Active follow-up dispensing device based on non-contact distance measurement

Abstract

The invention discloses an active follow-up dispensing device based on non-contact distance measurement, and belongs to the technical field of automatic equipment. The device comprises a dispensing execution mechanism, a non-contact distance measurement module, a motion control module and a main controller, the non-contact distance measuring module is installed on the side of a dispensing needle nozzle of a dispensing execution mechanism and used for measuring the distance between the needle nozzle and the surface of a workpiece in real time in the dispensing process, the main controller receives distance data, compares the distance data with a preset ideal working distance and generates a control instruction in real time, and the motion control module controls the dispensing execution mechanism according to the instruction. According to the automatic glue dispensing device, the problems of poor glue dispensing consistency, wire drawing, glue breaking and the like caused by uneven workpiece surfaces, clamp errors or workpiece warping are effectively solved, and the automatic glue dispensing device has the advantages that the automatic glue dispensing device is simple in structure, convenient to operate and high in practicability. And the dispensing quality and the production efficiency are improved.

Description

Technical Field

[0001] This invention relates to the field of automation equipment technology, and more specifically to an active follow-up dispensing device based on non-contact ranging. Background Technology

[0002] In industries such as electronic packaging, SMT assembly, and automotive electronics, dispensing is a critical process for ensuring product reliability. Traditional dispensing equipment typically assumes that the workpiece surface is flat or that its movement trajectory is preset. After the dispensing head is programmed with a planar trajectory, it maintains a fixed height in the Z-axis direction to perform the dispensing operation.

[0003] However, in actual production, various factors can cause changes in the actual distance between the dispensing nozzle and the workpiece surface:

[0004] 1. The workpiece itself has manufacturing tolerances or deformations, such as PCB board warping;

[0005] 2. The fixture has positioning errors or is uneven;

[0006] 3. The workpiece surface itself is a three-dimensional curved surface or an irregular shape.

[0007] When the distance between the dispensing nozzle and the workpiece surface is too large, it can easily lead to problems such as inaccurate glue dot positioning, glue stringing, and difficulty in controlling the glue volume. If the distance is too small, the nozzle may collide with the workpiece, scrape off the already coated glue, or even clog the nozzle. These problems seriously affect the consistency of dispensing quality and product yield.

[0008] Currently, although there are solutions that use contact probes or vision systems for height compensation, contact probes have slow response, are prone to wear, and are not suitable for high-speed continuous operation; vision systems are greatly affected by lighting and workpiece color, have complex processing algorithms, are difficult to guarantee real-time performance, and are also costly.

[0009] Therefore, there is an urgent need for a dispensing device that can respond to workpiece surface undulations in real time, quickly, and non-contactly, and can actively adjust the height of the dispensing head to maintain a constant distance during operation. Summary of the Invention

[0010] To address the aforementioned problems, the present invention aims to overcome the shortcomings of the prior art and provide an active follow-up dispensing device based on non-contact ranging, which can track the surface contour of the workpiece in real time, dynamically adjust the dispensing height, and ensure the consistency of the dispensing process.

[0011] To achieve the above technical objectives, the present invention adopts the following technical solution:

[0012] The active follow-up dispensing device based on non-contact ranging includes a dispensing actuator, a non-contact ranging module, a motion control module, and a main controller.

[0013] Dispensing actuator, used to complete the dispensing action;

[0014] A non-contact ranging module is fixedly installed on the side of the dispensing needle of the dispensing actuator, and is used to measure the instantaneous distance between the dispensing needle and the workpiece surface in real time.

[0015] A motion control module, connected to the dispensing actuator, is used to drive the dispensing actuator to move in the Z-axis direction perpendicular to the workpiece stage plane;

[0016] The main controller is connected to both the non-contact ranging module and the motion control module. The main controller is configured to receive the instantaneous distance, compare it with a preset ideal working distance, and output a control signal to the motion control module in real time based on the comparison result, so that the motion control module drives the dispensing actuator to perform Z-axis compensation motion to maintain a constant distance between the dispensing nozzle and the workpiece surface.

[0017] Furthermore, the non-contact ranging module is one of a laser displacement sensor, a confocal displacement sensor, or an ultrasonic ranging sensor.

