Sliding switch valve and refrigeration cycle system

Abstract

The present invention provides a sliding switching valve and a refrigeration circulation system that can reduce power consumption. The electromagnetic drive unit (5) of the sliding switching valve (1) has a pair of helical springs (52) disposed on both sides of the plunger (51) in the X direction and exerting force on the center of the plunger (51) in the X direction. The force of the pair of helical springs (52A, 52B) is balanced in a neutral position where the plunger (51) is separated from both of the pair of suction members (53), thereby enabling the plunger (51) to move away from the pair of suction members (53) not only by the driving force generated by the electromagnetic drive unit (5) but also by the force of the helical springs (52A, 52B), thus reducing the power consumption at the start of the movement of the plunger (51).

Description

Technical Field

[0001] This invention relates to a sliding switching valve and a refrigeration circulation system. Background Technology

[0002] Typically, switching valves are known that switch the flow path of fluid by moving the valve core using an electromagnetic drive unit with a solenoid coil, thereby opening and closing the valve port formed on the valve seat surface. As such a switching valve, a bypass valve configured to drive a four-way switching valve in a refrigeration cycle system has been proposed (for example, see Patent Document 1). In the switching valve described in Patent Document 1, instead of a spring, the efficiency reduction caused by spring force is suppressed by switching between two opposing electromagnetic actuators.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2011-241870 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In the switching valve described in Patent Document 1, a high-pressure fluid acts on the outside of the pilot valve core, while a low-pressure fluid acts on the inside. Therefore, the pilot valve core is pressed against the valve seat surface due to the pressure difference. At this time, the greater the pressure difference, the greater the pressing force, resulting in higher sliding resistance when the pilot valve core and plunger move. To overcome this sliding resistance and allow the valve core and plunger to move, it is necessary to increase the magnetic force generated by the suction element. That is, when the pressure difference increases, it leads to increased power consumption, and it is desirable to reduce power consumption.

[0008] The purpose of this invention is to provide a sliding switching valve that can reduce power consumption.

[0009] Solution for solving the problem

[0010] The sliding switching valve of the present invention comprises: a valve body forming a valve chamber; a valve seat having a valve seat surface having at least one valve port and disposed within the valve chamber; a valve core that opens and closes the valve port relative to the valve chamber by sliding relative to the valve seat surface; and an electromagnetic drive unit that moves the valve core in a sliding direction along the valve seat surface. The electromagnetic drive unit is characterized by comprising: a plunger extending along the sliding direction and holding the valve core; a pair of suction members disposed on opposite sides of the plunger in the sliding direction; a pair of coils that energize the pair of suction members respectively; and a pair of spring members disposed on opposite sides of the plunger in the sliding direction and applying force to the plunger toward the center of the sliding direction. The pair of spring members are configured such that their forces are balanced when the plunger is separated from both sides of the pair of suction members.

[0011] According to the present invention described above, the forces of the pair of spring components are balanced at the position where the plunger separates from both of the pair of attractors. This allows the plunger to be moved away from the pair of attractors not only by the driving force generated by the electromagnetic drive unit but also by the forces of the spring components, thus reducing power consumption at the start of plunger movement. The magnetic force acting between the attractors and the plunger is inversely proportional to the square of their distance. Therefore, when the plunger is attracted to one attractor, the force required to attract the plunger through the other attractor is minimized. Conversely, the further the plunger is from the position where the forces are balanced, the greater the combined force of the pair of spring components. Therefore, the force acts in a way that assists movement, enabling the plunger to begin moving while reducing power consumption and resisting sliding resistance.

[0012] In this case, in the sliding switching valve of the present invention, it is preferable that a gap is formed between the plunger and the valve core in the sliding direction, and the shorter of the strokes of the plunger from the position attracted to either of the pair of suction members to the position where the forces of the pair of spring members are balanced is greater than the stroke formed by the gap in which the plunger can move relative to the valve core in the sliding direction. With this structure, when the plunger begins to move, it collides with the valve core, and this impact facilitates the initiation of valve core movement. At this time, the stroke of the plunger from the attracted position to the position where the forces are balanced is greater than the stroke of the plunger relative to the valve core, thereby allowing the plunger to collide with the valve core while utilizing the force of the spring members, as described above.

