CN114669644A

CN114669644A - Stamping die for machining

Info

Publication number: CN114669644A
Application number: CN202210301435.4A
Authority: CN
Inventors: 王媛; 杨晶; 陆玉兵
Original assignee: Luan Vocational and Technical College
Current assignee: Luan Vocational and Technical College
Priority date: 2022-03-24
Filing date: 2022-03-24
Publication date: 2022-06-28

Abstract

The invention discloses a stamping die for machining, which comprises a workbench, wherein a top plate is horizontally arranged at the position above the workbench, a plurality of support rods are connected between the lower end of the top plate and the top wall of the workbench, a driving chamber is arranged at the upper end of the top plate, a lower die seat is arranged on the top wall of the workbench corresponding to the position below the top plate, a lower die is arranged at the upper end of the lower die seat, a corresponding upper die seat is arranged at the position above the lower die seat in a sliding manner, and an upper die corresponding to the lower die is arranged at the lower end of the upper die seat; the roof of drive chamber is improved level and is equipped with driving motor, and fixed cover is equipped with the drive wheel on driving motor's the output, and the one side of keeping away from the axle center on the drive wheel lateral wall rotates and is connected with the connecting rod, and the connecting rod other end rotates and is connected with the actuating lever. The invention has compact structure and novel design, greatly improves the automation degree of stamping processing, greatly ensures the safety of operators during stamping processing, simultaneously ensures the precision of stamping processing, and greatly improves the processing efficiency of continuous stamping.

Description

Stamping die for machining

Technical Field

The invention relates to the technical field of machining equipment, in particular to a stamping die for machining.

Background

The mechanical processing refers to a process of changing the external dimension or performance of a workpiece by a mechanical device, and can be divided into cutting processing and pressure processing on the processing mode, wherein the pressure processing comprises rolling, forging, extruding, drawing, stamping, spinning and the like, and the forming can be realized by carrying out multiple stamping processing when processing parts with complex parts,

through the retrieval, application number CN 202020656283.6's patent discloses a stamping die is used in dysmorphism processing, including the operation panel, the one end fixed mounting at operation panel top has the support frame, the top fixed mounting of support frame has the hydraulic press, the bottom swing joint of hydraulic press has the telescopic link, the bottom of telescopic link and the equal fixed mounting in inside of operation panel have the magnetic flux device, cross slotted hole I has been seted up at the middle part of one of them magnetic flux device one side, cross fixed strip I has been cup jointed in the inside activity of cross slotted hole I, the circular telegram recess has been seted up at the positive middle part of support frame, the bottom fixed mounting of operation panel has the terrace die, cross slotted hole II has been seted up at the top of operation panel one side. This stamping die is used in dysmorphism processing through cross fixed strip and cross slotted hole, has realized carrying out the effect of quick dismantlement and installation with the terrace die, has solved when current mould is changed need disassemble and has installed a large amount of screw nuts and lead to the problem that wasted time and machining efficiency hang down, has improved the easy and simple to handle nature of equipment.

Above-mentioned device can not effectual carry out the stamping process of continuation, need carry out artifical pay-off, also can not guarantee the precision of artifical pay-off simultaneously to operating personnel's safety also does not have fine guarantee, and stamping process's efficiency is lower, and the ability of continuous punching press is relatively poor.

Disclosure of Invention

The invention aims to solve the problems that in the prior art, continuous stamping cannot be effectively carried out, manual feeding is needed, the precision of manual feeding cannot be guaranteed, the safety of operators is not well guaranteed, the stamping efficiency is low, and the continuous stamping capability is poor.

