connecting pieces according to defined dimensions, wherein each of the first connecting pieces comprises two symmetrically arranged fifth side plates and a third supporting plate connecting the bottoms of the two fifth side plates, the two fifth side plates of each of plurality of the first connecting pieces are connected with the longitudinal beams to realize the connection of the plurality of first connecting pieces with the sofa seat frame;producing two supporting legs according to defined dimensions to obtain a rack;connecting the third supporting plates of the first connecting pieces with the supporting legs to realize the connection of the sofa seat frame with the rack to obtain a sofa base assembly; andcompleting the production and assembly of the sofa according to the obtained sofa base assembly.

Therefore, the sofa production and assembly process provided by the invention breaks the traditional concept of sofa production and assembly, the sofa seat frame, the rack, the seat cushion, the sofa armrests, the sofa backrest and the sofa foot pad plate all adopt modular design, and the assembly connection between them is realized through a simple connection structure, thus greatly improving the production and assembly efficiency of the sofa, reducing the labor cost, and being suitable for large-scale assembly line industrial production.

Further, the step of “completing the production and assembly of the sofa according to the obtained sofa base assembly” further comprises the following steps:placing a seat cushion on the seat cushion supporting structure;processing the sofa fabric to set dimensions, and fixing a clamping strip on the edge of the sofa fabric, then wrapping the seat cushion with the sofa fabric, and fixing the sofa fabric to the sofa seat frame via the clamping strip on the sofa fabric, thus completing the production and assembly of the seat cushion; andinstalling sofa armrests and a sofa backrest on the sofa seat frame, and installing a sofa foot pad plate on the supporting legs, thus completing the production and assembly of the sofa.

In addition, a seventh aspect of the invention also provides a functional sofa production and assembly process, comprising the following steps:producing cross beams and longitudinal beams according to defined dimensions, and assembling the two cross beams and the two longitudinal beams to form a sofa seat frame;installing a plurality of serpentine springs between the two cross beams of the sofa seat frame to form a seat cushion supporting structure;producing a plurality of first connecting pieces according to defined dimensions, wherein each of the first connecting pieces comprises two symmetrically arranged fifth side plates and a third supporting plate connecting the bottoms of the two fifth side plates, the two fifth side plates of each of the plurality of first connecting pieces are connected with the longitudinal beams to realize the connection of the plurality of first connecting pieces with the sofa seat frame;producing parts of a functional rack according to defined dimensions and assembling the parts to obtain the functional rack; wherein the functional rack comprises two telescopic brackets arranged symmetrically, and each telescopic bracket comprises a seat frame mounting plate and a first mounting plate arranged on the seat frame mounting plate;connecting the third supporting plates of the first connecting pieces with the first mounting plates of the telescopic brackets to realize the connection of the sofa seat frame with the functional rack to obtain a functional sofa base assembly; andcompleting the production and assembly of the functional sofa according to the obtained functional sofa base assembly.

Therefore, the functional sofa production and assembly process provided by the invention breaks the traditional concept of functional sofa production and assembly, the sofa seat frame, the functional rack, the seat cushion, the sofa armrests, the sofa backrest and the sofa foot pad plate all adopt modular design, and the assembly connection among them is realized through a simple connection structure, thus greatly improving the production and assembly efficiency of the functional sofa, reducing the labor cost, and being suitable for large-scale assembly line industrial production.

Further, the step of “completing the production and assembly of the functional sofa according to the obtained functional sofa base assembly” further comprises the following steps:placing a seat cushion on the seat cushion supporting structure;processing the sofa fabric to set dimensions, and fixing a clamping strip on the edge of the sofa fabric, then wrapping the seat cushion with the sofa fabric, and fixing the sofa fabric to the sofa seat frame via the clamping strip on the sofa fabric, thus completing the production and assembly of the seat cushion; andinstalling a sofa backrest and a sofa foot pad plate on the telescopic brackets, and installing sofa armrests on the sofa seat frame, thus completing the production and assembly of the functional sofa.

To sum up, the sofa seat frame, the sofa base assembly, the sofa and the sofa production and assembly process provided by the invention have the following technical effects:

1) According to the sofa seat frame provided by the invention, the supporting structure for supporting the seat cushion can be formed by arranging the plurality of supporting elastic pieces between the two cross beams. As the longitudinal beams are provided with the first supporting plates, when the seat cushion is placed on the supporting structure, the first supporting plates can also give a certain supporting force to the seat cushion, thus improving the sitting comfort of users. In addition, when the sofa fabric is assembled, it is only necessary to install the clamping strip at the edge of the sofa fabric, and then clamp the clamping strip with the lower edges of the first side plates of the two longitudinal beams to fix the sofa fabric on the seat cushion to the sofa seat frame. The process is simple and convenient, not only improves the installation efficiency, but also facilitates disassembly, has a high fault tolerance rate and cannot cause material waste.

