Valve

Abstract

To provide a valve capable of easily constituting a communication path.SOLUTION: A valve body 51 has an annular valve body member 53 that can move toward and away from a valve seat 31, and a rod member 52 whose one end is inserted into the valve body member 53 and fixed to an inner surface 53a of the valve body member 53. The communication path 20 is formed by a side surface 52c of the rod member 52 and the inner surface 53a of the valve body member 53.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to valves, for example, valves for regulating the flow rate of a fluid. [Background technology]

[0002] BACKGROUND ART Valves are known in various fields that are provided in a flow path through which a fluid flows and are used to control the flow rate according to the opening degree of the valve.

[0003] For example, the valve in Patent Document 1 is a solenoid valve mainly composed of a housing, a valve seat, a valve element, a spring, a solenoid, and a bellows. The valve element is disposed within the housing so as to be movable in the axial direction. Between the housing and the valve element are provided a primary pressure chamber communicating with the suction port, a secondary pressure chamber communicating with the discharge port, and a back pressure chamber for the valve element on the axially opposite side of the secondary pressure chamber from the primary pressure chamber.

[0004] The secondary pressure chamber and the back pressure chamber are separated by a bellows disposed between the housing and the valve disc. The valve disc is pressed toward the valve seat by a spring. The valve disc is movable away from the valve seat in response to the electromagnetic force of the solenoid. The valve disc also has a communication hole that connects the primary pressure chamber and the back pressure chamber. As a result, the valve of Patent Document 1 maintains a closed state in which it abuts against the valve seat when it is not energized or until the electromagnetic force exceeds the biasing force of the spring. Once the electromagnetic force exceeds the biasing force of the spring, the valve separates from the valve seat and enters an open state. The communication hole also balances the pressures in the primary pressure chamber and the back pressure chamber, allowing forces acting on both axial sides of the valve disc to be offset. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 3-37487 (page 2, Figure 2) Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the communicating hole of the valve of Patent Document 1, a portion extending axially along the valve body and a portion extending radially are provided inside the valve body, making the work of forming the communicating hole in the valve body complicated.

[0007] The present invention has been made in view of the above-mentioned problems, and has as its object to provide a valve in which a communication passage can be easily constructed. [Means for solving the problem]

[0008] In order to solve the above problems, the valve of the present invention comprises: a valve housing having a valve seat between a primary pressure chamber and a secondary pressure chamber; a valve element disposed within the valve housing and operable by a solenoid; a spring that biases the valve body in a direction opposite to the driving direction of the solenoid; a bellows that separates the secondary pressure chamber from a back pressure chamber that is located on the opposite side of the secondary pressure chamber from the primary pressure chamber, The valve body is provided with a communication passage that communicates the primary pressure chamber with the back pressure chamber, A valve that controls the flow rate of a fluid passing through the primary pressure chamber and the secondary pressure chamber by opening and closing, the valve body includes an annular valve body member that can approach and separate from the valve seat, and a rod member that is fixed to an inner circumferential surface of the valve body member with one end inserted into the valve body member, The communication passage is defined by the side surface of the rod member and the inner peripheral surface of the valve body member. According to this, by simply fixing the rod member to the valve body member, a communication passage can be easily formed by the side surface of the rod member and the inner peripheral surface of the valve body member.

[0009] The side surface may be a flat surface having a notch shape extending in the axial direction from an end face on one end side of the rod member. This allows the communication passage to be easily formed by simply fixing a rod member having a notch on its side surface to the valve body member.Furthermore, fluid can flow in and out from the radial and circumferential sides of the notch.

[0010] The rod member has a circular cross section, The inner circumferential surface of the valve body member may have a circular cross section. This ensures a sufficient contact area between the side surface of the rod member and the inner circumferential surface of the valve body member.

[0011] The notch may extend to the inside of the bellows. This allows fluid to flow smoothly in and out between the primary pressure chamber and the back pressure chamber through the communication passage.

[0012] A plurality of the communication passages may be provided on the outer periphery of the rod member. With this, fluid can flow in and out through the plurality of notches, so that fluid can flow in and out smoothly between the primary pressure chamber and the back pressure chamber.