[0013] Furthermore, in the sliding switching valve of the present invention, it is preferable that the valve body has a high-pressure side port, the valve seat surface has a low-pressure side port, and a pair of connecting target ports disposed on both sides of the low-pressure side port in the sliding direction serve as the valve port. The valve core forms a communicating space opening towards the valve seat surface. When the plunger is attracted to either of the pair of suction members, the low-pressure side port is connected to either of the pair of connecting target ports. And when the plunger is positioned such that the forces of the pair of spring members are balanced, the high-pressure side port and the low-pressure side port can be connected via at least one of the pair of connecting target ports. With this structure, when high-pressure fluid flows into the valve chamber in a state where neither of the pair of suction members is energized, the fluid can flow into the low-pressure side port, and the pressure difference of the fluid acting on the valve core can be suppressed. Thus, even when fluid flows in before the operation of the sliding switching valve begins, the plunger can be easily moved, suppressing power consumption.

[0014] Furthermore, in the sliding switching valve of the present invention, it is preferable that a high-pressure side port is formed in the valve body, a low-pressure side port and a pair of connection target ports disposed on both sides of the sliding direction relative to the low-pressure side port are formed on the valve seat surface as the valve port, the valve core forms a communicating space opening toward the valve seat surface and is formed in a bowl shape, and has a pair of sidewall portions clamping the communicating space from the sliding direction, wherein the opening size in the sliding direction of at least one of the pair of connection target ports is larger than the sliding direction size of the front end face of the sidewall portion on the same side of the sliding direction.

[0015] With this structure, by positioning the front end faces of a pair of sidewalls of the valve core between the inner circumferential surfaces of the target port, the valve chamber, which serves as the outer space of the valve core, is connected to the target port, and the target port is also connected to the connecting space. This allows the valve chamber and the low-pressure side port to be connected via the target port and the connecting space. Even when neither of the two suction elements is energized, high-pressure fluid flowing from the high-pressure side port into the valve chamber flows into the low-pressure side port, suppressing the pressure difference of the fluid acting on the valve core. This facilitates plunger movement and reduces power consumption.

[0016] Furthermore, in the sliding switching valve of the present invention, it is preferable that the aforementioned pair of spring components are helical springs with equal spring characteristics. With this structure, the symmetry of the sliding switching valve in the sliding direction can be improved while balancing the forces at the position where the plunger separates from both of the pair of suction members. Additionally, the spring characteristics of a helical spring are mainly its spring constant and free length. The spring constant is determined by the material, wire diameter, coil diameter (outer diameter, inner diameter, or average diameter), and number of turns. However, while the spring constant and free length of a pair of helical springs are equal, the factors determining the spring constant can be different or the factors determining the spring constant can be the same.

[0017] The refrigeration cycle system of the present invention is characterized by comprising: a compressor that compresses a refrigerant as a fluid; a first heat exchanger that functions as a condenser in cooling mode; a second heat exchanger that functions as an evaporator in cooling mode; an expansion mechanism that causes the refrigerant to expand and depressurize between the first and second heat exchangers; the aforementioned sliding switching valve; and a four-way switching valve. According to the refrigeration cycle system of the present invention, power consumption can be reduced in the sliding switching valve as described above, and power consumption can also be reduced as a whole system.

[0018] Invention Effects

[0019] The sliding switching valve according to the present invention can reduce power consumption. Attached Figure Description

[0020] Figure 1 This is a schematic structural diagram of a refrigeration cycle equipped with a sliding switching valve, which is an example of the first embodiment of the present invention.

[0021] Figure 2 This is a cross-sectional view showing the aforementioned sliding switching valve.

[0022] Figure 3 This is a cross-sectional view showing a sliding switching valve as an example of the second embodiment of the present invention.

[0023] In the picture:

[0024] 1—Sliding switching valve, 2—Valve body, 2R—Valve chamber, 212A—Port (high-pressure side port), 3—Valve seat, 31—Valve seat surface, 32A, 32C—Valve port (connection target port), 32B—Valve port (low-pressure side port), 4, 7—Valve core, 4R, 7R—Connecting space, 5—Electromagnetic drive part, 51—Plunger, 514—Retaining part, 515—End face, 52A, 52B—Helical spring (spring component), 53—Suction element, 54—Coil, 71A, 71B—Side wall part, 61—Connector component (pipe part), 10—Four-way switching valve, 12—Slide valve, 19—Piston, A11, A12—Space, 100—Refrigeration cycle, 102—Compressor, 103—Outdoor heat exchanger (first heat exchanger), 104—Indoor heat exchanger (second heat exchanger), 105—Expansion valve (expansion mechanism). Detailed Implementation

[0025] [First Implementation Method]

