CN113324086B - Electromagnetic valve and preparation method thereof - Google Patents

Abstract

The invention discloses a solenoid valve which comprises a framework main body, wherein a coil is wound on the framework main body; the two contact pins are arranged at the end part of the framework main body, the two contact pins are electrically connected with a diode, and the two contact pins, the diode and the coil are electrically connected; keep off and glue the ring, keep off and glue the ring setting and be in the skeleton main part is equipped with the tip of two contact pins, just keep off glue the ring will two contact pins with the diode surrounds, wherein, keep off glue the ring with insulating medium can be injected into in the region that the skeleton main part encloses. The invention can be used in a severe environment, does not generate the phenomenon of leakage current, improves the safety factor, and has low cost and convenient assembly.

Description

Electromagnetic valve and preparation method thereof

Technical Field

The invention relates to an electromagnetic valve, in particular to an electromagnetic valve and a preparation method thereof.

Background

Electromagnetic valves (Electromagnetic valves) are electromagnetically controlled industrial devices, are basic automation elements for controlling fluids, belong to actuators, are not limited to hydraulic pressure and pneumatic pressure, and are used in industrial control systems to adjust the direction, flow rate, speed and other parameters of media. The electromagnetic valve can be matched with different circuits to realize expected control, and the precision and flexibility of the control can be ensured. There are many types of solenoid valves, with different solenoid valves functioning at different locations in the control system, the most common being check valves, safety valves, directional control valves, speed regulating valves, etc.

The prior art is as follows: the originally designed electromagnetic valve comprises a coil, a plunger, an ejector pin, a valve core, a valve sleeve and the like, is very easy to be abnormal under the condition of complicated working conditions, namely unstable input, and is easy to generate the dangerous condition of leakage current under the severe environment, and meanwhile, the ejector pin is high in manufacturing cost and difficult to assemble.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides the electromagnetic valve and the preparation method thereof, and the electromagnetic valve can be used in a severe environment, does not have the phenomenon of leakage current, improves the safety coefficient, and has low cost and convenient assembly.

In order to achieve the technical purpose, the invention adopts the following technical scheme: a solenoid valve comprises

The framework comprises a framework main body, wherein a coil is wound on the framework main body;

the two contact pins are arranged at the end part of the framework main body, the two contact pins are electrically connected with a diode, and the two contact pins, the diode and the coil are electrically connected;

keep off gluey ring, keep off gluey ring setting and be in the skeleton main part is equipped with the tip of two contact pins, just keep off gluey ring will two contact pins with the diode surrounds, wherein, keep off gluey ring with can pour into insulating medium into in the region that the skeleton main part encloses.

Further, the one end of two contact pins is the flexion, the flexion point embedding of flexion is in the skeleton main part, just the free tip of flexion passes through stretch out behind the through-hole on the skeleton main part the outside back of skeleton main part with the pin of diode is connected.

Further, the outer surface of the insulating medium is flush with the outer surface of the glue blocking ring; and the other ends of the two contact pins extend out of the insulating medium and are connected with a coil plastic package main body in an embedded mode.

Furthermore, a plunger is arranged in the framework main body along the axis direction of the plunger, an ejector pin is arranged on the plunger along the axis direction of the plunger, a front yoke is sleeved outside the part of the ejector pin exposed out of the plunger, one end face of the front yoke is in surface contact with the plunger, a groove is formed in the end face of the front yoke, a magnetic isolating sheet is arranged in the groove and attached to the end face of the groove, and the magnetic isolating sheet is sleeved on the ejector pin.

Further, the thimble is the cylinder structure.

Further, a plurality of notches and a plurality of protrusions are arranged on the magnetic isolation sheet.

Furthermore, a valve sleeve is embedded in the end portion, exposed out of the framework main body, of the front yoke, a valve core is arranged in the valve sleeve, one end face of the valve core is in contact with the ejector pin face, a spring is arranged at the other end portion of the valve core, and a plug is arranged outside the spring to limit the spring in the valve sleeve.

