Forming method of annular thin-wall oil bag and forming die thereof

Abstract

The present invention discloses a method for forming an annular thin-walled oil bladder and its forming mold. The method comprises: preparing a rubberized cloth; preparing a semi-finished air nozzle, polishing and cleaning the air nozzle skeleton, vulcanizing a layer of base film on the connecting plate of the air nozzle skeleton through an air nozzle pre-forming mold, sequentially arranging a layer of rubberized cloth and a layer of rubber sheet on the side of the base film facing the air nozzle; preparing a semi-finished bladder body, and extruding a long rubber hose through an extruder; making a semi-finished oil bladder, cutting an inflation hole on the hose and pasting the semi-finished air nozzle, and then plugging the two ends of the long rubber hose and rolling to form a closed loop; vulcanizing the oil bladder: placing the semi-finished oil bladder into the oil bladder forming mold, connecting the air nozzle to the inflation device, and then inflating and vulcanizing. According to the structural characteristics of each part of the annular thin-walled oil bladder, the air nozzle is molded and vulcanized to increase the bonding strength between the metal and the rubber, and the oil bladder as a whole is formed by inflation vulcanization, so that the product has a good appearance and high dimensional accuracy.

Description

Technical Field

[0001] The invention belongs to the technical field of rubber molding dies, and in particular relates to a molding method of an annular thin-wall oil bag and a molding die thereof. Background Art

[0002] The annular thin-walled oil bladder is a high-strength, oil-resistant, and air-aging-resistant rubber product. Its exterior is in contact with oil and its interior is in contact with air. It can operate at a maximum temperature of 150°C and is required to withstand repeated air pressure shocks without leaking, and must meet the requirements of a long service life.

[0003] Due to the complex structure of the annular thin-walled oil bladder, including the air nozzle and the inflatable bladder, the traditional annular thin-walled oil bladder is generally prepared by vulcanization in a vulcanizer. The vulcanizer is a device that vulcanizes rubber products with steam. For annular thin-walled oil bladders, this vulcanization method has the following disadvantages: 1. High hardware cost, requiring the purchase of large pressure vessels and equipping them with corresponding safety valves, pressure gauges, thermometers and other instruments; 2. High energy consumption, requiring a large amount of steam or electricity for heating and insulation; 3. Low production efficiency, only a certain number of products can be vulcanized each time, and manual operation is required to open and close the tank door; 4. Unstable product quality, prone to problems such as poor rubber self-adhesion, low compressive strength at the air nozzle, poor product appearance quality, low dimensional accuracy, and low product density. Summary of the Invention

[0004] The invention provides a forming method of an annular thin-wall oil bladder and a forming die thereof, which solves the problems of high production cost, low production efficiency and unstable product quality caused by the current use of annular thin-wall oil bladders in a vulcanizing tank for vulcanization.

[0005] In order to achieve the above object, the technical solution of the present invention is as follows:

[0006] The forming method of the annular thin-walled oil bag comprises:

[0007] Preparation of rubberized cloth: coating glue on both sides of the base cloth treated with hydrophilicity and adhesion, and drying for later use, wherein the glue is prepared from nitrile rubber and ethyl ester solvent;

[0008] Preparing a semi-finished gas nozzle: polishing and cleaning the gas nozzle frame, vulcanizing a layer of base film on the connecting plate of the gas nozzle frame through a gas nozzle pre-forming mold, and sequentially placing a layer of the rubberized cloth and a layer of rubber sheet on the side of the base film facing the gas nozzle opening;

[0009] Preparation of semi-finished capsule: Extruding a long rubber tube through an extruder;

[0010] Making the oil bag semi-finished product: cutting an inflation hole on the rubber hose and pasting the air nozzle semi-finished product, then plugging the two ends of the long rubber hose and rolling them to form a closed loop.

[0011] Vulcanized oil bladder: Place the semi-finished oil bladder into the oil bladder forming mold, connect the air nozzle to the inflation device, and then inflate and vulcanize.

[0012] Furthermore, a plug is used to plug the air nozzle opening of the air nozzle frame, and then a semi-finished film is placed on the connecting plate of the air nozzle frame, and is placed in an air nozzle pre-forming mold to be vulcanized to form a basic film of the air nozzle frame.

[0013] Furthermore, both sides of the vulcanized base film are roughened, cleaned with ethyl ester, and then padded with an oval rubberized cloth, and a rubber sheet is placed on the rubberized cloth.

