Electric valve

Abstract

To provide a motor valve which enables improvement of durability and seating stability of a main valve body.SOLUTION: A motor valve 1 includes: a valve body 10 which includes a main valve chamber 11 and a first port 14a; a main valve body 30 which moves close to or separates from the first port 14a; a needle valve 40 which moves close to or separates from an auxiliary valve port 35 provided within the main valve body 30; and a drive part 50 which drives the needle valve 40. The needle valve 40 is provided with a valve holder 42 extending in an axis X direction and connected to the drive part 50. A resin female screw member 20 which guides movement of the main valve body 30 and the needle valve 40 in the axis X direction is fixed to the valve body 10. The female screw member 20 is provided with: a holder guide 23 which extends in the axis X direction and can slide on an outer wall surface of a side wall 43 of the valve holder 42; and a main valve guide 26 which extends in the axis X direction and can slide on an outer wall surface or an inner wall surface of a side wall 31 of the main valve body 30.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a motor-operated valve. [Background technology]

[0002] Conventionally, there is known a motor-operated valve that includes a valve body with an internal valve chamber, and a main valve element and a sub-valve element that are arranged within the valve body (see, for example, Patent Document 1). As shown in Figure 2 of Patent Document 1, the motor-operated valve described in Patent Document 1 includes a valve body 1, a threaded rod 7 extending in the axial direction, a cylindrical connecting sleeve 4 connected to the tip of the threaded rod 7, a needle valve 5 (sub-valve element) housed in the connecting sleeve 4, and a needle valve sleeve 3 (main valve element) that is fitted onto the outside of the connecting sleeve 4 and slides along the connecting sleeve 4. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Chinese Patent Publication No. 10643914 Summary of the Invention [Problem to be solved by the invention]

[0004] In the motor-operated valve described above, a female threaded member 8, which has a female thread that threads onto a threaded rod 7, is fixed to the valve body 1. The outer wall surface of the needle valve sleeve 3 slides against part of the inner wall surface of the female threaded member 8, thereby guiding the needle valve sleeve 3 in the axial direction. The connecting sleeve 4 slides against the needle valve sleeve 3 and moves axially. The needle valve sleeve 3 then moves axially to open and close a valve port 12 opening in the valve body 1, thereby controlling the flow rate of fluid entering and leaving the main valve chamber 11. However, in the motor-operated valve described above, the female threaded member 8, the needle valve sleeve 3, and the connecting sleeve 4 are arranged in a series relationship, guiding each other, and displacement of each component affects the other components. For example, displacement of the connecting sleeve 4 can change the position of the needle valve sleeve 3, potentially compromising the stability of the needle valve sleeve 3 when seated on the valve seat around the valve port 12, resulting in valve leakage. Furthermore, in this type of motor-operated valve, the needle valve sleeve 3 and the connecting sleeve 4 may be made of metal, and in this case, the needle valve sleeve 3 and the connecting sleeve 4 may wear away from each other, potentially reducing the sliding durability of the needle valve sleeve 3.

[0005] An object of the present invention is to provide an electrically operated valve that can improve the durability and seating stability of a main valve body. [Means for solving the problem]

[0006] In order to solve the above problems and achieve the object, the electric valve of the present invention is an electric valve comprising a cylindrical valve body having a valve chamber and a first port, a cylindrical main valve body that is close to or away from the first port, a needle valve that is close to or away from a sub-valve port provided on the main valve body, and a drive unit that drives the needle valve in the axial direction, and is further comprising: a cylindrical valve holder that is provided on the needle valve, extends in the axial direction, and is connected to the drive unit; and a resin guide member that is fixed to the valve body and guides the axial movement of the main valve body and the needle valve, and is characterized in that the guide member is provided with a first guide portion that extends in the axial direction and is slidable on the outer wall surface of the valve holder, and a second guide portion that extends in the axial direction and is slidable on the outer wall surface or inner wall surface of the main valve body.

[0007] According to the present invention, the valve holder can be guided by sliding the valve holder axially relative to the first guide portion of the guide member fixed to the valve body. The main valve element can be guided by sliding the main valve element axially relative to the second guide portion of the guide member. That is, the guide member, which is fixed to the valve body and does not move, includes a portion for guiding the valve holder and a portion for guiding the main valve element. Therefore, the valve holder and the main valve element are reliably guided by the guide member without affecting each other, thereby stabilizing the operation of the valve holder and the main valve element. This improves the stability of the main valve element when it seats on the valve seat around the first port. Furthermore, by using a resin guide member, wear between the main valve element and the second guide portion is reduced compared to a configuration using a metal guide member, for example, and the sliding durability of the main valve element can be improved. Therefore, an electrically operated valve with improved durability and seating stability of the main valve element can be provided.

