Electrically Driven Valve

Abstract

To prevent a torsional load from being applied to a sealing material when it is attached to a flow path block, to improve reliability of a seal between the flow path block and a valve body.SOLUTION: An electric drive valve 11 comprises: a valve body 12 having a valve chamber 13, a first flow path hole 14, and a second flow path hole 15; a valve element 18 that moves toward and away from a valve seat 17; and a drive device 23 that drives the valve element. The valve body has: a flange part 12c that protrudes outward from an outer peripheral surface; a lower body 12b that is a portion below the flange part; and an upper body 12a that is a portion above the lower body. A sealing material 21 is provided on a lower surface of the flange part. A ring-shaped press screw 45 is provided around the upper body above the flange part to press the flange part downward.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electrically driven valve, and more particularly to a seal structure between a valve body and a flow path block of a cartridge-type electrically driven valve. [Background technology]

[0002] Electric valves and solenoid valves (collectively referred to as "electrically driven valves" in this application) that use an electrically driven device such as an electric motor or an electromagnetic actuator to open and close a refrigerant flow path or control the refrigerant flow rate have traditionally been used in refrigeration cycle devices equipped with a refrigerant circuit, such as air conditioners, refrigerators, and refrigeration devices.

[0003] Another example of such an electrically driven valve (hereinafter, an explanation will be given using a motor-operated valve as an example) is a cartridge-type motor-operated valve. As shown in FIG. 5 , this allows the motor-operated valve (valve body 53) to be incorporated into a refrigerant circuit simply by screwing the motor-operated valve into a valve mounting hole 52 of a flow path block 51, which has a refrigerant inlet path 42 and an outlet path 43. The valve mounting hole 52 has a female thread 52a on its inner circumferential surface, and the valve body 53 has a male thread 53a on its outer circumferential surface that engages with the female thread 52a. The valve body 53 also has a valve chamber 13, an inlet hole 14 that communicates with the inlet path 42 and allows the refrigerant to flow into the valve chamber 13, and an outlet hole 15 that communicates with the outlet path 43 and allows the refrigerant to flow out of the valve chamber 13. The valve body 53 includes a valve element 18 that is driven by an electric motor (not shown) and moves back and forth relative to a valve seat 17 (valve seat member 16) provided in the outlet hole 15, thereby controlling the flow rate of the refrigerant.

[0004] With this cartridge-type motor-operated valve, for example, when a manufacturer of the motor-operated valve (referred to as the "valve manufacturer") provides the motor-operated valve to a customer, a manufacturer of a refrigeration cycle device, the valve manufacturer and the customer can share specifications such as the external size of the valve body 53 and the positions of the inlet hole 14 (inlet passage 42) and the outlet hole 15 (outlet passage 43) in advance, and the customer can manufacture the flow path block 51 as part of the refrigeration cycle device. The customer can then simply screw the motor-operated valve into the flow path block 51 to complete the refrigeration cycle device. This allows the customer to efficiently manufacture refrigeration cycle devices. Furthermore, if the motor-operated valve needs to be replaced during maintenance of the refrigeration cycle device, the replacement can be performed with the same simple operation.

[0005] Furthermore, the following Patent Document 1 is a document that discloses such a cartridge-type motor-operated valve. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-149505 Summary of the Invention [Problem to be solved by the invention]

[0007] Incidentally, a cartridge-type motor-operated valve requires a seal structure to prevent refrigerant from leaking to the outside between the motor-operated valve (valve body 53) screwed into the valve mounting hole 52 of the flow path block 51 and the flow path block 51. Conventionally, this seal structure has been configured such that a flange portion 54 extending outward from the valve mounting hole 52 is formed on the upper end of the valve body 53 (see FIG. 5), and when the motor-operated valve is screwed into the valve mounting hole 52 to mount it, a seal material (gasket) 55 is sandwiched between the flange portion 54 and the upper surface of the flow path block 51 (around the valve mounting hole 52).

[0008] However, the conventional sealing structure has room for improvement in terms of reliability. Specifically, in the conventional structure, when the motor-operated valve is screwed in and tightened, the rotating motor-operated valve drags the gasket 55, applying a torsional load. Therefore, if the gasket 55 is deformed or damaged, the sealing performance may be reduced, and refrigerant leakage may occur.

