JP2024114419A - Composite valve and composite valve control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To downsize a composite valve.

SOLUTION: A composite valve 1 includes: a first valve 10 having a large diameter; a second valve 12 having a diameter that is smaller than that of the first valve 10; and a single solenoid 3 for driving the first valve 10 and the second valve 12 to open and close them. Energization control to the solenoid 3 controls the opening of the second valve 12, whereby the second valve 12 works as an expansion valve.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a composite valve that includes a large-diameter valve and a small-diameter valve.

With the recent spread of electric vehicles, the development of their air conditioning systems is also progressing. Since electric vehicles do not have a heat source from an internal combustion engine, they use heat pump-type air conditioning and heating equipment that uses a refrigerant for both cooling and heating, and operates in a cycle.

Such vehicle heating and cooling systems have a refrigeration cycle that includes a compressor, an exterior heat exchanger, an expansion device, an evaporator, an interior heat exchanger, etc., and the refrigerant circulation passage is switched between heating and cooling operations. In other words, multiple refrigerant circulation passages are formed, and therefore the number of control valves for controlling the flow of the refrigerant is also increased. For this reason, it is important that these control valves can be accommodated as compactly as possible within the limited space of the vehicle.

To deal with this problem, a composite valve has been proposed in which multiple control valves are assembled into a unit in a common body. The valve parts of each control valve are housed in a common body, and each valve part is opened and closed by a single actuator. This type of composite valve is more compact overall than a valve in which each control valve is provided as a standalone unit.

Specifically, a combined valve (motorized valve) has been proposed in which a large-diameter valve (also called a "large-diameter valve") and a small-diameter valve (also called a "small-diameter valve") are driven by a single motor (see Patent Document 1). By arranging such a combined valve in the refrigerant circulation passage, the small-diameter valve can function as an expansion valve, while the large-diameter valve can function as an opening/closing valve.

JP 2020-41596 A

Since such combined valves have complex mechanisms, such as a screw feed mechanism that converts the rotational motion of the rotor into the translational motion of the valve body, the actuator tends to be large and heavy. In this respect, there was room for improvement.

One of the objectives of the present invention is to realize a compact composite valve.

One aspect of the present invention is a combined valve. This combined valve comprises a first valve with a large diameter, a second valve with a smaller diameter than the first valve, and a single solenoid that drives the first valve and the second valve to open and close. The opening of the second valve is controlled by controlling the supply of electricity to the solenoid, and the second valve functions as an expansion valve.

In this embodiment, a solenoid is used as a common actuator for both the first and second valves, making it possible to realize a more compact combined valve than would be possible if a motor were used.

Another aspect of the present invention is a combined valve control device. This combined valve control device includes a combined valve that drives a large-diameter first valve and a small-diameter second valve with a single solenoid to open and close, and a control unit that controls the current supplied to the solenoid. The combined valve includes a body on which a first valve seat is formed, a first valve body that is detachable from the first valve seat to open and close the first valve, a second valve seat provided in an internal passage of the first valve body, a second valve body that is detachable from the second valve seat to open and close the second valve, and an operation connection mechanism that connects or releases the operation of the first valve body and the second valve body depending on the current supply state to the solenoid and connects the operation of the second valve body and the first valve body when the second valve is fully open. The solenoid is controlled by a PWM method in the process of changing the opening degree of each of the first valve and the second valve. The control unit temporarily increases the rate of change of the current supplied to the solenoid in a predetermined stroke region of the first valve body where the first valve is in a partially open state.

According to this aspect, since a solenoid is used as an actuator shared by both the first and second valves, a combined valve can be realized in a compact size compared to when a motor is used. In addition, since a PWM method is used to control the current flow to the solenoid, problems such as abnormal noise caused by the first valve body hitting the first valve seat due to minute vibrations when the valve is opened slightly (so-called valve knocking) can easily occur, particularly with a large-diameter first valve. In this regard, according to this aspect, by temporarily increasing the rate of change of the current supplied to the solenoid, it is possible to quickly escape from the stroke region where valve knocking is likely to occur, and to prevent or suppress the generation of abnormal noise. In other words, it becomes easier to avoid problems that can occur when a solenoid is used as an actuator.

The present invention aims to achieve a compact composite valve.

1 is a cross-sectional view illustrating a schematic structure of a combined valve according to a first embodiment. FIG. 4 is a partially enlarged view showing the operation of the combined valve. FIG. 4 is a diagram showing the valve opening characteristics of a combined valve. FIG. 11 is a cross-sectional view illustrating a schematic structure of a combined valve according to a modified example. FIG. 11 is a cross-sectional view illustrating a schematic structure of a combined valve according to a second embodiment. FIG. 4 is a partially enlarged view showing the operation of the combined valve. FIG. 4 is a diagram showing the valve opening characteristics of a combined valve. 13 is a cross-sectional view illustrating a schematic structure of a combined valve according to a modified example. FIG. 11 is a diagram illustrating a current supply control when the combined valve is a normally open valve. FIG. 11 is a diagram illustrating energization control when the combined valve is a normally closed valve. FIG.

