1. A fixing structure of an adjusting screw mechanism, which adjusts the compression amount of an elastic body by a screw mechanism, the screw mechanism is composed of a male screw part and a female screw part which can be adjusted mutually in the deformation direction of the elastic body,

the fixing structure of the above-described adjusting screw mechanism is characterized in that,

the male thread portion and the female thread portion of the adjusting screw mechanism are made of a resin member, and the male thread portion and the female thread portion are fixed to each other by welding at an interface of a thread joining portion.

2. The fixing construction of an adjusting screw mechanism according to claim 1,

the male screw portion and the female screw portion are fixed to each other only at a part of an interface of the screw-coupled portion by welding.

3. The fixing construction of an adjusting screw mechanism according to claim 1 or 2,

in a state where the male thread portion and the female thread portion are screwed together, a sum of a radial clearance of the female thread valley bottom and a radial clearance of the male thread valley bottom is 20% or more of a difference between the female thread valley bottom diameter and the male thread valley bottom diameter.

4. The fixing structure of an adjusting screw according to any one of claims 1 to 3,

the adjustment screw mechanism is configured to adjust a compression amount of the elastic body generating the load in a direction opposite to a direction of the load generated by driving the actuator.

5. A valve device configured to control an opening degree of a valve port through which a fluid flows by a valve body, and having a fixed structure of the adjusting screw mechanism according to claim 4,

the above-mentioned valve device is characterized in that,

the valve body is configured to transmit a driving force of the driving actuator to the valve body.

6. The valve device according to claim 5,

the valve body and the valve port are configured as an expansion valve that throttles the refrigerant flowing in from the inflow passage, expands the refrigerant, and flows out from the outflow passage.

7. A refrigeration cycle system comprises a compressor, a condenser, an evaporator and a throttling device, and is characterized in that,

use of the valve device according to claim 6 as the above-mentioned throttling means.

Background

Conventionally, in a valve device, for example, japanese patent application laid-open No. 2014-5906 (patent document 1) discloses a technique of adjusting an operating characteristic of a valve body (valve member) by an adjusting screw mechanism for adjusting a compression amount of an elastic body assembled in the valve. In patent document 1, the coil spring (compression spring) is an elastic body.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2014-5906

Disclosure of Invention

Problems to be solved by the invention

As the fixing structure of the adjusting screw mechanism in patent document 1, a fixing structure by caulking of metals, a fixing structure by applying an adhesive to a screw portion, or the like is used.

However, in the fastening structure by caulking, it is difficult to use a resin member for the screw mechanism, and it is necessary to form the screw mechanism from a metal member, which imposes a limitation on weight reduction of the valve device. In addition, in the fixing structure by the adhesive, it takes time until the adhesive is dried, and there is a problem that the processing time becomes long.

The invention aims to realize weight reduction and shorten processing time in a valve device using a fixing structure of an adjusting screw mechanism for adjusting the compression amount of an elastic body by a screw mechanism consisting of an external screw thread part and an internal screw thread part.

Means for solving the problems

In the fixing structure of the adjusting screw according to the present invention, the compression amount of the elastic body is adjusted by a screw mechanism including a male screw portion and a female screw portion which are mutually adjustable in a deformation direction of the elastic body, and the fixing structure of the adjusting screw is characterized in that the male screw portion and the female screw portion of the adjusting screw are formed of a resin member, and the male screw portion and the female screw portion are mutually fixed by welding at an interface of a screw-joining portion.

In this case, it is preferable that the fixing structure of the adjusting screw mechanism is characterized in that the male screw portion and the female screw portion are fixed to each other by welding only at a part of an interface of the screw coupling portion.

Preferably, the fixing structure of the adjusting screw mechanism is characterized in that, in a state in which the male screw portion and the female screw portion are threadedly engaged, a sum of a radial clearance of the female screw valley bottom and a radial clearance of the male screw valley bottom is 20% or more of a difference between the female screw valley bottom diameter and the male screw valley bottom diameter.

