Dispensing device with glue breaking control function and dispensing equipment

Abstract

The utility model provides a dispensing device with a glue breaking control function, which is used in the field of dispensing equipment and comprises a needle head, a glue cylinder and an air pressure component, the needle head and the air pressure component are respectively and fixedly connected with the glue cylinder, and the air pressure component can generate positive pressure or negative pressure to extrude or suck back glue in the glue cylinder from the needle head. The utility model further provides dispensing equipment which comprises the dispensing device. According to the glue dispensing device with the glue breaking control function, glue extrusion is stopped by rapidly reducing the pressure in the glue barrel, glue between the needle head and a workpiece is rapidly sucked back to the needle head, and after glue connection between the needle head and the workpiece is broken (glue breaking), the glue on the needle head is kept in a static state in a gravity counteracting mode through small negative pressure; and the phenomenon of fine tail caused by excessive glue on the surface of the workpiece and untimely suction of the glue is avoided, so that the dispensing quality is improved, and the device is suitable for high-precision dispensing.

Description

TECHNICAL FIELD

[0001] The utility model relates to the point gum technical field especially relates to a kind of point gum device and point gum equipment with glue breaking control function. BACKGROUND

[0002] Point gum device is a kind of fluid (usually glue) is controlled, and fluid is coated on the surface of workpiece device. Among them, pneumatic point gum valve is commonly used one kind of point gum device, it is by the compressed air of glue pipe delivery, and glue is extruded. With air pressure cut-off, negative pressure back absorption and so on, control glue discharge flow. The point gum control method is by the size adjustment of air pressure, flow control, air pressure back absorption, replacement needle tube and so on Control mode, make final glue output meet product requirement.

[0003] The control mode of the above-mentioned pneumatic point gum valve is relatively mature, and is widely used in the application of a variety of low-cost products, but the point gum control mode has certain limitations. Mainly in, when stopping point gum, because there is a certain volume of compressed gas between the inside of glue cylinder and the pipeline communicated with glue cylinder, when the air pressure in the inside of glue cylinder is adjusted from positive pressure to negative pressure, a certain time is needed. In this period of time, although the air pressure in the inside of glue cylinder gradually decreases, the glue in the inside of glue cylinder still flows out through the needle. For example, when single point gum, the actual amount of glue flowing out will exceed the required amount, and when line drawing point gum, the "thin tail" phenomenon will occur, which reduces the point gum quality and is difficult to meet the requirements of high-precision point gum process.

[0004] Therefore, it is necessary to improve the point gum device and point gum equipment in the prior art. INVENTION CONTENTS

[0005] Therefore, the purpose of the utility model is to overcome the defects in the prior art, and provide a point gum device and point gum equipment with glue breaking control function to improve the point gum precision and point gum quality.

[0006] To solve the above technical problems, the utility model provides a kind of point gum device with glue breaking control function, for point gum equipment field, including needle, glue cylinder and air pressure component, the needle and the air pressure component are fixedly connected with the glue cylinder, the air pressure component can generate positive pressure or negative pressure for the glue in the inside of the glue cylinder is extruded or sucked back from needle.

[0007] Specifically, the air pressure component includes a positive pressure generator, a negative pressure generator and a first control valve, the glue cylinder, the positive pressure generator and the negative pressure generator are connected with the first control valve, and the first control valve is used to control the gas flow of the glue cylinder, the positive pressure generator and the negative pressure generator.

[0008] Specifically, the first control valve is a three-way valve with three connectors. The second and third connectors of the first control valve are connected to the positive pressure generator and the negative pressure generator, respectively. The first connector of the first control valve is connected to the rubber sleeve, which is used to control the rubber sleeve to be connected to one of the positive pressure generator and the negative pressure generator, while the other is disconnected.

[0009] Specifically, the negative pressure generator is an adjustable air pressure generating end, and the negative pressure generator includes an adjustment unit for switching the air pressure of the negative pressure generator.

