Rubber tube forming system

Abstract

The invention relates to the technical field of forming, and particularly discloses a rubber tube forming system which comprises an extrusion die module, a fiber reinforcement module, an extrusion driving module and a cooling and shaping module. The extrusion die module realizes uniform flow of a rubber matrix and short fibers and annular distribution of the fibers through a conical expansion die; the fiber-reinforced module adopts cellulose short fibers as a reinforcing material, and the bonding strength of the fibers and a rubber matrix is improved through surface modification; the extrusion driving module provides stable extrusion pressure and extrusion speed and dynamically adjusts the pressure and the speed; and the cooling and shaping module cools the extruded rubber tube from a high-temperature state to a stable state through water-air combined cooling. The problems of complex process and high cost are solved, and meanwhile, the production efficiency of the rubber tube is improved.

Description

Technical Field

[0001] The present invention relates to the field of molding technology, and more particularly to a hose molding system. Background Art

[0002] At present, rubber hoses are widely used in automotive cooling systems, industrial hoses, fluid transportation and other fields. Traditional hose molding technology relies on the reinforcement of long fiber fabrics, such as braiding or twisting processes. Although these methods can effectively improve the strength of the hose, the process is complicated and the cost is high, and it is difficult to achieve hose molding of complex shapes. In the existing public document 1 (Design of a new composite hose molding die [J]. Rubber and Plastic Technology and Equipment, 2001), a new composite hose molding die design is proposed. The hose molding die is designed with a reasonable flow channel so that the pressure and flow rate of the outer layer of rubber material are uniform from the time the outer layer of rubber material enters the mold cavity to the surface of the inner layer of rubber material. A hollow core insert is added to the mold cavity so that the inner layer of rubber material flows from the inner hole and the outer layer of rubber material flows along the outer wall, respectively controlling the flow of the inner and outer layers of rubber material. However, the inner and outer layers of rubber material of the hose molding die flow together in the mold cavity and cannot be independently controlled. In the existing open document 2 (cord wrap hose forming machine [J]. Rubber Technology and Equipment, 1993), a cord wrap hose forming machine is proposed. The hose forming machine consists of a machine body (head and tail), an intermediate bracket, a self-propelled trolley, an infrared parking device and an electrical part. However, due to the use of a DC motor and high synchronization requirements, the electrical part is relatively complex. In addition, in the prior art, the bending hose requires secondary processing, resulting in low production efficiency and poor economy. Therefore, there is an urgent need for a hose forming system that is efficient, economical and low-cost. Summary of the invention

[0003] In order to overcome the above-mentioned defects of the prior art, the present invention provides a hose molding system, which realizes uniform flow of rubber matrix and short fibers and circumferential distribution of fibers through a conical expansion mold, reduces economic costs, meets target bending radius and molding quality requirements by adjusting mold parameters, improves production efficiency, adopts cellulose short fibers, improves the bonding strength of the rubber matrix after surface modification, controls fiber length and concentration, and adds additives to ensure reinforcement effect and dispersibility, so as to solve the problems raised in the above-mentioned background technology.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A hose molding system comprises an extrusion die module, a fiber reinforcement module, an extrusion drive module and a cooling and shaping module; the extrusion die module realizes uniform flow of rubber matrix and short fibers and circumferential distribution of fibers through a conical expansion die, and meets target bending radius and molding quality requirements by adjusting the radius of the inner needle and the outer wall of the conical expansion die; the fiber reinforcement module uses cellulose short fibers as reinforcement materials, and improves the bonding strength between the fibers and the rubber matrix through surface modification; the extrusion drive module provides stable extrusion pressure and extrusion speed, and dynamically adjusts the pressure and speed; the cooling and shaping module cools the extruded hose from a high temperature state to a stable state through water-air combined cooling;

