JP4351622B2 - Flow control valve, expansion valve for refrigeration cycle apparatus, and refrigeration cycle apparatus - Google Patents

Description

The present invention relates to a flow rate control valve, an expansion valve for a refrigeration cycle apparatus, and a refrigeration cycle apparatus, and more particularly to a flow rate control valve, an expansion valve, and a refrigeration cycle used in a refrigeration cycle apparatus using a CO ₂ refrigerant, etc. It relates to the device.

  The expansion valve used in the refrigeration cycle apparatus is roughly divided into a temperature type expansion valve having a pressure sensing part by a diaphragm or bellows and a temperature detection part by a temperature sensing cylinder, and an electric type that sets the valve opening degree by driving a stepping motor. There are expansion valves and electromagnetic expansion valves that set the valve opening degree by electromagnetic force (for example, Patent Documents 1, 2, and 3).

  The temperature type expansion valve detects the degree of superheat from the secondary pressure (evaporation pressure) acting on the pressure sensing part and the temperature sensed by the temperature sensing tube (evaporator outlet temperature), and the degree of superheat of the refrigerant gas sucked into the compressor Although the flow rate of the refrigerant flowing through the evaporator is controlled so as to achieve the set superheat degree, there are problems of hunting and that the superheat degree set value can only be changed manually by matching with the refrigeration system.

  In particular, in the temperature expansion valve of a refrigeration cycle that uses an in-vehicle engine-driven non-capacity control compressor, the pressure on the low-pressure side suddenly drops during rapid acceleration of the vehicle, whereas the temperature sensed by the temperature sensing cylinder is a time constant. Due to the influence of the above, an operation delay is caused, so that hunting is likely to occur. For this reason, the evaporator blowout air temperature fluctuates and the passenger compartment temperature is not stable.

In addition, when considering a temperature expansion valve of a refrigeration cycle apparatus using a CO ₂ refrigerant, the pressure-resistant design specification of a pressure-sensitive portion (pressure-sensitive element) such as a bellows or a diaphragm becomes difficult, and the problem is that the expansion valve is expensive. There is also.

  The electric expansion valve with a stepping motor specifies the valve opening with the driving pulse of the stepping motor so that the superheat detected by the superheat sensor becomes the set superheat, thereby adjusting the valve opening and adjusting the evaporator The flow rate of the refrigerant flowing in the vehicle is controlled by a delay in the valve opening adjustment operation, but during a transitional state or when the load suddenly fluctuates, the vehicle in the refrigeration cycle using a non-capacity control compressor driven by an engine During rapid acceleration, there is a time delay for the valve opening to follow the state change.

  For this reason, it is easy to raise | generate hunting, the evaporator blowing air temperature is fluctuate | varied, and vehicle interior temperature is hard to be stabilized. Moreover, a separately installed superheat degree sensor and controller are required, and the cost is higher than that of the temperature type expansion valve.

  The electromagnetic expansion valve controls the valve opening by PWM current value control to the electromagnetic coil so that the degree of superheat detected by the superheat degree sensor becomes the set superheat degree. Compared with the electric expansion valve with a stepping motor, it requires a superheat degree sensor and controller separately installed. In comparison, the cost is unavoidable.

  In addition, both the electric expansion valve driven by the stepping motor and the electromagnetic expansion valve have a detection delay as a sensor unit due to variations in the installation of the separately installed superheat degree sensor on the piping and the time constant of the superheat degree sensor itself. Therefore, the controllability becomes worse.

  In addition, there is a so-called differential pressure expansion valve that controls the flow rate of the refrigerant flowing through the evaporator by adjusting the valve opening degree by the refrigerant differential pressure before and after the throttle on the inlet side of the evaporator (for example, Patent Document 4). ).

  However, since this differential pressure expansion valve controls the flow rate of the refrigerant flowing through the evaporator by the refrigerant differential pressure before and after the throttle on the inlet side of the evaporator, the superheat degree of the refrigerant gas sucked into the compressor is set to the set superheat degree. It is difficult to control properly.

  In addition to the expansion valve, a refrigeration cycle apparatus in which a superheat degree control valve is provided in a refrigerant passage between the outlet side of the evaporator and the inlet side of the compressor, and the superheat degree of the sucked refrigerant is controlled by the superheat degree control valve. And a superheat degree control valve used in the refrigeration cycle apparatus (for example, Patent Document 5).

The refrigeration cycle apparatus that controls the flow rate of the refrigerant according to the superheat degree on the outlet side of the evaporator by the superheat degree control valve can appropriately perform control to set the superheat degree of the refrigerant gas sucked into the compressor to the set superheat degree. However, this refrigeration cycle apparatus requires a separate superheat degree control valve in addition to the expansion valve, which complicates the system configuration and increases the cost.
JP 60-142175 A Japanese Patent No. 2615021 JP 2004-93031 A JP 2004-218918 A Japanese Patent Publication No. 7-21373

The problem to be solved by the present invention is that the expansion valve used in the refrigeration cycle apparatus has self-controllability, little operation delay, and the degree of superheat of the refrigerant gas sucked into the compressor regardless of a sudden change in the cycle state In the refrigeration cycle apparatus using the CO ₂ refrigerant, the problem of the pressure resistance design specification does not occur.

  The flow control valve according to the present invention includes a first inlet port, a first outlet port, a valve port provided between the first inlet port and the first outlet port, and a second inlet. A valve housing having a port, a second outlet port, a flow path chamber provided between the second inlet port and the second outlet port, and an opening degree of the valve port by axial movement A valve body having a flow rate adjusting portion for adjusting; a valve shaft portion that is movably moved in the axial direction into the flow passage chamber; and provided in the valve shaft portion in the flow passage chamber, and flows through the flow passage chamber. A pressure receiving plate that applies a fluid dynamic pressure in the valve opening direction; and an adjustment spring that biases the valve body in the valve closing direction.

  The expansion valve for a refrigeration cycle apparatus according to the present invention includes a first inlet port connected to the outlet side of the condenser, a first outlet port connected to the inlet side of the evaporator, and the first inlet port. A valve port provided between the first outlet port, a second inlet port connected to the outlet side of the evaporator, a second outlet port connected to the inlet side of the compressor, A valve housing having a flow passage chamber provided between a second inlet port and the second outlet port; a flow rate adjusting portion for adjusting an opening degree of the valve port by axial movement; and the flow passage A valve body having a valve shaft portion that has entered the chamber so as to be movable in the axial direction; and provided in the valve shaft portion in the flow path chamber, the dynamic pressure of the refrigerant flowing through the flow path chamber is exerted in the valve opening direction. A pressure receiving plate, and an adjustment spring for urging the valve body in the valve closing direction.

  The expansion valve for a refrigeration cycle apparatus according to the present invention preferably has spring load variable setting means for variably setting the initial set load of the adjustment spring. As the spring load variable setting means, there is an adjusting screw member that takes charge of the adjustment spring and can change the mounting position in the axial direction by screw engagement, and further, a spring load setting value, in other words, a setting value of the superheat degree. An electric motor for rotating the adjustment screw member can be provided so that the adjustment screw member can be changed by an external operation.

  The expansion valve for the refrigeration cycle apparatus according to the present invention is preferably an electromagnetic coil that urges the valve body in the valve closing direction or the valve opening direction by an electromagnetic suction force so that the set value of the superheat degree can be changed by an external operation. Have the device.

  The refrigeration cycle apparatus according to the present invention controls the flow rate of refrigerant flowing from the condenser to the evaporator in response to the dynamic pressure of the refrigerant flow on the outlet side of the compressor, condenser, evaporator, and evaporator. And an expansion valve.

  The refrigeration cycle apparatus according to the present invention includes the expansion valve for the refrigeration cycle apparatus according to the above-described invention.

