Valve

Abstract

To provide a valve capable of smoothly changing pressure.SOLUTION: A valve comprises: a housing 60 that comprises a pressure-sensing body 62 having a sealed space inside, and divides a first space S1 into which discharge fluid Pd flows, a second space S2 into which control fluid Pb flows, and a third space S3 into which suction fluid Ps flows; and a valve body 61 which allows the fluid in the second space S2 to flow in and out by being seated on and removed from the housing 60. A pressure-receiving surface for the suction fluid Ps is larger than a pressure-receiving surface for the discharge fluid Pd.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to valves, for example valves for controlling pressure. [Background technology]

[0002] 2. Description of the Related Art Scroll compressors are one type of compressor used in various industrial fields. This type of compressor is not only highly efficient but also quiet, and therefore is used in a wide range of applications, such as in refrigeration cycles.

[0003] The scroll compressor is equipped with a scroll compression mechanism consisting of a fixed scroll with a spiral wrap and a movable scroll with a spiral wrap, and an eccentric mechanism that is attached to a rotating shaft and rotates the movable scroll eccentrically.The movable scroll slides relative to the fixed scroll while rotating eccentrically, thereby pressurizing a refrigerant fluid supplied from low-pressure chambers on the outer diameter sides of both scrolls, and discharging the high-pressure refrigerant from a discharge hole formed in the center of the fixed scroll.

[0004] In this type of scroll compressor, when the pressure in the discharge chamber, from which the refrigerant compressed by the scroll compression mechanism is discharged, increases, a force acts in a direction that separates the movable scroll from the fixed scroll.

[0005] The scroll compressor of Patent Document 1 is provided with a communication passage that communicates the discharge chamber with a back pressure chamber formed on the back side of the movable scroll, and the communication passage is provided with an orifice. A part of the compressed refrigerant in the discharge chamber is decompressed and adjusted by the orifice and supplied to the back pressure chamber, and presses the movable scroll toward the fixed scroll, preventing the movable scroll from moving away from the fixed scroll.

[0006] The scroll compressor also has a pressure regulating valve that adjusts the pressure in the back pressure chamber by releasing it to the low pressure chamber. When the force pushing the valve body in the valve opening direction due to the pressure in the back pressure chamber exceeds the force pushing the valve body in the valve closing direction due to the pressure in the low pressure chamber and the biasing force of the spring, the pressure regulating valve opens and the refrigerant in the back pressure chamber flows into the low pressure chamber, decreasing the pressure in the back pressure chamber. This prevents the movable scroll from being excessively pressed against the fixed scroll due to an increase in pressure in the back pressure chamber, which would hinder the smooth operation of the movable scroll. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2022 / 009769 (Page 1, Figure 1) Summary of the Invention [Problem to be solved by the invention]

[0008] However, the scroll compressor of Patent Document 1 has a structure in which a portion of the refrigerant in the discharge chamber is supplied at a constant rate to the back pressure chamber through an orifice, and there is a problem in that the change in pressure in the back pressure chamber is small relative to the change in pressure in the discharge chamber, and it takes time for the pressure in the back pressure chamber to reach an appropriate pressure.

[0009] The present invention has been made in view of the above-mentioned problems, and has an object to provide a valve capable of smoothly changing pressure. [Means for solving the problem]

[0010] In order to solve the above problems, the valve of the present invention comprises: a housing including a pressure sensor having a sealed space therein, the housing dividing a first space into which a discharge fluid flows, a second space into which a control fluid flows, and a third space into which a suction fluid flows; a valve body that allows fluid to flow in and out of the second space by being seated on and removed from the housing, The pressure receiving surface for the suction fluid is larger than the pressure receiving surface for the discharge fluid. This makes it possible to provide a valve which smoothly changes the pressure of the control fluid in accordance with the pressure of the discharge fluid by allowing both the forces of the discharge fluid and the suction fluid to act on the valve body, while reducing the influence of the pressure of the discharge fluid, which is relatively higher than that of the suction fluid, and increasing the influence of the pressure of the suction fluid.

[0011] The force of the discharge fluid and the force of the suction fluid may be applied to the valve body in the same direction. According to this, the force due to the discharge fluid and the force due to the intake fluid can be applied in a direction opposite to the force due to the control fluid, so that the pressure of the control fluid can be smoothly changed according to the pressure of the discharge fluid and the pressure of the intake fluid.

[0012] The third space may be disposed on an opposite side of the second space from the first space. This makes it easy to form the pressure receiving surfaces for the discharge fluid and the intake fluid so as to reduce the influence of the pressure of the discharge fluid, which has a relatively higher pressure than the intake fluid, and to increase the influence of the pressure of the intake fluid.

[0013] The coefficient of the pressure receiving surface for the intake fluid may be 1 or more. This makes it possible to increase the effect of the pressure of the intake fluid acting on the valve body.

