JP7479059B2 - Pilot Operated Solenoid Valve - Google Patents

Description

The present invention relates to a pilot-operated solenoid valve.

Conventionally, pilot-type solenoid valves have been known that open and close the fluid flow path by driving a pilot valve element with an electromagnetic actuator and opening and closing the main valve element in response to the pilot valve element.

Patent Document 1 discloses a pilot-type solenoid valve in which, when the coil is energized, the pilot valve body is pulled up together with the plunger, opening the pilot valve seat, and the pressure on the top surface of the valve body is balanced with the pressure on the secondary port side through the leakage passage, resulting in the valve body being pushed up from below by the pressure in the valve chamber and the force of the valve spring, opening the valve seat.

Japanese Patent Application Laid-Open No. 02-283985

In this type of pilot-operated solenoid valve, an annular stopper is provided on the valve body to limit the rise of the valve disc, preventing the pilot valve seat from coming into contact with the pilot valve disc again and causing unstable operation if the valve disc rises too far.

The conventional technology section of Patent Document 1 discloses that a jig or similar tool is used to push an annular stopper into the valve body, and while maintaining this state, it is secured in place by welding, brazing, or other methods.

However, it is difficult to fix a stopper inserted inside the valve body to the valve body by welding from the outside, and the conventional technology section of Patent Document 1 does not disclose how to weld the stopper. On the other hand, brazing a stopper inserted inside the valve body to the valve body gives rise to the following problems.

First, the brazing material must penetrate from the outside of the valve body to the stopper, which lengthens the brazing distance, taking more time and increasing the cost of materials. Furthermore, when brazing, the valve body with the stopper and other parts attached must be placed in an electric furnace and heated to a high temperature of, for example, around 800°C to melt the brazing material, but materials that can withstand such high temperatures must be used, limiting the freedom of component selection. Furthermore, post-brazing processing such as washing with hot water and buffing is required, which increases the number of manufacturing steps.

To address this issue, Patent Document 1 discloses a technique in which a C-shaped stopper is pushed into the valve body with a tool, elastically deforming it to reduce its diameter, and then expanding it by returning it to a groove formed on the inner circumference at the rear of the valve body, and fitting it into the groove for installation.

However, according to the technology of Patent Document 1, when the stopper is pushed along the inner circumference of the valve body, the open end of the stopper can rub against the inner circumference and damage it. Since the inner circumference of the cylindrical valve body is the surface against which the plunger slides, if the inner circumference is damaged, the plunger may get caught on the scratch as it moves back and forth, which can lead to problems such as sticking. In addition, the groove that engages the stopper needs to be formed inside the valve body at a relatively distance from the end of the cylindrical part, making groove processing difficult.

The present invention aims to provide a pilot-operated solenoid valve that is highly reliable while keeping manufacturing costs low.

The pilot type solenoid valve according to the present invention comprises:
a valve body including a valve chamber communicating with an inlet opening and an outlet opening;
a main valve body that is movable relative to the valve body and that seats on or moves away from a valve seat in the valve chamber;
a pilot valve body driven by a plunger of an actuator;
a guide pipe in which the plunger is slidable;
and an annular stopper that limits the movement of the main valve body.
an outer periphery of the stopper is fitted into an inner periphery of the valve body and an inner periphery of the guide pipe,
The valve body, the guide pipe, and the stopper are fixed together by welding.

The present invention provides a pilot-operated solenoid valve that is highly reliable while keeping manufacturing costs down.

FIG. 1 is a vertical cross-sectional view showing a pilot type solenoid valve according to a first embodiment. FIG. 2 is a vertical cross-sectional view showing a state in which the pilot type solenoid valve of this embodiment is assembled. FIG. 3 is a vertical sectional view showing a pilot type solenoid valve according to the second embodiment. FIG. 4 is a vertical sectional view showing a pilot type solenoid valve according to the third embodiment. FIG. 5 is a vertical sectional view showing a pilot type solenoid valve according to the fourth embodiment. FIG. 6(a) is a vertical cross-sectional view of the stopper of this embodiment, and FIG. 6(b) is a bottom view of the stopper. FIG. 7 is a vertical sectional view showing a pilot type solenoid valve according to the fifth embodiment. FIG. 8 is a vertical sectional view showing a pilot type solenoid valve according to the sixth embodiment.