[0010] Specifically, the negative pressure generator includes a first negative pressure generating circuit, a second negative pressure generating circuit, and a second control valve; the first control valve, the first negative pressure generating circuit, and the second negative pressure generating circuit are respectively connected to the second control valve; the second control valve is used to control the gas flow between the first control valve and the first negative pressure generating circuit and the second negative pressure generating circuit to switch the gas pressure of the negative pressure generator.

[0011] Specifically, the second control valve is a three-way valve with three connectors. The fifth and sixth connectors of the second control valve are connected to the first negative pressure generating circuit and the second negative pressure generating circuit, respectively. The third connector of the first control valve is connected to the fourth connector of the second control valve, which is used to control the third connector of the first control valve to be connected to one of the first negative pressure generating circuit and the second negative pressure generating circuit, while the other is disconnected.

[0012] Specifically, the negative pressure generated by the first negative pressure generating circuit is less than that generated by the second negative pressure generating circuit.

[0013] Specifically, the dispensing device with glue-cut-off control function also includes a control system, which is connected to the first control valve and the second control valve and is used to switch the air pressure of the air pressure component.

[0014] Specifically, the control system is also connected to the first negative pressure generating circuit, the second negative pressure generating circuit, and the positive pressure generator. Only one air pressure generating end is connected to the rubber tube at any given time. The control system is used to shut off the other two air pressure generating ends that are not connected to the rubber tube.

[0015] This utility model also provides a dispensing device, including a dispensing apparatus with dispensing cut-off control function as described in any of the preceding claims.

[0016] In summary, compared with the prior art, the dispensing device and equipment with glue-cut-off control function of this utility model cuts off the glue output by quickly reducing the pressure inside the glue cylinder and then drawing the glue back into the needle, thus avoiding excessive glue on the workpiece surface and the formation of a thin tail, thereby improving the dispensing quality and making it suitable for high-precision dispensing. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 It is a process flow diagram of existing technology.

[0019] Figure 2 This is a system schematic diagram of existing technology.

[0020] Figure 3 It is a graph of pressure inside the rubber sleeve versus time in the existing technology.

[0021] Figure 4 It is a graph showing the speed of glue dispensing from the needle versus time in existing technology.

[0022] Figure 5 This is a schematic diagram of the existing dispensing technology.

[0023] Figure 6 This is a process flow diagram of this utility model.

[0024] Figure 7 This is a system schematic diagram of this utility model.

[0025] Figure 8 This is a graph showing the pressure inside the rubber cylinder versus time in this utility model.

[0026] Figure 9 This is a graph showing the speed of glue dispensing from the needle versus time in this utility model.

[0027] Figure 10 This is a schematic diagram of the dispensing process of this utility model.

[0028] Figure 11 This is a schematic diagram of the working principle of the control system of this utility model.

[0029] In the above-mentioned figures, the reference numerals for the embodiments of this utility model are as follows:

[0030] 1. Dispensing valve; 11. Glue cartridge; 12. Needle; 2. Positive pressure generator; 3. First negative pressure generating circuit; 4. Second negative pressure generating circuit; 5. First control valve; 6. Second control valve; 7. Control system; 8. Workpiece; 9. Negative pressure generator. Detailed Implementation

[0031] The specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some, not all, of the embodiments of this utility model. Based on the description of this utility model, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this utility model.

[0032] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0033] The terms “upper,” “lower,” “left,” “right,” “front,” “back,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of description and simplification, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0034] The terms “first,” “second,” “third,” etc., are used merely to distinguish elements with similar properties, not to indicate or imply relative importance or a specific order.

[0035] The terms “include,” “comprising,” or any other variation thereof are intended to cover non-exclusive inclusion, which includes not only the elements listed but also other elements not expressly listed.

[0036] The following detailed description uses specific examples.

[0037] like Figure 1 The image shows a prior art dispensing control method, which includes the following steps:

[0038] Step S1: Preparation, obtain the dispensing path of dispensing valve 1;

[0039] Step S2: Pressurize the dispensing valve 1 to the starting position of the dispensing path, increase the air pressure in the glue cartridge 11 to P1, keep the pressure constant, and while squeezing the glue out of the needle 12, move the dispensing valve 1 along the dispensing path to perform dispensing.

