CN110756634A

CN110756634A - Cold-push forming method with straight pipe elbow

Info

Publication number: CN110756634A
Application number: CN201810824171.4A
Authority: CN
Inventors: 丛华
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-07-25
Filing date: 2018-07-25
Publication date: 2020-02-07
Anticipated expiration: 2038-07-25
Also published as: CN110756634B

Abstract

The invention discloses a cold-push forming method with a straight pipe elbow, which comprises a mould and a combined mould core structure, wherein the mould is provided with a curved channel, the combined mould core structure is positioned in the curved channel, and the mould core structure comprises a guide piece, a first elbow module, a second elbow module, a third elbow module and a shaping piece. The cold-push forming method with the straight pipe elbow comprises the following steps: the pipe orifice sleeve of the pipe is arranged on the guide piece of the combined type mold core structure, the pipe is pushed to move towards the bending channel, the whole combined type mold core structure is sleeved by the cold-pushed pipe, and the pipe is shaped to be provided with a straight pipe elbow. And pulling out the guide piece positioned in the straight pipe elbow, wherein the guide piece is linked with the first elbow module to be pulled out. And pulling out the shaping piece positioned in the elbow with the straight pipe, wherein the shaping piece is linked with the second elbow module to be pulled out. And taking out the third elbow module in the straight pipe elbow to obtain the complete straight pipe elbow. The technology solves the problems of forming, demoulding and outer arc reduction rate of the elbow with the straight pipe.

Description

Cold-push forming method with straight pipe elbow

Technical Field

The invention relates to a cold-push forming method, in particular to a cold-push forming method with a straight pipe elbow.

Background

In the prior art, there is no mature method for manufacturing the elbow with straight pipe, and the common elbow and elbow with straight pipe are defined as two different products in the industry, and most common existing technologies for manufacturing the common elbow have the following ways:

the first mode is a rotary drawing type technology, the bending machine in the prior art can only enable the curvature radius of the formed elbow to reach the size which is close to 1.5 times of the diameter of the elbow, and the wall thickness reduction rate of the outer side of the elbow exceeds 50 percent, which is completely not in line with the requirements of international standard specifications. Such elbows are only used in low end or civil industries and cannot be used in high industrial requirements, military industries or in construction articles for the transport of corrosive liquids.

The second mode is a cold push technology, a pipe to be manufactured is directly pushed into a mould with a bend through pressure, the pipe is limited by the outside of the mould with the bend, the pipe at the bend can be limited by the mould with the bend to deform, namely, when the pipe is bent to manufacture a bend, a mould core is added in the pipe to serve as a limitation, so that the pipe is limited by the mould core inwards in a deformation state, cannot excessively deform into the pipe, and is limited by the bend when deforming outwards, the pipe needs to be matched with a mould core structure to be shaped and limited by an external mould, and the thickness reduction rate of the outer side wall of the pipe is reduced as much as possible to meet the standard. Although the mode of increasing the mold core can solve the problem of the wall thickness reduction rate of the outer side of the elbow, the elbow with the straight pipe cannot be manufactured, because the mold core in the elbow can be clamped in the part of the straight pipe after the elbow with the straight pipe is manufactured, and the mold core cannot be taken out from the elbow with the straight pipe.

The third type is a lace type inner core which is also used for 90-degree elbow depoling, and is formed by firstly assembling a die core structure which is split into a plurality of parts, then supporting the die core structure in a hydraulic mode, carrying out cold pushing on a pipe to be manufactured through the die core structure and a die to form an elbow, then recovering the hydraulic supporting force of the die core structure, disassembling the die core structure, and sequentially taking out the die core structure from the elbow. However, in this way, it is still impossible to manufacture the elbow with the straight pipe, and the whole technology and structure are too complicated, and the mold core is questionable about its feasibility in the process of disengaging the elbow, and is likely to be an unrealizable technology in the actual production.

The processing methods in the prior art can only manufacture common elbows and cannot manufacture elbows with straight pipes, and the reason is that the two ends of the elbow with the straight pipes are respectively provided with the straight pipes with the pipe diameter length, so that the mold core in the prior art cannot be pulled out and separated from the elbow with the straight pipes after the process is finished.

Although the elbow with the straight pipe has obvious convenience and connection mode selectivity in installation and use, a good method which can ensure that the outer arc reduction rate of a product reaches the standard and can smoothly loose the core and demould the product is not found in the prior art.

