JP2000120907A - Motor-operated expansion valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor-operated expansion valve capable of miniaturization of itself and saving of installation space by eliminating one supporting mechanism to form the whole into a nearly T shaped form in the motor- operated valve provided with a refrigerant flow control mechanism. SOLUTION: A bottomed cylindrical valve element 19, on the side wall of which an opening 21 is provided, is accommodated in a refrigerant passage-pipe 2 in which a refrigerant passage is formed straight. A spindle pin 11 whose tip is formed into a tapered conical shape, and a driving mechanism for moving the spindle pin 11 in the direction crossing the refrigerant passage-pipe 2 at right angles are provided. Then, a flow control mechanism for controlling the flow rate of the refrigerant by positioning the valve element 19 and fixing it in the refrigerant passage-pipe 2 so that the tip of the spindle pin 11 is engaged with the opening 21, and by controlling a clearance provided to be opened or closed between the tip of the spindle pin 11 and the opening 21 by means of the movement of the spindle pin 11, is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor-operated expansion valve which is connected to a refrigeration cycle and controls the flow rate and pressure reduction of refrigerant.

[0002]

2. Description of the Related Art A conventional electric expansion valve is disclosed in
There is one described in Japanese Patent No. 100920. In this electric expansion valve, a slider member is provided in a through-flow space in a valve casing to which a fluid pipe is connected, and the slider member is moved up and down by a driving device to adjust an opening degree of a through-flow passage formed in the slider member. With this, the flow rate of the refrigerant is controlled.

[0003]

In such an electric expansion valve, the vertical movement direction of the slider member and the flowing direction of the refrigerant are orthogonal to each other, so that the movement accuracy of the slider member is opposed to the flow of the refrigerant. In order to secure the slider member, a structure for supporting the slider member from both upper and lower sides is adopted. For this reason, the support mechanism of the slider member is provided on both sides of the refrigerant flow path tube, which limits the downsizing of the electric expansion valve and the space saving for installation when the expansion valve is incorporated in equipment.

The present invention improves the conventional flow rate adjusting mechanism of an electric expansion valve, and eliminates the need for one support mechanism, thereby substantially reducing the entirety.
The present invention provides an electric expansion valve which is formed in a shape of a letter and which can reduce the size of the electric expansion valve and save space for installation.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention accommodates a bottomed cylindrical valve body having an opening in a side wall in a refrigerant flow path pipe having a refrigerant flow path formed linearly. And
A spindle pin having a tapered conical tip and a drive mechanism for moving the spindle pin in a direction perpendicular to the refrigerant flow pipe are provided, and the valve body is engaged with the tip of the spindle pin and the opening. It is positioned and fixed in the refrigerant flow pipe. The movement of the spindle pin controls the clearance between the tip of the spindle pin and the opening to constitute a flow rate adjusting mechanism for adjusting the flow rate of the refrigerant. In this way, the direction of the refrigerant passing through the opening and the direction of movement of the spindle pin are made to coincide with each other, the spindle pin is supported in a cantilever manner, and the outer shape is formed substantially in a T-shape. It is intended to make it.

As a specific configuration of the electric expansion valve, as described in claim 2, a valve receiver which is positioned by contacting the tip of a valve body is fixed in a refrigerant flow pipe, and the valve receiver is fixed to the valve receiver. A refrigerant introduction hole communicating with the outer peripheral space of the valve body is opened, and the flow path of the refrigerant can be constituted by the inner space, the opening, the outer peripheral space of the valve body, and the refrigerant introduction hole of the valve body.

Further, by manufacturing this valve body from a brass material, it is possible to eliminate the need for a flux when brazing and fixing the same in the refrigerant flow pipe.

Further, by making the opening shape of the rear end face of the valve body a polygonal shape, the positioning of the valve body in the rotation direction can be easily performed by using a jig and a tool matching the opening shape.

According to a fifth aspect of the present invention, a plurality of protrusions are formed on the bottom surface of a coil of a step motor or a pulse motor for driving a spindle pin, and the protrusions are formed along an outer peripheral edge of a coil mounting plate. Are arranged to form a concave portion for fitting and fixing the coil. With this configuration, it is possible to fix the coil at an arbitrary rotation angle, inhibit the rotation of the coil after the coil is mounted, and reliably drive the spindle pin.

