JP4028281B2 - Electric control valve - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric control valve, and more particularly to an electric control valve for controlling the refrigerant flow rate of a refrigerant circuit in a household refrigerator or the like.
[0002]
[Prior art]
As an electric control valve for controlling the refrigerant flow rate of the refrigerant circuit in a domestic refrigerator or the like, a one-rotation type using a stepping motor as disclosed in JP-A-8-31823, or Japanese Patent Publication No. 2-6299. A multi-rotation type using a feed screw mechanism as shown in Japanese Unexamined Patent Publication No. 7-47656 and Japanese Unexamined Patent Publication No. 2000-291817 is known.
[0003]
Electric control valves, both single-rotation type and multi-rotation type using a feed screw mechanism, when fully closed and fully opened, the rotor rotates further and excessive load is applied to the valve body and valve. In order to avoid acting on the contact part with the seat, the feed screw part, etc., and to obtain reproducibility accuracy by correspondence between the valve position and the excitation pulse of the stepping motor, the movable side stopper and the fixed stopper are used. Collision type (door-to-door type) fully closed stopper and fully open stopper are incorporated.
[0004]
[Problems to be solved by the invention]
In the collision type (door-to-door type) full-closed stopper and full-open stopper, a stopper collision noise and vibration are generated each time the valve is fully closed and fully opened. In particular, a large stopper collision noise and vibration are generated during initialization, and quietness is required. In an electric control valve that controls the refrigerant flow rate of a refrigerant circuit in an indoor unit of a household refrigerator or an air conditioner, stopper impact noise and vibration become a problem.
[0005]
In particular, in a multi-rotation type electric control valve using a feed screw mechanism, if a thrust stopper with a screw part is adopted, a screw biting phenomenon will occur and it will become impossible to operate, so a mechanical radial stopper is provided. As a result, problems such as stopper impact noise and vibration occur.
[0006]
In an electric control valve as disclosed in Japanese Patent Application Laid-Open No. 2000-291817, it is possible to avoid an excessive load from acting on the valve portion when the valve is fully closed due to idling by the friction spring. Therefore, even if it operates in either one of the fully closed state and the fully closed state, both cannot be operated, and a fully open side stopper or the like is required.
[0007]
The present invention has been made to solve the above-mentioned problems, and an unreasonable load acts on the valve portion and a screw biting phenomenon occurs when the valve is fully closed or fully opened. We provide a motorized control valve that reliably avoids this phenomenon, and provides repeatable tracking and excitation phase matching without causing stopper collision noise and vibration each time it is fully closed or fully opened. The purpose is that.
[0008]
[Means for Solving the Problems]
In order to achieve the above-described object, an electric control valve according to the present invention converts a rotary motion of an electric motor composed of a stepping motor having a rotor whose outer peripheral surface portion is multipolar magnetized into a linear motion by a feed screw mechanism. A fully closed position is set by opening and closing the body, and the valve body is seated on the valve seat, and the axial movement of the valve shaft provided integrally with the valve body in a direction away from the valve seat is caused by the thrust stopper. In the electric control valve in which a fully open position is set by being regulated, and a magnet type torque limiter is provided in the middle of the path for transmitting the rotational force from the electric motor to the valve body ,
The torque limiter is fixed to a valve shaft provided integrally with the valve body, and is magnetically coupled to a rotor end surface portion that is multi-pole magnetized at the same pitch as the multi-pole magnetization of the outer peripheral surface portion of the rotor. It has a valve shaft side member made of a magnetic material or a magnet that adsorbs to the magnet .
[0009]
According to the electric control valve of the present invention, the torque limiter is fixed to the valve shaft provided integrally with the valve body, and multipolar magnetization is performed at the same pitch as the multipolar magnetization of the outer peripheral surface portion of the rotor of the stepping motor. Since the valve shaft side member made of magnetic material or magnet that is magnetically attracted between the rotor end surface portion is provided, the torque limiter is directly connected between the rotor of the stepping motor and the valve body within the excessive torque limit. Torque is transmitted and the valve element is driven to open and close by the rotational force generated by the stepping motor. When fully closed or fully open, the valve element is seated on the valve seat, or the opening and closing movement of the valve element is restricted by a thrust stopper, etc. in the state, when the valve body by a stepping motor any more is about to be driven, the stepping motor the valve shaft side member of the torque limiter slip between the rotor Becomes idle state, an excessive load is and the contact portion between the valve body and the valve seat is avoided that acts on the feed screw portion and the like.