Below, an embodiment of a pilot-operated solenoid valve according to the present invention will be described with reference to the drawings. In this specification, the direction from the pilot valve body toward the suction element is referred to as "upward," and the opposite direction is referred to as "downward."

[First embodiment]
FIG. 1 is a vertical cross-sectional view showing a pilot type solenoid valve 1 according to a first embodiment, and shows the valve in a closed state.
The pilot type solenoid valve 1 shown in the figure is used in, for example, a refrigeration cycle of a chiller or the like, and is used in combination with an electromagnetic actuator 20 .

The pilot-operated solenoid valve 1 comprises a valve body 10, a main valve body 15 slidably inserted into the valve body 10, a pilot valve body 35 that is movable relative to the main valve body 15 and driven by a plunger 30 of an electromagnetic actuator 20, and a guide pipe 32 that guides the plunger 30. The axis of the pilot-operated solenoid valve 1 is designated as L.

The valve body 10, made of metal (e.g., stainless steel), has a valve chamber CA inside, and has a bottomed cylindrical shape with a side wall 12 and a bottom wall 13 connected to each other. A hollow inner cylindrical portion 13b is connected to the central upper surface of the bottom wall 13, protruding upward coaxially with the side wall 12, and an outlet opening 13a is formed inside the hollow inner cylindrical portion 13b, which connects the outside of the valve body 10 to the valve chamber CA. The area near the upper end of the inner cylindrical portion 13b is thinner than the lower side, and the upper end of the inner cylindrical portion 13b forms the valve seat 14. An outflow pipe OT is connected and fixed to the bottom wall 13 by brazing or the like so as to communicate with the outlet opening 13a.

The side wall 12 of the valve body 10 is made up of a thick portion 12a on the bottom wall 13 side and a thin portion 12b that is thinner than the thick portion 12a but has the same inner diameter. A step 12c is formed on the inner circumference near the upper end of the thin portion 12b.

An inlet opening 12d is formed in the thick-walled portion 12a, and the inlet pipe IT is connected and fixed to the thick-walled portion 12a by brazing or the like so as to communicate with the inlet opening 12d. The axis of the inlet pipe IT is O.

The main valve body 15, which is made of metal (e.g., stainless steel) and has a generally cylindrical shape, is made up of a large diameter section 15a, a small diameter section 15b that is smaller in diameter than the large diameter section 15a, and a medium diameter section 15c that is smaller in diameter than the large diameter section 15a but larger in diameter than the small diameter section 15b, all connected coaxially.

The lower surface of the medium diameter portion 15c is in contact with an annular body (valve body) 16 made of resin (e.g., PTFE). A crimped cylindrical portion 15d protruding downward from the center of the lower surface of the medium diameter portion 15c penetrates the inside of the annular body 16, and the annular body 16 is held in the main valve body 15 by crimping the lower end of the crimped cylindrical portion 15d so that it expands in diameter radially outward in a flange shape. The lower surface of the annular body 16 faces the inner cylindrical portion 13b of the valve body 10 radially outward of the crimped cylindrical portion 15d. In the closed valve state of FIG. 1, the annular body 16 of the main valve body 15 sits on the valve seat 14 to close the outlet opening 13a. The annular body 16 is made of resin, which is more flexible than metal, so it has high sealing performance when seated on the valve seat 14, and the valve seat 14 is less likely to wear out even when used for a long period of time. It is preferable that the outer diameter of the annular body 16 is equal to or smaller than the outer diameter of the medium diameter portion 15c.

A communication hole 15e is formed in the center of the main valve body 15, penetrating vertically and coaxially with the axis L. A reduced diameter hole (pilot port) 15f, which is smaller in diameter than the remaining portions, is formed near the upper end of the communication hole 15e.

When the main valve body 15 is assembled in the valve chamber CA of the valve body 10, the large diameter portion 15a slidably fits against the inner circumference of the side wall 12 above the inlet opening 12d. At this time, a small gap is formed between the side wall 12 and the large diameter portion 15a, allowing the refrigerant to pass through.

A coil spring 17 is disposed in the valve chamber CA between the main valve element 15 and the valve body 10. The lower end of the coil spring 17 abuts against the upper surface of the bottom wall 13 between the thick-walled portion 12a and the inner cylindrical portion 13b of the valve body 10, and the upper end of the coil spring 17 abuts against the lower surface of the large-diameter portion 15a, and the coil spring 17 urges the main valve element 15 upward relative to the valve body 10 along the axis L.

