JP6069924B2 - Expansion valve - Google Patents

Description

  The present invention relates to an expansion valve configured to be able to open and close a refrigerant flow path for expanding refrigerant by a valve seat provided at the tip of a plunger and a valve seat having a small-diameter refrigerant flow path (orifice).

  2. Description of the Related Art Conventionally, a pulse-type electronic expansion valve that adjusts the degree of expansion of a refrigerant by opening and closing an electromagnetic valve has been known as a refrigerant expansion unit provided in a refrigerant cycle device used for cooling and heating of vending machines or the like. (For example, refer to Patent Document 1).

  An example of the configuration of this type of electronic expansion valve is shown in FIG. An electronic expansion valve 100 shown in FIG. 6 is used in a refrigerant cycle device in which a refrigerant circuit is configured by a compressor, a condenser, an evaporator, and the like (not shown), and is connected to a high-pressure inlet pipe 101 through which high-pressure refrigerant flows. And an outlet port 108 to which a low-pressure outlet pipe 107 through which low-pressure refrigerant expanded through a small-diameter refrigerant passage (orifice) 106 formed in the valve seat 104 flows is connected. The refrigerant flow path 106 is controlled to open and close by moving the plunger 116 supported by the lower end of the yoke 112 via the coil spring 114 by a magnetic circuit formed by the electromagnetic coil 110 and the yoke 112.

Japanese Patent Laid-Open No. 53-1352

  As shown in FIG. 6, in the electronic expansion valve 100, when energization of the electromagnetic coil 110 is turned on, the plunger 116 retreats against the urging force of the coil spring 114, and the distal end surface 116 a of the plunger 116 is in the valve seat 104. The refrigerant flow path 106 is opened away from the center. On the other hand, when the energization to the electromagnetic coil 110 is turned off, the plunger 116 moves forward by the urging force of the coil spring 114, and the front end surface 116a is landed (contacted) on the valve seat 104 to close the refrigerant flow path 106 (FIG. 6). (See the plunger 116 indicated by a broken line in the inside). In order to perform these movements at a high speed, if the force necessary for moving the plunger 116 is large, the drive section tends to be enlarged. Further, if the pressure difference between the refrigerant flow paths (orifices) is large, the required pulling force of the plunger 116 is increased, leading to an increase in cost and an increase in power consumption due to an increase in the size of the electromagnetic coil.

  In addition, since the electronic expansion valve 100 uses the plunger 116 that is a movable member, a certain amount of gap 120 is provided between the outer peripheral surface of the plunger 116 and the inner peripheral surface of the case 118 that houses the plunger 116. Is provided. For this reason, depending on the movable state of the plunger 116, as shown in FIG. As a result, even when the energization of the electromagnetic coil 110 is turned off, the tip end surface 116a of the plunger 116 cannot be brought into close contact with the valve seat 104, refrigerant leakage from the refrigerant flow path 106 occurs, and the refrigerant cycle The capacity will decrease and the power consumption will increase.

  In addition, when the valve seat surface 104a is large, as shown in FIG. 8, the distance from the outer peripheral ends of the valve seat 104 to the refrigerant flow path 106 becomes longer, and a pulling-down force of the plunger 116 due to the decompression of the refrigerant occurs. This increases the pulling force, leading to an increase in the size of the magnetic circuit.

  Note that there are other types of electronic expansion valves other than the configuration in which the flat distal end surface 116a of the plunger 116 is landed (contacted) on the valve seat 104 as a valve body like the electronic expansion valve 100 described above. There is also a configuration in which the refrigerant flow path is closed by an electromagnetic valve using a valve body. The use of a ball-type valve body has the advantage that the influence of the inclination of the plunger can be reduced. However, due to its structure, a large force is required to open and close the valve body. In a refrigerant cycle using a refrigerant that causes a difference, the magnetic circuit can be increased in size and cost.

  The present invention has been made in consideration of the above-described problems of the prior art. The valve structure is miniaturized, in particular, the valve seat surface is miniaturized to suppress an increase in driving force necessary to open and close the valve body, and It aims at providing the expansion valve which can reduce a leak.