Disclosure of Invention

In order to solve the above problems, the present invention provides a cold-push forming method with a straight pipe elbow, which comprises a mold and a combined mold core structure, wherein the mold is provided with a curved channel, the combined mold core structure is located in the curved channel, and the combined mold core structure comprises a guide, a first elbow module, a second elbow module, a third elbow module and a fixed part, and is characterized in that the cold-push forming method with the straight pipe elbow comprises the following steps: sleeving a pipe orifice of the pipe on a guide piece of the combined mold core structure; pushing the pipe to move towards the bending channel; the cold-pushing pipe sleeve is used for sleeving the whole combined type mold core structure, and molding the pipe into a straight pipe elbow, wherein the pipe is limited by the combined type mold core structure inwards, and the outer wall of the pipe is limited by the bent channel outwards.

The guide piece is pulled, the guide piece is linked with a first shaft rod to move to one end along a first waist-shaped hole, the first shaft rod is abutted against one end in the first waist-shaped hole, the first shaft rod drives a first connecting rod, a first fixing through hole of the first connecting rod drives a first pivot shaft, the first pivot shaft is linked with a first elbow module, the first elbow module pivots along a pipeline path with a straight pipe elbow through the first pivot shaft, the first elbow module moves along the pipeline and is separated from a third elbow module and a second elbow module, and the first elbow module is taken out from the pipeline with the straight pipe elbow.

Pulling the fixed piece, wherein the fixed piece is used for linking the second shaft rod to move to one end along the second waist-shaped hole, the second shaft rod is abutted against one end in the second waist-shaped hole and drives the second connecting rod, a second fixed through hole of the second connecting rod drives the second pivot shaft, the second pivot shaft is linked with the second elbow module, the second elbow module pivots along a pipeline path with a straight pipe elbow through the second pivot shaft, the second elbow module moves along the pipeline and is separated from the third elbow module, and the second elbow module is taken out of the pipeline with the straight pipe elbow; and taking out the third elbow module in the pipeline with the straight pipe elbow.

The combined mold core structure is easy to assemble and disassemble, and is used for manufacturing elbows with straight pipes by cold pushing, and the elbows with straight pipes are manufactured by the pipes through the combined mold core structure and the mold. The shape of the part of the bending part with the straight pipe elbow mold core is not limited by the angle of the straight pipe, namely the shape of the bending part is not clamped in the pipe of the straight pipe due to the limitation of the bending angle, and the pipe of the straight pipe can be smoothly taken out. Thus, the combined mold core structure is separated from the elbow with the straight pipe in a partitioning manner by a simple mechanical structure mode, so that the complete manufacturing process of the elbow with the straight pipe is completed. The cold-push forming method for the straight pipe elbow can simplify the manufacturing process of the cold-push forming straight pipe elbow.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a perspective view of the combined mold core structure for cold-push forming of straight pipe elbows in accordance with the present invention.

Fig. 2 is an exploded view of the modular core structure for cold-forming straight bends according to the present invention.

Fig. 3 is a combination schematic diagram of the combined mold core structure for cold-pushing and forming the straight pipe elbow of the invention.

Fig. 4 is a schematic view of the straight pipe elbow cold forming equipment with the combined mold core structure.

Fig. 5 is a first flowchart of the manufacturing steps of the cold-push forming method for a straight pipe elbow according to the present invention.

Fig. 6 is a flow chart of the second manufacturing step of the cold-push forming method for a straight pipe elbow according to the present invention.

Fig. 7 is a schematic view showing a first manufacturing process of the cold-push forming method for a straight pipe elbow according to the present invention.

Fig. 8 is a schematic diagram of a second manufacturing process of the cold-push forming method for a straight pipe elbow according to the present invention.

Fig. 9 is a third schematic view of the manufacturing process of the cold-push forming method for a straight pipe elbow according to the present invention.

Fig. 10 is a fourth schematic view of the manufacturing process of the cold-push forming method for a straight pipe elbow according to the present invention.

Fig. 11 is a schematic diagram of a fifth manufacturing process of the cold-push forming method for a straight pipe elbow according to the present invention.

Fig. 12 is a sixth schematic manufacturing process diagram of the cold-push forming method for a straight pipe elbow according to the present invention.

Fig. 13 is a manufacturing process diagram seven of the cold-push forming method for a straight pipe elbow according to the present invention.

Fig. 14 is a schematic view eight illustrating the manufacturing process of the cold-push forming method for a straight pipe elbow according to the present invention.

Fig. 15 is a schematic view nine of the manufacturing process of the cold-push forming method for a straight pipe elbow according to the present invention.

Fig. 16 is a schematic view showing a manufacturing process ten of the cold-push forming method for a straight pipe elbow according to the present invention.

Detailed Description

In the following description, for purposes of explanation, numerous implementation details are set forth in order to provide a thorough understanding of the various embodiments of the present invention. It should be understood, however, that these implementation details are not to be interpreted as limiting the invention. That is, in some embodiments of the invention, such implementation details are not necessary. In addition, some conventional structures and components are shown in simplified schematic form in the drawings.

