Adjustable timing sequence gas distribution valve

Abstract

The utility model provides an adjustable time sequence gas distribution valve which comprises a valve body, a base plate arranged in the valve body, a heat regenerator channel arranged on the base plate and communicated with a compressor, and a valve element rotationally connected into the valve body and capable of controlling the gas inlet state of the heat regenerator channel. A detection system capable of detecting the rotating position of the valve element through optical positioning is further arranged in the valve body. The positioning plate is arranged on the valve element and can rotate along with the valve element, the detection plate and the positioning plate are coaxially arranged, the optical sensor set is arranged on the inner wall of the valve body and can detect the positioning plate and the detection plate respectively, and the positioning plate and the detection plate are each provided with a notch part used for detection of the optical sensor set. According to the utility model, the specific position of the valve core rotor can be accurately detected, and low-cost and high-reliability rotor position detection is realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to a gas distribution structure technical field of low temperature refrigerator, especially a kind of adjustable time sequence gas distribution valve. BACKGROUND

[0002] GM refrigerator cycle is proposed by William Gifford and Howard McMahon in the late 1950s, with the advantages of simple structure, high efficiency and reliability, strong stability, etc., and it is the only low temperature refrigerator that realizes industrialized mass production in the world;As a small cryogenic cold source, it is widely used in low temperature vacuum pump, low temperature electronics research, nuclear magnetic resonance imaging instrument and superconducting strong electricity, etc. The occasion that needs stable low temperature environment.

[0003] GM refrigerator is mainly composed of compressor, gas distribution valve and cold head three major components;Among them, rotary valve is the key component connecting compressor and cold head, by controlling the opening and closing of high and low pressure valve, direct current working medium can be converted into low frequency alternating flow working medium;For GM type low frequency refrigerator Loss analysis shows that the whole machine of refrigerator Loss mainly concentrates in compressor and gas distribution valve, about 80%~90% of the input electric power of whole machine, and the isothermal compression efficiency of helium compressor can only reach about 50% at present, and it is difficult to have room for improvement, so reducing the Loss of gas distribution valve is crucial for improving the efficiency of GM type refrigerator.

[0004] Plane rotary valve is mainly composed of valve core and matching plane structure, as shown in Figure 1 Valve core is rotated by synchronous motor, so that the load of refrigerator is connected with high pressure gas source and low pressure gas source in a cycle respectively, and refrigeration capacity is realized by circulation and repetition; Figure 2 The opening degree of the plane rotary valve in a cycle is shown, since the rotating speed of synchronous motor is relatively uniform in the whole cycle, so its opening degree will be uniformly converted from closed to fully open, and then from fully open to closed, and the fully open time of valve accounts for very short time in the whole running cycle, which leads to the reduction of effective area of rotary valve orifice, the reduction of working medium into refrigerator, and the reduction of refrigerator efficiency and refrigeration capacity.

[0005] As a key parameter of GM refrigerator, timing is defined as the ratio of exhaust time to intake time, i.e. the time ratio of gas undergoing expansion and compression process inside the refrigerator; GM refrigerators of different structural sizes usually have a corresponding optimal timing value, so that the performance of the refrigerator reaches the optimal value. On the other hand, the motor operating frequency and the rotary valve structure are extremely important for optimizing the timing. However, due to the use of relatively expensive materials and the need for professional precision machining, the design and manufacturing cost of the rotary valve is often high; therefore, adjusting the speed of the rotary valve to achieve the optimal timing is of great significance to improve the overall efficiency of the refrigerator.

[0006] Document (CN 117145744A) proposes an improvement idea, which uses a stepper motor instead of a synchronous motor as a driving source, and adjusts the motor speed through pulse modulation, so that the gas distribution valve can quickly reach the fully open or fully closed state; at the same time, a relative position detection method based on the origin reference is used, which detects the rotor displacement by counting from the initial position of the rotor, but this method has the risk of origin misjudgment and counting error, which may cause rotor positioning error and position feedback error. Practical new type content

[0007] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide an adjustable timing gas distribution valve to solve the problems of small application range and low detection accuracy of the rotor detection device of the rotary valve in the prior art.

