JP2000266214A - Flow rate control device for fluid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically carry out a joining of a body portion of a flow rate control device for a fluid and a part joined thereto by a silver-soldering in a hydrogen reducing furnace, to realize a reduction in an operation step and to realize a uniformity of a joining quality. SOLUTION: This flow rate control device body is provided with a cylindrical body 2 to which an inflow pipe 4 for making a fluid flow into and an outflow pipe 5 for making a liquid flow out are connected, and in which a fluid outflow passage for introducing fluid flowing into the inside through the inflow pipe 4 is provided on a tip end surface side. A connection (connection portion Y) of the inflow pipe 4 and an outflow pipe 5 to the body portion 2 is carried out by soldering in a hydrogen reducing furnace. A mounting (mounting part W) of the driving source accommodation bodies 22, 23 against the body portion 2 is carried out by a soldering in a hydrogen reducing furnace.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a fluid flow control device using a stepping motor or the like as a valve opening / closing drive source.

[0002]

2. Description of the Related Art Conventionally, as a device for controlling a flow rate of a refrigerant in a refrigerator or an air conditioner, there is a device using an electromagnetic valve or a device using a needle valve.

However, a flow control device using a solenoid valve is
Generally, one of the settings of opening and closing is performed.
It is not suitable for fine adjustment of the flow rate. Also, one of the problems is that a loud sound is generated at the time of the opening and closing operation. In addition, in either the open or closed state, the solenoid valve must be energized to maintain the state. And there is a problem in terms of power consumption.

[0004] On the other hand, a flow control device using a needle valve is generally a cylindrical main body having a fluid outflow passage for guiding a fluid flowing into the inside through an inflow pipe to an outflow pipe at a tip end side. And a carriage that is housed in the main body so as to be movable along the central axis direction in the main body, and that opens and closes the fluid outflow passage. And a drive source for reciprocating along the center axis direction of the carriage. The carriage is reciprocally moved, and the reciprocating force is transmitted to the needle valve to open and close the valve.

More specifically, a stepping motor or the like is used as a driving source, the rotational force of the stepping motor is converted into reciprocating motion, and the reciprocating motion is output. , The operation noise is less problematic than that of the solenoid valve, and the flow rate can be finely adjusted.

However, many flow control devices using the needle valve generally have a large size motor as a drive source. This is presumably because many of them are mainly used for controlling the flow rate of refrigerant such as air conditioners. That is, in the case of an air conditioner, since the difference between the pressure on the inflow side of the refrigerant and the pressure on the outflow side when the refrigerant is shut off is large, it is necessary to move the needle valve with a large thrust.
This inevitably increases the size of the motor for driving the valve.

However, there is a space problem in using a device using the needle valve as it is in a refrigerant flow control device in a refrigerator or the like. In the case of refrigerators,
In order to increase the space in the food storage, it is required to make each component as small as possible. Therefore, it is needless to say that the fluid control device for the refrigerant must be miniaturized as much as possible. However, if the size of the motor is reduced, a problem arises in that a torque required for performing reliable flow control cannot be obtained.

Further, the needle valve has a delicate positional relationship between the center axis of the moving direction of the needle valve and the center axis of the fluid outflow passage into which the needle valve is inserted in order to perform highly accurate control. Therefore, there is also a problem that high-precision design techniques and empirical know-how during assembly are required.

In addition, this type of fluid control device often uses copper, brass, stainless steel called SUS or the like for its material depending on its constituent elements in consideration of durability, corrosion resistance and the like. For example, the main body is made of brass, the inflow pipe and the outflow pipe for guiding fluid to the main body and flowing out from the main body are made of copper, and the drive source housing that stores the drive source is made of stainless steel, etc. It is a suitable material. In particular, the main body may have a complicated shape. Brass is used in consideration of machinability and cost, and stainless steel (SUS) is used in the drive source housing in consideration of durability and rust prevention. Copper is often used for the inflow and outflow pipes in consideration of corrosion resistance.

[0010] When these are joined, they are generally joined by brazing in consideration of confidentiality and joining strength. Conventionally, when joining by such brazing, in most cases, flux is applied to the joined portion and brazing is performed manually. When performing this brazing, there is no particular problem with the brass material and the copper material, but there are some problems when brazing the brass material and the stainless steel material.