[0008] Preferably, the valve body is provided with a second port that opens in a direction intersecting the axial direction, the guide member is formed with a cylindrical main valve guide that extends in the axial direction and opens toward the first port, the inner wall surface of the main valve guide forming the second guide portion, and at least a portion of the outer wall surface of the main valve guide being positioned so as to overlap the second port when viewed from the direction through which the second port passes. With this configuration, the main valve element can be moved in the axial direction while being guided by the inner wall surface of the main valve guide. At this time, at least a portion of the outer wall surface of the main valve guide overlaps the second port when viewed from the direction through which the second port passes. Therefore, for example, fluid flowing into the valve chamber from the second port is more likely to come into contact with the outer wall surface of the main valve guide, making the main valve element less susceptible to direct fluid pressure. This prevents the main valve element from becoming unstable due to fluid pressure.

[0009] Furthermore, when the distance that the main valve element can move in the axial direction is defined as a lift amount, and the axial length of the sliding portion between the main valve element and the second guide portion is defined as a guide amount, the minimum value of the guide amount is greater than the maximum value of the lift amount. With this configuration, the main valve element can always be guided in the axial direction by the second guide portion by an amount greater than the lift amount of the main valve element. Therefore, since the second guide portion can always guide the main valve element when it moves in the axial direction, it is possible to stabilize the behavior of the main valve element, for example, when it seats on the valve seat or when it leaves the valve seat.

[0010] The drive unit is provided with a drive shaft connected to the valve holder and extending toward the opposite side from the first port, and the drive shaft has an external thread on its outer circumferential surface. The guide member is an internally threaded member including a female thread that threads onto the male thread to form a screw feed mechanism, a cylindrical holder guide that is continuous with the female thread and opens toward the first port, and a cylindrical main valve guide that is continuous with the holder guide and opens toward the first port, the inner wall surface of the holder guide forming the first guide portion, and the inner or outer wall surface of the main valve guide forming the second guide portion. With this configuration, the drive shaft is moved axially by threading the male thread with the female thread of the internally threaded member, and the valve holder connected to the drive shaft can be moved axially while being guided by the inner wall surface of the holder guide. Furthermore, the main valve element can be moved axially while being guided by the inner or outer wall surface of the main valve guide of the internally threaded member. In this way, by guiding the valve holder and the main valve body with a single female screw member, it is possible to improve the seating stability of the main valve body described above.

[0011] Furthermore, a first guide clearance, which is a radial gap intersecting the axial direction, is formed between the first guide portion and the valve holder, and a second guide clearance, which is a radial gap intersecting the axial direction, is formed between the second guide portion and the main valve body, and the first guide clearance is larger than the second guide clearance. According to this configuration, by making the first guide clearance larger than the second guide clearance, the slidability of the valve holder is further improved, thereby improving the operability of the needle valve. Furthermore, according to this, the second guide clearance is smaller than the first guide clearance, and the second guide portion and the main valve body are closer to each other, which makes it easier for the main valve body to slide on the second guide portion, thereby improving the seating stability of the main valve body. This makes it difficult for the sub-valve port to displace, thereby improving the accuracy of controlling the flow rate of fluid between the needle valve and the sub-valve port. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a motor-operated valve that can improve the durability and seating stability of the main valve body. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a cross-sectional view taken along the axial direction of a motor-operated valve according to a first embodiment of the present invention. [Figure 2] 2 is a cross-sectional view of the motor-operated valve taken along the axial direction in a state in which the needle valve is raised from the state shown in FIG. 1. [Figure 3] FIG. 2 is a cross-sectional view taken along the axial direction of the motor-operated valve with fluid flowing from the first joint pipe side. [Figure 4] FIG. 2A is a perspective view of the main valve body, and FIG. 2B is a side view of the main valve body. [Figure 5] FIG. 10 is a cross-sectional view taken along the axial direction of the motor-operated valve according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] A first embodiment of the present invention will be described below with reference to Figures 1 to 4. Note that the concept of "upper and lower" in the following description corresponds to the upper and lower in Figure 1, but this is for convenience of explanation only and does not necessarily correspond to the upper and lower during manufacture and use of the motor-operated valve 1, and does not limit the directions. As shown in Figure 1, the motor-operated valve 1 includes a valve body 10, an internally threaded member 20 (guide member), a main valve element 30, a needle valve 40 serving as a sub-valve element, and an actuator 50. The valve body 10 is formed in a substantially cylindrical shape using a metal material such as brass or stainless steel, and includes a main valve chamber 11 (valve chamber) therein. A bottom wall 12 is provided at the lower end of the valve body 10, and a through-hole 12a is formed in the center of the bottom wall 12, penetrating the valve body 10 in the direction of the axis X. A cylindrical small-diameter portion 13 is formed at the opening edge of the through-hole 12a, protruding downward and extending in the direction of the axis X of the valve body 10. A valve seat member 14 formed in an annular shape is fixed to the opening edge portion on the upper end side of the small diameter portion 13 (i.e., the opening edge portion of the through hole 12a), and the inside of the valve seat member 14 forms a first port 14a that communicates with the inside and outside of the main valve chamber 11.