[0040] Step S3: Reduce pressure and cut off glue. When the dispensing valve 1 moves to the end of the dispensing path, reduce the air pressure in the glue cartridge 11 to a negative pressure of size P3 to reduce the glue dispensing speed of the needle 12 to 0.

[0041] Step S4: Stabilize pressure and control adhesive, maintain the negative pressure in the glue cartridge 11 at P3 to prevent adhesive from flowing out from the needle 12.

[0042] Based on the above dispensing control method, the system structure schematic diagram of the existing dispensing device is as follows: Figure 2 As shown, it includes:

[0043] Dispensing valve 1, which includes a glue cartridge 11 and a needle 12 connected in communication;

[0044] The first control valve 5, the output end of the first control valve 5 is connected to the rubber sleeve 11;

[0045] Positive pressure generator 2 and negative pressure generator 9 are respectively connected to the two input terminals of the first control valve 5. Positive pressure generator 2 is used to adjust the air pressure in the glue cartridge 11 to a positive pressure of P1, so that compressed air is input into the glue cartridge 11 to squeeze the glue through the needle 12 and apply it to the surface of the workpiece 8. Negative pressure generator 9 is used to adjust the air pressure in the glue cartridge 11 to a negative pressure of P3, so as to reduce the glue dispensing speed of the needle 12 to 0. Specifically, positive pressure generator 2 is a glue dispensing pressure regulating valve, and negative pressure generator 9 is a back suction negative pressure generator.

[0046] The control system 7 is electrically connected to the first control valve 5, the negative pressure generator 9, and the positive pressure generator 2 to control the operation of the first control valve 5, the negative pressure generator 9, and the positive pressure generator 2.

[0047] After adopting the above dispensing control method and structure, the pressure versus time curve inside the glue cartridge 11 during dispensing is shown in the figure below. Figure 3 As shown in the figure, the curve of the dispensing speed of needle 12 versus time is as follows. Figure 4 As shown, at time t0, the control system 7 controls the first control valve 5 to operate and the positive pressure generator 2 to start, so that the positive pressure generator 2 injects compressed air into the rubber cylinder 11 through the first control valve 5 until the air pressure in the rubber cylinder 11 rises to P1, and is maintained until time t1.

[0048] During the aforementioned time period, the air pressure inside the glue cartridge 11 first rises from P3 to P1, and then remains at the level of P1. Correspondingly, the glue dispensing speed of the needle 12 first rises from 0 to v1, and then remains at a stable level of v1, so that the needle 12 expels glue onto the surface of the workpiece 8 for dispensing.

[0049] When the dispensing valve 1 moves to the end of the dispensing path, the control system 7 controls the first control valve 5 and the negative pressure generator 9 to operate, so that the negative pressure generator 9 is connected to the glue cartridge 11 through the first control valve 5, while the positive pressure generator 2 is disconnected from the glue cartridge 11, thereby drawing out the air in the glue cartridge 11, so that the air pressure in the glue cartridge 11 gradually decreases, eventually forming a negative pressure of P3. At the same time, the dispensing speed of the needle 12 is 0.

[0050] When performing step S3, such as Figure 3 and Figure 4 As shown, from time t1 to time t2, the pressure inside the glue cartridge 11 gradually decreases from P1 to P3, while the glue dispensing speed gradually decreases from v1 to 0. Because there is a relatively long time interval between t1 and t2, a long, thin tail is easily formed on the surface of the workpiece 8 at the final moment of dispensing, such as... Figure 5 As shown, this reduces dispensing quality and accuracy, making it unsuitable for high-precision dispensing applications.

[0051] In existing technologies, to minimize the thin tail phenomenon, it is necessary to stop the glue output and quickly cut off the glue flow within a shorter time, i.e., less than t2-t1. This requires increasing the back suction force (negative pressure value) to minimize the volume of back suction air. However, increasing the back suction force will easily cause the glue to be drawn back into the needle 12 while air enters the needle 12 and mixes with the glue, which does not meet the process requirements.

[0052] Based on the above factors, this utility model provides a dispensing device and dispensing equipment with glue breakage control function, as shown below.