In addition, instead of the above-mentioned refrigerant flow pipe, a refrigerant flow path body which forms a linear refrigerant flow path by treating a metal body,
A refrigerant flow path body having a linear refrigerant flow path formed by die casting of a metal such as aluminum can be used. By adopting such a refrigerant flow path body, reliability against vibration and durability can be improved. Hereinafter, the configuration of the present invention will be described in detail with reference to the drawings.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS The drawings show a specific embodiment based on the present invention, and FIGS. 1 to 7 show a first embodiment. In the present embodiment, the electric expansion valve is a T-stage 2 (a steel pipe that communicates with a steel pipe) that is a refrigerant flow path pipe having a linear refrigerant flow path formed in a lower stage of a main body 1 that is a casing that houses components therein. As shown in FIG. 1, a cylindrical pulse motor coil 3 is fixed to the outer periphery of the main body 1, and the entire outer shape is formed in an inverted T-shape.

A leaf spring 4 is attached to the lower surface of the coil 3. The leaf spring 4 is formed by punching SUS spring steel into a donut shape, and has a plurality of key-shaped projections 5 a to 5 d provided on the lower surface of the coil 3. Projection insertion notch 6 at corresponding position
a to 6d are formed on the periphery, and the projection insertion cuts 6a
6d are fitted to the projections 5a to 5d. Note that the projection insertion cuts 6a to 6d may be arranged at positions that can correspond to a plurality of different types of coils.

Inside the leaf spring 4, three inner dowels 7 a to 7 c protruding downward are provided at intervals of 120 degrees, while a flange is formed on a shell cover 8 forming the bottom surface of the main body 1. Along the outer peripheral edge, the inner dowels 7a to 7c
8a into which the coil 3 is fitted to fix the coil 3 to the outer periphery of the main body 1.
Are formed. The recesses 8a are arranged at equal intervals so that the coils 3 can be fixed at positions rotated by a predetermined rotation angle on the outer periphery of the main body 1. In this example, twelve coils are arranged in one circumference at intervals of 30 degrees, the coil 3 can be fixed at an arbitrary position at a rotation angle of every 30 degrees, and lead wires are taken out when the electric expansion valve is incorporated in the device. Part 3a
Can be freely set to an optimal position. If six recesses 8a are arranged every 60 degrees,
The coil 3 can be fixed at a rotation angle of every 0 degree.

A spindle pin 11 is provided at the axis of the main body 1 and held by a cylindrical holder 10 formed by aluminum die casting. The tip of the spindle pin 11 is formed in a tapered conical shape. The holder 10 does not depart from the gist of the present invention even if it is manufactured by cutting or forging by NC. The upper end of the spindle pin 11 is fixed to the holder 10 and is constantly urged downward by a spring 12 housed in the holder 10. Holder 1
Disk-shaped stoppers 13 and 14 are caulked and fixed to the upper and lower surfaces of the main body 1, and stoppers 15 and 16 are provided on the upper and lower surfaces of the main body 1 so as to face these.

[0015] As shown in FIG.
The US material is cut out with a press and then cut and raised to form a cut and raised piece 13a.
Similarly, cut and raised pieces 14a, 15a, 16
a is formed. These stoppers 13, 14,
Reference numerals 15 and 16 denote a range of movement of the spindle pin 11 as a pair.
3 and 14 rotate, and the opposing cut-and-raised pieces 13a and 1
The top dead center (full open) of the spindle pin 11 is set at the position where the 5a abuts, and the bottom dead center (fully closed) is set at the position where the opposing cut-and-raised pieces 14a and 16a abut. The positions of the top dead center and the bottom dead center are determined by the cut and raised pieces 13a and 14a.
It can be adjusted by setting the heights of a, 15a, and 16a.

A female screw is formed on the inner peripheral surface of the holder 10, and a holder receiver 17 having an external thread formed on the outer peripheral surface thereof is fixedly provided in the vertical portion 2 a of the T-tail 2 at a lower end portion. The rotation of the holder 10 causes the interlocking spindle pin 11 to move up and down along the axis of the holder receiver 17.

The shell cover 8 is made of a T-
And the lower part of the main body 1 to seal the bottom surface of the main body 1 while sealing the head of the main body 1 with the shell cover 9 to secure the airtightness of the main body 1. As a result, leakage of the refrigerant is prevented.

