Pressure regulating valve

Abstract

The present invention provides a pressure regulating valve equipped with an adjusting spring and a pressure-sensitive component. By suppressing the lateral force generated by the adjusting spring, this pressure regulating valve can reduce sliding resistance and hysteresis. A pressure regulating valve (100a) includes: a valve body (5) having a valve seat (18); a valve needle (30) having a valve portion (32) capable of contacting and separating from the valve seat (18); a pressure-sensitive unit (40) that flexes in the axial direction and has a pressure-sensitive component (41) that applies a force to the valve portion (32); an adjusting spring unit (50) having an adjusting spring (53) that applies a force to the valve portion (32) in the valve closing direction; and a connecting mechanism (70) that forms a centripetal engagement with unevenness between the pressure-sensitive unit (40) and the adjusting spring unit (50). The adjusting spring (53) is a wave spring. Since this wave spring suppresses the lateral force, it can reduce sliding resistance and hysteresis.

Description

Technical Field

[0001] The present invention relates to a pressure regulating valve having an adjusting spring and a pressure-sensitive member. Background Art

[0002] In a pressure regulating valve, the valve opening is controlled according to pressure fluctuations by providing an adjusting spring and a pressure-sensitive member.

[0003] For example, Figure 6 discloses a pressure regulating valve (hereinafter referred to as "conventional pressure regulating valve") using a helical spring and a pressure-sensitive bellows as an adjusting spring and a pressure-sensitive member, respectively. In the conventional pressure regulating valve 300, an inflow pipe 301 and an outflow pipe 302 are connected to a valve housing 310, and a ball valve 330 that can contact and separate from a valve seat 318 is provided in a valve chamber 311 that communicates between the above components. Further, the conventional pressure regulating valve 300 includes a pressure-sensitive unit 340 that applies a force to the ball valve 330 in the valve closing direction, an adjusting spring unit 350, and a rectifying element unit 390 that applies a force to the ball valve 330 in the valve opening direction (see Patent Document 1). Here, the pressure-sensitive unit 340 includes a pressure-sensitive bellows 341, a bellows lower cover 342, a bellows upper cover 343, and a connecting rod 345. Further, the adjusting spring unit 350 includes a spring support member 351, an adjusting screw member 352, and an adjusting spring 353 clamped between the spring support member 351 and the adjusting screw member 352.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent Laid-Open No. 6-229481 Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] First, the pressure-sensitive unit 340 and the adjusting spring unit 350 are engaged with each other via the connecting rod 345. One end portion and the other end portion of the connecting rod 345 are respectively fitted to the bellows lower cover 342 and the spring support member 351 that can move in the radial direction via a first guide vane 346 and a second guide vane 355 formed of an elastic member. Further, the central portion of the connecting rod 345 is inserted into an insertion hole 343a provided in the bellows upper cover 343, but a minute gap is provided between the connecting rod 345 and the insertion hole 343a. Through this minute gap, atmospheric pressure is introduced into the internal space of the pressure-sensitive bellows 341, and on the other hand, the secondary side pressure P2 is introduced into the external space of the pressure-sensitive bellows 341. Further, the rectifying element unit 390 transmits the acting force of the helical spring 392 to the ball valve 330 via the rectifying element 391.

[0009] Here, the existing pressure regulating valve 300 uses a helical spring as the regulating spring 353. When the helical spring is compressed, the inclination angles of the wound wire are not all uniformly changed, so the central axis of the helical spring inclines, generating many acting forces (lateral forces) not along the central axis C.

[0010] Therefore, even if the helical spring is assembled with high precision in the existing pressure regulating valve 300, when compressed, the lateral force generated by the helical spring is transmitted to the connecting rod 345, causing the connecting rod 345 to slide relative to the insertion through-hole 343a in a state inclined with respect to the central axis C. As a result, there is a problem of an increase in the sliding resistance between the connecting rod 345 and the insertion through-hole 343a (hereinafter, referred to as "the existing problem point (increase in sliding resistance)"), and the hysteresis becomes larger.

[0011] An object of the present invention is to provide a pressure regulating valve including a regulating spring and a pressure-sensitive component, which can reduce the sliding resistance and lower the hysteresis by suppressing the lateral force generated by the regulating spring.

[0012] Means for solving the problem

[0013] To solve the above problem, the pressure regulating valve includes: a valve body having a valve seat; a valve needle having a valve portion that can contact and separate from the valve seat; a pressure-sensitive unit that flexes in the axial direction and has a pressure-sensitive component that applies a force to the valve portion; a regulating spring unit having a regulating spring that applies a force to the valve portion in the valve-closed direction via the pressure-sensitive component; and a connecting mechanism that forms a centripetal engaging protrusion and recess between the pressure-sensitive unit and the regulating spring unit, and the regulating spring is a wave spring.

[0014] Moreover, the pressure regulating valve may be configured such that the regulating spring unit further includes a spring support member having a convex portion and an adjusting screw member having a concave portion, and the valve needle side and the regulating spring unit side of the wave spring are respectively supported by the convex portion and the concave portion, and the spring support member can rotate relative to the pressure-sensitive unit via the connecting mechanism.

[0015] Moreover, the pressure regulating valve may be configured such that the static friction force generated between the valve needle side of the wave spring and the spring support member is set to be larger than the static friction force generated between the spring support member and the connecting mechanism.

[0016] Moreover, the pressure regulating valve may be configured such that flat annular seat portions are respectively provided at both ends of the wave spring.

[0017] Further, the pressure regulating valve may be configured such that the use range of the wave spring is set while avoiding the inflection point of the spring constant in such a manner that the wave spring has a linear characteristic from the valve closed state to the fully open state of the valve portion.

[0018] Further, the pressure regulating valve may be configured such that the wave spring is housed in a spring housing of the valve body separated from the control fluid.

[0019] Further, the pressure regulating valve may be configured to use carbon dioxide as the control fluid.

[0020] Further, the pressure regulating valve may be configured such that the pressure-sensitive unit further includes a cover on the side of the adjustment spring unit having a cylindrical sliding portion communicating in the axial direction, and the connection mechanism includes a connection member having a circular side portion when viewed from the axial direction, and the side portion of the connection member makes point contact with the sliding portion.

[0021] Further, the pressure regulating valve may be configured such that the pressure-sensitive unit further includes: a connecting rod, an end portion on the side of the adjustment spring unit of the connecting rod being arranged so as to be insertable into the sliding portion; and the pressure-sensitive member formed of a bellows for pressure sensitivity, an end portion on the side of the valve needle of the bellows for pressure sensitivity being connected to the connecting rod, and an end portion on the side of the adjustment spring unit of the bellows for pressure sensitivity being fixed so as not to be relatively displaceable with respect to the valve body, and the connection mechanism further includes an engaging portion provided at the axial center portion of the end portion on the side of the valve needle of the adjustment spring unit, and the engaging portion and the connection member have concave and protruding shapes, forming a concave-convex engagement.