[0011]
Further, the electric control valve according to the present invention, before Kiben shaft side member provided with a plurality of suction piece in the circumferential direction with a pitch corresponding to 2 times the pitch of the multipolar magnetized of the rotor-side magnet A multi-leg structure can be formed, and excitation phase matching can be performed.
[0012]
Further, the electric control valve according to the present invention, before Kiben shaft side member can be assumed to be multipolar magnetized in the circumferential direction with the same pitch of the multipolar magnetized in the rotor-side magnet, transfer Torque up and excitation phase matching can be performed.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
1 to 5 show an embodiment of an electric control valve according to the present invention.
[0015]
The electric control valve 10 has a disk-shaped lower lid member 11 made of stainless steel, and a cap-like nonmagnetic material rotor case 12 whose periphery is hermetically connected to the lower lid member 11 by welding or the like. A sealed rotor chamber 13 that also serves as a valve chamber is defined inside.
[0016]
An inlet port 15 connected to the inlet joint pipe 14 and an outlet port 17 connected to the outlet joint pipe 16 are formed through the lower lid member 11.
[0017]
A rotor 18 is rotatably provided in the rotor chamber 13. The rotor 18 is a rotor with a multipolar magnet having an outer peripheral surface multipolarly magnetized (peripheral multipolar magnetized portion 18A), and a stepping motor 20 with a stator coil unit 19 fitted and mounted on the outer periphery of the rotor case 12. Is configured. The outer peripheral multipole magnetized portion 18A is alternately magnetized with a pitch P in the N pole and S pole along the generatrix direction of the rotor outer periphery.
[0018]
The stator coil unit 19 is detachably attached to the outer periphery of the rotor case 12, and includes a plurality of upper and lower cylindrical winding portions 21, 22 and bobbins 23, 24 made of an electrically insulating resin. The upper and lower metal outer casings 26 and 28 are formed in a comb-teeth shape, and the metal magnetic pole tooth material 30 is formed in a plurality of magnetic pole teeth 29 and 31 in a comb-teeth shape. , 32, a metal mounting bracket plate 34 having an engaging claw 33 that engages with the lower lid member 11, a lead wire 35 electrically connected to the windings of the winding portions 21, 22, and hard rubber Alternatively, it has an outer cover 36 made of synthetic resin, and is potted and sealed with a thermosetting resin 37 having an electrical insulating property such as epoxy resin or polyurethane filled inside the outer cover 36.
[0019]
A sheet member 38 is positioned on the upper surface of the lower lid member 11 by engaging a positioning embossing convex portion 11A formed in the lower lid member 11 with a fixing engagement hole 38A formed through the sheet member 38. It is fixed (see FIG. 2). The seat member 38 is formed with a valve port 39 that is aligned with the outlet port 17 formed at the center of the lower lid member 11, and a valve seat 39 </ b> A is formed therearound.
[0020]
As shown in FIG. 2, the seat member 38 has guide leg fixing engagement holes 38B formed in three locations, and the guide leg fixing engagement holes 38B have legs of the five-virtual shaped guide member 40. An engagement piece 40B formed at the tip of the portion 40A is engaged. By this engagement, the guide member 40 is fixed on the sheet member 38.
[0021]
A female screw member 41 is provided inside the guide member 40. The female screw member 41 has a female screw hole 42 and is slidably engaged with the leg portion 40A of the guide member 40 by a concave groove 41A formed on the outer peripheral surface, and the annular portion 40C of the guide member 40 and the sheet member 38 are engaged. Only a predetermined gap e (see FIG. 1) can be displaced in the axial direction (vertical direction) with respect to the sheet member 38 and the guide member 40. The female screw member 41 cannot be rotationally displaced by the engagement between the concave groove 41A and the leg portion 40A.
[0022]
A male screw shaft 44 integral with the needle valve body 43 is threadedly engaged with the female screw hole 42. The needle valve body 43 moves in the axial direction (valve lift direction) by screw engagement between the female screw hole 42 and the male screw shaft 44 by the rotation of the male screw shaft 44, and as shown in FIG. Is fully closed to close the valve port 39.
[0023]
The needle valve 43 integrally has a valve shaft 45 on the extension of the male screw shaft 44. The valve shaft 45 rotatably passes through a central hole 18C formed in the central hub portion 18B of the rotor 18 and engages with a bottomed bearing hole 46A of the bearing member 46 at an upper end portion 45A. The bearing member 46 is engaged with a bearing recess 12 </ b> A formed in the ceiling portion of the rotor case 12.
