KR100339598B1 - Piston structure for linear compressor - Google Patents

Abstract

The present invention relates to a piston structure of a linear compressor, and the present invention is inserted into a linear cylinder fixedly coupled to the stator of the linear motor, and coupled to the mover of the linear motor to linearly inside the cylinder. A cylindrical first member reciprocating; A cylindrical second member through which a gas flow path for guiding refrigerant gas into the compression chamber of the cylinder is inserted into and fixed to the first member, the front end surface of which is located inward of the front end surface of the first member; A gas pocket is formed to communicate with the gas flow path of the second member, and is inserted to slide freely within a flow range in which both sides are limited by the first member and the second member, and the first member is formed on the main wall of the gas pocket. By forming the cap-shaped third member so that the gas through-holes are formed to be opened and closed by the gas, not only can it prevent the damage of the valve due to the accumulation of fatigue even after long-term use, but also the gas through-holes are always opened and closed at a constant position, so It proceeds smoothly and improves the reliability of the compressor.

Description

Piston structure of linear compressor {PISTON STRUCTURE FOR LINEAR COMPRESSOR}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the piston structure of a linear compressor, and more particularly, to the piston structure of a linear compressor that enables easy and robust coupling of the intake valve.

In general, the linear compressor is coupled to the magnet assembly forming the mover of the linear motor in place of the crankshaft so that the piston is integrally fixed to the magnet assembly. FIG.

As shown in the drawing, a conventional linear compressor has a compression unit (C) installed in a transverse direction inside a casing (V) filled with oil on a bottom surface thereof to suck, compress, and discharge refrigerant, and the compression unit (C). It is fixed to the outside of the oil feeder is configured to supply oil to the sliding portion (O).

The compression unit (C) includes an annular frame (1), a cover (2) fixedly installed on one side of the frame (1), and a cylinder (3) fixed laterally in the center of the frame (1). An inner stator assembly 4A fixed to the outer circumferential surface of the frame 1 supporting the cylinder 3 and an outer stator assembly 4B fixed with a predetermined gap on the outer circumferential surface of the inner stator assembly 4A; The magnet assembly 5 interposed between the inner and outer stator assemblies 4A and 4B, which constitutes the mover of the linear motor, and is integrally fixed to the magnet assembly 5 so as to slide in the cylinder 3. The inner and outer resonant springs 7A and 7B which guide the piston 6 to suction and compress the refrigerant gas and the magnet assembly 5 to continuously resonate in the air gap between the inner and outer stator assemblies 4A and 4B. And pieces attached to the tip of the cylinder 3 Is made by a discharge valve assembly (8) for restricting discharge of the compressed gas during the reciprocating motion of (6).

The piston 6 has a head portion 6b formed on the front side of the body portion 6a having a predetermined length, and a connecting portion 6c connected to the magnet assembly 5 on the rear side of the body portion 6a. Is formed, and a gas flow path F for guiding the refrigerant gas to the cylinder 3 is formed in the center of the trunk portion 6a.

The gas passage F has a first gas passage 6d formed to have a predetermined depth among the body portions 6a, and passes through the head portion 6b so as to communicate with the first gas passage 6d. The second gas passage 6e is formed. In addition, the inlet valve 9 which opens and closes the second gas passage 6e to restrict the intake of the refrigerant gas is fastened to the front end surface of the gas passage F by a fixing bolt B.

SP, which is not described in the drawings, is a suction pipe.

The linear compressor as described above is operated as follows.

That is, when a current is applied to the inner and outer stator assemblies 4A and 4B so that the magnet assembly 5 linearly reciprocates, the piston 6 coupled thereto reciprocates linearly inside the cylinder 3. The pressure difference is generated in the cylinder (3), and the refrigerant gas in the casing (V) is sucked into the cylinder (3) through the gas flow path (F) of the piston (6) by the pressure difference in the cylinder (3). The process of compression ejection is repeated.

At this time, during the suction stroke in which the piston 6 moves to the rear side, the refrigerant gas is pushed down by the suction valve 9 while passing through the first gas passage 6d and the second gas passage 6e. The valve 9 should be firmly mounted to the piston 6 so that the reliability of the compressor can be maintained firmly without departing from the reciprocating motion of the piston 6. For this reason, as shown in FIG. 2, a method of fastening the suction valve 9 to the front end surface of the head part 6b of the piston 6 by using a separate fixing bolt B has been proposed.

