Reciprocating resin injection device

Abstract

The present invention relates to the technical field of composite material molding, and more particularly to a reciprocating resin injection device comprising an injection unit, a curing unit, and a control unit. The injection unit comprises a first resin injector and a first resin dispenser, the first resin injector having a first inlet pipe and a first outlet pipe, the first inlet pipe being provided with a first inlet valve component, and the first outlet pipe being provided with an outlet valve component. The curing unit comprises a forming mold and a melt pressure sensor, the forming mold being provided with a mold injection port stop valve and a mold outlet stop valve, the first outlet pipe being connected to the mold injection port stop valve. The control unit comprises an industrial control computer, a programmable logic controller, and a sensor transmitter. The programmable logic controller receives pressure information and converts it into feed information based on the pressure information. The industrial control computer obtains the change in volume of a first floating inner cavity based on the feed information. This device solves the problem of difficulty in real-time monitoring of resin inventory in a tank under high-temperature environments.

Description

Technical Field

[0001] The present invention relates to the technical field of composite material molding, in particular to a reciprocating resin injection device. Background Art

[0002] The main principle of Resin Transfer Molding (RTM) technology is to first lay out a designed preform in the mold cavity, then use an injection device to inject a special resin system into the mold cavity, and the resin flow will expel the gas in the mold cavity while impregnating the fibers. After heating, curing, cooling and demolding, a composite material part can be obtained. Common injection equipment includes a method of injecting high-pressure gas into the injection tank to drive the resin in the tank for injection, and a method of injecting the resin in the syringe through an injection plug. Because it is difficult to monitor the resin inventory in the tank in real time under high temperature environments, for the injection method driven by high-pressure gas, when the amount of resin is insufficient, the high-pressure gas will enter the part through the injection pipeline and cause product defects. When using the injection plug to push the resin injection method, when injecting large amounts of resin, the size of the thrust mechanism is positively correlated with the resin capacity, and the equipment cost is high. Therefore, it is necessary to improve the above problems. Summary of the Invention

[0003] The present invention mainly addresses the above problems and proposes a reciprocating resin injection device, the purpose of which is to solve the problem that it is difficult to monitor the resin inventory in the tank in real time under high temperature environment.

[0004] To achieve the above object, the present invention provides a reciprocating resin injection device, comprising:

[0005] An injection unit includes at least a first resin injector and a first resin dispenser, wherein the first resin injector has a first inlet pipe for allowing resin to enter the first resin injector and a first outlet pipe for discharging the resin in the first resin injector. The other end of the first inlet pipe is connected to the first resin dispenser. The first inlet pipe is provided with a first inlet valve component for controlling the flow of resin in the pipe into the first resin injector, and the first outlet pipe is provided with an outlet valve component for controlling the flow of resin in the pipe out of the pipe. The first resin injector includes a first body and a first servo electric cylinder. The first body is provided with a first floating inner cavity formed by a first resin injector upper ram, a first resin injector lower ram, and an inner wall of the first body, and a first limit component for limiting the stroke of the first resin injector upper ram. The first servo electric cylinder is used to drive the first resin injector upper ram to move within the first floating inner cavity to press the resin in the first floating inner cavity into the first outlet pipe. The first floating inner cavity is connected to the first inlet pipe and the first outlet pipe.

[0006] a curing unit, the curing unit comprising at least a molding die and a melt pressure sensor, the molding die having a product mold cavity and provided with a mold glue injection port shut-off valve and a mold glue outlet shut-off valve communicating with the product mold cavity, wherein the first glue outlet pipeline is communicated with the mold glue injection port shut-off valve, and the melt pressure sensor is used to measure the resin injection pressure at the position of the mold glue injection port shut-off valve; and

[0007] A control unit, the control unit at least includes an industrial control computer, a programmable logic controller, and a sensor transmitter, wherein the programmable logic controller is connected to the melt pressure sensor through the sensor transmitter, and is used to receive pressure information measured by the melt pressure sensor and convert the measured pressure information into feed information for controlling the movement of the first servo electric cylinder; the industrial control computer is used to obtain the change in the volume of the first floating inner cavity based on the feed information.

[0008] Furthermore, a sealing groove is provided on the upper surface of the first resin injector pressing head, and a sealing strip is filled in the sealing groove.

