Patent Description:
An electric drive valve such as a solenoid valve opening and closing a valve with the use of an actuator has been conventionally used in a refrigeration cycle system which is provided with a refrigerant cycle, for example, an air conditioner, a refrigeration device and a freezing device.

Further, as the electric drive valve mentioned above, a pilot type solenoid valve controlling a main valve body opening and closing a flow channel for a refrigerant with a small pilot valve has been used, in particular in a case where a large-diameter valve is required.

Further, the following patent literature <NUM> is provided as a literature which discloses an invention in which a valve main body is formed according to a hollow extrusion molding.

Similar electric drive valves are disclosed by <CIT>, <CIT>, <CIT>, <CIT> and <CIT>.

However, the invention described in the patent literature <NUM> mentioned above relates to an expansion valve, and can not be directly applied to manufacturing of an electric drive valve.

Therefore, an object of the present invention exists in a point of manufacturing cost reduction of an electric drive valve by enabling reduction of a used amount in a material forming a valve main body.

In order to solve the problem mentioned above and achieve the object, an electric drive valve according to the present invention comprises the features of claim <NUM>. Preferred embodiments of the invention are defined in the subclaims. An electric drive valve according to the present invention includes a valve main body which has a valve chamber in an inner portion thereof, a first flow channel port which is formed in the valve main body and communicates with the valve chamber, a second flow channel port which is formed in the valve main body and communicates with the valve chamber, a valve port which has a valve seat and is disposed between the second flow channel port and the valve chamber in such a manner as to be open to the valve chamber, a valve body which moves in a direction of a center axis, and an actuator which drives the valve body, and the valve main body is formed by a hollow extruded material which has a through hole extending in an axial direction. Further, in the electric drive valve, a center axis of the second flow channel port is consistent with a center axis of the through hole.

In the electric drive valve according to the present invention, the valve main body is formed by the hollow extruded material having the through hole. Therefore, a used amount of the material can be reduced and a manufacturing cost can be reduced at an amount that the portion of the through hole is hollow, in comparison with the conventional electric drive valve in which the valve main body is cut out of a raw material block (block-like raw material lump) according to a cutting work. Further, even in a case where a planar portion mentioned later is disposed in an outer peripheral surface of the valve main body, a working process for forming the planar portion can be omitted by forming the valve main body with the extruded material, and a used amount of the material can be reduced in comparison with a case where the planar portion is formed from a columnar raw material block according to the cutting work.

The material constructing the valve main body is an aluminum alloy. However, the material is not necessarily limited to the aluminum alloy, but the valve main body can be formed by the other material in the present invention. An effect of reduced manufacturing cost on the basis of reduced material usage can be also obtained in the same manner even in the other constructing material.

Further, in the electric drive valve according to the present invention, the valve seat is preferably formed in an inner peripheral surface portion of the through hole with the use of the through hole. This is for the purpose of applying a high durability to the valve seat which repeatedly contacts with and separates from the valve body. More specifically, a mechanical strength is generally enlarged in an outer peripheral surface portion and an inner peripheral surface portion of the hollow extruded material since a metal crystal grain is refined in the outer peripheral surface portion and the inner peripheral surface portion of the hollow extruded material due to a shear stress caused by friction between a raw material metal flowing in metal mold and a metal mold surface when molding. Therefore, the durability of the valve seat can be improved by forming the valve seat in the inner peripheral surface portion.

Further, the electric drive valve according to the present invention is a cartridge type electric drive valve fixed to a housing member (which may be also called simply as "housing") by inserting the valve main body into a valve fixing hole formed in the housing member which includes an inflow channel for refrigerant and an outflow channel for refrigerant. According to an aspect of the present invention, an outer peripheral surface of an upper end portion of the valve main body is provided with a pair of planar portions which are parallel to a center axis of the valve main body and expand in parallel to each other.

According to the aspect mentioned above, the electric drive valve can be gripped in such a manner as to hold the pair of planar portions therebetween when attaching the electric drive valve to the housing member, and an attaching work of the electric drive valve to the housing member can be easily performed. In particular, in a case of adopting a structure that the electric drive valve is fixed by forming a female screw on an inner peripheral surface of the valve fixing hole, forming a male screw engaging with the female screw on an outer peripheral surface of the valve main body, and screwing the valve main body to the valve fixing hole of the housing member, a fastening work can be achieved by holding the pair of planar portions therebetween in such a manner as to fasten a bolt with a wrench and screwing the electric drive valve to the housing member (the valve fixing hole) on the basis of the provision of the pair of planar portions as mentioned above.

Further, in the present invention, any one of the first flow channel port and the second flow channel port forms an inflow port which allows the refrigerant to flow into the valve chamber (is communicated with the inflow channel of the housing member in a case of the cartridge type electric drive valve as mentioned above), and the other forms an outflow port which allows the refrigerant to flow out of the valve chamber (is communicated with the outflow channel of the housing member in a case of the cartridge type electric drive valve as mentioned above).

Further, in the aspect including the pair of planar portions, the valve main body may be provided in a side surface portion of the valve main body with two openings which are communicated with the valve chamber and can form the first flow channel port, one of these two openings may be adapted to be arranged directly under one of the pair of planar portions, and the other of these two openings may be adapted to be arranged directly under the other of the pair of planar portions. This is because of convenience when the electric drive valve is attached to the housing member.

