CN115284002A

CN115284002A - Long pipe diameter expanding device and diameter expanding method

Info

Publication number: CN115284002A
Application number: CN202210888433.XA
Authority: CN
Inventors: 石建德; 王贤勇; 殷吕; 朱廷焕; 万建波; 张志国; 朱飞
Original assignee: Shanghai Baolong Automobile Technology Anhui Co ltd
Current assignee: Shanghai Baolong Automobile Technology Anhui Co ltd
Priority date: 2022-07-22
Filing date: 2022-07-22
Publication date: 2022-11-04

Abstract

The application provides a long pipe diameter expanding device and a diameter expanding method, and relates to the field of long pipe diameter expansion. The device comprises an expansion pipe die, wherein the expansion pipe die is relatively fixed with a working table top on a hydraulic press; the lower die is relatively fixed with the lower working table surface of the hydraulic machine and comprises a guide stripper, a lower die fixing plate and a positioning mandrel, and all the parts of the lower die are relatively fixed by a connecting device; a guide material returning hole is formed in the guide material returning device and is in clearance fit with the pipe expanding die, and the minimum clearance between the guide material returning hole and the pipe expanding die is larger than zero; the lower die fixing plate is fixed on the lower working table surface of the hydraulic press, a first long hole is formed in the lower die fixing plate, and a workpiece to be expanded is sleeved on the positioning mandrel through the first long hole. The technical problem that the coaxiality level of a workpiece after the diameter expansion of the conventional diameter expansion device cannot meet the technical requirements is solved.

Description

Long pipe diameter expanding device and diameter expanding method

Technical Field

The invention relates to the field of long pipe expansion, in particular to a long pipe expansion device and an expansion method.

Background

The damper is mainly used for suppressing vibration when the spring absorbs vibration and rebounds and impact from a road surface. When the road surface passes through the uneven road surface, although the shock absorption springs can filter the vibration of the road surface, the springs can generate reciprocating motion, and the shock absorbers are used for inhibiting the spring from jumping. The traditional double-cylinder shock absorber for the vehicle mainly comprises a rubber bushing assembly, a lifting ring, a bottom cover, a bottom valve assembly, a piston rod, a working cylinder, an oil storage cylinder, a guider, an oil seal, shock absorber oil and the like. When the upper end and the lower end of the shock absorber move relatively, hydraulic oil is throttled through a certain valve system channel, and pressure difference exists at the two ends of the valve to form damping force, so that the damping characteristic of the shock absorber is realized.

The diameter of a cylinder barrel of an oil storage cylinder of a rear shock absorber of a car does not need to be designed into two parts with different thicknesses, but the cylinder barrel of the rear shock absorber of the car needs to be designed into two parts with different thicknesses according to design requirements so as to reduce the development of parts such as oil seals, guides, spring discs and the like by using the existing mature parts as much as possible, when the rear shock absorber needs to be designed into the structure, the coaxiality requirement on the two parts with different thicknesses is very high, generally, the coaxiality requirement does not exceed 0.6mm, otherwise, the product is easy to cause eccentric wear of a piston rod and a working cylinder under the frequent action of lateral force, and the shock absorber fails in the early stage.

In the pipe diameter expanding production, the diameter expanding tool designed based on the existing equipment comprises four parts, namely a diameter expanding die, a material returning mechanism, a lower positioning seat and a coarse positioning tool, the coaxiality level of the processed oil storage cylinder is far beyond the technical requirement and is less than or equal to 0.6mm, most of the processed oil storage cylinder is between 3 and 6mm, even 8mm is achieved, in order to meet the performance requirement of a product, the oil storage cylinder after the diameter expanding of an operator A is finished needs to be manually corrected, a simple screw press is utilized, an operator B is responsible for taking a workpiece and placing the workpiece on two V-shaped supports on the table surface of the press, C, D two operators operate a press handle to rotate the screw to press the middle part of the oil storage cylinder downwards, after the workpiece is pressed once, the workpiece B is detected by a dial indicator to correct the workpiece or not to meet the requirement, if the workpiece is pressed at the right time, the workpiece needs to be pressed and rotated 180 degrees around the axis to correct again, one workpiece needs to be repeatedly corrected for many times, and the workpiece needs to be repeatedly corrected for many times, and in fact, the pipe wall thickness is not more than the coaxial range of less than 0.6 mm.