[0022] The effects of the invention are as follows.

[0023] According to the present invention, it is possible to provide a pressure regulating valve including an adjustment spring and a pressure-sensitive member, and the pressure regulating valve can reduce the sliding resistance and reduce the hysteresis by suppressing the lateral force generated by the adjustment spring. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a cross-sectional view showing the valve closed state of the pressure regulating valve according to the first embodiment of the present invention, (a) shows an overall view of the pressure regulating valve, and (b) shows an enlarged view of the area surrounded by the dashed line Ib in (a).

[0025] Figure 2 is a view showing Figure 1 the appearance of the wave spring in a perspective view.

[0026] Figure 3 is a view showing Figure 2 the non-linear characteristic load-deflection curve of the wave spring.

[0027] Figure 4 It is a partial enlarged view of the upper connection mechanism of the pressure regulating valve which is a modified example of the first embodiment.

[0028] Figure 5 It is a cross-sectional view showing the closed valve state of the pressure regulating valve of the second embodiment.

[0029] Figure 6 It is a cross-sectional view showing the closed valve state of the pressure regulating valve with an adjusting spring and a pressure-sensitive member in the prior art.

[0030] Symbol Explanation

[0031] 100a, 100b, 200—pressure regulating valve, 5, 205—valve body, 10, 210—valve housing, 11, 211—inlet port, 12, 212—outlet port, 15—valve chamber, 16—bellows accommodation chamber, 18—valve seat, 20—spring housing, 30—valve needle (valve core), 40, 240—pressure-sensitive unit, 41—pressure-sensitive bellows (pressure-sensitive member), 43, 143—bellows upper cover (cover on the adjusting spring unit side), 43a—insertion through-hole, 43c—sliding portion, 45, 245—linking rod, 50—adjusting spring unit, 51—spring support member, 51a—boss portion (convex portion), 51b—flange portion (convex portion), 52—adjusting threaded member, 52a—annular wall portion (concave portion), 52b—upper surface portion (concave portion), 53—adjusting spring (corrugated spring), 53c—peak portion, 53d—lower end portion, 53s—separation portion, 53sd—lower seat portion, 53st—stepped portion, 53su—upper seat portion, 53u—upper end portion, 53t—contact portion, 53v—valley portion, 60—lower connection mechanism, 63—ball, 70, 170, 270—upper connection mechanism (connection mechanism), 71, 271—lower engaging portion, 72—upper engaging portion, 73b, 173b—connecting member, 241—pressure-sensitive diaphragm (pressure-sensitive member), 242—diaphragm lower cover, 243—diaphragm upper cover (cover on the adjusting spring unit side), 244—pressing plate, C—central axis, L1, L2—maximum valve lift. Detailed Embodiments

[0032] Refer to Figures 1 to 5 , and the embodiments of the present invention will be described in detail. However, the present invention is not limited to the embodiments.

[0033] 〈Regarding Terms〉

[0034] In the description of this specification, "upper" and "lower" indicate "the side of the adjustment spring unit" and "the side of the valve needle". In the description of this specification and the claims, "one end" and "the other end" indicate "the side of the valve needle" and "the side of the adjustment spring unit". In the description of this specification and the claims, "the effective pressure-receiving area of the bellows for pressure sensitivity" indicates the pressure-receiving area that is an approximate value calculated as the average inner diameter based on the minimum inner diameter (the inner diameter of the "valley" part in the corrugated shape of the bellows for pressure sensitivity protruding toward the central axis) and the maximum inner diameter (the inner diameter of the "peak" part in the corrugated shape of the bellows for pressure sensitivity protruding in the direction away from the central axis of the central axis). In the description of this specification and the claims, "capable of guiding" includes the case of "capable of sliding". In the description of this specification and the claims, "concavo-convex engagement" indicates the case where the concave shape and the protruding shape are respectively engaged in the axial direction.

[0035] (First Embodiment)

[0036] 〈Regarding the Structure of the Pressure Regulating Valve〉

[0037] Use Figure 1 , the pressure regulating valve 100a of the first embodiment of the present invention will be described. The pressure regulating valve 100a mainly includes a valve body 5, a valve needle (spool) 30, a pressure-sensitive unit 40, and an adjustment spring unit 50. Hereinafter, a lower connection mechanism 60 and an upper connection mechanism (connection mechanism) 70 are added to each structure of the pressure regulating valve 100a and described in sequence. In addition, in the pressure regulating valve 100a, it is assembled to the valve body 5 in a state where it is indirectly engaged from one end side to the other end side in the order of the valve needle 30, the pressure-sensitive unit 40, and the adjustment spring unit 50. Here, a wave spring is used as the adjustment spring 53 in the pressure regulating valve 100a of the present embodiment, but this will be described in detail below. In this wave spring, a plurality of contact portions 53t formed in the circumferential direction (refer to Figure 2 ) are arranged in a staggered manner along the spring central axis direction. Therefore, in the pressure regulating valve 100a of the present embodiment, when the wave spring is compressed, the plurality of contact portions 53t always become fulcrums, reliably transmit the acting force along the central axis C, suppress the lateral force, and thus can eliminate the existing problem points (the increase in sliding resistance) and reduce the hysteresis.

[0038] The valve body 5 is composed of a valve housing 10 connected to the inflow pipe 1 and the outflow pipe 2, and a spring housing 20 joined to the other end portion of the valve housing 10 by riveting or the like. The valve body 5 is made of an appropriate material such as a metal such as brass, iron, aluminum, stainless steel, or a resin material such as polyphenylene sulfide (PPS).

[0039] The valve housing 10 is a hollow cylindrical component having a through hole penetrating along the central axis C. In this through hole, an inlet port 11 connected to the inflow pipe 1, a valve needle guide hole 13, a valve needle storage chamber 14, a valve chamber 15, and a bellows storage chamber 16 are provided in a communicating manner. The valve needle guide hole 13 is set to have an inner diameter smaller than that of the valve needle storage chamber 14, and an annular stepped portion 17 is provided at the connecting portion between the valve needle guide hole 13 and the valve needle storage chamber 14. Further, the valve chamber 15 is set to have an inner diameter larger than that of the valve needle storage chamber 14, and an annular valve seat 18 is provided at the connecting portion between the valve chamber 15 and the valve needle storage chamber 14.

[0040] In addition, the valve housing 10 also has a through hole penetrating from the valve chamber 15 in the radial direction, and an outlet port 12 connected to the outflow pipe 2 is provided in this through hole. Thus, in the closed valve state, it is configured such that the secondary side pressure P2 can be introduced into the valve chamber 15 and the bellows storage chamber 16 via the outlet port 12.