Please refer to fig. 1, which is a perspective view of a combined mold core structure for cold-forming a straight pipe elbow according to the present invention. As shown in the drawings, the present embodiment provides a modular core structure 1 for cold-push forming of a straight pipe elbow. The combined mold core structure 1 is used as a mold for cold-push forming of a pipe in a combined state. After the pipe is formed by cold pushing, the combined type mold core structure 1 can be disassembled in the pipe with the straight pipe elbow through a simple mechanical structure, and the disassembled combined type mold core structure 1 can be separated from the pipe with the straight pipe elbow in a partitioning manner, so that the manufacturing process of forming the pipe with the straight pipe elbow by cold pushing is completed.

Please refer to fig. 2 and fig. 3, which are an exploded view and an assembled view of the combined mold core structure for cold-forming a straight pipe elbow according to the present invention. In the present embodiment, the modular mold core structure 1 for cold-forming a straight pipe elbow comprises a straight guiding section 11, an elbow section 13 and a shaping section 15. The guide straight pipe section 11 is provided with a guide piece 111, a first connecting rod 113 and a first shaft rod 115, one end of the guide piece 111 is provided with a first groove 110, two ends of the first shaft rod 115 are fixed on the upper inner side wall and the lower inner side wall in the first groove 110, the first connecting rod 113 is provided with a first waist-shaped hole 1131 and a first fixing perforation 1133, the first waist-shaped hole 1131 and the first fixing perforation 1133 are respectively positioned at two ends of the first connecting rod 113, and the waist-shaped length of the first waist-shaped hole 1131 is greater than the aperture of the first fixing perforation 1133. The first connecting rod 113 is located in the first groove 110, the first shaft 115 passes through the first kidney-shaped hole 1131 of the first connecting rod 113, and the first shaft 115 reciprocates along the first kidney-shaped hole 1131. The first connecting rod 113 may be cylindrical, flat or chain-shaped, and serves as a connecting structure between the guide 111 and the first elbow module 131.

The elbow section 13 has a first elbow module 131, a second elbow module 133 and a third elbow module 135, one end of the first elbow module 131 is attached to one end of the second elbow module 133, the first elbow module 131 and the second elbow module 133 are attached to the same side of the third elbow module 135, and the first elbow module 131, the second elbow module 133 and the third elbow module 135 form a mold core with curvature. The other end of the first elbow module 131 has a first pivot 1311 and a first notch 1313, two ends of the first pivot 1311 are fixed to two upper and lower inner sidewalls of the first notch 1313, the first pivot 1311 penetrates through the fixing through hole 1133 of the first connecting rod 113, the first connecting rod 113 pivots relative to the first elbow module 131, the other end of the second elbow module 133 has a second pivot 1331 and a second notch 1333, and two ends of the second pivot 1331 are fixed to two upper and lower inner sidewalls of the second notch 1333. One end of the first elbow module 131 has a first positioning notch 1312, one end of the second elbow module 133 has a second positioning notch 1332, the first positioning notch 1312 and the second positioning notch 1332 are combined to form the positioning slot 130, the middle of the third elbow module 135 has a positioning pin 132, and the positioning pin 132 is embedded in the positioning slot 130, thereby facilitating the mutual attachment and fixation among the first elbow module 131, the second elbow module 133 and the third elbow module 135.

The shaping section 15 has a shaping element 151, a second connecting rod 153 and a second shaft 155, one end of the shaping element 151 has a second groove 150, two ends of the second shaft 155 are fixed to the upper and lower inner sidewalls of the second groove 150, the second connecting rod 153 has a second waist-shaped hole 1531 and a second fixing through hole 1533, the second waist-shaped hole 1531 and the second fixing through hole 1533 are respectively located at two ends of the second connecting rod 153, and the waist-shaped length of the second waist-shaped hole 1531 is greater than the aperture of the second fixing through hole 1533. The second connecting rod 153 is located in the second groove 150, the second shaft 155 passes through the second waist-shaped hole 1531 of the second connecting rod 153, the second shaft 155 reciprocates along the second waist-shaped hole 1531, the second pivot shaft 1331 of the second elbow module 133 passes through the second fixing through hole 1133, and the second connecting rod 153 pivots relative to the second elbow module 133.

