Heating press for vulcanising a vehicle tyre

Abstract

The invention relates to a heating press (1) for vulcanising a vehicle tyre (5), having a heating-press upper part (4) and a heating-press lower part (3), wherein the heating-press upper part (4) and the heating-press lower part (3) are designed to receive a vehicle tyre (5), to place it under pressure and to heat it, wherein the heating press (1) has a central mechanism (6) having gas outlet openings for setting a pressure in the vehicle tyre (5) and filling the vehicle tyre (5) with a heating medium, wherein the heating press (1) has a heating-medium processing unit (2) for processing the heating medium. The invention also relates to a method for operating a heating press (1) for vulcanising a vehicle tyre (5).

Description

[0001] Description

[0002] HEATING PRESS FOR VULCANIZING A VEHICLE TIRE

[0003] The invention relates to a heating press for vulcanizing a vehicle tire, comprising an upper heating press part and a lower heating press part, wherein the upper heating press part and the lower heating press part are designed to receive, pressurize, and heat a vehicle tire.

[0004] Furthermore, the invention relates to a method for operating a heating press for vulcanizing a vehicle tire.

[0005] Heating presses are known that feature a bellows with which the vehicle tire is positioned and pressed into the tire heating mold. Steam is used to heat the bellows, which allows for a high heat input into the bellows. The steam condenses and partially precipitates in the bellows, reducing the heat input in the lower area. This results in uneven heat input into the vehicle tire. Furthermore, the steam escapes at the end of the heating process, which reduces energy efficiency.

[0006] Furthermore, curing presses are known that heat bellows with dry gases, which increases energy efficiency. Such curing presses can also be designed without bellows, as no condensate is produced. However, the disadvantage of such curing presses is that the specific energy introduced by dry gases is lower than that of steam, resulting in less heat being transferred into the bellows. The vulcanization process on the inside of the vehicle tire is slowed, and the process time is increased.

[0007] Against this background, the invention is based on the object of designing a heating press and a method in such a way that a uniform and particularly high heat flow in the vehicle tires is enabled with high energy efficiency.

[0008] This object is achieved by a heating press according to the features of patent claim 1 and a method according to the independent claim. The subclaims relate to particularly useful developments of the invention.

[0009] According to the invention, a heating press for vulcanizing a vehicle tire is provided, comprising an upper heating press part and a lower heating press part, wherein the upper heating press part and the lower heating press part are configured to receive, pressurize, and heat a vehicle tire. The heating press has a central mechanism with gas outlet openings for adjusting a pressure in the vehicle tire and filling the vehicle tire with a heating medium. The heating press has a heating medium processing unit for processing the heating medium, wherein the heating medium processing unit has an inlet heater for heating the heating medium that pressurizes the vehicle tire, wherein the inlet heater is connected to the central mechanism in a heating medium-conducting manner. The heating press has a circulation heater, independent of the inlet heater, for heating the heating medium circulating through the vehicle tire.Independent means that the circulation heater can be operated independently of the inflow heater and / or regulates the temperature of the circulating heating medium without affecting the inflow heater, for example, because the heating medium is routed through the inflow heater. The heating press has a circulation pump, which is connected to the circulation heater and the vehicle tire in a way that conducts the heating medium.

[0010] This design of the heating medium processing unit allows the use of dry gases, eliminating condensate, while enabling a high and precisely adjusted heat flow. This is made possible by the inlet heater tempering a high volume flow, which then flows into the vehicle tire. To achieve a high energy input after setting a higher overpressure in the vehicle tire, a high volume flow of the heating medium into the vehicle tire is enabled by the circulation heater with the circulation pump. The circulation heater and the circulation pump form a closed circuit with the vehicle tire at constant pressure during the heating phase. A particularly energy-efficient and uniform energy input with a particularly high heat flow is made possible.

[0011] A preferred embodiment provides that the lower part of the heating press has a lower bead ring and the upper part of the heating press has an upper bead ring, wherein the bead rings have a geometry for forming a gas-tight seal with a bead of a vehicle tire, sealing the vehicle tire to form an enclosed area. This enables the immediate adjustment of pressure in the vehicle tire. A bellows can be omitted, thus eliminating the need for heating a bellows and the thermal resistance of the bellows, thereby increasing energy efficiency and reducing process time.