[0006] In the extrusion die module, the die offset determines the final shape of the hose, and the offset and the hose bending radius satisfy: Where R is the radius of the hose, r 1 is the radius of the needle inside the mold, r 2 is the radius of the mold outer wall, δ is the lateral offset of the mold center axis; the offset δ is related to the radius r of the mold inner needle 1 , the radius of the mold outer wall r 2 The relationship between them is: Where t is the wall thickness of the hose; the thin side wall thickness t min satisfy Among them, t 0 is the ideal tube wall thickness, the thick side wall thickness t max satisfy Verify the wall thickness ratio optimization conditions: η, where η is the preset wall thickness ratio threshold. If the wall thickness ratio does not meet the requirement, the radius r of the needle in the mold is adjusted. 1 and the radius r of the mold outer wall 2 To optimize the offset, recalculate the bending radius R until the bending radius R = R terget , where R terget is the target bending radius.

[0007] As a further solution of the present invention, the extrusion die module realizes the uniform flow of the rubber matrix and the short fibers and the circumferential distribution of the fibers through a conical expansion die, and meets the target bending radius and molding quality requirements by adjusting the radius of the inner needle and the outer wall of the conical expansion die, including the following specific contents: the extrusion die module includes a conical expansion die, and the conical expansion die makes the rubber matrix and the fibers flow uniformly along the extrusion direction through a gradually expanding die cavity, and realizes the circumferential distribution of the fibers in the cross section. The conical expansion die includes an inlet part, a conical expansion section, a die outlet section and an offset mechanism. The inlet part is responsible for guiding the raw materials into the die, and at the same time, the internal fixed needle ensures the stability of the center flow of the rubber and short fiber mixture. The fixed needle determines the center position of the material during the extrusion process, and its diameter D 1 It needs to match the inner diameter of the target hose to ensure the accuracy of molding; the tapered expansion section guides the material flow through the gradually expanding cavity, causing the short fibers in the rubber matrix to change from disordered distribution to orderly arrangement along the circumferential direction. The expansion angle is controlled between 10° and 15° to avoid excessive flow shear stress of the material at the die outlet; the geometry of the die outlet section is annular to ensure that the material forms a uniform tube wall thickness after extrusion. The die outlet section is combined with the die offset to achieve complex hose bending molding; the extrusion die module uses an offset mechanism to cause a certain lateral offset of the center axis of the die to form a curved hose. The offset is defined as the maximum moving distance of the center axis of the die in the lateral direction, and the offset is controlled between 0.5mm and 1.5mm.

[0008] In the process of hose molding, process temperature and pressure control are important factors to ensure molding quality and uniform fiber distribution. The temperature control of the extrusion die module needs to be adjusted in sections according to the functions of each area, including the inlet part, the tapered expansion section and the die outlet section. The temperature of the inlet part is set at 65-95°C to ensure that the rubber matrix and the short fibers can be fully mixed and have appropriate fluidity in the early stage without premature vulcanization. The temperature range of the tapered expansion section is set to 120-140°C. The fluidity of the rubber matrix is ​​improved by moderate temperature, while avoiding fiber detachment or breakage caused by high temperature, ensuring that the fibers are evenly distributed along the circumferential direction. The temperature of the die outlet section is maintained at 95-120°C to stabilize the shape of the formed hose and avoid deformation due to excessive fluidity before cooling. At the same time, the control of the extrusion pressure affects the flow rate of the material and the stability of the fiber distribution, and the pressure is maintained between 10-14MPa to form a stable flow field in the mold. Excessive pressure may cause uncontrolled fiber arrangement, while too low pressure will lead to insufficient molding and uneven wall thickness.

