JP7619635B2 - Expansion valve - Google Patents

Description

The present invention relates to an expansion valve.

Conventionally, for refrigeration cycles used in air conditioners installed in automobiles, a temperature expansion valve with a built-in temperature sensing mechanism that adjusts the amount of refrigerant passing through depending on the temperature has been used. The valve body of such an expansion valve has an inlet port through which high-pressure refrigerant is introduced and a valve chamber that communicates with the inlet port.

The spherical valve disc is disposed within the valve chamber, facing the valve seat of the valve hole that opens into the valve chamber. The valve disc is supported by a support member disposed within the valve chamber, and is biased toward the valve seat by a coil spring installed between the support member and an adjustment screw attached to the valve body. The valve disc is driven via the valve rod by the power element, controlling the opening of the throttle passage between the valve seat. The refrigerant that passes through the valve hole is sent to the evaporator side from the outlet port.

Here, the high-pressure refrigerant sent to the inlet port of the expansion valve may experience pressure fluctuations (pulsations) due to the operation of the compressor, which may cause the valve body to vibrate and generate abnormal noise. For this reason, an anti-vibration spring has been proposed to prevent the valve body from vibrating (see, for example, Patent Document 1).

In the expansion valve described in Patent Document 1, the spherical valve body is welded to a support member called a valve body support, and the assembly is performed so that the vibration-proof spring is sandwiched between this valve body support and the coil spring.

JP 2018-25332 A

In recent years, from the perspective of environmental protection, there has been a demand for reduced fuel consumption for engine-equipped vehicles, and for BEVs (Battery Electric Vehicles), which use only battery power to drive the wheels, there is a demand for an extended driving range on a single charge. Here, reducing the weight of the vehicle can meet both demands, and is considered effective regardless of the drive system. Therefore, there is a strong demand for reducing the weight of air conditioning units installed in vehicles, and reducing the weight of the expansion valves used in these units is also effective in differentiating the product from similar products.

One idea for making the expansion valve lighter is to change to a lighter material. However, considering the increased cost and impact on durability that would accompany a change in material, it would be preferable to use the same material but make it lighter, which would also be expected to reduce costs by reducing the amount of material used.

The present invention aims to provide an expansion valve that can be made lighter and less expensive while still using the same materials as conventional valves.

In order to achieve the above object, the expansion valve according to the present invention comprises:
a valve body having a valve seat in a valve chamber;
a valve body that seats on the valve seat to prevent passage of a fluid and that separates from the valve seat to allow passage of the fluid;
a valve body support including an insertion portion and a flange portion protruding from the insertion portion in a direction perpendicular to the axis, the valve body support being connected to the valve body;
a coil spring into which the insertion portion is fitted and which biases the valve body toward the valve seat via the valve body support;
a vibration-proof member sandwiched between the flange portion and the coil spring,
the vibration-proof member includes a base having an opening through which the insertion portion passes, and a plurality of legs extending from the base and abutting against an inner wall of the valve chamber,
The present invention is characterized in that, in a cross section perpendicular to the axis of the valve body support, at least one of the outer periphery of the insertion portion and the inner periphery of the opening is non-circular, and the outer periphery of the insertion portion and the inner periphery of the opening are in contact at three or more points along the circumferential direction.

The present invention makes it possible to provide an expansion valve that is lighter and less expensive, for example, while still using materials that are the same as conventional ones.

FIG. 1 is a schematic cross-sectional view showing an example in which an expansion valve 1 according to a first embodiment is applied to a refrigerant circulation system. FIG. 2 is a perspective view showing a valve body, a valve body support, a valve body vibration isolation spring, and a coil spring in an exploded state. FIG. 3 is a perspective view of the valve body and the valve body support as viewed from below. FIG. 4 is a bottom view of the valve body and the valve body support. FIG. 5 is a top view of the coil spring. FIG. 6 is a perspective view showing a valve body, a valve body support according to the second embodiment, a valve body vibration isolation spring, and a coil spring in an exploded state. FIG. 7 is a perspective view of the valve body and the valve body support according to the second embodiment, as viewed from below. FIG. 8 is a bottom view of the valve body and the valve body support according to the second embodiment. FIG. 9 is a perspective view showing a valve body, a valve body support according to the third embodiment, a valve body vibration isolation spring, and a coil spring in an exploded state. FIG. 10 is a perspective view of the valve body and the valve body support according to the third embodiment, as viewed from below. FIG. 11 is a bottom view of the valve body 3 and the valve body support according to the third embodiment. FIG. 12 is a perspective view showing the valve body 3, the valve body support according to the fourth embodiment, the valve body vibration-proof spring according to the fourth embodiment, and the coil spring in an exploded state. FIG. 13 is a top view of the valve body vibration-proof spring. FIG. 14 is a perspective view of the valve body and the valve body support according to the fifth embodiment, as viewed from below. FIG. 15 is a bottom view of the valve body and the valve body support according to the fifth embodiment. FIG. 16 is a side view of the valve body and a valve body support according to a modified example. FIG. 17 is a perspective view showing the valve body 3, the valve body support, the valve body vibration-proof spring according to the sixth embodiment, and the coil spring in an exploded state. FIG. 18 is a top view of the valve body vibration-proof spring. FIG. 19 is an exploded perspective view showing a valve body, a valve body support according to the seventh embodiment, a valve body vibration isolation spring according to the seventh embodiment, and a coil spring. FIG. 20 is an exploded perspective view showing the valve body, the valve body support according to the eighth embodiment, the valve body vibration isolation spring according to the eighth embodiment, and the coil spring. 13 is a cross-sectional view of a valve body support and a valve body vibration-proof spring according to a modified example, viewed in the axial direction. FIG.