[0013] The communication passages may be evenly spaced around the outer periphery of the rod member. This allows the notches through which the fluid flows in and out to be arranged in a well-balanced manner on the outer periphery of the rod member. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a cross-sectional view of a valve according to a first embodiment of the present invention. [Figure 2] 2 is a cross-sectional view taken along the line AA in FIG. 1. [Figure 3] FIG. 3 is an enlarged cross-sectional view of a main part showing a valve in a closed state. [Figure 4] FIG. 3 is an enlarged cross-sectional view of a main part showing a valve in a closed state. [Figure 5] 2 is a cross-sectional view of a valve according to a second embodiment of the present invention taken along the same line as line AA in FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A valve according to the present invention will be described below with reference to the following examples. [Example]

[0016] A valve according to a first embodiment will be described with reference to Figures 1 to 4. The valve in this embodiment is adopted as an expansion valve constituting a refrigeration cycle, and will be described as performing an opening and closing operation to adjust the flow rate of a refrigerant flowing down a flow path.

[0017] The valve in this embodiment is employed as an expansion valve that constitutes a refrigeration cycle, and will be described as opening and closing to adjust the flow rate of refrigerant flowing down a flow path.

[0018] As shown in FIG. 1, the expansion valve 1 is mainly composed of a valve housing 10 as a housing, a valve element 51, a solenoid 80, a bellows 40, and a base plate 41.

[0019] The valve housing 10 is formed in a generally cylindrical shape from a metal or resin material. The valve housing 10 is provided with a primary pressure chamber S1, a secondary pressure chamber S2, and a back pressure chamber S3. The primary pressure chamber S1 is provided at the left end of the valve housing 10 and is connected to the primary pressure side of the refrigeration cycle. The secondary pressure chamber S2 is provided within the valve housing 10 and is connected to the secondary pressure side of the refrigeration cycle via through holes 10c, 10c. The back pressure chamber S3 is provided at the right end of the valve housing 10 and is connected to the internal space of the solenoid 80. In other words, the back pressure chamber S3 is formed by the valve housing 10 and the solenoid 80.

[0020] The valve housing 10 is provided with a through hole 10a that axially connects the primary pressure chamber S1 and the secondary pressure chamber S2, a through hole 10b that axially connects the secondary pressure chamber S2 and the back pressure chamber S3, and two through holes 10c, 10c that extend radially from the secondary pressure chamber S2.

[0021] A valve seat member 30 is press-fitted and fixed from the left side onto the inner peripheral surface that defines the through-hole 10a. A tapered surface that expands in diameter toward the right is formed on the inner diameter side of the right end of the valve seat member 30 (see FIG. 2). This tapered surface serves as a valve seat 31 with which a valve body member 53, described later, comes into contact and separates.

[0022] Valve element 51 is composed of rod member 52, which is a cylindrical body with a substantially constant cross section, and cylindrical valve element member 53 attached to the left end of rod member 52. Valve element 51 and valve seat 31 form valve 70, which controls the flow rate and opening / closing of the flow path as valve element 51 moves relative to valve housing 10.

[0023] The right end of the rod member 52 is inserted into and fixed to the movable iron core 84 of the solenoid 80, and the left end of the rod member 52 is inserted into and fixed to the inner circumferential surface 53a of the valve body member 53. The valve body member 53 and the rod member 52 are made of a metal material or a resin material. The left end surface 53d of the rod member 52 is fixed so as to be flush with the left end surface of the valve body member 53.

[0024] 1 and 2, rod member 52 has notches 52a, 52a at its left end. Notches 52a, 52a are provided on the outer circumferential surface of rod member 52 at symmetrical positions across axis C of rod member 52. In other words, the left end of rod member 52 is composed of notches 52a, 52a and a solid portion 52b remaining other than notches 52a, 52a, and an outer circumferential surface 52c of solid portion 52b is fixed to an inner circumferential surface 53a of valve body member 53.

[0025] The outer peripheral surface 52c of the solid portion 52b and the inner peripheral surface 53a of the valve body member 53 may be fixed to each other by press-fitting, welding, adhesive bonding, etc. Furthermore, the outer peripheral surface 52c of the solid portion 52b is the side surface of the rod member 52, i.e., the outer peripheral surface of the rod member 52.

[0026] The notch 52a extends axially rightward from the left end surface 53d of the rod member 52 beyond the valve body member 53. That is, the notch 52a extends to a space S3' within the bellows 40, which will be described later.

[0027] The notch 52a is formed by one flat surface 52e and does not have a side wall in the circumferential direction of the rod member 52. At the right end of the notch 52a, an end surface 52f of the remaining rod member 52 exists (see FIG. 3). The end surface 52f extends perpendicular to the axial direction.