[0009] In particular, in recent years, the use of CO2 refrigerants, which have high operating pressures, has been promoted in refrigeration cycle devices from the perspectives of improving safety and reducing environmental impact. Therefore, there is a need for a more reliable sealing structure that prevents refrigerant leakage even with such high-pressure refrigerants.

[0010] SUMMARY OF THE INVENTION Therefore, an object of the present invention is to improve the reliability of the seal between the valve body and the flow path block. [Means for solving the problem]

[0011] In order to solve the above problems and achieve the object, the electrically driven valve of the present invention is an electrically driven valve comprising: a valve body having a valve chamber, a first passage hole communicating with the valve chamber and serving as either an inlet or outlet hole for the refrigerant, and a second passage hole communicating with the valve chamber and serving as the other of the inlet and outlet holes for the refrigerant; a valve element that moves toward and backward relative to a valve seat formed in the valve chamber; and a drive device that drives the valve element, wherein the valve body has a flange portion that protrudes outward from the outer peripheral surface of the valve body, a lower body that is the portion below the flange portion, and an upper body that is the portion above the lower body, and a sealing material is provided on the underside of the flange portion, and a ring-shaped press screw is provided around the upper body that is above the flange portion and presses the flange portion downward.

[0012] In this application, the direction from the valve seat toward the actuator is defined as "up," and the direction from the actuator toward the valve seat is defined as "down," and based on this concept of "up" and "down," terms related to up and down, such as "upper" and "lower," "upper surface" and "lower surface," "upper side" and "lower side," are used. Note that, because the electrically driven valve of the present invention can be used in various orientations, "down" does not necessarily mean the direction of gravity and "up" does not necessarily mean the direction opposite to gravity.

[0013] The electrically driven valve according to the present invention is a cartridge-type electrically driven valve that is mounted on a flow path block.

[0014] The flow path block includes a valve mounting hole capable of receiving an electrically driven valve, a first flow path that opens to the inner surface of the valve mounting hole and serves as either an inflow path or an outflow path for the refrigerant, and a second flow path that opens to the inner surface of the valve mounting hole and serves as the other of the inflow path and an outflow path for the refrigerant.

[0015] The valve mounting hole has an upper hole portion with a large inner diameter that has a female thread formed on its inner surface and extends from the top surface of the flow path block to the bottom surface, a lower hole portion with a small inner diameter that continues from the upper hole portion toward the bottom surface of the flow path block, and a ring-shaped step portion formed between the upper hole portion and the lower hole portion.

[0016] The first and second flow passage holes are formed in the lower main body. When the electrically driven valve is mounted in the valve mounting hole, the lower main body is fitted into the lower hole, the first flow passage hole communicates with the first flow passage, the second flow passage hole communicates with the second flow passage, and a ring-shaped gap is formed between the outer circumferential surface of the upper main body and the inner circumferential surface of the upper hole, and the cap screw is accommodated in this gap. The cap screw has a male thread on its outer circumferential surface that screws into the female thread formed in the valve mounting hole. When screwed into the gap, it presses the flange portion downward, thereby sandwiching a sealing material between the flange portion and the stepped portion. The sealing material may include a metal plate and sealing material layers made of rubber or resin provided on the upper and lower surfaces of the metal plate.

[0017] To install the electrically driven valve according to the present invention in a flow path block, the valve body is inserted into the valve mounting hole of the flow path block, and then the cap screw is threaded into the clearance space while engaging with the female thread of the valve mounting hole, and then tightened. This screwing operation causes the cap screw to advance downward within the upper hole (clearance space) and abut against the upper surface of the flange, and then press the flange downward toward the stepped portion. Therefore, the seal material provided on the underside of the flange is sandwiched between the flange and the stepped portion, achieving a seal between the valve body and the flow path block.

[0018] Furthermore, when screwing in the above-mentioned pressure screw, instead of screwing in the valve body as in the past, the pressure screw, which is a separate part from the valve body (flange portion) and is attached to the surface opposite the sealing material (the upper surface of the flange portion), is rotated to press the flange portion linearly downward (without rotation), so the sealing material is not subjected to torsional load (or even if the valve body rotates in response to the rotation of the pressure screw, the rotation is slight and the torsional load on the sealing material is very small), and the sealing material can be prevented from being deformed or damaged.

