JP6615841B2 - Electric valve and refrigeration cycle system - Google Patents

Description

  The present invention relates to a motor-operated valve and a refrigeration cycle system using the motor-operated valve.

  An electric valve used for a package air conditioner, a room air conditioner, a refrigerator, or the like is known (for example, Patent Document 1). In this electric valve 100, as shown in FIG. 6, when the stepping motor is driven and the rotor 103 rotates, the valve body 114 moves in the direction of the central axis L ′ by the screw feeding action of the female screw 131a and the male screw 121a. To do. Thereby, adjustment which opens and closes the valve port 121 is made, and the flow rate of the refrigerant flowing in from the pipe joint 111 and flowing out from the pipe joint 112 is controlled.

CN1055887906A

By the way, in the conventional motor-operated valve, the screw member constituting the screw is mainly made of metal.
However, metal screws manufactured by cutting, rolling, etc. have the merit that relatively high dimensional accuracy can be obtained, but there are many parts and it is difficult to miniaturize the motorized valve, and the friction coefficient However, there is a problem that there is a limit to improvement in durability. Therefore, in recent years, from the viewpoint of solving such a problem, the number of motor-operated valves adopting a resin screw member having a low friction coefficient and excellent durability in the motor-operated valve having the above-described structure is increasing.

  However, resin screw members are basically manufactured by injection molding, so when using a motorized valve that uses resin screw members, it is sufficient for dimensional changes such as sink marks and return that are characteristic of resin molding. You have to be careful.

  FIG. 7A is an enlarged view of a main part (inside the circle in FIG. 6) of the female screw member 131. As shown in FIG. 7 (a), in the female screw member 131 of the motor-operated valve 100 described above, the wall thickness of the side wall 140 in which the female screw 131a is formed on the inner periphery differs vertically.

  When the wall thickness of the side wall 140 is different, there is a difference in the amount of sink marks and warpage between the thick wall portion 140a and the thin wall thickness portion 140b after injection molding. This is due to the fact that the thicker wall portion 140a has a larger amount of shrinkage when the resin hardens than the thinner wall portion 140b. Therefore, actually, the shape of the female screw member 131 after the injection molding does not become the ideal shape of FIG. 7A. For example, as shown in the circle of FIG. As curing progresses, an inner warp or the like in which the inner diameter on the lower end side gradually narrows occurs in the thick wall portion 140a, and the portion where the female screw 131a is formed may be deformed.

  Thus, when the dimension of the female screw member 131 changes, the contact portion between the female screw 131a and the male screw 121a (see FIG. 6) becomes non-uniform, so that the surface pressure load of the screw can be kept constant. It becomes difficult to stably maintain the operability and durability of the screw.

  An object of the present invention is to provide an electric valve capable of maintaining excellent operability and durability even when the screw member is made of resin, and a refrigeration cycle system using the electric valve.

The motor operated valve of the present invention is
This is an electric valve that converts the rotational movement of the rotor into a linear movement by screwing the male screw member and the female screw member, and moves the valve element accommodated in the valve body in the axial direction based on this linear movement. And
The female screw member is
Formed by resin material,
A cylindrical first side wall including a portion where an internal thread is formed on the inner peripheral surface;
A second side wall formed continuously with the first side wall, wherein the female thread is not formed on the inner peripheral surface ;
A valve body accommodating portion that is a cylindrical side wall that extends from the second side wall to the opposite side of the first side wall and is not formed with the female screw ;
The first wall thickness defined by the radial distance from the thread valley of the female thread of the first side wall to the outer peripheral surface of the first side wall is from the inner peripheral surface of the second side wall to the outer peripheral surface. Formed thinner than the second wall thickness defined by the radial distance to
In the portion of the first side wall where the female screw is formed, the inner diameter of the second side wall is larger than the first inner diameter defined by the diameter formed by the thread valley of the female screw. The defined second inner diameter is formed large,
In addition, the first wall thickness is equalized.

