CN112959706A

CN112959706A - Open type magnetic circuit induction heating tire direct-pressure vulcanization method and device

Info

Publication number: CN112959706A
Application number: CN202110156054.7A
Authority: CN
Inventors: 张有忱; 杨卫民; 薛爽; 阎华�; 张莉彦; 丁玉梅
Original assignee: Beijing University of Chemical Technology
Current assignee: Beijing University of Chemical Technology
Priority date: 2021-02-04
Filing date: 2021-02-04
Publication date: 2021-06-15

Abstract

The invention discloses a method and a device for vulcanizing a tire by direct pressure through induction heating of an open type magnetic circuit. The position of the silicon steel sheet is controlled to enable the magnetic force line to just pass through the position needing to be heated, so that the method is suitable for the tire vulcanization process with similar specifications. The device of the invention consists of an open type magnetic circuit unit, an inner mold unit and a tire outer mold, a proper amount of conductive fibers can be doped at the tire shoulder part with thicker tire, and after the electromagnetic coil is electrified, the conductive fibers generate heat due to a high-frequency alternating electromagnetic field, so that the heat generated inside the tire is transferred outwards, the phenomenon of uneven vulcanization degree can be relieved, and the heating efficiency can be improved.

Description

Open type magnetic circuit induction heating tire direct-pressure vulcanization method and device

Technical Field

The invention belongs to the technical field of tire vulcanization, and particularly relates to a method and equipment for directly pressing and vulcanizing an open-type magnetic circuit induction heating tire.

Background

Vulcanization, as the final step in the tire manufacturing process, has a very important impact on tire performance. In the traditional vulcanization process of the tire, the green tire is heated by introducing superheated water into the bladder. Because of its low efficiency, the method is improved to introduce high temperature steam and high pressure nitrogen gas into the capsule to heat the green tire, but the method still has the following disadvantages: 1. the required vulcanization time is different due to different thicknesses of all parts of the tire, and the phenomenon of uneven vulcanization degree often occurs in the traditional vulcanization process, namely, the thicker tire shoulder part is not completely vulcanized, and the thinner tire tread part is already in an over-vulcanization state; 2. the curing bladder is made of a rubber material, cannot obtain a stable shape due to its elasticity after being expanded and compressed, and is also cured along with the green tire, thereby deteriorating the quality of tire curing. In the subsequent use process of the tire, in order to meet the dynamic balance condition, a balancing weight needs to be added, so that the energy loss is increased; 3. during the vulcanization process, the bladder needs to be frequently inflated and deflated, so that the service life of the bladder is uncertain and the bladder may need to be frequently replaced; 4. the temperature and the pressure are coupled in the vulcanization process, and the temperature or the pressure cannot be independently adjusted, so that the vulcanization process condition is difficult to control; 5. high-temperature steam is condensed into liquid water above the capsule and accumulated below the capsule due to small density of the high-temperature steam, so that temperature difference exists between the top and the bottom of the capsule, the capsule cannot uniformly transfer heat in the axial direction, and the quality of a final product is influenced; 6. the heat transfer medium has a low thermal conductivity and loses much energy during the heat transfer from the heat transfer medium to the tire, resulting in increased production costs. In the subsequently produced tire electromagnetic induction heating technology, an independent electromagnetic induction heating module needs to be arranged on each tile block, and the inner mold driving mechanism enables the axial distance of the central mechanism to be too large, so that the structure and the control are complex.

Disclosure of Invention

The invention aims to provide an open-type magnetic circuit induction heating tire direct-pressure vulcanization method and equipment which can adjust the heating position according to the vulcanization requirement, are suitable for vulcanizing a series of tire products with similar specifications, have less magnetic leakage and high magnetic field utilization rate and aim to overcome the defects in the vulcanization process.

The technical scheme adopted for realizing the purpose is as follows: a direct-pressure vulcanizing method for tyre by induction heating of open-type magnetic circuit features that the original steel material is changed into ceramic material, the supporting blocks made of steel material are inlaid on the external surface of internal and external moulds, and the electromagnetic induction heating module of original internal and external moulds is changed into induction heating of open-type magnetic circuit. When the tire is vulcanized, the C-shaped magnetizer moves to a designated position to enable the tire and the mold to be positioned at the opening center position of the magnetic circuit, the high-frequency or medium-frequency alternating current generates an alternating magnetic field, the inner mold and the outer mold cut magnetic lines of force, eddy current is generated on the surface of the metal supporting block, and the temperature of the supporting block is rapidly increased by utilizing the heat effect of the eddy current and the tire is heated through heat conduction. The position of the silicon steel sheet is controlled to enable the magnetic force line to just pass through the position needing to be heated, so that the method is suitable for the tire vulcanization process with similar specifications. Meanwhile, the C-shaped magnetizer in the open-type magnetic circuit improves the utilization rate of the magnetic circuit, not only can improve the heating efficiency, but also can prevent the magnetic leakage from interfering the outside. In addition, a proper amount of conductive fibers are doped in the thicker shoulder part of the tire, so that the shoulder part can generate heat internally due to a high-frequency alternating magnetic field in the vulcanization process of the tire.