In the fixing structure of the adjusting screw mechanism, it is preferable that the adjusting screw mechanism is configured to adjust a compression amount of the elastic body generating the load in a direction opposite to a direction of the load generated by driving the actuator.

The valve device according to the present invention is a valve device configured to control an opening degree of a valve port through which a fluid flows by using a valve body, and includes a fixed structure of the adjusting screw mechanism, and is characterized in that the valve device is configured to transmit a driving force of the driving actuator to the valve body.

In this case, the valve body and the valve port are preferably configured as an expansion valve that throttles the refrigerant flowing from the inflow passage, expands the refrigerant, and flows out from the outflow passage.

The refrigeration cycle system of the present invention is a refrigeration cycle system including a compressor, a condenser, an evaporator, and a throttle device, and is characterized in that the valve device is used as the throttle device.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the fixing structure of the adjusting screw mechanism, the valve device, and the refrigeration cycle system of the present invention, the male screw portion and the female screw portion of the adjusting screw mechanism are formed of resin members, and the male screw portion and the female screw portion are fixed by ultrasonic welding, so that weight reduction and reduction in processing time can be achieved.

Drawings

Fig. 1 is a partial sectional view of a cooling device including a temperature type expansion valve as a valve device according to an embodiment of the present invention.

Fig. 2 is an enlarged cross-sectional view of a main portion of an adjusting screw mechanism in the temperature type expansion valve according to the embodiment.

Fig. 3 is an enlarged cross-sectional view of a main portion of modification 1 of the adjusting screw according to the embodiment.

Fig. 4 is a schematic view showing a process of ultrasonic welding in the embodiment.

Fig. 5 is a diagram showing modification 2 of the adjusting screw according to the embodiment.

Fig. 6 is a diagram showing a refrigeration cycle system according to an embodiment of the present invention.

In the figure:

1-adjusting screw mechanism, 11-female screw portion, 12-male screw portion, 13-adjusting screw, 14-adjusting spring, 2-valve main body, 2A-lower side portion, 2B-upper side portion, 21-side opening, 22-lower end opening, 23-valve guide hole, 24-working shaft guide hole, 25-refrigerant passing portion, 26-spring chamber, 27-pressure equalizing hole, 3-driving actuator, 3A-upper cover, 3B-lower cover, 3C-retaining member, 31-flange portion, 32-valve seat portion, 33-valve port, 34-diaphragm, 35-diaphragm chamber, 36-pressure equalizing chamber, 37-pressure plate, 38-working shaft, 38 a-lower end portion, 39-coil spring, 4-valve core, 41-inner space, 42-through hole, 43-needle portion, 5-temperature sensing cylinder, X-axis, 10-temperature type expansion valve, 20-housing, 20A-valve unit fitting hole, 20B-inflow path, 20C-outflow path, 100-compressor, 200-condenser, 300-evaporator, 400-accumulator.

Detailed Description

Hereinafter, an embodiment of a fixing structure of an adjusting screw, a valve device, and a refrigeration cycle according to the present invention will be described with reference to the drawings.

Fig. 6 is a diagram showing a main part of a refrigeration cycle of a cooling apparatus using a temperature type expansion valve according to an embodiment, and the refrigeration cycle of the embodiment will be described first. In fig. 6, reference numeral 10 denotes a temperature type expansion valve of the embodiment, reference numeral 100 denotes a compressor, reference numeral 200 denotes a condenser, reference numeral 300 denotes an evaporator, and reference numeral 400 denotes an accumulator, and these are connected in a ring shape by a pipe to constitute a refrigeration cycle. As will be described later, the thermal expansion valve 10 is assembled in a housing 20, and includes a diaphragm-type drive actuator 3, a temperature sensing cylinder 5, for example, the same as a conventional temperature sensing cylinder, and a capillary tube 6. The inflow passage 20B of the casing 20 is connected to an outlet-side pipe 200a of the condenser 200, and the outflow passage 20C of the casing 20 is connected to an inlet-side pipe 300a of the evaporator 300. The evaporator 300 is disposed in parallel in contact with a heating element, not shown, to be cooled, or in an indoor ambient gas to be cooled for air conditioning or refrigeration, and the temperature sensing cylinder 5 is attached to an outlet-side pipe 300b of the evaporator 300.