That is, when brazing a brass material and a stainless steel material, there is a problem that chrome present on the surface of the stainless steel material has an adverse effect on the brazing and a good bonding state cannot be obtained. To cope with this, the brazing temperature may be raised to about 1000 degrees.
When the temperature is raised to 000 degrees, there arises a problem that the brass material cannot withstand the temperature and is deformed or melted.

Therefore, conventionally, brazing of a brass material and a stainless steel material by hand is performed by a skilled operation of locally applying a high temperature only to a joint portion and instantaneously completing the brazing. That is the fact. According to this, the high temperature is not applied to the entire main body, the adverse effect of the temperature is minimized, and the joining between the stainless steel material and the brass material becomes possible.

[0013]

However, in the case of the above-mentioned brazing by hand, a skilled technique is required, and since it is a manual operation, there are many variations in joining quality of a joining portion, and further, workability is increased. There is also a problem in terms of production efficiency. In addition, in the case of brazing by hand, it is necessary to apply a flux to the joint portion and perform brazing. After applying flux and brazing,
Since the applied portion of the flux is oxidized later, it is necessary to remove the oxide film.

As described above, conventionally, a brazing operation by hand is performed, and thereafter, an operation of removing an oxide film is also performed. Therefore, many operation steps are required, productivity is low, and the cost is low. The result is reflected,
As described above, there are many problems in terms of variations in the joining quality of the joining portions.

To cope with this, it is conceivable to automatically join by brazing in a hydrogen reduction furnace (here, silver brazing). However, silver brazing by this hydrogen reduction furnace is not limited to the parts to be joined,
In this case, with the inflow / outflow pipe and the entire drive source housing attached to the main body, silver brazing is performed on the joining portion by immersion in a hydrogen reduction furnace.

What is problematic here is the joining of the brass main body and the stainless steel driving source housing. In other words, as described above, in order to avoid the effect of chromium present on the surface of the stainless steel material, the temperature of silver brazing must be set at 100 ° C.
The temperature may be raised to about 0 degrees, but if the temperature is raised to 1000 degrees, there arises a problem that the brass material cannot withstand the temperature and is deformed or melted out.

As described above, silver brazing by the hydrogen reduction furnace applies a temperature to the entire main body, so that the silver brazing temperature by the hydrogen reduction furnace cannot be too high. Since brass generally has the property of melting at 800 ° C. or higher, it is necessary to perform a process that allows silver brazing at a temperature sufficiently lower than this. By the way, silver brazing by a hydrogen reduction furnace can be performed at a temperature of about 700 to 780 degrees, so if silver brazing is performed at this temperature, joining with the drive source housing can be performed without adversely affecting the main body. Will be.

Therefore, the present invention makes it possible to automatically join the main body of the fluid flow control device and the parts to be joined thereto by silver brazing in a hydrogen reduction furnace, thereby reducing the number of working steps. Further, it is an object of the present invention to provide a fluid flow control device capable of making the joining quality uniform.

[0019]

In order to achieve the above object, according to the first aspect of the present invention, an inflow pipe for inflowing a fluid and an outflow pipe for outflow of a fluid are connected, and flowed into the interior through the inflow pipe. In a fluid flow rate control device having a cylindrical main body having a fluid outflow passage for guiding a fluid to an outflow pipe at a tip end side, connection of an inflow pipe and an outflow pipe to the main body is performed by brazing with a hydrogen reduction furnace. I'm trying to do it.

According to a second aspect of the present invention, there is provided a fluid outflow path to which an inflow pipe for inflowing a fluid and an outflow pipe for outflow of the fluid are connected, and which guides the fluid flowing into the inside through the inflow pipe to the outflow pipe. A main body having a cylindrical shape, a carriage housed in the main body so as to be movable along a central axis direction in the main body, and opening and closing a fluid outflow passage, and a rear end face side of the main body. A drive source having a drive shaft for reciprocating the carriage along a central axis direction in the main body, and a drive source housing that houses at least a part of the drive source and is attached to the rear end face side of the main body. In the fluid flow control device, the drive source housing is attached to the main body by brazing using a hydrogen reduction furnace.

The invention described in claim 3 is the invention according to claim 1.
Or in the fluid flow control device according to 2, wherein the main body is made of brass, and when brazing to the main body by the hydrogen reduction furnace is performed, if the object to be joined is a stainless steel material, the stainless steel material is used. After nickel-phosphorous plating is applied to the surface of the substrate, brazing is performed in a hydrogen reduction furnace.