According to the method, the open magnetic circuit induction heating tire direct-pressure vulcanizing device consists of an open magnetic circuit unit, an inner mold unit and a tire outer mold.

The centre form unit includes tile structure and cylinder mechanism, tile structure adopts ceramic material, inlay the supporting shoe that steel made at its surface, tile structure divides into wide tile and narrow tile, wherein wide tile uses double cylinder to drive, narrow tile uses single cylinder to drive, cylinder mechanism includes small-size cylinder and central base, wherein cylinder mechanism circumference align to grid, the crisscross range upon range of cylinder in the same installation direction, the last downside at single tile actuating cylinder is installed respectively to wide tile actuating double cylinder, the cylinder is connected to the internal surface of centre form in order to guarantee the stationarity of motion, the concertina movement through control cylinder piston rod drives the concertina movement of centre form tile, central base supplies the cylinder installation fixed.

The open type magnetic circuit unit is composed of a C-shaped magnetizer, a silicon steel sheet and an electromagnetic coil, wherein the C-shaped magnetizer is divided into an integral type magnetizer and a split type magnetizer, the integral magnetizer can control the in and out of the magnetizer after mold closing or before mold opening through translation motion, the split type magnetizer can complete folding or separating motion after mold closing or before mold opening through translation motion, the silicon steel sheet is attached to the magnetizer to form a bulge so as to form an open type magnetic circuit, and the silicon steel sheet can move or rotate according to a certain angle according to heating requirements. The hollow electromagnetic coil is wound at the circumferential position of the silicon steel sheet, an alternating magnetic field is generated after high-frequency or medium-frequency alternating current is introduced, and cooling water is introduced into the hollow electromagnetic coil to prevent overheating during work.

The outer tire mold comprises an upper substrate, a lower substrate, a mold sleeve and an outer mold, wherein the outer mold is made of ceramic materials, pattern blocks made of steel are assembled on the inner surface of the outer mold, and the mold sleeve is driven to move by the up-and-down movement of a piston rod of an oil cylinder, so that the opening and closing of the outer mold are controlled. The upper and lower substrates are made of ceramic materials, supporting blocks made of steel materials are embedded on the surfaces, in contact with the tires, of the upper and lower substrates, the lower substrate is fixed on the base, and the upper substrate is controlled to lift through an oil cylinder piston and provides a mold locking force.

The invention relates to a direct-pressure tire vulcanizing method and device by induction heating of an open-type magnetic circuit, which have the advantages that: 1. the material of the tile in the original direct-pressure vulcanization process is changed from steel to ceramic, the supporting block made of steel is embedded on the surface of the mold close to the tire, and heat is transferred to the tire after the surface of the rigid supporting block generates heat in the vulcanization process, so that the rigid support of the tire in the vulcanization process is maintained, and the loss of heat in the transfer process is reduced.

2. Get rid of the electromagnetic induction heating module that is furnished with behind every tile fragment among the original electromagnetic induction heating tire vulcanization technology, change into using integral outside open-type magnetic circuit induction heating, change the control mode into a pair of heating solenoid's overall control by original several electromagnetic induction module difference control correspondingly, not only can reduce the magnetism and reveal, improve the utilization efficiency in magnetic field, can alleviate the influence of magnetic leakage to the surrounding environment moreover to practice thrift manufacturing cost, reduce the control degree of difficulty.

3. The silicon steel sheet bulge on the magnetizer in the open-type magnetic circuit can be subjected to position adjustment according to heating requirements, so that the device has universality and can be used for vulcanizing a series of tire products with similar specifications.

4. Improve original centre form drive mode for using cylinder mechanism drive for central axial space reduces by a wide margin, and the cylinder action is quick, makes the mould flexible time shorten.