[0014] The coefficient of the pressure receiving surface of the discharge fluid may be less than one. This makes it possible to reduce the effect of the pressure of the discharge fluid acting on the valve body, and to make the effect of the pressure of the intake fluid more pronounced. [Brief description of the drawings]

[0015] [Figure 1] 1 is a schematic configuration diagram showing a scroll compressor to which a valve according to a first embodiment of the present invention is applied. [Diagram 2] FIG. 1 is a cross-sectional view showing a valve in a closed state according to a first embodiment of the present invention. [Diagram 3]FIG. 2 is a cross-sectional view showing an open state of the valve according to the first embodiment of the present invention. [Figure 4] FIG. 4 is a diagram showing the characteristics of the pressure of a control fluid relative to the pressure of an intake fluid and the pressure of a discharge fluid in the valve of the first embodiment according to the present invention. [Diagram 5] FIG. 4 is a diagram comparing the pressure characteristics of a control fluid in the valve of the first embodiment according to the present invention with those in a conventional valve. [Figure 6] FIG. 4 is a cross-sectional view showing a valve according to a second embodiment of the present invention. [Figure 7] FIG. 11 is a cross-sectional view showing a valve according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A valve according to the present invention will be described below with reference to the accompanying drawings. EXAMPLES

[0017] A valve according to a first embodiment will be described with reference to Fig. 1 to Fig. 5. The valve of the present invention is applied to a rotary machine including an eccentric mechanism, for example, a scroll compressor C that sucks, compresses, and discharges a refrigerant as a fluid used in an air conditioning system of an automobile, etc. In this embodiment, the refrigerant is a gas mixed with mist-like lubricating oil.

[0018] First, a description will be given of the scroll compressor C. As shown in Fig. 1, the scroll compressor C is mainly composed of a housing 1, a rotating shaft 2, an inner casing 3, a scroll compression mechanism 4, a side seal 7, a thrust plate 8, and a drive motor M.

[0019] The housing 1 is composed of a cylindrical casing 11 and a cover 12 that closes an opening of the casing 11. An opening in the casing 11 on the axially opposite side to the opening closed by the cover 12 is closed by a drive motor M.

[0020] Inside the casing 11, there are formed a low pressure chamber 20 to which low pressure refrigerant, i.e., suction fluid Ps, is supplied from a refrigerant circuit (not shown) through the suction port 10, a high pressure chamber 30 serving as a discharge chamber from which high pressure refrigerant compressed by the scroll compression mechanism 4, i.e., discharge fluid Pd, is discharged, and a back pressure chamber 50 to which a part of the refrigerant compressed by the scroll compression mechanism 4 together with lubricating oil, i.e., control fluid Pb, is supplied via a control valve V1. The back pressure chamber 50 is formed inside a cylindrical inner casing 3 housed inside the casing 11.

[0021] A discharge communication passage 13 is formed in the cover 12, which communicates between a refrigerant circuit (not shown) and the high pressure chamber 30. A back pressure communication passage 14 is also formed in the cover 12, which communicates between the high pressure chamber 30 and the back pressure chamber 50 and branches off from the discharge communication passage 13. An oil separator 6 is provided in the discharge communication passage 13 to separate lubricating oil from the refrigerant.

[0022] The inner casing 3 is fixed with its axial end abutting against an end plate 41a of a fixed scroll 41 that constitutes the scroll compression mechanism 4. A suction communication passage 15 that penetrates radially is formed in the side wall of the inner casing 3. That is, the low pressure chamber 20 is formed from the outside of the inner casing 3 to the inside of the inner casing 3 via the suction communication passage 15. The suction fluid Ps supplied to the inside of the inner casing 3 through the suction communication passage 15 is sucked into the scroll compression mechanism 4.

[0023] The scroll compression mechanism 4 is mainly composed of a fixed scroll 41 that is fixed in a sealed manner to the cover 12 , and a movable scroll 42 that is housed inside the inner casing 3 .

[0024] The fixed scroll 41 is made of metal and has a spiral wrap 41b that protrudes from the surface of a disk-shaped end plate 41a, i.e., the end face of the end plate 41a that faces the movable scroll 42, towards the movable scroll 42. The fixed scroll 41 also has a recess 41c that is recessed in the opposite direction to the cover 12 on the inner diameter side of the back surface of the end plate 41a, i.e., the end face of the end plate 41a that abuts against the cover 12, and the high pressure chamber 30 is defined by this recess 41c and the cover 12.

[0025] The movable scroll 42 is made of metal and has a spiral wrap 42b that protrudes from the surface of a disk-shaped end plate 42a, i.e., the end face of the end plate 42a that faces the fixed scroll 41, toward the fixed scroll 41. The movable scroll 42 also has a boss 42c that protrudes from the center of the back surface of the end plate 42a. An eccentric portion 2a formed on the rotating shaft 2 is inserted into the boss 42c so as to be rotatable relative to the boss 42c. In this embodiment, the eccentric portion 2a of the rotating shaft 2 and the counterweight portion 2b that protrudes radially outward from the rotating shaft 2 form an eccentric mechanism that eccentrically rotates the rotating shaft 2.

[0026] When the rotary shaft 2 is driven to rotate by the drive motor M, the eccentric portion 2a rotates eccentrically, and the movable scroll 42 slides relative to the fixed scroll 41 while maintaining its posture with the eccentric rotation. At this time, the movable scroll 42 rotates eccentrically with respect to the fixed scroll 41, and with this rotation, the contact position of the wraps 41b, 42b moves sequentially in the rotation direction, and the compression chamber 40 formed between the wraps 41b, 42b moves toward the center and gradually shrinks. As a result, the intake fluid Ps sucked from the low pressure chamber 20 formed on the outer diameter side of the scroll compression mechanism 4 to the compression chamber 40 is compressed, and finally, a high-pressure discharge fluid Pd is discharged to the high pressure chamber 30 through the discharge hole 41d provided in the center of the fixed scroll 41.

[0027] The side seal 7 is made of resin, has a rectangular cross section and an annular shape when viewed in the axial direction, and is fixed to the back surface of the end plate 42a of the movable scroll 42. The side seal 7 is formed with a sliding surface 7a that comes into contact with a sliding surface 8a formed on the thrust plate 8.

