KR20190000590A - Refrigerator and method for controlling a linear compressor - Google Patents

Abstract

According to the present invention, a control method of a linear compressor comprises the following steps of: determining an initial operation stroke included in one stroke section selected among a plurality of stroke sections based on an indoor temperature and a predetermined temperature input through an input unit; operating linear compressor by the initial operation stroke; and varying an operation stroke in the selected stroke section in accordance with a change in the indoor temperature, sensed while the linear compressor is operated.

Description

[0001] The present invention relates to a refrigerator and a linear compressor,

The present invention relates to a control method of a refrigerator and a linear compressor.

The cooling system is a system that generates cool air by circulating a coolant, and repeats the process of compressing, condensing, expanding, and evaporating the coolant. To this end, the cooling system includes a compressor, a condenser, an expansion device and an evaporator. The cooling system may be installed in a refrigerator or an air conditioner as a household appliance.

Generally, a compressor is a mechanical device that receives power from a power generating device such as an electric motor or a turbine to increase pressure by compressing air, refrigerant or various other operating gases. .

Such a compressor is broadly classified into a reciprocating compressor that compresses the refrigerant while linearly reciprocating the piston inside the cylinder so as to form a compression space in which a working gas is sucked and discharged between the piston and the cylinder. A rotary compressor for compressing the refrigerant while the roller is eccentrically rotated along the inner wall of the cylinder and a compression space for sucking and discharging the working gas between the roller and the cylinder, a scroll compressor in which a compression space in which an operating gas is sucked and discharged is formed between a fixed scroll and a fixed scroll and the orbiting scroll rotates along the fixed scroll to compress the refrigerant.

In recent years, among the reciprocating compressors, there has been developed a linear compressor in which a piston is directly connected to a driving motor that reciprocates linearly, so that compression efficiency can be improved without mechanical loss due to motion switching and a simple structure is constructed.

Normally, the linear compressor is configured to suck and compress the refrigerant while discharging the refrigerant while moving the piston in the sealed shell by reciprocating linear motion within the cylinder by the linear motor.

Korean Patent Laid-Open Publication No. 10-2006-0074966, which is a prior art document, discloses a control method of a linear compressor.

A control method of a linear compressor disclosed in the prior art discloses a technique of varying the stroke of an actual piston according to a load.

However, in the linear compressor to which the control method is applied, oil is contained in the bottom surface of the closed container, and oil can be supplied between the piston and the cylinder by the oil supply device that pumps the oil.

The oil supply device is operated by the vibration generated in accordance with the reciprocating linear motion of the piston to pump the oil.

However, in the case of a linear compressor in which oil is pumped and lubricated as in the prior art, when the stroke of the piston is varied according to the load, the amount of pumping oil is reduced when the stroke is reduced.

At this time, when the stroke of the piston is lowered to a certain stroke or less according to the load, lubrication reliability is not ensured. Therefore, even if the stroke determined according to the load is lower than the minimum stroke, There is a problem that the effect of saving is small.

An object of the present invention is to provide a control method of a linear compressor in which an operation region can be increased by lubricating a piston using a refrigerant gas.

It is another object of the present invention to provide a control method of a linear compressor in which power consumption can be reduced because there is no restriction on the minimum stroke for ensuring lubrication reliability.

According to another aspect of the present invention, there is provided a method of controlling a linear compressor, including the steps of: determining an initial operation stroke belonging to a stroke section selected from a plurality of stroke sections based on a room temperature and a target temperature inputted through an input section ; Operating the linear compressor with the initial operation stroke; And varying a driving stroke in the selected one-stroke section in accordance with a change in the sensed room temperature during operation of the linear compressor.

For example, the linear compressor is a compressor that uses a refrigerant gas for lubrication of a piston without using oil for lubrication.

Even if the operating stroke determined by the room temperature sensed in the state in which the target temperature is not changed is out of the selected one stroke section during the operation of the linear compressor in one operating stroke of the selected one stroke section, It is possible to operate with a driving stroke within a selected one stroke section.

