Outer pipe for push rod and machining process of outer pipe

Abstract

According to the technical scheme, the outer pipe is characterized in that glass fiber strips are tightly arranged in the annular direction of a pipe body, and the length direction of the glass fiber strips is consistent with the direction of the pipe body; the felt is wrapped outside the glass fiber strips and integrally wraps the whole glass fiber strips; in the process, glass fiber strips and felts are unwound through a fiber yarn frame and a felt frame; the tightly-arranged glass fiber strips are wrapped by the felt, the overall performance of the fibers is improved, and the overall structural strength is improved in cooperation with the bonding effect of the glue.

Description

Technical Field

[0001] This invention relates to an outer tube for a push rod and its manufacturing process. Background Technology

[0002] Electric linear actuators are common telescopic drive mechanisms. The outer tube of the actuator is mostly made of aluminum alloy. Aluminum alloy is used as the manufacturing material, but because aluminum alloy is expensive, the cost of making the frame is also high. Therefore, in the prior art, fiber reinforced resin composite material is used to process the frame to replace aluminum, steel and other components. The patent document with announcement number CN111331881A and titled "Automatic Production Equipment and Method for Pultruded Profiles of Composite Materials" discloses a method for processing composite material tubes.

[0003] However, the outer tube of the electric actuator requires strong structural strength. Relying solely on fiber yarn and glue for bonding results in relatively low overall structural strength, making it difficult to meet the requirements of the actuator's outer tube. Summary of the Invention

[0004] The purpose of this invention is to provide an outer tube for a push rod, which uses felt to wrap tightly arranged glass fiber strips to improve the overall strength of the fibers. Combined with the bonding effect of adhesive, this increases the overall structural strength.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0006] An outer tube for a push rod includes: an annular tube body; glass fiber strips arranged closely along the annular direction of the tube body, the length direction of the glass fiber strips being consistent with the direction of the tube body; a felt wrapped around the glass fiber strips, the felt integrally wrapping the entire glass fiber strips; and glue filling the space between the felt and the glass fiber strips.

[0007] Preferably, the inner circumference of the tube is provided with multiple protrusions, and the length direction of the protrusions is consistent with the length direction of the tube.

[0008] Preferably, there are nine raised strips.

[0009] Preferably, the cross-section of the tube includes an arc-shaped surface, with lateral surfaces fixed at both ends of the arc, the two lateral surfaces being arranged close together, and the close ends of the two lateral surfaces being connected to the bottom surface.

[0010] Preferably, the cross-section of the tube includes an arc-shaped surface, with lateral surfaces fixed at both ends of the arc, the two lateral surfaces being arranged close together, and the close ends of the two lateral surfaces being connected to the bottom surface.

[0011] Preferably, there are four raised strips arranged along the inner edge of the arc-shaped surface.

[0012] Preferably, there is one protrusion arranged along the inner edge of one side surface and two protrusions arranged along the inner edge of the other side surface; there is one protrusion arranged along the inner edge of the bottom surface and one protrusion arranged along the inner edge where the bottom surface and a side surface meet.

[0013] Preferably, the surface of the glass fiber strip is roughened, and the roughened surfaces of some adjacent glass fibers are intertwined.

[0014] A processing method for an outer tube involves unwinding glass fiber strips and felt using a fiber yarn frame and a felt frame; the glass fiber strips and felt enter a mold; the tube is then molded by injection molding; it is then dried; and finally, it is cut.

[0015] Preferably, the unwound glass fiber strip is roughened.

[0016] In summary, the present invention has at least one of the following beneficial effects:

[0017] The use of felt to wrap the tightly arranged fiberglass strips enhances the overall integrity of the fibers. Combined with the bonding effect of adhesive, this increases the overall structural strength.

[0018] Multiple raised strips arranged inside the tube can increase its bending strength. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the arrangement of glass fiber strips and felt in the mold core in the embodiment;

[0020] Figure 2 This is a schematic diagram of the cross-section inside the mold in the embodiment;

[0021] Figure 3 This is a schematic diagram of the outer tube cross-section in the embodiment;

[0022] Figure 4 This is a schematic diagram of the glass fiber strips and felt being introduced into the mold in the embodiment.

[0023] Figure 5 This is a schematic diagram of the fiberglass strip roughening process in the embodiment.

