JP2013130271A - Electrically-operated valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrically-operated valve in which, when fluid is made to flow in a second flow direction, a downward load (force acting in a valve closing direction) can be decreased as much as possible to thereby employ a valve opening spring whose spring load is smaller, permitting downsizing, high capacity, electric power saving, etc.SOLUTION: A back pressure chamber 30 and a valve opening 9 are set to be approximately the same in diameter. In the valve body 20, there is provided a pressure equalizing passage 32 whose lower end surface is opened in order to make the valve opening 9 or a second gateway 12 and the back pressure chamber 30 communicate with each other. The dimension of each part is set so that a value obtained by dividing an opening area SX of the pressure equalizing passage by a valve opening area Sc becomes 0.5 or larger and smaller than 1.0.

Description

  The present invention relates to a motor-operated valve suitable for use in a heat pump type air conditioning system or the like, and in particular, a fluid flows in both directions (a first flow direction and a second flow direction opposite thereto) and at least one direction. Relates to a motor-operated valve corresponding to a flow path through which a large flow rate flows.

  Conventionally, as this type of electric valve, for example, a valve chamber, a lateral first inlet / outlet opening in the valve chamber, a vertical valve port opening in the valve chamber, and a second inlet / outlet connected to the valve port are provided. A valve body having a valve body disposed to be capable of being raised and lowered in the valve chamber to open and close the valve port, a valve opening spring that urges the valve body in a valve opening direction, and a spring of the valve opening spring. It has been considered that the valve body is controlled to descend against the force, and as a result, an elevating drive means having an electric motor for elevating the valve body (see, for example, Patent Document 1). .

  In the motor-operated valve, the diameter of the valve port and the diameter of the back pressure chamber defined above the valve body are set to be substantially the same, and the valve port or the second inlet / outlet and the back pressure chamber In order to communicate, the pressure equalizing passage is provided so as to penetrate the valve body up and down, and the valve port or the second inlet / outlet pressure is introduced into the back pressure chamber through the pressure equalizing passage, thereby closing the valve. Balances the pressing force acting on the valve body (force acting in the valve closing direction) and the pushing force (force acting in the valve opening direction) (cancel the differential pressure), thereby reducing the driving torque of the valve body, Some attempts have been made to reduce the size, increase the capacity, and save power of the motor-operated valve (see, for example, Patent Document 2).

JP 2008-267464 A JP 2000-320711 A

  However, like the motor-operated valve described in Patent Document 2, the diameter of the valve port and the chamber diameter of the back pressure chamber are set to be substantially the same, and the valve body is vertically penetrated to cancel the differential pressure. In the case where the pressure equalizing passage is provided, when the fluid flows in the first flow direction (first inlet / outlet → second inlet / outlet), the force that pushes up the valve body rather than the force that pushes down the valve body when the valve is opened. When an upward load is generated on the valve body and fluid flows in the second flow direction (second inlet / outlet → first inlet / outlet), the valve body is more than the force that pushes up the valve body when the valve is opened. When the fluid is flowed in the first direction and when the fluid is flowed in the second direction, the direction of the load acting on the valve body when the valve is opened is increased. Change.

  Therefore, when such a pressure balance structure is to be applied to a motor-operated valve equipped with a valve opening spring, the downward load becomes a force that pushes down the valve body in the valve closing direction. In order to be able to use the spring, it is desirable to make the downward load (force acting in the valve closing direction) acting on the valve body as small as possible when the fluid is flowed in the second flow direction.

  The present invention has been made in view of the above circumstances, and its object is to make the downward load (the force acting in the valve closing direction) as small as possible when the fluid flows in the second flow direction. Therefore, it is an object of the present invention to provide a motor-operated valve that can further reduce the size, increase the capacity, save power, and the like by using a valve-opening spring having a smaller spring load.

  In order to achieve the above object, the motor-operated valve according to the present invention basically includes a valve chamber, a first lateral inlet / outlet opening in the valve chamber, and a valve seat with a vertical valve seat opening in the valve chamber. And a valve body having a second inlet / outlet connected to the valve port, a valve body arranged to be movable up and down in the valve chamber to open and close the valve port, and an electric motor for raising and lowering the valve body And a valve opening spring for urging the valve body in the valve opening direction, and the diameter of the valve port and the diameter of the back pressure chamber defined above the valve body are approximately A pressure equalization passage having a lower end surface opened to communicate the valve opening and the back pressure chamber is provided in the valve body, and a lower end opening area of the pressure equalization passage is defined as the valve opening area. The dimension of each part is set so that the value divided by ≦ 0.5 is less than 1.0.

