JP2992232B2 - solenoid valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve which is used by connecting to a pipeline for oil, water, air-conditioning refrigerant and the like.

[0002]

2. Description of the Related Art A conventional solenoid valve shown in FIG.
A valve body 4 provided with a valve port 3 and a cylinder connection port 4a in the middle of the flow path of the outlet passage 2 and a holder 15 screwed to the cylinder connection port 4a of the valve body 4 via a ring 11. A cylinder cylinder 6 having an opening at the valve port, which is connected to the connection port 4a so as to protrude in a direction perpendicular to the flow path by the holder screwing;
A plunger 7 having a valve portion 10 that comes into contact with and separates from the valve port 3 and that is inserted into the cylinder tube 6 so as to be movable in a valve opening direction and a valve closing direction, and disposed outside the cylinder tube 6. And an attraction element 5 fitted to the end of the cylinder cylinder 6 for attracting and moving the plunger 7 in the valve opening direction by magnetic attraction by energization of the coil 14.
And a spacer 9 fitted and held in the concave portion of the suction element 5 at the plunger facing end to prevent an impact metal sound when the plunger 7 is sucked by the suction element 5, and between the suction element 5 and the plunger 7. And a plunger biasing spring 8 for resiliently moving the plunger 7 in the valve closing direction when the coil 14 is demagnetized.

The spring 8 is a compression spring which is fitted in a bottomed hole at the end of the plunger 7 facing the attraction element, and is supported at both ends by the bottom of the hole and the spacer 9, and the spring 8 is inserted therein. In the bottomed hole of the plunger 7, an equalizing hole 7a formed from the outer periphery of the plunger is opened. The valve section 1
Numeral 0 designates a valve which is separate from the plunger 7 and which is fitted into a recess at the end of the plunger, and a washer 12 at the periphery of the recess.
It is fixed by caulking through.

[0004] The coil 14 is surrounded by a housing 13.
The housing 13 and the holder 1 are fixed.
The packing 16 is interposed between the packing 5 and the packing 5.

In the solenoid valve having the above-described structure, a magnetic circuit is formed when power is supplied to the electromagnetic coil 14, and the plunger 7 has the spring 8, the weight of the plunger 7, and the fluid applied to the inlet passage 1 and the outlet passage 2. The suction port 5 is attracted to the suction element 5 against the pressure difference, the cross-sectional area of the valve port 3 (the pressure receiving area load), and the valve port 3 is opened, and the fluid flows from the inlet passage 1 to the outlet passage 2.

When the power supply of the electromagnetic coil 14 is cut off, the plunger 7 is separated from the suction element 5 by the biasing force of the spring 8 and the weight of the plunger 7 and moves in the valve closing direction to move the valve port 3.
Close.

[0007]

The above-mentioned conventional solenoid valve has the following features.
The valve opening operation and the valve closing operation are performed instantaneously and cannot be performed gently. For example, as shown in a refrigeration cycle for a car air conditioner shown in FIG.
If there is no occupant in the rear seat, for example, if there is no occupant in the rear seat, the solenoid valve 18b provided on the refrigerant inlet side of the rear seat refrigerant evaporator 20b is closed to eliminate waste of cooling output. ing.

The solenoid valves 1 are also provided at the refrigerant inlet side of the front-seat refrigerant evaporator 20a and the refrigerant evaporator 20c for the refrigerator.
8a and 18c are provided, and the valves are opened and closed as necessary to measure the efficiency of the cooling output. Note that reference numerals 19a, 19b, and 19c shown in FIG. 5 are expansion valves, 21 is a condenser,
22 is a compressor, 23 is a liquid receiver, and 24 is a receiver tank.

However, in the refrigeration cycle, the inlet side solenoid valves 18a to 18c of the refrigerant evaporators 20a to 20c are provided.
When each of the solenoid valves is suddenly opened when the cooling operation is performed by opening the valve 18c, the high-pressure liquid refrigerant on the solenoid valve inlet side expands the expansion valves 19a to 19c.
Since the low-pressure gas refrigerant in the refrigerant evaporators 20a to 20c is rapidly released via the refrigerant 19c, vibration noise (noise like shooting an empty cannon) due to pulsation of the fluid (refrigerant) and abnormal pressure change is generated in the piping, There was a problem that the quietness of the cabin was impaired.