In particular, in the cartridge type electric drive valve, the valve main body (a lower portion or an intermediate portion of the valve main body) fitted to the valve fixing hole of the housing member is provided with the flow channel port (one of the first flow channel port and the second flow channel port) which is communicated with the inflow channel (the flow channel opening open to the valve fixing hole) of the housing member, and the flow channel port (the other of the first flow channel port and the second flow channel port) which is communicated with the outflow channel (the flow channel opening open to the valve fixing hole) of the housing member. However, these flow channel ports are hard to be visually confirmed after the valve main body is inserted into the valve fixing hole.

Particularly, in a case where the flow channel port is disposed in the side surface of the valve main body (in this case, the flow channel opening in the housing side to be communicated is also formed in a side surface (an inner peripheral surface) of the valve fixing hole), the flow channel port (the side surface flow channel port) formed on the side surface of the valve main body moves in a peripheral direction along the outer peripheral surface of the valve main body by rotating the electric drive valve around an axis. Therefore, it is not necessarily easy to make the flow channel port confront with the flow channel opening in the housing side and accurately communicate the flow channel port with the flow channel opening.

Therefore, in the aspect mentioned above according to the present invention, a position of the flow channel port (the opening) can be adapted to be known on the basis of the planar portion which is easy to be visually confirmed after fitting the valve main body to the valve fixing hole, by forming the flow channel port (the opening which can be used as the first flow channel port or the second flow channel port) just below the planar portion formed in the upper end portion of the valve main body, in other words, by conforming the formed position of the planar portion to the formed position of the flow channel port with respect to the position of the valve main body as seen from the axial direction. This configuration particularly has an effect by a configuration in which the cartridge type electric drive valve and the housing member are fixed according to the other methods than the screwing method as mentioned above (for example, a configuration using a fixing plate <NUM> in <FIG>).

Thus, it is possible to accurately attach the electric drive valve to the housing member, that is, to attach the electric drive valve to the housing member in such a manner that the flow channel port of the electric drive valve and the flow channel of the housing member confront with each other without being misaligned in a peripheral direction and are completely communicated with each other, so that it is possible to improve a workability when attaching the electric drive valve. When fitting to the valve fixing hole of the housing member, the upper end portion of the valve main body may protrude out of the valve fixing hole and the planar portion may be exposed from the valve fixing hole, or a whole of the valve main body may be fixed to the valve fixing hole (in this case, the planar portion is also accommodated within the valve fixing hole, however, the planar portion can be visually confirmed from the upper surface of the valve fixing hole).

Further, in a case where the flow channel port is disposed in a bottom surface of the valve main body, the center axis of the valve main body is preferably adapted to coincide with the center axis of the valve fixing hole in the flow channel port (the bottom surface flow channel port), and the flow channel opening in the housing side is preferably adapted to be formed in the center portion of the valve fixing hole as well as arranging the flow channel port in the center portion of the bottom surface of the valve main body. According to the configuration as mentioned above, the flow channel port in the electric drive valve side and the flow channel opening in the housing side are not relatively misaligned even if the valve main body is rotated around the center axis, and both elements (the flow channel port in the electric drive valve side and the flow channel opening in the housing side) can be communicated only by inserting the valve main body into the valve fixing hole.

The number of the planar portions are not limited to one set, but two or more sets of planar portions may be provided. For example, in a case where two sets of planar portions are provided, an outer peripheral surface of an upper end portion of the valve main body may be provided further with the other one pair of planar portions which are parallel to a center axis of the valve main body, expand in parallel to each other and are orthogonal to the pair of planar portions.

Further, in a case where the other one pair of planar portions are further provided as mentioned above, the valve main body is preferably provided in a side surface portion of the valve main body with four openings which can communicate with the valve chamber and can be formed as the first flow channel port or the second flow channel port, a first opening among these four openings is preferably arranged directly under one of a pair of planar portions, a second opening among these four openings is preferably arranged directly under the other of the pair of planar portions, a third opening among these four openings is preferably arranged directly under one of the other pair of planar portions, and a fourth opening among these four openings is preferably arranged directly under the other of the other pair of planar portions.

This is because the position of the opening can be known on the basis of the position of the planar portion in the same manner as the case where the one set (one pair) of planar portions are provided. Further, according to the aspect that four openings are provided as mentioned above, the flow channel port (the opening) of the valve main body can be better confronted with the flow channel opening in the housing side in a case where a screwing type fixing configuration such as a second embodiment mentioned later is employed. More specifically, in the case of the screwing type fixing configuration, the position of the opening moves not only in the peripheral direction but also in the axial direction by rotating the valve main body (goes toward the bottom surface of the valve fixing hole by screwing the valve main body into the valve fixing hole). However, the more the number of the openings disposed in the peripheral direction is, the more finely the relative position between the opening and the flow channel opening in the axis direction can be adjusted, so that the flow channel port (the opening) of the valve main body can be arranged with respect to the flow channel opening in the housing side without any misalignment in the axial direction (or with a little misalignment).

The electric drive valve according to the present invention or each of the aspects may be a pilot type electric drive valve including a pilot valve which is interposed between the valve body and the actuator. In this case, the valve body is driven by the actuator via the pilot valve.

The pilot type electric drive valve may be a cartridge type electric drive valve fixed to a housing member by inserting the valve main body into a valve fixing hole formed in the housing member which is provided with an inflow channel for the refrigerant and an outflow channel for the refrigerant. In this case, an outer peripheral surface of an upper end portion of the valve main body is provided with a pair of planar portions which are parallel to a center axis of the valve main body and expand in parallel to each other, the first flow channel port is an inflow port which is formed in a side surface portion of the valve main body and just below any one of the pair of planar portions, and allows the refrigerant to flow into the valve chamber, the second flow channel port is an outflow port which is formed in a bottom surface portion of the valve main body and allows the refrigerant to flow out of the valve chamber, and the valve port is formed between the second flow channel port and the valve chamber.

Further, in the pilot type electric drive valve mentioned above, the valve main body may be provided in a side surface portion of the valve main body with at least two openings which communicate with the valve chamber and can be formed as the first flow channel port, one of these two openings may be arranged just below one of the pair of planar portions, and the other of these two openings may be arranged directly under the other of the pair of planar portions. The purpose for disposing a pair of planar portions and the purpose for arranging the opening disposed in the side surface portion of the valve main body directly under the planar portion are as already mentioned.

According to the present invention, the manufacturing cost of the electric drive valve can be reduced by reducing the used amount of the material for forming the valve main body and the working man hour.

The other objects, features and advantages of the present invention are made apparent by the following description of embodiments of the present invention described on the basis of the accompanying drawings. In the drawings, same reference numerals denote the same or corresponding portions.

A description will be given below of an electric drive valve (a solenoid valve) according to an embodiment of the present invention. First of all, a description will be given of a valve main body used in the solenoid valve along the lines of a manufacturing process. Next, a description will be given of the solenoid valve using the valve main body as first and second embodiments. The valve main body mentioned below is used in the solenoid valve according to the second embodiment. However, the valve main body used in the solenoid valve according to the first embodiment can be manufactured through the similar process.

As shown in <FIG>, in order to manufacture a valve main body, a hollow extruded material (hereinafter, also refer simply to as "extruded material") <NUM> having an approximately cylindrical shape is manufactured according to an extrusion molding. The extruded material <NUM> is made of an aluminum alloy, has in a center portion thereof a through hole 1a extending in a vertical direction (an axial direction), and is provided in an outer peripheral surface thereof with a pair of flat surfaces 2a and 2b which are parallel to a center axis A and expand in parallel to each other, and the other pair of flat surfaces 2c and 2d which are parallel to the center axis A, expand in parallel to each other and are orthogonal to the pair of flat surfaces 2a and 2b.

In the present embodiment, the valve main body is manufactured from the extruded material <NUM> having the shape as mentioned above. Therefore, in comparison with a case where the valve main body is cut out of the columnar raw material block such as the prior art, it is possible to reduce a construction material for the valve main body at such a degree that the through hole 1a and the flat surfaces 2a, 2b, 2c and 2d are formed, and it is possible to reduce a manufacturing cost of the solenoid valve. Further, a part (an upper portion, refer to reference signs 45a, 45b, 45c and 45d in <FIG>) of the flat surfaces 2a, 2b, 2c and 2d can be used as the planar portion in the present invention. Therefore, it is possible to omit a step of forming a planar portion according to a cutting work.

Further, a hole (an opening) is formed by cutting the extruded material <NUM> from an upper surface side as shown by an arrow C1 in <FIG>, the hole to which a valve chamber (a main valve chamber) <NUM> and a connecting member <NUM> mentioned later are fitted. Further, an outer peripheral surface of a valve main body <NUM> is formed by cutting the extruded material <NUM> from a side surface side as shown by an arrow C2 in <FIG>. In <FIG>, hatching lines are applied to portions to be formed according to the cutting work.

<FIG> and <FIG> show a state in which the cutting work is finished. As shown in these drawings, a lower portion of the through hole 1a (refer to <FIG>) is used as a valve port <NUM> for allowing the refrigerant to flow out of the valve chamber <NUM>, and a valve seat (a main valve seat) <NUM> is formed in an upper end portion of the valve port <NUM>. As mentioned above, in an inner peripheral surface portion (an inner peripheral surface and a portion near the inner peripheral portion) of the through hole 1a, a metallic crystal is refined and densified by application of a shear stress caused by a friction between a raw material metal flowing within a metal mold and a metal mold surface when molding, and a mechanical strength of the inner peripheral surface portion becomes higher. Therefore, a durability of the valve seat <NUM> can be improved by forming the valve seat <NUM> with the use of the portion.

Further, these two sets of flat surfaces (the pair of flat surfaces 2a and 2b and the other pair of flat surfaces 2c and 2d) are cut in their lower portions from their intermediate portions according to the cutting work from the side surface, and are left only in the upper end portion of the valve main body <NUM> (refer to reference signs 45a, 45b, 45c and 45d). These upper end portions 45a, 45b, 45c and 45d of the remaining flat surfaces are the planar portion in the present invention, and can be used for confirming the positions of the openings 4a, 4b, 4c and 4d (the inflow port <NUM>) when the solenoid valves <NUM> and <NUM> are attached to a housing <NUM> as mentioned later, and fastening the valve main body <NUM> screwed into a valve fixing hole <NUM>.

Further, grooves 3a and 3b for installing sealing members (an upper O-ring <NUM> and a lower O-ring <NUM>) are formed in an outer peripheral surface of the valve main body <NUM>.

Finally, as shown in <FIG> and <FIG>, openings 4a, 4b, 4c and 4d (hatched portions in <FIG>), a male screw 5b and a female screw 5a are formed, the openings 4a, 4b, 4c and 4d capable of forming the inflow port <NUM>, the male screw 5b provided for screwing into a valve fixing hole <NUM> of a housing member <NUM>, and the female screw 5a provided for screwing a connecting member <NUM> connecting an electromagnetic actuator <NUM> serving as an actuator. A solenoid valve <NUM> according to a first embodiment mentioned later is fixed to the housing member <NUM> with the use of a fixing plate <NUM> without being screwed. Therefore, the male screw 5b in the outer peripheral surface is not necessarily formed in the valve main body <NUM> which is used in the solenoid valve <NUM> according to the first embodiment.

Further, four openings 4a, 4b, 4c and 4d are pierced in the valve main body <NUM>, and are formed directly under the four planar portions 45a, 45b, 45c and 45d (in such a manner that the positions of the openings 4a to 4d coincide with the positions of the planar portions 45a to 45d in the peripheral direction). Thus, the positions of the openings 4a to 4d can be confirmed on the basis of the positions of the planar portions 45a to 45d after the lower portion of the valve main body <NUM> is inserted into the valve fixing hole <NUM> of the housing <NUM>.

Describing the planar portions 45a to 45d and the openings 4a to 4d differently, in the present embodiment, four planar portions 45a to 45d (same applies to the flat surfaces 2a to 2d) are formed in such a manner that the directions of the adjacent planar portions (perpendicular lines of the planar portions 45a to 45d) form an angle of <NUM> degrees each other (are orthogonal to each other) (for example, look forward, rearward, leftward and rightward). Four openings 4a to 4d are also formed on the peripheral surface of the valve main body <NUM> in such a manner that the directions of the adjacent openings (directions of the axes of the openings 4a to 4d) form an angle of <NUM> degrees each other (are orthogonal to each other) (for example, look forward, rearward, leftward and rightward), in the same manner as the planar portions 45a to 45d. Further, the direction (the position in the peripheral direction of the valve main body <NUM>) of each of the planar portions 45a to 45d is adapted to coincide with the direction (the position in the peripheral direction of the valve main body <NUM>) of each of the openings 4a to 4d.

Only one set of planar portions <NUM> (a pair of planar portions 45c and 45d) may be provided as shown in <FIG>. In this case, the opening <NUM> may be formed directly under each of the planar portions <NUM> (45c and 45d) one by one (refer to reference signs 4c and 4d), that is, for example, two openings may be totally formed.

A description will be given below of the solenoid valve with the use of the valve main body <NUM>.

As shown in <FIG>, a solenoid valve <NUM> according a first embodiment of the present invention is provided with a valve portion <NUM> which opens and closes a flow channel for refrigerant, and an electromagnetic actuator <NUM> which drive the valve portion <NUM>, is a solenoid valve which controls a refrigerant flow in a refrigeration cycle equipment, for example, a heat pump type heating and cooling system, and is a pilot type solenoid valve which controls a main valve body <NUM> opening and closing a refrigerant flow channel by a pilot valve. Further, the solenoid valve <NUM> is a so-called cartridge type solenoid valve which can be embedded in the refrigeration cycle equipment by fixing to a housing member <NUM> including an inflow channel <NUM> and an outflow channel <NUM> for refrigerant, and is a normal open type (normally open type) valve which comes to a valve open state when not being energized.

Each of the drawings shows a two-dimensional coordinate which appropriately represents a longitudinal direction, a lateral direction and a vertical direction and is orthogonal to each other, and the following description will be given on the basis of these directions. However, since the solenoid valve according to the present invention and each of the embodiments can be used in various directions, the directions are provided as a matter of convenience, and do not restrict a configuration of each of portions of the present invention.

The solenoid valve <NUM> according to the present embodiment has a valve main body <NUM>, an inflow port <NUM>, a valve port <NUM>, a valve seat (a main valve seat) <NUM>, a valve body (a main valve body) <NUM>, a lower coil spring (a compression coil spring) <NUM> and a connecting member <NUM> as a valve portion <NUM> (a main valve). The valve main body <NUM> is provided in an inner portion thereof with a valve chamber (a main valve chamber) <NUM> which allows the refrigerant to pass through. The inflow port <NUM> is pierced in a side surface (a peripheral surface) of the valve main body <NUM> in such a manner as to allow the refrigerant to flow into the main valve chamber <NUM>. The valve port <NUM> is provided in a lower end thereof with an outflow port <NUM> for refrigerant, passes through a bottom surface portion of the valve main body <NUM> in a vertical direction and forms a discharge channel for discharging the refrigerant from the main valve chamber <NUM>. The main valve seat <NUM> is formed in an upper end of the valve port <NUM>. The main valve body <NUM> opens and closes the valve port <NUM> by moving forward and backward (upward and downward) with respect to the main valve seat <NUM>. The compression coil spring <NUM> energizes upward the main valve body <NUM>. The connecting member <NUM> connects the electromagnetic actuator <NUM> to the valve main body <NUM>.

The valve main body <NUM> is made of a hollow extruded material, and is manufactured by applying the manufacturing process mentioned above to the extruded material. Therefore, the valve main body <NUM> is provided in an upper portion thereof with a plurality of (four in the present embodiment and a second embodiment mentioned later) planar portions 45a, 45b, 45c and 45d, and is provided in a valve main body side surface directly under each of the planar portions 45a, 45b, 45c and 45d with a plurality of (totally for in the present embodiment and the second embodiment mentioned later) openings 4a, 4b, 4c and 4d which can be used as the inflow port <NUM>.

The inflow port <NUM> is one of these four openings 4a, 4b, 4c and 4d. Further, the valve port <NUM> and the outflow port <NUM> use the through hole 1a of the hollow extruded material <NUM>, and the main valve seat <NUM> is formed in an inner peripheral surface portion of the through hole 1a.

The connecting member <NUM> has a flange portion 41a having a ring shape and a cylinder portion 41b having a cylindrical shape, and is integrally provided with a stator <NUM> (mentioned later) in an upper surface center portion of the flange portion 41a. The ring-shaped flange portion 41a is arranged in an upper surface portion of the valve main body <NUM> in such a manner as to close an upper surface opening of the valve main body <NUM>, and has a center hole. The cylindrical cylinder portion 41b extends vertically downward from a lower surface of the flange portion 41a. The cylinder portion 41b is provided in an outer peripheral surface thereof with a male screw 41c engaging with a female screw 5a which is formed in an inner peripheral surface of the upper surface opening of the valve main body <NUM>, and fixes the connecting member <NUM> to the valve main body <NUM> by screwing the cylinder portion 41b to the upper surface opening of the valve main body <NUM>. Further, an upper portion of the main valve body <NUM> is fitted and inserted to the cylinder portion 41b in such a manner as to be slidable in the vertical direction, and an inner upper surface of the cylinder portion 41b forms a stopper surface which stops the main valve body <NUM> by the contact with the upper surface of the main valve body <NUM> when opening the valve.

Further, a pilot passage <NUM> and a pressure equalizing channel <NUM> are formed in the main valve body <NUM>. The pilot passage <NUM> passes through in a center portion of the main valve body <NUM> in a vertical direction and allows the main valve chamber <NUM> and a pilot chamber <NUM> (mentioned later) to communicate. The pressure equalizing channel <NUM> passes through the main valve body <NUM> in the vertical direction in the same manner and allows the main valve chamber <NUM> and the pilot chamber <NUM> to communicate, however, has a smaller diameter than that of the pilot passage <NUM>. The main valve chamber <NUM> according to the present embodiment is a space between the main valve body <NUM> and the main valve seat <NUM> and a space facing the inflow port <NUM>.

A pilot valve is provided between an upper surface of the main valve body <NUM> and the electromagnetic actuator <NUM>. Specifically, an inner side of a center hole of the flange portion 41a in the connecting member <NUM> is set to the pilot chamber <NUM>, a pilot valve seat <NUM> is formed in an upper end (an upper surface center portion of the main valve body <NUM>) of the pilot passage <NUM> which is open to the pilot chamber <NUM>, and a pilot valve body <NUM> is provided in such a manner as to come close to and away from the pilot valve seat <NUM>. The pilot valve body <NUM> is fixed to a lower end of a plunger <NUM> (mentioned later), and opens and closes the pilot passage <NUM> by moving up and down together with the plunger <NUM>. The pilot chamber <NUM> according to the present embodiment is a space which is formed in the upper side of the main valve body <NUM>.

In the meantime, the electromagnetic actuator <NUM> has a coil <NUM>, a stator <NUM> and the plunger <NUM>. The coil <NUM> is formed by applying a winding wire to a bobbin <NUM>. The stator <NUM> is arranged in an inner side of the coil <NUM>. The plunger <NUM> is attracted to the stator <NUM> on the basis of a magnetic force generated by the coil <NUM>. The bobbin <NUM> is provided in a center portion thereof with a tubular portion, and is arranged within the tubular portion in a state in which the stator <NUM> and the plunger <NUM> are housed in a sleeve <NUM>. The sleeve <NUM> is a bottomless and covered (closed in an upper surface and opened in a lower surface) tubular member, is fixed in a lower end portion thereof to an outer peripheral surface of the stator <NUM>, and forms an enclosed space in an upper surface portion of the valve main body <NUM> together with the connecting member <NUM>. The plunger <NUM> is housed in the sleeve <NUM> in such a manner as to be slidable in a vertical direction, is provided between the plunger <NUM> and the stator <NUM> with an upper coil spring (a compression coil spring) <NUM> which biases upward the plunger <NUM>, and biases the pilot valve body <NUM> in a valve opening direction.

On the other hand, the housing member <NUM> is provided with a valve fixing hole <NUM>, an inflow channel <NUM>, and an outflow channel <NUM>. The valve fixing hole <NUM> can fix the solenoid valve <NUM>. The inflow channel <NUM> is open to an inner peripheral surface of the valve fixing hole <NUM>. The outflow channel <NUM> is open to a bottom surface of the valve fixing hole <NUM>. The housing member <NUM> is attached to the solenoid valve <NUM> by inserting a lower portion of the valve main body <NUM> into the valve fixing hole <NUM> in such a manner that the inflow port <NUM> (any of the four openings 4a, 4b, 4c and 4d mentioned above) formed in the side surface (the peripheral surface) of the valve main body <NUM> confronts with an opening portion of the inflow channel <NUM> to the valve fixing hole <NUM>, and thereafter pressing a flange portion 12a formed in an upper outer peripheral surface of the valve main body <NUM> against an upper surface of the housing member <NUM> by means of a fixing plate <NUM> which is fixed to the upper surface of the housing member <NUM> by a fixing screw <NUM>.

A step portion <NUM> engaging with the flange portion 12a of the valve main body <NUM> is formed in the fixing plate <NUM>, an upward movement of the valve main body <NUM> is controlled by the step portion <NUM>, and the valve main body <NUM> is fixed to the housing member <NUM>. Further, the fixing of the coil <NUM> is simultaneously performed when the fixing plate <NUM> is fixed. More specifically, the coil <NUM> is fixed while fitting and inserting the sleeve <NUM> to the tubular portion of the bobbin <NUM>, and a lower peripheral edge of the coil cover <NUM> covering the coil <NUM> is thereafter fixed to the upper surface of the fixing plate <NUM> by the fixing screw <NUM>.

The outflow port <NUM> in the bottom surface of the valve main body faces an opening portion to the valve fixing hole <NUM> of the outflow channel <NUM> in the housing member <NUM> by inserting the valve main body <NUM> into the bottom surface of the valve fixing hole <NUM>, and communicates with the outflow channel <NUM>. Further, by the provision of the sealing members <NUM> and <NUM> on the outer peripheral surface of the valve main body <NUM> in such a manner as to hold the inflow port <NUM> (each of the openings 4a, 4b, 4c and 4d) in the vertical direction, the sealing is achieved between the outer peripheral surface of the valve main body <NUM> and the inner peripheral surface of the valve fixing hole <NUM>. More specifically, the upper O-ring <NUM> is installed within the groove 3a which is formed at the position above the inflow port <NUM> (each of the openings 4a to 4d), and the lower O-ring <NUM> is installed within the groove 3b which is formed at the position below the inflow port <NUM> (each of the openings 4a to 4d). Thus, even if the refrigerant flows out of the openings 4a, 4b and 4d which is not used as the inflow port <NUM> to an external portion of the valve main body <NUM> (into the valve fixing hole <NUM>), it is possible to prevent the refrigerant from leaking out of the upper surface of the valve fixing hole <NUM> or flowing out to the outflow channel <NUM>.

A description will be given below of a motion of the solenoid valve according to the present embodiment.

In the valve open state shown in <FIG>, the pilot passage <NUM> is opened, and the high-pressure refrigerant is discharged to the outflow channel <NUM> through the pilot passage <NUM> without accumulating within the pilot chamber <NUM>, the high-pressure refrigerant flowing into the main valve chamber <NUM> from the inflow channel <NUM> and flowing into the pilot chamber <NUM> through the pressure equalizing channel <NUM>. Therefore, the pressure within the pilot chamber <NUM> is not enlarged, the main valve body <NUM> is pressed against the lower surface of the connecting member <NUM> (the flange portion 41a) by the biasing force of the lower coil spring <NUM> biasing the main valve body <NUM> upward (a valve opening direction), and the valve open state is maintained. Thus, the refrigerant flowing into the main valve chamber <NUM> from the inflow channel <NUM> through the inflow port <NUM> flows out of the outflow port <NUM> to the outflow channel <NUM> through the valve port <NUM> (refer to arrows F1 and F2).

The plunger <NUM> is sucked to the stator <NUM> by energizing the coil <NUM> within the electromagnetic actuator <NUM>. As a result, the plunger <NUM> moves down against the biasing force of the upper coil spring <NUM>, and allows the pilot valve body <NUM> to seat on the pilot valve seat <NUM>. Thus, the pilot passage <NUM> is closed, the refrigerant pressure introduced into the pilot chamber <NUM> through the pressure equalizing channel <NUM> is accumulated without being discharged through the pilot passage <NUM>, and the pressure within the pilot chamber <NUM> rises up. A force for pressing the main valve body <NUM> downward is generated by the refrigerant pressure within the pilot chamber <NUM> (accurately, a differential pressure between the pilot chamber <NUM> and the main valve chamber <NUM>), and a suction force of the stator <NUM> (a downward force sucking the plunger <NUM>). When the force for pressing the main valve body <NUM> downward goes beyond the upward biasing force of the lower coil spring <NUM>, the main valve body <NUM> moves down and seats on the main valve seat <NUM>. Thus, there comes to a valve closed state in which the valve port <NUM> is closed.

On the other hand, when the energization of the coil <NUM> stops from the valve closed state, the suction force of the stator <NUM> disappears and the plunger <NUM> is released from the stator <NUM>. As a result, the plunger <NUM> is pushed back upward by the upper coil spring <NUM>, the pilot valve body <NUM> is disconnected from the pilot valve seat <NUM> and the pilot passage <NUM> is released. Then, the refrigerant accumulated within the pilot chamber <NUM> is discharged to the outflow channel <NUM> through the pilot passage <NUM>, and the pressure within the pilot chamber <NUM> is lowered. Further, the differential pressure for pulling the main valve body <NUM> upward is generated in upper and lower surfaces of the main valve body <NUM> since a cross sectional area of the pilot passage <NUM> is greater than that of the pressure equalizing channel <NUM>. In addition, the lower coil spring <NUM> has a biasing force for pulling the main valve body <NUM> upward. Thus, the main valve body <NUM> is pushed up, the main valve body <NUM> is disconnected and the valve port <NUM> is released, thereby achieving a valve open state (refer to <FIG>) in which the refrigerant flow channel from the inflow channel <NUM> to the outflow channel <NUM> via the main valve chamber <NUM> is opened.

As shown in <FIG> and <FIG>, a solenoid valve <NUM> according to a second embodiment of the present invention is a so-called cartridge type pilot solenoid valve which is attached to the housing member <NUM> including the inflow channel <NUM> and the outflow channel <NUM> for the refrigerant, in the same manner as the first embodiment. However, the solenoid valve <NUM> is a normal closed type (normally closed type) solenoid valve which comes to a valve closed state when not being energized. In the description of the present embodiment, same reference numerals and signs are attached to the same or corresponding configurations as or to those of the first embodiment, a redundant explanation will be omitted, and a description will be given mainly on different points.

The solenoid valve <NUM> according to the present embodiment adopts a screwing type fixing configuration as a fixing method to the housing member <NUM>. Specifically, a female screw <NUM> is formed in an inner peripheral surface of the valve fixing hole <NUM> of the housing member <NUM>, a male screw 5b engaging with the female screw <NUM> is disposed in the outer peripheral surface of the valve main body <NUM>, and the solenoid valve <NUM> can be fixed to the housing member <NUM> by screwing the valve main body <NUM> to the valve fixing hole <NUM>.

The valve main body <NUM> is made of the hollow extruded material <NUM> mentioned above, is worked according to the processes mentioned with reference to <FIG>, and is provided with two sets of planar portions 45a, 45b, 45c and 45d, and the openings 4a, 4b, 4c and 4d pieced directly under the respective planar portions 45a to 45d, one (the opening 4d in the present embodiment) of the openings 4a to 4d being set to the inflow port <NUM>. The planar portions 45a to 45d can be used for confirming the positions of the openings 4a to 4d in the peripheral direction when screwing the valve main body <NUM> to the valve fixing hole <NUM> as already mentioned, and can be also used when performing the fastening work.

The valve port <NUM> and the main valve seat <NUM> formed by using the through hole 1a are disposed in a bottom surface portion of the valve main body <NUM>, and the main valve body <NUM> moving up and down with respect to the main valve seat <NUM> is disposed within the main valve chamber <NUM>. The main valve body <NUM> is supported in an upper portion thereof by a cylinder portion 12b formed in an upper end portion of the valve main body <NUM> so as to be slidable in a vertical direction. Further, a lower coil spring <NUM> biasing the main valve body <NUM> upward is disposed between a bottom surface of the main valve chamber <NUM> and the main valve body <NUM>.

A connecting member <NUM> having a center hole is installed in an upper opening of the valve main body <NUM> (an upper surface of the cylinder portion 12b). The connecting member <NUM> is provided in an outer peripheral surface thereof with a male screw 41c which engages with the female screw 5a formed in an inner peripheral surface of the upper opening of the valve main body <NUM>, and is fixed to the valve main body <NUM> by being screwed to the upper opening of the valve main body <NUM>. Further, a lower end portion of the sleeve <NUM> is fitted and fixed to the center hole of the connecting member <NUM>.

A pilot chamber <NUM> is formed in an upper surface of the main valve body <NUM>, and the pilot valve body <NUM> is arranged within the pilot chamber <NUM>. The pilot valve body <NUM> is fixed to a lower end portion of the plunger <NUM> which is slidably housed in a lower portion of the sleeve <NUM>, and moves up and down together with the plunger <NUM>. The pilot valve body <NUM> opens and closes the pilot passage <NUM> by coming into contact with and away from (contacting with and disconnecting from) the pilot valve seat <NUM> which is formed in an upper center portion of the main valve body <NUM>.

Further, the upper surface of the main valve body <NUM> is protruded in a peripheral edge portion thereof upward. Thus, the peripheral edge portion comes into contact with the lower surface of the connecting member <NUM> when the main valve body <NUM> is pushed up by the lower coil spring <NUM> and moves up, so that the main valve body <NUM> stops. In a valve opened (fully opened) state corresponding to the stop state (a state in which the main valve body <NUM> comes into contact with the lower surface of the connecting member <NUM>), the plunger <NUM> is at the highest position where the plunger <NUM> is sucked to the stator <NUM>, a fixed gap is formed between the pilot valve body <NUM> in the lower end of the plunger and the pilot valve seat <NUM> in the upper center portion of the main valve body, and the pilot passage <NUM> is opened.

The electromagnetic actuator <NUM> is provided with a coil <NUM>, a plunger <NUM> and a stator <NUM> in the same manner as the first embodiment. The coil <NUM> is formed by applying the winding wire to the bobbin <NUM>. The plunger <NUM> and the stator <NUM> is arranged within the tubular portion in a center portion of the bobbin in a state of being housed in the sleeve <NUM>. In the meantime, in the present embodiment, the sleeve <NUM> is a bottomless and coverless (closed in both an upper surface and a lower surface) tubular member and is provided with the stator <NUM> in such a manner as to close the upper surface of the sleeve <NUM>. An upper coil spring <NUM> biasing the plunger <NUM> downward is disposed between the plunger <NUM> and the stator <NUM> which are housed in the lower portion of the sleeve <NUM>. Further, in the same manner as the first embodiment, an upper O-ring <NUM> is disposed in an outer peripheral surface of the valve main body above the inflow port <NUM> (each of the openings 4a to 4d), and a lower O-ring <NUM> is disposed in the outer peripheral surface of the valve main body below the inflow port <NUM> (each of the openings 4a to 4d).

A description will be next given of a motion of the solenoid valve according to the present embodiment.

In a valve closed state shown in <FIG>, the pilot valve body <NUM> seats on the pilot valve seat <NUM> and the pilot passage <NUM> is closed. Therefore, an internal pressure of the pilot chamber <NUM> communicating with the main valve chamber <NUM> via the pressure equalizing channel <NUM> becomes equal to the pressure within the main valve chamber <NUM>. On the other hand, the pressure within the valve port <NUM> becomes lower than the main valve chamber <NUM>, and the main valve body <NUM> seats on the main valve seat <NUM> by the pressure (accurately, the differential pressure between the pilot chamber <NUM> and the space within the valve port <NUM>), so that the valve closed state is maintained.

When the coil <NUM> within the electromagnetic actuator <NUM> is energized, the plunger <NUM> is sucked to the stator <NUM>. As a result, the plunger <NUM> moves up against the biasing force of the upper coil spring <NUM>, the pilot valve body <NUM> is disconnected from the pilot valve seat <NUM> and the pilot passage <NUM> is opened. Thus, the refrigerant introduced into the pilot chamber <NUM> through the pressure equalizing channel <NUM> is discharged to the outflow channel <NUM> through the pilot passage <NUM>, and the pressure within the pilot chamber <NUM> is lowered. Further, the differential pressure pulling up the main valve body <NUM> is generated in the upper and lower surfaces of the main valve body <NUM> since a cross sectional area of the pilot passage <NUM> is greater than that of the pressure equalizing channel <NUM>. In addition, the lower coil spring <NUM> has a biasing force for pulling up the main valve body <NUM>. Therefore, the main valve body <NUM> is pushed up, thereby forming a valve opened state in which the valve port <NUM> is opened. The pushed-up main valve body <NUM> runs into the lower surface of the connecting member <NUM> and is stopped. Therefore, the pilot valve seat <NUM> in the upper center portion of the main valve body does not come into contact with the lower surface of the pilot valve body <NUM> and the pilot valve is not closed, so that the pilot passage <NUM> is kept opened.

On the contrary, when the energization of the coil <NUM> is stopped from this valve opened state, the suction force of the stator <NUM> disappears and the plunger <NUM> is disconnected from the stator <NUM>. As a result, the plunger <NUM> is pushed back downward by the upper coil spring <NUM>, the pilot valve body <NUM> seats on the pilot valve seat <NUM> and the pilot passage <NUM> is closed. Then, the refrigerant flowing into the pilot chamber <NUM> through the pressure equalizing channel <NUM> is accumulated within the pilot chamber <NUM>, the pressure within the pilot chamber <NUM> is increased, and the main valve body <NUM> is pushed down against the biasing force of the lower coil spring <NUM> by this pressure (accurately, the differential pressure between the pilot chamber <NUM> and the main valve chamber <NUM> facing the inflow port <NUM>) and seats on the main valve seat <NUM>, thereby forming a valve closed state (refer to <FIG>) in which the valve port <NUM> is closed.

The embodiments according to the present invention are described above. However, it is apparent for a person skilled in the art that the present invention is not limited to these embodiments, but can be variously modified within the scope of the claims.

For example, all of the solenoid valves according to the embodiments are the pilot type valves. However, the present invention is not limited to the pilot type valve, but can be applied to a direct-acting type valve. Further, all of the solenoid valves according to the embodiments are the cartridge type valves.

Further, the solenoid valve according to the present invention is used in the refrigeration cycle equipment including the refrigerant cycle, typically such as the air conditioner and the freezer and refrigerator. Further, the present invention is not limited to the solenoid valve, but can be applied to an electric drive valve, for example, a motor valve including an actuator moving a valve body with the use of a motor.

Claim 1:
An electric drive valve comprising:
a valve main body (<NUM>) which has a valve chamber (<NUM>) in an inner portion thereof;
a first flow channel port which is formed in the valve main body (<NUM>) and communicates with the valve chamber (<NUM>);
a second flow channel port which is formed in the valve main body (<NUM>) and communicates with the valve chamber (<NUM>);
a valve port (<NUM>) which has a valve seat (<NUM>) and is disposed between the second flow channel port and the valve chamber (<NUM>) in such a manner as to be open to the valve chamber (<NUM>);
a valve body (<NUM>) which moves in a direction of a center axis (A); and
an actuator (<NUM>) which drives the valve body (<NUM>);
wherein the valve main body (<NUM>) is formed by a hollow extruded material of an aluminium alloy which has a through hole (1a) extending in an axial direction of the center axis (A);
characterized in that
the electric drive valve is a cartridge type electric drive valve configured to be fixed to a housing member (<NUM>) by inserting the valve main body (<NUM>) into a valve fixing hole (<NUM>) formed in the housing member (<NUM>) which is provided with an inflow channel for refrigerant and an outflow channel for refrigerant,
the second flow channel port is an outflow port (<NUM>) which is formed in a center of a bottom surface portion of the valve main body (<NUM>) and configured to be connected to the outflow channel (<NUM>) of the housing member (<NUM>), allowing the refrigerant to flow out of the valve chamber (<NUM>),
the center axis (A) of the valve main body (<NUM>) is adapted to coincide with the center axis (A) of the valve fixing hole (<NUM>),
a center axis (A) of the second flow channel port (<NUM>) is consistent with a center axis (A) of the through hole (1a),
a lower portion of the through hole (1a) is used as the valve port (<NUM>), and
the valve seat (<NUM>) is formed in an upper end portion of the valve port (<NUM>).