  In a preferred embodiment, the seal surface of the valve body that contacts and separates from the valve seat substantially makes a line contact with the valve seat such as a conical surface, a spherical surface, or an elliptical surface so as to obtain a required sealing property. Consists of curved surfaces.

  In the motor operated valve according to the present invention, the dimensions of each part are set so that the value obtained by dividing the pressure equalizing passage opening area by the valve opening area is 0.5 or more. Therefore, when the fluid is flowed in the second flow direction, Therefore, the downward load (force acting in the valve closing direction) can be kept within an allowable range, which enables the use of a valve opening spring with a smaller spring load, resulting in a reduction in size, capacity, and saving. Electricity can be achieved.

The longitudinal cross-sectional view which shows the valve closing state of 1st Example of the electrically operated valve which concerns on this invention. The longitudinal cross-sectional view which shows the valve opening state of 1st Example shown by FIG. The longitudinal cross-sectional view which shows the valve closing state of 2nd Example of the motor operated valve which concerns on this invention. It is a graph with which it uses for description of the effect of the motor operated valve which concerns on this invention, and shows the relationship between the load which acts on a valve body, and a pressure equalization passage opening area.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a longitudinal sectional view showing a valve closing state of a first embodiment of the electric valve according to the present invention, and FIG. 2 is a longitudinal sectional view showing a valve opening state of the electric valve of the first embodiment shown in FIG. It is.

  The illustrated motor-operated valve 1 is suitable for use as, for example, an expansion valve in a heat pump type air conditioning system, and a fluid (refrigerant) is flowed in both directions (the first flow direction and the opposite second flow direction), And it is a bidirectional | two-way flow-type motor-operated valve corresponding to the flow path through which a large flow volume flows at least in one direction.

  In the figure, a motor-operated valve 1 includes a valve body 5 having a cylindrical base 6 made of sheet metal, a valve body 20 disposed in the valve body 5 so as to be movable up and down, and a valve body 20 for raising and lowering the valve body 20. And a stepping motor 50 attached to the upper side of the main body 5.

  The tubular body 6 of the valve body 5 is formed with a valve chamber 7 and is fitted with a lateral first inlet / outlet (conduit joint) 11 that opens into the valve chamber 7. A valve seat member 8 having a vertical valve opening 9 and a valve seat 8a formed in the valve chamber 7 is fixed to the valve chamber 7, and a second inlet / outlet (conduit joint) connected to the valve port 9 is fixed to the valve seat member 8. ) 12 is attached.

  A stepped cylindrical base 13 is attached to the upper surface opening of the cylindrical base body 7, and the lower end of a can 58 constituting a part of the motor 50 is welded to the upper end of the base 13. It is joined. A cylindrical holding member 14 with a partition wall 14c is fixed to the inner peripheral side of the cylindrical base 13 by press-fitting or the like, and the upper part of the cylindrical holding member 14 is provided with a female screw 15i on the lower inner periphery so that it is threaded. The bearing member 15 is fixed by caulking. Immediately above the partition wall 14c of the cylindrical holding member 14 is a spring chamber 14a in which a valve opening spring 25 made of a compression coil spring is accommodated.

  Further, the valve body 20 has a valve body portion 20A having an inverted truncated cone shape at a lower portion that opens and closes the valve port 9 by contacting and separating from the valve seat 8a of the valve seat member 8, and a body portion 20B having a smaller diameter. The upper portion of the body portion 20B is slidably inserted into the valve body guide hole 14b below the partition wall 14c in the cylindrical holding member 14. The lower surface of the valve body 20A is a sealing surface 20a formed of a conical surface that is substantially in line contact with the valve seat 8a so as to obtain a required sealing property.

