Linear compressor piston top dead center detection device, linear compressor and refrigerating system

Abstract

The utility model relates to the technical field of mechanical automation control, and provides a linear compressor piston top dead center detection device, a linear compressor and a refrigeration system.The detection device comprises a Hall coil, a controller and conductor metal, and the Hall coil is arranged on an inner stator of the linear compressor; the conductor metal is positioned in a sine alternating magnetic field generated by the Hall coil; the controller comprises an LC oscillating circuit, a conversion measuring circuit and a compressor driving circuit which are connected in sequence, and the Hall coil forms an inductance element of the LC oscillating circuit. According to the device for detecting the top dead center of the piston of the linear compressor, the top dead center of the piston of the linear compressor is accurately detected and controlled by utilizing electromagnetic coupling between a sine alternating magnetic field generated by the Hall coil and an eddy current magnetic field generated on the conductor metal, so that the interference of piston offset on the detection of the top dead center is eliminated; the cylinder collision phenomenon of the linear compressor is prevented, the working reliability and the operation efficiency of the compressor are improved, and stable and efficient operation of the linear compressor is guaranteed.

Description

TECHNICAL FIELD

[0001] The utility model relates to mechanical automation control technical field especially, relates to a linear compressor piston top dead center detection device, linear compressor and refrigeration system. BACKGROUND

[0002] Linear compressor retains the high advantage of piston compressor volume efficiency, and the mechanical drive mechanism is saved, mechanical efficiency is high, simple structure, strong reliability, can be widely applied to low temperature, refrigeration and heat pump system. Linear compressor adopts free piston structure, and piston displacement is easily affected by external working condition, when the compressor is under different suction and discharge pressure, piston offset changes, causes the stroke required for piston to reach top dead center position to change, and the movement center position of piston in high pressure ratio system is more obvious. Through circuit balance equation And dynamics balance equation Solve piston stroke, and then carry out top dead center position detection and control, and the movement center offset will cause inaccurate top dead center control, and the nonlinearity of linear motor characteristic parameter also brings the error of piston stroke calculation, brings great challenge to compressor top dead center judgment and control, and cylinder collision phenomenon is easy to occur, especially under the sudden change working condition of compressor operation suction and discharge pressure, cylinder collision phenomenon is easy to occur.

[0003] In the prior art, the inflection point of the phase difference between the current and the piston displacement is used to judge the top dead center position caused by the interference of working condition change, and the inaccurate top dead center detection of the compressor also causes the cylinder collision phenomenon. The traditional method of detecting piston stroke of linear compressor by relying on displacement sensor generally has the problems of high cost, complex installation and poor adaptability to harsh working environment (such as high temperature, high vibration and strong electromagnetic interference). In addition, the sensor is large in size, which is difficult to meet the demand of miniaturization and integration of linear compressor, thereby limiting its wide application. UTILITY MODEL CONTENTS

[0004] The utility model provides a linear compressor piston top dead center detection device to solve the defects of inaccurate linear compressor top dead center control and easy cylinder collision in the prior art, realize improving the accuracy of linear compressor top dead center detection, reduce the manufacturing cost of linear compressor, and promote the application of linear compressor in low temperature, refrigeration and heat pump system.

[0005] The utility model also provides a linear compressor piston top dead center detection device, which comprises:

[0006] The Hall coil is arranged on the inner stator of the linear compressor, the conductor metal is located in the sinusoidal alternating magnetic field generated by the Hall coil, the controller comprises LC oscillation circuit, conversion measurement circuit and compressor driving circuit connected in sequence, the Hall coil constitutes the inductance element of the LC oscillation circuit, and the controller further comprises a control circuit, and the conversion measurement circuit and the compressor driving circuit are connected with the control circuit.

[0007] According to the linear compressor piston top dead point detection device, the Hall coil is arranged on the stator of the linear compressor on the side close to the exhaust valve, and the conductor metal is arranged on the piston on the side close to the exhaust valve corresponding to the Hall coil.

[0008] According to the linear compressor piston top dead point detection device, the Hall coil is arranged on the stator of the linear compressor on the side close to the exhaust valve, and the conductor metal is arranged on the piston on the side close to the exhaust valve corresponding to the Hall coil.

