Grinding process and grinding machine for low-temperature polyester coating production

Abstract

The invention relates to the field of grinding, and discloses a low-temperature polyester coating production-based grinding miller which comprises a rack, a motor, an output pipeline, a hopper and a grinding mechanism are mounted on the rack, the grinding mechanism comprises a grinding shell, the grinding shell comprises an upper grinding tank, a lower grinding tank and a housing, an upper grinding assembly and a feeding assembly are arranged in the upper grinding tank, and a lower grinding assembly is arranged in the lower grinding tank; the feeding assembly receives raw materials falling from the interior of the hopper and drags the raw materials to be located between the upper grinding assembly and the tank wall of the upper grinding tank, the upper grinding assembly is used for conducting primary grinding on the raw materials, and a guide plate used for guiding the raw materials subjected to primary grinding into the lower grinding tank is arranged between the upper grinding tank and the lower grinding tank. And a lower grinding assembly used for conducting secondary grinding on the raw materials is arranged in the lower grinding tank, a fan is arranged in the housing, and in the grinding process, the fan is continuously started, and one-way airflow from top to bottom is formed in the grinding housing.

Description

Technical Field

[0001] The invention relates to the field of grinding, and in particular to a grinding process and a grinding machine for producing low-temperature polyester coatings. Background Art

[0002] The production process of low-temperature polyester coatings includes a grinding step. For example, the Chinese invention patent application with application publication number CN114106304A discloses a low-temperature curing weather-resistant polyester resin, a low-temperature curing weather-resistant powder coating and a preparation method. It discloses that the preparation method includes a crushing, grinding and screening step, that is, the raw materials are crushed and ground, and then filtered to obtain a powder with a particle size that meets the requirements.

[0003] Based on the search for grinding technology, a Chinese invention patent application was found, and its application publication number is CN113019662A, which discloses a multi-stage raw material grinding system, which can be connected to a secondary grinding pump and a secondary ball mill to achieve the purpose of multiple grinding. However, this multiple grinding method has some shortcomings: its essence is to grind the raw materials in sequence through multiple grinding structures to improve the grinding effect. However, on the one hand, it requires the cooperation of multiple grinding structures, and the structure is relatively complex and cumbersome. On the other hand, after each grinding, there are more or less powders that meet the grinding requirements. These powders are mixed in the raw materials that do not meet the grinding requirements, and will participate in the next grinding action, which will cause some interference to the next grinding of the raw materials.

[0004] Based on the above, the present invention proposes a grinding process and a grinding machine for producing low-temperature polyester coatings. Summary of the invention

[0005] In order to solve the problems mentioned in the above background, the present invention provides a grinding process and a grinding machine for producing low-temperature polyester coatings.

[0006] In order to achieve the above technical objectives, the technical solution adopted by the present invention is as follows.

[0007] A grinding machine for producing low-temperature polyester coatings, comprising a frame, a motor, an output pipe, a hopper and a grinding mechanism are installed on the frame, the grinding mechanism comprises a grinding shell, and the grinding shell comprises an upper grinding tank, a lower grinding tank and a cover shell distributed from top to bottom; An upper grinding assembly and a feeding assembly are arranged in the upper grinding tank. The feeding assembly is used to receive the raw materials dropped from the hopper and pull the raw materials between the upper grinding assembly and the tank wall of the upper grinding tank. The upper grinding assembly is used to perform the first grinding of the raw materials. A guide plate is provided between the upper grinding jar and the lower grinding jar for guiding the raw materials after the first grinding into the lower grinding jar; A lower grinding assembly for performing a second grinding of the raw materials is arranged in the lower grinding tank; A fan is arranged inside the cover, a connecting pipe is arranged on the outer surface of the cover, the end of the connecting pipe is connected to the output pipe, an air pipe is arranged on the tank cover of the upper grinding tank, and during the grinding process, the fan is continuously started, and the air enters the grinding shell through the connecting pipe and is output through the output pipe.

[0008] Furthermore, the upper grinding jar includes an upper grinding chamber in the shape of a truncated cone with a diameter decreasing from top to bottom, and the upper grinding assembly includes a support, the center line of the support coincides with the axial center line of the upper grinding chamber, and the outer surface of the support is arrayed with multiple grinding units along the circumferential direction of the upper grinding chamber.