  As described above, the inner diameter of the second side wall having a thick wall thickness without a female screw formed on the inner peripheral surface is made larger than the inner diameter of the portion of the first side wall having the thin wall thickness. Thus, even when an inner warp or the like occurs in the second side wall having a large wall thickness when the resin is cured, the dimensional change of the female screw can be suppressed. For this reason, even if it is a case where an internal thread member is shape | molded with resin, the outstanding operativity and durability can be maintained. Further, by making the wall thickness of the portion of the first side wall where the female screw is formed equal, it is possible to suppress the occurrence of a dimensional change in the portion of the first side wall where the female screw is formed. .

Moreover, the motor operated valve of the present invention is
The outer peripheral surface of the portion where the female screw is formed on the first side wall is flat.
Thereby, the effect which suppresses the dimensional change of the internal thread formed in the inner peripheral wall surface of the 1st side wall can be heightened.

Moreover, the motor operated valve of the present invention is
The first wall thickness is smaller than the first inner diameter.
As a result, voids and sink marks can be prevented from occurring in the portion of the first side wall where the female screw is formed.

Moreover, the motor operated valve of the present invention is
The first side wall includes an extended portion extending in the axial direction toward the second side wall;
A third wall thickness defined by a radial distance from the inner peripheral surface to the outer peripheral surface of the extension portion is thinner than the first wall thickness;
The third inner diameter defined by the diameter of the inner peripheral surface of the extension portion is larger than the first inner diameter.
As a result, even when an internal warp or the like occurs in the second side wall, it is possible to prevent the influence from affecting the first side wall.

In addition, the refrigeration cycle system of the present invention,
A refrigeration cycle system including at least a compressor, a condenser, an expansion valve, and an evaporator, wherein the motor-operated valve is used as the expansion valve.

  The invention according to the present invention provides a motor-operated valve capable of maintaining excellent operability and durability even when the screw member is made of resin, and a refrigeration cycle system using the motor-operated valve. Can do.

It is sectional drawing of the motor operated valve which concerns on embodiment. It is a principal part expanded sectional view of the internal thread member integrated in the motor operated valve concerning an embodiment. It is a principal part expanded sectional view of the modification of the internal thread member integrated in the motor operated valve which concerns on embodiment. It is sectional drawing of the motor operated valve which concerns on other embodiment. It is a principal part expanded sectional view of the internal thread member integrated in the motor operated valve concerning other embodiments. It is sectional drawing of the conventional motor operated valve. It is a principal part expanded sectional view of the internal thread member integrated in the conventional motor operated valve.

  Hereinafter, an electric valve according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing an electric valve 2 according to an embodiment. In the present specification, “upper” or “lower” is defined in the state of FIG. That is, the rotor 4 is located above the valve member 17.

In the motor-operated valve 2, the valve main body 30 is integrally connected by welding or the like below the opening side of a case 60 made of a non-magnetic material and having a cylindrical cup shape.
Here, the valve body 30 is made of a metal such as stainless steel and has the valve chamber 11 therein. A first pipe joint 12 that directly communicates with the valve chamber 11 and a second pipe joint 15 that communicates with the valve chamber 11 via a valve port 16a described later are fixedly mounted on the valve body 30. Both the first pipe joint 12 and the second pipe joint 15 are formed of a metal such as stainless steel or copper.

  Further, a valve seat member 16 fixedly attached to the valve body 30 and the second pipe joint 15 is provided inside the valve body 30. A cylindrical guide portion 16b for guiding the valve member 17 is formed above the valve seat member 16, and a valve port 16a having a circular cross section is formed below.

  The rotatable rotor 4 is accommodated in the inner periphery of the case 60, and the valve shaft 41 is disposed on the shaft core portion of the rotor 4 via the bush member 33. The valve shaft 41 and the rotor 4 coupled by the bush member 33 move integrally in the vertical direction while rotating. A male screw 41 a is formed on the outer peripheral surface near the middle portion of the valve shaft 41. In the present embodiment, the valve shaft 41 functions as a male screw member.

On the outer periphery of the case 60, a stator including a yoke, a bobbin, and a coil (not shown) is arranged, and the rotor 4 and the stator constitute a stepping motor.
As will be described later, the valve shaft holder 6, which has a function of forming a screw thread A between the valve shaft 41 and suppressing the inclination of the valve shaft 41, is relative to the valve body 30. It is fixed so that it cannot rotate.