Further, the invention described in claim 4 is the third invention.
In the fluid flow control device described above, a process of applying nickel-phosphorus plating to the surface of a stainless steel material is performed, a thermal diffusion process is performed, and then brazing is performed by a hydrogen reduction furnace.

The fifth aspect of the present invention provides the third aspect of the present invention.
Alternatively, in the fluid flow control device according to 4, the thickness of the nickel-phosphorous plating is 3.5 μm ± 0.5 μm.

According to a sixth aspect of the present invention, in the fluid flow control device according to any one of the first to fifth aspects, the brazing is silver brazing.

As described above, the present invention relates to a fluid flow control device for reciprocating a drive shaft by a drive source and thereby reciprocating a carriage within a main body to control opening and closing of a fluid outflow passage. The main body and the parts connected to it (fluid inflow and outflow pipes,
The connection with the drive source housing is automatically performed by silver brazing in a hydrogen reduction furnace. This eliminates the need to apply the flux that was required during brazing by hand, and eliminates the cumbersome work steps such as the work of removing the oxide film that had been conventionally performed, thereby improving productivity and further improving the productivity. Since this is a typical brazing operation, the quality can be made uniform.

At this time, if the object to be joined to the brass body is a stainless material, the surface of the stainless material is plated with nickel and phosphorus, and then brazed by a hydrogen reduction furnace. . Accordingly, the joining can be performed without being affected by the chrome on the surface of the stainless steel, so that the joining can be performed at a temperature at which the brass is not adversely affected.

Further, by performing the heat diffusion treatment after the nickel-phosphorus plating, the bonding strength can be greatly improved. By setting the thickness of the nickel-phosphorus plating to 3.5 μm ± 0.5 μm, the bonding strength can be further increased. In addition, by using silver brazing as the brazing, brazing can be performed at a relatively low temperature of 800 ° C. or less.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIGS. 1 to 3 illustrate the overall structure of a fluid flow control device according to an embodiment of the present invention. FIG. 1 is a side sectional view, and FIG. 2 is a side view showing an external structure. 3 is a front view of FIG. 2 viewed from the direction of arrow A.

The fluid flow control device 1 shown in FIGS. 1, 2 and 3 can be roughly described in terms of the external configuration. The main unit 2 is attached to the rear end of the main unit 2. A motor (hereinafter, referred to as a stepping motor in this embodiment, which is a stepping motor) 3 as a drive source for driving the opening and closing of a valve (which will be described in detail later), and a motor 3 A pipe on the inflow side of the fluid (hereinafter, referred to as an inflow pipe) 4 and a pipe on the outflow side of the fluid (hereinafter, referred to as an outflow pipe) 5. The inflow pipe 4 and the outflow pipe 5
Is made of copper.

The stepping motor 3 is provided with a stator portion 32 around which a coil 31 is wound, a rotor portion 33 disposed inside the stator portion 32 so as to face the stator portion 32, and provided in the center axis direction of the rotor portion 33. Rotary shaft support hole 33
This has a configuration having a rotating shaft 34 as a drive shaft rotatably supported by a.

In this state, the power supply unit 36 supplies the coil 3
By supplying power to the motor 1, the rotor unit 33 rotates. The stator section 32 around which the coil 31 is wound is housed in a stator housing body 38, and the stator housing body 38 can be detachably attached to the main body 2 by a holder 40 described later. In addition,
The stator portion 32 has a structure in which the coil 31 is integrated with the pole teeth of the stator portion 32 by resin and the coil 31 is sealed.

In this embodiment, the main body 2 has a cylindrical shape made of brass. Then, a bearing 21 for rotatably instructing the rotation shaft 34 of the stepping motor 3 is fixed to the rear end side of the main body 2 in a state of being press-fitted therein. In addition, a flange-shaped plate 22 that is joined to the main body 2 by automatic brazing is provided at a rear end portion of the main body 2 (the joining portion is indicated by W). In this connection, the automatic brazing is performed by silver brazing using a hydrogen reduction furnace (in some cases, copper brazing is also possible, but silver brazing is preferable. Do).

The flange-shaped plate 22 is made of stainless steel.
The rotor housing case 23 made of stainless steel for housing the rotor unit 33 is positioned by the three pins 22a, and thereafter, the two are joined by TIG welding (the joint is shown as V).

The joining of the flange-shaped plate 22 and the rotor storage case 23 is completed when the joining of the flange-shaped plate 22, the inflow pipe 4, and the outflow pipe 5 to the main body 2 is completed. This process is performed as a final step in which all the parts are stored and some of the components of the stepping motor 3 are stored in the rotor storage case 23. Note that the flange-shaped plate 22 and the rotor storage case 23 are collectively referred to as a drive source storage body.

