A device for forming internal bosses on steel pipes

Abstract

The present application discloses a steel pipe inner boss forming device for processing and forming the inner boss of a steel pipe. The steel pipe inner boss forming device includes a mounting plate, a positioning shaft, a guiding shaft, multiple inner molds, an elastic ring, a driving part, and multiple outer punching convex dies. The positioning shaft is arranged on one side of the mounting plate; the guiding shaft is arranged at the end of the positioning shaft far from the mounting plate, and the diameter of the end of the guiding shaft far from the positioning shaft is smaller than that of the other end; the multiple inner molds are arranged at intervals in the circumferential direction of the guiding shaft on the periphery of the guiding shaft and have the freedom to move axially along the guiding shaft; the elastic ring is sleeved on the outer periphery of each inner mold and provides a force for each inner mold to fit the guiding shaft; the driving part is sleeved on the outer periphery of the positioning shaft; the multiple outer punching convex dies correspond to the multiple inner molds one by one and are arranged on the side of the driving part away from the mounting plate, and the outer punching convex dies move radially along the positioning shaft in response to the driving force of the driving part. The steel pipe inner boss forming device of the present application is simple and fast to operate as a whole and can be reused.

Description

Technical Field

[0001] This application relates to the technical field of steel pipe processing equipment, and particularly to a forming device for internal bosses of steel pipes. Background Art

[0002] In traditional solutions, the forming of internal bosses of steel pipes is completed by manual or assisted pressing with simple tooling. However, the above solutions have low working efficiency, and it is difficult to meet the design requirements for the position accuracy and shape accuracy of the internal bosses. Summary of the Invention

[0003] The main purpose of this application is to provide a forming device for internal bosses of steel pipes, aiming to solve the problems that the forming of internal bosses of steel pipes by manual or assisted pressing with simple tooling has low working efficiency and it is difficult to meet the design requirements for the position accuracy and shape accuracy of the internal bosses.

[0004] To achieve the above purpose, this application provides a forming device for internal bosses of steel pipes, which is used for the processing and forming of internal bosses of steel pipes. The forming device for internal bosses of steel pipes includes a mounting plate, a positioning shaft, a guiding shaft, multiple internal molds, an elastic ring, a driving part, and multiple external punching bosses. The positioning shaft is arranged on one side of the mounting plate and its axial direction is the same as the thickness direction of the mounting plate; the guiding shaft is arranged at the end of the positioning shaft away from the mounting plate and its axial direction is the same as the axial direction of the positioning shaft. The diameter of the end of the guiding shaft away from the positioning shaft is smaller than that of the other end; multiple internal molds are arranged at intervals around the guiding shaft in the circumferential direction of the guiding shaft and have the freedom to move along the axial direction of the guiding shaft. The outer circumference of each internal mold is sleeved with a steel pipe, and each internal mold is provided with a recess; the elastic ring is sleeved on the outer circumference of each internal mold and provides a force for each internal mold to fit the guiding shaft; the driving part is sleeved on the outer circumference of the positioning shaft; multiple external punching bosses correspond to the multiple internal molds one by one and are arranged on the side of the driving part away from the mounting plate. The external punching boss moves along the radial direction of the positioning shaft in response to the driving force of the driving part, so as to cooperate with the recess on the corresponding internal mold to press out internal bosses on the steel pipe.

[0005] Optionally, each internal mold is provided with a recess on its outer circumference; the external punching boss includes a moving part and a pressing rod. The moving part is connected to the driving part; the pressing rod is fixed on the side of the moving part away from the driving part and its extending direction is the same as its moving direction. The end of the pressing rod close to the corresponding internal mold extends out of the moving part and is provided with a protruding part that cooperates with the recess.

[0006] Optionally, the guiding shaft is sequentially divided into a first diameter section, a diameter changing section, and a second diameter section in a direction away from the positioning shaft, and the diameter of the first diameter section is greater than that of the second diameter section; wherein, in the thickness direction of the mounting plate, the axial length of the first diameter section and the axial length of the second diameter section are both greater than the length of the inner mold.

