JPH073087Y2 - High pressure fluid sealing device - Google Patents

Description

[Detailed Description of the Invention] (Industrial field of application) The present invention is applied to a high-pressure fluid device handling an ultra-high pressure fluid of several thousands kg / cm ² , and seals between the high-pressure side cylinder and the plunger. The present invention relates to a high pressure fluid seal device suitable for.

(Prior Art) An example of a conventional high-pressure fluid seal device is shown in Japanese Examined Patent Publication No. 55-6790. This prior art is a tubular packing member in which the packing housed in the packing box of the high pressure side cylinder has a conical outer peripheral surface that is reduced toward the high pressure side,
This conical outer peripheral surface is formed by combining an O-ring interposed in an annular space having a triangular cross section formed by the inner peripheral surface of the packing box and the like. Then, as the fluid pressure on the high-pressure chamber side becomes higher, the O-ring is pressed in a narrower direction of the space having a triangular cross section, and the O-ring is strongly adhered to the conical outer peripheral surface and the inner peripheral surface of the packing box. Further, the force of the O-ring pressing the conical outer peripheral surface causes a force in the contracting direction to act on the inner hole of the tubular packing member, so that the O-ring strongly adheres to the plunger.
In this way, the ultrahigh pressure fluid is sealed.

By the way, in the above-mentioned conventional technique, the higher the fluid pressure on the high-pressure chamber side, the more the O-ring is pressed in the narrower direction of the space having the triangular cross section, so that strong elastic deformation is forced. For this reason, the O-ring is liable to be damaged at an early stage, and plastic deformation is likely to occur, so that the function as the packing is not easily lost. Further, the inner peripheral surface of the packing box is expanded by the ultra-high pressure fluid, and a gap is created between the inner peripheral surface of the packing box and the outer peripheral surface of the tubular packing member, and the O-ring protrudes into the gap and is bitten and damaged. easy. For these reasons, the above-mentioned conventional technique has a problem that the service life is short.

Therefore, a technique for improving the above conventional technique is disclosed in Japanese Patent Publication No. 61-
No. 8311. In the technique disclosed in Japanese Patent Publication No. 61-8311, an elastic packing member having a substantially pentagonal cross section having a conical inner peripheral surface in close contact with the conical outer peripheral surface of a tubular packing member is used instead of the O-ring. It is characterized by being inserted in a triangular annular space.

(Problems to be solved by the invention) By the way, in the technique disclosed in Japanese Patent Publication No. 61-8311, the elastic ring has a substantially pentagonal cross section, so that
Compared to the ring, the degree of elastic deformation is reduced, and it does not stick out in the gap between the tubular packing member and the inner peripheral surface of the packing box, and the elastic ring is less damaged and the service life is extended. . However, the elastic ring is interposed in the annular space having a triangular cross section, and is strongly pressed in the narrow direction of the space having a triangular cross section by the fluid pressure to cause plastic deformation, so that the service life is not yet sufficient.

The present invention has been made in view of the circumstances of the conventional high-pressure fluid seal device as described above, and provides a high-pressure fluid seal device having a long service life by avoiding plastic deformation without deforming the packing strongly. With the goal.

(Means for Solving the Problems) In order to achieve such an object, the high-pressure fluid sealing device of the present invention is configured as follows.

First, the high-pressure fluid seal device of the present invention stores the packing in the packing box of the high-pressure side cylinder forming the high-pressure chamber,
In a high-pressure fluid seal device for sealing between the high-pressure side cylinder and a plunger inserted in the high-pressure chamber, the packing is formed by combining a tubular packing member and a ring-shaped packing member, and the tubular packing member is A step portion having an inner hole that fits in a watertight manner with the plunger and a wall surface facing the high pressure chamber side, a conical outer peripheral surface connected to the step portion and contracting toward the high pressure chamber side, and a conical outer peripheral surface facing the high pressure chamber side And a cylindrical outer peripheral surface connected to each other, the outer periphery of the tip end portion of the cylindrical outer peripheral surface is fitted into a hole of a top adapter provided on the high pressure chamber side in the packing box, and the ring-shaped packing member is It is more elastic than the tubular packing member, and is inscribed in the conical outer peripheral surface and circumscribes the inner peripheral surface of the packing box.