[0053] like Figure 7 As shown, this utility model embodiment provides a dispensing device with glue-cut-off control function, which is used in the field of dispensing equipment. It includes a needle 12, a glue cartridge 11 and a pneumatic assembly. The needle 12 and the pneumatic assembly are respectively fixedly connected to the glue cartridge 11. The pneumatic assembly can generate positive or negative pressure to squeeze or draw back the glue in the glue cartridge 11 from the needle 12.

[0054] Specifically, the pneumatic assembly has positive pressure P1, negative pressure P2, and P3 pressure ( Figure 8 The pneumatic component can switch between three working states: negative pressure (P3) and negative pressure (P4).

[0055] In this embodiment, the pneumatic assembly includes a positive pressure generator 2, a negative pressure generator 9, and a first control valve 5. The rubber sleeve 11, the positive pressure generator 2, and the negative pressure generator 9 are respectively connected to the first control valve 5. The first control valve 5 is used to control the gas flow between the rubber sleeve 11 and the positive pressure generator 2 and the negative pressure generator 9.

[0056] Specifically, the positive pressure generator 2 generates a positive pressure P1, and the negative pressure generator 9 generates a negative pressure P2 or P3. Figure 8 The negative pressure P3 in the middle), the first control valve 5 is used to control the air pressure component to switch between these three working states.

[0057] In this embodiment, the first control valve 5 is a three-way valve with three connectors. The second and third connectors of the first control valve 5 are connected to the positive pressure generator 2 and the negative pressure generator 9, respectively. The first connector of the first control valve 5 is connected to the rubber sleeve 11, which controls the rubber sleeve 11 to be connected to one of the positive pressure generator 2 and the negative pressure generator 9, while the other is disconnected. The second connector is the input end, and gas is input from the positive pressure generator 2 to the first control valve. The third connector is the output end, and gas is output from the first control valve 5 to the negative pressure generator 9. The first connector can be either an output end or an input end. When the rubber sleeve 11 is connected to the positive pressure generator 2, the first connector is the output end; when the rubber sleeve 11 is connected to the negative pressure generator 9, the first connector is the input end.

[0058] In this embodiment, the negative pressure generator 9 is an adjustable air pressure generating end. The negative pressure generator 9 includes an adjustment part for switching the air pressure of the negative pressure generator 9.

[0059] In another embodiment of this example, the negative pressure generator 9 includes a first negative pressure generating circuit 3, a second negative pressure generating circuit 4, and a second control valve 6; the first control valve 5, the first negative pressure generating circuit 3, and the second negative pressure generating circuit 4 are respectively connected to the second control valve 6; the negative pressure generated by the first negative pressure generating circuit 3 is less than that generated by the second negative pressure generating circuit 4; the second control valve 6 is used to control the gas flow between the first control valve 5 and the first negative pressure generating circuit 3 and the second negative pressure generating circuit 4 to switch the gas pressure of the negative pressure generator 9.

[0060] Specifically, the air pressure generated by the first negative pressure generating circuit 3 is negative pressure P2, and the air pressure generated by the second negative pressure generating circuit 4 is air pressure P3. Figure 8 The negative pressure P3), and the second control valve 6 are used to control the amount of air pressure output by the negative pressure generator 9 to the first control valve 5.

[0061] In this embodiment, the second control valve 6 is a three-way valve with three connectors. The fifth and sixth connectors of the second control valve 6 are connected to the first negative pressure generating circuit 3 and the second negative pressure generating circuit 4, respectively. The third connector of the first control valve 5 is connected to the fourth connector of the second control valve 6, which is used to control the first control valve 5 to be connected to one of the first negative pressure generating circuit 3 and the second negative pressure generating circuit 4, while the other is disconnected. The fifth and sixth connectors are both output terminals, and gas is output from the second control valve 6 to the first negative pressure generating circuit 3 or the second negative pressure generating circuit 4; the fourth connector is an input terminal, and gas is input from the first control valve 5 to the second control valve 6.

