Temperature detecting and heating device for printer nozzle

Abstract

The utility model discloses a temperature detection and heating device for a printer nozzle, which comprises a master control IC (integrated circuit), an ADC (analog-to-digital converter) conversion module, a nozzle and a 24V power output module, and is characterized in that the nozzle comprises a nozzle temperature detection resistor and a nozzle heating wire; according to the utility model, accurate monitoring and dynamic control of the temperature of the nozzle can be realized through temperature detection of the printer nozzle and the heating device, so that the problem of insufficient voltage output precision in the existing high-voltage waveform control design is effectively solved. Specifically, a nozzle temperature signal is converted into a digital signal in real time through the ADC conversion module, and whether heating treatment is needed is judged by the master control IC, so that the temperature stability of the nozzle is ensured, the printing quality problem caused by unstable voltage output is avoided, and the temperature of the nozzle can be accurately controlled through closed-loop control and precise circuit design. While the voltage output precision is improved, the printing effect is remarkably improved, and the service life of the nozzle is remarkably prolonged.

Description

Technical Field

[0001] The utility model relates to the field of printers, in particular to a temperature detection and heating device for a printer nozzle. Background Art

[0002] At present, most printers design the high-voltage waveform control mainly for switching control of high-voltage output. However, this design has great defects in the precision control of voltage output. It is very difficult to achieve precise control of high-precision voltage, which can lead to instability of voltage output and affect the printing quality. Summary of the Invention

[0003] In order to solve the above-mentioned existing technical problems, the utility model provides a temperature detection and heating device for a printer nozzle.

[0004] The technical solution of the utility model is realized as follows:

[0005] A temperature detection and heating device for a printer nozzle of the utility model includes a main control IC, an ADC conversion module, a nozzle, and a 24V power output module. The nozzle includes a nozzle temperature detection resistor and a nozzle heating wire;

[0006] The resistance value of the nozzle temperature detection resistor changes with the temperature. Through the ADC conversion module, the analog voltage is converted into a digital signal, and then the temperature information of the nozzle is transmitted to the main control IC through the I2C protocol. The main control IC judges whether to heat the nozzle according to the detected nozzle temperature value. When the detected nozzle temperature value is lower than the set value, the main control IC controls the 24V power output module to heat the nozzle. When the temperature reaches the specified temperature, the 24V power output module is turned off to stop heating. When the 24V power output module heats the nozzle, the nozzle temperature detection resistor also changes. The nozzle temperature is monitored in real time through the nozzle to perform real-time heating control on the nozzle.

[0007] Further, the ADC conversion module includes a chip U10. The first pin of the chip U10 is connected to the ground through a first capacitor C186. One end of the first capacitor C186 is also connected to a first resistor R112. The first resistor R112 is connected to a second resistor R110 through a signal connection point of a first nozzle temperature detection resistor. The second pin of the chip U10 is connected to the ground through a second capacitor C185. One end of the second capacitor C185 is also connected to a third resistor R111. The third resistor R111 is connected to a fourth resistor R109 through a signal connection point of a third nozzle temperature detection resistor. The third pin of the chip U10 is connected to the ground through a third capacitor C40. One end of the third capacitor C40 is also connected to a fifth resistor R54. The fifth resistor R54 is connected to a sixth resistor R21 through a signal connection point of a fourth nozzle temperature detection resistor. The fourth pin of the chip U10 is connected to the ground through a fourth capacitor C43. One end of the fourth capacitor C43 is also connected to a seventh resistor R42. The seventh resistor R42 is connected to an eighth resistor R97 through a signal connection point of a second nozzle temperature detection resistor. The second resistor R110, the fourth resistor R109, the sixth resistor R21, and the sixth resistor R21 are all connected to AD_VCC.

[0008] Further, the fifth pin of the chip U10 is connected to P0.24SCL through a ninth resistor R199. The ninth resistor R199 is also connected to an eleventh resistor R247 through a tenth resistor R248. The eleventh resistor R247 is also connected to the sixth pin of the chip U10 and one end of a twelfth resistor R198 respectively. The other end of the twelfth resistor R198 is connected to P0.23. The eleventh resistor R247 is also connected to the eighth pin of the chip U10. The eighth pin of the chip U10 is also connected to the ground through a fifth capacitor C184. The fifth capacitor C184 is also connected to VDDR through a first inductor.