5. In the vulcanization process, as heat is conducted from the upper surface and the lower surface of the supporting block to the middle, the thicker tire shoulder part obtains heat from the thinner tire tread part, the temperature of the tire shoulder part is higher, the temperature of the tire tread part is lower, and meanwhile, the uneven degree of tire vulcanization can be reduced by controlling and matching the heat generation and the heat conduction rate through the outside.

6. Because a proper amount of conductive fibers are doped at the thicker tire shoulder part of the tire, when the electromagnetic coil is electrified, the conductive fibers generate heat due to a high-frequency alternating electromagnetic field, so that the heat generated inside the tire is transferred outwards, the phenomenon of uneven vulcanization degree can be relieved, and the heating efficiency can be improved.

Drawings

Fig. 1 is a schematic structural diagram of an open-type magnetic circuit induction heating tire direct-pressure vulcanizing device in a vulcanizing working state by using an integral magnetizer.

Fig. 2 is a schematic structural diagram of a split type magnetizer used by the open type magnetic circuit induction heating tire direct-pressure vulcanizing device in a vulcanizing working state.

Fig. 3 is a schematic structural view of an open-type magnetic circuit induction heating tire direct-pressure vulcanizing device according to the present invention, in which an integral magnetizer is used in an un-mold-closing state.

Fig. 4 is a schematic structural view of a split type magnetizer used in an open type magnetic circuit induction heating tire direct-pressure vulcanizing device of the present invention in an un-mold closing state.

Fig. 5 is a schematic structural view of different installation modes of an open-type magnetic circuit unit using an integral magnetizer, an auxiliary silicon steel sheet and an auxiliary coil in the open-type magnetic circuit induction heating tire direct-pressure vulcanizing device.

Fig. 6 is a schematic structural view of different installation modes of an open-type magnetic circuit unit using a split magnetizer, an auxiliary silicon steel sheet and an auxiliary coil in the open-type magnetic circuit induction heating tire direct-pressure vulcanizing device.

Fig. 7 is a schematic cross-sectional view of an open magnetic circuit induction heating tire direct-pressure vulcanizing device in an open state of an inner mold unit.

Fig. 8 is a schematic structural diagram of an inner mold, an outer mold, upper and lower substrates and a tire in the open-type magnetic circuit induction heating tire direct-pressure vulcanizing device of the invention.

In the figure: a C-type magnetizer; 2. silicon steel sheets; 3. an electromagnetic coil; 4. an upper substrate; 5. a tire; 6. an inner mold narrow tile; 7. an outer mold; 8. die sleeve; 9. a lower substrate; 10. the narrow tile drives the air cylinder; 11. a base; 12. a cylinder fixing support; 13. a wide tile driving cylinder; 14. inner mould wide tile; 15. auxiliary silicon steel sheets; 16. an auxiliary coil; 17. a support block; 18. conductive fibers.

Detailed Description

The invention relates to an open-type magnetic circuit induction heating tire direct-pressing vulcanizing device, as shown in figures 1-4, 7 and 8, an electromagnetic induction heating module configured in a tile block in the original electromagnetic induction heating tire direct-pressing vulcanizing device is changed into open-type magnetic circuit integral induction heating, an inner mold unit comprises a tile block mechanism and a cylinder mechanism, the tile block mechanism is divided into an inner mold wide tile 14 and an inner mold narrow tile 6 which are respectively driven by a wide tile driving cylinder 13 and a narrow tile driving cylinder 10, wherein the inner mold wide tile 14 is driven by double cylinders, the inner mold narrow tile 6 is driven by a single cylinder, the inner mold tile is made of ceramic materials, a supporting block 17 is embedded on the outer surface of the inner mold tile, after the tile block mechanism is opened, the outer contour curve of the supporting block 17 is consistent with the inner contour curve of a tire, the cylinder mechanism comprises the narrow tile driving cylinder 10, the wide tile driving cylinder 13 and a cylinder fixing support 12, wherein the wide tile driving cylinder 13 and the narrow tile driving cylinder 10 are arranged in, the driving cylinders are uniformly arranged in the circumferential direction, one end of each driving cylinder is installed on the cylinder fixing support 12, the other end of each driving cylinder is connected to the inner surface of the inner die, the telescopic motion of the wide tile 14 and the narrow tile 6 of the inner die is driven by controlling the telescopic motion of a piston rod of each driving cylinder, and the cylinder fixing support 12 and the base 11 are fixedly connected through bolts. When vulcanization is not started, the driving cylinder is in a contraction state, after the green tire 5 is placed on the lower base plate 9 by the tire assembling hand, gas with certain pressure is introduced into the driving cylinder and kept until vulcanization is finished, the cylinder piston rod drives the inner mold to move outwards to the inner surface of the tire, after vulcanization is finished, the cylinder reversely introduces gas and drives the inner mold to contract together, and the tire 5 after vulcanization is removed by the tire disassembling hand.