[0015] A first coupling pipe 15, serving as a pipe for a fluid (e.g., a refrigerant), is inserted into the opening at the lower end of the small diameter portion 13. The first coupling pipe 15 is fixed to the valve body 10 by brazing or the like, and its interior is in communication with the main valve chamber 11 via a first port 14a. A second port 16a, which opens in the radial direction of the valve body 10 (a direction intersecting the direction of the axis X) and communicates with the inside and outside of the main valve chamber 11, is formed in a side wall 16 of the valve body 10. A second coupling pipe 17, serving as a pipe for a fluid (e.g., a refrigerant), is inserted into the second port 16a. The second coupling pipe 17 is fixed to the valve body 10 by brazing or the like, and its interior is in communication with the main valve chamber 11 via the second port 16a. A case 18, formed in a cylindrical shape with a bottom, is airtightly fixed to the upper end of the side wall 16 by welding or the like at its open end edge. In this embodiment, the valve seat member 14 is formed separately from the valve body 10 and is fixed to the opening edge of the through hole 12a, but the valve seat member 14 may also be formed integrally with the valve body 10.

[0016] A female thread member 20 made of a resin material and formed into a substantially cylindrical shape is fixed to the upper end side of the valve body 10. The female thread member 20 has a cylindrical press-fit portion 21 that is press-fitted into the upper end opening of the valve body 10. An annular flange portion 22 that protrudes radially outward is integrally provided to the press-fit portion 21 by insert molding, and the flange portion 22 is fixed to the upper end of the side wall 16 of the valve body 10 by welding or the like. A cylindrical holder guide 23 that is continuous with the press-fit portion 21 and extends upward in the direction of the axis X is formed at the upper end of the press-fit portion 21. A holder guide hole 23a that is coaxial with the axis X and penetrates the holder guide 23 in the direction of the axis X is formed at the center of the holder guide 23. One end of the holder guide hole 23a is continuous with a shaft guide hole 25 (and the female thread portion 25a) described below, and the other end extends into the interior of the press-fit portion 21 and opens downward (toward the first port 14a). The inner wall surface of the holder guide hole 23a (ie, the inner wall surface of the holder guide 23) is slidable on the outer wall surface of a side wall 43 of the valve holder 42, which will be described later, and constitutes a first guide portion in the present invention.

[0017] A cylindrical shaft guide 24 is formed at the upper end of the holder guide 23, continuing from the holder guide 23 and extending upward in the direction of the axis X. A spiral guide groove 24a is formed on the outer wall surface of the shaft guide 24, and a coil-shaped slider 24b is installed in the guide groove 24a. Claws 24c protruding radially outward are formed on the slider 24b, and the claws 24c are adapted to abut against magnet pins 53 of a magnet rotor 52, which will be described later. A shaft guide hole 25 is formed at the center of the shaft guide 24, penetrating in the direction of the axis X. One end of the shaft guide hole 25 opens upward, and the other end communicates with the holder guide hole 23a. A female thread 25a is formed on the inner wall surface of the shaft guide hole 25. The female thread 25a is threadedly engaged with a male thread 56 of a drive shaft 55, which will be described later, and together with the male thread 56, constitutes a screw feed mechanism A.

[0018] A cylindrical main valve guide 26 is formed at the lower end of the press-fit portion 21, continuing from the press-fit portion 21 and extending downward in the direction of the axis X. The main valve guide 26 is formed so that its lower end is located below the axis X2 of the second port 16a described above. As a result, at least a portion of the outer wall surface 26a of the main valve guide 26 is positioned so as to overlap with the second port 16a when viewed from the direction in which the second port 16a penetrates. A main valve guide hole 26b is formed at the center of the main valve guide 26, penetrating in the direction of the axis X and coaxial with the axis X. One end of the main valve guide hole 26b extends into the press-fit portion 21 and communicates with the holder guide hole 23a described above, and the other end opens downward.

