CN112622160A

CN112622160A - Injection molding system of chair seat frame and device for mounting nut on injection mold

Info

Publication number: CN112622160A
Application number: CN202011362955.3A
Authority: CN
Inventors: 王江林
Original assignee: Henglin Home Furnishings Co Ltd
Current assignee: Henglin Home Furnishings Co Ltd
Priority date: 2020-11-27
Filing date: 2020-11-27
Publication date: 2021-04-09

Abstract

The invention discloses an injection molding system of a chair seat frame and a device for mounting nuts on an injection mold, which comprises a nut discharging device, a fixed mold and a manipulator, wherein the nut discharging device comprises a first workbench, a second driving mechanism, a discharging assembly and a detection assembly, the second driving mechanism, the discharging assembly and the detection assembly are mounted on the first workbench, the discharging assembly comprises a discharging plate, two first discharging assemblies, two second discharging assemblies and four third discharging assemblies, the two first discharging assemblies, the two second discharging assemblies and the four third discharging assemblies are symmetrically arranged on the discharging plate, a first discharging hole and a second discharging hole are formed in each first discharging assembly, a third discharging hole is formed in each second discharging assembly, and a fourth discharging hole is formed in each third discharging assembly; the technical scheme realizes the mechanized and automatic nut pre-embedding on the fixed die; the speed of embedded nuts is improved, the production efficiency of the chair seat frame is further improved, the embedded positions of the nuts are greatly prevented from being subjected to error, and the qualification rate of chair seat frame products is improved.

Description

Injection molding system of chair seat frame and device for mounting nut on injection mold

Technical Field

The invention relates to the technical field of injection molding, in particular to an injection molding system of a chair seat frame and a device for mounting a nut on an injection mold.

Background

With the continuous development of economy and the continuous progress of society, various material consumer goods are provided for the life of people so as to enrich the living standard of people, and a plastic product is one of a plurality of material consumer goods.

It is well known that the cooperation of an injection molding machine and an injection mold is one of the most common ways to manufacture plastic products. Wherein, for the plastic chair seat frame that pre-buried there is the nut assembly to form, its manufacturing process is: operating personnel buries the nut in injection mold's movable mould or cover half, then makes movable mould and cover half compound die by the injection molding machine, and the injection molding machine carries out the pressurize and solidifies after pouring into the molten liquid into injection mold at last to pre-buried in chair seat frame with the nut, thereby make chair seat frame carry out the be assembled between/be connected with other positions of chair conveniently with the help of pre-buried nut.

However, those skilled in the art find that the following disadvantages exist in the process of embedding the nut into the moving mold or the fixed mold of the injection mold by the operator during the use process:

1) the speed of manually embedding the nuts is low, and the influence on the production efficiency of the chair seat frame is large;

2) errors also exist in the pre-embedded positions of the nuts, and the qualification rate of chair seat frame products is influenced;

3) the manual embedded nuts can only depend on manual detection to detect whether the nuts are completely embedded, so that the phenomenon of missing embedding is endless, and the qualification rate of the chair seat frame product is influenced.

Disclosure of Invention

In order to solve the problems, the invention aims to overcome the defects of the prior art and provide an injection molding system of a chair seat frame and a device for mounting nuts on an injection mold.

In order to achieve the purpose, the invention adopts the following technical scheme:

the utility model provides a device of last installation nut of injection mold of chair seat frame, includes nut discharge device, cover half and manipulator, its characterized in that:

the nut discharging device comprises a first workbench, a second driving mechanism, a discharging assembly and a detection assembly, wherein the second driving mechanism, the discharging assembly and the detection assembly are arranged on the first workbench;

the manipulator further comprises a first cross beam, a second cross beam, a first mounting seat, a second mounting seat, a first automatic telescopic rod and a clamping device, wherein two ends of the first cross beam face to the left and right directions respectively and are fixedly mounted at the top end of the injection molding machine, the first mounting seat is mounted on the first cross beam through a left-right moving mechanism, the second cross beam is fixedly connected with the first mounting seat, two ends of the second cross beam face to the front and back directions respectively, the second mounting seat is mounted on the second cross beam through a front-back moving mechanism, two ends of the first automatic telescopic rod and two ends of the second automatic telescopic rod face to the up and down directions respectively, the first automatic telescopic rod is fixedly mounted on the second mounting seat, the second automatic telescopic rod is fixedly mounted on the second mounting seat or the first automatic telescopic rod, and the clamping device is rotatably mounted at the bottom end of the first automatic telescopic rod, the manipulator is sequentially provided with a first stopping position, a second stopping position, a fourth stopping position and a fifth stopping position;

the first stopping position is the initial position of the manipulator, the second stopping position is the position where the manipulator grabs the nut, the fourth stopping position is the position where the manipulator places the nut on the fixed die, and the fifth stopping position is the position where the manipulator detects whether the nut is installed on the fixed die.

Preferably, the chair seat frame comprises a front supporting bar, a right supporting bar, a rear supporting bar, a left supporting bar, a first supporting bar, two second supporting bars, two third supporting bars and a fourth supporting bar which are integrally formed and arc-shaped, the front supporting bar, the right supporting bar, the rear supporting bar and the left supporting bar enclose into a circle to form the chair frame, the front supporting bar and the rear supporting bar are the same in shape and are respectively positioned at the front side and the rear side of the chair frame, the left supporting bar and the right supporting bar are the same in shape and are respectively positioned at the left side and the right side of the chair frame, the two ends of the first supporting bar are respectively connected with the left supporting bar and the right supporting bar, the two second supporting bars are distributed in parallel, the two ends of the two second supporting bars are equally distributed and are respectively connected with the first supporting bar and the rear supporting bar, the two third supporting bars are symmetrically distributed, and the, two ends of the other third supporting bar are respectively connected with the right supporting bar and the other second supporting bar, and two ends of the fourth supporting bar are respectively connected with the two second supporting bars;

two first nut pre-buried holes, two second nut pre-buried holes, two third nut pre-buried holes, two fourth nut pre-buried holes and two fifth nut pre-buried holes are symmetrically distributed on the chair seat frame, wherein the first nut pre-buried holes, the second nut pre-buried holes and the third nut pre-buried holes are located on the third supporting bar, the first nut pre-buried holes and the second nut pre-buried holes are located on the outer side of the third nut pre-buried holes, the fourth nut pre-buried holes are located at the connecting position of the second supporting bar and the third supporting bar, and the fifth nut pre-buried holes are located at the connecting position of the first supporting bar and the second supporting bar;

the first discharging hole corresponds to the first nut pre-embedding hole, the second discharging hole corresponds to the second nut pre-embedding hole, the third discharging hole corresponds to the third nut pre-embedding hole, and the fourth discharging hole corresponds to the fourth nut pre-embedding hole and the fifth nut pre-embedding hole.