[0009] Furthermore, the grinding unit includes a grinding bracket arranged on a support along the radial sliding of the upper grinding chamber, a spring is arranged between the grinding bracket and the support, a grinding roller is installed on the suspended end of the grinding bracket, and the grinding roller is in the shape of a truncated cone with a vertical axis and a diameter decreasing from top to bottom. Initially, under the elastic force of the spring, the outer cylindrical surface of the grinding roller fits against the cavity wall of the upper grinding chamber, and the outer cylindrical surface of the grinding roller is provided with a grinding groove, the length direction of the grinding groove is parallel to the extension direction of the generatrix of the grinding roller, and a plurality of grinding grooves are arranged in an array along the circumferential direction of the grinding roller.

[0010] Furthermore, a convex tube is provided on the tank cover, and the convex tube is connected to the lower end of the hopper; A connecting shaft coaxial with the upper grinding chamber is provided on the support, and the feeding assembly includes a receiving ring coaxially arranged on the upper end of the connecting shaft, the upper end surface of the receiving ring is provided with an annular groove, and the outer cylindrical surface of the receiving ring is provided with a feeding pipe, the feeding pipe is arranged obliquely and the highest point is connected to the receiving ring, the feeding pipe is connected to the annular groove, and the annular groove is connected to the convex pipe.

[0011] Furthermore, initially, there is line contact between the grinding roller and the upper grinding chamber. When grinding occurs, the rotation direction of the upper grinding assembly is named the grinding rotation direction. The raw material output through the end of the feed pipe falls onto the wall of the upper grinding chamber and falls into a position close to the upper end of the line contact and is located in front of the line contact along the grinding rotation direction.

[0012] Furthermore, the lower grinding jar includes a lower grinding chamber in the shape of a truncated cone with a diameter decreasing from top to bottom, and a guide plate in the shape of a cone with a diameter increasing from top to bottom. The upper end of the guide plate is located in the upper grinding chamber and the lower end is located in the lower grinding chamber. The structure of the lower grinding assembly is consistent with that of the upper grinding assembly.

[0013] Furthermore, a return assembly is provided between the cover shell and the guide plate.

[0014] Further, the return assembly includes a fixed pipe, the upper pipe opening of the fixed pipe is connected to the fixed hole arranged on the upper end of the guide plate, the fixed pipe is coaxial with the upper grinding chamber, and the lower grinding assembly is provided with an avoidance hole for avoiding the fixed pipe; A sleeve shaft in the shape of a hollow shaft is provided at the lower end of the lower grinding assembly. The sleeve shaft is sleeved on the outside of the fixed pipe. The lower end of the sleeve shaft is closed and the lower closed end is coaxially connected with the auger arranged in the fixed pipe. The motor is used to drive the sleeve shaft to rotate. The upper end of the auger is connected to the upper grinding assembly through a reducer, and the fan is arranged on the sleeve shaft.

[0015] Furthermore, the outer circumferential surface of the sleeve shaft is provided with an outer feed port near the lower end, and the outer circumferential surface of the fixed pipe is provided with an inner feed port near the lower pipe opening. During the rotation of the sleeve shaft, the outer feed port can be connected with the inner feed port.