For example, when the operating stroke determined by the room temperature sensed in the state where the target temperature is not changed is out of the selected one stroke section during the operation of the linear compressor during one operating stroke of the selected one stroke section, The linear compressor can be operated with the lowest stroke or the maximum stroke of the selected one stroke section.

For example, when the operating stroke determined by the sensed room temperature deviates from the selected one stroke period during the operation of the linear compressor with the operating stroke within the selected one-stroke interval, the linear compressor calculates the operating stroke Lt; / RTI >

The operation stroke determined by the sensed room temperature is lower than the first minimum stroke of the first stroke section in the course of operating the linear compressor in one operation stroke within the first stroke section having the smallest stroke value among the plurality of stroke sections In a small case, the linear compressor can operate at the first lowest stroke.

According to another aspect, a refrigerator includes a cabinet forming a storage compartment; A door that opens and closes the storage room; A linear compressor provided in the cabinet; A temperature sensor provided in the cabinet or the door, for detecting the room temperature; An input unit provided in the door or the cabinet for inputting a target temperature of the storage chamber; And a compressor control unit for controlling the linear compressor, wherein the compressor control unit controls the linear compressor based on at least one stroke selected from a plurality of stroke intervals, based on a room temperature sensed by the temperature sensor and a target temperature input through the input unit, Wherein the linear compressor is operated at a determined initial operating stroke, and in accordance with a change in the sensed room temperature during operation of the linear compressor, the operating stroke of the linear compressor at the selected one- .

According to the proposed invention, since the linear compressor uses the gas bearing without pumping the oil, it is possible to set a plurality of minimum strokes and set one of the minimum strokes of the plurality of minimum strokes according to the room temperature and the target temperature, The operation area can be increased, and the power consumption can be reduced.

1 is an external perspective view showing a configuration of a linear compressor according to an embodiment of the present invention;
2 is an exploded perspective view of a shell and a shell cover of a linear compressor according to an embodiment of the present invention;
3 is an exploded perspective view of internal components of a linear compressor according to an embodiment of the present invention.
4 is a cross-sectional view taken along line I-I 'of FIG.
5 is a block diagram of a refrigerator including a linear compressor according to an embodiment of the present invention.
6 is a flowchart illustrating a method of controlling a linear compressor according to an embodiment of the present invention.
7 is a flowchart for explaining a specific method for varying a driving stroke.
FIG. 8 is a view showing a comparison between a conventional stroke and a stroke according to the present invention; FIG.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference symbols as possible even if they are shown in different drawings. In the following description of the embodiments of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the difference that the embodiments of the present invention are not conclusive.

In describing the components of the embodiment of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected or connected to the other component, Quot; may be "connected," "coupled," or "connected. &Quot;

2 is an exploded perspective view of a shell and a shell cover of a linear compressor according to an embodiment of the present invention. FIG. 3 is a cross-sectional view of an embodiment of the present invention, Fig. 4 is a cross-sectional view taken along line I-I 'of Fig. 1. Fig.

1 to 4, a linear compressor 10 according to an embodiment of the present invention may include a shell 101 and a shell cover 102, 103 coupled to the shell 101. In a broad sense, the shell covers 102 and 103 can be understood as one configuration of the shell 101. [

On the lower side of the shell 101, the legs 50 can be engaged. The legs 50 may be coupled to the base of the product on which the linear compressor 10 is installed. For example, the article may include a refrigerator, and the base may include a machine room base of the refrigerator. As another example, the product may include an outdoor unit of the air conditioner, and the base may include a base of the outdoor unit.

The shell 101 has a substantially cylindrical shape, and may be disposed to lie in the lateral direction or to lie in the axial direction. 1, the shell 101 may be elongated in the transverse direction and may have a somewhat lower height in the radial direction. That is, since the linear compressor 10 can have a low height, when the linear compressor 10 is installed in the machine room base of the refrigerator, the height of the machine room can be reduced.