[0019] It is advisable to apply a lubricant (such as grease or oil) between the cap screw and the flange during the above procedure to prevent the cap screw and flange from rotating together when screwing in, especially during the tightening operation, and to prevent the rotation of the cap screw from being transmitted to the sealing material via the flange. [Effects of the Invention]

[0020] According to the electrically driven valve of the present invention, no (or almost no) torsional load is applied to the sealing material when it is attached to the flow path block, thereby improving the reliability of the seal between the valve body and the flow path block.

[0021] Other objects, features, and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments of the present invention, which is given with reference to the accompanying drawings. In the drawings, the same reference numerals indicate the same or corresponding parts. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a vertical cross-sectional view showing an electrically driven valve (closed state) according to one embodiment of the present invention. [Figure 2] FIG. 2 is a vertical cross-sectional view showing the electrically driven valve (open state) according to the embodiment. [Figure 3] FIG. 3 is an enlarged longitudinal sectional view showing a main part (portion B in FIG. 1) of the electrically driven valve according to the embodiment. [Figure 4] FIG. 4 is an enlarged longitudinal cross-sectional view of a portion (portion C in FIG. 3) where a gasket is installed in the electrically driven valve according to the embodiment. [Figure 5] FIG. 5 is a longitudinal sectional view similar to FIG. 3, showing a main part (corresponding to part B in FIG. 1) of a conventional electrically driven valve. DETAILED DESCRIPTION OF THE INVENTION

[0023] An electrically driven valve according to one embodiment of the present invention will be described with reference to Figures 1 to 4. Note that in each figure, two-dimensional coordinates representing the up-down and left-right directions, which are orthogonal to each other, are appropriately displayed, and the following description will be based on these directions. However, the electrically driven valve of this invention and this embodiment can be used in various orientations, and the directions are used for the sake of convenience in the description, and the configuration of each part of the present invention is in no way limited by these directions. Furthermore, although the terms "vertical" and "horizontal" are used, the vertical direction coincides with the up-down direction, and the direction perpendicular to the vertical direction is the horizontal direction, which includes the left-right direction.

[0024] As shown in Figures 1 to 4, the electrically driven valve 11 according to this embodiment is a so-called cartridge-type motor-operated valve that is incorporated into a refrigeration cycle device, such as a heat pump type heating and cooling system, by being attached to a flow path block 37 provided in the refrigeration cycle device to control the flow rate of the refrigerant.

[0025] Describing each part in detail, the flow path block 37 has a valve mounting hole 38 into which the motor-operated valve 11 can be fitted, an inlet channel 42 that penetrates horizontally through the side wall of the flow path block 37 and opens onto the side surface (inner peripheral surface) of the valve mounting hole 38, and an outlet channel 43 that penetrates vertically through the bottom surface of the flow path block 37 and opens onto the bottom surface of the valve mounting hole 38. The valve mounting hole 38 consists of an upper hole portion 39 that includes an opening (referred to as the "top surface opening") on the top surface (upper surface) of the flow path block 37, and a lower hole portion 40 that extends downward from the upper hole portion 39. The lower hole portion 40 has a smaller inner diameter than the upper hole portion 39, and as a result, a ring-shaped step portion 41 is formed between the upper hole portion 39 and the lower hole portion 40.

[0026] On the other hand, the motor-operated valve 11 has a valve body 12 having a valve chamber 13 therein, a valve element 18 that is provided inside the valve chamber 13 so as to be able to move up and down, an electric motor 23 that drives the valve element 18, a speed reduction mechanism 30 that reduces the rotation generated by the electric motor 23, a transmission mechanism (feed screw mechanism) 32 that converts the rotation reduced by the speed reduction mechanism 30 into linear motion and transmits it to the valve element, and a can (sealed container) 19 that forms an airtight space on the upper surface of the valve body 12.

