High-precision electromagnetic plunger metering pump

Abstract

The invention discloses a high-precision electromagnetic plunger metering pump which comprises a pump body, a valve body, an electromagnetic control device and a plunger assembly. The electromagnetic control device comprises a movable iron core which is movably arranged and an electromagnet assembly for controlling the movable iron core to move; the plunger assembly comprises a positioning ring, a buffering heat insulation ring and a plunger rod, the positioning ring is provided with a containing groove and a via hole, a first rotation limiting structure is arranged between the positioning ring and the pump body, the buffering heat insulation ring is arranged in the containing groove and connected to the movable iron core, and a second rotation limiting structure is arranged between the buffering heat insulation ring and the positioning ring. The plunger rod penetrates through the via hole and extends into the plunger moving groove, and a sealing assembly is arranged between the periphery of the plunger rod and the plunger moving groove. The arrangement of the buffer heat insulation ring can prevent the heat of the movable iron core from being transmitted to the plunger rod, limit the rotation of the positioning ring relative to the pump main body and limit the rotation of the buffer heat insulation ring relative to the positioning ring, so that the plunger rod can be ensured to hit the same position of the plunger moving groove every time, and the quantification is more accurate.

Description

Technical Field

[0001] The invention relates to the field of electromagnetic metering pump technology, in particular to a high-precision electromagnetic plunger metering pump. Background Art

[0002] A metering pump is a metering pump whose output flow rate remains unchanged under the condition of constant speed. Simply put, after the speed of the metering pump is selected, its flow rate cannot be adjusted. Taking the electromagnetic metering pump as an example, there are currently two main forms: rubber diaphragm type and ceramic plunger type. The rubber diaphragm type has defects such as low quantitative accuracy, easy aging and rupture of the diaphragm, and poor reliability. Its structure cannot meet the high-precision quantitative requirements. The ceramic plunger type has higher quantitative accuracy than the rubber diaphragm type. However, in the ceramic plunger metering pump in the prior art, the ceramic plunger is connected to the moving iron core. The fixed iron core will generate heat during operation and then transfer it to the moving iron core and then to the ceramic plunger, which is easy to affect the reagent flowing into the metering pump. In addition, due to the influence of processing errors (such as flatness), the ceramic plunger is prone to swaying rotation in the pump body, resulting in the ceramic plunger being unable to ensure that each strike is at the same position of the pump body, resulting in a deviation in the repeatability accuracy in the quantitative calibration process before leaving the factory, affecting the installation and production personnel in judging the correct value of the metering pump.

[0003] Therefore, it is necessary to design a new technical solution to solve the above problems. Summary of the invention

[0004] In view of this, the present invention aims at the deficiencies in the prior art, and its main purpose is to provide a high-precision electromagnetic plunger metering pump, wherein the moving iron core is connected to the plunger rod through a buffer insulation ring. The setting of the buffer insulation ring can prevent the heat of the moving iron core from being transferred to the plunger rod on the one hand, and on the other hand, it can prevent the plunger rod from hitting the pump body too quickly. A first rotation limiting structure is provided between the positioning ring and the pump body to limit the rotation of the positioning ring relative to the pump body, and a second rotation limiting structure is provided between the buffer insulation ring and the positioning ring to limit the rotation of the buffer insulation ring relative to the positioning ring. This can ensure that the plunger rod hits the same position of the plunger active groove each time, making the metering more accurate. At the same time, it can reduce the flatness processing requirements for the metering pump, thereby reducing the production cost.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A high-precision electromagnetic plunger metering pump, comprising:

[0007] A pump body, wherein the pump body is provided with a first mounting groove and a suction and discharge port, the pump body is provided with a quantitative channel connected to the suction and discharge port, an end of the quantitative channel away from the suction and discharge port is connected to the first mounting groove through a plunger movable groove, and the pump body is also provided with a first liquid inlet channel and a first liquid outlet channel;

[0008] A valve body, the valve body is provided with a main channel and a second liquid inlet channel and a second liquid outlet channel which can be communicated with the main channel, the main channel is connected to the suction and discharge port, the second liquid inlet channel is connected to the first liquid inlet channel, and the second liquid outlet channel is connected to the first liquid outlet channel;