2) According to the sofa seat frame provided by the invention, the arranged second side plates not only make the overall structure of the longitudinal beams stabler, but also improve the firmness of connection with the cross beams and the bottom rack, thus improving the overall stability of the sofa seat frame and increasing the supporting strength of the sofa seat frame.

3) According to the sofa seat frame provided by the invention, the installation efficiency between the sofa seat frame and the sofa rack can be improved by arranging the plurality of first connecting pieces on the sofa seat frame. In addition, since the first connecting pieces are provided with the third supporting plates, the supporting area of the joint between the sofa seat frame and the sofa rack is increased, the overall supporting strength of the sofa rack to the sofa seat frame is further improved, and the sofa seat frame is stabler and firmer.

4) According to the sofa seat frame provided by the invention, the hooks integrally formed on each cross beam by the stamping process have higher strength than the existing hooks welded or connected to a cross beam by other forms, and are less likely to be damaged under the pulling action of the supporting elastic pieces, thus prolonging the service life of the sofa seat frame, simplifying the assembly process, and omitting the step of welding the hooks.

5) According to the sofa seat frame provided by the invention, the arrangement of the protrusion on each hook can not only prevent the supporting elastic piece from being separated from the hook during use, but also avoid bending the end of the supporting elastic piece to reinforce the connection with the hook when the supporting elastic piece is hooked, thus reducing the assembly steps and improving the assembly efficiency.

6) According to the sofa base assembly provided by the invention, the third supporting plates are arranged to be connected with the supporting legs, so that the supporting area of the joint between the sofa seat frame and the supporting legs can be improved, thereby improving the supporting strength of the rack to the sofa seat frame and making the sofa seat frame stabler and firmer. In addition, the supporting legs made of a metal material are adopted for replacing the existing wooden frame structure, so that the structure is simple, and the supporting strength is higher, and the overall stability of the sofa base is improved.

7) According to the functional sofa base assembly provided by the invention, the third supporting plates are arranged to be connected with the first mounting plates, so that the supporting area of the joint between the sofa seat frame and the functional rack is improved, thereby improving the overall supporting strength of the functional rack to the sofa seat frame and making the sofa seat frame stabler and firmer.

8) According to the sofa production and assembly process provided by the invention, the traditional concept of sofa production and assembly is broken, the sofa seat frame, the rack, the seat cushion, the sofa armrests, the sofa backrest and the sofa foot pad plate all adopt modular design, and the assembly connection among them is realized through a simple connection structure, so that the sofa production and assembly efficiency is greatly improved, the labor cost is reduced, and the sofa production and assembly process provided by the invention is suitable for large-scale assembly line industrial production.

9) The functional sofa production and assembly process provided by the invention breaks the traditional concept of sofa production and assembly, the sofa seat frame, the functional rack, the seat cushion, the sofa armrests, the sofa backrest and the sofa foot pad plate all adopt modular design, and the assembly connection among them is realized through a simple connection structure, thus greatly improving the production and assembly efficiency of the functional sofa and reducing the labor cost, and the functional sofa production and assembly process provided by the invention is suitable for large-scale assembly line industrial production.

Wherein, the description of Reference Numerals is as follows:

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

For better understanding and implementation, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention.

Unless otherwise defined, all technical and scientific terms used herein have the same meanings as generally understood by those skilled in the art of the present invention. Terms used herein in the description of the invention are for the purpose of describing specific embodiments only and are not intended to limit the invention.

Referring toFIGS.1-5, the invention discloses a sofa seat frame1which comprises two cross beams12arranged at intervals and two longitudinal beams11connecting the two cross beams12, and a plurality of supporting elastic pieces13are arranged between the two cross beams12. In the embodiment, the two cross beams12and the two longitudinal beams11are both symmetrically arranged and the ends of the two cross beams12and the ends of the two longitudinal beams11are connected mutually to form a rectangular frame structure; and the two cross beams12and the two longitudinal beams11can be fixed by screwing or welding.

In the embodiment, the cross beam12and the longitudinal beam11are both metal pieces, of course, in other embodiments, the cross beam12and the longitudinal beam11can also be made by injection molding of engineering plastic or by combining metal with the engineering plastic.

Referring toFIG.1, each longitudinal beam11comprises a first side plate112, a second side plate113arranged at a distance from the first side plate112, and a first supporting plate111connecting the top of the first side plate112with the top of the second side plate113. The first supporting plate111is used for supporting a seat cushion, and the first side plate112is used for being detachably connected with sofa fabric on the seat cushion. In this embodiment, the longitudinal beam11is in an inverted U shape, and the first supporting plate111is in a strip-shaped flat plate shape and is parallel to the horizontal plane; and the first side plate112and the second side plate113are both connected to the first supporting plate111in an L shape. Preferably, the upper surface of the first supporting plate111is flush with the upper surface of the cross beam12so as to better support the seat cushion. The first side plate112and the second side plate113are two vertical plates having the same height, and are respectively arranged on two sides of the lower end of the first supporting plate111. The first side plate112is located on the outer side of the rectangular frame structure so as to facilitate connection with the sofa fabric on the seat cushion; and the second side plate113is located on the inner side of the rectangular frame structure.