Further, in the high-pressure fluid seal device of the present invention, the conical outer peripheral surface is extended from the position where the ring-shaped packing member is inscribed to the high-pressure chamber side instead of the cylindrical outer peripheral surface of the cylindrical packing member, The outer periphery of the tip end portion of the conical outer peripheral surface may be fitted into a conical hole provided in the top adapter.

Then, a chamfer is formed on the outer periphery of the distal end portion of the cylindrical outer peripheral surface on the high pressure chamber side, and a conical inner peripheral surface to which the chamfer is connected is formed in the hole of the top adapter, and the cylindrical packing member is pressurized to a high pressure. It is also possible to form a packing land that is pressed and held on the chamber side by screwing it into the opening of the packing box.

(Operation) Since the tubular packing member has a step portion having a wall surface facing the high pressure chamber side and a conical outer peripheral surface which is continuous with the step portion and reduces toward the high pressure chamber side, the conical outer circumference Even if the ring-shaped packing member that is inscribed in the inner surface is strongly pressed by the pressure of the high-pressure fluid, it is formed in the wall shape of the step, the conical outer surface, and the inner peripheral surface of the packing box. As a result, elastic deformation is restricted and extreme deformation does not occur. Further, since the tubular packing member has a tubular outer peripheral surface connected to the high-pressure chamber side from the conical outer peripheral surface into which the ring-shaped packing member is fitted, the tubular outer peripheral surface is moved in the inner hole direction by fluid pressure. It is pressed and contracted, and the inner hole adheres more strongly to the plunger. Since the top adapter having a hole into which the outer circumference of the tip of the cylindrical outer peripheral surface fits is provided on the high-pressure chamber side in the packing box, the position of the ring-shaped packing member can be restricted to secure an appropriate crushing allowance. And a reliable initial seal is obtained. Also,
The outer circumference of the tip of the cylindrical outer peripheral surface is fitted to the top adapter to restrict the expansion of the inner hole of the tip of the tubular packing member,
No fluid gap creates a gap with the plunger.

Further, if the cylindrical outer peripheral surface is extended from the position where the ring-shaped packing member is fitted to the high-pressure chamber side, the extended portion is pressed and contracted in the inner hole direction by the fluid pressure, and is stronger against the plunger. The inner hole is in close contact. Moreover, since the outer diameter is smaller as it is closer to the tip, elastic deformation is facilitated, and the inner hole of the tubular packing member can be brought into close contact with the plunger from the tip on the high pressure chamber side according to the fluid pressure.

Then, a chamfer is provided on the outer periphery of the end portion of the cylindrical outer peripheral surface on the high pressure chamber side, a conical inner peripheral surface overlapping with the chamfer is formed on the top adapter, and a packing land screwed into the opening of the packing box, If the tubular packing member is pressed and held by the top adapter, the packing land can be tightened to shrink the tip of the tubular packing member and bring the inner hole into close contact with the plunger.

(Embodiment) An embodiment of the high-pressure fluid sealing device of the present invention will be described below with reference to FIGS. 1 to 3. FIG. 1 is a sectional view of an embodiment in which the high-pressure fluid sealing device of the present invention is applied to a pressure booster for generating an ultrahigh-pressure fluid, and FIG. 2 is an enlarged sectional view of an essential part of FIG. FIG. 3 is a diagram for explaining the action of force by the ultrahigh pressure fluid.

1 to 3, a low pressure chamber 2 is formed in the low pressure side cylinder 1, and a piston 3 reciprocates in the low pressure chamber 2. Further, a high pressure side cylinder 4 is provided so as to be connected to the low pressure side cylinder 1, and a high pressure chamber 5 is formed in the high pressure side cylinder 4. A plunger 6 provided integrally with the piston 3 is arranged so as to straddle between the low pressure chamber 2 and the high pressure chamber 5, and the tip of the plunger 6 is configured to reciprocate in the high pressure chamber 5. It Further, a check valve 7 that is opened only when the fluid is supplied to the high pressure chamber 5 and a check valve 8 that is opened only when the high pressure fluid generated in the high pressure chamber 5 is sent out are provided. Connected by piping.
Further, the high pressure side cylinder 4 is formed with a packing box 9 which is opened to the low pressure chamber 2 and has a bottomed hole coaxial with the high pressure chamber 5, and a large diameter screw hole 10 is formed in the opening. A rigid top adapter 11, a tubular packing member 12, a backup ring 13, and a rigid bottom adapter 14 are sequentially fitted and inserted into the packing box 9 from the high-pressure chamber 5 side, and the packing land is screwed into the screw hole 10. These are pressed and held at 15. Further, as will be described later, the top adapter 11
An annular space is formed by the cylindrical packing member 12 and the inner peripheral surface of the packing box 9, and the ring-shaped packing member is formed therein.
16 are placed.

