JPH0128273B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a solenoid valve suitable for refrigerators, etc., in which the main valve element quickly and reliably closes and opens the valve when the solenoid is energized or de-energized. The present invention relates to an energized closed type pilot-operated solenoid valve which can adjust the opening degree of the main valve body from the outside.

[Conventional technology]

An example of an energized closed type pilot operated solenoid valve used in a refrigeration system is shown in Japanese Utility Model Application No. 58-2487. As shown in FIG. 4, when the electromagnetic valve is not energized (the state shown in the figure), as the plunger 9 descends, the rod 1 fixed to the tip of the plunger
0, the pilot valve 7 is pressed downward and the spring 8a
The pilot valve hole e is opened against the elastic force of is formed, and in this flow path, the cross-sectional area α between the main valve body 3 and the inner wall of the cavity c is set smaller than the cross-sectional area β between the pilot valve hole e, so that the The amount flowing out from the top surface (back surface) is larger than the amount flowing in, and the fluid pressure on the top surface of the main valve body 3 is lower than the pressure on the bottom surface, and this pressure difference acts on the cross-sectional area of the main valve body 3. 3 floats upward, comes into contact with a stopper 4 and stops, opening the main valve seat 2.

Next, when the electromagnetic coil 18 is energized, the plunger 9 is attracted to the attractor 15 by the excitation of the electromagnetic coil 18, and the rod 10 at the tip of the plunger closes the pilot valve hole e. The fluid entering from the inlet A is closed while reaching the lower surface of the pilot valve hole e through the cavity c, the space α, the guide holes a and b, etc., and the fluid pressure on the upper and lower surfaces of the main valve body 3 becomes equal. The main valve body 3 is lowered by its own weight and the elasticity of the spring interposed between the main valve body 3 and the stopper 4, and closes the main valve seat 2.

As described above, the opening/closing operation of the energized closed type pilot operated solenoid valve is performed by energizing the electromagnetic coil 18,
First, the pilot valve 7 is operated by the de-energization signal to open or close the pilot valve hole e, and thereby the main valve body 3 is opened or closed by the fluid pressure difference generated between the upper and lower surfaces of the main valve body 3. It is something. Therefore, after the pilot valve 7 opens, until a certain pressure difference is generated between the upper and lower surfaces of the main valve body 3 (during valve opening operation),
Alternatively, there is a slight time delay until the pilot valve 7 closes and the pressure difference between the upper and lower surfaces of the main valve body 3 becomes equal (during valve closing operation), and the opening/closing operation of the main valve body 3 does not occur quickly after the opening/closing signal is input. There was a problem that it was not carried out.

[Problem to be solved by the invention]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to provide an energized closed type pilot-operated solenoid valve that can quickly and reliably close and open a main valve body when the solenoid is energized or de-energized.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a cylindrical main valve element to a valve body so as to be able to slide freely in the axial direction while being biased toward the main valve seat by a main valve spring, and the cylindrical main valve element A pilot valve hole is bored in the main body part of the main valve body, and a small guide hole is bored in the cylindrical part, and the pilot valve body is movable inside the cylindrical main valve body while being urged toward the pilot valve hole by a pilot valve spring. The rod portion of the pilot valve body is inserted into the pilot valve hole to form an annular orifice larger in cross-sectional area than the small guide hole, and a flow rate adjusting device supporting the cylindrical main valve body is attached to the valve. At the same time as being screwed onto the main body, the operating shaft of the flow rate regulator is extended outside the valve main body, and a plunger spring is resiliently mounted on a plunger of a solenoid provided opposite to the cylindrical main valve body. When the solenoid is de-energized, the pressing part of the plunger contacts the rod part of the pilot valve element to open the pilot valve hole against the pilot valve spring, and also contacts the main body part of the cylindrical main valve element. A structure is adopted in which the main valve seat is opened against the main valve spring.

[Effect]

When the plunger is attracted by the solenoid, the cylindrical main valve body follows the plunger and slides within the valve body by the force of the main valve spring. At this time, the cylindrical main valve body is quickly replenished with fluid from the small guide hole, and no pressure drop occurs due to the increase in volume within the cylindrical main valve body, so the cylindrical main valve body quickly moves to the main valve seat. Can be closed.

When the solenoid is de-energized and the plunger is released from suction, the force of the plunger spring causes the pressing part to push the rod part of the pilot valve body to open the pilot valve hole and open the cylindrical main valve body. Push to open the main valve seat. At this time, since the cross-sectional area of the annular orifice in the pilot valve hole is larger than that of the small guide hole, the pressure inside the cylindrical main valve body decreases, and the cylindrical main valve body quickly completes the valve opening operation.

