An expander and an internal rotation extrusion molding device

Abstract

This invention relates to the field of pipe forming and processing equipment, specifically an expander and an internal rotation extrusion forming device. The expander includes a mandrel and a retainer; the retainer has a through hole into which the mandrel is inserted; the mandrel includes a tapered section near its front end; the retainer includes a small-diameter section near the front end and a large-diameter section away from the front end; a limiting ring is fitted externally on the side of the small-diameter section away from the front end; a planar thrust bearing is provided between the limiting ring and the large-diameter section; a receiving groove is provided on the side of the small-diameter section near the front end, and needle rollers are installed in the receiving groove; the number of receiving grooves is two or more. After the guide tube contacts the limiting ring, it remains relatively stationary, and the assembly serves as a support frame, reducing weight. The wobbling is reduced when the mandrel rotates, and the radial resultant force of the needle rollers working together facilitates the coaxial automatic alignment of the expander and the guide tube.

Description

Technical Field

[0001] This invention relates to the field of pipe forming and processing equipment technology, and in particular to an expander and an internal rotation extrusion forming device. Background Technology

[0002] Roll forming involves using a circumferentially rolling roller to apply radial force, pressing the pipe wall material into a grooved sleeve, thereby connecting the conduit and the sleeve. Internal rotation extrusion forming equipment is used for expanding the inner diameter of the pipe during pipe forming.

[0003] Existing internal rotation extrusion molding equipment, such as Chinese Patent No. CN208810960U, discloses an internal rotation extrusion molding device, in which the expander includes a mandrel, a retainer, and a housing. In use, the housing needs to be fixed on the expander moving assembly. First, the front end of the retainer is inserted into the designated position inside the guide tube. Then, the mandrel is driven to rotate, so that the mandrel slowly moves forward to extrude the guide tube.

[0004] In the aforementioned equipment, due to the heavy weight of components such as the housing, they must be fixed to the expander's moving assembly to achieve alignment between the expander and the guide tube. However, the expander's moving assembly is large and immobile, which hinders the flexible use of the internal rotation extrusion molding device and limits its applicable scenarios. Summary of the Invention

[0005] The purpose of this invention is to address the problem that existing expanders rely on expander moving components, and to provide an expander that reduces weight through structural optimization, reduces wobbling when the mandrel is connected to the power mechanism for rotation, and incorporates multiple rollers that act simultaneously on the inner wall of the catheter, with the radial resultant force enabling coaxial alignment of the expander and the catheter. This avoids the use of expander moving components, achieving a lightweight and flexible expander.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] An expander includes a mandrel and a retainer; the retainer has a through hole, the mandrel is inserted into the through hole, and one end of the expander inserted into a conduit is a front end;

[0008] The mandrel includes a tapered section near the front end, the diameter of which gradually decreases in the direction pointing towards the front end; the retainer includes a small-diameter section near the front end and a large-diameter section away from the front end; a limiting ring is fitted around the side of the small-diameter section away from the front end; a planar thrust bearing is provided between the limiting ring and the large-diameter section; a receiving groove is provided on the side of the small-diameter section near the front end, and a needle roller is provided in the receiving groove; the number of receiving grooves is two or more.

[0009] In use, the catheter to be expanded is inserted from the front end. After the catheter end face contacts the limiting ring, the friction between the catheter and the limiting ring increases, keeping the limiting ring and catheter relatively stationary. The planar thrust bearing reduces the friction between the retainer and the limiting ring, with only the main body of the retainer rotating. The combination of the catheter and the limiting ring acts as a support frame, eliminating the need for moving components in the expander and thus reducing the overall weight of the device. With the reduced weight, only the rear end of the mandrel is connected to the power mechanism. When the mandrel rotates, the effects of gravity and inertia on the device are reduced, decreasing overall device sway and facilitating automatic self-alignment of the mandrel and catheter. The radial resultant force of the needle rollers working together further facilitates coaxial automatic self-alignment of the expander and catheter. This makes the entire device lightweight and suitable for various applications.

[0010] As a preferred embodiment of the present invention, the number of the receiving slots is 3 to 5.

[0011] In a preferred embodiment of the present invention, the small-diameter section is provided with a positioning groove, and the limiting ring is provided with an insertion hole, in which a positioning pin is provided; one end of the positioning pin extends into the positioning groove. The positioning pin and the positioning groove define the position of the limiting ring. The limiting ring is fitted onto the small-diameter section and can rotate relative to the retainer. When the limiting ring is not in contact with the guide tube, the limiting ring rotates together with the retainer; when the limiting ring is relatively stationary under the frictional force of the guide tube, the retainer and the limiting ring rotate relative to each other.