[0009] Further, the chip U10 is a MAX1037E, which is a conversion chip with 4-channel ADC input;

[0010] The P0.23 is an SDA signal pin, and the P0.24 is an SCL signal pin, which are used to read the analog voltage values of the 4-channel ADC input; The fourth capacitor C43, the third capacitor C40, the second capacitor C185, and the first capacitor C186 are filter capacitors, which are used to prevent transient voltage waveforms caused by external interference from affecting the read voltage values; The VDDR is the power supply voltage of the chip U10; The AD_VCC is the power supply for the nozzle temperature detection resistor.

[0011] Further, the 24V power output module includes a chip U1. The first pin of the chip U1 is connected to the third pin of the chip U1. The third pin of the chip U1 is connected to the ground. The second pin of the chip U1 is connected to the fourth pin of the chip U1. The fourth pin of the chip U1 is connected to the ground through a first diode D42. The first diode D42 is also connected to the ground through a thirteenth resistor R214. The thirteenth resistor R214 is also connected to one end of a sixth capacitor C200 and a fourteenth resistor R215 respectively. The other ends of the sixth capacitor C200 and the fourteenth resistor R215 are also connected to each other and to the emitter of a first triode Q20. The collector of the first triode Q20 is connected to one end of a fifteenth resistor R213 through a 12V voltage. The other end of the fifteenth resistor R213 is connected to the base of the first triode Q20. The base of the first triode Q20 is also connected to the base of a second diode Q21 and the collector of a third diode Q19 respectively. The emitter of the second diode Q21 is connected to the emitter of the first triode Q20. The emitter of the second diode Q21 is connected to the emitter of the third diode Q19. The emitter of the third diode Q19 is also connected to the ground. The base of the third diode Q19 is connected to the fifteenth resistor R212 through a second diode D41. The fifteenth resistor R212 is connected to C6.

[0012] Further, the fifth pin of the chip U1 is connected to the sixth pin of the chip U1. The sixth pin of the chip U1 is also connected to one end of a third diode D11 and a sixteenth resistor R180 respectively. The other end of the sixteenth resistor R180 is connected to the second pin of a nozzle heating wire interface J38. The other end of the third diode D11 is connected to the first pin of the nozzle heating wire interface J38. The seventh pin of the chip U1 is connected to the eighth pin of the chip U1. The eighth pin of the chip U1 is also connected to one end of a seventeenth resistor R179 and a fourth diode D10 respectively. The other ends of the seventeenth resistor R179 and the fourth diode D10 are connected to each other and to the first pin of the nozzle heating wire interface J38. The first pin of the nozzle heating wire interface J38 is connected to 24V_OUT.

[0013] Further, the 12V is the driving voltage, 24V_OUT is the load power supply voltage, and C6 is the IO signal from the single-chip microcomputer; the third diode Q19 and the first triode Q20 are NPN triodes, and the second diode Q21 is a PNP triode; U1 is an NMOS; the fourteenth resistor R215 is a current-limiting resistor; the second diode D41 is a switching diode, which is connected in series with the triode base to increase the threshold of signal input conduction and enhance the anti-interference ability; the first diode D42 is a voltage-regulating diode, which is used to limit the Ugs of the MOS transistor within the maximum value; the fourth diode D10 is an SK36, which is a Schottky diode and is used to discharge the inductive load to protect the MOS transistor; the seventeenth resistor R179 and the sixteenth resistor R180 are protection resistors to prevent the external load from short-circuiting and damaging the MOS transistor.