In FIG. 1, the electromagnetic actuator 20 has a resin-molded coil unit 22 for energizing the coil unit 22, a housing 21 arranged to cover the coil unit 22, a bottomed cylindrical or columnar attractor 25 arranged on the upper inner periphery of the coil unit 22 and fixed to the housing 21 by bolts 28, and a plunger 30 arranged with its upper end facing the lower end of the attractor 25.

A retaining hole 31 is provided at the bottom end of the plunger 30. A pilot valve body 35 consisting of a ball is housed in this retaining hole 31. The pilot valve body 35 is fixed by crimping a rivet portion 31a that protrudes cylindrically from the bottom end of the plunger 30 inward, with a portion of its underside exposed.

As the plunger 30 moves downward, the pilot valve body 35 moves in the valve closing direction, and as the plunger 30 moves upward, the pilot valve body 35 moves in the valve opening direction. A back pressure chamber CD is formed between the plunger 30 and the main valve body 15.

At the top end of the plunger 30, there is a vertical hole (spring chamber) 30a into which the valve-closing spring 26, which is a coil spring, is inserted and locked, and a horizontal hole (pressure equalizing hole) 30b that connects the bottom of the vertical hole 30a to the outside of the plunger 30.

A thin-walled guide pipe 32 is disposed between the coil unit 22 and the attractor 25. The plunger 30 is slidably inserted into the guide pipe 32. The upper end 32a of the guide pipe 32 is fixed to the outer circumferential step of the attractor 25 by TIG welding or the like. The lower end 32b of the guide pipe 32 protrudes from the lower end of the housing 21 and is welded to the thin-walled portion 12b of the valve body 10 as described below. It is preferable that the thickness and inner diameter of the guide pipe 32 are equal to the thickness and inner diameter of the upper end of the thin-walled portion 12b.

A metal (e.g., stainless steel) annular stopper 18 is tightly fitted into the step 12c of the valve body 10. The stopper 18 is arranged to protrude upward from the upper end of the thin-walled portion 12b. The axial length of the stopper 18 is approximately twice the length from the upper end of the thin-walled portion 12b to the step 12c, but is not limited to this.

(Assembly of pilot operated solenoid valve)
2 is a vertical cross-sectional view showing the assembled state of the pilot type solenoid valve 1 of this embodiment, and shows the state before the electromagnetic actuator 20 is assembled. The coil spring 17 and the main valve body 15 are assembled to the valve body 10 to which the inlet pipe IT and the outlet pipe OT are connected in advance. At this time, the elastic force of the coil spring 17 urges the main valve body 15 upward relative to the valve body 10, and the annular body 16 is separated from the valve seat 14.

Then, the stopper 18 is brought closer from the thin-walled portion 12b side, and the outer periphery of the stopper 18 is fitted into the inner periphery of the thin-walled portion 12b while the end of the stopper 18 is abutted against the step portion 12c. The stopper 18 is held by the step portion 12c with its upper end protruding upward from the thin-walled portion 12b. At this time, the lower side of the stopper 18 is fitted into the thin-walled portion 12b and the upper side of the stopper 18 is fitted into the guide pipe 32, so that the axes of the guide pipe 32 and the valve body 10 can be aligned.

While holding the stopper 18 and the guide pipe 32 with a jig to maintain this state, the thin-walled portion 12b and the guide pipe 32 are TIG-welded. The lower end of the guide pipe 32 and the upper end of the thin-walled portion 12b, which are in contact with each other, are welded (for example, by TIG welding or laser welding) from the outer periphery over the entire circumferential direction (at the position where the lower end of the guide pipe 32 and the upper end of the thin-walled portion 12b are in contact), forming a welded portion W (FIG. 1) over the entire circumference, and connecting (fixing) the guide pipe 32 and the thin-walled portion 12b . At this time, a part of the stopper 18 near the lower end of the guide pipe 32 and the upper end of the thin-walled portion 12b is also melted by the transfer of welding heat, and then solidified, and fixed to the guide pipe 32 and the thin-walled portion 12b , so that the stopper 18 does not slide relative to the step portion 12c even when vibration is applied.

Then, the plunger 30 holding the pilot valve body 35, the valve-closing spring 26 (coil spring 26), and the attractor 25 are assembled into the guide pipe 32, and the guide pipe 32 and the attractor 25 are TIG-welded. At this time, the pilot valve body 35 is positioned radially inside the stopper 18 (see FIG. 1). Furthermore, the upper periphery of the guide pipe 32 is fitted into the inside of the housing 21 equipped with the coil unit 22, and the housing 21 is fixed to the attractor 25 using the bolts 28.