However, such a conventional suction valve coupling structure is a thin plate suction valve (9) is fastened by the fixing bolt (B), the opening and closing portion (9a) of the suction valve (9) is repeatedly rotated during the opening and closing operation of the piston ( The second gas through hole (6e) of 6) is out of this due to the inhalation of the refrigerant gas did not proceed smoothly there was a problem that the compression function is reduced.

In addition, since the fastening hole 9b for fastening the fixing bolt B to the suction valve 9 is formed, there is a problem that the structural strength is lowered.

In addition, since the head portion of the fixing bolt (B) is located in the form of protruding into the compression space of the cylinder (3), dead volume is generated to reduce the compression efficiency as well as the protruding fixing bolt ( The head part of B) makes it difficult to sense the position of the top dead center and the bottom dead center of the piston 6, which makes the stroke control of the reciprocating motion of the piston 6 difficult.

In view of these problems, in the "patent coupling structure of the linear compressor" of the Korean Patent Application No. 99-64796 dated Dec. 29, 1999, the intake valve 9 is shown in FIGS. 3A and 3B. In the present invention, a method of directly mounting the piston 6 by welding (W) has been proposed, and in the "valve coupling structure of the linear compressor", which is the same as the domestic patent application (99-64804), it is shown in FIGS. 4A and 4B. As described above, a method of inserting a separate welding medium M into the front end surface of the piston 6 and welding the suction valve 9 to the welding medium M is mounted.

However, as described above, the method of welding the suction valve 9 to the front end face of the piston 6 is cast iron in which the piston 6 is castable, while the suction valve 9 is made of high carbon spring steel and the piston 6 ) And the intake valve (9) is different, there is a risk of adversely affecting the reliability of the compressor due to poor welding.

In addition, the method of using a separate welding medium (M) has a weak welding strength of the welding medium (M) and the piston (6), and when separated for long periods of use, there is a risk of lowering the reliability of the compressor as described above.

The present invention has been made in view of the problems with the conventional valve coupling structure as described above, and an object of the present invention is to provide a piston structure of a linear compressor that can be stably coupled to the suction valve and the piston.

1 is a longitudinal sectional view showing an example of a conventional linear compressor.

2A and 2B are a perspective view and a longitudinal sectional view showing a suction valve and a piston structure of a conventional linear compressor.

3A and 3B are a perspective view and a longitudinal sectional view showing another embodiment of the intake valve and piston structure of a conventional linear compressor.

Figures 4a and 4b is a perspective view and a longitudinal sectional view showing another embodiment of the intake valve and piston structure of a conventional linear compressor.

5 is a longitudinal sectional view showing an example of the linear compressor of the present invention.

6 and 7 are an exploded perspective view and a longitudinal sectional view showing a suction valve and a piston structure of the linear compressor of the present invention.

FIG. 8 is a cross-sectional view taken along the line “I-I” of FIG. 7.

Figure 9a and Figure 9b is a longitudinal sectional view showing the operation of the piston for the linear compressor of the present invention.

** Description of symbols for the main parts of the drawing **

3: cylinder 100: piston

110: first member for the piston body 111: through hole

112: locking jaw 113: sliding hole

114: connecting portion 120: second member for the stopper

121: connecting portion 130: third member for the valve

131: gas pocket 132: gas through hole

133: stopping plate portion F: gas flow path

In order to achieve the object of the present invention, a cylindrical insert is slidably inserted into a linear cylinder fixedly coupled to a stator of a linear motor, and coupled to a mover of the linear motor to linearly reciprocate in the interior of the cylinder. A first member;

A cylindrical second member through which a gas flow path for guiding refrigerant gas into the compression chamber of the cylinder is inserted into and fixed to the first member, the front end surface of which is located inward of the front end surface of the first member;

A gas pocket is formed to communicate with the gas flow path of the second member, and is inserted to slide freely within a flow range in which both sides are limited by the first member and the second member, and the first member is formed on the main wall of the gas pocket. A piston structure of a linear compressor is provided, comprising a third member having a cap shape in which a gas through hole is formed to be opened and closed by the cap.