A method of making a solenoid valve, the method comprising the steps of:

the coil is wound on the framework main body, the two contact pins penetrate through the end parts of the framework main body, and the diode is connected to the end parts of the two contact pins; placing the glue blocking ring at the end part of the framework main body, enabling the glue blocking ring to surround the two contact pins and the diode, enabling a cavity to be formed between the glue blocking ring and the framework main body, injecting the insulating medium into the cavity, enabling the insulating medium to be flush with the outer end face of the framework main body, and sleeving the coil plastic package main body outside the framework main body to form a coil part;

will the thimble is installed the axis of plunger is downthehole, will magnetic shielding sheet cover is established on the thimble, will the plunger the thimble with magnetic shielding sheet places in the skeleton main part, the length of thimble does not surpass the skeleton main part will a pot head of preceding yoke is established outside the thimble and is arranged in inside the skeleton main part.

Further, the method also comprises the following substeps: will two contact pins the flexion wear to establish the skeleton main part in the through-hole, make the flexion stretches out the through-hole is outside, and stretches out outside the tip of flexion is equipped with a connection face, two pins of diode are connected respectively two connect on the face.

Further, when the insulating medium is injected into the cavity, the diode is completely wrapped in the insulating medium.

In conclusion, the invention achieves the following technical effects:

1. according to the invention, the diode is added in the coil to improve the stability of the coil, prevent the coil from being broken down by reverse voltage and pulse voltage in a severe environment and improve the safety performance;

2. according to the invention, glue is filled and sealed at a specific position of the coil, and the diode is protected in the injection molding process, so that the possibility of leakage current at the joint of the diode and the contact pin is greatly reduced, and meanwhile, the short circuit and open circuit conditions of the coil caused by the flowing of internal soldering tin are also prevented;

3. the invention changes the original split copper thimble into the combined mode of the non-magnetic material thimble and the copper magnetic separation sheet, thereby reducing the cost;

4. the oil path in the electromagnetic valve is changed, and the oil flowing mode adopted by the invention does not flow through the interior of the thimble, so that the strength of the thimble is improved, the manufacturing process difficulty is reduced, and the efficiency is improved;

5. the manufacturing process comprises the following steps: firstly, forming a framework, wherein the framework comprises a contact pin, a back yoke bush and a framework main body, then winding and connecting, connecting an enameled wire and the contact pin by adopting a welding process, then connecting a diode by adopting a welding process, assembling a glue blocking ring after connecting the diode to form a cavity, encapsulating glue, and then carrying out integral plastic package; after plastic packaging, pressing a guide sleeve, sleeving a sealing ring, pressing a shell and a shaft sleeve, and completing a coil part; the plunger and the thimble are assembled in a press-fitting manner, the magnetic shielding sheet is sleeved on the thimble, and the whole is placed into the coil; the shaft sleeve is pressed into the front yoke iron; the filter screen is sleeved in the valve sleeve, the valve core and the spring are placed in the valve sleeve, then the plug is pressed to form a whole, and the whole is pressed into the front yoke; and after the front yoke iron is sleeved with the sealing ring, the whole body is pressed into the shell, and finally the sealing ring is installed to finish the assembly of the electromagnetic valve.

Drawings

FIG. 1 is a general schematic view of a solenoid valve provided in an embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view of FIG. 1;

FIG. 3 is an exploded schematic view of FIG. 1;

FIG. 4 is an exploded view of part A of FIG. 3;

FIG. 5 is a connection relationship between the pin and the diode;

FIG. 6 illustrates the connection between the pin and the body of the cage;

fig. 7 is a schematic view showing a state where the pin is mounted on the bobbin main body;

FIG. 8 is a schematic view showing a state after the insulating medium is injected;

FIG. 9 is a schematic view of a skeletal body;

FIG. 10 is an exploded view of portion B of FIG. 3;

FIG. 11 is a schematic view of the connection between the thimble and the magnetic shielding sheet;

FIG. 12 is a schematic view showing the connection relationship between the thimble and the valve sleeve and the front yoke;

FIG. 13 is an exploded view of portion C of FIG. 3;

fig. 14 is a schematic view showing the relationship between the valve sleeve and the front yoke;

FIG. 15 is a schematic drawing of liquid oil strike;

FIG. 16 is a graph showing the comparison of the performance of the plunger material used in the present embodiment with that of the present plunger material;

fig. 17 is a graph showing the change in saturation magnetic flux density before and after heat treatment of the plunger material used in the present embodiment;