[0026] The first embodiment of the present invention will be described with reference to the accompanying drawings. The sliding switching valve 1 of this embodiment is provided, for example, in a refrigeration cycle 100. The refrigeration cycle 100 is used in air conditioners such as indoor air conditioners, combination air conditioners, and multi-split air conditioners, and includes: a compressor 102 that compresses a refrigerant as a fluid; an outdoor heat exchanger 103 that functions as a condenser as a first heat exchanger in cooling mode; an indoor heat exchanger 104 that functions as an evaporator as a second heat exchanger in cooling mode; an expansion valve 105 that serves as an expansion mechanism for expanding and depressurizing the refrigerant between the outdoor heat exchanger 103 and the indoor heat exchanger 104; a four-way switching valve 10; and a pilot solenoid valve, i.e., the sliding switching valve 1, that controls the switching of the flow path of the four-way switching valve 10, all connected via refrigerant piping. Furthermore, the expansion mechanism is not limited to the expansion valve 105 and may also be a capillary tube.

[0027] The freezing cycle 100 is in Figure 1 In the cooling mode (refrigeration operation), indicated by the solid arrow, a refrigeration cycle is formed in which the refrigerant flows in the following sequence: compressor 102, four-way switching valve 10, outdoor heat exchanger 103, expansion valve 105, indoor heat exchanger 104, four-way switching valve 10, and compressor 102. Conversely, in the heating mode (heating operation), indicated by the dashed arrow, a heating cycle is formed in which the refrigerant flows in the following sequence: compressor 102, four-way switching valve 10, indoor heat exchanger 104, expansion valve 105, outdoor heat exchanger 103, four-way switching valve 10, and compressor 102. The switching between this heating and cooling cycles is achieved by the switching action of the sliding switching valve 1 on the four-way switching valve 10.

[0028] The four-way switching valve 10 is a known structure, comprising: a cylindrical valve body 11; a slide valve 12 slidably disposed inside the valve body; a high-pressure side conduit (D connector) 13 communicating with the discharge port of the compressor 102; a low-pressure side conduit (S connector) 14 communicating with the suction port of the compressor 102; an indoor side conduit (E connector) 15 communicating with the indoor heat exchanger 104; and an outdoor side conduit (C connector) 16 communicating with the outdoor heat exchanger 103. The valve body 11 is configured as an integrally sealed cylinder by means of plugs 17 and 18 that block its axial ends, and forms spaces A11 and A12 that axially clamp the piston 19 that moves the slide valve 12.

[0029] The sliding switching valve 1 in this embodiment has the structure of a four-way switching valve, such as... Figure 2 As shown, the device includes a valve body 2, a valve seat 3, a valve core 4, an electromagnetic drive 5, and connector components 61-64. The flow path of the fluid is switched by moving the valve core 4 along a predetermined sliding direction. Hereinafter, the sliding direction of the valve core 4 is defined as the X direction, and the two directions orthogonal to the X direction and mutually orthogonal to each other are defined as the Y direction and the Z direction. The up and down directions in the Z direction are... Figure 2 Based on.

[0030] The valve body 2 has a block-shaped valve housing 21 and a pair of cylindrical plunger housings 22A and 22B connected to both sides of the valve housing 21 in the X direction, and has a valve chamber 2R inside them. Sometimes, one side of the plunger housing 22A relative to the valve housing 21 ( Figure 2 The left side of the plunger housing 22B is sometimes referred to as one side in the X direction. Figure 2 The right side of the plunger housing 22A and 22B is referred to as the other side in the X direction. The suction element 53, which will be described later, is airtightly fixed at the end of the plunger housing 22A and 22B on the side opposite to the valve housing 21, and the valve chamber 2R is closed.

[0031] On the side of the valve housing 21, on one side in the Z direction ( Figure 2 An installation opening 211 is formed on the lower side of the middle, and on the other side in the Z direction ( Figure 2 A connecting portion 212 is formed on the upper side of the middle part. The connecting portion 212 has a port 212A and is connected to a connector member 61 as described later.

[0032] The valve seat portion 3 is separately constructed from the valve body 2, forming an integral cylindrical shape extending along the Z direction. The valve seat portion 3 is inserted into the mounting opening 211 and fixed by brazing, and the valve seat surface 31, which is its upper surface, is disposed within the valve chamber 2R. The valve seat portion 3 has three valve ports 32A to 32C that open into the valve seat surface 31, and mounting holes are formed that communicate with each of the valve ports 32A to 32C. The valve seat surface 31 is a planar sliding contact surface extending along the XY plane.

[0033] The mounting holes communicating with valve ports 32A~32C are through holes extending along the Z direction and are respectively connected to connector components 62~64. The mounting holes are arranged in a straight line along the X direction relative to valve ports 32A~32C, and are configured in a triangular shape in the XY plane.