In the present embodiment, one end of the straight guiding pipe 11 has a first concave shoulder 121, one end of the first bend module 131 and the third bend module 135 has a first shoulder 141, and the first concave shoulder 121 and the first shoulder 141 are engaged with each other, so that the straight guiding pipe 11 and the bend 13 are combined with each other. The length of the convex portion of the first shoulder 141 is slightly less than the depth of the concave portion of the first concave shoulder 121, and the length of the convex portion is less than the distance d1 that the first shaft 115 can be displaced along the first waist-shaped hole 1131, so that after the first shaft 115 of the guide member 111 is displaced along the first waist-shaped hole 1131 by the distance d1, the first shoulder 141 and the first concave shoulder 121 are completely disengaged, so that the first fixing hole 1133 of the first shaft 115 pulls the first pivot shaft 1311 or pivots the first pivot shaft 1311, and the above-mentioned operation is not affected by the first shoulder 141 of the first elbow module 131. Furthermore, the second bend module 133 and the third bend module 135 have a second shoulder 143 at a common end thereof, the shaping member 15 has a second concave shoulder 161 at an end thereof, and the second shoulder 143 and the second concave shoulder 161 are engaged with each other, so that the shaping segment 15 and the bend segment 13 are coupled with each other. The length of the convex portion of the second shoulder 143 is slightly less than the depth of the concave portion of the second shoulder 161, and the length of the convex portion is less than the distance d2 that the second shaft 155 is displaceable along the second kidney-shaped hole 1531. The interlocking relationship is the same as the relationship between the first waist-shaped hole 1131, the first shoulder 141 and the first concave shoulder 121, so that the shape-fixing member 151 is not affected by the second shoulder 143 of the second bend module 133 when it pivots relative to the second bend module 133 through the second connecting rod 153. It should be noted that the cross-sectional height of the first shoulder 141 and the second shoulder 143 is greater than the semicircular height of the combined mold core structure 1, and the cross-sectional height of the tip of the first shoulder 141 and the second shoulder 143 is less than or equal to the semicircular height of the combined mold core structure 1, so that the first elbow module 131 or the second elbow module 133 will not interfere with the wall surface of the straight pipe elbow when being pulled out from the formed straight pipe elbow.

Please refer to fig. 4, which is a schematic diagram of a straight pipe elbow cold forming apparatus with a combined mold core structure according to the present invention. As shown in the drawing, in the present embodiment, the cold forming apparatus 2 with a straight pipe elbow is used for cold-push forming with a straight pipe elbow on the pipe 3. The cold forming equipment 2 with the straight pipe elbow is provided with a combined mold core structure 1. The cold forming equipment 2 with the straight pipe elbow further comprises a first die holder 17, a second die holder 19, a first power module 21 and a second power module 23. The first die shoe 17 has a first die channel 170, the first die channel 170 having a curvature. The second die shoe 19 is located above the first die shoe 17, the second die shoe 19 has a second die channel 190, the second die channel 190 corresponds to the first die channel 170, the second die channel 190 is identical to the first die channel 170, the second die channel 190 and the first die channel 170 are combined into the curved channel 18, wherein the curvature of the curved channel 18 is in an angle range of 90 degrees to less than 180 degrees (the curvature refers to a channel included angle), in other words, the curvature of the curved channel 18 is an angle within 90 degrees from a straight channel. The curvature of the modular core structure 1 matches the curvature of the curved channel 18. The outer diameter of the combined mold core structure 1 needs to be smaller than the inner diameter of the pipe 3, so that the gap distance between the inner wall of the curved channel 18 and the outer wall of the combined mold core structure 1 is larger than the thickness of the pipe wall with the straight pipe elbow formed by cold-pushing the pipe 3. The first power module 21 and the second power module 23 are devices for providing pressure to the tube 31 for shaping, such as hydraulic cylinders or other mechanical power.

In this embodiment, the first mold seat 17 and the second mold seat 19 are combined to form an outline mold 20 with a straight pipe elbow cold forming device. The first die holder 17 includes a first clamp 171 and a first die 173, the first die 173 is disposed on the first clamp 171, wherein the first die 173 includes a first die block 172, a bottom surface of the first die block 172 is located and fixed on a worktable, the first die block 172 has a first die channel 170 and a plurality of first positioning structures 174, and the plurality of first positioning structures 174 are located around the first die channel 170. The first fixture 171 includes a first base 1711, a plurality of first grooves 1713, and a plurality of first fixing members 1715, wherein the plurality of first grooves 1713 are located on the surface of the first base 1711, which carries the first module 172, the plurality of first fixing members 1715 are disposed in the plurality of first grooves 1713, the first mold 173 further includes a first side groove 1731, the first side groove 1731 is located on the side surface of the first module 172, and the plurality of first fixing members 1715 are fastened to the first side groove 1731.