Disclosure of Invention

In view of the defects of the prior art, the invention provides a long pipe expanding device and an expanding method, which aim to solve the technical problem that the coaxiality level of an oil storage cylinder after the expansion of the conventional expanding device cannot meet the technical requirements.

To achieve the above and other related objects, the present invention provides a long tube expansion device. The method comprises the following steps: the pipe expanding die is relatively fixed with the upper working table surface of the hydraulic press; the lower die is relatively fixed with the lower working table surface of the hydraulic machine and comprises a guide stripper, a lower die fixing plate and a positioning mandrel, and all the parts of the lower die are relatively fixed by a connecting device; a guide material returning hole is formed in the guide material returning device, the guide material returning hole is in clearance fit with the pipe expansion die, and the minimum clearance between the guide material returning hole and the pipe expansion die is larger than zero; the lower die fixing plate is fixed on the lower working table surface of the hydraulic press, a first long hole is formed in the lower die fixing plate, and a workpiece to be expanded is sleeved on the positioning mandrel through the first long hole.

In an embodiment of the application, the connecting device comprises a feed rod and a sleeve, the feed rod sequentially penetrates through a guide material returning fixing plate fixed with a guide material returning device, a lower die fixing plate and a mandrel fixing plate fixed with a positioning mandrel from top to bottom, external threads are arranged at two ends of the feed rod, and first nuts are connected to two ends of the feed rod in a threaded manner; the outer wall of the feed rod is sleeved with a plurality of sections of sleeves, and the sleeves limit the distance between the guide material returning fixing plate, the lower die fixing plate and the mandrel fixing plate.

In an embodiment of the present application, the tube expansion die includes an expansion die base, an expansion die working portion, and a guiding portion; the end part of the expansion die base body is provided with an installation step, and the end part provided with the installation step is also provided with an expansion die internal thread hole; the expansion die working part is axially provided with an expansion die mounting hole penetrating through the expansion die working part, and the expansion die mounting hole is sleeved on the mounting step; the expansion die working part comprises a cylindrical area and a circular truncated cone area, the diameter of the cylindrical area is the same as that of the expansion die base body, and the circular truncated cone area is close to the guide part; the diameter of the main body of the guide part is the same as that of the end part of the circular truncated cone region far away from the cylindrical region, one end of the guide part is provided with an expansion die external thread rod, and the expansion die external thread rod is matched with the expansion die internal thread hole; the other end of the guide part is provided with a conical guide head, and an arc-shaped transition area is arranged between the conical guide head and the guide part main body.

In an embodiment of the application, a guide internal thread hole is formed in the end portion of the conical guide head, the direction of the guide internal thread hole is the same as the direction of the expansion die internal thread hole, and a first fastening bolt is arranged in the guide internal thread hole.

In an embodiment of the present application, the lower mold further includes a V-shaped block and a first fixing plate for fixing the V-shaped block, the first fixing plate is provided with a second long hole, and the V-shaped block and the positioning mandrel are matched to roughly position the workpiece to be expanded.

In an embodiment of the present application, the first long hole and the second long hole are both waist-shaped holes, and the workpiece to be expanded is sleeved on the positioning mandrel after moving along a connecting line between a vertex of the end wall of the first long hole and a vertex of the end wall of the second long hole.

In this application embodiment, the V type region of V type piece is equipped with magnet, magnet adsorbs treat bloated work piece, treat the tip cover of bloated work piece in location dabber, lateral wall by during magnet adsorbs, treat to expand work piece axis and expand tube die axis coincidence.

In an embodiment of the present application, the width of the first long hole is not less than twice the diameter of the expanded workpiece.

In this application embodiment, first nut is equipped with radial open slot, first nut axial is equipped with the locking screw hole through radial open slot, the threaded locking hole is equipped with locking bolt.