The following describes in detail an embodiment of the present invention with reference to the drawings. In the following description, for convenience, the positional relationship of each structure may be expressed based on the illustrated state. In addition, in the following embodiments and their modified examples, substantially identical components are given the same reference numerals, and their description will be omitted as appropriate.

[First embodiment]
FIG. 1 is a cross-sectional view that illustrates a schematic structure of a combined valve according to a first embodiment.
The combined valve 1 is applied to a heat pump type vehicle air conditioner. This air conditioner has a refrigeration cycle including a compressor, an exterior heat exchanger, an expansion device, an evaporator, an interior heat exchanger, etc., and the function of the exterior heat exchanger is switched between heating operation and cooling operation. During heating operation, the exterior heat exchanger functions as an evaporator. During this, the interior heat exchanger releases heat as the refrigerant circulates through the refrigeration cycle, and the air in the vehicle cabin is warmed by this heat. During cooling operation, the exterior heat exchanger functions as a condenser. At this time, the refrigerant condensed in the exterior heat exchanger is decompressed and expanded by the expansion device to become a gas-liquid two-phase refrigerant, which is then evaporated in the evaporator. The air in the vehicle cabin is cooled by the latent heat of evaporation.

The combined valve 1 is disposed, for example, between an indoor heat exchanger and an outdoor heat exchanger, and functions as an on-off valve that opens and closes the refrigerant circulation passage during cooling operation, and as an expansion valve that throttles and expands the refrigerant flowing through the refrigerant circulation passage during heating operation.

The combined valve 1 comprises a large-diameter first valve 10 (large-diameter valve) and a small-diameter second valve 12 (small-diameter valve), and these valves are driven to open and close by a single solenoid 3. The combined valve 1 functions as an opening and closing valve by opening and closing the first valve 10, and functions as an expansion valve by adjusting the opening degree of the second valve 12. The combined valve 1 is a so-called normally open valve, and both the first valve 10 and the second valve 12 are fully open when the solenoid 3 is off (not energized).

The combined valve 1 is constructed by assembling a body 2 and a solenoid 3 in the axial direction. A valve hole 14 (first valve hole) is provided on the axis of the body 2, and a valve seat 16 (first valve seat) is formed at the downstream opening.

The solenoid 3 comprises a stepped cylindrical core 20 coaxially assembled to the body 2, a bottomed cylindrical sleeve 22 (non-magnetic material) coaxially assembled to the core 20, a plunger 24 housed inside the sleeve 22 and facing the core 20 in the axial direction, and an electromagnetic coil 26 wound around the sleeve 22. Note that this figure is a schematic diagram, and therefore the structure of the connection between the body 2 and the core 20 is not shown.

The core 20 has an expanded diameter at the connection portion with the body 2, and a valve body 30 (first valve body) is disposed inside the expanded diameter portion. A guide hole 28 is formed by the inner peripheral surface of the expanded diameter portion. The valve body 30 is cylindrical with a bottom, and is slidably supported in the guide hole 28. The valve body 30 opens and closes the first valve 10 by attaching and detaching from the valve seat 16 from the downstream side. Meanwhile, a valve hole 32 (second valve hole) is formed in the middle of the internal passage of the valve body 30. A valve seat 34 (second valve seat) is formed at the upstream opening of the valve hole 32.

The valve body 30 is cylindrical with a bottom that has a sufficient thickness. A back pressure chamber 36 is formed at the back of the valve body 30 (the side opposite the valve hole 14). The back pressure chamber 36 is a space surrounded by the core 20 and the valve body 30. A valve chamber 38 is formed inside the valve body 30. A disk-shaped engagement member 40 is fixed to the end of the valve body 30. The engagement member 40 has an insertion hole 42 in its center.

A plurality of communication holes 31 (small holes) are provided through the bottom of the valve body 30 in parallel with the axis. The upstream opening of these communication holes 31 is the inlet port 33. The communication holes 31 communicate the valve hole 14 and the valve chamber 38. The communication holes 31, the valve chamber 38, and the insertion hole 42 constitute a "communication passage" that communicates the valve hole 14 and the back pressure chamber 36. In addition, a downstream passage 35 extending perpendicular to the axis is provided at the bottom of the valve body 30. The downstream passage 35 has an outlet port 37 that opens toward the downstream side of the valve hole 14. A seal ring 39 (O-ring) is fitted to the outer circumferential surface of the valve body 30, and the flow of the refrigerant through the gap between the valve body 30 and the guide hole 28 is restricted. In a modified example, a communication hole that communicates the valve chamber 38 and the back pressure chamber 36 may be provided in the valve body 30 in addition to the insertion hole 42.