[0016] A grinding process based on a grinding machine for low temperature polyester coating production: Step 1: The raw material in the hopper falls into the annular groove through the convex pipe. The bottom of the annular groove is arranged to be inclined. Under the guidance of the bottom of the annular groove, the raw material falls into the feeding pipe. Under the guidance of the inclined feeding pipe, the raw material falls into the upper grinding chamber. At the same time, the grinding roller of the upper grinding assembly rotates around the axis of the upper grinding chamber to achieve the first grinding of the raw material. Step 2: The raw material after the first grinding is guided by the guide plate and falls onto the cavity wall of the lower grinding chamber of the lower grinding tank. When the raw material moves down along the cavity wall of the lower grinding chamber, the lower grinding assembly grinds the raw material for the second time; Step 3: In step 1 and step 2, the fan is continuously started, and air enters the grinding shell through the connecting pipe and is output through the output pipe, forming a unidirectional airflow. Under the traction of the airflow, the powder that meets the grinding requirements is output together with the airflow and no longer participates in the next grinding; Step 4: After the second grinding, the raw materials that do not meet the grinding requirements are pulled back into the lower grinding chamber by a return assembly disposed between the cover shell and the guide plate to continue grinding.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. In this scheme, when the grinding roller grinds the raw material, in addition to the spring, the centrifugal force generated by the rotation of the grinding roller will also be applied to the raw material, so the grinding effect is relatively good. On this basis, the grinding roller is in a truncated cone shape, and the outer cylindrical surface of the grinding roller is provided with grinding grooves. The length direction of the grinding grooves is parallel to the extension direction of the generatrix of the grinding roller. There are several grinding grooves arranged in an array along the circumferential direction of the grinding roller. Therefore, as the raw material moves downward, under the same downward movement distance, the grinding effect of the raw material is better, that is, the lower the raw material moves, the finer the grinding. Furthermore, the lower the raw material moves, the denser the distribution of the grinding grooves on the surface of the grinding roller is, and the grinding roller with denser grinding grooves grinds finer and has better grinding effect. Therefore, in this scheme, the grinding fineness and grinding effect of the first grinding action increase from top to bottom, and there is a multiple grinding effect. Compared with the multiple grinding structures of coarse grinding-fine grinding in the prior art, this scheme simplifies the structure, but the grinding accuracy and grinding effect are significantly improved; 2. In this solution, the feeding assembly and the upper grinding assembly are integrated, which has the advantage that the raw materials entering the upper grinding chamber can be ground by the grinding roller at the first time, and after the grinding is completed, the raw materials enter the lower grinding chamber, thereby realizing continuous grinding and greatly improving the grinding efficiency; 3. In this scheme, the powder that meets the grinding requirements is screened by airflow. The airflow flows from top to bottom in the grinding shell. With the existence of the grinding groove and the scraper, the powder that meets the grinding requirements can be pulled by the airflow at the first time and discharged with the airflow, without participating in the subsequent grinding and without interfering with the subsequent grinding; 4. The setting of the return component can pull the raw materials that do not meet the grinding requirements to participate in the grinding again. Therefore, the quality of the powder obtained by this solution is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 is a schematic diagram of the structure of the grinding mechanism; Figure 3 is a cross-sectional view of the grinding mechanism; Figure 4 is the internal schematic diagram of the grinding mechanism; Figure 5 It is a schematic diagram of the upper grinding assembly and the feeding assembly; Figure 6 is a partial schematic diagram of the upper grinding assembly; Figure 7 It is a front view of the grinding roller and the scraper; Figure 8 A schematic diagram of a vaginal plate, a lower grinding assembly, a return assembly, and a fan; Fig. 9is a partial schematic diagram of the lower grinding assembly; Fig.10 A cross-sectional view of the return assembly.

[0019] The reference numerals in the accompanying drawings are: 100, frame; 101, motor; 102, output pipe; 103, hopper; 104, auxiliary assembly; 1041, auxiliary shaft; 1042, blade; 1043, stirring element; 1044, eccentric wheel; 200, grinding mechanism; 201, upper grinding tank; 2011, air pipe; 2012, tank cover; 2013, convex pipe; 202, lower grinding tank; 203, cover; 2031, connecting pipe; 204, upper grinding assembly; 2041, support; 2042. Grinding bracket; 2043. Spring; 2044. Grinding roller; 2045. Scraper; 2046. Speed ​​reducer; 2047. Connecting shaft; 205. Guide plate; 206. Lower grinding assembly; 207. Fan; 208. Return assembly; 2081. Auger; 2082. Fixed pipe; 2083. Sleeve shaft; 2084. External feed port; 2085. Internal feed port; 209. Feeding assembly; 2091. Receiving ring; 2092. Feeding pipe. DETAILED DESCRIPTION

[0020] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation mode, structure, characteristics and effects of the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0021] Reference Figure 1-Figure 10 A grinding machine for producing low-temperature polyester coatings includes a frame 100, on which a motor 101, an output pipe 102, a hopper 103 and a grinding mechanism 200 are installed, wherein the hopper 103 is used to supply raw materials to the grinding mechanism 200, and the grinding mechanism 200 is used to grind the raw materials. The powder obtained after grinding is output to the outside through the output pipe 102, and the motor 101 is used to provide power for the grinding mechanism 200.