[0041] The spring housing 20 is a hollow cylindrical component having a through hole penetrating along the central axis C, and a spring storage chamber 21 is provided. Further, an internal thread portion 22 is provided on the inner peripheral side of the other end portion of the spring housing 20, and it is threadedly engaged with an external thread portion 52c provided on the outer peripheral side of the adjustment screw member 52 so as to be axially movable. Through this threaded engagement portion, the atmosphere is always introduced into the spring storage chamber 21.

[0042] Next, the valve needle 30 will be described. The valve needle 30 includes a cylindrical guide portion 31 extending toward one end side in the axial direction, a substantially frustoconical valve portion 32 provided on the other end side, and an annular spring support portion 33 provided between the guide portion 31 and the valve portion 32. Further, the valve needle 30 has an internal flow path 34 extending along the central axis C in the guide portion 31 and penetrating the guide portion 31 on the other end side in the radial direction. The valve needle 30 is made of a metal such as stainless steel.

[0043] The guide portion 31 of the valve needle 30 is arranged so as to be axially guided in the valve needle guide hole 13 of the valve housing 10. Here, the gap formed between the outer diameter of the guide portion 31 and the inner diameter of the valve needle guide hole 13 is set to be small, and strict tolerance management is performed. Further, the valve needle 30 is always biased in the valve opening direction by a valve spring 6 clamped between the spring support portion 33 of the valve needle 30 and the stepped portion 17 of the valve housing 10. In this way, the valve needle 30 is guided in a stable state in the axial direction, and when viewed from the direction of the central axis C, the center position of the valve needle 30 always coincides with that of the valve seat 18, so that flow rate instability and valve leakage can be improved.

[0044] Regarding the axial movement of the valve needle 30, it is generated by the pressure difference between the primary-side pressure P1 and the secondary-side pressure P2, the acting force of the pressure-sensitive bellows 41 and the adjusting spring 53 on the other end of the valve portion 32, the acting force of the valve spring 6 on the spring support portion 33, etc., which will be described in detail below. By using the above external forces, the valve portion 32 can move in a contact-separable manner relative to the valve seat 18, thereby determining the valve opening degree. Here, by making the stepped portion 45c of the connecting rod 45 abut against the bellows upper cover 43, the maximum valve lift amount L1 from the closed valve state to the fully open valve state where the valve needle 30 becomes the maximum valve lift state is defined. In addition, in the pressure regulating valve 100a of the present embodiment, different from the fully open valve state where the maximum valve lift state is achieved, there is a fully open valve state where the valve opening amount is a state of flowing a predetermined flow rate before the stepped portion 45c of the connecting rod 45 abuts against the bellows upper cover 43.

[0045] Next, the pressure-sensitive unit 40 will be described. The pressure-sensitive unit 40 is composed of a pressure-sensitive bellows (pressure-sensitive component) 41, a bellows upper cover (cover on the adjusting spring unit side) 43, and a connecting rod 45 having one end and the other end extending along the central axis C. One end and the other end of the pressure-sensitive bellows 41 extending along the central axis C are respectively connected to one end of the connecting rod 45 and the bellows upper cover 43, and apply a force to the valve portion 32 in the valve closing direction. The pressure-sensitive unit 40 is made of a metal such as stainless steel and is housed in the bellows housing chamber 16 of the valve housing 10.

[0046] The pressure-sensitive bellows 41 is respectively connected to one end of the connecting rod 45 and the bellows upper cover 43, so that the secondary-side pressure P2 is always introduced into the external space of the pressure-sensitive bellows 41 via the valve chamber 15 and the bellows housing chamber 16. On the other hand, the atmosphere is always introduced into the internal space of the pressure-sensitive bellows 41 via the gap formed between the small-diameter portion 45b of the connecting rod 45 and the insertion hole 43a of the bellows upper cover 43 and the gap formed between the sliding portion 43c of the connecting member 73b and the bellows upper cover 43. And in the pressure-sensitive bellows 41, the dimensional relationships of each part are set such that the outer diameter of the peak portion and the inner diameter of the valley portion of the corrugated shape are always in a non-contact state with the valve housing 10 and the connecting rod 45 respectively.

[0047] The connecting rod 45 has a large-diameter portion 45a having a substantially cylindrical shape extending toward one end side in the axial direction and a small-diameter portion 45b having a substantially cylindrical shape extending from the large-diameter portion 45a toward the other end side in the axial direction. A flange portion 45d that protrudes radially and connects one end of the pressure-sensitive bellows 41 is formed at one end of the large-diameter portion 45a. And a ring-shaped stepped portion 45c is formed between the large-diameter portion 45a and the small-diameter portion 45b.

[0048] The bellows upper cover 43 has: an insertion through-hole 43a that extends concentrically along the central axis C and is for inserting the small-diameter portion 45b of the connecting rod 45; a bellows upper cover joint portion 43b that connects to the other end portion of the pressure-sensitive bellows 41; and a cylindrical sliding portion 43c that extends concentrically along the central axis C, has an inner diameter set larger than the inner diameter of the insertion through-hole 43a, and is for inserting the small-diameter portion 45b of the connecting rod 45 and for the connecting member 73b to slide. Here, the pressure-sensitive unit 40 is fixed to the valve body 5 via the welding portion w in a non-relatively displaceable manner. The welding portion w indicates the region where the bellows upper cover 43 and the other end portion of the valve housing 10 are welded to each other. By adjusting the axial position of the welding portion w, individual differences in the length of the pressure-sensitive unit 40, assembly errors in assembling to the valve body 5, etc. can be absorbed.

[0049] In the present embodiment, one end side of the pressure-sensitive unit 40 has a structure in which the pressure-sensitive bellows 41 is connected to the flange portion 45d of the connecting rod 45, but is not limited thereto. For example, it may be configured such that the pressure-sensitive bellows 41 having a covered-shaped lower end portion or a bellows lower cover in a form in which the flange portion 45d is separated from one end portion of the connecting rod 45 is used, the flange portion 45d is omitted from the connecting rod 45, and one end portion of the connecting rod 45 is connected to the covered-shaped lower end portion or the bellows lower cover. Further, by making one end portion of the connecting rod 45 in a connection form that can move in the radial direction with respect to the covered-shaped lower end portion or the bellows lower cover, inclination of the connecting rod 45 with respect to the central axis C, asymmetry of the pressure-sensitive bellows 41, etc. can be absorbed.

[0050] In the present embodiment, the other end side of the pressure-sensitive unit 40 has a structure in which the pressure-sensitive bellows 41 is connected to the bellows upper cover 43, but is not limited thereto. For example, it may be configured such that the pressure-sensitive bellows 41 having a flange-shaped upper end portion is used, the bellows upper cover 43 is omitted, and the outer edge of the upper end portion of the pressure-sensitive bellows 41 is fixed to the inner wall of the valve housing 10 serving as the valve body 5 in a non-relatively displaceable manner, and the valve housing 10 is used as the bellows upper cover 43. Thus, when the upper end portion of the pressure-sensitive bellows 41 is fixed to the inner wall of the valve housing 10, the insertion through-hole 43a and the sliding portion 43c of the bellows upper cover 43 are formed on the inner wall of the valve housing 10.

