Pneumatic control device and compaction control method

Abstract

The application discloses a pneumatic control device and a pressing control method, and particularly relates to the technical field of ultrasonic welding, which comprises a driving device, a pressure sensor assembly, a controller, an original point switch, a measuring assembly and a welding assembly. The driving device is fixedly connected with the pressure sensor assembly. The pressure sensor assembly is connected with the welding assembly. The pressure sensor assembly comprises a first spring, a second spring, a connecting rod and a pressure sensor. The upper end of the connecting rod is fixedly connected with the pressure sensor. The lower end of the connecting rod penetrates into the welding assembly. The first spring is sleeved on the connecting rod and arranged between the pressure sensor and the welding assembly. The second spring is sleeved on the connecting rod and arranged in the welding assembly. The application calculates the pressure position control point by the grating ruler and the pressure sensor, and is used for control in the welding process. The first spring and the second spring can reduce the pressure impact caused by inertia. The control parameters of welding are obtained by setting the pressing parameter test before welding, and the welding head is convenient to replace.

Description

Technical Field

[0001] This invention relates to the field of ultrasonic welding technology, and more specifically, to a pneumatic control device and a clamping control method. Background Technology

[0002] Ultrasonic welding utilizes high-frequency vibration waves transmitted to the surfaces of two objects to be welded. Under pressure, the surfaces rub against each other, causing fusion between molecular layers. The main components of an ultrasonic welding system include an ultrasonic generator, transducer, amplitude transformer, welding head triplet assembly, mold, and frame. Ultrasonic welding can be applied to ultrasonic plastic welding.

[0003] Existing plastic welding machines' pneumatic pressure control devices, when rapidly pressing down, incorporate relative pressure interference from the welding head's own inertia. Excessive instantaneous pressure can damage the workpiece before ultrasonic welding even begins. Conversely, slow pressing reduces work efficiency. In practical use, welding heads are changed depending on the product being welded. The weight of the welding head itself needs to be calculated to determine the actual pressure acting on the workpiece during pressing, increasing the workload of pressure calculations when changing welding heads.

[0004] CN216635433U discloses a spring buffer mechanism for ultrasonic plastic welding, which solves the problem that excessive instantaneous pressure will damage the workpiece before ultrasonic welding. The existing technology does not solve the problem of the influence of the welding component's own gravity during the welding process, as well as the inconvenience caused by pressure calculation when replacing the welding head. Summary of the Invention

[0005] To address the above problems, embodiments of the present invention provide a pneumatic control device and method that can reduce the impact of the welding head's own weight on pressure detection while rapidly pressing down, and reduce the impact of welding head weight changes on the accuracy of pressure acquisition when the welding head is replaced.

[0006] To achieve the above objectives, a pneumatic control device is provided, comprising: a drive device, a pressure sensing component, a controller, a home switch, a measuring component, and a welding component. The drive device is fixedly connected to the pressure sensing component, and the pressure sensor component is connected to the welding component. The pressure sensor component includes a first spring, a second spring, a connecting rod, and a pressure sensor. The upper end of the connecting rod is fixedly connected to the pressure sensor, and the lower end of the connecting rod passes through the welding component. The first spring is sleeved on the connecting rod and disposed between the pressure sensor and the welding component. The second spring is sleeved on the connecting rod and disposed within the welding component.

[0007] Furthermore, the welding assembly includes a welding head and an assembly mounting housing, wherein the welding head is detachably connected to the assembly mounting housing.

[0008] Furthermore, a through hole is provided above the component mounting housing, the connecting rod is sleeved in the through hole, and the inner diameters of the first spring and the second spring are both larger than the diameter of the through hole.

[0009] Furthermore, the origin switch and the controller are electrically connected.

[0010] Furthermore, the measuring component is a grating ruler, which is electrically connected to the controller.

[0011] Furthermore, the driving device is a cylinder.

[0012] The upper end of the pressure sensor is fixedly connected to the output end of the cylinder, and the pressure sensor is used to detect the pressure value between the welding head and the workpiece.

[0013] Another aspect of the present invention provides a clamping control method for a pneumatic control device, the method comprising, based on the pneumatic control device:

[0014] The clamping parameter test is used to obtain process parameters during the test; the process parameters include the position L of the welding head when the pressure changes abruptly, the detected pressure value F, the velocity V of the welding head, the maximum pressure Fmax when the velocity is zero, and the position L of the welding head when the maximum pressure is reached.