[0018] Furthermore, the measuring optical path of the non-contact ranging module is set at an angle to the axis of the dispensing needle, and its measuring focus is located at a predetermined distance in front of the dispensing nozzle.

[0019] Furthermore, the motion control module includes at least one of a servo motor, a stepper motor, or a piezoelectric ceramic driver, and a corresponding transmission mechanism.

[0020] Furthermore, the main controller is a PLC, an industrial computer, or an embedded motion control card.

[0021] Furthermore, the dispensing actuator also includes a dispensing valve for controlling the dispensing of adhesive, the dispensing valve being electrically connected to the main controller.

[0022] Furthermore, the main controller is also configured to perform look-ahead processing and motion compensation on the instantaneous distance signal based on the motion path and speed of the dispensing actuator in the XY plane, so as to eliminate system response delay.

[0023] The beneficial effects of this invention are:

[0024] 1. High consistency: Through active follow-up control, the height variation caused by uneven workpiece is completely eliminated, ensuring the consistency of glue dot shape, glue line width and glue amount.

[0025] 2. High quality: Effectively avoids defects such as stringing, glue breakage, and needle tip touching the workpiece, significantly improving product yield.

[0026] 3. High adaptability: It can automatically adapt to various complex curved surfaces and irregular workpieces, eliminating the need for tedious 3D surface trajectory programming for each workpiece, greatly improving production flexibility.

[0027] 4. High efficiency: It adopts high-speed non-contact ranging and fast-response motion control, which can realize high-speed continuous operation on the production line without reducing the production cycle.

[0028] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the active follow-up dispensing device based on non-contact ranging according to the present invention.

[0030] Figure 2 This is a side view of the active follow-up dispensing device based on non-contact ranging according to the present invention.

[0031] Figure 3 This is the present invention. Figure 2 Enlarged diagram of point A.

[0032] Figure reference numerals: 1 Dispensing actuator; 11 Dispensing needle; 12 Dispensing valve; 2 Non-contact ranging module; 3 Motion control module; 4 Workpiece; 5 Main controller; D Instantaneous measurement distance; D0 Preset ideal working distance; L Look-ahead distance; ΔD Height deviation. Detailed Implementation

[0033] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0034] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, 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, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0035] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" 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 in this invention based on the specific circumstances.

[0036] The following is combined with Figures 1 to 3 The present invention describes an active follow-up dispensing device based on non-contact ranging, which mainly includes a dispensing actuator 1, a non-contact ranging module 2, a motion control module 3, and a main controller 5.

[0037] The dispensing actuator 1 includes a dispensing nozzle 11 and a dispensing valve 12, used to perform dispensing actions. The dispensing actuator 1 is fixed to the Z-axis motion slide of the motion control module 3 via a mounting plate. In this embodiment, the motion control module 3 is a precision ball screw module driven by a servo motor, responsible for providing precise displacement in the Z-axis direction. The dispensing valve 12 on the dispensing actuator 1 is connected to a pressure tank or metering pump via a glue tube, and its on / off state is controlled by the main controller 5.

[0038] The non-contact ranging module 2 is fixedly installed on the side of the dispensing nozzle 11 of the dispensing actuator 1, with its measurement direction pointing towards the workpiece surface. It is used to measure the instantaneous distance between the nozzle and the workpiece surface at extremely high frequency in real time during the dispensing process. The non-contact ranging module 2 uses a miniaturized laser displacement sensor, rigidly mounted on the dispensing actuator 1 via a dedicated bracket, ensuring it is located to the side and rear of the dispensing nozzle 11. Figure 2 As shown, the laser beam of the sensor forms an angle β of 15-45 degrees with the axis of the dispensing nozzle 11. This mounting method ensures that the sensor's measurement focus falls in front of the dispensing nozzle 11's outlet, generating a "look-ahead distance" L. When the dispensing actuator 1 moves along the X / Y direction, the sensor can measure the height information of the workpiece 4 in front in advance.

[0039] The motion control module 5 is connected to the dispensing actuator 1 and is responsible for driving the dispensing actuator 1 to perform precise movements in the Z-axis direction. In this embodiment, the main controller 5 is a high-performance embedded motion control card, which simultaneously controls the X, Y, and Z-axis movements of the entire system, the opening and closing of the dispensing valve 12, and the data acquisition of the non-contact ranging module 2.

