Thermal insulation magnetic attraction reversing mechanism of pneumatic spraying machine
By installing a thermal insulation sleeve with low thermal conductivity and a permanent magnet inside the piston hole of the pneumatic sprayer, the problems of poor sealing and dead spots at low temperatures are solved, ensuring the sealing reliability of the sprayer and the smoothness of the reversing mechanism, thereby improving the stability of paint output and coating efficiency.
Patent Information
- Application Number
- CN202610010908.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-06
- Publication Date
- 2026-02-10
AI Technical Summary
The reversing mechanism of pneumatic sprayers is prone to frost and dead spot problems under low temperature conditions, which can lead to poor sealing, air leakage, jamming and equipment shutdown.
The insulation sleeve and permanent magnet design are made of engineering plastic with low thermal conductivity. By setting the upper and lower insulation sleeves in the upper and lower sections of the piston hole, the temperature conduction efficiency is reduced, and the magnetic attraction of the permanent magnet ensures that the sliding cover and the slide plate are in close contact, preventing the sliding cover from staying in the dead position.
It effectively prevents the sealing ring from shrinking and deforming and the piston hole from freezing, ensuring sealing reliability and smooth airflow switching, improving motion accuracy and paint output stability, avoiding equipment downtime, and improving coating efficiency.
Smart Images
Figure CN121490926A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of pneumatic spraying machine technology, specifically to a pneumatic spraying machine with a temperature-insulating magnetic commutation mechanism. Background Technology
[0002] The reversing mechanism of pneumatic sprayers has always had two major drawbacks: frost buildup and dead spots. Frost buildup occurs because the process of compressed air being discharged from the sprayer's cylinder into the atmosphere can be approximated as adiabatic expansion. As the compressed air is discharged, its volume increases rapidly, doing work, but during this process, there is almost no heat exchange between the air and the surrounding environment. According to the first law of thermodynamics, the internal energy of the gas decreases accordingly, and since the internal energy of air is directly related to temperature, the temperature drops. The compressed air initially contains dissolved water vapor. When the temperature drops below the dew point of the water vapor, the water vapor first condenses into liquid water. When the temperature remains below 0°C, the liquid water directly sublimates into solid frost or ice. All parts through which the compressed air passes during discharge, including the air distribution block's intake and exhaust channels, slide rails, sliding covers, and sliding cover cavities, will gradually accumulate frost and ice. When the contact surface between the slide plate and the sliding cover freezes, the poor seal will cause air leakage, leading to a reversing malfunction in the spray painting machine. In low-temperature environments during winter, the low temperature can cause the sealing ring on the reversing piston to shrink, resulting in air leakage and causing a reversing malfunction in the spray painting machine. Furthermore, the low temperature can also cause ice to form inside the piston hole, leading to a reversing malfunction in the spray painting machine. The so-called dead point refers to the situation where, during the reversing of the spray painting machine, the reversing piston, driving the sliding cover, stops at the symmetrical middle position of the upper and lower slide plate. The upper and lower channels of the slide plate are simultaneously blocked by the sliding cover, preventing the spray painting machine from both intake and exhaust, thus causing a malfunction.
[0003] Therefore, the present invention aims to further explore a pneumatic spraying machine temperature-insulating magnetic commutation mechanism to improve the reliability of the commutation mechanism and further reduce the failure rate. Summary of the Invention
[0004] The present invention mainly provides a pneumatic spraying machine temperature-insulating magnetic reversing mechanism to solve the problems of frost and dead spots in the existing technology.
[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A pneumatic spraying machine's thermal insulation magnetic reversing mechanism includes a cylinder, an air distribution block, a sliding plate, a sliding cover, a reversing piston, a lower thermal insulation sleeve, and an upper thermal insulation sleeve. The cylinder's side wall is provided with an air distribution chamber boss, and a piston hole is longitudinally formed within the boss. A sliding cover cavity is formed in the middle of the air distribution chamber boss, communicating with the piston hole and dividing the piston hole into upper and lower sections. A lower thermal insulation sleeve and a lower plug are provided in the lower section of the piston hole, and an upper thermal insulation sleeve and an upper plug are provided in the upper section. The reversing piston is disposed within the lower and upper thermal insulation sleeves, and a sliding cover is provided within the sliding cover cavity, with the sliding cover slidably embedded in the groove of the reversing piston.
[0006] Furthermore, the lower insulation sleeve, upper insulation sleeve, reversing piston, sliding cover, upper plug, and lower plug are all made of engineering plastics with low thermal conductivity.
[0007] Furthermore, a permanent magnet is provided inside the sliding cover, and the sliding plate is made of ferromagnetic stainless steel.