FIG. 18 shows the results of experiments on different film thicknesses of the plunger material used in this example.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present invention.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or may be connected through the use of two elements or the interaction of two elements. The specific meanings of the above terms in the present invention can be understood according to specific situations by those of ordinary skill in the art.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

Example (b):

as shown in fig. 1, a solenoid valve structurally includes:

as shown in fig. 2, the framework body 7 is provided with a coil 8 wound on the framework body 7;

the two contact pins 2 are arranged at the end part of the framework main body 7, the two contact pins 2 are electrically connected with the diode 3, and the two contact pins 2, the diode 3 and the coil 8 are electrically connected;

keep off and glue ring 4, keep off that glue ring 4 sets up the tip that is equipped with two contact pins 2 in skeleton main part 7, and keep off that glue ring 4 surrounds two contact pins 2 and diode 3, wherein, keep off and glue ring 4 and can inject insulating medium 5 into in the region that skeleton main part 7 encloses.

Specifically, as shown in fig. 3, an exploded view of fig. 1 is provided, as shown in fig. 4, an exploded view of a portion a of fig. 3 is provided, and as shown in fig. 4, the portion a is a coil portion of the solenoid valve, and includes: the lead frame comprises a frame main body 7, a guide sleeve 10 in the frame main body 7, a first shaft sleeve 12 in the frame main body 7, a coil 8 wound outside the frame main body 7, two pins 2 arranged at the end part of the frame main body 7, a diode 3 connected with the pins 2, a glue blocking ring 4 surrounding the pins 2 and the diode 3, an injected insulating medium 5, a back yoke sleeve 6 arranged on the frame main body 7, a coil plastic package main body 1 and a first sealing ring 11.

As shown in fig. 5 and 6, two through holes 71 are opened at the end of the frame body 7, the shape of the through holes 71 is similar to a right angle, and two ports of the through holes 71 are disposed on different side surfaces. As shown in fig. 5, one end of the two pins 2 is a bent portion 211, a bending point of the bent portion 211 is embedded in the frame body 7, and a free end of the bent portion 211 passes through the through hole 71 on the frame body 7 and then extends out of the frame body 7 to be connected with the pin 311 of the diode 3. Specifically, the bending portions 211 of the two pins 2 are inserted into the through holes 71 of the frame body 7, so that the bending portions 211 extend out of the through holes 71, a connection surface 222 is disposed at an end of the bending portion 211 extending out, and the two pins 311 of the diode 3 are respectively connected to the two connection surfaces 222. The connection between the pin 2 and the pin 311 can be any manner of soldering, wire connection, and other electrical connection, and is not described herein.

The through hole 71 is injection molded, and specifically, the pin 2 and the back yoke bush 6 are directly injected with plastic for injection molding after being positioned in a mold.

The invention adds the diode in the coil, improves the stability of the electromagnetic valve, can work normally under the condition of interference of an input source, reduces the failure rate, prolongs the service cycle and particularly prevents reverse high voltage and pulse voltage from puncturing the coil. In the prior art, reverse high voltage and pulse voltage may break down a coil to cause damage to the coil, and may cause damage to a switch contact in a circuit, which affects the service life of the contact and causes a circuit to be disconnected, and the arrangement of a diode can prevent the coil from being damaged and prevent the contact from being damaged.

The outer surface of the insulating medium 5 is flush with the outer surface of the glue blocking ring 4, short circuit can occur during injection molding under the condition of tin soldering, and open circuit caused by separation of welding points can also occur, the welding points are close, and the experimental standard is difficult to pass during thermal shock and cold experiments, so that the welding points are protected by adopting a glue form, and the glue adopts high-temperature-resistant insulating glue; the other ends of the two pins 2 extend out of the insulating medium 5 and are connected with the coil plastic package main body 1 in an embedded mode. The arrangement of the insulating medium 5 can prevent leakage current and improve safety performance.