[0040] Its workflow is as follows:

[0041] 1. Initialization: After the system starts, the main controller 5 loads the preset dispensing plane trajectory (XY coordinates) and ideal working distance D0 (e.g., 2mm).

[0042] 2. Start dispensing: The main controller 5 controls the motion control module 3 to drive the dispensing actuator 1 to move to the starting point and open the dispensing valve 12.

[0043] 3. Real-time measurement and compensation: When the dispensing actuator 1 moves along the preset trajectory, the non-contact distance measuring module 2 continuously measures the instantaneous distance D between its focal point and the surface of the workpiece 4 at a frequency of thousands of times per second.

[0044] The main controller 5 reads the distance D in real time. Due to the included angle β and the look-ahead distance L, the main controller 5 can accurately calculate the height of the working surface below the dispensing nozzle 11 when it moves to the current measurement point based on the geometric relationship and the current movement speed, thereby predicting the future distance between the nozzle and the point.

[0045] The main controller 5 compares the predicted future distance with D0 and calculates the height deviation ΔD = D - D0.

[0046] The main controller 5 immediately converts the deviation ΔD into motion commands (pulses or analog signals) for the Z-axis servo motor through a PID control algorithm.

[0047] The Z-axis servo motor drives the dispensing actuator 1 to perform slight lifting and lowering in the Z direction, precisely compensating for the height deviation ΔD.

[0048] 4. Cyclic execution: Step 3 above is executed cyclically throughout the entire dispensing path, forming a closed-loop control system to ensure that the dispensing nozzle 11 "suspends" above the undulating workpiece surface and always maintains a constant distance D0.

[0049] Through this active follow-up control, even if the workpiece 4 has obvious warping or a complex curved surface, the dispensing process can be carried out stably, and a highly consistent dispensing effect can be obtained.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. An active follow-up dispensing device based on non-contact ranging, characterized in that, include: Dispensing actuator (1) is used to complete the dispensing action; The non-contact ranging module (2) is fixedly installed on the side of the dispensing nozzle (11) of the dispensing actuator (1) and is used to measure the instantaneous distance between the dispensing nozzle (11) and the surface of the workpiece (4) in real time. The motion control module (3) is connected to the dispensing actuator (1) and is used to drive the dispensing actuator (1) to move in the Z-axis direction perpendicular to the workpiece table plane; The main controller (5) is electrically connected to the non-contact ranging module (2) and the motion control module (3) respectively. The main controller (5) is configured to receive the instantaneous distance and compare it with the preset ideal working distance. Based on the comparison result, it outputs a control signal to the motion control module (3) in real time, so that the motion control module (3) drives the dispensing actuator (1) to perform Z-axis compensation movement to maintain a constant distance between the dispensing nozzle (11) and the surface of the workpiece (4).

2. The active follow-up dispensing device based on non-contact ranging according to claim 1, characterized in that, The non-contact ranging module (2) is one of a laser displacement sensor, a confocal displacement sensor, or an ultrasonic ranging sensor.

3. The active follow-up dispensing device based on non-contact ranging according to claim 2, characterized in that, The measurement optical path of the non-contact ranging module (2) is set at an angle to the axis of the dispensing needle (11), and its measurement focus is located at a predetermined distance in front of the dispensing nozzle (11).

4. The active follow-up dispensing device based on non-contact ranging according to claim 1, characterized in that, The motion control module (3) includes at least one of a servo motor, a stepper motor or a piezoelectric ceramic driver, and a transmission mechanism associated with it.

5. The active follow-up dispensing device based on non-contact ranging according to claim 1, characterized in that, The main controller (5) is a PLC, industrial computer, or embedded motion control card.

6. The active follow-up dispensing device based on non-contact ranging according to any one of claims 1 to 5, characterized in that, The dispensing actuator (1) further includes a dispensing valve (12) for controlling the dispensing of adhesive, and the dispensing valve (12) is electrically connected to the main controller (5).

7. The active follow-up dispensing device based on non-contact ranging according to claim 6, characterized in that, The main controller (5) is also configured to perform look-ahead processing and motion compensation on the instantaneous distance signal based on the motion path and speed of the dispensing actuator (1) in the XY plane, so as to eliminate system response delay.

Images