[0007] Optionally, the diameter of the positioning shaft is greater than the diameter of the first diameter section and less than the inner diameter of the steel pipe; when the inner mold abuts against the positioning shaft, the recessed part is located on the movement path corresponding to the protruding part.

[0008] Optionally, the steel pipe inner boss forming device further includes a limiting piece and a spring. The limiting piece is fixed to the end of the guiding shaft away from the positioning shaft; the spring is sleeved on the outer periphery of the guiding shaft, one end of the spring is connected to each inner mold, and the other end of the spring is connected to the limiting piece.

[0009] Optionally, in the thickness direction of the mounting plate, the sum of the minimum length of the spring and the length of the inner mold is less than the length of the second diameter section.

[0010] Optionally, multiple axially extending sliding grooves are provided on the outer periphery of the guiding shaft, and the multiple sliding grooves correspond to the multiple inner molds one by one; the steel pipe inner boss forming device further includes multiple limiting pins, and the multiple limiting pins are fixedly arranged on the side of each inner mold that fits with the guiding shaft one by one and the axis is the same as the radial direction of the guiding shaft, and each limiting pin is inserted into the corresponding sliding groove and is in sliding fit with the corresponding sliding groove.

[0011] Optionally, when the inner mold fits with the guiding shaft, the length of the limiting pin is less than the depth of the sliding groove.

[0012] Optionally, an arc-shaped through groove is provided on the outer periphery of each inner mold, and the elastic ring passes through the arc-shaped through grooves on each inner mold.

[0013] Optionally, the steel pipe inner boss forming device further includes a positioning ring, and the positioning ring is sleeved on the outer periphery of the positioning shaft and abuts against one end of the steel pipe; wherein, the outer diameter of the steel pipe is greater than the inner diameter of the positioning ring and less than the outer diameter of the positioning ring.

[0014] The embodiment of the present application proposes a device for forming an inner boss of a steel pipe, wherein the inner mold is located at one end of the guide shaft close to the positioning shaft, and the steel pipe is sleeved on the outer periphery of each inner mold. At this time, each inner mold is located between the steel pipe and the positioning shaft, and the driving part drives each outer punch to move radially along the positioning shaft and squeeze the steel pipe, so that the inner boss is squeezed out at the position corresponding to the recessed portion on the steel pipe, and the inner boss is located in the corresponding recessed portion. Then, the driving part drives each outer punch to move radially along the positioning shaft and away from the steel pipe, and at this time, the steel pipe is moved along the thickness direction of the mounting plate. , so that the steel pipe is away from the mounting plate, and the steel pipe drives the inner mold to move away from the mounting plate synchronously through the cooperation of the inner boss and the recessed part. During the process, the elastic ring always clamps the inner mold to make the inner mold fit with the guide shaft. When the inner mold moves to the end of the guide shaft away from the positioning shaft, the recessed parts on each inner mold are separated from the corresponding inner boss, and the steel pipe and the inner mold can be separated, and the inner boss forming of the steel pipe can be completed. The overall operation of the steel pipe inner boss forming device is simple and fast and can be reused. The position and shape of the inner boss on each steel pipe are controllable, with high precision and can be mass-produced. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of the overall structure of a steel pipe inner boss forming device provided in an embodiment of the present application;

[0016] Figure 2 for Figure 1 A magnified view of the structure at center A;

[0017] Figure 3 for Figure 1 Another perspective structural diagram of the embodiment;

[0018] Figure 4 for Figure 1 A cross-sectional view of the inner mold of the embodiment;

[0019] Figure 5 A schematic diagram of the overall structure of a steel pipe inner boss forming device provided in an embodiment of the present application when the steel pipe is removed;

[0020] Figure 6 for Figure 5 A cross-sectional view of the inner mold of the embodiment.

