JPH0435584Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to a seal structure for a reciprocating compressor, and in particular, the invention relates to a seal structure for a reciprocating compressor, and in particular, the end of a piston seal of a thick plate is brought into contact with a mounting groove by caulking or the like. , relates to a seal structure that ensures long life, low noise, and smooth operation.

(Prior Art) Generally, a piston seal is attached to a reciprocating piston in order to maintain its airtightness and guide the cylinder wall surface, but this seal is easy to manufacture, has a long life, and does not deform. Low and smooth operation is required.

The conventional seal structure of this type of compressor is as follows:
For example, there are those shown in FIGS. 5 and 6. Fifth
In the figure, 1 is a reciprocating type compressor, and the compressor 1 is broadly divided into a motor 2, a crank mechanism 3, and a compression mechanism 4. The motor 2 rotates a shaft 2a using power supplied from the outside, and drives a connecting rod 6 via a crankshaft 5. A piston 8 is connected to the end of the connecting rod 6 via a piston pin 7, and the piston 8 slides in the vertical direction in the figure in the cylinder 9 to compress the air in the cylinder 9. A first piston seal 1 is installed on the side of the piston.
0 and a second piston seal 11 are installed, and these seals 10 and 11 are made of a material that is highly wear resistant and self-lubricating and is resistant to seizure, such as resin such as tetrafluoroethylene.

Each seal 10, 11 has an annular groove 1 formed on the side surface of the piston 8, as shown in detail in FIG.
2 and 13, respectively, and especially in the groove 12, an O-ring 14 is inserted inside the first piston seal 10. The first piston seal 10 is pressed toward the wall surface of the cylinder 9 by the reaction force of the O-ring 14, and maintains the airtightness of the compression chamber 15 defined by the cylinder 9 and piston 8. Further, the second piston seal 11 is wider than the first piston seal 10 and serves as a guide when the piston 8 slides on the wall surface of the cylinder 9. The second piston seal 11 is slightly smaller than the groove 13, and there is a gap L at its end.
(L=about 0.1 to 0.3 mm) is provided.

Again, in FIG. 5, a cylinder head 16 is disposed above the cylinder 9, and the cylinder head 16 has an air intake port 17 and an air filter 1.
8, suction valve 19, discharge valve 20 and discharge port 2
1. Note that two sets of O-rings 22 and 23 are installed between the cylinder 9 and the cylinder head 16 to keep the compression chamber 15 airtight. In such a compressor 1, when the piston 8 reciprocates within the cylinder 9, air is drawn from the air intake port 17 to the air filter 1.
8. After taking in external air through the suction valve 19 and compressing it in the compression chamber 15, the compressed air is discharged from the discharge valve 20 through the discharge port 21.

(Problems to be solved by the invention) However, in the seal structure of such a conventional compressor, the second
The piston seal 11 has a gap L in the axial direction with the groove 13, and is configured to be used in a free state with so-called axial play (play), so the compressor 1 operates and the piston 8 When the groove 13 reciprocates, the second piston seal 11 moves in the axial direction by the gap L within the groove 13.
There was a problem in that a tapping sound was generated between the wall surface of the piston and the end surface of the second piston seal 11, and the operation noise was loud.

On the other hand, in order to eliminate the gap L and absorb the backlash and difference in thermal expansion coefficient between the piston and the rider ring (corresponding to the second piston seal), a plurality of convex portions are added to the rider ring. It has also been proposed to provide one (see Japanese Utility Model Publication No. 59-534).
However, in this case, although the rattling noise can be suppressed to some extent, it is inconvenient that the plate thickness of the rider ring cannot be increased and its wear allowance cannot be increased to lengthen the life. Since such rider rings are exposed to severe wear conditions due to the reciprocating motion of the piston, a long life is particularly desirable. This is also related to the process of forming the rider ring. When forming the rider ring from a flat plate into a ring shape, the center part of the plate is deformed into a cross-section that sinks into the inside, as shown in Figure 3. This inevitably increases the diameter of the axial end, making it unusable. Further, when the rider ring is formed into a ring shape by cutting, there is also the problem that it is difficult to provide a convex portion for absorbing backlash and absorbing a difference in thermal expansion coefficient.

(Purpose of the invention) Therefore, the present invention eliminates the gap between the piston seal and the mounting groove by cutting out a portion of the end of the piston seal, forming it into a ring shape, and expanding the axial edge by caulking or the like. Even with thick plate rider rings, there is no rattling or bulging due to thermal expansion, there is little noise, and smooth operation can be ensured.The production accuracy of the rider ring is not required, and it is easy to manufacture. The purpose is to provide a compressor seal structure that can be formed and has a long life.

(Means for Solving the Problems) In order to achieve the above object, the compressor seal structure according to the present invention includes a piston seal installed in a mounting groove on the outer periphery of a piston that is inserted into a cylinder and reciprocates within the cylinder. In the seal structure of a compressor in which the piston seal guides piston sliding against the cylinder wall surface, the piston seal is partially cut out and formed into a ring shape by cutting or the like, and at least a portion of the axial end edge of the piston seal is formed by caulking or the like. The expansion portion is expanded in the axial direction by the expansion portion, and the tip of the expansion portion is brought into contact with the edge of the mounting groove.

