JP2023146028A - Motor-operated valve - Google Patents

Abstract

To reduce a sense of incompatibility with respect to the external appearance that a motor-operated valve which has a housing of a motor constituted with a resin component through laser deposition has.SOLUTION: A motor-operated valve comprises a stator unit including a case in a cylinder shape, a stator arranged in the case and fitted coaxially onto a can, a circuit board arranged inside the case, and a lid body forming a space including the circuit board with the case. While the case consists of a laser absorptive resin member, the lid body consists of a laser transmissive resin member, and the case and lid body are joined through laser deposition to form a space. The laser absorptive resin member is so colored as to have a lightness V satisfying 0≤V≤5 and a saturation C satisfying of C≤1 on the Munsell colorimetric system. The laser transmissive resin member is so colored as to have a lightness V satisfying 1≤V≤5 and a saturation C satisfying C≤1 on the Munsell colorimetric system, and also have a transmissivity of 20% or larger when irradiated with laser light of 900 nm in wavelength.SELECTED DRAWING: Figure 3

Description

TECHNICAL FIELD The present invention relates to a motor-operated valve whose exterior resin parts are welded together using a laser.

Automotive air conditioners are generally configured by arranging a compressor, a condenser, an expansion device, an evaporator, etc. in a refrigeration cycle. The refrigeration cycle is provided with various control valves for controlling the flow of refrigerant, such as an expansion valve serving as an expansion device. With the spread of electric vehicles and the like in recent years, electric valves having a motor in their driving portions are being widely adopted as such control valves.

Since such a motor-operated valve incorporates an electromagnetic coil and other electrical components constituting a motor, as well as a circuit board, it is necessary to prevent moist outside air and dust from entering the valve. Therefore, high airtightness is ensured by laser welding the resin parts that make up the motor housing.

As a technique for laser welding resin parts together in this way, one is made of a laser-absorbing resin member, the other is a laser-transparent resin member, and with both parts in contact, a laser beam is applied from the laser-transparent resin member side. A technique of irradiation is adopted (see Patent Document 1). As a result, the laser beam passes through the laser-transparent resin member, is absorbed by the laser-absorbing resin member, generates heat, and the end face of the laser-absorbing resin member that comes into contact with the laser-transparent resin member melts. Thereafter, the melted portions solidify, thereby achieving welding of both members.

JP2017-24180A

By the way, the laser transmittance and absorption properties of a resin part depend on the pigment of the resin part. The closer to black the dye, the higher the absorption, but the lower the transparency. Therefore, the color tones of the resin parts that constitute the housing generally differ from each other, which can sometimes create an unnatural appearance. In particular, many laser-transparent resin members are white in color, and as they deteriorate over time in high-temperature environments and further discolor, there is a concern that the appearance may deteriorate.

The present invention has been made in view of these problems, and one of its purposes is to reduce the appearance of an electric valve in which the motor housing is constructed by laser welding resin parts. It is in.

An embodiment of the present invention is an electric valve. This electric valve consists of a body, a valve body that opens and closes the valve by moving into and out of a valve hole provided in the body, a rotor that drives the valve body in the opening and closing direction of the valve, and a rotor that is fixed to the body and drives the valve in the direction of opening and closing the valve. A can that is a cylindrical member contained therein and defines an internal space where fluid pressure acts and an external space where fluid pressure does not act; a case having a cylindrical shape; and a case disposed within the case and coaxially inserted outside the can. The stator unit includes a stator, a circuit board disposed inside a case, and a lid that forms a space between the case and the case to contain the circuit board. While the case is made of a laser-absorbing resin member, the lid is made of a laser-transparent resin member, and a space is formed by laser welding the case and the lid. The laser-absorbing resin member is colored so that the brightness V satisfies 0≦V≦5 and the chroma C satisfies C≦1 in the Munsell color system. The laser-transparent resin member is colored so that the brightness V satisfies 1≦V≦5 and the chroma C≦1 in the Munsell color system, and the transmittance when irradiated with laser light with a wavelength of 900 nm or more is 20. % or more.