[0009] Furthermore, when the volume of the first floating cavity is the largest, the sealing strip contacts the upper pressure head of the first resin injector, and the static friction between the contact surfaces is greater than the injection pressure of the first floating cavity resin on the sealing strip during injection.

[0010] Furthermore, the first resin injector upper pressure head, the first resin injector lower pressure head, the first body and the sealing strip are all detachable structures.

[0011] Furthermore, the sealing strip is a silicone rubber sealing strip.

[0012] Furthermore, when the injection unit is provided with a second resin syringe and a second resin injector having the same structure and connection relationship as the first resin syringe and the first resin injector, the first glue outlet pipeline and the second glue outlet pipeline are merged into the main glue injection pipeline through a three-way interface, and the main glue injection pipeline is connected to the mold glue injection port stop valve.

[0013] Furthermore, a heat-insulating component is provided on the main glue injection pipeline.

[0014] Furthermore, the first resin injector includes a high-pressure air source and a first resin injection tank, wherein the high-pressure air source and the first resin injection tank are connected through a pressure pipeline, and a first pressure electrical proportional valve and a first pressure pipeline shut-off valve are provided on the pressure pipeline, and the first resin injection tank outlet is provided with the first glue inlet pipeline.

[0015] Furthermore, the first glue inlet valve component includes a first glue inlet stop valve arranged on the first glue inlet pipeline; the glue inlet stop valve is provided with a mechanical connecting rod for driving the opening and closing action of the glue inlet stop valve, and the mechanical connecting rod is connected to the output end of the first rotary cylinder.

[0016] Furthermore, the curing unit also includes a resin collection barrel, which is connected to the mold glue outlet stop valve through a collection pipe, and a glue outlet pipeline stop valve is provided on the collection pipe; the resin collection barrel is also connected to the vacuum source through an air pipe, and a vacuum stop valve is also provided on the air pipe.

[0017] The above-mentioned technical solution of the present invention has the following advantages: the first resin injector injects resin into the first resin syringe, and then the first servo electric cylinder in the first resin syringe transports the resin in the first resin syringe to the product mold cavity for molding. During the injection into the product mold cavity, the melt pressure sensor in the device can measure the injection pressure of the resin at the mold injection port stop valve position. The industrial control computer controls the travel speed of the first servo electric cylinder through the PID controller in the programmable logic controller based on the resin injection pressure at the mold injection port stop valve position measured by the melt pressure sensor in the main injection pipeline, thereby controlling the resin injection pressure at the mold injection port stop valve position to be equal to the injection process pressure set at time t after the injection process begins. The industrial control computer then measures the downward travel distance of the upper pressure head of the first resin syringe, and obtains the resin injection volume at this time based on the travel distance, that is, the change in the volume of the first floating inner cavity, thereby achieving the purpose of real-time monitoring of resin usage under high temperature conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of a reciprocating resin injection device provided by an embodiment of the present invention.

[0019] Figure 2 This is a structural schematic diagram of a resin injector provided by an embodiment of the present invention.

[0020] In the picture:

[0021] 10. Injection unit; 110. First resin injector; 111. First body; 112. First servo cylinder; 113. Push rod; 114. Upper pressure head of first resin injector; 115. Lower pressure head of first resin injector; 116. First position-limiting component; 117. Sealing strip; 118. First injector support; 119. First glue outlet pipeline; 1101. First floating inner cavity; 120. First resin injector; 121. High-pressure gas source; 122. Pressure pipeline; 123. First pressure electric proportional valve; 124. First pressure pipeline shut-off valve; 125. First resin injection tank; 126. First glue inlet pipeline; 130, first glue inlet valve component; 131, first glue inlet stop valve; 132, mechanical connecting rod; 133, first rotary cylinder; 140, glue outlet valve component; 141, glue outlet stop valve for first glue injection pipeline; 142, coupling; 143, second rotary cylinder; 144, solenoid valve; 145, third rotary cylinder; 146, glue outlet stop valve for second glue injection pipeline; 150, second resin injector; 151, second glue outlet pipeline; 160, second resin injector; 170, main glue injection pipeline; 171, insulation component; 180, second glue inlet valve component; 181, second glue inlet stop valve; 190, three-way connector;

[0022] 20. Curing unit; 210. Forming mold; 220. Melt pressure sensor; 230. Product mold cavity; 240. Mold injection port shut-off valve; 250. Mold discharge port shut-off valve; 260. Fiber preform; 270. Resin collection barrel; 271. Collection pipe; 272. Glue discharge line shut-off valve; 280. Vacuum source; 281. Air pipe; 282. Vacuum shut-off valve;

[0023] 30. Control unit; 31. Sensor transmitter; 32. Programmable logic controller; 33. Industrial control computer. DETAILED DESCRIPTION

[0024] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0025] In the description of the present invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended only to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0027] In one aspect of the present invention, a reciprocating resin injection device is provided. Figure 1 、 Figure 2 As shown, the following components may be included, but are not limited to.