  On the other hand, the stepping motor 50 is composed of a yoke 51, a bobbin 52, a coil 53, a resin mold cover 54, and the like. The stator 55 is externally fixed to the can 58, and is rotatably disposed in the can 58. 56 has a rotor 57 fixed to the inside of the upper portion thereof. Further, on the inner peripheral side of the rotor 57, a sun gear 41 provided integrally with the rotor support member 56, a fixed ring gear 47 fixed to the tip of a cylindrical body fixed to the cylindrical holding member 14, A planetary gear 42 that meshes with the sun gear 41 and the fixed ring gear 47, a carrier 44 that rotatably supports the planetary gear 42, a ring-shaped output gear 45 that meshes with the planetary gear 42, and an anchor to the output gear 45 A mysterious planetary gear type speed reduction mechanism 40 including the output shaft 46 and the like is provided. The number of teeth of the fixed ring gear 47 is different from the number of teeth of the output gear 45.

  An output shaft 46 is fixed to the output gear 45. A lower portion of the support shaft 49 is inserted through a hole provided in the upper portion of the output shaft 46, and the carrier 44 and the sun gear 41 (rotor support member 56) are inserted through the support shaft 49.

  The support member 48 has substantially the same diameter as the inner diameter of the can 58, and the upper portion of the can 58 and the rotor support member 56 are arranged inside the can 58. The upper portion of the support shaft 49 is inserted into a hole provided in the center portion of the support member 48.

  The output shaft 46 of the speed reduction mechanism 40 is rotatably inserted in the upper part of the bearing member 15 with a female thread, and the rotation of the output shaft 46 is provided in the bearing member 15 and is screwed into the screw 15i. The screw 17e is transmitted to a rotary elevating shaft 17 with a male thread. A slit-like fitting portion 46a is provided at the lower portion of the output shaft 46, and a plate-like portion 17a that is slidably fitted to the slit-like fitting portion 46a is provided on the rotary elevating shaft 17 so as to project. When the shaft 46 rotates, the rotary elevating shaft 17 is raised and lowered while rotating by the screw feed by the female screw 15i and the male screw 17e.

  A stepped cylindrical thrust transmission member 23 is disposed below the rotary elevating shaft 17 so as to transmit the thrust downward of the rotary elevating shaft 17 via the ball 18 and the ball seat 19. Since the ball 18 is interposed, only the downward thrust is transmitted from the rotary lift shaft 17 to the thrust transmission member 23 even if the rotary lift shaft 17 is lowered while rotating, and no rotational force is transmitted. .

  The thrust transmission member 23 includes, in order from the top, a large-diameter upper portion 23a in which the ball seat 19 is fitted on the inner periphery, and an intermediate body portion 23b that is slidably inserted into the partition wall 14c of the cylindrical holding member 14. The intermediate body portion 23b is formed of a small-diameter lower portion 23c having a diameter smaller than that of the intermediate body portion 23b, and a plurality of horizontal holes opened in a through-hole 32d constituting an upper portion of a pressure equalizing passage 32 described later and a back-pressure chamber 30 described later. 32e is provided. The upper end opening of the through hole 32d is closed by the ball seat 19.

  The small diameter lower portion 23c of the thrust transmission member 23 is fitted and fixed to the upper fitting hole 20d of the valve body 20 by press fitting or the like, and the valve body 20 and the thrust transmission member 23 are moved up and down integrally. A pressing member 24 is sandwiched and fixed between the upper end surface of the valve body 20 and the lower end step portion of the intermediate body portion 23b of the thrust transmission member 23 when the small diameter lower portion 23c is press-fitted. A seal member 38 such as an O-ring is mounted between the annular groove provided at the upper end of the valve body 20 and the valve body guide hole 14b.

  A valve opening spring 25 made of a compression coil spring is disposed in the spring chamber 14a above the partition wall 14c of the cylindrical holding member 14 with its lower end in contact with the partition wall 14c. In order to transmit the urging force (lifting force) of the spring 25 to the valve body 20 via the thrust transmission member 23, a lifting spring receiving body 28 having hook-like hook portions 28a and 28b on the upper and lower sides is arranged. The upper hooking portion 28 a of the pulling spring receiving body 28 is placed on the valve opening spring 25, and the lower hooking portion 28 b is configured to hook the lower end step portion of the large-diameter upper portion 23 a of the thrust transmission member 23.