[0028] The thrust plate 8 is made of metal, has an annular shape, and has a seal ring 43 fixed thereto, which contacts the inner peripheral end surface of the inner casing 3. As a result, the thrust plate 8 functions as a thrust bearing that receives the axial load of the movable scroll 42 via the side seal 7.

[0029] Additionally, the side seal 7 and the seal ring 43 divide the inside of the inner casing 3 into a low pressure chamber 20 formed on the outer diameter side of the movable scroll 42 and a back pressure chamber 50 formed on the back side of the movable scroll 42. The back pressure chamber 50 is formed as an enclosed space by a seal ring 44 fixed to the inner periphery of a through hole 3a provided in the center of the inner casing 3, sealing between the back pressure chamber 50 and the rotating shaft 2 inserted through the through hole 3a.

[0030] A back pressure communication passage 14 is formed through the cover 12, the fixed scroll 41, and the inner casing 3, and connects the high pressure chamber 30 and the back pressure chamber 50, and is provided with a control valve V1 as a valve.

[0031] A part of the discharge fluid Pd from the high pressure chamber 30 that is supplied to the control valve V1 together with the lubricating oil separated by the oil separator 6 is adjusted in pressure to a control fluid Pb and is supplied to the back pressure chamber 50.

[0032] The inner casing 3 is provided with a pressure relief hole 16 that penetrates radially and connects the low pressure chamber 20 and the back pressure chamber 50, and an orifice 45 is provided within the pressure relief hole 16.

[0033] Next, the control valve V1 as a valve in this embodiment will be described with reference to Figures 2 and 3. In the following description, the left and right sides as viewed from the front in Figures 2 and 3 are the left and right sides of the control valve.

[0034] As shown in FIG. 2, the control valve V1 of the first embodiment is mainly composed of a housing 60, a valve member 61 as a valve body, a bellows 62 which is a pressure-sensitive body having a sealed space therein and biases the valve member 61 in a seating direction, i.e., in a valve-closing direction, and a pressure driver 67 which biases the valve member 61 in a disengaging direction, i.e., in a valve-opening direction.

[0035] The housing 60 includes a bellows 62, and defines a first space S1 communicating with the high pressure chamber 30, a second space S2 communicating with the back pressure chamber 50, and a third space S3 communicating with the low pressure chamber 20. The housing 60 includes a valve hole 63a that communicates between the first space S1 and the second space S2. It is sufficient that the housing 60 defines at least a portion of the first space S1, the second space S2, and the third space S3.

[0036] The housing 60 is made up of a first divided body 63 and a second divided body 64. The first divided body 63 includes a cylindrical base portion 63b and an annular protrusion portion 63c.

[0037] The cylindrical base 63b is provided with a communication hole 63d that penetrates in the radial direction and communicates with the back pressure chamber 50. A partition wall 63e extending toward the inner diameter side is provided at the left end of the cylindrical base 63b, and a valve hole 63a is provided in the partition wall 63e. A tapered surface that widens the valve hole 63a toward the left is formed on the inner diameter side of the left surface of the partition wall 63e, and the tapered surface serves as a valve seat 65 with which a spherical portion 61b of a valve member 61 described below comes into contact and separates. In other words, the housing 60 and the valve member 61 come into contact and separate to form a valve that controls the flow rate and the flow path.

[0038] A circular support member 66 is press-fitted into the right end of the cylindrical base 63b, and a through hole 66a is provided in the support member 66. A pressure driver 67 and a disc spring 68 are disposed in the space surrounded by the inner peripheral surface of the cylindrical base 63b, the partition wall 63e, and the support member 66, and the space on the axial left side of the pressure driver 67 is the second space S2 into which the control fluid Pb flows. The space on the axial right side of the pressure driver 67 is the third space S3 into which the suction fluid Ps flows.

[0039] The pressure driver 67 has a large-diameter disk-shaped base 67a and a protrusion 67b. The protrusion 67b protrudes leftward from the left end of the base 67a, has a smaller diameter than the base 67a, and abuts against the spherical portion 61b of the valve member 61.

[0040] There is a very small gap between the inner peripheral surface of the cylindrical base 63b and the outer peripheral surface of the base 67a of the pressure driver 67, and the sliding allows the pressure driver 67 to move in the axial direction. In addition, an annular groove 67c is formed on the outer peripheral surface of the base 67a, and an O-ring 69 is provided in the groove 67c to prevent the refrigerant from moving between the second space S2 and the third space S3.

[0041] The pressure driver 67 biases the valve member 61 in the unseating direction, i.e., in the valve opening direction, by the biasing force of a disc spring 68 provided between the right end of the base 67a and the support member 66 and the force of the intake fluid Ps flowing into the third space S3. An axial right end face 67d of the base 67a of the pressure driver 67 serves as a pressure receiving surface that receives the fluid pressure in the third space S3, and an axial left end face 67e of the base 67a serves as a pressure receiving surface that receives the fluid pressure in the second space S2.

[0042] The second divided body 64 has a cylindrical shape, and the right end portion of the second divided body 64 is fitted onto the annular protrusion 63c of the first divided body 63.

[0043] The second divided body 64 is provided with a communication hole 64a that penetrates in the radial direction and communicates with the high pressure chamber 30. The space surrounded by the inner circumferential surface of the second divided body 64, the inner circumferential surface of the annular protrusion 63c of the first divided body 63, and the partition wall portion 63e forms a first space S1 into which the discharge fluid Pd flows.