  The superheat control in the expansion valve and the refrigeration cycle apparatus according to the present invention has a correlation between the refrigerant superheat degree and the refrigerant density, and the operation principle is that the refrigerant density correlates exclusively with the dynamic pressure of the refrigerant flow in the constant flow path, The flow rate of the refrigerant flowing into the evaporator is controlled in response to the dynamic pressure exclusively of the refrigerant flow on the outlet side of the evaporator, and the superheat degree of the refrigerant gas sucked into the compressor is self-controlled to the set superheat degree. In other words, the expansion valve according to the present invention is a self-controlled dynamic pressure expansion valve. The flow control valve according to the present invention is also used exclusively as a self-control type dynamic pressure expansion valve.

Thereby, even if there is little operation delay and sudden change of the cycle state occurs, the superheat degree of the refrigerant gas sucked into the compressor is appropriately controlled to the set superheat degree. Furthermore, even when the superheat degree of the refrigerant at the outlet of the evaporator becomes 0 ° C due to a sudden change in the cycle state, the dryness value is detected and moves, so it is set earlier than the conventional temperature expansion valve. It is controlled so that the degree of superheat is reached. Moreover, not only the superheat setting but also the dryness setting can be set. In addition, since a pressure-sensitive part as in the temperature type expansion valve is not required, the problem of the pressure-resistant design specification does not occur even in the refrigeration cycle apparatus using the CO ₂ refrigerant.

  Embodiment 1 of an expansion valve (flow control valve) and a refrigeration cycle apparatus according to the present invention will be described with reference to FIG.

  The expansion valve according to the first embodiment is configured as an energization closed electromagnetic expansion valve 10. The electromagnetic expansion valve 10 has a valve housing 11. The valve housing 11 includes a first inlet port 12, a first outlet port 13, a valve port 14 provided between the first inlet port 12 and the first outlet port 13, and a second An inlet port 15 and a second outlet port 16 are formed.

  Apart from the flow path including the valve port 14 between the first inlet port 12 and the first outlet port 13, the valve housing 11 cooperates with a stationary attractor 31 of an electromagnetic coil device 30 to be described later. Between the two inlet ports 15 and the second outlet port 16, a flow passage chamber 17 for detecting dynamic pressure is defined.

  The valve housing 11 includes a valve body support hole 18 penetrating a valve housing 11 portion that divides a flow path including the first inlet port 12, the first outlet port 13, and the valve port 14 and the flow path chamber 17. The hollow shaft-shaped valve body 20 is supported so as to be movable in the axial direction (vertical direction) by a guide member 48 that is press-fitted and fixed to the lower part of the fixed attractor 31 of the electromagnetic coil device 30 described later.

  The valve body 20 adjusts the opening degree of the valve port 14 by moving in the axial direction to quantitatively control the flow rate of the fluid flowing through the valve port 14, and the valve body support hole 18 from the flow rate adjustment section 21. And a valve shaft portion 22 that penetrates and projects into the flow path chamber 17.

  The valve body 20 reduces the valve opening when the flow rate adjustment unit 21 approaches the valve port 14 by the downward movement, and conversely, the flow rate adjustment unit 21 moves away from the valve port 14 by the upward movement. Increase the valve opening.

  A pressure receiving plate 23 is provided in a portion of the valve shaft portion 22 located in the flow path chamber 17. The pressure receiving plate 23 is pressed against a snap ring 24 that is locked to the valve shaft portion 22 by a valve spring 25 that is a compression coil spring, and is attached to a predetermined position of the valve shaft portion 22 while restraining upward displacement. The valve spring 25 is sandwiched between the bottom of the flow path chamber 17 and the pressure receiving plate 23 and biases the valve body 20 in the valve opening direction.

  The pressure receiving plate 23 flows into the flow channel chamber 17 from the second inlet port 15 and flows out of the flow channel chamber 17 from the second outlet port 16 to thereby reduce the dynamic pressure of the fluid flowing through the flow channel chamber 17. The upward direction, that is, the valve opening direction is exerted.

  An appropriate gap 26 is set between the outer edge of the pressure receiving plate 23 and the inner wall surface of the flow path chamber 17 so that only the dynamic pressure acts on the pressure receiving plate 23.

  An electromagnetic coil device 30 is attached to the upper portion of the valve housing 11. The electromagnetic coil device 30 is fixedly attached to the upper end of the plunger tube 32, the fixed suction element 31 fixed to the upper part of the valve housing 11 by caulking, the plunger tube 32 fixedly attached to the upper part of the fixed suction element 31, and the plunger tube 32. An upper cover plug 33 and an adjustment screw member 34 screw-engaged with the upper cover plug 33. Airtight O-rings 35 and 36 are attached to the fixed suction element 31 and the adjustment screw member 34, respectively.

  A coil unit 41 including an outer rod 37, a magnetic path guide member 38, a coil portion 39, an electric connector 40 for energizing the coil, and the like are fixed to the outer peripheral portions of the fixed attractor 31 and the plunger tube 32.

  A central through hole 42 is formed through the fixed suction element 31 in the axial direction. The valve shaft portion 22 of the valve body 20 penetrates the central through hole 42 so as to be movable in the axial direction without contact, and penetrates the guide member 48 that is press-fitted and fixed to the lower portion of the fixed suction element 31 in a contact state. The upper end portion 27 of the valve shaft portion 22 is located in the plunger chamber 43 defined inside the plunger tube 32. The upper end portion 27 of the valve shaft portion 22 is inserted into the plunger 44 of the electromagnetic coil device 30 with a slight clearance.

  The fixed attractor 31 has a magnetic attraction surface 45 at the upper end surface, and attracts the lower end surface 46 of the plunger 44 toward the magnetic attraction surface 45 by a magnetic attraction force generated according to a coil current energized to the coil portion 39. To do. This magnetic attraction force acts as a downward force on the connecting body of the plunger 44 and the valve body 20, and biases the valve body 20 in the valve closing direction.

  An adjustment spring 28 using a compression coil spring is attached between the plunger 44 and the adjustment screw member 34. The adjustment spring 28 biases the connecting body of the plunger 44 and the valve body 20 in the descending direction, that is, the valve closing direction.

  The electromagnetic expansion valve 10 configured as described above is incorporated in a refrigeration cycle apparatus such as an air conditioner including a compressor 1001, a condenser 1002, and an evaporator 1003, and the first inlet port 12 is connected to a refrigerant pipe 1004. Is connected to the outlet side of the condenser 1002, the first outlet port 13 is connected to the inlet side of the evaporator 1003 by the refrigerant pipe 1005, and the second inlet port 15 is connected to the outlet side of the evaporator 1003 by the refrigerant pipe 1006. The second outlet port 16 is connected to the inlet side of the compressor 1001 by the refrigerant pipe 1007. The outlet side of the compressor 1001 is connected to the inlet side of the condenser 1002 by a refrigerant pipe 1008.

  With this connection, the flow rate adjusting unit 21 of the valve body 20 that adjusts the opening degree of the valve port 14 controls the flow rate of the refrigerant flowing to the evaporator 1003, and the pressure receiving plate 23 moves the refrigerant flow on the outlet side of the evaporator 1003. Pressure is exerted in the valve opening direction, and a load in the valve opening direction is generated exclusively by this dynamic pressure. Thus, the electromagnetic expansion valve 10 controls the flow rate of the refrigerant flowing to the evaporator 1003 in response to the dynamic pressure of the refrigerant flow on the outlet side of the evaporator 1003.

  Since the valve body 20 has a hollow shaft shape and the hollow portion 29 communicates with the plunger chamber 43, the internal pressure of the plunger chamber 43 is between the first inlet port 12 and the first outlet port 13. The pressure of the refrigerant on the outlet side of the condenser 1002 passing through the flow path including the valve port 14, that is, the pressure corresponding to the condensation pressure Pc.