A terminal 108 may be provided on the outer surface of the shell 101. The terminal 108 may deliver external power to the motor 140 (see FIG. 3) of the linear compressor 10. The terminal 108 may be connected to the lead of the coil 141c (see FIG. 3).

On the outside of the terminal 108, a bracket 109 is provided. The bracket 109 may include a plurality of brackets surrounding the terminal 108. The bracket 109 may function to protect the terminal 108 from an external impact or the like.

Both sides of the shell 101 are configured to be open. On both sides of the opened shell 101, the shell covers 102 and 103 can be coupled. In detail, the shell covers 102 and 103 include a first shell cover 102 coupled to one side of the shell 101 that is opened, and a second shell cover 102 coupled to the other side of the shell 101, (103). By the shell covers 102 and 103, the inner space of the shell 101 can be sealed.

1, the first shell cover 102 is located on the right side of the linear compressor 10 and the second shell cover 103 is located on the left side of the linear compressor 10 . In other words, the first and second shell covers 102 and 103 may be disposed to face each other.

The linear compressor 10 may further include a plurality of pipes 104 and 105 provided in the shell 101 or the shell covers 102 and 103 to suck and discharge the refrigerant.

The plurality of pipes 104 and 105 includes a suction pipe 104 for allowing refrigerant to be sucked into the linear compressor 10 and a discharge pipe 105 for discharging the compressed refrigerant from the linear compressor 10 ).

For example, the suction pipe 104 may be coupled to the first shell cover 102. The refrigerant can be sucked into the linear compressor (10) along the axial direction through the suction pipe (104). Of course, it is also possible that the suction pipe 104 is coupled to the shell 101 at a position adjacent to the first shell cover 102.

The discharge pipe 105 may be coupled to the shell 101. The refrigerant sucked through the suction pipe 104 can be compressed while flowing in the axial direction. The compressed refrigerant can be discharged through the discharge pipe 105.

The linear compressor 10 includes a compressor main body 100 and a plurality of support devices 200 and 300 for supporting the compressor main body 100 against at least one of the shell 101 and the shell covers 102 and 103 ).

The compressor main body 100 includes a cylinder 120 provided in the shell 101, a piston 130 linearly reciprocating in the cylinder 120, and a driving force And a motor 140 for driving the motor. When the motor 140 is driven, the piston 130 can reciprocate in the axial direction.

The compressor main body 100 may further include a suction muffler 150 coupled to the piston 130 for reducing noise generated from the refrigerant sucked through the suction pipe 104.

The refrigerant sucked through the suction pipe 104 flows into the piston 130 through the suction muffler 150. For example, in the course of the refrigerant passing through the suction muffler 150, the flow noise of the refrigerant can be reduced.

Define the direction.

The term "axial direction" can be understood as a direction in which the piston 130 reciprocates, that is, a lateral direction in FIG. Of these "axial directions", the direction from the suction pipe 104 toward the compression space P, that is, the direction in which the refrigerant flows is referred to as "forward" and the opposite direction is defined as "rearward".

On the other hand, the term "radial direction" can be understood as a direction perpendicular to the direction in which the piston 130 reciprocates and in the longitudinal direction of Fig.

The axis of the compressor main body means the axial center line of the piston 130. [

The piston 130 may include a piston body 131 formed in a substantially cylindrical shape and a piston flange portion 132 extending in a radial direction from the piston body 131. The piston body 131 reciprocates within the cylinder 120 and the piston flange 132 can reciprocate outside the cylinder 120.

The cylinder 120 may receive at least a portion of the first muffler 151 and at least a portion of the piston body 131.