[0024]
The tip surface (movable stopper surface) 45B of the upper end 45A of the valve shaft 45 and the bottom surface (fixed stopper surface) 46B of the bottomed bearing hole 46A form a fully open thrust stopper, and the needle valve 43 The fully open position is determined by the tip surface 45B of the valve shaft 45 coming into contact with the bottom surface 46B of the bottomed bearing hole 46A, and corresponds to the maximum valve lift amount between the tip surface 45B and the bottom surface 46B in the fully closed state. A gap h is generated.
[0025]
Similar to the outer peripheral multipolar magnetized portion 18A, the upper end surface of the rotor 18 is magnetized alternately with N and S poles with a pitch P to form an end surface multipole magnetized portion 18D, which is a torque limiter rotor. It has a side magnet.
[0026]
A valve shaft side member 47 of a torque limiter is fixed to the valve shaft 45. The valve shaft side member 47 is made of a magnetic material, and includes an annular plate portion 47A that is magnetically attracted to the end face multipole magnetized portion 18D. The annular plate portion 47A is connected to the bearing member 46. It is urged toward the end face multipolar magnetized portion 18D by a compression coil spring 48 provided therebetween. The surface (attracting surface) where the annular plate portion 47A faces the end face multipole magnetized portion 18D may be coated with a highly slippery resin such as a fluorine plunger with good slidability.
[0027]
The transmission torque obtained by magnetic attraction between the end face multipole magnetized portion 18D and the annular plate portion 47A is set to be slightly larger (Tmax + α), where Tmax is the maximum required torque for valve opening / closing. The torque limiter transmission torque (Tmax + α) can be adjusted arbitrarily by setting the magnetizing force of the end face multipole magnetized portion 18D, the adsorption area between the end face multipole magnetized portion 18D and the annular plate portion 47A, and the gap between them. It can be carried out. This adsorption area can be set to any appropriate value depending on the radial width of the end face multipolar magnetized portion 18D and the annular plate portion 47A.
[0028]
Next, the operation of the electric control valve 10 configured as described above will be described.
1 and 4 show a normal fully closed state (fully closed point). In this fully closed state, there is a predetermined gap e between the upper end of the female screw member 41 and the annular portion 40C of the guide member 40. .
[0029]
If the stepping motor 20 is further excited in the valve closing direction and the rotor 18 is rotated in the valve closing direction from the fully closed state (fully closed point), the rotational force (torque) is within the excessive torque limit. Is transmitted to the valve shaft 45 and the male screw shaft 44 by magnetic attraction between the end face multipolar magnetized portion 18D and the annular plate portion 47A of the valve shaft side member 47, and these rotate. At the fully closed point, the needle valve body 43 is seated on the valve seat portion 39A and cannot be lowered any further, so that the female screw member 41 is moved upward by screw engagement by the rotation of the male screw shaft 44, and is shown in FIG. As described above, the female screw member 41 is lifted from the upper surface of the sheet member 38 by a predetermined gap e, and the upper end of the female screw member 41 contacts the annular portion 40C of the guide member 40. In this state, initialization is performed on the fully closed side, and reproducible followability is obtained by re-excitation in the valve opening direction from the initialization end phase.
[0030]
In the initialized state where the upper end of the female screw member 41 is in contact with the annular portion 40C of the guide member 40, when the stepping motor 20 is further excited in the valve closing direction, a torque greater than a required value (Tmax) is applied to the female screw member 41. Therefore, slip occurs between the end face multipolar magnetized portion 18D of the rotor 18 and the annular plate portion 47A of the valve shaft side member 47, and the rotor 18 idles due to the torque limiter action, and the female screw hole 42 Excessive torque is prevented from acting on the screw engaging portion between the male screw shaft 44 and the male screw shaft 44.
[0031]
As a result, it is possible to prevent the leadle valve body 43 from being excessively pressed against the valve seat portion 39A and biting into the valve port 39 or from being bitten at the screw engaging portion on the fully closed side. Since the rotor 18 is idled by sliding contact between the annular plate portion 47A whose surface is coated with a highly slippery material and the end face multipole magnetized portion 18D, a large frictional sound or vibration is generated in a low friction state. It is done without it.
[0032]
When the stepping motor 20 is excited in the valve opening direction from the normal fully closed state (full closing point) shown in FIGS. 1 and 4 and the rotor 18 is rotated in the valve opening direction, A rotational force (torque) is transmitted to the valve shaft 45 and the male screw shaft 44 by magnetic attraction between the end face multipolar magnetized portion 18D of the rotor 18 and the annular plate portion 47A of the valve shaft side member 47, and these rotate. As the male screw shaft 44 rotates, the needle valve body 43 moves upward by screw engagement, the needle valve body 43 moves away from the valve seat portion 39A, and as shown in FIG. The effective opening area of the valve port 39 increases with the valve lift L).