[0022] Reference Figure 2-Figure 4 The grinding mechanism 200 includes a grinding shell, and the grinding shell includes an upper grinding jar 201, a lower grinding jar 202 and a cover shell 203 distributed from top to bottom, wherein: The upper grinding tank 201 is provided with an upper grinding assembly 204 and a feeding assembly 209. The feeding assembly 209 is used to receive the raw materials dropped from the hopper 103 and to pull the raw materials between the upper grinding assembly 204 and the tank wall of the upper grinding tank 201. The upper grinding assembly 204 is used to grind the raw materials for the first time. It should be noted that the first grinding has multiple grinding effects, which will be described in detail later. A guide plate 205 is provided between the upper grinding jar 201 and the lower grinding jar 202 to guide the raw materials after the first grinding into the lower grinding jar 202; The lower grinding tank 202 is provided with a lower grinding assembly 206 for performing a second grinding of the raw material; A fan 207 is arranged in the housing 203, and a connecting pipe 2031 is arranged on the outer surface of the housing 203. The end of the connecting pipe 2031 is connected to the output pipe 102. An air pipe 2011 is arranged on the tank cover 2012 of the upper grinding tank 201. During the grinding process, the fan 207 is continuously started, and air enters through the connecting pipe 2031 and is output through the output pipe 102, forming a unidirectional airflow. Under the traction of the airflow, the powder that meets the grinding requirements is output together with the airflow and no longer participates in the next grinding. A return component 208 is provided between the cover 203 and the guide plate 205. Although there are two grinding actions, a small amount of raw materials that do not meet the grinding requirements will still accumulate in the cover 203. Therefore, the return component 208 can pull this part of the raw materials to fall onto the guide plate 205 and continue to participate in the second grinding.

[0023] Upper grinding assembly 204 and feeding assembly 209: Reference Figure 2-Figure 7 A convex pipe 2013 is provided on the tank cover 2012, and the convex pipe 2013 is connected to the lower end of the hopper 103.

[0024] The upper grinding jar 201 includes an upper grinding chamber in the shape of a truncated cone with a diameter decreasing from top to bottom.

[0025] The upper grinding assembly 204 includes a support 2041 , the center line of the support 2041 coincides with the axis line of the upper grinding chamber, and a plurality of grinding units are arranged in an array on the outer surface of the support 2041 along the circumferential direction of the upper grinding chamber.

[0026] The grinding unit includes a grinding bracket 2042 which is set on a support 2041 along the radial sliding of the upper grinding chamber. A spring 2043 is set between the grinding bracket 2042 and the support 2041. The elastic coefficient of the spring 2043 is relatively large. A grinding roller 2044 is installed on the suspended end of the grinding bracket 2042. The grinding roller 2044 is in the shape of a truncated cone with a vertical axis and a diameter decreasing from top to bottom. Initially, under the elastic force of the spring 2043, the outer cylindrical surface of the grinding roller 2044 fits against the wall of the upper grinding chamber.

[0027] The outer circumferential surface of the grinding roller 2044 is provided with a grinding groove, the length direction of the grinding groove is parallel to the extension direction of the generatrix of the grinding roller 2044 , and a plurality of grinding grooves are arranged in an array along the circumferential direction of the grinding roller 2044 .

[0028] The support 2041 is provided with a connecting shaft 2047 coaxial with the upper grinding chamber.

[0029] The feeding assembly 209 includes a receiving ring 2091 coaxially arranged at the upper end of the connecting shaft 2047, the upper end surface of the receiving ring 2091 is provided with an annular groove, the outer cylindrical surface of the receiving ring 2091 is provided with a feeding pipe 2092, the feeding pipe 2092 is arranged at an angle and the highest point is connected to the receiving ring 2091, and the feeding pipe 2092 is connected to the annular groove.

[0030] Initially, the grinding roller 2044 is in line contact with the upper grinding chamber. When grinding occurs, the rotation direction of the upper grinding component 204 is named the grinding rotation direction. The raw material output through the end of the feed tube 2092 will fall onto the wall of the upper grinding chamber and fall into a position close to the upper end of the line contact and in front of the line contact along the grinding rotation direction. Therefore, after the raw material falls into the upper grinding chamber, the rotation of the upper grinding component 204 can grind the raw material. Furthermore, a plurality of feed tubes 2092 are provided corresponding to the number of upper grinding components 204.