[0027] The valve body 12 is a cylindrical member having a ring-shaped flange portion 12c that protrudes horizontally outward from the outer circumferential surface, a lower body 12b that is the portion below the flange portion 12c, and an upper body 12a that is the portion above the lower body 12b.

[0028] A gasket 21 is provided on the underside of the flange portion 12c, and when the valve body 12 is inserted into the valve mounting hole 38 to mount the motor-operated valve 11 on the flow path block 37, the flange portion 12c abuts against the step portion 41 via the gasket 21. At this time, the lower body 12b is fitted into the lower hole portion 40 of the valve mounting hole 38. Furthermore, the lower end of the upper body 12a is disposed in the upper hole portion 39 of the valve mounting hole 38, and the upper portion protrudes upward from the top opening (the upper surface of the flow path block 37).

[0029] With the valve body 12 inserted into the valve mounting hole 38, a ring-shaped clearance space 44 is formed between the outer peripheral surface of the upper body 12a and the inner peripheral surface of the upper hole portion 39. This clearance space 44 is a space for threading in a press screw 45 that fastens and fixes the valve body 12 to the flow path block 37. The press screw 45 is a cylindrical (ring-shaped) screw with a male thread 45a on its outer peripheral surface that screws into a female thread 39a formed on the inner peripheral surface of the upper hole portion 39. To fix the motor-operated valve 11 to the flow path block 37, after inserting the valve body 12 into the valve mounting hole 38, the press screw 45 is screwed into the upper hole portion 39 while threading into the female thread 39a. The screwed-in press screw 45 presses the flange portion 12c against the stepped portion 41, preventing the valve body 12 (motor-operated valve 11) from slipping out of the valve mounting hole 38. In this fixed state, the gasket 21 provided on the lower surface of the flange portion 12c is sandwiched between the step portion 41, thereby realizing a seal between the valve body 12 and the flow path block 37.

[0030] As shown enlarged in FIG. 4, the gasket 21 is provided with sealing material layers 21b made of a sealing material such as rubber on the upper and lower surfaces of the metal plate 21a.

[0031] Furthermore, when the cap screw 45 is screwed in, the flange portion 12c and gasket 21 are pressed downward by the cap screw 45 without rotating and are pressed against the stepped portion 41, so the gasket 21 is not twisted as in the conventional structure, and deformation or damage to the gasket 21 can be prevented. This improves the reliability of the seal provided by the gasket 21. Furthermore, even if the cap screw 45 is tightened, the flange portion 12c protruding outward from the outer peripheral surface of the valve body 12 is simply clamped between the cap screw 45 and the stepped portion 41. Therefore, unlike the conventional structure in which the valve body 53 is screwed in, a torsional load is not applied to the entire valve body 12, causing distortion.

[0032] The valve chamber 13, inlet hole 14, and outlet hole 15 are formed in the lower main body 12b. Specifically, the valve chamber 13 is formed in the interior center of the lower main body 12b. The inlet hole 14 penetrates horizontally through the side surface of the lower main body 12b and opens to the side surface (inner peripheral surface) of the valve chamber 13, and communicates with the inlet channel 42 when the valve main body 12 is attached to the valve attachment hole 38. The outlet hole 15 penetrates vertically through the bottom surface of the lower main body 12b and opens to the bottom surface of the valve chamber 13, and communicates with the outlet channel 43 when the valve main body 12 is attached to the valve attachment hole 38.

[0033] A cylindrical valve seat member 16 is fixed to the outflow hole 15. The valve seat member 16 has a valve seat 17 on its upper surface. A valve element 18 moves back and forth (up and down) relative to the valve seat 17, thereby controlling the flow rate of the refrigerant. A through-hole 12d in the upper part of the lower body 12b (the upper surface of the valve chamber 13) serves as a valve element guide hole that supports the valve element 18 so that it can slide up and down.

[0034] In addition, in order to prevent the refrigerant from leaking short-circuiting from the inlet hole 14 (inlet path 42) to the outlet hole 15 (outlet path 43), the outer surface of the lower end of the lower main body 12b is provided with a sealing material (O-ring) 22 interposed between it and the inner surface of the pilot hole portion 40 of the flow path block 37.