The compressor 100 compresses the refrigerant flowing through the refrigeration cycle, and the compressed refrigerant is condensed and liquefied by the condenser 200 and flows into the thermal expansion valve 10 through the inflow passage 20B. The refrigerant flowing into the thermal expansion valve 10 is decompressed (expanded) and flows into the evaporator 300 through the outflow passage 20C. The evaporator 300 evaporates and gasifies a part of the refrigerant, the refrigerant in a gas-liquid mixed state flows into the accumulator 400, and the gas-phase refrigerant circulates from the accumulator 400 to the compressor 100. The evaporator 300 evaporates and gasifies a part of the refrigerant to absorb heat from a heat generating body, air, and the like. Thereby, the heat generating body, the air, or the like is cooled. Further, a gas is sealed in the temperature sensing cylinder 5 by adsorption filling or the like, and the temperature sensing cylinder 5 is connected to the driving actuator 3 by a capillary tube 6.

Fig. 1 is a partial sectional view of a cooling device including a thermal expansion valve as a valve device according to an embodiment, and fig. 2 is an enlarged sectional view of a main portion of an adjusting screw mechanism in the thermal expansion valve. Note that the concept of "up and down" in the following description corresponds to up and down in the drawing of fig. 1, and the axis X indicated by the one-dot chain line corresponds to the center line of the valve port 33 described later and to the movement direction of the operating shaft 38 and the valve element 4.

The cooling device of this embodiment is a device in which the temperature-type expansion valve 10 of the embodiment is mounted on the housing 20. The valve housing 20 is entirely made of a metal member, and the valve unit mounting hole 20A, the inflow passage 20B, and the outflow passage 20C are formed in the housing 20. The valve unit attachment hole 20A has: a small diameter chamber 20a1 having a cylindrical shape centered on the axis X below in the direction of the axis X; a cylindrical large diameter chamber 20a2 centered on the axis X above the small diameter chamber 20a 1; and a thin cylindrical drive actuator chamber 20A3 centered on the axis X above the large diameter chamber 20a 2. The thermal expansion valve 10 is fitted into the valve unit mounting hole 20A.

The thermal expansion valve 10 is composed of a valve main body 2, a drive actuator 3, a valve element 4, and a temperature sensing cylinder 5 (see fig. 6). Further, an O-ring P, Q is provided between the valve body 2 and the housing 20, at an end of the small diameter chamber 20a1 on the large diameter chamber 20a2 side and an end of the large diameter chamber 20a2 on the drive actuator chamber 20A3 side, and airtightness between the inflow passage 20B and the outflow passage 20C is ensured by the O-ring P. Further, the O-ring Q ensures airtightness between the valve main body 2 and the housing 20 with respect to the external space.

The valve main body 2 is made of a resin member and is housed in the small diameter chamber 20a1 and the large diameter chamber 20a2 of the housing 20. The lower portion 2A of the valve body 2 housed in the small diameter chamber 20a1 is formed in a cylindrical shape having an axial direction along the axis X, and has a side opening 21 on a side surface thereof and a lower end opening 22 at a lower end thereof. A valve guide hole 23 is formed in the upper inner periphery of the lower portion 2A, and the valve body 4 is accommodated in the valve guide hole 23. A female screw portion 11 is formed inside the lower end opening 22 of the lower portion 2A in the axis X direction, and an adjusting screw 13 made of a resin member is disposed inside the female screw portion. An external thread portion 12 is formed on the outer periphery of the adjustment screw 13, the external thread portion 12 is screwed to the internal thread portion 11, and an adjustment spring 14 as an "elastic body" is disposed between the adjustment screw 13 and the valve body 4. The female screw portion 11, the adjusting screw 13, and the adjusting spring 14 constitute the adjusting screw mechanism 1. A through hole 13a and a driver hole 13b are formed in the center of the adjustment screw 13.