[0051] In the pressure regulating valve 100a of the present embodiment, a lower connecting mechanism 60 is disposed between the axially opposed surfaces of the valve needle 30 and the pressure-sensitive unit 40.

[0052] The lower connecting mechanism 60 is composed of a pair of recessed portions 61 and 62 formed on the axially opposed surfaces of the valve needle 30 and the pressure-sensitive unit 40, and a ball 63 clamped between the pair of recessed portions 61 and 62 in a manner of forming an uneven engagement. The pair of recessed portions 61 and 62 are formed at the axial center portions of the upper end surface of the valve portion 32 and the lower end surface of the large-diameter portion 45a, and are composed of a conical lower recessed portion 61 and an upper recessed portion 62. The conical shape has a bottom surface concentric with the central axis C and a vertex located on the central axis C. Further, the ball 63 is made of a metal such as stainless steel.

[0053] Thus, the valve needle 30 is arranged in such a manner that it can be guided along the central axis C within the valve needle guide hole 13 of the valve housing 10. Therefore, the central position of the lower recessed portion 61 is always located on the central axis C. And, since a centripetal force acts on the upper recessed portion 62 via the lower recessed portion 61 and the ball 63, the central position of the upper recessed portion 62 is independently arranged on the central axis C. Thereby, it is possible to suppress the transmission of a force not along the central axis C caused by the asymmetry of the bellows 41 for pressure-sensitive use or the like to the valve needle 30, and it is possible to reduce the sliding resistance of the valve needle 30. In addition, in the present embodiment, the lower recessed portion 61 and the upper recessed portion 62 each have a conical shape, but it is not limited thereto. For example, they may also have a spherical shape.

[0054] 〈Regarding the adjustment spring unit〉

[0055] The adjustment spring unit 50 is composed of a spring bracket member 51, an adjustment threaded member 52, and an adjustment spring 53 clamped between the spring bracket member 51 and the adjustment threaded member 52 and applying a force to the valve portion 32 in the valve closing direction. The spring bracket member 51 and the adjustment threaded member 52 are made of appropriate materials such as metals such as brass, iron, aluminum, and stainless steel, and resin materials such as polyphenylene sulfide (PPS), and are housed in the spring housing chamber 21 of the spring housing 20. By threadedly engaging the external thread portion 52c provided on the outer peripheral side of the adjustment threaded member 52 with the internal thread portion 22 provided on the inner peripheral side of the other end portion of the spring housing 20 and moving the adjustment threaded member 52 in the axial direction, the force of the adjustment spring 53 can be adjusted, and further, the pressure (set value) for opening the valve needle 30 can be adjusted.

[0056] 〈Regarding the wave spring〉

[0057] The pressure regulating valve 100a of the present embodiment employs a multi-wound wave spring (hereinafter referred to as "wave spring") as the adjustment spring 53. As Figure 2As shown, the adjusting spring 53 composed of a wave spring is formed by bending a wire having a rectangular cross-sectional shape into a sine wave shape at a predetermined pitch, forming peaks 53c and valleys 53v in the direction along the spring central axis, and winding the wire spirally between the upper end portion 53u and the lower end portion 53d, thereby integrally forming a cylindrical shape. The wave spring is made of stainless steel such as SUS304, and contact portions 53t and separation portions 53s where the peaks 53c and valleys 53v facing each other in the spring central axis direction come into contact with and separate from each other are alternately formed in the winding direction and are arranged in a staggered manner along the spring central axis direction.

[0058] Therefore, in the pressure regulating valve 100a of the present embodiment, when the wave spring is compressed, a plurality of contact portions 53t always serve as fulcrums, reliably transmit the acting force along the central axis C, and suppress the lateral force. Thus, the existing problem points (increase in sliding resistance) can be eliminated and the hysteresis can be reduced. And when the wave spring is compressed, the contact portions 53t serve as fulcrums. On the other hand, the separation portions 53s are deflected in the spring central axis direction, whereby the spring constant can be increased with a small wire diameter. Therefore, compared with the existing pressure regulating valve 300, the adjusting spring 53 of the pressure regulating valve 100a of the present embodiment is made lighter and lower-profile, so that the pressure regulating valve 100a can be made smaller.

[0059] Here, since the wave spring has the contact portions 53t, there is a concern that the spring characteristics of the wave spring may change due to the adhesion of the control fluid, oil, foreign matter, etc. to the contact portions 53t, resulting in an increase or decrease in the sliding resistance of the contact portions 53t. Therefore, the wave spring of the pressure regulating valve 100a of the present embodiment is separated from the control fluid, etc. and is housed in the spring housing 20 of the valve body 5, so that the wave spring can be used without changing the spring characteristics.

[0060] At the upper end portion 53u and the lower end portion 53d of the wave spring, flat wires that are wound for more than one turn and do not form a sine wave shape are used as the upper side seat portion 53su and the lower side seat portion 53sd.

[0061] Therefore, in the present embodiment, annular upper side seat portions 53su and lower side seat portions 53sd (seat portions) are formed at the upper end portion 53u and the lower end portion 53d (both end portions) of the wave spring. Thus, the acting force of the wave spring can be uniformly transmitted in the circumferential direction to the adjusting screw member 52 and the spring support member 51 via the upper side seat portion 53su and the lower side seat portion 53sd.

[0062] 〈Regarding the load-deflection curve graph of the wave spring〉

[0063] In a wave spring, due to compression, the contact portion 53t always becomes a fulcrum, and flexure occurs in the separation portion 53s, so that the contact state between the peak portion 53c and the valley portion 53v in the contact portion 53t changes from a line contact state to a surface contact state. Therefore, the load-deflection curve of this wave spring has non-linear characteristics.

[0064] Here, Figure 3 as an example, the load-deflection characteristics of a wave spring having non-linear characteristics including two spring constant inflection points are shown. In this load-deflection characteristic, a plurality of linear characteristics are combined via spring constant inflection points (corresponding to Figure 3 points where the flexure in is about 50% and about 80%).

[0065] In the pressure regulating valve 100a of the present embodiment, the use range of the wave spring is set so as to avoid the spring constant inflection point in such a manner that the wave spring has linear characteristics from the valve closing state of the valve portion 32 to the fully open valve state where a predetermined flow rate flows, so that smooth control can be performed. Specifically, as Figure 3 shown, the set length of the wave spring at the time of assembly is set so as to include the flexure corresponding to the valve lift amount of the valve needle 30 from the valve closing state to the fully open valve state within the use range (1) and the use range (2) that avoid the spring constant inflection point.

[0066] Moreover, in the pressure regulating valve 100a of the present embodiment, one type of wave spring is used to correspond to various control fluids. For example, when carbon dioxide is used as the control fluid, since the use pressure becomes higher, the use range (2) with less flexibility can be set, and when refrigerants such as HFC and HFO are used as the control fluid, since the use pressure becomes lower, the use range (1) with greater flexibility can be set.