After the contact pin 2 and the diode 3 are installed, the glue blocking ring 4 is placed on the framework main body 7, the position of the framework main body 7, which is connected with the contact pin, is surrounded by the contact pin and the diode by the glue blocking ring 4 to form a cavity, as shown in fig. 7, an insulating medium 5 such as glue and the like is injected into the cavity, as shown in fig. 8, the whole cavity is blocked by the glue, so that the glue blocking ring 4, the diode 3, the contact pin 2 and the framework main body 7 form a whole, the glue can play a role of insulation and electric leakage prevention, and the part electrically connected between the diode 3 and the contact pin 2 is tightly wrapped, so that the situation of short circuit or open circuit can not occur due to the fact that soldering tin melts and flows in the plastic packaging process. The bonding performance of the glue and the metal piece is superior to that of plastic, so that the conductor area of the coil exposed in the plastic is greatly reduced, and the high-voltage insulation effect of the coil is greatly improved after high-temperature and low-temperature impact and soaking in ionized water. For example, in a thermal shock experiment, a coil is soaked in ionized water after being stored at a high temperature, and high-voltage leakage current is measured after ten cycles, so that the design requirement needs to be met. Generally, after ten cycles, part of the coil exceeds the limit value, part of leakage current obviously rises, the coil filled with glue basically has no fluctuation of leakage current, and the leakage amount of the coil is one order of magnitude lower than that of other coils.

As shown in fig. 9, the bobbin body 7 is divided into two parts, one part is used for mounting a pin, the other part is used for mounting a coil, specifically, a certain gap 73 is left between the two parts, the two parts are fixedly connected by a plurality of connecting blocks 74, wherein a back yoke bush 6 is arranged in the gap 73, and a plurality of openings 61 are formed on the circumference of the back yoke bush 6 for clamping the plurality of connecting blocks 74. In addition, the coil plastic package main body 1 is provided with a gap identical to the gap 73 and a connecting portion identical to the connecting block 74, and the back yoke bush 6 is simultaneously fitted on the coil plastic package main body 1 and the bobbin main body 7, as shown in fig. 4, the dotted line in the figure indicates the position of the back yoke bush 6 on the coil plastic package main body 1 and the bobbin main body 7.

In addition, as shown in fig. 9, a ring groove 72 is formed in an outer circumference of one of the portions for winding the coil 8, the coil 8 is formed by an enameled wire, after the winding is completed, one end of the coil 8 is electrically connected to the pin 2, and a welding manner or a cable connection or any other manner capable of achieving electrical connection may be adopted, which is not described herein again.

As shown in fig. 2, the coil plastic package main body 1 is sleeved on the outside of the framework main body 7, the coil 8 is fixed between the coil plastic package main body 1 and the framework main body 7, and in addition, the contact pin 2 penetrates through the coil plastic package main body 1 to leave a joint for connecting to other components. The coil plastic package main body 1 is also provided with a shell 9 outside, and a first sealing ring 11 is arranged between the shell 9 and the coil plastic package main body 1 for sealing.

As shown in fig. 2, a plunger 13 is disposed inside the frame body 7, the plunger 13 is an important part of the solenoid valve, and a first bushing 12 is disposed between the plunger 13 and the frame body 7.

As shown in fig. 2, and with reference to fig. 3 and 10, fig. 10 is an exploded view of part B of fig. 3, and as shown in fig. 10, includes a front yoke 19, a fourth seal ring 17, a fifth seal ring 18, a second sleeve 16, an ejector pin 15, and a magnetism isolating sheet 14. As shown in fig. 2, a plunger 13 is disposed in the frame body 7 along the axial direction thereof, a thimble 15 is disposed in the plunger 13 along the axial direction thereof, wherein the plunger 13 and the thimble 15 are assembled by press-fitting, a front yoke 19 is sleeved outside a portion of the thimble 15 exposed out of the plunger 13, one end surface of the front yoke 19 is in surface contact with the plunger 13, a groove is formed in the end surface of the front yoke 19, a magnetism isolating sheet 14 (shown in fig. 10) is disposed in the groove, the magnetism isolating sheet 14 is attached to the end surface of the groove, the magnetism isolating sheet 14 is sleeved on the thimble 15, and the magnetism isolating sheet 14 can isolate a portion of magnetic force to prevent the electromagnetic force from being too large.

