Electromagnetic coil unit

Abstract

To provide an electromagnetic coil unit capable of improving a radiation performance.SOLUTION: By arranging a shaft line A1 of a winding 41 so as to be deviated from a center part of a cross plate part 51 in a X direction, a temperature difference can be generated in both sides of the X direction while nipping the shaft line A1 in an inner part of an outer case 5 and a space of a circumference of a coil part 4, and an air flow of the X direction can be generated by the temperature difference. A Y direction dimension of the coil part 4 is 64 to 87% of an interval of both of a pair of coupling plate parts 53 and 54, and the air flow of them can pass effectively between the coil part 4 and the coupling plate parts 53 and 54, and can improve a radiation performance.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an electromagnetic coil unit used in a solenoid valve. [Background technology]

[0002] Generally, solenoid valves are known in which a fixed core arranged inside a winding is excited by passing current through the winding, thereby moving a movable core and switching a flow path. One proposed solenoid valve includes a frame that holds a solenoid coil as a winding inside and forms a magnetic path (see, for example, Patent Document 1). In the solenoid valve described in Patent Document 1, the frame is formed as a single component, having an end plate that abuts against one end of the hollow bobbin in the central axis direction, a pair of side plates connected to the end plate, and extensions extending from each of the side plates toward the central axis. This improves magnetic flux loss compared to a frame with a C-shaped cross section. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-113991 Summary of the Invention [Problem to be solved by the invention]

[0004] In the solenoid valve described in Patent Document 1, although a magnetic path is formed surrounding the winding in a rectangular cylindrical frame, reducing magnetic flux loss, the heat generated when current is applied to the winding is difficult to dissipate to the outside of the frame. For example, if the cross-sectional area or number of turns of the conductor wire constituting the winding is reduced to reduce the amount of conductor wire used, in order to reduce costs, the resistance value increases or the current required to ensure magnetomotive force increases. Because resistance loss, which causes heat generation, increases depending on both the current and the resistance value, reducing the amount of conductor wire used as described above increases the likelihood of heat generation. For this reason, there has been a demand for improved heat dissipation performance in electromagnetic coil units used in electromagnetically driven valves.

[0005] An object of the present invention is to provide an electromagnetic coil unit that can improve heat dissipation performance. [Means for solving the problem]

[0006] The electromagnetic coil unit of the present invention is an electromagnetic coil unit for switching flow paths in a solenoid valve, comprising a coil portion and an outer casing arranged outside the coil portion, wherein the coil portion has a winding formed in a spiral shape around a predetermined axis, the outer casing has a pair of crossing plate portions that sandwich the coil portion from the direction of the axis, and a pair of connecting plate portions that connect the pair of crossing plate portions, and is formed in a rectangular cylindrical shape with an extension direction that is perpendicular to both the opposing direction of the pair of crossing plate portions and the opposing direction of the pair of connecting plate portions, the axis is positioned offset from the center of the crossing plate portions in the extension direction, and the dimension of the coil portion in the opposing direction of the pair of connecting plate portions is 64 to 87% of the spacing between the pair of connecting plate portions.

[0007] According to the present invention, the axis of the winding is offset from the center of the crossing plate portion, so that the winding has a portion close to the external space and a portion far from the external space in the extension direction of the outer casing. Because the winding is more easily cooled closer to the external space, a temperature difference can be generated on both sides of the axis inside the outer casing and in the space around the coil portion. This temperature difference generates a pressure difference, which can generate an airflow from the high-pressure side (low-temperature side) to the low-pressure side (high-temperature side). (In other words, this temperature difference generates a density difference, which can generate an airflow from the high-density side (low-temperature side) to the low-density side (high-temperature side).) As described above, the dimension of the coil portion in the opposing direction of the pair of connecting plate portions, which is perpendicular to the direction in which the airflow is generated (extension direction), is 64 to 87% of the distance between the pair of connecting plate portions. This allows the airflow to pass efficiently between the coil portion and the connecting plate portions, improving heat dissipation performance.