[0028] The injection unit 10 may include at least one first resin injector 110, one first resin injector 120, one first injection valve component 130, and one discharge valve component 140. On this basis, a second resin injector 150 having the same structure as the first resin injector 110, a second resin injector 160 having the same structure as the first resin injector 120, and a second injection valve component 180 having the same structure as the first injection valve component 130 may be further provided. The injection unit 10 realizes continuous injection at a constant injection pressure through the alternating motion of the two groups of resin injections, thereby achieving the purpose of improving efficiency.

[0029] In this embodiment, the first resin injector 110 has a first inlet pipe 126 for allowing resin to enter the first resin injector 110 and a first outlet pipe 119 for delivering the resin in the first resin injector 110. The other end of the first inlet pipe 126 is connected to the first resin injector 120. The first inlet pipe 119 is provided with a first inlet valve component 130 for controlling the flow of resin in the pipe into the first resin injector 110, and the first outlet pipe 119 is provided with a outlet valve component 140 for controlling the flow of resin in the pipe out of the pipe. It can be understood that the first resin injector 120 injects resin into the first inlet pipe 126, so that the resin is injected into the first resin injector 110 under the action of the first inlet pipe 126. The first resin injector 110 delivers the injected resin to the first outlet pipe 119. The first inlet valve component 130 and the first outlet valve component 140 are used to control the opening and closing of the first inlet pipe 126 and the first outlet pipe 119.

[0030] The technical solution of the present disclosure will be described below by taking a first resin injector 110 disclosed in the present application as an example.

[0031] According to an example of the present disclosure, Figure 1-Figure 2As can be seen from the schematic diagram of the resin syringe structure shown, the first resin syringe 110 may include a first body 111 that forms the entirety or at least a portion of its appearance, a first servo electric cylinder 112, and a first syringe support 118. The first body 111 is provided with a first floating inner cavity 1101 composed of a first resin syringe upper pressure head 114, a first resin syringe lower pressure head 115, and an inner wall of the first body 111, and a first limiting component 116 for limiting the stroke of the first resin syringe upper pressure head 114. The first limiting component 116 is used to limit the upward movement of the first resin syringe upper pressure head 114. A guide pin is provided between the first resin syringe upper pressure head 114 and the first resin syringe lower pressure head 115. The first servo electric cylinder 112 is used to drive the first resin syringe upper pressure head 114 to move upward in the first floating inner cavity 1101. 01 displacement, so as to press the resin in the first floating inner cavity 1101 into the first glue outlet pipeline 119, the first floating inner cavity 1101 is connected with the first glue inlet pipeline 126 and the first glue outlet pipeline 119, the glue outlet of the first glue outlet pipeline 119 is connected to the curing unit 20, and the first resin injector lower pressure head 115 is connected to the first injector support 118 and fixed inside the injection unit; the first resin injector upper pressure head 114 of the first resin injector 110 is controlled by the first servo electric cylinder 112 to reach the limit position, the first glue inlet valve component 130 is opened, and the first resin injector 120 introduces resin into the first floating inner cavity 1101 of the first resin injector 110, and the first servo electric cylinder 112 applies pressure to the push rod 113 to inject the resin in the first floating inner cavity 1101 into the curing unit 20 through the first glue outlet pipeline 119.

[0032] Please continue to refer to Figure 1 The curing unit 20 includes at least a molding mold 210 and a melt pressure sensor 220. The molding mold 210 has a product mold cavity 230, and the molding mold 210 is provided with a mold glue injection port stop valve 240 and a mold glue outlet stop valve 250 connected to the product mold cavity 230, wherein the first glue outlet pipeline 119 is connected to the mold glue injection port stop valve 240, and the melt pressure sensor 220 is used to measure the resin injection pressure at the position of the mold glue injection port stop valve 240.