[0028] 1, the solenoid 80 is mainly composed of a casing 81 having an opening 81a that opens axially leftward, a fixed core 82 fixedly disposed on the right side within the casing 81, a movable core 84 disposed on the left side of the fixed core 82, a coil spring 85 disposed between the fixed core 82 and the movable core 84 and biasing the movable core 84 axially leftward, which is the direction in which the valve 70 closes, and an exciting coil 86 wound around the outside of the fixed core 82 via a bobbin. The movable core 84 is axially movable between the valve housing 10 and the fixed core 82.

[0029] The base plate 41 is an annular plate made of a metal or resin material and is axially sandwiched between the valve housing 10 and the casing 81, and separates the secondary pressure chamber S2 from the back pressure chamber S3.

[0030] A rod member 52 is inserted into a through-hole 41a at the center of the base plate 41, and the rod member 52 is slidable on an inner circumferential surface 41c that constitutes the through-hole 41a. The back pressure chamber S3 and the space S3' inside the bellows 40 communicate with each other through a gap between the rod member 52 and the inner circumferential surface 41c of the through-hole 41a (see FIG. 3).

[0031] The bellows 40 is a so-called formed bellows formed by pressing a metal plate into a bellows shape with multiple continuous peaks, and has a uniform thickness. The bellows 40 is arranged in a sealed state between the valve body member 53 and the base plate 41, and together with the base plate 41, it defines the secondary pressure chamber S2 and the back pressure chamber S3.

[0032] As shown in Figures 1 and 2, when the left end of the rod member 52 is fixed to the inner surface 53a of the valve body member 53, the inner surface 53a of the valve body member 53 and the notches 52a, 52a provide communication passages 20, 20 connecting the primary pressure chamber S1 and the back pressure chamber S3 at symmetrical positions across the axis C of the rod member 52.

[0033] Next, the operation of the valve element 51, that is, the opening and closing operation of the valve 70, will be described with reference to Figures 1 to 4. Figures 3 and 4 show a cross section at a position rotated approximately 90 degrees in the circumferential direction from the state of Figure 1.

[0034] First, we will explain the state when the expansion valve 1 is not energized. As shown in Figures 1 and 3, when the expansion valve 1 is not energized, the movable iron core 84 is pressed axially leftward by the biasing forces of the coil spring 85 and the bellows 40, the valve body 51 moves axially leftward, the valve body member 53 abuts against the valve seat 31, and the valve 70 is closed.

[0035] At this time, a force (FP1) due to the pressure of the fluid on the valve disc 51 acts on the valve disc 51 to the right in the axial direction, a force (FP2) due to the pressure of the fluid on the valve disc 51 acts on the valve disc 51 to the left in the axial direction, the biasing force (Fsp1) of the coil spring 85, and the biasing force (Fbel) of the bellows 40. In other words, with the leftward direction being positive, a force Frod=FP2+Fsp1+Fbel-FP1 acts on the valve disc 51.

[0036] The force (FP1) when the valve 70 is closed is a force acting on the effective pressure-receiving surface A of the valve body member 53 due to the pressure of the fluid in the primary pressure chamber S1.

[0037] On the other hand, the force (FP2) is a force acting on the effective pressure receiving surface B of the valve body member 53 due to the pressure of the fluid in the space S3'.

[0038] In this embodiment, the effective pressure-receiving surfaces A and B of the valve body member 53 are formed to have the same area. Furthermore, the primary pressure chamber S1 and the space S3' are connected through the connecting passages 20, 20 and are at the same pressure. Therefore, the effects of the force due to the pressure of the fluid in the primary pressure chamber S1 and the space S3' (i.e., the back pressure chamber S3) acting on both sides of the valve body 51 in the direction of movement are canceled out. Note that the force due to the pressure of the fluid in the secondary pressure chamber S2 and the space S3' also acts on the bellows 40, but as is well known in the art, this force is canceled out on both axial sides.

[0039] Next, we will explain the outline of the energized state of the expansion valve 1. As shown in Figures 1 and 3, when the expansion valve 1 is energized, that is, during normal control, or so-called duty control, and the electromagnetic force (Fsol) generated by applying current to the solenoid 80 exceeds the force Frod (Fsol > Frod), the movable iron core 84 is attracted toward the fixed iron core 82, that is, to the right in the axial direction, and the valve element 51 fixed to the movable iron core 84 moves axially rightward together with the movable iron core 84, causing the valve element member 53 of the valve element 51 to separate from the valve seat 31 in the valve housing 10, and the valve 70 is opened.