In the invention, the thimble 15 is in a cylindrical structure, and the thimble 15 is made of integral copper material for machining treatment in the prior art, so that the material cost and the manufacturing cost are high. The invention divides the original integral copper material into two parts, one part is the thimble 15, adopts a cylindrical structure, does not need to be provided with a hole, does not need to use the copper material, can be similar to stainless steel and other non-magnetic conductive materials with superior price, and the other part is the magnetic separation sheet 14 made of the copper material, has simple manufacture for a circular structure, consumes less materials and saves the cost of the parts. Meanwhile, the manufacturing cost is saved: the original thimble is changed into an integral cylindrical structure and then the strength of the thimble is increased, the existing thimble is made of copper materials and is softer, meanwhile, the hollow structure is arranged inside the thimble and used for oil flowing, the strength of the thimble is low, the part is interference press-fitted, the low strength of the part can cause difficulty in assembly, the consistency and the magnitude of interference of the part are high, the process control requirement is high, and the manufacturing cost is high.

The invention adds a diode to protect the circuit part, adds the magnetic shielding sheet and changes the structure of the thimble to increase the stability of the whole device.

As shown in fig. 11, the thimble 15 is a solid structure, and the magnetism-isolating sheet 14 is provided with a plurality of recesses 141 and a plurality of protrusions 142, wherein the plurality of recesses 141 and the plurality of protrusions 142 are provided on one side surface of the magnetism-isolating sheet 14, and the plurality of recesses 141 and the plurality of protrusions 142 are provided on the other opposite side surface, and the plurality of recesses 141 and the plurality of protrusions 142 are also provided on the other opposite side surface, and the protrusions 142 on one side surface correspond to the recesses 141 on the other side surface, and the concave-convex structure can enhance the strength and generate a gap to prevent the attachment to the surface of the yoke or the plunger.

As shown in fig. 12, the thimble 15 has an assembly structure: one end part of the thimble 15 is pressed in the plunger 13, the other end part extends into the front yoke 19, so that the front yoke 19 is in surface contact with the plunger 13, a groove 191 is formed in the end surface of the front yoke 19, the magnetism isolating sheet 14 is placed in the groove 191 and sleeved on the thimble 15, and the thimble 15 is of a solid structure and is not provided with any hole. The magnetism isolating sheet 14 is in a ring shape, and the outer diameter of the magnetism isolating sheet 14 is smaller than the diameter of the groove 191. In addition, the invention adopts a cylindrical thimble 15 and a magnetic separation sheet 14, and the invention correspondingly improves the oil-running mode: the front yoke 19 is provided with a first through hole 192 along the length direction of the whole solenoid valve, the end of the first through hole 192 is communicated with the groove 191, and the outer diameter of the magnetism isolating piece 14 is smaller than or equal to the distance from the first through hole 192 to the axis of the front yoke 19, that is, the magnetism isolating piece 14 does not block the first through hole 192, so that oil can conveniently flow through the first through hole 192. The plunger 13 is provided with a first channel 131 and a second channel 132 along the axial direction, wherein the first channel 131 and the second channel 132 can be butted with the first through hole 192 through the groove 191 respectively for communicating oil. In addition, the first channel 131 and the second channel 132 are radially symmetrical along the plunger 13.

Fig. 13 is an exploded view of part C of fig. 3, and includes a valve sleeve 20, a filter screen 24, a second sealing ring 21, a third sealing ring 25, a valve core 22, a spring 23, and a plug 26, where, in combination with fig. 3, the end of the front yoke 19 exposed out of the skeleton main body 7 is embedded with the valve sleeve 20, the valve core 22 is arranged in the valve sleeve 20, one end surface of the valve core 22 is in surface contact with the thimble 15, the other end of the valve core 22 is provided with the spring 23, and the spring 23 is externally provided with a plug 26 for limiting the spring 23 in the valve sleeve 20.

As shown in fig. 14, the front yoke 19 has a circular structure and the valve sleeve 20 has a circular structure, wherein a portion of the valve sleeve 20 extending into the front yoke 19 is provided with a gap 201, and the gap 201 allows the valve sleeve 20 to leave an inlet of oil when extending into the front yoke 19.

