CN113565968A

CN113565968A - Piston type electronic expansion valve

Info

Publication number: CN113565968A
Application number: CN202110934607.7A
Authority: CN
Inventors: 李进; 潘璇; 熊志生
Original assignee: Oechsler Plastic Products Taicang Co Ltd
Current assignee: Oechsler Plastic Products Taicang Co Ltd
Priority date: 2021-08-16
Filing date: 2021-08-16
Publication date: 2021-10-29

Abstract

The invention belongs to the technical field of control valves, and particularly relates to a piston type electronic expansion valve. The piston type electronic expansion valve is provided with a valve shell, wherein a power cavity, an overflow cavity, a liquid inlet cavity and a liquid outlet cavity are arranged in the valve shell; a liquid inlet is arranged on the wall of the liquid inlet cavity and is used for liquid to flow in; a liquid outlet is arranged on the wall of the liquid discharge cavity for discharging liquid; an overflow port is arranged on the wall of the overflow cavity for liquid to overflow, and an overflow valve is arranged on the overflow passage; a first through hole is arranged between the overflow cavity and the liquid inlet cavity, and a second through hole is arranged between the liquid inlet cavity and the liquid discharge cavity; the first through hole and the second through hole have the same cross section and are arranged oppositely; a piston is slidably arranged in the first through hole and the second through hole; the side wall of the piston is provided with a spiral groove which is not communicated with the front end face of the piston; and a power assembly is arranged in the power cavity and drives the piston to move forwards and backwards. The piston type electronic expansion valve has the advantages of convenient and accurate flow control, good reliability, low failure rate and long service life.

Description

Piston type electronic expansion valve

Technical Field

The invention belongs to the technical field of control valves, and particularly relates to a piston type electronic expansion valve.

Background

In various cooling/heating apparatuses such as air conditioners, refrigerators, heat pump water heaters, etc., an electronic expansion valve is generally used to regulate the flow rate of a fluid.

The electronic expansion valve usually includes two parts of motor with step motor and valve body component as executive component, the valve body component includes valve body with refrigerant flow path inlet and flow path outlet, valve core placed in the inner cavity of valve body and valve core seat with valve port portion, and the pulse signal is inputted into the motor of driving component to drive valve core to make movement relative to valve port portion so as to change the refrigerant flow rate of valve port portion and attain the goal of regulating refrigerant flow rate of flow path outlet to control heat exchange balance in air conditioner or refrigerator. Therefore, the flow curve in the electronic expansion valve is a key technical characteristic and directly determines the working efficiency of the refrigeration system.

In the current electronic expansion valve product, when the coil is electrified, a magnetic field is generated, so that the driving rod of the magnetic telescopic material is extended to push the displacement transfer rod to act, and the displacement transfer rod pushes the valve rod to move around the rotating shaft, so that the distance between the valve rod and the liquid inlet is changed. The distance between the valve rod and the liquid inlet can be adjusted by adjusting the current in the coil, so that the flow of the refrigerant is controlled. Although the electronic expansion valve has relatively low manufacturing cost and simple structure, the electronic expansion valve has low control precision, poor sealing performance and high energy loss. In the electronic expansion valve, the opening and closing switching is realized by repeatedly touching the valve needle and the valve seat, so that the deformation and damage of the contact part are easily caused, the flow rate is unstable, and a small amount of metal fragments and powder can be peeled off from the contact part even if the valve needle is touched for a long time, and the poor action of the valve needle is caused. In addition, at the moment of starting or locking the valve, the 'water hammer' effect of the liquid has a large impact effect on the valve and the pipeline, so that the failure rate is increased, and the service life is severely limited.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a piston type electronic expansion valve.

The invention provides a piston type electronic expansion valve, which is provided with a valve shell, wherein the interior of the valve shell is divided into a plurality of chambers, including a power chamber, an overflow chamber, a liquid inlet chamber and a liquid outlet chamber; a liquid inlet is arranged on the wall of the liquid inlet cavity and is used for liquid to flow in; a liquid outlet is arranged on the wall of the liquid discharge cavity for discharging liquid; an overflow port is arranged on the wall of the overflow cavity for liquid to overflow, and an overflow valve is arranged on the overflow passage; a first through hole is arranged between the overflow cavity and the liquid inlet cavity, and a second through hole is arranged between the liquid inlet cavity and the liquid discharge cavity; the first through hole and the second through hole have the same cross section and are arranged oppositely; a piston is slidably arranged in the first through hole and the second through hole; the side wall of the piston is provided with a spiral groove which is not communicated with the front end face of the piston; and a power assembly is arranged in the power cavity and drives the piston to move forwards and backwards. The direction of movement of the piston when sliding into the discharge chamber is defined as forward, and the opposite direction is defined as backward.