When the cooling operation is stopped, the solenoid valve 18
When a to 18c are suddenly closed, the condenser 21 is connected to the receiver 23.
And evaporators 20a-2 via expansion valves 19a-19c
Since the flow of the refrigerant toward 0c is suddenly blocked, vibration noise due to the pulsation (water hammer) of the refrigerant is generated in the pipe portion,
There was a problem that the quietness of the cabin was impaired.

In the conventional solenoid valve shown in FIG. 4, when power is supplied to the electromagnetic coil 14, the plunger 7 instantaneously moves in the valve opening direction to open the valve. This is caused by instantaneous movement in the valve closing direction to close the valve.

The present invention has been devised to solve the above-mentioned conventional problems. The object of the present invention is to moderate the plunger operation at the time of opening and closing the valve so that vibration noise due to pulsation of the fluid does not occur. An object of the present invention is to provide an improved solenoid valve.

[0013]

In order to achieve the above object, the present invention provides a valve body 4 having a valve port 3 provided in the middle of a flow path between an inlet passage 1 and an outlet passage 2; It has a cylinder cylinder 6 that opens to the valve port provided and a valve section 10 that comes into contact with and separates from the valve port 3 and is inserted into the cylinder 6 so as to be movable in the valve opening direction and the valve closing direction. Plunger 7
And an electromagnetic coil 1 disposed outside the cylinder 6
4 and the coil 1 fitted to the end of the cylinder 6.
4, a suction element 5 for attracting and moving the plunger 7 in the valve opening direction by a magnetic attractive force generated by the energization of the coil 4. The plunger 7 is incorporated between the suction element 5 and the plunger 7 and is closed when the coil 14 is demagnetized. In a solenoid valve including a plunger biasing spring 8 that resiliently moves in a valve direction, a seal packing 25 that is slidable on the inner peripheral surface of the cylinder cylinder 6 is provided on the plunger 7 .
A damper for forming a cutout groove or a small hole a for narrowing the flow of fluid for gradually discharging fluid, and for easing the plunger operation in a space partitioned by the packing 25 between the plunger 7 and the suction element 5 It is characterized by having a chamber 27.

[0014]

According to the electromagnetic valve having the above construction, when the valve is opened (when the plunger 7 is attracted to the suction element 5 by energization of the electromagnetic coil 14 and the valve port 3 is opened), the damper formed by the seal packing 25 is used. Since the inflow fluid in the chamber 27 is gradually discharged through the notch groove 28 or the small hole 28a having the throttle function, the valve opening operation of the plunger 7 is performed slowly, and the passage area of the valve port 3 is gradually opened, and the inlet port is opened. From passage 1 to exit passage 2
The flow of the fluid toward the fluid can be moderated, whereby the pulsation of the fluid is suppressed, and the occurrence of abnormal vibration noise is prevented.

When the valve is closed (when the electromagnetic coil 14 is demagnetized and the plunger 7 is moved in the valve closing direction by the biasing force of the spring 8 and the valve port 3 is closed), the fluid on the flow path side is filled with the fluid. Notch groove 28 or small hole 28 of packing 25 having a squeezing action
a gradually flows into the damper chamber 27 through
The valve closing operation of the plunger 7 is performed gently, the passage area of the valve port 3 is gradually closed, and the flow of the fluid from the inlet passage 1 to the outlet passage 2 can be cut off gently. It is suppressed and the occurrence of abnormal vibration noise is prevented.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of a solenoid valve according to one embodiment of the present invention will be specifically described below with reference to FIGS. Figure
In the figure, reference numeral 4 denotes a valve body provided with a valve port 3 and a cylinder connection port 4a in the middle of the flow path between the inlet passage 1 and the outlet passage 2, and 6 denotes a cylinder cylinder opening at the valve port. A holder 15 is screwed to the cylindrical connection port 4a of the main body 4 via the O-ring 11. The holder 15 is connected to the connection port 4a so as to protrude in a direction orthogonal to the flow path by the screwing of the holder.