[0009] As a further solution of the present invention, the fiber-reinforced module uses cellulose staple fibers as reinforcing materials, and improves the bonding strength between the fibers and the rubber matrix by surface modification, including the following specific contents: the fiber-reinforced module uses cellulose staple fibers as reinforcing materials. The fiber length is controlled to be less than 12 mm to ensure that it can be evenly distributed during the extrusion process, and to avoid increased flow resistance or limited orientation due to excessive length. Before the fiber is used, the fiber surface is treated with reagents such as formaldehyde or hexamethylenetetramine to generate reactive functional groups, which react with the rubber matrix during the vulcanization process to form chemical bonds and improve the bonding strength between the fiber and the matrix interface. The modified fiber not only has higher dispersibility, but also can be effectively embedded in the rubber matrix, providing an additional "skeleton effect" to enhance the hoop modulus and tear resistance of the hose. In addition, in order to ensure the uniform dispersion of the modified fiber in the matrix, the fiber-reinforced module also uses a dispersant and a plasticizer to reduce the tendency of agglomeration between the fibers.

[0010] When the fiber concentration is too low, the reinforcement effect of the hose is not obvious, and the hoop strength and shape retention ability cannot be improved; when the fiber concentration is too high, the dispersion of the fiber in the matrix decreases, and agglomeration areas are easily formed, resulting in uneven mechanical properties and unbalanced wall thickness distribution. Therefore, the fiber reinforcement module controls the fiber at 50-70phr.

[0011] As a further solution of the present invention, the extrusion drive module provides stable extrusion pressure through a hydraulic drive device, and the stepper motor control unit realizes an extrusion speed of 3-8cm / s, and the real-time monitoring unit dynamically adjusts the pressure and speed, including the following specific contents: the extrusion drive module includes a hydraulic drive device, a stepper motor control unit and a real-time monitoring unit; the hydraulic drive device is composed of a hydraulic cylinder, a hydraulic pump and a pressure regulating valve, the hydraulic cylinder provides thrust through servo control technology, the hydraulic pump provides a continuous and controllable hydraulic oil flow, a proportional valve is used for flow regulation, and the pressure regulating valve is used to prevent pressure fluctuations during the extrusion process; through the hydraulic drive device, the extrusion pressure is maintained within the range of 10-14Mpa. The stepper motor control unit is responsible for controlling the extrusion speed, and the extrusion speed is set between 3-8cm / s.

[0012] The real-time monitoring unit includes a pressure sensor, a speed sensor and a mold position sensor. The pressure sensor monitors the motion state of the hydraulic drive device, and the speed sensor monitors the operating state of the stepper motor control unit. The pressure sensor can capture the pressure fluctuation in the hydraulic zone drive device with a response speed of milliseconds, and dynamically adjust the output flow of the hydraulic pump by linking with the pressure regulating valve to ensure that the extrusion pressure is always stable within the range of 10-14MPa; the speed sensor monitors the running speed of the stepper motor in real time, so that the extrusion speed is synchronized with the mold offset movement, thereby preventing the material from flowing unevenly or the fiber arrangement is disordered due to speed mismatch; the mold position sensor is responsible for tracking the real-time changes of the mold offset δ, ensuring that the offset δ is consistent with the target bending radius R terget match.

[0013] As a further solution of the present invention, the cooling and shaping module cools the extruded hose from a high temperature state to a stable state by water-air combined cooling, and uses a shape-maintaining unit to ensure that the orientation of the short fibers and the shape of the hose are not affected by thermal expansion and contraction during the cooling process, including the following specific contents: the cooling and shaping module quickly cools the extruded hose from a high temperature state to a stable state, while ensuring that the orientation of the short fibers is not affected by thermal expansion or collective contraction of the rubber. The cooling and shaping module ensures that the shape and performance of the hose are optimized and stabilized during the cooling process by means of a cooling medium, a shape-maintaining unit, and a multi-region segmented cooling technology. Cooling media include water, air and a combination of water and air. Water cooling can quickly take away the heat in the rubber matrix and reduce the temperature of the hose from the extrusion temperature (95-120°C) to about 50-60°C in a short time, thereby quickly fixing the orientation of the short fibers and the initial shape of the rubber. However, the cooling rate of water cooling is too fast, resulting in a large temperature difference between the inner and outer walls, which causes the accumulation of stress in the rubber matrix. Air cooling can gradually reduce the temperature of the hose by utilizing the low thermal conductivity of air, avoiding the accumulation of stress in the rubber matrix or the destruction of the fiber orientation caused by rapid cooling. However, the cooling efficiency of air cooling is low, the heat conduction speed is slow, and a long cooling time is required to fix the rubber. The tube is cooled to room temperature; therefore, the cooling and shaping module adopts water-air combined cooling. In the initial stage of cooling, water cooling is used for rapid cooling, and the high-temperature hose temperature after extrusion is quickly reduced to 50-60°C to lock the circumferential orientation of the fiber and the initial shape of the rubber, while avoiding deformation of the material due to excessive fluidity at high temperature. In the later stage of cooling, it is switched to air cooling, and the internal stress that may be accumulated during the rapid cooling process is released by gradually cooling to room temperature (20-25°C). The slow cooling process of air cooling can ensure the dimensional stability of the rubber matrix and the retention of the bending shape, and avoid warping or dimensional deviation caused by excessive temperature difference.