A magnet 18 is mounted on the outer periphery of the holder 10 so that the holder 10 is rotated by a rotating magnetic field generated by the coil 3. Therefore, the rotation direction of the magnetic field is switched to change the rotation direction of the holder 10, and the vertical movement direction of the spindle pin 11 is switched. Here, since the coil 3 is fixed to the outer periphery of the main body 1 by the leaf spring 4 and the shell cover 8, the outer periphery of the main body 1 does not rotate due to the reaction of the magnetic force of the magnet 18 when the coil 3 is energized. 11 can be reliably driven to a predetermined position. The coil 3, the magnet 18, and the holder 10 constitute a drive mechanism for moving the spindle pin 11 up and down.

In the linear portion 2b of the T-tail 2, a valve body 19 formed in a cylindrical shape with a closed bottom and a closed end is housed from one side, and a valve receiver 20 is inserted from the other side. Valve body 1
9. The valve receiver 20 is made of yellow steel, and after fitting (or press-fitting) into the linear portion 2b, each is brazed so as to be in close contact with the inner wall of the linear portion 2b. Therefore, the use of the yellow steel material eliminates the need for a brazing flux.

An opening 21 communicating with the inside of the valve body 19 is formed in a side wall of the valve body 19, and the opening 21 has a shape in which the tip is fitted and closed when the spindle pin 11 is lowered.
And are aligned. The outer diameter of the valve element 19 where the opening 21 is opened is set smaller than the outer diameter of the rear end portion joined to the inner wall of the linear portion 2b by brazing, and the outer shape is formed in two steps. As a result, the portion where the opening 21 is opened is housed in the linear portion 2b to form a space on the outer periphery, and an appropriate position on the periphery of the valve receiver 20 is cut out so as to communicate with the outer peripheral space. The valve receiver 20 has refrigerant introduction holes 20a and 20b.

The front and rear positions of the valve body 19 in the linear portion 2b are adjusted by bringing the distal end of the valve body 19 into contact with a valve receiver 20 press-fitted at a predetermined position in the linear portion 2b. Done. The opening shape of the rear end face of the valve element 19 is formed in a hexagonal shape, and the positioning of the opening 21 with the tip of the spindle pin 11 is performed by inserting a jig such as a hexagonal wrench into the hexagonal opening 22. The rotation is performed. Here, since the position on the circumference of the opening 21 is formed at a position corresponding to the hexagonal shape, the opening 21 is adjusted by adjusting the rotation angle of the opening 22.
Can be adjusted in rotation position. As described above, by making the opening shape of the rear end face of the valve element 19 into a polygonal shape, the positioning of the valve element in the rotation direction can be easily performed by a jig that matches the opening shape. As described above, the valve body 19
At first, the press-fitting of the valve receiver 20 into the linear portion 2b, the press-fitting of the valve body 19 into the linear portion 2b and the alignment, and the brazing of the valve body 19 and the valve receiver 20 are performed in this order. Can be

The flow of the refrigerant in the T-stage 2 is such that the refrigerant flowing from the side A of the linear portion 2b (solid arrows in FIG. 1) passes through the refrigerant introduction holes 20a and 20b and is in the outer space of the valve body 19. And flows into the valve body 19 at a set flow rate controlled by a flow rate adjusting function based on a separation gap between the opening 21 and the tip of the spindle pin 11, and flows out from the other side of the linear portion 2b. Switch the direction of flow of the refrigerant to change the
The refrigerant flowing from the other side of b (dashed arrow in FIG. 1)
It is distributed in the reverse order.

The operation of the motor-operated expansion valve configured as described above continuously outputs pulses (a predetermined number of pulses) to the coil 3 until the holder 10 reaches the bottom dead center. At this bottom dead center, the tip of the spindle pin 11 is previously adjusted by the spring 12 so as to reliably close the opening 21. Therefore, the opening 21 is kept closed by a certain number of pulses when the spindle pin 11 is driven upward.

Next, the number of pulses corresponding to the desired opening (the flow rate of the refrigerant) is output to the coil 3 and the spindle pin 1
1 is moved upward, and the flow rate is adjusted to a predetermined flow rate by a flow rate adjusting function based on a gap between the opening 21 and the tip of the spindle pin 11. Thereafter, a pulse corresponding to the desired increase or decrease of the opening is output to control the flow rate of the refrigerant between the top dead center and the bottom dead center of the spindle pin 11.

FIGS. 8 and 9 show another embodiment of the present invention. In place of the T-tails 2 of the preceding example, a refrigerant passage body 30 having a straight refrigerant passage formed by hollowing out a brass material. (Corresponding to a refrigerant channel tube). Refrigerant channel 30
Is a mold formed so as to form a linear coolant flow path, and can also be manufactured by die-casting a metal such as aluminum.