  Therefore, when the motor 50 (rotor 57) is rotated in one direction, the rotary elevating shaft 17 is lowered, for example, while being rotated by the screw feed by the female screw 15i and the external screw 17e. The transmission member 23 and the valve body 20 are pushed down against the urging force of the valve opening spring 25. Finally, the valve body portion 20a of the valve body 20 is seated on the valve seat shut-off portion 8a and the valve port 9 is closed. . On the other hand, when the motor 50 (rotor 57) is rotated in the other direction, for example, the rotary elevating shaft 17 is raised while being rotated by screw feed by the female screw 15i and the male screw 17e, and accordingly, the thrust transmission member 23 and the valve The body 20 is pulled up by the urging force of the valve opening spring 25, and the valve body portion 20a is lifted from the valve seat shut-off portion 8a to open the valve port 9.

  A back pressure chamber 30 is defined between the pressing member 24 and the partition wall 14 c of the cylindrical holding member 14 above the valve body 20. Further, in the valve body 20, a skirt portion 32 a, a thick passage portion 32 b, and a narrow passage portion 32 c having an opening at the lower end are formed in order from the bottom in order to communicate the tip portion of the valve body 20 and the back pressure chamber 30. A pressure equalizing passage 32 is provided. The narrow passage 32c communicates with the back pressure chamber 30 through a through hole 32d and a lateral hole 32e. Here, in order to balance (cancel the differential pressure) the push-down force (force acting in the valve-closing direction) acting on the valve body in the valve-closed state and the push-up force (force acting in the valve-opening direction) acting on the valve body, The diameter of the back pressure chamber 30 and the diameter of the valve port 9 are set to be substantially the same.

  In the motor-operated valve 1 of the first embodiment, the diameter of the valve port 9 is Dc (for example, about 10 to 15 mm), and the opening area (hereinafter referred to as the valve port area) is Sc. Further, the lower end passage diameter DX of the pressure equalizing passage 32 is D5, the opening area (hereinafter referred to as pressure equalizing passage opening area) SX is S5, and the pressure equalizing passage opening area S5 is the valve opening area Sc. The divided value S5 / Sc is 0.7 (the dimensions of each part are set so that S5 / Sc is 0.7).

  On the other hand, in the motor-operated valve 2 of the second embodiment shown in FIG. 3, the diameter of the valve port 9 is Dc (for example, about 10 to 15 mm) and the opening area (hereinafter referred to as the valve port) is the same as in the first embodiment. Area) is Sc, whereas the lower end passage diameter DX of the pressure equalizing passage 32 is D6 larger than D5, and the pressure equalizing passage opening area SX is S6 larger than S5. A value S6 / Sc obtained by dividing the area S6 by the valve opening area Sc is 0.9 (the dimensions of each part are set so that S6 / Sc is 0.9). In FIG. 3, the same reference numerals as those in FIGS. 1 and 2 represent the same or equivalent parts.

  Here, in order to examine more closely the relationship between the load (upward load, downward load) acting on the valve body 20 and the value SX / Sc obtained by dividing the pressure equalizing passage opening area SX by the valve opening area Sc, In addition to the pressure equalizing passage opening area SX having S5 and S6, the pressure equalizing passage opening area SX having S1, S2, S3, S4 (smaller order) smaller than S5 and S7 larger than S6 were prepared. In this case, S1 / Sc = 0.05, S2 / Sc = 0.10, S3 / Sc = 0.30, S4 / Sc = 0.50, S5 / Sc = 0.70, S6 / Sc = 0.90. S7 / Sc = 0.95, and for these seven types of motor-operated valves, the first flow direction (first inlet / outlet 11 → second inlet / outlet 12) and the second flow direction (second inlet / outlet 12 → first FIG. 4 shows the result of analyzing the change in the load acting on the valve body 20 for both the inlet / outlet 11).

  In FIG. 4, the horizontal axis represents a value Kx / Sc obtained by dividing the valve opening area Kx by the valve opening area Sc. The vertical axis represents the load acting on the valve body, the positive value represents the load acting upward on the valve body, and the negative value represents the load acting downward on the valve body.

