JP4476902B2 - Solenoid expansion valve - Google Patents

Description

  The present invention relates to a refrigerant electromagnetic expansion valve used in an air conditioner.

3 and 4 are explanatory views of a conventional electromagnetic expansion valve.
A valve body 10 of an electromagnetic expansion valve, generally indicated by reference numeral 1, has passages 12 and 14 through which refrigerant passes, and an orifice 18 and a valve chamber 16 are formed between the passages 12 and 14.
The valve shaft 30 has a valve portion 32 and a guide portion 34 provided at the tip of the valve portion 32. The valve shaft 30 is slidably supported by the guide member 40. A seat member 45 different from the guide member 40 has a valve seat 42 and is fixed to the valve body 10 by a screw portion 44. A bearing 46 that slidably supports the guide portion 34 of the valve shaft 30 is press-fitted into the guide member 40.

A nut member 54 is attached to the lower end portion of the sheet 45 using a screw portion 51.
The nut member 54 supports the lower end portion of the spring 52, and the upper end portion of the spring 52 supports the tip end of the valve shaft 30 via the receiving member 50. The spring 52 biases the valve shaft 30 in the valve opening direction.
A sealing nut 20 is fixed to the lower end portion of the valve body 10 by a screw portion 22.
The refrigerant from the refrigerant passage 14 flows through the orifice 18 and the passage 12 through the orifice member 13. The passage 19 formed in the valve body 10 and the passage 47 formed in the seat 45 introduce the refrigerant on the passage 12 side to both ends of the valve shaft 30 and balance the force applied to the valve shaft 30 by the refrigerant pressure.

An electromagnetic driving device 100 is disposed on the upper portion of the valve body 10. The electromagnetic drive device 100 has a housing 105 fixed to the valve body 10 by a screw portion 102, and a pipe member 110 made of a nonmagnetic material is fixed to the center portion of the housing 105.
An electromagnetic coil 120 wound around a bobbin 122 is disposed outside the pipe member 110. An attractor 130 made of a magnetic material is fixed to a lower end portion of the pipe member 110 facing the valve body 10 side.
The suction element 130 slidably guides the push rod 160 integrated with the plunger 150 by the sleeves 132 and 134.

  When the electromagnetic coil 120 is energized, the attractor 130 attracts the plunger 150 toward the attractor 130 by the generated magnetic force. As the plunger 150 moves, the push rod 160 pushes down the valve shaft 30 and brings the valve portion 32 closer to the valve seat 42 side. By increasing the value of the current flowing through the electromagnetic coil 120, the valve lift is reduced.

FIG. 5B shows changes when the horizontal axis represents the control current value and the vertical axis represents the valve lift.
A spring 170 is disposed on the top of the plunger 150 and cushions the plunger 150 from colliding with the top of the cylindrical member 110 when the electromagnetic coil 120 is de-energized. A lid member 140 is fixed to the upper opening of the housing 105.

4A and 4B are explanatory views showing the operation of the electromagnetic expansion valve 1 shown in FIG. 3, wherein FIG. 4A shows a non-energized state and FIG. 4B shows a conductive state.
While the electromagnetic coil 120 is not energized, no magnetic force that attracts the plunger 150 to the attractor 130 is generated.
When the electromagnetic coil 120 is energized, an attractive force due to a magnetic force is generated in the attractor 130, and a force that pulls the plunger 150 toward the attractor 130 is generated. As the control current value to the electromagnetic coil 120 increases, the force F ₁ due to the magnetic field also increases, and the displacement S ₁ is generated in the plunger 150 by the force F ₁ in the direction orthogonal to the movement axis. The push rod 160 integrated with the plunger 150 is guided by sleeves 132 and 134 provided above and below the suction element 130.

Therefore, when the deviation _{S 1} of the plunger 150 is generated, the push rod 160 is inclined, the movement of the sliding resistance is deteriorated between the sleeve 132 and the push rod 160, in the axial direction _{A 1} of the plunger 150 the valve shaft The smooth movement of the valve is impaired, and the valve lift performance deteriorates.

As shown in FIG. 5B, the tendency is particularly prominent when a large control current is applied to the electromagnetic coil 120.
This type of electromagnetic expansion valve is also disclosed in the following patent document.
Next, instead of the structure of the conventional electromagnetic expansion valve shown in FIGS. 3 and 4, a structure in which the push rod is extended to above the plunger and the upper and lower push rods of the plunger are guided by the sleeve is conceivable.
In the structure described above, the upper and lower sleeves need to be attached to separate members, and these members need to be fixed by welding or the like. In addition, it is difficult to ensure the coaxiality of the upper and lower sleeves, and the entire expansion valve is increased in size.
JP 2004-116825 A

  An object of the present invention is to provide an electromagnetic expansion valve that solves the above-described problems.

The electromagnetic expansion valve of the present invention includes a housing fixed to the valve body, a pipe member standing at the center of the housing, an electromagnetic coil disposed outside the pipe member, and a valve body side of the pipe member. An attractor comprising an electromagnetic drive device comprising: an attractor that is fixed; a plunger that is slidably mounted in a pipe member; and a push rod that is connected to the plunger and passes through the attractor and contacts the valve shaft. Is provided with a sliding bearing in which the outer diameter portion slidably guides the inner diameter portion of the plunger.
Preferably, the sliding bearing is a cylindrical member, and the upper end position of the sliding bearing is set so as to enter the inside of the plunger from the position of the suction surface of the plunger and / or the suction element.

