Partitioned and segmented temperature control tire electric energy vulcanization process

Abstract

The invention discloses a tire electric energy vulcanization process with partitioned and segmented temperature control. External temperature partitioned control is adopted to assist in internal temperature and internal pressure control. Wherein the outer temperature zone control is divided into seven zones by a tire section zone; the hot plate is used for adjusting the electric heating coil at the position of the partition of the corresponding tire section, so that the hot plate and the mold shell transmit different temperatures to the partition of the corresponding tire section. Regulation and control of internal pressure, internal temperature and external temperature in the vulcanizing process are achieved by adjusting the pressure of gas introduced into the tire capsule and combining partition heating control of the heater and the hot plate in the capsule, supplement is provided for internal temperature control in an external temperature partition control mode, the accuracy of internal temperature control is improved, and the temperature difference of all positions of the inner surface of the tire can be smaller than 2 DEG C; the temperature uniformity in the capsule in the vulcanization process is good, the situation that the thicker part is insufficiently vulcanized or the thinner part is over-vulcanized is avoided, and the energy consumption of the tire vulcanization procedure is greatly reduced while the tire performance is improved.

Description

Technical Field

[0001] This invention belongs to the field of tire vulcanization technology, specifically relating to a tire electro-vulcanization process with zoned and segmented temperature control. Background Technology

[0002] The tire vulcanization process requires maintaining specific temperature conditions. Currently, steam is the primary heat source for tire vulcanization. Steam or superheated water is introduced into the tire bladder to maintain a certain temperature and pressure. Throughout the vulcanization process, the steam or superheated water circulates continuously. Steam is mainly generated by heating coal or natural gas. However, due to strict restrictions on coal use and high natural gas prices, the cost of steam used in tire vulcanization is relatively high. In reality, the heat transferred from the circulating steam or superheated water to the tire is quite limited, especially during the pressure holding stage where temperature control becomes difficult. Furthermore, it's impossible to achieve zoned control of the external temperature based on the thickness of different tire parts, or segmented adjustment of the internal temperature and pressure according to the vulcanization progress. The significant temperature difference between the inside and outside also affects the uniformity of the overall tire temperature during vulcanization, leading to insufficient vulcanization in thicker areas or over-vulcanization in thinner areas, thus impacting tire performance. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a tire electro-curing process with zoned and segmented temperature control, which solves the problems of temperature control during the tire curing process, large internal and external temperature differences, and poor overall uniformity in the aforementioned background art, and also solves the problem of high energy consumption.

[0004] The technical solution adopted by the present invention to solve its technical problem is as follows: a tire electro-curing process with zoned and segmented temperature control is provided, wherein the tire cross-section is divided into seven zones; wherein the tire crown part is the fourth zone, and the other six zones are symmetrically arranged on both sides of the fourth zone; the first and seventh zones are the tire bead parts; the second and sixth zones are the tire sidewall parts; and the third and fifth zones are the tire shoulder parts.

[0005] By adjusting the electric heating coils at the corresponding partition positions of the hot plate, the hot plate and the mold shell transmit different temperatures to the corresponding partitions of the tire section. The first and seventh partitions are set to 140-150℃, the second and sixth partitions to 130-140℃, the third and fifth partitions to 145-160℃, and the fourth partition to 140-150℃.

[0006] Preferably, the hot plate is composed of upper and lower hot plates and a mold shell. Each hot plate is arranged with the central mechanism as the center and three heating zones are set around the central mechanism, which correspond to the first to third and fifth to seventh zones of the tire cross section, respectively; the mold shell corresponds to the fourth zone.

[0007] Preferably, each heating zone of the hot plate and the mold shell uses an independent electric heating coil.

[0008] Preferably, the first and seventh sections begin at the tire lip toe of the upper and lower molds and end at the upper end of the triangular rubber of the upper and lower molds, with a length accounting for 15%-20% of the total outer perimeter of the tire section, and a projected length on the upper and lower hot plates accounting for 40%-45% of the total projected length of the upper and lower hot plates.