[0031] The process of first grinding of raw materials is as follows: The raw material in the hopper 103 passes through the convex pipe 2013 and falls into the annular groove. The bottom of the annular groove can be arranged in an inclined manner. Under the guidance of the inclined bottom of the groove, the raw material falls into the feeding pipe 2092. Under the guidance of the inclined feeding pipe 2092, the raw material falls into the upper grinding chamber. During the downward movement of the raw material in the upper grinding chamber, the raw material is ground by the grinding roller 2044 of the upper grinding assembly 204 in a rotating state. Specifically: The grinding roller 2044 is in a truncated cone shape, and the outer circumferential surface of the grinding roller 2044 is provided with grinding grooves, and the length direction of the grinding grooves is parallel to the extension direction of the generatrix of the grinding roller 2044, and a plurality of grinding grooves are arranged in an array along the circumferential direction of the grinding roller 2044. Therefore, as the raw material moves downward, under the condition of the same downward movement distance, the grinding effect of the raw material is better, that is, the further the raw material moves downward, the finer the grinding. Furthermore, the further downward the grinding grooves on the surface of the grinding roller 2044 are distributed, the denser the distribution of the grinding grooves, and the grinding of the grinding roller 2044 with denser grinding grooves is finer and has a better grinding effect. Therefore, in this scheme, the grinding fineness and grinding effect of the first grinding action are increased from top to bottom, and there is a multiple grinding effect. Compared with the multiple grinding structures of coarse grinding-fine grinding in the prior art, this scheme simplifies the structure, but the grinding accuracy and grinding effect are significantly improved; Furthermore, during grinding, the fan 207 will start. Due to the existence of the grinding groove, the powder that meets the grinding requirements can be drawn by the airflow and discharged along with the airflow without participating in the subsequent grinding and without interfering with the subsequent grinding.

[0032] Guide plate 205 and lower grinding assembly 206: Reference Figure 3 , Figure 4 , Figure 8 and Fig. 9 The lower grinding jar 202 includes a lower grinding chamber in the shape of a truncated cone with a diameter decreasing from top to bottom.

[0033] The guide plate 205 is in the shape of a cone with a diameter increasing from top to bottom. The upper end of the guide plate 205 is located in the upper grinding chamber and the lower end is located in the lower grinding chamber. The raw material after being ground by the upper grinding assembly 204 falls onto the guide plate 205 and is guided to the lower grinding chamber by the guide plate 205. In this process, on the one hand, the guide plate 205 guides the dispersion effect, so that the powder that meets the grinding requirements and the raw material that does not meet the grinding requirements are dispersed, which is more conducive to the powder flowing and outputting with the air flow. On the other hand, the guide plate 205 guides the raw material that does not meet the grinding requirements to fall onto the cavity wall of the lower grinding chamber, and the raw material moves downward along the cavity wall of the lower grinding chamber. The structure of the lower grinding assembly 206 is consistent with that of the upper grinding assembly 204. During the process of the raw material moving downward along the cavity wall of the lower grinding chamber, the lower grinding assembly 206 grinds the raw material for the second time. Because the raw material has undergone the first grinding, the grinding roller of the lower grinding assembly 206 may not be provided with a grinding groove, or a grinding groove may be provided to increase the grinding effect.

[0034] Return component 208: Reference Figure 6 and Figure 8-Figure 10 The return component 208 includes a fixed pipe 2082, an upper pipe opening of the fixed pipe 2082 is connected to a fixed hole arranged at the upper end of the guide plate 205, the fixed pipe 2082 is coaxial with the upper grinding chamber, and the upper grinding chamber is coaxial with the lower grinding chamber.

[0035] The lower grinding assembly 206 is provided with an avoidance hole for avoiding the fixed pipe 2082 .

[0036] A sleeve shaft 2083 in the shape of a hollow shaft is provided at the lower end of the lower grinding assembly 206 , and the sleeve shaft 2083 is sleeved on the outside of the fixed pipe 2082 .

[0037] The lower end of the sleeve shaft 2083 is closed and the lower closed end is coaxially connected to the auger 2081 disposed in the fixed pipe 2082.

[0038] The motor 101 is used to drive the sleeve shaft 2083 to rotate, and the sleeve shaft 2083 rotates with the lower grinding component 206 and the auger 2081. The upper end of the auger 2081 is connected to the upper grinding component 204 through the reducer 2046, and the auger 2081 rotates with the upper grinding component 204. It should be noted that due to the existence of the feeding component 209, the raw materials can be accurately sent to the position of the grinding roller 2044 of the upper grinding component 204 for grinding. However, when the raw materials after the first grinding fall into the second grinding chamber, this effect cannot be achieved between the raw materials and the lower grinding component 206. Therefore, the rotation speed of the lower grinding component 206 and the auger 2081 is relatively fast, and in order to achieve the grinding effect, the rotation speed of the upper grinding component 204 needs to be relatively slow. Therefore, the reducer 2046 is provided.

[0039] The outer cylindrical surface of the sleeve shaft 2083 is provided with an outer feed port 2084 near the lower end, and the outer cylindrical surface of the fixed pipe 2082 is provided with an inner feed port 2085 near the lower pipe mouth. During the rotation of the sleeve shaft 2083, the outer feed port 2084 can be connected with the inner feed port 2085. In the lower grinding chamber, the raw materials that do not meet the grinding requirements enter the fixed pipe 2082 through the outer feed port 2084 and the inner feed port 2085, are pulled by the auger 2081, fall into the guide plate 205 through the fixed hole, and re-participate in the grinding.