[0009] An electromagnetic control device, the electromagnetic control device comprising a movable moving iron core and an electromagnet assembly for controlling the movement of the moving iron core;

[0010] The plunger assembly comprises a positioning ring, a buffer heat-insulating ring and a plunger rod, wherein the positioning ring is arranged in a first mounting groove, the positioning ring is provided with a receiving groove and a through hole connected to the receiving groove for the plunger rod to pass through, a first rotation limiting structure is arranged between the positioning ring and the pump body, the first rotation limiting structure is used to prevent the positioning ring from rotating relative to the pump body, the electromagnetic control device fixes the positioning ring in the first mounting groove, the buffer heat-insulating ring is arranged in the receiving groove and is connected to the moving iron core, a second rotation limiting structure is arranged between the buffer heat-insulating ring and the positioning ring, a second mounting groove is arranged at one end of the buffer heat-insulating ring away from the moving iron core, the plunger rod is arranged in the second mounting groove, and one end of the plunger rod away from the buffer heat-insulating ring passes through the through hole and extends into the plunger movable groove, a sealing assembly is arranged between the outer periphery of the plunger rod and the plunger movable groove, and the electromagnet assembly drives the plunger rod to move in the plunger movable groove through the moving iron core.

[0011] As a preferred solution, the first rotation limiting structure includes a positioning pin and a positioning hole. The positioning hole is formed on the outer periphery of the positioning ring and the wall surface of the first mounting groove, and the positioning pin is inserted into the positioning hole.

[0012] As a preferred scheme, the second rotation limiting structure includes a first rotation limiting surface and a second rotation limiting surface, wherein the first rotation limiting surfaces are provided with two opposite or adjacent first rotation limiting surfaces, and the two first rotation limiting surfaces are provided on the outer periphery of the buffer heat insulation ring, and the second rotation limiting surfaces are provided with two second rotation limiting surfaces, and the two second rotation limiting surfaces are provided on the wall surface of the accommodating groove and correspond to the first rotation limiting surface, and the wall surface of the accommodating groove is provided with avoidance grooves on both sides of the second rotation limiting surface for preventing interference between the first rotation limiting surface and the second rotation limiting surface.

[0013] As a preferred solution, a protruding column is provided at one end of the moving iron core away from the electromagnet assembly, and correspondingly, a recess matching the protruding column is provided at one end of the buffer heat insulation ring close to the moving iron core, and the recess is clamped in the protruding column. A positioning groove is provided on the outer periphery of the protruding column of the moving iron core, and correspondingly, the buffer heat insulation ring is provided with a positioning convex portion matching the positioning groove, and the positioning convex portion is clamped in the positioning groove.

[0014] As a preferred solution, one end of the buffer heat-insulating ring close to the moving iron core is fixed to one end of the moving iron core away from the electromagnet assembly by means of structural adhesive.

[0015] As a preferred embodiment, the sealing assembly includes an O-ring and a sealing ring, the sealing ring has a through hole, and the sealing ring is respectively provided with a first annular extension portion and a second annular extension portion extending from both ends of the through hole, and the wall surface of the plunger movable groove is provided with a three-stage stepped groove, the positioning ring and the plunger rod together fix the sealing ring to a section of the three-stage stepped groove close to the positioning ring, the plunger rod fixes the first annular extension portion to a section of the three-stage stepped groove away from the positioning ring, the sealing ring and the first annular extension portion fix the O-ring to the middle section of the three-stage stepped groove, and the plunger rod fixes the second annular extension portion to the through hole.

[0016] As a preferred embodiment, a valve body mounting portion is extended from the side of the pump body, the valve body is fixed on the valve body mounting portion, the quantitative channel includes a transverse section and a first vertical section and a second vertical section connected to the transverse section, the transverse section passes through the valve body mounting portion, the valve body mounting portion is provided with a plug for sealing the end of the transverse section, the suction and discharge port is provided at one end of the first vertical section away from the transverse section, and the plunger movable groove is provided at one end of the second vertical section away from the transverse section.

[0017] As a preferred solution, the valve body is a three-way valve.