[0009] Preferably, the second and sixth sections begin at the upper end of the upper and lower mold triangular rubber and end at the lower end of the upper and lower mold tire crown, with a length accounting for 10%-15% of the total outer perimeter of the tire section, and a projected length on the upper and lower hot plates accounting for 30%-35% of the total projected length of the upper and lower hot plates.

[0010] Preferably, the third and fifth sections begin at the end of the crown of the upper and lower molds and end at the end of the shoulder of the upper and lower molds, with a length accounting for 5%-10% of the total outer perimeter of the tire section, and the projected length on the upper and lower hot plates accounting for 20%-25% of the total projected length of the upper and lower hot plates.

[0011] Preferably, the fourth section is located between the two ends of the upper and lower mold shoulders, and its length accounts for 30%-35% of the total length of the tire cross section. Its projected height on the mold shell is the mold shell height.

[0012] Preferably, the internal pressure and internal temperature of the vulcanization process are controlled by adjusting the gas pressure introduced into the tire bladder in combination with the heater inside the bladder, and the internal pressure and internal temperature of the vulcanization process are assisted by the external temperature zone control method.

[0013] Preferably, the vulcanization process includes the following steps:

[0014] (1) Tire shaping stage: Low-pressure nitrogen gas of 0.01-0.10 MPa is introduced into the bladder;

[0015] (2) Initial stage of vulcanization: 0.6-1.6MPa low-pressure nitrogen gas is introduced into the capsule and heated to 180-230℃ by the heater inside the capsule, and maintained for 1-5 minutes;

[0016] (3) Vulcanization heating stage: 2.0-2.8MPa high-pressure nitrogen gas is introduced into the capsule and heated to 180-230℃ by the heater inside the capsule, and maintained for 10-20 minutes;

[0017] (4) Vulcanization and pressure holding stage: Maintain the internal pressure of the capsule at 2.0-2.8MPa, stop heating, and maintain for 20-40 minutes;

[0018] (5) Vulcanization leak detection stage: Close the air inlet and outlet valves in the airbag, detect the pressure drop inside the airbag, and determine the airbag sealing status by the degree of pressure drop. This stage is maintained for 1-2 minutes.

[0019] (6) Vulcanization and mold opening stage: The nitrogen in the airbag is discharged to complete the tire vulcanization and the tire is removed.

[0020] Preferably, in step (4), the internal temperature of the capsule is monitored in real time by a temperature sensing element, and heating is restarted when the internal temperature is lower than 150-170°C.

[0021] Compared with the prior art, this technical solution has the following advantages:

[0022] 1. This invention regulates the internal pressure, internal temperature, and external temperature of the vulcanization process by adjusting the gas pressure inside the tire bladder and combining the bladder heater and hot plate zone heating control. This improves tire performance while introducing electric heating into the tire vulcanization process, significantly reducing energy consumption in the tire vulcanization process.

[0023] 2. The external temperature control of the present invention divides the tire into zones and uses hot plates and mold shells with independent electric heating coils for each zone to achieve zoned and segmented temperature control of the tire. This breaks the limitation of the traditional vulcanization process where it is difficult to continue temperature control during the pressure holding stage. The internal temperature of the tire can be supplemented at any time when needed, which has an important effect on improving tire yield and production efficiency.

[0024] 3. The present invention provides more precise and convenient internal temperature control under external temperature supplementation. On the one hand, it ensures good temperature uniformity inside the capsule during the vulcanization process, with a temperature difference of less than 2°C across the inner surface of the tire. The thicker parts of the tire receive more heat, while the thinner parts receive less energy, thus preventing insufficient vulcanization in the thicker parts or over-vulcanization in the thinner parts during the vulcanization process. Attached Figure Description

[0025] Figure 1 This is a schematic diagram showing seven zones defined by the tire's cross-section;

[0026] Figure 2 This is a schematic diagram showing the partitioning of the upper and lower heating plates.