The application also provides a long pipe expanding method, which comprises the steps of cutting off, namely cutting off the material into a workpiece to be expanded with a proper length; rough turning, wherein two ends of the workpiece to be expanded are roughly turned; expanding a pipe of a workpiece to be expanded, wherein the expanding pipe uses any one long pipe expanding device; finish turning, wherein the end part of the workpiece after the pipe expansion is finish turned; and expanding the three convex hulls, and expanding the three convex hulls on the workpiece.

By combining the prior art, the invention has the beneficial effects that:

the problems that an existing diameter expanding device is poor in positioning reference, an existing diameter expanding die is unreasonable in connecting structure and the like cause that the coaxiality level of an expanded oil storage cylinder is lower than the technical requirements of products. After the diameter of the workpiece is expanded, manual adjustment and correction are needed, a large amount of time is wasted, and the production efficiency is low.

This application carries out relatively fixed through direction stripper, lower mould fixed plate, location dabber, has guaranteed the axiality between each part of bed die. The four parts of the original tool are changed into two parts, so that the assembly requirements among the tools are effectively reduced, and the assembly precision is improved. Through set up direction material returned hole on direction stripper, be convenient for carry on the material returned after the footpath expands on the one hand, on the other hand has guaranteed the axiality between expand tube die and the bed die to the effectual axiality that improves work piece footpath district and not footpath district that expands.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic view of a conventional long tube diameter expanding device;

FIG. 2 is a schematic view of a prior art screw press;

FIG. 3 is a schematic structural diagram of an exemplary embodiment of the present application;

FIG. 4 is a schematic view of an exemplary tube expansion die configuration of the present application;

FIG. 5 is a schematic view of an exemplary pilot reject zone configuration of the present application;

FIG. 6 is a schematic view of an exemplary lower die retaining plate of the present application;

FIG. 7 is a schematic view of an exemplary V-block region of the present application;

FIG. 8 is a schematic view of an exemplary positioning mandrel configuration of the present application;

FIG. 9 is a schematic view of a portion of an exemplary linking device of the present application;

fig. 10 is a schematic view of an exemplary expanded workpiece processing arrangement according to the present application.

Description of the element reference numerals

100. Expanding the pipe die; 110. expanding the die matrix; 111. mounting a step; 112. expanding a die internal threaded hole; 120. a die expansion working section; 121. a die expansion mounting hole; 122. a cylindrical region; 123. a circular platform area; 130. a guide portion; 131. an external threaded rod of the expansion die; 132. a conical guide head; 133. an arc transition zone; 134. a guide internal threaded hole; 135. a first fastening bolt; 140. expanding a die fixing plate; 150. a die expansion mounting part; 200. a lower die; 210. guiding the material stripper; 211. guiding a material returning hole; 212. a guide material returning fixing plate; 220. a lower die fixing plate; 221. a first long hole; 230. positioning the mandrel; 231. a mandrel fixing plate; 232. an arc-shaped connecting part; 240. a connecting device; 241. a polished rod; 242. a sleeve; 243. a first nut; 244. a locking threaded hole; 245. a check bolt; 246. a through hole; 247. a radial open slot; 248. a gasket; 250. a V-shaped block; 251. a first fixing plate; 252. a magnet; 253. a second long hole; 300. a workpiece to be expanded; 400. an upper working table; 500. a lower working table surface.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It is to be noted that the features in the following embodiments and examples may be combined with each other without conflict. It is also to be understood that the terminology used in the examples is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention. Test methods in which specific conditions are not specified in the following examples are generally carried out under conventional conditions or under conditions recommended by the respective manufacturers.

When numerical ranges are given in the examples, it is understood that both endpoints of each of the numerical ranges and any number between the two endpoints are optional unless otherwise specified in the invention. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs and the description of the present invention, and any methods, apparatuses, and materials similar or equivalent to those described in the examples of the present invention may be used to practice the present invention.

It should be understood that the terms "upper", "lower", "left", "right", "middle" and "a" used herein are used for descriptive purposes only and are not intended to limit the scope of the present invention, and that the relative relationship between the terms and the terms should be construed as the scope of the present invention without substantial change in the technical spirit.