When the piston type electronic expansion valve is used, liquid flows into the liquid inlet cavity from the liquid inlet, and the piston moves back and forth. When the piston moves to the front position, the liquid in the liquid inlet cavity passes through the second through hole through the spiral groove, enters the liquid discharge cavity, is discharged from the liquid discharge port, and is in a valve opening state at the moment. When the piston moves to the back position, the spiral groove exits the second through hole, the second through hole is filled with the piston, and liquid in the liquid inlet cavity cannot enter the liquid outlet cavity, so that the valve is in a closed state. When the valve is suddenly closed, the piston rapidly moves to a rear position, liquid from the liquid inlet pipe flows into the overflow cavity through the spiral groove under the inertia effect, and the overflow valve is opened and releases pressure along with the increase of the pressure in the overflow cavity, so that the pipeline and the valve structure are protected. Because the spiral groove is arranged on the surface of the piston, the piston can be accurately arranged in the first through hole and the second through hole in a penetrating mode, and radial shaking cannot be generated. In addition, in the process of the back-and-forth movement of the piston, the abrasion of the inner surfaces of the first through hole and the second through hole and the outer surface of the piston is uniform, and local serious abrasion is avoided, so that high matching precision can be kept in the long-term use process, the service life is long, and the reliability is high.

Furthermore, the section of the spiral groove close to the front is an adjusting section, and the section of the adjusting section is gradually reduced from the back to the front. Due to the existence of the adjusting section, when the piston moves back and forth, the sectional area of the channel formed between the piston and the second through hole changes, so that the flow rate of the liquid can be controlled by controlling the position of the piston. Preferably, the cross section of the adjusting section is linearly reduced from back to front, so that a relatively linear flow characteristic curve is obtained, and automation and accurate control are facilitated.

Furthermore, a threaded hole extending forwards is formed in the rear end face of the piston; sealing elements such as sealing rings, stuffing box sealing assemblies and the like are arranged between the power cavity and the overflow cavity at intervals; a threaded shaft penetrates through the sealing element from the power cavity to extend into the overflow cavity and is in threaded fit connection with the threaded hole; the power component drives the threaded shaft to rotate, so that the piston is driven to move back and forth. Preferably, the threaded shaft has an external thread at a portion thereof located in front of the seal, and the other portions are not provided with the external thread.

Further, the power assembly comprises a driving wheel, a first driven wheel, a second driven wheel, a speed reducer and a torque limiter; two ends of the torque limiter are respectively connected with the output end of the speed reducer and the threaded shaft; the input end of the speed reducer is connected with a second driven wheel, and the first driven wheel is simultaneously meshed with the second driven wheel and the driving wheel; the driving wheel is driven by a motor to rotate, and the motor can be arranged in the power cavity or outside the power cavity. The motor generates rotary driving force after being electrified, the rotary driving force is transmitted to the threaded shaft through the first driven wheel, the second driven wheel, the speed reducer and the torque limiter in sequence, the threaded shaft rotates to drive the piston to move, and the opening and closing of the valve are controlled. Wherein, the speed reducer plays the roles of reducing speed and increasing torque; the torque limiter slips when the torque is too large, and the motor and the power assembly are protected.

The reducer may take many forms, for example a planetary reducer, which may be single stage or multi-stage, and a single stage planetary reducer is used as an example of a possible application method. The speed reducer comprises an inner gear ring, a planet carrier, a planet wheel and a sun wheel; the inner gear ring is fixed in the power cavity, a planet carrier and a sun gear are rotatably arranged in the inner gear ring, a group of planet gears are arranged on the planet carrier in an annular array mode, the inner gear ring is meshed around the planet gears, and the sun gear is meshed in the center of the planet gears; the planet carrier is connected with the torque limiter shaft, and the sun gear is connected with the second driven wheel shaft.

Further, the overflow port is preferably connected to the drainage chamber to form an overflow path. When the valve is suddenly closed, a small amount of liquid overflowing from the overflow port can be directly led into the liquid discharge cavity, so that the water hammer effect is prevented. Of course, the waste water can be discharged to other places, such as an additional storage tank or direct emptying (suitable for non-toxic and harmless media such as water).

Furthermore, the overflow valve is a one-way valve, and the liquid in the overflow cavity overflows when the pressure of the liquid exceeds the maximum limit pressure of the overflow valve.

Furthermore, the overflow valve comprises a valve pipe, a valve ball and a pressure spring which are arranged in the valve pipe; the valve pipe is integrally in a circular pipe shape, one end of the valve pipe is provided with a horn-shaped reducing opening, and the valve ball is pressed at the horn-shaped reducing opening by the pressure spring.