[0008] Furthermore, a second permanent magnet is provided at the bottom of the sliding cover cavity near the air inlet.
[0009] Furthermore, a first sealing ring and a second type of sealing ring are provided between the reversing piston and the lower and upper insulation sleeves.
[0010] Furthermore, a thermal insulation sleeve sealing ring is provided between the lower section of the thermal insulation sleeve corresponding to the lower section of the piston hole and between the upper section of the thermal insulation sleeve corresponding to the upper section of the piston hole.
[0011] Beneficial effects: By installing upper and lower insulation sleeves in the upper and lower sections of the piston bore respectively, the first and second sealing rings on the reversing piston can be prevented from directly contacting the inner wall of the piston bore. This significantly reduces the conduction efficiency of the low temperature generated during compressed air discharge, prevents the first and second sealing rings on the reversing piston from shrinking and deforming due to excessively low temperatures, and ensures a tight fit between the sealing rings and the inner bore of the insulation sleeve. This solves the problem of air leakage caused by the shrinkage of the sealing rings in low-temperature environments during winter, ensures reliable sealing of the reversing piston, and eliminates malfunctions such as reversing jamming and failure caused by air leakage. Furthermore, the insulation sleeves can prevent ice formation inside the piston bore from obstructing the movement of the reversing piston, ensuring smooth airflow switching of the reversing mechanism. Meanwhile, the continuous and stable magnetic attraction generated by the permanent magnet can firmly attach the sliding cover to the surface of the slide plate, completely eliminating the gap between the sliding cover and the slide plate. This not only enhances the sealing performance of the contact surface between the slide plate and the sliding cover, reduces airflow leakage, and ensures precise switching of the air intake and exhaust paths, but also avoids the deviation of the reversing stroke caused by the gap, improves the action accuracy of the reversing mechanism, ensures that each reversal is accurate, improves the stability of the coating pressurization output, and thus ensures the uniformity of the coating. Moreover, the magnetic attraction of the permanent magnet has a directional attraction effect. During the movement of the sliding cover driven by the reversing piston, it can form a continuous guiding pull on the sliding cover, preventing the sliding cover from deviating or getting stuck during the movement. In the critical process of reversing, when the sliding cover moves to the symmetrical middle position of the upper and lower slide plates (i.e., the dead point), the magnetic attraction will forcefully pull the sliding cover to move towards the nearest channel area in coordination with the movement of the reversing piston, preventing the sliding cover from staying at the dead point position. This solves the problem of the machine stopping due to the sliding cover blocking the upper and lower channels of the slide plate, ensuring the continuous and cyclical operation of the reversing mechanism and avoiding equipment downtime that affects coating efficiency. Attached Figure Description
[0012] Figure 1This is a schematic diagram of the thermal insulation magnetic commutation mechanism in this embodiment; Figure 2 A diagram showing the dead points; Reference numerals in the attached drawings: 1. Lower plug; 2. Lower insulation sleeve; 2M. Insulation sleeve sealing ring; 3. Gas distribution block; 4. Slide plate; 5. Sliding cover; 5C. Sliding cover permanent magnet; 5Q. Sliding cover cavity; 6. Reversing piston; 6M1. First sealing ring; 6M2. Second sealing ring; 6K. Piston hole; 7. Upper insulation sleeve; 8. Upper plug; 9. Cylinder; 9T. Gas distribution chamber boss; 10. Cylinder piston; 11. Second permanent magnet; 12. Lower cylinder cover. Detailed Implementation
[0013] The following will provide a more detailed description of the technical solution of the pneumatic spraying machine temperature insulation magnetic reversing mechanism according to the present invention, with reference to the embodiments.
[0014] In the description of this invention, 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, 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; 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 this invention based on the specific circumstances.
[0015] As shown in Figure 1, a pneumatic spraying machine temperature-insulating magnetic reversing mechanism of this embodiment includes a cylinder 9, a cylinder piston 10, an air distribution block 3, a sliding plate 4, a sliding cover 5, a reversing piston 6, a lower temperature insulation sleeve 1, and an upper temperature insulation sleeve 7. The cylinder piston 10 is disposed inside the cylinder 9, and the cylinder piston 10 divides the cylinder 9 into an upper cylinder chamber and a lower cylinder chamber. The side wall of the cylinder 9 is provided with an air distribution chamber boss 9T, and the height of the air distribution chamber boss 9T is the same as the height of the cylinder 9. Two upper main air passages communicating with the upper cylinder chamber are horizontally opened near the top wall of the air distribution chamber boss 9T. Two lower main air passages communicating with the lower cylinder chamber are horizontally opened near the opening of the cylinder 9. The air distribution chamber boss 9T is located between the two upper main air passages and the two lower main air passages. The piston hole 6K is longitudinally formed and extends vertically. A sliding cover cavity 5Q is formed in the middle of the valve chamber boss 9T. The sliding cover cavity 5Q is connected to the piston hole 6K and divides the piston hole 6K into upper and lower sections. The lower section of the piston hole 6K is provided with a lower heat insulation sleeve 2 and a lower plug 1. The upper section of the piston hole 6K is provided with an upper heat insulation sleeve 7 and an upper plug 8. The reversing piston 6 is disposed in the lower heat insulation sleeve 2 and the upper heat insulation sleeve 7. The sliding cover cavity 5Q and the side wall of the valve chamber boss 9T are provided with an air inlet for receiving compressed air. A sliding cover 5 is provided in the sliding cover cavity 5Q and slides into the groove of the reversing piston 6.