[0019] The inner diameter of the main valve guide hole 26b is larger than the inner diameter of the holder guide hole 23a, thereby forming a step 27 at the connecting portion between the holder guide hole 23a and the main valve guide hole 26b. The inner wall surface of the main valve guide hole 26b (i.e., the inner wall surface of the main valve guide 26) is slidable on the outer wall surface of the side wall 31 of the main valve element 30, which will be described later, and constitutes the second guide portion of the present invention. In this way, the female threaded member 20 is fixed to the valve body 10 via the press-fit portion 21 and the flange portion 22, and the first guide portion (the inner wall surface of the holder guide hole 23a) and the second guide portion (the inner wall surface of the main valve guide hole 26b) allow the main valve element 30 and the needle valve 40 to slide, thereby guiding the movement of the main valve element 30 and the needle valve 40 in the direction of the axis X. In this embodiment, the inner wall surface of the main valve guide hole 26b is slidable on the outer wall surface of the side wall 31 of the main valve element 30, and this inner wall surface of the main valve guide hole 26b is used as the second guide portion, but this is not limiting, and for example, the outer wall surface 26a of the main valve guide 26 may be slidable on the inner wall surface of the side wall 31 of the main valve element 30, and this outer wall surface 26a of the main valve guide 26 may be used as the second guide portion. In other words, the second guide portion is slidable on the outer wall surface or inner wall surface of the main valve element 30.

[0020] As the resin material for forming the female screw member 20, from the viewpoint of sliding property and durability with the above-mentioned valve holder 42 and main valve body 30, for example, PPK (polyphenylene sulfide) or PEEK (polyether ether ketone) is preferred, and it is even more preferable to add a filler such as PTFE (polytetrafluoroethylene), CF (glass), GF (carbon), or graphite.

[0021] The main valve element 30 is a valve member that seats on or off (i.e., moves close to or away from) the first port 14a. As shown in FIGS. 4A and 4B, it is formed in a generally cylindrical shape extending in the direction of axis X and includes an auxiliary valve chamber 30a therein. In this embodiment, the outer diameter of the main valve element 30 is slightly smaller than the inner diameter of the main valve guide bore 26b, so that a portion of the main valve element 30 is positioned within the main valve guide bore 26b. The outer wall surface of the side wall 31 of the main valve element 30 faces the inner wall surface of the main valve guide bore 26b in the radial direction with a small gap therebetween and is slidable along the inner wall surface of the main valve guide bore 26b. Note that this gap (the gap between the outer wall surface of the side wall 31 of the main valve element 30 and the inner wall surface of the main valve guide bore 26b) is referred to as a second guide clearance. As shown in FIG. 1, the radial dimension of the second guide clearance is indicated by the symbol W2 and is defined as the second dimension W2.

[0022] With this configuration, the main valve element 30 is movable in the direction of the axis X while being guided by the inner wall surface of the main valve guide hole 26b. One or more (three in this embodiment) communication holes 32 are formed in the side wall 31 of the main valve element 30, penetrating in the radial direction, and the communication holes 32 connect the main valve chamber 11 and the sub-valve chamber 30a. A protruding portion 34 that protrudes downward and can be seated on the valve seat member 14 is formed in the bottom wall 33 of the main valve element 30, and a tapered sub-valve port 35 whose diameter increases downward is formed in the center of the protruding portion 34. The sub-valve port 35 is capable of communicating with the sub-valve chamber 30a, the main valve chamber 11, and the first port 14a. As shown in FIG. 1, the lift amount L1, which is the distance that the main valve body 30 can move upward in the direction of the axis X, is determined by the distance in the direction of the axis X between the upper end of the side wall 31 of the main valve body 30 and the step portion 27 of the above-mentioned female screw member 20.

[0023] 1 is in the lowest position, the guide amount L2, which is the distance in the axial direction of the portion of the side wall 31 of the main valve element 30 that faces the inner wall surface of the main valve guide hole 26b in this state (i.e., the length in the axial direction of the portion where the main valve element 30 slides against the second guide part), is greater than the lift amount L1 in this state. In this way, if the lift amount L1 is the distance that the main valve element 30 can move upward in the axial direction of the main valve element 30 and the guide amount L2 is the length in the axial direction of the portion where the main valve element 30 slides against the main valve guide hole 26b, the minimum value of the guide amount L2 is greater than the maximum value of the lift amount L1.

[0024] The needle valve 40 is a valve member that moves close to or away from the sub-valve port 35 of the main valve body 30, and includes a needle portion 41 that is inserted into the sub-valve port 35. The needle portion 41 is formed in a generally conical shape that decreases in diameter as it extends downward. The upper portion of the needle portion 41 is formed in a columnar shape, and this upper portion is inserted into and fixed to the lower end of a cylindrical valve holder 42. The valve holder 42 is formed to extend in the direction of the axis X. The outer diameter of the valve holder 42 is formed slightly smaller than the inner diameter of the holder guide hole 23a described above, so that a portion of the valve holder 42 is positioned within the holder guide hole 23a.