[0062] Specifically, when the first control valve 5 controls the rubber sleeve 11 to connect with the positive pressure generator 2, the air pressure output by the pneumatic assembly is positive pressure P1; when the first control valve 5 controls the rubber sleeve 11 to connect with the second control valve 6, if the second control valve 6 controls the first control valve 5 to connect with the first negative pressure circuit 3, then the air pressure output by the pneumatic assembly is negative pressure P2; if the second control valve 6 controls the first control valve 5 to connect with the second negative pressure circuit 4, then the air pressure output by the pneumatic assembly is P3. Figure 8 The negative pressure P3 in the cylinder is easily adjusted to the P3 value. Specifically, in the three working states, the pressure in the cylinder 11 is adjusted to P1, P2 and P3 air pressure (P3) through three air pressure generating ends and two control valves, so as to perform dispensing, dispensing and suction operations respectively.

[0063] In this embodiment, the dispensing device with adhesive cut-off control function also includes a control system 7, which is connected to the first control valve 5 and the second control valve 6 and is used to switch the air pressure of the air pressure component.

[0064] Specifically, the first control valve 5, the second control valve 6, and the three air pressure generating terminals (positive pressure generator 2, first negative pressure generating circuit 3, and second negative pressure generating circuit 4) are all controlled by the control system 7. With this structure, the control system 7 controls the connection and disconnection of the positive pressure generator 2, the first negative pressure generating circuit 3, and the second negative pressure generating circuit 4 with the glue cartridge 11 by controlling the opening and closing of the first control valve 5 and the second control valve 6. Adjusting and switching the working state of the air pressure components achieves rapid adjustment of the air pressure inside the glue cartridge 11, thereby improving the dispensing quality and accuracy.

[0065] In this embodiment, the control system 7 is also connected to the first negative pressure generating circuit 3, the second negative pressure generating circuit 4 and the positive pressure generator 2. At any given time, only one air pressure generating end is connected to the rubber tube 11. The control system 7 is used to shut down the other two air pressure generating ends that are not connected to the rubber tube 11.

[0066] like Figure 6As shown below, the dispensing control method of the dispensing device with glue-cut-off control function according to an embodiment of the present invention is described, including:

[0067] Step S1: Pressure boosting dispensing: Increase the air pressure in the glue cartridge 11 to positive pressure P1 and keep the pressure constant. The positive pressure in the glue cartridge 11 will squeeze the glue out of the needle 12 for dispensing.

[0068] Step S2: Pressure Reduction and Adhesive Cut-off: When dispensing is complete, reduce the air pressure inside the glue cartridge 11 from positive pressure P1 to negative pressure P2. The negative pressure P2 is less than the air pressure P3 inside the glue cartridge 11 before dispensing (P3 air pressure corresponds to...). Figure 8 The negative pressure P3 is greater than the negative pressure P2 (the suction force of air pressure P2 is stronger), and is used to quickly draw the glue between the needle 12 and the workpiece back to the needle 12, thus breaking the glue connection between the needle 12 and the workpiece;

[0069] Step S3: Pressure Increase and Adhesive Suction: After the adhesive on the needle 12 is disconnected from the adhesive on the workpiece, the air pressure inside the adhesive cartridge 11 is increased from negative pressure P2 to P3. This is used to keep the adhesive on the needle in a stationary state by counteracting gravity. Specifically, the adhesive is drawn back to protrude beyond the bottom end of the needle 12 or flush with the bottom end of the needle 12.

[0070] In this embodiment, the positive or negative value of the air pressure represents the direction of airflow. Positive pressure means that the airflow (glue) flows from the glue cartridge 11 to the needle 12, and negative pressure means that the airflow (glue) flows from the glue cartridge 11 to the needle 12. The absolute value of the air pressure (i.e., the magnitude of the value) represents the speed of the airflow (the magnitude of the pressure). The greater the air pressure, the faster the airflow speed (the speed at which the glue moves).