Preferably, the first side plate112, the second side plate113and the first supporting plate111are integrally formed by bending. The first side plate112, the second side plate113and the first supporting plate111are formed by bending the same steel plate in order to facilitate processing and maintain the relatively high supporting strength of the longitudinal beam11. It should be noted that the first side plate112, the second side plate113and the first supporting plate111are not limited to the integrally formed structure, and can also be fixed by welding.

Therefore, each longitudinal beam11is provided with the first supporting plate111, and when the seat cushion is placed on the plurality of supporting elastic pieces13, the first supporting plates111can also give a certain supporting force to the seat cushion, thus improving the sitting comfort of users. Secondly, when the sofa fabric is assembled, it is only necessary to install a clamping strip at the edge of the sofa fabric, and then clamp the clamping strip on the sofa fabric with the lower edges of the first side plates112of the two longitudinal beams11, so that the sofa fabric on the seat cushion can be fixed to the sofa seat frame1. The process is simple and convenient, not only improves the installation efficiency, but also facilitates disassembly, has a high fault tolerance rate, and cannot cause material waste. In addition, by arranging the second side plates113, not only is the overall structure of the longitudinal beams11stabler, but also the firmness of its connection with the cross beams12and the bottom rack is improved, thus improving the overall stability of the sofa seat frame1and increasing its supporting strength. In addition, each longitudinal beam11is arranged in an inverted U shape, so that the structure of the longitudinal beam11is stabler and the supporting strength is higher, thus improving the overall supporting strength of the sofa seat frame1.

In addition, each first supporting plate111is further provided with a plurality of reinforcing ribs1111, so that the strength of the longitudinal beam11is enhanced and the structure of the longitudinal beam11is stabler.

Referring again toFIG.1, each cross beam12comprises a third side plate122, a fourth side plate123arranged at a distance from the third side plate122, and a second supporting plate121connecting the top of the third side plate122with the top of the fourth side plate123. The third side plate122is used for being detachably connected with the sofa fabric on the seat cushion, and the fourth side plate123is used for being connected with two ends of the longitudinal beam11. In the present embodiment, the cross beam12is in an inverted U shape, and the second supporting plate121is also in a strip-shaped flat plate shape and is parallel to the horizontal plane; the third side plate122and the fourth side plate123are both connected to the second supporting plate121in an L shape. Preferably, the upper surface of the second supporting plate121is flush with the upper surface of the first supporting plate111of the longitudinal beam11. The third side plate122and the fourth side plate123are two vertical plates having different heights. The height of the fourth side plate123is higher than that of the third side plate123, and the third side plate122and the fourth side plate123are respectively arranged on two sides of the lower part of the second supporting plate121. The third side plate122is located on the outer side of the rectangular frame structure, and the fourth side plate123is located on the inner side of the rectangular frame structure.

Preferably, the third side plate122, the fourth side plate123and the second supporting plate121are integrally formed by bending. The third side plate122, the fourth side plate123and the second supporting plate121are formed by bending the same steel plate in order to facilitate processing and maintain the relatively high supporting strength of the cross beam12. It should be noted that the third side plate122, the fourth side plate123and the second supporting plate121are not limited to the integrally formed structure, and can also be fixed by welding. Further, reinforcing plates124are arranged at two ends of each cross beam12, and the reinforcing plates124are connected to the third side plate122and the fourth side plate123.

Therefore, when the sofa fabric is assembled, it is only necessary to install the clamping strip at the edge of the sofa fabric, and then clamp the clamping strip on the sofa fabric with the lower edges of the third side plates122of the two cross beams12, so that the sofa fabric on the seat cushion can be fixed to the sofa seat frame1. The process is simple and convenient, not only improves the installation efficiency, but also facilitates disassembly, has a high fault tolerance rate, and cannot cause material waste. In addition, each cross beam12is arranged in an inverted U shape, and the reinforcing plates124are arranged at the two ends of the cross beam12, so that the structure of the cross beam12is stabler and the supporting strength is higher.

In addition, since the two ends of the longitudinal beams11are connected to the fourth side plates123of the two cross beams12respectively, the structure of the sofa seat frame1thus formed is stabler and the supporting strength is higher. Admittedly, in other preferred embodiments, it is also possible to connect the two ends of the cross beams12to the second side plates113of the two longitudinal beams11, and to arrange the reinforcing plates124at the two ends of each longitudinal beam11.

Referring toFIGS.1-5, each cross beam12is provided with a plurality of hooks125for connecting the supporting elastic pieces13. The plurality of hooks125are integrally formed on each of the two cross beams12by a stamping process and are uniformly arranged in the axial direction of the cross beam12, and the hooks125on the two cross beams12are symmetrically arranged. In the present embodiment, the plurality of hooks125are formed by stamping the second supporting plate121and the fourth side plate123.