According to this aspect, the laser-absorbing resin member constituting the case and the laser-transmitting resin member constituting the lid have brightness and chroma values in a range close to blackish. Therefore, there is less discomfort in appearance when the case and the lid are welded together. Even if both members deteriorate over time, the appearance will not deteriorate due to discoloration. Since a laser beam transmittance of 20% or more is ensured in the laser-transparent resin member, welding performance between the case and the lid is also ensured.

According to the present invention, in an electric valve whose motor housing is formed by laser welding of resin parts, it is possible to reduce an unnatural appearance of the electric valve.

1 is a cross-sectional view showing the structure of an electric valve according to an embodiment. It is a figure showing the welding structure of the case and the lid in a stator unit. FIG. 3 is a diagram schematically showing the color tone of the case and the lid. It is a figure showing the effect when the color tone of the embodiment is adopted for the case and the lid.

Embodiments of the present invention will be described in detail below 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. Further, in the following embodiments and modifications thereof, substantially the same components are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

The electric valve of this embodiment is applied to a refrigeration cycle of an automobile air conditioner. The refrigeration cycle includes a compressor that compresses circulating refrigerant, a condenser that condenses the compressed refrigerant, an expansion valve that expands the condensed liquid refrigerant and sends it out as a mist, and evaporates the mist refrigerant. An evaporator is provided that cools the air inside the vehicle using the latent heat of vaporization. The electric valve functions as the expansion valve.

FIG. 1 is a sectional view showing the structure of an electric valve according to an embodiment.
The electric valve 1 is constructed by assembling a valve body 2 and a motor unit 3. The valve main body 2 has a body 5 that accommodates a valve portion. The body 5 is constructed by assembling a first body 6 and a second body 8 coaxially.

The upper part of the second body 8 is fixed to the lower part of the first body 6. A valve hole 22 is provided so as to pass through the bottom of the second body 8 in the axial direction, and a valve seat 24 is formed at the upper end opening of the valve hole 22 . An inlet port 26 is provided at the side of the second body 8, and an outlet port 28 is provided at the bottom. A valve chamber 30 is formed inside the first body 6 and the second body 8. The inlet port 26 and the outlet port 28 communicate with each other via a valve chamber 30. The inlet port 26 introduces refrigerant from the upstream side (condenser side) into the valve chamber 30. The outlet port 28 leads the refrigerant to the downstream side (evaporator side) of the valve chamber 30.

An operating rod 32 extending from the rotor 60 of the motor unit 3 is inserted into the inside of the body 5 . The actuation rod 32 passes through the valve chamber 30. A valve body 34 is integrally provided at the lower part of the operating rod 32. The valve portion is opened and closed by attaching and detaching the valve body 34 to and from the valve seat 24 from the valve chamber 30 side.

A guide member 36 is erected at the center of the upper part of the first body 6 . A male thread 38 is formed on the outer circumferential surface of the guide member 36 at the center in the axial direction. A lower end portion of the guide member 36 is fixed to the center of the upper part of the first body 6, and is fixed coaxially thereto. The guide member 36 supports the actuating rod 32 slidably in the axial direction by its inner circumferential surface, and rotatably supports the rotating shaft 62 of the rotor 60 by its outer circumferential surface. A spring 46 is interposed between the actuating rod 32 and the guide member 36 to bias the valve body 34 in the valve closing direction.

On the other hand, the motor unit 3 is configured as a three-phase stepping motor including a rotor 60 and a stator 64. The motor unit 3 has a cylindrical can 66 with a bottom, a rotor 60 is disposed inside the can 66, and a stator 64 is disposed outside the can 66. The can 66 is a bottomed cylindrical member that covers the space in which the valve body 34 and its drive mechanism are arranged, and also houses the rotor 60. The can 66 acts with the inner pressure space (internal space) on which the pressure of the refrigerant acts. An external non-pressure space (external space) is defined. The can 66 is made of non-magnetic metal and is assembled coaxially with the upper end of the first body 6 so that its lower part is fitted over the upper end of the first body 6. A space surrounded by the body 5 and the can 66 forms the pressure space.