[0014] The shape-maintaining unit limits and maintains the internal and external shapes of the hose through the dual effects of internal support and external guide rail mold. In the cooling tank of the shape-maintaining unit, an inflatable internal support device is placed inside the hose, and a stable support force is formed by adjusting the internal air pressure to prevent the tube wall from collapsing due to shrinkage during the cooling process. The external guide rail mold is installed along the outside of the hose and is designed according to the target geometric shape of the bent hose. The outer wall of the hose is fixed in the mold through physical constraints to avoid bending shape deviation caused by cold shrinkage effect or material weight.

[0015] The technical effects and advantages of a hose molding system of the present invention are as follows: the present invention utilizes a conical expansion mold to achieve uniform flow of the rubber matrix and short fibers and circumferential distribution of the fibers, adjusts mold parameters to meet target bending radius and molding quality requirements, and controls temperature and pressure to ensure molding quality; utilizes cellulose short fibers through surface modification to improve bonding strength, controls fiber length and concentration, and adds additives to ensure reinforcement effect and dispersibility; combines hydraulic and stepper motor control with real-time monitoring to stabilize extrusion pressure and speed, and synchronize the two; the hose molding system overcomes the problems of complex process, high cost, difficulty in molding complex shapes, and secondary processing, and improves hose production efficiency and economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The figure is a schematic structural diagram of a hose forming system of the present invention.

[0017] Figure 2 The figure is a schematic diagram of the structure of a glue flow channel in the prior art.

[0018] Figure 3 The present invention is a structural schematic diagram of a winding hose forming machine in the prior art.

[0019] Figure 4 It is a schematic structural diagram of the conical expansion die of the present invention.

[0020] Figure 5 It is a structural schematic diagram of the external guide rail mold of the present invention. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] Example 1

[0023] See also Figure 1As shown in the structural schematic diagram, an embodiment of the present invention provides a hose molding system, which includes an extrusion die module, a fiber reinforcement module, an extrusion drive module and a cooling and shaping module; the extrusion die module realizes uniform flow of rubber matrix and short fibers and circumferential distribution of fibers through a conical expansion die, and meets the target bending radius and molding quality requirements by adjusting the radius of the inner needle and the outer wall of the conical expansion die; the fiber reinforcement module uses cellulose short fibers as reinforcing materials, and improves the bonding strength between the fibers and the rubber matrix through surface modification; the extrusion drive module provides stable extrusion pressure through a hydraulic drive device, and a stepper motor control unit realizes an extrusion speed of 3-8 cm / s, and the pressure and speed are dynamically adjusted by a real-time monitoring unit; the cooling and shaping module cools the extruded hose from a high temperature state to a stable state through water-air combined cooling, and uses a shape maintaining unit to ensure that the short fiber orientation and the hose shape are not affected by thermal expansion and contraction during the cooling process.

