A method and device for clamping array composite tubes using internal expansion units

Abstract

The present invention provides a method and device for clamping an array composite tube using an internal expansion unit. The present invention includes a clamping body and an internal expansion unit connected to the clamping body, the internal expansion unit includes a mandrel and a retractable claw sleeved on the mandrel, the array composite tube blank to be processed is placed on the supporting surface of the clamping body, the mandrel enters the corresponding composite tube, the retractable claw is used to insert the mandrel from above the composite tube and then clamped inside the composite tube, an electromagnetic clamping mechanism is provided between the clamping body and the mandrel, which is used to ensure that the array composite tube and the clamping body remain fixed after the retractable claw is clamped. During the clamping process of the array composite tube, the in-plane position of the internal expansion unit can be adaptive to the position of the corresponding composite tube axis, theoretically suppressing the clamping stress generated by the inaccurate in-plane position of the composite tube axis. The clamping process of the present invention is simple and easy to use.

Description

Technical Field

[0001] The invention relates to the field of clamping technology, and in particular to a method and a device for clamping an array composite tube using an internal expansion unit. Background Art

[0002] The array composite tube is a typical honeycomb structure, which is made of a single cylindrical shell composite tube unit through two-dimensional close arrangement. Figure 1 As shown, it has the advantages of low density, high axial stiffness, excellent impact resistance, vibration reduction, and strong performance designability, and can be used in the manufacture of industrial products such as aerospace and chemical industry. Similar to the honeycomb structure, the array composite tube is generally used in the form of a "sandwich" structure, that is, it is assembled as a sandwich structure with the upper and lower skins. When the skin has a specific surface shape requirement, the array composite tube needs to be processed into a matching shape by mechanical processing.

[0003] Reliable and stable clamping is the basis for high-quality processing of array composite tubes. However, during the preparation of array composite tubes, there are glue layers between composite tube units and errors in the outer diameter of composite tubes. Therefore, adjacent composite tubes cannot be tangent at the same time, and the position of the composite tube axis in the horizontal plane will float within a certain range. When a fixed-position clamping unit is used to clamp the array composite tube, a large local clamping stress will be introduced, and the stress release and clamping rebound deformation after processing will lead to a deterioration in the surface shape accuracy of the processed surface. Therefore, a clamping device and method with self-adaptive in-plane position is needed, in which the position of the clamping unit in the horizontal plane can float freely within the corresponding range according to the position of the specified composite tube, thereby reducing the clamping stress and improving the processing accuracy. Summary of the invention

[0004] In view of the technical problems raised above, a method and device for clamping an array composite tube using an internal expansion unit is provided. The technical means adopted by the present invention are as follows:

[0005] A composite tube array clamping device using an internal expansion unit comprises a clamping body and an internal expansion unit connected to the clamping body, the internal expansion unit comprises a mandrel and a retractable clamping claw sleeved on the mandrel, the composite tube array blank to be processed is placed on a supporting surface of the clamping body, the mandrel enters into the corresponding composite tube, the retractable clamping claw is used to insert the mandrel from above the composite tube and then clamped into the inside of the composite tube, an electromagnetic clamping mechanism is provided between the clamping body and the mandrel, which is used to ensure that the composite tube array and the clamping body remain fixed after being clamped by the retractable clamping claw.

[0006] Furthermore, the electromagnetic clamping mechanism comprises an electromagnetic suction cup and a floating connection plate, the spindle is fixed to the threaded hole of the floating connection plate through the thread at the lower end, and the floating connection plate is placed on the electromagnetic suction cup.

[0007] Furthermore, the retractable claw comprises a lower cone block, a claw, an upper cone block and a cone block pressure plate. The lower cone block, the claw, the upper cone block and the cone block pressure plate are sequentially inserted into the mandrel from above the composite tube. The cone block pressure plate and the mandrel are connected together by threads. The expansion and tightening of the composite tube is completed by adjusting the pressing position of the cone block pressure plate.