The stator 64 is constructed by arranging a plurality of salient poles at equal intervals on the inner circumference of a laminated core 70. The laminated core 70 is constructed by laminating annular cores in the axial direction. A bobbin 74 equipped with a coil 73 (electromagnetic coil) is attached to each salient pole. The stator 64 is disposed within a resin case 76 and coaxially inserted into the can 66 .

The stator 64 is provided integrally with the case 76 in this embodiment. The case 76 is obtained by injection molding of a resin material having corrosion resistance, and has a cylindrical shape. The stator 64 is covered with a molded resin by injection molding (also referred to as "insert molding" or "mold molding"). Hereinafter, a unit including a molded product of the stator 64 and the case 76 will also be referred to as a "stator unit 78." The stator unit 78 has a hollow structure, and is assembled to the body 5 while coaxially passing through the can 66.

A seal ring 82 (O-ring) is fitted onto the upper outer peripheral surface of the first body 6. A seal ring 82 is interposed between the upper outer circumferential surface of the first body 6 and the lower inner circumferential surface of the case 76, thereby preventing external atmosphere (such as water) from entering the gap between the can 66 and the stator 64. Prevented.

The rotor 60 includes a cylindrical rotor core 102 assembled to a rotating shaft 62, a rotor magnet 104 provided on the outer peripheral surface of the rotor core 102, and a sensor magnet 106 provided on the upper end surface of the rotor core 102. The rotor core 102 is assembled to the rotating shaft 62. The rotor magnet 104 is magnetized (magnetized) into a plurality of poles in its circumferential direction. The sensor magnet 106 is also magnetized (magnetized) into multiple poles.

The rotating shaft 62 is a cylindrical shaft with a bottom and is fitted onto the guide member 36 . A female thread 108 is formed on the lower inner peripheral surface of the rotating shaft 62 and meshes with the male thread 38 of the guide member 36 . The rotational movement of the rotor 60 is converted into the axial movement of the actuating rod 32 by the screw feeding mechanism 109 formed by these threaded parts. Thereby, the valve body 34 moves (raises and lowers) in the axial direction, that is, in the opening and closing direction of the valve section.

The upper part of the actuating rod 32 is reduced in diameter and passes through the bottom part 112 of the rotating shaft 62. An annular stopper 114 is fixed to the upper end of the actuation rod 32. On the other hand, a spring 116 is interposed between the operating rod 32 and the bottom portion 112 to bias the operating rod 32 downward (that is, in the valve closing direction). With this configuration, when the valve is opened, the actuating rod 32 is displaced integrally with the rotor 60 in such a manner that the stopper 114 is locked to the bottom portion 112. On the other hand, when the valve is closed, the spring 116 is compressed by the reaction force that the valve element 34 receives from the valve seat 24. At this time, the valve body 34 can be pressed against the valve seat 24 by the elastic reaction force of the spring 116, and the seating performance (valve closing performance) of the valve body 34 can be improved.

The motor unit 3 has a circuit board 118 outside the can 66. The circuit board 118 is fixed inside the case 76. The circuit board 118 includes a drive circuit for driving the motor, a control circuit for outputting a control signal to the drive circuit, a communication circuit for the control circuit to communicate with an external device, and a circuit for supplying power to each circuit and the motor. Power supply circuit etc. are mounted. The upper end opening of the case 76 is closed by fitting a lid 77 with a spigot. The case 76 and the lid 77 are welded together along the spigot fitting portion 130 to constitute a housing of the motor. A circuit board 118 is contained in a space S surrounded by the case 76 and the lid 77.

The case 76 is provided with a connector forming portion 120. That is, the connector forming portion 120 is integrally molded with the case 76 using mold resin. The connector forming part 120 integrally has terminals 122 connected to the circuit board 118 inside and protects them. The terminals 122 include a power supply terminal and a communication terminal (these are also referred to as "external connection terminals"). Stator unit 78 includes stator 64 , case 76 , circuit board 118 , terminals 122 , connector forming section 120 , and lid 77 . The case 76 is provided with a leak hole 124 that communicates the inside of the connector forming portion 120 with the space S. The function of the leak hole 124 will be described later.

