Double-cavity tube double-bend mold structure

Abstract

This invention discloses a double-cavity tube double-bending die structure, including an inner cavity bending mechanism and an outer cavity bending mechanism. The inner cavity bending mechanism includes a first wheel die, a first clamping die, and a first guiding die. The first wheel die has a first wheel shaft hole and an arc-shaped first tube groove with a semi-circular cross-section. The outer cavity bending mechanism includes a second wheel die, a second clamping die, and a second guiding die. The second wheel die has a second wheel shaft hole and a third tube groove. The double-cavity tube double-bending die structure of this invention uses bending dies to process both the inner and outer cavities. When bending the inner cavity using a tube bending machine, bending radii of different sizes of tubes can be processed, with minimal deformation of the inner and outer cavities. The clamping die provides fixation during inner and outer cavity bending, preventing twisting of the inner and outer cavities. The bending die design is simple, production operation is easy, and processing costs are low.

Description

Technical Field

[0001] This invention belongs to the field of single-beam bicycle technology, and in particular relates to a double-cavity tube double bending die structure. Background Technology

[0002] Single-beam bicycles are very common, but their frame strength is still weaker than that of double-beam bicycles, especially electric bicycles, where the strength cannot meet the requirements. Therefore, in the design, designers use double-cavity tubing to enhance its strength. The outer cavity of the double-cavity tubing is the main beam, and the inner cavity is the reinforcing tube. A small cavity is made between the inner and outer cavities. Cutting through the small cavity results in two cavities, and the inner cavity is then opened up to form the reinforcing tube.

[0003] In order to pry open the inner cavity in the machining room, the existing method is to use CNC machining equipment to cut the double-cavity tube in the middle, then use a tube expanding press to open a prying mold, use a tube expanding mandrel to pry open the inner cavity, and then open a bending mold to bend the outer cavity.

[0004] Existing methods for opening double-cavity tubes have requirements for the opening arc and opening radius. If the radius is too small or the opening is too large, the inner cavity will deform or sink. During opening, the inner and outer cavities cannot be fixed and are prone to twisting. The outer cavity bending mold design is complex and costly. Summary of the Invention

[0005] The technical problem to be solved by this invention is: This invention utilizes a pipe bending machine to design a pipe bending structure mold, and all inner and outer cavities are processed using the pipe bending mold. The bending radius of both the inner and outer cavities of the double-cavity pipe can be processed. The inner and outer cavities are fixed by clamping molds during pipe bending, and there is no twisting phenomenon in the inner and outer cavities.

[0006] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: a double-cavity tube double-bending mold structure, including an inner cavity tube bending mechanism and an outer cavity tube bending mechanism;

[0007] The internal tube bending mechanism includes a first wheel mold, a first clamping mold, and a first guide mold. The first wheel mold has a first wheel shaft hole and an arc-shaped first tube groove with a semi-circular cross-section. The first clamping mold has a straight second tube groove with a semi-circular cross-section and a first fixing key. The first fixing key has a first pin hole. The first guide mold has a stepped pressure plate. The left side of the stepped pressure plate is flush with the left side of the first clamping mold. The lower end of the stepped pressure plate is in contact with the first clamping mold. The first clamping mold and the first guide mold are fixedly installed on the first tube bending machine. The first clamping mold is fixedly installed on the first tube bending machine through the first pin hole (i.e., a pin) on its first fixing key. The first wheel mold is sleeved and fixedly installed on the drive shaft of the first tube bending machine through the first wheel shaft hole.

[0008] The external cavity bending mechanism includes a second wheel mold, a second clamping mold, and a second guide mold. The second wheel mold is provided with a second wheel shaft hole and a third pipe groove. The rear end section of the third pipe groove is a semi-circular structure, and the front end section is a planar structure that matches the external cavity branch pipe. The second clamping mold is provided with a fourth pipe groove with a semi-circular cross section and a second fixing key. The second fixing key is provided with a second pin hole. The second guide mold is provided with a fifth pipe groove corresponding to the structure of the fourth pipe groove. The second clamping mold and the second guide mold are fixedly installed on the second bending machine platform. The second clamping mold is fixedly installed on the second bending machine platform through the second pin hole and pin on its second fixing key. The second wheel mold is sleeved and fixedly installed on the drive shaft of the second bending machine through the second wheel shaft hole. The second wheel mold is also provided with an internal cavity pipe groove.

[0009] Preferably, the radius of the first, second, third, fourth, and fifth pipe grooves is 0.5mm-1mm smaller than the radius of the pipe material.