[0044] A through hole 64b is provided at the left end of the second divided body 64, and a cover member 9 whose axial position can be adjusted relative to the second divided body 64 is screwed into the through hole 64b and attached. Note that the cover member 9 may be fixed to the second divided body 64 by various fixing means other than screwing, but it is preferable that the axial position is adjustable.

[0045] A bellows 62 that is expandable and contractable in the axial direction is disposed between the cover member 9 and the valve member 61. The bellows 62 is composed of a metal bellows-shaped body 62a and a closing part 62b that closes the opening at the right end in the axial direction of the body 62a, and the inside is kept in a vacuum. The opening at the left end in the axial direction of the body 62a is closed by the cover member 9. Furthermore, the vacuum in the present invention is defined by the Japanese Industrial Standards (JIS Z 8126) as "a state of space filled with gas at a pressure lower than normal atmospheric pressure."

[0046] The valve member 61 is fixed to the right end of the blocking portion 62b.

[0047] The valve member 61 has a disk-shaped base 61a and a spherical portion 61b protruding axially rightward from the base 61a. The base 61a is formed with a larger diameter than the bellows 62, and the axially right end of the coil spring 70 abuts against the axially left end face of the base 61a. The axially left end of the coil spring 70 abuts against the bottom face of the second divided body 64. That is, the coil spring 70 is disposed on the outer diameter side of the bellows 62.

[0048] The spherical portion 61b is disposed in the first space S1. The spherical surface of the spherical portion 61b is formed so as to be able to approach and separate from the valve seat 65. In this embodiment, the spherical portion 61b and the valve seat 65 form a DB valve that adjusts the pressure of the control fluid Pb by the pressure of the discharge fluid Pd.

[0049] Next, the opening and closing operation of the control valve V1 will be described. As shown in FIG. 2, the valve member 61 is subjected to a force (F Ps ) and the force due to the control fluid Pb in the second space S2 (F Pb ) and the force (F Pd ) and the force due to the fluid P0 in the bellows 62 (F P0 ) and the biasing force of the bellows 62 (F b ) and the biasing force of the disc spring 68 (F sp) is acting on the valve member 61 (i.e., the left direction is positive, and the force F v =F Ps +F Pd -F Pb -F P0 +F sp -F b In this embodiment, since the inside of the bellows 62 is a vacuum, the force of the fluid P0 inside the bellows 62 does not act, and it can be considered that P0 = 0. In this embodiment, the coil spring 70 is included in the bellows 62, and the biasing force of the coil spring 70 provided on the outer diameter side of the bellows 62 is the substantial biasing force (F b ).

[0050] Specifically, the pressure of the intake fluid Ps in the third space S3 acts on the effective pressure-receiving area C1 of the base portion 67a in the axial leftward direction. That is, the valve member 61 is subjected to a force (F Ps )=Ps×C1 is in effect.

[0051] Further, the pressure of the discharge fluid Pd in ​​the first space S1 acts in the axial left direction on the area obtained by subtracting the effective pressure receiving area B1 of the spherical portion 61b from the effective pressure receiving area A1 of the bellows 62. That is, the valve member 61 is subjected to a force (F Pd )=Pd×(A1-B1) is at work.

[0052] The pressure receiving surface (A1-B1) of the discharged fluid Pd is narrower than the pressure receiving surface (C1) of the suctioned fluid Ps (A1-B1 <C1)。

[0053] On the other hand, the pressure of the control fluid Pb in the second space S2 acts in the axial right direction on the area obtained by subtracting the effective pressure receiving area B1 of the spherical portion 61b from the effective pressure receiving area C1 of the base portion 67a. That is, the valve member 61 is subjected to a force (F Pb )=Pb×(C1-B1) is at work.

[0054] In addition, the pressure receiving surface (A1-B1) of the discharge fluid Pd is narrower than the pressure receiving surface (C1-B1) of the control fluid Pb (A1-B1 <C1-B1)。

[0055] Further, the pressure of the fluid P0 in the bellows 62 acts in the axial right direction on the effective pressure-receiving area A1 of the bellows 62. That is, the valve member 61 is subjected to a force (F P0 )=P0×A1 acts, and the Pb characteristic formula shown in the following formula (1) holds. Note that the numbers for areas A1, B1, and C1 are omitted in the formula. The same applies to the following formulas.

[0056]

number

[0057] In this embodiment, since the inside of the bellows 62 is a vacuum and it can be considered that P0=0, the Pb characteristic equation shown in the following equation (2) holds true with the left direction being positive.

[0058]

number

[0059] In other words, the force (F Pd ) and the force due to the suction fluid Ps (F Ps ) and the biasing force of the disc spring 68 (F sp ) is the force acting in the axial direction to the right due to the control fluid Pb (F Pb ) and the biasing force of the bellows 62 (F b ), the valve member 61 is pressed axially to the right, i.e., in the valve closing direction, so that the spherical portion 61b seats on the valve seat 65 and the control valve V1 is closed (see FIG. 2).

[0060] On the other hand, the force due to the discharged fluid Pd acting in the axial left direction (F Pd ) and the force due to the suction fluid Ps (F Ps ) and the biasing force of the disc spring 68 (Fsp ) is the force acting in the axial direction to the right due to the control fluid Pb (F Pb ) and the biasing force of the bellows 62 (F b ), the valve member 61 is pressed axially leftward, i.e., in the valve opening direction, causing the spherical portion 61b to separate from the valve seat 65, and the control valve V1 to be in an open state (see FIG. 3).