Preferably, the second driving mechanism comprises a second cylinder, two second sliding chutes and two second sliding members, the two second sliding members are fixedly mounted on the lower surface of the discharging plate, the two second sliding chutes are located on the first workbench, the two second sliding chutes are respectively located on the front side and the rear side of the second cylinder, the two second sliding members are respectively located on the front side and the rear side of the second cylinder, and the second cylinder pushes the discharging plate to move through the sliding fit of the second sliding chutes and the second sliding members, so that the discharging plate has a discharging position and a feeding position;

wherein, whether detecting element deposits the nut in through infrared ray or forced induction detection first blowing hole, second blowing hole, third blowing hole and fourth blowing hole to only when detecting element detects all first blowing hole, second blowing hole, third blowing hole and fourth blowing hole in all when all depositing the nut, the blowing position could be followed to the flitch and the pay-off position.

Preferably, the first discharging assembly comprises a first fixing block, two first supporting columns, two first springs and a first discharging block, the first fixing block is fixedly installed on the discharging plate, the first discharging block is fixedly connected with the two first supporting columns, the two first supporting columns can be installed on the first fixing block in a vertically moving mode, the two first springs are respectively installed on the two first supporting columns in a sleeved mode, the top ends of the first springs are abutted against the first discharging block, the bottom ends of the first springs are abutted against the first fixing block, and the first discharging hole and the second discharging hole are both located on the first discharging block;

the second discharging assembly comprises a second fixing block, two second supporting columns, two second springs and a second discharging block, the second fixing block is fixedly installed on the discharging plate, the second discharging block is fixedly connected with the two second supporting columns, the two second supporting columns can be installed on the second fixing block in a vertically moving mode, the two second springs are respectively installed on the two second supporting columns in a sleeved mode, the top ends of the second springs are abutted against the second discharging block, the bottom ends of the second springs are abutted against the second fixing block, and the third discharging hole is located in the second discharging block;

the third discharging assembly comprises a third fixing block, two third supporting columns, two third springs and a third discharging block, the third fixing block is fixedly arranged on the discharging plate, the third discharging block is fixedly connected with the two third supporting columns, the two third supporting columns can be vertically moved and are arranged on the third fixing block, the two third springs are respectively sleeved on the two third supporting columns, the top ends of the third springs are abutted against the third discharging block, the bottom ends of the third springs are abutted against the third fixing block, and the fourth discharging hole is positioned on the two third discharging blocks; the fifth discharging holes are positioned on the other two third discharging blocks.

Preferably, the left-right moving mechanism comprises a first air cylinder, two first sliding grooves and two first sliding parts, the first air cylinder is fixedly mounted on the first cross beam, the two first sliding grooves are located on the first cross beam, the two first sliding parts are fixedly connected with the first mounting seat, the two first sliding parts are in sliding fit with the two first sliding grooves, and an extension rod of the first air cylinder is fixedly connected with the first mounting seat and pushes the first mounting seat to reciprocate on the first cross beam;

the front-back moving mechanism comprises a third cylinder, two third sliding grooves and two third sliding parts, the third cylinder is fixedly installed on the second cross beam, the two third sliding grooves are located on the second cross beam, the two third sliding parts are fixedly connected with the second installation base, the two third sliding parts are in sliding fit with the two third sliding grooves, and an extension rod of the third cylinder is fixedly connected with the second installation base and pushes the second installation base to move on the second cross beam in a reciprocating mode.

As preferred, still be equipped with the fourth cylinder, fourth cylinder fixed mounting is on first automatic telescopic link, clamping device includes first mounting panel and installs a plurality of centre gripping subassembly on first mounting panel, the bottom of first automatic telescopic link is articulated with the mid portion of first mounting panel, the extension bar of fourth cylinder is articulated with first mounting panel, the fourth cylinder makes clamping device have first rotation stop position and second rotation stop position, when clamping device is located first rotation stop position, first mounting panel is in the horizontality, a plurality of centre gripping subassembly is towards below, when clamping device is located the second rotation stop position, first mounting panel is in vertical state, first mounting panel is located the place ahead of first automatic telescopic link, a plurality of centre gripping subassembly is towards the place ahead.

Preferably, when the manipulator is in the first rest position, the gripping device is in the first rotational rest position;

when the manipulator is at the second stop position, the clamping device is at the first rotation stop position;

when the manipulator is at the fourth stopping position, the clamping device is located at the second rotating stopping position;

when the manipulator is in the fifth rest position, the gripping device is in the second rotational rest position.

Preferably, the clamping assembly comprises a sixth cylinder, a transmission assembly, a third mounting seat, a mounting shaft and two clamping pieces, the sixth cylinder is fixedly connected with the first mounting plate, the third mounting seat is fixedly mounted on the sixth cylinder, the transmission assembly and the mounting shaft are mounted on the third mounting seat, the two clamping pieces are sleeved and mounted on the mounting shaft, one side face of each clamping piece is tightly attached to the third mounting seat, the sixth cylinder controls the two clamping pieces to move through the transmission assembly, when an extension bar of the sixth cylinder extends, the two clamping assemblies move oppositely, and when the extension bar of the sixth cylinder retracts, the two clamping assemblies move oppositely.

Preferably, the sucker assembly is a flat vacuum sucker.