A compression space P in which the refrigerant is compressed by the piston 130 is formed in the cylinder 120. A suction hole 133 for introducing a refrigerant into the compression space P is formed in a front portion of the piston body 131. A suction hole 133 is formed in front of the suction hole 133, A suction valve 135 is provided. At a substantially central portion of the suction valve 135, a fastening hole to which a predetermined fastening member is coupled is formed.

A discharge cover 160 which forms a discharge space 160a of the refrigerant discharged from the compression space P and a discharge cover 160 which is coupled to the discharge cover 160 and is disposed in front of the compression space P, There is provided a discharge valve assembly 161, 163 for selectively discharging the compressed refrigerant. The discharge space 160a may include a plurality of spaces defined by inner walls of the discharge cover 160. [ The plurality of space portions are arranged in the front-rear direction and can communicate with each other.

The discharge valve assemblies 161 and 163 are provided with a discharge valve 161 that opens when the pressure in the compression space P becomes equal to or higher than the discharge pressure and causes the refrigerant to flow into the discharge space of the discharge cover 160, And a spring assembly 163 provided between the discharge cover 161 and the discharge cover 160 to provide an elastic force in the axial direction.

The discharge valve 161 is coupled to the spring assembly 163 and the rear portion or rear surface of the discharge valve 161 is positioned to be capable of supporting the front surface of the cylinder 120. When the discharge valve 161 is supported on the front surface of the cylinder 120, the compression space P is maintained in a closed state. When the discharge valve 161 is separated from the front surface of the cylinder 120, The space P is opened so that the compressed refrigerant in the compression space P can be discharged.

The compression space (P) is a space formed between the suction valve (135) and the discharge valve (161). The suction valve 135 is provided at one side of the compression space P and the discharge valve 161 can be provided at the other side of the compression space P, have.

When the pressure in the compression space P becomes lower than the discharge pressure and becomes lower than the suction pressure in the course of reciprocating linear motion of the piston 130 in the cylinder 120, the suction valve 135 is opened, And sucked into the compression space (P). On the other hand, when the pressure in the compression space P becomes equal to or higher than the suction pressure, the refrigerant in the compression space P is compressed while the suction valve 135 is closed.

On the other hand, when the pressure in the compression space P becomes equal to or higher than the discharge pressure, the spring assembly 163 is deformed forward to open the discharge valve 161, and the refrigerant is discharged from the compression space P , And is discharged to the discharge space of the discharge cover (160). When the discharge of the refrigerant is completed, the spring assembly 163 provides a restoring force to the discharge valve 161 so that the discharge valve 161 is closed.

The compressor main body 100 may further include a cover pipe 162a coupled to the discharge cover 160 and discharging the refrigerant flowing through the discharge space 160a of the discharge cover 160. [

The compressor main body 100 may further include a loop pipe 162b coupled to the cover pipe 162a and transmitting the refrigerant flowing through the cover pipe 162a to the discharge pipe 105 have. One side of the loop pipe 162b may be coupled to the cover pipe 162a and the other side may be coupled to the discharge pipe 105. [

The compressor body 100 may further include a frame 110. The frame 110 fixes the cylinder 120. For example, the cylinder 120 may be press-fitted into the inside of the frame 110.

The frame 110 is disposed to surround the cylinder 120. That is, the cylinder 120 may be positioned to be received inside the frame 110. The discharge cover 160 may be coupled to the front surface of the frame 110 by fastening members.

A gas hole 114 is formed in the frame 110 to flow the refrigerant discharged from the discharge valve 161. The cylinder 120 is formed with a gas inlet 126 through which the gas refrigerant flowing through the gas hole 114 flows.

The gas inlet 126 may be recessed radially inwardly from the outer circumferential surface of the cylinder 120. The gas inlet 126 may have a circular shape along an outer circumferential surface of the cylinder 120 with respect to an axial center line.

The cylinder 120 may include a cylinder nozzle 125 extending radially inwardly from the gas inlet 126. The cylinder nozzle 125 may extend to the inner circumferential surface of the cylinder 120.