[0012] As a preferred embodiment of the present invention, the axial direction of the needle roller is at an angle to the axial direction of the mandrel, and the angle is in the range of 1° to 60°.

[0013] As a preferred embodiment of the present invention, a plurality of the receiving grooves are evenly distributed circumferentially along the small diameter section.

[0014] As a preferred embodiment of the present invention, the planar thrust bearing is a needle roller planar thrust bearing. Using a needle roller planar thrust bearing allows for greater axial force, further reducing the resistance between the limiting ring and the cage. Combined with the reduction in resistance due to weight reduction, this enables the entire system to meet the resistance requirements of processing more specifications of conduits.

[0015] In a preferred embodiment of the invention, the mandrel includes a cylindrical segment on the side away from the front end, the outer diameter of which is adapted to the inner diameter of the cage. The outer diameter of the cylindrical segment is slightly smaller than the inner diameter of the cage. This allows the cylindrical segment to provide support for the rear end of the cage; the combination of the guide tube and the limiting ring provides support for the front end of the cage; thereby reducing device sway.

[0016] In a preferred embodiment of the present invention, a limiting protrusion is provided on the cylindrical section, the limiting protrusion being located on the outer side of the retainer away from the front end. The limiting protrusion prevents the mandrel from being inserted into the retainer beyond a preset distance. Furthermore, the limiting protrusion prevents the retainer from detaching from the rear end of the mandrel.

[0017] In a preferred embodiment of the present invention, a blocking member is provided at the front end of the mandrel, and the projection of the outer periphery of the blocking member on the retainer is located within the end face of the small-diameter section. The blocking member can prevent the retainer from falling off the front end of the mandrel, and together with the limiting protrusion, the mandrel and the retainer form a whole, so that the retainer will not separate from the mandrel during movement, which is convenient for operation.

[0018] In a preferred embodiment of the present invention, the blocking member is a circular piece, the diameter of which is larger than the inner diameter of the retainer and smaller than the outer diameter of the small-diameter section. Setting the blocking member as a circular piece also serves as a guide when the front end is inserted into the conduit.

[0019] An internal rotation extrusion molding apparatus includes a power mechanism and an expander as described above. The power mechanism is capable of driving a mandrel to rotate. The power mechanism has a connecting port, and the rear end of the mandrel has a connecting section. After the connecting section is inserted into the connecting port, there is a circumferential gap between the connecting section and the connecting port. After the expander is assembled to the power mechanism, the gap between the components allows for slight wobbling. During use, it cooperates with the needle roller at the front end, facilitating automatic self-alignment.

[0020] As a preferred embodiment of the present invention, the connecting section is a square shaft and the connecting port is a square opening.

[0021] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0022] 1. In the expander of this invention, after the guide tube contacts the limiting ring, the limiting ring and the guide tube remain relatively stationary, with only the main body of the retainer rotating. The combination of the guide tube and the limiting ring acts as a support frame, eliminating the need for moving components in the expander and thus reducing the weight of the entire device. During mandrel rotation, the effects of gravity and inertia on the device are reduced, decreasing overall device sway. The radial resultant force from the combined action of the needle rollers facilitates the coaxial self-alignment of the expander and the guide tube. This results in a lightweight device suitable for various applications.

[0023] 2. The expander of the present invention, with a fixed power mechanism, expands the range of processes that can be performed with the same power due to the reduced weight of the expander. It can be applied to the expansion of conduits of different diameters, and also to different filling ratio requirements for the same specification.

[0024] 3. The expander of the present invention, by setting a limiting protrusion at the rear end of the mandrel and a blocking member at the front end of the mandrel, makes the mandrel and the retainer form an integral whole, so that the retainer will not separate from the mandrel during movement, which is convenient for operation.

[0025] 4. In the internal rotation extrusion molding device of the present invention, after the expander is assembled to the power mechanism, there is a gap between the components, which can be slightly shaken. During use, it cooperates with the front needle roller to facilitate automatic self-alignment. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of the expander of the present invention.

[0027] Figure 2 This is a schematic front view of the expander of the present invention.

[0028] Figure 3 yes Figure 2 A schematic diagram of the cross-section at point AA.

[0029] Figure 4 This is an exploded view of the expander of the present invention.