[0067] In addition, when carbon dioxide is used as the control fluid, the required design load of the adjusting spring 53 becomes higher. Therefore, when a helical spring is used as the adjusting spring 53, there is a concern that the influence of the lateral force will be more obvious. In contrast, the pressure regulating valve 100a in the present embodiment uses a wave spring as the adjusting spring 53. Therefore, even when carbon dioxide is used as the control fluid, the plurality of contact portions 53t always become fulcrums, and the acting force can be reliably transmitted along the central axis C, so that the lateral force can be more effectively suppressed. Therefore, the pressure regulating valve 100a in the present embodiment can reduce hysteresis even in a large use pressure range from low pressure to high pressure, and thus the versatility can be improved.

[0068] Here, the adjusting spring 53 of the pressure regulating valve 100a in this embodiment uses a wave spring to replace the helical spring of the existing pressure regulating valve 300. Here, compared with the helical spring, the number of turns of the wave spring becomes extremely large. Therefore, there is a concern that the problems caused by the expansion in diameter and rotation of the helical spring during compression, which the existing pressure regulating valve 300 has, will occur more significantly in the wave spring of the pressure regulating valve 100a in this embodiment. Therefore, in the pressure regulating valve 100a of this embodiment, by studying the support mechanism of the wave spring, the problems caused by the expansion in diameter and rotation during compression are suppressed.

[0069] First, the support mechanism of the helical spring in the existing pressure regulating valve 300 will be described, and the problems caused by the expansion in diameter and rotation of the helical spring during compression will be described.

[0070] 〈Regarding the support mechanism of the helical spring in the existing pressure regulating valve〉

[0071] As Figure 6 shown, in the support mechanism of the helical spring of the existing pressure regulating valve 300, the outer diameters of the boss portions of the spring support member 351 and the adjusting screw member 352 are each made smaller than the inner diameter of the adjusting spring 353 formed by the helical spring, and the boss portions of the spring support member 351 and the adjusting screw member 352 are inserted into the lower end side and the upper end side of the adjusting spring 353 for support. Here, the lower end side of the adjusting spring 353 is supported by the rotatable connecting rod 345 via the spring support member 351, but due to the lateral force generated by the adjusting spring 353, the connecting rod 345 is inclined. As a result, the sliding resistance between the connecting rod 345 and the insertion hole 343a increases, and the spring support member 351 connected to the connecting rod 345 becomes a state where it is difficult to rotate.

[0072] Here, due to compression, the adjusting spring 353, although slightly, has its coil diameter enlarged as it flexes, increasing the clearance with respect to the boss portions on the lower end side and the upper end side. Therefore, there is a concern that since it is prone to deviate radially, it becomes prone to tilting, and the lower end portion and the upper end portion rotate about the central axis C, causing the adjusting spring 353 to slide relative to the spring support member 351 and the adjusting screw member 352. Further, when observing the adjusting spring 353 from the spring central axis direction, stepped portions (not shown) serving as the winding start portion or the winding end portion are formed between the lower end portion and the upper end portion of the adjusting spring 353 and the wire material overlapping with the lower end portion and the upper end portion. Thus, in the existing pressure regulating valve 300, the lower end portion and the upper end portion of the adjusting spring 353 are compressed relative to the spring support member 351 and the adjusting screw member 352, rotating while rubbing against the stepped portions, so a smooth rotational movement cannot be performed, and there is a concern of becoming a problem of causing the adjusting spring 353 to vibrate (hereinafter, referred to as "problem point of the spring (vibration caused by rotation)").

[0073] Here, assume that as the pressure regulating valve 100a in the present embodiment, the support mechanism of the helical spring in the existing pressure regulating valve 300 is directly adopted, and only the wave spring is used instead of the helical spring. In this case, compared with the helical spring, the number of turns of the wave spring is extremely large, so the rotation range of the lower end portion 53d and the upper end portion 53u of the wave spring during compression becomes larger, and the problem point of the spring (vibration caused by rotation) is more significantly generated, and there is a concern that it is difficult to perform more accurate flow rate adjustment.

[0074] 〈Regarding the support mechanism of the wave spring〉

[0075] Therefore, in the pressure regulating valve 100a of the present embodiment, a support mechanism for the wave spring completely different from that of the existing pressure regulating valve 300 is adopted. As Figure 1 shown, this support mechanism for the wave spring is composed of a spring support member 51, an adjusting screw member 52, and an upper connecting mechanism 70 disposed between the connecting rod 45 and the spring support member 51.

[0076] The spring support member 51 has a boss portion (convex portion) 51a extending toward the other end side in the direction of the central axis C, and a convex edge portion (convex portion) 51b provided on one end side for the lower seat portion 53sd of the wave spring (refer to Figure 2 ) to be seated. And the adjusting screw member 52 has an annular wall portion (concave portion) 52a extending toward the one end side in the direction of the central axis C, and an upper seat portion 53su for the wave spring (refer to Figure 2)The seated upper surface portion (concave portion) 52b. Here, in the support mechanism of the corrugated spring of the present embodiment, by making the outer diameter of the boss portion 51a of the spring bracket member 51 slightly smaller than the inner diameter of the corrugated spring and inserting the boss portion 51a into the lower end side of the corrugated spring, a gap is provided in the radial direction for the corrugated spring to slide, and the corrugated spring is supported on the flange portion 51b in the axial direction. And by making the inner diameter of the annular wall portion 52a of the adjustment screw member 52 slightly larger than the outer diameter of the corrugated spring and inserting the upper end side of the corrugated spring into the annular wall portion 52a, a gap is provided in the radial direction, and the corrugated spring is supported on the upper surface portion 52b in the axial direction.

[0077] The upper connection mechanism 70 includes: a pair of engaging portions 71, 72 formed on the axially opposed surfaces of the connecting rod 45 and the spring bracket member 51; and a connecting member 73b having a spherical shape and clamped between the pair of engaging portions 71, 72 in a manner that forms an uneven engagement. The pair of engaging portions 71, 72 are formed at the center portions of the upper end surface of the small-diameter portion 45b and the lower end surface of the spring bracket member 51, and are composed of a conical lower engaging portion 71 and an upper engaging portion 72. The conical shape has a bottom surface formed concentrically with the central axis C and a vertex located on the central axis C. And the connecting member 73b is made of a metal such as stainless steel.