The outer tire mold comprises an upper substrate 4, a lower substrate 9, a mold sleeve 8 and an outer mold 7, wherein the upper substrate 4, the lower substrate 9 and the outer mold 7 are made of ceramic materials, as shown in fig. 3, fig. 4, fig. 7 and fig. 8, supporting blocks 17 made of steel materials are respectively embedded on the surfaces adjacent to the tire, the mold sleeve 8 is driven to move longitudinally through the up-and-down movement of an oil cylinder piston rod, so that the opening and closing of the outer mold 7 are controlled, the lower substrate 9 is fixed on a base 10, and the upper substrate 4 is also controlled to lift through the oil cylinder piston and provide mold locking. When the unvulcanized tire 5 is placed on the upper substrate 4, the cylinder piston drives the upper substrate 4 and the die sleeve 8 to move downwards, and the die sleeve 8 moves downwards to press the outer die 7 to the tire 5, so that the die assembly is completed. After vulcanization is finished, the oil cylinder piston moves upwards to drive the upper substrate 4 and the die sleeve 8 to move upwards, and the outer die 7 moves outwards along with the oil cylinder piston to finish die opening.

The open type magnetic circuit unit is composed of a C-shaped magnetizer 1, a silicon steel sheet 2 and an electromagnetic coil 3, wherein the C-shaped magnetizer 1 is divided into an integral magnetizer and a split type magnetizer, the integral C-shaped magnetizer is placed on one side and can be controlled to enter and exit after die assembly or before die opening through translational motion, the split type magnetizer divides the magnetizer into a plurality of segments to be uniformly placed around, the movement of each segment of magnetizer is controlled to complete the folding or separation of the magnetizer after the die assembly or before the die opening, the silicon steel sheet 2 is attached to the C-shaped magnetizer 1 to form a bulge so as to form an open type magnetic circuit, and the opening type magnetic circuit can move or rotate according to a certain angle according to heating requirements. The hollow electromagnetic coil 3 is wound on the silicon steel sheet 2, an alternating magnetic field is generated after high-frequency or medium-frequency alternating current is introduced, the supporting block generates eddy current due to cutting of magnetic lines of force, and due to the heat effect of the eddy current, the surface of the metal supporting block generates heat, so that the vulcanization of the tire is completed through heat conduction. In order to prevent the hollow electromagnetic coil 3 from being overheated during operation, cooling water is introduced into the hollow electromagnetic coil for cooling. For the vulcanization process of tires with different specifications, the required heating effect can be achieved by adjusting the position of the silicon steel sheet 2 or attaching the auxiliary silicon steel sheet 15 to the side edge of the C-shaped magnetizer 1 as a supplement, as shown in fig. 5 and 6. In addition, the auxiliary coil 16 may be wound on the side of the C-type magnetic conductor 1 as needed to increase the magnetic induction intensity in the magnetic circuit. At the same time, the heating time can be further adjusted by adjusting the amplitude or frequency of the alternating current passed to the electromagnetic coil 3 or the auxiliary coil 16.

The invention relates to a direct-pressure vulcanization method of an open-type magnetic circuit induction heating tire, wherein a C-shaped magnetizer 1, a silicon steel sheet 2 and an electromagnetic coil 3 form an open-type magnetic circuit, an unvulcanized tire 5 and a mold are placed at the center of an opening of the magnetic circuit, when high-frequency or medium-frequency alternating current is introduced into the electromagnetic coil, a metal supporting block 17 in the mold generates eddy current due to cutting of magnetic lines of force, heat is generated by the heat effect of the eddy current, and then the tire 5 is vulcanized through heat conduction. In addition, as shown in fig. 8, the conductive fibers 18 are doped in the shoulder portion of the tire 5, and heat is generated under the action of the alternating magnetic field, so that the simultaneous heating from the inside and the outside of the tire is completed. The C-shaped magnetizer 1 not only can concentrate magnetic force lines and further improve the heat efficiency, but also can avoid the influence of magnetic flux leakage on other parts. The silicon steel sheet 2 is not completely fixed on the C-shaped magnetizer 1, and can be moved or rotated by a certain angle according to heating requirements, and an auxiliary silicon steel sheet 15 or an auxiliary winding 16 can be added on the side edge of the C-shaped magnetizer 1 to achieve an ideal heating effect.