Hereinafter, the piston structure of the linear compressor according to the present invention will be described in detail based on the embodiment shown in the accompanying drawings.

Figure 5 is a longitudinal sectional view showing an example of the linear compressor of the present invention, Figures 6 and 7 are an exploded perspective view and a longitudinal sectional view showing a suction valve and a piston structure of the linear compressor of the present invention, Figure 8 is a "I-I of FIG. "Line section.

As shown therein, the linear compressor having a piston structure according to the present invention includes a casing V having a predetermined internal volume, filled with oil on a bottom thereof, and provided with a suction pipe SP and a discharge pipe (not shown), An annular frame 1 elastically supported by the casing V, a cover 2 fixed to the rear side of the frame 1, and a cylinder 3 fixed laterally to the center of the frame 1. ), An inner stator assembly 4A fixed to the outer circumferential surface of the cylinder 3, an outer stator assembly 4B fixed with a predetermined gap on the outer circumferential surface of the inner stator assembly 4A, and the inner stator assembly ( The magnet assembly 5 interposed in the gap between 4A) and the outer stator assembly 4B for linear reciprocating motion, and integrally fixed to the magnet assembly 5 and inserted in the cylinder 3 so as to slide in the magnet 3 described above. Linear reciprocating with the assembly (5) Piston 100 for sucking and compressing the fluid flowing into the casing (V) through the flow path (F) into the cylinder (3), and guides the reciprocating motion of the magnet assembly (5) together with the piston (100) An inner resonant spring 7A and an outer resonant spring 7B which are elastically supported so as to be elastically supported, and a discharge valve assembly 8 mounted on the front end surface of the cylinder 3 to limit the discharge of refrigerant gas.

The piston 100 is slidably inserted into the cylinder 3 so as to linearly reciprocate in the interior of the cylinder 3, and a first member 110 for the piston body, and the first member 110. A stopper second member 120 through which the gas flow path F is formed so as to be inserted into and fixed to the cylinder 3, and between the first member 110 and the second member 120. A gas through hole which is inserted to slide freely within a certain flow range and is in communication with the gas flow path F and communicates with the gas pocket 131 and opened and closed by the first member 110. 132 is formed of a third member 130 for the suction valve.

The first member 110 is usually fastened and fixed to the magnet assembly 5 with a bolt, and a through hole 111 into which the second member 120 is inserted and fixed is formed, and the through hole 111 is formed therein. At the distal end of the engaging jaw portion 112, which limits the bottom dead center of the third member 130 during the suction stroke is formed stepped inward, the gas pocket of the third member 130 in the center of the engaging jaw 112 ( 131, a sliding hole 113 is formed in which the outer peripheral surface is slipped.

The second member 120 has a gas flow path F formed therein and is press-fitted into the through-hole 111 of the first member 110 or fastened to the rear end by bolts B as in this embodiment. The tip is coupled to the locking step 112 of the first member 110 and the flow range (R) of the third member 130. Since the second member 120 serves as a stopper for limiting the top dead center of the third member 130 during compression and discharge stroke, the second member 120 may be provided in a ring shape and press-fit into the first member 110. Since the flow path resistance of the suction refrigerant is generated, it is preferably formed to be long enough to be inserted into the end of the first member 110.

The third member 130 is formed in a cap shape in which a gas pocket 131 is provided so as to communicate with the gas flow path F of the second member 120 therein, and the first member 110 is formed on the outer peripheral surface of the end thereof. A disk-shaped locking plate 133 is formed to be caught by the front end surfaces of the locking jaw portion 112 and the second member 120. Several gas through holes 132 that are opened at the suction stroke of the first member 110 and the second member 120 at the end of the gas pocket 111 of the third member 130 and closed during the compression and discharge stroke are arc-shaped. It is formed into a cross section or the like.

In addition, the third member 130 is formed so that the front end surface of the third member 130 coincides with the front end surface of the first member 110 during compression and discharge stroke, while the gas cylinder hole 132 can be fully opened during the suction stroke. It is desirable to be.

In the drawings, the same reference numerals are given to the same parts as in the prior art.

In the drawings, reference numerals 114 and 121 are connection parts, and 114a and 121a are fastening holes.

The general operation of the linear compressor having the piston structure of the present invention as described above is similar to the conventional.