[0021] In the figure: 1. Mounting plate; 11. Steel pipe; 2. Positioning shaft; 3. Guide shaft; 31. Limiting plate; 32. Spring; 4. Inner mold; 41. Limiting pin; 5. Elastic ring; 6. Driving part; 7. External punch; 71. Moving part; 72. Extrusion rod; 8. Positioning ring.

[0022] The realization of the objectives, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0023] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0024] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If this specific posture changes, the directional indications will also change accordingly.

[0025] In the present invention, unless otherwise clearly defined and limited, terms such as "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the connection inside two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0026] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, such descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the meaning of "and / or" appearing throughout the text includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or a solution that satisfies both A and B at the same time. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0027] Reference Figures 1 to 6, the embodiment of the present application provides a steel tube inner boss forming device, which is used for processing and forming the inner boss of a steel tube 11. The steel tube inner boss forming device may include a mounting plate 1, a positioning shaft 2, a guide shaft 3, multiple inner molds 4, an elastic ring 5, a driving part 6 and multiple outer punches 7. The positioning shaft 2 is arranged on one side of the mounting plate 1 and its axial direction is the same as the thickness direction of the mounting plate 1; the guide shaft 3 is arranged at one end of the positioning shaft 2 away from the mounting plate 1 and its axial direction is the same as the axial direction of the positioning shaft 2. The diameter of the end of the guide shaft 3 away from the positioning shaft 2 is smaller than the diameter of the other end; the multiple inner molds 4 are arranged on the circumference of the guide shaft 3. The inner molds 4 are arranged at intervals on the periphery of the guide shaft 3 and have the freedom to move axially along the guide shaft 3. The outer periphery of each inner mold 4 is sleeved on the steel pipe 11 and each inner mold 4 is provided with a recessed portion; the elastic ring 5 is sleeved on the outer periphery of each inner mold 4 and provides each inner mold 4 with a force to fit the guide shaft 3; the driving part 6 is sleeved on the outer periphery of the positioning shaft 2; a plurality of external punches 7 correspond one-to-one to the plurality of internal molds 4 and are arranged on the side of the driving part 6 away from the mounting plate 1, and the external punches 7 move radially along the positioning shaft 2 in response to the driving force of the driving part 6, so as to cooperate with the recessed portion on the corresponding inner mold 4 to press out an inner boss on the steel pipe 11.

[0028] The embodiment of the present application proposes a steel tube inner boss forming device, in which the inner die 4 is located at one end of the guide shaft 3 close to the positioning shaft 2, and the steel tube 11 is sleeved on the outer circumference of each inner die 4. At this time, each inner die 4 is located between the steel tube 11 and the positioning shaft 2, and the driving part 6 drives each outer punch 7 to move radially along the positioning shaft 2 and squeeze the steel tube 11, so that the position corresponding to the recessed portion on the steel tube 11 is squeezed out with the inner boss, and the inner boss is located in the corresponding recessed portion, and then the driving part 6 drives each outer punch 7 to move radially along the positioning shaft 2 and away from the steel tube 11, and at this time, the steel tube 11 is moved along the thickness direction of the mounting plate 1, so that the steel tube 11 is away from the mounting plate 1, and the steel tube 11 drives the inner die 4 to synchronously move away from the mounting plate 1 through the cooperation of the inner boss and the recessed portion. During the process, the elastic ring 5 always clamps the inner die 4, so that the inner die 4 fits the guide shaft 3, as shown in FIG. Figure 6 As shown, when the inner mold 4 moves to the end of the guide shaft 3 away from the positioning shaft 2, the recessed portions on each inner mold 4 are separated from the corresponding inner bosses, and the steel tube 11 and the inner mold 4 can be separated, and the inner boss forming of the steel tube 11 can be completed. The overall operation of the steel tube inner boss forming device is simple and fast and can be reused. The position and shape of the inner bosses on each steel tube 11 are controllable, with high precision, and can be mass-produced.