[0027] Among them, the first section 11, the second section 12, the third section 13, the fourth section 3, the fifth section 23, the sixth section 22, the seventh section 21, the upper and lower mold tire lips A1 and A2, the upper end points of the upper and lower mold triangular rubber B1 and B2, the lower and upper mold tire crown tail end points C1 and C2, and the upper and lower mold tire shoulder end points D1 and D2. Detailed Implementation

[0028] It should be noted that the terms "center," "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] In the following embodiments, the total length of the tire section perimeter is: the total length starting from the tire bead at one end of the tire section, along the tire sidewall and tire crown to the tire bead at one end of the tire section.

[0030] Example

[0031] This embodiment describes a segmented, temperature-controlled tire electro-vulcanization process, wherein:

[0032] I. Regulation of external temperature:

[0033] The tire cross-section is divided into seven sections; the fourth section (3) is the crown area, and the other six sections are symmetrically arranged on both sides of the fourth section; the first and seventh sections (11 and 21) are the tire bead areas; the second and sixth sections (12 and 22) are the tire sidewall areas; and the third and fifth sections (13 and 23) are the tire shoulder areas.

[0034] By adjusting the electric heating coils at the corresponding partition positions of the hot plate, the hot plate and the mold shell transmit different temperatures to the corresponding partitions of the tire section. The first and seventh partitions 11 and 21 are set to a temperature of 140-150℃, the second and sixth partitions 12 and 22 are set to a temperature of 130-140℃, the third and fifth partitions 13 and 23 are set to a temperature of 145-160℃, and the fourth partition 3 is set to a temperature of 140-150℃.

[0035] The hot plate consists of upper and lower hot plates and a mold shell. Each hot plate has three heating zones around the central mechanism, corresponding to the first to third and fifth to seventh zones of the tire cross-section, respectively. The mold shell corresponds to the fourth zone, 3. Each heating zone of the hot plate and the mold shell uses an independent electric heating coil.

[0036] like Figure 1 , specifically:

[0037] Sections 1 and 7, 11 and 21: The thicker tire bead area, starting from the tire bead toes A1 / A2 of the upper and lower molds (the intersection of the tire bead and the inner surface), and ending near the upper end points B1 / B2 of the upper and lower mold triangular rubber (the end points of the triangular rubber near the thinnest point of the tire sidewall). Its length accounts for 15%-20% of the total outer perimeter of the tire section. The projected lengths of tire sections 11 and 21 on the upper and lower hot plates are H11 / H21, accounting for 40%-45% of the total projected length H1 of the upper and lower hot plates (the part that only contacts the mold).

[0038] Sections 2 and 6, 12 and 22: The thinner sidewall portion of the tire, starting near the upper end point B1 / B2 of the upper and lower mold triangular rubber (the end point of the triangular rubber closest to the thinnest point of the sidewall) and ending near the end point C1 / C2 of the tire crown of the upper and lower molds. Its length accounts for 10%-15% of the total outer perimeter of the tire section. The projected lengths of tire sections 12 and 22 on the upper and lower hot plates are H12 / H22, accounting for 30%-35% of the total projected length H1 of the upper and lower hot plates (the part that only contacts the mold).

[0039] Sections 3 and 5, 13 and 23: The thicker shoulder area of ​​the tire, starting near the end point C1 / C2 of the upper and lower mold crown and ending at the end point D1 / D2 of the upper and lower mold shoulder, with a length accounting for 5%-10% of the total outer perimeter of the tire section; the projected length of tire sections 13 and 23 on the upper and lower hot plates is H13 / H23, accounting for 20%-25% of the total projected length H1 of the upper and lower hot plates (only the part in contact with the mold).

[0040] Section 3: The thicker crown portion of the tire, located between the shoulder endpoints D1 and D2 of the upper and lower molds, with a length accounting for 30%-35% of the total outer perimeter of the tire section; the projected height of tire section 3 on the tread block hot plate (mold shell) is H3, which is the height of the tread block hot plate (mold shell) (only the height in contact with the tread block is calculated).