As described above, the electromagnetic expansion valve of the present invention includes the sliding bearing that slidably supports the inner diameter portion of the plunger that slides within the pipe member by the magnetic force of the attractor. Even when a horizontal force is applied, it only moves in parallel and does not fall down with respect to the axis.
Therefore, the change in the sliding resistance of the plunger or push rod is alleviated and the control accuracy of the valve lift is improved.

FIG. 1 is an explanatory diagram of an electromagnetic expansion valve according to the present invention.
The electromagnetic expansion valve denoted as a whole by reference numeral 1 </ b> A includes a valve main body 10 and an electromagnetic driving device 200 disposed on the valve main body 10.
The valve main body 10 and its internal structure are the same as those of the valve main body 10 described in FIG.

The electromagnetic drive device 200 has a housing 205 fixed to the valve body 10 by a screw portion 202, and a pipe member 210 made of a nonmagnetic material is fixed to the center portion of the housing 205.
An electromagnetic coil 220 wound around a bobbin 232 is disposed on the outer periphery of the pipe member 210. An attractor 230 made of a magnetic material is press-fitted into a lower end portion of the pipe member 210 facing the valve body 10 side. The upper part of the pipe member 210 and the opening of the housing 205 are sealed with a lid member 240.

A plunger 250 made of a magnetic material is disposed inside the pipe member 210 so as to face the attractor 230. A push rod 260 is integrally connected to the plunger 250, and the lower end of the push rod 260 abuts on the upper end of the valve shaft 30.
The inner diameter portion 232 of the suction element 230 has a sufficient gap to avoid interference with the push rod 260. A pipe-shaped sliding bearing 270 standing on the upper portion of the suction element 230 guides the push rod 260 in a slidable manner.

The sliding bearing 270 has a length that is sufficiently larger than the diameter of the push rod 260 so as to extend above the position of the attracting surface of the plunger 250 and / or the suction element 230, so that the push rod 260 can be stabilized. Slide to guide.
That is, the upper end position of the sliding bearing 270 is higher than the position of the suction surface of the plunger and / or the suction element 230 and closer to the lid member 240 side. The sliding bearing 270 enters the plunger.

FIG. 2 is an explanatory diagram showing the operation of the present invention.
FIG. 2A shows the non-energized state of the electromagnetic coil 220, and FIG. 2B shows the energized state.
The sliding bearing 270 is set to have such a size that its inner diameter portion 270 a guides the push rod 260 slidably and its outer diameter portion 270 b slides and guides the inner diameter portion 250 a of the plunger 250.

When energized electromagnetic coil 220, the electromagnetic coil 220 and the cover member 240, a magnetic field is generated around the attractor 230, the plunger 250 also receives force _{F 1} in the direction perpendicular to the sliding direction.
Plunger 250 receives the force _{F 1} is moved in the _{B 1} direction perpendicular to the sliding direction _{A 1.} At this time, the plunger 250 and the push rod 260 move in parallel, and the inner diameter portion 250a of the plunger 250 comes into contact with the outer diameter portion 270b of the sliding bearing 270.
The plunger 250 in this state is guided by the sliding bearing 270 is guided smoothly along the sliding direction A _1.

  As shown in FIG. 5A, the valve lift control with respect to the control current value applied to the electromagnetic coil 220 becomes smooth by this action.

Sectional drawing of the electromagnetic expansion valve of this invention. Explanatory drawing which shows the effect | action of the electromagnetic expansion valve of this invention. Sectional drawing of the conventional electromagnetic expansion valve. Explanatory drawing which shows the effect | action of the conventional electromagnetic expansion valve. The figure which shows the characteristic of the solenoid valve of this invention and the conventional solenoid valve.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1A Electromagnetic expansion valve 10 Valve main body 18 Orifice 30 Valve shaft 32 Valve part 40 Guide member 42 Valve seat 50 Receiving member 52 Spring 200 Electromagnetic drive device 205 Housing 210 Pipe member 220 Electromagnetic coil 230 Attractor 240 Lid member 250 Plunger 260 Push rod 270 sliding bearing

Claims (2)

A valve body having an orifice and a valve seat through which refrigerant passes, a valve shaft having a valve portion that is separated from and in contact with the valve seat, a spring that biases the valve shaft in the valve opening direction, and a valve shaft that is fixed to the valve body An electromagnetic expansion valve provided with an electromagnetic drive device that drives the valve in the valve closing direction by electromagnetic force,
The electromagnetic drive device includes a housing fixed to the valve body, a pipe member erected at the center of the housing, an electromagnetic coil disposed outside the pipe member, and a suction fixed to the valve body side of the pipe member. A plunger, a plunger slidably mounted in the pipe member, and a push rod connected to the plunger and penetrating the suction element to contact the valve shaft,
An electromagnetic expansion valve characterized in that the suction element includes a sliding bearing in which an outer diameter portion slidably guides an inner diameter portion of the plunger. The electromagnetic type bearing according to claim 1, wherein the sliding bearing is a cylindrical member, and an upper end position of the sliding bearing is set to a position approaching a shape that enters the inside of the plunger from the adsorption surface position of the plunger and / or the suction element. Expansion valve.

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