[0034] The valve core 4 is, for example, a spool-type pilot valve core made of synthetic resin, formed into a bowl shape (dome shape) with an opening facing the valve seat surface 31. A communicating space 4R is formed inside the valve core 4, which connects the central valve port 32B and one side valve port 32A while keeping the other side valve port 32C out of communication, or connects the central valve port 32B and the other side valve port 32C while keeping one side valve port 32A out of communication.

[0035] The electromagnetic drive unit 5 includes a pair of drive units 5A and 5B, a plunger 51, and helical springs 52A and 52B, and causes the valve core 4 to slide along the X direction. The pair of drive units 5A and 5B each include an attraction member 53, a coil 54 for energizing the attraction member 53, and a housing 55. Thus, the electromagnetic drive unit 5 has a pair of attraction members 53 and a pair of coils 54. Drive unit 5A is located on one side of the X direction, and drive unit 5B is located on the other side of the X direction.

[0036] The plunger 51 is integrally formed from a magnetic material into a cylindrical shape extending along the X direction. It has a small-diameter portion 511 at the center in the X direction and large-diameter portions 512A and 512B disposed on both sides of the small-diameter portion 511 in the X direction. The outer diameter of the large-diameter portions 512A and 512B is slightly smaller than the inner diameter of the plunger housings 22A and 22B. The large-diameter portions 512A and 512B are guided along the X direction by the plunger housings 22A and 22B. On one side of the plunger 51 in the Z direction, a D-shaped cut portion 513 is formed throughout the large-diameter portion 512A and the small-diameter portion 511. The D-shaped cut portion 513 is opposite to the valve seat surface 31.

[0037] Furthermore, in this embodiment, the plunger 51 is composed of a single component, but the plunger may also be composed of multiple components. For example, it may have a magnetic part that is attracted by the attracting element and a non-magnetic part, with the valve core held in place by the non-magnetic part. That is, the plunger includes a magnetic part that is attracted by the attracting element and a part that slides and moves together with the magnetic part.

[0038] A concave retaining portion 514 with an opening toward the valve seat surface 31 is formed on the Z-direction side of the small diameter portion 511 where the D-shaped cut portion 513 is formed. The valve core 4 is disposed and retained in the retaining portion 514. A helical spring 515 is provided on the inner side of the retaining portion 514 to apply force to the valve core 4 on the Z-direction side.

[0039] On one end of the suction member 53 of the large diameter portions 512A and 512B, a recess 516 for receiving each of the helical springs 52A and 52B is formed, and a pressure equalization hole 517 communicating between the recess 516 and the surface with the D-shaped cut portion 513. The pair of helical springs 52A and 52B are spring components that apply force to the center portion of the plunger 51 in the X direction, and their spring characteristics are equal. When neither of the pair of drive units 5A and 5B is supplied with power, the pair of helical springs 52A and 52B balances the forces to stop the plunger 51 at the center portion in the X direction; this stopping position of the plunger 51 is called the "neutral position." The plunger 51 separates from both the pair of suction members 53 in the neutral position. Furthermore, in this embodiment, the pair of helical springs 52A and 52B are components of the same specification and have the same characteristics except for manufacturing errors. That is, the spring constant and free length of a pair of helical springs 52A and 52B are equal to each other, and the material, wire diameter, outer diameter, inner diameter, average diameter and number of turns of the coil, which are factors that determine the spring constant, are equal to each other.

[0040] When the plunger 51 is positioned in the neutral position, the valve core 4, which is held in place by the plunger 51, is also positioned within the neutral range. Furthermore, a gap is formed between the valve core 4 and the plunger 51 as described later, allowing the valve core 4 to move relative to the plunger 51. Therefore, the valve core 4 is not positioned in a predetermined position, but rather within the neutral range. Within the neutral range, the communication space 4R of the valve core 4 communicates only with the central valve port 32B, and not with the left and right valve ports 32A and 32C.

[0041] The equalizing hole 517 has a portion that communicates with the recess 516 and extends in the X direction, and a portion that communicates with the portion extending in the X direction and extends in the Z direction to communicate with the surface where the D-shaped cut portion 513 is formed. The D-shaped cut portion 513 has an asymmetrical shape in the X direction. Therefore, in the large-diameter portion 512B on the side where the D-shaped cut portion 513 is not formed, the portion extending in the X direction in the equalizing hole 517 is formed to be longer, and the portion extending in the Z direction is also located near the center in the X direction. By forming the equalizing hole 517 and the D-shaped cut portion 513 as described above, the spaces on both sides of the plunger 51 in the X direction are not sealed and will not adhere to the suction member 53. In addition, by forming the small-diameter portion 511, the upper and lower spaces of the plunger 51 in the valve chamber 2R are connected.

