Pumping device and injection molding equipment

Abstract

The invention discloses a material pumping device and injection molding equipment. The material pumping device comprises a support and a material pumping device, the material pumping mechanism comprises a first cylinder barrel vertically arranged on the support, a first piston is arranged in the first cylinder barrel to divide the first cylinder barrel into a first upper cavity and a first lower cavity, the upper portion of the first cylinder barrel is provided with a first discharging port communicated with the first upper cavity, and the lower portion of the first cylinder barrel is provided with a second discharging port communicated with the first lower cavity; a first one-way valve is arranged at the first discharge port, and a second one-way valve is arranged at the second discharge port; the piston shaft is arranged in the first cylinder barrel in a penetrating mode in the vertical direction, and the first piston is fixedly arranged on the piston shaft; the driving mechanism is arranged on the bracket and is used for driving the piston shaft to move up and down; and the material supply mechanism is used for supplying a liquid material with positive pressure to the first upper cavity when the piston shaft moves downwards, and is used for supplying the liquid material with positive pressure to the first lower cavity when the piston shaft moves upwards. The material pumping device can realize continuous output of the liquid material.

Description

Technical Field

[0001] The present application relates to the technical field of injection molding, and in particular to a material pumping device and injection molding equipment. Background Art

[0002] When using injection molding equipment to process products, it is usually necessary to transport the liquid material contained in the barrel to the injection device, and then inject the liquid material into the mold through the injection device to form the target product.

[0003] However, the efficiency of conveying liquid materials to the injection device in the prior art is low and cannot meet the processing requirements well. To this end, the relevant technology proposes a pumping device, including a cylinder and a split piston movably arranged in the cylinder, the piston divides the internal space of the cylinder into an upper chamber and a lower chamber, the upper chamber is connected to a feeding pipeline for outputting liquid materials, and the lower chamber has a feed port provided with a one-way valve. When the piston is driven to move upward, the piston closes and squeezes the liquid material in the upper chamber, thereby pumping the liquid material in the upper chamber into the feeding pipeline. At the same time, a negative pressure is formed in the lower chamber to suck the liquid material in the barrel into the lower chamber from the feed port; when the piston is driven to move downward, the piston opens and squeezes the liquid material in the lower chamber, so that the liquid material in the lower chamber enters the upper chamber, and the piston is continued to be driven downward, thereby pumping part of the liquid material entering the upper chamber into the feeding pipeline.

[0004] However, during the operation of the above-mentioned pumping device, when the driving piston moves downward, since the lower chamber is in a negative pressure state, the piston needs to move downward for a certain distance first to change the negative pressure in the lower chamber into a positive pressure. At this time, the piston needs to continue to be driven downward to pump the liquid material into the feeding pipeline normally. As a result, the output of liquid material will be interrupted every time the pumping device switches to the working condition of driving the piston to move downward during continuous operation, and continuous output of liquid material cannot be achieved. Summary of the invention

[0005] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a pumping device that can achieve continuous output of liquid materials.

[0006] The present application also proposes an injection molding device having the above-mentioned material pumping device.

[0007] According to the first aspect of the present application, the pumping device comprises: a bracket; a pumping mechanism, comprising a first cylinder vertically arranged on the bracket, a first piston being arranged in the first cylinder to divide the internal space of the first cylinder into a first upper chamber and a first lower chamber, a first discharge port connected to the first upper chamber being arranged at the upper portion of the first cylinder, a second discharge port connected to the first lower chamber being arranged at the lower portion of the first cylinder, a first one-way valve being arranged at the first discharge port, and a second one-way valve being arranged at the second discharge port; a piston shaft vertically penetrated in the first cylinder, the first piston being fixedly arranged on the piston shaft; a driving mechanism being arranged on the bracket and used for driving the piston shaft to move up and down; a feeding mechanism being used for supplying liquid material with positive pressure to the first upper chamber when the piston shaft moves downward, and for supplying liquid material with positive pressure to the first lower chamber when the piston shaft moves upward.