The tubular packing member 12 is formed of a resin having excellent wear resistance, such as nylon or Teflon, has an inner hole 12a having an inner diameter for closely fitting with the plunger 6, and is in close contact with the inner peripheral surface of the packing box 9. It has an outer peripheral surface 12b. Further, a step portion having a wall surface 12c facing the high pressure chamber 5 side is formed, and a conical outer peripheral surface 12d is formed which is connected to the step portion and reduces the outer diameter toward the high pressure chamber 5 side. A cylindrical outer peripheral surface 12e is formed in a continuous manner at the tip of the outer peripheral surface 12d. In addition,
The inner hole 12a may have a conical shape so that the low pressure chamber 2 side has the same inner diameter as the outer diameter of the plunger 6 and the diameter decreases toward the high pressure chamber 5 side. The top adapter 11 has an outer peripheral surface that fits into the packing box 9 and an inner hole that allows the plunger 6 to pass through, and a bottomed hole into which the outer periphery of the tip end of the cylindrical outer peripheral surface 12e of the tubular packing member 12 fits. 11a is provided. The ring-shaped packing member 16 formed of an O-ring or the like is formed of soft synthetic rubber or natural rubber that is more elastic than the tubular packing member 12, and has a conical outer peripheral surface of the tubular packing member 12.
The size is set so as to be inscribed in 12d and circumscribed on the inner peripheral surface of the packing box 9 to obtain an appropriate crushing margin. Further, the backup ring 13 has an inner hole that is in close contact with the plunger 6 and an outer peripheral surface that contacts the inner peripheral surface of the packing box 9.
The bottom adapter 14 has an inner hole through which the plunger 6 loosely fits and an outer peripheral surface that fits on the inner peripheral surface of the packing box 9. Further, the packing land 15 has an inner hole through which the plunger 6 loosely fits, and a bottomed hole into which the bottom adapter fits, and a screw screwed into the screw hole 10 is engraved on the outer peripheral surface.

In such a configuration, the position of the top adapter 11 is restricted, the ring-shaped packing member 16 is positioned and an appropriate crushing allowance is provided, and the inner peripheral surface of the packing box 9 and the conical outer peripheral surface of the tubular packing member 12 are provided. While contacting with 12d with a predetermined pressure, the plunger 6 comes into close contact with the inner hole 12a of the tubular packing member 12, and an initial seal is obtained. Therefore, an appropriate pressure fluid is caused to flow into the low pressure chamber 2 side to move the piston 3 to the first position.
When moved to the right in the figure, the plunger 6 is placed in the high pressure chamber 5.
Is projected to increase the pressure of the fluid in the high pressure chamber 5 to generate an ultrahigh pressure fluid. The pressure (F _{1 in} FIG. 3) of this ultrahigh pressure fluid causes the ring-shaped packing member 16 to be pressed and moved to the low pressure chamber 2 side. Then, the conical outer peripheral surface 12d increases the crushing margin, and the contact pressure also increases accordingly, and the sealing effect increases. And if it contacts the wall surface 12c of the step,
The elastic deformation of the ring-shaped packing member 16 is restricted to a substantially U-shaped cross section formed by the wall surface 12c, the conical outer peripheral surface 12d, and the inner peripheral surface of the packing box 9, and the contact surface is not deformed extremely. The pressure can be increased. In addition, the tubular packing member 12
The cylindrical outer peripheral surface 12e is pressed and shrunk in the direction of the inner hole 12a by the pressure of the ultrahigh pressure fluid (F _{2 in} FIG. 3), and the inner hole 12a is brought into closer contact with the plunger 6. Therefore, the sealing effect for the ultrahigh pressure fluid is increased. Here, since the bottomed hole 11a of the top adapter 11 is fitted to the tip of the tubular outer peripheral surface 12e of the tubular packing member 12, the inner hole 12a of the tip of the tubular outer peripheral surface 12e is expanded. Deformation is restricted, and it is effective for surely maintaining the sealing effect between the tubular packing member 12 and the plunger 6.