  In the above-described electromagnetic expansion valve 10, the spring load of the adjustment spring 28 is F1, the load due to the magnetic attractive force of the electromagnetic coil device 30 is F2, the load generated on the pressure receiving plate 23 is F3, the spring load of the valve spring 25 is F4, Assuming that a differential pressure load, which will be described later, acting on the flow rate adjusting unit 21 of the body 20 is F5, the vector of each load is as shown in FIG. 2, and the balance equation is expressed by the equation (1).

F1 + F2 + F5 = F3 + F4 (1)
Therefore, the balance value (set superheat degree) of the electromagnetic expansion valve 10 can be varied by changing the load F2 due to the magnetic attractive force by controlling the coil current value of the electromagnetic coil device 30 within the range satisfying the balance equation (1). Can be set. As a matter of course, when the electromagnetic coil device 30 is not energized, that is, when the load F2 due to the magnetic attractive force of the electromagnetic coil device 30 is 0, the electromagnetic expansion valve 10 is fully opened.

  By the way, the load F3 generated in the pressure receiving plate 23 is expressed by Expression (2).

F3 = F + F3A (2)
Among these, F is a load generated by the dynamic pressure of the refrigerant flow flowing through the flow path chamber 17, and F3A is an area difference {(D3 ² −D1) between the outer diameter D1 of the valve body 20 and the outer diameter D3 of the pressure receiving plate 23. ² ) A load generated by a differential pressure (Psh−Psl) between the pressure Psh of the second inlet port 15 and the pressure Psl of the second outlet port 16 with respect to π} / 4, and the expression F3A = {(Psh−Psl) It is indicated by (D3 ² -D1 ² ) π} / 4.

The differential pressure load F5 acting on the flow rate adjusting portion 21 of the valve body 20 is a condensation pressure Pc with respect to the area difference {(D1 ² −D2 ² ) π} / 4 between the outer diameter D1 of the valve body 20 and the inner diameter D2 of the valve port 14. Is a generated load due to a differential pressure (Pc−Pe) between the evaporation pressure Pe and the evaporation pressure Pe, and is represented by the formula F5 = {(Pc−Pe) · (D1 ² −D2 ² ) π} / 4. Accordingly, the valve body 20 is affected by the condensation pressure Pc, and the valve opening / closing characteristics can be shifted in the valve closing direction by increasing the differential pressure (Pc−Pe).

  In addition, the influence of differential pressure | voltage (Pc-Pe) can be made zero by making the outer diameter D1 of the valve body 20 and the inner diameter D2 of the valve port 14 into the same diameter.

Here, the relationship between the superheat degree of the refrigerant on the evaporator outlet side of the refrigeration cycle apparatus and the refrigerant density by the CO ₂ refrigerant (R-744), the relationship between the refrigerant density and the pressure-receiving plate generation load, the superheat degree, the dryness degree, and the pressure receiving pressure. The relationship with the plate generation load will be described with reference to FIGS.

  FIG. 3 is a Mollier diagram focused on when the refrigerant at the outlet side of the evaporator is superheated, and FIG. 4 shows the degree of superheat SH and the refrigerant density ρ at the outlet side of the evaporator when the refrigerant is also superheated at the outlet side of the evaporator. Shows the relationship. When the superheat degree SH of the evaporator outlet side refrigerant increases, the refrigerant density ρ on the evaporator outlet side decreases accordingly.

  FIG. 5 is a Mollier diagram focused on when the refrigerant on the evaporator outlet side is wet steam, and FIG. 6 is also the dryness X and the refrigerant density ρ on the evaporator outlet side when the refrigerant is on the evaporator outlet side. Shows the relationship. When the dryness X of the evaporator outlet side refrigerant increases, the refrigerant density ρ on the evaporator outlet side decreases accordingly.

  FIG. 7 shows the relationship between the refrigerant density ρ on the evaporator outlet side and the generated load F due to the dynamic pressure of the refrigerant flow flowing through the flow path chamber 17. When the refrigerant density ρ on the evaporator outlet side decreases, the dynamic pressure of the refrigerant flow flowing through the flow path chamber 17 increases.

  Here, the principle that the generated load F due to the dynamic pressure of the refrigerant flow flowing through the flow path chamber 17 increases when the refrigerant density ρ on the evaporator outlet side decreases will be described.

  First, in the steady flow, the following continuous equation holds.

Mass flow rate = ρQ = ρVA = constant (3)
Here, ρ: density, Q: volume flow rate, V: flow velocity, A: channel cross-sectional area In this equation (3), when the density ρ decreases with a constant mass flow rate ρQ, the channel cross-section bond A becomes Since it is constant, the flow velocity V increases. Assuming that the superheat degree SH of the evaporator outlet side refrigerant has increased due to an increase in the evaporator load with constant valve lift (flow path cross-sectional area A constant) and constant mass flow rate ρQ, The refrigerant density ρ on the outlet side of the vessel decreases. For example, when the density ρ is reduced to ½, the flow velocity V is doubled. Therefore, when the density ρ decreases to 1 / n, the flow velocity V becomes n times.

  Next, the dynamic pressure is expressed by the following formula (4).

Dynamic pressure Pa = total pressure Pt−static pressure Ps = (1/2) ρ · V ² (4)
In the dynamic pressure plate flowmeter, the following relationship is established.

Load generated by dynamic pressure f∝ρ · V ² (5)
Equation (4) represents that the dynamic pressure Pa is proportional to ρ · V ² , and Equation (5) represents that the load f generated by the dynamic pressure is proportional to ρ · V ² . .

From the relationship of Equation (5), when the density ρ decreases to 1 / n and the flow velocity V increases n times, the right term of Equation (5) becomes (ρ / n) (nV) ² The generated load f due to the dynamic pressure increases n times. On the other hand, when the density ρ increases n times and the flow velocity V decreases to 1 / n, the right term of the equation (5) is expressed as dynamic pressure by (ρ · n) (V / n) ² . The generated load f is reduced by 1 / n times.

  Therefore, when the density ρ decreases, the generated load f due to dynamic pressure increases, and when the density ρ increases, the generated load f due to dynamic pressure decreases. From the relationship of equation (4), the same relationship holds for the dynamic pressure Pa.

  FIG. 8 shows the relationship between the superheat degree SH of the refrigerant on the evaporator outlet side, the dryness X of the refrigerant on the evaporator outlet side, and the pressure receiving plate generation load F3. When the superheat degree SH and the dryness degree X of the refrigerant on the evaporator outlet side increase, the pressure receiving plate generation load F increases. As a result, when the superheat degree SH or dryness X of the refrigerant at the outlet side of the evaporator increases, the valve opening increases as the pressure plate generation load F increases, and the refrigerant flow rate to the evaporator 1003 increases. The degree of superheat SH and the degree of dryness X of the refrigerant on the outlet side are reduced.

  FIG. 9 shows the generated load (F1 + F2) obtained by adding the generated load at the set position of the electromagnetic expansion valve 10, that is, the adjustment spring load F1 and the load F2 due to the magnetic attractive force of the electromagnetic coil device 30, and the coil current. Showing the relationship. In FIG. 9, with the coil currents Ia to Ib, the generated load (F1 + F2) changes proportionally in the range of Fa to Fb, and a predetermined superheat degree set value variable width (control region) is obtained.