[0009] According to the linear compressor piston top dead point detection device, the Hall coil comprises a hollow cylindrical shape wound by metal wires, and the metal wires are wound at least two turns along the axial direction of the hollow cylindrical shape.

[0010] According to the linear compressor piston top dead point detection device, the Hall coil comprises a hollow cylindrical shape wound by metal wires, and the metal wires are wound at least two turns along the axial direction of the hollow cylindrical shape.

[0011] According to the linear compressor piston top dead point detection device, the Hall coil comprises a hollow cylindrical shape wound by metal wires, and the metal wires are wound at least two turns along the axial direction of the hollow cylindrical shape.

[0012] According to the linear compressor piston top dead point detection device, the Hall coil comprises a hollow cylindrical shape wound by metal wires, and the metal wires are wound at least two turns along the axial direction of the hollow cylindrical shape.

[0013] The utility model also provides a linear compressor, including the linear compressor piston top dead point detection device as described above.

[0014] The utility model also provides a refrigeration system, including evaporimeter, throttle valve, condenser, linear compressor and temperature sensor as described above, the temperature sensor is used for detecting the temperature of evaporimeter outlet, and the temperature sensor is connected with the controller of linear compressor.

[0015] The linear compressor piston upper dead point detection device provided by the utility model, through the Hall coil is built-in in the linear compressor, utilizes the electromagnetic coupling between the sinusoidal alternating magnetic field generated by the Hall coil and the electric eddy current magnetic field generated on the conductor metal, realizes accurate detection and control on the linear compressor piston upper dead point, eliminates the piston offset interference on the upper dead point detection, prevents the cylinder collision phenomenon of the linear compressor, improves the working reliability and compressor operation efficiency, and guarantees the stable and efficient operation of the linear compressor.

[0016] Meanwhile, the utility model discloses a linear compressor piston position is converted into the frequency variation of LC circuit of Hall coil, finally is converted into voltage signal, cancels the sensor component, and the Hall coil volume is small, and the power consumption is low, and the conversion measurement circuit is integrated into the compressor controller, simplifies the linear compressor structure, is favorable to realize the miniaturization integration of linear compressor, reduces the manufacturing difficulty and cost of linear compressor, and improves the overall reliability. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical scheme in the utility model or prior art, the following will be to the embodiment or prior art description needed to use the drawing a simple introduction, obviously, the following description in the drawing is some embodiments of the utility model, for those skilled in the art, without creative labor, according to these drawings, other drawings can also be obtained.

[0018] Figure 1 It is the electromagnetic field simplified schematic diagram of Hall coil and piston provided by the utility model.

[0019] Figure 2 It is the equivalent circuit diagram of Hall coil and piston provided by the utility model.

[0020] Figure 3 It is the overall structure diagram of the embodiment of the utility model on Medis type linear motor.

[0021] Figure 4 It is the overall structure diagram of the embodiment of the utility model on Redlich type linear motor.

[0022] Figure 5 It is the installation structure schematic diagram of Hall coil provided by the embodiment of the utility model.

[0023] Figure 6 It is the measurement circuit diagram of the embodiment of the utility model.

[0024] Figure 7 It is the structure schematic diagram of offline calibration system provided by the utility model.

[0025] Figure 8Is the curve schematic diagram of the offline calibration system provided by the utility model.

[0026] Figure 9 Is the linear compressor refrigeration system schematic diagram of the utility model embodiment.

[0027] Reference signs:

[0028] 1, hall coil;2, controller;21, LC oscillation circuit;22, conversion measurement circuit;23, compressor drive circuit;24, control circuit;3, inner stator;4, conductor metal;5, cylinder;6, terminal;7, horizontal holder;8, laser displacement sensor;9, display;10, mover;100, compressor;200, evaporator;300, temperature sensor;400, condenser;500, throttle valve. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and advantage of the utility model more clear, below, combining with the drawing in the utility model, the technical scheme in the utility model is clearly and completely described, obviously, the described embodiment is a part of the embodiment of the utility model, rather than all the embodiment. Based on the embodiment in the utility model, all other embodiments obtained by the person skilled in the art without making creative labor belong to the scope of protection of the utility model.

[0030] In the description of the utility model embodiment, it needs to be explained that the orientation or position relation indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is the orientation or position relation shown in the drawing, and is only for the convenience of describing the utility model embodiment and simplifying the description, and cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, a particular orientation and operation, therefore, cannot be understood as the limitation of the utility model embodiment. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0031] Below, combining with the drawing in the utility model, the technical scheme in the utility model is clearly and completely described. Figures 1-6 The utility model discloses a linear compressor piston top dead center detection device.