[0008] To achieve the above-mentioned purposes and other related purposes, the present application provides an adjustable timing gas distribution valve, which comprises a valve body, a bottom plate arranged in the valve body, a regenerator channel arranged on the bottom plate and communicating with a compressor, and a valve core rotatably connected in the valve body and capable of controlling the intake state of the regenerator channel, and a detection system capable of detecting the rotational position of the valve core by optical positioning is further arranged in the valve body; the detection system comprises a positioning plate arranged on the valve core and capable of rotating with the valve core, a detection plate coaxially arranged with the positioning plate, and an optical sensor group arranged on the inner wall of the valve body and capable of detecting the positioning plate and the detection plate respectively, and the positioning plate and the detection plate both have a notch part for detection of the optical sensor group.

[0009] By using the above technical scheme, the specific position of rotation is judged by detecting the notches on the positioning plate and the detection plate, so that the optical sensor group only needs to identify whether the notches exist or not, without using high-performance sensors, and an economic photoelectric sensor can meet the detection requirements; the system performs binary encoding processing on the sensor output signal: when the notch part is detected, the output signal is recorded as logic "1"; when the notch part is not detected, the output signal is recorded as logic "0"; therefore, when the system is configured with n sensors, the combination of detection signals of each sensor can form 2n different combinations, which can represent 2n different positions of the valve core, and the system can accurately detect the position of the valve core through the combination of detection signals of each sensor. nDifferent encoding modes, each of which corresponds to a specific absolute position of the rotor, thereby achieving 2 n Position detection, which can accurately detect the specific position of the valve core rotor, realizes low-cost and high-reliability rotor position detection.

[0010] By detecting whether the rotor is positioned at the specified position, the accuracy and reliability of the system operation can be ensured.

[0011] In an embodiment of the utility model, the positioning plate is provided with a first gap part for positioning the optical sensor group, and the detection plate is provided with a second gap part for positioning the optical sensor group.

[0012] In an embodiment of the utility model, a stepping motor for driving the valve core to rotate is arranged in the valve body, and the valve core is provided with a rotating shaft linked with the stepping motor.

[0013] In an embodiment of the utility model, the optical sensor group comprises a positioning sensor, a first sensor and a second sensor arranged along the axial direction of the rotating shaft, the first sensor is arranged opposite to the positioning sensor, the first sensor and the second sensor are located in the same horizontal plane and are distributed around the detection plate axis.

[0014] In an embodiment of the utility model, a high-pressure opening for high-pressure intake and a low-pressure groove arranged beside the high-pressure opening for low-pressure exhaust are arranged on the valve core and can communicate with the passage of the regenerator.

[0015] In an embodiment of the utility model, a plurality of first gap parts are arranged, and the first gap parts are distributed corresponding to the direction of the high-pressure opening and the low-pressure groove of the valve core, the first gap parts are used for positioning sensor identification, and the second gap parts are arranged around the detection plate axis and are used for first sensor and second sensor identification.

[0016] In an embodiment of the utility model, a driving member for driving the valve core to rotate is arranged in the valve body, the valve core is provided with a rotating shaft linked with the driving member, the positioning plate and the detection plate are both mounted on the rotating shaft, and the detection plate is located above the positioning plate.

[0017] In an embodiment of the utility model, one low-pressure groove is arranged at the center of the valve core, and two high-pressure openings are arranged on both sides of the low-pressure groove.

[0018] In an embodiment of the utility model, four first gap parts are arranged, and the four first gap parts are uniformly arranged around the rotating shaft axis, the two second gap parts are perpendicular to each other, and the first sensor and the second sensor are perpendicular to each other.

[0019] As described above, the adjustable timing valve of this invention has the following advantages: It uses a pulse-modulated stepper motor with fully adjustable speed, enabling rapid full-opening / full-closing operation of the valve, increasing the average opening degree of the valve, and freely adjusting the intake and exhaust time parameters to achieve optimal timing control of the valve distribution, thereby reducing losses in the valve distribution system and improving the overall efficiency of the refrigeration unit; the rotor position detection device uses multiple ordinary optical sensors to detect the notch state of the detection plate, and determines the absolute position of the rotor through binary signal combination, achieving low-cost, high-reliability rotor position detection, significantly reducing system cost and structural complexity compared to traditional absolute encoders. Attached Figure Description

[0020] Figure 1 The diagram shows the chassis and valve core structure disclosed in the embodiments of this utility model.