[0061] In this embodiment, when the effective pressure receiving diameter of the bellows 62 is 4.9 mm, the effective pressure receiving diameter of the spherical portion 61b of the valve member 61 is 3.4 mm, and the effective pressure receiving diameter of the base portion 67a of the pressure driver 67 is 11.4 mm, the biasing force of the disc spring 68 (F sp ) and the biasing force of the bellows 62 (F b ) is approximately constant and can be expressed by the constant a, so the above-mentioned Pb characteristic formula is Pb = 0.1Pd + 1.1Ps + a. In other words, the coefficient of the pressure receiving surface of the intake fluid Ps is 1 or more, and the coefficient of the pressure receiving surface of the discharge fluid Pd is less than 1, and the force (F) due to the intake fluid Ps acting in the same axial leftward direction is Ps ) and the force due to the discharged fluid Pd (F Pd ), the effect of the pressure of the discharge fluid Pd acting on the valve member 61 is small, and the effect of the pressure of the suction fluid Ps is significant.

[0062] This can also be confirmed by the fact that, as shown in Figure 4, for a control valve V1 having the above-mentioned Pb characteristic equation, when the pressure of the intake fluid Ps is fixed at three values ​​(a high value, a low value, and a value intermediate between the high and low values) and the pressure of the discharge fluid Pd is increased, the rate of pressure increase of the control fluid Pb in response to the pressure increase of the discharge fluid Pd is low, and the rate of pressure increase of the control fluid Pb in response to the pressure increase of the intake fluid Ps is high.

[0063] As described above, the control valve V1 is resistant to the force (F Pd ) and the force due to the suction fluid Ps (F PsWhile causing both of them to act on the valve body, by reducing the influence of the pressure of the discharge fluid Pd that is relatively higher in pressure than the suction fluid Ps and increasing the influence of the pressure of the suction fluid Ps, the pressure of the control fluid Pb can be smoothly changed according to the pressure of the discharge fluid Pd. Further, compared with the conventional control valve, the control valve V1 of the present invention can easily realize the pressure of the control fluid Pb corresponding to the pressure of the discharge fluid Pd, that is, the back pressure (load), as shown by the power loss improvement area in FIG. 5, and can reduce power loss and poor compression under a wide range of operating conditions in the scroll compressor C.

[0064] In addition, since the pressure receiving surface (A1 - B1) of the discharge fluid Pd is narrower than the pressure receiving surface (C1) of the suction fluid Ps (A1 - B1 < C1), while suppressing the influence of the pressure of the discharge fluid Pd that is relatively higher in pressure than the suction fluid Ps on the valve member 61, the influence of the pressure of the suction fluid Ps can be relatively increased. According to this, it is possible to suppress the valve member 61 from moving abruptly due to a rapid pressure change of the discharge fluid Pd.

[0065] Also, since the pressure receiving surface (A1 - B1) of the discharge fluid Pd is narrower than the pressure receiving surface (C1 - B1) of the control fluid Pb (A1 - B1 < C1 - B1), while suppressing the influence of the pressure of the discharge fluid Pd that is relatively higher in pressure than the control fluid Pb on the valve member 61, the influence of the pressure of the control fluid Pb can be relatively increased. According to this, it is possible to suppress the valve member 61 from moving abruptly due to a rapid pressure change of the discharge fluid Pd.

[0066] In addition, on the valve member 61, by causing the force by the discharge fluid Pd and the force by the suction fluid Ps to act in the same direction, the force by the discharge fluid Pd and the force by the suction fluid Ps can be made to act in a direction opposite to the force by the control fluid Pb. Therefore, the pressure of the control fluid Pb can be smoothly changed according to the pressure of the discharge fluid Pd and the pressure of the suction fluid Ps.

[0067] In addition, the third space S3 into which the suction fluid Ps flows is disposed on the opposite side of the first space S1 into which the discharge fluid Pd flows, relative to the second space S2 into which the control fluid Pb flows, so that the pressure-receiving surfaces for the discharge fluid Pd and the suction fluid Ps can be easily formed so as to reduce the influence of the pressure of the discharge fluid Pd, which has a relatively higher pressure than the suction fluid Ps, and to increase the influence of the pressure of the suction fluid Ps. More specifically, the effective pressure-receiving area A1 of the bellows 62, the effective pressure-receiving area B1 of the spherical portion 61b of the valve member 61, and the effective pressure-receiving area C1 of the base portion 67a of the pressure driver 67 in this embodiment can be easily designed.

[0068] Furthermore, by using the bellows 62 disposed in the first space S1, it is easy to adjust the effective pressure receiving area A1 of the bellows 62 which constitutes the pressure receiving surface for the discharge fluid Pd.

[0069] Furthermore, in the control valve V1, the coefficient of the pressure receiving surface of the intake fluid Ps in the Pb characteristic equation is 1 or more, so that the effect of the pressure of the intake fluid Ps acting on the valve member 61 can be made large.

[0070] In addition, since the coefficient of the pressure-receiving surface of the discharge fluid Pd in ​​the Pb characteristic equation is less than 1, the control valve V1 can reduce the effect of the pressure of the discharge fluid Pd acting on the valve member 61 and make the effect of the pressure of the intake fluid Ps even more pronounced.

[0071] In this embodiment, the pressure of the intake fluid Ps flowing into the third space S3 can be maintained at a predetermined pressure or higher by the orifice 45 (see FIG. 1, etc.) provided in the pressure relief hole 16 that communicates between the low pressure chamber 20 and the back pressure chamber 50 of the scroll compressor C. In addition, the pressure of the intake fluid Ps fluctuates less than the pressure of the discharge fluid Pd, so it is easy to use it as a reference pressure, and the pressure of the control fluid Pb can be stably controlled.