[0071] After the above improvements, since the negative pressure P2 is less than the air pressure P3, the suction force of the negative pressure increases when the dispensing valve 1 stops dispensing at the key position of the dispensing path. This significantly shortens the dispensing stop time. After dispensing stops, the dispensing speed of the needle 12 is 0, and the air pressure in the glue cartridge 11 is then raised to the negative pressure of P3. The glue changes from downward flow to upward flow, causing a change in the flow direction and drawing back some of the glue that has been discharged from the needle 12. This achieves rapid separation of the glue connected to the needle 12 from the glue applied to the workpiece 8, achieving the purpose of rapid glue cut-off. Due to the viscosity of the glue when the glue is cut off, some glue outside the needle 12 is "pulled" to the surface of the workpiece 8, filling the reduced glue volume during the time when the negative pressure in the glue cartridge 11 drops from P1 to P2. This improves the thin tail phenomenon and enhances dispensing accuracy and quality.

[0072] After the glue is cut off, the air pressure inside the glue cartridge 11 rises to the negative pressure of P3. At this stage, the glue flows back, rising from 0 to a certain speed and then decelerating until it stops, and finally being drawn back into the needle 12.

[0073] In this embodiment, the P3 pressure is negative or zero pressure, and the P3 pressure is used to keep the glue stationary relative to the needle 12. Specifically, some glues are fluid and easily drip from the needle 12, so the P3 pressure is preferably a low negative pressure to hold the glue in place and prevent it from dripping.

[0074] In this embodiment, the dispensing step further includes:

[0075] Step S11: Obtain the movement path of needle 12;

[0076] Step S12: Move the needle 12 to the starting position of the movement path;

[0077] Step S13: As glue is squeezed out from needle 12, needle 12 moves along the moving path to the end position.

[0078] In another embodiment of this example, the dispensing step further includes:

[0079] Step S11: Obtain the location information of the dispensing position;

[0080] Step S12: Move the needle 12 to the dispensing position;

[0081] Step S13: While the glue is being squeezed out from the needle 12, the needle 12 remains stationary at the glue application point.

[0082] In this embodiment, the process further includes the following after the pressure boosting and adhesive absorption step:

[0083] Step S4: Pressure stabilization and glue control: Maintain constant air pressure inside glue cartridge 11 to prevent glue from flowing out of needle 12 and wait for the next glue application.

[0084] In this embodiment, after the pressure boosting and adhesive suction step, the adhesive at the needle tip 12 is flush with or slightly protrudes from the needle tip 12. The bottom of the adhesive is flush with the bottom of the needle tip 12, preventing the adhesive from protruding beyond the bottom of the needle tip 12. This avoids the problem of excessive adhesive at the initial dispensing stage due to adhesive protruding beyond the bottom of the needle tip 12, which would reduce dispensing accuracy.

[0085] After adopting the above-mentioned dispensing control method and dispensing device with dispensing cut-off function, the dispensing valve 1 can perform dispensing in multiple stages, such as... Figure 8 and Figure 9 As shown (assuming that at time t0, dispensing valve 1 is already at the starting position of the dispensing path):

[0086] 1. The first stage, also known as the dispensing stage, specifically spans from time t0 to t1. Control system 7 activates the first control valve 5, simultaneously starting the positive pressure generator 2. This connects the positive pressure generator 2 to the glue cartridge 11 via the first control valve 5, rapidly increasing the pressure within the cartridge 11 to positive pressure P1, and then maintaining this pressure. During this pressure increase, the glue dispensing speed of the needle 12 increases from 0 to v1, with the dispensing direction of the needle 12 pointing downwards, thus dispensing glue onto the surface of the workpiece 8.

[0087] 2. The second stage, also known as the glue-cut-off stage, specifically spans from time t1 to t3. Control system 7 activates the first control valve 5 and the second control valve 6, while simultaneously starting the first negative pressure generating circuit 3. This connects the first negative pressure generating circuit 3 to the glue cartridge 11, rapidly reducing the pressure inside the cartridge 11 to a negative pressure of P2. At time t3, the glue dispensing speed of the needle 12 decreases to 0. However, some glue outside the needle 12 remains disconnected from the glue on the surface of the workpiece 8. Due to the adhesive's viscous effect during glue cut-off, this portion of glue outside the needle 12 is "pulled" to the surface of the workpiece 8, mitigating the thin tail phenomenon. Since P2 is less than P3, meaning the output negative pressure of the first negative pressure generating circuit 3 is lower than the output negative pressure of the second negative pressure generating circuit 4, (t3-t1) < (t2-t1). Therefore, the air pressure inside the glue cartridge 11 can be rapidly reduced, significantly shortening the glue dispensing stop time. Furthermore, during the glue dispensing stop process, the rapid decrease in air pressure inside the glue cartridge 11 causes the glue to disconnect.