[0018] As a preferred embodiment, the electromagnet assembly includes a pressure plate, a skeleton, a fixed iron core, a coil, and an iron shell. The pressure plate is fixed on the pump body and is used to fix the positioning ring in the first mounting groove. The iron shell is fixed on the pressure plate and fixes the skeleton in the iron shell. The skeleton includes an inner cavity and an outer cavity separated from the inner cavity. The moving iron core is movably arranged at one end of the inner cavity close to the pump body, and the fixed iron core is arranged at one end of the inner cavity away from the pump body. An elastic member for driving the moving iron core to move toward the pump body is sandwiched between the fixed iron core and the moving iron core, and the coil is arranged in the outer cavity.

[0019] As a preferred embodiment, the electromagnet assembly also includes an adjusting nut, and the end of the fixed iron core away from the moving iron core extends out of the iron shell and is provided with a threaded portion. The adjusting nut is connected to the threaded portion and is used to adjust the position of the fixed iron core in the inner cavity.

[0020] Compared with the prior art, the present invention has obvious advantages and beneficial effects. Specifically, it can be seen from the above technical solution that:

[0021] Mainly, the moving iron core is connected to the plunger rod through a buffer insulation ring. The setting of the buffer insulation ring can prevent the heat of the moving iron core from being transferred to the plunger rod on the one hand, and can prevent the plunger rod from hitting the pump body too quickly on the other hand. A first rotation limiting structure is arranged between the positioning ring and the pump body to limit the rotation of the positioning ring relative to the pump body, and a second rotation limiting structure is arranged between the buffer insulation ring and the positioning ring to limit the rotation of the buffer insulation ring relative to the positioning ring. This can ensure that the plunger rod hits the same position of the plunger active groove each time, making the metering more accurate. At the same time, it can reduce the flatness processing requirements for the metering pump, thereby reducing the production cost.

[0022] In order to more clearly illustrate the structural features and effects of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a three-dimensional schematic diagram of a preferred embodiment of the present invention;

[0024] Figure 2 It is an exploded schematic diagram of a preferred embodiment of the present invention;

[0025] Figure 3 It is a cross-sectional schematic diagram of a preferred embodiment of the present invention;

[0026] Figure 4 yes Figure 3 A partial enlarged view of the middle A;

[0027] Figure 5 is another cross-sectional schematic diagram of a preferred embodiment of the present invention;

[0028] Figure 6 It is a schematic diagram of the assembly of the plunger assembly of the preferred embodiment of the present invention.

[0029] Description of the accompanying drawings:

[0030] 10. Pump body 11. Valve body installation part

[0031] 12. Plug 101, first installation groove

[0032] 102, suction and discharge port 103, quantitative channel

[0033] 1031, transverse section 1032, first vertical section

[0034] 1033, second vertical section 104, plunger movable groove

[0035] 105, first liquid inlet channel 106, first liquid outlet channel

[0036] 107, three-stage stepped groove 20, valve body

[0037] 201, main channel 202, second liquid inlet channel

[0038] 203, second liquid outlet channel 30, electromagnetic control device

[0039] 31. Moving iron core 311. convex column

[0040] 312, positioning groove 32, electromagnet assembly

[0041] 321, pressing plate 322, skeleton

[0042] 323, fixed iron core 324, coil

[0043] 325, iron shell 326, inner cavity

[0044] 327, outer cavity 328, elastic member

[0045] 329, threaded portion 40, plunger assembly

[0046] 41. Positioning ring 411. Accommodating groove

[0047] 412, via 42, buffer insulation ring

[0048] 421, second installation groove 422, recess

[0049] 423, positioning protrusion 424, plug hole

[0050] 425, first glue injection hole 426, second glue injection hole

[0051] 43. plunger rod 431. annular groove

[0052] 50. First rotation limiting structure 51. Positioning pin

[0053] 52. Positioning hole 60. Second rotation limiting structure

[0054] 61. First rotation limiting surface 62. Second rotation limiting surface

[0055] 70. Sealing assembly 71. O-ring

[0056] 72. Sealing ring 721. Through hole

[0057] 722, first annular extension portion 723, second annular extension portion

[0058] 80. Adjusting nut 90. Avoiding air groove

[0059] 100. Pump housing. DETAILED DESCRIPTION

[0060] First of all, it should be noted that in the description of the present invention, the terms "up", "down", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0061] Please refer to Figures 1 to 6 As shown, it shows the specific structure of a preferred embodiment of the present invention, including a pump body 10, a valve body 20, an electromagnetic control device 30 and a plunger assembly 40.