[0008] The present invention also discloses a clamping method of the above-mentioned array composite tube clamping device using an internal expansion unit, comprising the following steps:

[0009] Step 1: Place the array composite tube blank to be processed on the supporting surface of the clamping body, and ensure that all mandrels enter the corresponding composite tubes, and then insert the lower cone block, the clamping claw, the upper cone block, and the cone block pressing plate into the mandrel from above the composite tube in sequence;

[0010] Step 2, the claws expand and contact the inner surface of the composite tube;

[0011] Step 3: The position of the clamping device in the horizontal plane is automatically adjusted according to the position of the clamped composite pipe without clamping stress;

[0012] Step 4: Ensure that the array composite tube and the clamp body remain fixed by turning on the electromagnetic clamping mechanism.

[0013] Furthermore, in step 2, the cone block pressure plate is rotated by a special wrench to apply a preset pre-tightening force to expand the claws.

[0014] Furthermore, in step 4, the electromagnetic chuck is turned on, and a preset magnetic field force is generated between the electromagnetic chuck and the steel floating connecting plate. The magnetic field force of the two will also increase the maximum static friction force between the contact surfaces of the two, thereby limiting the position of the clamping device in the horizontal plane.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] During the clamping process of the array composite tube, the position of the internal expansion unit in the plane direction can be adaptive to the position of the corresponding composite tube axis, theoretically suppressing the clamping stress caused by the inaccurate position of the composite tube axis in the plane. The clamping process is simple and easy to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] Figure 1 This is a schematic diagram of the structure of the array composite tube of the present invention.

[0019] Figure 2 It is a schematic diagram of the cross-sectional structure of the present invention.

[0020] Figure 3 It is a cross-sectional schematic diagram of the overall clamping of the array composite tube of the present invention.

[0021] Figure 4 This is a schematic axonometric diagram of the overall clamping of the array composite tube of the present invention.

[0022] In the figure: 1, electromagnetic suction cup, 2, floating connecting plate, 3, mandrel, 4, composite tube, 5, cone block pressure plate, 6, upper cone block, 7, claws, 8, lower cone block, 9, clamping body. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] like Figures 2 to 4 As shown, an embodiment of the present invention discloses a method and device for clamping an array composite tube using an internal expansion unit, including a clamp body 9 and an internal expansion unit connected to the clamp body, the internal expansion unit including a mandrel 3 and a retractable clamping claw sleeved on the mandrel 3, the array composite tube blank to be processed is placed on the supporting surface of the clamp body 9, the mandrel 3 enters into the corresponding composite tube 4, the retractable clamping claw is used to insert the mandrel from above the composite tube 4 and then clamped inside the composite tube 4, an electromagnetic clamping mechanism is provided between the clamp body 9 and the mandrel 3, which is used to ensure that the array composite tube 4 and the clamp body 9 remain fixed after the retractable clamping claw is clamped.

[0025] The electromagnetic clamping mechanism includes an electromagnetic chuck 1 and a floating connecting plate 2. The mandrel 3 is fixed to the threaded hole of the floating connecting plate 2 through the thread at the lower end. The floating connecting plate 2 is placed on the electromagnetic chuck 1. When the axis position of the clamping device is inconsistent with the axis position of the composite pipe to be expanded, after the clamping claw 7 is placed, the clamping device is driven by the radial force of the composite pipe on the clamping claw 7. The bottom surface of the floating connecting plate 2 fits with the upper surface of the electromagnetic chuck 1, and the clamping device can be moved by overcoming the maximum static friction force generated by the gravity of the clamping device, so that the clamping device can move in the horizontal plane.

[0026] The retractable claws include a lower cone block 8, a claw 7, an upper cone block and a cone block pressing plate 5. The lower cone block 8, the claw 7, the upper cone block 6 and the cone block pressing plate 5 are sequentially inserted into the mandrel 3 from above the composite tube 4. The cone block pressing plate 5 and the mandrel 3 are connected together by threads. The expansion and tightening of the composite tube is completed by adjusting the pressing position of the cone block pressing plate 5.

