Valve

Abstract

Provided is a valve capable of smoothly changing the pressure of a back pressure fluid. A valve (V1) is provided with: a housing (60) having a high-pressure space (S2) into which a high-pressure fluid (Pd) flows, back-pressure spaces (S3, S3 ') into which a back-pressure fluid (Pb) flows, and a low-pressure space (S1) into which a low-pressure fluid (Ps) flows; and a valve body (61) disposed in the housing (60) so as to be capable of relative movement. The housing (60) has a first passage (73) provided between the high-pressure space (S2) and the back-pressure space (S3) and a second passage (78) provided between the back-pressure space (S3 ') and the low-pressure space (S1), and the valve body (61) has a first valve body part (72) for controlling the opening degree of the first passage (73) and a second valve body part (77) for controlling the opening degree of the second passage (78). The first valve body part (72) and the second valve body part (77) are linked in such a manner that the respective movement directions are opposite in the opening direction and the closing direction.

Description

Technical Field

[0001] This invention relates to valves, such as valves for controlling pressure. Background Technology

[0002] As one of the compressors used in various industrial fields, there is the scroll compressor. This type of compressor not only has high compression efficiency but also low noise, so it is used in many aspects such as refrigeration cycles.

[0003] The scroll compressor is constructed as follows: it has a scroll compression mechanism and a rotating shaft, etc. The scroll compression mechanism consists of a fixed scroll disk with vortex-shaped vortex teeth and a movable scroll disk with vortex-shaped vortex teeth. The rotating shaft causes the movable scroll disk to rotate eccentrically. By causing the movable scroll disk to slide relative to the fixed scroll disk in an eccentric rotation, the fluid supplied as refrigerant from the suction chamber on the outer diameter side of the two scroll disks is pressurized, and high-pressure refrigerant is ejected from the ejection port formed in the center of the fixed scroll disk.

[0004] In this type of scroll compressor, when the pressure in the ejection chamber of the refrigerant compressed by the scroll compressor increases, a force acts in the direction that moves the movable scroll away from the fixed scroll.

[0005] Patent Document 1 describes a scroll compressor equipped with a gas supply passage that connects the ejection chamber to a back pressure chamber formed on the back side of the movable scroll. A portion of the gas supply passage functions as a fixed throttling section. A portion of the compressed refrigerant in the ejection chamber is depressurized and supplied to the back pressure chamber through the slit, pressing the movable scroll toward the fixed scroll, thus preventing the movable scroll from moving away from the fixed scroll.

[0006] Furthermore, the scroll compressor is equipped with an extraction passage connecting the back pressure chamber and the suction chamber. A back pressure control valve is installed in the extraction passage. The back pressure control valve has a front housing, a housing, and a valve core. The front housing and the housing form a first valve chamber communicating with the discharge chamber, a second valve chamber communicating with the back pressure chamber, and a third valve chamber communicating with the suction chamber. The valve core is housed within the front housing and the housing in a reciprocating manner, and together with a valve seat located between the third valve chamber and the second valve chamber, forms a BS valve that allows the flow rate of the extraction passage between the back pressure chamber and the suction chamber to be variable. Moreover, the valve core moves in the opening or closing direction according to the discharge pressure, back pressure, and suction pressure, thereby adjusting the opening degree of the BS valve.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 2010-150967 (pp. 5-8) Figure 1 ) Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] In the scroll compressor described in Patent Document 1, when there is a tendency for insufficient back pressure, the valve core of the back pressure control valve moves in the closing direction, and the BS valve opens slightly or closes completely. At this time, refrigerant is continuously supplied to the back pressure chamber via the gas supply passage in the scroll compressor, thus enabling the pressure in the back pressure chamber to rise.

[0012] Furthermore, when there is an excess back pressure, the valve core of the back pressure control valve moves in the opening direction, and the opening degree of the BS valve increases, which can reduce the pressure in the back pressure chamber. However, even if there is an excess back pressure and the BS valve is open, refrigerant will continue to be supplied to the back pressure chamber through the gas supply passage, so there is a problem that time is spent until the pressure in the back pressure chamber reaches the appropriate pressure.

[0013] This invention was made in view of such a problem, and its purpose is to provide a valve that enables the pressure of a backpressure fluid to change smoothly.

[0014] Methods for solving problems

[0015] To address the aforementioned issues, the valve of the present invention comprises: a housing having a high-pressure space for the inflow of a high-pressure fluid, a back-pressure space for the inflow of a back-pressure fluid, and a low-pressure space for the inflow of a low-pressure fluid; and a valve core disposed in the housing in a manner capable of relative movement, wherein the housing has a first passage disposed between the high-pressure space and the back-pressure space and a second passage disposed between the back-pressure space and the low-pressure space, the valve core having a first valve core portion for controlling the opening degree of the first passage and a second valve core portion for controlling the opening degree of the second passage, the first valve core portion and the second valve core portion being linked in a manner where their respective directions of movement are opposite in the opening and closing directions.

[0016] Therefore, when the opening of the first passage decreases, the opening of the second passage increases, and when the opening of the second passage decreases, the opening of the first passage increases, thus enabling smooth changes in the pressure of the back pressure fluid. Furthermore, back pressure adjustment can be performed using only a valve, thereby simplifying the structure of the installed equipment.

[0017] Alternatively, the back pressure space can be a first back pressure space that can be connected to the first passage and a second back pressure space that can be connected to the second passage and separated from the first back pressure space.

[0018] This prevents fluid from flowing directly from a space with relatively high pressure into a space with relatively low pressure.

[0019] Alternatively, the valve core may have a connecting portion that connects the first valve core portion and the second valve core portion.

[0020] This allows the first valve core and the second valve core to be easily linked.

[0021] Alternatively, the housing and the connecting part may be sealed.

[0022] This prevents fluid from flowing directly from a space with relatively high pressure into a space with relatively low pressure.

[0023] Alternatively, the valve may have a force-applying unit that applies force to the valve core in one direction. The valve is configured to include the pressure Pd of the high-pressure fluid, the pressure Pb of the back-pressure fluid, the pressure Ps of the low-pressure fluid, the effective cross-sectional area A of the first valve core, the effective cross-sectional area B of the connecting portion, the effective cross-sectional area C of the second valve core, and the force F of the force-applying unit. sp It satisfies the following mathematical expression 1:

Mathematical Formula 1

[0024] Therefore, it is possible to determine the pressure of the high-pressure fluid Pd, the pressure of the back-pressure fluid Pb, the pressure of the low-pressure fluid Ps, and the force F applied by the force-applying unit. sp This allows the valve core to move smoothly.

[0025] Alternatively, the effective cross-sectional area A and the effective cross-sectional area C may be larger than the effective cross-sectional area B.