In this embodiment, the same components as those in the previous embodiment are denoted by the same reference numerals, and description thereof is omitted. This coolant flow path body 30 is cut in the order of the first stage 31, 34, the second stage 32, 35, the third stage 33, 36 in which the inner diameters are sequentially reduced from the left and right sides, and then communicates at the center. Thus, a linear coolant passage 40 is formed. The number of steps to be cut is not limited to three steps as long as a predetermined inner diameter is obtained, and may be two steps or four or more steps.

In the third stage 33, a donut-shaped valve receiver 37 is inserted and brazed to the step, and is fixed to the valve receiver 37 in the same manner as the valve receiver 20. Holes 37a and 37b are opened.

The valve body 38 inserted into the refrigerant flow passage 40 from the other side is formed in a closed bottomed cylindrical shape with one end closed similarly to the valve body 19, and has an opening 41 communicating with the inside of the valve body 38. Is set up on the side wall. The rear end of the valve body 38 has a flange 3
8a is formed, an O-ring 39 is provided in the circumferential groove of the flange 38a, and the flange 38a is sealed.
And is positioned in contact with the stepped portion. After brazing the flange 38a to the inner wall of the third step 36, the valve body 38 is fixed by caulking the tip piece 38b to the valve receiver 37. As in the previous example, the opening 41 is shaped so as to be closed when the tip of the spindle pin 11 is fitted, and is aligned with a predetermined gap between the opening 41 and the tip of the spindle pin 11. It is configured to adjust to the refrigerant flow rate.

The holder 30 is hermetically joined to an opening opened from the upper surface so as to be orthogonal to the coolant passage 40, and the holder receiver 17 is joined to the main body 1 by the shell cover 8. A road body 30 is attached.
The spindle pin 11 and its driving mechanism are configured in the same manner as in the previous example, and output a number of pulses corresponding to a desired opening degree (flow rate of the refrigerant) to the coil to move the spindle pin 11 up and down to control the flow rate of the refrigerant. .

Refrigerant piping 4 connected to refrigerant flow path body 30
4 and 45, flange bodies 42 and 43 by aluminum die-casting or machined are attached, and refrigerant pipes 44 and
45 is expanded and fixed. Here, the refrigerant pipe 44,
The center of 45 and the center of the valve body 38 coincide with each other, and the tips of the refrigerant pipes 44 and 45 protrude from the flange bodies 42 and 43 to the extent that they can be accommodated in the second stages 32 and 35. O-rings 55 and 56 are provided.

The coolant passage 30 is provided in the flanges 42 and 43.
Bolt through holes 46 and 47 are formed at positions corresponding to the screw holes 48 and 49 formed in the left and right side walls of the bolts 50 and 5.
1 and the flange bodies 42 and 43 are attached to the refrigerant flow path body 30, and the refrigerant pipes 44 and 45 are connected. The flanges 42 and 43 are provided with projections 52 and 53 that fit into holes 54 (only one is shown) drilled at arbitrary positions on the left and right side walls of the coolant flow path 30, so that alignment can be performed easily. It is configured to be. Note that the flange members 42, 4
The airtightness may be ensured by brazing the joint portion between the refrigerant flow path body 3 and the refrigerant flow path body 30.
Are connected to each other, and this through hole and the bolt through hole 4
By tightening the bolts 6 and 47 with a single bolt and nut, the refrigerant pipes 44 and 45 can be connected.

As described above, in the present embodiment, the refrigerant flow path body 30 formed of a metal body is used, and the refrigerant pipes 44 and 45 are connected together with the flange bodies 42 and 43 so that they are firmly connected. Thin portions are reduced, and cracking of the refrigerant pipes 44 and 45 due to vibration and peeling of brazing are suppressed. In particular, reliability and durability when used in vehicles such as automobiles can be improved. Things.

[0033]

As described above, the electric expansion valve of the present invention
Since the gap between the tip of the spindle pin 11 moving in the direction orthogonal to the refrigerant flow pipe 2 and the opening 21 formed in the side wall of the valve body 19 is controlled to adjust the flow rate of the refrigerant, the spindle pin 11 By making the direction of movement of the spindle pin 11 coincide with the direction of flow of the refrigerant around the spindle pin 11, the spindle pin 11 can be supported in a cantilever manner, and the support mechanism and the drive mechanism can be simplified. As a result, the electric expansion valve is formed in a substantially T-shaped small size, and can save space when incorporated into the device.