[0041] To ensure that each section of the tire receives a different external temperature from the mold, the hot plate and mold shell need to be divided into sections. Different temperatures are set for each section of the hot plate and mold shell using independent electric heating coils, which are then transmitted to the mold, thus ensuring that each section of the tire reaches the preset external temperature. For example... Figure 2 , specifically:

[0042] Upper and lower hot plate partitions R11 and R21: The inner ring of the hot plate near the central mechanism, its width is equal to the projection length of tire partitions 11 and 21 on the upper and lower hot plates, which is H11 and H21. The temperature of this hot plate partition is set between 140-150℃.

[0043] Upper and lower heating plate partitions R12 and R22: Located near the outer ring of upper and lower heating plate partitions R11 and R21, their width is equal to the projected length of tire partitions 12 and 22 on the upper and lower heating plates, which is H12 and H22. The temperature of this heating plate partition is set between 130-140℃.

[0044] Upper and lower heating plate partitions R13 and R23: Located near the outer ring of upper and lower heating plate partitions R12 and R22, their width is equal to the projection length of tire partitions 13 and 23 on the upper and lower heating plates, which is H13 and H23. The temperature of this heating plate partition is set between 145-160℃.

[0045] Fourth section 3: This section is the mold shell, and its height is the projection height H3 of tire section 3 on the mold shell. The temperature of this section is set between 140-150℃.

[0046] II. The tire vulcanization process is carried out under external temperature control. The specific internal temperature and internal pressure control includes the following steps:

[0047] (1) Tire shaping stage: Low-pressure nitrogen gas of 0.01-0.10MPa is introduced into the bladder to play a shaping role;

[0048] (2) Initial vulcanization stage: Low-pressure nitrogen gas (0.6-1.6 MPa) is introduced into the bladder, and the bladder is heated to 180-230℃ by the heater inside the bladder, and maintained for 1-5 minutes; this stage further shapes and keeps the tire warm. Compared with the traditional steam heating process, this stage allows the tire to achieve a higher temperature in the initial vulcanization stage while reducing the initial pressure. This makes it easier for the bladder to heat up and transfer heat to the tire surface, while the lower initial pressure allows the tire to fill the mold more evenly, improving the tire yield.

[0049] (3) Vulcanization heating stage: High-pressure nitrogen gas of 2.0-2.8MPa is introduced into the capsule and heated to 180-230℃ by the heater inside the capsule, and maintained for 10-20 minutes; this serves to keep the temperature and pressure.

[0050] (4) Vulcanization and pressure holding stage: The internal pressure of the capsule is maintained at 2.0-2.8MPa, and heating is stopped. During this stage, the internal temperature of the capsule is monitored in real time by a temperature sensing element. When the internal temperature is lower than the lower limit of the process standard (150-170℃), heating is restarted to ensure the temperature required for vulcanization. This stage lasts for 20-40 minutes and serves to keep the temperature and pressure.

[0051] (5) Vulcanization and leak detection stage: Close the air inlet and outlet valves in the airbag, detect the pressure drop inside the airbag, and determine the airbag sealing status by the degree of pressure drop. This stage lasts for 1-2 minutes.

[0052] (6) Vulcanization and mold opening stage: The nitrogen in the airbag is discharged to complete the tire vulcanization and the tire is removed.

[0053] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions 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. A zoned and segmented temperature-controlled tire electro-curing process, characterized in that: External temperature zone control is adopted: The tire cross-section is divided into seven sections; the fourth section is the crown area, and the other six sections are symmetrically arranged on both sides of the fourth section; the first and seventh sections are the tire bead area; the second and sixth sections are the tire sidewall area; and the third and fifth sections are the tire shoulder area. By adjusting the electric heating coils at the corresponding partition positions of the hot plate, the hot plate and the mold shell transmit different temperatures to the corresponding partitions of the tire section. The first and seventh partitions are set to 140-150℃, the second and sixth partitions to 130-140℃, the third and fifth partitions to 145-160℃, and the fourth partition to 140-150℃.