As mentioned above, the second die holder 19 includes the second clamp 191 and the second die 193, the second die 193 is disposed on the second clamp 191, wherein the second die 193 includes the second module 192, the second module 192 has the second die channel 190 and the second positioning structures 194, and the second positioning structures 194 are disposed around the second die channel 190. The second fixture 191 includes a second housing 1911, a plurality of second grooves 1913, and a plurality of second fixing members 1915, the plurality of second grooves 1913 are located on the surface of the second housing 1911 carrying the second module 192, the plurality of second fixing members 1915 are disposed in the plurality of second grooves 1913, the second mold 193 further includes a second side groove 1931, the second side groove 1931 is located on the side surface of the second module 192, and the plurality of second fixing members 1915 are fastened to the second side groove 1931. Thus, when the second mold 193 is assembled to the first mold 173, the first positioning structures 174 of the first module 172 and the second positioning structures 194 of the second module 192 are engaged with each other.

Referring to fig. 2 again, in the present embodiment, the combined mold core structure 1 is located in the curved channel 18. Wherein the male end of the guide 111 of the modular core structure 1 has a perforation 1110, the elastic pin 1113 is located in the male end, and a part of the elastic pin 1113 protrudes out of the orifice of the perforation 1110. The other end of the setting piece 151 of the modular core structure 1 has a positioning rod 1511. For convenience of operation of the elastic pin 1113, the elastic pin 1113 is adjusted to be horizontally disposed in the drawing, and actually, for convenience of operation, the elastic pin 1113 is vertically disposed in the guide 111.

The first power module 21 is located at one end of the curved channel 18, the first power module 21 has a first driving member 211 and a push rod 213, one end of the push rod 213 is connected to the first driving member 211, the other end of the push rod 213 has a receiving hole 210, a pushing portion 212 is around the opening of the receiving hole 210, and the inner wall of the receiving hole 210 sequentially has a pushing surface 214 and a fixing groove 216 from outside to inside. The second power module 23 is located at the other end of the curved channel 18, the second power module 23 has a second driving element 231 and a fixing element 233, one end of the fixing element 233 is connected to the second driving element 231, the other end of the fixing element 233 fixes one end of a positioning rod 1511, and the positioning rod 1511 is used for fixing the positions of the elbow section and the straight tube section, in other words, fixing the position of the combined mold core structure 1 in the curved channel 18.

Fig. 5 to 16 are a flow chart showing a first manufacturing step, a second manufacturing step, and a first manufacturing process, a second manufacturing process, of the cold-push forming method for a straight pipe elbow according to the present invention. As shown in the drawings, in the embodiment, the tube 3 is taken first, the tube 3 has a pipe 31, two ends of the pipe 31 are respectively a first pipe opening 311 and a second pipe opening 313, wherein the first pipe opening 311 and the second pipe opening 313 of the tube 3 are both inclined surfaces.

Referring to fig. 7, the tube opening surface of the first tube opening 311 of the tube 3 abuts against the pushing portion 212 at the other end of the pushing rod 213, and the outward-protruding inclined end of the first tube opening 311 is used as the outer side of the straight tube bend to be manufactured, so that when the tube 3 is bent, the tube 3 is subjected to the compensation effect of the material extending from the inner side to the outer side of the bent portion, wherein the outer diameter of the pushing portion 212 is smaller than the inner diameter of the curved channel 18, and the inner diameter of the curved channel 18 is equal to or larger than the diameter of the tube 3, so that the pushing rod 213 can push the tube 3, and the pushing rod 213 and the tube 3 enter the curved channel 18 together.

Referring to fig. 7 and 8, in step S11, the opening of the tube 3 is sleeved on the guide 111 of the combined mold core structure 1. In the present embodiment, the second pipe opening 313 is sleeved on the guide 111, and the inner diameter of the pipe opening of the tube 3 is close to the outer diameter of the combined mold core structure 1.

In step S13, the tube 3 is pushed to move toward the curved passage 18. In the present embodiment, the first power module 21 drives the push rod 213, and the push portion 212 of the push rod 213 pushes the tube 3 to be sleeved on the combined mold core structure 1 for shaping, and the tube 3 moves into the curved channel 18.

Referring to fig. 9, in step S15, the pipe 3 is pushed by cold to cover the entire combined mold core structure 1, and the pipe 3 is shaped to have a straight pipe bend, wherein during the cold-pushing process of the pipe 3, the pipe 3 is limited by the combined mold core structure 1 inward, and the outer wall of the pipe 3 is limited by the curved channel 18 outward, so that the pipe 3 is guided by the combined mold core structure 1 and the curved channel 18 to extend in a uniformly curved manner. The receiving hole 210 of the push rod 213 is sleeved with the convex end of the guide 111, the outer diameter of the convex end of the guide 111 is smaller than the aperture of the receiving hole 210 of the push end of the push rod 213, the elastic pin 1113 is located in the moving path of the push surface 214 and the fixed groove 216, the elastic pin 1113 is compressed by the moving push surface 214, the push surface 214 is an inclined surface, and the elastic pin 1113 is compressed progressively by the push surface 214. The elastic pin 1113 may be a spring, and those skilled in the art can select the most suitable structure according to the actual requirement, and the structure is not limited to the structure illustrated in the present embodiment.