In order to achieve the above object, an expansion valve according to claim 1 of the present invention is provided at least between an inlet port through which a refrigerant flows in, an outlet port through which the refrigerant flows out, and between the inlet port and the outlet port. A case having a valve chamber, a valve seat disposed in the valve chamber, and formed with a refrigerant flow path for expanding the refrigerant flowing into the valve chamber from the inlet port and flowing out to the outlet port; and an electromagnetic coil The valve seat is opposed to the valve seat in a manner of moving forward and backward by energizing on / off to the valve seat, and is biased toward the valve seat by the biasing means, and from the valve seat by energizing the electromagnetic coil. An expansion valve that includes a plunger that can open and close the refrigerant flow path by contacting (landing) the valve seat by energizing off the electromagnetic coil, and a valve body under the plunger. The valve body had, or with high-pressure refrigerant to both the valve body and the valve seat has a groove for distribution, the valve seat surface on which the valve body and the valve seat abuts a valve having an orifice in the central portion The seat surface and the valve seat surface arranged on the outer side through the groove are formed at the same height .

  According to the present invention, by installing the groove portion through which the high-pressure refrigerant flows in the valve seat, the negative pressure region of the valve seat surface where the valve body and the valve seat abut when the valve body is opened is reduced, and the valve body can be operated with a smaller force. Can be raised. In addition, by providing a valve seat surface that is the same height as the valve seat surface having an orifice on the outer side of the groove, it is possible to prevent instability (tilt) of the valve body that occurs when the valve seat surface is made smaller. . As a result, the blockage of the refrigerant flow path is improved, and refrigerant leakage can be reduced. In addition, since the valve seat surface having an orifice in the center can be formed inside the groove, the pulling-down force due to the decompression of the refrigerant can be reduced, and the pulling-up force can be suppressed, so that the electromagnetic coil constituting the magnetic circuit can be downsized. Is possible.

FIG. 1 is an overall configuration diagram of a refrigerant cycle device including an electronic expansion valve according to the present invention. FIG. 2 is a side sectional view of the electronic expansion valve according to the present invention, FIG. 2 (a) shows a state in which energization of the electronic expansion valve is turned on, and FIG. 2 (b) shows a state of the valve seat according to the present invention. FIG. FIG. 3 is a side sectional view of the electronic expansion valve according to the present invention, in which a groove is formed on the valve body side. FIG. 4 is a side sectional view of the electronic expansion valve according to the present invention, in which the valve body is formed in a plate shape. FIG. 5 is a side sectional view of the electronic expansion valve according to the present invention, in which a communication hole is formed in a plate-like valve body. FIG. 6 is a side sectional view showing a configuration of a conventional electronic expansion valve. FIG. 7 is a side sectional view showing a state where the valve seat surface is small and the plunger is inclined in the electronic expansion valve shown in FIG. FIG. 8 is a side sectional view showing a state in which the valve seat surface is enlarged in the electronic expansion valve shown in FIG.

DESCRIPTION OF EMBODIMENTS Hereinafter, an expansion valve according to the present invention will be described in detail with reference to the accompanying drawings by giving preferred embodiments in relation to a refrigerant cycle device provided with the expansion valve.
FIG. 1 is an overall configuration diagram of a refrigerant cycle device 12 including an electronic expansion valve (expansion valve) 10 according to an embodiment of the present invention. The refrigerant cycle device 12 is used, for example, as a cooling and heating device for a vending machine, and cools and heats the three product storages 14a, 14b, and 14c, respectively, and maintains the sales products such as canned beverages at a predetermined temperature. belongs to. Needless to say, the electronic expansion valve 10 can be applied to a refrigerant cycle device used for, for example, an indoor or vehicular air conditioner or various showcases other than the vending machine.

First, an example of the configuration of the refrigerant cycle device 12 will be described.
As shown in FIG. 1, the refrigerant cycle device 12 includes a compressor 16, an external heat exchanger 18, an auxiliary heat exchanger 20, an internal heat exchanger 22, and an electronic expansion that are arranged in a machine room of a vending machine (not shown). The valve 10, the evaporator 24 and the heating heat exchanger 26 disposed in the commodity storage 14a, the evaporator 28 disposed in the commodity storage 14b, and the evaporator disposed in the commodity storage 14c. 30 and these are connected by a pipe filled with a predetermined amount of refrigerant (for example, carbon dioxide) to constitute a refrigerant circuit. The product storage 14b is further provided with a heater 32 for heating the interior.

  The compressor 16 sucks low-temperature and low-pressure refrigerant from the suction port via the suction-side pipe 34, compresses it, and discharges it from the discharge port to the discharge-side pipe 35, for example, Consists of a two-stage compression type. The discharge side pipe 35 is branched in two directions by a three-way valve 36, one pipe 38 is connected to the external heat exchanger 18, and the other pipe 40 is disposed in the product storage 14a for heating. Connected to the heat exchanger 26. Then, by controlling the switching of the three-way valve 36, the refrigerant discharged from the compressor 16 is selectively distributed to the external heat exchanger 18 or the heating heat exchanger 26.