[0025] The outer wall surface of the side wall 43 of the valve holder 42 faces the inner wall surface of the holder guide hole 23a in the radial direction with a small gap therebetween and is slidable along the inner wall surface of the holder guide hole 23a. The above-mentioned gap (the gap between the inner wall surface of the holder guide hole 23a and the outer wall surface of the side wall 43 of the valve holder 42) is referred to as the first guide clearance. As shown in FIG. 1, the radial dimension of the first guide clearance is indicated by the symbol W1 and is defined as the first dimension W1. The first dimension W1 is set larger than the above-mentioned second dimension W2. In other words, the first guide clearance is set larger than the second guide clearance.

[0026] A through-hole 44 is formed in the upper end of the valve holder 42, penetrating in the direction of axis X. The lower end of a drive shaft 55 (described later) is inserted through the through-hole 44. A columnar spring retainer 45 is installed inside the valve holder 42, facing the needle portion 41 in the direction of axis X. A spring 46 is interposed between the lower end surface of the spring retainer 45 and the needle portion 41, thereby biasing the needle portion 41 toward the sub-valve port 35. An annular washer 47 is installed on the upper end surface of the spring retainer 45. The inner diameter of the washer 47 is set smaller than the inner diameter of the through-hole 44 and the outer diameter of a flange 57 of the drive shaft 55 (described later). This prevents the drive shaft 55 from slipping out of the through-hole 44 with the flange 57 sandwiched between the washer 47 and the spring retainer 45. This connects the valve holder 42 and the drive portion 50.

[0027] The drive unit 50 drives the needle valve 40 in the direction of the axis X and includes a stepping motor 51. The stepping motor 51 includes a stator coil (not shown) arranged outside the case 18, a magnet rotor 52 arranged inside the case 18 and surrounded by the stator coil, and other components (not shown), such as a yoke and exterior member. The stator coil is connected to a control unit (not shown) and receives pulse signals from the control unit to rotate the magnet rotor 52 clockwise or counterclockwise about the axis X by a predetermined rotation angle in accordance with the pulse signal. The magnet rotor 52 is formed into a cylindrical shape by molding a base material containing magnetic powder. Magnet pins 53 are formed on the inner peripheral surface of the magnet rotor 52 as protrusions that protrude radially inward and extend in the direction of the axis X.

[0028] When the magnet rotor 52 rotates, the magnet pin 53 abuts against the claw portion 24c of the slider 24b, transmitting the rotational force of the magnet rotor 52 to the slider 24b. With this configuration, when the magnet rotor 52 rotates, the rotational force is transmitted to the slider 24b via the claw portion 24c of the slider 24b, causing the slider 24b to rotate. An upper end stopper (not shown) is formed at the upper end of the guide groove 24a in which the slider 24b is installed, and a lower end stopper 24d is formed at the lower end of the guide groove 24a. When the claw portion 24c abuts against the upper end stopper or the lower end stopper 24d, the rotation of the slider 24b is stopped. When the rotation of the slider 24b stops, the rotation of the magnet rotor 52 is restricted. The magnet rotor 52, whose rotation is restricted by the upper end stopper, is restricted from moving upward, and the magnet rotor 52, whose rotation is restricted by the lower end stopper 24d, is restricted from moving downward. In other words, the uppermost and lowermost positions of the magnet rotor 52 are determined by the upper end stopper and the lower end stopper 24d.

[0029] A drive shaft 55 is attached to the center of the magnet rotor 52 via a bushing 54. The drive shaft 55 is rotatable around the axis X together with the magnet rotor 52 and is movable in the axis X direction. A male threaded portion 56 that screws into the female threaded portion 25a of the female threaded member 20 is formed on the outer peripheral surface of the drive shaft 55, and together with the female threaded portion 25a, constitutes a screw feed mechanism A. A flange 57 having an outer diameter larger than the inner diameter of the washer 47 described above is formed on the lower end of the drive shaft 55, and the upper surface of this flange 57 abuts against the lower surface of the washer 47, preventing the drive shaft 55 from slipping out of the valve holder 42.

[0030] Next, the operation of the motor-operated valve 1 will be described. The motor-operated valve 1 of this embodiment constitutes a heat pump type refrigeration cycle together with, for example, a compressor, a flow path switching valve, an indoor heat exchanger, and an outdoor heat exchanger (not shown), and functions as an expansion valve in the refrigeration cycle. In the refrigeration cycle, the flow direction of the refrigerant (fluid) compressed by the compressor is switched between two directions by the flow path switching valve. This switching of the refrigerant flow direction switches the motor-operated valve 1 between a flow rate control state shown in FIGS. 1 and 2 and a fully open state shown in FIG. 3. In the flow rate control state shown in FIG. 1, the main valve element 30 is seated on the valve seat member 14, and the needle portion 41 blocks the sub-valve port 35 to close the valve, and the flow rate of the refrigerant is zero.