[0016] The lower insulation sleeve 2, upper insulation sleeve 7, reversing piston 6, sliding cover 5, lower plug 1, and upper plug 8 are all made of engineering plastics with low thermal conductivity. Specifically, low thermal conductivity means a thermal conductivity as low as 0.25-0.5 W / (mK). The spraying machine cylinder 9 and air distribution block 3 are generally made of cast aluminum alloy ZL101 or ZL104 with a thermal conductivity of 140-150 W / (mK). The difference in thermal conductivity between the two is 280-600 times, which can greatly delay the time for the low temperature generated by the compressed air discharge to be conducted to the first sealing ring 6M1 and the second sealing ring 6M2 on the reversing piston 6. This greatly reduces the possibility of the first sealing ring 6M1 and the second sealing ring 6M2 on the reversing piston 6 contracting due to low temperature and causing air leakage, which may lead to reversing failure of the spraying machine. It also greatly reduces the possibility of the piston hole 6K freezing due to low temperature, which may cause reversing failure of the spraying machine.
[0017] A permanent magnet 5C is installed inside the sliding cover 5, and the sliding plate 4 is made of ferromagnetic stainless steel. The attraction of the permanent magnet 5C firmly adheres the sliding cover 5 to the sliding plate 4 without gaps, effectively preventing ice formation on the contact surface between the sliding plate 4 and the sliding cover 5. A second function of the permanent magnet 5C inside the sliding cover 5 is to prevent it from remaining in a dead position. When the reversing piston 6 moves the sliding cover 5 to the symmetrical middle position of the sliding plate 4, the position of the permanent magnet 5C inside the sliding cover 5 is directly opposite the air intake / exhaust slot gap on the sliding plate 4, and the magnetic attraction is at its weakest. When the reversing piston 6 moves the sliding cover 5 to the upper or lower end of the sliding plate 4, the position of the permanent magnet 5C inside the sliding cover 5 is directly opposite the metal solid on the sliding plate 4, and the magnetic attraction is at its strongest. Under the magnetic traction of the permanent magnet 5C inside the sliding cover 5, the sliding cover 5 either stays at the upper end of the slide plate 4 or at the lower end of the slide plate 4, but cannot stay at the dead point position in the middle of the slide plate 4. This greatly reduces the probability that when the sliding cover 4 stays at this position, the upper channel and the lower channel of the slide plate 4 are simultaneously blocked by the sliding cover 5.
[0018] A second permanent magnet 11 is installed at the bottom of the sliding cover cavity 5Q near the air inlet. Its function is to adsorb ferromagnetic impurities such as rust remaining in the compressed air delivered through the metal pipe.
[0019] A first sealing ring 6M1 and a second type sealing ring 6M2 are provided between the reversing piston 6 and the lower insulation sleeve 2 and the upper insulation sleeve 7. The first sealing ring 6M1 is a Y-type sealing ring, and the second sealing ring 6M2 is an O-type sealing ring. The function of providing the second type sealing ring 6M2 is to reduce the possibility of the two sealing rings contracting due to low temperature and causing gas leakage.
[0020] A thermal insulation sleeve sealing ring 2M is provided between the lower section of the lower thermal insulation sleeve 2 and the upper section of the upper thermal insulation sleeve 7 corresponding to the upper section of the piston hole 6K.
[0021] In operation, both cylinder 9 and the lower cylinder cover 12 are equipped with pilot valve bodies. The piston 10 moves up and down, actuating the pilot valve rod on the pilot valve body, thereby changing the air intake direction and causing the reversing piston 6 inside the insulation jacket to reciprocate. The entire device achieves continuous and stable pressurization and delivery of the coating material through the reciprocating movement of the reversing piston 6. (Appendix) Figure 2 This is a demonstration of the positions of the sliding cover 5 and the sliding plate 4 when a dead spot occurs during normal use of a pneumatic sprayer.