The refrigerant flowing through the cylinder nozzle 125 flows into the space between the inner circumferential surface of the cylinder 120 and the outer circumferential surface of the piston body 131.

The gas refrigerant flowing through the cylinder nozzle 125 to the outer circumferential surface of the piston body 131 provides a floating force to the piston 130 to perform a gas bearing function with respect to the piston 130.

In this specification, the piston 130 reciprocates between a top dead center (TDC) and a bottom dead center (BDC), and a distance between the top dead center (TDC) and the bottom dead center (BDC) may be referred to as a driving stroke.

Here, the bottom dead center (BDC) is a position where the piston (130) is moved for suction of refrigerant, and the TDC is a position where the piston (130) is moved for compression of refrigerant.

The compressor main body 100 may further include a motor 140.

The motor 140 includes an outer stator 141 fixed to the frame 110 so as to surround the cylinder 120 and an inner stator 148 spaced inward from the outer stator 141, And a permanent magnet 146 positioned in the space between the outer stator 141 and the inner stator 148.

The permanent magnets 146 can reciprocate linearly by mutual electromagnetic forces with the outer stator 141 and the inner stator 148.

The permanent magnet 146 may be installed on the magnet frame 138. The magnet frame 138 has a substantially cylindrical shape and may be arranged to be inserted into a space between the outer stator 141 and the inner stator 148.

 4, the magnet frame 138 is coupled to the piston flange portion 132, extends in the outer radial direction, and can be bent forward. The permanent magnet 146 may be installed at a front portion of the magnet frame 138. When the permanent magnet 146 reciprocates, the piston 130 can reciprocate axially together with the permanent magnet 146.

A stator cover 149 is provided at one side of the outer stator 141. That is, one side of the outer stator 141 may be supported by the frame 110 and the other side may be supported by the stator cover 149.

The linear compressor 10 may further include a cover fastening member 149a for fastening the stator cover 149 and the frame 110 together. The cover fastening member 149a may extend forward toward the frame 110 through the stator cover 149 and may be coupled to the frame 110. [

The inner stator 148 is fixed to the outer periphery of the frame 110. The inner stator 148 is formed by laminating a plurality of laminations in the circumferential direction from the outside of the frame 110.

The compressor main body 100 may further include a supporter 137 for supporting the piston 130. The supporter 137 is coupled to the rear side of the piston 130 and the suction muffler 150 penetrates the inside of the supporter 137. The piston flange portion 132, the magnet frame 138, and the supporter 137 may be fastened by a fastening member.

The compressor body 100 may further include a back cover 170 coupled to the stator cover 149 and extending rearward.

In detail, the back cover 170 includes, but is not limited to, three support legs, which can be coupled to the rear surface of the stator cover 149. The back cover 170 may be spring-supported to the supporter 137.

The compressor main body 100 may further include an inflow guide unit 156 coupled to the back cover 170 to guide inflow of the refrigerant into the suction muffler 150. At least a portion of the inflow guide portion 156 may be inserted into the suction muffler 150.

The compressor main body 100 may further include a plurality of resonance springs 176a and 176b whose natural frequencies are adjusted so that the piston 130 can resonate.

The plurality of resonance springs 176a and 176b includes a first resonance spring 176a supported between the supporter 137 and the stator cover 149 and a second resonance spring 176b between the supporter 137 and the back cover 170 And a second resonant spring 176b supported. By the action of the plurality of resonance springs (176a, 176b), stable movement of the reciprocating piston in the linear compressor (10) is performed and vibration or noise generation due to the movement of the piston can be reduced.

The plurality of support devices 200 and 300 include a first support device 200 coupled to one side of the compressor body 100 and a second support device 300 coupled to the other side of the compressor body 100, .

The axial vibration and the radial vibration of the compressor body 100 are absorbed by the plurality of supporting devices 200 and 300 so that the compressor body 100 is moved to the shell 101 or the shell covers 102 and 103, Can be prevented from directly colliding with each other.