[0031] When the stepping motor 51 is driven from this state, the magnet rotor 52 and the drive shaft 55 rotate, and the magnet rotor 52 and the drive shaft 55 move upward in the direction of the axis X due to the screw feed mechanism A between the male thread portion 56 and the female thread portion 25a. At this time, the needle valve 40 rises in accordance with the movement of the drive shaft 55, and the sub-valve port 35 opens. As a result, the refrigerant flows through the second joint pipe 17 (second port 16a), the main valve chamber 11, the communication hole 32, the sub-valve chamber 30a, the sub-valve port 35, and the first joint pipe 15 (first port 14a) in this order. At this time, as described above, at least a portion of the outer wall surface 26a of the main valve guide 26 of the female thread member 20 is positioned so as to overlap the second port 16a when viewed from the direction in which the second port 16a penetrates. Therefore, the fluid flowing from the second port 16a to the main valve chamber 11 is more likely to come into contact with the outer wall surface 26a of the main valve guide 26, making it less likely that the main valve element 30 will be directly affected by the pressure of the fluid. As the needle valve 40 rises, the gap between the needle portion 41 and the sub-valve port 35 gradually increases, increasing the flow rate of the fluid through the sub-valve port 35 and the flow rate of the fluid from the main valve chamber 11 to the sub-valve chamber 30a. As a result, the needle valve 40 is subjected to pressure in a direction intersecting the axis X. However, in this embodiment, the valve holder 42 of the needle valve 40 is guided by sliding against the inner circumferential surface of the holder guide hole 23a, making it less likely that the drive shaft 55 and the needle valve 40 will vibrate, resulting in stable operation of the drive shaft 55 and the needle valve 40.

[0032] 2, when the needle valve 40 is at its uppermost position, the sub-valve port 35 is fully opened, and the flow rate in the flow control state is maximized. On the other hand, when the refrigerant flow direction in the refrigeration cycle is switched from this state, the refrigerant flows from the first joint pipe 15 side to the main valve chamber 11. When the refrigerant flows from the first joint pipe 15 into the main valve chamber 11, the main valve element 30 is separated from the valve seat member 14 due to the pressure difference between the inside of the first joint pipe 15 and the inside of the main valve chamber 11, and as shown in FIG. 3, the main valve element 30 rises in the direction of the axis X.

[0033] In this embodiment, the outer wall surface of the side wall 31 of the main valve element 30 slides against and is guided by the inner wall surface of the main valve guide hole 26b, making the main valve element 30 less likely to vibrate and stabilizing its operation. When the main valve element 30 leaves its seat, the first port 14a opens to the main valve chamber 11, establishing the fully open state described above. Refrigerant passing through the first port 14a flows sequentially through the main valve chamber 11, the second port 16a, and the second joint pipe 17. In the fully open state, refrigerant flows at a flow rate greater than the maximum flow rate in the flow control state described above. In the fully open state, the motor-operated valve 1 does not control the flow rate, unlike in the flow control state described above, and functions as a piping for the refrigeration cycle. When the inflow of fluid from the first joint pipe 15 stops, the main valve element 30 descends due to gravity and the pressure difference between the main valve chamber 11 and the first joint pipe 15, and then seats on the valve seat member 14 again. In this way, the motor-operated valve 1 functions as a pipe or as a device for controlling the flow rate of the refrigerant, depending on the flow direction of the refrigerant.

[0034] As described above, according to the embodiment described above, the valve holder 42 can be guided by sliding in the direction of axis X against the inner wall surface (first guide portion) of the holder guide hole 23a in the female thread member 20 (guide member) fixed to the valve body 10. The main valve element 30 can be guided by sliding in the direction of axis X against the inner wall surface of the main valve guide hole 26b in the female thread member 20 or the outer wall surface 26a (second guide portion) of the main valve guide 26. In other words, since the female thread member 20, which is fixed to the valve body 10 and does not move, has a portion that guides the valve holder 42 and a portion that guides the main valve element 30, the valve holder 42 and the main valve element 30 are reliably guided by the female thread member 20 without affecting each other, and this stabilizes the operations of the valve holder 42 and the main valve element 30.

[0035] This improves the stability when the main valve element 30 seats on the valve seat member 14 (valve seat). Furthermore, by making the female thread member 20 from resin, wear on the main valve element 30 and main valve guide 26 can be suppressed compared to a configuration using a female thread member made of metal, for example, and the sliding durability of the main valve element 30 can be improved. Therefore, it is possible to provide a motor-operated valve 1 that can improve the durability and seating stability of the main valve element 30.