[0029] Specifically, when the steel tube inner boss forming device is used, the mounting plate 1 can be placed on a plane. At this time, the thickness direction of the mounting plate 1 can be the direction of gravity. After the steel tube 11 is formed and separated from the inner mold 4, the inner mold 4 falls back to the end of the guide shaft 3 close to the positioning shaft 2 by its own gravity, so that the steel tube inner boss forming device can be used next time.

[0030] Among them, using the steel pipe inner boss forming device, only three steps are needed to complete the forming of the steel pipe 11. The first step is to put the steel pipe 11 on the outer periphery of the inner mold 4. The second step is to control the outer punch 7 to move back and forth once along the radial direction of the positioning shaft 2 through the driving part 6, thereby squeezing the steel pipe 11 and moving away from the steel pipe 11 after the extrusion is completed. The third step is to move along the thickness direction of the mounting plate 1 and pull out the steel pipe 11. The overall operation is simple and the work efficiency is high.

[0031] It should be understood that the thickness direction of the mounting plate 1 does not necessarily have to be the same as the gravity direction, as long as the inner mold 4 can fall back to the end of the guide shaft 3 close to the positioning shaft 2 by its own gravity.

[0032] It should be noted that if Figure 4 As shown, the side of the inner mold 4 close to the guide shaft 3 is in contact with the guide shaft 3, and the side of the inner mold 4 away from the guide shaft 3 is sleeved with the steel pipe 11, so the side of the inner mold 4 close to the guide shaft 3 and the side away from the guide shaft 3 are both arc-shaped. In this application, the side of the inner mold 4 close to the guide shaft 3 is recorded as the inner periphery of the inner mold 4, and the side of the inner mold 4 away from the guide shaft 3 is recorded as the outer periphery.

[0033] like Figure 3 and Figure 4 As shown, in the present application, there are three inner dies 4 and the three inner dies 4 are evenly arranged on the periphery of the guide shaft 3 along the circumferential direction, and there are also three corresponding outer punches 7.

[0034] refer to Figure 2 and Figure 4 In an exemplary embodiment, the outer punch 7 may include a moving part 71 and an extrusion rod 72, the moving part 71 is connected to the driving part 6; the extrusion rod 72 is fixed to the side of the moving part 71 away from the driving part 6 and the extension direction is the same as its own moving direction, and the extrusion rod 72 extends from the moving part 71 at one end close to the corresponding inner mold 4 and is provided with a protrusion that cooperates with the recessed part.

[0035] Specifically, the driving part 6 can be a hydraulic chuck or a pneumatic chuck, etc. The hydraulic chuck can drive the claws set on itself to move radially along the positioning shaft 2, and the moving part 71 can be fixed to the claws on the hydraulic chuck. At this time, when the hydraulic chuck drives the claws to move radially along the positioning shaft 2, the claws drive the moving part 71 and the extrusion rod 72 to move synchronously. Among them, there are many existing hydraulic chucks, and the hydraulic chucks are not described in detail here.

[0036] It should be understood that one end of the extrusion rod 72 close to the corresponding inner die 4 extends out a moving part 71 and is provided with a convex part that cooperates with the concave part. In this way, when the extrusion rod 72 moves radially along the positioning shaft 2, the convex part is driven to contact the steel pipe 11 first, and the corresponding part on the steel pipe 11 is extruded to form an inner boss. The inner boss is located in the concave part on the corresponding inner die 4. After that, the hydraulic chuck is used to drive each extrusion rod 72 away from the steel pipe 11 to separate the convex part from the steel pipe 11, and then the subsequent operations can be carried out.