[0008] According to the pumping device of the embodiment of the present application, at least the following beneficial effects are achieved: when the piston shaft is driven to move upward by the driving mechanism, the first piston is driven to move upward, so that the volume of the first upper chamber is reduced, thereby squeezing the liquid material in the first upper chamber, so that the liquid material in the first upper chamber is squeezed out from the first discharge port to the injection device, and at the same time, the feeding mechanism supplies liquid material with positive pressure to the first lower chamber. When the piston shaft is driven to move downward by the driving mechanism, the first piston is driven to move downward, so that the volume of the first lower chamber is reduced, thereby squeezing the liquid material in the first lower chamber, so that the liquid material in the first lower chamber is squeezed out from the second discharge port to the injection device, and at the same time, the feeding mechanism supplies liquid material with positive pressure to the first upper chamber. Compared with the prior art, when the pumping device of the embodiment of the present application is pumping, because the feeding mechanism can provide liquid material with positive pressure, the first piston will not be interrupted in the output of liquid material due to the need to eliminate negative pressure, whether it is in the working condition of moving upward or moving downward, thereby achieving continuous output of liquid material.

[0009] According to some embodiments of the present application, the feeding mechanism includes a second cylinder vertically arranged on the bracket and located below the first cylinder, a second piston is arranged in the second cylinder to divide the internal space of the second cylinder into a second upper chamber and a second lower chamber, a first feed port connected to the second lower chamber is arranged at the lower end of the second cylinder, a third one-way valve is arranged at the first feed port, the lower part of the piston shaft passes through the first cylinder and extends into the second cylinder, an avoidance through hole is arranged on the second piston, the lower part of the piston shaft is penetrated in the avoidance through hole, the diameter of the lower part of the piston shaft is smaller than the aperture of the avoidance through hole, and the lower part of the piston shaft corresponds to the second active The plug is provided with a pushing portion and a first sealing portion, the pushing portion is located above the second piston, the first sealing portion is located below the second piston, the distance between the pushing portion and the first sealing portion is greater than the axial dimension of the second piston along the piston axis, the upper portion of the first cylinder is provided with a second feed port connected to the first upper chamber, the lower portion of the first cylinder is provided with a third feed port connected to the first lower chamber, the upper portion of the second cylinder is provided with a third discharge port connected to the second upper chamber, the third discharge port leads to the second feed port and the third feed port, the second feed port is provided with a fourth one-way valve, and the third feed port is provided with a fifth one-way valve.

[0010] According to some embodiments of the present application, the pumping device also includes a feed pipe, which is arranged on the bracket or the first cylinder, and the feed pipe extends from the upper part of the second cylinder to the upper part of the first cylinder, and the second feed port, the third feed port and the third outlet are all connected to the feed pipe.

[0011] According to some embodiments of the present application, the pumping device also includes a return pipe, which is arranged on the bracket or the second cylinder, one end of the return pipe is connected to the feed pipe, and the other end of the return pipe extends to the lower part of the second cylinder and is used to lead to a barrel containing liquid materials, and an overflow valve is provided at one end of the return pipe close to the feed pipe.

[0012] According to some embodiments of the present application, the pumping device also includes a discharge pipe, which is arranged on the bracket or the first cylinder, the first discharge port and the second discharge port are both connected to the discharge pipe, and one end of the discharge pipe has a fourth discharge port.

[0013] According to some embodiments of the present application, the third one-way valve includes a valve body and a valve core, the valve body is arranged at the first feed port, a material channel is arranged on the valve body, the valve core is movably arranged in the material channel, the diameter of the valve core is smaller than the diameter of the material channel, and a second sealing portion located above the valve body is arranged on the upper part of the valve core.

[0014] According to some embodiments of the present application, a pressure plate is provided at the lower end of the second cylinder, and the pressure plate is used to seal the barrel mouth of the barrel containing the liquid material and fit the liquid surface of the liquid material.

[0015] According to some embodiments of the present application, an openable and closable exhaust port is provided on the pressure plate.