Preferably, the fixed die is provided with a plurality of mounting columns, and the manipulator sleeves a plurality of nuts in the clamping device on the mounting columns;

still be equipped with a plurality of proximity switch, proximity switch includes switch portion and response portion, and a plurality of response portion installs respectively on a plurality of erection column, and a plurality of switch portion installs the upper portion at the holder.

An injection molding system of a chair seat frame comprises the device for mounting the nut on the injection mold of the chair seat frame.

The invention has the beneficial effects that:

1) the nut pre-embedding device has the advantages that the nut pre-embedding device is arranged on the fixed die, and the nut pre-embedding device is arranged on the manipulator, so that the nut pre-embedding device can realize mechanization and automation on the fixed die; the speed of pre-embedding the nuts is improved, and the production efficiency of the chair seat frame is further improved;

2) according to the invention, the nut is embedded through the manipulator, so that the error of the embedded position of the nut is greatly avoided, and the qualification rate of the chair seat frame product is improved;

3) the method and the device have two times of detection in the process of embedding the nuts, the first time is to detect whether the operator stores the nuts in each discharging hole so as to ensure that the manipulator cannot miss the grabbing during grabbing, and the second time is to detect whether the manipulator places all the nuts on the fixed die so as to ensure that the process of embedding the nuts is not missed and improve the qualification rate of chair seat frame products.

Drawings

FIG. 1 is a schematic view of the robot of the present invention in a first rest position;

FIG. 2 is a schematic view of the robot of the present invention in a second rest position;

FIG. 3 is a schematic view of the robot of the present invention in a third rest position;

FIG. 4 is a schematic view of the robot of the present invention in a fourth rest position;

FIG. 5 is a schematic view of the robot of the present invention in a fifth rest position;

FIG. 6 is a schematic view of the robot of the present invention in a sixth rest position;

FIG. 7 is a first schematic view of the robot of the present invention in a seventh parked position;

FIG. 8 is a second schematic view of the robot of the present invention in a seventh rest position;

FIG. 9 is a schematic view of a discharge apparatus of the present invention;

FIG. 10 is a schematic view of a clamping device of the present invention;

FIG. 11 is a schematic view of a clamping assembly of the present invention;

FIG. 12 is a schematic view of a clamp assembly of the present invention;

FIG. 13 is a schematic view of a stationary mold according to the present invention;

fig. 14 is a schematic view of a chair seat frame according to the present invention.

Description of reference numerals: 1. a nut discharging device; 2. an injection molding machine; 3. a manipulator; 401. a front supporting bar; 402. a right support bar; 403. a rear supporting strip; 404. a left support bar; 405. a first support bar; 406. a second supporting strip; 407. a third supporting strip; 408. a fourth supporting strip; 409. a first nut pre-buried hole; 410. a second nut pre-buried hole; 411. a third nut pre-buried hole; 412. a fourth nut pre-buried hole; 413. a fifth nut pre-buried hole; 30. a suction cup device; 31. a clamping device; 10. a discharge plate; 11. a first discharging assembly; 12. a second discharging component; 13. a third discharging assembly; 32. a first cross member; 33. a second cross member; 34. a first automatic telescopic rod; 35. a second automatic telescopic rod; 110. a first discharge hole; 111. a second discharge hole; 120. a third discharge hole; 130. a fourth discharge hole; 310. a first mounting plate; 311. a clamping assembly; 3110. a sixth cylinder; 3111. a third mounting seat; 3112. installing a shaft; 3113. a clamping member; 3114. a rack; 3115. a bull gear; 3116. a pinion gear; 3117. a fourth spring; 312. a first clamping and fixing block; 313. a second clamping fixed block; 314. a third clamping fixed block; 20. moving the mold; 21. fixing a mold; 210. and (6) mounting the column.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be considered as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, unless otherwise specified, "a plurality" means two or more unless explicitly defined otherwise.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

The first embodiment is as follows:

the utility model provides an injection moulding system of chair seat frame, includes nut discharge device 1, injection molding machine 2 and manipulator 3, injection molding machine 2 is the common equipment on the market, and the details are not given here again, generally speaking injection molding machine 2 includes first actuating mechanism, the gating system, as shown in fig. 12 movable mould 20 and cover half 21, movable mould 20 and cover half 21 fixed mounting are in injection molding machine 2, manipulator 3 snatchs the nut from nut discharge device 1 and puts into cover half 21 on, first actuating mechanism promotes movable mould 20 and removes in order to accomplish the compound die process with cover half 21, and the gating system accomplishes the process of moulding plastics.

In this embodiment, as shown in fig. 14, the chair seat frame includes a front support bar 401, a right support bar 402, a rear support bar 403, a left support bar 404, a first support bar 405, two second support bars 406, two third support bars 407 and a fourth support bar 408, which are integrally formed and are all arc-shaped, the front support bar 401, the right support bar 402, the rear support bar 403 and the left support bar 404 are formed into a circle to form the chair frame, the front support bar 401 and the rear support bar 403 are identical in shape and are respectively located at the front and rear sides of the chair frame, the left support bar 404 and the right support bar 402 are identical in shape and are respectively located at the left and right sides of the chair frame, the two ends of the first support bar 405 are respectively connected to the left support bar 404 and the right support bar 402, the two second support bars 406 are arranged in parallel, and the two ends of the two second support bars 406 are respectively connected, two third support bars 407 are symmetrically distributed, wherein two ends of one third support bar 407 are respectively connected with the left support bar 404 and one second support bar 406, two ends of the other third support bar 407 are respectively connected with the right support bar 402 and the other second support bar 406, and two ends of the fourth support bar 408 are respectively connected with the two second support bars 406;

two first nut embedded holes 409, two second nut embedded holes 410, two third nut embedded holes 411, two fourth nut embedded holes 412 and two fifth nut embedded holes 413 which are symmetrically distributed are arranged on the chair seat frame, wherein the first nut embedded holes 409, the second nut embedded holes 410 and the third nut embedded holes 411 are located on the third supporting strip 407, the first nut embedded holes 409 and the second nut embedded holes 410 are located on the outer side of the third nut embedded holes 411, the fourth nut embedded holes 412 are located at the connecting position of the second supporting strip 406 and the third supporting strip 407, and the fifth nut embedded holes 413 are located at the connecting position of the first supporting strip 405 and the second supporting strip 406.