FIG. 4A is a plan view of the flange-shaped plate 22 viewed from the front side, and FIG.
FIGS. 4A and 4B are cross-sectional views as viewed in the direction of the arrows, and illustrations of parts that are not particularly necessary for the description here are omitted. By the way, the collar plate 22
Is joined to the main body 2 by silver brazing using a hydrogen reduction furnace, but silver brazing using a hydrogen reduction furnace cannot be performed as it is for the reasons described above.

Therefore, in the present invention, in order to enable silver brazing in a hydrogen reduction furnace, nickel-phosphorus (Ni.P) plating is performed on the stainless steel flange plate 22, and thereafter, A silver brazing process is performed using a hydrogen reduction furnace. In addition, since the bonding strength after silver brazing may not be satisfied with a specific specification only by performing the Ni-P plating, the Ni-P plating may be performed.
Preferably, a thermal diffusion treatment is performed. After this heat diffusion treatment, silver brazing is performed in a hydrogen reduction furnace.

That is, the N-shaped plate 22 is simply N
When the i.P plated material is silver brazed by a hydrogen reduction furnace, a sufficient bonding strength between the silver braze and the surface of the Ni.P plating can be obtained, but the Ni.P plating and its base material are used. This is because there may be a case where the joining strength of the stainless steel (flange-shaped plate 22) can be obtained only to an extent that does not satisfy the special specifications. In this type of fluid flow control device, a pressure of several tens of atmospheres may be applied to the inside of the main body 2 depending on the application, and a very high level of bonding strength of a portion connected to the main body 2 is required. There are cases.

To cope with this, the flange plate 22
Is subjected to a heat diffusion treatment after Ni.P plating. By performing this thermal diffusion treatment, some of the elements constituting stainless steel diffuse to the Ni · P plating side, and the bonding between the metals occurs, resulting in a state like a kind of alloy, and the bonding strength between the two is extremely high. Things.

When Ni.P plating is applied to the flange plate 22, it is preferable to apply Ni.P plating to the entire flange plate 22, but it may be partial. When Ni.P plating is partially performed as described above, it is necessary to perform Ni.P plating at least on a portion where silver brazing is performed. At this time, in order to increase the bonding strength, it is necessary to apply Ni.P plating not only to the portion appearing on the surface but also to the portion where the silver brazing is considered to flow.

Further, it was confirmed by experiments that when the Ni-P plating was applied to the flange plate 22, the plating thickness was optimally 3.5 μm ± 0.5 μm. That is, it was confirmed that the bonding strength with the main body 2 was highest when the thickness of the Ni · P plating was in the range of 3.5 μm ± 0.5 μm. The reason for this is that if the plating thickness is greater than 4.0 μm, even if a thermal diffusion treatment is performed thereafter, the degree of progress of thermal diffusion is reduced, so that peeling of the plating interface occurs with a small stress. If the thickness is less than 3.0 μm, iron or chrome on the surface of stainless steel diffuses to the surface of the Ni · P plating, and the flow of silver brazing is deteriorated. If some degree of strength deficiency can be tolerated, the Ni / P plating thickness should be 3.
It may be in the range of 5 μm ± 1.0 μm.

By the way, since the material of the inflow pipe 4 and the outflow pipe 5 is made of copper, the main body 2 and the inflow pipe 4 and the outflow pipe 5 are joined without performing a process such as NiP plating. Silver brazing by a hydrogen reduction furnace becomes possible.

FIG. 5 shows a joining process of the flange plate 22, the inflow pipe 4, and the outflow pipe 5 to the main body 2 described above. First, Ni.P plating is performed on the flange plate 22. Step F1 and its thermal diffusion treatment step F2
After that, it is attached to the main body 2 (at this time, the inflow pipe 4 and the outflow pipe 5 are attached to the main body 2), and is immersed in a hydrogen reduction furnace. A silver brazing step F3 is performed. The silver brazing temperature in the silver brazing step using this hydrogen reduction furnace was 700 to 780 ° C., and the silver brazing treatment time was between 10 minutes and 30 minutes.