Further, by rotating the operating shaft extending from the flow rate regulator, the distance between the cylindrical main valve body and the main valve seat (valve lift) can be easily adjusted.

〔Example〕

FIG. 1 is a longitudinal cross-sectional view showing an energized closed type pilot operated solenoid valve according to the present invention.
The cylindrical main valve element 3 has its main body part 3b facing the upper surface (sealing part 3d), and has the cylindrical part 3c slidably in contact with the inner wall of the valve body 1, and the lower end of the cylindrical part 3c is connected to the valve body 3. It is supported on a flow rate regulator 20 screwed onto the main body 1. Furthermore, a pilot valve hole e is provided in the center of the main body portion 3b, and a small guide hole b is provided above the cylindrical portion 3c for conducting the inside and outside of the cylindrical main valve body 3. A main valve spring 3a that biases the cylindrical main valve body 3 toward the main valve seat 2 is provided between the flow rate regulator 20 and the main valve spring 3a.
has been mediated.

Further, the flow rate regulator 20 has an operation shaft 28 extending outside the valve body 1, and by rotating the operation shaft 28, the flow rate regulator 20 is moved forward and backward, and the cylindrical main valve body The distance between the seal portion 3d of No. 3 and the main valve seat 2 is adjustable.

Further, a pilot valve body 7 having a rod portion 7a inserted into the pilot valve hole e is slidably housed inside the flow rate regulator 20 within the cylindrical main valve body 3. In addition to forming a valve seat 7b for opening and closing the pilot valve hole e, a pilot valve spring 7c is interposed for urging the valve seat 7b in the direction of closing the pilot valve hole e.

Furthermore, a plunger 9 of a solenoid is installed on the same axis as the cylindrical main valve body 3 and the pilot valve body 7.
A concave pressing portion 9b is formed at the lower end of the pilot valve body 7.
a, the tip of the rod portion 7a can be freely brought into and out of contact with the bottom surface 9c of the concave pressing portion 9b, and the lower end of the peripheral wall 9d of the concave pressing portion 9b is connected to the main body portion 3 of the cylindrical main valve body 3.
The peripheral wall 9d is provided with a through hole a that conducts the inside and outside of the peripheral wall 9d, and a plunger spring 9a that biases the plunger 9 toward the cylindrical main valve body 3 is interposed.

Then, the length from the tip of the rod portion 7a to the valve seat 7b of the pilot valve body 7 is set to be greater than the sum of the depth of the concave pressing portion 9b and the thickness of the main body portion 3b of the cylindrical main valve body 3. Between the rod portion 7a that passes through the pilot valve hole e and the pilot valve hole e
The cross-sectional area is set to be larger than the cross-sectional area of the small guide hole b of the cylindrical portion 3c.

In the figure, 14 is the solenoid plunger pipe, 15
is the fixed iron core (attractor), 17 is the outer box nut, 18
19 is an electromagnetic coil, 19 is an outer case, 21 is an operating shaft gasket, 22 is a gasket holder, 23 is a gasket, 24
25 is an operating shaft cap nut, 25 is an electromagnetic case fixing nut, 26 is a lower cover, and 27 is a fixing bolt.

Next, the operation of this embodiment will be explained.

When the energization signal is input to the electromagnetic coil 18, the plunger 14 moves the fixed iron core 1 as shown in FIG.
5 and rises against the plunger spring 9a. The cylindrical main valve body 3 which was pressed against the upper surface of the main body part 3b by the tip of the circumferential wall 9d of the concave pressing part provided at the tip of the plunger 14 and descended to open the main valve seat 2, and the bottom surface 9c of the concave pressing part The pilot valve body 7, which was pressed down by the rod portion 7a and opened the pilot valve hole e, follows the rise of the plunger 9 and is supported by the elasticity of the main valve spring 3a and the pilot valve spring 7c. Rise. At this time, the fluid pressure change (decrease) due to the increase in the volume inside the cylindrical main valve body 3 is compensated for by the fluid being replenished from the small conduit hole b, the conduit hole a, and the pilot valve hole e. The fluid pressure inside and outside the body 3 is always kept equal, so that the cylindrical main valve body 3 is not hindered in rising, and the cylindrical main valve body 3 quickly seats on the main valve seat 2 and stops.

Simultaneously with the operation of the cylindrical main valve body 3, the pilot valve body 7 is pushed against the valve seat 7 by the elasticity of the pilot valve spring 7c.
Raise until b is pressed into pilot valve hole e,
When the plunger 9 is raised to its highest level, the bottom surface 9 of the concave pressing part
c and the tip of the rod portion 7a are spaced apart, the concave pressing portion peripheral wall 9d and the upper surface of the main portion 3b are spaced apart, the pilot valve body 7 closes the pilot valve hole e, and the cylindrical main valve body 3 closes the main valve seat 2. to stop the flow of fluid.