The stopper 18 may be assembled by pressing it into the thin-walled portion 12b. In this case, the frictional force acting between the stopper 18 and the inner circumference of the thin-walled portion 12b exceeds the elastic force of the coil spring 17, so even if the elastic force of the coil spring 17 is transmitted to the stopper 18 via the main valve body 15, the stopper 18 will not disengage from the thin-walled portion 12b, and therefore the main valve body 15 is prevented from coming out of the valve body 10. This eliminates the need to prevent the main valve body 15 from coming out using a jig, for example, and saves the effort of assembly and jig management.

After the stopper 18 is press-fitted, the guide pipe 32 is brought close to the valve body 10 from above, the inner circumference of the guide pipe 32 is fitted onto the outer circumference of the stopper 18 protruding from the thin-walled portion 12b, and the guide pipe 32 is lowered using the stopper 18 as a guide until its lower end 32b abuts against the upper end of the thin-walled portion 12b. This aligns the axes of the guide pipe 32 and the valve body 10. The guide pipe 32 and the thin-walled portion 12b are then connected by welding, and the stopper 18 is fixed (attached) to the guide pipe 32. The assembly process will not be described below.

According to this embodiment, the butted ends of the guide pipe 32 and the valve body 10 are circumferentially welded, so the weld length is short and assembly time can be shortened. In addition, since only the butted ends of the guide pipe 32 and the valve body 10 are heated by the welding heat, the main valve body 15 is hardly heated and the annular body 16 made of resin is not denatured, which increases the freedom of material selection. Furthermore, post-processing is easier than with brazing, and the assembly man-hours for the pilot-operated solenoid valve 1 can be reduced.

(Operation of pilot operated solenoid valve)
The operation of the pilot type solenoid valve 1 will be described. Here, the pressure in the inlet pipe IT is assumed to be higher than the pressure in the outlet pipe OT. In the valve-closed state shown in Fig. 1, the pilot valve body 35, which is urged downward together with the plunger 30 by the elastic force of the valve-closing spring 26, closes the upper end of the reduced diameter hole 15f of the communication hole 15e. As a result, a pressure difference occurs between the pressure in the back pressure chamber CD and the pressure at the outlet opening 13a across the main valve body 15, and the main valve body 15 is pushed downward against the elastic force of the coil spring 17, and the annular body 16 is seated on the valve seat 14.

In the closed valve state, the fluid introduced into the valve chamber CA from the inlet pipe IT through the inlet opening 12d passes between the large diameter portion 15a of the main valve body 15 and the side wall 12 of the valve body 10 and is introduced into the back pressure chamber CD. As a result, the pressure difference between the pressure in the back pressure chamber CD and the pressure at the outlet opening 13a is maintained, so that the annular body 16 is maintained seated on the valve seat 14. The fluid introduced into the back pressure chamber CD is also guided to the gap space CE formed between the suction element 25 and the plunger 30 through the gap between the outer peripheral surface of the plunger 30 and the inner peripheral surface of the guide pipe 32, the horizontal hole 30b, and the vertical hole 30a, as shown in FIG. 1.

When the coil unit 22 is energized from a power source (not shown) in the pilot solenoid valve 1 in the closed state, the plunger 30 is attracted to the attractor 25, causing the pilot valve body 35 to rise in the valve opening direction. At this time, the internal pressures of the back pressure chamber CD and the clearance space CE are equal, so the operation of the plunger 30 is not impeded.

When the reduced diameter hole 15f of the main valve body 15 is opened by the rise of the pilot valve body 35, the fluid in the back pressure chamber CD flows out to the outlet opening 13a through the communication hole 15e (including the pilot port). This reduces the pressure in the back pressure chamber CD, reducing the pressure difference between the pressure in the back pressure chamber CD and the pressure at the outlet opening 13a, and the main valve body 15 rises due to the pressure difference with the valve chamber CA. The upper end of the raised main valve body 15 abuts against the lower end of the stopper 18 and is held stably in a biased state due to the pressure difference.

When the coil unit 22 is de-energized, the elastic force of the valve-closing spring 26 causes the pilot valve body 35 to descend together with the plunger 30, closing the upper end of the reduced diameter hole 15f of the communication hole 15e. Then, the pressure in the back pressure chamber CD rises, forcing the main valve body 15 downward against the elastic force of the coil spring 17, and the annular body 16 seats on the valve seat 14.