The following describes an embodiment of the present invention with reference to the drawings.

(Definition)
In this specification, the direction from the valve disc 3 to the actuating rod 5 is defined as the "upward direction," and the direction from the actuating rod 5 to the valve disc 3 is defined as the "downward direction." Therefore, in this specification, regardless of the attitude of the expansion valve 1, the direction from the valve disc 3 to the actuating rod 5 is called the "upward direction."
In addition, in this specification, "contact at three or more points along the circumferential direction" means that, when the inner circumference and the outer circumference are in point contact, the contact points are in contact at three or more points over a range of more than 180 degrees in the circumferential direction in a plane perpendicular to the axis, so that the inner circumference and the outer circumference are fixed to each other in the direction perpendicular to the axis, and when the inner circumference and the outer circumference are in line contact, it is considered that they are in contact at three or more points, and further it means that they are in line contact over a range of more than 180 degrees, either continuously or discontinuously, in the plane perpendicular to the axis, so that the inner circumference and the outer circumference are fixed to each other in both the tangent direction of the line contact and the direction perpendicular to the tangent.
In addition, "the minimum circumscribing circle diameter is equal to the inner diameter" and "the maximum inscribing circle diameter is equal to the outer diameter" include cases where the two are completely equal, as well as cases where they are substantially equal (for example, differing only within the range of manufacturing tolerances of the parts).

(First embodiment)
An overview of an expansion valve 1 in a first embodiment will be described with reference to Fig. 1. Fig. 1 is a schematic cross-sectional view showing an example in which the expansion valve 1 in this embodiment is applied to a refrigerant circulation system 100. In this embodiment, the expansion valve 1 is fluidly connected to a compressor 101, a condenser 102, and an evaporator 104. The axis of the expansion valve 1 is designated as L.

The expansion valve 1 comprises a valve body 2 having a valve chamber VS, a valve element 3, a biasing device 4, an actuating rod 5, a ring spring 6, and a power element 8. The axis of the expansion valve 1 is L.

The valve body 2 has a first flow path 21, a second flow path 22, and a return flow path 23 in addition to the valve chamber VS. The first flow path 21 is a supply side flow path, and a refrigerant (also called a fluid) is supplied to the valve chamber VS via the supply side flow path. The second flow path 22 is a discharge side flow path, and the fluid in the valve chamber VS is discharged to the outside of the expansion valve via the working rod insertion hole 27 and the discharge side flow path. The first flow path 21 and the valve chamber VS are connected by a connection path 21a with a smaller diameter than the first flow path 21.

The spherical valve element 3 is disposed within the valve chamber VS. When the valve element 3 is seated on the annular valve seat 20 of the valve body 2, the first flow path 21 and the second flow path 22 are not in communication. On the other hand, when the valve element 3 is separated from the valve seat 20, the first flow path 21 and the second flow path 22 are in communication.

The lower end of the actuating rod 5, which is inserted with a gap into the actuating rod insertion hole 27, is in contact with the upper surface of the valve body 3. The actuating rod 5 can also press the valve body 3 in the valve opening direction against the biasing force of the biasing device 4. When the actuating rod 5 moves downward, the valve body 3 moves away from the valve seat 20, and the expansion valve 1 opens.

The actuating rod 5 extends from the valve body 3 to the power element 8 along the axis L, via the actuating rod insertion hole 27, the central hole 28, the annular portion 26, the return flow passage 23, and the communication passage 2b, which are coaxially formed in the valve body 2. The inner diameter of the annular portion 26 is larger than the inner diameter of the central hole 28, which slidably holds the actuating rod 5. An actuating rod vibration-proof spring 6, which has a vibration-proofing function for the actuating rod 5, is disposed in the annular portion 26. Details of the actuating rod vibration-proof spring 6 are described in, for example, JP 2018-25332 A, so a description thereof will be omitted here.

Note that both the second flow path 22 and the return flow path 23 are located on the low pressure side in the refrigeration cycle, but the former is relatively high pressure because the refrigerant passes through the evaporator 104 and is subject to pressure loss. Therefore, the second flow path 22 is sometimes referred to as the high pressure flow path, and the return flow path 23 is sometimes referred to as the low pressure flow path.

Next, the power element 8 will be described. The power element 8 is attached to a recess 2a provided at the top of the valve body 2. The recess 2a is connected via a communication passage 2b to a return flow path 23 in the valve body 2, through which the refrigerant from the evaporator 104 passes.

The power element 8 has a plug 81, an upper cover member 82, a diaphragm 83, a stopper member 84, and a receiving member 86.

A hole 82a is formed at the top of the upper cover member 82, which can be sealed with a plug 81.