  A substantially cylindrical blocker ring 24 is welded to the lower end of the valve shaft 41. Above this blocker ring 24, a flange 24a projecting outward is formed, and is in contact with the upper part of a valve spring 27 described later.

  The valve shaft holder 6 is a member composed of a first side wall 6a, a second side wall 6b, a valve body accommodating portion 6c, and a flange portion 6f. Here, the first side wall 6a has a cylindrical shape including a portion in which a female screw 6d is formed in a predetermined range in the direction of the central axis L of the inner peripheral surface (hereinafter referred to as a portion in which the female screw 6d is formed). It is a side wall. The second side wall 6b is a cylindrical side wall that forms a step projecting outward and is continuous with the first side wall 6a. Moreover, the valve body accommodating part 6c is a cylindrical side wall extended from the 2nd side wall 6b and accommodating the valve member 17 mentioned later inside. Furthermore, the flange portion 6f is a member that protrudes outward from the valve body housing portion 6c.

  In the present embodiment, the valve shaft holder 6 functions as a female screw member, and the male screw 41 a formed on the outer periphery of the valve shaft 41 and the inner periphery of the first side wall 6 a of the valve shaft holder 6. A screw thread A shown in FIG. 1 is constituted by the formed female screw 6d.

  The first side wall 6a, the second side wall 6b, and the valve body accommodating portion 6c are made of a resin material such as PPS (polyphenylene sulfide) resin, and the flange portion 6f is made of a metal such as stainless steel. Has been. The configuration of the main part of the valve shaft holder 6 will be described in detail later.

Inside the valve body accommodating portion 6c, the cylindrical guide portion 16b of the valve seat member 16 is arranged so that the outer periphery thereof is in close contact, and further, the valve member 17 is arranged inside the cylindrical guide portion 16b. Yes.
The valve member 17 is made of stainless steel, brass, or the like, and includes a valve body 17a that opens and closes the valve port 16a, and a cylindrical valve guide 17b formed above the valve body 17a. Here, a compressed valve spring 27 and a spring receiver 35 are accommodated in the valve guide 17b. A cylindrical valve bush 25 having an inner diameter smaller than that of the valve guide 17b is welded to the upper end portion of the valve guide 17b.

  Here, the valve shaft 41 is inserted in a loose state so as to be rotatable with respect to the valve guide 17b and displaceable in the radial direction, and the blocker ring 24 is rotatable with respect to the valve guide 17b. And it arrange | positions in the valve guide 17b so that it can displace to radial direction. The valve shaft 41 is inserted through the valve bush 25, and the upper surface of the flange portion 24 a of the blocker ring 24 is disposed so as to face the lower surface of the valve bush 25. The outer diameter of the flange 24a is larger than the inner diameter of the valve bush 25, thereby preventing the valve shaft 41 from coming off.

  Since the valve shaft 41 and the valve guide 17b are movable in the radial direction, the valve member 17 and the valve member 17 are not required to have a high degree of concentric mounting accuracy with respect to the arrangement positions of the valve shaft holder 6 and the valve shaft 41. The concentricity is obtained.

  Next, the main part of the valve shaft holder 6 in the embodiment will be described. FIG. 2 is an enlarged cross-sectional view of a portion shown in a circle of FIG. 1 which is a main part of the valve shaft holder 6. As shown in FIG. 2, in the present embodiment, the first side wall 6a refers to the side wall in the range from the upper end of the valve shaft holder 6 to the upper end 7a of the step in the central axis L direction. Further, the second side wall 6b indicates a side wall constituted by the step itself from the upper end 7a of the step to the lower end 7b of the step.

  The wall thickness W1 of the portion of the first side wall 6a where the female screw 6d is formed is defined by the radial distance from the thread valley of the female screw 6d to the outer peripheral surface of the first side wall 6a. The wall thickness W2 of the second side wall 6b is defined by the radial distance from the inner peripheral surface to the outer peripheral surface of the second side wall 6b.