In this embodiment, as shown in fig. 8, the nut discharging device 1 includes a first workbench, and a second driving mechanism, a discharging assembly and a detecting assembly mounted on the first workbench, where the discharging assembly includes a discharging plate 10, and two first discharging assemblies 11, two second discharging assemblies 12 and four third discharging assemblies 13 mounted on the discharging plate 10 and symmetrically distributed, the first discharging assemblies 11 are provided with first discharging holes 110 corresponding to first nut pre-burying holes 409 and second discharging holes 111 corresponding to second nut pre-burying holes 410, the second discharging assemblies 12 are provided with third discharging holes 120 corresponding to third nut pre-burying holes 411, and the third discharging assemblies 13 are provided with fourth discharging holes 130 corresponding to fourth nut pre-burying holes 412 and fifth nut pre-burying holes 413;

the manipulator 3 further comprises a first cross beam 32, a second cross beam 33, a first mounting seat, a second mounting seat, a first automatic telescopic rod 34, a second automatic telescopic rod 35, a clamping device 31 and a sucker device 30, wherein two ends of the first cross beam 32 face to the left and right directions respectively and are fixedly mounted on the top end of the injection molding machine 2, the first mounting seat is mounted on the first cross beam 32 through a left-right moving mechanism, the second cross beam 33 is fixedly connected with the first mounting seat, two ends of the second cross beam 33 face to the front and back directions respectively, the second mounting seat is mounted on the second cross beam 33 through a front-back moving mechanism, two ends of the first automatic telescopic rod 34 and the second automatic telescopic rod 35 face to the up and down directions respectively, the first automatic telescopic rod 34 is fixedly mounted on the second mounting seat, the second automatic telescopic rod 35 is fixedly mounted on the second mounting seat or the first automatic telescopic rod 34, the clamping device 31 is rotatably installed at the bottom end of the first automatic telescopic rod 34, the suction cup device 30 is rotatably installed at the bottom end of the second automatic telescopic rod 35, the clamping device 31 is located at the left side of the suction cup device 30, and the clamping device 31 and the suction cup device 30 sequentially have a first stop position as shown in fig. 1, a second stop position as shown in fig. 2, a third stop position as shown in fig. 3, a fourth stop position as shown in fig. 4, a fifth stop position as shown in fig. 5, a sixth stop position as shown in fig. 6, and a seventh stop position as shown in fig. 7 and 8 according to the forming process of the chair seat frame;

when the detection assembly detects that nuts are stored in the first discharging hole 110, the second discharging hole 111, the third discharging hole 120 and the fourth discharging hole 130, the second driving mechanism pushes the discharging assembly to move from the discharging position to the discharging position, the mechanical arm 3 moves downwards from the first stopping position to the second stopping position, the clamping device 31 grabs the nuts in the discharging assembly, then the mechanical arm 3 moves upwards to the first stopping position, then the mechanical arm 3 slides leftwards to the third stopping position, and the third stopping position is located above the injection molding machine 2;

after the injection molding of the previous chair seat frame is completed in the injection molding machine 2, the movable mold 20 and the fixed mold 21 are separated, then the manipulator 3 moves downwards and forwards to a fourth stop position to place the nuts on the clamping device 31 on the fixed mold 21, and then the manipulator 3 moves backwards and forwards to a fifth stop position to detect whether the nuts on the fixed mold 21 are completely loaded or not; then the mechanical arm 3 sequentially moves backwards, upwards, leftwards and backwards to a sixth stop position, after the sucker device 30 grabs the chair seat frame on the movable die 20, the mechanical arm 3 sequentially moves forwards, upwards, rightwards, backwards and downwards to a seventh stop position, the sucker device 30 puts down the chair seat frame, and then the mechanical arm 3 moves upwards and forwards to the first stop position.

Like this, adopt 3 automatic completion embedded nuts of manipulator, compare in artifical embedded nut, the embedded speed of nut has been improved, and when first sucking disc snatchs the nut at the beginning, be equipped with and detect for the first time, in order to ensure that the nut does not have the omission in initial blowing in-process, and place the nut back on cover half 21 at first sucking disc, still be equipped with and detect for the second time, in order to ensure that the nut does not have the omission at the in-process of pay-off and loading, the phenomenon of burying of no omission has been ensured basically takes place, and then very big improvement the qualification rate of chair seat frame product.

In this embodiment, the second driving mechanism includes a second cylinder, two second sliding chutes and two second sliding members, the two second sliding members are fixedly mounted on the lower surface of the discharging plate 10, the two second sliding chutes are located on the first workbench, the two second sliding chutes are respectively located on the front and rear sides of the second cylinder, the two second sliding members are respectively located on the front and rear sides of the second cylinder, and the second cylinder pushes the discharging plate 10 to move through the sliding fit of the second sliding chutes and the second sliding members, so that the discharging plate 10 has a discharging position and a feeding position; the material placing position refers to a position where the material discharging plate 10 is located when an operator places nuts in the first material placing hole 110, the second material placing hole 111, the third material placing hole 120 and the fourth material placing hole 130, and the material feeding position refers to a position where the material discharging plate 10 is located when the clamping device 31 takes away the nuts placed in the first material placing hole 110, the second material placing hole 111, the third material placing hole 120 and the fourth material placing hole 130.

It is worth to be noted that, only when the detection assembly detects that all the nuts are placed in the first discharging hole 110, the second discharging hole 111, the third discharging hole 120 and the fourth discharging hole 130, the operator presses the button for starting the second cylinder to be effective; further preferably, the detection assembly detects whether nuts are stored in the first discharging hole 110, the second discharging hole 111, the third discharging hole 120 and the fourth discharging hole 130 through infrared rays or pressure sensing.