Therefore, the hooks125formed by stamping have higher strength than the existing hooks125connected to the cross beam12by welding or other forms, and are less likely to be damaged under the elastic force of the supporting elastic pieces13, thereby prolonging the service life of the whole sofa, simplifying the assembly process and omitting the step of welding the hooks125.

Specifically, each hook125is substantially C-shaped. Each hook125is also provided with a protrusion1251for preventing the unhooking of the supporting elastic piece13. The protrusion1251not only prevents the supporting elastic piece13from being separated from the hook125during use, but also avoids bending the end of the supporting elastic piece13to reinforce the connection with the hook125when the supporting elastic piece13is hooked, thereby reducing the assembly steps and improving the assembly efficiency.

In the present embodiment, each supporting elastic piece13is a serpentine spring. The two ends of the serpentine spring are respectively movably hooked on the hooks125of the two cross beams12. As such, a plurality of serpentine springs are arched upward toward the sitting face of the sofa seat frame1, thereby forming an arc-shaped sitting surface, which has good vibration damping performance and improves the sitting comfort of users. Admittedly, in other preferred embodiments, the supporting elastic piece13can also be a rubber band or a combination of a serpentine spring and the rubber band to achieve the effect of elastically supporting the seat cushion of the sofa.

Referring toFIGS.1-2, the sofa seat frame1further comprises a plurality of first connecting pieces14, and in this embodiment, four first connecting pieces14are symmetrically arranged on the longitudinal beams11in pairs. Each first connecting piece14comprises two fifth side plates142arranged at intervals and a third supporting plate141connecting the bottoms of the two fifth side plates142. Specifically, the first connecting piece14is in a U shape, and the third supporting plate141is in a flat plate shape and is parallel to the horizontal plane; the two fifth side plates142are connected to the third supporting plate141in an L shape, and the two fifth side plates142are symmetrically arranged on two sides of the upper part of the third supporting plate141.

Preferably, the two fifth side plates142and the third supporting plate141are integrally formed by bending. In order to facilitate processing and maintain the relatively high supporting strength of the first connecting piece14, the two fifth side plates142and the third supporting plate141are formed by bending the same steel plate. It should be noted that the two fifth side plates142and the third supporting plate141are not limited to the integrally formed structure, and can also be fixed by welding.

Referring toFIGS.3-4, specifically, one fifth side plate142of each first connecting piece14is connected to the side face of the first side plate112of the longitudinal beam11close to the second side plate113, the other fifth side plate142is connected to the side face of the second side plate113of the longitudinal beam11away from the first side plate112, and the third supporting plate141is detachably connected to the sofa rack.

In this embodiment, the two fifth side plates142are fixed to the first side plate112and the second side plate113by welding, respectively, and the third supporting plate141is fixed to the sofa rack by bolted connection.

As a result, each first connecting piece14is arranged in a U shape, so that the structure of the first connecting piece14is stabler and the supporting strength is higher. By arranging the third supporting plates141to be connected with the sofa rack, the supporting area at the joint of the sofa seat frame1and the sofa rack can be increased, thereby improving the overall supporting strength of the sofa rack to the sofa seat frame1and making the sofa seat frame1stabler and firmer.

Referring toFIGS.6-7, the invention also provides a sofa base assembly comprising the sofa seat frame1in Embodiment 1 and a rack3, and the rack3comprises two oppositely arranged supporting legs31. In the present embodiment, each supporting leg31is substantially inverted U-shaped and is made of a metal material. Therefore, the supporting legs31made of a metal material are adopted for replacing the existing wooden frame structure, not only have a simple structure, but also have higher supporting strength and improve the overall stability of the sofa base.

Referring toFIGS.6-7, the third supporting plates141on the sofa seat frame1are detachably connected to the top surfaces of the supporting legs31. In the present embodiment, the third supporting plates141and the supporting legs31are fixed by means of bolts or screws.

Therefore, by arranging the third supporting plates141to be connected with the supporting legs31, the supporting area at the joints between the sofa seat frame1and the supporting legs31can be increased, the supporting strength of the rack3to the sofa seat frame1can be improved, and the sofa seat frame1can be stabler and firmer.

Referring toFIG.8, the invention also provides a functional sofa base assembly, which comprises the sofa seat frame1in Embodiment 1 and a functional rack4. The functional rack4comprises a first base41and two telescopic brackets43symmetrically arranged on the first base41, and the first base41and the telescopic brackets43are both made of a metal material. The first base41is formed by two strip-shaped first underframes411arranged in parallel, and each telescopic bracket43comprises a seat frame mounting plate4321and first mounting plates43211fixed to the seat frame mounting plate4321and perpendicular to the seat frame mounting plate4321, and the first mounting plate43211is parallel to the horizontal plane. In the present embodiment, there are four first mounting plates43211, and the first mounting plates43211are symmetrically arranged on the seat frame mounting plates4321of the two telescopic brackets43in pairs.

Preferably, in order to ensure that the first mounting plate43211has greater supporting strength, the first mounting plate43211is formed by bending the seat frame mounting plate4321, and an opening is formed between the first mounting plate43211and the seat frame mounting plate4321. It should be noted that the first mounting plate43211and the seat frame mounting plate4321are not limited to the integrally bending formed structure, and can also be fixed by welding.