The diaphragm 83 is made of a thin plate material with multiple concentric circular projections and recesses.

The stopper member 84 has a disk portion and a cylindrical portion that is coaxially connected to the lower surface of the disk portion, and a fitting hole 84c is formed in the center of the lower end of the cylindrical portion.

The receiving member 86 has a flange portion having an outer diameter approximately the same as the outer diameter of the upper cover member 82, and a hollow cylindrical portion connected to the lower end of the flange portion, and a male thread 86c is formed on the outer periphery of the hollow cylindrical portion.

When assembling the power element 8, first the outer peripheries of the flanges of the top cover member 82, diaphragm 83, and receiving member 86 are overlapped, and then the outer peripheries are circumferentially welded together by, for example, TIG welding, laser welding, plasma welding, etc.

Next, the working gas is injected into the space surrounded by the top cover member 82 and the diaphragm 83 (called the pressure actuated chamber PA) through the hole 82a formed in the top cover member 82, and then the hole 82a is sealed with a plug 81, and the plug 81 is fixed to the top cover member 82 using projection welding or the like.

At this time, the diaphragm 83 is pressurized by the working gas sealed in the pressure actuated chamber PA in such a way that it bulges toward the receiving member 86, and is supported by abutting against the upper surface of the stopper member 84 disposed in the lower space LS surrounded by the diaphragm 83 and the receiving member 86. In addition, since the disk portion of the stopper member 84 is held by the receiving member 86, the stopper member 84 will not come out of the power element 8.

When assembling the power element 8 to the valve body 2, the upper end of the actuating rod 5 is fitted into the fitting hole 84c of the stopper member 84, and the actuating rod 5 is inserted into the valve body 2 while passing through the actuating rod vibration isolation spring 6 attached to the valve body 2. Furthermore, the male thread 86c of the receiving member 86 is screwed into the female thread of the recess 2a of the valve body 2, and the power element 8 is fixed to the valve body 2 by screwing it in. In this state, the lower space LS of the power element 8 is connected to the return flow path 23, i.e., the same internal pressure is applied.

Next, the biasing device 4 will be described. In FIG. 1, the biasing device 4 has a coil spring 41 made of circular wire wound in a spiral shape, a valve body support 42 attached to the upper end of the coil spring 41 and supporting the valve body 3, a spring receiving member 43 attached to the valve body 2 while supporting the lower end of the coil spring 41, and a valve body vibration isolation spring (vibration isolation member) 44. The spring receiving member 43 seals the valve chamber VS of the valve body 2 and has the function of supporting the end of the coil spring 41 that biases the valve body 3 toward the valve seat 20.

The spherical valve body 3 is welded to the top surface of the valve body support 42, and the two are integrated.

Figure 2 is a perspective view showing the valve body 3 and valve body support 42, the valve body vibration-proof spring 44, and the coil spring 41 in an exploded state. Figure 3 is a perspective view of the valve body 3 and valve body support 42 from below. Figure 4 is a bottom view of the valve body 3 and valve body support 42. Figure 5 is a top view of the coil spring 41.

The valve body support 42 has a disk-shaped flange 42a and a roughly hexagonal column-shaped insertion portion 42b connected to the underside of the flange 42a. A chamfer 42d is formed around the entire circumference of the lower end of the insertion portion 42b. A recess 42c is formed in the center of the upper surface of the flange 42a, which protrudes perpendicular to the axis of the insertion portion 42b (i.e., has a larger diameter than the minimum circumscribing circle of the insertion portion 42b), and the valve body 3 is fitted into and welded to the recess 42c. The axis of the valve body support 42 coincides with the axis L of the expansion valve 1 in the assembled state. The valve body support 42 can be formed by press molding, forging, etc.

The cross section of the insert 42b perpendicular to the axis is a uniform hexagon (non-circular) shape except for the chamfer 42d, and as shown in FIG. 4, the vertices of the hexagon in the cross section are located on the minimum circumscribing circle C1 of diameter φa centered on the axis. Therefore, compared to a cylindrical case, the insert 42b requires less material between its outer periphery and the minimum circumscribing circle C1, resulting in a reduction in weight and material.

In FIG. 2, the valve body vibration-proof spring 44 is made up of a base 44a and a leg piece 44b connected together, and can be formed by press molding from an elastic plate material such as stainless steel or its alloy.

The base 44a is a generally annular portion that forms the upper portion of the valve body vibration-proof spring 44, and has a circular mounting hole (also called an opening) 44c in the center. The inner diameter φb of the mounting hole 44c is equal to the inner diameter φc of the coil spring 41 (see FIG. 5). With the insertion portion 42b of the valve body support 42 inserted into the mounting hole 44c, the base 44a is attached so that it is sandwiched between the underside of the flange portion 42a of the valve body support 42 and the upper end of the coil spring 41.

In this embodiment, the diameter φa of the smallest circumscribing circle C1 of the insertion portion 42b is equal to the inner diameter φb of the mounting hole 44c and the inner diameter φc of the coil spring 41, so that the outer periphery of the insertion portion 42b abuts against the inner periphery of the mounting hole 44c and the inner periphery of the coil spring 41 at six points corresponding to the vertices of the hexagon, excluding the chamfer 42d, in the cross section perpendicular to the axis. As a result, the insertion portion 42b (i.e., the valve body support 42 and the valve body 3) is fixed to the coil spring 41 while ensuring coaxiality in the direction perpendicular to the axis. It is optional to provide a slit or notch in the inner periphery of the mounting hole 44c at a portion that does not abut against the outer periphery of the insertion portion 42b, and this is also the case in the embodiments described below.