  The valve opening area Kx indicates the minimum area (fluid passage area) of the truncated cone portion connecting the valve seat 8a and the seal surface 20a, as indicated by the symbol Kx in FIG. Therefore, it increases as the lift amount of the valve body 20 increases.

  From FIG. 4, in the first flow direction (first inlet / outlet 11 → second inlet / outlet 12), a value SX / Sc obtained by dividing the pressure equalizing passage opening area SX (S1 to S7) by the valve opening area Sc is obtained. Except when it is smaller than 0.30 and close to the fully open state (Kx / Sc is 0.8 or more), the load acting on the valve body is greater than 0, and an upward load is generated on the valve body 20 I understand.

  On the other hand, in the second flow direction (second inlet / outlet 12 → first inlet / outlet 11), the load acting on the valve body is less than 0 regardless of the size of the pressure equalizing passage opening area SX (S1 to S7). The valve body 20 becomes smaller and a downward load is generated. In this case, particularly when the value SX / Sc obtained by dividing the pressure equalizing passage opening area SX by the valve opening area Sc is smaller than 0.30, the downward load is unacceptable to the valve body 20 as Kx / Sc increases. (A force exceeding 40 [N], indicated by a region Ez in FIG. 4) acts, and this is a factor that the spring load of the valve opening spring 25 cannot be reduced so much.

  In this case, the larger the value SX / Sc obtained by dividing the pressure equalizing passage opening area SX by the valve port area Sc, the smaller the downward load acting on the valve body 20, and SX / Sc is 0.50 or more (first embodiment). If the motor-operated valve 1 of the example is 0.70 and the motor-operated valve 2 of the second embodiment is 0.90), the downward load does not exceed 40 [N] and can be suppressed within an allowable range.

  Thus, when the fluid is flowed in the second flow direction by setting the dimensions of each part so that the value SX / Sc obtained by dividing the pressure equalizing passage opening area SX by the valve opening area Sc is 0.50 or more. , The downward load (force acting in the valve closing direction) can be kept within the allowable range, and therefore, a valve-opening spring with a smaller spring load can be used. As a result, the motor-operated valve is further reduced in size and capacity. Thus, power saving can be achieved.

  In this type of electric valve, in order to obtain a required sealing property (in order to increase the contact pressure), the sealing surface 20a that contacts and separates from the valve seat 8a in the valve body 20 has a conical surface, a spherical surface, an elliptical surface, and the like. The valve seat 8a must have a curved surface that is substantially in line contact with the valve seat 8a, and a flat valve cannot be used. Therefore, a value obtained by dividing the pressure equalizing passage opening area SX by the valve opening area Sc SX / Sc is about 0.95 at the maximum.

  Moreover, it cannot be overemphasized that the motor operated valve of this invention is applicable not only to a heat pump type | formula air conditioning system but other systems.

1, 2 Motorized valve 5 Valve body 7 Valve chamber 8 Valve seat member 8a Valve seat 9 Valve port 11 First inlet / outlet 12 Second inlet / outlet 20 Valve body 20a Sealing surface 25 Valve opening spring 28 Lifting spring receiver 30 Back pressure chamber 32 Pressure equalizing passage 50 Stepping motor 55 Stator 57 Rotor

Claims (2)

A valve body having a valve chamber, a lateral first inlet / outlet opening in the valve chamber, a valve port with a vertical valve seat opening in the valve chamber, and a second inlet / outlet connected to the valve port; A valve body disposed in the valve chamber so as to be able to be raised and lowered to open and close; elevating drive means having an electric motor for raising and lowering the valve body; and a valve opening spring for urging the valve body in a valve opening direction; The diameter of the valve opening and the diameter of the back pressure chamber defined above the valve body are set to be substantially the same, and the valve opening and the back pressure chamber are provided in the valve body. A motor-operated valve provided with a pressure equalizing passage having a lower end surface opened to allow communication,
The motor-operated valve is characterized in that dimensions of each part are set so that a value obtained by dividing a lower end opening area of the pressure equalizing passage by the valve opening area is 0.5 or more and less than 1.0.   The sealing surface of the valve body that contacts and separates from the valve seat is configured by a curved surface that is substantially in line contact with the valve seat, such as a conical surface, a spherical surface, and an elliptical surface, so as to obtain a required sealing property. The motor-operated valve according to claim 1, wherein:

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