Reference numeral 7 denotes a plunger which is inserted into the cylinder cylinder 6 so as to be movable in a valve opening direction and a valve closing direction. The plunger 7 has a valve portion 10 which comes into contact with and separates from the valve port 3. Fit the valve separate from 7 into the recess at the end of the plunger,
The peripheral edge of the recess is secured by caulking via a washer 12 (in this case, a gas vent hole 7c is provided in the peripheral edge of the recess to allow the fluid flowing into the valve fitting portion to flow to the outer peripheral side). However, it is also possible to integrally provide the valve portion 10 at the end of the plunger 7 facing the valve opening.

Numeral 14 denotes an electromagnetic coil disposed outside the cylinder 6, and 5 is fitted to the end of the cylinder 6, and the plunger 7 is opened in a direction in which the plunger 7 is opened by magnetic attraction by energization of the coil 14. A spacer 9 for preventing an impact metal sound when the plunger 7 is attracted to the suction element 5 is fitted and held in a concave end of the suction element 5 opposite to the plunger. The coil 14 is surrounded by a housing 13. The housing 13 is fixed to the suction element 5 with screws 17 and the like. A packing 16 is interposed between the housing 13 and the holder 15. You.

Reference numeral 8 denotes a plunger biasing spring which is incorporated between the attraction element 5 and the plunger 7 to resiliently move the plunger 7 in the valve closing direction when the coil 14 is demagnetized. 7 is a compression spring which is fitted in a bottomed hole at the end facing the suction element 7 and both ends of which are supported by the bottom of the hole and the spacer 9, and the bottomed hole of the plunger 7 into which the spring 8 is inserted. An equalizing hole 7a is formed from the outer periphery of the plunger.

Reference numeral 25 denotes an annular seal packing which is slidable on the inner peripheral surface of the cylinder cylinder 6 and is fitted to the valve-portion-side small-diameter portion 7b of the plunger 7, and a cylindrical outer bush 26 is fitted to the small-diameter portion 7b. By press-fitting, the outer peripheral edge of the packing is bent along the inner surface of the cylinder tube 6 in the direction of surrounding the bush, and is mounted so as to contact the inner surface of the cylinder tube 6.

The seal packing 25 has a notch groove 28 or a small hole 2 as shown in FIG.
8a is formed, and a space partitioned by the packing 25 between the plunger 7 and the suction element 5 is formed as a damper chamber 27 for slowing down the plunger operation.

The number of the notches 28 or small holes 28a can be one or more depending on the speed of the plunger 7 opening / closing valve to control the operation of the plunger. The seal packing 25 is made of a polymer material, such as Teflon, which can move on the inner peripheral surface of the cylinder 6 with as little sliding resistance as possible and has a good seal with the cylinder 6.

Next, the operation of the above embodiment will be described. Now, when the electromagnetic coil 14 is not energized and a high pressure acts on the inlet passage 1 side and a low pressure acts on the outlet passage 2 side, the damper chamber 27 communicates with the high pressure through the cutout groove 28 or the small hole 28a. And is in a high pressure state.

At this time, when a current is applied to the electromagnetic coil 14, a magnetic circuit is formed by the housing 13, the plunger 7, and the attraction element 5, and the plunger 7 is attracted to the attraction element 5 against the elasticity of the spring 8. You. Here, the pressure change in the damper chamber 27 partitioned by the seal packing 25 is as follows.
This means that the volume of the movement of the plunger 7 has been compressed, which corresponds to an increase in the pressure in the damper chamber 27.

The relationship is as shown in FIG.
The initial pressure of the damper chamber 27 is P1, the initial volume is V1, the pressure rise of the damper chamber 27 at a certain point when the plunger 7 is sucked and moved is ΔP1, and the volume compressed by the movement of the plunger 7 is ΔV1. Then, it is expressed by the following relational expression.