[0042] The concave retaining portion 514 has a pair of inner surfaces 514A and 514B facing each other in the X direction, and the valve core 4 held in the retaining portion 514 has a pair of side surfaces 4A and 4B on both sides in the X direction. The distance between the pair of inner surfaces 514A and 514B is greater than the distance between the pair of side surfaces 4A and 4B. As a result, a gap is formed in the X direction between the retaining portion 514 of the plunger 51 and the valve core 4, allowing the valve core 4 to move relative to the retaining portion 514 in the X direction. Preferably, when the inner surface 514A and the side surface 4A abut, the gap between the inner surface 514B and the side surface 4B on the opposite side is less than 1 mm. That is, the difference between the distance between the pair of inner surfaces 514A and 514B and the distance between the pair of side surfaces 4A and 4B is equivalent to the size of this gap. When the inner surface 514B and the side surface 4B abut, a gap of the same size is also formed.

[0043] The stroke of plunger 51 from the neutral position to the position where it is attracted to suction member 53, i.e., the half stroke, is equal to that of a pair of suction members 53. Such half stroke of plunger 51 is greater than the stroke of plunger 51 relative to valve core 4 that can move in the X direction (i.e., the size of the gap between the inner surfaces 514A, 514B and the sides 4A, 4B as described above), i.e., the relative stroke.

[0044] The attracting element 53 is formed into a cylindrical shape by a magnetic material and is configured to block the openings in the plunger housings 22A and 22B facing the X direction opposite to the plunger 51. It is joined to the plunger housings 22A and 22B by, for example, welding. A coil 54 is disposed on the outside of the plunger housings 22A and 22B in the X direction corresponding to the attracting element 53 and is supplied with electricity. When a voltage is applied to the coil 54 and current flows through it, the attracting element 53 is energized, and the plunger 51, being a magnetic material, is attracted by the attracting element 53 and moves in the X direction.

[0045] A connector 62 connected to a mounting hole communicating with one side of valve port 32A is connected to one side of space A12 of the four-way switching valve 10; a connector 63 connected to a mounting hole communicating with the central valve port 32B is connected to the low-pressure side conduit 14 of the four-way switching valve 10; a connector 64 connected to a mounting hole communicating with the other side of valve port 32C is connected to the other side of space A11 of the four-way switching valve 10; and a connector 61 connected to the connecting part 212 is connected to the high-pressure side conduit 13 of the four-way switching valve 10.

[0046] like Figure 2As shown, when valve core 4 is located on one side in the X direction and valve ports 32B and 32A are connected, valve ports 32B and 32A are closed relative to valve chamber 2R by valve core 4, while valve port 32C is open relative to valve chamber 2R. At this time, high-pressure fluid flowing from port 212A into valve chamber 2R passes through valve port 32C toward space A11 of the four-way switching valve 10. Valve port 32B is connected to the low-pressure side conduit 14, and space A12, connected to valve port 32A, becomes low-pressure. Therefore, space A11 is higher than space A12, and through this pressure difference, piston 19 and slide valve 12 of the four-way switching valve 10 move toward space A12.

[0047] With valve core 4 located on the opposite side in the X direction and valve ports 32B and 32C connected, valve ports 32B and 32C are closed relative to valve chamber 2R via valve core 4, while valve port 32A is open relative to valve chamber 2R. At this time, high-pressure fluid flowing from port 212A into valve chamber 2R passes through valve port 32A toward space A12 of the four-way switching valve 10. Valve port 32B is connected to the low-pressure side conduit 14, and space A11, connected to valve port 32C, becomes low-pressure. Therefore, space A12 is higher than space A11, and through this pressure difference, the slide valve 12 and piston 19 of the four-way switching valve 10 move toward space A11.

[0048] As described above, when the plunger 51 and valve core 4 move, due to the gap formed between the plunger 51 and valve core 4, after a period of idling where only the plunger 51 moves, the plunger 51 collides with the valve core 4. When the plunger 51 moves towards the X direction, the inner surface 514B and the side surface 4B abut, causing the valve core 4 to also move towards the X direction. When the plunger 51 stops due to being attracted by the suction member 53 on the X direction side, the abutment between the inner surface 514B and the side surface 4B is maintained, forming a gap G between the inner surface 514A and the side surface 4A. Then, when the plunger 51 begins to move towards the other side of the X direction, it initially moves in an idling state, with only the plunger 51 moving, and then the inner surface 514A and the side surface 4A collide, causing the valve core 4 to begin moving. Similarly, when the plunger 51 begins to move towards the X direction, the plunger 51 and valve core 4 also collide.