[0036] Furthermore, the main valve element 30 can be moved in the direction of the axis X while being guided by the inner wall surface of the main valve guide hole 26b (the inner wall surface of the main valve guide 26). At this time, at least a portion of the outer wall surface 26a of the main valve guide 26 overlaps with the second port 16a when viewed from the direction in which the second port 16a penetrates. Therefore, for example, fluid that flows into the main valve chamber 11 from the second port 16a is likely to come into contact with the outer wall surface 26a of the main valve guide 26, making the main valve element 30 less susceptible to the direct influence of the fluid pressure. This makes it possible to prevent the operation of the main valve element 30 from becoming unstable due to the influence of the fluid pressure.

[0037] Furthermore, according to this embodiment, the minimum value of the guide amount L2 is set larger than the maximum value of the lift amount L1, so that the main valve element 30 can always be guided in the direction of the axis X by the main valve guide 26 at an amount larger than the lift amount L1 of the main valve element 30. Therefore, when the main valve element 30 moves in the direction of the axis X, the main valve element 30 can always be guided by the main valve guide 26. Therefore, the behavior of the main valve element 30 can be stabilized, for example, when the main valve element 30 is seated on the valve seat member 14 or when the main valve element 30 is released from the valve seat member 14. Note that in this embodiment, the lift amount L1 is the distance that the main valve element 30 can move upward in the direction of the axis X, and the guide amount L2 is the distance in the direction of the axis X of the portion of the side wall 31 of the main valve element 30 that faces the inner wall surface of the main valve guide hole 26b. However, as described above, in addition to making the inner wall surface of the main valve guide hole 26b slidable against the outer wall surface of the side wall 31 of the main valve body 30, the outer wall surface 26a of the main valve guide 26 can be made slidable against the inner wall surface of the side wall 31 of the main valve body 30.

[0038] Therefore, the distance in the direction of the axis X of the portion of the inner wall surface of the side wall 31 of the main valve element 30 that faces the outer wall surface 26a of the main valve guide 26 may be set as the guide amount L2. Also in this case, by setting the minimum value of the guide amount L2 to be larger than the maximum value of the lift amount L1, the main valve element 30 can be always guided by the main valve guide 26 when it moves in the direction of the axis X, and the behavior of the main valve element 30 when it seats on the valve seat member 14 or when it leaves the valve seat member 14 can be stabilized.

[0039] Furthermore, by threading the male thread portion 56 with the female thread portion 25a of the female thread member 20, the drive shaft 55 is moved in the direction of the axis X, and the valve holder 42 connected to the drive shaft 55 can be moved in the direction of the axis X while being guided by the inner wall surface of the holder guide hole 23a (the inner wall surface of the holder guide 23). Furthermore, the main valve element 30 can be moved in the direction of the axis X while being guided by the inner wall surface of the main valve guide hole 26b of the female thread member 20 (the inner wall surface of the main valve guide 26) or the outer wall surface 26a of the main valve guide 26. Thus, guiding the valve holder 42 and the main valve element 30 with a single female thread member 20 can improve the seating stability of the main valve element 30. Furthermore, this configuration simplifies the structure of the guide members and reduces the number of parts of the guide members compared to a configuration in which the main valve element 30 and the valve holder 42 are guided by separate structures, thereby contributing to reducing the manufacturing cost of the motor-operated valve 1.

[0040] Furthermore, by making the first dimension W1 of the first guide clearance larger than the second dimension W2 of the second guide clearance, the slidability of the valve holder 42 is further improved, thereby improving the operability of the needle valve 40. Furthermore, by making the second guide clearance smaller than the first guide clearance and bringing the main valve guide 26 and the main valve element 30 closer together, the main valve element 30 can slide more easily on the main valve guide 26, thereby improving the seating stability of the main valve element 30. This makes it difficult for the sub-valve port 35 to displace, improving the accuracy of controlling the flow rate of fluid between the needle valve 40 and the sub-valve port 35.

[0041] The first embodiment of the motor-operated valve 1 has been described above in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and design changes within the scope of the present invention are also included in the present invention. FIG. 5 is a cross-sectional view of a motor-operated valve 1′ according to a second embodiment, taken along the axis X. The motor-operated valve 1′ of the second embodiment includes a female thread member 20′ and a main valve element 30′. The female thread member 20′ corresponds to the female thread member 20 described above, and the main valve element 30′ corresponds to the main valve element 30 described above. Note that components similar to those of the motor-operated valve 1 of the first embodiment are designated by reference numerals, and their description will be omitted or simplified. For ease of explanation, reference numerals for each component will be omitted as appropriate.