Referring to fig. 1 to 2, fig. 1 is a schematic view of a conventional long tube expanding device, and fig. 2 is a schematic view of a conventional screw press. The existing diameter expansion tool designed by equipment comprises four parts, namely a diameter expansion die, a material returning mechanism, a lower positioning seat and a coarse positioning tool, wherein the coaxiality level of the processed oil storage cylinder is far beyond the technical requirement and is less than or equal to 0.6mm, most of the processed oil storage cylinder is between 3 and 6mm, even 8mm is achieved, in order to meet the performance requirement of a product, the oil storage cylinder after the diameter expansion of an operator A is finished needs to be manually corrected, a simple screw rod press is utilized, an operator B is responsible for taking and placing a workpiece on two V-shaped supports on the table top of the press, C, D two operators operate a handle of the press to rotate the screw rod to press the middle part of the oil storage cylinder downwards, after one time of pressing, the operator B detects whether the workpiece meets the requirement by using a dial indicator, if the workpiece is pressed too early during the correction, the workpiece needs to be pressed downwards again around an axis by 180 degrees, often, one workpiece needs to be corrected repeatedly for five times and six times, and actually, because the wall of the pipe is thin, the coaxiality of the workpiece needs to be corrected to meet the range of less than or equal to be less than or equal to 0.6mm, and is very difficult.

Referring to fig. 3, fig. 3 is a schematic structural diagram of an exemplary embodiment of the present application, which is intended to provide a long pipe diameter expanding device to solve the problems of the conventional diameter expanding device that the coaxiality precision of a diameter expanding area and a diameter non-expanding area cannot meet the precision requirement, the requirements of repeated modification are required, and the production efficiency is low due to inaccurate positioning and unreasonable structure.

The long pipe expanding device mainly comprises an expanding pipe die 100 and a lower die 200, wherein the expanding pipe die 100 is detachably fixed on an upper working table 400 of the hydraulic machine, and the lower die 200 is detachably fixed on a lower working table 500 of the hydraulic machine.

Referring to fig. 4, fig. 4 is a schematic structural diagram of an exemplary tube expansion die 100 according to the present application. The tube expansion die 100 sequentially comprises an expansion die mounting part 150, an expansion die base body 110, an expansion die working part 120 and a guide part 130;

the expansion die mounting part 150 is matched with the expansion die fixing plate 140 for use, and the expansion die 100 is mounted by fixing the expansion die fixing plate 140 to the upper working table 400 of the hydraulic press. In an exemplary embodiment of the application, an upper sliding table of a hydraulic press is a square profile, a profile of an expansion die fixing plate 140 is a square profile with the same specification, and two right-angle positioning blocks are fixed on the rear side of the upper sliding table, so that convenience is brought to quick centering installation. When the pipe expanding die 100 is installed, the pipe expanding die 100 can be positioned and fixed only by pushing the expanding die fixing plate 140 to the right-angle positioning block. The existing clamping and adjusting process needs more than thirty minutes, the improved tube expansion die 100 only needs several minutes for clamping and adjusting, the time for replacing the die is greatly saved, and the working efficiency is improved.

The expansion die base body 110 provides connection support for each part of the expansion die 100, and in one embodiment of the present application, the diameter of the expansion die base body 110 is the same as the diameter of the tail part of the expansion die working part 120. The existing pipe expanding die 100 is integrally formed, so that in order to facilitate processing and save cost, the diameter of the expanding die base body 110 is far smaller than the tail of the expanding die working part 120, and the expanded workpiece is lack of continuous support, so that the expanded region is subjected to shrinkage deformation and bending. The utility model provides an expand die base member 110 diameter is the same with the afterbody diameter of the mould work portion that expands 120, in order to prevent the inner wall fish tail of the mould base member 110 after to the swell, avoid the work piece after the swell to take place shrink, crooked again, in this application an exemplary embodiment, the diameter of the mould base member that expands 110 slightly is less than the mould work portion 120 diameter 0.1 ~ 0.3mm that expands, effectual work piece for after the swell provides the support, avoid the work piece after the swell to take place serious shrinkage deformation, the processingquality of work piece has been improved. In an embodiment of the present application, the connection between the expansion die base 110 and the expansion die working portion 120 is provided with an installation step 111, which facilitates installation of the expansion die working portion 120, and the end portion of the expansion die base is further provided with an expansion die internal thread hole 112.

