阅读说明：本技术 一种封头绝热层快速模压预成型装置 (Quick mould pressing of head heat insulation layer is forming device in advance ) 是由 宗喜龙 武长毅 高志刚 杨咏华 刘丽霞 于 2020-12-14 设计创作，主要内容包括：本发明涉及固体火箭发动机封头绝热层模压预成型工艺过程,具体涉及一种封头绝热层快速模压预成型装置。包括阳模、阴模、导柱、导向套,通水孔,密封盖板,挡板及紧固螺栓,所述阴模、阳模合模靠导向套和导柱进行定位；所述阳模和阴模中设置通水孔,通水孔内部挡板与孔道间及通水孔与模具盖板间进行密封,通水孔密封通过密封盖板和紧固螺栓实现。所述模具阳模和阴模中增加多个可通循环介质的串并联孔道,使加热或降温循环介质直接通入模具内部。本发明对模具传热面积增加和传热距离减少,提高了模具的升温速率；模具内部通入冷水,提高了降温速率；循环介质直接对模具进行升降温,避免了压机压板升降温的能耗,降低了过程能耗。(The invention relates to a die-pressing preforming process for a heat insulating layer of a solid rocket engine head, in particular to a rapid die-pressing preforming device for the heat insulating layer of the head. The die comprises a male die, a female die, a guide post, a guide sleeve, a limber hole, a sealing cover plate, a baffle plate and a fastening bolt, wherein the female die and the male die are assembled and positioned by the guide sleeve and the guide post; and limber holes are formed in the male die and the female die, the space between the baffle plate inside the limber hole and the pore channel and the space between the limber hole and the die cover plate are sealed, and the limber hole sealing is realized through a sealing cover plate and a fastening bolt. A plurality of series-parallel pore canals which can be communicated with a circulating medium are added in the male die and the female die of the die, so that the heating or cooling circulating medium is directly communicated into the die. The invention increases the heat transfer area and reduces the heat transfer distance of the die, thereby improving the heating rate of the die; cold water is introduced into the die, so that the cooling rate is improved; the circulating medium directly heats and cools the die, so that the energy consumption of heating and cooling the press plate of the press is avoided, and the energy consumption of the process is reduced.)

1. The utility model provides a quick mould pressing of head heat insulation layer is forming device in advance which characterized in that: the die comprises a male die, a female die, a guide post, a guide sleeve, a limber hole, a sealing cover plate, a baffle plate and a fastening bolt, wherein the female die and the male die are assembled and positioned by the guide sleeve and the guide post; and limber holes are formed in the male die and the female die, the space between the baffle plate inside the limber hole and the pore channel and the space between the limber hole and the die cover plate are sealed, and the limber hole sealing is realized through a sealing cover plate and a fastening bolt.

2. The rapid prototyping apparatus for insulation barrier sheeting of claim 1 wherein: a plurality of series-parallel pore canals which can be communicated with a circulating medium are added in the male die and the female die of the die, so that the heating or cooling circulating medium is directly communicated into the die.

Technical Field

The invention relates to a die-pressing preforming process for a heat insulating layer of a solid rocket engine head, in particular to a rapid die-pressing preforming device for the heat insulating layer of the head.

Background

The heat insulating layer in the solid rocket engine mainly has the functions of preventing the combustion chamber shell from reaching the temperature which endangers the structural integrity in the working process of the engine, preventing the combustion products from scouring the shell, buffering the transmission of the shell strain to the propellant, preventing certain chemical components in the propellant from migrating to the engine wall to corrode the shell, limiting the combustion of the local surface of the propellant according to the design requirement, guiding the combustion products to enter the spray pipe in a laminar flow mode to the maximum extent possible, sealing the shell, accessories and joints thereof, preventing the gas from leaking and the hot combustion products from damaging the spray pipe, and preventing the pneumatic friction heat and the high-altitude radiation from invading to protect the explosive column when the missile is launched.