Claims

1. an open-type magnetic circuit induction heating tire direct pressure vulcanization method is characterized in that: the inner and outer mold materials are changed from original steel to ceramic materials, and the outer surface of the inner mold and the inner surface of the outer mold are inlaid with steel and made of The support block changes the electromagnetic induction heating module equipped with the original inner and outer molds to use open magnetic circuit induction heating; when the tire is vulcanized, the magnet guide moves to the designated position so that the tire and mold are located in the center of the opening of the magnetic circuit, and the high frequency Or intermediate frequency alternating current generates alternating magnetic field, and eddy current is generated on the surface of the metal support block after the inner and outer molds cut the magnetic field lines, and the thermal effect of the eddy current makes the temperature of the support block rise rapidly and heat the tire through heat conduction; by controlling the position of the silicon steel sheet The magnetic line of force just passes through the position where heating is required, so that the method is suitable for the vulcanization process of tires with similar specifications.

2. An open-type magnetic circuit induction heating tire direct pressure vulcanization device is characterized in that: it is composed of an open-type magnetic circuit unit, an inner mold unit and a tire outer mold, and the inner mold unit includes a pad mechanism and a cylinder mechanism, and the pad mechanism Using ceramic materials, the outer surface of the support block made of steel is inlaid. The block mechanism is divided into wide tiles and narrow tiles. The wide tiles are driven by double cylinders, and the narrow tiles are driven by a single cylinder; open magnetic circuit unit It is composed of a C-shaped magnetic conductor, a silicon steel sheet, and an electromagnetic coil. The silicon steel sheet is attached to the magnetic conductor to form a bulge to form an open magnetic circuit, and can be moved or rotated at a certain angle according to heating requirements; the hollow coil is wound on the silicon steel. In the circumferential position of the sheet, an alternating magnetic field is generated after high-frequency or intermediate-frequency alternating current is applied, and cooling water is passed through the hollow coil to prevent overheating during operation; the outer mold of the tire includes an upper substrate, a lower substrate, a mold sleeve and an outer mold. The outer mold is made of ceramic It is made of material, and its inner surface is equipped with pattern blocks made of steel. The up and down movement of the cylinder piston rod drives the mold sleeve to move, thereby controlling the opening and closing of the outer mold; the upper and lower base plates are made of ceramic materials, and the surface in contact with the tire is inlaid with A support block made of steel, the lower base plate is fixed on the base, and the upper base plate is controlled by the cylinder piston to lift and provide clamping force.

3. An open magnetic circuit induction heating tire direct pressure vulcanization device according to claim 2, characterized in that: the wide tile is driven by a double cylinder, the narrow tile is driven by a single cylinder, and the cylinder mechanism comprises a small cylinder and a center The base, in which the cylinder mechanism is evenly arranged in the circumferential direction, the cylinders in the same installation direction are staggered and stacked, the wide-tile driving double cylinder is respectively installed on the upper and lower sides of the single-tile driving cylinder, and the cylinder is connected to the inner surface of the inner mold to ensure smooth movement The telescopic movement of the inner mold block is driven by controlling the telescopic movement of the cylinder piston rod, and the central base is used for the cylinder to be installed and fixed.

4. The open-type magnetic circuit induction heating tire direct pressure vulcanization device according to claim 2, characterized in that: the C-type magnetic conductor is divided into two types: integral type or split type, and the integral type magnetic conductor moves through translation Control the entry and exit after the mold is closed or before the mold is opened; the split-type magnetizer completes the closing or separating movement after the mold is closed or before the mold is opened through translational movement.

5 . The open-type magnetic circuit induction heating tire direct pressure vulcanization device according to claim 2 , wherein an appropriate amount of conductive fibers are mixed into the thicker shoulder material of the tire. 6 .

6. The open-type magnetic circuit induction heating tire direct pressure vulcanization device according to claim 2, wherein the auxiliary coil is wound on the side of the C-shaped magnetic conductor to improve the magnetic induction intensity in the magnetic circuit, and the magnetic induction intensity in the magnetic circuit is increased by adjusting the The amplitude or frequency of the alternating current of the electromagnetic coil or auxiliary coil adjusts the heating time.

7 . The open-type magnetic circuit induction heating tire direct pressure vulcanization device according to claim 2 , wherein the auxiliary silicon steel sheet is attached to the side of the C-shaped magnetic conductor. 8 .