The expansion die working portion 120 is a direct working portion for expanding the diameter of the workpiece 300 to be expanded. In order to ensure the continuous use of the expansion die working part 120 and prolong the service life, the expansion die working part 120 of the application uses hard alloy materials, the hardness of the hard alloy materials reaches HRC 58-62, the surface smoothness of the hard alloy materials can reach Ra0.2, the service life of the expansion die 100 is prolonged, and scratches inside a workpiece after diameter expansion are reduced. The expansion die working portion 120 comprises an expansion die mounting hole 121, a cylindrical region 122 and a circular truncated cone region 123, the expansion die mounting hole 121 axially penetrates through the expansion die working portion 120, the expansion die working portion 120 is sleeved on the mounting step 111 of the expansion die 100 through the expansion die mounting hole 121, and the expansion die working portion 120 is convenient to assemble. The circular truncated cone area 123 is the smooth excessive region of diameter, and the circular truncated cone area 123 is treated bloated work piece 300 and is expanded footpath, and the work piece after the cylinder district 122 at first provides the support to expanding, and the work piece shrinkage force after just expanding is the biggest, and the design in cylinder district 122 has reduced the atress of expanded die base member 110, and is lower to the material requirement of expanded die base member 110, reduction in production cost.

The guide portion 130 provides a guide for the tube expansion die 100, and ensures that the workpiece 300 to be expanded is in a proper position during processing. One end of the guide part 130 close to the expansion die base body 110 is an expansion die external thread rod 131, and the expansion die external thread rod 131 is matched with the expansion die internal thread hole 112. In order to conveniently install the expansion die working portion 120, the expansion die internal thread hole 112 is formed, and when the expansion die working portion 120 is sleeved, the expansion die internal thread hole 112 is compressed, so that the expansion die working portion 120 is conveniently installed. After the installation is completed, the assembly strength needs to be ensured, and the external thread rod 131 of the expansion die is screwed into the internal thread hole 112 of the expansion die to support the expansion die base body 110, so that the expansion die working part 120 is convenient to disassemble and assemble, and the assembly strength of the expansion die working part 120 is ensured. In an embodiment of the present application, the external screw rod 131 is screwed into the internal screw hole 112 after the thread locking glue is applied, so as to prevent the external screw rod 131 from loosening from the internal screw hole 112 after a long-term operation, thereby reducing maintenance times.

The end of the guide 130 remote from the male screw rod 131 of the expansion die is provided with a conical guide head 132, and the conical guide head 132 facilitates the insertion of the guide 130 into the tube of the workpiece 300 to be expanded. An arc transition area 133 is arranged between the conical guide head 132 and the main body of the guide part 130, and compared with the existing flat head structure, the arc transition area 133 can avoid the problem that workpieces are scrapped due to the fact that materials are tucked into the pipe. In an embodiment of the present invention, an axial guide female screw hole 134 is provided in the conical guide head 132, the guide female screw hole 134 and the expansion die female screw hole 112 have the same direction of rotation, and a first fastening bolt 135 is screwed into the guide female screw hole 134, and preferably, the first fastening bolt 135 is a hexagon socket head cap screw. The external screw rod 131 of the expansion die needs to be screwed into the internal screw hole 112 of the expansion die, so that the external surface of the guide part 130 is prevented from being damaged during screwing for the convenience of stress, and the external surface of the guide part 130 can be prevented from being damaged by screwing the first fastening bolt 135.

The lower die 200 comprises a guiding stripper 210, a lower die fixing plate 220, a V-shaped block 250, a positioning mandrel 230 and a connecting device 240, wherein the connecting device 240 connects and fixes all parts of the lower die 200;

referring to fig. 5, fig. 5 is a schematic structural diagram of an exemplary guiding and returning area according to the present application. The guide stripper 210 is assembled on the guide stripper fixing plate 212, a guide stripper hole 211 penetrating through the guide stripper 210 is formed in the guide stripper 210, the guide stripper hole 211 is in clearance fit with the expansion die base body 110, the minimum clearance is larger than zero, and the maximum clearance is smaller than the wall thickness of a workpiece after pipe expansion. When the positioning installation of the lower die 200 is carried out, the lower die 100 moves downwards to freely pass through the guide material returning hole 211, so that the installation position of the lower die 200 is convenient to determine, the positioning precision can be improved on one hand, and the installation of the lower die 200 is convenient on the other hand. After the pipe expanding die 100 expands the diameter of the workpiece 300 to be expanded, the workpiece is tightly sleeved on the pipe expanding die 100, and when the pipe expanding die 100 is separated from the guide material returning hole 211, the workpiece is limited by the guide material returning device 210 to be separated from the pipe expanding die 100, so that the workpiece can be conveniently taken down after processing.