[0015] Calculate the contact position and deceleration position based on the process parameters obtained from the clamping test;

[0016] The calculated contact position and deceleration position are set as welding control parameters. After the test is completed, the welding assembly is lifted.

[0017] Initiate the clamping control to begin welding the workpiece.

[0018] Furthermore, the clamping parameter testing process includes:

[0019] S1: Start the clamping parameter test program.

[0020] S2: Control the welding assembly to descend at a low speed;

[0021] S3: Check if the pressure sensor detects a pressure surge. If no pressure surge is detected, continue with S2. If a pressure surge is detected, save the welding head position L1, the detected pressure value F1, and the welding head speed V1 at the time of the pressure surge, and then execute S4.

[0022] S4: Control the welding speed to decrease during descent;

[0023] S5: Is the downward pressure speed of the welding head zero? If not, proceed to step S4; if yes, proceed to step S6.

[0024] S6: Save the pressure value and welding head position when the speed is zero, i.e., the maximum pressure Fmax and the welding head position L2 at the maximum pressure;

[0025] S7: Control the welding assembly to lift and return to its initial position.

[0026] S8: Calculate the contact position and deceleration position based on the process parameters obtained from the clamping test, set the clamping control parameters, and start the clamping control.

[0027] Furthermore, the start-up clamping control includes:

[0028] S11: Start clamping control, main solenoid valve starts;

[0029] S12: Drives the welding assembly to descend at high speed, and monitors the speed of the welding head's current position in real time.

[0030] S13: Check if the welding head has reached the deceleration position. If the welding head has not reached the deceleration position, continue to execute S12. If the welding head has reached the deceleration position, execute S14.

[0031] S14: The throttle valve is activated, and the proportional valve is adjusted to the air pressure corresponding to the target pressure.

[0032] S15: Check if the target pressure has been reached. If not, continue with S14; if the target pressure has been reached, proceed with S16.

[0033] S16: Maintain the pressure position at the target pressure position;

[0034] S17: Compaction complete, throttle valve and main solenoid valve closed, control welding assembly to lift and return to initial position.

[0035] Compared with the prior art, the technical effects and advantages of the present invention are as follows:

[0036] This invention amplifies the pressure detection time by setting a first spring and a second spring, and can measure the pressure value data between 0 and the maximum pressure value when the welding head contacts the workpiece. It also reduces the detection pressure impact caused by inertia. By setting clamping parameters for testing before welding to obtain the control parameters for welding, the influence of welding head weight changes on the measurement can be eliminated.

[0037] This invention uses a grating ruler in conjunction with a pressure sensor to calculate the pressure position control point during the clamping parameter test, which is used to control the clamping parameters during welding. It eliminates the need for manual calculation and is easy to use. Attached Figure Description

[0038] Figure 1 This is a schematic diagram showing the pneumatic control device's welding head not in contact with the workpiece.

[0039] Figure 2This is a schematic diagram showing the contact between the welding head of the pneumatic control device and the workpiece.

[0040] Figure 3 This is a schematic diagram of the clamping parameter testing process.

[0041] Figure 4 This is a schematic diagram of the compression control process.

[0042] Figure 5 This is the pneumatic circuit diagram corresponding to the pneumatic device.

[0043] 1. Cylinder, 2. Grating ruler, 3. Controller, 4. Welding head, 5. Component mounting housing, 6. Workpiece, 7. First spring, 8. Second spring, 9. Pressure sensor, 10. Connecting rod, 11. Origin switch. Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] In the following description of the embodiments, the technical terms "first," "second," etc., are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly indicating the number, specific order, or primary and secondary relationship of the indicated technical features.

[0046] In the description of the following embodiments, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the following embodiments based on the specific circumstances.

[0047] Based on this, the present disclosure provides a pneumatic control device, including a drive device, a pressure sensing component, a controller 3, a home switch 11, a measuring component, and a welding component. The drive device is fixedly connected to the pressure sensing component, and the pressure sensor component is connected to the welding component. The pressure sensor component includes a first spring 7, a second spring 8, a connecting rod 10, and a pressure sensor 9. The upper end of the connecting rod 10 is fixedly connected to the pressure sensor 9, and the lower end of the connecting rod 10 passes through the welding component. The first spring 7 is sleeved on the connecting rod 10 and is disposed between the pressure sensor 9 and the welding component. The second spring 8 is sleeved on the connecting rod 10 and is disposed within the welding component.