[0049] Here, the details of the force acting on the plunger 51 in the X direction are explained. The magnetic attraction of the attracting member 53 and the combined force of the pair of helical springs 52A and 52B act on the plunger 51, causing the plunger 51 to move due to their resultant force. Here, when switching the target of the plunger 51's attraction, the force towards the newly attracted side (hereinafter referred to as the target switching side) is set as a positive force, and the force towards the opposite side (hereinafter referred to as the initial switching side) is set as a negative force. The magnetic attraction is inversely proportional to the square of the distance between the attracting member 53 and the plunger 51. In contrast, the individual forces of the helical springs 52A and 52B are proportional to the distance between the attracting member 53 and the plunger 51, and the combined force of the pair of helical springs 52A and 52B is proportional to the distance between the attracting member 53 and the plunger 51, and becomes 0 in the neutral position of the plunger 51.

[0050] When the plunger 51 is attracted by the initial attraction member 53 and the target attraction member 53 begins to attract, the target attraction member 53 and the plunger 51 are at their furthest apart, and the magnetic attraction force is at its minimum. Conversely, the combined force of the pair of helical springs 52A and 52B is at its maximum. Therefore, compared to a structure where only the magnetic attraction force acts, the combined force acting on the plunger 51 when the target attraction member 53 begins to attract increases. That is, by applying force to the plunger 51 towards a neutral position through the pair of helical springs 52A and 52B, an auxiliary attraction effect is obtained at the beginning of the attraction.

[0051] At this time, when the plunger 51 reaches the neutral position, it cannot receive the assistance of the pair of coil springs 52A and 52B to move the plunger 51. As mentioned above, the half stroke of the plunger 51 is greater than the relative stroke between the plunger 51 and the valve core 4, thus allowing the plunger 51 to collide with the valve core 4 before it reaches the neutral position.

[0052] Furthermore, when the plunger 51 begins to move, the magnetic attraction increases, while the force decreases. Therefore, based on the relationship between the magnetic attraction and the forces of the helical springs 52A and 52B, the resultant force sometimes decreases as the plunger approaches the neutral position. However, the static friction coefficient is greater than the kinetic friction coefficient. The force required to continue the movement of the plunger 51 is less than the force required to initiate the movement. Therefore, even with a smaller resultant force, it is difficult to stop the movement of the plunger 51. In other words, the voltage applied to the coil 54, the stroke of the plunger 51, and the spring characteristics are set in such a way that the resultant force exceeds the frictional force calculated based on the kinetic friction coefficient throughout the entire movable range of the plunger 51.

[0053] According to the above embodiment, the force of a pair of helical springs 52A and 52B is used to balance the plunger 51 at the neutral position where it is separated from the pair of suction members 53. This allows the plunger 51 to move away from the pair of suction members 53 by utilizing not only the driving force generated by the electromagnetic drive unit 5, but also the force of the helical springs 52A and 52B. This reduces the power consumption at the start of the movement of the plunger 51.

[0054] In addition, by having equal spring characteristics of a pair of helical springs 52A and 52B, the symmetry of the sliding switching valve 1 in the X direction can be improved while the forces are balanced in the neutral position where the plunger 51 is separated from both of the pair of suction members 53.

[0055] In addition, by forming an X-direction gap between the plunger 51 and the valve core 4, and by having the half-stroke of the plunger 51 greater than the relative stroke of the plunger 51 and the valve core 4, the valve core 4 can be easily started to move by utilizing the impact that causes the plunger 51 to collide with the valve core 4, and the plunger 51 can collide with the valve core 4 while utilizing the force of the helical springs 52A and 52B.

[0056] [Second Implementation]

[0057] In the second embodiment, structures common to the first embodiment are labeled with the same symbols, and explanations are omitted; the main focus is on the differences from the first embodiment. Structures not specifically described have the same shape and function as those in the first embodiment.

[0058] In the second embodiment, a sliding switching valve replaces valve core 4 and has valve core 7. Valve core 4 and valve core 7 differ in their main dimensions; therefore, the following uses an enlarged view showing the peripheral structure of valve core 7. Figure 3 The following explanation will be provided. In the first embodiment, the communicating space 4R of the valve core 4, positioned in the neutral range, communicates only with the central valve port 32B. In contrast, in the second embodiment, the valve core 7, positioned in the neutral range, communicates with the valve port 32B and the left and right valve ports 32A and 32C. The dimensional relationships between the various parts of the valve core 7 and the various parts on the valve seat surface 31 will be explained in detail.