  Since the wall thickness W1 is thinner than the wall thickness W2 of the second side wall 6b (W1 <W2), the first side wall 6a having the thinner wall thickness is hardened first after injection molding. However, the second side wall 6b having a thick wall thickness is cured later than that.

  The inner diameter D1 of the portion of the first side wall 6a where the female screw 6d is formed is defined by the diameter formed by the thread valley of the female screw 6d. The inner diameter D2 of the second side wall 6b is defined by the diameter of the inner peripheral surface of the second side wall 6b. The inner diameter D2 is formed larger than the inner diameter D1 (D1 <D2). As a result, after the valve shaft holder 6 is injection-molded, even if an inner warp or the like occurs on the second side wall 6b having a thick wall as the resin hardens (see FIG. 7B), the female screw 6d. It is possible to prevent the inner diameter D1 of the portion where the female screw 6d is formed from becoming uneven, such as the inner diameter D1 of the portion where the inner screw 6d is locally reduced.

  Further, the wall thickness W1 of the portion of the first side wall 6a where the female screw 6d is formed is equalized, and the wall thickness W1 is constant. In this case, the equal thickness does not mean that the wall thickness W1 is constant without any difference. For example, a step or a groove is not intentionally formed on the first side wall 6a. I mean. Strictly speaking, the first side wall 6a needs to have a punch taper necessary for performing the punching after injection molding. Interpreted as included within the scope.

  Thus, by making the wall thickness equal, the variation in the wall thickness W1 of the portion where the female screw 6d of the first side wall 6a is formed can be kept within a good range even after molding. It can suppress that a dimensional change arises in the part in which the internal thread 6d of the 1st side wall 6a was formed.

  In the present embodiment, it is assumed that the portion in which the female screw 6d is formed has a length in the central axis L direction of about 3 mm to 10 mm and a wall thickness W1 of about 1 mm to 3 mm. The inner diameter D1 is assumed to have a size substantially corresponding to the nominal diameters M2.0 to M7.0 of JIS B 0205 or JIS B 0209 defined by the Japanese Industrial Standard (hereinafter referred to as JIS).

  Further, the outer peripheral surface of the portion of the first side wall 6a where the female screw 6d is formed is formed flat, enhancing the effect of suppressing the dimensional change of the female screw 6d. Here, “flat” does not mean that there is no scratch on the surface, but means that the surface is smooth without undulations or irregularities.

  The wall thickness W1 of the portion of the first side wall 6a where the female screw 6d is formed is formed to be thinner than the inner diameter D1 of the portion of the first side wall 6a where the female screw 6d is formed ( W1 <D1). Thereby, it can suppress that a void and sink mark arise in the 1st side wall 6a.

  According to the invention relating to this embodiment, the main part of the valve shaft holder 6 has the above-described structure, so that the clearance of the screw screw A is reduced even when the valve shaft holder 6 is molded of resin. It is possible to prevent the deterioration of the slidability such as, and maintain excellent operability and durability. Moreover, since the dimensional change of the female screw 6d is suppressed, dimensional management and manufacturing management can be easily performed.

  In the above-described embodiment, the main part of the valve shaft holder 6 may be modified. For example, as shown in FIG. 3, the second side wall 6b side of the first side wall 6a extends in the direction of the central axis L, and the center between the upper end 7a and the lower end 7b of the step of the second side wall 6b. Shorten the distance in the direction of the axis L. Here, the wall thickness W3 of the extended portion 6k of the first side wall 6a is defined by the radial distance from the inner peripheral surface to the outer peripheral surface of the extended portion 6k. The female screw 6d is not formed on the inner peripheral surface of the extension portion 6k, and the wall thickness W3 of the extension portion 6k is thinner than the wall thickness W1 of the portion of the first side wall 6a where the female screw 6d is formed ( W3 <W1).

  Moreover, the internal diameter of the extension part 6k is prescribed | regulated by the diameter of the internal peripheral surface of the extension part 6k. FIG. 3 shows the case where the inner diameter of the extension portion 6k is the same as the inner diameter D2 of the second side wall 6b. However, the inner diameter of the extension portion 6k is formed by the female screw 6d of the first side wall 6a. What is necessary is just to be larger than the internal diameter D1 of the made part.