Referring to fig. 10, the pushing surface 214 is moved to compress the elastic pin 1113 until the fixing groove 216 corresponds to the elastic pin 1113, the elastic pin 1113 is stretched and fixed in the fixing groove 216, the tube 3 is pushed to be completely sleeved on the combined mold core structure 1, and the tube 3 is cold-pushed to form the straight tube elbow 4.

Referring to fig. 11, step S17 is performed in which the straight pipe section 11 is guided to move away from the elbow section 13, the first power module 21 pulls the push rod 213, the push rod 213 drives the guide 111 to move through the fixed relationship between the fixing groove 216 and the elastic pin 1113, the guide 111 drives the first shaft 115 to move to one end along the first kidney-shaped hole 1131, and the first shaft 115 abuts against one end in the first kidney-shaped hole 1131.

Referring to fig. 12, the first shaft 115 drives the first connecting rod 113, the first fixing through hole 1133 of the first connecting rod 113 drives the first pivot 1311, and the first pivot 1311 is coupled to the first elbow module 131. The first elbow module 131 is a part of the combined mold core structure 1 attached to the inner wall of the curved pipe 31 of the pipe 3, and the inner side of the first elbow module 131 has a curved surface attached to the pipe 31. When the first elbow module 131 is pulled by the first pivot 1311, the curved surface on the inner side of the first elbow module 131 moves from the inner wall attached to the curved pipe 31 to the inner wall of the linear pipe 31, and at the same time, the first elbow module 131 moves to the linear pipe 31, which means that the other end of the first elbow module 131 is separated from the second elbow module 133, and the outer side of the first elbow module 131 is separated from the third elbow module 135. Since the inner curved surface of the first elbow module 131 cannot be completely attached to the inner wall of the linear pipe 31, the first elbow module 131 pivots along the inner wall of the path of the pipe 41 with the straight pipe elbow 4 through the first pivot 1311, the inner curved surface of the first elbow module 131 abuts against the inner wall of the linear pipe 31 in a non-attachment manner, the outer side of the first elbow module 131 is not limited by the third elbow module 135, and the inner curved surface of the first elbow module 131 cannot be attached to the inner wall of the pipe 31, so that the volume of the inner curved surface of the first elbow module 131 is increased, and in this case, the first elbow module 131 moves along the pipe 41 and is separated from the second elbow module 133 and the third elbow module 135.

Referring to fig. 13, the first elbow module 131 is taken out from the pipe 41 with the straight pipe elbow 4. In addition, the groove bottom of the fixing groove 216 of the push rod 213 is further provided with a pin withdrawing hole 2161. The pin withdrawing hole 2161 penetrates the outer wall of the push rod 213. The user can insert the pin-removing hole 2161 through one end of the pin-removing rod (such as a tube or a rod) and press the elastic pin 1113, so that the elastic pin 1113 is compressed, and after the pin is removed from the fixing groove 216, the distance between the push rod 213 and the guide 111 is not limited, and the push rod 213 is separated from the guide 111.

Referring to fig. 14, step S19 is performed in which the shaping section 15 moves away from the elbow section 13, the second power module 23 pulls the fixing member 233, the fixing member 233 drives the shaping member 151 to move through the positioning rod 1511, the shaping member 151 drives the second shaft rod 155 to move to one end along the second waist-shaped hole 1531, and the second shaft rod 155 abuts against one end in the second waist-shaped hole 1531.

Referring to fig. 15, the second shaft 155 drives the second connecting rod 153, the second fixing through hole 1133 of the second connecting rod 153 drives the second pivot shaft 1331, and the second pivot shaft 1331 is linked with the second elbow module 133. The second elbow module 133 is a part of the combined mold core structure 1 attached to the inner wall of the pipe 31 at the bending section of the pipe 3, and the inner side of the second elbow module 133 has a bending surface attached to the pipe 31. When the second elbow module 133 is pulled by the second pivot shaft 1331, the curved surface of the inner side of the second elbow module 133 moves from the inner wall attached to the curved pipe 31 to the inner wall of the linear pipe 31, and at the same time, the second elbow module 133 moves to the linear pipe 31, which indicates that the outer side of the second elbow module 133 has been separated from the third elbow module 135. Since the inner curved surface of the first elbow module 131 cannot be completely attached to the inner wall of the linear pipe 31, the second elbow module 133 pivots along the inner wall of the path of the pipe 41 with the straight pipe elbow 4 through the second pivot shaft 1331, the inner curved surface of the second elbow module 133 abuts against the inner wall of the linear pipe 31 in a non-attachment manner, the outer side of the second elbow module 133 is not limited by the third elbow module 135, and the inner curved surface of the second elbow module 133 can also accommodate the portion with excessive volume due to the fact that the inner curved surface cannot be attached to the inner wall of the pipe 31, so that the second elbow module 133 moves along the pipe 41 and is separated from the third elbow module 135. Referring to fig. 14, the second elbow module 133 is taken out of the pipe 41 with the straight pipe elbow 4.