[0030] Icons: 1-Mandrel; 11-Conical section; 12-Cylindrical section; 13-Limiting protrusion; 14-Blocking element; 15-Screw; 16-Connecting section; 2-Cage; 21-Small diameter section; 22-Large diameter section; 23-Receiving groove; 3-Limiting ring; 31-Positioning pin; 4-Planar thrust bearing; 5-Needle roller. Detailed Implementation

[0031] The present invention will now be described in detail with reference to the accompanying drawings.

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0033] Example 1

[0034] An expander, such as Figure 1 , Figure 2 As shown, the dilator has a front end for inserting a catheter; it includes a mandrel 1 and a retainer 2; Figure 2 The right side is the front end. The retainer 2 has a through hole, and the mandrel 1 is inserted into the through hole; the end of the expander inserted into the guide tube is the front end.

[0035] The mandrel 1 includes a tapered section 11 near the front end, the diameter of which gradually decreases in the direction pointing towards the front end. The retainer 2 includes a small-diameter section 21 near the front end and a large-diameter section 22 away from the front end. A limiting ring 3 is fitted around the side of the small-diameter section 21 away from the front end. A planar thrust bearing 4 is provided between the limiting ring 3 and the large-diameter section 22. A plurality of receiving grooves 23 are provided on the side of the small-diameter section 21 near the front end, and needle rollers 5 are provided in the receiving grooves 23. The number of receiving grooves 23 is two or more. In this embodiment, the number of receiving grooves 23 is three. In other embodiments, the number can also be four, five, or six. Usually, all components are made of stainless steel, and due to the influence of material properties, a number of three is optimal. The small-diameter section 21 of the retainer 2 is at least smaller than the inner diameter of the conduit, and the outer diameter of the large-diameter section 22 is at least larger than the outer diameter of the conduit. In this embodiment, the outer diameter of the limiting ring 3 is the same as the diameter of the large-diameter section 22. The retainer 2 is a structural component with a through hole through which the mandrel 1 passes.

[0036] The axial direction of the needle roller 5 forms an angle with the axial direction of the mandrel 1, the angle ranging from 1° to 60°. Several receiving grooves 23 are evenly distributed circumferentially along the small diameter section 21. The planar thrust bearing is a needle roller type planar thrust bearing. Using a needle roller type planar thrust bearing allows for greater axial force, further reducing the resistance between the limiting ring and the cage. Combined with the reduction in resistance due to weight reduction, this allows the entire assembly to meet the resistance requirements of more specifications of conduit processing.

[0037] The mandrel 1 includes a cylindrical segment 12 on the side away from the front end, the outer diameter of which is adapted to the inner diameter of the retainer 2. The diameter of the through hole in the retainer is the same as the inner diameter of the retainer 2. The outer diameter of the cylindrical segment 12 is slightly smaller than the inner diameter of the retainer 2. This allows the cylindrical segment 12 to provide support for the rear end of the retainer 2; the combination of the guide tube and the limiting ring provides support for the front end of the retainer; thereby reducing the swaying of the device.

[0038] The cylindrical section 12 is provided with a limiting protrusion 13, which is located on the outer side of the retainer 2 away from the front end. The limiting protrusion 13 prevents the mandrel from being inserted into the retainer beyond a preset distance. Furthermore, the limiting protrusion 13 prevents the retainer 2 from detaching from the rear end of the mandrel 1. The front end of the mandrel 1 is provided with a blocking member 14, the projection of the outer periphery of the blocking member 14 onto the retainer 2 being located within the end face of the small-diameter section. The blocking member 14 prevents the retainer 2 from detaching from the front end of the mandrel 1. Combined with the limiting protrusion 13, this ensures that the mandrel 1 and the retainer 2 form a single unit, preventing the retainer from separating from the mandrel during movement, thus facilitating operation. Specifically, the blocking member 14 is a circular disc with a diameter larger than the inner diameter of the retainer 2 and a diameter smaller than the outer diameter of the small-diameter section 21. The circular shape of the blocking member 14 also serves as a guide when the front end is inserted into the conduit. In practice, the blocking member 14 can be fixed to the front end of the mandrel 1 using screw 15.

[0039] Exploded view of the structure as follows Figure 4 As shown, the small diameter section 21 is provided with a positioning groove, and the limiting ring 3 is provided with an insertion hole, in which a positioning pin 31 is provided; one end of the positioning pin 31 extends into the positioning groove. The positioning pin and the positioning groove are used to limit the position of the limiting ring 3.