Referring toFIGS.12-14, the third supporting plates141on the sofa seat frame1are connected to the first mounting plates43211of the telescopic brackets43, thereby realizing the detachable connection of the sofa seat frame1to the functional rack4. In the present embodiment, the third supporting plates141and the first mounting plates43211are connected and fixed by means of bolts or screws.

Therefore, the third supporting plates141are connected to the first mounting plates43211, so that the supporting strength of the functional rack4to the sofa seat frame1is improved, and the sofa seat frame1is stabler and firmer.

In addition, the first mounting plate43211is arranged at a middle position in the height direction of the seat frame mounting plate4321. As a result, by arranging the first mounting plate43211at the middle position in the height direction of the seat frame mounting plate4321, the height of the first mounting plate43211is lowered, so that the mounting height of the sofa seat frame is lowered, and the sitting comfort of the user is further improved.

Further, the third side plates122of the cross beams12close to a sofa backrest6are provided with an extension plate2for detachable connection with the sofa fabric on the seat cushion. The extension plate2is provided with a positioning hole21for fixing a power plug of a motor at the bottom of the functional sofa.

Therefore, by connecting the extension plate2to the sofa fabric on the seat cushion, the motor at the bottom of the sofa can be sealed to prevent articles or dust from falling into the motor to affect the motor at the bottom of the sofa.

Referring toFIGS.9-11, the functional rack4further comprises a linkage mechanism42for driving the telescopic brackets43to extend and retract, the linkage mechanism42comprises a first linkage lever421and a second linkage lever422, the first linkage lever421comprises a rotating square tube4211and a rotating angle iron4212, the rotating square tube4211and the rotating angle iron4212are connected. The central position of the rotating square tube4211is also provided with a first connecting bracket42111, and the central position of the second linkage lever422is provided with a second connecting bracket (not shown in the figure), both the first connecting bracket42111and the second connecting bracket are connected to a driving member (not shown in the figure). The first connecting bracket42111and the second connecting bracket generate relative displacement under the driving of the driving member, and the first linkage lever421and the second linkage lever422are driven to rotate, and further the left and right telescopic brackets43are driven to extend and retract.

Referring toFIGS.9-10, each telescopic bracket43comprises a backrest mechanism431, a seat plate linkage mechanism432and a leg extension mechanism433connected in sequence. The seat plate linkage mechanism432comprises a first supporting piece4322and a second supporting piece4323. One end of the first supporting piece4322and one end of the second supporting piece4323are rotatably connected with the seat frame mounting plate4321, and the other end of the first supporting piece4322and the other end of the second supporting piece4323are rotatably connected with the first underframe411, thereby forming a four-link mechanism. In addition, the seat plate linkage mechanism432further comprises a first seat frame bracket4324, which is fixedly connected to the seat frame mounting plate4321. Two ends of the second linkage lever422are connected to the left and right first seat frame brackets4324, respectively.

In addition, the backrest mechanism431further comprises a first back bar4311and a second mounting plate4312for mounting the sofa backrest6, one end of the first back bar4311is rotatably connected to the second mounting plate4312, and the other end is rotatably connected to the first seat frame bracket4324; the other end of the second mounting plate4312is rotatably connected to the seat frame mounting plate4321.

Therefore, when the driving member drives the second linkage lever422to rotate, the first seat frame bracket4324can be driven to rotate, and then the first back bar4311and the second mounting plate4312can be driven to rotate, and finally the backrest mechanism431can be tilted forward or backward.

In addition, the leg extension mechanism433comprises a first foot bar4331, a second foot bar4332, a third foot bar4333, a fourth foot bar4334, a fifth foot bar4335, and a third mounting plate4336for mounting the sofa foot pad plate7. One end of the first foot bar4331is rotatably connected to one side face of the seat frame mounting plate4321, the other end is rotatably connected to the second foot bar4332, one end of the fifth foot bar4335is rotatably connected to the second foot bar4332, and the other end is rotatably connected to the third mounting plate4336; one end of the third foot bar4333is rotatably connected to the other side face of the seat frame mounting plate4321, and the other end is rotatably connected to the fourth foot bar4334; the other end of the fourth foot bar4334is also rotatably connected to the fifth foot bar4335. In addition, the leg extension mechanism also comprises a first driving bracket423and a second driving bracket424. One end of the first driving bracket423is fixedly connected to the rotating square tube4211, and the other end is rotatably connected to the second driving bracket424. The other end of the second driving bracket424is rotatably connected to the first foot bar4331.

As such, when the driving member drives the first linkage lever421to rotate, the rotating square tube4211and the rotating angle iron4212can be simultaneously driven to rotate, thus driving the first driving bracket423, the second driving bracket424, the first foot bar4331, the second foot bar4332, the third foot bar4333, the fourth foot bar4334and the fifth foot bar4335to rotate, and finally driving the third mounting plate4336to rotate, thus realizing the extension and retraction motion of the leg extension mechanism433.

