JP6101469B2 - air compressor - Google Patents

Description

  The present invention relates to an air compressor.

  There exists patent document 1 as background art of this invention. Patent Document 1 includes a cylinder, a piston, and a lip ring that seals between the piston and the cylinder, and the thick lip portion and the thin portion are arranged at different positions in the circumferential direction on the annular lip portion of the lip ring. The reciprocating compressor arranged in is described.

JP 2008-248813 A

  In the reciprocating compressor that compresses the gas described in Patent Document 1, the lip ring that is attached to the piston and hermetically seals between the piston and the cylinder is affected by the oscillation of the piston.

  Here, in the lip ring provided in the reciprocating compressor of Patent Document 1, the thickness of the tip is equal to the thickness of the bent portion or thicker than the thickness of the bent portion. In particular, the thickness of the bent portion is equal to the thickness of the tip on the side that rises in the swing direction during the compression stroke. In this case, since the lip portion is not pressed against the inner surface of the cylinder even when internal pressure is applied, there is a problem that the sealing performance is deteriorated.

  In view of the above problems, an object of the present invention is to provide an air compressor that suppresses a decrease in sealing performance by changing the thickness of the tip with respect to the thickness of the bent portion in the circumferential direction. And

In order to solve the above problems, the present invention provides a cylinder in which a cylinder head is formed, a piston that reciprocates while swinging in the cylinder, and forms a compression chamber between the cylinder head, and the cylinder. A lip ring that seals between the piston, and the lip ring includes an attachment portion that is attached to a piston groove provided in the piston, and a lip portion that protrudes radially outward from the attachment portion. A bent portion that is bent between the attachment portion and the lip portion, and of the lip ring, the piston is compressed from the center of the lip ring during a compression stroke in which air is compressed in the cylinder. in a portion near the cylinder head, the wall thickness of the lip portion is formed smaller than the thickness of the bent portion, the lip ring is circumferentially half To provide an air compressor, characterized in that continuously changing the thickness of the lip in the region of the bottom.

  ADVANTAGE OF THE INVENTION According to this invention, the air compressor which suppressed the sealing performance fall can be provided by changing the thickness of a front-end | tip with respect to the thickness of a bending part in the circumferential direction.

It is sectional drawing of the piston and cylinder of the air compressor by the Example of this invention. It is sectional drawing of the lip ring in FIG. FIG. 2 is a cross-sectional view of a state in which a compression stroke of a piston and a cylinder in FIG. 1 is swung.

  Embodiments of an air compressor according to the present invention will be described below with reference to FIGS.

  The air compressor in a present Example is demonstrated using FIG.

  The air compressor in the present embodiment compresses air by the piston 21 reciprocating while swinging in the cylinder 1. The structure of the piston 21 will be described below.

  The piston 21 is provided in the cylinder 1 so as to be able to reciprocate, and is constituted by a disk-shaped retainer 24 fastened by a bolt 23 to a connecting rod 22 provided with a disk-shaped mounting flange 22A.

  Further, the mounting flange 22A of the connecting rod 22 has a recess 22B at the center. Further, the retainer 24 has a convex portion 24 </ b> A at the center, and fits with the concave portion 22 </ b> B of the connecting rod 22.

  The lip ring 25 provided on the outer peripheral side of the piston 21 is formed in a ring shape using a resin material, and seals between the piston 21 and the cylinder 1.

  The lip ring 25 is sandwiched between piston grooves formed by the connecting rod 22 and the retainer 24 and is fixed in a state of being fastened by a bolt 23.

  Further, the lip ring 25 includes a flat plate-like mounting portion 25A attached to the piston groove and a lip portion 25B projecting radially outward from the mounting portion 25A. The lip portion 25B is in sliding contact with the inner peripheral surface of the cylinder 1 with a tightening margin. ing.

  The lip ring 25 is a bent portion 25C that is bent in an L shape between the mounting portion 25A and the lip portion 25B.

  Here, the operation of the air compressor in the present embodiment will be described. In the intake stroke in which the piston 21 sucks air into the cylinder 1, the piston 21 moves while swinging in a direction (downward) away from the cylinder head 2 provided in the cylinder 21, and sucks air from the outside. . Here, the suction valve 7 provided in the valve plate 4 is opened, and air flows into a compression chamber formed between the piston 21 and the cylinder head 2. In the compression stroke in which the piston 21 compresses the air in the cylinder 1, the piston 21 moves while swinging toward the cylinder head 2 provided in the cylinder 21 to compress the air in the compression chamber. Here, the suction valve 7 provided on the valve plate 4 is closed and the discharge valve 8 is opened, so that compressed air is discharged toward a storage tank provided outside the cylinder 1.

  Here, the configuration of the lip ring 25 in the present embodiment will be described with reference to FIGS.

  As shown in FIGS. 2 and 3, the lip ring 25 is located on the side that rises upward in the oscillating direction in the oscillating state of the compression stroke (the E side in the drawing closer to the cylinder head 2 than the center of the lip ring 25). The thickness of the lip portion 25B is smaller than the thickness of the bent portion 25C within a range of half or less in the circumferential direction.