[0010] Preferably, the opening edge of the first tube groove of the first wheel mold is provided with an arc-shaped first wedge groove corresponding to its arc structure, and the opening edge of the second tube groove of the first clamping mold and the left side plate of the first guide mold are provided with a straight first wedge boss and a fourth wedge boss that cooperate with the first wedge groove.

[0011] The opening edge of the third tube groove of the second wheel mold is provided with an arc-shaped second wedge groove corresponding to its arc structure. The opening edges of the fourth and fifth tube grooves are provided with a straight second wedge boss and a third wedge boss that cooperate with the second wedge groove.

[0012] Preferably, the first wheel mold has an arc-shaped guide groove that is identical to the arc-shaped structure of the first tube groove.

[0013] Preferably, the first guide mold is provided with a first positioning slot.

[0014] Preferably, the second guide mold is provided with a second positioning slot.

[0015] Preferably, the second mold is provided with a mold keyway, which is fixedly connected to a disc on the drive shaft of the second pipe bending machine by a key.

[0016] Preferably, the first wheel mold is provided with wheel mold steps.

[0017] Compared with the prior art, the advantages of the present invention are: the inner and outer cavities of the double-cavity tube double-bending die structure of the present invention are all processed by the tube bending die. When the tube is bent by the inner cavity of the tube bending machine, the bending radius of the inner and outer cavities of tubes of different sizes can be processed, and the deformation of the inner and outer cavities is small. When the inner and outer cavities are bent by the tube bending machine, there is a clamping die to fix them, and there is no twisting phenomenon in the inner and outer cavities. The tube bending die design is simple, the production operation is easy, and the processing cost is low. Attached Figure Description

[0018] The invention will be further described below with reference to the accompanying drawings.

[0019] Figure 1 This is a three-dimensional structural diagram of the internal tube bending mechanism clamping the tube material from a horizontal perspective.

[0020] Figure 2 This is a three-dimensional structural diagram of the internal tube bending mechanism.

[0021] Figure 3 This is a three-dimensional structural diagram of the internal tube bending mechanism clamping the tube material from a top-down perspective.

[0022] Figure 4 This is a top view of an internal tube bending mechanism that clamps and fixes the tube material.

[0023] Figure 5 This is a rear view of the internal tube bending mechanism.

[0024] Figure 6 This is the front view of the internal tube bending mechanism.

[0025] Figure 7 This is a three-dimensional structural diagram of the external cavity bending mechanism for clamping the pipe material.

[0026] Figure 8 This is a schematic diagram of the structure in which the first curved structure is embedded and installed in the material groove of the inner cavity of the second mold.

[0027] Figure 9 This is the front view of the second guide module.

[0028] Figure 10 This is the right view of the second guide module.

[0029] Figure 11 This is the front view of the second clamping mold.

[0030] Figure 12 This is the right view of the second clamping mold.

[0031] Figure 13 This is a schematic diagram of the processing steps for pipe materials. Detailed Implementation

[0032] The present invention will now be described in detail with reference to specific embodiments:

[0033] A double-cavity tube double-bending mold structure includes an inner cavity tube bending mechanism and an outer cavity tube bending mechanism;

[0034] The internal tube bending mechanism includes a first wheel mold 11, a first clamping mold 12, and a first guide mold 13. The first wheel mold 11 is provided with a first wheel shaft hole 111 and an arc-shaped first tube groove 113 with a semi-circular cross-section. The first clamping mold 12 is provided with a straight second tube groove 122 with a semi-circular cross-section and a first fixing key 123. The first fixing key 123 is provided with a first pin hole 124. The first guide mold 13 is provided with a stepped pressure plate 133. The left side of the stepped pressure plate 133 is flush with the left side of the first clamping mold 12. The lower end of the stepped pressure plate 133 is in contact with the first clamping mold 12. The first clamping mold 12 and the first guide mold 13 are fixedly installed on the first tube bending machine. The first clamping mold 12 is fixedly installed on the first tube bending machine through the first pin hole 124 on its first fixing key 123, i.e., a pin. The first wheel mold 11 is sleeved and fixedly installed on the drive shaft of the first tube bending machine through the first wheel shaft hole 111.