[0014] Beneficial effects:

[0015] Through the temperature detection and heating device of the printer nozzle, precise monitoring and dynamic control of the nozzle temperature can be achieved, thus effectively solving the problem of insufficient voltage output accuracy in the existing high-voltage waveform control design. Specifically, the nozzle temperature signal is converted into a digital signal in real time through the ADC conversion module, and the main control IC judges whether heating treatment is required, so as to ensure the stability of the nozzle temperature and avoid printing quality problems caused by unstable voltage output. Through closed-loop control and precise circuit design, the utility model not only improves the voltage output accuracy, but also significantly improves the printing effect and the nozzle life. Description of the drawings

[0016] Figure 1 is a schematic diagram of the circuit framework of the present utility model;

[0017] Figure 2 is a schematic diagram of the ADC conversion module circuit of the present utility model;

[0018] Figure 3 is a schematic diagram of the 24V power output module circuit of the present utility model. Specific implementation manners

[0019] As Figures 1 - 3 shown, a temperature detection and heating device for a printer nozzle of the present utility model includes a main control IC, an ADC conversion module, a nozzle, and a 24V power output module. The nozzle includes a nozzle temperature detection resistor and a nozzle heating wire;

[0020] The temperature detection resistor of the nozzle changes with temperature, and its resistance value also changes. The analog voltage value divided by the temperature detection resistor of the nozzle will also change with temperature. Through the ADC conversion module, the analog voltage is converted into a digital signal, and then the temperature information of the nozzle is sent to the high-speed main control IC through the I2C protocol. The main control IC judges whether to heat the nozzle according to the detected nozzle temperature value. When the detected nozzle temperature value is lower than the set value, the main control IC controls the 24V power output module to heat the nozzle. When the temperature reaches the specified temperature, the 24V power output module is turned off to stop heating. When the 24V power output module heats the nozzle, the temperature detection resistor of the nozzle also changes. By monitoring the nozzle temperature in real time, a loop is formed to control the nozzle heating in real time.

[0021] Further, the ADC conversion module includes chip U10. The first pin of chip U10 is connected to the ground through the first capacitor C186. One end of the first capacitor C186 is also connected to the first resistor R112. The first resistor R112 is connected to the second resistor R110 through the signal connection point of the first nozzle temperature detection resistor. The second pin of chip U10 is connected to the ground through the second capacitor C185. One end of the second capacitor C185 is also connected to the third resistor R111. The third resistor R111 is connected to the fourth resistor R109 through the signal connection point of the third nozzle temperature detection resistor. The third pin of chip U10 is connected to the ground through the third capacitor C40. One end of the third capacitor C40 is also connected to the fifth resistor R54. The fifth resistor R54 is connected to the sixth resistor R21 through the signal connection point of the fourth nozzle temperature detection resistor. The fourth pin of chip U10 is connected to the ground through the fourth capacitor C43. One end of the fourth capacitor C43 is also connected to the seventh resistor R42. The seventh resistor R42 is connected to the eighth resistor R97 through the signal connection point of the second nozzle temperature detection resistor. The second resistor R110, the fourth resistor R109, the sixth resistor R21 and the sixth resistor R21 are all connected to AD_VCC.

[0022] Further, the fifth pin of chip U10 is connected to P0.24SCL through the ninth resistor R199. The ninth resistor R199 is also connected to the tenth resistor R248 and the eleventh resistor R247. The eleventh resistor R247 is respectively connected to the sixth pin of chip U10 and one end of the twelfth resistor R198. The other end of the twelfth resistor R198 is connected to P0.23. The eleventh resistor R247 is also connected to the eighth pin of chip U10. The eighth pin of chip U10 is also connected to the ground through the fifth capacitor C184. The fifth capacitor C184 is also connected to VDDR through the first inductor.

[0023] Further, the chip U10 is MAX1037E, which is a conversion chip with 4-channel ADC input;

[0024] The P0.23 is the SDA signal pin, and the P0.24 is the SCL signal pin, which are used to read the analog voltage values of the four-channel ADC input; The fourth capacitor C43, the third capacitor C40, the second capacitor C185, and the first capacitor C186 are filter capacitors, which are used to prevent the transient voltage waveform caused by external interference from affecting the read voltage value; The VDDR is the power supply voltage of the chip U10; The AD_VCC is the power supply for the nozzle temperature detection resistor.