The legs 44b extend radially from the outer periphery of the base 44a, and eight legs 44b of the same length are provided at equal angular intervals in the circumferential direction. Each leg 44b is bent into a roughly L-shape at an angle less than a right angle to the base 44a, and has a hemispherical protrusion 44d protruding outward near the tip.

When the biasing device 4 is installed in the valve chamber VS, the raised portion 44d resiliently contacts the upper inner wall of the valve chamber VS, but is designed not to enter the connection passage 21a of the valve body 2 even when the valve element 3 is in the lowest position.

(Expansion valve operation)
An example of the operation of the expansion valve 1 will be described with reference to Fig. 1. The refrigerant pressurized by the compressor 101 is liquefied by the condenser 102 and sent to the expansion valve 1. The refrigerant adiabatically expanded by the expansion valve 1 is sent to the evaporator 104, where it is heat exchanged with the air flowing around the evaporator. The refrigerant returning from the evaporator 104 is returned to the compressor 101 side through the expansion valve 1 (more specifically, the return flow path 23). At this time, by passing through the evaporator 104, the fluid pressure in the second flow path 22 becomes greater than the fluid pressure in the return flow path 23.

The expansion valve 1 is supplied with high-pressure refrigerant from the condenser 102. More specifically, the high-pressure refrigerant from the condenser 102 is supplied to the valve chamber VS via the first flow path 21.

When the valve body 3 is seated on the valve seat 20 (in other words, when the expansion valve 1 is closed), the first flow path 21 on the upstream side of the valve chamber VS and the second flow path 22 on the downstream side of the valve chamber VS are not in communication. On the other hand, when the valve body 3 is separated from the valve seat 20 (in other words, when the expansion valve 1 is open), the refrigerant supplied to the valve chamber VS is sent to the evaporator 104 through the actuating rod insertion hole 27 and the second flow path 22. The expansion valve 1 is switched between the closed state and the open state by the actuating rod 5 connected to the power element 8.

In FIG. 1, the power element 8 is provided with a pressure actuated chamber PA and a lower space LS separated by a diaphragm 83. Therefore, when the working gas in the pressure actuated chamber PA is liquefied, the working rod 5 moves upward, and when the liquefied working gas is vaporized, the working rod 5 moves downward. In this way, the expansion valve 1 is switched between the open and closed states.

Furthermore, the lower space LS of the power element 8 is connected to the return flow path 23. Therefore, the phase (gas phase, liquid phase, etc.) of the working gas in the pressure actuated chamber PA changes depending on the temperature and pressure of the refrigerant flowing through the return flow path 23, and the actuating rod 5 is driven. In other words, in the expansion valve 1 shown in FIG. 1, the amount of refrigerant supplied from the expansion valve 1 to the evaporator 104 is automatically adjusted depending on the temperature and pressure of the refrigerant returning from the evaporator 104 to the expansion valve 1.

In this embodiment, the valve body support 42 is made lighter, so the total mass of the valve body 3 and the valve body support is reduced and the natural frequency is increased, thereby making it possible to suppress resonance during operation of the expansion valve 1.

Second Embodiment
Fig. 6 is a perspective view showing the valve body 3, the valve body support 42A according to the second embodiment, the valve body vibration-proof spring 44, and the coil spring 41 in an exploded state. Fig. 7 is a perspective view of the valve body 3 and the valve body support 42A according to the second embodiment from below. Fig. 8 is a bottom view of the valve body 3 and the valve body support 42A according to the second embodiment. The valve body 3, the valve body vibration-proof spring 44, and the coil spring 41 are the same as those in the above-mentioned embodiment, so repeated explanations will be omitted. The valve body support 42A of this embodiment can be used in the expansion valve 1 of Fig. 1 by welding the valve body 3 to it.

The valve body support 42A has a disk-shaped flange 42Aa and a columnar insertion portion 42Ab with a hexapetal-like cross section that is connected to the underside of the flange 42Aa. A chamfer 42Ad is formed around the entire circumference of the lower end of the insertion portion 42Ab. A recess 42Ac is formed in the center of the upper surface of the flange 42Aa, which protrudes perpendicular to the axis of the insertion portion 42Ab, and the valve body 3 is fitted into and welded to the recess 42Ac. The axis of the valve body support 42A coincides with the axis L of the expansion valve 1 in the assembled state. The valve body support 42A can be formed by press molding, forging, etc.