[0032] As Figure 1The utility model discloses an upper dead point detection device of linear compressor piston provides, including hall coil 1, controller 2 and conductor metal 4, hall coil 1 sets up on the inner stator 3 of linear compressor, conductor metal 4 is located in the sinusoidal alternating magnetic field of hall coil 1 generation, controller 2 includes the LC oscillation circuit 21 of connection in proper order, conversion measurement circuit 22 and compressor drive circuit 23, and hall coil 1 constitutes the inductance element of LC oscillation circuit 21, controller 2 still includes control circuit 24, and conversion measurement circuit 22 and compressor drive circuit 23 are connected with control circuit 24.

[0033] As Figure 1 And Figure 2 The utility model provides a detection device, through being built -in hall coil 1 in linear compressor, utilize the electromagnetic coupling between the sinusoidal alternating magnetic field of coil generation and the electric eddy current magnetic field of conductor metal 4 generation, realize accurate detection and control to linear compressor piston upper dead point, prevent linear compressor from happening to knock cylinder phenomenon, improve work reliability and compressor operating efficiency, guarantee the stable high -efficient operation of linear compressor.

[0034] As Figure 3 In a feasible embodiment of the utility model, the hall coil 1 is arranged on the stator of the linear compressor on the side close to the exhaust valve, and the conductor metal 4 is arranged on the piston mover on the side close to the exhaust valve corresponding to the hall coil.

[0035] As Figure 4 In a feasible embodiment of the utility model, the hall coil 1 is arranged on the stator of the linear compressor on the side away from the exhaust valve, and the conductor metal 4 is arranged on the piston mover on the side away from the exhaust valve corresponding to the hall coil.

[0036] As Figure 5 That is, the hall coil 1 is attached to the end face of the inner stator 3 close to the conductor metal 4, the energized wire is connected to the terminal 6 by punching on the inner stator 3 and the cylinder 5, and then connected to the controller 2.

[0037] According to the Faraday electromagnetic induction law, the hall coil 1 is supplied with high-frequency sinusoidal alternating current, a sinusoidal alternating magnetic field is generated around, the conductor metal 4 located in the alternating magnetic field generates induced current, and the induced current generates a new alternating magnetic field that hinders the change of the original magnetic field. Through the electromagnetic coupling between the hall coil 1 and the conductor metal 4, the equivalent impedance and the equivalent inductance of the hall coil 1 change. The conductor metal 4 reciprocates in the cylinder 5, the distance between the conductor metal 4 and the hall coil 1 changes, and the change amount of the equivalent impedance and the equivalent inductance of the hall coil 1 changes. When the piston reaches the upper dead point position, the change amount reaches the maximum value.

[0038] As Figure 6As shown, the Hall coil 1 is used as the inductance element of the LC oscillation circuit 21, the equivalent inductance of the Hall coil 1 is changed due to the eddy current effect, the oscillation frequency of the LC oscillation circuit 21 is changed, the corresponding voltage is read by the conversion measurement circuit 22, and the piston stroke of the linear compressor is detected by comparing the voltage with the calibration value.

[0039] In a feasible embodiment of the utility model, the Hall coil 1 includes hollow cylindrical shape winding by metal wire, and the metal wire is at least wound two turns along the hollow cylindrical shape axial direction.

[0040] In a feasible embodiment of the utility model, the Hall coil 1 includes hollow cylindrical shape winding by metal wire, and the metal wire is at least wound two turns along the hollow cylindrical shape axial direction.

[0041] Therefore, the linear compressor piston top dead center detection device provided by the utility model can realize accurate detection of the top dead center position when the linear compressor produces piston deviation under large pressure difference, eliminates the interference of piston deviation on top dead center detection, prevents piston cylinder collision, improves the adaptability and reliability of linear compressor top dead center control, and simplifies the structure of linear compressor by converting the piston position of linear compressor into the frequency change of LC circuit composed of Hall coil and finally into voltage signal, reduces the manufacturing difficulty and cost of linear compressor and improves the overall reliability.