[0025] Working principle:

[0026] The 4 nozzles have four-channel temperature detection resistors. The temperature detection resistors and four 10K pull-up resistors, namely the eighth resistor R97, the sixth resistor R21, the fourth resistor R109, and the second resistor R110, form a voltage division circuit. According to different temperatures, the divided analog voltage values are different. Further, the chip U10 converts the read temperature detection value into digital signals SDA and SCL, and then transmits the read temperature information value back to the main control IC through the SDA and DCL signals.

[0027] Further, the 24V power output module includes the chip U1. The first pin of the chip U1 is connected to the third pin of the chip U1. The third pin of the chip U1 is connected to the ground. The second pin of the chip U1 is connected to the fourth pin of the chip U1. The fourth pin of the chip U1 is connected to the ground through the first diode D42. The first diode D42 is also connected to the ground through the thirteenth resistor R214. The thirteenth resistor R214 is also respectively connected to one end of the sixth capacitor C200 and the fourteenth resistor R215. The other ends of the sixth capacitor C200 and the fourteenth resistor R215 are also connected to each other and connected to the emitter of the first triode Q20. The collector of the first triode Q20 is connected to one end of the fifteenth resistor R213 through a 12V voltage. The other end of the fifteenth resistor R213 is connected to the base of the first triode Q20. The base of the first triode Q20 is also respectively connected to the base of the second diode Q21 and the collector of the third diode Q19. The emitter of the second diode Q21 is connected to the emitter of the first triode Q20. The emitter of the second diode Q21 is connected to the emitter of the third diode Q19. The emitter of the third diode Q19 is also connected to the ground. The base of the third diode Q19 is connected to the fifteenth resistor R212 through the second diode D41. The fifteenth resistor R212 is connected to C6.

[0028] Further, the fifth pin of the chip U1 is connected to the sixth pin of the chip U1. The sixth pin of the chip U1 is also connected to one end of the third diode D11 and the sixteenth resistor R180 respectively. The other end of the sixteenth resistor R180 is connected to the second pin of the nozzle heating wire interface J38. The other end of the third diode D11 is connected to the first pin of the nozzle heating wire interface J38. The seventh pin of the chip U1 is connected to the eighth pin of the chip U1. The eighth pin of the chip U1 is also connected to one end of the seventeenth resistor R179 and the fourth diode D10 respectively. The other ends of the seventeenth resistor R179 and the fourth diode D10 are connected to each other and connected to the first pin of the nozzle heating wire interface J38. The first pin of the nozzle heating wire interface J38 is connected to 24V_OUT.

[0029] Further, the 12V is the driving voltage, 24V_OUT is the load supply voltage, and C6 is the IO signal from the single-chip microcomputer; the third diode Q19 and the first triode Q20 are NPN triodes, and the second diode Q21 is a PNP triode; U1 is an NMOS; the fourteenth resistor R215 is a current-limiting resistor; the second diode D41 is a switching diode, which is connected in series with the base of the triode to increase the threshold of signal input conduction and enhance the anti-interference ability; the first diode D42 is a zener diode, which is used to limit the Ugs of the MOS transistor within the maximum value; the fourth diode D10 is an SK36, which is a Schottky diode and is used to discharge the inductive load to protect the MOS transistor; the seventeenth resistor R179 and the sixteenth resistor R180 are protection resistors to prevent the external load from short-circuiting and damaging the MOS transistor.

[0030] Working principle:

[0031] When the C6 signal is a high level above 1.4V, the current passes through the fifteenth resistor R212 and the second diode D41 to provide a bias current for the third diode Q19 triode, and the third diode Q19 conducts. As Figure 3 shown, point A is at a low level, about 0.3V, and point C is at a low level. At this time, the NMOS Ugs voltage of the chip U1 is less than the turn-on voltage and is in the cut-off state. The PMOS D pole and S pole are not conducting, and the load switch is closed; when the C6 signal is at a low level, the third diode Q19 has no bias current and is in the cut-off state. Point A is at a high level of 12V, point B is the emitter follower output high level, and the potential of point C is about Uc = R214 / (R215 + R214)*(12 - 0.7)V. The PMOS Ugs voltage of the chip U1 is greater than the turn-on voltage, and the PMOS D pole and S pole are conducting, and the load switch is opened.