Referring to fig. 16, step S21 is performed to take out the third elbow module 135 in the pipe 41 with the straight pipe elbow 4. Thus, the structure with the straight pipe elbow 4 can be completely obtained.

Referring to fig. 4, in the present embodiment, the straight pipe elbow cold forming apparatus with combined mold core structure 1 further includes a third power module 25, and the third power module 25 is located at one side of the curved channel 18. The third power module 25 is identical in structure and function to the second power module 23. When a straight pipe elbow with a 45-degree angle or a 30-degree angle needs to be formed, only the first module 172 of the first mold 193 needs to be replaced by a third module, the third module is fixed on the first clamp 171, the third module is provided with a third mold channel and a plurality of third positioning structures, the third positioning structures are located around the third mold channel, and the curvature of the third mold channel is different from that of the first mold channel 170. Similarly, the second module 192 of the second mold 193 is replaced with a fourth module, and the fourth module is fixed to the second clamp 191, and has a fourth mold channel and a plurality of fourth positioning structures, wherein the plurality of fourth positioning structures are located around the fourth mold channel, and the curvature of the fourth mold channel is the same as the curvature of the third mold channel. The third positioning structures and the fourth positioning structures are mutually embedded, the third mould channel is combined with another bent channel combined by the fourth mould channel, wherein the bending degree of the other bent channel is within an angle range from more than 90 degrees to less than 180 degrees (the bending angle refers to a channel included angle), in other words, the bending angle of the other bent channel is within an angle range from a straight channel to less than 90 degrees. The curvature of the modular core structure 1 matches the curvature of the other curved channel.

In the present embodiment, the bending angle of the other curved channel does not exceed 90 degrees, i.e. when the straight channel bends 30 degrees or 45 degrees, the elbow section 13 of the combined mold core structure 1 can replace the first elbow module 131, the second elbow module 133 and the third elbow module 135 with two symmetrical elbow modules as mold cores, because the shapes of the bending parts of the two symmetrical elbow modules are not limited by the angle of the straight pipe, namely, the shape of the bending part can not be blocked in the pipe of the straight pipe due to the limitation of the bending angle, the pipe can be smoothly taken out of the pipe of the straight pipe, wherein two outer ends of the symmetrical modules are respectively combined at one end of the guide straight pipe section 11 and one end of the shaping section 15, the two ends of the symmetrical modules corresponding to the two ends of the straight guiding pipe section 11 and the shaping section 15 are respectively a combination structure of a shoulder and a concave shoulder, which is not described herein.

After the third power module 25 is located at one end of another curved channel and the second power module 23 is located at the other end of another curved channel, the combined mold core structure corresponding to another curved channel is replaced, and the pipe 3 can be bent into an elbow with a straight pipe at another angle after the combined mold core structure is assembled. In the present embodiment, the curved channel and the combined mold core structure of the matching module are selected according to the desired curvature of the tube 3. The third power module 25 is also arranged according to the position of one end of the curved path.

In summary, the present embodiment provides a combined mold core structure for cold-push forming of a straight tube elbow, where the combined mold core structure includes a guide, a first elbow module, a second elbow module, a third elbow module, and a fixing element. The modular core structure is located within the curved channel. The pipe orifice of the pipe to be manufactured is sleeved with a guide piece of a combined type mold core structure, the pipe is pushed into a curved channel in a cold pushing mode, the bending degree and the pipe wall thickness of the pipe are limited by the outer wall of the combined type mold core structure and the inner wall of the curved channel, the pipe is shaped into a straight pipe elbow, the inner side of the curved section with the straight pipe elbow extends outwards, and the outer arc thinning rate is not more than about 10%.