P1 V1 = (P1 + ΔP1) (V1-ΔV1) The compressed volume (pressure rise ΔP1) is divided by a notch groove 28 or a small hole 28a provided in the seal packing 25 and having a throttling action.
Through the valve chamber 29 (fluid flow path) side, the plunger 7 is gently moved in the valve opening direction to be attracted to the suction element 5, and the valve port 3 is opened as shown in FIG. Becomes

When the current to the electromagnetic coil 14 is cut off, the plunger 7 moves in the valve closing direction by the elastic force of the spring 8. In this case, as the plunger 7 moves, the internal volume of the damper chamber 27 increases, and the internal pressure decreases. The initial pressure of the damper chamber 27 is P2, the volume at that time is V2, the pressure drop of the damper chamber 27 at a certain point when the plunger 7 is moved by the spring 8 in the valve closing direction is ΔP2, and the increased volume is ΔV2. Then, P2 V2 = (P2- △ P2) (V
2 + △ V2).

The fluid on the flow path side corresponding to the increased volume (pressure drop ΔP2) is introduced into the damper chamber 27 through the notched groove 28 or the small hole 28a provided in the seal packing 25 and having a throttling action as shown in FIG. By gradually supplying (inflow) as described above, the plunger 7 is gradually moved in the valve closing direction, and the valve port 3 is finally closed as shown in FIG.

The size of the cutout groove 28 or the small hole 28a is determined by the pressure on the inlet side, the pressure on the outlet side, and the size of the electromagnetic coil 14.
The open / close valve of the plunger 7 is designed to be able to move within a certain period of time in any use condition, such as the voltage applied to the fluid and the type of fluid.

[0030]

According to the solenoid valve of the present invention, as described above, the space partitioned by the seal packing 25 between the plunger 7 and the suction element 5 is used as the damper chamber 27, so that the plunger 7 is attracted to the suction element 5. It is possible to reduce the metal noise generated at the time of collision even without the spacer 9.

Further, since the vibration of the pipe due to the generation of the liquid hammer noise can be prevented, the fatigue destruction caused by the repetition of the vibration of the pipe and the repeated increase in the pressure can be suppressed, and the effect of extending the life of the equipment can be obtained.
This has the effect of eliminating the need for external vibration and sound insulation. Furthermore, since only the seal packing 25 is required for the conventional solenoid valve, it is economical and easy to assemble.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a configuration of a solenoid valve according to an embodiment of the present invention, wherein FIG. 1A is a longitudinal sectional view of the entire solenoid valve, and FIG. 1B is an enlarged sectional view of a main part.

FIG. 2 is a perspective view for explaining a configuration of a plunger incorporated in the solenoid valve, a configuration of a seal packing, and a mounting method.

FIG. 3 is a diagram (A) and (B) showing an operation state of the solenoid valve.
(C) Operation | movement explanatory drawing of the principal part shown as (D).

FIG. 4 is a longitudinal sectional view showing a conventional solenoid valve.

FIG. 5 is a circuit diagram of a refrigeration cycle for a car air conditioner incorporating a conventional solenoid valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Inlet passageway, 2 ... Outlet passageway, 3 ... Valve port, 4 ... Valve body, 5 ... Suction piece, 6 ... Cylinder cylinder, 7 ... Plunger, 8 ... Plunger biasing spring, 9 ... Spacer, 10 ... Valve section, 13 ... Housing, 14 ... Electromagnetic coil, 15 ... Holder, 25 ... Seal packing, 26 ... Outer bush, 27 ... Damper chamber, 28 ... Notch groove of seal packing, 28a ... Small hole of seal packing.

Claims (1)

(57) [Claims] A valve body provided with a valve port in the middle of a flow path between an inlet passage and an outlet passage; a cylinder cylinder provided in the valve body that opens at the valve port; and a valve that comes into contact with and separates from the valve port. A plunger having a portion and inserted into the cylinder cylinder so as to be movable in a valve opening direction and a valve closing direction, an electromagnetic coil disposed outside the cylinder cylinder, and fitted to an end of the cylinder cylinder. An attraction element for attracting and moving the plunger in a valve opening direction by magnetic attraction by energization of the coil, and a plunger incorporated between the attraction element and the plunger to repel the plunger in a valve closing direction when the coil is demagnetized; A plunger biasing spring for moving the plunger, a seal packing slidable on the inner peripheral surface of the cylinder cylinder is provided on the plunger, and the seal packing gradually discharges fluid.
A cutout groove or a small hole for restricting the flow of fluid to be discharged is formed, and a space partitioned by the packing between the plunger and the suction element is formed as a damper chamber for easing the plunger operation. valve.