CN104249111B - Combined bending molding die for thin-walled rectangular tube - Google Patents

Abstract

Thin-walled rectangular tube compound bending forming die, including: bending die, insert, clamp block, press block, E-bend anti-wrinkle block and H-bend anti-wrinkle block, bending die, insert, clamp block, press block are both E Bend and H-bend functions. The bending die is positioned through pin holes and keyways, and fixed on the machine tool with screws; the insert is positioned with screws and fixed on the bending die; the clip is positioned through the keyway and fixed on the machine tool with screws; the pressing block is positioned through the keyway and fixed with screws On the machine tool; the E-bend anti-wrinkle block and the H-bend anti-wrinkle block are positioned through the keyway and fixed with screws. Among them, the bending die, insert block, clip block and pressure block all have E-curve grooves and H-curve grooves. In bending forming, the pipe to be bent is placed in the bending groove, and under the action of the machine tool, the bending die, insert and clamp block are rotated by the bed, the pressing block is fed by the bed, and the anti-wrinkle block is fixed . The invention can simultaneously realize H-bending and E-bending, has high degree of automation, is easy to operate, reduces assembly times, improves forming precision, and has compact structure.

Description

Composite Bending Die for Thin-walled Rectangular Tube

1. Technical field

The invention relates to a numerically controlled bending pipe processing die, in particular to a composite bending forming die for a thin-walled rectangular pipe.

2. Background technology

Thin-walled rectangular tube bending parts have been widely used in the fields of aviation, aerospace, communication, satellite and microwave measurement because they can meet the requirements of light weight, large capacity and low loss of products. Numerical control bending technology is an advanced plastic processing technology produced by combining traditional pipe bending technology with the development of machine tool industry and numerical control technology. It has become an important direction for the research and development of advanced plastic processing technology in the 21st century. There are three types of bending structures for rectangular tubes: one is the bending form along the direction of the narrow surface of the rectangular tube, which is easier to bend and form, usually called E-bend, and the obtained bending piece is 1; the other is along the direction of the wide surface of the rectangular tube The bending form is difficult to form, usually called H-bending, and the number of bending pieces obtained is 2; one kind of bending structure with both E-bending and H-bending is called composite bending, and the number of bending pieces obtained is 3.

At present, with the continuous improvement of modern industry's requirements for the shape complexity of bent parts, compound bending of thin-walled rectangular tubes has become an important processing field. However, at present, the bending of thin-walled rectangular tubes is mainly a single-process E-bend or a single-process H-bend, and there is less involvement in the composite bending of both E-bend and H-bend. Single-process E-bend or single-process H-bend can only achieve a single bending method of pipe fittings. In order to realize the composite bending of pipe fittings, it is necessary to separately implement E-bend and H-bend on the E-bend mold and H-bend mold, which reduces the production efficiency; and increases the number of mold assembly times, making it difficult to guarantee the bending accuracy.

3. Contents of the invention

In order to meet the needs of modern processing for compound bending of thin-walled rectangular tubes, improve the production efficiency and bending accuracy of compound bending of pipe fittings, and at the same time realize the E-bend and H-bend of thin-walled rectangular tubes, this invention designs a set of thin-walled rectangular tubes. Composite bending mold.

The present invention includes bending die 4, insert 5, clamping block 6, pressing block 7, E bending anti-wrinkle block 8 and H bending anti-wrinkling block 9, bending die 4, inserting block 5, clamping block 6, and pressing block 7 are both With E-bend and H-bend functions.