In the Ni / P plating step F1 shown in FIG. 5, an electrolytic Ni plating step F11 is further performed, and then an electroless Ni plating step F12 is performed.
Although the electrolytic Ni plating step (plating thickness is about 0.3 μm) F11 is performed to improve the adhesion, the electrolytic Ni plating step F11 may be omitted and only the electroless Ni plating step F12 may be performed. Note that the electroless N
i-plating is Ni-P plating.

Good results can be obtained by performing the joining process in the joining process step as shown in FIG. 5. Particularly, in the joining between the brass main body 2 and the stainless steel flange plate 22, the stainless steel is used. It was difficult 700 as it was
It has been found that sufficient bonding strength can be obtained even by silver brazing at a low temperature of ７780 degrees.

As described above, the brass main body 2 and the stainless steel flange plate 22 can be silver-brazed by a hydrogen reduction furnace at a temperature of 700 to 780 ° C., which does not adversely affect the brass material. The process shown in FIG. 5 includes a Ni.P plating (plating thickness 3.5 μm ± 0.5 μm) process F1 for the flange-shaped plate 22, a heat diffusion process F2 performed as necessary, and a subsequent process. This is because it is attached to the main body 2 and is subjected to a silver brazing step F3 using a hydrogen reduction furnace.

The connection between the main body 2 and the inflow pipes 4 and outflow pipes 5 made of copper can be made without plating or the like.
The zinc is released from the brass main body 2 and adheres to the surfaces of the copper inflow pipe 4 and the outflow pipe 5, and the surfaces of the inflow pipe 4 and the outflow pipe 5 are brassized into brass, which is an alloy of zinc and copper. Is done.

In this embodiment, such a phenomenon is effectively used. That is, when this fluid flow control device is actually installed in a plant or the like, the distal ends of the inflow pipe 4 and the outflow pipe 5 are connected to a copper pipe for piping, and thus the connection is not made of brass. It is desirable to increase the strength of the other parts. Therefore, only the tip portion to be connected is preliminarily masked or the like, and then immersed in a hydrogen reduction furnace.

The flange plate 2 with respect to the main body 2 is
2. The description of the joining of the inflow pipe 4 and the outflow pipe 5 ends, and the description returns to the description of the configuration of the fluid flow control device.

The rotating shaft 34 of the stepping motor 3 is rotatably supported by the bearing 21 of the main body 2, and a screw is formed on the shaft of the rotating shaft 34. On the other hand, a screw portion is also provided in the rotation shaft support through hole 21a of the bearing portion 21 so that both are screwed together.

As a result, when the rotor 33 rotates,
The rotor part 33 and its rotating shaft 34 move linearly in the axial direction while rotating inside the main body part 2 along the central axis direction of the rotating shaft 34. Here, the rotation direction of the rotor unit 33 that advances the rotation shaft 34 in the insertion direction of the main body 2 (the end direction of the main body 2) is referred to as forward rotation. Therefore, when the rotation of the rotor section 33 is reversed (reverse rotation), the rotor section 33 is rotated.
The rotation shaft 34 moves toward the rear end of the main body 2.

The carriage 24 is attached to the tip of the rotating shaft 34. This carriage 24
Moves in the main body 2 together with the rotating shaft 34 as the rotor 33 rotates forward and backward. This carriage 2
A sphere 25 serving as a valve is housed inside the carriage 4 and near the tip of the carriage 24, and a coil-shaped pressure spring serving as an elastic member is provided between the sphere 25 and the above-mentioned rotating shaft 34. 26 are interposed.

Also, between the sphere 25 and the pressure spring 26,
The plate 27 is interposed, and a force is applied to the sphere 25 toward the tip of the carriage 24 by the extension force of the pressure spring 26. The tip of the carriage 24 is opened so that a part of the spherical surface of the sphere 25 is exposed from the carriage 24. In addition, the load at the time of assembling the pressure spring 26 is changed to the sphere 25 under the pressure of the fluid actually used.
Is set to a load that does not vibrate.

An inflow pipe 4 is attached to the side surface near the tip of the main body 2, and an outflow pipe 5 is attached to the tip portion. Fluid (here, refrigerant) passing through the inflow pipe 4 is Once inside the main body 2, it exits to the outflow pipe 5 through a thin fluid outflow passage 28 provided at the tip of the main body 2. The inflow pipe 4 and the outflow pipe 5 are also joined to the main body 2 by silver brazing in a hydrogen reduction furnace in the same manner as the connection between the flange-shaped plate 22 and the main body 2. The silver brazing portions of the inflow pipe 4 and the outflow pipe 5 and the main body 2 are denoted by reference symbol Y, respectively.