[0008] On the other hand, if the dimensions of the coil are too large relative to the distance between the pair of connecting plates, the gap between the coil and the connecting plates becomes small, making it difficult for air to pass through and making it difficult to achieve sufficient heat dissipation performance.Also, if the dimensions of the coil are too small relative to the distance between the pair of connecting plates, it becomes difficult to create the temperature and pressure differences described above, making it difficult to generate airflow, and the magnetic path of the outer casing acting as a yoke becomes longer, reducing magnetic efficiency.

[0009] In this case, in the electromagnetic coil unit of the present invention, it is preferable that the outer casing is disposed on the solenoid valve so that the extending direction of the outer casing is along the vertical direction and the axis is disposed below the central portion. With this configuration, in addition to the airflow generated by the temperature difference, this airflow can be made to pass between the coil portion and the connecting plate portion as an ascending airflow, thereby further improving heat dissipation performance.

[0010] Furthermore, in the electromagnetic coil unit of the present invention, it is preferable that the deviation of the axis from the center is 2 to 10% of the dimension of the crossing plate portion in the extension direction. With this configuration, it is easy to generate the above-mentioned airflow while suppressing an increase in size. Furthermore, it is more preferable that this deviation is 3 to 8% of the dimension of the crossing plate portion in the extension direction. With this configuration, it is easy to further suppress an increase in size while generating the above-mentioned airflow. On the other hand, if the deviation is too large relative to the above-mentioned dimension of the crossing plate portion, the electromagnetic coil unit is likely to become large. Furthermore, if the deviation is too small relative to the above-mentioned dimension of the crossing plate portion, it is difficult to generate a temperature difference and generate an airflow. [Effects of the Invention]

[0011] According to the electromagnetic coil unit of the present invention, it is possible to improve heat dissipation performance. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic configuration diagram of a refrigeration cycle provided with a solenoid valve according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view showing the solenoid valve. [Figure 3] FIG. 2 is a plan view showing the solenoid valve. DETAILED DESCRIPTION OF THE INVENTION

[0013] An embodiment of the present invention will be described with reference to the drawings. The electromagnetic coil unit 1 of this embodiment is used in a solenoid valve 102 as shown in FIG. 1, and the solenoid valve 102 constitutes, for example, a refrigeration cycle 100 as shown in FIG. 1. The refrigeration cycle 100 is used in air conditioners such as room air conditioners, package air conditioners, and multi-air conditioners. The refrigeration cycle 100 includes a compressor 103 that compresses a refrigerant fluid; an outdoor heat exchanger 104 that serves as a first heat exchanger and functions as a condenser in a cooling mode; an indoor heat exchanger 105 that serves as a second heat exchanger and functions as an evaporator in the cooling mode; an expansion valve 106 that expands and reduces the pressure of the refrigerant between the outdoor heat exchanger 104 and the indoor heat exchanger 105; a four-way switching valve 101; and a solenoid valve 102 that serves as a pilot solenoid valve that controls switching of the flow path of the four-way switching valve 101. These components are connected by refrigerant piping. The expansion means is not limited to the expansion valve 106, and a capillary may be used.

[0014] 1, the refrigeration cycle 100 constitutes a cooling cycle in which a refrigerant flows in the order of compressor 103, four-way switching valve 101, outdoor heat exchanger 104, expansion valve 106, indoor heat exchanger 105, four-way switching valve 101, and compressor 103. On the other hand, in a heating mode (heating operation) indicated by a dashed arrow, the refrigeration cycle 100 constitutes a heating cycle in which a refrigerant flows in the order of compressor 103, four-way switching valve 101, indoor heat exchanger 105, expansion valve 106, outdoor heat exchanger 104, four-way switching valve 101, and compressor 103. Switching between the heating cycle and the cooling cycle is performed by the switching operation of the four-way switching valve 101 using the solenoid valve 102.

[0015] The four-way switching valve 101 is well known and comprises a cylindrical valve body 111, a slide valve 112 slidably provided inside the valve body, a high-pressure side conduit (D joint) 113 communicating with the discharge port of the compressor 103, a low-pressure side conduit (S joint) 114 communicating with the suction port of the compressor 103, an indoor side conduit (E joint) 115 communicating with the indoor heat exchanger 105, and an outdoor side conduit (C joint) 116 communicating with the outdoor heat exchanger 104. The valve body 111 has plugs 117 and 118 that close both axial ends thereof, and is configured as an entirely sealed cylinder, with spaces A11 and A12 formed therebetween that axially sandwich a piston 119 that moves the slide valve 112.