Referring toFIG.9, the functional rack4is further provided with at least one balance bar44, and two ends of the balance bar44are fixedly connected to the left and right first supporting pieces4322respectively. In this embodiment, the balance bar44is a circular tube. In other embodiments, the balance bar44can also be a square tube or other shaped bar. Therefore, by arranging the balance bar44, the stability of the sofa can be enhanced, and the force balancing effect of the telescopic brackets43on the left and right sides of the sofa can be ensured.

Referring toFIG.10, the functional rack4is further provided with at least one anti-torsion bar45, and two ends of the anti-torsion bar45are fixedly connected to the left and right second supporting pieces4323respectively. In this embodiment, the anti-torsion bar45is a circular tube. In other embodiments, the anti-torsion bar45can also be a square tube or other shaped bar. As a result, by arranging the anti-torsion bar45, it is possible to prevent the telescopic brackets43on the two sides from twisting and being unevenly stressed on the two sides during extending or retracting.

Referring again toFIGS.9-11, which are schematic diagrams showing the functional rack4of the present invention in three states: state of sitting posture, state of leisure posture and state of lying posture respectively. As shown inFIG.9, when the functional rack4is in the state of sitting posture, the telescopic brackets43are in a retracted state, and the backrest mechanisms431and the leg extension mechanisms433are retracted toward the middle. As shown inFIG.10, when the functional rack4is in the state of leisure posture, the backrest mechanisms431are kept at the same angle as in the state of sitting posture, while the leg extension mechanisms433extend forward. As shown inFIG.11, when the functional rack4is in the state of lying posture, the backrest mechanisms431are tilted backward, while the leg extension mechanisms433are kept in the same state as in the state of leisure posture.

Referring toFIGS.12-14, which are schematic diagrams showing the functional sofa base assembly of the present invention in three states of sitting posture, leisure posture and lying posture respectively.

Referring toFIGS.15-18, the invention also provides a sofa comprising the sofa base assembly of Embodiment 2, a seat cushion and sofa fabric (not shown in the figure) wrapping the seat cushion, sofa armrests5, a sofa backrest6and a sofa foot pad plate7. The edge of the sofa fabric is provided with a clamping strip which is clamped with the lower edges of the first side plates112of the two longitudinal beams11and the lower edges of the third side plates122of the two cross beams12. Therefore, the installation process is simple and convenient, not only is the installation efficiency improved, but also the disassembly is convenient, the fault tolerance rate is high, and material waste cannot be caused.

In addition, the sofa is further provided with a second connecting piece81, and the sofa backrest is detachably connected with the sofa seat frame1through the second connecting piece81. In the present embodiment, there are two second connecting pieces81, which are symmetrically arranged on the two longitudinal beams11. Each second connecting piece81comprises a fourth supporting plate811and a sixth side plate812connected with the fourth supporting plate811. Specifically, the second connecting piece81is substantially L-shaped, the fourth supporting plate811is parallel to the horizontal plane, and the sixth side plate812is perpendicular to the fourth supporting plate811. Preferably, the fourth supporting plate811and the sixth side plate812are integrally formed by bending. At the same time, the fourth supporting plate811and the sixth side plate812are formed by bending the same steel plate in order to facilitate processing and maintain the relatively high supporting strength of the second connecting piece81. It should be noted that the fourth supporting plate811and the sixth side plate812are not limited to the integrally formed structure, and can also be fixed by welding.

Specifically, the fourth supporting plate811is connected to the first supporting plate111of the longitudinal beam11, and the sixth side plate812is connected to the sofa backrest6. In this embodiment, the fourth supporting plate811and the first supporting plate111are fixed by means of bolts or screws, and the sixth side plate812and the sofa backrest6are fixed by means of bolts or screws.

Therefore, the fourth supporting plate811is arranged to be connected with the first supporting plate111, so that the supporting strength of the sofa base assembly to the sofa backrest6is improved, and the sofa backrest6is stabler and firmer.

In addition, the sofa is also provided with a third connecting piece82, and the sofa foot pad plate7is detachably connected to the supporting leg31through the third connecting piece82. In the present embodiment, there are two third connecting pieces82which are symmetrically arranged on the two supporting legs31. Each third connecting piece82comprises a fifth supporting plate821and a seventh side plate822connected with the fifth supporting plate821. Specifically, the third connecting piece82is substantially L-shaped. Preferably, the fifth supporting plate821and the seventh side plate822are integrally formed by bending. The fifth supporting plate821and the seventh side plate822are formed by bending the same steel plate in order to facilitate processing and maintain the relatively higher supporting strength of the third connecting piece82. It should be noted that the fifth supporting plate821and the seventh side plate822are not limited to the integrally formed structure, and can also be fixed by welding.

Referring toFIG.17, the seventh side plate822is connected to the side face of the supporting leg31facing the inside of the sofa seat frame1, and the fifth supporting plate821is detachably connected to the sofa foot pad plate7. In this embodiment, the seventh side plate822and the supporting leg31are fixed by welding, and the fifth supporting plate821and the sofa foot pad plate7are fixed by bolts or screws.