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

a stamping die for machining comprises a workbench, wherein a top plate is horizontally arranged at a position above the workbench, a plurality of support rods are connected between the lower end of the top plate and the top wall of the workbench, a driving chamber is arranged at the upper end of the top plate, a lower die holder is arranged on the top wall of the workbench corresponding to the position below the top plate, a lower die is arranged at the upper end of the lower die holder, a corresponding upper die holder is arranged at the position above the lower die holder in a sliding manner, and an upper die corresponding to the lower die is arranged at the lower end of the upper die holder; a driving motor is horizontally arranged on the top wall of the driving chamber, a driving wheel is fixedly sleeved on the output end of the driving motor, a connecting rod is rotatably connected to one side of the side wall of the driving wheel far away from the axis, the other end of the connecting rod is rotatably connected with a driving rod, the driving rod vertically extends downwards to penetrate through the top plate and is fixedly connected to the top wall of the upper die base, a sliding sleeve is sleeved on the outer side of the driving rod and is vertically embedded on the top plate, a material tray is rotatably mounted on the top wall of the workbench, a plurality of material receiving openings matched with the lower dies are formed in the material tray at equal intervals corresponding to the positions of the lower dies, sliding rails are horizontally and symmetrically arranged at the positions, corresponding to the two sides of the material receiving openings, of the upper end of the material tray, sliding blocks are symmetrically and slidably mounted in the sliding rails, a tension spring is connected between the two sliding blocks, the upper ends of the sliding blocks are rotatably connected with two interlocking rods at the same side, the other ends of the two interlocking rods at the same side are hinged with each other ends, clamping claws perpendicular to the sliding rails are symmetrically and slidably arranged in the material receiving openings, the connecting frames are connected between the two sides of each clamping jaw and the corresponding side wall of the corresponding sliding block, and corresponding synchronizing rods are vertically and fixedly installed on the bottom wall of the upper die base above the hinged position of the corresponding linkage rods.

Preferably, a plurality of guide pillars are vertically arranged on the bottom wall of the upper die base, a plurality of guide sleeves matched with the guide pillars are vertically arranged on the top wall of the lower die base, the inner bottom wall of each guide sleeve is connected with a buffer spring, and a plurality of openings matched with the guide pillars are formed in the material disc at equal intervals.

Preferably, the annular lateral wall outside sliding connection of charging tray has a plurality of stable splint, and stable splint are all through support fixed mounting on the workstation roof.

Preferably, a plurality of elastic telescopic rods are vertically and fixedly installed on the top wall of the upper die base, and the other ends of the elastic telescopic rods are vertically and fixedly installed on the bottom wall of the top plate.

Preferably, the vertical suspension that is the shape of falling L that is equipped with in roof one side of workstation, one of them connects the open-ended top position of material to be equipped with the door-shaped frame, and the door-shaped frame corresponds the articulated top position of department of two pairs of trace and all is equipped with corresponding clamp plate, door-shaped frame upper end fixed connection is served in telescopic cylinder's flexible, and the vertical fixed mounting of telescopic cylinder is on the suspension.

Preferably, the coaxial fixedly connected with main shaft in charging tray upper end, the vertical upwards extension of main shaft and fixed cover are equipped with the interlock wheel, the interlock wheel outside is rotated the cover and is equipped with the ring gear, ring gear lower extreme coaxial coupling has hollow rotating shaft, hollow rotating shaft rotates and installs on the roof of roof, the ring gear meshing has the rack, rack slidable mounting is on the roof of roof, rack roof one side is rotated and is connected with the connecting rod, the connecting rod other end rotates and is connected with the interlock board, interlock board horizontal sliding sleeve is established on the actuating lever, and interlock board upper end sliding connection has assorted synchronizing plate, synchronizing plate fixed cover is established on the actuating lever.

More preferably, the annular inner wall of the toothed ring is provided with a plurality of inner ratchets at equal intervals, the annular side wall of the linkage wheel is provided with a plurality of mounting grooves and is rotatably connected with pawls matched with the inner ratchets, and a return spring is connected between the pawls and the inner wall of the mounting grooves.

More preferably, a plurality of sliding columns are vertically installed in the inner cavity of the driving chamber, and the sliding columns are in sliding connection with the linkage plate and the synchronous plate.

More preferably, the upper and lower sides of the plurality of sliding columns corresponding to the linkage plate are respectively sleeved with a compression spring.