[0014] Furthermore, before the step of vulcanizing the oil bladder, the semi-finished oil bladder product is immersed in a water tank to check the air tightness.

[0015] Furthermore, the oil bag forming mold includes an upper mold, a middle mold, a mold core, a lower mold and an inflation device. The upper mold, the middle mold, the mold core and the lower mold cooperate with each other to form a molding cavity of the annular thin-walled oil bag inflation bag body. The molding cavity is an annular cavity structure. An air nozzle channel is opened outward from the middle mold, and the air nozzle channel is connected to the mold cavity. The air nozzle channel is used to accommodate the air nozzle of the annular thin-walled oil bag, and the air nozzle is connected outwardly to the inflation device.

[0016] Furthermore, the inflation device includes a pipe joint, the inner end of the pipe joint is connected to the air nozzle, the outer end of the pipe joint is connected to the inflation tube through a pipe sleeve and a nut, and the inflation tube is externally connected to the air source and the pressure gauge.

[0017] Furthermore, a screw hole is provided on the middle mold above the air nozzle passage, and a countersunk screw is provided in the screw hole.

[0018] Furthermore, a sealing ring is provided on the contact surface between the pipe joint and the gas nozzle.

[0019] Furthermore, the inflation tube is an inflation copper tube.

[0020] Furthermore, the cross-section of the molding cavity is rectangular, circular or elliptical.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The method of the present invention adopts two molding methods, compression molding and inflation vulcanization, according to the structural characteristics of each part of the annular thin-walled oil bladder. The air nozzle is molded and vulcanized to increase the bonding strength between metal and rubber, and the oil bladder is formed by inflation vulcanization as a whole, so that the product has a good appearance and high dimensional accuracy.

[0023] 2. The method of the present invention covers the air nozzle frame with a layer of rubberized cloth, which greatly improves the pressure-bearing capacity of the air nozzle. The rubberized cloth covering the air nozzle is designed to be elliptical, which effectively avoids wrinkling of the fabric and ensures the bonding strength between the air nozzle and the hose.

[0024] 3. The capsule semi-finished product of the method of the present invention is extruded by an extruder, and the die is preheated before extrusion to reduce the viscosity of the rubber material. The semi-finished product after extrusion has a smooth and flat appearance, few overlapping parts of the product, and a strong pressure bearing capacity.

[0025] 4. The method of the present invention uses nitrile rubber as the matrix material of the rubber solution for rubberized cloth. The material has high bonding strength with the base cloth and good compatibility with hydrogenated nitrile rubber. As a transition layer between the base cloth and the hydrogenated nitrile rubber, the bonding strength between the two can be increased without delamination.

[0026] 5. The molding mold of the present invention adopts a three-opening mold structure design, the mold structure is simple and the operability is strong. It uses an inflation device to connect to an external air source to complete the mold compression inflation vulcanization molding in the mold molding cavity. The annular thin-walled oil bag product prepared by the molding mold has high bonding strength at the joint, high compressive strength at the air nozzle, high product dimensional accuracy, good appearance quality and high production efficiency.

[0027] 6. The mold of the present invention adopts an annular structure design as a whole, which is light in weight, accurate in positioning and high in matching precision, easy to open and close the mold, and has a long service life.

[0028] 7. The inflation device of the mold of the present invention is sealed and connected to the gas nozzle through the cooperation of the sealing ring and the conical surface, so the sealing effect is good and the gas supply and pressurization are stable.

[0029] Of course, the implementation of the various technical solutions of the present invention does not necessarily require achieving all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying any creative work, they can also obtain drawings of other embodiments based on these drawings.

[0031] Figure 1 This is a schematic diagram of the overall structure of the annular thin-walled oil bag in Example 1 of the present invention;

[0032] Figure 2 This is a schematic structural diagram of the mold according to Example 1 of the present invention;

[0033] Figure 3 This is a schematic structural diagram of an inflation device according to embodiment 1 of the present invention;

[0034] Figure 4 This is a schematic structural diagram of the valve frame according to embodiment 1 of the present invention;

[0035] Figure 5This is a structural diagram of a semi-finished gas nozzle according to Example 1 of the present invention;

[0036] In the figure, 1-annular thin-walled oil sac, 101-inflatable sac body, 102-air nozzle, 1021-air nozzle skeleton, 1022-connecting plate, 1023-polished surface, 1024-rubberized cloth, 1025-circular rubber sheet, 1026-air nozzle base film, 2-upper mold, 3-middle mold, 301-countsunk screw, 4-mold core, 5-lower mold, 6-inflating device, 601-pipe joint, 602-sealing ring, 603-sleeve, 604-inflating tube, 605-nut. DETAILED DESCRIPTION

[0037] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present disclosure.