The flow of the refrigerant flowing into the main body 2 through the inflow pipe 4 and flowing through the fluid outflow path 28 to the outflow pipe 5 is caused by the movement of the carriage 24, and the sphere 25 is moved toward the fluid outflow path 28. The contact state or the non-contact state is controlled. In this embodiment, it is possible to control the flow rate of the refrigerant to be finely adjusted, but it is possible to control the refrigerant to flow therethrough or to block the flow, that is, to turn on the refrigerant (the state where the refrigerant passes). ) Or off (a state in which the flow of the refrigerant is blocked), which is suitable for use in such a case. An example in which such a case is used will be described.

The fluid outflow passage 28 provided on the distal end surface of the main body 2 is
The contact surface of the sphere 25 of the fluid outflow passage 28 has the same curvature as the sphere of the sphere 25 in order to obtain a reliable off state. (Concave surface). The curved surface can be obtained by strongly pressing a sphere having the same shape as the sphere 25 at the manufacturing stage.

The rotating shaft 34 and the rotor 33 are configured to be integrally rotatable. Then, the rotating shaft 34 and the rotor unit 3
3 (in this case, all parts to be housed in the main body 2 such as the carriage 24 are attached), and the rotor housing case 23 is
3 is joined by TIG welding to the flange plate 22 attached to the main body 2.

Then, the stator 32 around which the coil 31 is wound is mounted so as to cover the outer periphery of the side surface of the drive source housing. The stator portion 32 includes a stator housing 38
It is attached to the main body 2 in a state of being stored in the main body 2. In addition,
When attaching the stator housing 38 to the main body 2, the starter housing 38 is detachably held by the holder 40 with respect to the main body 2.

Next, the on / off control of the flow of the refrigerant in the fluid flow rate control device configured as described above will be described.

First, when the sphere 25 in the carriage 24 is not in contact with the fluid outflow passage 28 of the main body 2, the refrigerant flowing through the inflow pipe 4 enters the main body 2 and then flows through the fluid outflow passage 28. And flows out to the outflow pipe 5. In this state, to perform the operation of turning off the flow of the refrigerant, the coil 31 is turned on so that the rotor 33 of the stepping motor 3 rotates forward. Thereby, the rotor unit 33
Rotates forward, and the rotational force of the rotor portion 33 is
And the rotation shaft 34 also rotates forward.

Since the screw cut on the rotating shaft 34 and the screw cut on the bearing 21 are screwed together, the rotation of the rotor 33 (forward rotation) causes the rotor 33 to rotate. The rotating shafts 34 move linearly in the main body 2 toward the distal end thereof. Eventually, the sphere 25 in the carriage 24 attached to the tip of the rotating shaft 34 becomes the fluid outflow passage 28 provided at the tip of the main body 2.
Abut.

As described above, when the sphere 25 comes into contact with the fluid outflow passage 28 of the main body 2, the spherical surface of the sphere 25 comes into surface contact with the curved surface formed in the fluid outflow passage 28, thereby ensuring the flow of the refrigerant. Can be prevented. In this state, the stepping motor 3 may be driven. However, in order to absorb an assembly error or the like, the driving is usually continued further. However, the force pressing the sphere 25 is absorbed by the pressure spring 26. Then, a force that presses the fluid outflow passage 28 with a force equal to or greater than a predetermined force acts on the sphere 25 by the extension force of the pressure spring 26, and a reliable contact state can be obtained.

The pressure spring 26 functions to obtain a reliable contact state by pressing the sphere 25 against the fluid outflow passage 28, and at the same time, forces the sphere 25 against the tip of the carriage 24. So that
The rattle of the sphere 25 is prevented. Thus, the sphere 25 can be prevented from vibrating due to the pressure of the refrigerant, and the occurrence of noise due to the vibration of the sphere 25 can be prevented.

In this state, it is assumed that the coil 31 is energized so as to reverse the rotation of the rotor 33 in order to turn on the flow of the refrigerant from the state where the flow of the refrigerant is turned off. Then, the rotor unit 33 starts to rotate in the reverse direction.
The rotational force of the rotor unit 33 is transmitted to the rotating shaft 34, the rotating shaft 34 performs a reverse rotation operation together with the rotor unit 33, moves in a direction to exit the main unit 2, and the stepping motor 3 operates by a predetermined number of steps. Then, the sphere 25 engages with the tip of the carriage 24. Thereafter, when the rotor unit 33 further rotates in the reverse direction, the sphere 25 starts to move together with the carriage 24, separates from the fluid outflow passage 28 of the main body unit 2,
It is in a state where the refrigerant flows (ON state).