[0040] The fan 207 is disposed on the sleeve shaft 2083 , and the rotation of the sleeve shaft 2083 brings the fan 207 with it.

[0041] In the preferred embodiment, during the grinding process, it is inevitable that a small amount of powder will adhere to the outer cylindrical surface of the grinding roller 2044. Due to the influence of adhesion, it is difficult for this part of powder to flow along with the airflow. Figure 7 A scraper 2045 is provided on the grinding bracket 2042 , and the scraper 2045 is in contact with the outer cylindrical surface of the grinding roller 2044 . During the grinding process, the powder attached to the grinding roller 2044 is scraped off by the scraper 2045 .

[0042] A preferred embodiment, referring to FIG. Figure 2 and Figure 4An auxiliary component 104 is arranged in the hopper 103, and the auxiliary component 104 includes an auxiliary shaft 1041. The lower end of the auxiliary shaft 1041 is connected to the upper grinding component 204, for example, connected to the connecting shaft 2047. The outside of the auxiliary shaft 1041 is provided with blades 1042 and an eccentric wheel 1044. The blades 1042 are located at the bottom of the hopper 103, and the upper end of the auxiliary shaft 1041 is provided with a stirring member 1043 located in the hopper 103. Its significance lies in that, during grinding, the upper grinding component 204 rotates with the auxiliary shaft 1041, the eccentric wheel 1044 will vibrate, and the blades 1042 and the stirring member 1043 will stir, so that the raw materials in the hopper 103 fall smoothly into the annular groove of the feeding component 209.

[0043] A grinding process based on a grinding machine for low temperature polyester coating production: Step 1: The raw material in the hopper 103 falls into the annular groove through the convex pipe 2013. The bottom of the annular groove can be arranged in an inclined manner. Under the guidance of the inclined bottom of the groove, the raw material falls into the feeding pipe 2092. Under the guidance of the inclined feeding pipe 2092, the raw material falls into the upper grinding chamber. During the downward movement of the raw material in the upper grinding chamber, it is ground by the grinding roller 2044 of the upper grinding assembly 204 in a rotating state. Specifically: The grinding roller 2044 is in a truncated cone shape, and the outer circumferential surface of the grinding roller 2044 is provided with grinding grooves, and the length direction of the grinding grooves is parallel to the extension direction of the generatrix of the grinding roller 2044, and a plurality of grinding grooves are arranged in an array along the circumferential direction of the grinding roller 2044. Therefore, as the raw material moves downward, under the condition of the same downward movement distance, the grinding effect of the raw material is better, that is, the further the raw material moves downward, the finer the grinding. Furthermore, the further downward the grinding grooves on the surface of the grinding roller 2044 are distributed, the denser the distribution of the grinding grooves, and the grinding of the grinding roller 2044 with denser grinding grooves is finer and has a better grinding effect. Therefore, in this scheme, the grinding fineness and grinding effect of the first grinding action are increased from top to bottom, and there is a multiple grinding effect. Compared with the multiple grinding structures of coarse grinding-fine grinding in the prior art, this scheme simplifies the structure, but the grinding accuracy and grinding effect are significantly improved; Step 2: The raw material after the first grinding is guided by the guide plate 205 and falls onto the cavity wall of the lower grinding chamber. When the raw material moves down along the cavity wall of the lower grinding chamber, the lower grinding assembly 206 grinds the raw material for the second time; Step 3: In step 1 and step 2, the fan 207 is continuously started, air enters through the connecting pipe 2031, and is output through the output pipe 102, forming a unidirectional airflow. Under the traction of the airflow, the powder that meets the grinding requirements is output together with the airflow and no longer participates in the next grinding; After the second grinding, the raw materials that do not meet the grinding requirements enter the fixed pipe 2082 through the external feed port 2084 and the internal feed port 2085, are pulled by the auger 2081, fall into the guide plate 205 through the fixed hole, and participate in the grinding again.