[0022] By adopting this structure, and by setting an upper insulating sleeve 7 and a lower insulating sleeve 2 in the upper and lower sections of the piston bore 6K respectively, the first sealing ring 6M1 and the second sealing ring 6M2 on the reversing piston 6 can be prevented from directly contacting the inner wall of the piston bore 6K. This significantly reduces the conduction efficiency of the low temperature generated during compressed air discharge, and prevents the first sealing ring 6M1 and the second sealing ring 6M2 on the reversing piston 6 from shrinking and deforming due to excessively low temperature. This ensures a tight fit between the sealing ring and the inner hole of the insulating sleeve, thereby solving the problem of air leakage caused by the shrinkage of the sealing ring in low-temperature environments in winter. This ensures the reliable sealing of the reversing piston 6 and eliminates malfunctions such as reversing jamming and failure caused by air leakage. In addition, the insulating sleeve can prevent the piston bore 6K from freezing inside, which would cause the reversing piston 6 to move obstructed, thus ensuring the smooth airflow switching of the reversing mechanism. Meanwhile, the continuous and stable magnetic attraction generated by the permanent magnet 5C can firmly attract the sliding cover 5 to the surface of the slide plate 4, completely eliminating the gap between the sliding cover 5 and the slide plate 4. This not only enhances the sealing performance of the contact surface between the slide plate 4 and the sliding cover 5, reducing airflow leakage and ensuring precise switching of the intake and exhaust paths, but also avoids the deviation of the reversing stroke caused by the gap, improves the action accuracy of the reversing mechanism, ensures that each reversal is accurate, improves the stability of the coating pressurization output, and thus ensures the uniformity of the coating. Moreover, the magnetic attraction of the permanent magnet 5C has a directional attraction effect, which is also present on the reversing piston 6. During the movement of the sliding cover 5, a continuous guiding force can be formed on the sliding cover 5 to prevent the sliding cover 5 from deviating or getting stuck during the movement. In the critical process of reversing, when the sliding cover 5 moves to the middle position of the upper and lower symmetrical position of the slide plate 4 (i.e., the dead point), the magnetic attraction will forcefully pull the sliding cover 5 to move towards the nearest channel area in conjunction with the movement of the reversing piston 6, preventing the sliding cover 5 from staying at the dead point position. This solves the problem of the machine freezing due to the sliding cover 5 blocking the upper and lower channels of the slide plate 4, ensuring the continuous and cyclical operation of the reversing mechanism and avoiding equipment shutdown that affects coating efficiency.
[0023] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A pneumatic spraying machine with a heat-insulating magnetic reversing mechanism, characterized in that: The device includes a cylinder, a valve block, a sliding plate, a sliding cover, a reversing piston, a lower insulating sleeve, and an upper insulating sleeve. The cylinder has a valve chamber boss on its side wall, and a piston hole is longitudinally formed within the valve chamber boss. A sliding cover cavity is formed in the middle of the valve chamber boss, communicating with the piston hole and dividing the piston hole into upper and lower sections. A lower insulating sleeve and a lower plug are provided in the lower section of the piston hole, and an upper insulating sleeve and an upper plug are provided in the upper section of the piston hole. The reversing piston is disposed within the lower and upper insulating sleeves, and a sliding cover is provided within the sliding cover cavity, with the sliding cover slidably embedded in the groove of the reversing piston.
2. The pneumatic spraying machine temperature-insulating magnetic reversing mechanism according to claim 1, characterized in that: The lower insulation sleeve, upper insulation sleeve, reversing piston, sliding cover, upper plug, and lower plug are all made of engineering plastics with low thermal conductivity.
3. The pneumatic spraying machine temperature-insulating magnetic reversing mechanism according to claim 1, characterized in that: The sliding cover contains a permanent magnet, and the sliding plate is made of ferromagnetic stainless steel.
4. The pneumatic spraying machine temperature-insulating magnetic reversing mechanism according to claim 1, characterized in that: A second permanent magnet is installed at the bottom of the sliding cover cavity near the air inlet.
5. The pneumatic spraying machine temperature-insulating magnetic reversing mechanism according to claim 1, characterized in that: A first sealing ring and a second type sealing ring are provided on the reversing piston between the lower insulation sleeve and the upper insulation sleeve.
6. The pneumatic spraying machine temperature-insulating magnetic reversing mechanism according to claim 1, characterized in that: A thermal insulation sleeve sealing ring is provided between the lower section of the thermal insulation sleeve corresponding to the lower section of the piston hole and between the upper section of the thermal insulation sleeve corresponding to the upper section of the piston hole.