[0033] In this embodiment, resin is injected into the product mold cavity 230 of the curing unit 20 via the first glue outlet line 119. When a second resin injector 150, a second resin dispenser 160, and a second glue inlet valve assembly 180 are provided, the second resin injector 150 has a second glue outlet line 151. The first glue outlet line 119 and the second glue outlet line 151 merge through a three-way interface 190 to form a main glue injection line 170. The main glue injection line 170 is connected to the mold glue inlet shut-off valve 240. The main glue injection line 170 is connected to the mold glue inlet shut-off valve 240 at the portion where it connects to the mold glue inlet shut-off valve 240. The melt pressure sensor 220 is connected to measure the resin injection pressure at the mold glue inlet shut-off valve 240. Resin is injected into the product mold cavity 230, and the resin flow displaces gas from the product mold cavity 230 while simultaneously impregnating the fiber preform 260. The composite material part is then heated, cured, cooled, and demolded to obtain the composite material part.

[0034] The control unit 30 includes at least an industrial control computer 33, a programmable logic controller 32, and a sensor transmitter 31. The melt pressure sensor 220 is connected to the programmable logic controller 32 via the sensor transmitter 31 and is used to measure the resin injection pressure of the mold injection port stop valve 240 and transmit the measured pressure signal to the programmable logic controller 32. The programmable logic controller 32 is used to convert the measured pressure signal into a feed signal for the travel speed of the first servo electric cylinder 112. The industrial control computer 33 is connected to the first resin injector 110 and the second resin injector 150 via the programmable logic controller 32 and is used to control the first resin injector 120 to inject resin into the first resin injector 110 and the second resin injector 160 to inject resin into the second resin injector 150. The industrial control computer 33 is also connected to the first glue inlet valve component 130, the second glue inlet valve component 180, and the glue outlet valve component 140 via the programmable logic controller 32 and is used to control the opening and closing of the first glue inlet valve component 130, the second glue inlet valve component 180, and the glue outlet valve component 140.

[0035] In the above embodiment, the first resin injector 120 injects the resin into the first resin syringe 110, and then the first servo electric cylinder 112 in the first resin syringe 110 transports the resin in the first resin syringe 110 to the product cavity 230 of the molding die 210 for molding. During the injection process into the product cavity 230, the melt pressure sensor 220 in the device can measure the injection pressure of the resin at the position of the mold injection port stop valve 240. The industrial control computer 33 reads the mold injection port according to the melt pressure sensor 220 in the main injection line 170. The resin injection pressure at the shutoff valve 240 position is controlled by the PID controller in the programmable logic controller 32, which controls the travel speed of the first servo cylinder 112. This, in turn, controls the resin injection pressure at the mold injection port shutoff valve 240 position to be equal to the injection process pressure set at time t after the injection process begins. The industrial control computer 33 then measures the downward travel distance of the first resin injector's upper ram 114. This distance is used to determine the resin injection volume at that time, i.e., the change in the volume of the first floating inner cavity 1101 during a single process step. This allows for real-time monitoring of resin usage. When resin flows out of the mold outlet shutoff valve 250, the fiber preform 260 in the molding die 210 is completely filled with resin. The resin usage for the entire injection process is calculated based on the number of process steps recorded by the industrial control computer 33. This allows for real-time monitoring of resin usage during the resin injection process under high-temperature conditions while preventing high-pressure gas from entering the finished part.

[0036] It should be noted that, in this embodiment, the injection unit 10 is divided into a normal temperature area and a first high temperature area by dotted lines. Some components of the first resin injector 120 (i.e., the high-pressure gas source 121, the pressure line 122, the first pressure electrical proportional valve 123, and the first pressure line stop valve 124), some components of the first glue inlet valve component 130 (i.e., the mechanical connecting rod 132 and the first rotary cylinder 133), some components of the first resin injector 110 (i.e., the first servo electric cylinder 112), some components of the glue outlet valve component 140 (i.e., the high-pressure gas source 121, the second rotary cylinder 143, the solenoid valve 144, and the third rotary cylinder 145), and some components of the second resin injector 160, the second glue inlet valve component 180, and the second resin injector 150 are in the normal temperature area to avoid damage to these components caused by high temperature. The remaining parts are in the first high temperature area, so that the resin can be kept in a molten state. In this embodiment, the interior of the dotted line of the curing unit 20 is the second high-temperature area, and the molding mold 210 and the melt pressure sensor 220 are in the second high-temperature area; during the injection process, the pipeline between the injection unit 10 and the curing unit 20 is insulated by the insulation component 171 to keep the resin in the pipeline in a molten state; after the injection process is completed, the melt pressure sensor 220, the resin collection barrel 270 and the vacuum source 280 are removed from the curing unit 20, and the molding mold 210 in the curing unit 20 is heated to the resin curing temperature until the entire curing process is completed.