[0037] Reference Figure 2 、 Figure 5 and Figure 6 , in an exemplary embodiment, the guide shaft 3 is sequentially divided into a first diameter section, a diameter change section and a second diameter section in the direction away from the positioning shaft 2, and the diameter of the first diameter section is greater than the diameter of the second diameter section; wherein, in the thickness direction of the mounting plate 1, the axial length of the first diameter section and the axial length of the second diameter section are greater than the length of the inner die 4.

[0038] Specifically, as Figure 2 shown, in the thickness direction of the mounting plate 1, the length of the first diameter section is greater than the length of the inner die 4. When the inner die 4 is completely located in the first diameter section, the arc surfaces where the outer peripheries of each inner die 4 are located are all parallel to the axial direction of the guide shaft 3, and the inner periphery of the steel pipe 11 is also parallel to the axial direction of the guide shaft 3. In this way, the inner periphery of the steel pipe 11 fits more closely with the outer peripheries of each inner die 4, effectively preventing the steel pipe 11 from shaking.

[0039] It should be understood that when the inner die 4 is in the first diameter section, the inner boss forming operation of the steel pipe 11 is completed. When the steel pipe 11 moves away from the mounting plate 1 in the thickness direction of the mounting plate 1, the steel pipe 11 drives the inner die 4 to move axially along the guide shaft 3 through the cooperation of the inner boss and the concave part, passes through the diameter change section and completely enters the second diameter section. As Figure 5 and Figure 6 shown, at this time, the concave part on the inner die 4 is separated from the corresponding inner boss on the steel pipe 11, and the steel pipe 11 moving in the thickness direction of the mounting plate 1 cannot drive the inner die 4 to move. The inner die 4 falls back into the first diameter section by its own gravity. At this time, the formed steel pipe 11 is separated from the inner die 4, and then the forming operation of the next steel pipe 11 can be carried out.

[0040] Among them, when the inner die 4 passes through the diameter transformation section, the elastic ring 5 always presses each inner die 4, so that each inner die 4 closely adheres to the guide shaft 3, that is, when each inner die 4 passes through the diameter transformation section, each inner die 4 approaches each other, and the inner boss on the steel pipe 11 does not change, so that the concave part on each inner die 4 is gradually separated from the corresponding inner boss. When the inner die 4 is in the second diameter section, the distance between the concave part on each inner die 4 and the corresponding inner boss reaches the maximum. As Figure 6 shown, at this time, the steel pipe 11 can be separated from the inner die 4.

[0041] It should be noted that the diameter change of the guide shaft 3 at each position in its own axial direction is continuous. In other words, there is no stepped surface on the guide shaft 3.

[0042] Reference Figure 2 , in an exemplary embodiment, the diameter of the positioning shaft 2 is greater than the diameter of the first diameter section and less than the inner diameter of the steel pipe 11; when the inner mold 4 abuts against the positioning shaft 2, the recessed part is located on the moving path of the corresponding protruding part.

[0043] Specifically, when the diameter of the positioning shaft 2 is greater than the diameter of the first diameter section and less than the inner diameter of the steel pipe 11, when the inner mold 4 returns to the first diameter section, it will abut against the positioning shaft 2, preventing the inner mold 4 from detaching from the guide shaft 3.

[0044] Furthermore, that is, when the inner mold 4 returns to the first diameter section, it will abut against the positioning shaft 2. At this time, the recessed part is located on the moving path of the corresponding protruding part. In other words, at this time, a new steel pipe 11 can be directly sleeved on the outer periphery of the inner mold 4 to perform a new round of inner boss forming operation on the steel pipe 11, without adjusting the position of the inner mold 4, making it more efficient to use.

[0045] Reference Figure 1 and Figure 5 , in an exemplary embodiment, the steel pipe inner boss forming device may further include a limiting piece 31 and a spring 32. The limiting piece 31 is fixed to one end of the guide shaft 3 away from the positioning shaft 2; the spring 32 is sleeved on the outer periphery of the guide shaft 3, one end of the spring 32 is connected to each inner mold 4, and the other end of the spring 32 is connected to the limiting piece 31.