[0059] The valve core 7 is a bowl-shaped component that forms a communicating space 7R, similar to the valve core 4 in the first embodiment, and has a pair of sidewall portions 71A and 71B that sandwich the communicating space 7R from the X direction. The sidewall portions 71A and 71B divide the communicating space 7R and the space outside it in the X direction. The front end faces (the faces that slide in contact with the valve seat surface 31) of the sidewall portions 71A and 71B have equal dimensions in the X direction, and this dimension is set as L1. Furthermore, when the periphery of the front end faces of the sidewall portions 71A and 71B is chamfered, the dimension L1 is also a dimension that takes into account the chamfer, and the dimension L1 reduces the amount of chamfer.

[0060] The opening dimensions in the X direction of the left and right valve ports 32A and 32C, which are connected to the target ports, and the central valve port 32B are equal, and this opening dimension is set as L2. In addition, when the periphery of valve ports 32A~32C is chamfered, the opening dimension L2 also takes into account the chamfer dimension, and the opening dimension L2 increases the amount of chamfer.

[0061] The opening size in the X direction at the front end of the connecting space 7R is set to L3. Furthermore, when the periphery of the front end face of the side wall portions 71A and 71B is chamfered, the opening size L3 also takes into account the chamfer size, and the opening size L3 increases the amount of chamfer.

[0062] The interval between the central valve port 32B and valve port 32A is equal to the interval between valve port 32B and valve port 32C, and this interval is set to L4. In addition, when the periphery of valve ports 32A~32C is chamfered, the interval L4 also takes into account the chamfer size, and the interval L4 reduces the amount of chamfer.

[0063] The opening size L2 of valve ports 32A and 32C is larger than the size L1 of side wall portions 71A and 71B. Furthermore, the opening size L3 of the communicating space 7R is larger than the sum of the opening size L2 of the central valve port 32B, the distance L4 between the central valve port 32B and valve port 32A, and the distance L4 between valve ports 32B and 32C. In other words, the opening size L3 of the communicating space 7R is larger than the distance between the left and right valve ports 32A and 32C.

[0064] Based on the aforementioned dimensional relationships, when the central axis of the valve port 32B, which is the central part of the valve seat 3 in the X direction, and the center of the communicating space 7R, which is the central part of the valve core 7 in the X direction, are aligned, the sidewall portions 71A and 71B are located within the respective ranges of the valve ports 32A and 32C, respectively. Thus, the valve ports 32A and 32C are connected to both the space outside the valve core 7 (i.e., the valve chamber 2R) and the communicating space 7R. That is, the communicating space 7R is connected to the valve chamber 2R via the valve ports 32A and 32C. Furthermore, the communicating space 7R is also connected to the valve port 32B.

[0065] Furthermore, in this embodiment, the intervals between the central valve port 32B and valve port 32A, and between valve port 32B and valve port 32C, are equal, but these intervals can also be different. When the smaller of these intervals is set as L4', as long as half of the opening size L3 of the communicating space 7R is larger than the sum of half of the opening size L2 of the central valve port 32B and the smaller interval L4', the communicating space 7R and the valve chamber 2R can be connected via the valve port on the side where the smaller interval L4' is formed. At this time, the opening size L2 of valve ports 32A and 32C only needs to be larger than the size L1 of the sidewall portions 71A and 71B of the valve core 7, at least on the side where the smaller interval L4' is formed.

[0066] When no voltage is applied to the pair of coils 54, the forces of the pair of helical springs 52 are balanced, thus the plunger 51 is in a neutral position, and the valve core 7 is also in a neutral range. When the valve core 7 is in the center of the neutral range, as described above, the valve seat portion 3 and the center portion of the valve core 7 in the X direction are aligned with each other. Even if the valve core 7 is biased towards either of the valve cores in the X direction within the neutral range, the valve chamber 2R and the communication space 7R are connected via at least one of the valve ports 32A and 32C, and the high-pressure side port 212A and the low-pressure side valve port 32B are connected.

[0067] Before voltage is applied to the pair of coils 54, when a portion of the refrigeration cycle 100 is started, fluid flows into the sliding switching valve with the plunger 51 in the neutral position and the valve core 7 in the neutral range. Even in this condition, the high-pressure fluid flowing into the valve chamber 2R through the high-pressure side port 212A and the low-pressure side valve port 32B flows toward the valve port 32B, reducing the pressure difference of the fluid acting on the valve core 7.