  FIG. 10 shows the relationship between the valve lift amount of the electromagnetic expansion valve 10 and various generated loads. In FIG. 10, a characteristic line La shows the relationship between the valve lift amount of the valve body 20 and the spring load F4 of the valve spring 25, and a characteristic line Lbh shows the electromagnetic expansion valve 10 when the coil current value = “large” (Ib). The characteristic line Lbn shows the relationship between the generated load (F1 + F2) at the set position and the valve lift amount of the valve body 20, and the characteristic line Lbn shows the generated load at the set position of the electromagnetic expansion valve 10 when the coil current value is “medium”. F1 + F2) and the valve lift amount of the valve body 20, the characteristic line Lbl shows the generated load (F1 + F2) at the set position of the electromagnetic expansion valve 10 and the valve body 20 when the coil current value = “small” (Ia). The relationship with the valve lift amount of each is shown. Point Bn indicates an equilibrium point when the coil current value = “medium” as an example of the equilibrium point.

  Next, as shown in FIG. 1, the operation of the electromagnetic expansion valve 10 incorporated in the refrigeration cycle apparatus will be described in detail.

  When the superheat degree SH of the refrigerant at the outlet side of the evaporator matches the set superheat degree, since the formula (1) is in a balanced relationship, the upper and lower forces are balanced, and the valve lift position at this time is maintained.

  When the superheat degree SH is smaller than the set superheat degree, the load F3 generated on the pressure receiving plate 23 is reduced by the generated load ΔF due to the dynamic pressure, so the right term of the equation (1) becomes small and the valve body 20 is in the valve closing direction. Move to. Thereby, the amount of refrigerant flowing into the evaporator 1003 decreases, the superheat degree SH increases, and the superheat degree SH approaches the set superheat degree.

  In addition, when the superheat degree is 0 ° C. and the dryness degree X of the refrigerant at the outlet side of the evaporator is 1 or less, when the dryness degree X becomes smaller, the load F3 generated on the pressure receiving plate 23 is reduced by the generated load ΔF due to dynamic pressure. Therefore, the right term of Formula (1) becomes small, and the valve body 20 moves in the valve closing direction. As a result, the amount of refrigerant flowing into the evaporator 1003 decreases, the dryness X and the superheat degree SH increase, and the superheat degree SH approaches the set superheat degree.

  On the other hand, when the superheat degree SH becomes larger than the set superheat degree, the load F3 generated on the pressure receiving plate 23 is increased by the generated load ΔF due to dynamic pressure, so the right term of the equation (1) becomes large and the valve body 20 Moves in the valve opening direction. As a result, the amount of refrigerant flowing into the evaporator 1003 increases, the superheat degree SH decreases, and the superheat degree SH approaches the set superheat degree.

  In this electromagnetic expansion valve 10, the set superheat degree is variably set by the coil current control of the electromagnetic coil device 30, and when the increase or decrease in the refrigerant superheat degree SH on the evaporator outlet side with respect to the set superheat degree, the deviation is generated. Since the valve opening is self-controlled in the direction of eliminating the refrigerant, the refrigerant superheat degree SH on the evaporator outlet side can always be controlled to a stable superheat degree.

Further, since the electromagnetic expansion valve 10 does not require a pressure-sensitive part using a diaphragm or bellows like a temperature type expansion valve, there is no problem with the pressure resistance design specification even in a refrigeration cycle apparatus using a CO ₂ refrigerant.

  In the electromagnetic expansion valve 10 of the embodiment shown in FIG. 1, the lower joint side is a first inlet port 12, and the lateral joint side is a first outlet port 13. As shown, the side joint side may be the first inlet port 12 and the lower joint side may be the first outlet port 13. In this case, the valve opening / closing characteristic shifts in the valve opening direction due to an increase in the differential pressure (Pc−Pe). In FIG. 11, parts corresponding to those in FIG. 1 are denoted by the same reference numerals as those in FIG.

  FIG. 12 shows an embodiment of the electromagnetic expansion valve 10 applied to the block type main body structure. In FIG. 12 as well, portions corresponding to those in FIG. 1 are denoted by the same reference numerals as those in FIG.

  A second embodiment of the expansion valve (flow control valve) and the refrigeration cycle apparatus according to the present invention will be described with reference to FIG. In FIG. 13 as well, portions corresponding to those in FIG. 1 are denoted by the same reference numerals as those in FIG. 1, and description thereof is omitted.

  The expansion valve according to the second embodiment is configured as an energization open type electromagnetic expansion valve 50. In the second embodiment, the mounting direction of the valve spring 25 is different from that of the first embodiment, and the valve spring 25 is sandwiched between the ceiling portion of the flow path chamber 17 and the pressure receiving plate 23 to close the valve body 20. Energize in the direction.

  An electromagnetic coil device 60 is attached to the upper portion of the valve housing 11. The electromagnetic coil device 60 includes an attachment member 61 fixed to the upper part of the valve housing 11 by caulking or the like, a plunger tube 62 fixedly attached to the upper part of the attachment member 61, and a fixed suction fixedly attached to the upper end of the plunger tube 62. It has a child 63 and an adjusting screw member 64 screwed to the fixed suction element 63. Airtight O-rings 65 and 66 are attached to the attachment member 61 and the adjustment screw member 64, respectively.

  A coil unit 70 including an outer rod 67, a magnetic path guide member 68, a coil portion 69, and the like is fixed to the outer peripheral portion of the plunger tube 62.

  A central through hole 71 is formed through the attachment member 61 in the axial direction. The valve shaft portion 22 of the valve body 20 penetrates the central through hole 71 so as to be movable in the axial direction without contact, and penetrates the guide member 76 that is press-fitted and fixed to the lower portion of the mounting member 61 in a contact state. The hollow shaft-shaped valve body 20 is supported by the guide member 76 and the valve body support hole 18 of the valve housing 11 so as to be movable in the axial direction (vertical direction). The upper end portion 27 of the valve shaft portion 22 is located in a plunger chamber 72 defined inside the plunger tube 62. The upper end portion 27 of the valve shaft portion 22 is caulked and fixed to a plunger 73 of the electromagnetic coil device 70.

  The fixed attractor 63 has a magnetic attraction surface 74 at the lower end surface, and attracts the upper end surface 75 of the plunger 73 toward the magnetic attraction surface 74 side by a magnetic attraction force generated according to a coil current energized to the coil portion 69. To do. This magnetic attractive force acts on the connecting body of the plunger 73 and the valve body 20 as an upward force, and biases the valve body 20 in the valve opening direction.

  An adjustment spring 28 using a compression coil spring is attached between the plunger 73 and the adjustment screw member 64. As in the first embodiment, the adjustment spring 28 biases the connecting body of the plunger 73 and the valve body 20 in the downward direction, that is, the valve closing direction.

  In this embodiment as well, the pressure receiving plate 23 is in the flow channel chamber 17, flows into the flow channel chamber 17 from the second inlet port 15, and flows out of the flow channel chamber 17 from the second outlet port 16. As a result, the dynamic pressure of the fluid flowing through the flow path chamber 17 is exerted in the upward direction, that is, the valve opening direction.

  Similarly to the electromagnetic expansion valve 10 of the first embodiment, the electromagnetic expansion valve 50 is incorporated in a refrigeration cycle apparatus such as an air conditioner including a compressor 1001, a condenser 1002, and an evaporator 1003, and has a first inlet port. 12 is connected to the outlet side of the condenser 1002 by the refrigerant pipe 1004, the first outlet port 13 is connected to the inlet side of the evaporator 1003 by the refrigerant pipe 1005, and the second inlet port 15 is connected to the evaporator side by the refrigerant pipe 1006. The second outlet port 16 is connected to the inlet side of the compressor 1001 by the refrigerant pipe 1007. The outlet side of the compressor 1001 is connected to the inlet side of the condenser 1002 by a refrigerant pipe 1008.