[0046] Specifically, as Figure 1 shown, the spring 32 is always in a compressed state. As Figure 1 shown, when the inner mold 4 abuts against the positioning shaft 2, the spring 32 always gives the inner mold 4 a force close to the positioning shaft 2, so that the recessed part on the inner mold 4 is on the moving path of the protruding part, effectively preventing the inner mold 4 from shaking.

[0047] As Figure 5 shown, when the inner mold 4 moves into the second diameter section, the steel pipe 11 is separated from the inner mold 4, and the spring 32 will push the inner mold 4 to move axially along the guide shaft 3 and abut against the positioning shaft 2. At this time, the subsequent inner boss forming operation of the steel pipe 11 can be carried out; thus, when the steel pipe 11 is separated from the inner mold 4, the inner mold 4 can move into the first diameter section through the spring 32 without relying on the gravity of the inner mold 4 to slide down. Then, when using this steel pipe inner boss forming device, the thickness direction of the mounting plate 1 does not need to be limited and can be installed and used according to the actual situation.

[0048] Reference Figure 5, in an exemplary embodiment, in the thickness direction of the mounting plate 1, the sum of the minimum length of the spring 32 and the length of the inner mold 4 is less than the length of the second diameter section.

[0049] Specifically, when the spring 32 is compressed to the state as shown in Figure 5 , in the thickness direction of the mounting plate 1, the length of the spring 32 reaches the minimum. Here, the minimum length of the spring 32 can be understood as the minimum working length of the spring 32, and the sum of the minimum length of the spring 32 and the length of the inner mold 4 is less than the length of the second diameter section. Thus, the inner mold 4 can be completely within the second diameter section, so that the recess on the inner mold 4 is completely separated from the inner boss on the steel pipe 11, and finally the steel pipe 11 is separated from the inner mold 4.

[0050] Refer to Figure 2 and Figure 4 , in an exemplary embodiment, multiple chutes extending along the axial direction of the guide shaft 3 are provided on the outer periphery of the guide shaft 3; the multiple chutes correspond to multiple inner molds 4 one by one; the steel pipe inner boss forming device may further include multiple limit pins 41, and the multiple limit pins 41 are fixedly arranged on the side of each inner mold 4 in contact with the guide shaft 3 one by one and the axial direction is the same as the radial direction of the guide shaft 3, and each limit pin 41 is inserted into the corresponding chute and is in sliding fit with the corresponding chute.

[0051] Specifically, as shown in Figure 2 and Figure 4 , limit pins 41 are fixedly arranged on the inner periphery of each inner mold 4, and the limit pins 41 are in sliding fit with the corresponding chutes on the guide shaft 3. When each inner mold 4 moves along the axial direction of the guide shaft 3, each limit pin 41 slides in the corresponding chute, and the limit pin 41 abuts against the side wall of the corresponding chute. Thus, when the steel pipe 11 is sleeved on the outer periphery of each inner mold 4, the inner mold 4 cannot rotate around the axial direction of the guide shaft 3, that is, the recess is always on the moving path of the protrusion, so that the recess and the protrusion can cooperate to extrude and form an inner boss on the steel pipe 11.

[0052] In an exemplary embodiment, when the inner mold 4 is in contact with the guide shaft 3, the length of the limit pin 41 is less than the depth of the chute.

[0053] Specifically, the depth direction of the chute is the same as the radial direction of the guide shaft 3, then the depth of the chute refers to the length of the chute in the radial direction of the guide shaft 3. When the length of the limit pin 41 is less than the depth of the chute, when the inner mold 4 drives the limit pin 41 to move, the limit pin 41 will not be pushed by the chute to generate a displacement in the radial direction of the guide shaft 3, ensuring that the inner mold 4 is always in contact with the guide shaft 3. Among them, the depth of the chute in the first diameter section, the depth of the variable section, and the depth of the second diameter section can be the same.