[0078] Here, when viewed from the direction of the central axis C, the radius of the circular side portion of the connecting member 73b is set to be slightly smaller than the radius of the sliding portion 43c, so a very narrow gap is formed between the side portion of the connecting member 73b and the sliding portion 43c. Thus, the side portion of the connecting member 73b and the sliding portion 43c are always in a point contact state, and the movement in the radial direction is restricted, so the central position of the connecting member 73b is always arranged near the central axis C. And since the connecting member 73b, whose movement in the radial direction is restricted, acts on the lower engaging portion 71 and the upper engaging portion 72 with a centripetal force respectively, the central positions of the lower engaging portion 71 and the upper engaging portion 72 are independently arranged near the central axis C. Further, the small-diameter portion 45b of the connecting rod 45 is set to be inserted into the insertion through hole 43a along the central axis C in a non-contact state. In this way, the upper connection mechanism 70 can suppress the inclination of the connecting rod 45 with respect to the central axis C and reduce the sliding resistance with the sliding portion 43c, thereby reducing hysteresis.

[0079] 〈Regarding the operation of the corrugated spring support mechanism during compression〉

[0080] As Figure 2 shown, similar to the helical spring, stepped portions 53st are formed on the upper side seat portion 53su and the lower side seat portion 53sd where the upper end side and the lower end side of the corrugated spring face the upper end portion 53u and the lower end portion 53d.

[0081] First, as Figure 1 shown, on the upper end side of the corrugated spring, the upper seat portion 53su of the corrugated spring is seated on the upper surface portion 52b of the adjusting screw member 52, and the outer peripheral surface of the corrugated spring is supported in such a manner that there is a gap between the inner peripheral surface of the annular wall portion 52a of the adjusting screw member 52. Thus, when the corrugated spring expands in diameter during compression, the gap between the corrugated spring and the adjusting screw member 52 becomes narrower, so that it is difficult for the corrugated spring to deviate in the radial direction. As a result, the stepped portion 53st on the upper end side of the corrugated spring rotates while rubbing against the upper surface portion 52b of the adjusting screw member 52. Even if the corrugated spring vibrates, the outer peripheral surface of the corrugated spring can contact the inner peripheral surface of the annular wall portion 52a of the adjusting screw member 52, and thus the vibration generated by the corrugated spring can be effectively attenuated.

[0082] Next, on the lower end side of the corrugated spring, the lower seat portion 53sd of the corrugated spring is seated on the convex edge portion 51b of the spring support member 51, and the inner peripheral surface of the corrugated spring is supported in such a manner that there is a gap between the outer peripheral surface of the boss portion 51a of the spring support member 51. Here, the static friction force generated between the lower seat portion 53sd of the corrugated spring and the convex edge portion 51b of the spring support member 51 (surface contact) is set to be larger than the static friction force generated between the spring support member 51 and the connecting member (connecting mechanism) 73b (annular line contact). Further, an engaging projection and recess that can rotate are formed between the pressure-sensitive unit 40 and the adjusting spring unit 50. Thus, when the corrugated spring is compressed, the lower seat portion 53sd of the corrugated spring does not rub against the convex edge portion 51b of the spring support member 51 due to the large static friction force, but rotates integrally. As a result, the spring support member 51 can rotate relative to the pressure-sensitive unit 40 via the upper connecting mechanism 70.

[0083] Therefore, the pressure regulating valve 100a of the present embodiment has a support mechanism for the corrugated spring. Thus, during compression, the outer peripheral surface on the upper end side of the corrugated spring can contact the inner peripheral surface of the annular wall portion 52a of the adjusting screw member 52, and thus the vibration generated by the corrugated spring can be effectively attenuated. Also, during compression, the lower end side of the corrugated spring does not move relative to the spring support member 51, and thus the vibration generated by the corrugated spring can be suppressed by the stepped portion 53st. As a result, the pressure regulating valve 100a of the present embodiment can eliminate the problem points (vibration caused by rotation) of the spring of the existing pressure regulating valve 300, and thus can perform more accurate flow rate adjustment.

[0084] 〈Regarding the operation of the pressure regulating valve〉

[0085] The operation of the pressure regulating valve 100a will be described. Here, the refrigerant circuit will be used as an example for the object of the pressure regulating valve 100a, but it is not limited thereto. In the pressure regulating valve 100a, the inlet port 11 is connected to the inflow pipe 1 on the high-pressure (primary side pressure P1) side, and the outlet port 12 is connected to the outflow pipe 2 on the low-pressure (secondary side pressure P2) side.

[0086] (When the primary side pressure P1 is lower than the set value)

[0087] When the primary side pressure P1 is lower than the set value (for example, the state where the discharge pressure of the compressor decreases, etc.), as Figure 1 shown, the valve part 32 seats on the valve seat 18, becoming a closed valve state. At this time, the secondary side pressure P2 is introduced into the external space of the pressure-sensitive bellows 41 serving as the bellows storage chamber 16 via the valve chamber 15.

[0088] First, as the pressure acting in the opening direction of the valve part 32, the secondary side pressure P2 × effective pressure-receiving area S1 is generated in the pressure-sensitive bellows 41 (refer to Figure 1 (b)). Here, the effective pressure-receiving area S1 of the pressure-sensitive bellows 41 refers to the pressure-receiving area calculated based on the average inner diameter of the minimum inner diameter and the maximum inner diameter based on the corrugated shape.

[0089] Next, as the pressure acting in the opening direction of the valve part 32, the primary side pressure P1 × pressure-receiving area S2 is generated in the valve needle 30 (refer to Figure 1 (b)), on the other hand, as the pressure acting in the closing direction of the valve part 32, the secondary side pressure P2 × pressure-receiving area S2 is generated in the valve needle 30 (refer to Figure 1 (b)). Further, as the force acting in the closing direction of the valve part 32, the force F1 based on the pressure-sensitive bellows 41 and the force F2 of the adjustment spring 53 are applied to the valve needle 30. In addition, as the force acting in the opening direction of the valve part 32, the force of the valve spring 6 is applied to the valve needle 30. The force of this valve spring 6 is a force that cancels the self-weight of the valve needle 30, so it is not introduced into the following (Equation 1).

[0090] Therefore, the balance of the external forces acting on the valve needle 30 of the pressure regulating valve 100a can be expressed as follows.

[0091] P2 × S1 + P1 × S2 = P2 × S2 + F1 + F2 (Equation 1)

[0092] Here, P1: primary side pressure [N / mm 2

[0093] P2: secondary side pressure [N / mm 2

[0094] ​​S1: Effective compression area of the bellows 41 for pressure sensitivity [mm 2

[0095] S2: Compression area of the valve part 32 surrounded by the valve seat 18 [mm 2

[0096] F1: Acting force of the bellows 41 for pressure sensitivity [N]

[0097] F2: Acting force of the adjusting spring 53 [N]

[0098] (Equation 1) can be arranged as P2×S1 + P1×S2 - P2×S2 = F1 + F2. Here, the effective compression area S1 of the bellows 41 for pressure sensitivity is set to be the same as the compression area S2 of the valve part 32 surrounded by the valve seat 18.