That is, when a current is applied to the inner and outer stator assemblies 4A and 4B and the magnet assembly 5 performs a linear reciprocating motion, the piston 100 coupled thereto reciprocates the inside of the cylinder 3 in a linear manner. The pressure difference is generated in the cylinder (3), and the refrigerant gas in the casing (V) is sucked into the cylinder (3) through the gas flow path (F) of the piston 100 by the pressure difference in the cylinder (3). The process of compression ejection is repeated.

Looking at this in more detail as follows.

First, as shown in FIG. 9A, when the first member 110 of the piston 100 performs a suction stroke while moving to the right side of the drawing together with the second member 120, the first member 110. The third member 130, which is slipperyly inserted, is moved along the through-hole 111 of the first member 110 to the left side of the drawing by the suction refrigerant, and in the process, the third member 130 is moved. The gas cylinder hole 132 is opened while the front end side of the first member 110 is deviated from the sliding hole 113 of the first member 110 and the suction refrigerant flows into the compression space (unsigned) of the cylinder 3 through the gas cylinder hole 132. do. At this time, the locking member 133 provided at the rear end of the third member 130 is caught by the locking jaw portion 112 of the first member 110 and the movement is restricted, so that the third member 130 is the first member 110. Is completely prevented from escaping to the tip side.

Next, as illustrated in FIG. 9B, when the first member 110 of the piston 100 performs compression and discharge stroke while moving to the left side of the drawing together with the second member 120, the third member described above is performed. While the member 130 is pushed to the right side of the drawing by the refrigerant gas filled in the compression space (unsigned) on the tip end side side, the gas through hole 132 is driven by the sliding hole 113 of the first member 110. Is blocked. At this time, while the locking plate 133 provided at the rear end of the third member 130 is caught by the front end surface of the second member 120, the third member 130 is completely moved to the rear end side of the first member 110. Slipping is prevented.

In this way, by limiting the suction of the refrigerant gas without installing a thin suction valve on the front end surface of the piston, it is possible to prevent damage due to the accumulation of fatigue generated when the thin valve valve is used. In addition, even if the third member rotates during operation, the gas through-hole is always opened and closed at a constant position, so that the suction and discharge of the refrigerant gas proceeds smoothly, thereby improving the reliability of the compressor.

The piston structure of the linear compressor according to the present invention includes a first member coupled to a mover of the linear motor to linearly reciprocate in the cylinder, and a gas flow path guiding refrigerant gas to the compression chamber of the cylinder. And a third member having a second member inserted into the first member and fixed to the first member, and a third member having a gas through hole inserted to slide freely in the flow range between the first member and the second member and opened and closed by the first member. Even if it is used for a long time, not only the valve damage due to fatigue accumulation can be prevented in advance, but also the gas through-hole is always opened and closed at a constant position, so that the intake and discharge of refrigerant gas proceeds smoothly, thereby improving the reliability of the compressor.

Claims (3)

A cylindrical first member slidably inserted into the linear cylinder fixedly coupled to the stator of the linear motor and coupled to the mover of the linear motor to linearly reciprocate in the cylinder; A cylindrical second member through which a gas flow path for guiding refrigerant gas into the compression chamber of the cylinder is inserted into and fixed to the first member, the front end surface of which is located inward of the front end surface of the first member; A gas pocket is formed to communicate with the gas flow path of the second member, and is inserted to slide freely within a flow range in which both sides are limited by the first member and the second member, and the first member is formed on the main wall of the gas pocket. A piston structure of a linear compressor, characterized in that made of a cap-shaped third member so that the gas through-hole is opened and closed by. According to claim 1, Wherein the third member is caught on the locking step portion formed to be stepped inward on the inner peripheral surface of the front end of the first member to limit the bottom dead center of the third member during the suction stroke, And a locking plate portion is formed on the front end surface of the second member positioned in the above-mentioned locking range of the first member to limit the top dead center of the third member during compression and discharge stroke. Piston structure of the compressor. 3. The flow range of claim 2, wherein the flow range is from a point at which the gas through hole of the third member can be completely opened during the suction stroke to a point where the tip surface of the third member coincides with the tip surface of the first member during compression and discharge stroke. The piston structure of the linear compressor.