[0021] Figure 2 This displays the change in valve opening degree within one cycle in this utility model.

[0022] Figure 3 This displays the changes in the opening degree of the gas distribution valve;

[0023] Figure 4 The diagram shown is a schematic diagram of the valve body in an embodiment of this utility model;

[0024] Figure 5a The diagram shows the structural layout of the positioning plate of the detection unit at this location, viewed from above.

[0025] Figure 5b This is a diagram showing the structure of the detection plate in the detection section at this location, viewed from above.

[0026] Figure 5c The image shown is a 3D view of the positioning plate and the detection plate.

[0027] Figure 6 This embodiment contains a table showing the signal modes of each sensor used for position detection and their corresponding connection ports.

[0028] Figure 7 A flowchart for rotor position detection and adjustment.

[0029] Component designation explanation

[0030] 1. Valve body; 2. Chassis; 3. Regenerator channel; 4. Low-pressure side of compressor; 5. Valve core; 6. Positioning sensor; 7. Positioning plate; 7a. First notch; 8a. First sensor; 8b. Second sensor; 9. Rotating shaft; 10. Detection plate; 10a. Second notch; 11. Spring; 12. Stepper motor; 13. High-pressure opening; 14. Low-pressure groove. Detailed Implementation

[0031] The following specific embodiments illustrate the implementation of the present application, and those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in the specification.

[0032] Please refer to Figures 1 to 7 It should be understood that the structure, proportion, size, etc. shown in the drawings attached to the specification are only used to understand and read the content disclosed in the specification for those skilled in the art, and are not used to limit the implementation conditions of the present application, so they do not have technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effects and purposes that can be achieved by the present application, should still fall within the scope of the technical content disclosed by the present application. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" used in the specification are only for the convenience of clear description, and are not used to limit the scope of the present application. The change or adjustment of the relative relationship, without substantially changing the technical content, is also considered as the scope of the present application.

[0033] As shown in Figure 1 , Figure 2 The present application provides an adjustable timing gas distribution valve, which comprises a valve body 1, a bottom plate 2 arranged in the valve body 1, a regenerator channel 3 arranged on the bottom plate 2 and communicated with a compressor, and a valve core 5 rotatably connected in the valve body 1 and capable of controlling the inlet state of the regenerator channel 3. The valve body 1 further comprises a detection system capable of detecting the rotation position of the valve core 5 by optical positioning. The regenerator channel 3 is communicated with the low-pressure side 4 of the compressor. The periodic switching of the regenerator channel 3 with the high-pressure side and the low-pressure side of the compressor is realized by the rotation of the valve core 5. The bottom plate 2 is a stator, and the valve core 5 is a rotor.

[0034] A gas flow channel is arranged in the middle of the valve core 5. The lower end of the valve core 5 is precisely matched with the inner wall of the bottom plate by a spring 11. Two high-pressure openings 13 and one low-pressure groove 14 are arranged at the upper end of the valve core 5. The low-pressure groove 14 is arranged at the center of the valve core 5, and the high-pressure openings 13 are arranged on both sides of the low-pressure groove 14. The high-pressure openings 13 are used to guide the high-pressure gas source, and the low-pressure groove 14 is used to connect the low-pressure gas source.

[0035] In the working process, the high-pressure openings 13 and the low-pressure groove 14 of the valve core 5 correspond to the bottom plate regenerator channel 3 independently, and control the high-pressure inlet state and the low-pressure exhaust state, respectively. A driving member is arranged in the valve body 1 for driving the rotation of the valve core 5. The valve core 5 has a rotating shaft 9 connected with the driving member. The driving member is a stepping motor 12, which is connected with the center shaft of the valve core 5 through the rotating shaft 9, to realize the reliable switching of the valve core 5 between the two working states and ensure the efficient operation of the system.