[0072] In addition, the biasing force (F b ) acts in the axial right direction. This prevents the valve member 61 from rattling when the control valve V1 is in the closed state.b By changing the pressure at which the valve member 61 operates, the set pressure can be changed appropriately by changing the pressure at which the valve member 61 operates, making it easy to adjust the valve opening. b ) can be easily adjusted.

[0073] In addition, the biasing force (F sp ) acts axially leftward via the pressure driver 67. This makes it easier to move the valve member 61 in the valve opening direction, and makes it easier to adjust the valve opening degree by the disc spring 68.

[0074] In this embodiment, an example has been given of a form in which the coil spring 70 is provided outside the bellows 62, but this is not limited thereto. A biasing means such as a coil spring may be provided inside the bellows 62, and further, the body portion 62a itself may serve as the biasing means. EXAMPLES

[0075] Next, a valve according to a second embodiment will be described with reference to Fig. 6. Note that a description of the same configuration as in the first embodiment will be omitted.

[0076] 6, the control valve V2 of the second embodiment is mainly composed of a housing 260, a valve member 261 as a valve body, a bellows 262 that urges the valve member 261 in a direction to unseat, i.e., in a direction to open the valve, and a disc spring 268 that urges the valve member 261 in a direction to seat, i.e., in a direction to close the valve. Note that a communication hole that communicates between the high pressure chamber 30 and the back pressure chamber 50 is formed in the scroll compressor to which the control valve V2 is applied, and an orifice 245 is provided in the communication hole.

[0077] The housing 260 includes a bellows 262 and defines a first space S201 communicating with the high pressure chamber 30, a second space S202 communicating with the back pressure chamber 50, and a third space S203 communicating with the low pressure chamber 20.

[0078] The housing 260 is provided with a communication hole 260b that penetrates radially and communicates with the high pressure chamber 30, and a communication hole 260c that communicates with the back pressure chamber 50. A partition wall portion 260d that extends radially inward is provided at approximately the center of the housing 260 in the axial direction, and a through hole 260a that communicates with the first space S201 and the second space S202 is provided in the partition wall portion 260d.

[0079] An annular step 260e is formed on the inner circumferential surface of the right end opening of the housing 260 at a position axially to the right of a communication hole 260c that communicates with the backpressure chamber 50, and an inner diameter side corner of this annular step 260e serves as a valve seat 265 with which the tapered surface 261b of the valve member 261 comes into contact and separates. In other words, a valve hole 260f is formed axially to the left of the annular step 260e.

[0080] In the second embodiment, the tapered surface 261b and the valve seat 265 form a BS valve that adjusts the pressure of the control fluid Pb by the pressure of the intake fluid Ps.

[0081] A circular support member 266 is press-fitted into the right end of the housing 260, and a through hole 266a is provided in the support member 266. The valve member 261 and the disc spring 268 are disposed in the space surrounded by the inner circumferential surface of the housing 260, the partition wall portion 260d, and the support member 266, and the space on the axial left side of the valve member 261 forms a second space S2 into which the control fluid Pb flows. The space on the axial right side of the valve member 261 forms a third space S3 into which the suction fluid Ps flows.

[0082] The valve member 261 includes a large diameter portion 261a, a tapered surface 261b that tapers leftward from the large diameter portion 261a, and a small diameter portion 261c. The small diameter portion 261c is inserted into the through hole 260a of the housing 260, and the left end of the small diameter portion 261c abuts against the right end of the closing portion 262b of the bellows 262.

[0083] There is a very small gap between the inner peripheral surface of the through hole 260a and the outer peripheral surface of the small diameter portion 261c of the valve member 261, and the sliding allows the valve member 261 to move in the axial direction. Also, an annular groove portion 261d is formed on the outer peripheral surface of the small diameter portion 261c, and an O-ring 269 is provided in the groove portion 261d to prevent the refrigerant from moving between the first space S201 and the second space S202.

[0084] A cover member 209 whose axial position can be adjusted relative to the housing 260 is attached by screwing to the left end of the housing 260 .

[0085] An axially expandable and contractible bellows 262 is disposed between the cover member 209 and the valve member 261. The bellows 262 is composed of a metal bellows-shaped body 262a and a closing part 262b that closes the opening at the axial right end of the body 262a, and the inside is kept in a vacuum. In this second embodiment, a coil spring 270 is disposed inside the bellows 262.

[0086] The valve member 261 is subjected to a force (F Pd ) and the force (F Pb ) and the force (F Ps ) and the biasing force of the bellows 62 (F b ) and the biasing force of the disc spring 68 (F sp ) is acting on the valve member 261 (i.e., the leftward direction is positive, and the force F v =F Ps +F Pd -F Pb +F sp -F b is at work.)

[0087] Specifically, the pressure of the intake fluid Ps in the third space S3 acts on the effective pressure-receiving area C2 of the tapered surface 261b in the axial leftward direction. That is, the valve member 261 is subjected to a force (F Ps )=Ps×C2 is in effect.

[0088] Further, the pressure of the discharge fluid Pd in ​​the first space S1 acts in the axial left direction on the area obtained by subtracting the effective pressure receiving area B2 of the small diameter portion 261c from the effective pressure receiving area A2 of the bellows 62. That is, the valve member 261 is subjected to a force (F Pd )=Pd×(A2-B2) is at work.