  With this connection, also in the present embodiment, the flow rate adjusting unit 21 of the valve body 20 that adjusts the opening degree of the valve port 14 controls the flow rate of the refrigerant flowing to the evaporator 1003, and the pressure receiving plate 23 is on the outlet side of the evaporator 1003. The dynamic pressure of the refrigerant flow is exerted in the valve opening direction, and a load in the valve opening direction is generated. Thus, the electromagnetic expansion valve 50 controls the flow rate of the refrigerant flowing to the evaporator 1003 in response to the dynamic pressure of the refrigerant flow on the outlet side of the evaporator 1003.

  In the above-described electromagnetic expansion valve 50, the spring load of the adjustment spring 28 is F1, the load due to the magnetic attractive force of the electromagnetic coil device 60 is F2, the load generated on the pressure receiving plate 23 is F3, the spring load of the valve spring 25 is F4, Assuming that the differential pressure load acting on the flow rate adjusting unit 21 of the body 20 is F5, the vector of each load is as shown in FIG. 14, and the balance equation is expressed by equation (6).

F1 + F4 + F5 = F2 + F3 (6)
Therefore, the balance value (set superheat degree) of the electromagnetic expansion valve 50 can be varied by changing the load F2 caused by the magnetic attractive force by controlling the coil current value of the electromagnetic coil device 60 within the range satisfying the balance equation (6). Can be set.

Also in this embodiment, the load F3 generated in the pressure receiving plate 23 is expressed by Expression (2). That is, F3 = F + F3A, F is a generated load due to the dynamic pressure of the refrigerant flow through the flow path chamber 17, and F3A is an area difference between the outer diameter D1 of the valve body 20 and the outer diameter D3 of the pressure receiving plate 23 { This is a load generated by the differential pressure (Psh−Psl) between the pressure Psh of the second inlet port 15 and the pressure Psl of the second outlet port 16 with respect to (D3 ² −D1 ² ) π} / 4, and the expression F3A = { (Psh−Psl) · (D3 ² −D1 ² ) π} / 4.

Further, the differential pressure load F5 acting on the flow rate adjusting portion 21 of the valve body 20 is condensed with respect to the area difference {(D1 ² −D2 ² ) π} / 4 between the outer diameter D1 of the valve body 20 and the inner diameter D2 of the valve port 14. It is a load generated by the pressure difference (Pc−Pe) between the pressure Pc and the evaporation pressure Pe, and is represented by the formula F5 = {(Pc−Pe) · (D1 ² −D2 ² ) π} / 4. As a result, the valve body 20 is affected by the condensation pressure Pc, and the valve opening / closing characteristics can be shifted in the valve closing direction by increasing the differential pressure (Pc−Pe).

  Also in this embodiment, by making the outer diameter D1 of the valve body 20 and the inner diameter D2 of the valve port 14 the same diameter, the influence of the differential pressure (Pc-Pe) can be made zero, By using the first inlet port 12 on the joint side and the first outlet port 13 on the lower joint side, the valve opening / closing characteristics can be shifted in the valve opening direction due to an increase in the differential pressure (Pc-Pe).

  FIG. 15 shows the relationship between the valve lift amount of the electromagnetic expansion valve 50 and various generated loads. In FIG. 15, the characteristic line La shows the relationship between the valve lift amount of the valve body 20 and the spring load F4 of the valve spring 25, and the characteristic line Lbh shows the adjustment spring load F1 when the coil current value = “large” (Ib). The characteristic load Lbn is generated when the coil current value is “medium” and the relationship between the generated load (F1 + F2) obtained by adding the load F2 due to the magnetic attractive force of the electromagnetic coil device 60 and the valve lift amount of the valve body 20 The relationship between the load (F1 + F2) and the valve lift amount of the valve body 20, and the characteristic line Lbl shows the relationship between the generated load (F1 + F2) and the valve lift amount of the valve body 20 when the coil current value = “small” (Ia). Each is shown. Point Bn indicates an equilibrium point when the coil current value = “medium” as an example of the equilibrium point.

  The electromagnetic expansion valve 50 variably sets the set superheat degree by controlling the coil current of the electromagnetic coil device 60, and in the same manner as the electromagnetic expansion valve 10 of the first embodiment described above, in response to the dynamic pressure received by the pressure receiving plate 23, It operates so that there is no deviation between the superheat degree SH of the refrigerant on the outlet side of the evaporator and the set superheat degree. In other words, when the refrigerant superheat degree SH on the evaporator outlet side increases or decreases with respect to the set superheat degree, the valve opening is self-controlled in a direction to eliminate the deviation. Thereby, the refrigerant superheat degree SH on the evaporator outlet side can be controlled to a stable superheat degree at all times.

Further, the electromagnetic expansion valve 50 does not require a pressure-sensitive part using a diaphragm or bellows unlike a temperature type expansion valve, so that there is no problem with the pressure resistance design specification even in a refrigeration cycle apparatus using a CO ₂ refrigerant.

  In addition, since the energization open type electromagnetic expansion valve 50 as in the second embodiment is closed when not energized, the expansion valve is preferably closed when the refrigeration cycle apparatus such as an air conditioner is off. Considering this, it can be said that a power saving effect is obtained and energy saving is excellent.

  A third embodiment of the expansion valve (flow control valve) and the refrigeration cycle apparatus according to the present invention will be described with reference to FIG. Also in FIG. 16, parts corresponding to those in FIG. 1 are denoted by the same reference numerals as those in FIG. 1, and description thereof is omitted.

  The expansion valve according to the third embodiment is configured as an electric expansion valve 80 driven by a stepping motor. A stepping motor 90 is attached to the upper portion of the valve housing 11.

  The stepping motor 90 is provided in a rotor chamber 93 defined inside a mounting member 91 fixed to the upper part of the valve housing 11 by caulking or the like, and a can-shaped rotor case 92 fixedly mounted on the upper part of the mounting member 91. And a rotor shaft 97 (adjustment screw member) having a male screw portion 96 threadedly engaged with the female screw portion 95 of the female screw member 94.

  The stepping motor 90 is further provided in the rotor chamber 93 so as to be rotatable and movable in the axial direction. The stepping motor 90 is fixedly connected to the rotor shaft 97 and has a multi-pole magnetized outer periphery, and the rotation of the rotor 98. It has a stopper part 99 for limiting the number of times and a stator coil unit 100 fixedly mounted on the outer peripheral part of the rotor case 92.

  The stator coil unit 100 is a resin-sealed type having an outer casing 101, upper and lower two-stage coil portions 102, a plurality of magnetic pole tooth portions 103, an electrical connector 104 for energizing coils, and the like.

  A central through hole 105 is formed through the attachment member 91 in the axial direction. The valve shaft portion 22 of the valve body 20 penetrates the center through hole 105 so as to be movable in the axial direction without contact, and penetrates the guide member 89 that is press-fitted and fixed to the lower portion of the mounting member 91 in a contact state. The hollow shaft-like valve body 20 is supported by the guide member 89 and the valve body support hole 18 of the valve housing 11 so as to be movable in the axial direction (vertical direction). The upper end portion 27 of the valve shaft portion 22 is located in the rotor chamber 93.

  A lower spring receiving member 106 is fixedly attached to the upper end portion 27 of the valve shaft portion 22. An upper spring receiving member 108 is engaged and attached to the lower end portion 107 of the rotor shaft 97. An adjustment spring 109 formed by a compression coil spring is sandwiched between the upper spring receiving member 108 and the lower spring receiving member 106. The adjustment spring 109 is sandwiched between the upper spring receiving member 108 and the lower spring receiving member 106 to urge the valve body 20 in the descending direction, that is, the valve closing direction.

  The rotor 98 of the stepping motor 90 rotates by applying a pulse to the coil portion 102, and the rotor shaft 97 moves in the axial direction while rotating by the screw engagement between the female screw portion 95 and the male screw portion 96. As a result, the upper spring receiving member 108 is displaced in the axial direction, and the spring load of the adjustment spring 109 is variably set according to this displacement.