Therefore, the fifth supporting plate821is arranged to be connected with the sofa foot pad plate7, so that the supporting strength of the sofa base assembly to the sofa foot pad plate7is improved, and the sofa foot pad plate7is stabler and firmer.

In addition, the sofa further comprises fourth connecting pieces83through which the sofa armrest5is detachably connected to the sofa seat frame1. Each fourth connecting piece83comprises a first member831and a second member832, and the first member831is in sliding insertion fit with the second member832. In this embodiment, the first members831are connected to the longitudinal beams11, and the second members832are connected to the sofa armrests5. Admittedly, in other embodiments, the first members831can be connected to the sofa armrests5and the second members832can be connected to the longitudinal beams11.

Referring toFIG.16, the first member831comprises a first substrate8311, two guide rails8312arranged at intervals on the first substrate8311, and a stopper8313arranged on the first substrate8311and located under the two guide rails8312, the first substrate8311is connected to the first side plate112of the longitudinal beam11; the second member832comprises a second substrate8321and two guide bars8322arranged at intervals on the second substrate8321, the second substrate8321is connected to the side face of the sofa armrest5; the two guide bars8322are respectively in sliding insertion fit with the two guide rails8312.

Specifically, the first substrate8311is in a strip-shaped plate shape, and the guide rail8312is of a first bent structure formed by bending the side edge of the first substrate8311toward one surface of the first substrate8311; the stopper8313is of a second bent structure formed by bending one side edge of the first substrate8311near the end toward one surface of the first substrate8311; both the first bent structure and the second bent structure are bent toward the same surface of the first substrate8311.

In this embodiment, the first bent structure is bent two times and is in an L shape; the second bent structure is bent one time. Admittedly, in other embodiments, the first and second bent structures can be in other shapes; at the same time, the two guide rails8312may not be limited to the integrally bending formed structure, and can also be fixed to the first substrate8311by welding.

Specifically, the second substrate8321is also in a strip-shaped plate shape, and the guide bar8322is of a third bent structure formed by bending the side edge of the second substrate8321toward one surface of the second substrate8321.

In this embodiment, the third bent structure is bent three times and is in the shape of “Π”; admittedly, in other embodiments, the third bent structure can be in other shapes. At that same time, the two guide bars8322may not be limited to the integrally bending formed structure, and can also be fixed to the second substrate8321by welding.

Further, the width between the two guide rails8312gradually decreases in the axial direction of the first substrate8311, and the width between the two guide bars8322gradually decreases in the axial direction of the second substrate8321. As a result, when the two guide bars8322are inserted into the two guide rails8312, the guide bars and the guide rails are in tighter fit, thereby improving the stability of the assembly of the sofa armrest5.

In addition, the first substrate8311and the second substrate8321are each provided with a plurality of bolt holes8314which are uniformly arranged in the axial direction of the first substrate8311and the second substrate8321, respectively. The first member831and the second member832are positioned via the bolt holes8314and connected by bolts.

Therefore, after the first member831and the second member832are in sliding insertion fit, the first member831and the second member832are fixed by two methods: one is to abut the two guide bars8322of the second member832against the stopper8313of the first member831; and the other is to align the bolt holes8314in the first substrate8311of the first member831with the bolt holes8314in the second substrate8321of the second member832, and then complete connection with bolts. The two fixing methods are adopted to improve the flexibility of the assembly of the sofa armrest5.

In addition, in this embodiment, the sofa armrests5, the sofa backrest6and the sofa foot pad plate7are all integrally formed by a blow molding process. Therefore, the sofa armrests5, the sofa backrest6and the sofa foot pad plate7made by the blow molding process not only ensure the required strength, but also reduce the weight and improve the production efficiency.

The sofa production and assembly process in the embodiment specifically comprises the following steps:producing cross beams12and longitudinal beams11according to the defined dimensions and assembling the two cross beams12and the two longitudinal beams11to form the sofa seat frame1;installing a plurality of serpentine springs between the two cross beams12of the sofa seat frame1to form a cushion supporting structure;producing first connecting pieces14according to defined dimensions, and connecting the two fifth side plates142of each first connecting piece14with the first side plate112and the second side plate113of the longitudinal beam11, respectively, to realize the connection of the first connecting pieces14with the sofa seat frame1;producing supporting legs31according to the defined dimensions to obtain a rack3;connecting the third supporting plates141of the first connecting pieces14to the supporting legs31to realize the connection of the sofa seat frame1with the rack3to obtain the sofa seat assembly;placing a seat cushion on the seat cushion supporting structure;processing the sofa fabric to set dimensions, and fixing a clamping strip on the edge of the sofa fabric, then wrapping the seat cushion with the sofa fabric, and clamping the sofa fabric with the lower edges of the first side plates112of the two longitudinal beams11and the lower edges of the third side plates122of the two cross beams12through the clamping strip on the sofa fabric, so as to fix the sofa fabric to the sofa seat frame1, thus completing the production and assembly of the seat cushion; andinstalling the sofa armrests5and the sofa backrest6on the sofa seat frame1, and installing the sofa foot pad plate7on the supporting legs31, thus completing the production and assembly of the sofa.