[0048] In actual use, the drive device drives the welding assembly to move downwards. When the welding assembly contacts the workpiece, a sudden change in force occurs due to the speed and its own weight. Through the first spring 7 and the second spring 8, both springs are in a compressed state before contact with the workpiece, ensuring a relatively stable connection of the welding assembly during welding. Due to the weight of the welding assembly, the compressed length of the first spring 7 is less than that of the second spring 8. At the instant the welding assembly contacts the workpiece, the first spring 7 is compressed, and the second spring 8 is stretched. The use of the first spring 7 and the second spring 8 reduces the impact of inertia on the detection pressure and, through buffering, allows the measuring component and pressure sensor to detect the pressure change range immediately upon contact, thus amplifying the pressure detection time at the moment of contact with the workpiece.

[0049] For example, the welding assembly includes a welding head 4 and an assembly mounting housing 5. The welding head 4 is detachably connected to the assembly mounting housing 5. A through hole is provided on the upper part of the assembly mounting housing 5, and the connecting rod 10 is sleeved in the through hole. The inner diameters of the first spring 7 and the second spring 8 are both larger than the diameter of the through hole. The upper end of the second spring 8 is fixedly connected to the upper mounting housing 51. When the first spring 7 is compressed, the second spring 8 is extended. By setting the first spring 7 and the second spring 8, a buffering effect can be achieved to prevent damage to the workpiece during the welding process. Furthermore, the second spring 8 can provide good buffering when it comes into contact with the workpiece during the welding process, thus increasing the time from detecting a sudden change to reaching the maximum pressure, thereby amplifying the pressure detection time.

[0050] For example, the origin switch and the controller are electrically connected. The origin switch is used to detect when the welding assembly returns to the starting position, serving as the reference origin for the control parameters.

[0051] For example, the measuring component is a grating ruler 2, which is electrically connected to the controller 3. The grating ruler 2 is used to transmit the detected signal to the controller 3. The controller 3 calculates the moving distance, moving speed and acceleration of the welding head 4 based on the detected data.

[0052] For example, the driving device is a cylinder 1, and the upper end of the pressure sensor 9 is fixedly connected to the output end of the cylinder 1. The pressure sensor 9 is used to detect the pressure value between the welding head 4 and the workpiece 6.

[0053] Based on the above-mentioned pneumatic control device, the clamping parameters need to be controlled and set before replacing welding head 4. The clamping control method of the pneumatic control device is as follows:

[0054] The clamping parameter test is used to obtain process parameters during the test. In actual use, cylinder 1 drives the welding assembly to move downwards, the welding head 4 contacts the workpiece 6 and presses down, and the grating ruler 2 detects pulse feedback to the controller 3. Based on the feedback A-phase and B-phase pulses, the position and moving speed of the welding head 4 can be monitored in real time. When the welding head 4 contacts the workpiece 6, the first spring 7 is compressed and the second spring 8 extends. After receiving the pressure change detected by the pressure sensor 4, the controller 3 saves the current position as the contact position L1, the current pressure as the contact pressure F1, and the current speed as the contact speed V1. At this time, cylinder 1 continues to press down until the cylinder clamps the workpiece to a stationary state. At this time, the A-phase and B-phase pulses no longer alternate and the moving speed is 0. When the clamping speed is 0, the current position is saved again as the maximum position L2 and the current pressure is saved as the maximum pressure Fmax.

[0055] The contact position and deceleration position are calculated based on the process parameters obtained from the clamping test; the calculation process is as follows:

[0056] Fmax - F1 = △F

[0057] L2-L1=△L

[0058] L11 = L1 - (△L / △F) * F1

[0059] Where Fmax is the maximum pressure, F1 is the contact pressure, ΔF is the test pressure difference, and ΔL / ΔF is the unit pressure stroke change.

[0060] L2 is the welding head position at maximum pressure, L1 is the welding head position at contact pressure, ΔL is the test stroke difference, and L11 is the calculated contact position.

[0061] Welding deceleration position calculation

[0062] S=(V max 2-V1²) / (2*a)

[0063] L21=L11-S

[0064] Where S is the deceleration distance, V max V1 is the maximum speed, V21 is the minimum speed, a is the acceleration, which can be calculated by measuring with a grating ruler, and L21 calculates the deceleration position.