  As described above, when the extension portion 6k is formed on the first side wall 6a, the extension portion 6k having a thin wall thickness is cured before the second side wall 6b after the injection molding. Even when the warp or the like occurs, the influence can be prevented from reaching the first side wall 6a. Therefore, it is possible to further suppress deformation of the portion of the first side wall 6a where the female screw 6d is formed.

Further, in the valve shaft holder 6 of the above-described embodiment, the case where the second side wall 6b and the valve body accommodating portion 6c are formed below the first side wall 6a is described as an example. As shown in FIG. 4, an inverted valve shaft holder 6 ′ in which a second side wall 6 b is positioned above the first side wall 6 a and a valve body housing portion 6 c is further disposed above the second side wall 6 b is used as an electric valve. 200 may be incorporated. Here, the 2nd side wall 6b is formed above the part in which the internal thread 6d of the 1st side wall 6a was formed. Also in this case, as shown in the enlarged view of the main part of the valve shaft holder 6 'in FIG. 5, the wall thickness W1 of the portion of the first side wall 6a where the female screw 6d is formed is set to the wall thickness of the second side wall 6b. By forming it thinner than W2 (W1 <W2) and forming the inner diameter D2 of the second side wall 6b larger than the inner diameter D1 of the portion of the first side wall 6a where the female screw 6d is formed (D1 <D2). The dimensional change of the female screw 6d can be suppressed.
Further, it is more preferable that the wall thickness W1 is formed to be thinner than the inner diameter D1 (W1 <D1), and it is possible to suppress the occurrence of voids or sink marks on the first side wall 6a.

  The motor-operated valves 2 and 200 of the present embodiment are, for example, expansion valves provided between the condenser and the evaporator in a refrigeration cycle system including a compressor, a condenser, an expansion valve, and an evaporator. Used.

2,200 Electric valve 6, 6 'Valve shaft holder (female screw member)
6a 1st side wall 6b 2nd side wall 6d Female thread 6k Extension part 17 Valve member 17a Valve body 17b Valve guide 30 Valve main body 41 Valve shaft 41a Male thread

Claims (5)

This is an electric valve that converts the rotational movement of the rotor into a linear movement by screwing the male screw member and the female screw member, and moves the valve element accommodated in the valve body in the axial direction based on this linear movement. And
The female screw member is
Formed by resin material,
A cylindrical first side wall including a portion where an internal thread is formed on the inner peripheral surface;
A second side wall formed continuously with the first side wall, wherein the female thread is not formed on the inner peripheral surface ;
A valve body accommodating portion that is a cylindrical side wall that extends from the second side wall to the opposite side of the first side wall and is not formed with the female screw ;
The first wall thickness defined by the radial distance from the thread valley of the female thread of the first side wall to the outer peripheral surface of the first side wall is from the inner peripheral surface of the second side wall to the outer peripheral surface. Formed thinner than the second wall thickness defined by the radial distance to
In the portion of the first side wall where the female screw is formed, the diameter of the inner peripheral surface of the second side wall is larger than the first inner diameter defined by the diameter formed by the thread valley of the female screw. The defined second inner diameter is formed large,
The motor-operated valve is characterized in that the first wall thickness is equalized.   The motor-operated valve according to claim 1, wherein a surface of an outer periphery of a portion where the female screw is formed on the first side wall is flat.   The motor-operated valve according to claim 1, wherein the first wall thickness is thinner than the first inner diameter. The first side wall includes an extended portion that extends in the axial direction toward the second side wall;
A third wall thickness defined by a radial distance from the inner peripheral surface to the outer peripheral surface of the extension portion is thinner than the first wall thickness;
The motor-operated valve according to any one of claims 1 to 3, wherein a third inner diameter defined by a diameter of an inner peripheral surface of the extension portion is larger than the first inner diameter.   A refrigeration cycle system including at least a compressor, a condenser, an expansion valve, and an evaporator, wherein the motor-operated valve according to any one of claims 1 to 4 is used as the expansion valve. system.

Images