[0042] The linear compressor piston top dead center detection device provided by the utility model will be described below, and the linear compressor piston top dead center detection device described below can be correspondingly referred to the linear compressor top dead center detection control method described above.

[0043] As shown in the figure, Figure 7 As shown, the offline calibration system includes a horizontal holder 7, a laser displacement sensor 8 and a display 9, the laser displacement sensor 8 is arranged on the horizontal holder 7, and the display 9 is connected with the laser displacement sensor 8, in the offline calibration process, the horizontal holder 7 is adjusted to keep the laser displacement sensor 8 perpendicular to the end face of the conductor piston 4, the linear compressor is started, the voltage is gradually increased to make the compressor run to the top dead center, and the voltage value read by the measurement circuit at this moment is recorded, and the result is shown in the figure. Figure 8 As shown in the figure,

[0044] The control method of the linear compressor piston top dead center detection device provided by the utility model includes:

[0045] Step S1, calibrate the corresponding relationship between the Hall coil output voltage and the distance of the piston from the top dead center.

[0046] In step S1, the output voltage of the Hall coil has a certain relationship with the position of the piston away from the top dead center. In order to accurately detect the position of the piston, the relationship needs to be calibrated first. In the calibration process, the output voltage of the Hall coil at different piston positions may be measured, and the data is recorded.

[0047] In step S2, a high-frequency sinusoidal alternating voltage is applied to the Hall coil. When the distance between the Hall coil and the mover conductor changes, the oscillation frequency of the LC oscillation circuit formed by the Hall coil changes. The frequency signal is converted into a voltage signal by a frequency-voltage conversion and detection circuit, and the real-time output voltage of the Hall coil is read.

[0048] In step S2, according to Faraday's law of electromagnetic induction, a high-frequency sinusoidal alternating voltage is applied to the Hall coil, and a sinusoidal alternating magnetic field is generated around the coil. The conductor piston located in the alternating magnetic field generates an induced current, which in turn generates a new alternating magnetic field that hinders the change of the original magnetic field.

[0049] The change in the oscillation frequency of the LC oscillation circuit is converted into a frequency signal, and the real-time output voltage of the Hall coil can be read by a frequency-voltage conversion and detection circuit. The real-time output voltage reflects the current position information of the piston.

[0050] In step S3, the real-time output voltage of the Hall coil is compared with the corresponding relationship between the output voltage of the Hall coil and the distance of the piston away from the top dead center, and the linear compressor is controlled to operate at the top dead center.

[0051] In step S3, the real-time output voltage of the Hall coil is compared with the corresponding relationship between the output voltage of the Hall coil and the distance of the piston away from the top dead center, and the linear compressor is controlled to operate at the top dead center.

[0052] In step S4, according to the load feedback, the output electrical parameters of the linear compressor drive circuit are adjusted to keep the real-time output voltage of the Hall coil less than the corresponding voltage of the piston top dead center calibrated by the control chip, and the capacity adjustment is performed to realize the stable load at the set target and ensure the compressor operation without cylinder collision.

[0053] In step S4, the compressor continuously receives load feedback signals during operation. According to these load feedback signals, the output electrical parameters of the compressor drive circuit are adjusted to adjust the capacity of the compressor. The purpose of the adjustment is to keep the real-time output voltage of the Hall coil less than the corresponding voltage of the piston top dead center calibrated by the control chip, so as to avoid the compressor from appearing cylinder collision and other failures.

[0054] More specifically, in step S1, calibrating the corresponding relationship between the output voltage of the Hall coil and the distance of the piston away from the top dead center comprises:

[0055] S11, install the Hall coil to the linear compressor, start the compressor to run in no-load.

[0056] In step S11, the linear compressor does not compress the gas, and only runs the linear compressor.

[0057] S12, after the Hall coil is applied with a high-frequency sinusoidal alternating voltage, the oscillation frequency of the LC oscillator formed by the Hall coil changes.

[0058] S13, the output voltage of the Hall coil is measured through the conversion measurement circuit, and the distance of the piston end from the top dead center position is measured through the displacement sensor.

[0059] S14, the corresponding relationship between the output voltage of the Hall coil and the distance of the piston from the top dead center position when the linear compressor does not compress the gas is obtained.

[0060] The second aspect embodiment of the utility model provides a linear compressor, because including linear compressor piston top dead center detection device as described above, therefore possess various advantages as described above.