Referring toFIGS.19-22, the invention also provides a functional sofa comprising the functional sofa base assembly of Embodiment 3, a seat cushion and sofa fabric (not shown in the figure) wrapping the seat cushion, sofa armrests5, a sofa backrest6, and a sofa foot pad plate7. Wherein, the edge of the sofa fabric is provided with a clamping strip, and the sofa fabric is detachably connected with the lower edges of the first side plates112of the two longitudinal beams11and the lower edges of the third side plates122of the two cross beams12through the clamping strip. In this embodiment, the structure, number and installation position of the clamping strip are the same as those in Embodiment 4, and will not be repeated here.

In addition, the backrest mechanism431of each telescopic bracket43comprises a second mounting plate4312for mounting the sofa backrest6, which is detachably connected to the functional rack4through the second mounting plates4312. In the present embodiment, the sofa backrest6and the second mounting plates4312are connected by means of bolts or screws.

In addition, the leg extension mechanism433of each telescopic bracket43comprises a third mounting plate4336for mounting the sofa foot pad plate7, which is detachably connected to the functional rack4through the third mounting plates4336. In this embodiment, the sofa foot pad plate7and the third mounting plates4336are connected by bolts.

In addition, the functional sofa further comprises fourth connecting pieces83through which the sofa armrest5is detachably connected to the sofa seat frame1. In the present embodiment, the structure, number and installation position of the fourth connecting pieces83are the same as those in Embodiment 4, and will not be repeated here.

In addition, in this embodiment, the sofa armrests5, the sofa backrest6and the sofa foot pad plate7are all integrally formed by a blow molding process.

Referring toFIGS.20-22, which are schematic diagrams showing the functional sofa (with the right sofa armrest removed) of the present invention in three states of sitting posture, leisure posture and lying posture respectively.

The functional sofa production and assembly process in the embodiment comprises the following steps:producing cross beams12and longitudinal beams11according to the defined dimensions and assembling the two cross beams12and the two longitudinal beams11to form a sofa seat frame1;installing a plurality of serpentine springs between the two cross beams12of the sofa seat frame1to form a cushion supporting structure;producing first connecting pieces14according to defined dimensions, and connecting the two fifth side plates142of each first connecting piece14to the first side plate112and the second side plate113of the longitudinal beam11, respectively, to realize the connection of the first connecting pieces14with the sofa seat frame1;producing parts of a functional rack4according to defined dimensions and assembling the parts to obtain the functional rack4;connecting the third supporting plates141of the first connecting pieces14to the first mounting plates43211of the telescopic brackets43to realize the connection of the sofa seat frame1with the functional rack4to obtain a functional sofa base assembly; andplacing a seat cushion on the seat cushion supporting structure;processing the sofa fabric to set dimensions, and fixing a clamping strip on the edge of the sofa fabric, then wrapping the seat cushion with the sofa fabric, and clamping the sofa fabric with the lower edges of the first side plates112of the two longitudinal beams11, the lower edges of the third side plates122of the cross beams12close to a sofa foot pad plate7and the lower edge of an extension plate2on the cross beams12close to a sofa backrest6through the clamping strip on the sofa fabric, so as to fix the sofa fabric to the sofa seat frame1, thus completing the production and assembly of the seat cushion; andinstalling the sofa backrest6and the sofa foot pad plate7on the telescopic brackets43, and installing the sofa armrests5on the supporting legs31, thus completing the production and assembly of the sofa.

Referring toFIGS.23-25, the invention also provides a three-seater sofa, which comprises the sofa in Embodiment 4, the functional sofa in Embodiment 5 and a second base9, wherein the sofa is arranged in the middle position, and the functional sofa is respectively arranged in the left position and the right position (the functional sofa in the left position has no right armrest, and the functional sofa in the right position has no left armrest). The second base9is formed by two strip-shaped second underframes91arranged in parallel, and the second underframes91are perpendicular to the two first underframes411of the first base41.

Specifically, the two second underframes91are connected to two ends of the first underframes411and two ends of the supporting legs31, respectively. In the present embodiment, the second underframes91, the first underframes411and the support legs31are fixed by bolts or screws.

Referring toFIGS.23-25, which are schematic diagrams showing the three-seater sofa (with the right sofa armrest of the functional sofa in the right position removed) of the present invention in three states of sitting posture, leisure posture and lying posture respectively.

The technical means disclosed in the scheme of the invention are not limited to the technical means disclosed in the above embodiment, but also include a technical scheme composed of any combination of the above technical features. It should be noted that for those of ordinary skill in the art, a number of modifications and embellishments may be made without departing from the principles of the present invention, and these modifications and embellishments are also considered to be the scope of protection of the present invention.