[0016] According to some embodiments of the present application, the driving mechanism is one of a linear motor, an electric push rod, a cylinder, and a hydraulic cylinder.

[0017] According to the second aspect of the present application, the injection molding equipment includes the pumping device according to the first aspect of the present application.

[0018] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0020] Figure 1 It is a schematic structural diagram of a pumping device and a material barrel in accordance with an embodiment of the present application;

[0021] Figure 2 is a cross-sectional schematic diagram of a pumping device according to an embodiment of the present application;

[0022] Figure 3 yes Figure 2 A partial schematic diagram of the first cylinder portion;

[0023] Figure 4 yes Figure 2 A partial schematic diagram of the second cylinder portion;

[0024] Figure 5 is a schematic diagram of a state in which the pushing portion of an embodiment of the present application is separated from the second piston and the first sealing portion is abutted against the second piston;

[0025] Figure 6 is a schematic diagram of a state in which the first sealing portion and the second piston are separated and the pushing portion abuts against the second piston in one embodiment of the present application;

[0026] Figure 7 is a schematic diagram of a state in which the second sealing portion of an embodiment of the present application is separated from the valve body;

[0027] Figure 8 It is a schematic diagram of a state in which the second sealing portion of an embodiment of the present application abuts against the valve body.

[0028] Reference numerals:

[0029] Barrel a, bracket 100, first cylinder 210, first piston 220, first one-way valve 230, second one-way valve 240, fourth one-way valve 250, fifth one-way valve 260, piston shaft 300, pushing part 310, first sealing part 320, driving mechanism 400, second cylinder 510, second piston 520, avoidance through hole 521, third one-way valve 530, valve body 531, material channel 5311, valve core 532, second sealing part 533, sixth one-way valve 540, feed pipe 600, return pipe 700, overflow valve 710, discharge pipe 800, fourth discharge port 810, pressure plate 900. DETAILED DESCRIPTION

[0030] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0031] In the description of the present application, it should be understood that if orientation descriptions are involved, the orientations or positional relationships indicated, such as up, down, front, back, left, and right, are based on the orientations or positional relationships shown in the accompanying drawings. This is only for the convenience of describing the present application and simplifying the description, and does 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, it should not be understood as a limitation on the present application.

[0032] In the description of this application, if the words "some", "greater than", "less than", "exceed", "above", "below", "within" etc. appear, "some" means one or more, "more" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number, and "above", "below", "within", etc. are understood to include the number.

[0033] In the description of this application, if the words "first", "second", etc. appear, they are only used to distinguish technical features and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0034] In the description of this application, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in this application based on the specific content of the technical solution.

[0035] Reference Figures 1 to 8 According to an embodiment of the present application, the pumping device includes a bracket 100, a pumping mechanism, a piston shaft 300, a driving mechanism 400 and a feeding mechanism.

[0036] Specifically, the pumping mechanism includes a first cylinder 210 vertically arranged on the bracket 100, a first piston 220 is arranged in the first cylinder 210 to divide the internal space of the first cylinder 210 into a first upper chamber and a first lower chamber, a first discharge port connected to the first upper chamber is arranged at the upper portion of the first cylinder 210, a second discharge port connected to the first lower chamber is arranged at the lower portion of the first cylinder 210, a first check valve 230 is arranged at the first discharge port, and a second check valve 240 is arranged at the second discharge port, a piston shaft 300 is vertically penetrated in the first cylinder 210, the first piston 220 is fixedly arranged on the piston shaft 300, a driving mechanism 400 is arranged on the bracket 100 and is used to drive the piston shaft 300 to move up and down, and a feeding mechanism is used to supply liquid material with positive pressure to the first upper chamber when the piston shaft 300 moves downward, and is used to supply liquid material with positive pressure to the first lower chamber when the piston shaft 300 moves upward.