[0024] In this embodiment, see Figure 2 The structural schematic diagram shown is a new type of composite hose forming mold design proposed in the prior art. The hose forming mold is designed with a reasonable flow channel to make the pressure and flow rate of the outer layer rubber material uniform from the outer layer rubber material entering the mold cavity to the inner layer rubber surface particle point, and add a hollow insert in the mold cavity to make the inner layer rubber material flow from the inner hole and the outer layer rubber material flow along the outer wall, respectively controlling the flow of the inner and outer layers of rubber material. However, the inner and outer layers of the hose forming mold flow together in the mold cavity and cannot be independently controlled; refer to Figure 3 The structural schematic diagram shown is a winding hose forming machine proposed in the prior art, which consists of a machine body (head and tail), an intermediate bracket, a self-propelled trolley, an infrared parking device and an electrical part. However, due to the use of a DC motor and higher synchronization requirements, the electrical part is relatively complex.

[0025] Furthermore, the extrusion die module realizes uniform flow of the rubber matrix and the short fibers and circumferential distribution of the fibers through a conical expansion die, and meets the target bending radius and molding quality requirements by adjusting the radius of the inner needle and the outer wall of the conical expansion die, including the following specific contents: the extrusion die module includes a conical expansion die, such as Figure 4 As shown, the tapered expansion die allows the rubber matrix and the fiber to flow evenly along the extrusion direction through the gradually expanding die cavity, while achieving circumferential distribution of the fiber in the cross section. The tapered expansion die includes an inlet portion, a tapered expansion section, a die outlet section, and an offset mechanism. The inlet portion is responsible for guiding the raw material into the die, while ensuring the stability of the center flow of the rubber and short fiber mixture through the internal fixed needle. The fixed needle determines the center position of the material during the extrusion process, and its diameter D 1It needs to match the inner diameter of the target hose to ensure the accuracy of molding; the tapered expansion section guides the material flow through the gradually expanding cavity, causing the short fibers in the rubber matrix to change from disordered distribution to orderly arrangement along the circumferential direction. The expansion angle is controlled between 10° and 15° to avoid excessive flow shear stress of the material at the die outlet; the geometry of the die outlet section is annular to ensure that the material forms a uniform tube wall thickness after extrusion. The die outlet section is combined with the die offset to achieve complex hose bending molding; the extrusion die module uses an offset mechanism to cause a certain lateral offset of the center axis of the die to form a curved hose. The offset is defined as the maximum moving distance of the center axis of the die in the lateral direction, and the offset is controlled between 0.5mm and 1.5mm.

[0026] The mold offset determines the final shape of the hose. The relationship between the offset and the hose bending radius satisfies the following formula: Where R is the radius of the hose, r 1 is the radius of the needle inside the mold, r 2 is the radius of the mold outer wall, and δ is the lateral offset of the mold center axis. The existence of the offset will lead to uneven distribution of the hose wall thickness. Therefore, the offset is optimized by adjusting the radius of the mold inner needle and the radius of the mold outer wall to achieve the target bending radius R. terget , the offset δ and the radius r of the needle in the mold 1 , the radius of the mold outer wall t 2 The relationship between them is: Where t is the wall thickness of the hose. Since the offset will cause uneven wall thickness, the thin side wall thickness t min The calculation formula is: Among them, t 0 is the ideal tube wall thickness, the thick side wall thickness t max The calculation formula is: Verify whether the wall thickness ratio meets the optimization conditions: Where η is the preset wall thickness ratio threshold. If the wall thickness ratio does not meet the requirement, the radius r of the needle in the mold is adjusted. 1 and the radius r of the mold outer wall 2 To optimize the offset, recalculate the bending radius R until the bending radius R = R terget .