[0033]
When the valve lift amount L = h from the fully closed point, as shown in FIG. 5, the tip surface 45B of the valve shaft 45 comes into contact with the bottom surface 46B of the bottomed bearing hole 46A and is fully opened. When the stepping motor 20 is further excited in the valve opening direction from this fully open state (fully open point), a torque greater than a required value (Tmax) acts on the female screw member 41. Slip occurs between the magnetized portion 18D and the annular plate portion 47A of the valve shaft side member 47, and the rotor 18 idles due to the torque limiter action, and excessive torque is applied to the screw engaging portion between the female screw hole 42 and the male screw shaft 44. Is avoided from acting.
[0034]
As a result, it is possible to prevent the screw engaging portion from being bitten on the fully open side.
[0035]
As described above, since the rotor 18 idles due to the torque limiter action on both the fully closed side and the fully open side, an unreasonable load acts on the valve portion without the need for a radial stopper, and the screw bites. Occurrence of the sticking phenomenon can be avoided, and an irritating stopper collision sound or vibration is not generated each time the valve is fully closed or fully opened.
[0036]
As shown in FIG. 7, the magnetic adsorption surface of the torque limiter valve shaft side member 47 with the end surface multipolar magnetized portion 18D is replaced with an outer peripheral multipole as shown in FIG. A valve shaft having a multi-leg structure in which a plurality of attracting pieces 47B are provided in the circumferential direction at a pitch corresponding to a pitch 2P that is twice the multipolar magnetization pitch P of the magnetized portion 18A and the end face multipolar magnetized portion 18D. The side member 47 ′ is used, and the valve shaft side member 47 is configured to be attracted to the rotor 18 by the plurality of attracting pieces 47B in the same phase as the multipolar magnetization phase of the outer peripheral multipolar magnetized portion 18A. Can do. In this case, the circumferential width W of the suction piece 47B is P ≧ W ≧ (P / 2).
[0037]
Also in this case, the torque limiter transmission torque (Tmax + α) is adjusted by setting the magnetizing force of the end face multipole magnetized portion 18D, the attracting area between the end face multipole magnetized portion 18D and the attracting piece 47B, and the gap between them. The adsorption area can be arbitrarily determined by the circumferential width W of the attracting piece 47B and the radial dimension B (see FIG. 7) in addition to the radial width dimension of the end face multipole magnetized portion 18D. It is possible to set to an appropriate value.
[0038]
In addition, this makes it possible to perform excitation phase alignment with high accuracy without requiring a special operation in the case of a mechanical stopper structure or a base phase in which a valve phase that defines the excitation phase is determined.
[0039]
8 and 9 show the main part of another embodiment of the electric control valve according to the present invention. 8 and 9, parts corresponding to those in FIGS. 1 to 5 are denoted by the same reference numerals as those in FIGS. 1 to 5, and description thereof is omitted.
[0040]
In this embodiment, the magnetic attraction surface with the end face multipole magnetized portion 18D of the valve shaft side member 47 ″ of the torque limiter is the multipole magnet of the outer peripheral multipole magnetized portion 18A and the end face multipole magnetized portion 18D. The valve shaft side magnet 47C is magnetized in the circumferential direction with the same pitch as the magnetic pitch P.
[0041]
In addition, a spacer 49 made of a non-magnetic material having a thickness t for adjusting the gap between the attracting surfaces of the valve shaft side magnet 47C and the end face multipolar magnetized portion 18D of the rotor 18 is sandwiched. ing. In order to obtain high slidability (low friction), the spacer 49 is made of a highly slippery material such as fluororesin, or the surface of a plate made of aluminum alloy or copper alloy is coated with a highly slippery material such as fluororesin. It is comprised by what.
[0042]
According to this configuration, the torque limiter is magnetically attracted by the end face multipolar magnetized portion 18D of the rotor 18 and the magnet of the valve shaft side magnet 47C. Since the multipolar magnetization pitch of the outer peripheral multipolar magnetized portion 18A and the end face multipolar magnetized portion 18D and the multipolar magnetization pitch of the valve shaft side magnet 47C are the same, excitation phase matching can be performed. it can.
[0043]
Further, the transmission torque of the torque limiter can be arbitrarily adjusted by adjusting the gap between the end face multipolar magnetized portion 18D of the rotor 18 and the attracting surface of the valve shaft side magnet 47C by selecting the thickness t of the spacer 49. In addition, the idling of the rotor 18 by the torque limiter is performed through the spacer 49 which is made of a highly slippery material or whose surface is coated with a highly slippery material, so that it is accompanied by a large frictional sound and vibration with low friction. Done without.