Referring to fig. 6, fig. 6 is a schematic view of an exemplary lower mold fixing plate 220 according to the present application. When the lower die 200 is assembled to the lower table 500 of the hydraulic press, most of the area of the lower die 200 will be disposed below the lower table 500. The lower mold fixing plate 220 is provided with a first long hole 221, and the workpiece 300 to be expanded is inserted into the lower mold 200 from the first long hole 221, in this embodiment, the first long hole 221 is a kidney-shaped hole. Two through holes 246 are formed in the lower mold fixing plate 220 to facilitate connection by the connecting device 240.

Referring to fig. 7, a schematic diagram of an exemplary V-block 250 of the present application is shown. The V-shaped block 250 is fixed on the first fixing plate 251, two through holes 246 are formed in the first fixing plate 251 to facilitate connection of the connecting device 240, a second long hole 253 is formed in the first fixing plate 251, the second long hole 253 is a hole through which the workpiece 300 to be expanded is inserted into the lower mold 200.

Referring to fig. 10, fig. 10 is a schematic view illustrating the processing and placing of an exemplary workpiece 300 to be expanded in order to place the workpiece 300 to be expanded, wherein after the workpiece 300 to be expanded passes through the upper end point of the first long hole 221 and the upper end point of the second long hole 253 in sequence, the workpiece 300 to be expanded is sleeved on the positioning mandrel 230. In an embodiment of the present application, the upper end point is a vertex at one end of the kidney-shaped hole close to the worker standing area, that is, a vertex at the middle of the arc-shaped area of the kidney-shaped hole.

In an exemplary embodiment of the present application, a magnet 252 is embedded in the V-shaped block 250, and when the workpiece 300 to be expanded is inserted into the positioning mandrel 230, the magnet 252 attracts the workpiece 300 to be expanded, and the attracting position is biased to the rear side of the worker station area, that is, the workpiece 300 to be expanded is attracted to the side of the worker station area close to the positioning mandrel 230, and rotates to the side far away from the worker station area, and substantially keeps coaxial with the tube expansion die 100. After the workpiece 300 to be expanded is inserted, a worker pushes the workpiece 300 to be expanded backwards, the workpiece 300 to be expanded is close to the magnet 252, so that the workpiece 300 to be expanded is adsorbed by the magnet 252, the workpiece 300 to be expanded is further sleeved on the positioning mandrel 230 under the action of gravity in the process that the workpiece 300 to be expanded rotates backwards, the axis of the workpiece 300 to be expanded is further close to and overlapped with the axis of the tube expansion die 100, and the guide portion 130 is convenient to insert into the workpiece 300 to be expanded.

Referring to fig. 8, fig. 8 is a schematic structural view of an exemplary positioning mandrel 230 of the present application. The positioning mandrel 230 is fixed on the mandrel fixing plate 231, and through holes 246 are formed at both sides of the mandrel fixing plate 231 to facilitate connection of the connecting device 240. The top surface of positioning mandrel 230 is equipped with arc connecting portion 232 to in waiting to expand work piece 300 and insert on positioning mandrel 230, the bottom of positioning mandrel 230 is equipped with the spacing portion that is greater than the main part diameter, treats that to expand work piece 300 carries on spacingly.

In an embodiment of the present application, the connecting device 240 includes two polish rods and six sleeves 242, the polish rod 241 sequentially penetrates through the through holes 246 of the guiding and returning fixing plate 212, the lower mold fixing plate 220, the first fixing plate 251 and the mandrel fixing plate 231, both ends of the polish rod 241 are provided with external threads, and the external threads are connected with the first nut 243 through threads. The sleeves 242 are respectively disposed between the guide and material return fixing plate 212 and the lower mold fixing plate 220, between the lower mold fixing plate 220 and the first fixing plate 251, and between the first fixing plate 251 and the mandrel fixing plate 231, and are used to limit the distance between the fixing plates.