The operating rod 44 extends from the plunger 24 and penetrates the core 20 coaxially. A valve body 46 (second valve body) is provided at the tip of the operating rod 44. The operating rod 44 slidably penetrates the insertion hole 42 of the valve body 30, and the valve body 46 is disposed in the valve chamber 38. The valve body 46 opens and closes the second valve 12 by attaching and detaching from the valve seat 34 from the upstream side. A spring 48 (biasing member) is interposed between the plunger 24 and the core 20, which biases the operating rod 44 in the valve opening direction of the valve body 46. The spring 48 functions as a so-called "off spring" for fully opening the first valve 10 (large diameter valve) when the solenoid 3 is not energized.

In this embodiment, the valve body 46 has a tapered detachable portion 47 that is detachable from the valve seat 34, and a spool portion 49 that is inserted into and removed from the valve hole 32. In the stroke region where the spool portion 49 is inserted into the valve hole 32 and the detachable portion 47 is removed from the valve seat 34, the opening of the second valve 12 is maintained at a constant small opening (hereinafter, this state is also referred to as the "spool state").

A spring retainer 50 protruding in the radial direction is provided near the valve body 46 on the operating rod 44, and an engagement member 52 is provided to engage with the spring retainer 50. The spring retainer 50 is, for example, an E-ring. The engagement member 52 is cylindrical and is coaxially inserted and fixed to the operating rod 44. One end face of the engagement member 52 (the end face opposite the spring retainer 50) is engageable (detachable) with one end face of the engagement member 40. A spring 54 (biasing member) is interposed between the bottom of the valve body 30 and the spring retainer 50, which biases the valve body 30 in the valve closing direction (the direction in which the engagement member 40 and the engagement member 52 are engaged).

As shown, by engaging the engaging member 40 and the engaging member 52, the valve body 46 and the valve body 30 can be connected so as to be displaceable together via the operating rod 44, that is, they can be operatively connected. In other words, the engaging member 40 provided on the valve body 30, the engaging member 52 provided on the operating rod 44, and the spring 54 provided between the valve body 30 and the engaging member 52 constitute an "operational connection mechanism" that connects or releases the operation of the valve body 30 and the valve body 46.

Next, the operation of the control valve will be described.
In this embodiment, a PWM (Pulse Width Modulation) method is adopted for controlling the energization of the solenoid 3. The PWM control performs energization control by supplying a pulse current of a predetermined frequency (e.g., about 400 Hz), and changes the duty ratio of the pulse current to change the supplied current value. The control unit 100 executes the energization control.

The control unit 100 outputs a pulse signal set to a predetermined duty ratio to the drive circuit 102, and causes the drive circuit 102 to output a current pulse corresponding to that duty ratio to drive the solenoid 3. The control unit 100 includes a CPU that executes various arithmetic processes, a ROM that stores various control programs, a RAM that is used as a work area for storing data and executing programs, an input/output interface, and the like. The control unit 100 has a PWM output unit that outputs a pulse signal of a specified duty ratio, but since the configuration itself is well known, a detailed description will be omitted. The combined valve 1, the control unit 100, and the drive circuit 102 constitute a "combined valve control device."

Figure 2 is a partially enlarged view showing the operation of the combined valve 1. Figure 2(A) shows a state in which both the first valve 10 and the second valve 12 are open, Figure 2(B) shows a state in which the first valve 10 is closed and the second valve 12 is open, and Figure 2(C) shows a state in which both the first valve 10 and the second valve 12 are closed. The following explanation will be based on Figure 1, with reference to Figure 2 as appropriate.

When the solenoid 3 in the combined valve 1 is not energized (off), no suction force acts between the core 20 and the plunger 24. Meanwhile, the biasing force of the spring 48 acts in a direction that moves the plunger 24 away from the core 20. This biasing force is transmitted to the valve body 46 via the operating rod 44. As a result, the second valve 12 is fully open (FIG. 2(A)). At this time, the engaging member 52 engages with the engaging member 40, and the operating rod 44 lifts the valve body 30, so that the first valve 10 is also fully open. This opens the refrigerant circulation passage.

When a control current is supplied to the solenoid 3, the core 20 attracts the plunger 24. This causes the operating rod 44 to be biased in the direction of closing the first valve 10 and the second valve 12. At this time, the duty ratio of the PWM control can be increased to increase the value of the current supplied to the solenoid 3, and the first valve 10 (large diameter valve) can be operated in the direction of closing (Figure 2 (B)). The load of the spring 54 biases the valve body 46 in the direction of opening the valve, so the second valve 12 remains fully open until the first valve 10 closes.