The combined mold core structure in the straight pipe elbow is disassembled, the first elbow module is pulled out through a simple mechanical structure, the side face of the first elbow module is attached to the inner wall of the straight pipe elbow, when the inner side face of the first elbow module is moved to the inner wall of the straight pipe which is not attached to the inner wall of the straight pipe elbow which is not attached to the inner side face of the straight pipe elbow, the outer side of the first elbow module is not limited by the third elbow module, the inner side of the first elbow module has more volume due to the fact that the pipe wall is not attached to the inner side of the first elbow module, the outer side of the first elbow module does not have the limitation of the third elbow module, and the more volume of the first elbow module can be. Therefore, the shape of the bending part of the first elbow module is not limited by the angle of the straight pipe, namely the shape of the bending part is not clamped in the pipe of the straight pipe due to the limitation of the bending angle, the pipe of the straight pipe can be smoothly separated, and the second elbow module is the same as the first elbow module, so the description is omitted. Thus, the combined mold core structure is separated from the elbow with the straight pipe in a partitioning manner by a simple mechanical structure mode, so that the complete manufacturing process of the elbow with the straight pipe is completed. The invention can simplify the manufacturing process of forming the straight pipe elbow by cold pushing.

The foregoing description shows and describes several preferred embodiments of the invention, but as aforementioned, it is to be understood that the invention is not limited to the forms disclosed herein, but is not to be construed as excluding other embodiments and is capable of use in various other combinations, modifications, and environments and is capable of changes within the scope of the inventive concept as expressed herein, commensurate with the above teachings, or the skill or knowledge of the relevant art. And that modifications and variations may be effected by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A cold-push forming method with a straight pipe elbow comprises a mold and a combined mold core structure (1), wherein the mold is provided with a curved channel (31), the combined mold core structure (1) is positioned in the curved channel (31), the combined mold core structure comprises a guide piece (111), a first elbow module (131), a second elbow module (133), a third elbow module (135) and a shaping piece (151), and the cold-push forming method with the straight pipe elbow is characterized by comprising the following steps:

sleeving a pipe orifice of a pipe (3) on the guide piece (111) of the combined mold core structure (1);

-pushing the tube (3) towards the curved channel (31);

cold-pushing the pipe (3) to sleeve the whole combined type mold core structure (1), and shaping the pipe (3) into a straight pipe elbow, wherein the pipe (3) is limited by the combined type mold core structure (1) inwards, and the outer wall of the pipe (3) is limited by the bent channel (31) outwards;

pulling the guide piece (111), the guide piece (111) is linked with the first shaft lever (115) to move to one end along the first waist-shaped hole (1131), the first shaft lever (115) abuts against one end in the first kidney-shaped hole (1131), the first shaft lever (115) drives the first connecting rod (113), the first fixing through hole (1133) of the first connecting rod (113) drives the first pivot shaft (1331), the first pivot shaft (1331) is linked with the first elbow module (131), the first elbow module (131) pivots along the pipeline path with the straight pipe elbow through the first pivot shaft (1331), the first elbow module (131) moves along the pipeline (31), separating from the third elbow module (135) and the second elbow module (133), and taking out the first elbow module (131) from the pipeline (31) with the straight pipe elbow;

the shaping piece (151) is pulled, the shaping piece (151) is linked with the second shaft lever (155) to move to one end along the second waist-shaped hole (1531), the second shaft lever (155) abuts against one end in the second waist-shaped hole (1531), the second shaft lever (155) drives the second connecting rod (153), the second fixed through hole (1133) of the second connecting rod (153) drives the second pivot shaft (1331), the second pivot shaft (1331) is linked with the second elbow module (133), the second elbow module (133) pivots along the pipeline path with the straight pipe elbow through the second pivot shaft (1331), the second elbow module (133) moves along the pipeline (31), and the second elbow module (133) is taken out of the third elbow module (135) and taken out of the pipeline (31) with the straight pipe elbow; and

and taking out the third elbow module (135) in the pipeline (31) with the straight pipe elbow.

2. The cold-push forming method of a straight pipe elbow as claimed in claim 1, characterized in that before the step of fitting the mouth of the pipe (3) over the guide (111) of the modular core structure (1), the curved channel (31) of the mould is selected to match the desired curvature of the pipe (3).

3. The cold-push forming method of a straight pipe elbow according to claim 2, characterized in that the degree of curvature of the combined core structure (1) and the curved channel (31) are matched to each other.

4. The cold-push forming method for a straight pipe elbow according to claim 1, wherein in the step of fitting the mouth of the pipe (3) to the guide (111) of the modular core structure (1), the mouth diameter of the pipe (3) is larger than the outer diameter of the modular core structure (1).

5. The cold-push forming method for straight pipe bends according to claim 1, characterized in that in the step of fitting the mouth of a pipe (3) over the guide (111) of the modular core structure (1), the distance of the passage inner wall from the outer wall of the modular core structure (1) according to the curved passage (31) is greater than the wall thickness of the pipe (3).