Referring to fig. 9, fig. 9 is a schematic structural diagram of a portion of an exemplary connecting device 240 according to the present application. In order to prevent the loose connection in the use process, a radial opening groove 247 is arranged on the side wall of the first nut 243, the end part of the first nut is tapped with a locking threaded hole 244 passing through the radial opening groove 247, a locking bolt 245 is connected in the locking threaded hole 244 in a threaded manner, and in the embodiment of the application, a gasket 248 is prevented between the locking bolt 245 and the first nut 243. Through setting up locking screw hole 244 and check bolt 245, let the nut produce the self-locking power, the effectual first nut 243 that prevents is not hard up. In an embodiment of the present application, the anti-loosening threaded hole 244 is M6 standard, the torque of the first nut 243 and the external thread of the polish rod exceeds 120n.m, and the connection firmness is effectively ensured.

The application also claims a long pipe expanding method, the existing expanding method is that the supplied materials are firstly cut off, then the end face is roughly turned, the three convex hulls are expanded, then pipe expanding and correction are carried out, and finally finish turning of the end face is carried out.

Through above-mentioned long tube expansion device, the effectual time of shortening the expand tube has improved the yields of expand tube, for the production efficiency who improves the product, reduces unnecessary extravagant, and the long tube expansion method of this application request protection includes:

cutting off incoming materials to obtain a workpiece 300 to be expanded with a proper length;

rough turning is carried out on two ends of the workpiece 300 to be expanded, so that the end faces are perpendicular to the axis of the workpiece 300 to be expanded, and the coaxial precision of the expanded tube is improved;

thirdly, expanding the tube, wherein the tube expanding device of any one of the long tube expanding devices is used for expanding the tube, so that the yield of the expanded tube is improved;

step four, finish turning, wherein finish turning is carried out on two ends of the workpiece, so that the length precision requirement of the finished workpiece is ensured;

and step five, expanding the three-convex hull, namely expanding the pipe from inside to outside at the designed position according to the required shape and size to process the three-convex hull for fixing the metal spring tray.

In an exemplary embodiment of the present application, a rough wash step is added after step one to clear the cut debris and service the rough car.

In an exemplary embodiment of the application, after the second step, the pipe is firstly subjected to fine cleaning, and oil stain removal, chip removal and rust prevention treatment are performed on the pipe, so that a few iron chips generated by rough turning are prevented from influencing the subsequent processes.

In an exemplary embodiment of the application, after the fourth step, the fine cleaning is performed again, so that oil stain, chips and rust of the pipes are removed.

Through the long tube diameter expanding device of this application, the yields that can effectual improvement expand tube shortens the tube expansion time, and bloated three convex closure becomes for the process of consuming time longest. Therefore, the three-convex hull is placed in the last process, thereby reducing unnecessary time waste.

The long pipe diameter expanding device and the diameter expanding method have the beneficial effects of improving the die changing efficiency, improving the coaxiality precision and effectively improving the production efficiency. Therefore, the invention effectively overcomes some practical problems in the prior art, thereby having high utilization value and use significance. The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.

Claims

1. A long pipe expanding device is characterized by comprising:

the pipe expanding die (100), the pipe expanding die (100) and a working table top (400) on the hydraulic machine are relatively fixed;

the lower die (200) is relatively fixed with a lower working table top (500) of the hydraulic press, the lower die (200) comprises a guide stripper (210), a lower die fixing plate (220) and a positioning mandrel (230), and all the lower die parts are relatively fixed by a connecting device (240);

a guide material returning hole (211) is formed in the guide material returning device (210), the guide material returning hole (211) is in clearance fit with the pipe expansion die (100), and the minimum clearance between the guide material returning hole (211) and the pipe expansion die (100) is larger than zero;

the lower die fixing plate (220) is fixed on a lower working table top (500) of the hydraulic press, a first long hole (221) is formed in the lower die fixing plate (220), and a workpiece (300) to be expanded is sleeved on the positioning mandrel (230) through the first long hole (221).