If the electromagnetic coil 18 is de-energized in this state,
As shown in FIG. 1, the plunger 9 quickly descends due to its own weight and the elasticity of the plunger spring 9a, and first, the bottom surface 9c of the concave pressing portion presses the tip of the rod portion 7a, lowering the pilot valve body 7, and releasing the pilot valve. The valve hole e is opened and the fluid inside the cylindrical main valve body 3 is released from the pilot valve hole e to the outlet side flow path (secondary side) B.
At this time, fluid enters the cylindrical main valve body 3 from the small guide hole b of the cylindrical part 3c to the inlet side (primary side) A, but the cross-sectional area of the annular orifice formed by the pilot valve hole e and the rod part 7a is Since the cross-sectional area of the small guide hole b is set larger than the cross-sectional area of the small introducing hole b, the pressure inside the cylindrical main valve body 3 decreases, creating a pressure difference between it and the primary fluid pressure, and the cylindrical main valve body 3 descends. In this state, the tip of the concave pressing portion peripheral wall 9d contacts and presses the upper surface of the main body portion 3b, so that the cylindrical main valve body 3 quickly and reliably descends, and the cylindrical main valve body 3 The fluid inside is discharged into the secondary flow path B from the pilot valve hole e and the communication port a of the concave pressing portion 9b, and the cylindrical main valve body 3 is
The lower end of the cylindrical portion 3c is brought into contact with the upper surface of the flow rate regulator 20.

Further, by extending the operating shaft 28 to the flow rate adjuster 20 and changing the threaded length of the flow rate adjuster 20 from the outside, the valve lift when the valve is opened can be easily set. In this, the main valve body 3 is cylindrical,
It has a structure in which the lower end of the cylindrical portion 3c is supported on a flow rate regulator 20 that is screwed into the valve body 1 so as to be able to move forward and backward. Under normal conditions, the valve is de-energized and the valve is in an open state, and the valve is in a closed state only when necessary. In applications, it has the effect of being able to adjust the normal flow rate depending on the situation.

Moreover, the cylindrical main valve body 3 and the pilot valve body 7 are
Since it has a symmetrical shape with respect to the fluid inlet A and the fluid outlet B, it can be used without any problem even when the fluid flows in the forward or reverse direction when the valve is opened.

Next, an example in which the energized closed type pilot operated solenoid valve according to the present invention is applied to a refrigeration system of a refrigerated carrier ship will be described.

The hold of a refrigerated carrier is divided into multiple rooms.
Each chamber is provided with two or more evaporators, each of which is designed to maintain a predetermined temperature for each stored item, such as fish, meat, fruit, etc.

Figure 3 shows an example of a refrigeration system equipped with two evaporators and a hot gas defrost circuit. During cooling operation, the refrigerant flows from the compressor C through the X-Y flow path of the three-way switching valve V. through the condenser K, liquid receiving tank R, check valve _C3 , and the two evaporators in the freezer compartment F.
Solenoid valves S ₁ and S ₂ of the present invention provided at each inlet of E ₁ and E ₂
(open state), the pressure is reduced by the thermostatic expansion valves X ₁ and X ₂ , and the gas is supplied to the evaporators E ₁ and E ₂ .

C ₁ and C ₂ are check valves that prevent inflow from the S ₁ and S ₂ directions. The gas exchanges heat with the indoor load in the evaporators E ₁ and E ₂ , passes through the outlet electromagnetic valves S ₃ and S ₄ (open), is separated into gas and liquid in the accumulator A, and then returns to the compressor C. That is, it circulates along the route shown by the solid line in the figure. In this case, the defrost circuit's stop valves V ₁ and V ₂ are closed.

During defrosting, the refrigerant flow is controlled by the three-way switching valve V
When switching to the X-Z flow path and defrosting the first evaporator _E1 , open the solenoid valves _S1 , _S2 , _S4 , close _S3 , open the blocking valve _V1 , and open the valve _V2. shall be closed. As shown by the dotted line arrow in the figure, the refrigerant flows through the blocking valve V ₁ → heat exchanger E ₁ (condenser in this case) → check valve C ₁ → solenoid valve S ₁ → solenoid valve S ₂ → expansion valve X ₂ → Evaporator E ₂ → Solenoid valve
It circulates along the path S ₄ →accumulator A →compressor C.

In this case, the flow direction of the solenoid valve _S1 is opposite to the normal flow, but due to the structure of the present invention shown in Fig. 1, it can be used without any problem even if the fluid flow is in the forward or reverse direction when the valve is opened. It is something.