[0037] As a preferred example of this embodiment, Figure 2 As shown, a sealing groove is provided on the upper surface of the first resin injector pressing head 115 , and a sealing strip 117 is filled in the sealing groove.

[0038] After the first resin injector's upper ram 114 reaches the limit position of the first stopper 116, the sealing strip 117 filled in the sealing groove remains compressed. The sealing strip 117 contacts the first resin injector's upper ram 114, and the static friction between the contact surfaces is greater than the injection pressure exerted by the resin in the first floating cavity 1101 during injection. After the first resin injector's upper ram 114 reaches its maximum downward stroke, the volume of the first floating cavity 1101 is minimized. At this point, the sealing strip 117 compresses and deforms to fill the sealing groove of the first resin injector's lower ram 115. In this embodiment, an optional material for the sealing strip 117 is a silicone rubber sealing strip.

[0039] After the injection process is completed, the resin pipeline in the injection unit 10 is removed. Among them, the first resin injector upper pressure head 114, the first resin injector lower pressure head 115, the first body 111, and the sealing strip 117 are all detachable structures. In some embodiments, the first body 111 and the first limiting component 116 are an integrated structure. During detachment, the first resin injection tank 125, the second resin injection tank, the first resin injector 110, and the second resin injector 150 are removed. The first body 111 and the first limiting component 116 are removed from the two groups of injectors, and the resin injector upper pressure head and the resin injector lower pressure head are separated. The working surfaces of the resin injector upper pressure head and the resin injector lower pressure head are cleaned with solvent respectively, and the sealing strip 117 is replaced. By adopting this connection structure, residual resin after the injection process can be easily cleaned.

[0040] As a preferred example of this embodiment, a heat-insulating member 171 is provided on the main glue injection pipeline 170 to allow the resin to have sufficient fluidity so as to be filled into the product mold cavity 230 .

[0041] As a preferred example of this embodiment, taking the first resin injector 120 as an example, it includes a high-pressure gas source 121 and a first resin injection tank 125, wherein the high-pressure gas source 121 and the first resin injection tank 125 are connected through a pressure pipeline 122, and the pressure pipeline 122 is provided with a first pressure electrical proportional valve 123 and a first pressure pipeline stop valve 124, and the glue outlet of the first resin injection tank 125 is provided with a first glue inlet pipeline 126.

[0042] As a preferred example of this embodiment, the first glue inlet valve component 130, the second glue inlet valve component 180 and the glue outlet valve component 140, wherein the first glue inlet stop valve 131 and the first rotary cylinder 133 are connected to the mechanical connecting rod 132 through a coupling 142, the first glue injection pipeline glue outlet stop valve 141 and the second rotary cylinder 143 are connected to the mechanical connecting rod 132 through a coupling 142, the second glue injection pipeline glue outlet stop valve 146 and the third rotary cylinder 145 are connected to the mechanical connecting rod 132 through a coupling 142, the second glue inlet stop valve 181 and the fourth rotary cylinder are connected to the mechanical connecting rod through a coupling, the first rotary cylinder 133, the second rotary cylinder 143, the third rotary cylinder 145, and the fourth rotary cylinder are all connected to the solenoid valve 144 and the high-pressure gas source 121; and are all used to drive the mechanical connecting rod to move, thereby controlling the opening and closing of each valve.

[0043] In some embodiments, the first pressure electrical proportional valve 123 , the second pressure electrical proportional valve, the first servo electric cylinder 112 , the second servo electric cylinder and each solenoid valve 144 are connected to the programmable logic controller 32 and controlled by the industrial control computer 33 .

[0044] As a preferred example of this implementation, Figure 1 As shown, the curing unit 20 also includes a resin collecting barrel 270, which is connected to the mold glue outlet stop valve 250 via a collecting pipe 271, and a glue outlet pipeline stop valve 272 is provided on the collecting pipe 271; the resin collecting barrel 270 is also connected to the vacuum source 280 through an air pipe 281, and a vacuum stop valve 282 is also provided on the air pipe 281.