[0062] The pump body 10 is provided with a first installation groove 101 and a suction and discharge port 102, and the pump body 10 is provided with a quantitative channel 103 connected to the suction and discharge port 102, and the end of the quantitative channel 103 away from the suction and discharge port 102 is connected to the first installation groove 101 through a plunger movable groove 104, and the pump body 10 is also provided with a first liquid inlet channel 105 and a first liquid outlet channel 106;

[0063] See also Figure 2 , Figure 3 and Figure 5 As shown, specifically, a valve body mounting portion 11 extends from the side of the pump body 10, the quantitative channel 103 includes a transverse section 1031 and a first vertical section 1032 and a second vertical section 1033 connected to the transverse section 1031, the transverse section 1031 passes through the valve body mounting portion 11, and the arrangement of the transverse section 1031 passing through the valve body mounting portion 11 facilitates the processing and manufacturing of the transverse section 1031, the valve body mounting portion 11 is provided with a plug 12 for blocking the end of the transverse section 1031, the suction and discharge port 102 is arranged at the end of the first vertical section 1032 away from the transverse section 1031, the first liquid inlet channel 105 and the first liquid outlet channel 106 are respectively arranged on both sides of the first vertical section 1032, and the plunger movable groove 104 is arranged at the end of the second vertical section 1033 away from the transverse section 1031.

[0064] The valve body 20 is provided with a main channel 201 and a second liquid inlet channel 202 and a second liquid outlet channel 203 which can be communicated with the main channel 201. The main channel 201 is communicated with the suction and discharge port 102, the second liquid inlet channel 202 is communicated with the first liquid inlet channel 105, and the second liquid outlet channel 203 is communicated with the first liquid outlet channel 106.

[0065] See also Figure 2 and Figure 5As shown, specifically, the valve body 20 is fixed to the bottom of the valve body mounting portion 11, and the valve body 20 is parallel to the pump body 10; in this embodiment, the valve body 20 is a three-way valve, and the second liquid inlet channel 202 and the second liquid outlet channel 203 are respectively arranged on both sides of the main channel 201, which can be used for switching of suction and discharge of liquid to achieve quantitative metering.

[0066] The electromagnetic control device 30 includes a movable moving iron core 31 and an electromagnetic assembly 32 for controlling the movement of the moving iron core 31; the plunger assembly 40 includes a positioning ring 41, a buffer heat-insulating ring 42, and a plunger rod 43. The positioning ring 41 is arranged in the first installation groove 101. The positioning ring 41 is provided with a receiving groove 411 and a through hole 412 connected to the receiving groove 411 for the plunger rod 43 to pass through. A first rotation-limiting structure 50 is provided between the positioning ring 41 and the pump body 10. The first rotation-limiting structure 50 is used to prevent the positioning ring 41 from rotating relative to the pump body 10. The electromagnetic control device 30 fixes the positioning ring 41 in the first installation groove 101. The buffer heat-insulating ring 42 is arranged in the receiving groove. 411 and connected to the moving iron core 31, the buffer heat insulation ring 42 can be made of rubber material, a second rotation limiting structure 60 is arranged between the buffer heat insulation ring 42 and the positioning ring 41, the end of the buffer heat insulation ring 42 away from the moving iron core 31 is provided with a second mounting groove 421, the plunger rod 43 is arranged in the second mounting groove 421, the plunger rod 43 can be a ceramic plunger rod 43, the end of the plunger rod 43 away from the buffer heat insulation ring 42 passes through the through hole 412 and extends into the plunger movable groove 104, a sealing component 70 is arranged between the outer periphery of the plunger rod 43 and the plunger movable groove 104, and the electromagnet component 32 drives the plunger rod 43 to move in the plunger movable groove 104 through the moving iron core 31;