[0035] The external tube bending mechanism includes a second wheel mold 21, a second clamping mold 22, and a second guide mold 23. The second wheel mold 21 is provided with a second wheel shaft hole 211 and a third tube groove 213. The rear end section of the third tube groove 213 is a semi-circular structure, and the front end section is a planar structure that matches the external tube 04. The second clamping mold 22 is provided with a fourth tube groove 222 with a semi-circular cross section and a second fixing key 223. The second fixing key 223 is provided with a second pin hole 224. The second guide mold 23 is provided with a fifth tube groove 233 corresponding to the structure of the fourth tube groove 222. The second clamping mold 22 and the second guide mold 23 are fixedly installed on the second tube bending machine. The second clamping mold 22 is fixedly installed on the second tube bending machine through the second pin hole 224 and the pin on its second fixing key 223. The second wheel mold 21 is sleeved and fixedly installed on the drive shaft of the second tube bending machine through the second wheel shaft hole 211. The second wheel mold 21 is also provided with an internal tube material groove 215.

[0036] The radius of the first tube groove 113, the second tube groove 122, the rear end of the third tube groove 213, the fourth tube groove 222, and the fifth tube groove 233 is 0.5mm-1mm smaller than the radius of the tube material 0, which makes it easier to clamp the tube material 0 and prevent the tube material from sliding forward.

[0037] The opening edge of the first tube groove 113 of the first wheel mold 11 is provided with an arc-shaped first wedge groove 114 corresponding to its arc structure. The opening edge of the second tube groove 122 of the first clamping mold 12 and the left side plate of the first guide mold 13 are provided with a straight first wedge boss 1221 and a fourth wedge boss 132 that cooperate with the first wedge groove 114. During the rotation of the first wheel mold 11, the first wedge groove 114 and the first wedge boss 1221 are engaged, which can ensure that the mold cavities between the first wheel mold 11 and the first clamping mold 12 are not misaligned.

[0038] The opening edge of the third tube groove 213 of the second wheel mold 21 is provided with an arc-shaped second wedge groove 214 corresponding to its arc structure. The opening edges of the fourth tube groove 222 and the fifth tube groove 233 are provided with straight second wedge bosses 221 and third wedge bosses 232 that cooperate with the second wedge groove 214. During the rotation of the second wheel mold 21, the third tube groove 213 fits with the second wedge bosses 221 and 232, which can ensure that the mold cavity between the second wheel mold 21 and the second clamping mold 22 and the second guide mold is not misaligned.

[0039] The first wheel mold 11 is provided with an arc-shaped guide groove 112 that has the same arc structure as the first pipe groove 113. The arc-shaped guide groove 112 is embedded in the arc-shaped guide protrusion provided on the first pipe bending machine. The purpose of the arc-shaped guide groove 112 is to prevent the mold cavity from misaligning when the first wheel mold 11 and the first clamping mold 12 clamp the pipe material 0.

[0040] The first guide mold 13 is provided with a first positioning slot 131, and the second guide mold 23 is provided with a second positioning slot 231. The first positioning slot 131 and the second guide mold 23 can be embedded and fixed with the first pipe bending machine and the six strip-shaped protrusions on the first pipe bending machine respectively, which can ensure the accuracy of the installation position and prevent the first guide mold 13 and the second guide mold 23 from being displaced during use.

[0041] In actual use, the second wheel mold 21 is supported only by the drive shaft of the second pipe bending machine. The second wheel mold 21 is provided with a wheel mold keyway 212, which is fixedly connected to the disc on the drive shaft of the second pipe bending machine by a key.

[0042] The first wheel mold 11 is provided with a wheel mold step 115. The wheel mold step 115 can reduce the material used in the first wheel mold 11, thereby reducing the overall weight and cost. The thickness of the step surface where the first wheel shaft hole 111 is located is determined according to the length of the drive shaft of the first pipe bending machine.

[0043] In process A, the base material tube 0 is milled to form a dividing groove 02, so that the front end of the tube 0 is divided into an inner cavity branch tube 03 and an outer cavity branch tube 04.

[0044] like Figure 3 As shown, the rear end of the pipe 0 is clamped and fixed between the first wheel mold 11 and the first clamping mold 12. The stepped pressure plate 133 is embedded in the partition groove 02. The stepped pressure plate 133 separates and supports the inner cavity branch pipe 03 and the outer cavity branch pipe 04. The first pipe bending machine drives the first wheel mold 11 to rotate clockwise to bend the inner cavity branch pipe 03 into the first bent structure 05 in process B. After this process is completed, the pipe 0 is removed from the inner cavity bending mechanism, and the end of the first bent structure 05 is cut off to obtain the structure in process C.