[0037] When the piston shaft 300 is driven to move upward by the driving mechanism 400, the first piston 220 is driven to move upward, so that the volume of the first upper chamber is reduced, thereby squeezing the liquid material in the first upper chamber, so that the liquid material in the first upper chamber is squeezed out from the first discharge port to the injection device, and at the same time, the feeding mechanism supplies liquid material with positive pressure to the first lower chamber. When the piston shaft 300 is driven to move downward by the driving mechanism 400, the first piston 220 is driven to move downward, so that the volume of the first lower chamber is reduced, thereby squeezing the liquid material in the first lower chamber, so that the liquid material in the first lower chamber is squeezed out from the second discharge port to the injection device, and at the same time, the feeding mechanism supplies liquid material with positive pressure to the first upper chamber. Compared to the prior art, when the pumping device of the embodiment of the present application is pumping material, since the feeding mechanism can provide liquid material with positive pressure, the output of the liquid material will not be interrupted due to the need to eliminate negative pressure regardless of whether the first piston 220 is in an upward moving condition or a downward moving condition, thereby achieving continuous output of the liquid material.

[0038] The first one-way valve 230 is used to prevent the pumped liquid material from flowing back into the first upper chamber through the first discharge port, and the second one-way valve 240 is used to prevent the pumped liquid material from flowing back into the first lower chamber through the second discharge port.

[0039] Reference Figures 3 to 6 In some embodiments, the feeding mechanism includes a second cylinder 510 vertically arranged on the bracket 100 and located below the first cylinder 210, a second piston 520 is arranged in the second cylinder 510 to separate the internal space of the second cylinder 510 into a second upper chamber and a second lower chamber, and a first feed port connected to the second lower chamber is arranged at the lower end of the second cylinder 510 (i.e., the end of the second cylinder 510 away from the first cylinder 210), and a first feed port is arranged at the first feed port. There is a third one-way valve 530, the lower part of the piston shaft 300 passes through the first cylinder 210 and extends into the second cylinder 510, and the second piston 520 is provided with an avoidance through hole 521 that vertically penetrates the second piston 520. The lower part of the piston shaft 300 is penetrated in the avoidance through hole 521, and the diameter of the lower part of the piston shaft 300 is smaller than the aperture of the avoidance through hole 521, so that there is a gap between the part of the piston shaft 300 located in the avoidance through hole 521 and the hole wall of the avoidance through hole 521. The lower part of the piston shaft 300 is provided with a pushing portion 310 and a first sealing portion 320 corresponding to the second piston 520. The pushing portion 310 is located above the second piston 520 and is used to push the second piston 520 to move downward. The first sealing portion 320 is located below the second piston 520. The first sealing portion 320 is used to block the avoidance through hole 521 and to push the second piston 520 to move upward. The distance between the pushing portion 310 and the first sealing portion 320 is greater than the axial size of the second piston 520 along the piston shaft 300. The upper part of the first cylinder 210 is provided with a second feed port connected to the first upper chamber, the lower part of the first cylinder 210 is provided with a third feed port connected to the first lower chamber, the upper part of the second cylinder 510 is provided with a third discharge port connected to the second upper chamber, the third discharge port leads to the second feed port and the third feed port, the second feed port is provided with a fourth one-way valve 250, and the third feed port is provided with a fifth one-way valve 260.