In FIG. 16, reference symbol ML ₀ indicates a position where the stepping motor lift amount is zero (rotor lift position), and reference symbol MLmax indicates a position where the stepping motor lift amount is maximum (rotor lowering position).

  Also in this embodiment, the pressure receiving plate 23 is in the flow channel chamber 17, flows into the flow channel chamber 17 from the second inlet port 15, and flows out of the flow channel chamber 17 from the second outlet port 16. Thus, the dynamic pressure of the fluid flowing through the flow path chamber 17 is exerted in the upward direction, that is, the valve opening direction.

  Similarly to the electromagnetic expansion valve 10 of the first embodiment, the electric expansion valve 80 is incorporated in a refrigeration cycle apparatus such as an air conditioner including a compressor 1001, a condenser 1002, and an evaporator 1003, and has a first inlet. The port 12 is connected to the outlet side of the condenser 1002 by the refrigerant pipe 1004, the first outlet port 13 is connected to the inlet side of the evaporator 1003 by the refrigerant pipe 1005, and the second inlet port 15 is evaporated by the refrigerant pipe 1006. The second outlet port 16 is connected to the inlet side of the compressor 1001 through the refrigerant pipe 1007. The outlet side of the compressor 1001 is connected to the inlet side of the condenser 1002 by a refrigerant pipe 1008.

  With this connection, also in the present embodiment, the flow rate adjusting unit 21 of the valve body 20 that adjusts the opening degree of the valve port 14 controls the flow rate of the refrigerant flowing to the evaporator 1003, and the pressure receiving plate 23 is on the outlet side of the evaporator 1003. The dynamic pressure of the refrigerant flow is exerted in the valve opening direction, and a load in the valve opening direction is generated. Thereby, the electric expansion valve 80 controls the flow rate of the refrigerant flowing to the evaporator 1003 in response to the dynamic pressure of the refrigerant flow on the outlet side of the evaporator 1003.

  In the electric expansion valve 80 described above, the spring load of the adjustment spring 109 is F1, the load generated on the pressure receiving plate 23 is F3, the spring load of the valve spring 25 is F4, and the flow adjusting unit 21 of the valve body 20 is described later. Assuming that the differential pressure load is F5, the vector of each load is as shown in FIG. 17, and the balance equation is expressed by equation (7).

F1 + F5 = F3 + F4 (7)
Also in this embodiment, the load F3 generated in the pressure receiving plate 23 is expressed by Expression (2). That is, F3 = F + F3A, F is a generated load due to the dynamic pressure of the refrigerant flow through the flow path chamber 17, and F3A is an area difference between the outer diameter D1 of the valve body 20 and the outer diameter D3 of the pressure receiving plate 23 { This is a load generated by the differential pressure (Psh−Psl) between the pressure Psh of the second inlet port 15 and the pressure Psl of the second outlet port 16 with respect to (D3 ² −D1 ² ) π} / 4, and the expression F3A = { (Psh−Psl) · (D3 ² −D1 ² ) π} / 4.

Further, the differential pressure load F5 acting on the flow rate adjusting portion 21 of the valve body 20 is condensed with respect to the area difference {(D1 ² −D2 ² ) π} / 4 between the outer diameter D1 of the valve body 20 and the inner diameter D2 of the valve port 14. It is a load generated by the pressure difference (Pc−Pe) between the pressure Pc and the evaporation pressure Pe, and is represented by the formula F5 = {(Pc−Pe) · (D1 ² −D2 ² ) π} / 4. Accordingly, the valve body 20 is affected by the condensation pressure Pc, and the valve opening / closing characteristics can be shifted in the valve closing direction by increasing the differential pressure (Pc−Pe).

  Also in this embodiment, by making the outer diameter D1 of the valve body 20 and the inner diameter D2 of the valve port 14 the same diameter, the influence of the differential pressure (Pc-Pe) can be made zero, By using the first inlet port 12 on the joint side and the first outlet port 13 on the lower joint side, the valve opening / closing characteristics can be shifted in the valve opening direction due to an increase in the differential pressure (Pc-Pe).

  As shown in FIG. 18, the spring load F <b> 1 of the adjustment spring 109 changes proportionally according to the lift amount of the stepping motor 80. Thereby, the equilibrium value (set superheat degree) of the electric expansion valve 80 is variably set.

  FIG. 18 shows the relationship between the adjustment spring load F 1 and the lift amount of the stepping motor 80 at the set position of the electric expansion valve 80. In FIG. 18, with the stepping motor lift amounts MLa to MLb, the generated load F1 changes proportionally in the range of Fa to Fb, and a predetermined superheat degree set value variable width (control range) is obtained.

  FIG. 19 shows the relationship between the valve lift amount of the electric expansion valve 80 and various generated loads. In FIG. 19, a characteristic line La indicates the relationship between the valve lift amount of the valve body 20 and the spring load F4 of the valve spring 25, and a characteristic line Lbh indicates an adjustment spring load F1 when the stepping motor lift amount = “large” (MLb). The characteristic line Lbn represents the relationship between the adjustment spring load F1 and the valve lift amount of the valve body 20 when the stepping motor lift amount = “medium”, and the characteristic line Lbl represents the stepping motor lift amount. The relationship between the adjustment spring load F1 and the valve lift amount of the valve body 20 when the motor lift amount is “small” (MLa) is shown. Point Bn indicates an equilibrium point when the stepping motor lift amount is “medium” as an example of the equilibrium point.

  This electric expansion valve 80 variably sets the degree of superheat set by pulse control of the stepping motor 90, and in the same way as the electromagnetic expansion valve 10 of the first embodiment described above, in response to the dynamic pressure received by the pressure receiving plate 23, the electric expansion valve 80 evaporates. It operates so that the deviation between the superheat degree SH of the refrigerant on the outlet side of the vessel and the set superheat degree is eliminated. In other words, when the refrigerant superheat degree SH on the evaporator outlet side increases or decreases with respect to the set superheat degree, the valve opening is self-controlled in a direction to eliminate the deviation. Thereby, the refrigerant superheat degree SH on the evaporator outlet side can be controlled to a stable superheat degree at all times.

Further, since the electric expansion valve 80 does not require a pressure-sensitive part using a diaphragm or bellows unlike a temperature expansion valve, there is no problem with the pressure-resistant design specification even in a refrigeration cycle apparatus using a CO ₂ refrigerant.

  Embodiment 4 of an expansion valve (flow control valve) and a refrigeration cycle apparatus according to the present invention will be described with reference to FIG. In FIG. 20 as well, portions corresponding to those in FIG. 1 are denoted by the same reference numerals as those in FIG. 1, and description thereof is omitted.

  The expansion valve according to the fourth embodiment is configured as a manual expansion valve 110. The manual expansion valve 110 has a manual spring load setting unit 111 at the top of the valve housing 11.

  The manual spring load setting unit 111 is an adjustment screw member that also serves as a spring case member 112 fixedly mounted on the upper portion of the valve housing 11 by caulking or the like, and an upper spring receiving member screw-engaged with the spring case member 112 by a screw portion 113. 114. Airtight O-rings 115 and 116 are attached to the spring case member 112 and the adjustment screw member 114, respectively.

  A central through hole 117 is formed through the spring case member 112 in the axial direction. The valve shaft portion 22 of the valve body 20 penetrates the center through hole 117 so as to be movable in the axial direction without contact, and penetrates the guide member 121 that is press-fitted and fixed to the lower portion of the spring case member 112 in a contact state. The guide member 121 and the valve body support hole 18 of the valve housing 11 support the hollow shaft-shaped valve body 20 so as to be movable in the axial direction (vertical direction). The upper end portion 27 of the valve shaft portion 22 is located in the spring chamber 118 inside the spring case member 112.

  A lower spring receiving member 119 is fixedly attached to the upper end portion 27 of the valve shaft portion 22. An adjustment spring 120 formed of a compression coil spring is sandwiched between an adjustment screw member 114 and a lower spring receiving member 119 that form an upper spring receiving member. The adjustment spring 120 is sandwiched between the adjustment screw member 114 and the lower spring receiving member 119 to urge the valve body 20 in the descending direction, that is, the valve closing direction.

  In the manual spring load setting unit 111, the screw amount of the adjustment screw member 114 is adjusted by manual operation, whereby the adjustment screw member 114 is displaced in the axial direction, and the spring load of the adjustment spring 120 is variable according to this displacement. Is set.

In FIG. 20, symbol S ₀ indicates the minimum screwing position of the adjustment screw member 114, and symbol Smax indicates the maximum screwing position of the adjustment screw member 114.

  Also in this embodiment, the pressure receiving plate 23 is in the flow channel chamber 17, flows into the flow channel chamber 17 from the second inlet port 15, and flows out of the flow channel chamber 17 from the second outlet port 16. Thus, the dynamic pressure of the fluid flowing through the flow path chamber 17 is exerted in the upward direction, that is, the valve opening direction.

  As with the electromagnetic expansion valve 10 of the first embodiment, the manual expansion valve 110 is incorporated in a refrigeration cycle apparatus such as an air conditioner including a compressor 1001, a condenser 1002, and an evaporator 1003, and has a first inlet. The port 12 is connected to the outlet side of the condenser 1002 by the refrigerant pipe 1004, the first outlet port 13 is connected to the inlet side of the evaporator 1003 by the refrigerant pipe 1005, and the second inlet port 15 is evaporated by the refrigerant pipe 1006. The second outlet port 16 is connected to the inlet side of the compressor 1001 through the refrigerant pipe 1007. The outlet side of the compressor 1001 is connected to the inlet side of the condenser 1002 by a refrigerant pipe 1008.

  With this connection, also in the present embodiment, the flow rate adjusting unit 21 of the valve body 20 that adjusts the opening degree of the valve port 14 controls the flow rate of the refrigerant flowing to the evaporator 1003, and the pressure receiving plate 23 is on the outlet side of the evaporator 1003. The dynamic pressure of the refrigerant flow is exerted in the valve opening direction, and a load in the valve opening direction is generated. Accordingly, the manual expansion valve 110 controls the flow rate of the refrigerant flowing to the evaporator 1003 in response to the dynamic pressure of the refrigerant flow on the outlet side of the evaporator 1003.

  In the manual expansion valve 110 described above, the spring load of the adjustment spring 120 is F1, the load generated on the pressure receiving plate 23 is F3, the spring load of the valve spring 25 is F4, and the flow rate adjusting unit 21 of the valve body 20 is described later. Assuming that the differential pressure load is F5, the vector of each load is as shown in FIG. 21, and the balance equation is expressed by equation (8).

F1 + F5 = F3 + F4 (8)
Also in this embodiment, the load F3 generated in the pressure receiving plate 23 is expressed by Expression (2). That is, F3 = F + F3A, F is a generated load due to the dynamic pressure of the refrigerant flow through the flow path chamber 17, and F3A is an area difference between the outer diameter D1 of the valve body 20 and the outer diameter D3 of the pressure receiving plate 23 { This is a load generated by the differential pressure (Psh−Psl) between the pressure Psh of the second inlet port 15 and the pressure Psl of the second outlet port 16 with respect to (D3 ² −D1 ² ) π} / 4, and the expression F3A = { (Psh−Psl) · (D3 ² −D1 ² ) π} / 4.

Further, the differential pressure load F5 acting on the flow rate adjusting portion 21 of the valve body 20 is condensed with respect to the area difference {(D1 ² −D2 ² ) π} / 4 between the outer diameter D1 of the valve body 20 and the inner diameter D2 of the valve port 14. It is a load generated by the pressure difference (Pc−Pe) between the pressure Pc and the evaporation pressure Pe, and is represented by the formula F5 = {(Pc−Pe) · (D1 ² −D2 ² ) π} / 4. As a result, the valve body 20 is affected by the condensation pressure Pc, and the valve opening / closing characteristics can be shifted in the valve closing direction by increasing the differential pressure (Pc−Pe).

  Also in this embodiment, by making the outer diameter D1 of the valve body 20 and the inner diameter D2 of the valve port 14 the same diameter, the influence of the differential pressure (Pc-Pe) can be made zero, By using the first inlet port 12 on the joint side and the first outlet port 13 on the lower joint side, the valve opening / closing characteristics can be shifted in the valve opening direction due to an increase in the differential pressure (Pc-Pe).

  As shown in FIG. 22, the spring load F <b> 1 of the adjustment spring 120 changes in proportion to the screwing amount of the adjustment screw member 114, that is, the adjustment screw tightening lift amount. Thereby, the equilibrium value (setting superheat degree) of the manual expansion valve 110 is variably set.

  FIG. 22 shows the relationship between the adjustment spring load F1 and the tightening lift amount of the adjustment screw member 114 at the set position of the manual expansion valve 110. In FIG. 22, the generated load F1 is proportionally changed in the range of Fa to Fb with the tightening lift amounts SLa to SLb of the just screw member 114, and a predetermined superheat degree set value variable width (control range) is obtained.

  FIG. 23 shows the relationship between the valve lift amount of the manual expansion valve 110 and various generated loads. Also in FIG. 23, the characteristic line La shows the relationship between the valve lift amount of the valve body 20 and the spring load F4 of the valve spring 25, and the characteristic line Lbh shows the adjustment spring load when the tightening lift amount = “large” (SLb). The relationship between F1 and the valve lift amount of the valve body 20, the characteristic line Lbn is the relationship between the adjustment spring load F1 and the valve lift amount of the valve body 20 when the tightening lift amount is “medium”, and the characteristic line Lbl is The relationship between the adjustment spring load F1 and the valve lift amount of the valve body 20 when the tightening lift amount is “small” (SLa) is shown. Point Bn represents an equilibrium point when the tightening lift amount is “medium” as an example of the equilibrium point.

  This manual expansion valve 110 sets the set superheat degree to a predetermined value by a manual adjustment screw member 114, and in response to the dynamic pressure received by the pressure receiving plate 23, similarly to the electromagnetic expansion valve 10 of the first embodiment described above. The operation is performed so that the deviation between the superheat degree SH of the refrigerant on the evaporator outlet side and the set superheat degree is eliminated. In other words, when the refrigerant superheat degree SH on the evaporator outlet side increases or decreases with respect to the set superheat degree, the valve opening is self-controlled in a direction to eliminate the deviation. Thereby, the refrigerant superheat degree SH on the evaporator outlet side can be controlled to a stable superheat degree at all times.

Further, the manual expansion valve 110 does not require a pressure-sensitive part using a diaphragm or bellows unlike a temperature expansion valve, so that there is no problem with the pressure resistance design specification even in a refrigeration cycle apparatus using a CO ₂ refrigerant.

Incidentally, the refrigerant used in the refrigeration cycle apparatus according to the present invention is not limited to R-744 (CO _2), specified flon, such as R-22, R-134a, R-410A, R-407C, Alternative chlorofluorocarbons such as R-404A, ammonia refrigerants such as R-717, hydrocarbon refrigerants such as R-600a (isobutane), and the like may be used.

It is sectional drawing and a block diagram which show Embodiment 1 of the expansion valve (flow control valve) and refrigeration cycle apparatus by this invention. It is explanatory drawing which shows the vector of the valve body action load of the expansion valve by Embodiment 1. Is a Mollier diagram focusing when superheated steam evaporator outlet side of the refrigerant of the refrigeration cycle apparatus according to CO ₂ refrigerant (R-744). CO is a graph showing the relationship between the superheat and the refrigerant density at the time of the superheated vapor of the evaporator outlet side of the refrigerant of the refrigeration cycle apparatus according to _second refrigerant (R-744). Is a Mollier diagram focusing upon wet steam outlet of the evaporator side of the refrigerant of the refrigeration cycle apparatus according to CO ₂ refrigerant (R-744). It is a graph showing the relationship between the refrigerant density of the dryness and the evaporator outlet side during wet vapor of the evaporator outlet side of the refrigerant of the refrigeration cycle apparatus according to CO ₂ refrigerant (R-744). 3 is a graph showing a relationship between a refrigerant density on an evaporator outlet side and a pressure receiving plate generation load of the expansion valve according to the first embodiment. It is a graph which shows the relationship between the superheat degree and the dryness of the refrigerant | coolant of an evaporator exit side, and the pressure-receiving-plate generating load of the expansion valve by Embodiment 1. It is a graph which shows the relationship between the generated load in the setting position of the expansion valve by Embodiment 1, and a coil electric current value. It is a graph which shows the valve lift amount of the expansion valve by Embodiment 1, and the relationship of generated load. It is sectional drawing and a block diagram which show the deformation | transformation embodiment of the expansion valve and refrigeration cycle apparatus by Embodiment 1. It is sectional drawing which shows other deformation | transformation embodiment of the expansion valve by Embodiment 1. It is sectional drawing and a block diagram which show Embodiment 2 of the expansion valve (flow control valve) and refrigeration cycle apparatus by this invention. It is explanatory drawing which shows the vector of the valve body action load of the expansion valve by Embodiment 2. FIG. It is a graph which shows the valve lift amount of the expansion valve by Embodiment 2, and the relationship of various generated loads. It is sectional drawing and a block diagram which show Embodiment 3 of the expansion valve (flow control valve) and refrigeration cycle apparatus by this invention. It is explanatory drawing which shows the vector of the valve body action load of the expansion valve by Embodiment 3. It is a graph which shows the relationship between the adjustment spring load in the setting position of the expansion valve by Embodiment 3, and stepping motor lift amount. It is a graph which shows the valve lift amount of the expansion valve by Embodiment 3, and the relationship of various generated loads. It is sectional drawing and a block diagram which show Embodiment 4 of the expansion valve (flow control valve) and refrigeration cycle apparatus by this invention. It is explanatory drawing which shows the vector of the valve body action load of the expansion valve by Embodiment 4. It is a graph which shows the relationship between the adjustment spring load in the setting position of the expansion valve by Embodiment 4, and the amount of tightening of an adjustment screw member. It is a graph which shows the relationship between the valve lift amount of the expansion valve by Embodiment 4, and various generated loads.

Explanation of symbols

10, 50 Electromagnetic expansion valve 11 Valve housing 12 First inlet port 13 First outlet port 14 Valve port 15 Second inlet port 16 Second outlet port 17 Channel chamber 18 Valve body support hole 20 Valve body 21 Flow rate Adjustment part 22 Valve shaft part 23 Pressure receiving plate 24 Snap ring 25 Valve spring 26 Gap 27 Upper end part 28, 109, 120 Adjustment spring 29 Hollow part 30, 60 Electromagnetic coil device 31, 63 Fixed attractor 32, 62 Plunger tube 33 Top cover plug 34 Adjusting screw member 35, 36, 65, 66, 115, 116 O-ring 37, 67, 101 Outer casing 38, 68 Magnetic path guide member 39, 69, 102 Coil portion 40, 104 Electrical connector 41, 70 Coil unit 42, 71, 105, 117 Center through hole 43, 72 Plunger chamber 44, 73 Nanger 45, 74 Magnetic attracting surface 46 Lower end surface 61, 91 Mounting member 64 Adjust screw member 75 Upper end surface 80 Electric expansion valve 90 Stepping motor 92 Rotor case 93 Rotor chamber 94 Female screw member 95 Female screw portion 96 Male screw portion 97 Rotor shaft 98 Rotor 99 Stopper portion 100 Stator coil unit 103 Magnetic pole tooth portion 106 Lower spring receiving member 107 Lower end portion 108 Upper spring receiving member 110 Manual expansion valve 111 Manual spring load setting portion 112 Spring case member 113 Screw portion 114 Adjusting screw member 118 Spring Chamber 119 Lower spring receiving member 1001 Compressor 1002 Condenser 1003 Evaporator 1004 to 1008 Refrigerant piping

Claims (8)

A first inlet port; a first outlet port; a valve port provided between the first inlet port and the first outlet port; a second inlet port; and a second outlet port And a valve housing having a flow path chamber provided between the second inlet port and the second outlet port;
A flow rate adjusting unit that adjusts the opening degree of the valve port, and a shaft that penetrates the valve housing from the flow rate adjusting unit and protrudes toward the flow path chamber, and moves in an axial direction with respect to the valve housing A valve body that can be supported, and a valve body in which the flow rate adjusting unit moves in the opening / closing direction of the valve port by movement in the axial direction of the valve shaft with respect to the valve housing;
The valve shaft portion is provided in the valve shaft portion located in the flow passage chamber, and the dynamic pressure of the fluid flowing through the flow passage chamber from the second inlet port toward the second outlet port is A pressure receiving plate exerted in the valve opening direction of the valve port;
An adjustment spring for urging the valve body in the valve closing direction;
Having a flow control valve. Provided between the first inlet port connected to the outlet side of the condenser, the first outlet port connected to the inlet side of the evaporator, and between the first inlet port and the first outlet port Valve port, a second inlet port connected to the outlet side of the evaporator, a second outlet port connected to the inlet side of the compressor, the second inlet port and the second outlet A valve housing having a flow path chamber provided between the port and
A flow rate adjusting unit that adjusts the opening degree of the valve port, and a shaft that penetrates the valve housing from the flow rate adjusting unit and protrudes toward the flow path chamber, and moves in an axial direction with respect to the valve housing A valve body that can be supported, and a valve body in which the flow rate adjusting unit moves in the opening / closing direction of the valve port by movement in the axial direction of the valve shaft with respect to the valve housing;
The dynamic pressure of the fluid flowing in the flow path chamber from the second inlet port toward the second outlet port is provided in the valve shaft portion located in the flow path chamber of the valve shaft portion. A pressure receiving plate exerted in the valve opening direction of the valve port;
An adjustment spring for urging the valve body in the valve closing direction;
An expansion valve for a refrigeration cycle apparatus.   The expansion valve for a refrigeration cycle apparatus according to claim 2, further comprising spring load variable setting means for variably setting an initial set load of the adjustment spring.   The expansion valve for a refrigeration cycle apparatus according to claim 3, wherein the spring load variable setting means includes an adjustment screw member that takes charge of the adjustment spring and is capable of changing the mounting position in the axial direction by screw engagement.   The expansion valve for a refrigeration cycle apparatus according to claim 4, further comprising an electric motor for rotating the adjustment screw member.   The expansion valve for a refrigeration cycle apparatus according to any one of claims 2 to 4, further comprising an electromagnetic coil device that urges the valve body in a valve closing direction or a valve opening direction by an electromagnetic suction force.   A refrigeration cycle apparatus having a compressor, a condenser, an evaporator, and an expansion valve that controls the flow rate of refrigerant flowing from the condenser to the evaporator in response to the dynamic pressure of the refrigerant flow on the outlet side of the evaporator .   A refrigeration cycle apparatus comprising the expansion valve for a refrigeration cycle apparatus according to any one of claims 2 to 6.

Images