[0042] In the female thread member 20', an annular groove 28 that opens downward is formed in the lower end surface of the press-fit portion 21'. The annular groove 28 is formed so that its outer diameter is larger than the outer diameter of the main valve guide 26', allowing the upper end of the main valve guide 26' to be inserted therein. The outer diameter of the main valve guide 26' is formed slightly smaller than the inner diameter of the main valve element 30', so that the side wall 31' of the main valve element 30' is positioned outside the main valve guide 26'. The inner wall surface of the side wall 31' of the main valve element 30' faces radially opposite the outer wall surface 26a' of the main valve guide 26' with a small gap therebetween and is slidable along the outer wall surface 26a'. Although not shown, in this embodiment, the above-mentioned gap (the gap between the inner wall surface of the side wall 31' of the main valve body 30' and the outer wall surface 26a' of the main valve guide 26') is called the second guide clearance, and the second dimension W2, which is the radial dimension of this second guide clearance, is smaller than the first dimension W1, as in the first embodiment.

[0043] As described above, the main valve element 30′ includes a side wall 31′ whose inner diameter is larger than the outer diameter of the main valve guide 26′. When the main valve element 30′ leaves the valve seat member 14 and rises in the direction of the axis X, the upper end of the side wall 31′ abuts against the bottom surface of the annular groove 28, thereby restricting the rise of the main valve element 30′. Although not shown, in this embodiment, the lift amount L1 is determined by the distance in the direction of the axis X between the upper end of the side wall 31′ of the main valve element 30′ and the bottom surface of the annular groove 28. Furthermore, the guide amount L2 is determined by the distance in the direction of the axis X of the portion of the inner wall surface of the side wall 31′ of the main valve element 30′ that faces the outer wall surface 26a′ of the main valve guide 26′ (i.e., the length in the direction of the axis X of the portion that slides with the second guide portion).

[0044] In this embodiment, too, when the main valve element 30' shown in FIG. 5 is positioned at its lowest end position, the guide amount L2 in this state is greater than the lift amount L1 in this state. That is, the minimum value of the guide amount L2 is greater than the maximum value of the lift amount L1. The second embodiment configured in this manner can also achieve the same functions and effects as the first embodiment. Furthermore, in the second embodiment, the volume of the sub-valve chamber 30a' can be increased compared to a configuration in which the main valve element 30 is disposed inside the main valve guide 26. [Explanation of symbols]

[0045] X axis 1. Motor-operated valve 10 Valve body 11 Valve chamber 14a Port 1 20 Female thread member (guide member) 23 Holder guide (first guide part) 26 Main valve guide (second guide part) 30 Main valve body 35 Sub-valve port 40 Needle valve 42 Valve holder 50 Drive unit

Claims

1. An electrically operated valve comprising: a cylindrical valve body having a valve chamber and a first port; a cylindrical main valve element disposed close to or away from the first port; a needle valve disposed close to or away from an auxiliary valve port provided in the main valve element; and a drive unit that drives the needle valve in an axial direction, a cylindrical valve holder provided on the needle valve, extending in the axial direction and connected to the drive unit; a resin guide member fixed to the valve body to guide the axial movement of the main valve element and the needle valve, An electric valve characterized in that the guide member is provided with a first guide portion extending in the axial direction and slidable on the outer wall surface of the valve holder, and a second guide portion extending in the axial direction and slidable on the outer wall surface or inner wall surface of the main valve body.

2. The valve body is provided with a second port that opens in a direction intersecting the axial direction, The guide member is formed with a cylindrical main valve guide that extends in the axial direction and opens toward the first port, an inner wall surface of the main valve guide constitutes the second guide portion; 2. The motor-operated valve according to claim 1, wherein at least a portion of an outer wall surface of the main valve guide is positioned so as to overlap the second port when viewed from the direction in which the second port penetrates.

3. 2. The motor-operated valve according to claim 1, wherein the lift amount is the distance that the main valve body can move in the axial direction, and the guide amount is the axial length of the sliding portion between the main valve body and the second guide portion, and the minimum value of the guide amount is greater than the maximum value of the lift amount.

4. the drive portion is provided with a drive shaft connected to the valve holder and extending to a side opposite to the first port side, and the drive shaft is provided with a male thread portion on an outer circumferential surface thereof, the guide member is a female threaded member including: a female threaded portion that threadably engages with the male threaded portion to form a screw feed mechanism; a cylindrical holder guide that is continuous with the female threaded portion and opens toward the first port; and a cylindrical main valve guide that is continuous with the holder guide and opens toward the first port, an inner wall surface of the holder guide constitutes the first guide portion; 2. The motor-operated valve according to claim 1, wherein an inner wall surface or an outer wall surface of the main valve guide constitutes the second guide portion.

5. A first guide clearance, which is a radial gap intersecting the axial direction, is formed between the first guide portion and the valve holder, A second guide clearance, which is a gap in the radial direction, is formed between the second guide portion and the main valve body, 2. The motor-operated valve according to claim 1, wherein the first guide clearance is larger than the second guide clearance.

Images