[0012] A further preferred embodiment provides that the circulation heater is connected to the central mechanism in such a way that the heating medium flowing through the circulation heater does not flow through the inflow heater and preferably does not flow through a heat exchanger and / or a heating medium storage tank. By constructing the circuit as compactly as possible, through which the flow is maintained at a constant pressure during the heating phase, heat loss to the environment can be reduced and energy efficiency increased. Furthermore, the inflow heater can be tempered during the heating phase for the subsequent heating process.

[0013] A further preferred embodiment provides that the heating medium processing unit comprises a heat exchanger, in particular a counterflow heat exchanger or a crossflow heat exchanger. The heat exchanger is connected in a heating medium-conducting manner to a supply line to the inflow heater and a discharge line from the central mechanism. A gas purification device is preferably arranged between the central mechanism and the circulation pump. A heat exchanger enables the thermal energy of the heating medium flowing out of the vehicle tire at the end of the heating process to be further utilized and can, for example, be transferred to the heating medium used for the subsequent heating process. Counterflow heat exchangers and crossflow heat exchangers have proven particularly suitable for this purpose.

[0014] A further preferred embodiment provides that the heating medium processing unit has a heating medium reservoir, wherein the heating medium reservoir is preferably filled by means of a compressor and, more preferably, is connectable to at least two heating presses. A heating medium reservoir can be provided in addition to or as an alternative to a heat exchanger and enables the repeated use of the same heating medium.

[0015] A further preferred embodiment provides for the heating medium to be a gas, preferably air or an inert gas, especially nitrogen. Dry gases have proven particularly suitable. Based on their combined properties, air and inert gases, especially nitrogen, have proven advantageous.

[0016] A further preferred embodiment provides that the heating medium processing unit, with the central mechanism, generates circulation of the heating medium in a bellows or a vehicle tire. Circulation of the heating medium in a bellows or a vehicle tire is understood here to mean the formation of a targeted flow in the bellows or the vehicle tire, thereby enabling a particularly uniform heat flow in the bellows or the vehicle tire.

[0017] A further preferred embodiment provides that the circulation pump generates a volume flow of at least 50 l / min, preferably of at least 100 l / min and more preferably of at least 150 l / min at a pressure of at least 8 bar, preferably at least 12 bar and more preferably at least 16 bar at a temperature of at least 120° C, preferably at a temperature of at least 150° C and more preferably at a temperature of at least 180° C. In order to be able to provide a sufficiently high heat flow, in particular at the start of the heating process, a high volume flow at high pressures and high temperatures has proven to be particularly suitable.

[0018] A further preferred embodiment provides that the inflow heater is adjustable to target temperatures, wherein the minimum target temperature is at least 120° C, preferably at least 150° C, more preferably at least 180° C, more preferably at least 210° C, more preferably at least 240° C, more preferably at least 270° C and more preferably at least 300° C. In order to be able to adapt the heating medium to the selected temperature of the heating process when increasing the pressure in the vehicle tire, an inflow heater with adjustable target temperatures has proven advantageous, since this shortens the process time. The higher the possible target temperature, the higher the heat flow that can be selected during the increase in pressure in the vehicle tire, thereby shortening the process time.

[0019] A further preferred embodiment provides that the inflow heater has a high heat capacity of at least 2 kJ / K, preferably at least 5 kJ / K, preferably at least 10 kJ / K, preferably at least 20 kJ / K, further preferably at least 30 kJ / K, further preferably at least 50 kJ / K and further preferably at least 80 kJ / K and a flow-over area of ​​at least 3 m 2 , preferably 10 m 2 , further preferably 30 m 2 , further preferably 80 m 2 , further preferably 120 m 2 and further preferably 180 m 2The high heat capacity of the inflow heater and the large surface area over which it flows allow the heating medium to flow into the inflow heater at a low temperature, while the heating medium flowing out of the inflow heater maintains the required temperature with high precision. This is complex and only possible with a heat generator with a low heat capacity that converts electrical energy into thermal energy, such as a heating filament, due to the dynamic nature of the process.

[0020] A further preferred embodiment provides for a preheating means, in particular a preheating means with adjustable and / or controllable power output, to be arranged on the inlet side of the inflow heater or upstream of the inflow heater in the inflow direction. This allows the temperature of the heating medium to be brought closer to its target temperature, thereby reducing the heat capacity and the surface area over which the heating medium flows, with a small temperature variance, for the heating medium flowing out of the inflow heater.

[0021] A further preferred embodiment provides that the circulation heater is a pipe trace heater or a continuous flow heater.

[0022] A further preferred embodiment provides that the upper and lower parts of the heating press are insulated in the area of ​​the contact surfaces with the bellows and preferably at their surfaces from the environment. This further increases the energy efficiency of the heating press.