[0089] On the other hand, the pressure of the control fluid Pb in the second space S2 acts in the axial right direction on the area obtained by subtracting the effective pressure receiving area B2 of the small diameter portion 261c from the effective pressure receiving area C2 of the tapered surface 261b. That is, the valve member 261 is subjected to a force (F Pb )=Pb×(C2-B2) is at work.

[0090] In the second embodiment, the pressure receiving surface (A2-B2) of the discharge fluid Pd, the pressure receiving surface (C2-B2) of the control fluid Pb, and the pressure receiving surface (C2) of the intake fluid Ps have the same magnitude relationship as in the first embodiment.

[0091] That is, the leftward direction is positive, and the above formula 1 holds true, the same as in the first embodiment.

[0092] As described above, the control valve V2 of the second embodiment is a BS valve that adjusts the pressure of the control fluid Pb by the pressure of the intake fluid Ps, that is, the pressure of the control fluid Pb is adjusted by releasing it into the third space S203 into which the intake fluid Ps with a relatively low pressure flows. However, in the same manner as in the first embodiment, the force (F Pd ) and the force due to the suction fluid Ps (F Ps ) is applied to the valve body, while reducing the influence of the pressure of the discharge fluid Pd, which has a relatively higher pressure than the intake fluid Ps, and increasing the influence of the pressure of the intake fluid Ps, thereby making it possible to smoothly change the pressure of the control fluid Pb in accordance with the pressure of the discharge fluid Pd. EXAMPLES

[0093] Next, a valve according to a third embodiment will be described with reference to Fig. 7. Note that a description of the same configuration as in the first and second embodiments will be omitted.

[0094] As shown in FIG. 7, the control valve V3 of this embodiment 3 is mainly composed of a housing 360, a valve member 361 as a valve body, a bellows 362 that urges the valve member 361 in a seating direction, i.e., in a valve closing direction, and a coil spring 368 that urges the valve member 361 in an unseating direction, i.e., in a valve opening direction.

[0095] The housing 360 includes a bellows 362, and divides a first space S301 communicating with the high pressure chamber 30, a second space S302 communicating with the back pressure chamber 50, and a third space S303 communicating with the low pressure chamber 20. In the third embodiment, the housing 360 further includes a first space S301' communicating with the high pressure chamber 30, the first space S301' being disposed outside the housing 360, more specifically, on the opposite side of the third space S303 from the first space S301.

[0096] The housing 360 is made up of a first divided body 363 and a second divided body 364 .

[0097] The second divided body 364 is provided with a communication hole 364b penetrating in the radial direction and communicating with the high pressure chamber 30, and a communication hole 364c communicating with the back pressure chamber 50. A partition wall 364d extending toward the inner diameter side is provided at approximately the center in the axial direction of the second divided body 364, and a valve hole 364a communicating with the first space S301 and the second space S302 is provided in the partition wall 364d. The inner diameter side corner of the left surface of the partition wall 364d serves as a valve seat 365 with which the tapered surface 361b of the valve member 361 comes into contact and separates. In other words, the housing 360 and the valve member 361 come into contact and separate to form a valve that controls the flow rate and the flow path.

[0098] The first division 363 is fitted onto the right end of the second division 364, and a through hole 363b is provided in the first division 363. The first division 363 is provided with a communication hole 363a that penetrates in the radial direction and communicates with the low pressure chamber 20.

[0099] The pressure driver 367 and the coil spring 368 are disposed in the space surrounded by the inner circumferential surface of the second divided body 364, the partition wall portion 364d, and the first divided body 363, and the space on the axial left side of the pressure driver 367 is the second space S302 into which the control fluid Pb flows in. The space on the axial right side of the pressure driver 367 is the third space S303 into which the suction fluid Ps flows in.

[0100] The pressure driver 367 includes a large diameter portion 367a and a small diameter portion 367b. The large diameter portion 367a is inserted into a guide hole 364f formed on the axial left side of an annular step portion 364e formed on the inner circumferential surface of the right end opening of the second divided body 364. The small diameter portion 367b protrudes rightward from the right end of the large diameter portion 367a, has a smaller diameter than the large diameter portion 367a, and is inserted into a through hole 363b of the first divided body 363. The right end of the small diameter portion 367b is subjected to the pressure of the discharge fluid Pd flowing into the other first space S301' provided outside the housing 360.

[0101] The valve member 361 includes a large diameter portion 361a, a tapered surface 361b that narrows in diameter from the large diameter portion 361a to the right, and a small diameter portion 361c that is inserted into a valve hole 364a of the second divided body 364. The left end of the large diameter portion 361a abuts against the right end of the closing portion 362b of the bellows 362.

[0102] The valve member 361 has a force (F Pd ) and the force (F Pb ) and the force (F Ps ) and the biasing force of the bellows 362 (F b ) and the biasing force of the coil spring 368 (F sp ) is acting on the valve member 261 (i.e., the leftward direction is positive, and the force F v =F Ps +F Pd -F Pb +F sp -Fb is at work.)

[0103] Specifically, the pressure of the intake fluid Ps in the third space S3 acts in the axial left direction on an area obtained by subtracting the effective pressure receiving area D3 of the small diameter portion 367b of the pressure driver 367 from the effective pressure receiving area C3 of the large diameter portion 367a of the pressure driver 367. That is, the valve member 361 is subjected to a force (F Ps )=Ps×(C3-D3) is at work.