The first support device 200 may be secured to the first shell cover 102 and the second support device 300 may be secured to the shell 101 at a location adjacent the second shell cover, The fixing bracket 101a can be fixed to the inner circumferential surface of the fixing bracket 101a.

5 is a block diagram of a refrigerator including a linear compressor according to an embodiment of the present invention.

Referring to FIG. 5, the linear compressor 10 may be installed in the refrigerator 1, for example.

Although not shown, the refrigerator 1 may include a cabinet forming a storage compartment and a door connected to the cabinet to open and close the storage compartment.

The refrigerator 1 may include a main controller 2 for performing overall control of the refrigerator 1.

The refrigerator 1 further includes at least one temperature sensor 4 capable of sensing a room temperature and / or a room temperature, an input unit 3 for setting a target temperature (or a set temperature) by a user, And a display unit 5 for displaying various states of the refrigerator 1.

The input unit 3 may be provided in the cabinet and / or the door.

The at least one temperature sensor 4 may be provided in the cabinet and / or the door.

The compressor (10) may further include a compressor controller (11) for controlling the operation of the compressor (10). The compressor control unit 11 may control the motor 140 as an example.

For example, the room temperature and the set target temperature may be transmitted from the main control unit 2 to the compressor control unit 11, and the compressor control unit 11 may control the motor 140 Can be controlled.

The operation frequency of the linear compressor 10 and / or the operation stroke may be varied by the control of the motor 140. [

Hereinafter, a method of controlling the linear compressor will be described.

FIG. 6 is a flow chart for explaining a control method of a linear compressor according to an embodiment of the present invention, FIG. 7 is a flowchart for explaining a specific control method for varying a stroke of operation, FIG. 2 is a view showing a comparison of a driving stroke according to an indoor temperature of a refrigerator; FIG.

6 to 8, when the refrigerator is powered on (S1), the linear compressor is powered on (S2).

The target temperature (set temperature) can be input through the input unit 3, and the room temperature can be sensed through the temperature sensor 4. [ At this time, if the target temperature is previously set through the input unit 3 and the power of the refrigerator 1 is turned off and then turned on again, the previously set target temperature stored in the memory can be recognized.

The compressor control unit 11 senses the recognized target temperature (set temperature) and the room temperature to determine an initial operation stroke (S3).

As the target temperature (set temperature) is low and the room temperature is high, the initial operating stroke is determined to be a large value.

On the other hand, as the target temperature (set temperature) is high and the room temperature is low, the initial operating stroke is determined to be a small value.

Then, the compressor control unit 11 operates the linear compressor 10 with the determined initial operation stroke. Then, the operation stroke is determined again according to the indoor temperature conversion, and the operation stroke is maintained or varied (S4).

Hereinafter, a method of varying the operation stroke will be described in detail.

In Fig. 7, three lowest strokes are set as an example, but not limited thereto, and two or more lowest strokes can be set.

In this specification, either the first to third lowest strokes can be determined depending on the room temperature and the target temperature (set temperature).

And, the second lowest stroke has a value larger than the first lowest stroke and a value smaller than the third lowest stroke.

In the present specification, a range of the third lowest stroke or more is referred to as a third stroke section, and a range of more than the second lowest stroke lock and the third lowest stroke may be referred to as a second stroke section.

Also, a range between the first minimum stroke and the second minimum stroke may be referred to as a first stroke period.

Therefore, the initial operation stroke determined in step S3 is located within one of the first to third lowest stroke sections.

In the course of operating the linear compressor 10 in the initial operation stroke, the room temperature is sensed in the temperature sensor 4 of the refrigerator (S41), and the sensed room temperature is transmitted to the compressor controller 11.

The compressor control unit 11 recalculates the operation stroke based on the sensed room temperature (S42).