[0088] 3. The third stage, also known as the back-suction stage, specifically occurs from time t3 to t4. Control system 7 maintains the state of the first control valve 5 and controls the second control valve 6 to operate, while the second negative pressure generating circuit 4 is activated. This connects the second negative pressure generating circuit 4 to the glue cartridge 11, raising the pressure inside the cartridge 11 to the negative pressure of P3 until time t4. During this process, the glue flows upwards, initially increasing in speed from 0, then decreasing to 0. When the glue speed decreases to 0 again, i.e., at time t4, the glue is drawn back into the needle 12, with the bottom of the drawn-back glue portion flush with the bottom of the needle 12. This prevents air from entering the needle 12 and affecting glue quality. It also prevents glue from protruding from the needle 12, which could lead to excessive glue volume in the initial stage of subsequent dispensing processes, thus affecting the quality of subsequent dispensing.

[0089] 4. The fourth stage, also known as the anti-backflow stage, specifically occurs after time t4. The control system 7 controls the second negative pressure generating circuit 4 to maintain operation, thereby keeping the negative pressure inside the glue cartridge 11 at P3 and preventing glue from dripping.

[0090] After the above four stages, the dispensing valve 1 of this utility model dispenses adhesive onto the surface of the workpiece 8, as shown in the schematic diagram. Figure 10 As shown, with Figure 5Compared with the dispensing operation of the prior art dispensing valve 1, it can significantly improve the "fine tail" phenomenon that occurs during the dispensing process, thereby improving the dispensing quality and meeting the requirements of high-precision dispensing.

[0091] like Figure 11 The diagram illustrates the working principle under different operating conditions. The arrows indicate the direction of gas flow, and the arrows emitted by control system 7 represent control signals. The working principle of control system 7 is as follows:

[0092] (1) such as Figure 11 As shown in (a), the initial state is as follows: all negative pressure generators 9 and positive pressure generators 2 are turned on, the second control valve 6 is connected to the second negative pressure generating circuit 4, and the first control valve 5 is connected to the second control valve 6 and the glue cartridge 11; this is equivalent to the second negative pressure generating circuit 4 and the glue cartridge 11 being connected, and the negative pressure P3 acting on the glue to prevent the glue from flowing out due to gravity;

[0093] (2) For example Figure 11 As shown in (b), when the control system 7 receives an external dispensing control signal, it drives the first control valve 5 to switch the first control valve 5 to be connected to the positive pressure generator 2 and the glue cartridge 11. The positive pressure P1 is connected to the glue cartridge, and the glue in the glue cartridge is squeezed out from the needle under pressure.

[0094] (3) such as Figure 11 As shown in (c), after the above switching is completed, the second control valve 6 is switched to be connected to the first negative pressure generating circuit 3 and the first control valve 5 to prepare for stopping the dispensing; at this time, since the first control valve 5 is connected to the positive pressure generator 2 and the glue cartridge 11, neither the second negative pressure generating circuit 4 nor the first negative pressure generating circuit 3 will function.

[0095] (4) such as Figure 11 As shown in (d), when the control system 7 receives an external stop dispensing signal, it drives the first control valve 5 to switch the first control valve 5 to be connected to the second control valve 6 and the glue cartridge 11. At this time, since the second control valve 6 is connected to the first negative pressure generating circuit 3 and the first control valve 5, the negative pressure P2 of the first negative pressure generating circuit 3 acts on the glue cartridge 11. Under the action of the larger negative pressure P2 (the suction force is greater than the negative pressure P3), the glue quickly stops dispensing and begins to flow in reverse, disconnecting the glue from the workpiece.