Specifically, the first discharging assembly 11 includes a first fixing block, two first supporting columns, two first springs and a first discharging block, the first fixing block is fixedly mounted on the discharging plate 10, the first discharging block is fixedly connected with the two first supporting columns, the two first supporting columns are mounted on the first fixing block in a manner of moving up and down, the two first springs are respectively mounted on the two first supporting columns in a sleeved manner, the top ends of the first springs are abutted against the first discharging block, the bottom ends of the first springs are abutted against the first fixing block, and the first discharging hole 110 and the second discharging hole 111 are both located on the first discharging block;

the second discharging assembly 12 comprises a second fixing block, two second supporting columns, two second springs and a second discharging block, the second fixing block is fixedly mounted on the discharging plate 10, the second discharging block is fixedly connected with the two second supporting columns, the two second supporting columns can be vertically moved and mounted on the second fixing block, the two second springs are respectively sleeved on the two second supporting columns, the top ends of the second springs are abutted against the second discharging block, the bottom ends of the second springs are abutted against the second fixing block, and the third discharging hole 120 is located on the second discharging block;

the third discharging assembly 13 comprises a third fixing block, two third supporting columns, two third springs and a third discharging block, the third fixing block is fixedly mounted on the discharging plate 10, the third discharging block is fixedly connected with the two third supporting columns, the two third supporting columns are mounted on the third fixing block in a vertically movable manner, the two third springs are respectively sleeved on the two third supporting columns, the top ends of the third springs are abutted against the third discharging block, the bottom ends of the third springs are abutted against the third fixing block, and the fourth discharging hole 130 is located on two of the third discharging blocks; the fifth discharging holes are positioned on the other two third discharging blocks.

So set up, because manipulator 3 when moving down to the second stop position from first stop position, because reasons such as machining error and assembly error, first sucking disc can not just be in the position that can hold the nut, consequently, set up first spring, second spring and third spring and make first sucking disc and nut flexible contact to when first sucking disc reachs the second stop position, first sucking disc has offset with the nut and makes the nut move down a distance, thereby firmly suck the nut.

Further preferably, the first discharging hole 110, the second discharging hole 111, the third discharging hole 120 and the fourth discharging hole 130 are tapered holes, so that an operator can conveniently place nuts in the first discharging hole 110, the second discharging hole 111, the third discharging hole 120 and the fourth discharging hole 130, and meanwhile, the nuts can be prevented from falling when the discharging assembly moves from the discharging position to the feeding position.

Preferably, the first discharging hole 110, the second discharging hole 111, the third discharging hole 120 and the fourth discharging hole 130 are provided with notches, the detecting assembly includes a plurality of pressure sensors and a plurality of transmission lines connected to the pressure sensors, and the plurality of pressure sensors are installed in the notches.

Further preferably, a rubber protective sleeve is further arranged and movably connected with the discharging plate 10, and the rubber protective sleeve comprises a plurality of transmission lines into a wire harness; when the discharging assembly moves between the discharging position and the feeding position in a reciprocating mode, if no rubber protective sleeve exists, the connecting position between the transmission line and the pressure sensor can be repeatedly pulled, and the transmission line is easy to fall off.

In the present embodiment, the gradual distance between the first discharging hole 110 and the discharging plate 10 is equal to the distance between the second discharging hole 111 and the discharging plate 10; the gradual distance between the first discharging hole 110 and the discharging plate 10 is larger than the gradual distance between the third discharging hole 120 and the discharging plate 10, and the gradual distance between the third discharging hole 120 and the discharging plate 10 is larger than the gradual distance between the fourth discharging hole 130 and the discharging plate 10; thus, the positions of the first nut burying hole 409, the second nut burying hole 410, the third nut burying hole 411, the fourth nut burying hole 412 and the fifth nut burying hole 413 in the chair seat frame can be corresponded.

In this embodiment, the left-right moving mechanism includes a first cylinder, two first sliding grooves and two first sliding members, the first cylinder is fixedly mounted on the first cross beam 32, the two first sliding grooves are located on the first cross beam 32, the two first sliding members are fixedly connected with the first mounting seat, the two first sliding members are in sliding fit with the two first sliding grooves, and an extension rod of the first cylinder is fixedly connected with the first mounting seat and pushes the first mounting seat to reciprocate on the first cross beam 32;

the back-and-forth movement mechanism comprises a third cylinder, two third sliding grooves and two third sliding parts, the third cylinder is fixedly installed on the second cross beam 33, the two third sliding grooves are located on the second cross beam 33, the two third sliding parts are fixedly connected with the second installation base, the two third sliding parts are in sliding fit with the two third sliding grooves, and an extension rod of the third cylinder is fixedly connected with the second installation base and pushes the second installation base to reciprocate on the second cross beam 33.

In this embodiment, a fourth air cylinder is further provided, the fourth air cylinder is fixedly installed on the first automatic telescopic rod 34, as shown in fig. 10, the clamping device 31 includes a first mounting plate 310 and a plurality of clamping assemblies 311 installed on the first mounting plate 310, as shown in fig. 11, a bottom of the first automatic telescopic rod 34 is hinged to a middle portion of the first mounting plate 310, an extension rod of the fourth air cylinder is hinged to the first mounting plate 310, the fourth air cylinder enables the clamping device 31 to have a first rotation stop position and a second rotation stop position, when the clamping device 31 is located at the first rotation stop position, the first mounting plate 310 is in a horizontal state, the plurality of clamping assemblies 311 faces downward, when the clamping device 31 is located at the second rotation stop position, the first mounting plate 310 is in a vertical state, the first mounting plate 310 is located in front of the first automatic telescopic rod 34, the plurality of gripping members 311 face forward.

In this embodiment, a fifth cylinder is further provided, which is fixedly mounted on the second automatic expansion link 35, the suction cup device 30 comprises a second mounting plate and a plurality of suction cup components mounted on the second mounting plate, the bottom of the second automatic expansion link 35 is hinged with the middle part of the second mounting plate, the extension rod of the fifth cylinder is hinged with the second mounting plate, said fifth air cylinder causes the suction cup means 30 to have a third and a fourth rotary stop position, when the suction cup device 30 is located at the third rotation stop position, the second mounting plate is in a horizontal state, the plurality of suction cup components face downward, when the suction cup means 30 is in the fourth rotation rest position, said second mounting plate is in a vertical position, the second mounting plate is located behind the second automatic telescopic rod 35, and the plurality of sucker components face the rear.