[0054] It should be understood that, as shown in Figure 2As shown, if the limit pin 41 is fixed to the inner circumference of the inner mold 4 by embedding, the length of the limit pin 41 here refers to the length that the limit pin 41 extends out of the inner mold 4 along its axial direction, rather than the overall length of the limit pin 41.

[0055] Reference Figure 2 , in an exemplary embodiment, arc-shaped through grooves are provided on the outer periphery of each inner mold 4, and the elastic ring 5 passes through the arc-shaped through grooves on each inner mold 4.

[0056] Specifically, as Figure shown, the arc-shaped through grooves on each inner mold 4 correspond end to end, and the elastic ring 5 passes through the arc-shaped through grooves on each inner mold 4. In this way, when the outer periphery of the inner mold 4 is in contact with the side wall of the steel pipe 11, it will not be affected by the elastic ring 5, and when the steel pipe 11 is sleeved on the outer periphery of the inner mold 4 or separated from the inner mold 4, it will not cause the elastic ring 5 to move along the axial direction of the guide shaft 3, ensuring the use effect of the elastic ring 5.

[0057] Furthermore, as ​ shown, there are two elastic rings 5, and the two elastic rings 5 are respectively close to the opposite ends of the inner mold 4 in the thickness direction of the mounting plate 1. In this way, the two elastic rings 5 can clamp each inner mold 4 and the guide shaft 3 more tightly and evenly, and the fitting effect between the inner mold 4 and the guide shaft 3 is better.

[0058] Reference ​ , in an exemplary embodiment, the steel pipe inner boss forming device may further include a positioning ring 8, and the positioning ring 8 is sleeved on the outer periphery of the positioning shaft 2 and abuts against one end of the steel pipe 11; wherein, the outer diameter of the steel pipe 11 is greater than the inner diameter of the positioning ring 8 and less than the outer diameter of the positioning ring 8.

[0059] Specifically, as ​ shown, the positioning ring 8 is located inside the hydraulic chuck. When the steel pipe 11 is sleeved on the outer periphery of the inner mold 4, one end of the steel pipe 11 close to the mounting plate 1 abuts against the positioning ring 8. In this way, by adjusting the length of the positioning ring 8 along its axial direction, the distance between the finally processed inner boss on the steel pipe 11 and one end of the steel pipe 11 close to the mounting plate 1 can be changed, facilitating the control of the processing position of the inner boss on the steel pipe 11.

[0060] Among them, adjusting the length of the positioning ring 8 along its axial direction can be achieved by increasing or decreasing the number of positioning rings 8. The axial directions of multiple positioning rings 8 are the same and they are all sleeved on the outer periphery of the positioning shaft 2. When the number of positioning rings 8 increases, the length of multiple positioning rings 8 along their axial direction increases, and the distance between the inner boss on the steel pipe 11 and one end of the steel pipe 11 close to the mounting plate 1 becomes smaller; when the number of positioning rings 8 decreases, the length of multiple positioning rings 8 along their axial direction decreases, and the distance between the inner boss on the steel pipe 11 and one end of the steel pipe 11 close to the mounting plate 1 becomes larger.

[0061] The above are only the preferred embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, shall be similarly included in the patent protection scope of the present application.