[0036] Before the valve core 5 enters either of its two working states, the drive mechanism operates in a fast-running mode. When the valve core 5 enters either of its two working states, the drive mechanism operates in a slow-running mode. When the valve distribution valve opens, the stepper motor 12 can move quickly to allow the valve to directly enter the fully open state. When the valve distribution valve is about to close, the stepper motor 12 also moves quickly to close it rapidly, thus achieving... Figure 3 The changes in valve opening shown; comparison Figure 3 and Figure 2 It can be seen from the two types of valve openings that, within one operating cycle, the average opening of the valve driven by stepper motor 12 is significantly higher than that driven by traditional synchronous motor. Therefore, the GM refrigeration machine using the valve driven by stepper motor 12 has significantly better cooling capacity and refrigeration efficiency than the traditional GM refrigeration machine.

[0037] The detection system includes a positioning plate 7 mounted on the valve core 5 and capable of rotating with the valve core 5, a detection plate 10 coaxially mounted with the positioning plate 7, and an optical sensor group mounted on the inner wall of the valve body 1 capable of detecting the positioning plate 7 and the detection plate 10 respectively. The optical sensor group includes a positioning sensor 6, a first sensor 8a, and a first sensor 8b arranged along the axial direction of the rotation axis 9. The position of the first sensor 8a is opposite to that of the positioning sensor 6. The first sensor 8a and the first sensor 8b are located in the same horizontal plane and are distributed around the axis of the detection plate 10.

[0038] Positioning sensor 6, first sensor 8a and second sensor 8b are all fixedly installed inside valve body 1, and each sensor includes a photoelectric sensor with a light-emitting element and a light-receiving element facing each other. Positioning plate 7 and detection plate 10 both have notches for detection by optical sensor group.

[0039] like Figure 5a As shown, the positioning plate 7 is provided with a first notch 7a for positioning the optical sensor group, and the detection plate 10 is provided with a second notch 10a for positioning the optical sensor group. The first notch is provided at the edge of the positioning plate 7. Multiple first notches 7a can be provided. In this embodiment, four first notches 7a are provided, corresponding to the four directions of the high pressure opening 13 and the low pressure groove 14 of the valve core 5. A positioning sensor 6 for detecting the first notch is provided on the side of the positioning plate 7 at the same axial position as the regenerator channel 3 of the valve core 5.

[0040] When the first notch 7a of the positioning plate is not aligned with the positioning sensor 6, the positioning plate blocks the light source and the light-receiving element outputs a signal "0"; when the first notch rotates to the detection position of the positioning sensor 6, the light passes through the notch and is received by the light-receiving element, and the output signal "1" is generated. At this time, the gas channel of the valve core 5 is connected to the chassis regenerator channel 3.

[0041] like Figure 5b , 5cAs shown, the position of the first sensor 8a is opposite to that of the positioning sensor 6, and the first sensor 8b is located at a 90° position adjacent to the first sensor 8a. The first sensor 8a and the first sensor 8b are perpendicular to each other. There are two second notches 10a on the detection plate 10, and the two second notches 10a are distributed perpendicularly to each other, corresponding to the first sensor 8a and the first sensor 8b respectively. When the rotor is positioned at the four positions where the positioning sensor 6 detects the first notch, the combination of the detection signals (signals "0" or "1") of each sensor is different.

[0042] The system processes the sensor output signals using binary encoding: when a notch is detected, the output signal is recorded as logic "1"; when no notch is detected, the output signal is recorded as logic "0". Therefore, when the system is configured with n sensors, the combination of the detection signals from each sensor can form a 2... n Two different encoding modes, each corresponding to a specific absolute position of the rotor, thus achieving 2 n Precise detection of each location.

[0043] like Figure 6 The data shows the combination modes of the detection signals of each sensor and the corresponding signal mode data of the connection status of the high and low pressure vents and the regenerator channel 3 in each mode.