The upper portion 2B of the valve main body 2, which is housed in the large diameter chamber 20a2, includes: a cylindrical work shaft guide hole 24 extending in the axis X direction above a valve seat portion 32a described later; a refrigerant passage portion 25 extending orthogonally to the working shaft guide hole 24; a spring chamber 26 formed in an annular deep groove around the working shaft guide hole 24 from the side of the drive actuator chamber 20a 3; and a pressure equalizing hole 27 for communicating the spring chamber 26 with the refrigerant passing portion 25.

The drive actuator 3 formed on the upper portion of the valve main body 2 is formed as an outer housing by a thin disc-shaped upper cover 3A and a lower cover 3B. The lower cover 3B has a flange portion 31 facing the upper cover 3A, and a cylindrical portion 32 connected to the flange portion 31 and having a bottomed cylindrical shape centered on the axis X. The lower cover 3B is integrally formed with the valve main body 2 by fitting the valve main body 2 into a cylindrical portion 32, and a valve seat portion 32a constituting the bottom of the cylindrical portion 32 is disposed on the lower end side of the working shaft guide hole 24 of the upper portion 2B of the valve main body 2. A valve port 33 centered on the axis X is formed in the center of the seat portion 32 a.

Further, the retaining member 3C is attached to the drive actuator chamber 20A3 of the housing 20, and the retaining member 3C is locked to the upper surface of the outer edge portion of the upper cover 3A of the drive actuator 3, so that the drive actuator 3 and the valve body 2 do not fall out of the valve unit attachment hole 20A.

A diaphragm 34 is provided between the upper cover 3A and the lower cover 3B, and a diaphragm chamber 35 and a pressure equalizing chamber 36 are defined by the diaphragm 34. A pressure plate 37 is disposed in the lower cover 3B, and an operating shaft 38 is connected to the pressure plate 37. Further, a coil spring 39 is disposed in the spring chamber 26 in a compressed state between the bottom of the spring chamber 26 and the platen 37. Thereby, the coil spring 39 biases the operating shaft 38 toward the diaphragm 34.

The working shaft 38 is slidably inserted through the working shaft guide hole 24. The lower end 38a of the operating shaft 38 is pin-shaped so as to have an outer diameter capable of passing through the valve port 33, and the lower end 38a of the operating shaft 38 penetrates the valve port 33. The lower end 38a of the operating shaft 38 transmits the operation of the diaphragm 34 to the valve element 4.

The valve body 4 is formed in a bottomed cylindrical shape having a closed upper surface and an open lower surface, and has an inner space 41 inside. Further, a through hole 42 that communicates the valve port 33 with the internal space 41 is formed in a part of the upper surface, and a needle portion 43 is provided in the center of the upper surface. The needle portion 43 is moved toward or away from the valve seat portion 32a to control the opening degree of the valve port 33. The lower end 38a of the operating shaft 38 abuts on the upper end of the needle portion 43.

According to the above configuration, the inflow path 20B receives the refrigerant from the condenser 200, the refrigerant is introduced into the valve unit mounting hole 20A, passes through the side opening 21 of the lower portion 2A and the wrench hole 13B and the through hole 13a of the adjusting screw 13, the inner space 41 and the through hole 42 of the valve body 4, the valve port 33, and the refrigerant passing portion 25 in this order, and is sent out from the outflow path 20C to the evaporator 300. When the internal pressure of the diaphragm chamber 35 increases or decreases in accordance with the temperature sensed by the temperature sensing cylinder 5, the diaphragm 34 deforms, and the diaphragm chamber 35 expands or contracts. Then, the operating shaft 38 moves in the axis X direction in accordance with the deformation of the diaphragm 34, and the valve opening, which is the gap between the valve port 33 and the needle portion 43 of the valve body 4, changes.