[0099] Therefore, in (Equation 1), the external force acting on the valve needle 30 due to the secondary-side pressure P2 is completely offset, and the above equation can be further arranged as P1×S2 = F1 + F2. In the pressure regulating valve 100a of the present embodiment, since it is easy to adjust the effective compression area S1 of the bellows 41 for pressure sensitivity, the effective compression area S1 is set to be the same as the compression area S2 of the valve part 32 surrounded by the valve seat 18, and the influence of the secondary-side pressure P2 can be offset. Thus, the pressure regulating valve 100a can variably control the opening degree according to the change in the primary-side pressure by axially moving the adjusting screw member 52 and appropriately setting the acting force F2 of the adjusting spring 53. In addition, the dimensions of each part of the pressure regulating valve 100a can be set using the actual compression area obtained through experiments, rather than being limited to the compression area (effective compression area) which is an approximate value calculated based on the average inner diameter of the minimum inner diameter and the maximum inner diameter of the corrugated shape.

[0100] (When the primary-side pressure P1 is higher than the set value)

[0101] When the primary-side pressure P1 is higher than the set value ((F1 + F2) / S2) (for example, in a state where the discharge pressure of the compressor rises, etc.), although not shown, the valve part 32 is separated from the valve seat 18 and becomes an open valve state. At this time, as the primary-side pressure P1 rises, the valve opening degree becomes larger. Here, the pressure regulating valve 100a of the present embodiment uses the bellows 41 for pressure sensitivity as the pressure-sensitive component, and thus a larger valve lift amount can be obtained.

[0102] ​​The pressure regulating valve 100a of the present embodiment uses a corrugated spring as the regulating spring 53, thereby being able to suppress the lateral force, eliminate the existing problem points (increase in sliding resistance), and reduce the hysteresis. Also, in the pressure regulating valve 100a of the present embodiment, as the support mechanism for the corrugated spring, the convex seating portions 51a, 51b and the concave seating portions 52a, 52b are used to support one end side and the other end side of the corrugated spring respectively, and a centripetal action and rotatable concavo-convex engagement is formed between the pressure-sensitive unit 40 and the regulating spring unit 50, thereby being able to eliminate the problem points of the spring (vibration caused by rotation) and enabling higher-precision flow regulation.

[0103] (Modification of the first embodiment)

[0104] Use Figure 4 The pressure regulating valve 100b of the modification of the first embodiment of the present invention will be described. In the pressure regulating valve 100b of the modification of the first embodiment, the spherical connecting member 73b in the upper connecting mechanism 70 is formed integrally with the other end side of the connecting rod 45, and the inner diameters of the sliding portion 43c and the insertion hole 43a are set to be the same, which is different from the pressure regulating valve 100a of the first embodiment, but the other basic structures are the same as those of the first embodiment. Here, the same reference numerals are assigned to the same components, and repeated descriptions are omitted.

[0105] The upper connecting mechanism (connecting mechanism) 170 of the modification of the first embodiment is composed of the upper engaging portion 72 of the spring bracket member 51 and the connecting member 173b integrally formed at the other end portion of the connecting rod 145. The conical upper engaging portion 72 and the spherical connecting member 173b face each other in the central axis C direction to form a concavo-convex engagement. Also, the bellows upper cover (cover on the regulating spring unit side) 143 of the modification of the first embodiment has a cylindrical sliding portion 143c that extends concentrically along the central axis C and is for the sliding of the connecting member 173b.

[0106] Here, when viewed from the central axis C direction, the radius of the circular side portion of the connecting member 173b is set to be slightly smaller than the radius of the sliding portion 143c, so a very narrow gap is formed between the side portion of the connecting member 173b and the sliding portion 143c. Thus, the side portion of the connecting member 173b and the sliding portion 143c are always in a line contact state, but by using a corrugated spring to suppress the lateral force, the central position of the small-diameter portion 145b of the connecting rod 145 is always arranged near the central axis C. Therefore, the upper connecting mechanism 170 can suppress the inclination of the connecting rod 145 relative to the central axis C, reduce the sliding resistance with the sliding portion 43c, and lower the hysteresis.

[0107] Thus, in the pressure regulating valve 100b of the modification of the first embodiment, by integrating the connecting member 73b in the first embodiment with the other end side of the connecting rod 45 and setting the inner diameters of the sliding portion 43c and the insertion hole 43a to be the same, in addition to obtaining the same effects as the first embodiment (reducing hysteresis, vibration caused by rotation, etc.), the burden on the assembly operation and component management can also be reduced.

[0108] (Second Embodiment)

[0109] Use Figure 5 The pressure regulating valve 200 of the second embodiment of the present invention will be described. In the pressure regulating valve 200 of the second embodiment, mainly a pressure-sensitive diaphragm 241 is used as the pressure-sensitive component instead of the pressure-sensitive bellows 41, and the flow direction of the control fluid is made opposite, which is different from the pressure regulating valve 100a of the first embodiment, but the other basic structures are substantially the same as those of the first embodiment. Here, the same reference numerals are assigned to the same components, and repeated descriptions are omitted.

[0110] The pressure-sensitive unit 240, the valve body 205, and the upper connecting mechanism (connecting mechanism) 270, which are mainly different between the pressure regulating valve 200 of the second embodiment and the pressure regulating valve 100a of the first embodiment, will be described in sequence.

[0111] First, the pressure-sensitive unit 240 is made of a metal such as stainless steel, and is composed of a pressure-sensitive diaphragm (pressure-sensitive component) 241, a diaphragm lower cover 242, a diaphragm upper cover (cover on the side of the adjusting spring unit) 243, a pressure plate 244 provided on the upper surface of the pressure-sensitive diaphragm 241, and a connecting rod 245 extending along the central axis C and having one end and the other end. Here, in a state where the pressure-sensitive diaphragm 241 is clamped between the diaphragm lower cover 242 and the diaphragm upper cover 243, the diaphragm lower cover 242, the pressure-sensitive diaphragm 241, and the diaphragm upper cover 243 are integrally fixed via the welding portion w.

[0112] The other end of the valve housing 210 is fixed to the opening of the diaphragm lower cover 242, so that the lower surface of the pressure-sensitive diaphragm 241 defines the pressure-sensitive chamber 242a. On the other hand, one end of the spring housing 20 is fixed to the diaphragm upper cover 243, and the atmosphere is always introduced. Further, the diaphragm upper cover 243 has a cylindrical sliding portion 243c and a limiting portion 243s that extend concentrically along the central axis C. By the limiting portion 243s abutting against the pressure plate 244, the maximum valve lift amount L2 of the valve needle 30 from the closed valve state to the fully open valve state where the valve is in the maximum valve lift state is defined.

[0113] The connecting rod 245 is constantly biased in the valve opening direction by an auxiliary spring 208 clamped between the valve housing 210 and a retaining ring 207 fixed near the other end of the connecting rod 245. The other end of the connecting rod 245 having a planar shape abuts against the lower surface of the pressure-sensitive diaphragm 241. The acting force of the auxiliary spring 208 is set such that the connecting rod 245 can always follow the pressure-sensitive diaphragm 241 in the abutting state.