[0023] According to the invention, a method is provided for operating a heating press for vulcanizing a vehicle tire, in particular a heating press according to the invention, comprising the steps:

[0024] - Positioning a vehicle tire in the heating press,

[0025] - generating a gas flow through an inlet heater to generate a tempered low overpressure in a vehicle tire,

[0026] - Starting a circulation pump and tempering the gas circulating through the vehicle tire,

[0027] - Closing the heating press,

[0028] - generating a gas flow through an inlet heater to generate a tempered higher overpressure in the vehicle tire,

[0029] - End the vulcanization process by reducing the overpressure in the vehicle tire, stopping the circulation pump, opening the heating press and removing the vehicle tire.

[0030] The process allows the use of dry gases, eliminating condensate, while generating a high and precisely adjusted heat flow. This is achieved by a high, tempered volume flow through the inlet heater, which then flows into the vehicle tire. To achieve a high energy input after setting a higher overpressure in the vehicle tire, a high volume flow of the heating medium is generated in the vehicle tire by the circulation heater with the circulation pump. This creates a particularly energy-efficient and even energy input with a particularly high heat flow.

[0031] The method provides for control or regulation of the tire pressure as well as temperature control or regulation of both the inlet heater and the circulation heater.

[0032] The invention allows for numerous embodiments. To further clarify its basic principle, one of them is shown in the drawing and will be described below. This shows in

[0033] Fig. 1 shows a heating press with a heating medium processing unit;

[0034] Figure 1 shows a heating press 1 with a heating medium processing unit 2. The left half of the heating press 1, the lower part 3 and the upper part 4, are shown in contact with each other. A vehicle tire 5 is located in the retracted heating press 1 during the vulcanization process. To heat the vehicle tire 5 from the inside, a heating medium, whose flow behavior is schematically indicated by arrows, flows through the vehicle tire 5. For this purpose, the heating medium is guided into and out of the vehicle tire 5 through the center mechanism 6. The heating medium processing unit 2 is conductively connected to the center mechanism 6.

[0035] The heating medium processing unit 2 is supplied with a heating medium via a heating medium line 7, which is preheated in a heat exchanger 8, in the form of a cross-type heat exchanger. The heating medium then flows through an inflow heater 9, where the heating medium is heated during inflation of the vehicle tire 5 to its desired temperature within the vehicle tire 5. The inflow heater 9 has a high heat capacity and a large overflow area, so that the heating medium leaves the inflow heater 9 at a nearly constant temperature, even at a high volume flow.The heating medium then flows through the center mechanism 6 into the vehicle tire 5, flows through it and then flows out of the vehicle tire 5 through the center mechanism 6 and is transported by a circulation pump 10 through a circulation heater 11 and a check valve 12 and is thereby heated again to a desired temperature and then flows through the center mechanism 6 and the vehicle tire 5 again.

[0036] When the heating process is terminated, the inlet valve 13 of the heating medium processing unit 2 is closed, and the circulation valve 14 and the outlet valve 15 of the heating medium processing unit 2 are opened. The heating medium flows from the vehicle tire 5 through the cross heat exchanger into a heating medium line 16 and transfers a portion of its thermal energy via the cross heat exchanger to the heating medium flowing in for the next heating process.

[0037] List of reference symbols

[0038] heating press

[0039] Heating medium processing unit

[0040] Heating press lower part

[0041] Heating press upper part

[0042] Vehicle tires

[0043] Center mechanism

[0044] Heating medium line heat exchanger inlet heater

[0045] Circulation pump

[0046] Circulation heater

[0047] Check valve

[0048] Inlet valve

[0049] Circulation valve

[0050] Outlet valve

[0051] Heating medium line

Claims

Patent claims 1. Heating press (1) for vulcanizing a vehicle tire (5), comprising a heating press upper part (4) and a heating press lower part (3), wherein the heating press upper part (4) and the heating press lower part (3) are configured to receive, pressurize, and heat a vehicle tire (5), wherein the heating press (1) comprises a center mechanism (6) with gas outlet openings for adjusting a pressure in the vehicle tire (5) and filling the vehicle tire (5) with a heating medium, wherein the heating press (1) comprises a heating medium processing unit (2) for processing the heating medium, characterized in that the heating medium processing unit (2) comprises an inlet heater (9) for heating the heating medium pressurizing the vehicle tire (5), wherein the inlet heater (9) is connected to the center mechanism (6) in a heating medium-conducting manner, and a independent circulation heater (11 ),for heating the heating medium circulating through the vehicle tire (5), and a circulation pump (10), wherein the circulation pump (10) is connected to the circulation heater (11) and the vehicle tire (5) in a heating medium-conducting manner.