[0065] After the clamping parameter test is completed, the welding assembly is lifted and returned to its initial position.

[0066] The calculated contact position L11 and deceleration position L21 are set as welding control parameters to control the welding head to start deceleration at the deceleration position L21.

[0067] Calculate the contact position and deceleration position based on the process parameters obtained from the clamping test, set the clamping control parameters, and start the clamping control.

[0068] In actual use, the welding head needs to be replaced according to the different needs of the welding products. The control parameters of the welding head during the clamping control process need to be obtained through the clamping parameter test program. No additional calculation is required, which makes the replacement of the welding head convenient and can eliminate the influence of the gravity of the welding components themselves, making the control parameters more accurate and improving the welding quality.

[0069] As attached Figure 3 As shown, the specific test control process for the clamping parameters is as follows:

[0070] S1: Start the clamping parameter test program.

[0071] S2: Control the welding assembly to descend at a low speed;

[0072] S3: Check if the pressure sensor detects a pressure surge. If no pressure surge is detected, continue with S2. If a pressure surge is detected, save the welding head position L1, the detected pressure value F1, and the welding head speed V1 at the time of the pressure surge, and then execute S4.

[0073] S4: Control the welding speed to decrease during descent;

[0074] S5: Is the downward pressure speed of the welding head zero? If not, proceed to step S4; if yes, proceed to step S6.

[0075] S6: Save the pressure value and welding head position when the speed is zero, i.e., the maximum pressure Fmax and the welding head position L2 at the maximum pressure;

[0076] S7: Control the welding assembly to lift and return to its initial position.

[0077] S8: Calculate the contact position and deceleration position based on the process parameters obtained from the clamping test.

[0078] As shown in Figure 5, the present invention is provided with corresponding control air circuits, which include a main solenoid valve, a proportional valve, a throttle switching valve, a high-speed throttle valve, and a low-speed throttle valve. The main solenoid valve is used to control the movement direction of the cylinder; the proportional valve is used to control the pressure of the welding head pressing down; the high-speed throttle valve is used to adjust the maximum descent speed; and the low-speed throttle valve is used to adjust the maximum pressing speed.

[0079] As attached Figure 4 As shown, the welding control program is set according to the calculated contact position L11 and deceleration position L21. The workpiece clamping control process is as follows:

[0080] S11: Start clamping control, main solenoid valve starts;

[0081] S12: Drives the welding assembly to descend at high speed, and monitors the speed of the welding head's current position in real time.

[0082] S13: Check if the welding head has reached the deceleration position L21. If the welding head has not reached the deceleration position L21, continue to execute S14. If the welding head has reached the deceleration position L21, execute S15.

[0083] S15: The throttle switching valve is activated and the proportional valve is adjusted to the air pressure corresponding to the target pressure.

[0084] S16: Check if the target pressure has been reached. If not, continue with S15; if the target pressure has been reached, proceed with S17.

[0085] S17: Maintain the pressure position at the target pressure position;

[0086] S18: Compaction complete. The throttling switching valve and main solenoid valve are closed, controlling the welding assembly to lift and return to the initial position, completing one welding cycle.

[0087] This invention improves equipment operating efficiency by controlling the welding assembly to run at high speed before the deceleration position, and then decelerating the welding head after the deceleration position. The high-speed operation of the welding assembly driven by the cylinder improves equipment operating efficiency. The deceleration begins after the deceleration position, so that the speed of the welding head is close to 0 when it contacts the workpiece. This prevents excessive impact force from damaging the workpiece during contact and effectively ensures the quality of welding.

[0088] 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. A pneumatic control device, comprising: A driving device, a pressure sensing component, a controller (3), a home switch (11), a measuring component, and a welding component are characterized in that the driving device is fixedly connected to the pressure sensing component, the pressure sensing component is connected to the welding component, the pressure sensing component includes a first spring (7), a second spring (8), a connecting rod (10), and a pressure sensor (9), the upper end of the connecting rod (10) is fixedly connected to the pressure sensor (9), the lower end of the connecting rod (10) passes through the welding component, the first spring (7) is sleeved on the connecting rod (10), the first spring (7) is disposed between the pressure sensor (9) and the welding component, the first spring (7) is compressed to achieve buffering when the welding component contacts the workpiece, the second spring (8) is sleeved on the connecting rod (10), the second spring (8) is disposed inside the welding component, the second spring (8) is stretched to achieve buffering when the welding component contacts the workpiece, the deformation of the first spring (7) and the second spring (8) amplifies the pressure detection time; The measuring component is a grating ruler (2), which is electrically connected to the controller (3) and is used to collect the position and speed parameters of the welding component and calculate the pressure position control point in conjunction with the pressure parameters of the pressure sensor (9). The origin switch (11) and the controller (3) are electrically connected to calibrate the initial position of the welding assembly and serve as the reference origin for calculating the pressure position control point; The pressure sensor (9) is used to detect the pressure value between the welding head (4) and the workpiece (6).