[0044] From the above description, we can see that: 1. In this scheme, when the grinding roller grinds the raw material, in addition to the spring, the centrifugal force generated by the rotation of the grinding roller will also be applied to the raw material, so the grinding effect is relatively good. On this basis, the grinding roller is in a truncated cone shape, and the outer cylindrical surface of the grinding roller is provided with grinding grooves. The length direction of the grinding grooves is parallel to the extension direction of the generatrix of the grinding roller. There are several grinding grooves arranged in an array along the circumferential direction of the grinding roller. Therefore, as the raw material moves downward, under the same downward movement distance, the grinding effect of the raw material is better, that is, the lower the raw material moves, the finer the grinding. Furthermore, the lower the raw material moves, the denser the distribution of the grinding grooves on the surface of the grinding roller is, and the grinding roller with denser grinding grooves grinds finer and has better grinding effect. Therefore, in this scheme, the grinding fineness and grinding effect of the first grinding action increase from top to bottom, and there is a multiple grinding effect. Compared with the multiple grinding structures of coarse grinding-fine grinding in the prior art, this scheme simplifies the structure, but the grinding accuracy and grinding effect are significantly improved; 2. In this solution, the feeding assembly and the upper grinding assembly are integrated, which has the advantage that the raw materials entering the upper grinding chamber can be ground by the grinding roller at the first time, and after the grinding is completed, the raw materials enter the lower grinding chamber, thereby realizing continuous grinding and greatly improving the grinding efficiency; 3. In this scheme, the powder that meets the grinding requirements is screened by airflow. The airflow flows from top to bottom in the grinding shell. With the existence of the grinding groove and the scraper, the powder that meets the grinding requirements can be pulled by the airflow at the first time and discharged with the airflow, without participating in the subsequent grinding and without interfering with the subsequent grinding; 4. The setting of the return component can pull the raw materials that do not meet the grinding requirements to participate in the grinding again. Therefore, the quality of the powder obtained by this solution is better.

[0045] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A grinding machine for producing low-temperature polyester coating, comprising a frame (100), characterized in that: A motor (101), an output pipe (102), a hopper (103), and a grinding mechanism (200) are mounted on the frame (100); the grinding mechanism (200) comprises a grinding shell, and the grinding shell comprises an upper grinding jar (201), a lower grinding jar (202), and a cover (203) arranged from top to bottom; An upper grinding assembly (204) and a feeding assembly (209) are arranged in the upper grinding jar (201); the feeding assembly (209) is used to receive raw materials dropped from the hopper (103) and to pull the raw materials between the upper grinding assembly (204) and the wall of the upper grinding jar (201); the upper grinding assembly (204) is used to perform a first grinding on the raw materials; A guide plate (205) is provided between the upper grinding jar (201) and the lower grinding jar (202) for guiding the raw materials after the first grinding into the lower grinding jar (202); A lower grinding assembly (206) for performing a second grinding on the raw material is arranged in the lower grinding tank (202); A fan (207) is arranged inside the housing (203); a connecting pipe (2031) is arranged on the outer surface of the housing (203); the end of the connecting pipe (2031) is connected to the output pipe (102); an air pipe (211) is arranged on the tank cover (212) of the upper grinding tank (201); during the grinding process, the fan (207) is continuously started, and air enters the grinding shell through the connecting pipe (2031) and is then output through the output pipe (102).

2. A grinding machine for producing low-temperature polyester coating according to claim 1, characterized in that: The upper grinding jar (201) comprises an upper grinding chamber in the shape of a truncated cone with a diameter decreasing from top to bottom, and the upper grinding assembly (204) comprises a support (2041), the center line of the support (2041) coincides with the axis center line of the upper grinding chamber, and the outer surface of the support (2041) is provided with a plurality of grinding units arranged in an array along the circumferential direction of the upper grinding chamber.

3. A grinding machine for producing low-temperature polyester coating according to claim 2, characterized in that: The grinding unit comprises a grinding bracket (2042) which is arranged on a support (2041) for radial sliding along an upper grinding chamber, a spring (2043) being arranged between the grinding bracket (2042) and the support (2041), a grinding roller (2044) being installed at a suspended end of the grinding bracket (2042), the grinding roller (2044) being in the shape of a truncated cone with a vertical axis and a diameter decreasing from top to bottom, and initially, under the elastic force of the spring (2043), the outer cylindrical surface of the grinding roller (2044) is in contact with the cavity wall of the upper grinding chamber, the outer cylindrical surface of the grinding roller (2044) is provided with a grinding groove, the length direction of the grinding groove is parallel to the extension direction of the generatrix of the grinding roller (2044), and a plurality of grinding grooves are arranged in an array along the circumferential direction of the grinding roller (2044).