  In the compression stroke, when the piston is in a horizontal state, as shown in FIG. 1, the lip portion 25B of the lip ring 25 comes into contact with the inner surface of the cylinder 1 and is pressed against the cylinder 1 by the internal pressure to seal it. Sealing performance does not deteriorate.

  Further, when the piston 21 is oscillating during the compression stroke, as shown in FIG. 3, the side descending downward in the oscillating direction (in the figure farther from the cylinder head 2 than the center of the lip ring 25). With respect to (D side), the lip portion 25B of the lip ring 25 comes into contact with the inner surface of the cylinder 1 and is pressed against the cylinder 1 by the internal pressure to be sealed, so that the sealing performance does not deteriorate.

  However, on the side that rises upward in the swinging direction (E side in the figure closer to the cylinder head 2 than the center of the lip ring 25), the vicinity of the bent portion 25C of the lip ring 25 contacts the inner surface of the cylinder 1 and the lip portion 25B. A force is applied so as to deform toward the inside (the center side of the lip ring 25). To do. When the thickness of the lip portion 25B is not smaller than the thickness of the bent portion 25C as in Patent Document 1, the lip portion 25B is deformed toward the inside (the center side of the lip ring 25). The lip portion 25B does not deform toward the outside (cylinder inner surface side) sufficiently due to the pressure of the compression chamber against the force, so that a gap is generated between the lip portion 25B and the inner surface of the cylinder 1, and the seal May be reduced.

  Here, in this embodiment, the lip ring 25 has a circumference on the side that rises upward in the oscillating direction in the oscillating state of the compression stroke (E side in the drawing closer to the cylinder head 2 than the center of the lip ring 25). The thickness of the lip portion 25B is smaller than the thickness of the bent portion 25C within a range of a half circumference or less in the direction. Therefore, even if there is a possibility that the vicinity of the bent portion 25C of the lip ring 25 may come into contact with the inner surface of the cylinder 1, it resists the force that the lip portion 25B is deformed toward the inner side (center side of the lip ring 25). Thus, the lip portion 25B is sufficiently deformed toward the outside (the inner peripheral surface side of the cylinder) by the pressure of the compression chamber. Thereby, the followability of the lip portion 25B is improved, and the deterioration of the sealing performance can be prevented.

  As described above, according to the present embodiment, it is possible to improve the sealing performance when the compression stroke is oscillated, and it is possible to improve the performance of the compressor.

  In the present embodiment, the thickness of the lip portion 25B is continuously changed in the circumferential direction. Thereby, processing becomes easy. Further, when there is a discontinuous point in the thickness, the lip portion 25B is likely to be broken, so that the life of the lip portion 25B can be improved by continuously changing the thickness.

  In the present embodiment, the thickness of the lip portion 25B is continuously increased toward the bent portion 25C. Thereby, the life of the lip portion 25B can be improved by increasing the thickness of the bent portion 25C and increasing the rigidity of the bent portion 25C that is likely to break.

  Further, in this embodiment, the thickness of the lip portion 25B is changed within a range equal to or less than a half circumference in the circumferential direction. Thereby, since it is sufficient to process the lip portion 25B by a necessary minimum amount, the lip portion 25B can be easily processed. In addition, on the (D side in the drawing farther from the cylinder head 2 than the center of the lip ring 25), the thickness of the lip portion 25B is not made larger than the thickness of the bent portion 25C, and the sealing performance at this portion is improved. It can be prevented from lowering.

  The embodiments described so far are merely examples of implementation in carrying out the present invention, and the technical scope of the present invention is not limitedly interpreted by these. That is, the present invention can be implemented in various forms without departing from the technical idea or the main features thereof.

1 Cylinder 2 Cylinder Head 4 Valve Plate 7 Suction Valve 8 Discharge Valve 21 Piston 22 Connecting Rod 24 Retainer 25 Lip Ring 25A Mounting Portion 25B Tip 25C Bent

Claims (4)

A cylinder formed with a cylinder head;
A piston that reciprocates while swinging in the cylinder, and forms a compression chamber with the cylinder head;
A lip ring that seals between the cylinder and the piston;
The lip ring is bent between a mounting portion that is attached to a piston groove provided in the piston, a lip portion that protrudes radially outward from the mounting portion, and the mounting portion and the lip portion. A bent portion,
Of the lip ring, the thickness of the lip portion is larger than the thickness of the bent portion in the portion closer to the cylinder head than the center portion of the lip ring during the compression stroke in which the piston compresses air in the cylinder. Forming a small ,
The air compressor according to claim 1, wherein the lip ring continuously changes the thickness of the lip portion within a range equal to or less than a half circumference in the circumferential direction .   2. The air compression according to claim 1, wherein the lip portion continuously changes its thickness in a circumferential direction in a portion closer to the cylinder head than a center portion of the lip ring during a compression stroke. Machine. 3. The thickness of the lip portion is continuously increased in the direction of the bent portion within a circumferential range in which the thickness of the lip portion is reduced. 3 . The air compressor described.   The lip ring is formed so that a thickness of the lip portion does not become larger than a thickness of the bent portion in a portion farther from the cylinder head than a center portion of the lip ring during the compression stroke. The air compressor according to claim 2.

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