JPS6231677Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cylinder structure for a compressor that prevents wear between the cylinder and the piston due to torsional moments generated in the piston.

In general, reciprocating type and rotary type compressors are known, and reciprocating types include Scotch yoke type and connecting rod type, but reciprocating type compressors have local parts in the piston and cylinder due to their structure. There is a problem that wear occurs. That is,
As shown in FIG. 1, a conventional Scotch yoke type compressor has a piston 3 slidably inserted into a hole 2 of a cylinder 1, and a guide 4 fixed to the end of the piston 3.
A crankshaft (not shown) is connected to the slider 5 via a pin 6, and the piston 3 is rotated by rotation of the crankshaft.
is slid within the hole 2 of the cylinder 1 to compress the fluid. In this case, when the crankshaft rotates clockwise, during the fluid compression stroke of the piston 3, a force A is applied to the distal end surface of the piston 3 in a direction that prevents the movement of the piston 3, and at the same time, the left half of the distal end surface of the piston 3 acts on the piston 3. A force B is added that tries to move 3 by overcoming the above force A. Therefore, a torsional moment is generated in the piston 3 in the direction shown by arrow C, causing the piston 3 to tilt within the hole 2 of the cylinder 1. This results in a situation where the piston 3 comes into pressure contact with the end of the hole 2 of the cylinder 1, and when viewed from the piston 3, the force shown by arrows D and E is locally received from the wall of the hole 2 of the cylinder 1. means. Therefore, the piston 3 and cylinder 1 are prone to wear, which sometimes causes galling. In addition, since small models do not use piston rings, the clearance increases when the piston 3 is tilted as described above.
It also has the disadvantage of leakage of compressed fluid and therefore reduced efficiency.

An object of the present invention is to provide a cylinder structure for a compressor that can prevent wear and galling of the piston and cylinder and reduce leakage of compressed fluid.

In order to achieve the above object, the present invention aims to prevent wear and galling by distributing the surface pressure between the piston and cylinder, and to reduce leakage of compressed fluid by reducing the clearance. Based on this knowledge, they discovered a cylinder structure in which a ring-shaped groove is provided on the periphery of the piston hole in the cylinder, concentrically with the hole, so that the periphery of the cylinder hole flexes in response to the inclination of the piston. be.

A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

As shown in FIG. 2, 1 is a cylinder, which is provided with a hole 2 into which a piston is slidably inserted;
A ring-shaped groove 7 is provided at the peripheral edge of the hole 2 so as to be concentric with the hole 2. Further, the end of the hole 2 is formed so that its inner diameter gradually decreases toward the end, as shown in FIG.
This can be easily obtained by finishing the piston hole 2 after forming the ring-shaped groove 7. That is, by providing the groove 7 before finishing the hole 2 (generally honing), the end of the hole 2 will bend in the radial direction and escape into the groove 7 due to the grinding pressure during machining, and will Since the relief becomes larger as it goes further, the finished shape becomes a cylinder 1 as shown in FIG. In FIG. 3, the inner diameter of the hole 2 before finishing is shown by a solid line, and the planned inner diameter of the hole 2 for finishing is shown by a phantom line.

According to this structure, when a torsional moment acts on the piston 3 during the reciprocating sliding operation of the piston 3 and the piston 3 tilts within the hole 2 of the cylinder 1, the groove 7 is provided as shown in FIG. Therefore, the peripheral edge of the hole 2 of the cylinder 1 is bent together with the piston 3. Due to this deflection, the force exerted on the peripheral edge of the hole 2 by the piston 3 is relaxed, and the surface pressure E of the piston 3 is dispersed. In addition, the clearance does not increase because the peripheral edge of the hole 2 moves together with the piston 3 from the position shown by the imaginary line in FIG. 4 to the position shown by the solid line. Since it gradually becomes smaller toward its ends, the clearance becomes smaller and the time until it becomes unusable due to wear becomes longer.

In the above embodiment, the explanation was given with reference to the drawing in which the groove 7 was provided at the peripheral edge of one end of the hole 2 of the cylinder 1.
The present invention is not limited to this, and the groove 7 may be provided at the other end peripheral portion of the hole 2 of the cylinder 1. At this time, the force shown by arrow D in FIG. 4 can be alleviated. Further, in the present invention, grooves 7 may be provided at the peripheral edges of both ends.

As is clear from the above explanation, the present invention provides the following effects.

(1) By providing a ring-shaped groove concentrically around the periphery of the cylinder hole, the end of the cylinder hole becomes flexible, and the force with which the piston presses the cylinder when the piston tilts can be reduced, and conversely, the surface pressure that the cylinder exerts on the piston can be dispersed.
As a result, wear on the piston and cylinder is reduced and galling is prevented.

(2) Since the bore end of the cylinder moves to follow the inclination of the piston, clearance can be kept small. Therefore, leakage of compressed fluid is reduced and the efficiency of the compressor is improved.

(3) By making the inner diameter of the cylinder hole end smaller toward the end, the clearance can be made smaller and the life of the cylinder due to wear can be extended.

(4) Even with a simple structure, it has a long service life and exhibits excellent effects such as usefulness.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an example of the cylinder structure of a conventional compressor, FIG. 2 is a cross-sectional view and side view showing an example of the cylinder structure of the compressor according to the present invention, and FIG. 2 is a cross-sectional view for explaining the method of forming the structure, and FIG. 4 is a cross-sectional view showing the operating state of the cylinder structure according to the present invention. In the figure, 1... cylinder, 2... hole, 3... piston, 7... groove.

Claims (1)

[Claims for Utility Model Registration] 1. In a compressor in which a piston is slidably inserted into a cylinder hole and fluid is compressed by the reciprocating motion of the piston, a ring-shaped ring is provided on the periphery of the cylinder hole concentrically with the hole. A compressor cylinder structure characterized by having grooves. 2. The cylinder structure for a compressor according to claim 1, wherein the end of the hole is formed so that its inner diameter gradually decreases toward the end. 3. The compressor cylinder structure according to claim 2, wherein the end of the hole is formed by finishing the piston hole after forming a ring-shaped groove.