2. The tire electro-vulcanization process with zoned and segmented temperature control according to claim 1, characterized in that: The hot plate is composed of upper and lower hot plates and a mold shell. Each hot plate is arranged with the central mechanism as the center and three heating zones are set around the central mechanism, which correspond to the first to third and fifth to seventh zones of the tire cross section respectively; the mold shell corresponds to the fourth zone.

3. The tire electro-vulcanization process with segmented and temperature-controlled heating according to claim 2, characterized in that: Each heating zone of the hot plate and mold shell uses an independent electric heating coil.

4. The tire electro-vulcanization process with segmented and temperature-controlled heating according to claim 1, characterized in that: The first and seventh sections begin at the tire lip and end at the upper end of the triangular rubber of the upper and lower molds, with a length accounting for 15%-20% of the total outer perimeter of the tire section, and a projected length on the upper and lower hot plates accounting for 40%-45% of the total projected length of the upper and lower hot plates.

5. The tire electro-vulcanization process with segmented and temperature-controlled heating according to claim 1, characterized in that: The second and sixth sections begin at the upper end of the upper and lower mold triangular rubber and end at the lower end of the upper and lower mold tire crown. Their length accounts for 10%-15% of the total outer perimeter of the tire section, and their projected length on the upper and lower hot plates accounts for 30%-35% of the total projected length of the upper and lower hot plates.

6. The tire electro-vulcanization process with segmented and temperature-controlled treatment according to claim 1, characterized in that: The third and fifth sections begin at the end of the crown of the upper and lower molds and end at the end of the shoulder of the upper and lower molds. Their length accounts for 5%-10% of the total outer perimeter of the tire section, and their projected length on the upper and lower hot plates accounts for 20%-25% of the total projected length of the upper and lower hot plates.

7. The tire electro-vulcanization process with segmented and temperature-controlled heating according to claim 1, characterized in that: The fourth section is located between the two ends of the upper and lower mold shoulders, and its length accounts for 30%-35% of the total length of the tire cross section. Its projected height on the mold shell is the mold shell height.

8. The tire electro-curing process with segmented and temperature-controlled heating according to claim 1, characterized in that: The internal pressure and internal temperature of the vulcanization process are assisted by external temperature zone control.

9. The tire electro-curing process with segmented and temperature-controlled heating according to claim 8, characterized in that: The internal pressure and temperature control during the vulcanization process includes the following steps: (1) Tire shaping stage: Low-pressure nitrogen gas of 0.01-0.10 MPa is introduced into the bladder; (2) Initial stage of vulcanization: 0.6-1.6MPa low-pressure nitrogen gas is introduced into the capsule and heated to 180-230℃ by the heater inside the capsule, and maintained for 1-5 minutes; (3) Vulcanization heating stage: 2.0-2.8MPa high-pressure nitrogen gas is introduced into the capsule and heated to 180-230℃ by the heater inside the capsule, and maintained for 10-20 minutes; (4) Vulcanization and pressure holding stage: Maintain the internal pressure of the capsule at 2.0-2.8MPa, stop heating, and maintain for 20-40 minutes; (5) Vulcanization leak detection stage: Close the air inlet and outlet valves in the airbag, detect the pressure drop inside the airbag, and determine the airbag sealing status by the degree of pressure drop. This stage is maintained for 1-2 minutes. (6) Vulcanization and mold opening stage: The nitrogen in the airbag is discharged to complete the tire vulcanization and the tire is removed.

10. The tire electro-curing process with segmented and temperature-controlled heating according to claim 9, characterized in that: In step (4), the internal temperature of the capsule is monitored in real time by a temperature sensing element. When the internal temperature is lower than 150-170℃, heating is restarted.

Images