[0061] As Figure 9 The utility model discloses third aspect embodiment provides linear compressor refrigeration system, including evaporimeter 200, throttling valve 500, condenser 400, linear compressor 100 and temperature sensor 300 as described above, temperature sensor 300 is used to detect the temperature of evaporimeter 200 export, and temperature sensor 300 is connected with the controller 2 of linear compressor 100,

[0062] The refrigeration system provided by the utility model increases temperature feedback control on the basis of basic refrigeration cycle, when target temperature is determined, the compressor runs first full stroke, when temperature reaches target temperature or refrigeration capacity is not high, starts variable capacity operation.

[0063] In the description of the embodiment of the utility model, it should be explained that, unless another explicit provision and limitation, the term "connected", "connection" should be broad sense understanding, for example, can be fixed connection, also can be detachable connection, or integral connection, can be mechanical connection, also can be electrical connection, can be directly connected, also can be indirectly connected through intermediate medium.

[0064] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "aspects", "specific aspects", or "some aspects" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or aspect are included in at least one embodiment or aspect of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or aspect. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or aspects. In addition, those skilled in the art can combine and combine the features of different embodiments or aspects described in the present application and the characteristics of different embodiments or aspects without contradiction.

[0065] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solution deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A device for detecting the top dead center of a linear compressor piston, characterized in that, include: The system comprises a Hall coil (1), a controller (2), and a conductor metal (4). The Hall coil (1) is mounted on the inner stator (3) of the linear compressor. The conductor metal (4) is located within the sinusoidal alternating magnetic field generated by the Hall coil (1). The controller (2) includes an LC oscillation circuit (21), a transformation measurement circuit (22), and a compressor drive circuit (23) connected in sequence. The Hall coil (1) constitutes the inductor of the LC oscillation circuit (21). The controller (2) also includes a control circuit (24), and the transformation measurement circuit (22) and the compressor drive circuit (23) are both connected to the control circuit (24).

2. The linear compressor piston top dead center detection device according to claim 1, characterized in that, The Hall coil (1) is arranged on the stator of the linear compressor on the side near the exhaust valve, and the conductor metal (4) is disposed on the piston on the side of the corresponding Hall coil near the exhaust valve.

3. The linear compressor piston top dead center detection device according to claim 1, characterized in that, The Hall coil (1) is arranged on the stator of the linear compressor on the side away from the exhaust valve, and the conductor metal (4) is disposed on the piston on the side of the corresponding Hall coil away from the exhaust valve.

4. The linear compressor piston top dead center detection device according to claim 1, characterized in that, The Hall coil (1) comprises a hollow cylinder wound with metal wire, and the metal wire is wound at least two turns along the axial direction of the hollow cylinder.

5. The linear compressor piston top dead center detection device according to claim 1, characterized in that, The Hall coil (1) comprises a hollow cylinder wound with metal wire, and a cylindrical magnetic core is axially arranged inside the hollow cylinder. The metal wire is wound at least two turns along the axial direction of the cylindrical magnetic core.

6. The linear compressor piston top dead center detection device according to claim 2, characterized in that, It also includes an offline calibration system, including a horizontal gimbal (7), a laser displacement sensor (8) and a display (9). The laser displacement sensor (8) is mounted on the horizontal gimbal (7), the display (9) is connected to the laser displacement sensor (8), and the laser displacement sensor (8) is perpendicular to the end face of the conductor metal (4).

7. The linear compressor piston top dead center detection device according to claim 1, characterized in that, It also includes a terminal block (6), and through holes are provided on the inner stator (3) and the cylinder (5). One end of the energized wire is connected to the Hall coil (1), and the other end is connected to the terminal block (6).

8. The linear compressor piston top dead center detection device according to claim 1, characterized in that, The high-frequency sinusoidal AC voltage supplied to the Hall coil (1) is low-voltage AC.

9. A linear compressor, characterized in that, Includes the linear compressor piston top dead center detection device as described in any one of claims 1-8.

10. A refrigeration system, characterized in that, The device includes an evaporator (200), a throttle valve (500), a condenser (400), a linear compressor (100) as described in claim 9, and a temperature sensor (300), the temperature sensor (300) being used to detect the temperature at the outlet of the evaporator (200), and the temperature sensor (300) being connected to the controller (2) of the linear compressor (100).

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