[0026] Therefore, the influence of back pressure fluids and low-pressure fluids can be greater than that of high-pressure fluids.

[0027] Alternatively, the housing may have a first valve seat disposed in the first passage and a second valve seat disposed in the second passage.

[0028] Therefore, by contacting the first valve core and the second valve core with the first valve seat and the second valve seat, the first passage and the second passage can be reliably sealed, thus enabling the pressure of the back pressure fluid to change more smoothly. Attached Figure Description

[0029] Figure 1 This is a schematic structural diagram of a scroll compressor that uses the valve of Embodiment 1 of the present invention.

[0030] Figure 2 This is a cross-sectional view of the valve in Embodiment 1 of the present invention.

[0031] Figure 3 This is a cross-sectional view of the valve in Embodiment 2 of the present invention. Detailed Implementation

[0032] Hereinafter, the manner in which the valve is used to implement the present invention will be described based on embodiments.

[0033] Example 1

[0034] Reference Figure 1 , Figure 2 The valve of Example 1 will be described. The valve of the present invention is applied to a scroll compressor C used in an air conditioning system of rotating machinery including an eccentric mechanism, such as an automobile. This scroll compressor C draws in, compresses, and ejects a refrigerant as a fluid. Furthermore, in this embodiment, the refrigerant is a gas, in a state mixed with a mist of lubricating oil.

[0035] First, let's explain the scroll compressor C. For example... Figure 1 As shown, the scroll compressor C mainly consists of a housing 1, a rotating shaft 2, an inner housing 3, a scroll compression mechanism 4, a side seal 7, a thrust plate 8, and a drive motor M.

[0036] The housing 1 consists of a cylindrical outer shell 11 and a cover 12 that closes the opening of the outer shell 11. The opening of the outer shell 11, which is on the opposite side in the axial direction to the opening closed by the cover 12, is closed by a drive motor M.

[0037] Inside the outer casing 11 are formed: a low-pressure chamber 20, which receives low-pressure refrigerant (Ps) via a refrigerant circuit (not shown) through the suction port 10; a high-pressure chamber 30, which receives high-pressure refrigerant (Pd) compressed by the scroll compressor 4; and a back-pressure chamber 50, which receives lubricating oil and a portion of the refrigerant compressed by the scroll compressor 4 (Pb) via a back-pressure control valve V1. The back-pressure chamber 50 is formed inside a cylindrical inner casing 3 housed within the outer casing 11.

[0038] The cover 12 has an ejection passage 13 that connects a refrigerant circuit (not shown) to the high-pressure chamber 30. Furthermore, the cover 12 has a branch from the ejection passage 13 that forms a portion of a back-pressure passage 14 that connects the high-pressure chamber 30 to the back-pressure chamber 50. Additionally, an oil separator 6 is provided in the ejection passage 13 to separate lubricating oil from the refrigerant.

[0039] The inner shell 3 is fixed in such a state that its axial end abuts against the end plate 41a of the fixed scroll disk 41 constituting the scroll compressor mechanism 4. Furthermore, a radially penetrating suction passage 15 is formed on the side wall of the inner shell 3. That is, the low-pressure chamber 20 is formed from the outside of the inner shell 3 into the interior of the inner shell 3 via the suction passage 15. The suction fluid Ps supplied to the interior of the inner shell 3 via the suction passage 15 is drawn into the scroll compressor mechanism 4.

[0040] The vortex compression mechanism 4 mainly consists of a fixed vortex disk 41 that is fixed in a sealed manner relative to the cover 12 and a movable vortex disk 42 housed inside the inner shell 3.

[0041] The fixed scroll plate 41 is made of metal and has vortex-shaped vortex teeth 41b. These vortex-shaped vortex teeth 41b protrude from the surface of the circular end plate 41a, i.e., the end face of the end plate 41a opposite to the movable scroll plate 42, toward the movable scroll plate 42. Furthermore, the fixed scroll plate 41 has a recess 41c formed on the inner diameter side of the back side of the end plate 41a, i.e., the end face of the end plate 41a that abuts against the cover 12. This recess 41c and the cover 12 divide the high-pressure chamber 30.

[0042] The movable scroll plate 42 is made of metal and has vortex-shaped vortex teeth 42b, which protrude from the surface of the circular end plate 42a, i.e., the end face of the end plate 42a opposite to the fixed scroll plate 41, toward the fixed scroll plate 41. Furthermore, the movable scroll plate 42 has a boss 42c protruding from the center of the back surface of the end plate 42a. The eccentric portion 2a formed on the rotating shaft 2 is rotatably inserted into the boss 42c. In this embodiment, the eccentric portion 2a of the rotating shaft 2 and the counterweight portion 2b protruding from the rotating shaft 2 in the outer diameter direction constitute an eccentric mechanism that causes the rotating shaft 2 to rotate eccentrically.

[0043] When the rotating shaft 2 is driven to rotate by the drive motor M, the eccentric part 2a rotates eccentrically, and the movable scroll plate 42 slides relative to the fixed scroll plate 41 while maintaining its posture. At this time, the movable scroll plate 42 rotates eccentrically relative to the fixed scroll plate 41. With this rotation, the contact position of the scroll teeth 41b and 42b moves sequentially in the direction of rotation, and the compression chamber 40 formed between the scroll teeth 41b and 42b gradually shrinks while moving towards the center. As a result, the suction fluid Ps drawn into the compression chamber 40 from the low-pressure chamber 20 formed on the outer diameter side of the scroll compression mechanism 4 is gradually compressed and finally ejected as high-pressure ejected fluid Pd into the high-pressure chamber 30 through the ejection hole 41d provided in the center of the fixed scroll plate 41.

[0044] The side seal 7 is made of resin, has a rectangular cross-section and appears annular when viewed axially, and is fixed to the back of the end plate 42a of the movable scroll plate 42. The side seal 7 has a sliding surface 7a that abuts against the sliding surface 8a formed on the thrust plate 8.

[0045] The thrust plate 8 is made of metal and is annular in shape, with a sealing ring 43 fixed thereon. The sealing ring 43 abuts against the inner circumferential end face of the inner shell 3. Thus, the thrust plate 8 functions as a thrust bearing, bearing the axial load of the movable scroll plate 42 via the side seal 7.

[0046] Furthermore, the side seal 7 and the sealing ring 43 divide the interior of the inner shell 3 into a low-pressure chamber 20 formed on the outer diameter side of the movable scroll plate 42 and a back-pressure chamber 50 formed on the back side of the movable scroll plate 42. The back-pressure chamber 50 is sealed with the rotating shaft 2 that penetrates and is inserted into the through hole 3a by the sealing ring 44, thereby forming a sealed space, wherein the sealing ring 44 is fixed to the inner circumference of the through hole 3a provided in the center of the inner shell 3.