The cross section of the insertion part 42Ab perpendicular to the axis is a uniform non-circular shape except for the chamfer 42Ad, and as shown in FIG. 8, the six vertices of the cross section are located on the minimum circumscribed circle C1 of diameter φa centered on the axis. Therefore, when the insertion part 42Ab is inserted into the mounting hole 44c of the valve body vibration-proof spring 44, the mounting hole 44c and the insertion part 42Ab are fixed without any play in the direction perpendicular to the axis. Furthermore, compared to a cylindrical case, the material of the insertion part 42Ab between its outer periphery and the minimum circumscribed circle C1 is reduced, resulting in weight reduction and material reduction. Since the diameter φa of the minimum circumscribed circle C1 is equal to the inner diameter φc of the coil spring 41, by inserting the insertion part 42Ab into the coil spring 41, a fixation without any play in the direction perpendicular to the axis is realized.

Third Embodiment
Fig. 9 is a perspective view showing the valve body 3, the valve body support 42D according to the third embodiment, the valve body vibration-proof spring 44, and the coil spring 41 in an exploded state. Fig. 10 is a perspective view of the valve body 3 and the valve body support 42D according to the third embodiment from below. Fig. 11 is a bottom view of the valve body 3 and the valve body support 42D according to the third embodiment. The valve body 3, the valve body vibration-proof spring 44, and the coil spring 41 are the same as those in the above-mentioned embodiments, so repeated explanations will be omitted. The valve body support 42D of this embodiment can be used in the expansion valve 1 of Fig. 1 by welding the valve body 3 to it.

The valve body support 42D has a disk-shaped flange 42Da and an insertion portion 42Db connected to the underside of the flange 42Da. The insertion portion 42Db is made up of three legs 42De that are implanted on the underside of the flange 42Da and extend parallel to the axis and are spaced apart in the circumferential direction, so that the cross-sectional shape of the insertion portion 42Db in the direction perpendicular to the axis is non-circular. The legs 42De each have a chamfer (partial conical surface) 42Dd formed on the outer periphery of the lower end.

A recess 42Dc is formed in the center of the upper surface of the flange portion 42Da, which protrudes perpendicular to the axis from the insertion portion 42Db, and the valve body 3 is fitted and welded into the recess 42Dc. The axis of the valve body support 42D coincides with the axis L of the expansion valve 1 in the assembled state. The valve body support 42D can be formed by press molding, forging, etc.

The legs 42De each have a common shape, and a part of their outer circumference is located on the minimum circumscribing circle C1 of diameter φa that is centered on the axis of the valve body support 42D and surrounds the entire insertion part 42Db as shown in FIG. 11. Therefore, when the insertion part 42Db is inserted into the mounting hole 44c of the valve body vibration-proof spring 44, the mounting hole 44c and the insertion part 42Db are fixed without any play in the direction perpendicular to the axis, and compared to a cylindrical case, the insertion part 42Db requires significantly less material, resulting in weight reduction and material savings. Since the diameter φa of the minimum circumscribing circle C1 is equal to the inner diameter φc of the coil spring 41, inserting the insertion part 42Db into the coil spring 41 achieves fixation without any play in the direction perpendicular to the axis.

In addition, from a different perspective, the valve body support 42D of this embodiment can also be said to have three equally spaced slits extending radially from the center of the cylindrical insertion portion 42Db, forming the leg portion 42De.

(Fourth embodiment)
Fig. 12 is a perspective view showing the valve body 3, the valve body support 42E according to the fourth embodiment, the valve body vibration-proof spring 44E according to the fourth embodiment, and the coil spring 41 in an exploded state. Fig. 13 is a top view of the valve body vibration-proof spring 44E. The valve body 3 and the coil spring 41 are the same as those in the above-mentioned embodiment, so a duplicated description will be omitted. The valve body support 42E and the valve body vibration-proof spring 44E of this embodiment can be used in the expansion valve 1 of Fig. 1.

The shape of the valve body support 42E is the same as in the first embodiment except for the insertion portion 42Eb, so a duplicated description will be omitted. The insertion portion 42Eb is cylindrical with an outer diameter φd.

The shape of the valve body vibration-proof spring 44E other than the mounting hole 44Ec of the base 44Ea (i.e., the leg pieces 44Eb and the raised portion 44Ed) is the same as in the first embodiment, so a duplicated description will be omitted. As shown in FIG. 13, the mounting hole 44Ec has a regular hexagonal shape, and the diameter of its maximum inscribed circle C2 is φe, which is equal to the outer diameter φd of the insertion portion 42Eb and the inner diameter φc of the coil spring 41 (see FIG. 5).

Since the outer diameter φd of the insertion portion 42Eb is equal to the diameter φe of the maximum inscribed circle C2 of the mounting hole 44Ec and the inner diameter φc of the coil spring 41, the outer periphery of the insertion portion 42Eb abuts at six points at the midpoints of each side of the mounting hole 44Ec, which is a regular hexagon, in a cross section perpendicular to the axis, and also abuts over the entire inner periphery of the coil spring 41. As a result, the insertion portion 42Eb (i.e., the valve body support 42E and the valve body 3) is fixed to the coil spring 41 while maintaining coaxiality in the direction perpendicular to the axis.

The mounting hole 44Ec has a uniform regular hexagonal (non-circular) shape when viewed in the axial direction, and as shown in FIG. 16, the midpoint of each side of the mounting hole 44Ec is located on the maximum inscribed circle C2 of diameter φe centered on the axis. Therefore, when the insertion portion 42Eb is inserted into the mounting hole 44Ec of the valve body vibration isolation spring 44E, the mounting hole 44Ec and the insertion portion 42Eb are fixed without any play in the direction perpendicular to the axis, and compared to a circular shape, the material of the mounting hole 44Ec between its inner circumference and the maximum inscribed and circumscribed circle C2 is reduced, resulting in weight reduction and material reduction.