[0045] In one aspect, the present invention provides an injection method for a reciprocating resin injection device. This method enables real-time monitoring of the resin level in a tank during the production of composite parts, preventing defects caused by high-pressure gas entering the part through the injection line when insufficient resin is present.

[0046] The injection method of the reciprocating resin injection device may include, but is not limited to, the following steps.

[0047] S1. Open the first glue injection pipeline glue outlet stop valve 141 and the second glue injection pipeline glue outlet stop valve 146, close the first glue inlet stop valve 131 and the second glue inlet stop valve 181, and then vacuum the mold glue injection port stop valve 240, the mold glue outlet stop valve 250, the glue outlet pipeline stop valve 272, the vacuum stop valve 282, the resin collection barrel 270, the molding mold 210, the first resin injector 110, the second resin injector 150 and the pipelines therebetween.

[0048] S2. Introduce the vacuum degassed resin into the first resin injection tank 125 and the second resin injection tank. Specifically, open the first pressure pipeline stop valve 124 and the second pressure pipeline stop valve; control the first pressure electrical proportional valve 123 and the second pressure electrical proportional valve through the industrial control computer 33 to increase the gas pressure in the first resin injection tank 125 and the second resin injection tank to the set resin injection pressure.

[0049] S3. The first servo electric cylinder 112 controls the upper ram 114 of the first resin injector to reach the limit position of the first limit component 116. At this time, the distance between the lower surface of the working cavity of the first resin injector upper ram 114 and the upper surface of the working cavity of the first resin injector lower ram 115 is ΔL. The first glue inlet stop valve 131 is opened, the glue outlet stop valve 141 of the first glue injection pipeline is closed, and high-pressure gas drives the resin into the first floating inner cavity 1101 of the first resin injector 110. The second servo electric cylinder controls the upper ram of the second resin injector to reach the limit position of the second limit component. At this time, the distance between the lower surface of the working cavity of the second resin injector upper ram and the upper surface of the working cavity of the second resin injector lower ram is ΔL. The second glue inlet stop valve 181 is opened, the glue outlet stop valve 146 of the second glue injection pipeline is closed, and the high-pressure gas drives the resin into the second floating inner cavity of the second resin injector 150.

[0050] A complete injection process includes steps S4 to S7:

[0051] S4. Close the first pressure line shutoff valve 124 and the first glue inlet shutoff valve 131. The industrial control computer 33 controls the second rotary cylinder 143 to open the first glue inlet line discharge shutoff valve 141 via the mechanical link 132. The first servo electric cylinder 112 applies downward pressure to the first resin injector upper pressure head 114 via the push rod 113, causing the resin to flow through the first discharge line 119 into the main glue inlet line 170 and be injected into the product mold cavity 230. During the resin injection process, the remaining gas in the line and the product mold cavity 230 can be discharged through the resin infiltration. The industrial control computer 33 controls the travel speed of the first servo electric cylinder 112 via the PID controller in the programmable logic controller 32 based on the resin injection pressure at the mold glue inlet shutoff valve 240 measured by the melt pressure sensor 220 in the main glue inlet line 170. This controls the resin injection pressure at the mold glue inlet shutoff valve 240 to be equal to the injection process pressure P set in the industrial control computer 33 at time t after the injection process begins. t When the industrial control computer 33 measures through the servo motor encoder that the downward travel distance of the first resin injector upper ram 114 reaches the working stroke ΔL-ΔLe, the servo motor stops and the industrial control computer 33 records the resin injection volume ΔV at this time, where ΔLe is the safety distance between the lower surface of the working cavity of the first resin injector upper ram 114 and the upper surface of the working cavity of the first resin injector lower ram 115 at this time, and ΔV is the change in volume of the first floating inner cavity 1101 from the beginning of the downward movement of the first resin injector upper ram 114 to the reaching of the working stroke ΔL-ΔLe.