[0104] Moreover, the pressure of the discharge fluid Pd in ​​one of the first spaces S1 acts in the axial left direction on an area obtained by subtracting the effective pressure receiving area B3 of the tapered surface 361b from the effective pressure receiving area A3 of the bellows 362. In addition, the pressure of the discharge fluid Pd in ​​the other first space S1 acts in the axial left direction on the effective pressure receiving area D3 of the small diameter portion 367b of the pressure driver 367. That is, the valve member 361 is subjected to a force (F Pd )=Pd×(A3-B3+D3) is at work.

[0105] On the other hand, the pressure of the control fluid Pb in the second space S2 acts in the axial right direction on an area obtained by subtracting the effective pressure receiving area B3 of the tapered surface 361b from the effective pressure receiving area C3 of the large diameter portion 367a of the pressure driver 367. That is, the valve member 361 is subjected to a force (F Pb )=Pb×(C3-B3) is at work.

[0106] That is, with the left direction being positive, the Pb characteristic equation shown in the following equation (3) holds true.

[0107]

number

[0108] As described above, the control valve V3 of the third embodiment is similar to the first embodiment in that it is resistant to the force (F Pd ) and the force due to the suction fluid Ps (F PsWhile causing both of them to act on the valve body, by reducing the influence of the pressure of the discharge fluid Pd, which is relatively higher in pressure than the suction fluid Ps, and increasing the influence of the pressure of the suction fluid Ps, the pressure of the control fluid Pb can be smoothly changed according to the pressure of the discharge fluid Pd. Further, the control valve V3 of the present Example 3 is provided with another first space S301' communicating with the high-pressure chamber 30 outside the housing 360, and by causing the pressure of the discharge fluid Pd to act axially leftward on the effective pressure-receiving area D3 of the small-diameter portion 367b of the pressure driving body 367, compared with the said Example 1, the coefficient of the pressure-receiving surface of the suction fluid Ps and the coefficient of the pressure-receiving surface of the discharge fluid Pd in the Pb characteristic formula can be adjusted.

[0109] In addition, in the present Example 3, by setting the effective pressure-receiving area D3 of the small-diameter portion 367b of the pressure driving body 367 to be larger than the effective pressure-receiving area B3 of the tapered surface 361b (B3 < D3), the case where the pressure-receiving surface (C3 - B3) of the control fluid Pb is made larger than the pressure-receiving surface (C3 - D3) of the suction fluid Ps is described as an example, but it is not limited thereto, and the size relationship between the effective pressure-receiving area B3 of the tapered surface 361b and the effective pressure-receiving area D3 of the small-diameter portion 367b of the pressure driving body 367 may be appropriately set according to the control characteristics (Pb characteristics) required for the control valve V3.

[0110] As described above, the embodiments of the present invention have been described with reference to the drawings. However, the specific configuration is not limited to these embodiments, and modifications and additions within the scope not departing from the gist of the present invention are also included in the present invention.

[0111] For example, in the said Examples 1 and 2, the form in which the pressure-receiving surface of the discharge fluid Pd is smaller than the pressure-receiving surface of the control fluid Pb was exemplified, but the pressure-receiving surface of the discharge fluid Pd may be the same as or larger than the pressure-receiving surface of the control fluid Pb.

[0112] Further, in the said Examples 1 and 3, the pressure driving body and the valve member may be configured to be separable or integrally connected.

[0113] In addition, in the above-mentioned first to third embodiments, the inside of the bellows, which is the pressure-sensing body, has been described as being vacuum, but the bellows may contain a fluid. Furthermore, the pressure-sensing body may be a diaphragm.

[0114] Further, in the above-mentioned first to third embodiments, the valve applied to the scroll compressor C used in the air conditioning system of an automobile or the like has been described, but the present invention is not limited to this, and the valve may be used to control various working fluids.

[0115] Further, in the above-described first to third embodiments, the valve is a pressure control valve. However, the valve may be, for example, an expansion valve disposed between a condenser and an evaporator in an air conditioning system, or a displacement control valve incorporated in a variable displacement compressor in an air conditioning system.

[0116] Furthermore, the intake fluid, discharge fluid, and control fluid may each be in the form of gas, liquid, or a mixture of gas and liquid.

[0117] Furthermore, the layout relationship between the first space, the second space, and the third space can be freely changed. [Explanation of symbols]

[0118] 60,260,360 Housing 61,261,361 Valve member (valve body) 62,262,362 Bellows (pressure sensor) 65,265,365 Valve seat 67,367 Pressure Driver 68,268 Disc spring 70,270 Coil spring 368 Coil Spring C Scroll Compressor Pb Control Fluid Pd discharge fluid Ps suction fluid S1, S201, S301, S301' First space S2,S202,S302 2nd space S3, S203, S303 Third Space V1~V3 control valve

Claims

1. a housing including a pressure sensor having a sealed space therein, the housing dividing a first space into which a discharge fluid flows, a second space into which a control fluid flows, and a third space into which a suction fluid flows; a valve body that allows fluid to flow in and out of the second space by being seated on and removed from the housing, A valve having a larger pressure receiving surface for the intake fluid than for the discharge fluid.

2. 2. The valve according to claim 1, wherein a force due to the discharge fluid and a force due to the suction fluid are applied to the valve element in the same direction.

3. The valve of claim 1 , wherein the third space is disposed on an opposite side of the second space from the first space.

4. 2. The valve according to claim 1, wherein the coefficient of the pressure receiving surface for the intake fluid is 1 or more.

5. 2. The valve of claim 1, wherein the coefficient of said discharge fluid receiving surface is less than one.

Images