[Second embodiment]
3 is a vertical cross-sectional view showing a pilot type solenoid valve 1A according to the second embodiment, in a valve closed state. In the second embodiment, the electromagnetic actuator 20 is the same as that in the first embodiment, and therefore the same reference numerals are used to denote the same components as those in the first embodiment, and a duplicated description will be omitted.

In this embodiment, the shapes of the side wall 12A, main valve body 15A, and stopper 18A of the valve body 10A are different. The rest of the configuration is the same as in the first embodiment, so the same reference numerals are used and repeated explanations are omitted.

The main valve body 15A, which is made of metal (e.g., stainless steel) and has a generally cylindrical shape, is composed of a sliding portion 15Ag, a large diameter portion 15Aa, a small diameter portion 15Ab, and a medium diameter portion 15Ac, which are arranged coaxially in this order. The outer diameter of the sliding portion 15Ag is smaller than the outer diameter of the large diameter portion 15Aa. As in the above-described embodiment, an annular body 16 is attached to the underside of the main valve body 15A by crimping.

The stopper 18A is made of metal (e.g., stainless steel). The axial length of the stopper 18A protruding from the upper end of the thin-walled portion 12Ab is preferably about three times the length from the upper end of the thin-walled portion 12Ab to the step portion 12Ac. As in the above-mentioned embodiment, the stopper 18A is fitted to the inner circumference of the thin-walled portion 12Ab of the valve body 10A and attached to the valve body 10A so that its end abuts against the step portion 12Ac, and has the function of guiding the guide pipe 32 during assembly. The lower end of the guide pipe 32 and the thin-walled portion 12Ab are welded to form a welded portion W, and the stopper 18A is fixed at the same time. However, since the heating of the stopper 18A is limited to a part of the outer circumference, the cylindricity of the inner circumference of the stopper 18A is ensured.

In this embodiment, the gap between the outer diameter of the sliding part 15Ag of the main valve body 15A and the inner diameter of the stopper 18A is smaller than the gap between the outer diameter of the large diameter part 15Aa of the main valve body 15A and the inner diameter of the side wall 12A. Therefore, when the main valve body 15A moves in the axial direction, sliding occurs between the outer surface of the sliding part 15Ag and the inner surface of the stopper 18A. When the valve is opened, the step between the large diameter part 15Aa of the raised main valve body 15A and the sliding part 15Ag abuts against the lower surface of the stopper 18A. The fluid introduced into the valve chamber CA from the inlet pipe IT through the inlet opening 12Ad passes between the large diameter part 15Aa of the main valve body 15A and the side wall 12A, and between the sliding part 15Ag and the stopper 18A, and is introduced into the back pressure chamber CD.

In the first embodiment described above, since the main valve body 15 slides against the side wall 12, processing is required to impart a surface roughness suitable for sliding over the entire range in which the large diameter portion 15a of the side wall 12 slides. In contrast, according to this embodiment, since sliding occurs between the outer peripheral surface of the sliding portion 15Ag and the inner peripheral surface of the stopper 18A, it is only necessary to perform the necessary processing on the limited range of the inner peripheral surface of the stopper 18A, which allows for cost reduction.

[Third embodiment]
4 is a vertical cross-sectional view showing a pilot type solenoid valve 1B of the third embodiment, showing a state in which the valve is closed. In the third embodiment, the electromagnetic actuator 20 is the same as that in the first embodiment, so the same reference numerals are used and a duplicated description is omitted.

In this embodiment, the configuration of the side wall 12B, main valve body 15B, and coil spring 17B of the valve body 10B is different. The other configurations are the same as in the first embodiment, so the same reference numerals are used and redundant explanations are omitted.

The side wall 12B is formed by connecting a thick portion 12Ba on the bottom wall 13 side to a thin portion 12Bb. An annular protruding portion (locking portion) 12Bh is formed on the inner circumference of the side wall 12B, above the inner end of the inlet opening 12Bd.

The main valve body 15B is made of metal (e.g., stainless steel) and is generally cylindrical. It is made up of a large diameter section 15Ba that can slide along the inner circumference of the side wall 12B, a small diameter section 15Bb that is longer in the axial direction than the large diameter section, and a medium diameter section 15Bc that are arranged coaxially in this order. As in the above-described embodiment, an annular body 16 is attached to the underside of the main valve body 15B by caulking.