As shown in fig. 15, the thick black lines show the inflow and outflow directions of the oil, wherein the oil enters the front yoke 19 through the gap 201, flows to the first through hole 192 and the groove 192, and then flows to the first passage 131 and the second passage 132 through the groove 192. In the figure, the arrow indicates the inflow direction, and the outflow direction indicates the return from the original path. The direction of the oil liquid is arranged in the valve sleeve 20, the front yoke 19 and the plunger 13, and the oil liquid does not flow through the thimble in the prior technical scheme. The oil-feeding mode can generate oil pressure fluctuation without directly influencing the action of the plunger.

In addition, the plunger 13 uses a self-developed material and a self-developed heat treatment process in order to increase the metal magnetic flux Φ and the magnetic permeability μ. Among these, materials developed autonomously: and sintering the soft magnetic material by powder.

In this example, the basic components of the powder sintered soft magnetic material are as follows:

new material composition

C

Si

S

P

Mn

Cu

Ni

Content (%)

≤0.03

≤0.03

≤0.02

≤0.03

0.3

≤0.2

≤0.2

As shown in the above table, the main material is Fe, the remaining elements include Mn of 0.3%, C of 0.03% or less, Si of 0.03% or less, S of 0.02% or less, P of 0.03% or less, Cu of 0.2% or less, and Ni of 0.2% or less.

Fig. 16 is a schematic diagram showing the comparison of the performance parameters of the powder sintered soft magnetic material used in the present invention and other plunger materials available at present, and the following table is a data comparison of the commonly used plunger materials:

categories	Representative Components	Saturation magnetic flux density (T)	Coercive force (A/m)	Initial permeability	Maximum magnetic permeability	Specific resistance (. mu.cm)
							Company adopted materials	Fe	2.2	80	150	10000	10
Grain-oriented silicon steel sheet	Fe-3%Si	2	10	2250	70000	50
							Electromagnetic stainless steel	Fe-12~18Cr	1.2	80	-	-	60

In fig. 16, it can be seen that the powder sintered soft magnetic material used in the present invention has a small coercive force (i.e., coercive force) and a large saturation magnetic flux density, and is very suitable for use as a flux-carrying component of a solenoid valve.

In the table above, compared with silicon steel and other common alloys, the coercivity of the material completely meets the use requirements (in the design of the electromagnetic valve, the coercivity cannot be large), and after a specific forming process and a heat treatment process, the material has high saturation magnetic flux density and excellent magnetic conductivity, and is a material with balanced characteristics and excellent cost performance.

Aiming at the powder sintered soft magnetic material used by the invention, a heat treatment process is developed independently: after the high-temperature heat treatment in the vacuum furnace, the steel sheet was cooled while being kept warm, and fig. 17 shows that the saturation magnetic flux density (T) was remarkably increased before and after the heat treatment.

As shown in fig. 17, the saturation magnetic flux density of the self-developed heat-treated part is significantly higher than that of the part before heat treatment at a low external magnetic field strength, for example, at an external magnetic field strength of 200A/M, the saturation magnetic flux density after heat treatment is about 8.5 times that before heat treatment, and at a field strength of 300A/M, the saturation magnetic flux density of the heat-treated part reaches the maximum value, and then the difference therebetween gradually decreases as the field strength increases. Relatively speaking, the heat-treated part can meet the expected magnetic flux density requirement of the part at a lower external magnetic field strength, namely, the requirement on external conditions is lower, and the manufacturing difficulty and the manufacturing cost of other parts are reduced. Meanwhile, compared with the original general materials, the final states of the materials are consistent, but the new materials after heat treatment have better performance under the condition of lower external magnetic field intensity.

The plunger 13 adopts an independently developed electroplating process for improving the surface roughness and the wear resistance, and the plating layer comprises the following components: and (4) TBD.

As shown in fig. 18, the electromagnetic force (i.e., attraction force) of the parts with three plating thicknesses was tested, and the electromagnetic force of the part with the plating thickness of 15u was relatively large, but the force value difference of the return stroke was large, the hysteresis was large, and the stability was insufficient. The electromagnetic force is larger when the thickness of the plating layer is 35u, the magnetic hysteresis is small, and the performance of the part is good. When the thickness of the coating is 70u, the hysteresis is slightly smaller than that of the coating 35u, but the electromagnetic force is obviously reduced, and the performance influence is larger, so that the electromagnetic attraction is large and the hysteresis is small (the difference of the stroke round-trip contrast force value is small) when the thickness of the coating is 35 u.