The internal heat insulation of the domestic engine steel shell is mostly a sheet heat insulation layer with controllable thickness and low ablation rate. The forming method mainly adopts the traditional manual patch forming process as a main part, and the heat insulating layer is mostly manufactured by a method of laminating and pasting, so that the production mode has low efficiency, the phenomena of heat insulating layer bulging (bubbles), pits, debonding and uneven thickness are easy to occur in the production process, the effective thickness of the heat insulating layer is reduced due to the pits, and the thermal protection capability is reduced; the bulge and the debonding can reduce the bonding strength between the heat insulation layer and the shell, and the heat insulation layer is extremely easy to be eroded by hot air flow during the operation of the engine, so that the structure of the heat insulation layer is damaged, and the heat protection fails. Meanwhile, the manual pasting process is poor in applicability, the engine with a small diameter is difficult for operators to insulate the shell, and the design basic progress of the engine with a small opening, a large slenderness ratio is restricted. With the diversification and the structural complication of the solid rocket engine, the manual pasting heat insulation process cannot meet the diversification and the complicated design requirements of the solid rocket engine. The above drawbacks are easily generated in the manual patch manufacturing process of the insulating layer. Therefore, in recent years, the head insulation layer and the manual debonding layer mould pressing preforming technology are developed and applied, the mould pressing preforming technology is a novel insulation layer forming technology, the head insulation layer structure is firstly mould pressed by using a mould and then is pasted on a shell, the method not only eliminates the overlapping of air bubbles, air gaps and insulation sheets generated by manual lamination, but also can move the overlapping seam of manual lamination to a combustion chamber cylinder body section, for an engine without end face fuel, the insulation layer at the cylinder body section part is hardly contacted with fuel gas, and the fuel column is a good insulation layer. On the other hand, the heat insulating layer manufactured by adopting the die pressing preforming process is compact and uniform, the thickness can also strictly meet the design requirement, the passive quality of the heat insulating layer of the engine shell is reduced, the quality of the engine is improved, and the ignition reliability is also improved.

The compression molding process of the heat insulating layer of the existing seal head comprises the following steps: heating the mould and the material by using a flat vulcanizing machine, applying pressure after the mould and the heat insulating material reach a certain temperature and have certain fluidity to enable the heat insulating material to be formed in the mould, maintaining the pressure and cooling until the prefabricated product has certain strength, then carrying out demoulding operation, measuring the thickness of the product after demoulding, and checking the apparent quality of the product. The specific process comprises the following steps:

1) preheating a mould: in order to increase the heat transfer efficiency and improve the temperature difference between the die and the press vulcanizer, the press vulcanizer is initially set at a temperature of 150 ℃ to preheat the die, and the temperature of the die and the temperature of the press are both increased. When the temperature of the die reaches 40 ℃, the set temperature of the vulcanizing press is adjusted to 80 ℃, the temperature of the die is continuously increased at the stage, and the temperature of the vulcanizing press is reduced. When the temperature of the mold is raised to 60-75 ℃ required by material molding and the temperature of the press vulcanizer is lowered to 80 ℃, the temperature of the mold and the temperature of the press vulcanizer are kept in a balanced state. The temperature rise curve is now shown in FIG. 1.

2) Preheating materials: and after the temperature of the die is constant, paving the heat-insulating material film with fixed weight in a die cavity, and preheating the materials for 20 min.

Compression molding: after the material is preheated uniformly, the pressure is applied to 10MPa, so that the material is molded in a mold cavity.

4) Pressure maintaining and temperature reduction: and (3) closing the heating system of the vulcanizing press, maintaining the pressure and cooling, and cooling the vulcanizing press, the mold and the molded product synchronously at the moment, wherein a cooling curve is shown in figure 2.

5) Demolding: when the temperature of the die and the die pressing product is reduced to be less than or equal to 40 ℃, the die pressing product is demoulded after having certain strength, and the thickness and the appearance of the product are measured and checked after demould, and the product is stored for standby after meeting the requirements.