A coil spring (also called a spring member) 17B is disposed between the main valve body 15B and the valve body 10B in the valve chamber CA. The lower end of the coil spring 17B abuts against the upper surface of the annular protrusion 12Bh of the valve body 10B, and the upper end of the coil spring 17B abuts against the lower surface of the large diameter portion 15Ba, and the coil spring 17B urges the main valve body 15B upward relative to the valve body 10B along the axis L.

According to this embodiment, the coil spring 17B is positioned above the inner end of the inlet opening 12Bd, so when the refrigerant flows from the inlet pipe IT into the valve chamber CA, it does not interfere with the coil spring 17B and cause vibration, and therefore abnormal noise caused by vibration can be suppressed. In addition, the medium diameter portion 15Bc and the annular body 16 of the main valve body 15B are shifted in the axial direction from the coil spring 17B, so there is no interference between them, and the diameter of the valve body 10B can be reduced and the axial movement of the main valve body 15B can be performed smoothly.

[Fourth embodiment]
5 is a vertical cross-sectional view showing a pilot type solenoid valve 1C according to the fourth embodiment, showing the state in which the valve is closed. In the fourth embodiment, the electromagnetic actuator 20 is the same as that in the first embodiment, and therefore the same reference numerals are used to denote the same components as those in the first embodiment, and redundant description will be omitted.

In this embodiment, the configuration of the stopper 18C is different. The rest of the configuration is the same as in the first embodiment, so the same reference numerals are used and duplicate explanations are omitted.

Figure 6(a) is a vertical cross-sectional view of stopper 18C, and Figure 6(b) is a bottom view of stopper 18C. Stopper 18C is formed by press-molding a metal (e.g., stainless steel) plate, and has a cylindrical peripheral wall 18Ca and an annular wall 18Cb connected to the lower end of peripheral wall 18Ca. Therefore, stopper 18C of this embodiment can be manufactured at a relatively low cost.

The lower surface of the annular wall 18Cb (the surface against which the main valve body 15 abuts) is formed with one or more (four in this example) radially extending grooves 18Cc with triangular cross sections at equal intervals in the circumferential direction, which are formed by a press mold (not shown). The cross-sectional shape and number of the grooves 18Cc are not limited.

Referring to FIG. 5, the stopper 18C is attached to the valve body 10 such that the outer periphery of the peripheral wall 18Ca fits into the inner periphery of the thin-walled portion 12b of the valve body 10 and the annular wall 18Cb abuts against the step portion 12c. A portion of the peripheral wall 18Ca protrudes from the upper end of the thin-walled portion 12b and serves to guide the guide pipe 32 during assembly. The lower end of the guide pipe 32 and the thin-walled portion 12b are welded to form a welded portion W, at which time the stopper 18C is also fixed.

When the valve is opened, the upper end of the main valve body 15, which has risen, comes into contact with the lower surface of the annular wall 18Cb of the stopper 18C. If the lower surface of the annular wall 18Cb were flat, the upper end of the main valve body 15 would not be easily separated from the lower surface of the annular wall 18Cb when the upper end of the main valve body 15 comes into contact with the lower surface of the annular wall 18Cb, and this could impede the valve closing operation. In contrast, according to this embodiment, a groove 18Cc is formed in the annular wall 18Cb to allow the refrigerant to flow in and out between the upper end of the main valve body 15 and the lower surface of the annular wall 18Cb, so that the upper end of the main valve body 15 and the annular wall 18Cb can be easily separated from each other. Note that instead of providing the groove 18Cc in the annular wall 18Cb, a similar groove may be provided on the upper end surface of the main valve body 15.

[Fifth embodiment]
7 is a vertical cross-sectional view showing a pilot type solenoid valve 1D of the fifth embodiment, showing a state in which the valve is closed. In the fifth embodiment, the electromagnetic actuator 20 is the same as that in the first embodiment, so the same reference numerals are used and a duplicated description will be omitted.

In this embodiment, the configuration of the main valve body 15D and the stopper 18D is different. The rest of the configuration is the same as in the first embodiment, so the same reference numerals are used and repeated explanations are omitted.

The main valve body 15D, which is made of metal (e.g., stainless steel) and has a generally cylindrical shape, is made up of a large diameter section 15Da, a small diameter section 15Db, and a medium diameter section 15Dc, which are arranged coaxially in this order. The upper part of the large diameter section 15Da is a small large diameter section 15Df with a reduced diameter to avoid interference with the stopper 18D. As in the above-mentioned embodiment, the annular body 16 is attached to the underside of the main valve body 15D by crimping.