The bending die includes an E-shaped groove 12 , an H-shaped groove 13 , screw holes 11 and 14 , a pin hole 10 , a base 15 and a keyway 16 . The bending die base is connected with the machine tool through the pin hole 10, the keyway 16 and the threaded hole 14. The curved model grooves 12 and 13 should be kept parallel to the plane where the base 15 is located to ensure the stability of the curved groove level. The width of the E-shaped groove 12 is equal to the size of the wide surface of the pipe fitting, and its depth is equal to 1/2 of the size of the narrow surface of the pipe fitting. The radius of the E-bend groove is equal to the difference between the E-bend bending radius of the pipe fitting and half the size of the narrow face of the pipe fitting. The width of the H-shaped groove 13 is equal to the size of the narrow face of the pipe fitting, and its depth is equal to 1/2 of the size of the wide face of the pipe fitting. The radius of the H-bend groove is equal to the difference between the H-bend bending radius of the pipe fitting and half of the wide surface size of the pipe fitting.

The insert includes an E-shaped groove 18 , an H-shaped groove 19 and a threaded hole 17 . The insert is fixed on the bending die through the threaded hole 17 and is integrated with the bending die. The size of the slot of the insert is the same as that of the corresponding slot of the bending die, and the center line of the slot should be kept at the same height after assembly. The inner surface of the groove should be polished with fine sandpaper to prevent the pipe from being scratched during bending.

The clamping block includes an E-shaped groove 20 , an H-shaped groove 21 , a keyway 22 and a threaded hole 23 . Keyways and threaded holes are mainly used for fixing. The keyway should be kept perpendicular to the groove to prevent the horizontal position of the groove from changing during the bending process. The clip-type groove matches the insert-type groove, and the corresponding grooves have the same size. The inner surface of the clamp-shaped groove should have a certain roughness, and it only needs to be polished with coarse sandpaper, which is conducive to clamping the pipe fittings and preventing the pipe fittings from slipping during the bending process.

The pressing block includes an E-shaped groove 24 , an H-shaped groove 25 , a threaded hole 26 and a keyway 27 . The keyway and threaded hole mainly act as a fixed pressing block to connect with the machine tool. The keyway should be kept perpendicular to the groove to prevent the horizontal height of the centerline of the groove from changing during the bending process. The size of the briquetting block groove is the same as the corresponding groove size of the clamping block.

The E-bend anti-wrinkle block includes a threaded hole 28 , a keyway 29 and a tangent arc 30 . Keyways and screw holes are mainly used for fixing. The tangent arc 30 is tangent to the bending die E-bending slot 12 and thus has the same radius as the bending die E-bending slot 12 .

The H-bend anti-wrinkle block includes a threaded hole 31 , a keyway 32 and a tangent arc 33 . Keyways and threaded holes are mainly used for fixing. The tangent arc 33 is tangent to the bending die H-shaped groove 13, so its radius is the same as that of the bending die H-shaped groove 13.

The invention has the advantages of compact structure, H-bend and E-bend can be realized at the same time; assembly times are reduced and forming precision is improved.

4. Description of drawings

Fig. 1 is a schematic diagram of a thin-walled rectangular tube numerically controlled bending part;

Figure 2 is a schematic diagram of the assembly of a thin-walled rectangular tube numerically controlled composite bending forming die;

Fig. 3 is a schematic diagram of a bending die with both E-curve and H-curve grooves;

Figure 4 is a schematic diagram of an insert with both E-bend and H-bend grooves;

Fig. 5 is a schematic diagram of a clamping block with both E-bend and H-bend grooves;

Fig. 6 is a schematic diagram of a briquetting block with both E-bend and H-bend grooves;

Figure 7 is a schematic diagram of an anti-wrinkle block suitable for E-bending;

Fig. 8 is a schematic diagram of an anti-wrinkle block suitable for H-bending;

Fig. 9 is a schematic diagram of the numerically controlled bending forming process of a thin-walled rectangular tube.

Among them: 1. E bending bending parts 2. H bending bending parts 3. Composite bending bending parts 4. Bending mold 5. Insert block 6. Clamp block 7. Press block 8. E bending anti-wrinkle block 9. H bend Anti-wrinkle block 10. Pin holes 11, 14, 17, 23, 26, 28, 31. Threaded holes 12, 18, 20, 24. E curved grooves 13, 19, 21, 25. H curved grooves 15. Bending Die base 16, 22, 27, 29, 32. Keyway 30, 33. Tangent arc 34. Mandrel 35. Rectangular pipe

5. Specific implementation

The present invention will be further described below in conjunction with the accompanying drawings and typical embodiments.