  On the outlet side of the external heat exchanger 18, the pipe 38 is connected to the distributor 42 through the auxiliary heat exchanger 20 and the internal heat exchanger 22 in order. The distributor 42 branches the pipe 38 in three directions, and the branched pipes 43a, 43b, and 43c are connected to the evaporators 24, 28, and 30 through the electronic expansion valve 10, respectively. The pipes 44 a, 44 b and 44 c merge with the suction side pipe 34 on the outlet side of the evaporators 24, 28 and 30, and are connected to the suction port of the compressor 16 through the internal heat exchanger 22. On the other hand, on the outlet side of the heating heat exchanger 26, the pipe 40 joins the pipe 38 between the external heat exchanger 18 and the auxiliary heat exchanger 20 and is connected to the inlet side of the auxiliary heat exchanger 20. The

  A fan (not shown) is disposed close to the external heat exchanger 18, the auxiliary heat exchanger 20, the evaporators 24, 28, 30 and the heating heat exchanger 26. The fan disposed close to the external heat exchanger 18 and the auxiliary heat exchanger 20 is for external air blowing, and is used for passing outside air around the external heat exchanger 18 and the like and sending it to the outside. is there. On the other hand, the fans disposed close to the evaporators 24, 28, 30 and the heat exchanger 26 for heating are used for ventilation in the cabinet, and the air heated or cooled by passing around the evaporator 24 or the like is placed in each cabinet. It is for circulation.

  In such a refrigerant cycle device 12, the number of revolutions of the compressor 16 and the opening degree of the electronic expansion valve 10 are changed, and further, the three-way valve 36 and the distributor 42 are appropriately controlled to be opened and closed so that each chamber has a desired interior. Can be managed in the temperature range.

  At this time, the refrigerant cycle device 12 can execute, for example, three operation modes (CCC operation, HCC operation, and HHC operation) according to the product type and climate conditions stored in the product storage 14a to 14c. . The CCC operation is an operation mode in which all the warehouses 14a to 14c are cooled (COLD), and the three-way valve 36 is switched to the pipe 38 side, and the distributor 42 is distributed in three ways. The HCC operation is an operation mode in which the product storage 14a is heated (HOT) and the product storages 14b and 14c are cooled (COLD), the three-way valve 36 is switched to the pipe 40 side, and the distributor 42 is connected to the pipe 44b. , 44c. The HHC operation is an operation mode in which the product storages 14a and 14b are heated (HOT) and the product storage 14c is cooled (COLD), the three-way valve 36 is switched to the pipe 40 side, and the distributor 42 is connected to the pipe 44c. The heater 32 is turned on. Of course, the operation mode of the refrigerant cycle device 12 may be other than the above, and the configuration of the refrigerant circuit to which the electronic expansion valve 10 is applied may also be a configuration other than the refrigerant cycle device 12.

Next, the configuration of the electronic expansion valve 10 will be described.
2 is a side sectional view of the electronic expansion valve 10 according to the present invention. FIG. 2 (a) shows a state in which the electronic expansion valve is energized, and FIG. 2 (b) shows the valve seat 56 according to the present invention. Detailed view is shown.

  The electronic expansion valve 10 controls the refrigerant flow rate and the refrigerant evaporation temperature by being pulse-driven under the control of a control device (not shown). As shown in FIG. 2A, the electronic expansion valve 10 is a valve formed between an inlet port 50 through which high-pressure refrigerant flows, an outlet port 52 through which low-pressure refrigerant flows out, and an inlet port 50 and outlet port 52. A chamber 54, a valve seat 56 disposed in the valve chamber 54, a plunger 60 that moves forward and backward in the valve chamber 54, an inlet port 50, an outlet port 52, and the valve chamber 54 are formed, and the plunger 60 is slid And a case 62 that can be accommodated.

  The inlet port 50 is connected to a pipe 43a (43b, 43c) serving as a high pressure inflow pipe, and the outlet port 52 is connected to a pipe 44a (44b, 44c) serving as a low pressure inflow pipe. The valve chamber 54 provided between the inlet port 50 and the outlet port 52 is formed by an internal space of a cylindrical case 62. The valve chamber 54 includes an inlet port 50, an outlet port 52, and an outlet port 52. A valve seat 56 is disposed so as to partition the space.