[0032] The temperature detection and heating device of the printer nozzle of the present utility model realizes real-time monitoring and dynamic control of the nozzle temperature through precise circuit design. The entire system first relies on the temperature detection resistor inside the nozzle. This resistor changes its resistance value with the change of temperature, thereby affecting the output voltage of the voltage division circuit formed by the pull-up resistor in series with it. This output voltage, as an analog signal, is converted into a digital signal through the ADC conversion module (using chip U10). Chip U10 can process four different temperature detection signals. After converting these signals into digital signals, they are transmitted to the main control IC through the I2C protocol. After receiving the temperature data, the main control IC will judge whether it is necessary to heat the nozzle according to the set temperature threshold. If it is detected that the nozzle temperature is lower than the set value, the main control IC will issue an instruction to start the 24V power output module to heat the nozzle. This heating process depends on the coordinated work of multiple electronic components, especially the control of triode Q19 and NMOS U1. When the signal C6 of the main control IC is at a low level, the circuit is adjusted through a series of resistors, capacitors and diodes to make NMOS U1 conduct, thereby supplying power to the nozzle heating wire and starting to heat. When the nozzle temperature reaches the set value, the main control IC will adjust the C6 signal to cut off the heating power supply and stop heating. The entire system forms a closed-loop control. By monitoring the temperature in real time and dynamically adjusting the heating state, it ensures that the nozzle temperature is stable within a suitable range, guarantees the printing effect and also extends the service life of the nozzle.

Claims

1. A temperature detection and heating device for a printer nozzle, characterized in that: It includes a main control IC, an ADC conversion module, a nozzle, and a 24V power output module. The nozzle includes a nozzle temperature detection resistor and a nozzle heating wire; The resistance value of the nozzle temperature detection resistor will change with the temperature change; the analog voltage is converted into a digital signal through the ADC conversion module, and the temperature information of the nozzle is transmitted to the high-speed main control IC through the I2C protocol; the main control IC determines whether to perform heating treatment on the nozzle according to the detected nozzle temperature value; when the detected nozzle temperature value is lower than the set value, the main control IC controls the 24V power output module to heat the nozzle, and when it is heated to the set temperature, the 24V power output module is turned off to stop heating; when the 24V power output module heats the nozzle, the nozzle temperature detection resistor will also change, and the nozzle temperature is monitored in real time by the nozzle, and the nozzle is heated in real time. Control.

2. A temperature detection and heating device for a printer nozzle according to claim 1, characterized in that: The ADC conversion module includes a chip U10, a first pin of the chip U10 is connected to the ground through a first capacitor C186, one end of the first capacitor C186 is also connected to a first resistor R112, the first resistor R112 is connected to a second resistor R110 through a signal connection point of a first nozzle temperature detection resistor, a second pin of the chip U10 is connected to the ground through a second capacitor C185, one end of the second capacitor C185 is also connected to a third resistor R111, the third resistor R111 is connected to a fourth resistor R109 through a signal connection point of a third nozzle temperature detection resistor, and a first ... The third pin is connected to the ground through the third capacitor C40, one end of the third capacitor C40 is also connected to the fifth resistor R54, the fifth resistor R54 is connected to the sixth resistor R21 through the signal connection point of the fourth nozzle temperature detection resistor, the fourth pin of the chip U10 is connected to the ground through the fourth capacitor C43, one end of the fourth capacitor C43 is also connected to the seventh resistor R42, the seventh resistor R42 is connected to the eighth resistor R97 through the signal connection point of the second nozzle temperature detection resistor, the second resistor R110, the fourth resistor R109, the sixth resistor R21 and the sixth resistor R21 are all connected to AD_VCC.

3. A temperature detection and heating device for a printer nozzle according to claim 2, characterized in that: The fifth pin of the chip U10 is connected to P0.24SCL through a ninth resistor R199, and the ninth resistor R199 is also connected to an eleventh resistor R247 through a tenth resistor R248. The eleventh resistor R247 is also connected to the sixth pin of the chip U10 and one end of the twelfth resistor R198 respectively, and the other end of the twelfth resistor R198 is connected to P0.