In the adjusting screw mechanism 1 of the thermal expansion valve 10, the adjusting spring 14 is provided below the valve element 4 and applies an upward biasing force, and the biasing force with respect to the valve element 4 can be adjusted by adjusting the amount of screwing of the screw 13 into the female screw portion 11. That is, since the force with which the valve body 4 presses the operating shaft 38 can be adjusted by adjusting the amount of screwing the adjusting screw 13, the pressure at which the valve port 33 starts to open, that is, the set pressure can be adjusted according to the introduction pressure of the diaphragm chamber 35. When the adjustment screw 13 is screwed (rotated), a wrench or the like is fitted into the wrench hole 13b of the adjustment screw 13 and rotated.

After the temperature type expansion valve 10 has adjusted the set pressure as described above, the adjustment screw 13 is fastened to the female screw portion 11 of the lower portion 2A of the valve main body 2. The valve main body 2 and the adjusting screw 13 are each a resin member (resin-made member), and are ultrasonically welded as shown in fig. 2. Ultrasonic welding is a process of melt-bonding the interface between the male thread portion and the female thread portion by ultrasonic vibration.

That is, in fig. 2, a melt-solidified layer D (a portion of an ellipse with thin hatching) is formed at a boundary portion between the female screw portion 11 of the lower portion 2A and the male screw portion 12 of the adjusting screw 13. Fig. 4 is a schematic view showing a process of ultrasonic welding, and the temperature-type expansion valve 10 is mounted on a fixing jig 40 provided with a stem 40 a. Specifically, the lever shaft 40a is inserted into the wrench hole 13B and the through hole 13A of the adjustment screw 13, and is placed in a state where the outer peripheral edges of the upper cap 3A and the lower cap 3B of the drive actuator 3 are lifted from the horizontal base 40B of the fixing jig 40. Then, the horn 50 is pressed against the lower portion 2A of the valve body 20 to perform ultrasonic welding.

Since the horn 50 is pressed toward the outer periphery of the lower portion 2A of the valve main body 2 from a direction perpendicular to the axis X (central axis), the pressed side of the lower portion 2A fusion-bonds the interface between the male thread portion and the female thread portion by ultrasonic vibration, but the opposite side to which the horn 50 is not pressed has a gap at the interface between the male thread portion and the female thread portion in accordance with the thread wobble and is not in contact with each other, and therefore there is an unwelded portion. Further, as shown in fig. 4, since the valve body 2 is moved downward by melting the side of the pressing horn 50 because it is placed in a state of being floated from the horizontal table 40b and melted in a direction perpendicular to the axis line X (central axis), the gap on the opposite side where the pressing horn 50 is not pressed is further opened between the threads, and welding is difficult. Therefore, the male screw portion and the female screw portion are fixed to each other by welding only in a part of the entire circumference of the interface of the screwed portions. Since a part of the screw-threaded portion remains without being melted, and the deviation in the axis X direction at the time of melting is suppressed, it is preferable to accurately adjust the compression amount of the elastic body. The fixing is only partially performed by welding, but depending on the melting conditions, the fixing strength is sufficient even partially.

In this embodiment, as shown in fig. 2, a defective portion is formed in a part of an outer peripheral portion (a portion corresponding to a ridge line of a spiral) of the male screw portion 12 of the adjustment screw 13. That is, the height of the ridge of one of the male screw portion 12 and the female screw portion 11 (the male screw portion 12) is smaller than the depth of the groove of the other one (the female screw portion 11). Thus, a space S1, which is a "melt reservoir", is formed between the mountain of the male screw portion 12 and the valley of the female screw portion 11. This prevents the molten resin from overflowing into the flow path or the like during ultrasonic welding, and thus prevents the overflow portion from falling off and flowing into the flow path of the refrigeration cycle as foreign matter, which is a problem.