Next, the compressor control section 11 determines whether the calculated operation stroke is equal to or greater than the third lowest stroke (S43). If the calculated operation stroke is equal to or greater than the third lowest stroke, the compressor control section 11, The operation stroke is varied in accordance with the room temperature within the range of the third lowest stroke or more (third stroke interval) (S44).

That is, when the stroke calculated based on the room temperature and the target temperature (set temperature) is equal to or greater than the third lowest stroke, the operation torque is changed in accordance with the variation of the room temperature (the target temperature 3 < / RTI > minimum stroke.

On the other hand, if it is determined in step S43 that the calculated operation stroke is less than the third lowest stroke, the compressor control section 11 can determine whether the calculated operation stroke is equal to or greater than the second lowest stroke (S45).

If it is determined in step S45 that the calculated operation stroke is equal to or greater than the second lowest stroke, the compressor control section 11 sets the operation stroke within the range between the second lowest stroke and the third lowest stroke (second stroke section) (S46).

That is, when the stroke calculated by the room temperature and the target temperature (set temperature) is equal to or higher than the second lowest stroke and lower than the third lowest stroke, the target temperature (set temperature) State), the operation squelch may be varied within the range between the second lowest stroke and the third lowest stroke.

At this time, when the operating stroke determined according to the variable of the room temperature in the state where the target temperature (set temperature) is not changed is out of the second stroke section, the operating stroke is the second lowest operating stroke Or a second maximum operating stroke (a value smaller than the third minimum operating stroke).

If the operation stroke determined based on the room temperature after the lapse of a predetermined time again deviates from the second stroke interval, the stroke interval is changed and the operation stroke within the first stroke interval or the third stroke interval may be determined have.

As another example, when the operating stroke determined according to the variation of the room temperature in the state where the target temperature (set temperature) is not changed is located in the first stroke section or the third stroke section, the compressor control section 11 , The stroke interval can be changed to determine the operation stroke in the changed stroke interval.

On the other hand, if it is determined in step S46 that the calculated operation stroke is less than the second lowest stroke, the compressor control section 11 can determine whether the calculated operation stroke is equal to or greater than the first minimum stroke (S47).

If it is determined in step S47 that the calculated operation stroke is equal to or larger than the first lowest stroke, the compressor control section 11 sets the operation stroke within the range between the first lowest stroke and the second lowest stroke (first stroke section) (S49).

That is, when the stroke calculated by the room temperature and the target temperature (set temperature) is equal to or greater than the first minimum stroke and less than the second minimum stroke, the target temperature (set temperature) is not varied State), the operating stroke can be varied within the range between the first lowest stroke and the second lowest stroke.

On the other hand, if it is determined in step S46 that the calculated operation stroke is less than the first minimum stroke, the compressor control unit 11 controls the linear compressor 10 to operate at the first lowest stroke (S48).

At this time, if the operation stroke determined in accordance with the variation of the indoor temperature in the state where the target temperature (set temperature) is not changed is larger than the stroke of the first stroke section, the operation stroke is set to the first maximum It can be recrystallized to a driving stroke (a value smaller than the second lowest driving stroke). If the operating stroke determined based on the room temperature after the lapse of a predetermined time again deviates from the first stroke range, the stroke interval may be changed and the operating stroke within the second stroke interval may be determined.

As another example, when the operating stroke determined according to the variation of the room temperature in the state where the target temperature (set temperature) is not changed is located in the second stroke section, the compressor control section 11 changes the stroke section , So that it is possible to determine the operation stroke in the changed second stroke section.

Referring to FIG. 8A, in the case of a linear compressor in which oil is pumped and lubricated as in the prior art, even if the room temperature is lowered, the operation stroke does not fall below the minimum stroke but operates with a predetermined single minimum stroke .

8 (b), in the case of a linear compressor using a gas bearing without pumping oil as in the present invention, a plurality of minimum strokes can be set, and depending on the room temperature and the target temperature Since the lowest stroke of one of the plurality of lowest strokes can be set, the operation area can be increased and power consumption can be reduced.