[0047] Furthermore, a back pressure control valve V1, which serves as a valve, is provided on the back pressure communication path 14, which is formed by covering the cover 12, the fixed scroll plate 41, and the inner shell 3 and connects the high pressure chamber 30 and the back pressure chamber 50. In other words, the back pressure control valve V1 is provided inside the shell 1, which is isolated from the external gas.

[0048] A portion of the ejected fluid Pd, which is supplied to the high-pressure chamber 30 of the back pressure control valve V1 along with the lubricating oil separated by the oil separator 6, is pressurized to become the control fluid Pb and supplied to the back pressure chamber 50.

[0049] Furthermore, the inner shell 3 is formed with a pressure relief port 16 that connects the back pressure control valve V1 to the low pressure chamber 20.

[0050] Next, use Figure 2 The back pressure control valve V1, which serves as a valve in this embodiment, will be described below. Figure 2 The left and right sides when viewed from the front are described as the left and right sides of the back pressure control valve V1.

[0051] like Figure 2 As shown, the back pressure control valve V1 in this embodiment 1 is mainly composed of a housing 60, a rod 61 as a valve core, and a helical spring 62 as a force-applying unit that presses the rod 61 in one direction.

[0052] The shell 60 is divided into a low-pressure space S1 communicating with the low-pressure chamber 20, a high-pressure space S2 communicating with the high-pressure chamber 30, and back-pressure spaces S3 and S3' communicating with the back-pressure chamber 50. In addition, the shell 60 only needs to divide at least a portion of the low-pressure space S1, the high-pressure space S2, and the back-pressure spaces S3 and S3'.

[0053] The shell 60 is composed of a first segment 63, a second segment 64 and a third segment 65 from the right side.

[0054] The first segment 63 has a peripheral wall 63a and a side wall 63b, and the first segment 63 is formed as a cylindrical shape with side walls that opens to the left in the axial direction.

[0055] The peripheral wall 63a is formed into a cylindrical shape extending axially. A connecting hole 63c is provided on the peripheral wall 63a, extending radially and communicating with the low-pressure chamber 20 and the low-pressure space S1. In this embodiment, the connecting holes 63c are arranged in two equal parts, but the number and arrangement can be appropriately changed. The same applies to the connecting holes 64f and 64k described later.

[0056] The inner diameter of the peripheral wall 63a is approximately the same throughout the entire axial range.

[0057] The side wall 63b is formed as a circular plate that closes the axial right end of the peripheral wall 63a.

[0058] Furthermore, a cylindrical protrusion 63d is formed on the sidewall 63b, protruding axially to the left from the center of the left end face of the sidewall 63b. The axial right end of the coil spring 62 is inserted into the protrusion 63d. This achieves radial positioning of the axial right end of the coil spring 62. The axial right end of the coil spring 62 abuts against the sidewall 63b.

[0059] The second segment 64 has, from the left side of the axial direction, a left large inner diameter peripheral wall 64a, a left middle inner diameter peripheral wall 64b, a small inner diameter peripheral wall 64c, a right middle inner diameter peripheral wall 64d, and a right large inner diameter peripheral wall 64e. The second segment 64 is formed into a cylindrical shape extending along the axial direction.

[0060] The left large inner diameter peripheral wall 64a is cylindrical in shape, extending axially. A connecting hole 64f is formed on the left large inner diameter peripheral wall 64a, which extends radially and communicates with the high-pressure space S2.

[0061] The outer diameter end of the connecting hole 64f is enlarged to form an annular recess 64g that opens towards the outer diameter side, communicating with the high-pressure chamber 30. A filter 66 is provided in the recess 64g to remove contaminants and other foreign matter contained in the refrigerant.

[0062] The left-side middle inner diameter peripheral wall 64b is cylindrical, extending axially to the right from the right end of the left-side large inner diameter peripheral wall 64a. The inner diameter of the left-side middle inner diameter peripheral wall 64b is smaller than the inner diameter of the left-side large inner diameter peripheral wall 64a. Furthermore, the left-side middle inner diameter peripheral wall 64b has an annular rim 64h extending from the left end of the left-side middle inner diameter peripheral wall 64b toward the inner diameter side.

[0063] The small inner diameter peripheral wall 64c is cylindrical, extending axially to the right from the right end of the left middle inner diameter peripheral wall 64b. A through hole 64j is formed in the radial center of the small inner diameter peripheral wall 64c, extending axially. The inner diameter of the small inner diameter peripheral wall 64c is smaller than the inner diameter of the left middle inner diameter peripheral wall 64b, and more specifically, smaller than the inner diameter of the eaves 64h.

[0064] The right-side inner diameter peripheral wall 64d is cylindrical, extending axially to the right from the right end of the small inner diameter peripheral wall 64c. A second back pressure space S3' and a second valve hole 64m are formed in the radial center of the right-side inner diameter peripheral wall 64d.

[0065] The second back pressure space S3' expands in diameter from the through hole 64j to the right axially, and then extends to the right axially with approximately the same diameter.

[0066] The second valve hole 64m expands in diameter from the second back pressure space S3' toward the axial right. The conical surface that defines the second valve hole 64m is the second valve seat 76.

[0067] The second valve core 77 of the lever 61 contacts and separates from the second valve seat 76. That is, the second valve seat 76 and the second valve core 77 constitute a BS valve 75, which controls the opening and closing of the second passage 78 between the curved surfaces 77a of the second valve seat 76 and the second valve core 77 by contacting and separating. Furthermore, the second valve core 77 can adjust the opening degree of the second passage 78 in response to the movement of the lever 61, thereby adjusting the flow rate. Hereinafter, the adjustment of the opening degree of the second passage 78 based on the movement of the lever 61 will sometimes also be described as the adjustment of the opening degree of the BS valve 75.

[0068] Furthermore, a connecting hole 64k is formed on the right inner diameter peripheral wall 64d, which is radially penetrating and communicating with the back pressure chamber 50 and the second back pressure space S3'.

[0069] The right-side large inner diameter peripheral wall 64e is cylindrical, extending axially to the right from the right end of the right-side middle inner diameter peripheral wall 64d. The inner diameter of the right-side large inner diameter peripheral wall 64e is larger than the inner diameter of the right-side middle inner diameter peripheral wall 64d, and more specifically, larger than the maximum diameter of the second valve seat 76.

[0070] The outer diameter of the right end of the second segment 64 is approximately the same throughout the axial direction, and is approximately the same as or slightly larger than the inner diameter of the peripheral wall 63a of the first segment 63.