[0068] According to the above embodiment, it achieves the same effect as the first embodiment described above. Furthermore, by connecting the high-pressure side port 212A and the low-pressure side port 32B via at least one of the valve ports 32A and 32C through the valve core 7 in the neutral position of the plunger 51, the frictional force generated by the pressure difference can be reduced, making it difficult to generate sliding resistance and thus saving energy.

[0069] Furthermore, by making the opening size L2 of valve ports 32A and 32C larger than the size L1 of sidewall portions 71A and 71B, it is possible to easily connect the high-pressure side port 212A and the low-pressure side valve port 32B as described above.

[0070] Furthermore, the present invention is not limited to the embodiments described above, and includes other structures that can achieve the objectives of the present invention. The variations shown below are also included in the present invention. For example, in the first and second embodiments described above, a gap is formed between the plunger 51 and the valve core 4, but it may also be configured such that no gap is formed between them, and the plunger and the valve core move integrally.

[0071] Furthermore, in the first and second embodiments described above, the spring characteristics of the helical springs 52, which are a pair of spring components, are equal to each other. However, the forces acting on the pair of spring components are balanced when the plunger is separated from the pair of suction members. In the case where the sliding switching valve is asymmetrical in the sliding direction, for example, the spring constant of one spring component can be made larger than that of the other, or the spring constants of both components can be made equal while the natural lengths are different.

[0072] Furthermore, the shape of the plunger is not limited to the first and second embodiments described above. For example, in the first and second embodiments, a D-shaped cut portion 513 is formed locally on the plunger 51, but a D-shaped cut portion that extends throughout the sliding direction can also be formed on the plunger.

[0073] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the specific structure is not limited to these embodiments, and design changes that do not depart from the spirit of the present invention are also included in the present invention.

Claims

1. A slide type switching valve comprising: a valve main body that forms a valve chamber; and a valve seat portion that has a valve seat surface in which at least one valve port is formed, and is provided in the valve chamber. A valve core that opens and closes the valve port relative to the valve chamber by sliding relative to the valve seat surface; and an electromagnetic drive unit that moves the valve core in a sliding direction along the valve seat surface, characterized in that... The electromagnetic drive unit includes: a plunger extending along the sliding direction and holding the valve core; a pair of suction members disposed on opposite sides of the sliding direction relative to the plunger; and a pair of coils that energize the pair of suction members respectively. And a pair of spring components, which are disposed on both sides of the plunger in the sliding direction, and apply force to the plunger toward the center of the sliding direction. The pair of spring components are configured such that their forces are balanced when the plunger is separated from both of the pair of suction members.

2. The sliding switching valve according to claim 1, characterized in that, A gap is formed between the plunger and the valve core in the sliding direction. The shorter of the strokes in which the plunger moves from a position attracted to either of the pair of suction members to a position where the forces of the pair of spring members are balanced is greater than the stroke formed by the gap in which the plunger can move relative to the valve core in the sliding direction.

3. The sliding switching valve according to claim 1 or 2, characterized in that, A high-pressure side port is formed in the valve body. The valve seat surface has a low-pressure side port and a pair of connection target ports disposed on both sides of the sliding direction relative to the low-pressure side port as the valve port. The valve core forms a communicating space that opens toward the valve seat side, allowing the low-pressure side port to communicate with either of the pair of connecting target ports when the plunger is attracted to either of the pair of suction members, and enabling the high-pressure side port and the low-pressure side port to communicate via at least one of the pair of connecting target ports when the plunger is positioned such that the forces of the pair of spring members are balanced.

4. The sliding switching valve according to claim 1 or 2, characterized in that, A high-pressure side port is formed in the valve body. The valve seat surface has a low-pressure side port and a pair of connection target ports disposed on both sides of the sliding direction relative to the low-pressure side port as the valve port. The valve core forms a communicating space that opens toward the valve seat surface and is shaped like a bowl, and has a pair of sidewall portions that clamp the communicating space from the sliding direction. The opening size in the sliding direction of at least one of the pair of connection target ports is larger than the sliding direction size of the front end face of the sidewall portion on the same side.

5. The sliding switching valve according to claim 1 or 2, characterized in that, The pair of spring components are helical springs with equal spring properties.

6. A refrigeration cycle system characterized by comprising: have: A compressor, which compresses a refrigerant as a fluid; The first heat exchanger functions as a condenser in cooling mode. The second heat exchanger functions as an evaporator in cooling mode. An expansion mechanism that causes the refrigerant to expand and depressurize between the first heat exchanger and the second heat exchanger; The sliding switching valve as described in claim 1 or 2; and Four-way switching valve.

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