Has the advantages that: compared with the prior art, the piston type electronic expansion valve provided by the invention has the advantages of convenient and accurate flow control, good reliability, low failure rate and long service life. When the spiral groove valve works, the on-off and the flow area of the spiral groove are changed through the movement of the piston, and the flow can be accurately controlled. When the device works, the fluid control part does not collide, the fluid control part does not deform, and metal fragments are not easy to generate. When the device works, the surfaces of all moving parts are uniformly abraded, local concentrated abrasion does not exist, and high matching precision can be maintained for a long time.

Drawings

Fig. 1 is a schematic view of the internal structure of the present invention.

Fig. 2, 3 and 4 are schematic views of a part of fig. 1.

Fig. 5 is a schematic structural view of the piston.

Fig. 6 is a schematic structural diagram of the present invention in a closed state.

In the figure, a valve housing 1, a power cavity 11, an overflow cavity 12, a liquid inlet cavity 13, a liquid discharge cavity 14, a liquid inlet 2, a liquid discharge port 3, an overflow port 4, an overflow valve 41, a first through hole 15, a second through hole 16, a piston 5, a spiral groove 51, a motor 8, a power assembly 9, an adjusting section 511, a threaded hole 52, a sealing member 6, a threaded shaft 7, a driving wheel 91, a first driven wheel 92, a second driven wheel 93, a speed reducer 94, a torque limiter 95, an inner gear ring 941, a planet carrier 942, a planet wheel 943, a sun wheel 944, a valve pipe 411, a valve ball 412 and a pressure spring 413 are arranged.

Detailed Description

The invention is further illustrated by the following examples, which are intended to illustrate the technical solutions of the invention more clearly and are not to be construed as a limitation.

Unless defined otherwise, technical or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The use of "first," "second," and similar terms in the present application do not denote any order, quantity, or importance, but rather the terms are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

Example 1

A piston type electronic expansion valve, as shown in figures 1 to 6, comprises a valve casing 1, wherein the interior of the valve casing 1 is divided into a plurality of chambers, including a power chamber 11, an overflow chamber 12, a liquid inlet chamber 13 and a liquid outlet chamber 14; a liquid inlet 2 is arranged on the wall of the liquid inlet cavity 13 for liquid to flow in; a liquid discharge port 3 is arranged on the wall of the liquid discharge cavity 14 for discharging liquid; an overflow port 4 is arranged on the cavity wall of the overflow cavity 12 for liquid to overflow, and an overflow valve 41 is arranged on an overflow passage; a first through hole 15 is arranged between the overflow cavity 12 and the liquid inlet cavity 13, and a second through hole 16 is arranged between the liquid inlet cavity 13 and the liquid discharge cavity 14; the first through hole 15 and the second through hole 16 have the same cross section and are arranged oppositely; a piston 5 is slidably arranged in the first through hole 15 and the second through hole 16; a spiral groove 51 is arranged on the side wall of the piston 5, and the spiral groove 51 is not communicated with the front end surface of the piston 5; a power assembly 9 is arranged in the power cavity 11, and the power assembly 9 drives the piston 5 to move back and forth. The direction of movement of piston 5 when sliding in discharge chamber 14 is defined as forward, and the opposite direction is defined as backward.

In this embodiment, the front section of the spiral groove 51 is an adjusting section 511, and the cross section of the adjusting section 511 is gradually reduced from back to front.

In this embodiment, a screw hole 52 extending forward is formed in the rear end surface of the piston 5; a sealing element 6 is arranged between the power cavity 11 and the overflow cavity 12 at intervals; a threaded shaft 7 extends from the power cavity 11 into the overflow cavity 12 through the sealing element 6 and is in threaded fit connection with the threaded hole 52; the power assembly 9 rotates the threaded shaft 7. The threaded shaft 7 has an external thread at a portion located in front of the seal member 6, and the other portions are not provided with the external thread.

In this embodiment, the power assembly 9 includes a driving wheel 91, a first driven wheel 92, a second driven wheel 93, a speed reducer 94, and a torque limiter 95; two ends of the torque limiter 95 are respectively connected with the output end of the speed reducer 94 and the threaded shaft 7; the input end of the speed reducer 94 is connected with a second driven wheel 93, and the first driven wheel 92 is simultaneously meshed with the second driven wheel 93 and the driving wheel 91; the driving wheel is driven to rotate by a motor 8.

In this embodiment, the speed reducer 94 is a planetary speed reducer, and includes an annular gear 941, a planet carrier 942, a planet gear 943, and a sun gear 944; an inner gear ring 941 is fixed in the power cavity 11, a planet carrier 942 and a sun gear 944 are rotatably arranged in the inner gear ring 941, a group of planet gears 943 are arranged on the planet carrier 942 in an annular array manner, the inner gear ring 941 is meshed around the planet gears 943, and the sun gear 944 is meshed in the center of the planet gears 943; the carrier 942 is connected to the torque limiter 95 shaft, and the sun gear 944 is connected to the second driven wheel 93 shaft.