[0027] In the process of hose molding, process temperature and pressure control are important factors to ensure molding quality and uniform fiber distribution. The temperature control of the extrusion die module needs to be adjusted in sections according to the functions of each area, including the inlet part, the tapered expansion section and the die outlet section. The temperature of the inlet part is set at 65-95°C to ensure that the rubber matrix and the short fibers can be fully mixed and have appropriate fluidity in the early stage without premature vulcanization. The temperature range of the tapered expansion section is set to 120-140°C. The fluidity of the rubber matrix is ​​improved by moderate temperature, while avoiding fiber detachment or breakage caused by high temperature, ensuring that the fibers are evenly distributed along the circumferential direction. The temperature of the die outlet section is maintained at 95-120°C to stabilize the shape of the formed hose and avoid deformation due to excessive fluidity before cooling. At the same time, the control of the extrusion pressure affects the flow rate of the material and the stability of the fiber distribution, and the pressure is maintained between 10-14MPa to form a stable flow field in the mold. Excessive pressure may cause uncontrolled fiber arrangement, while too low pressure will lead to insufficient molding and uneven wall thickness.

[0028] Furthermore, the fiber-reinforced module uses cellulose staple fibers as reinforcing materials, and improves the bonding strength between the fibers and the rubber matrix through surface modification, including the following specific contents: the fiber-reinforced module uses cellulose staple fibers as reinforcing materials. The fiber length is controlled to be less than 12 mm to ensure that it can be evenly distributed during the extrusion process, and to avoid increased flow resistance or restricted orientation due to excessive length. Before the fiber is used, the fiber surface is treated with reagents such as formaldehyde or hexamethylenetetramine to generate reactive functional groups, which undergo cross-linking reactions with the rubber matrix during the vulcanization process to form chemical bonds and improve the bonding strength between the fiber and the matrix interface. The modified fiber not only has higher dispersibility, but can also be effectively embedded in the rubber matrix, providing an additional "skeleton effect" to enhance the hoop modulus and tear resistance of the hose. In addition, in order to ensure the uniform dispersion of the modified fiber in the matrix, the fiber-reinforced module also uses dispersants and plasticizers to reduce the tendency of agglomeration between the fibers.

[0029] When the fiber concentration is too low, the reinforcement effect of the hose is not obvious, and the hoop strength and shape retention ability cannot be improved; when the fiber concentration is too high, the dispersion of the fiber in the matrix decreases, and agglomeration areas are easily formed, resulting in uneven mechanical properties and unbalanced wall thickness distribution. Therefore, the fiber reinforcement module controls the fiber at 50-70phr.

[0030] Furthermore, the extrusion drive module provides stable extrusion pressure through a hydraulic drive device, and the stepper motor control unit achieves an extrusion speed of 3-8cm / s, and the real-time monitoring unit dynamically adjusts the pressure and speed, including the following specific contents: the extrusion drive module includes a hydraulic drive device, a stepper motor control unit and a real-time monitoring unit; the hydraulic drive device is composed of a hydraulic cylinder, a hydraulic pump and a pressure regulating valve, the hydraulic cylinder provides thrust through servo control technology, the hydraulic pump provides a continuous and controllable hydraulic oil flow, and a proportional valve is used for flow regulation, and the pressure regulating valve is used to prevent pressure fluctuations during the extrusion process; through the hydraulic drive device, the extrusion pressure is maintained within the range of 10-14Mpa. The stepper motor control unit is responsible for controlling the extrusion speed, which is set between 3-8cm / s.

[0031] The real-time monitoring unit includes a pressure sensor, a speed sensor and a mold position sensor. The pressure sensor monitors the motion state of the hydraulic drive device, and the speed sensor monitors the operating state of the stepper motor control unit. The pressure sensor can capture the pressure fluctuation in the hydraulic zone drive device with a response speed of milliseconds, and dynamically adjust the output flow of the hydraulic pump by linking with the pressure regulating valve to ensure that the extrusion pressure is always stable within the range of 10-14MPa; the speed sensor monitors the running speed of the stepper motor in real time, so that the extrusion speed is synchronized with the mold offset movement, thereby preventing the material from flowing unevenly or the fiber arrangement is disordered due to speed mismatch; the mold position sensor is responsible for tracking the real-time changes of the mold offset δ, ensuring that the offset δ is consistent with the target bending radius R terget match.