2. Heating press (1) according to claim 1, characterized in that the heating press lower part (3) has a lower bead ring and the heating press upper part (3) has an upper bead ring, wherein the bead rings have a geometry for forming a gas-tight seal with a bead of a vehicle tire (5), for sealing the vehicle tire (5) to an enclosed area.

3. Heating press (1) according to claims 1 or 2, characterized in that the circulation heater (11) is connected to the central mechanism (6) in such a way that the heating medium flow flowing through the circulation heater (11) does not flow through the inflow heater (9) and preferably not through a heat exchanger (8) and / or a heating medium storage tank.

4. Heating press (1) according to one of the preceding claims, characterized in that the heating medium processing unit (2) has a heat exchanger (8), in particular a counterflow heat exchanger or a crossflow heat exchanger, wherein the heat exchanger (8) is connected in a heating medium-conducting manner to a supply line to the inflow heater (9) and a discharge line from the central mechanism (6), wherein preferably a gas cleaning device is arranged between the central mechanism (6) and the circulation pump (10).

5. Heating press (1) according to one of the preceding claims, characterized in that the heating medium processing unit (2) has a heating medium storage, wherein the heating medium storage is preferably filled by means of a compressor and more preferably is connectable to at least two heating presses (1).

6. Heating press (1) according to one of the preceding claims, characterized in that the heating medium is a gas, preferably air or an inert gas, in particular nitrogen.

7. Heating press (1) according to one of the preceding claims, characterized in that the heating medium processing unit (2) with the center mechanism (6) generates a circulation of the heating medium in a bellows or a vehicle tire (5).

8. Heating press (1) according to one of the preceding claims, characterized in that the circulation pump (10) generates a volume flow of at least 50 l / min, preferably of at least 100 l / min and more preferably of at least 150 l / min at a pressure of at least 8 bar, preferably at least 12 bar and more preferably at least 16 bar at a temperature of at least 120° C, preferably at a temperature of at least 150° C and more preferably at a temperature of at least 180° C.

9. Heating press (1) according to one of the preceding claims, characterized in that the inflow heater (9) is adjustable to target temperatures wherein the minimum target temperature is at least 120° C, preferably at least 150° C, more preferably at least 180° C, more preferably at least 210° C, more preferably at least 240° C, more preferably at least 270° C and more preferably at least 300° C.

10. Heating press (1) according to one of the preceding claims, characterized in that the inflow heater (9) has a high heat capacity of at least 2 kJ / K, preferably at least 5 kJ / K, preferably at least 10 kJ / K, preferably at least 20 kJ / K, further preferably at least 30 kJ / K, further preferably at least 50 kJ / K and further preferably at least 80 kJ / K and a flow-over area of ​​at least 3 m 2 , preferably 10 m 2 , further preferably 30 m 2 , further preferably 80 m 2 , further preferably 120 m 2 and further preferably 180 m 2 .

11. Heating press (1) according to one of the preceding claims, characterized in that a preheating means, in particular a preheating means whose power output is adjustable and / or controllable, is arranged on the inlet side of the inflow heater (9) or in the inflow direction in front of the inflow heater (9).

12. Heating press (1) according to one of the preceding claims, characterized in that the circulation heater (11) is a pipe trace heater or a continuous flow heater.

13. Heating press (1) according to one of the preceding claims, characterized in that the heating press upper part (4) and the heating press lower part (3) are insulated in the region of the contact surfaces with the bellows and preferably on their surfaces from the environment.

14. Method for operating a heating press (1) for vulcanising a vehicle tyre (5), in particular a heating press (1) according to one of the preceding claims, comprising the steps: - positioning a vehicle tire (5) in the heating press (1), - generating a gas flow through an inlet heater (9) to generate a tempered low overpressure in a vehicle tire (5), - starting a circulation pump (10) and tempering the gas circulating through the vehicle tyre (5), - Closing the heating press (1 ), - generating a gas flow through an inlet heater (9) to generate a tempered higher overpressure in the vehicle tire (5), - Terminating the vulcanization process by reducing the overpressure in the vehicle tire (5), stopping the circulation pump (10), opening the heating press (1) and removing the vehicle tire (5).

Images