23. The eleventh resistor R247 is also connected to the eighth pin of the chip U10, and the eighth pin of the chip U10 is also connected to the ground through a fifth capacitor C184, and the fifth capacitor C184 is also connected to VDDR through a first inductor.

4. A temperature detection and heating device for a printer nozzle according to claim 3, characterized in that: The chip U10 is MAX1037E, which is a conversion chip with 4 ADC inputs; the P0.23 is the SDA signal pin, and the P0.24 is the SCL signal pin, which are used to read the analog voltage values ​​of the four ADC inputs; the fourth capacitor C43, the third capacitor C40, the second capacitor C185 and the first capacitor C186 are filter capacitors, which are used to prevent the transient voltage waveform caused by external interference from affecting the read voltage value; the VDDR is the power supply voltage of the chip U10; the AD_VCC is the power supply for the nozzle temperature detection resistor.

5. A temperature detection and heating device for a printer nozzle according to claim 1, characterized in that: The 24V power output module includes a chip U1, wherein the first pin of the chip U1 is connected to the third pin of the chip U1, the third pin of the chip U1 is connected to the ground, the second pin of the chip U1 is connected to the fourth pin of the chip U1, the fourth pin of the chip U1 is connected to the ground through a first diode D42, the first diode D42 is also connected to the ground through a thirteenth resistor R214, the thirteenth resistor R214 is also respectively connected to one end of a sixth capacitor C200 and a fourteenth resistor R215, the other ends of the sixth capacitor C200 and the fourteenth resistor R215 are also connected to each other and to the emitter of a first transistor Q20, and the collector of the first transistor Q20 The electrode is connected to one end of the fifteenth resistor R213 through a 12V voltage, the other end of the fifteenth resistor R213 is connected to the base of the first triode Q20, the base of the first triode Q20 is also connected to the base of the second diode Q21 and the collector of the third diode Q19 respectively, the emitter of the second diode Q21 is connected to the emitter of the first triode Q20, the emitter of the second diode Q21 is connected to the emitter of the third diode Q19, the emitter of the third diode Q19 is also connected to ground, the base of the third diode Q19 is connected to the fifteenth resistor R212 through the second diode D41, and the fifteenth resistor R212 is connected to C6.

6. A temperature detection and heating device for a printer nozzle according to claim 5, characterized in that: The fifth pin of the chip U1 is connected to the sixth pin of the chip U1, and the sixth pin of the chip U1 is also connected to the third diode D11 and one end of the sixteenth resistor R180 respectively, the other end of the sixteenth resistor R180 is connected to the second pin of the nozzle heating wire interface J38, the other end of the third diode D11 is connected to the first pin of the nozzle heating wire interface J38, the seventh pin of the chip U1 is connected to the eighth pin of the chip U1, and the eighth pin of the chip U1 is also connected through the seventeenth resistor R179 and one end of the fourth diode D10 respectively, the other ends of the seventeenth resistor R179 and the fourth diode D10 are connected to each other and connected to the first pin of the nozzle heating wire interface J38, and the first pin of the nozzle heating wire interface J38 is connected to 24V_OUT.

7. A temperature detection and heating device for a printer nozzle according to claim 6, characterized in that: The 12V is the driving voltage, 24V_OUT is the load power supply voltage, and C6 is the IO signal from the single-chip microcomputer; the third diode Q19 and the first transistor Q20 are NPN transistors, and the second diode Q21 is a PNP transistor; U1 is NMOS; the fourteenth resistor R215 is a current limiting resistor; the second diode D41 is a switching diode, which is connected in series with the transistor base to increase the threshold of the signal input conduction and enhance the anti-interference ability; the first diode D42 is a voltage-stabilizing diode, which is used to limit the MOS tube Ugs to the maximum value; the fourth diode D10 is SK36, which is a Schottky diode, used to discharge the inductive load and protect the MOS tube; the seventeenth resistor R179 and the sixteenth resistor R180 are protection resistors to prevent the external load from short-circuiting and damaging the MOS tube.

Images