[0038] In the description of this patent, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing this patent and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on this patent.

[0039] In the description of this patent, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," "connected," and "set" should be understood in a broad sense. For example, they can refer to fixed connection or set, detachable connection or set, or integral connection or set. Those skilled in the art can understand the specific meanings of the above terms in this patent based on the specific circumstances. The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0040] See also Figure 1 The annular thin-walled oil bladder 1 prepared by the present invention includes an inflatable bladder body 101 and an air nozzle 102. The inflatable bladder body 101 is a closed annular structure, and its cross-section is generally circular or elliptical. The air nozzle 102 is connected to the outside of the inflatable bladder body 101 and is used to inflate the inflatable bladder body 101.

[0041] Example 1:

[0042] See also Figure 2The mold shown is a compression molding die for an annular thin-walled oil bladder. The molding die includes an upper mold 2, a middle mold 3, a mold core 4, a lower mold 5 and an inflation device 6. The upper mold 2, the middle mold 3, the mold core 4 and the lower mold 5 cooperate with each other to form a molding cavity for the annular thin-walled oil bladder 1 inflation bladder body 101. The molding cavity is an annular cavity structure. Figure 2 In this embodiment, the cross-section of the molding cavity is a rectangular structure.

[0043] The upper mold 2, the middle mold 3, the core 4, and the lower mold 5 are all annular structures, among which the core 4 is located at the inner ring position of the middle mold 3, and the molding cavity is between the core 4 and the middle mold 3. The upper end surfaces of the core 4 and the middle mold 3 match the upper mold 1, and the lower end surfaces of the core 4 and the middle mold 3 match the lower mold 5.

[0044] A gas nozzle channel is opened horizontally outward from the middle mold, and the gas nozzle channel is connected to the molding cavity. The gas nozzle channel is used to accommodate the gas nozzle 102 of the annular thin-walled oil bag 1, and the gas nozzle 102 is connected to the inflation device 6 outward; Figure 3 In this embodiment, the inflation device 6 includes a pipe joint 601, the center of the pipe joint 601 is an air passage, and a plug interface is provided at the inner end of the pipe joint 601. The pipe joint 601 is inserted into the outside of the gas nozzle 102 through the plug interface, and a sealing ring 602 is provided on the inner ring of the plug interface. The sealing ring 602 is used to seal the gap between the plug interface of the pipe joint 601 and the gas nozzle 102; the air passage opening at the outer end of the pipe joint 601 is connected to the inflation tube 604, and the inflation tube 604 is made of a copper tube, and its docking end is trumpet-shaped. The air passage opening at the outer end of the pipe joint 601 is conical, and the docking end of the inflation tube 604 is sleeved on the air passage opening at the outer end of the pipe joint 601, and then fixed by a sleeve 603 and a nut 605 to form a conical surface fit seal. The outer end of the inflation tube 604 is connected to the gas source and the pressure gauge to form a complete air intake channel.

[0045] A screw hole is provided on the middle mold 3 above the air nozzle passage, and a countersunk screw 301 is provided in the screw hole. The countersunk screw 301 can move downward to tighten and fix the air nozzle 102. The countersunk screw 301 prevents the air nozzle from moving during the vulcanization process.

[0046] Multiple sets of glue flow grooves are set on both sides of the molding cavity. In this embodiment, two sets of annular glue flow grooves are set on the upper end surface of the lower mold, and two sets of annular glue flow grooves are set on the upper end surfaces of the middle mold and the mold core, so that excess rubber can flow out smoothly and at the same time play a certain venting role in the molding cavity.

[0047] Since the upper mold 2, the middle mold 3, the mold core 4, and the lower mold 5 are all annular structures, in order to facilitate mold opening, an upper mold opening groove is provided on the lower outer edge of the upper mold 2, and a lower mold opening groove is provided on the lower outer edge of the middle mold. The upper and lower mold opening grooves facilitate mold opening, can reduce the friction of the entire mold during demolding, and prevent product deformation or damage.

[0048] The preparation method of the annular thin-walled oil sac of the present invention is described below:

[0049] According to the structural characteristics of each part of the annular thin-walled oil bladder, the molding process involved in the molding die of this embodiment mainly includes: 1. Compression vulcanization molding of the air nozzle. 2. Inflation vulcanization molding of the entire oil bladder.