[0040] At this time, an electromagnetic force (Fsol) acts on the valve element 51 in the axial right direction, and a force Frod acts on the valve element 51 in the axial left direction (that is, the force Frod-Fsol acts on the valve element 51, with the rightward direction being positive).

[0041] As described above, the communication passage 20 that communicates between the primary pressure chamber S1 and the back pressure chamber S3 is formed by the inner circumferential surface 53a of the valve body member 53 and the notch 52a of the rod member 52. Specifically, the communication passage 20 can be easily formed by simply fixing the outer circumferential surface 52c of the solid portion 52b of the rod member 52 to the inner circumferential surface 53a of the valve body member 53.

[0042] Furthermore, since the notch 52a extends to the space S3' inside the bellows 40, it is not necessary to form a groove such as a notch on the inner surface 53a of the valve body member 53 to form the communicating passage 20, which simplifies the structure of the valve body member 53.

[0043] Furthermore, a plurality of notches 52a (two in this embodiment) are provided on the outer periphery of the rod member 52. This allows fluid to flow in and out through the notches 52a, 52a, thereby allowing fluid to flow in and out smoothly between the primary pressure chamber S1 and the back pressure chamber S3 (i.e., space S3').

[0044] For example, if the pressure of the fluid in the primary pressure chamber S1 frequently fluctuates when the valve is closed, as shown in Figure 3, it is possible for the fluid to flow from the primary pressure chamber S1 to the space S3' through one notch 52a, and for the fluid to flow from the space S3' to the primary pressure chamber S1 through the other notch 52a.

[0045] Furthermore, as shown in FIG. 4, when the valve body 51 moves in the valve opening direction and the volume of the space S3' becomes smaller, both notches 52a, 52a allow fluid to flow from the space S3' to the secondary pressure chamber S2.

[0046] Furthermore, the notches 52a, 52a are equally spaced on the outer periphery of the rod member 52. In other words, the communicating passages 20, 20 are provided at symmetrical positions with respect to the axis C of the rod member 52, so the rod member 52 is less susceptible to the influence of the fluid passing through the communicating passages 20, 20.

[0047] Furthermore, the rod member 52 has a circular cross section, and the notch 52a is formed by one flat surface 52e. That is, the portion of the notch 52a disposed within the space S3' does not have a side wall formed in the circumferential direction of the rod member 52, allowing fluid to flow in and out smoothly from the radial direction and circumferential side.

[0048] Furthermore, the rod member 52 has a circular cross section, and the inner peripheral surface 53a of the valve body member 53 also has a circular cross section. This ensures a large contact area between the portion of the rod member 52 other than the notches 52a, 52a, i.e., the outer peripheral surface 52c of the solid portion 52b, and the inner peripheral surface 53a of the valve body member 53, so that the rod member 52 and the valve body member 53 can be stably connected.

[0049] Furthermore, since the rod member 52, to which the valve body member 53 is fixed at its left end, has its right end supported by the movable iron core 84, the left end of the rod member 52 is prone to bending radially. However, the inner surface 41c of the base plate 41 restricts the radial bending of the rod member 52, so that the valve body member 53 can be accurately moved toward and away from the valve seat 31.

[0050] In this embodiment, the left end surface 53d of the rod member 52 is fixed flush with the left end surface of the valve body member 53, but the left end surface of the rod member may be located to the right of the left end surface of the valve body member. Even in this case, a communication passage can be formed by the notch and the valve body member.

[0051] Furthermore, in this embodiment, the notch 52a extends to the space S3' inside the bellows 40, but this is not limiting. For example, the notch may be configured to fit inside the valve body member, and a groove may be provided on the inner circumferential surface of the valve body member, one end of which communicates with the notch and the other end of which communicates with the space inside the bellows. In this case, the notch and the groove can form a communication passage.

[0052] In addition, although the present embodiment illustrates an example in which two notches 52a, 52a are provided on the outer periphery of the rod member 52, the notches may be unevenly arranged on the outer periphery of the rod member. Also, the number of notches can be freely changed.

[0053] Furthermore, in this embodiment, the rod member 52 has a circular cross section, but it may have a rectangular cross section or the like.

[0054] In addition, in the above embodiment, the notch 52a is formed by one flat surface 52e, but this is not limited to this and may be, for example, a groove with a U-shaped cross section that opens in the radial direction, i.e., a groove with side walls.