[0071] The right end of the second segment 64 is pressed into and fixed to the inner side of the peripheral wall 63a of the first segment 63. The space surrounded by the peripheral wall 63a and side wall 63b of the first segment 63, and the right inner diameter peripheral wall 64d and right large inner diameter peripheral wall 64e of the second segment 64, is a low-pressure space S1 for the inflow of the suction fluid Ps.

[0072] The third segment 65 is formed as a cylindrical shape with steps on the outer side, having a large outer diameter peripheral wall 65a and a small outer diameter peripheral wall 65b sequentially from the left side of the axial direction.

[0073] The outer diameter circumferential wall 65a is cylindrical, extending axially.

[0074] The smaller outer diameter peripheral wall 65b is cylindrical, extending axially to the right from the right end of the larger outer diameter peripheral wall 65a. The outer diameter of the smaller outer diameter peripheral wall 65b is smaller than that of the larger outer diameter peripheral wall 65a.

[0075] The outer diameter of the small outer diameter peripheral wall 65b is approximately the same throughout the axial direction, and is approximately the same as or slightly larger than the inner diameter of the large inner diameter peripheral wall 64a on the left side of the second segment 64.

[0076] The small outer diameter peripheral wall 65b of the third segment 65 is pressed into and fixed to the inner side of the large inner diameter peripheral wall 64a on the left side of the second segment 64. Furthermore, the large outer diameter peripheral wall 65a of the third segment 65 abuts against the large inner diameter peripheral wall 64a on the left side of the second segment 64, thus positioning the third segment 65 axially. The space enclosed by the large inner diameter peripheral wall 64a on the left side, the middle inner diameter peripheral wall 64b on the left side, the small inner diameter peripheral wall 64c on the left side, and the third segment 65 constitutes a high-pressure space S2 for the ejected fluid Pd to flow into.

[0077] A first valve hole 65c is formed at the radial center of the large outer diameter peripheral wall 65a and the small outer diameter peripheral wall 65b, that is, at the radial center of the third segment 65.

[0078] The first valve orifice 65c extends from the high-pressure space S2 toward the axial left with approximately the same diameter, and then expands toward the axial left. The tapered surface that divides the portion that expands toward the axial left is the first valve seat 71.

[0079] The first valve core 72 of the lever 61 contacts and separates from the first valve seat 71. That is, the first valve seat 71 and the first valve core 72 constitute a DB valve 70, which controls the opening and closing of the first passage 73 between the curved surfaces 72a of the first valve seat 71 and the first valve core 72 by contacting and separating. Furthermore, the first valve core 72 can adjust the opening degree of the first passage 73 in response to the movement of the lever 61, thereby adjusting the flow rate. Hereinafter, the adjustment of the opening degree of the first passage 73 based on the movement of the lever 61 will sometimes also be described as the adjustment of the opening degree of the DB valve 70.

[0080] A first back pressure space S3 is formed radially at the center of the outer diameter peripheral wall 65a. The first back pressure space S3 is recessed from the left end face of the outer diameter peripheral wall 65a toward the axial right and opens toward the axial left. The first back pressure space S3 communicates with the back pressure chamber 50 and the first valve hole 65c.

[0081] The rod 61 is composed of a base 67 and an annular component 68.

[0082] The base member 67 is a stepped cylinder, and an annular member 68 (described later) is fixed to its right end. The left end of the base member 67 forms the first valve core portion 72. The right end of the base member 67 and the annular member 68 form the second valve core portion 77. Furthermore, a shaft portion 67a serves as a connecting part between the first valve core portion 72 and the second valve core portion 77 of the base member 67.

[0083] The first valve core 72 has a curved surface 72a, which is formed by narrowing from the left end of the first valve core 72 toward the right side of the axial direction to form part of a spherical shape.

[0084] The first valve core 72 is configured to span the first back pressure space S3 and the first valve port 65c. That is, the pressure of the ejected fluid Pd and the pressure of the control fluid Pb act on the first valve core 72 respectively. The effective cross-sectional area A1 of the first valve core 72 is approximately the same as the cross-sectional area of ​​the portion of the first valve core 72 that is in circumferential line contact with the first valve core 72 when it is seated on the first valve seat 71.

[0085] The shaft portion 67a is formed as a stepped cylinder that extends from the right end of the first valve core portion 72 toward the right side of the axial direction with approximately the same diameter, expands toward the right side of the axial direction, extends toward the right side of the axial direction with approximately the same diameter, and then narrows toward the right side of the axial direction.

[0086] The shaft portion 67a is inserted into the housing 60 from the first back pressure space S3 side, and is configured to span the first valve hole 65c, the high pressure space S2, the through hole 64j, the second back pressure space S3', the second valve hole 64m, and the low pressure space S1. That is, the pressure of the ejected fluid Pd, the pressure of the back pressure fluid Pb, and the pressure of the suction fluid Ps all act on the shaft portion 67a. The effective cross-sectional area B1 of the shaft portion 67a is the cross-sectional area of ​​the portion inserted through the through hole 64j, that is, the cross-sectional area of ​​the largest diameter main body portion 67b in the shaft portion 67a. The effective cross-sectional area B1 of the shaft portion 67a is smaller than the effective cross-sectional area A1 of the first valve core portion 72 (A1 > B1).

[0087] Furthermore, the outer peripheral surface of the large-diameter main body 67b and the inner peripheral surface of the small-diameter peripheral wall 64c that divides the through hole 64j are both smooth surfaces with the same diameter throughout the entire axial range, and the two surfaces can slide relative to each other. Moreover, the gap between the outer peripheral surface of the large-diameter main body 67b and the inner peripheral surface of the small-diameter peripheral wall 64c is extremely small, so the refrigerant will hardly move between the high-pressure space S2 and the second back-pressure space S3' through this gap.

[0088] Furthermore, an O-ring 69, serving as a sealing unit, is embedded in the large-diameter main body 67b. The O-ring 69 is embedded in the left inner diameter peripheral wall 64b of the second segment 64. The O-ring 69 allows axial movement of the rod 61 and seals the space between the shaft 67a and the left inner diameter peripheral wall 64b. That is, the O-ring 69 seals the space between the high-pressure space S2 and the second back pressure space S3'.

[0089] As described above, an eave 64h is formed at the left end of the left-side inner diameter peripheral wall 64b. Furthermore, a small inner diameter peripheral wall 64c is continuously formed at a position axially to the right of the left-side inner diameter peripheral wall 64b, i.e., on the low-pressure space S1 side. That is, an O-ring 69 is positioned axially between the eave 64h and the small inner diameter peripheral wall 64c, thus preventing the O-ring 69 from moving axially to the outer side of the left-side inner diameter peripheral wall 64b.