A magnetic sensor 119 is provided on the surface of the circuit board 118 facing the sensor magnet 106 . The magnetic sensor 119 faces the sensor magnet 106 in the axial direction via the bottom end wall of the can 66. As the rotor 60 rotates, the magnetic flux generated by the sensor magnet 106 changes. The magnetic sensor 119 detects the amount of displacement of the rotor 60 (rotation angle of the rotor 60) by capturing this change in magnetic flux. Based on the amount of displacement of the rotor 60, the axial position of the valve body 34 and the valve opening degree can be calculated.

A leak hole 124 is provided in the connector forming portion 120 . Prior to assembling the stator unit 78 to the body 5, the case 76 and the lid 77 are welded together. Therefore, as the can 66 is inserted into the stator unit 78, the pressure of the gas in the space S increases. If this pressure is too high, there is a risk that the circuit board 118 and the like stored in the space S may be damaged. In this embodiment, the leak hole 124 causes the internal pressure of the space S to leak into the connector forming portion 120 . Thereby, even if the can 66 is inserted into the stator unit 78 and the stator unit 78 is assembled to the body 5, damage to the circuit board 118 and the like can be prevented.

After the stator unit 78 is assembled to the body 5, the temperature in the space S changes when the electric valve 1 is operated. If the leak hole 124 does not exist and the case 76 is sealed, the internal pressure of the space S changes with this temperature change. When this internal pressure increases, problems such as damage to the circuit board 118, breakage of the welded portion in the stator unit 78, deformation of the case 76 and lid 77, and damage to the coil 73 occur. By providing the leak hole 124 and leaking the internal pressure of the space S to the inside of the connector forming portion 120, damage to the circuit board 118 can be prevented even when the electric valve 1 is operated.

In the above configuration, when the electric valve 1 is driven, the rotor 60 is moved in the vertical direction by the screw feeding mechanism 109 between the rotor 60 and the guide member 36. That is, the valve body 34 translates in the opening/closing direction of the valve portion, and the opening degree of the valve portion is adjusted to the set opening degree. This screw feed mechanism 109 converts the rotational movement of the rotor 60 around the axis into an axial movement (linear movement) of the actuating rod 32, and drives the valve body 34 in the opening/closing direction of the valve portion. When the electric valve 1 functions as an expansion valve, the valve portion is controlled to a small opening degree.

FIG. 2 is a diagram showing a welded structure between the case 76 and the lid 77 in the stator unit 78. 2(A) is an enlarged view of section A in FIG. 1, and FIG. 2(B) is a plan view of the stator unit 78.
The case 76 and the lid 77 are fitted with an annular spigot, and an annular contact surface 128 is formed between the upper surface of the open end of the case 76 and the lower surface of the peripheral edge of the lid 77. By irradiating the laser along the contact surface 128, the case 76 and the lid body 77 are welded together, thereby forming a space S. Here, in consideration of the laser transmittance of the lid 77, a laser beam having a wavelength of 900 nm or more (for example, 940 nm) is used. A laser welded portion 132 is formed along the spigot fitting portion 130 between the case 76 and the lid 77.

The lid body 77 is made of a laser-transparent resin material, and the case 76 is made of a laser-absorbing resin material. Both the case 76 and the lid 77 are made of crystalline resin such as polyphenylene sulfide (PPS) or polyamide 9T (PA9T), and have a glass content of 30 to 40% to ensure strength. In order to ensure laser transmission through the lid 77, the thickness t of the lid 77 at the laser welding portion 132 (laser transmission position) is 2 mm or less (1.2 mm in this embodiment). By adjusting the color tones of the case 76 and the lid 77, the characteristics with respect to laser light are made different.