The stopper 18D is formed by pressing a metal (e.g., stainless steel) plate material, and has a cylindrical peripheral wall 18Da and an annular wall 18Db connected to the upper end of the peripheral wall 18Da. Therefore, the stopper 18D of this embodiment can be manufactured at a relatively low cost. The inner diameter of the peripheral wall 18Da is preferably equal to the inner diameter of the side wall 12 on which the main valve body 15D slides.

The lower surface of the annular wall 18Db (the surface against which the main valve body 15D abuts) is formed with one or more (four here, although not all are shown) radially extending grooves 18Dc with triangular cross sections at equal intervals in the circumferential direction, which are formed by a press molding die (not shown). The cross-sectional shape and number of the grooves 18Dc are not limited.

The stopper 18D is attached to the valve body 10 so that the outer periphery of the peripheral wall 18Da fits into the inner periphery of the thin-walled portion 12b of the valve body 10 and the lower end of the peripheral wall 18Da abuts against the step portion 12c. As a result, a part of the peripheral wall 18Da protrudes from the upper end of the thin-walled portion 12b, and has the function of guiding the guide pipe 32 during assembly. The lower end of the guide pipe 32 and the thin-walled portion 12b are welded to form the welded portion W, at which time the stopper 18D is also fixed.

When the valve is opened, the upper end of the main valve body 15 rises and comes into contact with the lower surface of the annular wall 18Db of the stopper 18D protruding from the upper end of the thin-walled portion 12b. According to this embodiment, the annular wall 18Db is shifted upward from the upper end of the thin-walled portion 12b, so that the overall length of the valve body 10 along the axis L can be shortened.

Sixth Embodiment
8 is a vertical cross-sectional view showing a pilot type solenoid valve 1E according to the sixth embodiment, showing the state in which the valve is closed. In the sixth embodiment, the electromagnetic actuator 20 is the same as that in the first embodiment, so the same reference numerals are used and the repeated description will be omitted.

In this embodiment, the configurations of the main valve body 15E, the stopper 18E, and the coil spring 17E are different. The rest of the configuration is the same as in the first embodiment, so the same reference numerals are used and redundant explanations are omitted.

The main valve body 15E, which is made of metal (e.g., stainless steel) and has a generally cylindrical shape, is made up of a large diameter section 15Ea, a small diameter section 15Eb, and a medium diameter section 15Ec, which are arranged coaxially in this order. The upper part of the large diameter section 15Ea is a small large diameter section 15Ef with a reduced diameter to avoid interference with the stopper 18E. A flange section 15Eg that protrudes radially outward is formed at the upper end of the small large diameter section 15Ef. As in the above-mentioned embodiment, an annular body 16 is attached to the underside of the main valve body 15E by crimping.

The stopper 18E is formed by pressing a metal (e.g., stainless steel) plate material, and has a cylindrical peripheral wall 18Ea and an annular wall 18Eb connected to the lower end of the peripheral wall 18Ea. The stopper 18E of this embodiment has a shape similar to that of the stopper 18C of the fourth embodiment, and can be manufactured at a relatively low cost. The inner diameter of the annular wall 18Eb is larger than the outer diameter of the small-sized large-diameter portion 15Ef.

On the underside of the annular wall 18Eb, one or more (four here, though not all are shown) radially extending grooves 18Ec with triangular cross sections are formed at equal intervals in the circumferential direction by a press molding die (not shown). The cross-sectional shape and number of the grooves 18Ec are not limited.

The stopper 18E is attached to the valve body 10 so that the outer periphery of the peripheral wall 18Ea fits into the inner periphery of the thin-walled portion 12b of the valve body 10 and the lower end of the peripheral wall 18Ea abuts against the step portion 12c. As a result, a part of the peripheral wall 18Ea protrudes from the upper end of the thin-walled portion 12b and has the function of guiding the guide pipe 32 during assembly. The lower end of the guide pipe 32 and the thin-walled portion 12b are welded to form the welded portion W, at which time the stopper 18E is also fixed.