[0096] (5) such as Figure 11 As shown in (e), after a set time, the control system 7 controls the second control valve 6 to switch, switching the second control valve 6 to connect with the second negative pressure generating circuit 4 and the first control valve 5. The negative pressure P3 of the second negative pressure generating circuit 4 acts on the glue cylinder 11 to realize glue back suction control (counteracting the influence of glue gravity and stopping the flow).

[0097] (6) Maintain the current state and wait for the next dispensing signal;

[0098] (7) The control system 7 can adjust the glue cut-off and return flow by controlling the pressure and action time of the first negative pressure generating circuit 3;

[0099] (8) The control system 7 controls the pressure of the second negative pressure generating circuit 4 to counteract the glue overflow caused by the gravity of the glue in the glue tube;

[0100] (9) The control system 7 controls the dispensing speed and dispensing amount by controlling the magnitude and duration of the positive pressure.

[0101] This utility model embodiment also provides a dispensing device, including a dispensing device with dispensing cut-off control function as described in any of the above claims.

[0102] In summary, compared with the prior art, the dispensing device and equipment with glue-cut-off control function of this utility model, by quickly reducing the pressure inside the glue cylinder 11 to stop the glue output and then drawing the glue back into the needle, avoids excessive glue on the workpiece surface and the formation of a thin tail, thereby improving the dispensing quality and making it suitable for high-precision dispensing.

[0103] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the appended claims.

Claims

1. A dispensing device with adhesive cut-off control function, used in the field of dispensing equipment, characterized in that, It includes a needle, a glue cartridge, and a pneumatic assembly. The needle and the pneumatic assembly are respectively fixedly connected to the glue cartridge. The pneumatic assembly can generate positive or negative pressure to squeeze or draw back the glue in the glue cartridge from the needle. The pneumatic assembly includes a positive pressure generator, a negative pressure generator, and a first control valve. The rubber tube, the positive pressure generator, and the negative pressure generator are respectively connected to the first control valve. The first control valve is used to control the gas flow between the rubber tube and the positive pressure generator and the negative pressure generator. The first control valve is a three-way valve with three connectors. The second and third connectors of the first control valve are respectively connected to the positive pressure generator and the negative pressure generator. The first connector of the first control valve is connected to the rubber sleeve, which is used to control the rubber sleeve to be connected to one of the positive pressure generator and the negative pressure generator, and disconnected from the other. The negative pressure generator includes a first negative pressure generating circuit, a second negative pressure generating circuit, and a second control valve; the first control valve, the first negative pressure generating circuit, and the second negative pressure generating circuit are respectively connected to the second control valve; the second control valve is used to control the gas flow between the first control valve and the first negative pressure generating circuit and the second negative pressure generating circuit to switch the gas pressure of the negative pressure generator; The second control valve is a three-way valve with three connectors. The fifth and sixth connectors of the second control valve are connected to the first negative pressure generating circuit and the second negative pressure generating circuit, respectively. The third connector of the first control valve is connected to the fourth connector of the second control valve. This is used to control the third connector of the first control valve to be connected to one of the first negative pressure generating circuit and the second negative pressure generating circuit, while the other is disconnected.

2. The dispensing device with adhesive cut-off control function as described in claim 1, characterized in that, The negative pressure generator is an adjustable air pressure generating end, and the negative pressure generator includes an adjustment unit for switching the air pressure of the negative pressure generator.

3. The dispensing device with adhesive cut-off control function as described in claim 1, characterized in that, The negative pressure generated by the first negative pressure generating circuit is less than that generated by the second negative pressure generating circuit.

4. The dispensing device with adhesive cut-off control function as described in claim 1, characterized in that, The dispensing device with adhesive cut-off control function also includes a control system, which is connected to the first control valve and the second control valve and is used to switch the air pressure of the air pressure component.

5. The dispensing device with adhesive cut-off control function as described in claim 4, characterized in that, The control system is also connected to the first negative pressure generating circuit, the second negative pressure generating circuit, and the positive pressure generator. Only one air pressure generating end is connected to the rubber tube at any given time. The control system is used to shut off the other two air pressure generating ends that are not connected to the rubber tube.

6. A dispensing device, characterized in that, Including a dispensing device with adhesive cut-off control function as described in any one of claims 1-5.

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