According to the existing head insulation layer mould pressing preforming process, the existing process has the following defects:

the process temperature is difficult to accurately control, the mold has a temperature gradient from a heating plate of the flat vulcanizing machine to the center of the mold, so that the defects are easily caused due to nonuniform heating of materials, and the product percent of pass is low;

the temperature rise of the die is realized by heat transfer of an upper pressing plate and a lower pressing plate of the flat vulcanizing machine, the heat transfer efficiency is low, and the energy consumption is high;

the temperature reduction of the die and the temperature reduction of the flat vulcanizing machine are carried out synchronously in a natural environment, and the temperature reduction speed is low.

Disclosure of Invention

Technical problem to be solved by the invention

The invention provides a rapid die pressing preforming device for a heat insulating layer of an end socket, which can improve the heat transfer efficiency of a die, reduce the energy consumption in the process and reduce the temperature difference in a die cavity of the die so as to achieve the purposes of improving the production efficiency and improving the product quality.

Technical scheme adopted for solving technical problem

A head insulation layer rapid mould pressing preforming device comprises a male die, a female die, a guide pillar, a guide sleeve, a water through hole, a sealing cover plate, a baffle plate and a fastening bolt, wherein the female die and the male die are assembled and positioned by the guide sleeve and the guide pillar; and limber holes are formed in the male die and the female die, the space between the baffle plate inside the limber hole and the pore channel and the space between the limber hole and the die cover plate are sealed, and the limber hole sealing is realized through a sealing cover plate and a fastening bolt.

Furthermore, a plurality of series-parallel pore canals which can be communicated with circulating media are added in the male die and the female die of the die, so that the heating or cooling circulating media are directly communicated into the die.

Advantageous effects

Compared with the prior process, the rapid die pressing preforming technology has the following advantages:

the heat transfer area is increased, the heat transfer distance is reduced, and the temperature rise rate of the die is improved;

the cooling mode of the die is that cold water is introduced into the die, so that the cooling rate is improved;

the temperature of the die is directly increased or decreased by the circulating medium, so that the energy consumption of increasing or decreasing the temperature of the pressing plate of the pressing machine is avoided, and the energy consumption of the process is reduced;

the distance between the circulating medium and the mold cavity is small and uniform, and the temperature control precision of the mold is improved.

Drawings

FIG. 1: a temperature rise curve;

FIG. 2: a cooling curve;

FIG. 3: a schematic diagram of the external structure of the mold pressing die;

FIG. 4: a schematic diagram of the internal structure of the mold;

FIG. 5: the inner circulation medium of the mold runs a schematic diagram after the pore channel is unfolded;

wherein: 1-water hole baffle, 2-sealing cover plate, 3-fastening bolt, 4-water inlet and outlet, 5-water hole, 6-guide pillar, 7-male die, 8-female die, 9-hollow weight reduction and 10-guide sleeve.

Detailed Description

The invention is further described with reference to the accompanying drawings and specific embodiments:

the schematic diagram of the existing molding die is shown in fig. 3, which mainly comprises 1: male die, female die, guide pillar, uide bushing etc. The male die is of a hollow weight reduction structure, a die cavity of the die is of a product forming size after the female die and the male die are completely assembled, and the female die and the male die are assembled by positioning the female die and the male die by means of the guide sleeve and the guide pillar, so that the uniformity of the circumferential thickness of the product is guaranteed. The structure of the mold is optimized, the heat transfer mode of the mold is changed, as shown in fig. 4, namely, a plurality of series-parallel pore channels which can be communicated with the circulating medium are added in the male mold and the female mold of the mold, so that the heating or cooling circulating medium is directly communicated into the mold, the heat transfer area is increased, the heat transfer distance is reduced, the heat transfer efficiency is improved, and meanwhile, the surface of the cavity of the mold is not damaged. The schematic diagram of the circulating medium running hole in the mold after being unfolded is shown in figure 5.

After the structure of the die is optimized, heating and cooling water enters the water holes of the die from the water inlet and the water outlet, and flows out of the die after circulation of the water holes, so that the effect of heating and cooling the die is achieved. The water hole sealing is realized by a sealing cover plate and a fastening bolt.

In the mould structure after optimizing, the water hole divide into the multichannel and parallelly connected and a plurality of series connection, and the sealing process is carried out between inside baffle of water hole and pore and between water hole and mould clamp plate, has both improved heat transfer efficiency and guaranteed the intensity of mould and the complete of profile again.