A coil spring 17E is disposed between the main valve body 15E and the stopper 18E in the valve chamber CA. The coil spring 17E is preferably a tapered coil spring with a smaller diameter at the upper end than at the lower end. The lower end of the coil spring 17E abuts against the upper surface of the annular wall 18Eb of the stopper 18E, and the upper end of the coil spring 17E abuts against the lower surface of the flange portion 15Eg of the main valve body 15E, and the coil spring 17E biases the main valve body 15E upward relative to the valve body 10 along the axis L.

In the assembled state, the large diameter portion 15Ea below the small large diameter portion 15Ef of the main valve body 15E is below the annular wall 18Eb of the stopper 18E, and the flange portion 15Eg is above the annular wall 18Eb. Therefore, when the valve is opened, the step between the large diameter portion 15Ea and the small large diameter portion 15Ef of the raised main valve body 15 abuts against the underside of the annular wall 18Eb of the stopper 18E. According to this embodiment, the annular wall 18Eb is shifted upward from the upper end of the thin portion 12b, so that the overall length of the valve body 10 along the axis L can be shortened.

According to this embodiment, the coil spring 17E is positioned above the inner end of the inlet opening 12d, so when the refrigerant flows from the inlet pipe IT into the valve chamber CA, it does not interfere with the coil spring 17E and cause vibration, and therefore abnormal noise caused by vibration can be suppressed. In addition, the medium diameter section 15Ec of the main valve body 15E and the annular body 16 are positioned shifted in the axial direction from the coil spring 17E, so there is no interference between them, and the diameter of the valve body 10 can be reduced and the axial movement of the main valve body 15E can be performed smoothly.

The present invention is not limited to the above-described embodiment. Any of the components of the above-described embodiment may be modified within the scope of the present invention. Any of the components may be added or omitted in the above-described embodiment. For example, instead of the electromagnetic actuator 20, a motor actuator having a screw lift mechanism may be used as the actuator, or a normally open type electromagnetic actuator may be used.

1, 1A, 1B, 1C, 1D, 1E Pilot type solenoid valve 10, 10A, 10B Valve body 14 Valve seat 15, 15A, 15B, 15D, 15E Main valve body 16 Annular body 17, 17B, 17E Coil spring 18, 18A, 18C, 18D, 18E Stopper 20 Electromagnetic actuator 22 Coil unit 30 Plunger 35 Pilot valve body CA Valve chamber CD Back pressure chamber

Claims (8)

a valve body including a valve chamber communicating with an inlet opening and an outlet opening;
a main valve body that is movable relative to the valve body and that seats on or moves away from a valve seat in the valve chamber;
a pilot valve body driven by a plunger of an actuator;
a guide pipe in which the plunger is slidable;
and an annular stopper that limits the movement of the main valve body.
an outer periphery of the stopper is fitted into an inner periphery of the valve body and an inner periphery of the guide pipe,
The valve body, the guide pipe, and the stopper are fixed by welding.
A pilot operated solenoid valve. An outer peripheral surface of the main valve body slides against an inner peripheral surface of the stopper.
2. The pilot operated solenoid valve according to claim 1. The valve body has a locking portion disposed closer to the stopper than the inlet opening, and a spring member is disposed between the locking portion and the main valve body to bias the main valve body in a valve opening direction.
3. The pilot-operated solenoid valve according to claim 1 or 2. The stopper has a peripheral wall and an annular wall connected to an end of the peripheral wall, the outer periphery of the peripheral wall is fitted into the inner periphery of the valve body, and the annular wall abuts on an inner periphery step portion of the valve body.
4. The pilot type solenoid valve according to claim 1, wherein the pilot type solenoid valve is a valve that is connected to the pilot-operated solenoid valve. A spring member is disposed between the annular wall and the main valve body to bias the main valve body in a valve opening direction.
5. The pilot operated solenoid valve according to claim 4. The stopper has a peripheral wall and an annular wall connected to an end of the peripheral wall, the outer periphery of the peripheral wall is fitted into the inner periphery of the valve body, and the annular wall is disposed protruding from the valve body.
4. The pilot type solenoid valve according to claim 1, wherein the pilot type solenoid valve is a valve that is connected to the pilot-operated solenoid valve. A groove extending in a radial direction is formed on a surface of the annular wall against which the main valve body abuts.
7. The pilot type solenoid valve according to claim 4, wherein the pilot type solenoid valve is a valve that is connected to the pilot-operated solenoid valve. The main valve body is made of metal, and a resin valve body that can be seated on the valve seat is attached.
8. The pilot type solenoid valve according to claim 1,

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