[0032] Furthermore, the cooling and shaping module cools the extruded hose from a high temperature state to a stable state through water-air combined cooling, and uses a shape-maintaining unit to ensure that the short fiber orientation and the hose shape are not affected by thermal expansion and contraction during the cooling process, including the following specific contents: the cooling and shaping module quickly cools the extruded hose from a high temperature state to a stable state, while ensuring that the orientation of the short fibers is not affected by thermal expansion or collective contraction of the rubber. The cooling and shaping module ensures that the shape and performance of the hose are optimized and stabilized during the cooling process through cooling media, shape-maintaining units, and multi-region segmented cooling technology. Cooling media include water, air and a combination of water and air. Water cooling can quickly take away the heat in the rubber matrix and reduce the temperature of the hose from the extrusion temperature (95-120°C) to about 50-60°C in a short time, thereby quickly fixing the orientation of the short fibers and the initial shape of the rubber. However, the cooling rate of water cooling is too fast, resulting in a large temperature difference between the inner and outer walls, which causes the accumulation of stress in the rubber matrix. Air cooling can gradually reduce the temperature of the hose by utilizing the low thermal conductivity of air, avoiding the accumulation of stress in the rubber matrix or the destruction of the fiber orientation caused by rapid cooling. However, the cooling efficiency of air cooling is low, the heat conduction speed is slow, and a long cooling time is required to fix the rubber. The tube is cooled to room temperature; therefore, the cooling and shaping module adopts water-air combined cooling. In the initial stage of cooling, water cooling is used for rapid cooling, and the high-temperature hose temperature after extrusion is quickly reduced to 50-60°C to lock the circumferential orientation of the fiber and the initial shape of the rubber, while avoiding deformation of the material due to excessive fluidity at high temperature. In the later stage of cooling, it is switched to air cooling, and the internal stress that may be accumulated during the rapid cooling process is released by gradually cooling to room temperature (20-25°C). The slow cooling process of air cooling can ensure the dimensional stability of the rubber matrix and the retention of the bending shape, and avoid warping or dimensional deviation caused by excessive temperature difference.

[0033] The shape-maintaining unit limits and maintains the internal and external shapes of the hose through the dual functions of internal support and external guide rail mold. In the cooling tank of the shape-maintaining unit, an inflatable internal support device is placed inside the hose, which forms a stable support force by adjusting the internal air pressure to prevent the tube wall from collapsing due to contraction during the cooling process. Figure 5 As shown in the structural schematic diagram, the external guide rail mold is installed along the outside of the hose and is designed according to the target geometric shape of the bent hose. The outer wall of the hose is fixed in the mold through physical constraints to avoid bending shape deviation caused by shrinkage effect or material weight.

[0034] The present invention utilizes a conical expansion die to achieve uniform flow of the rubber matrix and short fibers and circumferential distribution of the fibers, adjusts die parameters to meet target bending radius and molding quality requirements, controls temperature and pressure to ensure molding quality; utilizes cellulose short fibers through surface modification to improve bonding strength, controls fiber length and concentration, and adds additives to ensure reinforcing effect and dispersibility; combines hydraulic and stepper motor control with real-time monitoring to stabilize extrusion pressure and speed, and synchronize the two; the hose molding system overcomes the problems of complex process, high cost, difficulty in molding complex shapes, and secondary processing, and improves hose production efficiency and economy.