By irradiating the contact surface 128 between the lid 77 and the case 76 with a laser from the lid 77 side, the laser passes through the lid 77 and is absorbed by the end surface 134 of the case 76 . A portion of the end face 134 of the case 76 melts due to the heat generated from the absorbed laser. The molten resin material accumulates in the gap between the spigot fitting part 130 and becomes a bridge part 135 that bridges the outer peripheral surface of the protrusion 136 of the lid body 77 and the open end part 138 of the case 76 and is fixed.

FIG. 3 is a diagram schematically showing the color tones of the case 76 and the lid 77. 3(A) shows the color tone of the case 76, and FIG. 3(B) shows the color tone of the lid body 77. Each figure shows brightness V and chroma C in the Munsell color system. The horizontal axis indicates saturation C, and the vertical axis indicates brightness V.

The laser-absorbing resin member that is the material of the case 76 is colored so that the brightness V satisfies 0≦V≦5 and the chroma C satisfies N≦C≦1 in the Munsell color system (FIG. 3(A)). :Refer to the hatched area surrounded by a dash-dotted line). By molding the crystalline resin described above containing a predetermined coloring agent, the case 76 exhibits the color tone described above. It is preferable that this laser-absorbing resin member can ensure a laser absorption rate of 90% or more for laser light with a wavelength of 900 nm or more.

On the other hand, the laser-transmissive resin member that is the material of the lid body 77 satisfies the brightness V of 1≦V≦5 and the saturation C of N≦C≦1 in the Munsell color system, and is irradiated with laser light with a wavelength of 900 nm or more. It is colored so that the transmittance is 20% or more (see FIG. 3(B): hatched area surrounded by a dashed-dotted line). By molding the above-mentioned crystalline resin containing a predetermined coloring agent, the lid body 77 exhibits the above-mentioned color tone. In this embodiment, the hue H of both is set to 5R in the Munsell color system, but it is not limited to this and can be selected as appropriate.

FIG. 4 is a diagram showing the effect when the color tone of the embodiment is adopted for the case and the lid. FIG. 4(A) is a photograph of a stator unit showing the effect of this embodiment, and FIG. 4(B) is a photograph of a stator unit showing the effect of a comparative example. In the comparative example, the case 76 has the same color tone as this embodiment to ensure laser absorption, while the lid 177 has a brightness V of 8≦V≦9 and a saturation C of N≦C≦1. And so. The color tone of the lid body 177 is one commonly adopted in the current market to ensure laser transparency.

In this experiment, we experimentally verified the change in color tone of the stator unit due to environmental changes. Specifically, in order to reproduce the state in which the electric valve is installed in the engine room of a vehicle, for each of the present embodiment and the comparative example, the stator unit was heated to 120 ° C. in a furnace and left for about 100 hours. A change in color tone was confirmed. This experiment simulated the state in which the electric valve 1 was mounted on a vehicle, and verified changes in the color tone of the case and lid body due to environmental deterioration.

According to the results of this experiment, in this embodiment, the change in color tone of both the case 76 and the lid body 77 was at a level that could not be visually confirmed. On the other hand, in the comparative example, there was a noticeable change in color tone in the lid body 177. As a result, it was confirmed that there was a large difference in color tone between the case 76 and the lid 177, and that the appearance was significantly deteriorated.

As explained above, in this embodiment, the laser-absorbing resin member that constitutes the case 76 and the laser-transparent resin member that constitutes the lid body 77 have a brightness V and a chroma C that are close to blackish. Has a range of values. Therefore, when the case 76 and the lid body 77 are welded together, there is less discomfort in appearance. Even if both members deteriorate over time, the appearance will not deteriorate due to discoloration. Since a laser beam transmittance of 20% or more in the laser-transmissive resin member is ensured, welding performance between the case 76 and the lid body 77 is also ensured.

Since crystalline resins tend to reflect light, their laser transmittance is generally low. This becomes more noticeable as the glass content increases. Therefore, the use of crystalline resin for the laser-transparent resin member tends to be disadvantageous for welding. In this regard, in this embodiment, the flatness of the abutment surface 128 between the lid body 77 and the case 76 is increased, and a bridge portion 135 made of a resin pool is formed in the gap between the spigot fitting portion 130, thereby improving welding performance. It is secured. In addition, by providing a leak hole 124 in the connector forming portion 120 and suppressing the increase in pressure in the space S, the laser welding portion 132 is less likely to be damaged even if the welding force is not large.