[0045] like Figure 7 and Figure 8 As shown, in process C, the rear end of the tube 0 is clamped and fixed between the second wheel mold 21 and the second clamping mold 22. The first bending structure 05 is embedded in the inner tube groove 215. The outer tube 04 is attached to the fifth tube groove 233 of the second guide mold 23. The second tube bending machine drives the second wheel mold 21 to rotate clockwise to bend the outer tube 04 into the second bending structure 06 in process D, thus obtaining the bicycle beam structure with reinforcing tube.

Claims

1. A double-lumen tube double-bending die structure, characterized in that: Includes internal tube bending mechanism and external tube bending mechanism; The internal tube bending mechanism includes a first wheel mold (11), a first clamping mold (12), and a first guide mold (13). The first wheel mold (11) is provided with a first wheel shaft hole (111) and an arc-shaped first tube groove (113) with a semi-circular cross-section. The first clamping mold (12) is provided with a straight second tube groove (122) with a semi-circular cross-section and a first fixing key (123). The first fixing key (123) is provided with a first pin hole (124). The first guide mold (13) is provided with a stepped pressure plate (133). The left side of the stepped pressure plate (133) is flush with the left side of the first clamping mold (12), and the lower end of the stepped pressure plate (133) is in contact with the first clamping mold (12). The first clamping mold (12) and the first guide mold (13) are fixedly installed on the first pipe bending machine. The first clamping mold (12) is fixedly installed on the first pipe bending machine through the first pin hole (124) on its first fixing key (123), i.e., the pin. The first wheel mold (11) is fixedly installed on the drive shaft of the first pipe bending machine through the first wheel shaft hole (111). The external cavity bending mechanism includes a second wheel mold (21), a second clamping mold (22), and a second guide mold (23). The second wheel mold (21) is provided with a second wheel shaft hole (211) and a third pipe groove (213). The rear end section of the third pipe groove (213) is a semi-circular structure, and the front end section is a planar structure that matches the external cavity branch pipe (04). The second clamping mold (22) is provided with a fourth pipe groove (222) with a semi-circular cross section and a second fixing key (223). The second fixing key (223) is provided with a second pin hole (224). The second guide mold (23) is provided with a fifth tube groove (233) corresponding to the structure of the fourth tube groove (222). The second clamping mold (22) and the second guide mold (23) are fixedly installed on the second tube bending machine. The second clamping mold (22) is fixedly installed on the second tube bending machine through the second pin hole (224) and the pin on its second fixing key (223). The second wheel mold (21) is fixedly installed on the drive shaft of the second tube bending machine through the second wheel shaft hole (211). The second wheel mold (21) is also provided with an inner tube material groove (215).

2. The double-lumen tube double-bending die structure according to claim 1, characterized in that: The radius of the rear end of the first pipe groove (113), the second pipe groove (122), the third pipe groove (213), the fourth pipe groove (222), and the fifth pipe groove (233) is 0.5mm-1mm smaller than the radius of the pipe material (0).

3. The double-lumen tube double-bending die structure according to claim 1, characterized in that: The first groove (113) of the first wheel mold (11) has an arc-shaped first wedge groove (114) corresponding to its arc structure at the opening edge. The second groove (122) of the first clamping mold (12) and the left side plate of the first guide mold (13) are provided with a straight first wedge boss (1221) and a fourth wedge boss (132) that cooperate with the first wedge groove (114). The third groove (213) of the second wheel mold (21) has an arc-shaped second wedge groove (214) corresponding to its arc structure at the opening edge. The fourth groove (222) and the fifth groove (233) have straight second wedge bosses (221) and third wedge bosses (232) that cooperate with the second wedge groove (214) at the opening edges.

4. The double-lumen tube double-bending die structure according to claim 1, characterized in that: The first wheel mold (11) has an arc-shaped guide groove (112) with the same arc structure as the first tube groove (113).

5. The double-lumen tube double-bending die structure according to claim 1, characterized in that: The first guide mold (13) is provided with a first positioning slot (131).

6. The double-lumen tube double-bending die structure according to claim 1, characterized in that: The second guide mold (23) is provided with a second positioning slot (231).

7. The double-lumen tube double-bending die structure according to any one of claims 1-6, characterized in that: The second wheel mold (21) is provided with a wheel mold keyway (212), which is fixedly connected to the disc on the drive shaft of the second pipe bending machine by a key.

8. The double-lumen tube double-bending die structure according to claim 1, characterized in that: The first wheel mold (11) is provided with a wheel mold step (115).

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