In this embodiment, the clamping assembly 311 includes a sixth cylinder 3110, a transmission assembly, a third mounting seat 3111, an installation shaft 3112 and two clamping members 3113, the sixth cylinder 3110 is fixedly connected to the first mounting plate 310, the third mounting seat 3111 is fixedly installed on the sixth cylinder 3110, the transmission assembly and the installation shaft 3112 are installed on the third mounting seat 3111, the two clamping members 3113 are installed on the installation shaft 3112 in a sleeved manner, one side surface of the two clamping members 3113 is tightly attached to the third mounting seat 3111, the sixth cylinder 3110 controls the two clamping members 3113 to move through the transmission assembly, when the extension bar of the sixth cylinder 3110 extends, the two clamping assemblies 311 move in opposite directions, and when the extension bar of the sixth cylinder 3110 retracts, the two clamping assemblies 311 move in opposite directions.

Further preferably, the transmission assembly includes rack 3114, two gear wheels 3115 and two pinion 3116, and the extension bar of sixth cylinder 3110 passes behind third mount pad 3111 and rack 3114 fixed connection, two pinion 3116, two gear wheels 3115 and installation axle 3112 fixed mounting on third mount pad 3111, gear wheel 3115 and pinion 3116 coaxial transmission, two pinion 3116 are located rack 3114 both sides respectively and with rack 3114 meshing transmission, two gear wheels 3115 are with two holder 3113 meshing transmission respectively.

More preferably, a fourth spring 3117 is further provided, the fourth spring 3117 is mounted on the mounting shaft 3112 in a sleeved manner, one end of the fourth spring 3117 abuts against one of the clamping members 3113, and the other end of the fourth spring 3117 abuts against the other clamping member 3113.

It is further preferable that the width of the holder 3113 is gradually reduced in a direction from the bottom of the holder 3113 to the top of the holder 3113, so that the holder 3113 is extended into each of the discharge holes to pick up the nut.

In this embodiment, two first clamping fixing blocks 312, two second clamping fixing blocks 313 and four third clamping fixing blocks 314 are further provided, the third clamping fixing block 314 is higher than the second clamping fixing block 313, the second clamping fixing block is higher than the first clamping fixing block 312, the third clamping fixing block 314 and the second clamping fixing block 313 are respectively and fixedly provided with a clamping component 311, the first clamping fixing block 312 is fixedly provided with two clamping components 311, the two clamping components 311 on the first clamping fixing block 312 correspond to the first nut pre-buried hole 409 and the second nut pre-buried hole 410, the clamping component 311 on the second clamping fixing block 313 corresponds to the third nut pre-buried hole 411, and the clamping components 311 on the third clamping fixing blocks 314 correspond to the fourth nut pre-buried hole 412 and the fifth nut pre-buried hole 413.

In this embodiment, the chuck assembly employs a flat type vacuum chuck.

In this embodiment, as shown in fig. 13, the fixed mold 21 is provided with a plurality of mounting posts 210, and the robot 3 sets a plurality of nuts in the clamping device 31 on the plurality of mounting posts 210.

In this embodiment, a plurality of proximity switches are further provided, each proximity switch includes a switch portion and an induction portion, the plurality of induction portions are respectively installed on the plurality of mounting posts 210, and the plurality of switch portions are installed on the upper portion of the clamping piece 3113, so that when the manipulator 3 moves to the fourth stop position to install the nut on the mounting posts 210 in a sleeved manner, the switch portion and the induction portion cannot be connected due to the blocking of the clamping piece 3113, and when the manipulator 3 moves to the fifth stop position, if the mounting posts 210 are sleeved with the nuts, the switch portion and the induction portion cannot be connected due to the blocking of the nuts, and if the mounting posts 210 are not sleeved with the nuts, the switch portion and the induction portion are connected to send a signal to stop injection molding; thus, the phenomenon that the manipulator 3 misses the nut during the transportation and the nut loading on the fixed die 21 to cause the disqualification of the chair seat frame product can be prevented.

The injection molding method of the chair seat frame adopts the injection molding system of the chair seat frame, and comprises the following specific steps:

the method comprises the following steps: an operator places a plurality of nuts in the first discharging hole 110, the second discharging hole 111, the third discharging hole 120 and the fourth discharging hole 130 respectively, then presses the starting button, and the discharging assembly moves from the discharging position to the discharging position;

step two: the manipulator 3 moves downwards from the first stop position to the second stop position, the clamping device 31 grabs the nuts in the discharging assembly, then the manipulator 3 moves upwards to the first stop position, then the manipulator 3 slides leftwards to the third stop position, and the third stop position is located above the injection molding machine 2; simultaneously, the discharging assembly moves from the discharging position to the discharging position;

step three: the manipulator 3 moves downwards and forwards to a fourth stop position in sequence to place the nut on the clamping device 31 on the fixed die 21;

step four: the manipulator 3 moves backwards and forwards to a fifth stopping position to detect whether the nuts on the fixed die 21 are completely loaded or not;

step five: the mechanical arm 3 sequentially moves backwards, upwards, leftwards and backwards to a sixth stop position so as to grab the injection-molded chair seat frame on the movable mold 20;

step six: the manipulator 3 moves forward, upward, rightward, rearward and downward to the seventh stop position in order to put down the seat frame of the chair, and then the manipulator 3 moves upward and forward to the first stop position.

It is worth mentioning that after the material discharging assembly in the step two moves from the material discharging position to the material discharging position, the step one can be repeated, so that the time for completing the injection molding of a chair seat frame product is reduced, and the working efficiency is improved.

In this embodiment, a detection assembly is further provided, which includes pressure sensors, and the detection assembly is respectively disposed in the gaps of the first discharging hole 110, the second discharging hole 111, the third discharging hole 120, and the fourth discharging hole 130, and when the nuts in the first discharging hole 110, the second discharging hole 111, the third discharging hole 120, and the fourth discharging hole 130 are all stored, that is, when all the pressure sensors sense pressure, the operator presses the start button to move the discharging assembly from the discharging position to the feeding position.