[0090] The right axial end of the large-diameter main body portion 67b of the shaft portion 67a is pressed into and fixed to the annular member 68. The annular member 68 is formed in an annular shape. The inner diameter of the annular member 68 is approximately the same as or slightly smaller than the outer diameter of the large-diameter main body portion 67b.

[0091] The right end of the shaft portion 67a protrudes axially to the right beyond the axial right edge of the annular member 68, and the axial left end of the helical spring 62 is inserted into the right end of the shaft portion 67a. This achieves radial positioning of the axial left end of the helical spring 62. Furthermore, the axial left end of the helical spring 62 abuts against the annular member 68.

[0092] The annular component 68 has a curved surface 77a, which is formed by expanding the diameter from the left end of the annular component 68 toward the axial right, thus forming part of a spherical shape.

[0093] The second valve core 77 is configured to span the second back pressure space S3' and the low pressure space S1. That is, the pressure of the control fluid Pb and the pressure of the suction fluid Ps act on the second valve core 77 respectively. The effective cross-sectional area C1 of the second valve core 77 is the cross-sectional area of ​​the second valve core 77 on the inner diameter side of the part of the second valve core 77 that makes line contact in the circumferential direction when it is seated on the second valve seat 76. In other words, it is approximately the same as the sum of the cross-sectional area of ​​the annular member 68 and the cross-sectional area of ​​the large-diameter main body 67b.

[0094] The effective cross-sectional area C1 of the second valve core 77 is larger than the effective cross-sectional area A1 of the first valve core 72 and the effective cross-sectional area B1 of the shaft 67a (C1 > A1 > B1).

[0095] The effective pressure-bearing area of ​​the rod 61, which is acted upon by the pressure of the control fluid Pb in the first back pressure space S3, is the effective cross-sectional area A1 of the first valve core 72.

[0096] The effective pressure-bearing area of ​​the rod 61, which is subjected to the pressure of the ejected fluid Pd, is the portion of the effective cross-sectional area A1 of the first valve core 72 that is closer to the outer diameter than the effective cross-sectional area B1 of the shaft portion 67a (A1-B1).

[0097] The effective pressure-bearing area A1 of the rod 61, which is acted upon by the pressure of the control fluid Pb in the first back pressure space S3, is larger than the effective pressure-bearing area (A1-B1) of the rod 61, which is acted upon by the pressure of the ejected fluid Pd (A1>(A1-B1)).

[0098] The effective pressure-bearing area of ​​the rod 61, which is acted upon by the pressure of the control fluid Pb in the second back pressure space S3', is the portion of the effective cross-sectional area C1 of the second valve seat 76 that is closer to the outer diameter than the effective cross-sectional area B1 of the shaft portion 67a (C1-B1).

[0099] The effective pressure-bearing area (C1-B1) of the rod 61 acting on the pressure of the control fluid Pb in the second back pressure space S3' is larger than the effective pressure-bearing area (A1-B1) of the rod 61 acting on the pressure of the ejected fluid Pd ((C1-B1) > (A1-B1)).

[0100] The effective pressure-bearing area of ​​rod 61, which is affected by the pressure of the inhaled fluid Ps, is the effective cross-sectional area C1 of the second valve core 77.

[0101] Next, the opening and closing operation of the back pressure control valve V1 will be explained. Furthermore, in this embodiment, the pressure of the ejected fluid Pd is mathematically represented as Pd, the pressure of the control fluid Pb is mathematically represented as Pb, and the pressure of the suction fluid Ps is mathematically represented as Ps.

[0102] In the housing 60, the intake fluid Ps flows into the low-pressure space S1, the ejected fluid Pd flows into the high-pressure space S2, and the control fluid Pb flows into the back pressure spaces S3 and S3'.

[0103] The force (F) generated by the pressure of the ejected fluid Pd acting on the effective pressure-bearing area (A1-B1) of rod 61 Pd =Pd×(A1-B1)), the force (F) generated by the pressure of the inhaled fluid Ps acting on the effective pressure-bearing area C1. Ps =Ps×C1) and the force F of the helical spring 62 sp Pressing the axis to the left (i.e., with left as positive, force F1=F) Pd +F Ps +F sp (Action applied to rod 61).

[0104] Furthermore, the force (F) generated by the pressure of the control fluid Pb in the first back pressure space S3 acting on the effective pressure area A1 of the rod 61 is... Pb1=Pb×A1) and the pressure of the control fluid Pb in the second back pressure space S3' act on the effective pressure area (C1-B1) to generate the force (F) Pb2 =Pb×(C1-B1))Press to the right along the axis (i.e., with right as positive, force F2=F Pb1 +F Pb2 (Action applied to rod 61).

[0105] The equilibrium equations for forces F1 and F2 are as follows, and it can be seen that they satisfy mathematical equation 1.

[0106] .

[0107] When force F1 changes from being in equilibrium with force F2 to being greater than force F2, rod 61 moves to the left axially (force F1 > force F2). Then, rod 61 comes to rest when force F1 and force F2 are in equilibrium (F1 = F2) or when the second valve core 77 sits on the second valve seat 76 of the housing 60.

[0108] When force F1 changes from being in equilibrium with force F2 to being smaller than force F2, rod 61 moves axially to the right (force F1 < force F2). Then, rod 61 comes to rest when force F1 and force F2 are in equilibrium (F1 = F2) or when the first valve core 72 sits on the first valve seat 71 of the housing 60.

[0109] In this way, the back pressure control valve V1 can make the rod 61 move smoothly according to the pressure of the ejected fluid Pd, the pressure of the control fluid Pb, the pressure of the suction fluid Ps, and the force of the helical spring 62.

[0110] When the first valve core 72 is in a position separated from the first valve seat 71 and the second valve core 77 is in a position separated from the second valve seat 76, the DB valve 70 and the BS valve 75 are in the open state.

[0111] More specifically, in DB valve 70 and BS valve 75, the more the rod 61 moves axially to the left, the farther the first valve core 72 is from the first valve seat 71, the larger the valve opening of DB valve 70, the closer the second valve core 77 is to the second valve seat 76, and the smaller the valve opening of BS valve 75.

[0112] In this embodiment, when the second valve core 77 is seated on the second valve seat 76 and the BS valve 75 is in the closed state, the first valve core 72 is located at the position furthest from the first valve seat 71, and the opening degree of the DB valve 70 is at its maximum.

[0113] In DB valve 70 and BS valve 75, the more the rod 61 moves axially to the right, the closer the first valve core 72 is to the first valve seat 71 and the smaller the valve opening of DB valve 70 becomes; the farther the second valve core 77 is from the second valve seat 76 and the larger the valve opening of BS valve 75 becomes.