[0044]
FIG. 10 shows an application example of the electric control valve 10 described above for a household refrigerator. The refrigerator for home uses a refrigerant loop in which a compressor 101, a condenser 102, a freezer capilla 103, and a freezer evaporator 104 are connected in order, and a freezer compartment provided by bypassing the freezer capilla 103. A series circuit of a capilla 105 and a refrigerator compartment evaporator 106 is provided, and the electric control valve 10 is provided on the downstream side of the refrigerator compartment evaporator 106. The electric control valve 10 controls the flow rate of the refrigerant flowing through the cold room capilla 105 and the cold room evaporator 106.
[0045]
【The invention's effect】
As understood from the above description, according to the electric control valve of the present invention, the magnet type torque limiter provided in the middle of the path for transmitting the rotational force from the electric motor to the valve body is provided integrally with the valve body. A valve shaft side member made of a magnetic material or magnet that is fixed to the valve shaft and magnetically adsorbed between the rotor end surface magnetized at the same pitch as the multipolar magnetization of the outer peripheral surface of the rotor. Since the stepping motor is idling due to the sliding action between the valve shaft side member of the torque limiter and the rotor of the stepping motor on both the fully closed side and the fully open side, there is no need for a radial stopper. It is possible to avoid excessive load acting on the valve part and the occurrence of screw biting, and there is no harsh stopper collision noise or vibration every time the valve is fully closed or fully opened. , Silence is caught that is.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an embodiment of an electric control valve according to the present invention.
FIG. 2 is an exploded perspective view of a main part of one embodiment of an electric control valve according to the present invention.
FIG. 3 is a longitudinal sectional view of an essential part showing a fully closed initialization state of one embodiment of the electric control valve according to the present invention.
FIG. 4 is a longitudinal sectional view of a main part showing a fully closed point state of one embodiment of the electric control valve according to the present invention.
FIG. 5 is a longitudinal sectional view of an essential part showing a fully open state of one embodiment of the electric control valve according to the present invention.
FIG. 6 is a graph showing a valve lift characteristic of one embodiment of the electric control valve according to the present invention.
FIG. 7 is a perspective view showing an essential part of a modification of one embodiment of the electric control valve according to the present invention.
FIG. 8 is a longitudinal sectional view showing a main part of another embodiment of the electric control valve according to the present invention.
FIG. 9 is an exploded perspective view of a main part of another embodiment of the electric control valve according to the present invention.
FIG. 10 is a refrigerant circuit diagram showing an application example of the electric control valve according to the present invention to a household refrigerator.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Electric control valve 11 Lower cover member 12 Rotor case 13 Rotor chamber 15 Inlet port 17 Outlet port 18 Rotor 18A Outer peripheral multipolar magnetized part 18D End face multipolar magnetized part 19 Stator coil unit 20 Stepping motor 41 Female screw member 43 Needle valve 44 Male screw shaft 45 Valve shaft 47 Valve shaft side member 47A Ring plate portion 47B Adsorption piece 47C Valve shaft side magnet 49 Spacer

Claims (3)

The rotary motion of an electric motor composed of a stepping motor having a rotor whose outer peripheral surface is magnetized is converted into a linear motion by a feed screw mechanism to open and close the valve body, and when the valve body is seated on the valve seat, A closed position is set, and an axial movement in a direction away from the valve seat of a valve shaft provided integrally with the valve body is restricted by a thrust stopper, so that a fully open position is set, and the motor moves from the motor to the valve body. In the electric control valve provided with a magnet type torque limiter in the middle of the path for transmitting the rotational force ,
The torque limiter is fixed to a valve shaft provided integrally with the valve body, and is magnetically coupled to a rotor end surface portion that is multi-pole magnetized at the same pitch as the multi-pole magnetization of the outer peripheral surface portion of the rotor. Has a valve shaft side member made of magnetic material or magnet
An electric control valve characterized by that. The valve shaft side member has a multi-leg structure in which a plurality of attracting pieces are provided in the circumferential direction with a pitch corresponding to twice the multi-pole magnetization of the rotor-side magnet. claim 1 Symbol mounting of the electric control valve. The valve shaft side member multipolar adhesive claim 1 Symbol mounting of the electric control valve, characterized in that it is multi-polar magnetized in the circumferential direction with the same pitch of magnetic of the rotor-side magnet.

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