As described above, even when applied to a sealing device of a device that generates an ultra-high pressure fluid, the ring-shaped packing member 16 is not extremely deformed, and plastic deformation and damage are less likely to occur, and the service life is long. Become. Then, when the use is stopped, the generation of the ultrahigh pressure fluid is also stopped, so that the ring-shaped packing member 16 gradually shifts the conical outer peripheral surface 12a toward the high-pressure chamber 5 side by its elastic force, recovers the elastic force and is plastic. Very little deformation and long service life. Further, since the inner hole 12a of the tubular packing member 12 is brought into close contact with the plunger 6 by the pressure of the ultrahigh pressure fluid, the sealing effect can be reliably maintained even if the inner hole 12a is worn.

FIG. 4 is a sectional view showing the main part of another embodiment of the high-pressure fluid sealing device of the present invention. In FIG. 4, the same members as those in FIG. 2 are designated by the same reference numerals, and the same or similar functions are designated by the same subscripts, and duplicated description will be omitted.

4 is different from FIG. 2 in the following points. First, the tubular outer peripheral surface 22e of the tubular packing member 22.
A chamfer 22f is formed on the outer periphery of the tip end of the, and a conical inner peripheral surface 21a overlapping the chamfer 22f is formed on the top adapter 21. The tip of the tubular packing member 22 does not contact the bottom surface of the bottomed hole forming the conical inner peripheral surface 21a of the top adapter 21. A second conical outer peripheral surface 22g is formed on the tubular packing member 22 instead of the stepped portion having the wall surface 12c, and is formed by the second conical outer peripheral surface 22g and the inner peripheral surface of the packing box 9. The wall surface facing the high-pressure chamber 5 and the cross-sectional shape of which matches the triangle-shaped annular space
A triangular ring 17 having 17a and formed of hard resin or the like is arranged.

In such a configuration, when the packing land 15 is retightened, the tip end of the cylindrical outer peripheral surface 22e is pressed and contracted in the inner hole 22a direction by the conical inner peripheral surface 21a of the top adapter 21,
The inner hole 22a is firmly brought into close contact with the plunger 6. Therefore, sliding of the plunger 6 causes the inner hole of the tubular packing member 22.
When 22a is worn, the sealing effect can be maintained by tightening packing land 11 tightly. Also, the diameter of the inner peripheral surface of the packing box 9 is expanded by the pressure of the ultrahigh pressure fluid, and the gap between the inner peripheral surface of the tubular packing member 22 and the outer peripheral surface 22b becomes large. Enlarged so that it contacts the inner peripheral surface. Therefore, the ring-shaped packing member 16 does not stick out and get caught in the gap.

FIG. 5 is a cross-sectional view of the essential parts of yet another embodiment of the high-pressure fluid sealing device of the present invention. In FIG. 5, the same members as those in FIG. 2 are designated by the same reference numerals, and the same or similar functions are designated by the same subscripts, and duplicated description will be omitted.

5 is different from FIG. 2 in the following points. First, the cylindrical packing member 32 has a cylindrical outer peripheral surface 12
Instead of e, a conical outer peripheral surface 32d is extended. Then, the top adapter 31 is penetrated with a conical inner hole 31a that overlaps with the extended conical outer peripheral surface 32d. Further, the ring-shaped packing member 36 is formed in a substantially quadrangular shape in contact with the conical outer peripheral surface 32d, the inner peripheral surface of the packing box 9 and the wall surface of the top adapter 31 on the low pressure chamber 2 side.

In such a configuration, the tubular packing member 32 has the high pressure chamber 5
The tip portion on the side has a smaller diameter and is easily elastically deformed, and the inner hole 32a of the tip portion is more surely brought into close contact with the plunger 6 by the pressure of the high-pressure fluid. Further, if the packing land 11 is appropriately retightened, the tip of the tubular packing member 32 can be easily reduced in the direction of the inner hole 32a by the conical inner hole 31a. The ring-shaped packing member 36 having a quadrangular cross section is
The contact area between the inner peripheral surface of the packing box 9 and the conical outer peripheral surface 32d of the tubular packing member 32 is widened, so that wear is reduced and service life is extended.

The ring-shaped packing members 16 and 36 are not limited to O-rings and quadrangular cross sections, and may be pentagonal cross sections or the like. Further, the application of the high-pressure fluid sealing device of the present invention is not limited to the pressure booster, and may be applied to a plunger pump, a swivel joint sealing device, or the like.

(Effects of the Invention) Since the high-pressure fluid sealing device of the present invention is configured as described above, it has special effects as described below.