By further increasing the duty ratio and increasing the value of the current supplied to the solenoid 3, the second valve 12 (small diameter valve) can be operated in the valve closing direction while keeping the first valve 10 closed (Figure 2 (C)). At this time, the opening degree of the second valve 12 can be controlled by adjusting the duty ratio, allowing the combined valve 1 to function as an expansion valve.

Figure 3 shows the valve opening characteristics of the combined valve 1. The horizontal axis of the figure shows the value of the current supplied to the solenoid, and the vertical axis shows the valve opening. For ease of explanation, A to C are written in Figure 3 to show the correspondence with the operating processes in Figures 2 (A) to (C).

The operation of each valve shown in FIG. 2 is expressed as the control characteristic shown in FIG. 3. That is, when the supply current value to the solenoid 3 is from zero to the first current value I1, both the first valve 10 and the second valve 12 maintain a fully open state (FIG. 2(A)). When the supply current value exceeds the first current value I1, the valve body 30 operates in the valve closing direction while the second valve 12 maintains a fully open state, and the opening degree of the first valve 10 changes. When the supply current value reaches the second current value I2, the valve body 30 seats on the valve seat 16, and the first valve 10 is in a closed state (fully closed state) (FIG. 2(B)). Therefore, the opening degree of the first valve 10 can be controlled by adjusting the supply current value between the first current value I1 and the second current value I2. This current control region in which the opening degree of the first valve 10 is variable is also called the "large diameter valve control region".

When the supply current value exceeds the second current value I2, the valve body 46 operates in the valve closing direction while the first valve 10 remains closed, and the opening degree of the second valve 12 changes. When the supply current value exceeds the third current value I3, the spool state is reached in which the spool portion 49 of the valve body 46 is inserted into the valve hole 32. The current control region in which this spool state occurs is also called the "spool region."

When the supply current value further reaches the fourth current value I4, the detachable portion 47 of the valve body 46 seats on the valve seat 34, completely closing the second valve 12 (FIG. 2(C)). Therefore, the opening degree of the second valve 12 can be controlled by adjusting the supply current value between the second current value I2 and the third current value I3. This current control region in which the opening degree of the second valve 12 is variable is also called the "small diameter valve control region." When the second valve 12 is made to function as an expansion valve, the supply current value is set to be close to the third current value I3.

In the illustrated example, the relationship between the supply current value and the valve opening degree in the large-diameter valve control region is a proportional relationship with a constant slope, but the slope of this valve opening characteristic can be changed by setting the load of the spring 48 (selecting the spring constant). By reducing the load of the spring 48, a valve opening characteristic can be obtained in which the valve opening degree changes in a step-like manner when a predetermined set current value is reached, making it easier for the first valve 10 to function as an open/close valve. Specifically, when the current value I1 is approximately equal to the current value I2 and a predetermined set current value is reached, a valve opening characteristic can be obtained in which the large-diameter valve opening degree changes instantly from fully open to fully closed or from fully closed to fully open.

Similarly, for the small bore valve control region, the relationship (slope) between the supply current value and the valve opening can be adjusted by setting the load of spring 54 (selecting the spring constant). In this embodiment, it is necessary to be able to control the second valve 12 at a small opening so that it functions as an expansion valve. For this reason, the load of spring 54 is made larger than the load of spring 48, and the slope of the valve opening characteristics in the small bore valve control region is made gentler as shown.

As described above, in this embodiment, the large-diameter first valve 10 and the small-diameter second valve 12 are driven to open and close by a single solenoid 3, so that the first valve 10 functions as an opening and closing valve and the second valve 12 functions as an expansion valve. Therefore, there is no need to provide an actuation conversion mechanism that converts rotation into translation, as in the case of using a motor as an actuator, and the combined valve 1 can be realized in a compact size.

[Modification]
FIG. 4 is a cross-sectional view that illustrates a schematic structure of a combined valve according to a modified example.
The combined valve 101 of this modification differs from the first embodiment in the arrangement of the off-spring. That is, a spring is not provided between the core 20 and the plunger 24, and a spring 148 is provided between the valve body 130 (first valve body) and the body 2 to bias the valve body 130 in the valve opening direction. In detail, a flange portion 132 protrudes radially outward from the outer circumferential surface of the valve body 130, and a spring 148 is interposed between the flange portion 132 and the body 2. The spring 148 functions as an off-spring. As in the first embodiment, the load of the spring 54 is set to be larger than the load of the spring 148.

In this modified example, the solenoid 3 is used as a common actuator for both the first valve 10 and the second valve 12, so the same effects as in the first embodiment can be obtained.