[0067] See also Figure 3 As shown, specifically, the electromagnet assembly 32 includes a pressure plate 321, a skeleton 322, a fixed iron core 323, a coil 324, and an iron shell 325. The pressure plate 321 is fixed on the pump body 10 and is used to fix the positioning ring 41 in the first mounting groove 101. The iron shell 325 is fixed on the pressure plate 321 and fixes the skeleton 322 in the iron shell 325. The skeleton 322 includes an inner cavity 326 and an outer cavity 327 separated from the inner cavity 326. The moving iron core 31 is movably arranged at one end of the inner cavity 326 close to the pump body 10, and the fixed iron core 323 is arranged at one end of the inner cavity 326 away from the pump body 10. An elastic member 328 for driving the moving iron core 31 to move toward the pump body 10 is sandwiched between the fixed iron core 323 and the moving iron core 31. The elastic member 328 can be a spring, and the coil 324 is arranged in the outer cavity 327;

[0068] Preferably, the electromagnet assembly 32 also includes an adjusting nut 80, and the end of the fixed iron core 323 away from the moving iron core 31 extends out of the iron shell 325 and is provided with a threaded portion 329. The adjusting nut 80 is connected to the threaded portion 329 and is used to adjust the position of the fixed iron core 323 in the inner cavity 326, thereby adjusting the suction and discharge volume; the outer cover of the iron shell 325 is provided with a pump housing 100, and the adjusting nut 80 is exposed at the bottom of the pump housing 100.

[0069] See also Figure 2 and Figure 6 As shown, the first rotation limiting structure 50 includes a positioning pin 51 and a positioning hole 52. The outer periphery of the positioning ring 41 and the wall surface of the first mounting groove 101 are provided with the positioning hole 52. The positioning pin 51 is inserted into the positioning hole 52.

[0070] The second rotation limiting structure 60 includes a first rotation limiting surface 61 and a second rotation limiting surface 62. The first rotation limiting surface 61 is provided with two oppositely or adjacently arranged first rotation limiting surfaces 61, and the two first rotation limiting surfaces 61 are provided on the outer periphery of the buffer heat insulation ring 42. The second rotation limiting surfaces 62 are provided with two second rotation limiting surfaces 62, and the two second rotation limiting surfaces 62 are provided on the wall surface of the accommodating groove 411 and correspond to the first rotation limiting surface 61. The wall surface of the accommodating groove 411 is provided with avoidance grooves 90 on both sides of the second rotation limiting surface 62 for preventing interference between the first rotation limiting surface 61 and the second rotation limiting surface 62. In the present embodiment, the first rotation limiting surfaces 61 are arranged in two oppositely arranged and symmetrically arranged.

[0071] See also Figure 3 As shown, the end of the moving iron core 31 away from the electromagnet assembly 32 is convexly provided with a convex column 311, and correspondingly, the end of the buffer heat insulation ring 42 close to the moving iron core 31 is concavely provided with a concave position 422 matching the convex column 311, and the concave position 422 is clamped in the convex column 311. The moving iron core 31 is provided with a positioning groove 312 on the outer periphery of the convex column 311, and correspondingly, the buffer heat insulation ring 42 is provided with a positioning convex portion 423 matching the positioning groove 312, and the positioning convex portion 423 is clamped in the positioning groove 312. The end of the buffer heat insulation ring 42 close to the moving iron core 31 is fixed to the moving iron core 31 away from the electromagnet assembly by structural glue. One end of the member 32; the outer periphery of the plunger rod 43 is provided with an annular groove 431, the outer periphery of the buffer heat-insulating ring 42 is provided with a plug hole 424 and a first glue injection hole 425 which are connected to the second mounting groove 421 and corresponding to the annular groove 431, the outer periphery of the buffer heat-insulating ring 42 is also provided with a second glue injection hole 426 corresponding to the bottom of the plunger rod 43, the plug hole 424 is penetrated by a latch, and the latch is clamped in the annular groove 431 to complete the positioning of the plunger rod 43 in the second mounting groove 421, and the structural glue is filled through the first glue injection hole 425 and the second glue injection hole 426 to complete the fixation of the plunger rod 43 in the second mounting groove 421.