In this embodiment, in step two, the suction cup device 30 is located at the third rotation stop position, and the clamping device 31 rotates from the second rotation stop position to the first rotation stop position;

in step three, the suction cup means 30 are rotated from the third rotation stop position to the fourth rotation stop position, and the gripping means 31 are rotated from the first rotation stop position to the second rotation stop position;

in step five, the suction cup device 30 is rotated from the fourth rotation rest position to the fourth rotation rest position, and the holding device 31 is located at the second rotation rest position.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made in the above embodiments by those of ordinary skill in the art without departing from the principle and spirit of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The utility model provides a device of last mounting nut of injection mold of chair seat frame, includes nut discharge device (1), cover half (21) and manipulator (3), its characterized in that:

the nut discharging device (1) comprises a first workbench, a second driving mechanism, a discharging assembly and a detection assembly, wherein the second driving mechanism, the discharging assembly and the detection assembly are installed on the first workbench, the discharging assembly comprises a discharging plate (10), two first discharging assemblies (11), two second discharging assemblies (12) and four third discharging assemblies (13) which are installed on the discharging plate (10) and are symmetrically distributed, a first discharging hole (110) and a second discharging hole (111) are formed in each first discharging assembly (11), a third discharging hole (120) is formed in each second discharging assembly (12), and a fourth discharging hole (130) is formed in each third discharging assembly (13);

the manipulator (3) further comprises a first cross beam (32), a second cross beam (33), a first mounting seat, a second mounting seat, a first automatic telescopic rod (34) and a clamping device (31), wherein two ends of the first cross beam (32) face to the left and right directions respectively and are fixedly mounted at the top end of the injection molding machine (2), the first mounting seat is mounted on the first cross beam (32) through a left-right moving mechanism, the second cross beam (33) is fixedly connected with the first mounting seat, two ends of the second cross beam (33) face to the front and back directions respectively, the second mounting seat is mounted on the second cross beam (33) through a front-back moving mechanism, two ends of the first automatic telescopic rod (34) and the second automatic telescopic rod (35) face to the up and down directions respectively, the first automatic telescopic rod (34) is fixedly mounted on the second mounting seat or the first automatic telescopic rod (34), the clamping device (31) is rotatably arranged at the bottom end of the first automatic telescopic rod (34), and the manipulator (3) is sequentially provided with a first stopping position, a second stopping position, a fourth stopping position and a fifth stopping position;

the sucker component adopts a flat vacuum sucker;

the first stopping position is the initial position of the manipulator (3), the second stopping position is the position where the manipulator (3) grabs the nut, the fourth stopping position is the position where the manipulator (3) places the nut on the fixed die (21), and the fifth stopping position is the position where the manipulator (3) is used for detecting whether the nut is installed on the fixed die (21).

2. The device for mounting nuts on an injection mold of a chair seat frame according to claim 1, wherein the chair seat frame comprises a front supporting bar (401), a right supporting bar (402), a rear supporting bar (403), a left supporting bar (404), a first supporting bar (405), two second supporting bars (406), two third supporting bars (407) and a fourth supporting bar (408) which are integrally formed and are all arc-shaped, the front supporting bar (401), the right supporting bar (402), the rear supporting bar (403) and the left supporting bar (404) enclose into a circle to form the chair frame, the front supporting bar (401) and the rear supporting bar (403) have the same shape and are respectively positioned at the front and rear sides of the chair frame, the left supporting bar (404) and the right supporting bar (402) have the same shape and are respectively positioned at the left and right sides of the chair frame, both ends of the first supporting bar (405) are respectively connected with the left supporting bar (404) and the right supporting bar (402), the two second support bars (406) are distributed in parallel, two ends of each of the two second support bars (406) are respectively connected with the first support bar (405) and the rear support bar (403), the two third support bars (407) are symmetrically distributed, two ends of one third support bar (407) are respectively connected with the left support bar (404) and one second support bar (406), two ends of the other third support bar (407) are respectively connected with the right support bar (402) and the other second support bar (406), and two ends of the fourth support bar (408) are respectively connected with the two second support bars (406);

two first nut embedded holes (409), two second nut embedded holes (410), two third nut embedded holes (411), two fourth nut embedded holes (412) and two fifth nut embedded holes (413) which are symmetrically distributed are arranged on the chair seat frame, wherein the first nut embedded holes (409), the second nut embedded holes (410) and the third nut embedded holes (411) are located on a third supporting strip (407), the first nut embedded holes (409) and the second nut embedded holes (410) are located on the outer side of the third nut embedded holes (411), the fourth nut embedded holes (412) are located at the connecting position of the second supporting strip (406) and the third supporting strip (407), and the fifth nut embedded holes (413) are located at the connecting position of the first supporting strip (405) and the second supporting strip (406);

the first discharging hole (110) corresponds to the first nut pre-buried hole (409), the second discharging hole (111) corresponds to the second nut pre-buried hole (410), the third discharging hole (120) corresponds to the third nut pre-buried hole (411), and the fourth discharging hole (130) corresponds to the fourth nut pre-buried hole (412) and the fifth nut pre-buried hole (413).

3. The device for mounting nuts on the injection mold of the chair seat frame as recited in claim 1, wherein the second driving mechanism comprises a second cylinder, two second sliding chutes and two second sliding members, the two second sliding members are fixedly mounted on the lower surface of the discharging plate (10), the two second sliding chutes are located on the first workbench, the two second sliding chutes are respectively located on the front side and the rear side of the second cylinder, the two second sliding members are respectively located on the front side and the rear side of the second cylinder, and the second cylinder pushes the discharging plate (10) to move through the sliding fit of the second sliding chutes and the second sliding members, so that the discharging plate (10) has a discharging position and a feeding position;

wherein, whether the nut is deposited in detecting element passes through first blowing hole (110), second blowing hole (111), third blowing hole (120) and fourth blowing hole (130) through infrared ray or forced induction detection to only when all first blowing hole (110), second blowing hole (111), third blowing hole (120) and fourth blowing hole (130) are all deposited with the nut in detecting element detects, row flitch (10) just can be followed the blowing position and moved to the pay-off position.