Designing a precise temperature control system of the die:

after the structure of the die is optimized, a die temperature control system is designed to realize the accurate control of the die temperature. The system comprises a water chilling unit, a hot water unit, a power transmission system, a heat preservation water tank, a circulating pipeline and the like. Wherein the water chilling unit and the water heating unit respectively provide flowing media required by cooling and heating the die; the power transmission system enables the temperature raising and reducing media to flow through the temperature raising and reducing medium pore passages of the die from the respective units and then return to the respective units; the control system transmits the measured medium temperature and the measured mould temperature to the controller, and the controller correspondingly adjusts the temperature of the temperature-raising medium, so that the control of the mould temperature is realized.

The required circulating medium and the heating/cooling power of the temperature control system need to be determined in the running process of the accurate temperature control system of the die:

1) selection of circulating medium:

the temperature of the existing preforming mold pressing is (60-75) DEG C, the temperature of the temperature raising medium is 80 ℃, the temperature is below the boiling point of water, and the influence of the water on the operation environment is small compared with that of heat conducting oil, so that the water is selected as the temperature raising and reducing medium.

2) Calculation of heating/cooling power

The heating/cooling power is calculated according to the formula

KW=W×△t×C×S/T

W-weight of die, Kg

Δ t-the temperature difference between the desired temperature and the starting temperature

Specific heat of C-

S-safety factor

T-time

The proportion of the power required by the heating/cooling of the heat-insulating material to the total power is too small to be ignored. The weight of the die is approximately calculated according to the external dimension (diameter 1000mm, height 400 mm) of the die, the temperature rise difference is calculated according to the temperature rise from room temperature 20 ℃ to 70 ℃, the temperature drop difference is calculated according to the temperature drop from 70 ℃ to 40 ℃, the temperature rise and fall time is selected for 30min, and the safety factor is selected to be 1.5.

Calculating the heating power of the system as follows:

KW= W×△t×C×S/T

=3.14×0.52×0.4×7800×0.11/860×（70-20）×1.5÷0.50

=47KW

the refrigerating power of the system is

KW = W×△t×C×S/T

=3.14×0.52×0.4×7800×0.11/860×（70-30）×1.5÷0.50

=28.2KW

Experiments are carried out for ten times after the technology of rapid compression molding of the heat insulating layer of the end socket is determined through experiments, and the method is compared with the prior process.

Analyzing the consumed time of the original process and the optimized process, wherein the analysis results are shown in table 1:

procedure of operation	The original process is time-consuming	Time consuming post-lifting process	Lifting situation
				Preparation process	It takes 20min	It takes 20min	Is free of
Material and plate vulcanizer temp. rise	320min	It takes 25min	Efficiency is improved by 13 times
				Compression molding	It takes 5min	It takes 5min	Is free of
Pressure maintaining and temperature reducing	Consuming 900min	It takes 15min	Efficiency is improved by 60 times
				Demolding, product appearance inspection and thickness measurement	It takes 20min	It takes 20min	Is free of
Total time consumption	1265min（21.1h）	85min（1.4h）	Increase by 15 times

TABLE 1 comparison of production cycles

As can be seen from Table 1, the optimized heating and pressure maintaining cooling processes respectively improve the efficiency by 13 times and 60 times, and the total process efficiency by 15 times.

Temperature contrast of mold cavity

In the molding process, after the temperature of the temperature measuring hole of the mold is constant to 70 ℃, the axial temperature and the radial temperature of the mold are respectively and simultaneously measured by a multi-point temperature tester, and the test data are shown in table 2.

TABLE 2 comparison of temperature uniformity of the mold cavities

As can be seen from Table 2, when the flat vulcanizing machine is used for heating the mold, the temperature of the axial cavity of the mold is about 5 ℃, namely, the temperature of the axial cavity close to the heating plate of the flat vulcanizing machine is higher, and the temperature of the axial cavity is about 1 ℃ when the mold is controlled by the mold temperature control system. The temperature uniformity is obviously improved.