[0027] A clamping method of an array composite tube clamping device using an internal expansion unit comprises the following steps:

[0028] Step 1: Place the array composite tube blank to be processed on the support surface of the clamp body 9, while ensuring that all mandrels 3 enter the corresponding composite tube 4, and then insert the lower cone block 8, the clamping claw 7, the upper cone block 6, and the cone block pressing plate 5 into the mandrel from above the composite tube in sequence;

[0029] Step 2: Use a special wrench to screw the threaded hole in the center of the cone block pressing plate 5 into the thread on the upper end of the mandrel 3, so that the cone block pressing plate 5 pushes the upper cone block 6 downward, and the upper cone block 6 and the lower cone block 8 approach each other, so that the claws 7 in contact with them are stretched open, and the cylindrical surface of the claws 7 contacts and squeezes the inner surface of the composite tube 4, so that the composite tube 4 is expanded;

[0030] Step 3: The position of the clamping device in the horizontal plane is automatically adjusted according to the position of the clamped composite pipe without clamping stress. This design can avoid the clamping stress caused by the position error between the composite pipe 4 and the clamping device.

[0031] Step 4: Ensure that the array composite tube and the clamp body remain fixed by turning on the electromagnetic clamping mechanism.

[0032] In step 4, the electromagnetic chuck 1 is turned on, and a preset magnetic field force is generated between the electromagnetic chuck 1 and the steel floating connecting plate 2. This magnetic field force can prevent the floating connecting plate 2 from detaching from the electromagnetic chuck 1 due to external force. At the same time, the magnetic field force of the two will also increase the maximum static friction between the contact surfaces of the two, thereby limiting the position of the clamping device in the horizontal plane.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An array composite tube clamping device using an internal expansion unit, characterized in that: It comprises a clamp body and an internal expansion unit connected to the clamp body, the internal expansion unit comprises a mandrel and a retractable clamping claw sleeved on the mandrel, the array composite tube blank to be processed is placed on the supporting surface of the clamp body, the mandrel enters into the corresponding composite tube, the retractable clamping claw is used to insert the mandrel from above the composite tube and then clamped inside the composite tube, an electromagnetic clamping mechanism is provided between the clamp body and the mandrel, which is used to ensure that the array composite tube and the clamp body remain fixed after the retractable clamping claw is clamped; The electromagnetic clamping mechanism includes an electromagnetic chuck and a floating connection plate, the spindle is fixed to the threaded hole of the floating connection plate through the thread at the lower end, and the floating connection plate is placed on the electromagnetic chuck; The retractable claws include a lower cone block, a claw, an upper cone block and a cone block pressing plate. The lower cone block, the claw, the upper cone block and the cone block pressing plate are sequentially inserted into the mandrel from above the composite tube. The cone block pressing plate and the mandrel are connected together by threads. The expansion and tightening of the composite tube is completed by adjusting the pressing position of the cone block pressing plate.

2. A method for clamping the array composite tube clamping device using the internal expansion unit according to claim 1, characterized in that: The steps include: Step 1: Place the array composite tube blank to be processed on the supporting surface of the clamping body, and ensure that all mandrels enter the corresponding composite tubes, and then insert the lower cone block, the clamping claw, the upper cone block, and the cone block pressing plate into the mandrel from above the composite tube in sequence; Step 2, the claws expand and contact the inner surface of the composite tube; Step 3: The position of the clamping device in the horizontal plane is automatically adjusted according to the position of the clamped composite pipe under no clamping stress; Step 4: Ensure that the array composite tube and the clamp body remain fixed by turning on the electromagnetic clamping mechanism.

3. The method according to claim 2, characterized in that In step 2, the cone block pressure plate is rotated by a special wrench to apply a preset pre-tightening force to expand the claws.

4. The method according to claim 2, characterized in that: In step 4, the electromagnetic chuck is turned on, and a preset magnetic field force is generated between the electromagnetic chuck and the steel floating connecting plate. The magnetic field force of the two will also increase the maximum static friction force between the contact surfaces of the two, thereby limiting the position of the clamping device in the horizontal plane.

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