[0072] See also Figure 4 As shown, the sealing assembly 70 includes an O-ring 71 and a sealing ring 72, the sealing ring 72 has a through hole 721, and the sealing ring 72 is respectively provided with a first annular extension portion 722 and a second annular extension portion 723 extending from both ends of the through hole 721, the wall surface of the plunger movable groove 104 is provided with a three-stage stepped groove 107, the positioning ring 41 and the plunger rod 43 together fix the sealing ring 72 to a section of the three-stage stepped groove 107 close to the positioning ring 41, the plunger rod 43 fixes the first annular extension portion 722 to a section of the three-stage stepped groove 107 away from the positioning ring 41, the sealing ring 72 and the first annular extension portion 722 fix the O-ring 71 to the middle section of the three-stage stepped groove 107, and the plunger rod 43 fixes the second annular extension portion 723 to the through hole 412;

[0073] Preferably, the extension length of the first annular extension portion 722 is greater than the extension length of the second annular extension portion 723, and the first annular extension portion 722 is arranged with a small opening at the top and a large opening at the bottom. The first annular extension portion 722 is arranged with a large opening at the top and a small opening at the bottom, and the arrangement of the second annular extension portion 723 can further prevent the reagent from entering the positioning ring 41.

[0074] The working principle of this embodiment is described in detail as follows:

[0075] When a specified current is passed through the coil 324, a magnetic field is generated, and the magnetic field passes through the iron shell 325, the fixed iron core 323 and the moving iron core 31 in sequence to form a magnetic circuit, and finally an electromagnetic force is formed between the fixed iron core 323 and the moving iron core 31, which attracts the moving iron core 31 and drives the plunger rod 43 to move downward, so that a negative pressure is formed in the plunger movable groove 104 of the pump body 10, and the liquid in the quantitative channel 103 is sucked.

[0076] After the liquid is sucked, the coil 324 is powered off, and the moving iron core 31, the buffer insulation ring 42 and the plunger rod 43 are separated from the fixed iron core 323 and move upwards until they are locked with the pump body 10 under the restoring force of the elastic member 328, completing the liquid discharge action.

[0077] The design emphasis of the present invention is:

[0078] Mainly, the moving iron core is connected to the plunger rod through a buffer insulation ring. The setting of the buffer insulation ring can prevent the heat of the moving iron core from being transferred to the plunger rod on the one hand, and can prevent the plunger rod from hitting the pump body too quickly on the other hand. A first rotation limiting structure is arranged between the positioning ring and the pump body to limit the rotation of the positioning ring relative to the pump body, and a second rotation limiting structure is arranged between the buffer insulation ring and the positioning ring to limit the rotation of the buffer insulation ring relative to the positioning ring. This can ensure that the plunger rod hits the same position of the plunger active groove each time, making the metering more accurate. At the same time, it can reduce the flatness processing requirements for the metering pump, thereby reducing the production cost.

[0079] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any slight modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A high-precision electromagnetic plunger metering pump, characterized in that: include: A pump body, wherein the pump body is provided with a first mounting groove and a suction and discharge port, the pump body is provided with a quantitative channel connected to the suction and discharge port, an end of the quantitative channel away from the suction and discharge port is connected to the first mounting groove through a plunger movable groove, and the pump body is also provided with a first liquid inlet channel and a first liquid outlet channel; A valve body, the valve body is provided with a main channel and a second liquid inlet channel and a second liquid outlet channel which can be communicated with the main channel, the main channel is connected to the suction and discharge port, the second liquid inlet channel is connected to the first liquid inlet channel, and the second liquid outlet channel is connected to the first liquid outlet channel; An electromagnetic control device, the electromagnetic control device comprising a movable moving iron core and an electromagnet assembly for controlling the movement of the moving iron core; The plunger assembly comprises a positioning ring, a buffer heat-insulating ring and a plunger rod, wherein the positioning ring is arranged in a first mounting groove, the positioning ring is provided with a receiving groove and a through hole connected to the receiving groove for the plunger rod to pass through, a first rotation limiting structure is arranged between the positioning ring and the pump body, the first rotation limiting structure is used to prevent the positioning ring from rotating relative to the pump body, the electromagnetic control device fixes the positioning ring in the first mounting groove, the buffer heat-insulating ring is arranged in the receiving groove and is connected to the moving iron core, a second rotation limiting structure is arranged between the buffer heat-insulating ring and the positioning ring, a second mounting groove is arranged at one end of the buffer heat-insulating ring away from the moving iron core, the plunger rod is arranged in the second mounting groove, and one end of the plunger rod away from the buffer heat-insulating ring passes through the through hole and extends into the plunger movable groove, a sealing assembly is arranged between the outer periphery of the plunger rod and the plunger movable groove, and the electromagnet assembly drives the plunger rod to move in the plunger movable groove through the moving iron core.

2. A high-precision electromagnetic plunger metering pump according to claim 1, characterized in that: The first rotation limiting structure includes a positioning pin and a positioning hole. The outer periphery of the positioning ring and the wall surface of the first installation groove are provided with the positioning hole, and the positioning pin is inserted into the positioning hole.

3. A high-precision electromagnetic plunger metering pump according to claim 1, characterized in that: The second rotation limiting structure includes a first rotation limiting surface and a second rotation limiting surface, wherein the first rotation limiting surface is provided with two adjacent or oppositely arranged first rotation limiting surfaces, the two first rotation limiting surfaces are provided on the outer periphery of the buffer heat insulation ring, and the second rotation limiting surfaces are provided with two second rotation limiting surfaces, the two second rotation limiting surfaces are provided on the wall surface of the accommodating groove and correspond to the first rotation limiting surface, and the wall surface of the accommodating groove is provided with avoidance grooves on both sides of the second rotation limiting surface for preventing interference between the first rotation limiting surface and the second rotation limiting surface.

4. A high-precision electromagnetic plunger metering pump according to claim 1, characterized in that: A protruding column is convexly provided at one end of the moving iron core away from the electromagnet assembly, and correspondingly, a recess matching the protruding column is concavely provided at one end of the buffer heat insulation ring close to the moving iron core, and the recess is clamped in the protruding column. The moving iron core is provided with a positioning groove on the outer periphery of the protruding column, and correspondingly, the buffer heat insulation ring is provided with a positioning convex portion matching the positioning groove, and the positioning convex portion is clamped in the positioning groove.

5. A high-precision electromagnetic plunger metering pump according to claim 4, characterized in that: One end of the buffer heat-insulating ring close to the moving iron core is fixed to one end of the moving iron core away from the electromagnet assembly through structural adhesive.

6. A high-precision electromagnetic plunger metering pump according to claim 1, characterized in that: The sealing assembly includes an O-ring and a sealing ring, the sealing ring has a through hole, the sealing ring is respectively extended with a first annular extension portion and a second annular extension portion at both ends of the through hole, the wall surface of the plunger movable groove is provided with a three-section stepped groove, the positioning ring and the plunger rod together fix the sealing ring to a section of the three-section stepped groove close to the positioning ring, the plunger rod fixes the first annular extension portion to a section of the three-section stepped groove away from the positioning ring, the sealing ring and the first annular extension portion fix the O-ring to the middle section of the three-section stepped groove, and the plunger rod fixes the second annular extension portion to the through hole.

7. A high-precision electromagnetic plunger metering pump according to claim 1, characterized in that: A valve body mounting portion is extended from the side of the pump body, the valve body is fixed on the valve body mounting portion, the quantitative channel includes a transverse section and a first vertical section and a second vertical section connected to the transverse section, the transverse section runs through the valve body mounting portion, the valve body mounting portion is provided with a plug for sealing the end of the transverse section, the suction and discharge port is provided at one end of the first vertical section away from the transverse section, and the plunger movable groove is provided at one end of the second vertical section away from the transverse section.

8. A high-precision electromagnetic plunger metering pump according to claim 7, characterized in that: The valve body is a three-way valve.

9. A high-precision electromagnetic plunger metering pump according to claim 1, characterized in that: The electromagnet assembly includes a pressure plate, a frame, a fixed iron core, a coil, and an iron shell. The pressure plate is fixed on the pump body and is used to fix the positioning ring in the first mounting groove. The iron shell is fixed on the pressure plate and fixes the frame in the iron shell. The frame includes an inner cavity and an outer cavity separated from the inner cavity. The moving iron core is movably arranged at one end of the inner cavity close to the pump body, and the fixed iron core is arranged at one end of the inner cavity away from the pump body. An elastic member for driving the moving iron core to move toward the pump body is sandwiched between the fixed iron core and the moving iron core, and the coil is arranged in the outer cavity.

10. A high-precision electromagnetic plunger metering pump according to claim 9, characterized in that: The electromagnet assembly also includes an adjusting nut. One end of the fixed iron core away from the moving iron core extends out of the iron shell and is provided with a threaded portion. The adjusting nut is connected to the threaded portion and is used to adjust the position of the fixed iron core in the inner cavity.

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