In other words, by providing the leak hole 124, the strength required for laser welding can be lowered, making it easier to use crystalline resin. By using crystalline resin, the motor-operated valve is also more resistant to humidity (durability against swelling and contraction) when placed in the engine room.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the specific embodiments, and it goes without saying that various modifications can be made within the scope of the technical idea of the present invention. Nor.

In the above embodiment, the laser-absorbing resin member that is the material of the lid 77 is colored so that the brightness V satisfies 0≦V≦5 and the saturation C satisfies N≦C≦1 in the Munsell color system. It was adopted. In a modified example, it may be colored so that the brightness V satisfies 1≦V≦5 and the saturation C satisfies N≦C≦1 in the Munsell color system. Alternatively, the brightness V may be set to 0≦V≦4 in consideration of laser absorption.

In this embodiment, the hue H of the case 76 and the lid 77 is 5R in the Munsell color system, but other hues such as 5Y, 5G, 10R can be selected as appropriate. One of the reasons for this is that since the brightness V and chroma C are set in a range close to black, differences due to hue are less likely to occur.

It should be noted that the present invention is not limited to the above-described embodiments and modified examples, and can be embodied by modifying the constituent elements without departing from the scope of the invention. Various inventions may be formed by appropriately combining a plurality of components disclosed in the above embodiments and modified examples. Furthermore, some components may be deleted from all the components shown in the above embodiments and modified examples.

1 Electric valve, 2 Valve body, 3 Motor unit, 5 Body, 22 Valve hole, 24 Valve seat, 26 Inlet port, 28 Outlet port, 30 Valve chamber, 32 Operating rod, 34 Valve body, 60 Rotor, 64 Stator, 66 can, 73 coil, 76 case, 77 lid, 78 stator unit, 109 screw feed mechanism, 118 circuit board, 119 magnetic sensor, 120 connector forming part, 122 terminal, 124 leak hole, 128 contact surface, 130 pilot fitting part, 132 laser welding part, 134 end face, 136 protrusion, 138 open end, S space.

Claims (5)

body and
a valve body that opens and closes a valve portion by coming into contact with and separating from a valve hole provided in the body;
a rotor for driving the valve body in an opening/closing direction of the valve portion;
a can, which is a cylindrical member fixed to the body and enclosing the rotor, defining an internal space where fluid pressure acts and an external space where fluid pressure does not act;
A case having a cylindrical shape, a stator disposed within the case and coaxially inserted into the can, a circuit board disposed inside the case, and the circuit board contained therein between the case and the case. a stator unit including a lid body forming a space for
Equipped with
The case is made of a laser-absorbing resin member, while the lid is made of a laser-transparent resin member, and the space is formed by laser welding the case and the lid,
The laser-absorbing resin member is colored so that the brightness V satisfies 0≦V≦5 and the saturation C satisfies C≦1 in the Munsell color system,
The laser-transparent resin member is colored so that the brightness V satisfies 1≦V≦5 and the saturation C satisfies C≦1 in the Munsell color system, and the transmittance when irradiated with laser light with a wavelength of 900 nm or more is An electrically operated valve characterized by a power consumption of 20% or more. The electric valve according to claim 1, wherein the laser-transparent resin member is made of crystalline resin. The motor-operated valve according to claim 2, wherein the thickness of the lid body at a position where the laser passes through is 2 mm or less. The stator unit includes a terminal connected to the circuit board, and a resin connector forming part that integrally has the terminal inside,
The connector forming part is integrally molded with the case using molded resin, and is characterized in that it is provided with a leak hole that allows pressure in a space containing the circuit board to leak to the outside. The electric valve according to claim 2 or 3. The electric valve according to any one of claims 1 to 4, wherein the lid body is spigot-fitted to the case, and the lid body and the case are laser welded along the spigot fitting part. .

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