Even if the carriage 24 moves to some extent (here, the carriage 24 moves away from the fluid outflow passage 25) due to the rotation of the stepping motor 3, the sphere 25 is forced out of the fluid by the urging force of the pressure spring 26. Since it is in contact with the road 28, the off state is maintained. Then, when the sphere 25 engages with the carriage 24 and slightly separates from the fluid outflow passage 28, the valve by the sphere 25 is fully opened and the refrigerant flows at a stretch. That is, the flow of the refrigerant can be digitally switched from the off state to the on state. In the fully opened state, the high-pressure refrigerant on the inflow pipe 4 side flows abruptly into the outflow pipe 5 at a negative pressure, so that the sphere 25 makes a rolling motion. By this rolling, the inflow of the refrigerant is performed more smoothly.

As described above, in this embodiment, by moving the carriage 24 in the direction of the fluid outflow passage 28 of the main body 2 by the stepping motor 3, the spherical surface of the sphere 25 held by the carriage 24 is moved. Is brought into contact with the fluid outflow passage 28 provided in the first stage to close the fluid outflow passage 28. On the other hand, by moving the carriage 24 away from the distal end of the main body 2, the spherical surface of the sphere 25 is brought into a non-contact state with the fluid outflow passage 28, and the fluid outflow passage 28
Is performed to open the. Thus, the flow of the fluid can be reliably controlled with a simple structure.

In this embodiment, the joining of the main body 2 to the inflow pipe 4 and the outflow pipe 5 and the joining of the main body 2 to the flange plate 22 are each performed by silver brazing in a hydrogen reduction furnace. Is going. At this time, since the flange plate 22 is made of stainless steel, it is necessary to use a hydrogen reduction furnace so that silver brazing can be performed at a temperature of about 700 to 780 degrees (a temperature that does not adversely affect brass). As shown in 5, a Ni · P plating step F1 of applying Ni · P plating to the surface of the stainless steel material is performed,
After Ni / P plating, a thermal diffusion treatment step F2 is performed, and a silver brazing step F3 using a hydrogen reduction furnace is performed.

As described above, the Ni.
By performing P plating, the influence of chrome on the surface of the stainless steel is eliminated, and the bonding strength can be greatly improved by performing a heat diffusion process thereafter. The thickness of the Ni / P plating is 3.5
By setting μm ± 0.5 μm, the bonding strength can be further increased.

By performing such processing, automatic silver brazing processing by a hydrogen reduction furnace becomes possible, and it is not necessary to apply a flux, which has been always used when brazing by hand, and the flux generated by the flux is generated. The troublesome post-processing for removing the oxide film can be eliminated, and the number of working steps can be reduced. Moreover,
Since the automatic brazing is performed by the hydrogen reduction furnace, the productivity can be significantly improved and the joining quality of the joining portion can be made uniform.

The above embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications can be made without departing from the spirit of the present invention. is there. For example, in the above embodiment,
The example in which the stepping motor 3 is used as the motor for driving the sphere 25 acting as the valve has been described. However, a motor other than the stepping motor may be used, or a mechanism other than the motor such as the solenoid may be used as the driving source. good.

In the above-described embodiment, the coil-shaped pressure spring 26 is used as a spring for applying a force for pressing the sphere 25 against the tip of the carriage 24. However, this pressure spring is not a coil-shaped spring. You may. For example, a plate spring may be used, and the sphere 25 may be pressed against the tip of the carriage 24 by the elastic force of the plate spring.

Further, the joining process for joining the brass material and the stainless steel material described in the above embodiment is not limited to the fluid flow control device.
The present invention can be applied to other fields that require a joining process. Further, although the main body 2 is preferably made of brass, another material having the same temperature characteristics as the brass may be used.

[0073]

As described above, claims 1 and 2
In the fluid flow control device described above, the connection between the main body of the flow control device and the parts (fluid inflow pipe and outflow pipe, and further, the driving source housing) connected thereto is brazed by a hydrogen reduction furnace. This eliminates the need to apply the flux that was required when brazing by hand, and eliminates the cumbersome work steps such as the removal of the oxide film, which was conventionally performed, resulting in a significant improvement in productivity. Furthermore, since the brazing operation is automatic, the quality can be made uniform.