[0035] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0036] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A hose forming system, characterized in that: It includes an extrusion die module, a fiber reinforcement module, an extrusion drive module and a cooling and shaping module; the extrusion die module realizes uniform flow of the rubber matrix and the short fibers and circumferential distribution of the fibers through a conical expansion die, and meets the target bending radius and molding quality requirements by adjusting the radius of the inner needle and the outer wall of the conical expansion die; The fiber reinforcement module uses cellulose short fibers as reinforcement materials, and improves the bonding strength between the fibers and the rubber matrix through surface modification; the extrusion drive module provides stable extrusion pressure and extrusion speed, and dynamically adjusts the pressure and speed; the cooling and shaping module cools the extruded hose from a high temperature state to a stable state through water-air combined cooling; In the extrusion die module, the die offset determines the final shape of the hose, and the offset and the hose bending radius satisfy: Where R is the radius of the hose, r1 is the radius of the inner needle of the mold, r2 is the radius of the outer wall of the mold, and δ is the lateral offset of the center axis of the mold; the relationship between the offset δ and the radius r1 of the inner needle of the mold and the radius r2 of the outer wall of the mold is: Where t is the wall thickness of the hose; the thin side wall thickness t min satisfy Among them, t0 is the ideal tube wall thickness, and the thick side wall thickness t max satisfy Verify the wall thickness ratio optimization conditions: Where η is the preset wall thickness ratio threshold. If the wall thickness ratio does not meet the requirement, the radius r1 of the inner needle of the mold and the radius r2 of the outer wall of the mold are adjusted to optimize the offset and the bending radius R is recalculated until the bending radius R=R tertget , where R tertget is the target bending radius.

2. A hose forming system according to claim 1, characterized in that: The conical expansion die in the extrusion die module includes an inlet part, a conical expansion section, a die outlet section and an offset mechanism. The inlet part guides the raw materials into the die, and the internal fixed needle ensures the stability of the central flow of the rubber and short fiber mixture. Its diameter D1 matches the target hose inner diameter. The conical expansion section cavity has an expansion angle of 10° to 15° from diameter D1 to D2. The die outlet section has a ring-shaped geometry, and the offset mechanism makes the lateral offset of the die center axis 0.5mm to 1.5mm.

3. A hose forming system according to claim 1, characterized in that The temperature control of the extrusion die module is adjusted in sections according to the function of each area. The temperature of the inlet part is 65-95°C, the temperature of the conical expansion section is 120-140°C, the temperature of the die outlet section is 95-120°C, and the extrusion pressure is 10-14MPa.

4. A hose forming system according to claim 1, characterized in that: The length of the cellulose short fibers in the fiber-reinforced module is less than 12 mm, and the surface is modified by using formaldehyde or hexamethylenetetramine reagent to generate reactive functional groups, which react with the rubber matrix through cross-linking during the vulcanization process.

5. A hose forming system according to claim 1, characterized in that: The hydraulic drive device in the extrusion drive module consists of a hydraulic cylinder, a hydraulic pump and a pressure regulating valve. The hydraulic cylinder provides thrust through servo control technology, the hydraulic pump provides hydraulic oil flow, a proportional valve is used to adjust the flow, and the pressure regulating valve prevents pressure fluctuations. The extrusion pressure is maintained at 10-14Mpa.

6. A hose forming system according to claim 1, characterized in that: The real-time monitoring unit in the extrusion drive module includes a pressure sensor, a speed sensor and a mold position sensor. The pressure sensor monitors the pressure fluctuation of the hydraulic drive device, the speed sensor monitors the running speed of the stepper motor, and the mold position sensor tracks the change of the mold offset.

7. A hose forming system according to claim 1, characterized in that: The cooling and shaping module adopts water-air combined cooling, and initially uses water cooling to reduce the hose temperature from 95-120° C. to 50-60° C., and later uses air cooling to reduce the hose temperature to 20-25° C.

8. A hose forming system according to claim 1, characterized in that: The shape maintaining unit in the cooling and shaping module includes an inflatable internal support device and an external guide rail mold. The internal support device is placed inside the hose to adjust the air pressure to support the tube wall. The external guide rail mold is installed along the outside of the hose and is designed according to the geometric shape of the bent hose to fix the outer wall of the hose.

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