[0040] When in use, the first feed port is connected to the barrel a containing the liquid material. When the piston shaft 300 is driven to move upward by the driving mechanism 400, the first sealing portion 320 is driven to abut against the second piston 520 to block the avoidance through hole 521 and push the second piston 520 to move upward, so that the volume of the second upper chamber is reduced, thereby squeezing the liquid material in the second upper chamber, so that the liquid material in the second upper chamber is squeezed out from the third discharge port. At this time, since the first upper chamber is in a positive pressure state due to the upward movement of the first piston 220, the liquid material squeezed out from the third discharge port is squeezed into the first lower chamber through the third feed port to supply the liquid material with positive pressure into the first lower chamber. At the same time, the volume of the second lower chamber is increased to form a negative pressure, so that the liquid material in the barrel a is sucked into the second lower chamber through the third one-way valve 530. When the piston shaft 300 is driven to move downward by the driving mechanism 400, the first sealing portion 320 is driven to separate from the second piston 520 to release the blockage of the avoidance through hole 521, so that the second upper chamber is connected to the second lower chamber. At the same time, the pushing portion 310 abuts against the second piston 520 and pushes the second piston 520 to move downward. In this process, the height changes of the second upper chamber and the second lower chamber are the same. Since the piston shaft 300 is inserted into the second upper chamber, the increased volume of the second upper chamber is smaller than the reduced volume of the second lower chamber, thereby squeezing the liquid material in the second lower chamber to make the second lower chamber The liquid material in the chamber is squeezed out into the second upper chamber through the avoidance hole 521. In addition, since the internal space of the second upper chamber is occupied by the piston shaft 300, the effective volume of the second upper chamber is much smaller than the effective volume of the second lower chamber. When the second upper chamber is filled with liquid material, the liquid material squeezed out of the second lower chamber through the avoidance hole 521 into the second upper chamber will be squeezed out through the third discharge port. At this time, since the first lower chamber is in a positive pressure state due to the downward movement of the first piston 220, the liquid material squeezed out from the third discharge port is squeezed into the first upper chamber through the second feed port to supply liquid material with positive pressure into the first upper chamber.

[0041] It can be understood that when the feeding mechanism adopts the above-mentioned structure, the driving mechanism 400 only needs to provide a driving force to drive the piston shaft 300 to move up and down. At this time, the piston shaft 300 can not only drive the first piston 220 to move up and down, so as to use the first cylinder 210 to continuously output liquid material to the injection device, but also drive the second piston 520 to move up and down, so as to use the second cylinder 510 to continuously supply liquid material with positive pressure to the first cylinder 210.

[0042] Among them, the third one-way valve 530 is used to prevent the liquid material in the second lower chamber from flowing back through the first feed port when the second piston 520 moves downward, the fourth one-way valve 250 is used to prevent the liquid material in the first upper chamber from flowing back through the second feed port when the first piston 220 moves upward, and the fifth one-way valve 260 is used to prevent the liquid material in the first lower chamber from flowing back through the third feed port when the first piston 220 moves downward.

[0043] Reference Figures 2 to 4 In some embodiments, a sixth one-way valve 540 is provided at the third discharge port to prevent backflow.

[0044] Reference Figures 1 to 4 In some embodiments, the pumping device of the embodiment of the present application further includes a feed pipe 600, which is arranged on the bracket 100 or the first cylinder 210, and the feed pipe 600 extends from the upper part of the second cylinder 510 to the upper part of the first cylinder 210, and the second feed port, the third feed port and the third discharge port are all connected to the feed pipe 600. The second feed port and the third feed port share a feed pipe 600, which is conducive to simplifying the pipeline structure. Of course, the second feed port and the third feed port can also be respectively connected to a feed pipe 600 connected to the third discharge port, which is not limited here.

[0045] Reference Figures 1 to 4 In some embodiments, the pumping device of the embodiment of the present application also includes a return pipe 700, which is arranged on the bracket 100 or the second cylinder 510, one end of the return pipe 700 is connected to the feed pipe 600, and the other end of the return pipe 700 extends to the lower part of the second cylinder 510 and is used to lead to the barrel a containing liquid material, and an overflow valve 710 is arranged at one end of the return pipe 700 close to the feed pipe 600. In the process of the second cylinder 510 supplying liquid material with positive pressure to the first cylinder 210, when the first cylinder 210 is filled with liquid material, the liquid material continued to be supplied by the second cylinder 510 will increase the pressure in the feed pipe 600. When the pressure in the feed pipe 600 reaches a preset value, the overflow valve 710 can be opened to allow the liquid material in the feed pipe 600 to flow back to the barrel a containing the liquid material through the return pipe 700, thereby relieving pressure, which is beneficial to improve the stability and reliability of the pumping device of the embodiment of the present application during operation.

[0046] It should be noted that the above-mentioned overflow valve 710 is also called a safety valve, which is divided into two categories: spring type and rod type, and belongs to the prior art. Its specific structure and working principle are not described in detail here.