Further, according to the third aspect of the present invention, when the object to be joined to the brass body is a stainless material, the surface of the stainless material is plated with nickel and phosphorus, and then the hydrogen is applied. Perform silver brazing with a reduction furnace. Accordingly, the joining can be performed without being affected by the chrome on the surface of the stainless steel, so that the joining can be performed at a temperature at which the brass is not adversely affected.

Further, by performing the heat diffusion treatment after the nickel-phosphorus plating, the bonding strength can be greatly improved. By setting the thickness of the nickel-phosphorus plating to 3.5 μm ± 0.5 μm, the bonding strength can be further increased. In addition, by using silver brazing as the brazing, it is possible to perform brazing at a relatively low temperature such as 700 to 780 degrees.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a fluid flow control device according to an embodiment of the present invention.

FIG. 2 is a side view showing the appearance of the fluid flow control device according to the embodiment of the present invention.

FIG. 3 is a front view of FIG. 2 as viewed from the direction of arrow A.

FIG. 4 is a view for explaining projections provided on the surface of a flange-shaped plate used in the fluid flow control device of FIG. 1,
(A) is a plan view of the collar plate viewed from the front side, (B)
FIG. 3 is a cross-sectional view of FIG.

5 is a view showing a joining process of a flange plate, an inflow pipe, and an outflow pipe with respect to a main body of the fluid flow control device shown in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fluid flow control device 2 Main part 3 Stepping motor (drive source) 4 Inflow pipe 5 Outflow pipe 21 Bearing 22 Flange plate (part of drive source storage body) 23 Rotor storage case (part of drive source storage body) ) 24 carriage 25 spherical body 26 pressure spring (elastic member) 28 fluid outflow path 31 coil 32 stator part 33 rotor part 33a rotation shaft support hole 34 rotation shaft (drive shaft) 38 stator housing 40 holder F1 Ni · P plating process F2 Thermal diffusion process F3 Silver brazing process using hydrogen reduction furnace

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Shingo Tanaka 1020 Moga, Iida City, Nagano Prefecture Sankyo Seiki Seisakusho Iida Plant (72) Inventor Hideo Sasaki 1020 Moga, Iida City, Nagano Prefecture Sankyo Seiki Seisakusho Iida factory F-term (reference) 3H013 CA06 3H051 AA01 BB01 BB10 CC15 DD01 EE08 FF08 FF15 3H052 AA01 BA26 BA35 CC09 CC11 DA01 EA11 EA16 3H062 AA02 AA15 BB31 BB33 CC02 FF38 GG04 HH09 HH08

Claims (6)

[Claims] An inflow pipe for inflowing a fluid and an outflow pipe for outflow of a fluid are connected to each other, and a fluid outflow path for guiding a fluid flowing into the inside through the inflow pipe to the outflow pipe is provided on a distal end surface side. A fluid flow control device having a cylindrical main body, wherein the connection of the inflow pipe and the outflow pipe to the main body is performed by brazing with a hydrogen reduction furnace. 2. A cylindrical body connected to an inflow pipe for inflowing a fluid and an outflow pipe for outflow of a fluid, and having a fluid outflow passage for guiding the fluid flowing into the inside through the inflow pipe to the outflow pipe. A carriage that is housed in the main body so as to be movable along a central axis direction in the main body, and opens and closes the fluid outflow passage;
A drive source disposed on the rear end face side of the main body portion and having a drive shaft for reciprocating the carriage along a center axis direction in the main body portion, and housing at least a part of the drive source; A fluid flow control device having a drive source housing attached to an end face side, wherein the mounting of the drive source housing to the main body is performed by brazing with a hydrogen reduction furnace. apparatus. 3. When the main body is made of brass and brazed to the main body by a hydrogen reduction furnace, if the object to be joined is a stainless material, the surface of the stainless material is made of nickel or nickel. 3. The method according to claim 1, wherein after the phosphor plating is performed, brazing is performed in a hydrogen reduction furnace.
A fluid flow control device according to any of the preceding claims. 4. The fluid according to claim 3, wherein the surface of the stainless steel material is subjected to nickel-phosphorus plating, heat diffusion treatment is performed, and then brazing is performed in a hydrogen reduction furnace. Flow control device. 5. The method according to claim 3, wherein the thickness of the nickel-phosphorous plating is 3.5 μm ± 0.5 μm.
Or the fluid flow control device according to 4. 6. The fluid flow control device according to claim 1, wherein the brazing is silver brazing.