In the high-pressure fluid sealing device according to the first aspect, the ring-shaped packing member is not extremely deformed even when the ultra-high-pressure fluid is generated, and plastic deformation or damage is not caused as much, and the service life is long. Further, the tubular packing member is pressed and contracted in the inner hole direction by the pressure of the high-pressure fluid, and the inner hole comes into close contact with the plunger, so that a reliable sealing effect is obtained. Then, the position of the ring-shaped packing member is restricted by the top adapter, an appropriate crushing allowance can be secured, and a reliable initial seal can be obtained. In addition, the expansion of the inner hole at the tip of the tubular packing member is restricted by the top adapter, and there is no gap between the tubular packing member and the plunger due to fluid pressure, ensuring the sealing effect between the tubular packing member and the plunger. Can be maintained at

Further, in the high pressure fluid sealing device according to claim 2,
The cylindrical packing member has a smaller diameter toward the high pressure chamber side and is easily elastically deformed, and the inner hole is pressed and contracted by the pressure of the high pressure fluid so as to come into close contact with the plunger from the tip portion, and the sealing effect is excellent.

Further, in the high-pressure fluid sealing device according to claim 3, when the inner hole of the tubular packing member is enlarged due to wear and the sealing effect is weakened, the packing land is retightened, whereby the tubular packing member is tightened. It is possible to reduce the inner hole at the tip end of the to make it closely contact with the plunger, maintain the sealing effect, and prolong the useful life.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment in which the high pressure fluid sealing device of the present invention is applied to a pressure booster for generating an ultrahigh pressure fluid.
FIG. 2 is an enlarged cross-sectional view of the main part of FIG. 1, and FIG.
FIG. 4 is a view for explaining the action of force by the ultra-high pressure fluid, FIG. 4 is a sectional view of an essential part of another embodiment of the high pressure fluid seal device of the present invention, and FIG. 5 is a high pressure fluid seal of the present invention. It is a principal part sectional drawing of another Example of an apparatus. 4: High pressure side cylinder, 5: High pressure chamber, 6: Plunger, 9: Packing box, 10: Screw hole, 11,21,31: Top adapter, 11a: Bottom hole, 12,22,32: Cylindrical packing member , 12a, 22a, 32a: inner hole, 1
2c, 22c, 32c: Wall surface, 12d, 22d, 32d: Conical outer peripheral surface, 12e, 22
e: cylindrical outer peripheral surface, 15: packing land, 16, 36: ring-shaped packing member, 21a: conical inner peripheral surface, 22f: chamfer, 31a: conical inner hole.

Claims (3)

[Scope of utility model registration request] 1. A high-pressure fluid seal device for accommodating a packing in a packing box of a high-pressure side cylinder forming a high-pressure chamber to seal between the high-pressure side cylinder and a plunger inserted into the high-pressure chamber. Is formed by combining a tubular packing member and a ring-shaped packing member, and the tubular packing member has a step portion having an inner hole that fits in a watertight manner with the plunger and a wall surface facing the high pressure chamber, and this step portion. It has a conical outer peripheral surface that is connected and contracts toward the high-pressure chamber side, and a cylindrical outer peripheral surface that is connected toward the high-pressure chamber side from the conical outer peripheral surface, and the tip outer periphery of the cylindrical outer peripheral surface is inside the packing box. Of the top adapter provided on the side of the high pressure chamber, the ring-shaped packing member is superior in elasticity to the tubular packing member and is inscribed in the conical outer peripheral surface and High pressure fluid seal apparatus characterized by being configured so as to circumscribe the inner peripheral surface of the down box. 2. The high-pressure fluid sealing device according to claim 1, wherein the conical outer peripheral surface is replaced with the cylindrical outer peripheral surface of the cylindrical packing member from the position where the ring-shaped packing member is inscribed. A high-pressure fluid sealing device, which is formed by extending to the side and fitting the outer circumference of the tip end portion of the conical outer peripheral surface into a conical hole provided in the top adapter. 3. The high-pressure fluid sealing device according to claim 1, wherein a chamfer is formed on an outer periphery of a tip portion of the cylindrical outer peripheral surface on the high-pressure chamber side, and the chamfer is in contact with the hole of the top adapter. A high-pressure fluid sealing device, comprising an inner peripheral surface, and a packing land for pressing and holding the tubular packing member toward the high-pressure chamber side is screwed into an opening of the packing box.