2. The pneumatic control device according to claim 1, characterized in that, The welding assembly includes a welding head (4) and an assembly mounting housing (5), wherein the welding head (4) is detachably connected to the assembly mounting housing (5).

3. The pneumatic control device according to claim 2, characterized in that, The component mounting housing (5) has a through hole on its upper part, the connecting rod (10) is sleeved in the through hole, and the inner diameters of the first spring (7) and the second spring (8) are both larger than the diameter of the through hole.

4. The pneumatic control device according to claim 1, characterized in that, The driving device is a cylinder (1).

5. The pneumatic control device according to claim 4, characterized in that, The upper end of the pressure sensor (9) is fixedly connected to the output end of the cylinder (1).

6. A pneumatic control device clamping control method, based on any one of the pneumatic control devices described in any one of 1 to 5, characterized in that, The method includes: The clamping parameter test is used to obtain process parameters during the test; the process parameters include the position L1 of the welding head when the pressure changes abruptly, the detected pressure value F1, the velocity V1 of the welding head, the maximum pressure Fmax when the velocity is zero, and the position L2 of the welding head when the maximum pressure is reached. The contact position and deceleration position are calculated based on the process parameters obtained from the clamping test; the calculation process is as follows: Fmax - F1 = △F L2-L1=△L L11 Where Fmax is the maximum pressure, F1 is the contact pressure, ΔF is the test pressure difference, and ΔL / ΔF is the unit pressure stroke change. L2 is the welding head position at maximum pressure, L1 is the welding head position at contact pressure, ΔL is the test stroke difference, and L11 is the calculated contact position. Welding deceleration position calculation S L21=L11-S Where S is the deceleration distance, V max V1 is the maximum speed, a is the minimum speed, and a is the acceleration, which is calculated by measuring and measuring with a grating ruler. L21 calculates the deceleration position. The calculated contact position and deceleration position are set as welding control parameters. After the test is completed, the welding assembly is lifted. Initiate the clamping control to begin welding the workpiece.

7. The pneumatic control device clamping control method according to claim 6, characterized in that, The clamping parameter testing process includes: S1: Start the clamping parameter test program. S2: Control the welding assembly to descend at a low speed; S3: Check if the pressure sensor detects a pressure surge. If no pressure surge is detected, continue with S2. If a pressure surge is detected, save the welding head position L1 at the time of the pressure surge, the detected pressure value F1, and the welding head speed V1, and then execute S4. S4: Control the welding speed to decrease during descent; S5: Is the downward pressure speed of the welding head zero? If not, proceed to step S4; if yes, proceed to step S6. S6: Save the pressure value and welding head position when the speed is zero, i.e., the maximum pressure Fmax and the welding head position L2 at the maximum pressure; S7: Control the welding assembly to lift and return to its initial position; S8: Calculate the contact position and deceleration position based on the process parameters obtained from the clamping test, set the clamping control parameters, and start the clamping control.

8. The pneumatic control device clamping control method according to claim 7, characterized in that, The start-up clamping control includes: S11: Start clamping control, start the main solenoid valve; S12: Drives the welding assembly to descend at high speed, and monitors the speed of the welding head's current position in real time. S13: Check if the welding head has reached the deceleration position. If the welding head has not reached the deceleration position, continue to execute S12; if the welding head has reached the deceleration position, execute S14. S14: The throttle switching valve is activated and the proportional valve is adjusted to the air pressure corresponding to the target pressure; S15: Check if the target pressure has been reached. If not, continue with S14; if the target pressure has been reached, proceed with S16. S16: Maintain the pressure position at the target pressure position; S17: Compaction complete, throttling switching valve and main solenoid valve close, control welding assembly to lift and return to initial position.

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