When defrosting evaporator E ₂ in Figure 3,
Solenoid valves S ₁ , S ₂ , S ₃ are open, S ₄ is closed, blocking valve V ₂ is open,
V ₁ is closed, heat exchanger E ₂ is used as a condenser,
The fluid flow in the solenoid valve _S2 is the opposite of the normal flow, as in the case of the first heat exchanger defrost. In this system, it is not possible to defrost the evaporators E ₁ and E ₂ at the same time, so the solenoid valves S ₃ and S ₄ are temporally switched using a timer, etc., and the blocking valves V ₁ and V ₂ are switched as well.

The solenoid valves S ₁ to _{S 4} used in this system are used in a de-energized state during normal use (during cooling operation).
Even during defrost, it is sufficient to energize either S ₃ or S ₄ , so it is much more effective in power saving than when using conventional energized open type solenoid valves, and it is possible to switch from normal operation to defrost operation or vice versa. The solenoid valve opens and closes quickly, which helps prevent deterioration of refrigerated products.Furthermore, the flow rate of the solenoid valve can be adjusted to the appropriate temperature depending on the type of refrigerated product. It has the following features.

〔Effect of the invention〕

As described above, the present invention provides a cylindrical main valve element that is biased toward the main valve seat by a main valve spring and is slidable in the axial direction with respect to the valve body, and the main body of the cylindrical main valve element A pilot valve hole is bored in the cylindrical main valve body, a small guide hole is bored in the cylindrical part, and a pilot valve body is provided in the cylindrical main valve body so as to be movable while being biased toward the pilot valve hole by a pilot valve spring. A rod portion of the pilot valve body is inserted into the pilot valve hole to form an annular orifice larger in cross-sectional area than the small guide hole, and a flow rate regulator supporting the cylindrical main valve body is screwed into the valve body. At the same time, the operating shaft of the flow rate regulator is extended outside the valve body, and a plunger spring is resiliently mounted on a plunger of a solenoid provided opposite to the cylindrical main valve body. When de-energized, the pressing part of the plunger contacts the rod part of the pilot valve element to open the pilot valve hole against the pilot valve spring, and also contacts the main body part of the cylindrical main valve element to open the pilot valve hole. Since the main valve seat is opened against the valve spring, the main valve body can be closed and opened quickly and reliably when the solenoid is energized or de-energized. If applied to solenoid valves for opening and closing, it is possible to accurately maintain a predetermined temperature and prevent quality deterioration of frozen products.

In addition, since the valve lift of the main valve body can be easily adjusted by rotating the operating shaft from the outside, in the above example,
Desired temperature can be easily set.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing the energized closed type pilot operated solenoid valve according to the present invention in the open state, FIG. FIG. 4 is a refrigeration system diagram showing an example in which the actuating solenoid valve is applied to a refrigerator. FIG. 4 is a longitudinal sectional view showing a conventional energized closed type pilot actuating solenoid valve. DESCRIPTION OF SYMBOLS 1... Valve body, 2... Main valve seat, 3... Cylindrical main valve body, 3a... Main valve spring, 3b... Main body part, 3c...
...Cylinder part, 7... Pilot valve body, 7a... Rod part, 7b... Valve seat, 7c... Pilot valve spring, 9... Plunger, 9a... Plunger spring, 9b... Pressing part, 20... Flow rate adjuster, 28
...Operation shaft, a...Conducting hole, b...Small conducting hole, e...
...Pilot valve hole.

Claims (1)

[Claims] 1. A cylindrical main valve body is provided on the valve body so as to be slidable in the axial direction while being biased toward the main valve seat by a main valve spring,
A pilot valve hole is bored in the main body part of the cylindrical main valve body, and a small guide hole is bored in the cylindrical part, and the pilot valve body is moved in the direction of the pilot valve hole by a pilot valve spring inside the cylindrical main valve body. A rod portion of the pilot valve body is inserted into the pilot valve hole to form an annular orifice larger in cross-sectional area than the small guide hole, and the cylindrical main valve body is supported. A flow rate adjusting device is screwed onto the valve body, and the operation shaft of the flow rate adjusting device is extended outside the valve body, and the plunger is connected to a plunger of a solenoid provided opposite to the cylindrical main valve body. A spring is resiliently installed, and when the solenoid is de-energized, the pressing part of the plunger comes into contact with the rod part of the pilot valve body to open the pilot valve hole against the pilot valve spring and open the cylindrical main valve body. 1. An energized closed type pilot operated solenoid valve, characterized in that the main valve seat is opened against the main valve spring by contacting the main body portion of the valve.