[0055] In the above embodiment, the bellows 40 is made of metal, but the present invention is not limited to this and the bellows 40 may be made of resin. [Example]

[0056] Next, a valve according to a second embodiment will be described with reference to Fig. 5. Note that a description of the same configuration as in the first embodiment will be omitted.

[0057] 5, the inner peripheral surface 153a of the valve body member 153 has a generally regular hexagonal shape when viewed in the axial direction. The rod member 152 has no notches and has a cylindrical shape with a constant cross section in the axial direction.

[0058] When the outer peripheral surface 152c of the rod member 152 is fixed to the inner peripheral surface 153a of the valve body member 153, communication passages 120 are formed near the corners of the inner peripheral surface 153a of the valve body member 153 (six in this embodiment).

[0059] As a result, the communication passage 120 can be easily formed by the outer peripheral surface 152c of the rod member 152 and the inner peripheral surface 153a of the valve member 153 simply by fixing the rod member 152 to the valve member 153.

[0060] Although the embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these embodiments, and the present invention also includes modifications and additions that do not deviate from the gist of the present invention.

[0061] For example, in the first and second embodiments, the valves are described as being configured to be applied to a refrigeration cycle, but the present invention is not limited to this and may be applied to a hydraulic circuit or may be modified as appropriate.

[0062] Furthermore, in the above-described first and second embodiments, the fluid passing through the valve is described as a heat transfer medium, but this is not limited to this, and the type of fluid may be changed as appropriate, such as water or air, the state of the fluid may be changed as appropriate, such as air, liquid, or mist, and the type and state of the fluid may be mixed.

[0063] In addition, in the first and second embodiments, the valve has been described as being configured to be used as an expansion valve, but is not limited to this and may be used as, for example, an on-off valve or a flow rate adjusting valve. Also, the valve may be a pressure reducing valve other than an expansion valve.

[0064] Furthermore, in the first and second embodiments, the valves are of a normally closed type that is in a closed state when de-energized, but this is not limiting and the valves may be of a normally open type that is in an open state when de-energized.

[0065] In addition, in the first and second embodiments, the effective pressure-receiving surfaces on both axial sides of the valve body member are described as having the same area, but this is not limiting and may be different. Even with this configuration, the force acting on the valve body can be reduced by the area where the effective pressure-receiving surfaces on both axial sides of the valve body member overlap.

[0066] In addition, in the first and second embodiments, the primary pressure acts on the valve element in the valve opening direction and the secondary pressure acts on the valve closing direction, but the primary pressure may act on the valve closing direction and the secondary pressure may act on the valve opening direction. In other words, although the embodiment shows a so-called normally closed type valve, the embodiment may also be a normally open type. [Explanation of symbols]

[0067] 1 Expansion valve (valve) 10 Valve housing (housing) 20 Communication path 30 Valve seat member 31 Valve seat 40 Bellows 41 Base Plate 51 Valve body 52 Rod member 52a Notch 52b Solid part 52e flat surface 53 Valve body member 53a Inner surface 70 valves 80 Solenoid 85 coil spring S1 Primary pressure chamber S2 Secondary pressure chamber S3 Back pressure chamber S3' Space inside the bellows

Claims

1. a valve housing having a valve seat between a primary pressure chamber and a secondary pressure chamber; a valve element disposed within the valve housing and operable by a solenoid; a spring that biases the valve body in a direction opposite to the driving direction of the solenoid; a bellows that separates the secondary pressure chamber from a back pressure chamber that is located on the opposite side of the secondary pressure chamber from the primary pressure chamber, The valve body is provided with a communication passage that communicates the primary pressure chamber with the back pressure chamber, a valve that controls a flow rate of a fluid passing through the primary pressure chamber and the secondary pressure chamber by opening and closing the valve, the valve body includes an annular valve body member that can approach and separate from the valve seat, and a rod member that is fixed to an inner circumferential surface of the valve body member with one end inserted into the valve body member, The communication passage is formed by the side surface of the rod member and the inner circumferential surface of the valve body member.

2. 2. The valve according to claim 1, wherein the side surface is a flat surface having a notch shape extending in the axial direction from an end face on one end side of the rod member.

3. The rod member has a circular cross section, 3. The valve according to claim 2, wherein the inner circumferential surface of the valve body member has a circular cross section.

4. 4. A valve according to claim 2 or 3, wherein the notch extends to the interior of the bellows.

5. 2. The valve according to claim 1, wherein a plurality of the communication passages are provided on the outer periphery of the rod member.

6. 6. The valve according to claim 5, wherein the communication passages are evenly spaced around the outer periphery of the rod member.

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