[0114] Next, the valve body 205 is composed of a valve housing 210 connected to the inflow pipe 201 and the outflow pipe 202, and a spring housing 20 coupled to the other end of the valve housing 210 via a pressure-sensitive unit 240.

[0115] The valve housing 210 is a hollow cylindrical member, provided with an inlet port 211 that penetrates the valve chamber 15 in the radial direction and is connected to the inflow pipe 201, an outlet port 212 that penetrates along the central axis C and is connected to the outflow pipe 202, and a pressure equalizing hole 213 formed at a position offset from the central axis C in the radial direction. By means of this pressure equalizing hole 213, in the valve closed state, the primary side pressure P1 is introduced into the pressure-sensitive chamber 242a of the pressure-sensitive unit 240 via the inlet port 211.

[0116] Furthermore, the upper connecting mechanism 270 is composed of the following components: a pair of engaging portions 271, 72 formed on the axially opposed surfaces of the pressure plate 244 and the spring support member 51; and a connecting member 73b having a spherical shape, which is clamped between the pair of engaging portions 271, 72 in a manner that forms a concave-convex engagement. The pair of engaging portions 271, 72 are formed at the axial center portions of the upper end surface of the pressure plate 244 and the lower end surface of the spring support member 51, and are composed of a conical lower engaging portion 271 and an upper engaging portion 72. This conical shape has a bottom surface formed concentrically with the central axis C and a vertex located on the central axis C.

[0117] Here, when viewed from the direction of the central axis C, the radius of the circular side portion of the connecting member 73b is set to be slightly smaller than the radius of the sliding portion 243c. Thus, an extremely narrow gap is formed between the side portion of the connecting member 73b and the sliding portion 243c. As a result, the side portion of the connecting member 73b and the sliding portion 243c are always in a point contact state, and the movement in the radial direction is restricted. Therefore, the central position of the connecting member 73b is always arranged near the central axis C. Moreover, since the connecting member 73b, whose movement in the radial direction is restricted, acts on the lower engaging portion 271 and the upper engaging portion 72 with a centripetal force respectively, the central positions of the lower engaging portion 271 and the upper engaging portion 72 are independently arranged near the central axis C. Thus, the upper connecting mechanism 270 can reduce the sliding resistance with the sliding portion 243c and reduce the hysteresis. In addition, the movable range (maximum valve lift amount L2) of the pressure-sensitive diaphragm 241 in the vertical direction is, for example, about 0.2 mm. Therefore, the sliding portion 243c formed by the thickness of the diaphragm upper cover 243 can be used for guiding.

[0118] In this way, in the pressure regulating valve 200 of the second embodiment, the pressure-sensitive diaphragm 241 is used as the pressure-sensitive component instead of the pressure-sensitive bellows 41, and the flow direction of the control fluid is reversed. Thus, in addition to obtaining the same effects as the first embodiment (reduction of hysteresis, vibration caused by rotation, etc.), by making the pressure-sensitive component, the flow direction of the control fluid, etc. conform to the usage purpose, the versatility can be improved.

[0119] <Other Modes>

[0120] The pressure regulating valves 100a, 100b, 200 of the present embodiment can be applied not only to the exemplified refrigerant circuit, but also to all fluid devices and fluid circuits of course. Moreover, the present invention is not limited to the above-described modes, embodiments, and modification examples described therein. Appropriate changes and deformations can be made without departing from the technical idea of the present invention.

Claims

1. A pressure regulating valve, characterized in that, it comprises: a valve body having a valve seat; a valve needle having a valve portion that can contact and separate from the above-mentioned valve seat; a pressure-sensitive unit that flexes in the axial direction and has a pressure-sensitive component that applies a force to the above-mentioned valve portion; an adjustment spring unit having an adjustment spring that applies a force to the above-mentioned valve portion in the valve-closed direction via the above-mentioned pressure-sensitive component; an upper connection mechanism that forms a centripetal engaging protrusion and recess between the above-mentioned pressure-sensitive unit and the above-mentioned adjustment spring unit; and a lower connection mechanism that forms a centripetal engaging protrusion and recess between the above-mentioned pressure-sensitive unit and the above-mentioned valve needle, the above-mentioned adjustment spring is a wave spring.

2. The pressure regulating valve according to claim 1, characterized in that, the above-mentioned adjustment spring unit further comprises a spring support member having a convex portion and an adjustment screw member having a concave portion, the valve needle side and the adjustment spring unit side of the above-mentioned wave spring are respectively supported by the above-mentioned convex portion and the above-mentioned concave portion, the above-mentioned spring support member can rotate relative to the above-mentioned pressure-sensitive unit via the above-mentioned upper connection mechanism.

3. The pressure regulating valve according to claim 1, characterized in that, the static friction force generated between the valve needle side of the above-mentioned wave spring and the spring support member is set to be greater than the static friction force generated between the spring support member and the above-mentioned upper connection mechanism.

4. The pressure regulating valve according to claim 1, characterized in that, flat annular seat portions are respectively provided at both ends of the above-mentioned wave spring.

5. The pressure regulating valve according to claim 1, characterized in that, the use range of the above-mentioned wave spring is set in a manner that the wave spring has a linear characteristic from the valve-closed state to the fully open state of the valve portion, avoiding the spring constant inflection point.

6. The pressure regulating valve according to claim 1, characterized in that, the above-mentioned wave spring is housed in a spring housing of the above-mentioned valve body separated from the control fluid.

7. The pressure regulating valve according to claim 1, characterized in that, carbon dioxide is used as the control fluid.

8. The pressure regulating valve according to claim 1, characterized in that, the above-mentioned pressure-sensitive unit further comprises a cover on the adjustment spring unit side having a cylindrical sliding portion communicating in the axial direction, the above-mentioned upper connection mechanism comprises a connection member having a circular side portion when viewed from the axial direction, the side portion of the above-mentioned connection member makes point contact with the above-mentioned sliding portion.

9. The pressure regulating valve according to claim 8, characterized in that, the above-mentioned pressure-sensitive unit further comprises: a connecting rod, the end portion on the adjustment spring unit side of the connecting rod is arranged in a manner that it can be inserted into the above-mentioned sliding portion; and the above-mentioned pressure-sensitive component composed of a pressure-sensitive bellows, the end portion on the valve needle side of the pressure-sensitive bellows is connected to the above-mentioned connecting rod, and the end portion on the adjustment spring unit side of the pressure-sensitive bellows is fixed in a manner that it cannot be displaced relative to the above-mentioned valve body, the above-mentioned upper connection mechanism further includes an engaging portion provided at the axial center portion of the end portion on the valve needle side of the above-mentioned adjustment spring unit, The above engaging portion and the above connecting member have a concave shape and a protruding shape toward the above adjusting spring unit side, forming a concave-convex engagement.

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