Fifth Embodiment
Fig. 14 is a perspective view of the valve body 3 and the valve body support 42B according to the fifth embodiment, as viewed from below. Fig. 15 is a bottom view of the valve body 3 and the valve body support 42B according to the fifth embodiment. The valve body 3, the valve body vibration-proof spring 44E, and the coil spring 41 are the same as those in the above-mentioned embodiments, so a duplicated description will be omitted. The valve body support 42B of this embodiment can be used in the expansion valve 1 of Fig. 1 together with the valve body vibration-proof spring 44E according to the fourth embodiment by welding the valve body 3 to the valve body support 42B.

The valve body support 42B is formed by connecting a disk-shaped flange portion 42Ba and an insertion portion 42Bb. The insertion portion 42Bb has a small diameter disk portion (insertion near portion) 42Be connected to the underside of the flange portion 42Ba, and a hexapetal-shaped cross-sectional columnar portion (insertion far portion) 42Bf connected to the lower end of the small diameter disk portion 42Be and having six vertices. It is preferable that the thickness of the small diameter disk portion 42Be is thicker than the thickness of the base portion 44Ea of the valve body vibration isolation spring 44E.

A chamfer 42Bd is formed around the entire circumference of the lower end of the hexapetal-shaped cross-sectional columnar portion 42Bf. A recess (not shown) is formed in the center of the upper surface of the flange portion 42Ba, which protrudes perpendicular to the axis from the insertion portion 42Bb, and the valve body 3 is fitted into and welded. The axis of the valve body support 42B coincides with the axis L of the expansion valve 1 in FIG. 1 in the assembled state. The valve body support 42B can be formed by press molding, forging, etc.

The cross section of the hexapetal-shaped columnar section 42Bf perpendicular to the axis is a uniform non-circular shape except for the chamfer 42Bd. On the other hand, the outer diameter of the small-diameter disk section 42Be is equal to the diameter φa of the smallest circumscribing circle C1 centered on the axis of the hexapetal-shaped columnar section 42Bf, and is also equal to the inner diameter φd of the mounting hole 44Ec of the valve body vibration-proof spring 44E and the inner diameter φc of the coil spring 41. Therefore, when the insertion section 42Bb is fitted into the mounting hole 44Ec and the inner circumference of the coil spring 41, the outer circumference of the small-diameter disk section 42Be abuts against the inner circumference of the mounting hole 44Ec at six points, and the outer circumference of the hexapetal-shaped columnar section 42Bf abuts against the inner circumference of the coil spring 41. As a result, the insertion portion 42Bb (i.e., the valve body support 42B and the valve body 3) is fixed to the coil spring 41 while maintaining coaxiality in the direction perpendicular to the axis.

The six-petal-shaped cross-sectional columnar portion 42Bf has a uniform non-circular cross-section perpendicular to the axis, except for the chamfer 42Bd, and as shown in FIG. 15, the six vertices of the cross-section are located on the smallest circumscribed circle C1 of diameter φa centered on the axis. Therefore, when the insertion portion 42Bb is inserted into the mounting hole 44Ec of the valve body vibration-proof spring 44E, the mounting hole 44Ec and the insertion portion 42Bb are fixed without any play in the direction perpendicular to the axis, and compared to a cylindrical case, the six-petal-shaped cross-sectional columnar portion 42Bf requires less material between its outer periphery and the smallest circumscribed circle C1, resulting in weight reduction and material savings.

(Modification)
16 is a side view of the valve 3 and a valve support 42C according to a modified example. As in the fifth embodiment, the valve support 42C is formed by connecting a disk-shaped flange 42Ca and an insertion portion 42Cb. The insertion portion 42Cb has a small diameter disk portion 42Ce connected to the lower surface of the flange 42Ca, and a hexapetal-shaped cross-sectional columnar portion 42Cf having six vertices connected to the lower end of the small diameter disk portion 42Ce.

When the valve body support 42C is formed by press molding or forging, a transition portion TR (shown by a dotted line in FIG. 16) with an arc-shaped cross section may be formed across the intersection of the flange portion 42Ca and the small diameter disk portion 42Ce. If the transition portion TR remains, the outer periphery of the upper end of the small diameter disk portion 42Ce will expand in diameter, which may prevent it from fitting accurately against the inner periphery of the mounting hole 44Ec of the valve body vibration isolation spring 44E.

In this modified example, the valve body support 42C is formed by press forming or forging, and then the transition portion TR is removed by machining as a post-processing step. As a result, as shown by the solid line in Figure 16, the lower surface of the flange portion 42Ca and the peripheral surface of the small diameter disk portion 42Ce can intersect at a right angle, and the outer diameter of the small diameter disk portion 42Ce matches the maximum inscribed circle of the mounting hole 44Ec of the valve body vibration isolation spring 44E, allowing the two to fit together with high precision.