Compared with the prior art, the invention has the beneficial effects that:

1. the part to be processed can be automatically placed on the lower die to be fed in a matched mode of the clamping claw during stamping, the processed part is clamped in a matched mode of resetting of the sliding block after stamping is completed, discharging is automatically completed, the automation degree of stamping is greatly improved, and the processing efficiency is greatly improved;

2. according to the invention, the gear ring and the rack are matched to drive the material tray to synchronously rotate during stamping processing to complete feeding and discharging, so that the automation degree of stamping processing is improved, the danger possibly generated by manual feeding during stamping is effectively avoided, the stamping processing safety is greatly improved, and the safety guarantee is provided for operators;

3. according to the invention, through the matching of the internal ratchet and the pawl, the reverse rotation of the material driven by the upper die during resetting is avoided, the same-direction continuous feeding of the material tray is ensured, the feeding capacity is improved, and the processing efficiency of continuous stamping is greatly improved.

4. The invention limits the position through the compression spring linkage plates 27 on the upper side and the lower side of the linkage plate, avoids the phenomenon that when the material tray rotates to a required position, the upper die continuously downwards punches to drive the linkage plate to downwards move so as to cause the rotation of the material tray, ensures that the material receiving opening is always in a proper position, and ensures the machining precision of punching.

The invention has compact structure and novel design, greatly improves the automation degree of stamping processing, greatly ensures the safety of operators during stamping processing, simultaneously ensures the precision of stamping processing and greatly improves the processing efficiency of continuous stamping.

Drawings

FIG. 1 is a schematic structural diagram of an appearance of a stamping die for machining according to the present invention;

fig. 2 is a schematic front structural view of a stamping die for machining according to the present invention;

FIG. 3 is a schematic structural view of part A of a stamping die for machining according to the present invention;

FIG. 4 is a schematic top view of a clamping jaw of a stamping die for machining according to the present invention;

fig. 5 is a schematic view of a pawl structure of a stamping die for machining according to the present invention.

In the figure: the device comprises a workbench 1, a support rod 2, a top plate 3, a driving chamber 4, a lower die holder 5, a lower die 51, an upper die holder 6, an upper die 61, a driving rod 7, a connecting rod 8, a driving wheel 9, a driving motor 10, a guide post 11, a guide sleeve 12, a material tray 13, a stabilizing splint 14, a main shaft 15, a slide rail 16, a slide block 17, a linkage rod 18, a clamping claw 19, a synchronous rod 20, a linkage wheel 21, a toothed ring 22, a pawl 23, a return spring 24, a rack 25, a connecting rod 26, a linkage plate 27, a synchronous plate 28, a slide column 29, a compression spring 30, a suspension 31, a portal frame 32 and a telescopic cylinder 33.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the 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, should not be construed as limiting the present invention.

Example one

Referring to fig. 1-5, a stamping die for machining comprises a workbench 1, a top plate 3 is horizontally arranged at a position above the workbench 1, a plurality of support rods 2 are connected between the lower end of the top plate 3 and the top wall of the workbench 1, a driving chamber 4 is arranged at the upper end of the top plate 3, a lower die holder 5 is mounted on the top wall of the workbench 1 corresponding to the position below the top plate 3, a lower die 51 is arranged at the upper end of the lower die holder 5, a corresponding upper die holder 6 is slidably arranged at the position above the lower die holder 5, an upper die 61 corresponding to the lower die 51 is arranged at the lower end of the upper die holder 6, stamping is completed by matching the upper die 61 with the lower die 51, and stamping of parts of different models is also conveniently performed by replacing the upper die 61 and the lower die 51; a driving motor 10 is horizontally arranged on the top wall of the driving chamber 4, a driving wheel 9 is fixedly sleeved on the output end of the driving motor 10, a connecting rod 8 is rotatably connected to one side of the side wall of the driving wheel 9 far away from the axis, a driving rod 7 is rotatably connected to the other end of the connecting rod 8, the driving rod 7 vertically extends downwards to penetrate through the top plate 3 and is fixedly connected to the top wall of the upper die base 6, a sliding sleeve is sleeved on the outer side of the driving rod 7, the sliding sleeve is vertically embedded on the top plate 3, the driving rod 7 is driven by the driving wheel 9 to vertically slide in a reciprocating manner by rotationally matching with the connecting rod 8 to drive the upper die 61 to perform continuous stamping, a material tray 13 is rotatably installed on the top wall of the workbench 1, a plurality of material receiving openings matched with the lower die 51 are equidistantly arranged at positions of the material tray 13 corresponding to the lower die 51, slide rails 16 are horizontally and symmetrically arranged at the positions of the two sides of the material receiving openings corresponding to the upper end of the material receiving opening, and sliders 17 are symmetrically installed in the slide rails 16, and be connected with extension spring between two sliders 17, slider 17 upper end all rotates and is connected with trace 18, and two trace 18 other ends of homonymy articulate each other, connect the material opening internal symmetry slip to be equipped with slide rail 16 direction vertically gripper jaw 19, gripper jaw 19 both sides all with be connected with the link between the corresponding slider 17 lateral wall, vertical fixed mounting has corresponding synchronizing bar 20 on the diapire of upper die base 6 correspondence trace 18 articulated department top position, treat through gripper jaw 19 and carry out the centre gripping with the part after the processing is accomplished, make things convenient for the pay-off and the ejection of compact of punching process, the efficiency of work piece processing is improved, the effectual artifical pay-off of punching process of having avoided, very big improvement the security of punching process.