At this time, since at least the first lowest stroke in the present invention is smaller than the single lowest stroke of the prior art, the power consumption can be reduced as the operation stroke of the linear compressor is lowered.

1: refrigerator 2: main control unit
3: Input unit 4: Temperature sensor
10: compressor 11: compressor control unit

Claims (10)

Determining an initial operation stroke belonging to one stroke section selected from a plurality of stroke sections based on the indoor temperature and the target temperature inputted through the input section;
Operating the linear compressor with the initial operation stroke;
And varying a driving stroke in the selected one stroke section in accordance with a change in the sensed room temperature during operation of the linear compressor. The method according to claim 1,
The linear compressor includes: a cylinder defining a compression space of a refrigerant;
A piston provided to be axially reciprocable within the cylinder;
A discharge valve provided at one side of the cylinder for selectively discharging compressed refrigerant in a compression space of the refrigerant; And
And a nozzle portion formed in the cylinder and through which at least a part of the refrigerant discharged through the discharge valve flows. The method according to claim 1,
Wherein the operation stroke determined by the sensed room temperature is smaller than the first minimum stroke of the first stroke section during the operation of the linear compressor in the operation stroke within the first stroke section having the smallest stroke value among the plurality of stroke sections , The linear compressor is operated at the first lowest stroke. The method according to claim 1,
When the operating stroke determined by the sensed room temperature deviates from the selected one stroke period during the operation of the linear compressor with the operating stroke within the selected one stroke section, And the stroke of the selected one stroke section is the minimum stroke or the maximum stroke of the selected one stroke section. The method according to claim 1,
When the operating stroke determined by the sensed room temperature deviates from the selected one stroke section during the operation of the linear compressor in the operating stroke within the selected one stroke section, the linear compressor operates in one operating stroke within the changed stroke section A method of controlling a linear compressor. A cabinet forming a storage chamber;
A door that opens and closes the storage room;
A linear compressor provided in the cabinet;
A temperature sensor provided in the cabinet or the door, for detecting the room temperature;
An input unit provided in the door or the cabinet for inputting a target temperature of the storage chamber; And
And a compressor controller for controlling the linear compressor,
The compressor control unit includes:
An initial operation stroke belonging to one stroke section selected from among a plurality of stroke sections is determined based on a room temperature sensed by the temperature sensor and a target temperature inputted through the input section, To make it work,
Wherein the operating stroke of the linear compressor is varied in the selected one stroke section in accordance with a change in the sensed room temperature during operation of the linear compressor. The method according to claim 6,
When the operating stroke determined by the sensed room temperature is smaller than the first minimum stroke of the first stroke section during the operation of the linear compressor with the operating stroke within the first stroke section having the smallest stroke value among the plurality of stroke sections , The compressor control unit controls the linear compressor to operate the linear compressor with the first lowest stroke. The method according to claim 6,
When the operating stroke determined by the detected indoor temperature in the state where the target temperature is not changed is out of the selected one stroke period during the operation of the linear compressor during one stroke of the selected one stroke section, , And controls the linear compressor to operate the linear compressor with a minimum stroke or a maximum stroke of the selected one-stroke section. The method according to claim 6,
When the operating stroke determined by the detected indoor temperature in the state where the target temperature is not changed is out of the selected one stroke period during the operation of the linear compressor during one stroke of the selected one stroke section, And controls the linear compressor to operate the linear compressor with one operating stroke within a changed stroke range. The method according to claim 6,
The linear compressor includes: a cylinder defining a compression space of a refrigerant;
A piston provided to be axially reciprocable within the cylinder;
A discharge valve provided at one side of the cylinder for selectively discharging compressed refrigerant in a compression space of the refrigerant; And
And a nozzle portion formed in the cylinder and through which at least a part of the refrigerant discharged through the discharge valve flows.

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