The removal of the transition portion formed between the flange portion and the insertion portion can be similarly applied to the above-mentioned embodiment and the embodiment described below. In particular, in the case of a non-circular insertion portion, the removal of the transition portion is sufficient only for the portion that abuts against the inner circumference of the mounting hole of the valve body vibration-proof spring, so the number of processing steps does not increase significantly.

Sixth Embodiment
Fig. 17 is a perspective view showing the valve body 3 and the valve body support 42E, the valve body vibration-proof spring 44F according to the sixth embodiment, and the coil spring 41 in an exploded state. Fig. 18 is a top view of the valve body vibration-proof spring 44F. The valve body 3, the valve body support 42E, and the coil spring 41 are the same as those in the above-mentioned embodiments, so a duplicated description will be omitted. The valve body support 42E and the valve body vibration-proof spring 44F of this embodiment can be used in the expansion valve 1 of Fig. 1.

The shape of the valve body vibration-proof spring 44F other than the mounting hole 44Fc of the base 44Fa (i.e., the leg piece 44Fb and the raised portion 44Fd) is the same as in the first embodiment, so a duplicated description will be omitted. As shown in FIG. 18, the mounting hole 44Fc has an eight-petal outline shape, and the diameter of its maximum inscribed circle C2 is φe, which is equal to the outer diameter φd of the insertion portion 42Eb and the inner diameter φc of the coil spring 41. Therefore, by inserting the insertion portion 42Eb into the coil spring 41, a fixation without any backlash in the direction perpendicular to the axis is achieved.

Since the outer diameter φd of the insertion portion 42Eb is equal to the diameter φe of the maximum inscribed circle C2 of the mounting hole 44Fc and the inner diameter φc of the coil spring 41, the outer periphery of the insertion portion 42Eb abuts at eight points closest to the center of the mounting hole 44Fc, which has an eight-petal outline, in a cross section perpendicular to the axis, and also abuts against the inner periphery of the coil spring 41 over the entire circumference. As a result, the insertion portion 42Eb (i.e., the valve body support 42E and the valve body 3) is fixed to the coil spring 41 while maintaining coaxiality in the direction perpendicular to the axis.

The mounting hole 44Fc has an eight-petal outline shape (non-circular) when viewed in the axial direction, and as shown in FIG. 18, the point of contact of the mounting hole 44Fc with the insertion portion 42Eb is located on the maximum inscribed circle C2 of diameter φe centered on the axis. Therefore, when the insertion portion 42Eb is inserted into the mounting hole 44Fc of the valve body vibration isolation spring 44F, the mounting hole 44Fc and the insertion portion 42Eb are fixed without any play in the direction perpendicular to the axis, and compared to a circular shape, the material of the mounting hole 44Fc between its inner circumference and the maximum inscribed and circumscribed circle C2 is reduced, resulting in weight reduction and material reduction.

Seventh Embodiment
19 is a perspective view showing the valve body 3, the valve body support 42, the valve body vibration-proof spring 44E, and the coil spring 41 in an exploded state. The valve body 3, the valve body support 42, the valve body vibration-proof spring 44E, and the coil spring 41 are the same as those in the above-mentioned embodiment, so a duplicated description will be omitted. The valve body support 42 and the valve body vibration-proof spring 44E of this embodiment can be used in the expansion valve 1 of FIG.

The insertion portion 42b of the valve body support 42 is a hexagonal column, and the mounting hole 44Ec of the valve body vibration-proof spring 44E is a hexagon corresponding to the insertion portion 42b when viewed in the axial direction. When the insertion portion 42b is fitted into the mounting hole 44Ec, the outer periphery of the insertion portion 42b and the inner periphery of the mounting hole 44Ec abut over the entire circumference. Compared to a cylindrical case, the insertion portion 42b requires less material, and even when the increase in material of the valve body vibration-proof spring 44E is taken into account, the total weight and material can be reduced. Since the minimum circumscribed circle diameter φa of the outer periphery of the insertion portion 42b is equal to the inner diameter φc of the coil spring 41, inserting the insertion portion 42b into the coil spring 41 achieves a fixation without any play in the direction perpendicular to the axis.

Eighth embodiment
20 is a perspective view showing the valve body 3, the valve body support 42A, the valve body vibration-proof spring 44F, and the coil spring 41 in an exploded state. The valve body 3, the valve body support 42A, the valve body vibration-proof spring 44F, and the coil spring 41 are the same as those in the above-mentioned embodiment, so a duplicated description will be omitted. The valve body support 42A and the valve body vibration-proof spring 44F of this embodiment can be used in the expansion valve 1 of FIG. 1.

The insertion portion 42Ab of the valve body support 42A is a columnar shape with a hexapetal cross section, and the mounting hole 44Fc of the valve body vibration-proof spring 44F is hexapetal-shaped corresponding to the insertion portion 42Ab when viewed in the axial direction. When the insertion portion 42Ab is fitted into the mounting hole 44Fc, the outer periphery of the insertion portion 42Ab and the inner periphery of the mounting hole 44Fc abut over the entire circumference. Compared to a cylindrical case, the insertion portion 42Ab requires less material, and even when the increase in material of the valve body vibration-proof spring 44F is taken into account, the total weight and material can be reduced. Since the minimum circumscribed circle diameter φa of the outer periphery of the insertion portion 42Ab is equal to the inner diameter φc of the coil spring 41, by inserting the insertion portion 42Ab into the coil spring 41, a fixation without any play in the direction perpendicular to the axis is achieved.