Claims

1. A steel pipe inner boss forming device, characterized in that: Used for processing and forming an inner boss of a steel pipe (11), the steel pipe inner boss forming device comprises: Mounting plate (1); A positioning shaft (2) is arranged on one side of the mounting plate (1) and has an axial direction that is in the same direction as the thickness of the mounting plate (1); A guide shaft (3) is provided at one end of the positioning shaft (2) away from the mounting plate (1) and has an axial direction that is the same as that of the positioning shaft (2); the diameter of the end of the guide shaft (3) away from the positioning shaft (2) is smaller than the diameter of the other end; A plurality of inner molds (4) are arranged at intervals on the periphery of the guide shaft (3) in the circumferential direction of the guide shaft (3) and have the freedom to move along the axial direction of the guide shaft (3); the outer periphery of each inner mold (4) is sleeved with the steel pipe (11) and each inner mold (4) is provided with a recessed portion; An elastic ring (5) is sleeved on the outer circumference of each inner mold (4) and provides a force for each inner mold (4) to fit the guide shaft (3); A driving portion (6) is sleeved on the outer circumference of the positioning shaft (2); A plurality of outer punches (7) are arranged in one-to-one correspondence with the plurality of inner dies (4) and are disposed on a side of the driving portion (6) away from the mounting plate (1); the outer punches (7) move radially along the positioning shaft (2) in response to a driving force of the driving portion (6) to cooperate with the corresponding recessed portions on the inner dies (4) to press out an inner boss on the steel pipe (11); A limiting piece (31) is fixed to an end of the guide shaft (3) away from the positioning shaft (2); A spring (32) is sleeved on the outer periphery of the guide shaft (3), one end of the spring (32) is connected to each of the inner molds (4), and the other end of the spring (32) is connected to the limiting piece (31); The guide shaft (3) is divided into a first diameter section, a diameter change section, and a second diameter section in sequence in a direction away from the positioning shaft (2), and the diameter of the first diameter section is larger than the diameter of the second diameter section; In the thickness direction of the mounting plate (1), the axial length of the first diameter section and the axial length of the second diameter section are both greater than the length of the inner mold (4).

2. The steel pipe inner boss forming device according to claim 1, characterized in that: The outer punch (7) comprises: A moving part (71) connected to the driving part (6); An extrusion rod (72) is fixed to a side of the moving portion (71) away from the driving portion (6) and extends in the same direction as its own moving direction. An end of the extrusion rod (72) close to the inner mold (4) extends out of the moving portion (71) and is provided with a protrusion that cooperates with the recessed portion.

3. The steel pipe inner boss forming device according to claim 2, characterized in that: The diameter of the positioning shaft (2) is larger than the diameter of the first diameter section and smaller than the inner diameter of the steel pipe (11); When the inner mold (4) contacts the positioning shaft (2), the recessed portion is located on a moving path corresponding to the raised portion.

4. The steel pipe inner boss forming device according to claim 1, characterized in that: In the thickness direction of the mounting plate (1), the sum of the minimum length of the spring (32) and the length of the inner mold (4) is less than the length of the second diameter section.

5. The steel pipe inner boss forming device according to claim 1, characterized in that: The outer periphery of the guide shaft (3) is provided with a plurality of slide grooves extending along its axial direction, and the plurality of slide grooves correspond one-to-one to the plurality of inner molds (4); the steel pipe inner boss forming device further includes: A plurality of limit pins (41) are fixed one by one on the side of each inner mold (4) that fits the guide shaft (3) and the axial direction is the same as the radial direction of the guide shaft (3). Each limit pin (41) is inserted into the corresponding slide groove and slides with the corresponding slide groove.

6. The steel pipe inner boss forming device according to claim 5, characterized in that: When the inner mold (4) is fitted with the guide shaft (3), the length of the limit pin (41) is smaller than the depth of the slide groove.

7. The steel tube inner boss forming device according to claim 1, characterized in that: The outer periphery of each inner mold (4) is provided with an arc-shaped through groove, and the elastic ring (5) passes through the arc-shaped through groove on each inner mold (4).

8. The steel pipe inner boss forming device according to claim 1, characterized in that: The steel tube inner boss forming device also includes: A positioning ring (8) is sleeved on the outer periphery of the positioning shaft (2) and contacts one end of the steel pipe (11); Wherein, the outer diameter of the steel pipe (11) is larger than the inner diameter of the positioning ring (8) and smaller than the outer diameter of the positioning ring (8).

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