4. The device for mounting nuts on an injection mold for a seat frame of a chair as claimed in claim 1, wherein said first discharging assembly (11) comprises a first fixing block, two first supporting pillars, two first springs and a first discharging block, said first fixing block is fixedly mounted on the discharging plate (10), said first discharging block is fixedly connected with said two first supporting pillars, said two first supporting pillars are movably mounted on the first fixing block up and down, said two first springs are respectively mounted on the two first supporting pillars in a sleeved manner, the top ends of said first springs are abutted against the first discharging block, the bottom ends of said first springs are abutted against the first fixing block, and said first discharging hole (110) and said second discharging hole (111) are both located on the first discharging block;

the second discharging assembly (12) comprises a second fixing block, two second supporting columns, two second springs and a second discharging block, the second fixing block is fixedly installed on the discharging plate (10), the second discharging block is fixedly connected with the two second supporting columns, the two second supporting columns can be installed on the second fixing block in a vertically moving mode, the two second springs are respectively installed on the two second supporting columns in a sleeved mode, the top ends of the second springs are abutted against the second discharging block, the bottom ends of the second springs are abutted against the second fixing block, and the third discharging hole (120) is located in the second discharging block;

the third discharging assembly (13) comprises a third fixing block, two third supporting columns, two third springs and a third discharging block, the third fixing block is fixedly arranged on the discharging plate (10), the third discharging block is fixedly connected with the two third supporting columns, the two third supporting columns can be vertically moved and are arranged on the third fixing block, the two third springs are respectively sleeved on the two third supporting columns, the top ends of the third springs are abutted against the third discharging block, the bottom ends of the third springs are abutted against the third fixing block, and the fourth discharging holes (130) are positioned on the two third discharging blocks; the fifth discharging holes are positioned on the other two third discharging blocks.

5. The device for mounting the nut on the injection mold of the chair seat frame according to claim 1, characterized in that the left-right moving mechanism comprises a first air cylinder, two first sliding grooves and two first sliding parts, the first air cylinder is fixedly mounted on the first cross beam (32), the two first sliding grooves are positioned on the first cross beam (32), the two first sliding parts are fixedly connected with the first mounting seat, the two first sliding parts and the two first sliding grooves are in sliding fit, an extension rod of the first air cylinder is fixedly connected with the first mounting seat and pushes the first mounting seat to reciprocate on the first cross beam (32);

the front-back moving mechanism comprises a third air cylinder, two third sliding grooves and two third sliding parts, the third air cylinder is fixedly installed on the second cross beam (33), the two third sliding grooves are located on the second cross beam (33), the two third sliding parts are fixedly connected with the second installation base, the two third sliding parts are in sliding fit with the two third sliding grooves, and an extension rod of the third air cylinder is fixedly connected with the second installation base and pushes the second installation base to move on the second cross beam (33) in a reciprocating mode.

6. The device for mounting nuts on an injection mold of a chair seat frame according to claim 1, wherein a fourth cylinder is further provided, the fourth cylinder is fixedly mounted on the first automatic telescopic rod (34), the clamping device (31) comprises a first mounting plate (310) and a plurality of clamping components (311) mounted on the first mounting plate (310), the bottom of the first automatic telescopic rod (34) is hinged with the middle part of the first mounting plate (310), an extension rod of the fourth cylinder is hinged with the first mounting plate (310), the fourth cylinder enables the clamping device (31) to have a first rotation stop position and a second rotation stop position, when the clamping device (31) is located at the first rotation stop position, the first mounting plate (310) is in a horizontal state, and the plurality of clamping components (311) face downward, when the clamping device (31) is located at the second rotation stop position, the first mounting plate (310) is in a vertical state, the first mounting plate (310) is located in front of the first automatic telescopic rod (34), and the plurality of clamping components (311) face towards the front.

7. A device for mounting nuts on an injection mould of a chair seat frame according to claim 6, characterized in that when the manipulator (3) is in the first rest position, the gripping means (31) are in the first rotation rest position;

when the manipulator (3) is in the second stop position, the clamping device (31) is in the first rotary stop position;

when the manipulator (3) is at the fourth stop position, the clamping device (31) is at the second rotation stop position;

when the manipulator (3) is in the fifth rest position, the gripping device (31) is in the second rotational rest position.

8. The device for mounting nuts on an injection mold for a seat frame of a chair according to claim 1, wherein the clamping assembly (311) comprises a sixth cylinder (3110), a transmission assembly, a third mounting seat (3111), a mounting shaft (3112) and two clamping members (3113), the sixth cylinder (3110) is fixedly connected with the first mounting plate (310), the third mounting seat (3111) is fixedly mounted on the sixth cylinder (3110), the transmission assembly and the mounting shaft (3112) are mounted on the third mounting seat (3111), the two clamping members (3113) are sleeved on the mounting shaft (3112), one side surface of the two clamping members (3113) is tightly attached to the third mounting seat (3111), the sixth cylinder (3110) controls the two clamping members (3113) to move through the transmission assembly, when the extension rod of the sixth cylinder (3110) extends, the two clamping members (311311) move towards each other, when the extension bar of the sixth cylinder (3110) is retracted, the two clamping assemblies (311) move apart.

9. The device for mounting the nut on the injection mold of the chair seat frame is characterized in that a plurality of mounting columns (210) are arranged on the fixed mold (21), and the manipulator (3) sleeves a plurality of nuts in the clamping device (31) on the plurality of mounting columns (210);

still be equipped with a plurality of proximity switch, proximity switch includes switch portion and response portion, and a plurality of response portion is installed respectively on a plurality of erection column (210), and the upper portion at holder (3113) is installed to a plurality of switch portion.

10. An injection molding system for a chair seat frame comprising a means for mounting a nut on an injection mold for a chair seat frame according to any one of claims 1 to 9.