[0016] The solenoid valve 102 of this embodiment is a well-known one having the configuration of a four-way switching valve, and includes a valve body 120, a valve seat 121, a valve element 122, an electromagnetic coil unit 1, and coupling members 123 to 126, and the fluid flow path is switched by the movement of the valve element 122 along a predetermined sliding direction (i.e., movement direction). Note that Fig. 1 is a schematic diagram showing how the components constituting the refrigeration cycle 100 are connected, and does not show the positional relationship, orientation, dimensions, etc. of the components. In particular, the detailed structure, arrangement, and orientation of the solenoid-driven valve 102 are as described below.

[0017] 2 and 3, the electromagnetic coil unit 1 includes a plunger 2, an attractor 3, a coil section 4, and an outer casing 5. When the winding 41 of the coil section 4 is energized, the attractor 3 is excited, and the plunger 2 moves toward the attractor 3, thereby moving the valve element 122 held by the plunger 2. When the flow path is switched in the solenoid valve 102, high-pressure fluid in the high-pressure side conduit 113 is introduced into one of the spaces A11 and A12 that sandwich the piston 119 in the axial direction, and low-pressure fluid in the low-pressure side conduit 114 is introduced into the other space, causing the piston 119 to move toward the low-pressure side space.

[0018] The coil section 4 has a winding 41, a molded section 42, and a bobbin 43, which are integrally formed by molding. The winding 41 is a solenoid coil in which a conductive wire 411 is wound spirally around the bobbin 43, centered on a predetermined axis A1. The molded section 42 is formed from molded resin, which is an insulator, so that the winding 41 is provided inside.

[0019] In the following description, the direction of the axis A1 is defined as the Z direction, and the plane perpendicular to the Z direction is defined as the XY plane. The X direction is also defined as the vertical direction.

[0020] The coil portion 4 has end surfaces 44, 45 on both sides in the Z direction, a curved portion 46 that is part of a cylinder centered on the axis A1, and a protruding portion 47 that protrudes from the curved portion 46 to one side in the X direction (upward in the vertical direction). The curved portion 46 is formed concentrically with the winding 41, and the protruding portion 47 is provided to connect the lead wire 6 to the winding 41. As such, the outer peripheral shape of the coil portion 4 is asymmetric on both sides of a plane that passes through the axis A1 and is along the YZ plane. The protruding portion 47 has a pair of flat portions 471 that are continuous with the curved portion 46 and extend toward one side in the X direction. The flat portions 471 are inclined with respect to the ZX plane.

[0021] The outer casing 5 has a pair of cross plate portions 51, 52 and a pair of connecting plate portions 53, 54 that connect the pair of cross plate portions 51, 52 to each other. The cross plate portion 51 extends along the XY plane and is provided so as to contact the end surface 44 of the coil portion 4 from the side opposite the valve seat portion 121. A through hole 511 for fixing the attractor 3 is formed in the cross plate portion 51. The center of this through hole 511 coincides with the center of the cylindrical attractor 3, and the attractor 3 is arranged concentrically with the winding 41. Therefore, the center of the through hole 511 coincides with the center of the winding 41 (i.e., the axis A1).

[0022] The through hole 511 is disposed vertically downwardly offset from the center of the cross plate portion 51 in the X direction. In FIG. 3, a line LN1 that passes through the center of the cross plate portion 51 in the X direction and extends in the Y direction is indicated by a dashed line, and the through hole 511 and the axis A1 are located below the line LN1. Therefore, in the solenoid valve 102, the axis A1 of the winding 41 is disposed downwardly offset from the center of the cross plate portion 51 in the X direction. The amount of offset ΔX of the axis A1 from the line LN1 is 2 to 10% of the X-direction dimension LX of the cross plate portion 51, and more preferably 3 to 8%.

[0023] A notch 512 for arranging the lead wire 6 is formed on the upper edge of the cross plate portion 51 in the X direction. In other words, the axis A1 is shifted to the side opposite to the side on which the notch 512 is formed.