The NC bending forming of thin-walled rectangular tubes is a complex nonlinear forming process under the influence of multiple factors, which requires the synergy and strict cooperation of various molds. During the pipe bending process, the adjustment of the assembly die is a particularly complex and important link.

(1) Assembly of the bending die. Because the bending die 4 has the least degree of freedom, it is only connected with the machine tool by the keyway 16, the threaded hole 14 and the pin hole 10, so the bending die is first fixed. The bending die base 15 is fixed through 4 threaded holes and keyways, and is connected with the machine tool. Considering the stability of the bending die, it is reinforced through the pin hole 10 to prevent the bending die from tilting.

(2) Assembly of inserts. The insert is fixed on the bending die through the threaded hole 17, and the height is adjusted so that the bending grooves 18, 19 are matched with 12, 13 respectively to ensure that the center line of the insert groove and the bending groove of the bending die are at the same level.

(3) Assembly of clamping block. The clamping block is connected with the machine tool through the keyway 22 and the threaded hole 23 . Clamp-type grooves and insert-type grooves fit together. Adjust the relative height, and observe whether the groove of the clamp block and the groove of the insert are at the same level, and its height can be adjusted by the screw on the clamp block. The clamping force of clamp block is controlled by CNC machine tool.

(4) Assembly of anti-wrinkle block. The anti-wrinkle block is connected with the machine tool through threaded holes 28, 31 and keyways 29, 32, and the anti-wrinkle block is fixed on the anti-wrinkle block support. The radii of the tangent arcs 30 and 33 of the anti-wrinkle block are respectively the same as the radius of the corresponding groove of the bending die, thus making it possible to fit together. It is necessary to ensure that the end of the anti-wrinkle block is flush with the tangent point of the bending die. The height of the anti-wrinkle block is determined by the straightness of the pipe itself and the adjustment of the machine tool to ensure that the height of the anti-wrinkle block and the bending die are at the same height.

(5) Assembly of briquettes. The pressing block is connected with the machine tool through the keyway 27 and the threaded hole 26 . Observe whether the cavities of the pressing block and the anti-wrinkle block are at the same height, and adjust the height of the pressing block through the adjusting screw on the pressing block. Alternately adjust the screws at both ends of the briquetting block, not only to ensure the position between the anti-wrinkle block and the briquetting block, but also to ensure the levelness of the briquetting block itself. The feeding speed of the briquetting block is controlled by the CNC machine tool, which is generally equal to the linear speed of the briquetting block.

The present invention is realized in this way: as shown in Figure 9, before bending, the rectangular pipe 35 is clamped between the insert 5 and the clamping block 6, the insert is fixed on the bending die 4 and is integrated with the bending die, and the tail is in the pressing block Between 7 and anti-wrinkle block 8 (or 9), there is mandrel 34 support inside (because the existing special patent of mandrel relates to, so this patent is no longer described in detail). When bending, the clamp block 6 pulls the pipe and turns it around the bending die to the set bending angle. The fitting of the pipe and the bending die makes the pipe reach the required bending radius, and then the mandrel is pulled out, the clamp and the pressure block are loosened, and the pipe is taken out , the bending die and clamp block are reset to complete a bending action. For the compound bending bending part 3 shown in Figure 1, first put the narrow surface of the pipe fitting into the H-bending groove of the bending die, and perform the H-bending according to the above steps. After completing a bend, put the wide surface of the pipe fitting into the E-bend groove for E-bend. In this way, compound bending of thin-walled rectangular tubes is realized. Since this bending die has 2 bending grooves, it can bend 2 pipes at the same time to realize E-bend and H-bend respectively. Since the bending die has already been assembled, there is no need to adjust the die again, thus improving efficiency and ensuring bending accuracy.