[0114] In this embodiment, when the first valve core 72 is seated on the first valve seat 71 and the DB valve 70 is in the closed state, the second valve core 77 is located at the position furthest from the second valve seat 76, and the BS valve 75 has the largest valve opening.

[0115] The valve opening of DB valve 70 and BS valve 75 varies from a maximum opening larger than the opening of a fixed throttling section like the slit in Patent Document 1, to the opening of the fixed throttling section, to an opening smaller than the opening of the fixed throttling section, and then to a closed state.

[0116] In addition, the range of valve opening of DB valve 70 and BS valve 75 can be appropriately adjusted, but preferably can be made smaller than the opening of a fixed throttling section like the slit in Patent Document 1.

[0117] As explained above, in the back pressure control valve V1 of this embodiment, when the opening degree of the first passage 73 decreases, the opening degree of the second passage 78 increases, and when the opening degree of the second passage 78 decreases, the opening degree of the first passage 73 increases.

[0118] For example, when the forces F1 and F2 are in equilibrium, and the pressure of the control fluid Pb becomes relatively greater than the pressures of the ejected fluid Pd and the suction fluid Ps, the opening of the first passage 73 decreases, while the opening of the second passage 78 increases. Since the opening of the first passage 73 becomes smaller than the opening of a fixed throttling section like the slit in Patent Document 1, the amount of refrigerant flowing into the first back pressure space S3 can be reduced compared to that fixed throttling section, thus allowing the pressure of the control fluid Pb to decrease smoothly.

[0119] Furthermore, since the opening of the second passage 78 is larger than that of the fixed throttling section like the slit in Patent Document 1, the pressure of the control fluid Pb can be reduced more smoothly.

[0120] Furthermore, when the forces F1 and F2 are in equilibrium, and the pressure of the control fluid Pb becomes relatively smaller than the pressures of the ejected fluid Pd and the suction fluid Ps, the opening of the first passage 73 increases, while the opening of the second passage 78 decreases. Since the opening of the first passage 73 becomes larger than the opening of a fixed throttling section like the slit in Patent Document 1, the amount of refrigerant flowing into the first back pressure space S3 can be increased compared to that fixed throttling valve, thus allowing the pressure of the control fluid Pb to rise smoothly.

[0121] Furthermore, since the opening of the second passage 78 is smaller than the opening of the fixed throttling section like the slit in Patent Document 1, the pressure of the control fluid Pb can rise more smoothly.

[0122] In this way, the back pressure control valve V1 allows for smooth changes in the pressure of the control fluid Pb. Furthermore, back pressure adjustment can be performed using only the back pressure control valve V1, thus simplifying the structure of the scroll compressor C.

[0123] Furthermore, the rod 61 is formed by connecting the first valve core 72 and the second valve core 77 with the shaft 67a, thus enabling the first valve core 72 and the second valve core 77 to be easily linked.

[0124] Furthermore, the second back pressure space S3' is a space separated from the first back pressure space S3. Refrigerant flowing from the high-pressure space S2 into the first back pressure space S3 temporarily flows into the back pressure chamber 50, and from the back pressure chamber 50 into the second back pressure space S3', it flows into the low-pressure space S1. In this way, the back pressure control valve V1 can prevent the ejected fluid Pd from directly flowing into the low-pressure space S1, thus preventing a decrease in the operating efficiency of the refrigeration cycle.

[0125] Furthermore, the first back pressure space S3 and the second back pressure space S3' are sealed by an O-ring 69, thus more reliably preventing the ejected fluid Pd from flowing directly into the low pressure space S1.

[0126] Furthermore, the effective cross-sectional areas A1 and C1 are larger than the effective cross-sectional area B1, thus increasing the influence of the control fluid Pb and the intake fluid Ps compared to the ejected fluid Pd.

[0127] Furthermore, the back pressure control valve V1 has a high-pressure space S2 between the first back pressure space S3 and the second back pressure space S3', and a low-pressure space S1 is provided on the side opposite to the high-pressure space S2, separated by the second back pressure space S3'. A rod 61 is inserted through the first back pressure space S3 into the low-pressure space S1.

[0128] Therefore, the effective pressure-bearing area (A1-B1) of the ejected fluid Pd can be reduced by utilizing the effective cross-sectional area B1, thus making it easy to make the influence of the control fluid Pb and the suction fluid Ps greater than that of the ejected fluid Pd.

[0129] Furthermore, the first valve core 72 is located at the end of the rod 61, thus enabling the pressure of the control fluid Pb to act on the entire area of ​​the effective cross-sectional area A1.

[0130] Furthermore, the second valve core 77 is located at the end of the rod 61, thus enabling the pressure of the suction fluid Ps to act on the entire area of ​​the effective cross-sectional area C1.

[0131] Furthermore, the housing 60 has a first valve seat 71 and a second valve seat 76. That is, the opening adjustment of the first passage 73 and the second passage 78 is a so-called lift-type. As a result, the back pressure control valve V1 can reliably close the first passage 73 and the second passage 78, thus enabling smoother changes in the pressure of the control fluid Pb.

[0132] Furthermore, the back pressure control valve V1 has a first valve core 72 and a second valve core 77 at both ends of the axial direction of the rod 61, so they can function as stop elements to each other, thus making the maximum opening of the first passage 73 and the second passage 78 approximately constant.

[0133] Furthermore, the back pressure control valve V1 functions to increase the force (F) of the coil spring 62. sp Press rod 61 axially to the left. In other words, the force (F) of the coil spring 62... sp This acts in the opening direction of DB valve 70 and in the closing direction of BS valve 75. That is, in this embodiment, DB valve 70 is normally open and BS valve 75 is normally closed.

[0134] Therefore, even if the scroll compressor C is stopped for a long time, and the pressures of the suction fluid Ps, discharge fluid Pd, and control fluid Pb are roughly equal, the back pressure control valve V1 can still appropriately maintain the opening of the first passage 73 and close the second passage 78 when the scroll compressor C starts, thus enabling the control fluid Pb to rise rapidly. This allows the pressure of the control fluid Pb to be adjusted quickly when the scroll compressor C starts.

[0135] Furthermore, in the housing 60, the second segment 64 is press-fitted and fixed to the first segment 63, and the press-fit amount can be varied within the range of the press-fit allowance. Therefore, not only can the force of the helical spring 62 be adjusted, but also the axial length of the housing 60 can be adjusted. Alternatively, the fixation between the first segment 63 and the second segment 64 can be either press-fitted or screwed together.