  The valve seat 56 is a cylindrical member having a groove that is swingably disposed at the bottom of the case 62 in which the outlet port 52 is formed with an opening, and a small-diameter refrigerant channel 64 passes through the center thereof. ing. The refrigerant flow path 64 communicates between the inlet port 50 and the outlet port 52, and functions as an orifice for expanding the high-pressure refrigerant to flow out as the low-pressure refrigerant.

  2B, the upper surface of the valve seat 56 is divided into a valve seat surface (middle) 57 and a valve seat surface (outer) 58 at the upper portion of the valve seat 56. A groove 59 is formed. For this reason, the groove 59 communicates with the high-pressure refrigerant in the pipe 43a (43b, 43c) serving as a high-pressure inflow pipe.

  The plunger 60 is a piston that can move back and forth (up and down in FIG. 2) in a cylindrical cylinder formed by the case 62, and a yoke 68 inserted in the upper part of the center hole 66 a of the cylindrical bobbin 66. The lower end is supported via a coil spring 70. The yoke 68 is fixed to the upper surface of the housing (outer yoke) 69 by a fixing screw 71. The coil spring 70 is a compression spring that biases the plunger 60 in the forward direction (downward). Thus, the yoke 68 and the case 62 are inserted into the center hole 66 a of the bobbin 66, and the plunger 60 can slide within the case 62.

  In the electronic expansion valve 10, when energization of the electromagnetic coil 72 wound around the bobbin 66 is turned on, a magnetic circuit formed by the electromagnetic coil 72 and the yoke 68 causes the lower end of the yoke 68 to pass through the coil spring 70. The supported plunger 60 moves backward (retreats) against the biasing force of the coil spring 70. On the other hand, when energization to the electromagnetic coil 72 is turned off, the plunger 60 moves forward (advances) by the biasing force of the coil spring 70.

Next, the operation of the electronic expansion valve 10 configured as described above will be described.
For example, when the CCC operation is being performed in the refrigerant cycle device 12, each electronic expansion valve 10 that controls the flow of the refrigerant to each evaporator 24, 28, 30 under the control of a control device (not shown) It is turned on / off by a predetermined pulse energization from an energizing device (not shown) to the electromagnetic coil 72. When each electronic expansion valve 10 is turned on, the plunger 60 is retracted (retracted) and separated from the valve seat 56, the refrigerant flow path 64 is opened, and when each electronic expansion valve 10 is turned off, the plunger 60 is advanced (advanced). Then, the front end surface 60a of the plunger 60 is landed (contacted) on the valve seat 56, and the refrigerant flow path 64 is closed. The refrigerant flow path 64 is opened and closed at a predetermined time period by turning on / off the pulse current, and the evaporation temperature of the refrigerant in the evaporators 24, 28, 30 is controlled to a predetermined temperature.

  Further, for example, when the HCC operation is performed in the refrigerant cycle device 12, the energization to the electronic expansion valve 10 that controls the flow of the refrigerant to the evaporator 24 is turned off under the control of a control device (not shown). The energization of each electronic expansion valve 10 that controls the flow of the refrigerant to the other evaporators 28 and 30 is turned on. Thus, in the electronic expansion valve 10 that controls the flow of the refrigerant to the evaporator 24, the front end surface 60 a of the plunger 60 is landed (contacted) on the valve seat 56 by the urging force of the coil spring 70 to close the refrigerant flow path 64. On the other hand, in each electronic expansion valve 10 that controls the flow of the refrigerant to the evaporators 28 and 30, the refrigerant flow path 64 is opened and closed, and the evaporation temperature of the refrigerant in the evaporators 28 and 30 is controlled to a predetermined temperature.

  As described above, in a state where the energization to the electronic expansion valve 10 is turned off, the plunger 60 is moved forward by the urging force of the coil spring 70, and the distal end surface 60a of the plunger 60 is landed (contacted) on the valve seat 56, and the refrigerant. The flow path 64 is closed. Further, in a state where the energization to the electronic expansion valve 10 is turned on, as shown in FIG. 2A, a predetermined pulse energization is turned on to the electromagnetic coil 72, and the plunger 60 resists the biasing force of the coil spring 70. Accordingly, the refrigerant flow path 64 is opened by moving away from the valve seat 56.

  Here, the valve chamber 54 communicating with the piping 43a (43b, 43c) serving as the high-pressure inflow pipe is a high-pressure portion, but as shown in FIG. 2B, the groove portion communicating with the high-pressure portion on the valve seat 56. 59 is formed, the edge surface distance between the high-pressure region and the low-pressure region blocked by the distal end surface 60a of the plunger 60 and the valve seat surface (medium) 57 is shortened, and the high-low pressure difference is reduced. The negative pressure region between the valve body 61 and the valve seat 56 is reduced, and the force to pull down the plunger 60 is suppressed.