[0024] The cross plate portion 52 extends along the XY plane and is provided so as to contact the end surface 45 of the coil portion 4 from the valve seat portion 121 side. A through hole 521 is formed in the cross plate portion 52, through which the valve body 120 is inserted. Note that the portions of the cross plate portion 52 on both sides in the Y direction across the through hole 521 may be connected to each other or may be independent from each other (i.e., as in Patent Document 1, the outer casing 5 may be formed, for example, by bending a single metal plate, with slits formed at the joints between the edges of the metal plate). The cross plate portions 51 and 52 have the same dimensions in the X and Y directions.

[0025] The connecting plate portions 53 and 54 connect the Y-direction ends of the pair of cross plate portions 51 and 52 to each other, and extend along the ZX plane.

[0026] As described above, the outer casing 5 is formed into an elongated rectangular cylindrical shape by the pair of cross plate portions 51, 52 and the pair of connecting plate portions 53, 54, and the extending direction thereof coincides with the X direction.

[0027] The outer casing 5 as described above forms a magnetic circuit and functions as a yoke. That is, magnetic flux passes from one end of the winding 41 to the other end, passes through the cross plate portion 51, the pair of connecting plate portions 53 and 54, passes through the cross plate portion 52, and returns to the coil portion 4 (or the magnetic flux passes in the opposite direction).

[0028] The relationship between the coil portion 4 and the outer casing 5 and the mode of heat dissipation will be described below. First, a gap is formed between the outer peripheral surface of the coil portion 4 (particularly the curved surface portion 46) and the connecting plate portions 53, 54. In this case, the Y-direction dimension L1 of the coil portion 4 is 64 to 87% of the distance L2 between the pair of connecting plate portions 53, 54 (i.e., the distance between the inner surfaces). Note that the Y-direction dimension L1 of the coil portion 4 means the maximum dimension in the Y direction.

[0029] Furthermore, because the axis A1 is offset downward with respect to the line LN1 as described above, the coil portion 4 is located near the lower opening of the cylindrical outer casing 5. As a result, when the coil portion 4 generates heat due to the passage of current, the lower side in the X direction is more easily cooled by the outside air than the upper side. That is, inside the outer casing 5 and in the space around the coil portion 4, the temperature is higher above the axis A1 than below. The pressure in the high-temperature region is relatively lower than that in the low-temperature region, and this pressure difference generates an airflow from the low-temperature side to the high-temperature side (from the bottom to the top) (in other words, the temperature difference generates a density difference, and an airflow is generated from the high-density side (low-temperature side) to the low-density side (high-temperature side)).

[0030] At this time, a gap is formed between the outer circumferential surface of the coil portion 4 and the connecting plate portions 53, 54, so that the airflow described above can pass between the coil portion 4 and the connecting plate portions 53, 54.

[0031] According to the present embodiment described above, the axis A1 of the winding 41 is positioned offset in the X direction from the center of the cross plate portion 51, which causes a temperature difference to occur on both sides of the axis A1 in the X direction inside the outer casing 5 and in the space around the coil portion 4, and this temperature difference can generate an airflow in the X direction. The Y direction dimension of the coil portion 4 is 64 to 87% of the distance between the pair of connecting plate portions 53, 54, which allows the airflow to pass efficiently between the coil portion 4 and the connecting plate portions 53, 54, thereby improving heat dissipation performance.

[0032] On the other hand, if the Y-direction dimension of the coil portion 4 is too large relative to the distance between the pair of connecting plate portions 53, 54, it becomes difficult to secure a gap therebetween, making it difficult for airflow to pass through and making it difficult to obtain sufficient heat dissipation performance. Also, if the Y-direction dimension of the coil portion 4 is too small relative to the distance between the pair of connecting plate portions 53, 54, it becomes difficult to create the temperature difference described above and generate airflow, and the magnetic path of the outer casing 5 serving as a yoke becomes longer, reducing magnetic efficiency.

[0033] Furthermore, since the rectangular cylindrical outer case 5 extends vertically and the axis A1 of the winding 41 is positioned below the center of the cross plate portion 51, rising air currents can pass between the coil portion 4 and the connecting plate portions 53, 54, further improving heat dissipation performance.