[0047] Reference Figures 1 to 4In some of the embodiments, the pumping device of the embodiment of the present application further includes a discharge pipe 800, the discharge pipe 800 is arranged on the bracket 100 or the first cylinder 210, the first discharge port and the second discharge port are both connected to the discharge pipe 800, and one end of the discharge pipe 800 has a fourth discharge port 810, and the fourth discharge port 810 is used to communicate with the injection device. The first discharge port and the second discharge port share a discharge pipe 800, which is conducive to simplifying the pipeline structure. Of course, the first discharge port and the second discharge port can also be respectively connected to a discharge pipe 800 connected to the injection device, which is not limited here.

[0048] Reference Figure 4 , Figure 7 and Figure 8 In some embodiments, the third one-way valve 530 includes a valve body 531 and a valve core 532. The valve body 531 is arranged at the first feed port. The valve body 531 is provided with a material channel 5311 which vertically penetrates the valve body 531. The valve core 532 is movably arranged in the material channel 5311. The diameter of the valve core 532 is smaller than the diameter of the material channel 5311, so that there is a gap between the part of the valve core 532 located in the material channel 5311 and the inner wall of the material channel 5311. The upper part of the valve core 532 is provided with a second sealing portion 533 located above the valve body 531. The second sealing portion 533 is used to block the material channel 5311. When the piston shaft 300 is driven to move upward by the driving mechanism 400, the second piston 520 is driven to move upward, so that the volume of the second lower chamber increases to form a negative pressure, so that the second sealing portion 533 is separated from the valve body 531 to release the blockage of the material channel 5311, and the liquid material in the barrel a can be sucked into the second lower chamber through the material channel 5311. When the piston shaft 300 is driven to move downward by the driving mechanism 400, the second piston 520 is driven to move downward, so that the volume of the second lower chamber decreases to form a positive pressure, so that the second sealing portion 533 is pressed against the valve body 531 to block the material channel 5311, and the liquid material in the second lower chamber can be prevented from flowing back through the material channel 5311 when the second piston 520 moves downward.

[0049] Reference Figure 1 , Figure 2 and Figure 4 In some embodiments, a pressure plate 900 is provided at the lower end of the second cylinder 510. The pressure plate 900 is used to seal the barrel mouth of the barrel a containing the liquid material and fit the liquid surface of the liquid material. When the second piston 520 moves upward, the pressure plate 900 can prevent gas from entering the barrel a containing the liquid material, so that negative pressure can be better formed in the second lower chamber to suck in the liquid material in the barrel a.

[0050] It should be noted that in some of the embodiments, the pressure plate 900 is provided with an openable and closable exhaust port (not shown in the figure). When the pressure plate 900 is placed in a barrel a containing liquid material, the exhaust port is opened to exhaust air so as to discharge the air between the pressure plate 900 and the liquid surface of the liquid material, so that the pressure plate 900 can fit the liquid surface of the liquid material. After the pressure plate 900 fits the liquid surface of the liquid material, the exhaust port is closed to prevent the liquid material from overflowing through the exhaust port. Specifically, a manual switch valve or a solenoid valve can be provided at the exhaust port to control the opening and closing of the exhaust port, or a detachable sealing plug can be provided at the exhaust port, and the opening and closing of the exhaust port can be achieved by disassembling and assembling the sealing plug, which is not limited here.

[0051] It should be noted that, in some of the embodiments, the driving mechanism 400 is one of a linear motor, an electric push rod, a cylinder, and a hydraulic cylinder.

[0052] The injection molding equipment according to the embodiment of the present application includes the above-mentioned material pumping device.

[0053] It can be understood that, since the injection molding equipment of the embodiment of the present application includes the above-mentioned pumping device, the injection molding equipment of the embodiment of the present application has all the technical effects of the above-mentioned pumping device.