[Second embodiment]
FIG. 5 is a cross-sectional view that illustrates a schematic structure of a combined valve according to the second embodiment.
The combined valve 201 of this embodiment is a so-called normally-closed valve, and differs from the first embodiment in that both the first valve 10 and the second valve 12 are closed when the solenoid 203 is off (de-energized). The combined valve 201 includes a first valve 10 (large diameter valve) and a second valve 12 (small diameter valve), and these valves are driven to open and close by a single solenoid 203.

The composite valve 201 is constructed by assembling a body 2 and a solenoid 203 in the axial direction. The solenoid 203 includes a cylindrical yoke 230 with a bottom that is coaxially assembled to the body 2, a core 220 that is coaxially assembled to the yoke 230 via a cylindrical sleeve 222 (non-magnetic material), a plunger 224 that is housed inside the sleeve 222 and faces the core 220 in the axial direction, and an electromagnetic coil 26 that is wound around the sleeve 222 and the core 220. The positional relationship of the core 220 and the plunger 224 with respect to the valve body 30 is different from that of the first embodiment. Note that this figure is a schematic diagram, and therefore the structure of the connection portion between the body 2 and the yoke 230 is omitted from the illustration.

The inner peripheral surface of the yoke 230 forms a guide hole 28, which supports the valve body 30 so that it can slide. An insertion hole 235 is provided in the center of the bottom of the yoke 230. An operating rod 244 extends from the plunger 224 and passes through the insertion hole 235. A valve body 46 is provided at the tip of the operating rod 244. The space surrounded by the yoke 230 and the valve body 30 forms the back pressure chamber 36. A spring 248 (biasing member) is interposed between the bottom of the yoke 230 and the valve body 30 in the back pressure chamber 36 to bias the valve body 30 in the valve closing direction.

A flange portion 53 that protrudes radially outward is provided at one end of the engagement member 52 (the end opposite the engagement member 40). A spring 254 (biasing member) that biases the valve body 46 in the valve closing direction (the direction that separates the engagement member 40 and the engagement member 52) is interposed between the flange portion 53 and the engagement member 40. The engagement members 40, 52, and spring 254 constitute an "operation connection mechanism" that connects or releases the operation of the valve body 30 and the valve body 46. In this embodiment, the load of the spring 248 is set to be greater than the load of the spring 254.

Next, the operation of the control valve will be described.
Fig. 6 is a partially enlarged view showing the operation of the combined valve 201. Fig. 6(A) shows a state in which both the first valve 10 and the second valve 12 are closed, Fig. 6(B) shows a state in which the first valve 10 is closed and the second valve 12 is open, and Fig. 6(C) shows a state in which both the first valve 10 and the second valve 12 are open. Below, a description will be given based on Fig. 5 with appropriate reference to Fig. 6.

When the solenoid 203 in the combined valve 201 is not energized (off), no suction force acts between the core 220 and the plunger 224. Meanwhile, the spring 248 urges the valve body 30 in the valve closing direction. Furthermore, the spring 254 urges the valve body 46 in the valve closing direction. This urging force also acts in the direction of moving the plunger 24 away from the core 20. As a result, both the first valve 10 and the second valve 12 are in the closed state (fully open state) (Figure 6 (A)). This blocks the refrigerant circulation passage.

When a control current is supplied to the solenoid 3, the core 220 attracts the plunger 224. As a result, the valve body 46 operates in the valve opening direction together with the operating rod 244. At this time, the combined valve 201 can function as an expansion valve by controlling the opening degree of the second valve 12 by adjusting the duty ratio of the PWM control. Since the load of the spring 248 is set to be greater than the load of the spring 254, the first valve 10 remains in a closed state until the second valve 12 is fully open (FIG. 6(B)).

By increasing the duty ratio and supplying a larger current to the solenoid 203, the valve body 30 can be opened against the biasing force of the spring 248 (FIG. 6(C)). At this time, the engagement member 52 engages with the engagement member 40, and the operating rod 244 lifts the valve body 30. By switching the duty ratio between the closed state and the fully open state of the first valve 10, the combined valve 201 can function as an opening and closing valve.

Figure 7 shows the valve opening characteristics of the combined valve 201. The horizontal axis of the figure shows the value of the current supplied to the solenoid, and the vertical axis shows the valve opening. For ease of explanation, A to C are written in Figure 7 to show the correspondence with the operating processes in Figures 6 (A) to (C).

The operation of each valve shown in FIG. 6 is expressed as the control characteristics shown in FIG. 7. That is, when the solenoid 203 is off, both the first valve 10 and the second valve 12 are in a closed state (fully closed state) (FIG. 6(A)). When the solenoid 203 is energized, the first valve 10 is in a closed state and the second valve 12 is in a spool state until the supply current value reaches the first current value I11. When the supply current value exceeds the first current value I11, the opening degree of the second valve 12 increases in proportion to the current value. The first valve 10 remains in a closed state. When the supply current value reaches the second current value I12, the second valve 12 is in a fully open state (FIG. 6(B)).