In this embodiment, as shown in fig. 1 and 2, vertically on the diapire of upper die base 6 be equipped with a plurality of guide pillars 11, vertically on the roof of lower die base 5 be equipped with a plurality ofly with guide pillar 11 assorted guide pin bushing 12, and all be connected with buffer spring in the guide pin bushing 12 on the diapire, the equidistant a plurality ofly seted up on charging tray 13 with guide pillar 11 assorted opening, the cooperation through guide pillar 11 and guide pin bushing 12 is guided last mould 61, very big improvement the stability and the precision of punching press man-hour.

In this embodiment, as shown in fig. 1 and 2, the outer side of the annular side wall of the material tray 13 is slidably connected with a plurality of stabilizing splints 14, and the stabilizing splints 14 are all fixedly mounted on the top wall of the workbench 1 through the bracket, so that the rotating stability of the material tray 13 is improved, smooth feeding and discharging is ensured, and the precision of stamping is ensured.

In this embodiment, as shown in fig. 2, a plurality of elastic telescopic rods are vertically and fixedly mounted on the top wall of the upper die base 6, and the other ends of the elastic telescopic rods are vertically and fixedly mounted on the bottom wall of the top plate 3, so that the sliding stability of the upper die 61 is improved.

In this embodiment, drive actuating lever 7 up-and-down reciprocating sliding is driven through drive wheel 9 normal running fit connecting rod 8, it carries out continuous punching press to drive last mould 61, simultaneously when processing charging tray 13 rotates to connect the position phase-match of material opening and lower mould 51, cooperation synchronizing rod 20 pushes down trace 18 when going up mould 61 and descends, it drives slider 17 and slides to drive gripper jaw 19 to both sides and open to both sides, the spare part that will treat processing is placed on lower mould 51, mould 61 presss from both sides the clamp fixedly simultaneously on the cooperation, go up mould 61 and continue down the completion punching press, it resets to go up mould 61 after the punching press is accomplished, gripper jaw 19 reverse movement carries out the centre gripping to the work piece that the punching press was accomplished, the ejection of compact is accomplished in the rotation of cooperation charging tray 13, punching press's security and machining efficiency have greatly been improved, the extrusion injury that stamping equipment caused operating personnel when the punching press has greatly been avoided to possible.

Example two

Referring to fig. 1 and 2, in this embodiment, the same as the first embodiment, what is more optimized lies in that a suspension 31 that is an inverted L-shape is vertically arranged on one side of the top wall of the workbench 1, one of them is provided with a door-shaped frame 32 above the material receiving opening, the door-shaped frame 32 is provided with corresponding pressure plates above the two pairs of linkage rod hinges, the upper end of the door-shaped frame 32 is fixedly connected to the telescopic end of a telescopic cylinder 33, the telescopic cylinder 33 is vertically and fixedly mounted on the suspension 31, the door-shaped frame 32 is driven by the telescopic cylinder 33 to open the clamping claws 19, the parts that are processed are conveniently sent out, the parts to be processed are clamped, and the efficiency of feeding and discharging is improved.