[0054] In the description of this specification, if the description involves reference terms such as "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples" and "some examples", it means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0055] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A pumping device, characterized in that: include: Bracket; A pumping mechanism, comprising a first cylinder vertically arranged on the bracket, a first piston arranged in the first cylinder to divide the internal space of the first cylinder into a first upper chamber and a first lower chamber, a first discharge port connected to the first upper chamber is arranged at the upper portion of the first cylinder, a second discharge port connected to the first lower chamber is arranged at the lower portion of the first cylinder, a first one-way valve is arranged at the first discharge port, and a second one-way valve is arranged at the second discharge port; A piston shaft is vertically inserted into the first cylinder, and the first piston is fixedly arranged on the piston shaft; A driving mechanism, disposed on the bracket and used to drive the piston shaft to move up and down; The feeding mechanism is used to supply liquid material with positive pressure to the first upper chamber when the piston moves axially downward, and is used to supply liquid material with positive pressure to the first lower chamber when the piston moves axially upward.

2. The pumping device according to claim 1, characterized in that: The feeding mechanism includes a second cylinder vertically arranged on the bracket and located below the first cylinder, a second piston is arranged in the second cylinder to divide the internal space of the second cylinder into a second upper chamber and a second lower chamber, a first feed port connected to the second lower chamber is arranged at the lower end of the second cylinder, a third one-way valve is arranged at the first feed port, the lower part of the piston shaft passes through the first cylinder and extends into the second cylinder, an avoidance through hole is arranged on the second piston, the lower part of the piston shaft is penetrated in the avoidance through hole, the diameter of the lower part of the piston shaft is smaller than the aperture of the avoidance through hole, and the lower part of the piston shaft is provided with a pushing valve corresponding to the second piston The pushing portion is located above the second piston, and the first sealing portion is located below the second piston. The distance between the pushing portion and the first sealing portion is greater than the axial dimension of the second piston along the piston axis. The upper portion of the first cylinder is provided with a second feed port connected to the first upper chamber, the lower portion of the first cylinder is provided with a third feed port connected to the first lower chamber, the upper portion of the second cylinder is provided with a third discharge port connected to the second upper chamber, the third discharge port leads to the second feed port and the third feed port, the second feed port is provided with a fourth one-way valve, and the third feed port is provided with a fifth one-way valve.

3. The pumping device according to claim 2, characterized in that: The pumping device also includes a feed pipe, which is arranged on the bracket or the first cylinder, and extends from the upper part of the second cylinder to the upper part of the first cylinder. The second feed port, the third feed port and the third discharge port are all connected to the feed pipe.

4. The pumping device according to claim 3, characterized in that: The pumping device also includes a return pipe, which is arranged on the bracket or the second cylinder, one end of the return pipe is connected to the feed pipe, and the other end of the return pipe extends to the lower part of the second cylinder and is used to lead to a barrel containing liquid materials. An overflow valve is provided at one end of the return pipe close to the feed pipe.

5. The pumping device according to claim 1, characterized in that: The pumping device also includes a discharge pipe, which is arranged on the bracket or the first cylinder, the first discharge port and the second discharge port are both connected to the discharge pipe, and one end of the discharge pipe has a fourth discharge port.

6. The pumping device according to claim 2, characterized in that: The third one-way valve includes a valve body and a valve core. The valve body is arranged at the first feed port. A material channel is arranged on the valve body. The valve core is movably arranged in the material channel. The diameter of the valve core is smaller than the diameter of the material channel. The upper part of the valve core is provided with a second sealing part located above the valve body.

7. The pumping device according to claim 2, characterized in that: A pressure plate is provided at the lower end of the second cylinder, and the pressure plate is used to block the barrel opening of the barrel containing the liquid material and fit the liquid surface of the liquid material.

8. The pumping device according to claim 7, characterized in that: The pressure plate is provided with an exhaust port which can be opened and closed.

9. The pumping device according to claim 1, characterized in that: The driving mechanism is one of a linear motor, an electric push rod, a cylinder, and a hydraulic cylinder.

10. An injection molding device, characterized in that: It comprises a pumping device as claimed in any one of claims 1 to 9.

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