4. A grinding machine for producing low-temperature polyester coating according to claim 3, characterized in that: A convex tube (2013) is provided on the tank cover (2012), and the convex tube (2013) is connected to the lower end of the hopper (103); A connecting shaft (2047) coaxial with the upper grinding chamber is arranged on the support (2041), and the feeding assembly (209) comprises a material receiving ring (2091) coaxially arranged on the upper end of the connecting shaft (2047), an annular groove is arranged on the upper end surface of the material receiving ring (2091), and a feeding pipe (2092) is arranged on the outer circumferential surface of the material receiving ring (2091), the feeding pipe (2092) is arranged in an inclined manner and connected to the material receiving ring (2091) at its highest point, the feeding pipe (2092) is connected to the annular groove, and the annular groove is connected to the convex pipe (2013).

5. A grinding machine for producing low-temperature polyester coating according to claim 4, characterized in that: Initially, there is line contact between the grinding roller (2044) and the upper grinding chamber. When the grinding action occurs, the rotation direction of the upper grinding component (204) is named the grinding rotation direction. The raw material output through the end of the feed pipe (2092) falls onto the wall of the upper grinding chamber and falls into a position close to the upper end of the line contact and is located in front of the line contact along the grinding rotation direction.

6. A grinding machine for producing low-temperature polyester coating according to claim 3, characterized in that: The lower grinding jar (202) comprises a lower grinding chamber in the shape of a truncated cone with a diameter decreasing from top to bottom, the guide plate (205) is in the shape of a cone with a diameter increasing from top to bottom, the upper end of the guide plate (205) is located in the upper grinding chamber, and the lower end is located in the lower grinding chamber, and the structure of the lower grinding assembly (206) is consistent with that of the upper grinding assembly (204).

7. A grinding machine for producing low-temperature polyester coating according to claim 1 or 6, characterized in that: A return assembly (208) is provided between the cover shell (203) and the guide plate (205).

8. A grinding machine for producing low-temperature polyester coating according to claim 7, characterized in that: The return assembly (208) comprises a fixed pipe (2082), the upper pipe opening of the fixed pipe (2082) is connected to a fixed hole provided at the upper end of the guide plate (205), the fixed pipe (2082) is coaxial with the upper grinding chamber, and the lower grinding assembly (206) is provided with an avoidance hole for avoiding the fixed pipe (2082); A sleeve shaft (2083) in the shape of a hollow shaft is arranged at the lower end of the lower grinding assembly (206); the sleeve shaft (2083) is sleeved on the outside of the fixed pipe (2082); the lower end of the sleeve shaft (2083) is closed and the lower closed end is coaxially connected to an auger (2081) arranged in the fixed pipe (2082); the motor (101) is used to drive the sleeve shaft (2083) to rotate; the upper end of the auger (2081) is connected to the upper grinding assembly (204) via a reducer (2046); and the fan (207) is arranged on the sleeve shaft (2083).

9. A grinding machine for producing low-temperature polyester coating according to claim 8, characterized in that: The outer circumferential surface of the sleeve shaft (2083) is provided with an outer feed port (2084) close to the lower end, and the outer circumferential surface of the fixed pipe (2082) is provided with an inner feed port (2085) close to the lower pipe opening. During the rotation of the sleeve shaft (2083), the outer feed port (2084) can be connected with the inner feed port (2085).

10. A grinding process based on a grinding machine for producing low-temperature polyester coatings as claimed in claim 5, characterized in that: The steps include: Step 1: The raw material in the hopper (103) passes through the convex pipe (2013) and falls into the annular groove. The bottom of the annular groove is arranged to be inclined. Under the guidance of the bottom of the annular groove, the raw material falls into the feeding pipe (2092). Under the guidance of the inclined feeding pipe (2092), the raw material falls into the upper grinding chamber. At the same time, the grinding roller (2044) of the upper grinding assembly (204) rotates around the axis of the upper grinding chamber to achieve the first grinding of the raw material. Step 2: the raw material after the first grinding is guided by the guide plate (205) and falls onto the cavity wall of the lower grinding chamber of the lower grinding tank (202). When the raw material moves downward along the cavity wall of the lower grinding chamber, the lower grinding assembly (206) grinds the raw material for the second time; Step 3: In step 1 and step 2, the fan (207) is continuously started, and air enters the grinding housing through the connecting pipe (2031) and is output through the output pipe (102), forming a unidirectional airflow. Under the traction of the airflow, the powder that meets the grinding requirements is output together with the airflow and no longer participates in the subsequent grinding; Step 4: After the second grinding, the raw materials that do not meet the grinding requirements are pulled back into the lower grinding chamber by the return assembly (208) disposed between the cover shell (203) and the guide plate (205) to continue grinding.

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