[0035] A reduced-diameter section 12e, which has a constant inner diameter but a reduced outer diameter, is formed at the upper end of the upper valve body 12a. A step is provided on the outer circumferential surface of the reduced-diameter section 12e, and a can 19 is welded and fixed to this step via a ring-shaped base member 20. The can 19 is a cylindrical metal container with a bottom and no lid (the bottom is open and the top is closed), and its interior forms an airtight space that communicates with the valve chamber 13. A rotor 25 that constitutes an electric motor 23 is rotatably housed inside the can 19.

[0036] In this embodiment, a stepping motor is used as the electric motor 23. This stepping motor 23 is made up of the rotor 25 housed in the can 19 and a stator 24 installed on the outside (outer periphery) of the can 19. The stator 24 includes a yoke 26, a coil 28 wound around a bobbin 27, and a resin molded cover 29 that covers the yoke 26 and the coil 28.

[0037] The rotor 25 is provided with the reduction mechanism 30, which reduces the rotation speed of the rotor 25. In this embodiment, the reduction mechanism 30 is a paradox planetary gear reduction mechanism, which is small and provides a large reduction ratio. The rotation reduced by the reduction mechanism 30 is output from an output gear 31.

[0038] The upper end of a valve element drive shaft 33 is connected to the output gear 31. The valve element drive shaft 33 constitutes the transmission mechanism 32, which converts the rotation slowed down by the speed reduction mechanism (paradox planetary gear reduction mechanism) 30 into linear motion and transmits it to the valve element 18.

[0039] That is, the valve element drive shaft 33 is disposed so as to extend vertically along the central axis A of the motor-operated valve 11, and is rotatably supported by a cylindrical bearing member 34 fitted into the upper part of the valve body 12 (upper body 12a). The lower end of the valve element drive shaft 33 is inserted into the upper end of the valve element 18, and a male thread 35 is formed on the outer circumferential surface. Meanwhile, a female thread 36 that screws into the male thread 35 is formed on the inner circumferential surface of the upper end of the valve element 18 into which the valve element drive shaft 33 is inserted. These male thread 35 and female thread 36 constitute a feed screw, and when the valve element drive shaft 33 connected to the output gear 31 rotates, the valve element 18 moves upward or downward due to the function of the feed screw.

[0040] In this embodiment, the central axis A of the valve body 12, valve seat member 16, valve seat 17, valve element 18, valve element drive shaft 33, and bearing member 34, as well as the rotation axis of the rotor 25, extend in the vertical direction and coincide with one another.

[0041] The operation of the motor-operated valve 11 according to this embodiment will be described as follows.

[0042] When current is supplied to the stator 24 (coil 28) so that the rotor 25 rotates in one direction from the closed valve state shown in FIG. 1, the rotation of the rotor 25 is decelerated by the reduction mechanism 30 and output from the output gear 31, rotating the valve element drive shaft 33. The rotation of the valve element drive shaft 33 is converted into linear motion by a feed screw, i.e., a male thread 35 provided on the valve element drive shaft 33 and a female thread 36 provided on the valve element 18, causing the valve element 18 to move upward. As a result, the valve element 18 separates from the valve seat 17, and the refrigerant that has flowed into the valve chamber 13 through the inlet passage 42 and the inlet hole 14 flows out of the outlet passage 43 through the outlet hole 15 (see arrow F in FIG. 2). Note that the amount of refrigerant passing through (refrigerant flow rate) in this open valve state can be adjusted by the amount of rotation of the rotor 25 (the distance between the valve seat 17 and the valve element 18).

[0043] On the other hand, when current is supplied to the stator 24 (coil 28) so that the rotor 25 rotates in the opposite direction from the open valve state, the rotation of the rotor 25 is decelerated and output from the output gear 31, causing the valve element drive shaft 33 to rotate in the opposite direction. This rotation of the valve element drive shaft 33 is converted into linear motion by the feed screw (external thread 35 and internal thread 36), causing the valve element 18 to move downward. When the valve element 18 then seats (contacts) on the valve seat 17, the flow path between the inlet channel 42 and inlet hole 14 and the outlet hole 15 and outlet channel 43 is blocked, resulting in a closed valve state (see FIG. 1).