[0050] The specific steps include:

[0051] Step S1: preparing rubber-coated cloth

[0052] Step S101, base fabric treatment: Weigh the treatment agent 589 resin, mix it with water in a ratio of 1:10 and put it into a stainless steel barrel, immerse the base fabric in the treatment liquid for hydrophilicity and adhesion treatment, and after the base fabric is fully soaked, remove the fabric and dry it for later use.

[0053] Step S102, preparation of glue solution: weigh ethyl ester and put it into a stainless steel barrel, then roll the re-refined nitrile rubber into a thin sheet of about 0.5 mm on an open mill, then mix the nitrile rubber and ethyl ester in a ratio of 1:3, and stir continuously to ensure that the nitrile rubber film is fully dissolved.

[0054] Step S103, glue coating: Cut the treated base fabric into pieces of a certain width, stretch the pieces tightly and fix them on the glue coating roller with a sewing machine, and evenly apply the prepared glue on both sides of the base fabric to ensure that the thickness of a single layer of glue is not less than 0.1 mm and the overall thickness of the glued fabric is (0.3-0.4) mm. After drying, wrap it with a clean plastic sheet for later use.

[0055] Step S2: preparing a semi-finished gas nozzle

[0056] Step S201, preparation of semi-finished basic film: the re-refined rubber material is turned into a film with a thickness of (2.5-3) mm, and the film is cut into square pieces with a specification of length (25-28) × width (25-28) mm for standby use.

[0057] Step S202, valve frame processing: First, the upper and lower surfaces of the connecting plate 1022 of the valve frame 1021 are polished with fine sandpaper. The polished surface 1023 is shown in FIG. Figure 4 ; Then wear latex gloves and use solvent to clean the entire air nozzle, dry it at room temperature for later use; finally, use adhesive to brush the connecting plate 1022 of the air nozzle skeleton 1021 in a clockwise direction and dry it at room temperature.

[0058] Step S203, air nozzle pre-forming and vulcanization: Use a plug to plug the air nozzle opening of the air nozzle frame (to prevent the rubber from flowing into the air nozzle during vulcanization), place the cut basic rubber semi-finished product on the connecting plate of the air nozzle frame, and send it into the air nozzle pre-forming mold for vulcanization. The vulcanization time is 150℃×4min.

[0059] Step S204: Roughen both sides of the vulcanized valve base film 1026 and clean it with ethyl ester. Then, place a layer of oval rubberized cloth 1024 on the base film facing the valve opening. The rubberized cloth has a major axis of (40-43) × a minor axis of (28-30) × an inner diameter of (10-12) mm. Then, place a circular rubber sheet 1025 with an outer diameter of (34-38) × an inner diameter of (10-12) mm and a thickness of (0.5-0.8) mm on the rubberized cloth 1024. The valve semi-finished product is completed. For the structure, see Figure 5 .

[0060] Step S3: preparing semi-finished capsules

[0061] Select a Ф16 die and a Ф14 core, preheat the die at (80-90)°C; use an extruder to extrude a hose with a size of Фinner (16.5-17.5) mm × thickness (1.2-1.4) mm × length (668-670) mm.

[0062] Step S4: Making semi-finished oil capsules

[0063] Step S401: put a small amount of release agent into the inner side of the hose and rotate it along the inner side of the hose wall to evenly cover the inner wall of the hose with a layer of release agent.

[0064] Step S402: Cut an inflation hole with a diameter of 6-8 mm at a distance of 110-130 mm from the edge of the hose, place the processed air nozzle semi-finished product in the inflation hole and paste it, and use a pressure roller to press and stick it firmly along the bonding surface.

[0065] Step S403: roughen the ends of the hose by 3-5 mm with a brush and then apply solvent. Insert one end of the hose into the other end to a length of 6-8 mm. Use a hand roller to roll and bond the hose together to form a closed loop.

[0066] Step S404: In order to ensure a firm bond to the bonding surface, the prepared oil bladder semi-finished product is immersed in a water tank to check the air tightness of the product to prevent leakage during subsequent inflation and vulcanization.

[0067] Step S5: Sulfurizing the oil bag

[0068] Step S501: Place the semi-finished oil bladder into an oil bladder forming mold, connect the air nozzle to the inflation device, and send it into a flat vulcanizer for pressure of (11-15) MPa.

[0069] Step S502: The inflation device inflates the oil bag through the air nozzle, adjusts the pressure to (0.4-0.6) MPa, and starts vulcanization. The vulcanization time is 150°C x 50 min.