In addition, when the valve body 19 is made of yellow steel and brazing is performed, the need for a flux is eliminated, the opening shape of the rear end face of the valve body 19 is made polygonal, the positioning of the valve body 19 is facilitated, and the electric expansion is performed. The valve assembly workability can be improved.

Further, the coil 3 is mounted by fitting a plurality of protrusions formed on the bottom surface into recesses arranged along the outer peripheral edge of the mounting plate, so that the coil 3 can be easily fixed at an arbitrary rotation angle. The rotation of the coil 3 is prohibited and the spindle pin 1
1 can be reliably driven.

In addition, instead of the refrigerant flow path pipe, a refrigerant flow path body 30 in which a metal body is treated to form a linear refrigerant flow path,
By employing the refrigerant flow path body 30 having a linear refrigerant flow path formed by die-casting a metal such as aluminum, reliability and durability against vibration can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a first embodiment of the present invention with a coil removed.

FIG. 2 is a plan view showing a state where a coil is removed.

FIG. 3 is a perspective view of the coil as viewed from below.

FIG. 4 is a side view as viewed from a direction A in FIG. 1;

FIG. 5 is a perspective view of a stopper.

FIG. 6 is a perspective view of a valve body.

FIG. 7 is a sectional perspective view showing a state where a coil is mounted.

FIG. 8 is a cross-sectional view of a refrigerant flow path body and a refrigerant pipe according to another embodiment of the present invention.

FIG. 9 is a perspective view of a refrigerant flow path body and a refrigerant pipe.

[Explanation of symbols]

 2 Refrigerant flow path pipe 3 Coil 7a to 7c Protrusion piece 8a Recess 11 Spindle pin 19 Valve body 20 Valve receiver 20a, 20b Refrigerant introduction hole 21 Opening 30 Refrigerant flow path body 40 Refrigerant flow path

Claims (7)

[Claims] An electric expansion valve having a refrigerant flow path formed linearly and a mechanism for adjusting a flow rate of a refrigerant flowing through the refrigerant flow path, wherein a refrigerant flow path pipe (2) having a refrigerant flow path formed linearly. ), A bottomed cylindrical valve body (19) having an opening (21) in the side wall is housed, and a spindle pin (11) having a tapered conical tip and a spindle pin (11). A drive mechanism for moving in a direction orthogonal to the refrigerant flow pipe (2);
The valve body (19) is positioned and fixed in the refrigerant flow pipe (2) so that the tip of the spindle pin (11) and the opening (21) engage with each other. Spindle pin (1
An electric expansion valve comprising a flow rate adjusting mechanism for adjusting the flow rate of the refrigerant by controlling the separation / contact gap between the tip of (1) and the opening (21). 2. A valve receiver (20), which is positioned by contacting the tip of the valve element (19), is fixed in the refrigerant flow pipe (2), and the outer periphery of the valve element (19) is fixed to the valve receiver (20). Refrigerant introduction holes (20a, 20b) communicating with the space are opened, and the flow path of the refrigerant flows through the internal space of the valve body (19), the opening (21), and the valve body (1).
The electric expansion valve according to claim 1, wherein the outer peripheral space of (9) and the refrigerant introduction holes (20a, 20b) are constituted. 3. The electric expansion valve according to claim 1, wherein the valve body (19) is made of a brass material. 4. The electric expansion valve according to claim 1, wherein the opening shape of the rear end face of the valve element (19) is polygonal. 5. A plurality of projecting pieces (7a to 7c) are formed on the bottom surface of a coil (3) of a step motor or a pulse motor for driving a spindle pin (11), and are formed on an outer peripheral edge of a mounting plate of the coil (3). A motor-operated expansion valve according to any one of claims 1 to 4, wherein recesses (8a) are arranged along which the projections (7a to 7c) are fitted to fix the coil (3). 6. A refrigerant flow passage (30) having a linear refrigerant flow passage (40) formed by treating a metal body instead of the refrigerant flow passage tube (2). 6. The electric expansion valve according to 3, 4, or 5. 7. A coolant passage (4) formed by die-casting a metal such as aluminum instead of the coolant passage pipe (2).
2. The method according to claim 1, wherein the refrigerant flow path body (30) having the above (0) is used.
The electric expansion valve according to 2, 3, 4 or 5.