[0136] Furthermore, in rod 61, base member 67 is press-fitted and fixed to annular member 6, allowing the press-fit amount to be variable within the press-fit allowance range. Therefore, the stroke of rod 61 can be adjusted, in other words, the maximum opening of DB valve 70 and BS valve 75 can be adjusted. Additionally, the fixing of annular member 68 and base member 67 can also be achieved through screwing, bonding, or thermoforming, and can be modified as appropriate.

[0137] Example 2

[0138] Next, refer to Figure 3 The valve of Example 2 will be described. Furthermore, repeated structural descriptions identical to those in the aforementioned examples will be omitted.

[0139] like Figure 3 As shown, the back pressure control valve V2 in this embodiment 2 is mainly composed of a housing 160, a rod 161, and a helical spring 62.

[0140] The housing 160 is composed of a first segment 63, a second segment 164, a third segment 165, and a cover component 169.

[0141] In the second segment 164, the diameter of the same diameter portion 164n extending axially with approximately the same diameter in the inner peripheral surface that divides the second back pressure space S13' is approximately the same as or slightly larger than the effective cross-sectional area C1 of the second valve core portion 177.

[0142] In the third segment 165, the diameter of the same diameter portion 165d extending axially with approximately the same diameter in the inner peripheral surface of the first valve hole 165c is approximately the same as or slightly larger than the effective cross-sectional area A1 of the first valve core portion 172.

[0143] A cover member 169 is screwed onto the inner circumferential surface of the opening at the left end of the third segment 165. The space enclosed by the third segment 165 and the cover member 169 is the first back pressure space S13. Alternatively, the cover member 169 can be fixed to the third segment 165 by various fixing means other than screwing, but preferably, its axial position can be adjusted.

[0144] The cover component 169 has an axially extending through-hole 169a formed on its outer diameter side. The through-hole 169a communicates with the first back pressure space S13 and the back pressure chamber 50.

[0145] The rod 161, which serves as the valve core, is composed of a base 167 and an annular component 168.

[0146] The base member 167 is formed as a stepped cylindrical part having, from the left side of the axial direction, a small-diameter main body 167a as a connecting part, a left large-diameter main body 167b as a connecting part, a second valve core 177, and a right large-diameter main body 167c.

[0147] The small-diameter main body 167a is formed into a cylindrical shape extending axially. The left end of the small-diameter main body 167a is pressed and fixed to the annular member 168. The left end of the small-diameter main body 167a and the annular member 168 constitute the first valve core 172.

[0148] The left large-diameter main body 167b is formed as a cylinder that extends axially to the right from the right end of the small-diameter main body 167a, expanding outwards and extending axially to the right with approximately the same diameter. The maximum cross-sectional area of ​​the left large-diameter main body 167b is the effective cross-sectional area B1.

[0149] The second valve core 177 is formed as a cylinder extending from the right end of the large-diameter main body 167b on the left side toward the right side of the axial direction with approximately the same diameter. The cross-sectional area of ​​the second valve core 177 is the effective cross-sectional area C1.

[0150] The outer peripheral surface of the second valve core 177 and the same diameter portion 164n of the second segment 164 of the housing 160 are smooth surfaces with the same diameter throughout the entire axial range, and the two surfaces can slide relative to each other.

[0151] In the second passage 178, the more the rod 161 moves to the left and the area of ​​radial overlap between the second valve core 177 and the portion 164n of the same diameter increases, the smaller the opening; conversely, the more the rod 161 moves to the right and the area of ​​radial overlap decreases, the larger the opening of the first passage 173. That is, the opening adjustment of the second passage 178 is a so-called spool valve type.

[0152] The right-side large-diameter main body portion 167c is formed as a cylinder extending from the right end of the second valve core portion 177 toward the axial right with approximately the same diameter, and then narrowing toward the axial right. The maximum cross-sectional area of ​​the right-side large-diameter main body portion 167c is the effective cross-sectional area B1.

[0153] The annular component 168 extends axially to the right with approximately the same diameter. The cross-sectional area of ​​the first valve core 172 is an effective cross-sectional area A1 that is approximately the same as the sum of the cross-sectional areas of the annular component 168 and the small-diameter main body 167a.

[0154] The outer peripheral surface of the first valve core 172 and the same diameter portion 165d of the third segment 166 of the housing 160 are smooth surfaces with the same diameter throughout the entire axial range, and the two surfaces can slide relative to each other.

[0155] In the first passage 173, the more the rod 161 moves to the right and the area of ​​radial overlap between the first valve core 172 and the portion 165d of the same diameter increases, the smaller the opening; conversely, the more the rod 161 moves to the left and the area of ​​radial overlap decreases, the larger the opening of the first passage 173. That is, the opening adjustment of the first passage 173 is a so-called spool valve type.

[0156] The movement of rod 161 to the leftward is restricted by its contact with the cover member 169 via the small-diameter main body 167a. At this time, the opening of the first passage 173 is at its maximum, and the opening of the second passage 178 is at its minimum and closed.

[0157] Furthermore, by adjusting the axial position of the cover component 169, the maximum opening of the first passage 173 can be varied.

[0158] Furthermore, the movement of rod 161 to the rightward is restricted by the contact between the right-side large-diameter main body portion 167c and the protrusion 63d in the housing 160. At this time, the opening of the second passage 178 is at its maximum, and the opening of the first passage 173 is at its minimum and closed.

[0159] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the specific structure is not limited to these embodiments, and changes and additions that do not depart from the spirit of the present invention are also included in the present invention.

[0160] For example, in the aforementioned embodiments 1 and 2, a structure in which the first valve core and the second valve core are connected by a connecting part and thus integrated is described. However, this is not a limitation; the first valve core and the second valve core may not be connected by a connecting part, but may be separately configured. For example, the structure may be as follows: the first valve core and the second valve core may be moved together by pressing against each other using an elastic member that presses the first valve core towards the second valve core and a force-applying unit that presses the second valve core towards the first valve core. Furthermore, as long as the first valve core and the second valve core can move in opposite directions in the valve opening and valve closing directions in conjunction with the pressure difference, they may also be separately configured in a non-contact position, both directly and indirectly.

[0161] Furthermore, in the aforementioned embodiments 1 and 2, the case where the rod is composed of a base member and an annular member was described, but it is not limited to this, and it may also be composed of a base member and two annular members.

[0162] Furthermore, in the aforementioned embodiments 1 and 2, the situation in which the first and second pathways can be closed was described, but it is not limited thereto, and a structure in which the first and second pathways are not closed can also be adopted.

[0163] Furthermore, in the aforementioned embodiments 1 and 2, the first valve core and the second valve core were described as functioning as stop members that restrict the movement of the valve core, but this is not the only case. Stop members that restrict the movement of the valve core may be provided separately from the first valve core and the second valve core.