[0044] In the above operation description, the refrigerant flows in through the inlet passage 42 and the inlet hole 14 and flows out through the outlet hole 15 and the outlet passage 43. However, it is also possible to use the electric valve 11 in the opposite manner, so that the refrigerant flows in through the outlet passage 43 and the outlet hole 15 and flows out through the inlet hole 14 and the inlet passage 42.

[0045] Although the embodiments of the present invention have been described above, the present invention is not limited to these, and it will be apparent to those skilled in the art that various modifications can be made within the scope of the claims.

[0046] For example, in the above embodiment, the valve element is driven by an electric motor, but it is also possible to configure a solenoid valve based on the present invention in which the valve element is driven by an electromagnetic actuator. [Explanation of symbols]

[0047] A Central axis (rotor axis) F Refrigerant flow 11 Electrically operated valve (electrically driven valve) 12,53 Valve body 12a Upper body 12b Lower body 12c,54 Flange 12d Through hole (valve body guide hole) 12e Reduced diameter part 13 Valve chamber 14 Inflow hole 15 Outflow hole 16 Valve seat member 17 Valve seat 18 Valve body 19 Can 20 Base member 21,55 Gasket (sealing material) 21a metal plate 21b sealing material layer 22 Sealing material (O-ring) 23 Electric motor (stepping motor) 24 Stator 25 rotors 26 York 27 Bobbin 28 coils 29 Resin mold cover 30 Reduction mechanism (paradoxical planetary gear reduction mechanism) 31 Output gear 32 Transmission Mechanism 33 Valve body drive shaft 34 Bearing material 35 Male thread 36 Female thread 37,51 Flow path block 38,52 Valve mounting hole 39 Upper hole part 39a, 52a female thread 40 pilot hole 41 Step 42 Inflow channel 43 Outflow channel 44 Interstitial Space 45 Cap screw 45a, 53a male thread

Claims

1. a valve body having a valve chamber, a first passage hole communicating with the valve chamber and serving as either an inlet or outlet hole for the refrigerant, and a second passage hole communicating with the valve chamber and serving as the other of the inlet or outlet hole for the refrigerant; a valve body that moves toward and away from a valve seat formed in the valve chamber; a drive device that drives the valve body; Equipped with A cartridge-type electrically driven valve attached to a flow path block, The flow path block includes: a valve mounting hole capable of receiving the electrically driven valve; a first flow path that opens to an inner surface of the valve mounting hole and serves as either an inflow path or an outflow path for a refrigerant; a second flow path that opens to an inner surface of the valve mounting hole and serves as the other of the inflow path and outflow path of the refrigerant; Equipped with The valve mounting hole is an upper hole portion having a large inner diameter and having a female thread formed on an inner peripheral surface thereof and extending from a top surface of the flow path block toward a bottom surface thereof; a lower hole portion having a smaller inner diameter and extending further from the upper hole portion toward a bottom surface of the flow path block; a step portion extending in a ring shape formed between the upper hole portion and the lower hole portion; and When the direction from the valve seat to the drive unit is defined as "up" and the direction from the drive unit to the valve seat is defined as "down," The valve body includes: a flange portion protruding outward from the outer circumferential surface of the valve body; a lower body that is a portion below the flange portion; an upper body that is a portion above the lower body; and A seal material is provided on the underside of the flange portion, a ring-shaped press screw is provided around the upper body above the flange portion to press the flange portion downward; the first flow passage hole and the second flow passage hole are formed in the lower body, When the electrically driven valve is mounted in the valve mounting hole, The lower body is fitted into the pilot hole, the first flow path hole communicates with the first flow path, the second flow path hole communicates with the second flow path, a ring-shaped clearance space is formed between the outer peripheral surface of the upper body and the inner peripheral surface of the upper hole portion, and the cap screw is housed in the clearance space; The press screw has a male thread on its outer circumferential surface that screws into the female thread, and presses the flange portion downward by being screwed into the gap space, As a result, the sealing material is sandwiched between the flange portion and the step portion. An electrically driven valve.

2. The sealing material is A metal plate; a sealing material layer made of rubber or resin provided on each of the upper and lower surfaces of the metal plate; have The electrically driven valve according to claim 1 .

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