In the embodiment of fig. 2, an example is shown in which the height of the ridge of one of the male screw portion 12 and the female screw portion 11 (the male screw portion 12) is smaller than the depth of the thread groove of the other one (the female screw portion 11), but the embodiment is not limited to a small example, and a modified example 1 of fig. 3 including the same dimension will be described. As shown in fig. 3, in the state before melting, the sum (a + B) of the difference [ a ] (radial clearance of the valley bottom of the female screw) between the diameter [ D1] of the valley of the female screw and the crest diameter (outer diameter) of the crest of the male screw) [ D2] and the difference [ B ] (radial clearance of the valley bottom of the male screw) between the inner diameter [ D3] of the female screw and the valley diameter [ D4] of the male screw is 20% or more of the difference [ C ] (radial length between the valley bottom of the male screw and the female screw) between the diameter [ D1] of the valley of the female screw and the valley bottom of the male screw, that is, (a + B)/C × 100 ≧ 20 in a ═ D1-D2, B ═ D3-D4, and C ═ D1-D4, and thus a gap S1 and a gap [ B ] which are gaps of "melting reservoirs" and a "S3 of gaps. This prevents the molten resin from overflowing into the flow path or the like during ultrasonic welding, and thus prevents the overflow portion from being displaced and flowing into the flow path of the refrigeration cycle as foreign matter, which may cause a problem.

Further, the total (a + B) of the difference [ a ] (radial clearance of the bottom of the female thread) between the diameter [ D1] of the valley of the female thread and the crest diameter (outer diameter) of the crest of the male thread [ D2] and the difference [ B ] (radial clearance of the bottom of the male thread) between the inner diameter [ D3] of the female thread and the diameter [ D4] of the valley of the male thread is preferably 30 to 40% of the difference [ C ] (radial length between the bottom of the male thread and the bottom of the female thread) between the diameter [ D1] of the valley of the female thread and the diameter [ D4] of the valley of the male thread, and thus, a space for releasing the molten resin can be sufficiently secured as compared with the above. Further, about 50% is more preferable.

Fig. 5 is a view showing a modification 2 of the adjusting screw according to the embodiment, in which the adjusting screw 13 ' of the modification 2 is provided with a missing portion which is not screwed with the female screw portion 11 at both outer end portions in the axis X direction of the male screw portion 12 ', and a space S2 which is a "melt reservoir" is provided between a portion of the missing portion of the crest of the male screw portion 12 ' and a valley of the female screw portion 11 at the missing portion. This prevents the molten resin G from overflowing into the flow path or the like during ultrasonic welding, and thus prevents the overflow portion from being displaced and flowing into the flow path of the refrigeration cycle as foreign matter, which may cause a problem.

The present invention is not limited to this embodiment, and includes other configurations and the like that can achieve the object of the present invention, and modifications and the like as shown below are also included in the present invention. In the above embodiment, the example of the temperature type expansion valve is shown as the valve device, but the present invention can be applied to a valve device including an adjusting screw mechanism based on screw coupling of male and female screws. For example, the present invention can be applied to a pressure regulating valve that adjusts the set pressure by adjusting the amount of deformation of a coil spring as in patent document 1. The present invention is not limited to a temperature-type expansion valve and a pressure-regulating valve, and may be applied to other valve devices such as an electromagnetic valve and an electrically-operated valve provided with a mechanism for regulating the amount of deformation of an elastic body such as a regulating spring. Further, the present invention can be applied to devices other than the valve device.

While the embodiments of the present invention have been described in detail with reference to the drawings, other embodiments have been described in detail, but the specific configurations are not limited to these embodiments, and design changes and the like that do not depart from the scope of the present invention are also included in the present invention.