JPH023013Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The invention relates to a piston ring extension device, and more specifically, it is used in a reciprocating compressor, a piston valve that reciprocates in a cylinder using gas pressure, an air cylinder driven valve, etc. It is used as a piston ring extension device.

Conventional technology Conventionally, oil-free reciprocating compressors have used piston rings to compress gas, and in order to reduce leakage of the compressed gas, the piston rings have been pressed against the inner wall of the cylinder. There is. There are various methods of pressing, and one of them is a method using a plunger as shown in FIG.

In FIG. 2, 21 is a cylinder, 22 is a piston, 23 is a groove provided along the circumference of the piston 22, 24 is a piston ring loosely fitted in the groove 23, and 25 is attached to the piston 22. 26 is a hollow cylindrical plunger shaft loosely inserted into the hole 25; 27 is a plunger fixed to the plunger shaft 26 so as to press the piston ring 24 against the inner wall of the cylinder 21; A coil spring is installed inside the plunger shaft 26 in a compressed state, 29 is a guide pin for the coil spring 28, and 30 is a spring receiving cushion.

Problems to be Solved by the Invention As shown in Fig. 2, in the conventional piston ring tensioning device, the coil spring 28 is installed in a compressed state, so the plunger 27 is always pushed out in the direction (the direction in which it is pushed out). 2 (rightward in Figure 2), and therefore the piston ring 24 is always pressed so as to be in close contact with the inner wall of the cylinder 21. However, the piston ring 24 is made of a material that is easily damaged, such as carbon. If, by any chance, the piston ring 24 in contact with the plunger 27 is worn out or damaged, the plunger 27 will slip out of the groove 23, and the plunger stem 26 and coil spring 28 will slip out of the hole 25, causing the plunger 27 to come out. is cylinder 2
1 and reciprocates with the piston 22, causing damage to the cylinder 21, breakage of the plunger 27, and damage to the piston 22. Another problem is that inspection and parts replacement are required within a short period of time in order to prevent the above-mentioned damage. The present invention attempts to solve these problems. That is, an object of the present invention is to provide a piston cylinder extension device in which even if the piston ring is damaged, the plunger will not come off and reach the cylinder, and the cylinder, piston, and other parts will not be damaged. The purpose is to

Means for Solving the Problem A coil spring is used as a tension spring, and it is provided so as to surround the outside of the plunger shaft, and one end of the spring is spread out and pressed against the groove of the piston so as to be stretched. The other end was fixed to the end of the plunger stem to prevent the plunger from slipping out of the groove of the piston. That is, in the structure of the present invention, a piston ring is installed in a groove provided along the outer periphery of the piston, and a coil spring and a plunger shaft are installed in a hole drilled in the piston, so that the spring's reaction In a piston ring extension device in which a plunger presses the piston ring against the inner wall of the cylinder by force, one end of the spring has a large diameter and presses against the groove of the piston, and the diameter near the one end is larger than the diameter of the piston. The diameter of the hole is larger than the diameter of the hole, and the other end is fixed to the edge of the hole, and the other end is fixed to the end of the plunger shaft, and the plunger shaft is inserted into the spring. The spring is inserted into the hole of the piston in a stretched state.

Function: The coil spring acts as a tension spring and causes the piston ring to come into close contact with the inner wall of the cylinder. However, since one end of the spring is in pressure contact with the groove of the piston and is under tension, the piston ring may be damaged. Even if the spring and plunger shaft do not come out of the piston hole,
Therefore, the plunger never slips out of the groove.

Embodiment FIG. 1 shows an embodiment of the present invention. 1st
In the figure, 1 is a cylinder, 2 is a piston, 3 is a groove provided along the circumference of the piston 2, and 4 is a groove provided along the circumference of the piston 2.
is a piston ring loosely fitted into the groove 3;
5 is a plunger, 6 is a hole drilled in the piston 2, 7 is a plunger shaft which is loosely inserted into the hole 6 with the plunger 5 fixed thereto, and 8 is a plunger shaft 7 which is loosely inserted into the hole 6. The coil spring passing through, 9 is one end of the spring 8, 10 is near one end 10, 11 is the other end of the spring 8, 12 is the edge surface of the hole 6, and 13 is the end of the plunger shaft 7. . That is,
The coil spring 8 has one end 9 with a larger diameter and comes into pressure contact with the groove 3 of the piston 2, and the diameter 10 near the one end 9 is larger than the diameter of the hole 6 of the piston 2 so that the hole 6, and the other end 11 is caulked and fixed to the end 13 of the plunger shaft 7. Moreover, the plunger shaft 7 passes through the coil spring 8, and the coil spring 8 is assembled into the hole 6 in an extended state.

In the piston ring extension device configured as shown in FIG.
One end 9 is in pressure contact with the groove 3 and is stretched, and the vicinity 10 of the one end 9 is locked with the edge surface 12 of the hole 6,
The other end 11 is fixed to the end 13 of the plunger mandrel 7 and is extended by the plunger mandrel 7, that is, in FIG. 1, the plunger mandrel 7 is pushed to the left. Therefore, the area between the vicinity 10 of one end 9 and the other end 11 of the coil spring 8 becomes a tension spring, and its reaction force acts to the right in FIG. , the plunger stem 7 and the plunger 5 are pushed to the right in FIG.

Therefore, in the event that the piston ring 4 is damaged, the coil spring 8 simply loses its deflection (extension amount), and the plunger 5 does not come out of the groove 3 of the piston 2. That is, one end 9 of the coil spring 8 is in pressure contact with the groove 3 and is stretched, so the coil spring 8 does not come out of the groove 3. This results in
The plunger shaft 7 whose end 13 is fixed to the other end 11 of the coil spring 8 also does not come out from the hole 6 of the piston 2, and the plunger 5 which is fixed to this plunger shaft 7 does not come out from the groove 3. . Therefore, the components explained in FIG. 2 are not damaged.

Effects of the invention In the present invention, one end of the coil spring has a large diameter and is in pressure contact with the groove of the piston, and the other end of the coil spring is fixed to the end of the plunger shaft. If one piston ring breaks, the coil spring or plunger will not come out of the groove of the piston. Therefore, if the piston ring breaks, nothing will be damaged, including the piston and cylinder.
This eliminates the need for early inspection of pistons and cylinders and early replacement of parts, significantly reducing running costs for users, and eliminating the need to change the shape or dimensions of conventional cylinders, pistons, piston rings, etc. , can be used as is. Moreover, since the coil spring has a function to prevent it from coming out of the groove, the number of parts does not increase.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway sectional view showing an embodiment of the present invention, and FIG. 2 is a partially cutaway sectional view showing an example of a conventional technique. 1...Cylinder, 2...Piston, 3...Groove,
4...Piston shilling, 5...Plunger, 6
... Hole, 7 ... Plunger stem, 8 ... Coil spring, 9 ... One end, 10 ... Near one end, 1
1...other end, 12...edge surface, 13...end.

Claims (1)

[Scope of utility model registration request] A piston ring is installed in a groove provided along the outer circumference of the piston, and a coil spring and a plunger shaft are installed in a hole drilled in the piston, so that the plunger pushes the piston ring due to the reaction force of the spring. In a piston ring extension device that presses against the inner wall of a cylinder, one end of the spring has a large diameter and presses against the groove of the piston, and the diameter near the one end is larger than the diameter of the hole of the piston. It is curved and is locked on the edge of the hole,
The other end is fixed to the end of the plunger mandrel, and the plunger mandrel passes through the spring and is assembled into the hole of the piston with the spring stretched. A piston ring extension device.