2. The long tube expanding device according to claim 1, wherein the connecting device (240) comprises a light bar (241) and a sleeve (242), the light bar (241) sequentially penetrates through a guiding material returning fixing plate (212) fixed with a guiding material returning device (210), a lower die fixing plate (220) and a mandrel fixing plate (231) fixed with a positioning mandrel (230) from top to bottom, both ends of the light bar (241) are provided with external threads, and both ends of the light bar (241) are in threaded connection with first nuts (243); the outer wall of the polish rod (241) is sleeved with a plurality of sections of sleeves (242), and the sleeves (242) limit the distance between the guide material returning fixing plate (212), the lower die fixing plate (220) and the mandrel fixing plate (231).

3. The long tube expanding device of claim 1, wherein the tube expanding die (100) comprises an expanding die base body (110), an expanding die working part (120) and a guiding part (130);

an installation step (111) is arranged at the end part of the expansion die base body (110), and an expansion die internal thread hole (112) is also arranged at the end part provided with the installation step (111);

the expansion die working part (120) is axially provided with an expansion die mounting hole (121) penetrating through the expansion die working part (120), and the installation step (111) is sleeved on the expansion die mounting hole (121); the expansion die working part (120) comprises a cylindrical area (122) and a circular truncated cone area (123), the diameter of the cylindrical area (122) is the same as that of the expansion die base body (110), and the circular truncated cone area (123) is close to the guide part (130);

the diameter of the main body of the guide part (130) is the same as that of the end part of the circular platform area (123) far away from the cylindrical area (122), one end of the guide part (130) is provided with an expansion die external thread rod (131), and the expansion die external thread rod (131) is matched with the expansion die internal thread hole (112); the other end of the guide part (130) is provided with a conical guide head (132), and an arc transition area (133) is arranged between the conical guide head (132) and the main body of the guide part (130).

4. The long tube expanding device according to claim 3, characterized in that the end of the conical guide head (132) is provided with a guide female screw hole (134), the guide female screw hole (134) is screwed in the same direction as the expansion die female screw hole (112), and a first fastening bolt (135) is arranged in the guide female screw hole (134).

5. The long tube expanding device of claim 1, wherein the lower die (200) further comprises a V-shaped block (250) and a first fixing plate (251) for fixing the V-shaped block (250), the first fixing plate (251) is provided with a second long hole (253), and the V-shaped block (250) is matched with the positioning mandrel (230) for coarsely positioning the workpiece to be expanded (300).

6. The long pipe expanding device of claim 5, wherein the first long hole (221) and the second long hole (253) are waist-shaped holes, and the workpiece (300) to be expanded slides downwards in an inclined way along a connecting line of the vertex of the end wall of the first long hole (221) and the vertex of the end wall of the second long hole (253) and then is sleeved on the positioning mandrel (230).

7. The long tube expanding device according to claim 6, wherein a magnet (252) is arranged in the V-shaped area of the V-shaped block (250), the magnet (252) adsorbs the workpiece (300) to be expanded, when the end of the workpiece (300) to be expanded is sleeved on the positioning mandrel (230) and the side wall of the workpiece to be expanded is adsorbed by the magnet (252), the axis of the workpiece (300) to be expanded is coincident with the axis of the tube expanding die (100).

8. The elongated tube expanding device of claim 1, wherein the width of the first elongated hole (221) is not less than twice the expanded diameter of the workpiece (300) to be expanded.

9. The elongated tubular pipe expanding device according to claim 2, characterized in that the first nut (243) is provided with a radial open slot (247), the first nut (243) is axially provided with a locking threaded hole (244) passing through the radial open slot (247), and a locking bolt (245) is arranged in the locking threaded hole (244).

10. A long pipe expanding method is characterized in that:

cutting, namely cutting the material into workpieces (300) to be expanded with proper length;

rough turning, wherein two ends of the workpiece (300) to be expanded are roughly turned;

expanding the tube by using the long tube expanding device according to any one of claims 1 to 9 on a workpiece (300) to be expanded;

finish turning, wherein the end part of the workpiece after the pipe expansion is finish turned;

and expanding the three convex hulls, and expanding the three convex hulls on the workpiece.