(Function) In the present invention, the piston seal is formed into a ring shape with a portion of its end cut out, and at least a portion of the end edge is expanded in the axial direction by caulking or the like, and the tip of the expanded portion is attached to the edge of the mounting groove. bring it into contact with. Therefore, the piston seal can be easily manufactured from a thick plate, has a long life, has no rattling or bulges due to thermal expansion, has little noise, and can ensure smooth operation.

(Example) Hereinafter, the present invention will be explained based on the drawings.

1 and 2 are diagrams showing an embodiment of a seal structure for a compressor according to the present invention. In explaining this embodiment, the same components as those of the conventional example are given the same numbers and the explanation thereof will be omitted.

In FIG. 1, this embodiment shows the second position of the piston 8.
The structure of the piston seal 31 is characteristic, and this part will be explained in detail. A second mounting groove 32 is provided in the piston 8, and a second piston seal 31 is mounted in the second mounting groove 32. Second
The piston seal 31 is formed by cutting a portion into a ring shape, and is easily manufactured. As shown in FIG. 2, the main parts of the second piston seal 31 are initially machined so that there is a predetermined gap with the wall surface 32a of the mounting groove 32, as shown by the broken line A. It is inserted into the mounting groove 32 in the same state. Thereafter, the end portion is caulked and expanded by pressing with a predetermined jig from the direction of arrow K in the figure, and the tip 31a of the expanded portion is expanded.
is brought into contact with the edge (wall surface) 32a of the mounting groove 32.
Accordingly, a portion of the end portion of the second piston seal 31 expands in the axial direction due to caulking, eliminating the above-mentioned gap.

In the above configuration, air is compressed within the cylinder 9 by the reciprocating motion of the piston 8 as in the conventional case, but the effects of this embodiment will be compared with the conventional one.

() Since the end of the second piston seal 31 is in contact with the wall surface 32a of the mounting groove 32 with no gap, it is possible to achieve the function of a guide when the piston 8 slides, while also preventing play in the axial direction. (axial movement) can be eliminated, and deformation due to thermal expansion can also be eliminated. As a result, it is possible to ensure smooth operation with less noise (tapping sound).

() In the case of this embodiment, the second piston seal 31 has the following characteristics compared to the one described in the publication cited as a conventional example.

(a) Since the second piston seal 31 has a simple shape, the structure is simple.

(b) Since the above-mentioned gap is eliminated, the tolerance in the axial direction of the second piston seal 31 may be coarse. Therefore, manufacturing is easy.

(c) The second piston seal 31 may be a cut product, and may have a thick plate.

Therefore, a large amount of wear allowance can be taken, and the durability is long, resulting in a long life. Incidentally, in the case of those described in conventional publications, there is a limit to the plate thickness. In order to have a long life, if the plate thickness is increased, the piston 8
When assembled to the rider cylinder 33 as shown in Figure 3.
The end of the cylinder bulges outward, making it impossible to insert it into the cylinder 9.

Note that the second piston seal 3 in the present invention
The position of the first caulking etc. is the second piston seal 31
As shown in another embodiment in FIG. 4, the end surface 41a of the second piston seal 41 is
It is also possible to swage a portion a predetermined distance toward the center.

(Effects) According to the present invention, the end of the piston seal is partially cut out and formed into a ring shape, and at least a portion of the end edge is expanded in the axial direction by caulking or the like, and the tip of the expanded portion is inserted into the mounting groove. Since it is in contact with the edge, manufacturing precision of the piston seal is not required.
The piston seal can be easily manufactured from a thick plate, has a long life, has no rattling or bulges due to thermal expansion, has little noise, and can ensure smooth operation.

[Brief explanation of the drawing]

Figures 1 and 2 are diagrams showing an embodiment of the seal structure of a compressor according to the present invention. Figure 1 is a partial cross-sectional view showing the overall structure, and Figure 2 is a cross-sectional view of the main part of the piston seal. 3 is a perspective view showing a piston seal of a conventional compressor seal structure, FIG. 4 is a sectional view of the main part of the piston seal showing another embodiment according to the present invention, and FIGS. 5 and 6 are FIG. 5 is a partial sectional view showing the entire structure of the seal structure of a conventional compressor, and FIG. 6 is a sectional view of the piston portion thereof. 1... Compressor, 8... Piston, 9... Cylinder, 12... Groove, 14... O-ring, 15... Compression chamber, 16... Cylinder head, 31, 41...
Second piston seal, 32... mounting groove.

Claims (1)

[Scope of utility model registration request] A compressor seal structure in which a piston seal is installed in a mounting groove on the outer periphery of a piston that is inserted into a cylinder and reciprocates within the cylinder, and the piston seal guides the sliding movement of the piston against the cylinder wall surface. A portion of the expanded portion is cut out and formed into a ring shape by cutting or the like, and at least a portion of the axial edge thereof is expanded in the axial direction by caulking or the like, and the tip of the expanded portion is brought into contact with the edge of the mounting groove. A compressor seal structure characterized by: