JP6031078B2 - Throttle device and refrigeration cycle system including the same - Google Patents

Description

  The present invention relates to a throttling device and a refrigeration cycle system including the same.

  As a refrigeration cycle system in an air conditioner, a system having a differential pressure type throttle device instead of a capillary tube as a throttle device has been proposed. The differential pressure type throttling device can optimally control the refrigerant pressure between the condenser outlet and the evaporator inlet in order to efficiently operate the compressor according to the outside air temperature, and can change the rotation speed of the compressor. Also in the refrigeration cycle system, the refrigerant pressure is optimally controlled in accordance with the rotational speed of the compressor from the viewpoint of labor saving. For example, the expansion device is joined to a primary side pipe connected to the condenser at one end where the refrigerant is introduced, and joined to a secondary side pipe connected to the evaporator at the other end where the refrigerant is discharged. ing.

  For example, as shown in Patent Document 1, the differential pressure type throttle device includes a cylindrical housing fixed to the inside of a body connected to a refrigerant passage. The housing has a refrigerant inlet and a refrigerant outlet. The housing has a strainer at the refrigerant inlet communicating with the valve hole and the fixed orifice. The fixed orifice communicates with the refrigerant outlet and the downstream outlet of the body through the space between the outer peripheral part of the housing and the inner peripheral part of the body. As a result, even when a valve body, which will be described later, is seated on the valve seat and the valve hole is in a closed state, the compressor lubricating oil dissolved in the refrigerant has a minimum flow rate (bleed amount) required for the operation of the compressor. ) Only from the refrigerant inlet to the downstream outlet of the body.

  A shaft and a piston connected to the valve body are movably disposed in the damper chamber of the housing. The shaft and the piston are urged by a spring that is arranged in the piston and urges the valve body to close the tip of the valve body with respect to the valve seat. The biasing force of the spring is adjusted by an adjusting screw screwed into the end of the housing. The tip surface of the above-mentioned valve body is formed in a substantially conical surface so as to abut against a valve seat formed at the opening edge periphery of the valve hole.

JP 2008-138812 A

  As shown in Patent Document 1, when the bleed amount is set by the above-described fixed orifice, the bleed amount is set when the set bleed amount varies due to the manufacturing error of the parts constituting each throttle device. It may be necessary to replace the housing to adjust to the proper amount. Also, if a foreign substance in the refrigerant that has not been captured by the strainer is clogged in the fixed orifice, it is not easy to remove the foreign substance, and the housing must be replaced. Furthermore, in the unlikely event that the valve body moves in a direction in which the valve hole is closed, the substantially conical surface of the valve body may bite into the valve seat formed on the periphery of the opening end of the valve hole.

  In view of the above problems, the present invention is a throttling device and a refrigeration cycle system including the same, in which the amount of bleed can be adjusted, and in the unlikely event, the valve body closes the valve hole. It is an object of the present invention to provide a throttling device that can avoid biting of the valve body against the valve seat, and a refrigeration cycle system including the same.

  In order to achieve the above-described object, a throttle device according to the present invention includes a primary chamber that is joined to a pipe of a refrigeration cycle system, is formed on the upstream side of a refrigerant flow rate adjustment unit, and refrigerant is introduced, and a refrigerant flow rate adjustment unit. A tube body having a secondary chamber formed on the downstream side from which the refrigerant is discharged, a valve seat having a valve port and partitioning the primary chamber and the secondary chamber, and constituting a part of the refrigerant flow rate adjustment unit; A needle member that is arranged so as to be close to or away from the valve port of the valve seat, has a tapered portion that controls the opening area of the valve port, and that constitutes a part of the refrigerant flow rate adjusting unit, and is disposed in the secondary chamber A biasing member disposed between the biasing member supporting portion and the needle member, and biasing the needle member in a direction approaching the valve port of the valve seat; The force acting on the needle member due to pressure is the biasing member A stopper member that supports the tip of the tapered tip of the needle member so that the opening area of the valve port has a predetermined value when the biasing force is not exceeded, and a tip of the tip of the needle member The portion has a large diameter portion larger than the diameter of the minimum diameter portion of the tapered portion of the needle member.

  The stopper member may be fixed to a cylindrical portion that extends toward the primary chamber and is formed integrally with the valve seat.

  In addition, a throttling device according to the present invention is provided in a pipe for supplying refrigerant, and has a guide tube having both ends of an open end communicating with the pipe, a valve seat formed in the guide tube and having a valve port, and a guide At least one communication path that is formed adjacent to the valve seat in the tube and communicates with the inner and outer peripheries of the guide tube, and is arranged to be close to or away from the valve port of the valve seat, and controls the opening area of the valve port A needle member having a tapered tip, a biasing member that is disposed between the needle member and one open end of the guide tube and biases the needle member in a direction adjacent to the valve port of the valve seat, and the needle When the force acting on the needle member due to the refrigerant pressure does not exceed the urging force of the urging member, the urging member urges the urging member. A stopper member that supports the tip of the needle member that is abutted so as to create a gap between the taper of the needle member and the peripheral edge of the valve port. The portion has a large diameter portion larger than the diameter of the minimum diameter portion of the tapered portion of the needle member. The stopper member may be partly or entirely formed of a porous material, and the guide tube is disposed with a predetermined gap on the inner peripheral portion of the tube body having an inner diameter larger than the outer diameter of the guide tube. It may be a thing.

  Furthermore, the refrigeration cycle system according to the present invention includes an evaporator, a compressor, and a condenser, and any one of the above-described throttle devices is disposed between the outlet of the condenser and the inlet of the evaporator. It is provided in the piping.

  According to the throttling device according to the present invention and the refrigeration cycle system including the same, when the force acting on the needle member due to the pressure of the refrigerant is not exceeded the urging force of the urging member, the tube body is disposed in the primary chamber. A stopper member is provided to support the tip of the tapered tip of the needle member so that the opening area of the valve port becomes a predetermined value, and the tip of the tapered tip of the needle member is larger than the inner diameter of the valve port. Because it has a large diameter portion that is small and larger than the diameter of the smallest diameter portion of the needle member, the amount of bleed can be adjusted, and in the unlikely event, the valve body closes the valve hole. Even when it moves in the direction, it is possible to avoid biting of the valve body against the valve seat.

It is a fragmentary sectional view which expands and shows the principal part of an example of the diaphragm | throttle device which concerns on this invention partially. It is a figure showing roughly composition of an example of a refrigerating cycle system provided with an example of an iris diaphragm concerning the present invention. It is a perspective view which shows the splash member used for the example shown by FIG. It is a fragmentary sectional view which expands and shows the principal part of an example of the diaphragm | throttle device which concerns on this invention partially. It is a characteristic view which shows the flow volume characteristic according to the differential pressure | voltage of the throttle part in the example shown by FIG. It is a fragmentary sectional view which shows another example of the stopper member in the example shown by FIG. It is sectional drawing which shows the structure of another example of the aperture_diaphragm | restriction apparatus which concerns on this invention. It is sectional drawing with which it uses for operation | movement description in the example shown by FIG.

  FIG. 2 shows a configuration of an example of a throttling device according to the present invention applied to an example of a refrigeration cycle system.

  For example, as shown in FIG. 2, the expansion device is disposed between the outlet of the condenser 6 and the inlet of the evaporator 2 in the piping of the refrigeration cycle system. The throttle device is joined to the primary side pipe Du1 at one end 10E1 of the tube body 10 to be described later, and joined to the secondary side pipe Du2 at the other end 10E2 of the tube body 10 from which the refrigerant is discharged. The primary side pipe Du1 connects the outlet of the condenser 6 and the throttle device, and the secondary side pipe Du2 connects the inlet of the evaporator 2 and the throttle device. Between the outlet of the evaporator 2 and the inlet of the condenser 6, as shown in FIG. 2, a pipe Du3 joined to the outlet of the evaporator 2 and a pipe Du4 joined to the inlet of the condenser 6 Thus, the compressor 4 is connected. The compressor 4 is driven and controlled by a control unit (not shown). Thereby, the refrigerant | coolant in a refrigerating-cycle system will be circulated along the arrow shown by FIG.

  The expansion device is integrated with the tube main body 10 joined to the pipe of the above-described refrigeration cycle system, the guide tube 18 fixed to the inner peripheral portion of the tube main body 10, and the end portion of the guide tube 18 near the primary side pipe Du1. The valve seat 18V that forms the refrigerant flow rate adjusting unit that adjusts the flow rate of the refrigerant, the needle member 20, the coil spring 16 that urges the needle member 20 toward the valve seat 18V, and the coil spring 16 includes a spring receiving portion 12 that supports one end portion of 16 and a stopper member 22 that receives a large-diameter portion 20PS of a needle member 20 to be described later as main elements.

  The tube body 10 having a predetermined length and diameter is made of, for example, a copper pipe or an aluminum pipe, and is joined to the primary side pipe Du1 connected to the condenser 6 at one end 10E1 into which the refrigerant is introduced. The other end 10E2 from which the refrigerant is discharged is joined to the secondary side pipe Du2 connected to the evaporator 2.

  An outer peripheral portion of the guide tube 18 is fixed to an intermediate portion that is separated from the one end 10E1 in the inner peripheral portion of the tube main body 10 by a predetermined distance. The guide tube 18 is fixed by the protrusion formed by the depression 10CA1 of the tube main body 10 by caulking process biting into the outer periphery thereof.

  The guide tube 18 is made of, for example, a copper pipe, a brass pipe, an aluminum pipe, or a stainless steel pipe, and has a spring receiving portion 12 at an end portion near the other end 10E2 of the tube body 10. A stopper member 22 is provided on the inner peripheral portion of the tube main body 10 at the end close to the one end 10E1. The spring receiving portion 12 is fixed by the protrusion formed by the depression 18CA1 of the guide tube 18 by caulking process biting into the outer peripheral portion thereof. The spring receiving portion 12 as the urging member support portion has a spring guide 12b with which one end of the coil spring 16 is engaged.

  In addition, the stopper member 22 is fixed to the inner peripheral portion 18a by the protrusion formed by the depression 18CA2 of the guide tube 18 by caulking process biting into the outer peripheral portion. The stopper member 22 is made of, for example, a metal porous material through which a refrigerant can pass or a cylindrical shape made of sintered metal. Both end surfaces of the stopper member 22 have substantially flat surfaces. A large-diameter portion 20PS of the needle member 20 to be described later is in contact with one end surface of both end surfaces of the stopper member 22. Thereby, the foreign material mixed in the refrigerant is also captured by the stopper member 22. Therefore, it is not necessary to provide a strainer or the like in the piping of the refrigeration cycle system.

The stopper member 22 is not limited to such an example. For example, as shown in FIG.
The stopper member 26 may be composed of a cylindrical core member 26B made of stainless steel or the like and a cylindrical member 26A surrounding the outer periphery of the core member 26B. The cylindrical member 26A is made of, for example, a metal porous material or a sintered metal. In FIG. 6, the same components as those in the example shown in FIG. 4 are denoted by the same reference numerals, and redundant description thereof is omitted.

  As shown in FIG. 2, between the spring receiving portion 12 and the stopper member 22, the inner peripheral portion of the guide tube 18 is communicated between the inner peripheral portion of the tube body 10 and the outer peripheral portion of the guide tube 18. A first communication hole 18b and a second communication hole 18c are formed. The diameter of the second communication hole 18c is set larger than the diameter of the first communication hole 18b.

  A valve seat 18V formed between the stopper member 22 and the second communication hole 18c in the guide tube 18 has a valve port 18P into which a tapered portion 20P in the needle member 20 described later is inserted in the inner central portion. Yes. The valve port 18P has a predetermined diameter φD1 and is formed to be wide toward the one end 10E1 along the central axis of the valve seat 18V.

  The needle member 20 is made of, for example, brass or stainless steel, and has a cylindrical main body 20B, a tapered portion 20P formed at an end of the main body 20B facing the valve seat 18V, and a coil in the main body 20B. And a projecting spring guide portion 20D formed at the end facing the other end of the spring 16.

  A joint portion between the main body portion 20B and the tapered portion 20P faces the second communication hole 18c. The other end portion of the coil spring 16 is engaged with the spring guide portion 20 </ b> D of the needle member 20. A spring guide portion 12 b is engaged with one end portion of the coil spring 16. The spring guide portion 20 </ b> D of the needle member 20 is provided with a spring member 24 that reduces the moving speed of the needle member 20. As shown in an enlarged view in FIG. 3, the spring member 24 includes, for example, three contact pieces 24a, 24b, and 24c that are made of a sheet metal material and integrally formed with the annular fixing piece 24A. ing. The spring guide portion 20D is inserted into the hole 24d of the fixed piece 24A.

  The three contact pieces 24a, 24b, and 24c are spaced apart from each other at an equal angle along the circumferential direction of the fixed piece 24A. As a result, the moving speed of the needle member 20 is reduced by the tips of the elastically displaceable contact pieces 24 a, 24 b, 24 c sliding on the inner peripheral surface of the guide tube 18 with a predetermined load.

  As shown in FIG. 1, the frustoconical tapered portion 20P having a predetermined taper angle has a base portion having a diameter larger than the diameter φD1 of the valve port 18P at a position separated from the valve port 18P. . A taper whose outer diameter decreases toward the tip of the taper 20P is applied to the boundary portion between the main body 20B and the base of the taper 20P. As described above, the taper faces the second communication hole 18c, and is chamfered so that the fluid that has passed through the throttle portion described later easily flows into the second communication hole 18c. A cylindrical portion having a uniform diameter is formed at a predetermined length at an end portion having a minimum diameter in the tapered portion 20P. The length from the position corresponding to the opening end of the valve port 18P in the tapered portion 20P to the above-described cylindrical portion is set to a predetermined length L. As a result, the valve opening can be increased in accordance with the differential pressure (the difference between the refrigerant inlet pressure on the one end 10E1 side and the refrigerant outlet pressure on the other end 10E2 side). When passing, the sound pressure level generated is suppressed.

  A large diameter portion 20PS having a diameter φD2 that is larger than the diameter in the vicinity of the cylindrical portion and slightly smaller than the diameter φD1 is formed at the most distal end portion of the tapered portion 20P that extends toward the stopper member 22. The thickness of the large diameter portion 20PS is set to a predetermined value T.

  At a position corresponding to the opening end of the valve port 18P in the outer peripheral portion of the tapered portion 20P of the needle member 20, the outer peripheral portion of the tapered portion 20P forms a predetermined gap with respect to the peripheral edge of the opening end portion of the valve port 18P. Has been placed. The large diameter portion 20PS is in contact with the flat surface of the stopper member 22 with a predetermined pressure corresponding to the difference between the biasing force of the coil spring 16 and the pressure of the refrigerant from the primary side pipe Du1. When the outer peripheral portion of the tapered portion 20P of the needle member 20 is separated from the peripheral edge of the open end portion of the valve port 18V as described above, the tapered portion 20P of the needle member 20 and the open end portion of the valve port 18V are separated from each other. A constriction is formed between them. The throttle portion refers to a portion (narrowest portion) where the intersection of the perpendicular line from the peripheral edge of the valve port 18V to the bus bar of the tapered detail 20P and the bus bar of the tapered detail 20P is closest to the edge of the valve port 18V. The area of the conical surface drawn by the perpendicular is the opening area of the diaphragm.

  As a result, a predetermined bleed amount passing through the aperture is set. In addition, since the large diameter portion 20PS of the tapered portion 20P of the needle member 20 is in contact with the flat surface of the stopper member 22, an undesired pressure acts on the needle member 20, and the tapered portion 20P of the needle member 20 becomes the valve seat. Biting into the open end of the 18V valve port 18P is avoided.

  Further, the outer peripheral portion of the tapered portion 20P of the needle member 20 is caused by the differential pressure (the difference between the refrigerant inlet pressure on the one end 10E1 side and the refrigerant outlet pressure on the other end 10E2 side) at the periphery of the opening end portion of the valve port 18V On the other hand, the separation start timing at which separation starts further is set based on the urging force of the coil spring 16. The spring constant of the coil spring 16 is set to a predetermined value.

Since the contact area of the large diameter portion 20PS on the flat surface of the stopper member 22 is larger than the cross-sectional area of the end portion of the tapered portion 20P so as to reduce the surface pressure, the wear of the large diameter portion 20PS of the needle member 20 is reduced. Suppressed and bleed flow hardly changes over time.
Further, when the large diameter portion 20PS comes into contact with the stopper portion 22, a biasing force in the valve closing direction by the coil spring 16 acts on the contact surface between the stopper portion 22 and the large diameter portion 20PS. Since the force in the valve opening direction also acts due to the pressure difference between the refrigerant pressure from the primary side pipe Du1 and the refrigerant pressure from the secondary side pipe Du2, this also suppresses wear of the large diameter portion 20PS of the needle member 20. This also makes it difficult for the bleed flow rate to change over time.

  The adjustment of the biasing force of the coil spring 16, that is, the adjustment of the reference height (set length) of the coil spring 16 corresponding to each refrigerant is performed, for example, in the following procedure. The reference height refers to the height of the coil spring 16 set so as to be the above-described predetermined separation timing of the tapered portion 20P of the needle member 20 corresponding to each refrigerant.

  First, when the stopper member 22 is fixed to the guide tube 18, first, the needle member 20 is inserted into the inner peripheral portion of the guide tube 18. Then, the needle member 20 is pressed against the valve seat 18V using a coil spring or the like, and then, the guide tube 18 into which the stopper member 22 is inserted is, for example, a bleed flow rate measuring device / caulking device using air as a fluid. After adjusting the position of the stopper member 22 relative to the guide tube 22 so that the air flow rate is equal to the target bleed flow rate, the stopper member 22 is caulked and fixed to the guide tube 18 so that the bleed is obtained. Adjustment of the flow rate is completed.

  When the spring receiving portion 12 is fixed, the guide tube 18 to which the stopper member 22 is fixed is defined in advance, for example, in a state where the guide tube 18 is arranged in a predetermined performance measuring / caulking device (not shown) in which air is fluidized. After adjusting the position of the spring receiving portion 12 with respect to the guide tube 22 based on the detection of the air flow rate with the applied pressure, the spring length of the coil spring 16 is fixed by caulking and fixing the spring receiving portion 12. Adjustment is completed.

  Accordingly, since an adjustment screw or the like for adjusting the spring length of the coil spring 16 is not required, the valve opening start pressure corresponding to each refrigerant can be adjusted, and the structure of the expansion device can be simplified and the manufacturing cost can be simplified. Can be reduced.

  In such a configuration, as shown in FIG. 2, when the force acting on the needle member 20 due to the refrigerant pressure does not exceed the urging force of the coil spring 16, the refrigerant passes along the direction indicated by the arrow through the primary side pipe Du1. The pressure of the refrigerant is reduced by passing through the one end 10E1 of the tube body 10, the inner peripheral portion 18a of the guide tube 18, the stopper member 22, and the above-described throttle portion, and then the refrigerant is second A predetermined bleed amount is discharged from the other end 10E2 through the communication hole 18c, the inner peripheral portion 18a of the guide tube 18 and the inner peripheral portion 10a of the tube body 10.

  Further, when the force acting on the needle member 20 due to the pressure of the refrigerant exceeds the urging force of the coil spring 16, the needle member in a direction in which the refrigerant flowing through the stopper member 22 and the above-described throttle portion is further away from the peripheral edge of the valve port 18V. 20 will be pressed. As a result, as shown in FIG. 5, the flow rate Q of the refrigerant gradually increases according to the characteristic line La rather than the bleed amount as the differential pressure DP increases, and the differential pressure DP is, for example, a predetermined value. When PA (0.3 Mpa) and the flow rate Q are equal to or greater than a predetermined value GA (2 liters), the flow rate increases rapidly according to the characteristic line La as the differential pressure DP increases. FIG. 5 shows a characteristic line La that represents the change in accordance with the refrigerant differential pressure, with the vertical axis representing the flow rate Q of the above-mentioned throttle section and the horizontal axis representing the above-mentioned refrigerant differential pressure DP. Although not shown in the figure, the characteristic line La may be a gentle curve convex downward due to the influence of pressure loss or the like in the piping.

  Furthermore, FIG. 7 shows a configuration of another example of the expansion device according to the present invention applied to an example of the refrigeration cycle system. In FIG. 7, the same components as those in the example shown in FIG. 2 are denoted by the same reference numerals, and redundant description thereof is omitted.

  Similar to the example shown in FIG. 2, the expansion device is disposed between the outlet of the condenser and the inlet of the evaporator in the piping of the refrigeration cycle system. The throttle device is joined to a primary side pipe at one end 10'E1 of a tube body 10 'to be described later, and joined to a secondary side pipe at the other end 10'E2 of the tube body 10' from which the refrigerant is discharged. Yes.

  The expansion device is provided on the tube body 10 ′ joined to the piping of the above-described refrigeration cycle system and the inner peripheral portion of the tube body 10 ′ near the primary side piping 10 ′ E 1, and adjusts the flow rate of the refrigerant. The valve seat 38 constituting the refrigerant flow rate adjusting unit, the needle member 20, the coil spring 28 that urges the needle member 20 toward the valve seat 38, and one end of the coil spring 28 are supported. In addition, the main element includes an urging force adjusting screw mechanism 33 that adjusts the urging force of the coil spring 28 and a stopper member 32 that is connected to the valve seat 38 and receives the large-diameter portion 20PS of the needle member 20. ing.

  The tube body 10 'having a predetermined length and diameter is made of, for example, a copper pipe or an aluminum pipe, and is joined to a primary side pipe connected to a condenser at one end 10'E1 into which a refrigerant is introduced. The other end 10′E2 from which the refrigerant is discharged is joined to the secondary side pipe connected to the evaporator.

  As shown in FIG. 7, the outer peripheral portion of the valve seat 38 is fixed to an intermediate portion spaced a predetermined distance from one end 10 ′ E <b> 1 in the inner peripheral portion of the tube main body 10 ′. The outer periphery of the valve seat 38 is fixed by the protrusion formed by the depression 10′CA1 of the tube main body 10 ′ by caulking process biting into the outer periphery. On the upstream side of the valve seat 38 in the tube body 10 ', a recess 10'CA3 for positioning the inserted primary side pipe is formed.

  The valve seat 38 has a valve port 38P into which the tapered portion 20P of the needle member 20 is inserted at the inner central portion. The valve port 38P has a predetermined diameter and is formed in a divergent shape toward the one end 10′E1 along the central axis of the valve seat 38. The male threaded portion of the stopper member 32 is screwed into the female threaded portion of the female threaded portion of the cylindrical portion as the cylindrical portion extending the inner peripheral surface forming the valve port 38P of the valve seat 38. The cylindrical stopper member 32 is made of, for example, stainless steel and has through holes 32a with a predetermined interval on a common circumference. The through hole 32 a penetrates along the central axis of the stopper member 32. Both end surfaces of the stopper member 32 have substantially flat surfaces. One end face of the both end faces of the stopper member 32 is in contact with the large diameter portion 20PS of the needle member 20.

  The stopper member 32 is not limited to such an example. For example, the stopper member 32 may be formed of a composite body including a cylindrical core member made of stainless steel and a cylindrical member surrounding the outer peripheral portion of the core member. Good. The cylindrical member may be made of, for example, a metal porous material or a sintered metal. Thereby, the foreign material mixed in the refrigerant is also captured by the stopper member 32. Therefore, it is not necessary to provide a strainer or the like in the piping of the refrigeration cycle system.

  The biasing force adjusting screw mechanism 33 includes an adjusting screw support portion 31 that is fixed to the inner peripheral portion of the tube main body 10 ′ and has a female screw portion, and an adjusting screw 30 that is engaged with the other end portion of the coil spring 28. It consists of

  The adjustment screw 30 has a male screw portion on the outer peripheral portion and a through hole 30a in the inner center portion. The male screw portion is fitted into the female screw of the adjustment screw support portion 31 fixed to the inner peripheral portion of the tube main body 10 ′. The adjustment screw support portion 31 is fixed by biting a protrusion formed by the depression 10′CA2 of the tube main body 10 ′ by caulking. At the end of the adjustment screw 30 on the side of the other end 10′E2 of the tube body 10 ′, a groove for engaging the tip of the driver is formed. As a result, the amount of deflection of the coil spring 28 is adjusted by turning and sending the adjustment screw 30 by the tip of the driver, so that the biasing force of the coil spring 28 is adjusted according to the design pressure of the refrigerant. Become. That is, at a predetermined differential pressure (the difference between the refrigerant inlet pressure on the one end 10′E1 side and the refrigerant outlet pressure on the other end 10′E2 side), the position of the needle member 20 in the tapered portion 20P is The urging force of the coil spring 28 is adjusted so as to be in the position of the specified lift amount.

  When the outer peripheral portion of the tapered portion 20P of the needle member 20 is separated from the peripheral edge of the open end portion of the valve port 38P as described above, the tapered portion 20P of the needle member 20 and the open end portion of the valve port 38P are separated from each other. A constriction is formed between them. The throttle portion refers to a point (narrowest portion) where the intersection of the perpendicular line from the peripheral edge of the valve port 38P to the bus bar of the tapered detail 20P and the bus bar of the tapered detail 20P is closest to the edge of the valve port 38P. The area of the conical surface drawn by the perpendicular is the opening area of the diaphragm.

  As a result, a predetermined bleed amount passing through the aperture is set. Further, since the large diameter portion 20PS of the tapered portion 20P of the needle member 20 is in contact with the flat surface of the stopper member 32, an undesired pressure acts on the needle member 20, and the tapered portion 20P of the needle member 20 becomes the valve seat. Biting into the open ends of the 38 valve ports 38P is avoided.

  Further, the outer peripheral portion of the tapered portion 20P of the needle member 20 is opened by the differential pressure (the difference between the refrigerant inlet pressure on the one end 10′E1 side and the refrigerant outlet pressure on the other end 10′E2 side). The separation start timing at which the separation starts from the peripheral edge of the end portion is set based on the urging force of the coil spring 28. The spring constant of the coil spring 28 is set to a predetermined value.

  Since the contact area of the large-diameter portion 20PS on the flat surface of the stopper member 32 is larger than the cross-sectional area of the end of the tapered portion 20P so as to reduce the surface pressure, the wear of the large-diameter portion 20PS of the needle member 20 is reduced. Suppressed and bleed flow hardly changes over time. Further, when the large diameter portion 20PS comes into contact with the stopper portion 32, the urging force in the valve closing direction by the coil spring 28 acts on the contact surface between the stopper portion 32 and the large diameter portion 20PS. Since the force in the valve opening direction also acts due to the pressure difference between the refrigerant pressure from the primary side pipe Du1 and the refrigerant pressure from the secondary side pipe Du2, this also suppresses wear of the large diameter portion 20PS of the needle member 20. This also makes it difficult for the bleed flow rate to change over time.

  In such a configuration, as shown in FIG. 7, when the force acting on the needle member 20 due to the pressure of the refrigerant does not exceed the urging force of the coil spring 28, the refrigerant passes along the direction indicated by the arrow through the primary side pipe. When supplied, the pressure of the refrigerant is reduced by passing through one end 10 ′ E 1 of the tube main body 10 ′, the through hole 32 a of the stopper member 32, and the above-mentioned throttle part, and then the refrigerant is the contact piece of the splash 24. A predetermined bleed amount is discharged from the other end 10'E2 through 24a, 24b, 24c, through the inner periphery 10'a of the tube body 10 ', and the through hole 30a.

  Further, when the force acting on the needle member 20 due to the pressure of the refrigerant exceeds the urging force of the coil spring 28, as shown in FIG. 8, the refrigerant flowing through the stopper member 32 and the above-described throttle portion causes the peripheral edge of the valve port 38 </ b> P. The needle member 20 is pressed against the urging force of the coil spring 28 in a direction further away from the coil spring 28. Thereby, as shown in FIG. 5, the flow rate Q of the refrigerant gradually increases along the characteristic line La from the bleed amount as the above-described differential pressure DP increases. When the value PA (0.3 Mpa) and the flow rate Q are equal to or greater than the predetermined value GA (2 liters), the flow rate increases rapidly along the characteristic line La as the differential pressure DP increases.

  Therefore, even in such an example, the amount of bleed can be adjusted, and even if the valve body moves in the direction of closing the valve hole, the bite of the valve body against the valve seat You can avoid sticking.

  In the example shown in FIGS. 2, 6, and 7 described above, the distal end portion of the tapered portion 20 </ b> P extending toward the stopper members 22, 26, and 32 has a diameter larger than the diameter near the cylindrical portion. The large-diameter portion 20PS having a diameter φD2 slightly smaller than the inner diameter of the valve port is integrally formed with the tapered portion 20P. However, the present invention is not limited to such an example. After being formed separately from 20P, the large-diameter portion and the tapered portion 20P may be integrated by a screw mechanism or joining. In such a case, the diameter of the large diameter portion can be set larger than the inner diameter of the valve port. Further, in the example shown in FIG. 2 and FIG. 7 described above, the large diameter portion is formed at the forefront of the tapered portion 20P. However, the present invention is not limited to such an example. When the concave portion into which the needle is inserted is formed on the end surface of the stopper member, the large-diameter portion of the needle member may be formed like a ridge at a position closer to the base side than the most distal end of the needle member.

10, 10 'Tube body 12 Spring receiving portion 18 Guide tube 18V Valve seat 18P Valve port 18PS Large diameter portion 20 Needle members 22, 26, 32 Stopper member

Claims (6)

A primary chamber that is joined to the piping of the refrigeration cycle system and is formed upstream of the refrigerant flow rate adjustment unit and into which refrigerant is introduced; and a secondary chamber that is formed downstream of the refrigerant flow rate adjustment unit and from which the refrigerant is discharged; A tube body having:
A valve seat having a valve port, partitioning the primary chamber and the secondary chamber, and constituting a part of the refrigerant flow rate adjustment unit;
A needle member that is arranged so as to be close to or away from the valve port of the valve seat, has a tapered portion that controls an opening area of the valve port, and forms a part of the refrigerant flow rate adjustment unit;
A biasing member disposed between the biasing member support and the needle member disposed in the secondary chamber, and biasing the needle member in a direction approaching the valve port of the valve seat;
When the force acting on the needle member due to the pressure of the refrigerant does not exceed the urging force of the urging member, the opening area of the valve port is set to a predetermined value. A stopper member that supports the tip of the tip of the needle member to be abutted,
2. A throttling device according to claim 1, wherein a tip end portion of the tapered portion of the needle member has a large diameter portion larger than a diameter of a minimum diameter portion of the tapered portion of the needle member.   The throttling device according to claim 1, wherein the stopper member extends toward the primary chamber side and is fixed to a cylindrical portion formed integrally with the valve seat. A guide tube which is arranged in a pipe for supplying a refrigerant and has open end portions communicating with the pipe at both ends;
A valve seat formed in the guide tube and having a valve port;
At least one communication passage formed adjacent to the valve seat in the guide tube and communicating with the inner periphery and the outer periphery of the guide tube;
A needle member having a taper for controlling an opening area of the valve port, the needle member being arranged to be close to or away from the valve port of the valve seat;
An urging member that is arranged between the needle member and one open end of the guide tube and urges the needle member in a direction approaching the valve port of the valve seat;
When the force acting on the needle member due to the pressure of the refrigerant does not exceed the biasing force of the biasing member, the biasing member is arranged between the needle member and the other opening end of the guide tube. A stopper member for supporting the tip of the tapered tip of the needle member so as to create a gap between the tapered tip of the needle member and the peripheral edge of the valve port;
2. A throttling device according to claim 1, wherein a tip end portion of the tapered portion of the needle member has a large diameter portion larger than a diameter of a minimum diameter portion of the tapered portion of the needle member.   The diaphragm apparatus according to claim 1 or 3, wherein a part or all of the stopper member is made of a porous material.   The diaphragm device according to claim 3, wherein the guide tube is disposed with a predetermined gap on an inner peripheral portion of a tube main body having an inner diameter larger than an outer diameter of the guide tube. An evaporator, a compressor, and a condenser;
6. The refrigeration cycle system, wherein the expansion device according to claim 1 is provided in a pipe disposed between an outlet of the condenser and an inlet of the evaporator. .

Images