And the surface can reach higher surface hardness after electroplating, and the wear resistance of parts is improved.

In addition, in order to achieve better dimensional stability and improve product stability (both lower friction coefficient and wear resistance are required and higher dimensional accuracy is required), the first shaft sleeve 12 and the second shaft sleeve 16 are processed by adopting a special process. The invention abandons the original heat treatment process, because the high-temperature heat treatment easily causes the deformation of the product and influences the dimensional stability. The invention adopts a special process, namely, low-temperature ion sulfurizing: after the metal parts are subjected to low-temperature ion sulfurization treatment, a layer of sulfide can be formed on the surface, and the sulfide layer with the thickness of 0.12 mm has good wear-resisting lubricating effect.

The performance parameters of the process are as follows: the sliding friction coefficient is reduced by 30%, the wear resistance is improved by 2-9 times, the friction temperature is reduced by 5-9 degrees, and the service life of parts is prolonged. Because the inner circle of the shaft sleeve, the thimble and the plunger are in sliding friction, and the outer circle of the shaft sleeve and other parts are assembled and fixed, the first shaft sleeve 12 and the second shaft sleeve 16 processed by the process work more smoothly, and the service life is longer.

A preparation method of a solenoid valve comprises the following steps:

a coil 8 is wound on the framework main body 7, the two pins 2 penetrate through the end part of the framework main body 7, and the diode 3 is connected to the end parts of the two pins 2; place fender glue ring 4 at skeleton main part 7 tip for keep off glue ring 4 and surround two contact pins 2 and diode 3, and, make and keep off and form a cavity between glue ring 4 and the skeleton main part 7, inject insulating medium 5 into this cavity, make insulating medium 5 and skeleton main part 7 outer terminal surface parallel and level, establish coil plastic envelope main part 1 at skeleton main part 7 overcoat, pressure equipment uide bushing 10 after the plastic envelope is accomplished sheathes in first sealing washer 11, shell 9 and first axle sleeve 12 impress, the coil part is accomplished.

The thimble 15 is assembled in an axial hole of the plunger 13 in a press-fitting manner, the magnetism isolating sheet 14 is sleeved on the thimble 15, the plunger 13, the thimble 15 and the magnetism isolating sheet 14 are placed in the framework main body 7, the length of the thimble 15 does not exceed the framework main body 7, and one end part of the front yoke 19 is sleeved outside the thimble 15 and is placed in the framework main body 7; the second shaft sleeve 16 is pressed into the front yoke 19, the filter screen 24 is sleeved into the valve sleeve 20, the valve core 22 and the spring 23 are placed into the valve sleeve 20, and then the plug 26 is pressed into the front yoke 19 to form a whole. After the front yoke 19 is sleeved with the fourth seal ring 17, the whole body is pressed into the shell 9, and finally, the fifth seal ring 18, the second seal ring 21 and the third seal ring 25 are installed, so that the electromagnetic valve assembly is completed.

The sub-step of "the two pins 2 are inserted into the end portions of the bobbin body 7, and the diode 3 is connected to the end portions of the two pins 2" further includes: the bending parts 211 of the two pins 2 are inserted into the through hole 71 of the frame body 7, so that the bending parts 211 extend out of the through hole 71, the end part of the bending part 211 extending out is provided with a connecting surface 222, and the two pins 311 of the diode 3 are respectively connected to the two connecting surfaces 222.

Wherein, when the insulating medium 5 is injected into the cavity, the diode 3 is completely wrapped in the insulating medium 5.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not intended to limit the present invention in any way, and all simple modifications, equivalent variations and modifications made to the above embodiments according to the technical spirit of the present invention are within the scope of the technical solution of the present invention.

Claims (9)

1. A solenoid valve, characterized by: comprises that

The coil winding device comprises a framework main body (7), wherein a coil (8) is wound on the framework main body (7);

the two contact pins (2) are arranged at the end part of the framework main body (7), the two contact pins (2) are electrically connected with a diode (3), and the two contact pins (2), the diode (3) and the coil (8) are electrically connected;

the glue blocking ring (4) is arranged at the end part of the framework main body (7) where the two contact pins (2) are arranged, the two contact pins (2) and the diode (3) are surrounded by the glue blocking ring (4), and an insulating medium (5) can be injected into a region surrounded by the glue blocking ring (4) and the framework main body (7);

a plunger (13) is arranged in the framework main body (7) along the axial direction of the framework main body, a thimble (15) is arranged in the plunger (13) along the axial direction of the plunger, a front yoke (19) is sleeved outside the part of the thimble (15) exposed out of the plunger (13), one end face of the front yoke (19) is in surface contact with the plunger (13), a groove is formed in the end face of the front yoke (19), a magnetism isolating sheet (14) is arranged in the groove, the magnetism isolating sheet (14) is attached to the end face of the groove, and the magnetism isolating sheet (14) is sleeved on the thimble (15);

a first through hole (192) is formed in the front yoke (19) along the length direction of the whole electromagnetic valve, the end part of the first through hole (192) is communicated with the groove, and the outer diameter of the magnetism isolating sheet (14) is smaller than or equal to the distance from the first through hole (192) to the axis of the front yoke (19);

the plunger (13) is provided with a first channel (131) and a second channel (132) along the axial direction, wherein the first channel (131) and the second channel (132) can be mutually butted with the first through hole 192 through the grooves respectively, and the first channel (131) and the second channel (132) are symmetrical along the radial direction of the plunger (13).

2. A solenoid valve according to claim 1, wherein: one end of the two contact pins (2) is a bending part (211), a bending point of the bending part (211) is embedded in the framework main body (7), and the free end part of the bending part (211) passes through the through hole (71) in the framework main body (7) and then extends out of the framework main body (7) and then is connected with the pin (311) of the diode (3).

3. A solenoid valve according to claim 2, wherein: the outer surface of the insulating medium (5) is flush with the outer surface of the glue blocking ring (4); the other ends of the two contact pins (2) extend out of the insulating medium (5) and then are connected with a coil plastic package main body (1) in an embedded mode.

4. A solenoid valve according to claim 3, characterised in that: the thimble (15) is of a cylindrical structure.

5. A solenoid valve according to claim 4 wherein: the magnetism isolating sheet (14) is provided with a plurality of notches (141) and a plurality of protrusions (142).

6. A solenoid valve according to claim 5 wherein: a valve sleeve (20) is embedded in the end portion, exposed out of the framework main body (7), of the front yoke (19), a valve core (22) is arranged in the valve sleeve (20), one end face of the valve core (22) is in surface contact with the ejector pin (15), a spring (23) is arranged at the other end portion of the valve core (22), and a plug (26) is arranged outside the spring (23) to limit the spring (23) in the valve sleeve (20).

7. A preparation method of an electromagnetic valve is characterized by comprising the following steps: a solenoid valve as claimed in claim 6, the method comprising the steps of:

the coil (8) is wound on the framework main body (7), the two pins (2) penetrate through the end part of the framework main body (7), and the diode (3) is connected to the end parts of the two pins (2); placing the glue blocking ring (4) at the end of the framework main body (7), enabling the glue blocking ring (4) to surround the two contact pins (2) and the diode (3), enabling a cavity to be formed between the glue blocking ring (4) and the framework main body (7), injecting the insulating medium (5) into the cavity, enabling the insulating medium (5) to be flush with the outer end face of the framework main body (7), and sleeving the coil plastic package main body (1) outside the framework main body (7) to form a coil part;

will thimble (15) is installed downthehole, will magnetic shield piece (14) cover is established on thimble (15), will plunger (13) thimble (15) with magnetic shield piece (14) are placed in skeleton main part (7), the length of thimble (15) does not surpass skeleton main part (7), will a pot head of preceding yoke (19) is established outside thimble (15) and is arranged in inside skeleton main part (7).

8. The method for manufacturing a solenoid valve according to claim 7, wherein: further comprising the substeps of: will two contact pins (2) flexion (211) wear to establish skeleton main part (7) in through-hole (71), make flexion (211) stretch out through-hole (71) outside, and stretch out outside the tip of flexion (211) is equipped with a connection face (222), two pins (311) of diode (3) are connected respectively two connect on face (222).

9. The method for manufacturing a solenoid valve according to claim 8, wherein: when the insulating medium (5) is injected into the cavity, the diode (3) is completely wrapped in the insulating medium (5).

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