[0024] In the picture:

[0025] 1. Tube body; 11. Arc-shaped surface; 12. Lateral surface; 13. Bottom surface;

[0026] 2. Convex strips;

[0027] 31. Fiberglass strips; 32. Felt;

[0028] 4. Mold; 41. Mold core; 42. Outer mold; 43. Injection port;

[0029] 51. Anhydrous ethanol chamber; 52. Light grinding chamber; 53. Dust-collecting drying chamber. Detailed Implementation

[0030] The present invention will be further described in detail below with reference to the accompanying drawings.

[0031] Example 1, an outer tube for a push rod, refer to Figure 1 and Figure 4 It includes: an annular tube 1; glass fiber strips 31 arranged closely along the annular direction of the tube 1, the length direction of the glass fiber strips 31 being consistent with the direction of the tube 1; a felt 32 wrapped around the glass fiber strips 31, the felt 32 integrally wrapping the entire glass fiber strips 31; and glue filling the space between the felt 32 and the glass fiber strips 31.

[0032] Felt 32 is made of polyester fiber; glass fiber strip 31 is made of alkali-free glass fiber.

[0033] The inner circumference of the tube body 1 is provided with nine protrusions 2, and the length direction of the protrusions 2 is consistent with the length direction of the tube body 1.

[0034] There are nine convex strips 2.

[0035] The cross-section of the tube body 1 includes an arc-shaped surface 11, with lateral surfaces 12 fixed at both ends of the arc. The two lateral surfaces 12 are arranged close together, and the close ends of the two lateral surfaces 12 are connected to the bottom surface 13.

[0036] The cross-section of the tube body 1 includes an arc-shaped surface 11, with lateral surfaces 12 fixed at both ends of the arc. The two lateral surfaces 12 are arranged close together, and the close ends of the two lateral surfaces 12 are connected to the bottom surface 13.

[0037] There are four raised strips 2 arranged along the inner edge of the arc-shaped surface 11.

[0038] There is one convex strip 2 arranged along the inner edge of one side surface 12, and two convex strips 2 arranged along the inner edge of the other side surface 12.

[0039] There is one protruding strip 2 arranged along the inner edge of the bottom surface 13, and there is one protruding strip 2 arranged along the inner edge where the bottom surface 13 connects with a side surface 12.

[0040] The mold core 41 and the outer mold 42 of the mold 4 form a mold cavity. The felt 32 and the glass fiber strip 31 are inside the mold cavity, and the glue is injected through the glue injection port 43.

[0041] Example 2, a processing method for an outer tube, is the same as the processing method for the outer tube in Example 1, specifically including the following steps:

[0042] Step 1: Use a dual-station synchronous unwinding machine, fiber yarn frame and felt 32 frame to unwind glass fiber strips 31 and felt 32, ensuring that glass fiber strips 31 and felt 32 are unwound at a uniform speed without stretching or deformation.

[0043] Step 2: The fiberglass strip 31 and the felt 32 enter the mold 4. The felt 32 is wound around the outside of the fiberglass strip 31 by the guide roller, forming a composite blank of fiber strip and felt 32 which enters the mold 4.

[0044] Step 3: Inject the prepared epoxy resin into mold 4 through the injection ports 43 at both ends of mold 4. The injection pressure is 0.3-0.5 MPa, and the injection temperature is 40-50℃. A bidirectional injection method is used to ensure uniform filling of the adhesive. Curing treatment: After injection, preliminary curing is carried out in the mold at a temperature of 60-70℃ for 30-45 minutes to allow the adhesive to initially cross-link and form.

[0045] Step 4: Then dry the tube. Take the pre-cured tube 1 out of the mold 4 and put it into the oven. Use a segmented drying process: First segment: temperature 80-90℃ to remove residual volatiles of glue; Second segment: temperature 100-110℃, time 2-3 hours to ensure that the glue is completely cured.

[0046] Step 5: Finally, cut the outer tube vertically using a cutting machine.

[0047] Example 3, a processing method for an outer tube, differs from Example 1 in that it specifically includes the following step 1: roughening treatment of the unwound glass fiber strip 31, referring to... Figure 5 ;

[0048] The roughening process is as follows:

[0049] ① First, glass fiber strip 31 is put into anhydrous ethanol tank 51 and immersed in anhydrous ethanol through guide rollers to remove floating glue and dust;

[0050] ② When the fiberglass strip 31 enters the light grinding box 52, the wiping cloth inside the light grinding box 52 comes into contact with the fiberglass strip 31 to remove the liquid from its surface. Then, the fiberglass strip 31 comes into contact with the abrasive roller inside the light grinding box 52, and the abrasive roller lightly grinds along the length of the fiberglass strip 31 until the surface is matte and short, fine hairs are formed on the surface; in other embodiments, sandpaper can also be used instead of abrasive roller.