[0052] S5. The industrial control computer 33 controls the second rotary cylinder 143 to close the first glue injection line's glue outlet shut-off valve 141 via the mechanical connecting rod 132, controls the first rotary cylinder 133 to open the first glue inlet shut-off valve 131 via the mechanical connecting rod 132, and controls the first resin injector's upper ram 114 to reach the limit position of the first limiting component 116 via the first servo electric cylinder 112. During the upward movement of the first resin injector's upper ram 114, high-pressure gas drives the resin into the first floating inner cavity 1101 of the first resin injector 110. After the first resin injector's upper ram 114 reaches the limit position of the first limiting component 116, the distance ΔL between the lower surface of its working cavity and the upper surface of the working cavity of the first resin injector's lower ram 115 is.

[0053] When the two resin injectors move alternately, after completing the first resin injection step, the second resin injection step is performed. In this case, step S5 and step S6 are performed synchronously, and step S7 and step S4 are performed synchronously to complete the continuous injection process.

[0054] S6. Close the second pressure line shutoff valve and the second glue inlet shutoff valve 181. The industrial control computer 33 controls the third rotary cylinder 145 to open the second glue injection line discharge shutoff valve 146 via a mechanical linkage. The second servo electric cylinder applies downward pressure on the upper pressure head of the second resin injector via a push rod, causing the resin to flow through the second discharge line 151 into the main glue injection line 170 and be injected into the product mold cavity 230. During the resin injection process, the remaining gas in the line and the product mold cavity 230 can be discharged through the resin infiltration. The industrial control computer 33 controls the travel speed of the second servo electric cylinder via the PID controller in the programmable logic controller 32 based on the resin injection pressure at the mold glue inlet shutoff valve 240 position measured by the melt pressure sensor 220 in the main glue injection line 170. This controls the resin injection pressure at the mold glue inlet shutoff valve 240 position to be equal to the injection process pressure P set in the industrial control computer 33 at time t after the injection process begins. t When the industrial control computer 33 measures through the servo motor encoder that the downward travel distance of the second resin injector upper ram reaches the working stroke ΔL-ΔLe, the servo motor stops and the industrial control computer 33 records the resin injection volume ΔV at this time, where ΔLe is the safety distance between the lower surface of the working cavity of the second resin injector upper ram and the upper surface of the working cavity of the second resin injector lower ram at this time, and ΔV is the change in the volume of the second floating inner cavity from the beginning of the downward movement of the second resin injector upper ram to the reaching the working stroke ΔL-ΔLe.

[0055] S7. Industrial control computer 33 controls third rotary cylinder 145 to close second glue injection line outlet shutoff valve 146 via a mechanical linkage, controls fourth rotary cylinder to open second glue inlet shutoff valve 181 via mechanical linkage 132, and controls the second servo electric cylinder to control the upper ram of the second resin injector to reach the limit position of the second limit member. During the upward movement of the upper ram of the second resin injector, high-pressure gas drives resin into the floating cavity of the second resin injector. After the upper ram of the second resin injector reaches the limit position of the second limit member, the distance between the lower surface of its working cavity and the upper surface of the working cavity of the lower ram of the second resin injector is ΔL.

[0056] Repeat steps S4 to S7 to complete the nth cycle step.

[0057] It should be noted that, in the repeated steps S4 to S7, the order of the repeated steps S4 to S7 can be changed according to different requirements, some steps can be omitted, and parts of some steps can be skipped. Single-step injection is also possible, and this embodiment does not impose any restrictions.

[0058] When the resin flows out of the mold glue outlet stop valve 250, the fiber preform 260 in the molding mold 210 is completely filled with resin. According to the number of all working steps recorded by the industrial control computer 33, the resin consumption Q=2×n×△V of the entire injection process is calculated.

[0059] After the injection process is completed, the resin pipeline in the injection unit 10 is removed, the first resin injection tank 125, the second resin injection tank, the first resin syringe 110 and the second resin syringe 150 are removed, the first limiting component 116 of the first resin syringe 110 and the second limiting component of the second resin syringe 150 are removed from the syringes, and the first resin syringe upper pressure head 114 and the first resin syringe lower pressure head 115, as well as the second syringe upper pressure head and the second resin syringe lower pressure head are separated, and the working surfaces of the first resin syringe upper pressure head 114 and the first resin syringe lower pressure head 115, as well as the second resin syringe upper pressure head and the second resin syringe lower pressure head are cleaned with solvent respectively, and the sealing strip 117 is replaced.

[0060] It will be apparent to those skilled in the art that the present application is not limited to the details and number of repetitions of the exemplary steps described above, and that the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments in the steps should be considered in all respects as illustrative and non-limiting. The scope of the present application is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be encompassed within the present application. Any reference signs in the claims should not be construed as limiting the claim to which they relate.