Therefore, the opening degree of the second valve 12 can be controlled by adjusting the supply current value between the first current value I11 and the second current value I12. This current control region in which the opening degree of the second valve 12 is variable is also called the "small diameter valve control region." When the second valve 12 is made to function as an expansion valve, the supply current value is set close to the first current value I11.

The slope of the valve opening characteristic can be changed by changing the load setting of the spring 254 (selection of the spring constant). By increasing the load of the spring 254 and making the slope of the valve opening characteristic gentler in the small diameter valve control region as shown in the figure, it becomes easier to control the second valve 12 at a small opening and to make it function as an expansion valve.

When the supply current value exceeds the second current value I12, the valve body 30 operates in the opening direction while the second valve 12 remains fully open, and the opening degree of the first valve 10 changes. When the supply current value reaches the third current value I13, the first valve 10 is fully open. Therefore, the opening degree of the first valve 10 can be controlled by adjusting the supply current value between the second current value I12 and the third current value I13. This current control region in which the opening degree of the first valve 10 is variable is also called the "large diameter valve control region."

In the illustrated example, the relationship between the supply current value and the valve opening degree in the large-diameter valve control region is proportional with a constant slope, but the slope of this valve opening characteristic can be changed by changing the load setting of the spring 248 (selection of the spring constant).

As explained above, in this embodiment as well, the large-diameter first valve 10 and the small-diameter second valve 12 are driven to open and close by a single solenoid 203, so that the first valve 10 functions as an opening and closing valve and the second valve 12 functions as an expansion valve. Therefore, as in the first embodiment, there is no need to provide an actuation conversion mechanism that converts rotation into translation, as in the case of using a motor as an actuator, and the combined valve 201 can be realized in a compact form.

[Modification]
FIG. 8 is a cross-sectional view that illustrates a schematic structure of a combined valve according to a modified example.
The combined valve 301 of this modification has a biasing structure for biasing the valve element 330 (first valve element) in the valve closing direction, which is different from that of the second embodiment. The combined valve 301 does not have the spring 248 as in the second embodiment, and biases the valve element 330 in the valve closing direction by the pressure (differential pressure) of the refrigerant acting on the valve element 330.

That is, by providing a step 332 on the outer peripheral surface of the valve body 330, the pressure receiving diameter φA of the back pressure received by the valve body 330 is made slightly larger than the pressure receiving diameter φB of the seal portion of the valve body 330 (φA>φB). Therefore, the pressure difference (P1-P2) between the upstream pressure P1 and the downstream pressure P2 acts in the valve closing direction on the pressure receiving area of the valve body 330 equivalent to the pressure receiving diameter difference (φA-φB). As a result, the valve body 330 is biased in the valve closing direction.

However, because the difference in the pressure receiving diameter is minute, the fluid pressure acting on the valve body 330 is almost cancelled. This reduces the resistance when the valve body 330 is pulled up in the valve opening direction, and prevents an increase in the solenoid force required to open the first valve 10.

In this modified example, the solenoid 203 is used as a common actuator for the first valve 10 and the second valve 12, so the same effects as in the second embodiment can be obtained.

The above describes a preferred embodiment of the present invention, but it goes without saying that the present invention is not limited to that specific embodiment, and various modifications are possible within the scope of the technical concept of the present invention.

[Other Modifications]
Although not mentioned in the above embodiments, when the PWM method is used to control the current supply to the solenoid, the valve body is likely to strike the valve seat when the large-diameter valve and the small-diameter valve are slightly opened (so-called valve striking), which can cause abnormal noise. In particular, the abnormal noise is likely to be louder for the large-diameter valve. Therefore, in the modified example, measures are taken to prevent abnormal noise by devising the current supply control to the solenoid.

Figure 9 shows the current control when the combined valve is a normally open valve. Figure 9 (A) shows the opening characteristics of the combined valve and corresponds to Figure 3. The horizontal axis shows the current value supplied to the solenoid, and the vertical axis shows the valve opening degree. Figure 9 (B) shows the current control method. The horizontal axis shows the stroke of the valve body from the fully open state in the valve closing direction, and the vertical axis shows the duty ratio set by PWM control.

In this modification, as shown in FIG. 9(A), when the first valve 10 is in a slightly open state (large-diameter valve slightly open region), the amount of change in the duty ratio is temporarily increased as shown in FIG. 9(B). That is, the control unit 100 temporarily increases the rate of increase of the current supplied to the solenoid in a predetermined stroke region (large-diameter valve slightly open region) of the valve body 30 where the first valve 10 is in a slightly open state, and instantaneously transitions the first valve 10 from the slightly open state to the closed state. In the illustrated example, the rate of increase is temporarily increased from the fifth current value I5 near the second current value I2. This allows the first valve 10 to quickly escape the stroke region where valve banging is likely to occur, and prevents or suppresses the generation of abnormal noise.