In this embodiment, overflow port 4 is connected to drain chamber 14 to form an overflow path.

In this embodiment, the relief valve 41 is a check valve. The relief valve 41 comprises a valve pipe 411, a valve ball 412 and a pressure spring 413 which are arranged in the valve pipe 411; the valve tube 411 is a circular tube, one end of the valve tube has a trumpet-shaped necking, and the valve ball 412 is pressed at the trumpet-shaped necking by the pressure spring 413.

The above embodiments are exemplary only, and are intended to illustrate the technical concept and features of the present invention so that those skilled in the art can understand the contents of the present invention and implement the present invention, and not to limit the scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. A piston type electronic expansion valve, characterized in that: the device is provided with a valve shell (1), wherein the interior of the valve shell (1) is divided into a plurality of chambers, including a power chamber (11), an overflow chamber (12), a liquid inlet chamber (13) and a liquid outlet chamber (14); a liquid inlet (2) is arranged on the wall of the liquid inlet cavity (13) for liquid to flow in; a liquid discharge port (3) is arranged on the wall of the liquid discharge cavity (14) for discharging liquid; an overflow port (4) is arranged on the wall of the overflow cavity (12) for liquid to overflow, and an overflow valve (41) is arranged on the overflow passage; a first through hole (15) is arranged between the overflow cavity (12) and the liquid inlet cavity (13), and a second through hole (16) is arranged between the liquid inlet cavity (13) and the liquid discharge cavity (14); the first through hole (15) and the second through hole (16) have the same cross section and are arranged oppositely; a piston (5) is arranged in the first through hole (15) and the second through hole (16) in a sliding way; a spiral groove (51) is arranged on the side wall of the piston (5), and the spiral groove (51) is not communicated with the front end face of the piston (5); a power assembly (9) is arranged in the power cavity (11), and the power assembly (9) drives the piston (5) to move back and forth;

the direction of movement of the piston (5) when sliding into the discharge chamber (14) is defined as the front, and the opposite direction is defined as the rear.

2. The piston-type electronic expansion valve of claim 1, wherein: the section of the spiral groove (51) close to the front is an adjusting section (511), and the section of the adjusting section (511) is gradually reduced from the back to the front.

3. The piston-type electronic expansion valve of claim 1, wherein: a threaded hole (52) extending forwards is formed in the rear end face of the piston (5); a sealing element (6) is arranged between the power cavity (11) and the overflow cavity (12) at intervals; a threaded shaft (7) penetrates through the sealing piece (6) from the power cavity (11) to extend into the overflow cavity (12) and is in threaded fit connection with the threaded hole (52); the power component (9) drives the threaded shaft (7) to rotate.

4. The piston-type electronic expansion valve of claim 3, wherein: the power assembly (9) comprises a driving wheel (91), a first driven wheel (92), a second driven wheel (93), a speed reducer (94) and a torque limiter (95); two ends of the torque limiter (95) are respectively connected with the output end of the speed reducer (94) and the threaded shaft (7); the input end of the speed reducer (94) is connected with a second driven wheel (93), and the first driven wheel (92) is simultaneously meshed with the second driven wheel (93) and the driving wheel (91); the driving wheel is driven by a motor (8) to rotate.

5. The piston-type electronic expansion valve of claim 4, wherein: the speed reducer (94) is a planetary speed reducer and comprises an inner gear ring (941), a planet carrier (942), a planet wheel (943) and a sun wheel (944); an inner gear ring (941) is fixed in the power cavity (11), a planet carrier (942) and a sun gear (944) are rotatably arranged in the inner gear ring (941), a group of planet gears (943) are arranged on the planet carrier (942) in an annular array mode, the inner gear ring (941) is meshed around the planet gears (943), and the sun gear (944) is meshed in the center of the planet gears (943); the carrier (942) is connected to the torque limiter (95) shaft, and the sun gear (944) is connected to the second driven wheel (93) shaft.

6. The piston-type electronic expansion valve of claim 1, wherein: the overflow port (4) is connected with the liquid discharge cavity (14) to form an overflow passage.

7. The piston-type electronic expansion valve of claim 1, wherein: the overflow valve (41) is a one-way valve.

8. The piston-type electronic expansion valve of claim 7, wherein: the overflow valve (41) comprises a valve pipe (411), a valve ball (412) arranged in the valve pipe (411) and a pressure spring (413); the valve pipe (411) is integrally in a circular pipe shape, one end of the valve pipe is provided with a horn-shaped reducing opening, and the valve ball (412) is pressed at the horn-shaped reducing opening by the pressure spring (413).