[0061] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A reciprocating resin injection device, characterized in that: include: An injection unit includes at least a first resin injector and a first resin dispenser, wherein the first resin injector has a first inlet pipe for allowing resin to enter the first resin injector and a first outlet pipe for discharging the resin in the first resin injector. The other end of the first inlet pipe is connected to the first resin dispenser. The first inlet pipe is provided with a first inlet valve component for controlling the flow of resin in the pipe into the first resin injector, and the first outlet pipe is provided with an outlet valve component for controlling the flow of resin in the pipe out of the pipe. The first resin injector includes a first body and a first servo electric cylinder. The first body is provided with a first floating inner cavity formed by a first resin injector upper ram, a first resin injector lower ram, and an inner wall of the first body, and a first limit component for limiting the stroke of the first resin injector upper ram. The first servo electric cylinder is used to drive the first resin injector upper ram to move within the first floating inner cavity to press the resin in the first floating inner cavity into the first outlet pipe. The first floating inner cavity is connected to the first inlet pipe and the first outlet pipe. a curing unit, the curing unit comprising at least a molding die and a melt pressure sensor, the molding die having a product mold cavity and provided with a mold glue injection port shut-off valve and a mold glue outlet shut-off valve communicating with the product mold cavity, wherein the first glue outlet pipeline is communicated with the mold glue injection port shut-off valve, and the melt pressure sensor is used to measure the resin injection pressure at the position of the mold glue injection port shut-off valve; and A control unit, the control unit at least includes an industrial control computer, a programmable logic controller, and a sensor transmitter, wherein the programmable logic controller is connected to the melt pressure sensor through the sensor transmitter, and is used to receive pressure information measured by the melt pressure sensor and convert the measured pressure information into feed information for controlling the movement of the first servo electric cylinder; the industrial control computer is used to obtain the change in the volume of the first floating inner cavity based on the feed information.

2. A reciprocating resin injection device according to claim 1, characterized in that: A sealing groove is provided on the upper surface of the first resin injector pressing head, and a sealing strip is filled in the sealing groove.

3. A reciprocating resin injection device according to claim 2, characterized in that: When the volume of the first floating cavity is the largest, the sealing strip contacts the upper pressure head of the first resin injector, and the static friction between the contact surfaces is greater than the injection pressure of the first floating cavity resin on the sealing strip during injection.

4. A reciprocating resin injection device according to claim 2, characterized in that: The first resin injector upper pressure head, the first resin injector lower pressure head, the first body and the sealing strip are all detachable structures.

5. A reciprocating resin injection device according to claim 2, characterized in that: The sealing strip is a silicone rubber sealing strip.

6. A reciprocating resin injection device according to claim 1, characterized in that: When the injection unit is provided with a second resin injector and a second resin injector having the same structure and connection relationship as the first resin injector and the first resin injector, the first glue outlet pipeline and the second glue outlet pipeline are merged into the main glue injection pipeline through a three-way interface, and the main glue injection pipeline is connected to the mold glue injection port stop valve.

7. A reciprocating resin injection device according to claim 6, characterized in that: The main glue injection pipeline is provided with a heat insulation component.

8. A reciprocating resin injection device according to claim 1, characterized in that: The first resin injector includes a high-pressure air source and a first resin injection tank, wherein the high-pressure air source and the first resin injection tank are connected via a pressure pipeline, a first pressure electrical proportional valve and a first pressure pipeline shut-off valve are provided on the pressure pipeline, and the first resin injection tank outlet is provided with the first glue inlet pipeline.

9. A reciprocating resin injection device according to claim 1, characterized in that: The first glue inlet valve component includes a first glue inlet stop valve arranged on the first glue inlet pipeline; the glue inlet stop valve is provided with a mechanical connecting rod for driving the opening and closing action of the glue inlet stop valve, and the mechanical connecting rod is connected to the output end of the first rotary cylinder.

10. The reciprocating resin injection device according to claim 1, characterized in that: The curing unit also includes a resin collection barrel, which is connected to the mold glue outlet stop valve through a collection pipe, and a glue outlet pipeline stop valve is provided on the collection pipe; the resin collection barrel is also connected to a vacuum source through an air pipe, and a vacuum stop valve is also provided on the air pipe.

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