Claims (6)

1. the mould of the compound rotary draw bending of a kind of thin-walled rectangular tube, it is characterised in that including bending die, insert, fixture block, briquetting with And E it is curved wrinkle resistant piece and H it is curved wrinkle resistant piece, bending die, insert, fixture block, briquetting have that E is curved and the curved functions of H concurrently；Bending die passes through pin Hole and keyway are positioned, and are screwed on lathe；Insert is located and fixed within bending die by screw, is connected with bending die It is integrated；Fixture block is positioned by keyway and is fixed on lathe by screw；Briquetting is positioned by keyway and is screwed in machine On bed；Curved wrinkle resistant piece and H curved wrinkle resistant piece of E is positioned by keyway and is fixed with screw；Wherein, bending die, insert, fixture block and Briquetting has the curved grooves of E and the curved grooves of H concurrently；In bending forming, tubing to be bent is placed in bending type groove, in lathe effect Under, bending die, insert and fixture block rotate with lathe, and briquetting does feed motion with lathe, and wrinkle resistant piece then maintains static.

2. as claimed in claim 1 a kind of thin-walled rectangular tube is combined the mould of rotary draw bending, it is characterised in that bending die passes through key Groove and pin are positioned on lathe, and are fixed on lathe using screw so that bending die type groove and base place plane Keeping parallelism, it is ensured that bending die type groove level height is stablized；The width of the curved grooves of E is equal to the size in pipe fitting width face, and its depth Degree is equal to the winding bilge radius of E of pipe fitting and the one of pipe fitting leptoprosopy size equal to the radius of the curved grooves of 1/2, E of pipe fitting leptoprosopy size Half difference；The width of the curved grooves of H is equal to the size of pipe fitting leptoprosopy, and its depth is equal to the curved grooves of 1/2, H of the wide face size of pipe fitting Radius be equal to pipe fitting the winding bilge radius of H and pipe fitting width face size half difference, during bending forming, rectangular tube be located at bend In model groove, and the rotation with bending die occurs bending and deformation.

3. as claimed in claim 1 a kind of thin-walled rectangular tube is combined the mould of rotary draw bending, it is characterised in that insert passes through screw It is fixed on bending die and is connected with bending die；Insert type groove size type groove corresponding with bending die is equivalently-sized, after assembling Type groove centrage should be maintained at sustained height；Because pipe fitting relative with insert generation can slide in BENDING PROCESS, in order to avoid drawing Hinder tube surface, type groove inner surface application fine sandpaper is polished.

4. as claimed in claim 1 a kind of thin-walled rectangular tube is combined the mould of rotary draw bending, it is characterised in that fixture block passes through keyway Positioned, and be screwed on lathe；Keyway should be vertical with type groove holding, prevents BENDING PROCESS medium cell horizontal level Variation；Fixture block type groove is engaged with insert type groove, and correspondence type groove is equivalently-sized；The inner surface of fixture block type groove should have certain thick Rugosity, only need to be polished with coarse sandpaper, be conducive to clamping pipe fitting, prevent pipe fitting in BENDING PROCESS from skidding.

5. as claimed in claim 1 a kind of thin-walled rectangular tube is combined the mould of rotary draw bending, it is characterised in that briquetting passes through keyway Positioned, and be attached with lathe with screw；Keyway should be vertical with type groove holding, prevents the medium-sized groove center line of BENDING PROCESS The variation of level height；Briquetting type groove size type groove corresponding with fixture block is equivalently-sized.

6. as claimed in claim 1 a kind of thin-walled rectangular tube is combined the mould of rotary draw bending, it is characterised in that E is curved wrinkle resistant piece and H Curved wrinkle resistant piece is positioned by keyway, and is screwed on lathe.