[0070] Step S503: After the vulcanization is completed, the inflation device is first closed, and then the pressure of the flat vulcanizing press is released, and then the mold is opened to take out the product.

[0071] The mold provided in this embodiment is light in weight, highly maneuverable, has high matching precision, and the inflation device has good sealing performance. The annular thin-walled oil sac product produced by this method has high dimensional precision, good appearance quality, and high production efficiency.

[0072] Example 2:

[0073] Different from Example 1, in this embodiment, the cross section of the molding cavity is circular.

[0074] The above examples are used to illustrate the present invention, which are only used to help understand the present invention and are not intended to limit the present invention. Those skilled in the art can make several simple deductions, modifications or substitutions based on the concept of the present invention.

Claims

1. A method for forming an annular thin-walled oil bag, characterized in that: include: Preparation of rubberized cloth: coating glue on both sides of the base cloth treated with hydrophilicity and adhesion, and drying for later use, wherein the glue is prepared from nitrile rubber and ethyl ester solvent; Preparing a semi-finished gas nozzle: polishing and cleaning the gas nozzle frame, vulcanizing a layer of base film on the connecting plate of the gas nozzle frame through a gas nozzle pre-forming mold, and sequentially placing a layer of the rubberized cloth and a layer of rubber sheet on the side of the base film facing the gas nozzle opening; Preparation of semi-finished capsule: Extruding a long rubber tube through an extruder; Making the oil bag semi-finished product: cutting an inflation hole on the rubber hose and pasting the semi-finished air nozzle, then plugging the two ends of the long rubber hose together and rolling them to form a closed loop; Vulcanizing oil bladder: Place the semi-finished oil bladder into the oil bladder forming mold, connect the air nozzle to the inflation device, and then inflate and vulcanize; The oil bladder forming mold includes an upper mold, a middle mold, a mold core, a lower mold and an inflation device. The upper mold, the middle mold, the mold core and the lower mold cooperate with each other to form a molding cavity of the annular thin-walled oil bladder inflation bladder body. The molding cavity is an annular cavity structure. The middle mold is provided with an air nozzle channel outwardly, which is connected to the mold cavity. The air nozzle channel is used to accommodate the air nozzle of the annular thin-walled oil bladder, and the air nozzle is externally connected to the inflation device. The inflation device includes a pipe joint, the center of the pipe joint is an airway, and an insertion port is provided at the inner end of the pipe joint. The pipe joint is inserted into the outside of the gas nozzle through the insertion port, and a sealing ring is provided on the inner ring of the insertion port, and the sealing ring is used to seal the gap between the insertion port of the pipe joint and the gas nozzle; the airway opening at the outer end of the pipe joint is connected to the inflation tube, and the inflation tube is made of a copper tube, and its connecting end is trumpet-shaped. The airway opening at the outer end of the pipe joint is conical, and the connecting end of the inflation tube is sleeved on the airway opening at the outer end of the pipe joint, and then fixed by a sleeve and a nut to form a conical surface fitting seal, and the outer end of the inflation tube is connected to the gas source and a pressure gauge.

2. The method for forming an annular thin-walled oil bag according to claim 1, characterized in that: Use a plug to plug the air nozzle opening of the air nozzle frame, then place the semi-finished film on the connecting plate of the air nozzle frame, and place it into the air nozzle pre-forming mold to vulcanize the basic film that forms the air nozzle frame.

3. The method for forming an annular thin-walled oil bag according to claim 2, characterized in that: Roughen both sides of the vulcanized base film, clean it with ethyl ester, place a layer of oval rubberized cloth on it, and then place a rubber sheet on the rubberized cloth.

4. The method for forming an annular thin-walled oil bag according to claim 1, characterized in that: Before the oil bladder vulcanization step, immerse the semi-finished oil bladder in a water tank to check its airtightness.

5. The compression molding die for the annular thin-walled oil bag according to claim 1, characterized in that: A screw hole is provided on the middle die and above the air nozzle passage, and a countersunk screw is provided in the screw hole.

6. The compression molding die for the annular thin-walled oil bag according to claim 5, characterized in that: The contact surface between the pipe joint and the gas nozzle is provided with a sealing ring.

7. The compression molding die for the annular thin-walled oil bag according to claim 6, characterized in that: The inflatable tube is an inflatable copper tube.

8. The compression molding die for the annular thin-walled oil bag according to claim 7, characterized in that: The cross section of the molding cavity is rectangular, circular or elliptical.

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