[0044] like Figure 7 As shown, this flowchart describes the rotor position detection and adjustment process. First, the target position of the rotor (the sequence number of the output port connected to the input port) is determined; then, the current position is detected through a combination of sensor signals; if the current position is inconsistent with the target position, the stepper motor 12 is driven until the positioning sensor 6 detects the first notch of the positioning plate 7; when the positioning sensor 6 detects the first notch, the current position of the rotor is detected based on the signals from the first sensor 8a and the first sensor 8b at this time, and it is confirmed whether the current position is consistent with the target position; this action is repeated, and if the current position of the rotor is consistent with the target position, the rotor positioning ends.

[0045] In summary, this invention utilizes a pulse-modulated stepper motor 12 with fully adjustable speed, enabling rapid full-opening / full-closing of the gas distribution valve, increasing the average opening degree of the valve, and freely adjusting the intake and exhaust timing parameters to achieve optimal gas distribution timing control, thereby reducing losses in the gas distribution system and improving the overall efficiency of the refrigeration unit. The rotor position detection device employs multiple ordinary optical sensors to detect the notch state of the position detection plate 10, and determines the absolute position of the rotor through binary signal combination, achieving low-cost and high-reliability rotor position detection, significantly reducing system cost and structural complexity compared to traditional absolute encoders.

[0046] Therefore, the utility model effectively overcomes various shortcomings in prior art and has high industrial utilization value.

[0047] The above embodiment only exemplarily illustrates the principle and effect of the utility model, and is not used for limiting the utility model. Any person skilled in the art can modify or change the above embodiment without departing from the spirit and category of the utility model. Therefore, all equivalent modifications or changes completed by those skilled in the art without departing from the spirit and technical thought disclosed by the utility model should be covered by the claims of the utility model.

Claims

1. An adjustable timing gas distribution valve, characterized by, The valve body, the bottom plate arranged in the valve body, the regenerator channel arranged on the bottom plate and communicated with the compressor, the valve core rotatably connected in the valve body and capable of controlling the inlet state of the regenerator channel, the detection system capable of detecting the rotation position of the valve core by optical positioning arranged in the valve body; the detection system comprises a positioning plate arranged on the valve core and capable of rotating with the valve core, a detection plate coaxially arranged with the positioning plate, and an optical sensor group arranged on the inner wall of the valve body and capable of detecting the positioning plate and the detection plate respectively, and the positioning plate and the detection plate both have a notch part for the detection of the optical sensor group.

2. The adjustable timing gas distribution valve of claim 1, wherein: The positioning plate is provided with a first notch part for positioning of the optical sensor group, and the detection plate is provided with a second notch part for positioning of the optical sensor group.

3. The adjustable timing gas distribution valve of claim 1, wherein: The optical sensor group comprises a positioning sensor, a first sensor and a second sensor arranged in the axial direction of the rotation axis, the first sensor is arranged opposite to the positioning sensor, the first sensor and the second sensor are located in the same horizontal plane and are distributed around the axis of the detection plate.

4. The adjustable timing gas distribution valve of claim 2, wherein: The valve core is provided with a high-pressure opening communicated with the regenerator channel for high-pressure inlet and a low-pressure groove arranged beside the high-pressure opening for low-pressure exhaust.

5. The adjustable timing gas distribution valve of claim 2, wherein: The first notch part is provided with a plurality of first notch parts, and the first notch parts are distributed corresponding to the direction of the high-pressure opening and the low-pressure groove of the valve core, the first notch part is used for positioning sensor identification, and the second notch part is provided with two second notch parts around the axis of the detection plate, which are used for first sensor and second sensor identification respectively.

6. The adjustable timing gas distribution valve of claim 1, wherein: The valve body is provided with a driving member for driving the rotation of the valve core, the valve core is provided with a rotation shaft connected with the driving member, the positioning plate and the detection plate are both mounted on the rotation shaft, and the detection plate is located above the positioning plate.

7. The adjustable timing gas distribution valve of claim 4, wherein: The low-pressure groove is provided with one and located at the center of the valve core, and the high-pressure opening is provided with two and arranged on both sides of the low-pressure groove.

8. The adjustable timing gas distribution valve of claim 5, wherein: The first notch part is provided with four first notch parts, and the four first notch parts are uniformly arranged around the axis of the rotation shaft, the two second notch parts are perpendicular to each other, and the first sensor and the second sensor are perpendicular to each other.

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