EXAMPLE III

Referring to fig. 1, 2 and 5, in this embodiment, basically the same as the first embodiment, it is more preferable that the upper end of the tray 13 is coaxially and fixedly connected with the main shaft 15, the main shaft 15 vertically extends upwards and is fixedly sleeved with the interlocking wheel 21, the outer side of the interlocking wheel 21 is rotatably sleeved with the toothed ring 22, the lower end of the toothed ring 22 is coaxially connected with the hollow rotating shaft, the hollow rotating shaft is rotatably installed on the top wall of the top plate 3, the toothed ring 22 is engaged with the rack 25, the rack 25 is slidably installed on the top wall of the top plate 3, one side of the top wall of the rack 25 is rotatably connected with the connecting rod 26, the other end of the connecting rod 26 is rotatably connected with the interlocking plate 27, the interlocking plate 27 is horizontally slidably sleeved on the driving rod 7, the upper end of the interlocking plate 27 is slidably connected with the matching synchronizing plate 28, the synchronizing plate 28 is fixedly sleeved on the driving rod 7, the interlocking plate 27 is driven to slide by the synchronizing plate 28 during stamping process, and the main shaft 15 is driven by the rack 25 and the toothed ring 22 to rotate, make things convenient for charging tray 13 to rotate with last mould 61 synchronous during stamping process, very big improvement the effect of pay-off and ejection of compact, simultaneously effectual energy utilization who improves driving motor 10.

In this embodiment, as shown in fig. 1, 2 and 5, a plurality of internal ratchets are arranged on the annular inner wall of the toothed ring 22 at equal intervals, a plurality of mounting grooves are formed in the annular side wall of the linkage wheel 21, the pawl 23 matched with the internal ratchets is connected to the annular side wall of the linkage wheel 21 in a rotating mode, a return spring 24 is connected between the pawl 23 and the inner wall of the mounting groove, reverse rotation is avoided when the linkage plate 27 is reset through the pawl 23, continuous feeding of the charging tray 13 is guaranteed, and the feeding effect of the charging tray 13 is improved.

In this embodiment, as shown in fig. 2, a plurality of sliding columns 29 are vertically installed in the inner cavity of the driving chamber 4, and the sliding columns 29 are slidably connected with both the linkage plate 27 and the synchronization plate 28, so as to improve the sliding stability of the linkage plate 27.

In this embodiment, as shown in fig. 2, the compression springs 30 are respectively sleeved on the upper and lower sides of the plurality of sliding posts 29 corresponding to the linkage plate 27, the linkage plate 27 is limited by the cooperation of the upper and lower compression springs 30, when the tray 13 rotates to a desired position, the linkage plate 27 is prevented from being driven to continuously move downward when the upper die 61 moves downward for punching, the material receiving opening is ensured to be in a suitable position, and the punching accuracy is ensured.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.

Claims

1. A stamping die for machining comprises a workbench (1) and is characterized in that a top plate (3) is horizontally arranged at the upper position of the workbench (1), a plurality of support rods (2) are connected between the lower end of the top plate (3) and the top wall of the workbench (1), a driving chamber (4) is arranged at the upper end of the top plate (3), a lower die holder (5) is installed on the top wall of the workbench (1) corresponding to the lower position of the top plate (3), a lower die (51) is arranged at the upper end of the lower die holder (5), a corresponding upper die holder (6) is arranged at the upper position of the lower die holder (5) in a sliding manner, and an upper die (61) corresponding to the lower die (51) is arranged at the lower end of the upper die holder (6);