[0051] ③ The fiberglass strip 31 enters the dust-collecting and drying box 53. The airflow generated by the suction cleans the abrasive debris, and the flowing airflow also dries the fiberglass strip 31.

[0052] The roughened glass fiber strips 31 and felt 32 are fed into the mold 4 together.

[0053] Its beneficial effects: After roughening, the surface of the glass fiber strip 31 forms short and fine hairs. Since the glass fiber strips 31 in the outer tube are squeezed together, the roughening of each other is intertwined and wrapped together. When bonded with glue, the intertwined roughening acts as a skeleton, making the adjacent glass fiber strips 31 combine into one. Most importantly, the glass fiber strips 31 in the outer tube are tightly arranged along the annular direction of the tube body 1. The annular arrangement of glass fiber strips 31 forms a closed-loop connection based on the intertwining of adjacent roughening, which greatly improves the overall structural strength of the tube body 1.

[0054] Furthermore, the napping will also come into contact with the felt 32 and puncture in the gaps of the felt 32, increasing the bonding strength between the felt 32 and the fiberglass strip 31.

[0055] This invention breaks through the conventional morphology of smooth glass fiber strips. A dry texturing process, involving anhydrous ethanol impurity removal, light grinding, and dust extraction, forms a short, fine hair structure on the surface of the glass fiber strips. Utilizing the tightly arranged annular structure of the glass fiber strips, the texturing of adjacent strips intertwines to form a closed-loop "fiber reinforcing skeleton." Combined with adhesive bonding, this transforms the simple physical bonding of the dispersed glass fiber strips into a dual combination of chemical bonding and physical winding, solving the technical problem of easy interlayer separation when relying solely on adhesive bonding between fiber strips. Simultaneously, the texturing of the glass fiber strip surface can penetrate into the gaps in the felt, achieving a dual connection of mechanical interlocking and adhesive bonding between the glass fiber strip and the felt, further enhancing the bonding strength of the composite structure and significantly improving the overall structural stability and tear resistance of the tube.

[0056] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. An outer tube for a push rod, characterized in that, include: Annular tube (1); Glass fiber strips (31) are arranged closely along the annular direction of the tube body (1), and the length direction of the glass fiber strips (31) is consistent with the direction of the tube body (1); The felt (32) is wrapped around the outside of the glass fiber strip (31), and the felt (32) wraps the entire glass fiber strip (31) as a whole; Adhesive is used to fill the space between the felt (32) and the fiberglass strip (31).

2. The outer tube for a push rod according to claim 1, characterized in that: The inner ring of the tube body (1) is provided with multiple protrusions (2), and the length direction of the protrusions (2) is consistent with the length direction of the tube body (1).

3. The outer tube for a push rod according to claim 2, characterized in that: There are nine convex strips (2).

4. The outer tube for a push rod according to claim 2, characterized in that: The cross-section of the tube (1) includes an arc-shaped surface (11), and two lateral surfaces (12) are fixed at both ends of the arc. The two lateral surfaces (12) are arranged close together, and the close ends of the two lateral surfaces (12) are connected to the bottom surface (13).

5. The outer tube for a push rod according to claim 3, characterized in that: The cross-section of the tube (1) includes an arc-shaped surface (11), and two lateral surfaces (12) are fixed at both ends of the arc. The two lateral surfaces (12) are arranged close together, and the close ends of the two lateral surfaces (12) are connected to the bottom surface (13).

6. The outer tube for a push rod according to claim 5, characterized in that: There are four raised strips (2) arranged along the inner edge of the arc-shaped surface (11).

7. The outer tube for a push rod according to claim 6, characterized in that: There is one convex strip (2) arranged along the inner edge of one side surface (12), and there are two convex strips (2) arranged along the inner edge of the other side surface (12); There is one convex strip (2) arranged along the inner edge of the bottom surface (13), and there is one convex strip (2) arranged along the inner edge of the bottom surface (13) and a side surface (12).

8. The outer tube for a push rod according to claim 1, characterized in that: The surface of the glass fiber strip (31) is roughened, and the roughened parts of some adjacent glass fibers are intertwined.

9. A processing technology for an outer tube, characterized by: Glass fiber strips (31) and felt (32) are unwound using a fiber yarn frame and a felt (32) frame; Fiberglass strips (31) and felt (32) are inserted into the mold (4); Injection molding is performed inside the mold (4); Then dry; Finally, cut it.

10. The processing technology according to claim 1, characterized in that: The unwound glass fiber strip (31) is roughened.

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