[0040] The limiting ring 3 is fitted onto the small-diameter section 21 and can rotate relative to the retainer 2. When the limiting ring 3 is not in contact with the conduit, it rotates together with the retainer 2; when the limiting ring is relatively stationary due to the friction of the conduit, the retainer and the limiting ring rotate relative to each other. In use, the conduit to be expanded is inserted from the front end. After the conduit contacts the limiting ring 3, the friction between the conduit and the limiting ring 3 increases, and the limiting ring 3 and the conduit remain relatively stationary, with only the main body of the retainer 2 rotating. The combination of the conduit and the limiting ring 3 acts as a support frame, avoiding the use of expander moving components, thereby reducing the weight of the entire device. With the reduced weight, only the rear end of the mandrel 1 is connected to the power mechanism. When the mandrel 1 rotates, the influence of the device's gravity and inertia is reduced, the overall sway of the device is reduced, and it is beneficial for the automatic alignment of the mandrel 1 and the conduit, achieving coaxiality between the mandrel and the conduit. This makes the entire device lightweight and suitable for various application scenarios.

[0041] Example 2

[0042] An internal rotation extrusion molding apparatus includes a power mechanism and an expander as described in Embodiment 1. The power mechanism is capable of driving a mandrel 1 to rotate. The power mechanism has a connecting port, and the rear end of the mandrel has a connecting section. After the connecting section is inserted into the connecting port, there is a circumferential gap between the connecting section and the connecting port. After the expander is assembled to the power mechanism, there is a gap between the components, allowing for slight wobbling. During use, it cooperates with the needle roller at the front end, facilitating automatic self-alignment. The connecting section is a square shaft, and the connecting port is a square opening.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An internal rotation extrusion molding apparatus, characterized in that, The device includes a power mechanism and an expander, the expander comprising a mandrel (1) and a retainer (2); the retainer (2) has a through hole, the mandrel (1) is inserted into the through hole; one end of the expander inserted into the conduit is the front end; The core rod (1) includes a tapered segment (11) near the front end, the diameter of which gradually decreases in the direction pointing towards the front end; The retainer (2) includes a small diameter section (21) near the front end and a large diameter section (22) away from the front end; a limiting ring (3) is sleeved on the side of the small diameter section (21) away from the front end, and the limiting ring (3) can rotate relative to the retainer (2); The outer diameter of the limiting ring (3) is the same as the diameter of the large diameter section (22); A planar thrust bearing (4) is provided between the limiting ring (3) and the large diameter section (22); The small diameter section (21) is provided with a receiving groove (23) on the side near the front end, and a needle roller (5) is provided in the receiving groove (23); The number of the receiving slots (23) is two or more; The mandrel (1) includes a cylindrical section (12) on the side away from the front end, the outer diameter of the cylindrical section (12) being adapted to the inner diameter of the retainer (2); The cylindrical section (12) is provided with a limiting protrusion (13), which is located on the outer side of the retainer (2) away from the front end; The front end of the mandrel (1) is provided with a blocking member (14), and the projection of the outer periphery of the blocking member (14) on the retainer (2) is located within the end face of the small diameter section (21); The blocking member (14) is a circular piece, the diameter of which is greater than the inner diameter of the retainer (2) and the diameter of which is smaller than the outer diameter of the small diameter section (21); The axial direction of the needle roller (5) is at an angle to the axial direction of the mandrel (1), and the angle is in the range of 1° to 60°. The small diameter section (21) is provided with a positioning groove, the limiting ring (3) is provided with an insertion hole, and a positioning pin (31) is provided in the insertion hole; one end of the positioning pin (31) extends into the positioning groove; The power mechanism can drive the mandrel (1) to rotate; The power mechanism is provided with a connection port, and the rear end of the core rod (1) is provided with a connection section (16). After the connection section (16) is inserted into the connection port, there is a gap between the connection section (16) and the connection port in the circumferential direction of the connection section.

2. The internal rotation extrusion molding apparatus according to claim 1, characterized in that, The number of the receiving slots (23) is 3 to 5.

3. The internal rotation extrusion molding apparatus according to claim 1, characterized in that, The planar thrust bearing (4) is a needle roller planar thrust bearing.

4. The internal rotation extrusion molding apparatus according to claim 1, characterized in that, Several of the receiving grooves (23) are evenly distributed circumferentially along the small diameter section (21).

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