the top wall of the driving chamber (4) is horizontally provided with a driving motor (10), the output end of the driving motor (10) is fixedly sleeved with a driving wheel (9), one side of the side wall of the driving wheel (9), far away from the axis, is rotatably connected with a connecting rod (8), the other end of the connecting rod (8) is rotatably connected with a driving rod (7), the driving rod (7) vertically extends downwards to penetrate through the top plate (3) and is fixedly connected to the top wall of the upper die base (6), the outer side of the driving rod (7) is sleeved with a sliding sleeve, the sliding sleeve is vertically embedded on the top plate (3), the top wall of the workbench (1) is rotatably provided with a material tray (13), the material tray (13) is equidistantly provided with a plurality of material receiving openings matched with the lower dies (51), the upper end of the material tray (13) is horizontally and symmetrically provided with sliding rails (16) corresponding to the positions of two sides of the material receiving openings, the sliding rails (17) are symmetrically and symmetrically arranged in the sliding rails (16), and be connected with extension spring between two slider (17), slider (17) upper end all rotates and is connected with trace (18), and two trace (18) other ends of homonymy articulate each other, connect the material opening internal symmetry slip to be equipped with slide rail (16) direction vertically gripper jaw (19), gripper jaw (19) both sides all with be connected with the link between the corresponding slider (17) lateral wall, vertical fixed mounting has corresponding synchronizing bar (20) on the diapire of upper die base (6) corresponding trace (18) articulated department top position.

2. The stamping die for machining according to claim 1, wherein a plurality of guide posts (11) are vertically arranged on the bottom wall of the upper die holder (6), a plurality of guide sleeves (12) matched with the guide posts (11) are vertically arranged on the top wall of the lower die holder (5), the inner bottom walls of the guide sleeves (12) are respectively connected with a buffer spring, and a plurality of openings matched with the guide posts (11) are equidistantly formed in the material tray (13).

3. The stamping die for machining according to claim 1, characterized in that a plurality of stabilizing clamping plates (14) are slidably connected to the outer side of the annular side wall of the material tray (13), and the stabilizing clamping plates (14) are fixedly mounted on the top wall of the workbench (1) through brackets.

4. The stamping die for machining according to claim 1, wherein a plurality of elastic telescopic rods are vertically and fixedly mounted on the top wall of the upper die holder (6), and the other ends of the elastic telescopic rods are vertically and fixedly mounted on the bottom wall of the top plate (3).

5. The stamping die for machining according to claim 1, wherein a suspension (31) in an inverted L shape is vertically arranged on one side of the top wall of the workbench (1), a door-shaped frame (32) is arranged above one material receiving opening, corresponding pressing plates are arranged above the hinged positions of the door-shaped frame (32) corresponding to the two pairs of linkage rods, the upper end of the door-shaped frame (32) is fixedly connected to the telescopic end of a telescopic cylinder (33), and the telescopic cylinder (33) is vertically and fixedly mounted on the suspension (31).

6. The stamping die for machining according to claim 1, wherein the upper end of the tray (13) is coaxially and fixedly connected with a main shaft (15), the main shaft (15) extends vertically upwards and is fixedly sleeved with a linkage wheel (21), a toothed ring (22) is rotatably sleeved outside the linkage wheel (21), the lower end of the toothed ring (22) is coaxially connected with a hollow rotating shaft, the hollow rotating shaft is rotatably installed on the top wall of the top plate (3), the toothed ring (22) is meshed with a rack (25), the rack (25) is slidably installed on the top wall of the top plate (3), one side of the top wall of the rack (25) is rotatably connected with a connecting rod (26), the other end of the connecting rod (26) is rotatably connected with a linkage plate (27), the linkage plate (27) is horizontally and slidably sleeved on the driving rod (7), and the upper end of the linkage plate (27) is connected with a matched synchronous plate (28) in a sliding way, and the synchronous plate (28) is fixedly sleeved on the driving rod (7).

7. The stamping die for machining according to claim 6, wherein a plurality of inner ratchets are arranged on the annular inner wall of the toothed ring (22) at equal intervals, a plurality of mounting grooves are formed in the annular side wall of the linkage wheel (21), pawls (23) matched with the inner ratchets are rotatably connected to the annular side wall of the linkage wheel, and a return spring (24) is connected between the pawls (23) and the inner wall of the mounting grooves.

8. A stamping die for machining according to claim 6, characterized in that a plurality of sliding columns (29) are vertically installed in the inner cavity of the driving chamber (4), and the sliding columns (29) are connected with the linkage plate (27) and the synchronization plate (28) in a sliding manner.

9. The stamping die for machining according to claim 6, wherein the upper and lower sides of the linking plate (27) corresponding to the plurality of sliding columns (29) are sleeved with compression springs (30).