  Further, as shown in the detailed view of the valve seat 56 in FIG. 2B, by providing the valve seat surface (outside) 58, instability (tilt) of the plunger 60 can be prevented. Here, the valve seat surface (outside) 58 may have a protruding shape, and the valve seat 56 and the valve body 61 are in contact with the valve seat surface (inside) 57 having the orifice 64 on the outside via the groove 59. Just do it.

  Further, as shown in FIG. 3, a similar effect can be obtained by forming a groove (valve element) 80 in the valve element 61 below the plunger 60. When the groove portion (valve element) 80 communicates with the high pressure portion of the valve chamber 54, the plunger 60 is moved by the reduction effect of the negative pressure region formed by the distal end surface 60 a of the plunger 60 and the valve seat surface 56 a on the upper surface of the valve seat 56. Suppresses the pulling force.

  As shown in FIG. 4, when the plate-like valve body 81 is configured on the lower surface of the valve body 61 below the plunger 60 and the groove portion 59 communicating with the high-pressure portion in the valve seat 56, The force of pulling down the plunger 60 is suppressed by the reduction effect of the negative pressure region formed by the distal end surface 81a and the valve seat surface 56a on the upper surface of the valve seat 56. In addition, the elastic effect and light weight of the plate-like valve body 81 have the effect of preventing refrigerant leakage and reducing the operating force.

  Further, as shown in FIG. 5, when the communication hole 82 of the plate-like valve body 81 is formed on the lower surface of the valve body 61 below the plunger 60, the communication chamber 83 filled with the high-pressure refrigerant is used similarly to the case of the groove portion. Further, the force of pulling down the plunger 60 is suppressed by the effect of reducing the negative pressure region formed by the tip end surface 81a of the plate-like valve body 81 and the valve seat surface 56a on the upper surface of the valve seat 56.

  As described above, according to the electronic expansion valve 10 according to the present embodiment, as shown in FIG. 2, either the front end surface 60 a of the valve body 61 below the plunger 60, the upper surface 56 a of the valve seat 56, or By forming the groove 59 for supplying the high-pressure refrigerant to both sides, the effect of reducing the negative pressure region formed by the tip surface 60a and the valve seat surface 56a can be achieved, and the force required to open and close the plunger can be suppressed. Therefore, the electromagnetic coil 72 constituting the magnetic circuit, that is, the electronic expansion valve 10 can be reduced in size and cost.

In addition, this invention is not limited to above-described embodiment, It can change freely in the range which does not deviate from the main point of this invention.
For example, what is necessary is just to suppress the pulling-down force of the plunger 60 by the reduction effect of a negative pressure area | region by providing the groove part 59 and connecting with a high voltage | pressure part.

10, 100 Electronic expansion valve 12 Refrigerant cycle device 50, 102 Inlet port 52, 108 Outlet port 54 Valve chamber 56, 86, 104 Valve seat 56a, 104a Valve seat surface 57 Valve seat surface (middle)
58 Valve seat surface (outside)
59 Groove 60, 116 Plunger 60a, 81a, 116a Tip surface 61, 117 Valve body 62, 118 Case 64, 84, 94, 106 Refrigerant flow path 68, 112 Yoke 70, 114 Coil spring 72, 110 Electromagnetic coil 80 Groove (valve body)
81 Plate-shaped valve body 82 Communication hole 83 Communication chamber

Claims (1)

A case having at least an inlet port through which the refrigerant flows, an outlet port through which the refrigerant flows out, and a valve chamber provided between the inlet port and the outlet port;
A valve seat disposed in the valve chamber and formed with a refrigerant flow path for expanding the refrigerant flowing into the valve chamber from the inlet port and flowing out to the outlet port;
The solenoid valve is disposed opposite to the valve seat in such a manner that the solenoid coil is energized on and off, and is biased toward the valve seat by an urging means, and the solenoid coil is energized to turn on the valve. An expansion valve that includes a plunger that is spaced apart from the seat, and that can contact (land) the valve seat by turning off the energization of the electromagnetic coil to open and close the refrigerant flow path, and a valve body below the plunger.
The valve seat or the valve body, or a groove portion through which a high-pressure refrigerant flows through both the valve seat and the valve body, and a valve seat surface that contacts the valve seat and the valve body, and an orifice in the center portion An expansion valve characterized in that a valve seat surface having a valve seat surface disposed on the outer side through the groove is formed at the same height .

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