(Modification)
In the seventh and eighth embodiments, the outer periphery of the insertion portion and the inner periphery of the mounting hole are made to coincide in shape, but this is not limited thereto. For example, as shown in Fig. 21, when viewed in the axial direction, the inner periphery of the mounting hole 44Gc may be made to have a regular hexagon (non-circular shape), and the outer periphery of the insertion portion 42Gb may be made to have an equilateral triangle (a non-circular shape different from that of the mounting hole 44Gc), with the three vertices of the regular hexagon abutting against the vertices of the equilateral triangle.

The present invention is not limited to the above-described embodiment. Any of the components of the above-described embodiment may be modified within the scope of the present invention. Any of the components of the above-described embodiment may be added or omitted.

1: Expansion valve 2: Valve body 3: Valve body 4: Biasing device 5: Actuating rod 6: Actuating rod vibration-proof spring 8: Power element 20: Valve seat 21: First flow path 22: Second flow path 23: Return flow path 26: Annular portion 27: Actuating rod insertion hole 41: Coil springs 42-42E: Valve body support 43: Spring receiving member 44, 44E, 44F: Valve body vibration-proof spring 100: Refrigerant circulation system 101: Compressor 102: Condenser 104: Evaporator VS: Valve chamber

Claims (14)

a valve body having a valve seat in a valve chamber;
a valve body that seats on the valve seat to prevent passage of a fluid and that separates from the valve seat to allow passage of the fluid;
a valve body support including an insertion portion and a flange portion protruding from the insertion portion in a direction perpendicular to the axis, the valve body support being connected to the valve body;
a coil spring into which the insertion portion is fitted and which biases the valve body toward the valve seat via the valve body support;
a vibration-proof member sandwiched between the flange portion and the coil spring,
the vibration-proof member includes a base having an opening through which the insertion portion passes, and a plurality of legs extending from the base and abutting against an inner wall of the valve chamber,
In a cross section perpendicular to the axis of the valve body support, at least one of an outer periphery of the insertion portion and an inner periphery of the opening is non-circular, and the outer periphery of the insertion portion and the inner periphery of the opening are in contact with each other at three or more points along a circumferential direction.
An expansion valve characterized by: In a cross section perpendicular to the axis of the valve body support, an outer periphery of the insertion portion is non-circular, and an inner periphery of the opening is circular.
2. The expansion valve according to claim 1 . In a cross section perpendicular to the axis of the valve body support, the minimum circumscribing circle diameter of the outer periphery of the insertion portion is equal to the inner diameter of the opening.
3. The expansion valve according to claim 2. In a cross section perpendicular to the axis of the valve body support, a minimum circumscribing circle diameter of an outer periphery of the insertion portion is equal to an inner diameter of the coil spring.
4. The expansion valve according to claim 2 or 3. In a cross section perpendicular to the axis of the valve body support, an outer periphery of the insertion portion is circular, and an inner periphery of the opening is non-circular.
2. The expansion valve according to claim 1 . In a cross section perpendicular to the axis of the valve body support, the maximum inscribed circle diameter of the inner circumference of the opening is equal to the outer diameter of the insertion portion.
6. The expansion valve according to claim 5. In a cross section perpendicular to the axis of the valve body support, the outer diameter of the insertion portion is equal to the inner diameter of the coil spring.
7. The expansion valve according to claim 5 or 6. The insertion portion has an insertion proximal portion and an insertion distal portion located farther from the flange portion than the insertion proximal portion,
The expansion valve as described in claim 1, characterized in that in a cross section perpendicular to the axis of the valve body support, the outer periphery of the insertion vicinity is circular, the inner periphery of the opening of the vibration-damping member is non-circular, and the outer periphery of the insertion vicinity and the inner periphery of the opening are in contact with each other. In a cross section perpendicular to the axis of the valve body support, the insertion portion has a non-circular shape, and a minimum circumscribed circle diameter of the insertion portion is equal to an inner diameter of the coil spring.
9. The expansion valve according to claim 8. The insertion portion has a plurality of legs extending along an axis of the valve body support and spaced apart in a circumferential direction.
3. The expansion valve according to claim 2. In a cross section perpendicular to the axis of the valve body support, a minimum circumscribing circle diameter surrounding the plurality of legs is equal to an inner diameter of the opening.
11. The expansion valve according to claim 10. In a cross section perpendicular to the axis of the valve body support, a minimum circumscribing circle diameter surrounding the plurality of legs is equal to an inner diameter of the coil spring.
12. The expansion valve according to claim 10 or 11. In a cross section perpendicular to the axis of the valve body support, an outer periphery of the insertion portion is non-circular, and an inner periphery of the opening is non-circular corresponding to the outer periphery of the insertion portion.
2. The expansion valve according to claim 1 . In a cross section perpendicular to the axis of the valve body support, a minimum circumscribing circle diameter of an outer periphery of the insertion portion is equal to an inner diameter of the coil spring.
14. The expansion valve according to claim 13.

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