Also, when the second valve 12 is in a slightly open state (small diameter valve slightly open region), the amount of change in the duty ratio is temporarily increased. That is, the control unit 100 temporarily increases the increase rate of the current supplied to the solenoid even in a predetermined stroke region of the valve body 46 (small diameter valve slightly open region) where the second valve 12 is in a slightly open state, and instantaneously transitions the second valve 12 from the slightly open state to the closed state. In the illustrated example, the increase rate of the duty ratio is temporarily increased from the sixth current value I6 near the fourth current value I4. This allows the second valve 12 to quickly escape the stroke region where valve banging is likely to occur, and prevents or suppresses the generation of abnormal noise.

The starting point for increasing the rate of increase in the supply current is set based on the vibration amplitude of each valve element by PWM control. For example, the starting point may be the current value at which the lift amount of each valve element from each valve seat reaches a predetermined stroke position that is greater than the vibration amplitude.

The same is true when a combined valve (normally open valve) is opened from a closed state. When the small-diameter valve slightly open region and the large-diameter valve slightly open region are reached, the rate of decrease in the duty ratio is temporarily increased. Specifically, the current control shown in FIG. 9(B) is followed in the opposite direction to that during the valve closing operation. In other words, in both the opening and closing operation of a combined valve (normally open valve), the rate of change of the current supplied to the solenoid is temporarily increased in the specified stroke region of each valve body where the small-diameter valve and the large-diameter valve are each slightly open.

Figure 10 shows the current control when the combined valve is a normally closed valve. Figure 10 (A) shows the opening characteristics of the combined valve and corresponds to Figure 7. The horizontal axis shows the current value supplied to the solenoid, and the vertical axis shows the valve opening degree. Figure 10 (B) shows the current control method. The horizontal axis shows the stroke of the valve body from the fully closed state in the valve opening direction, and the vertical axis shows the duty ratio set by PWM control.

In this modification, as shown in FIG. 10(A), in the small opening region of the second valve 12 (small opening region), the change in the duty ratio is temporarily increased as shown in FIG. 10(B). That is, the control unit 100 temporarily increases the increase rate of the current supplied to the solenoid in the stroke region of the valve body 46 (small opening region) where the second valve 12 is in a small opening state, and instantaneously transitions the second valve 12 from a closed state to an open state. In the illustrated example, the increase rate of the duty ratio is temporarily increased from the start of current flow until the fourth current value I14 is reached. This allows the second valve 12 to quickly escape the stroke region where valve banging is likely to occur, and prevents or suppresses the generation of abnormal noise.

Also, when the first valve 10 is in a slightly open state (large-diameter valve slightly open region), the amount of change in the duty ratio is temporarily increased. That is, the control unit 100 temporarily increases the rate of increase in the current supplied to the solenoid even in the stroke region of the valve body 30 where the first valve 10 is in a slightly open state (large-diameter valve slightly open region), and instantaneously transitions the first valve 10 from a closed state to an open state. In the illustrated example, the rate of increase in the duty ratio is temporarily increased until the fifth current value I15, which is close to the second current value I12, is reached. This allows the first valve 10 to quickly escape the stroke region where valve banging is likely to occur, and prevents or suppresses the generation of abnormal noise.

The end point for increasing the rate of increase in the supply current is set based on the vibration amplitude of each valve element by PWM control. For example, the end point may be when the current value reaches a predetermined stroke position where the lift amount of each valve element from each valve seat is greater than the vibration amplitude.

The same is true when a combined valve (normally closed valve) is operated from an open state to a closed state. When the similar small-diameter valve slightly open region and large-diameter valve slightly open region are reached, the rate of decrease in the duty ratio is temporarily increased. In other words, the current control shown in FIG. 10(B) can be followed in the opposite direction to that during the valve opening operation. In other words, in both the opening and closing operation of a combined valve (normally closed valve), the rate of change of the current supplied to the solenoid can be temporarily increased in the specified stroke region of each valve body where the small-diameter valve and the large-diameter valve are each slightly open.

In addition to temporarily increasing the amount of change in the duty ratio, another method of suppressing valve tapping in the small opening region of each valve is to temporarily change the PWM control frequency (PWM frequency). For example, when the supply current value increases, the PWM frequency may be temporarily increased from the first frequency f1 to the second frequency f2 (f1<f2). This makes it possible to reduce the current amplitude in the small opening region and suppress valve tapping.