[0164] Furthermore, in the aforementioned embodiments 1 and 2, the structure of the force-applying unit being a helical spring was described, but it is not limited to this; it can also be a helical wave spring, a leaf spring, or an air spring, and can be modified appropriately. As an example of an air spring, a pressure-sensitive body such as a bellows sealed with a gas such as nitrogen can be configured.

[0165] Furthermore, in the aforementioned embodiments 1 and 2, the structure in which the force-applying unit functions as a pressing spring was described, but it is not limited to this and can also be a tension spring. If the force-applying unit is a tension spring, the force-applying unit can be disposed in the first back pressure space.

[0166] Furthermore, in the aforementioned embodiments 1 and 2, it was described that the direction in which the force-applying unit applies force to the valve core is the opening direction of the DB valve and the closing direction of the BS valve. However, this is not limited to this; it could also be the closing direction of the DB valve and the opening direction of the BS valve. That is, regarding the valves, the DB valve could be normally closed and the BS valve normally open. With such a structure, it is easier to prevent excessive pressure rise of the back pressure fluid.

[0167] Furthermore, in the aforementioned embodiments 1 and 2, the structure of the back pressure control valve having a first back pressure space, a high pressure space, a second back pressure space, and a low pressure space arranged sequentially from the left side was described, but it is not limited to this. It is also possible to have a structure with a high pressure space, a first back pressure space, a low pressure space, and a second back pressure space arranged sequentially from the left side, or a structure with a high pressure space, a back pressure space, and a low pressure space arranged sequentially from the left side. It can be modified appropriately.

[0168] Furthermore, in the aforementioned embodiments 1 and 2, the effective cross-sectional areas A of the first valve core and C of the second valve core were described as being larger than the effective cross-sectional area B of the connecting portion. However, this is not a limitation and can be appropriately modified. For example, if the structure consists of a high-pressure space, a first back-pressure space, a low-pressure space, and a second back-pressure space arranged sequentially from the left side, then the effective cross-sectional area A of the first valve core is made smaller than the effective cross-sectional areas B of the connecting portion and C of the second valve core. This allows the influence of the back-pressure fluid and the low-pressure fluid to be greater than the influence of the high-pressure fluid.

[0169] Furthermore, in the aforementioned embodiments 1 and 2, the case where the sealing unit is an O-ring was described, but it is not limited to this. As long as it can seal between the high-pressure space and the low-pressure space, it can also be a lip packing seal, a gland packing seal, a labyrinth seal, etc., and can be modified appropriately.

[0170] Furthermore, while the aforementioned embodiments 1 and 2 described the case where the helical spring abuts against the second valve core, the configuration is not limited to this. It is also possible to configure the valve core separately from the second valve core, with a bearing member separately provided for the force exerted by the helical spring. With such a structure, the force of the helical spring can be varied by adjusting the position of the bearing member.

[0171] Furthermore, in the aforementioned embodiments 1 and 2, the back pressure connection was described in the case where only a back pressure connection equipped with a valve was provided, but it is not limited to this. A back pressure connection that connects the high-pressure chamber and the back pressure chamber can also be provided separately. Throttling orifices and valves can also be provided on the separately provided back pressure connection.

[0172] Furthermore, in the aforementioned embodiments 1 and 2, the description focused on the case where only a pressure relief port connecting the valve to the low-pressure chamber was provided. However, this is not the only possibility; a pressure relief port connecting the back-pressure chamber to the low-pressure chamber may also be provided. A throttling orifice or valve may also be provided at the additional pressure relief port.

[0173] Furthermore, in the aforementioned embodiments 1 and 2, the valve of the scroll compressor used in the air conditioning system of automobiles, etc., was described, but it is not limited thereto; the valve can also be used to control various working fluids.

[0174] Furthermore, in the aforementioned embodiments 1 and 2, examples of back pressure control valves were described, but for example, it could also be an expansion valve configured between the condenser and evaporator in an air conditioning system, or a capacity control valve assembled in a variable capacity compressor in an air conditioning system.

[0175] Furthermore, the intake fluid, the ejection fluid, and the control fluid can be any of the following states: gas, liquid, or a mixture of gas and liquid.

[0176] Label Explanation

[0177] 60: Housing; 61: Rod (valve core); 62: Helical spring (force application unit); 67a: Shaft (connecting part); 69: O-ring (sealing unit); 70: DB valve; 71: First valve seat; 72: First valve core; 73: First passage; 75: BS valve; 76: Second valve seat; 77: Second valve core; 78: Second passage; 160: Housing; 161: Rod (valve core); 167a: Small diameter main body ( 167b: Left large-diameter main body (connecting part); 172: First valve core; 173: First passage; 177: Second valve core; 178: Second passage; A1: Effective cross-sectional area; B1: Effective cross-sectional area; C1: Effective cross-sectional area; S1: Low-pressure space; S2: High-pressure space; S3, S13: First back pressure space; S3', S13': Second back pressure space; V1, V2: Back pressure control valve.

Claims

1. A valve having: A housing having a high-pressure space for the inflow of high-pressure fluid, a back-pressure space for the inflow of back-pressure fluid, and a low-pressure space for the inflow of low-pressure fluid; and The valve core is disposed in the housing in a manner that allows it to move relatively. in, The housing has a first passage disposed between the high-pressure space and the back-pressure space, and a second passage disposed between the back-pressure space and the low-pressure space. The valve core has a first valve core portion for controlling the opening degree of the first passage and a second valve core portion for controlling the opening degree of the second passage. The first valve core and the second valve core are linked together in opposite directions of movement in the opening and closing directions, respectively.

2. The valve according to claim 1, wherein, The back pressure space is a first back pressure space that can be connected to the first passage and a second back pressure space that can be connected to the second passage and is separated from the first back pressure space.

3. The valve according to claim 1, wherein, The valve core has a connecting portion that connects the first valve core portion and the second valve core portion.

4. The valve according to claim 3, wherein, The housing and the connecting part are sealed.

5. The valve according to claim 3, wherein, The valve has a force-applying unit that applies force to the valve core in one direction. The valve is configured to accommodate the pressure Pd of the high-pressure fluid, the pressure Pb of the back-pressure fluid, the pressure Ps of the low-pressure fluid, the effective cross-sectional area A of the first valve core, the effective cross-sectional area B of the connecting portion, the effective cross-sectional area C of the second valve core, and the force F of the force-applying unit. sp It satisfies the following mathematical expression 1: 【Mathematical Formula 1】 。 6. The valve according to claim 5, wherein, The effective cross-sectional area A and the effective cross-sectional area C are larger than the effective cross-sectional area B.

7. The valve according to any one of claims 1 to 6, wherein, The housing has a first valve seat disposed in the first passage and a second valve seat disposed in the second passage.

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