[0034] Furthermore, by setting the offset ΔX of the axis A1 of the winding 41 from the center of the cross plate portion 51 to 2 to 10%, and more preferably 3 to 8%, of the X-direction dimension LX of the cross plate portion 51, it is possible to easily generate the above-mentioned airflow while suppressing an increase in size. On the other hand, if the offset ΔX is too large relative to the dimension LX, the electromagnetic coil unit is likely to increase in size. On the other hand, if the offset ΔX is too small relative to the dimension LX, it is difficult to generate a temperature difference and therefore difficult to generate an airflow.

[0035] The present invention is not limited to the above-described embodiment, but includes other configurations that can achieve the object of the present invention, and the following modifications are also included in the present invention. In the above-described embodiment, the rectangular cylindrical outer casing 5 extends vertically, but the extension direction of the outer casing may be slightly inclined relative to the vertical direction. Furthermore, if airflow is likely to occur due to the temperature difference as described above, the extension direction of the outer casing may be along one direction within a horizontal plane.

[0036] In the above embodiment, the offset ΔX of the axis A1 of the winding 41 from the center of the cross plate portion 51 is set to 2 to 10%, and more preferably 3 to 8%, of the X-direction dimension LX of the cross plate portion 51. However, the offset is not limited to this range. For example, if the outer casing is sufficiently large relative to the winding, the offset may be increased to make a temperature difference more likely to occur. Alternatively, if a temperature difference is likely to occur, the offset may be decreased.

[0037] The embodiments of the present invention have been described in detail above with reference to the drawings, but the specific configurations are not limited to these embodiments, and the present invention also includes design changes and the like that do not deviate from the gist of the present invention.

[0038] [Example] In the electromagnetic coil unit 1 of the above embodiment, the ratio of the Y-direction dimension L1 of the coil portion 4 to the distance L2 between the pair of connecting plate portions 53, 54 was changed, and the temperature was measured to confirm the relative temperature increase (temperature increase ratio).

[0039] The common experimental conditions were an applied voltage of 240 V and 50 Hz, and the temperature was measured when the current was saturated while the current was being applied. The power consumption during the current application was also measured. The dimensions of the outer casing 5 were not changed, and only the Y-direction dimension L1 of the coil section 4 was changed, thereby changing the ratio between these dimensions L1 and L2. The ratio between dimensions L1 and L2, the measurement results for the temperature rise rate, and the measurement results for the power consumption are shown in Table 1.

[0040] [Table 1]

[0041] The temperature rise ratio was determined by dividing the temperature rise value in each example and comparative example by the temperature rise value in comparative example 1. Similarly, the power consumption ratio was determined by dividing the power consumption value in each example and comparative example by the power consumption value in comparative example 1. In examples 1 to 4 where the ratio of L1 to L2 was 64 to 85%, the temperature rise ratio was low. In this case, it was confirmed that the temperature rise ratio was low in examples 1 to 4 even when the power consumption ratio was taken into consideration. [Explanation of symbols]

[0042] 1... electromagnetic coil unit, 4... coil portion, 41... winding, 5... outer casing, 51, 52... cross plate portion, 53, 54... connecting plate portion, 102... solenoid valve, A1... axis

Claims

1. An electromagnetic coil unit for switching a flow path in a solenoid valve, the electromagnetic coil unit comprising a coil portion and an outer case disposed outside the coil portion, The coil portion has a winding formed in a spiral shape around a predetermined axis, the outer case has a pair of cross plate portions that sandwich the coil portion from the axial direction, and a pair of connecting plate portions that connect the pair of cross plate portions, and is formed in a quadrangular tubular shape whose extending direction is perpendicular to both the opposing direction of the pair of cross plate portions and the opposing direction of the pair of connecting plate portions, The axis is disposed so as to be shifted from a center portion of the cross plate portion in the extension direction, An electromagnetic coil unit characterized in that the dimension of the coil portion in the opposing direction of the pair of connecting plate portions is 64 to 87% of the distance between the pair of connecting plate portions.

2. 2. The electromagnetic coil unit according to claim 1, wherein the outer casing is disposed on the solenoid valve such that the extending direction of the outer casing is along the vertical direction and the axis is disposed below the central portion.

3. 3. The electromagnetic coil unit according to claim 1, wherein the amount of deviation of the axis from the central portion is 2 to 10% of the dimension of the cross plate portion in the extension direction.

Images