Alternatively, it is also possible to temporarily switch from PWM control to DC control when the valve reaches its partially open region. In that case, a PWM control circuit and a DC control circuit may be provided as the drive circuit, and the control unit may switch between them. This can eliminate the current amplitude in the partially open region and suppress valve banging.

In the above embodiment, an example was shown in which the combined valve was applied to a heat pump type vehicle heating and cooling system, but it goes without saying that the combined valve can also be applied to non-heat pump type refrigeration cycles used in engine vehicles, etc.

The motor-operated valve of the above embodiment is preferably applied to a refrigeration cycle that uses a refrigerant such as a fluorocarbon alternative (HFC-134a) as a refrigerant, but it can also be applied to a refrigeration cycle that uses a refrigerant with a high operating pressure such as carbon dioxide. In that case, an external heat exchanger such as a gas cooler is placed in the refrigeration cycle instead of a condenser.

In the above embodiment, an example was shown in which the motorized valve was applied to the refrigeration cycle of an automotive air conditioner, but the motorized expansion valve can be applied to any air conditioner equipped with an electric expansion valve, not limited to vehicles. The motorized valve may also be configured to control the flow of fluids other than refrigerant, such as hot water in a water heater or hydraulic fluid (hydraulic oil) in a hydraulic control device.

The present invention is not limited to the above-described embodiment and modifications, and can be embodied by modifying the components without departing from the spirit of the invention. Various inventions may be formed by appropriately combining multiple components disclosed in the above-described embodiment and modifications. In addition, some components may be deleted from all the components shown in the above-described embodiment and modifications.

1 Composite valve, 2 Body, 3 Solenoid, 10 First valve, 12 Second valve, 14 Valve hole, 16 Valve seat, 20 Core, 24 Plunger, 26 Electromagnetic coil, 28 Guide hole, 30 Valve body, 31 Communication hole, 32 Valve hole, 33 Inlet port, 34 Valve seat, 35 Downstream passage, 36 Back pressure chamber, 37 Outlet port, 38 Valve chamber, 39 Seal ring, 40 Engagement member, 42 Insertion hole, 44 Actuating rod, 46 Valve body, 47 Detachable portion, 48 Spring, 49 Spool portion, 52 Engagement member, 54 Spring, 101 Composite valve, 130 Valve body, 148 Spring, 201 Composite valve, 203 Solenoid, 220 Core, 224 Plunger, 230 Yoke, 244 Actuating rod, 248 Spring, 254 Spring, 301 Composite valve, 330 Valve body, 332 Step.

Claims (6)

A large-diameter first valve;
A second valve having a smaller diameter than the first valve;
a single solenoid for driving the first valve and the second valve to open and close;
Equipped with
A combined valve, characterized in that an opening degree of the second valve is controlled by controlling energization of the solenoid, and the second valve functions as an expansion valve. a body having a first valve seat formed therein;
a first valve body that is detachably attached to the first valve seat to open and close the first valve;
A second valve seat provided in an internal passage of the first valve body;
a second valve body that is detachably attached to the second valve seat to open and close the second valve;
an operation connection mechanism that connects or disconnects the operation of the first valve body and the second valve body in accordance with a state of current supply to the solenoid, and connects the operation of the second valve body and the first valve body when the second valve is in a fully open state;
2. The combination valve of claim 1, further comprising: an internal passage of the first valve body having an inlet port communicating with an upstream side of the first valve seat and an outlet port communicating with a downstream side of the first valve seat;
3. The combined valve according to claim 2, wherein the second valve seat is provided midway through a passage that connects the inlet port and the outlet port. The combined valve according to claim 1 or 2, characterized in that the opening degree of the first valve is controlled by controlling the supply of current to the solenoid. a composite valve in which a first valve with a large diameter and a second valve with a small diameter are opened and closed by a single solenoid;
A control unit that controls a current supplied to the solenoid;
Equipped with
The composite valve comprises:
a body having a first valve seat formed therein;
a first valve body that is detachably attached to the first valve seat to open and close the first valve;
A second valve seat provided in an internal passage of the first valve body;
a second valve body that is detachably attached to the second valve seat to open and close the second valve;
an operation connection mechanism that connects or disconnects the operation of the first valve body and the second valve body in accordance with a state of current supply to the solenoid, and connects the operation of the second valve body and the first valve body when the second valve is in a fully open state;
Including,
The solenoid is energized by a PWM method in the process of changing the opening degree of each of the first valve and the second valve,
The control unit temporarily increases a rate of change of the current supplied to the solenoid in a predetermined stroke region of the first valve body where the first valve is slightly open. The combined valve control device according to claim 5, characterized in that the control unit temporarily increases the rate of change of the current supplied to the solenoid in a predetermined stroke region of the second valve body where the second valve is in a partially open state.

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