JPH0658424A - Sealing device for superhigh pressure liquid - Google Patents

Abstract

PURPOSE:To keep off the worsening of sealability and prolong the life-time by installing a U-shaped seal ring in contact with an outer circumferential surface of a sliding member and an inner circumferential surface of a fixed member at the outside of this sliding member, and fitting a ring elastic sealing member in the inner part. CONSTITUTION:A sectional U-shaped seal ring 11 is interposed between a cylinder 1 as a cylindrical fixed member and a plunger 2 as a sliding member slidingly inserted to the cylinder 1 via a spacer 3, and a ring elastic sealing member 12 is fitted in this seal ring 11, thereby sealing up a superhigh pressure fluid. This seal ring is made up of a wear resistant material such as tungsten carbide or the like. With this constitution, this superhigh pressure water penetrated into the seal ring 11, pressing the elastic sealing member 12 under pressure, getting it elastically deformed in the radial direction, and thereby the seal ring 11 is forcibly pressed to the cylinder 1 and the plunger 2, thus sealability is secured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrahigh pressure liquid sealing device for preventing water leakage in a pressure booster used to generate ultrahigh pressure water in a water jet processing apparatus.

[0002]

2. Description of the Related Art FIG. 4 shows a main part of a general pressure intensifier used for generating ultrahigh pressure water in a water jet cutting system. here,
Reference numeral 1 is a cylinder (in other words, a fixed member), and a plunger (in other words, a sliding member) 2 is slidably inserted into the cylinder 1 via a spacer 3 and the plunger 2 A pressurizing chamber 5 is formed between the top surface 2 a of the cylinder 1 and the sealing head 4 arranged at the end of the cylinder 1. A base end portion 2b of the plunger 2 is connected to a hydraulic piston 6, and the plunger 2 is reciprocated in the spacer 3 by the hydraulic piston 6 so that the sealing head 4 moves in the pressurizing chamber 5 inward. The low-pressure water sucked into is pressurized to an ultra-high pressure (for example, about 3000 kg / cm ² ) and is supplied as ultra-high-pressure water from the sealing head 4 to the water jet (not shown) side. Reference numeral 7 is a backup ring for holding the sealing device A.

A sealing device A is provided between the cylinder 1 and the plunger 2 to prevent water leakage of the super high pressure water and to ensure the sealing performance. In the case of the illustrated water jet cutting system, the sealing device A is also arranged between the cylinder 1 and the sealing head 4.

This sealing device A, as shown in FIG.
A seal ring 31 having an L-shaped cross section, which includes a peripheral wall portion 31a that contacts the outer peripheral surface of the plunger 2 and a vertical wall portion 31b that extends radially outward from one end of the peripheral wall portion 31a, and the seal ring 31. And an O-ring 32 fitted in a space 33 surrounded by the inner peripheral surface of the cylinder 1, and the plunger 2 is attached by the seal ring 31.
The sealability between the cylinder 1 and the plunger 2 is ensured by the O-ring 32 while coping with the wear caused by the sliding of the.

[0005]

However, in the case of the above-described conventional sealing device, the vertical wall portion 31 of the seal ring 31 is used.
b has a uniform thickness to ensure its strength,
A relatively wide annular gap 34 is formed between the outer end surface of the vertical wall portion 31b and the inner peripheral surface of the cylinder 1.
On the other hand, the internal pressure of the pressurizing chamber 5 alternates between ultrahigh pressure and low pressure as the plunger 2 reciprocates.

Therefore, when the O-ring 32 is subjected to an extremely high pressure, a part of the O-ring 32 is pushed into the annular gap 34, and when a low pressure is applied, the O-ring 32 is restored by its own restoring force. Will be pulled back from 34. Moreover, since such an action is repeated alternately, the O-ring 32 gradually wears at the portion corresponding to the annular gap 34 to cause the "peeling phenomenon" (that is, the chain line in FIG. A crevice 35 occurs).

It has been pointed out that such a "peeling phenomenon" causes water leakage due to poor sealability and causes an increase in the running cost of the device due to a shortened life of the O-ring 32. Was there.

The present invention has been made in view of the above points, and prevents the "peeling phenomenon" of an elastic seal member (for example, an O-ring) to prevent deterioration of sealing performance and lengthening of the elastic seal member. The purpose is to extend the life.

[0009]

In the invention of claim 1, as means for solving the above-mentioned problems, as shown in the drawings, a cylindrical fixing member 1 and a spacer 3 in the fixing member 1 are provided.
A sealing device for an ultra-high pressure liquid, which seals an ultra-high pressure liquid invading between the fixing member 1 and the sliding member 2 between the sliding member 2 slidably inserted through the fixing member, 1, an outer peripheral wall portion 11a that abuts the inner peripheral surface of the sliding member 2, and an inner peripheral wall portion 11b that abuts the outer peripheral surface of the sliding member 2, and has a U-shaped cross section. The ring-shaped elastic seal member 12 is mounted.

In the invention of claim 2, as a means for solving the above-mentioned problems, as shown in the drawings, an O-ring is adopted as the elastic seal member 12 in the seal device for an ultrahigh pressure liquid according to claim 1. I am trying to do it.

According to a third aspect of the present invention, as a means for solving the above-mentioned problems, as shown in the drawings, in the seal device for an ultra-high pressure liquid according to the second aspect, the O-ring 1
The side of the ultrahigh-pressure liquid intruding in 2 is made flat.

[0012]

According to the invention of claim 1 or 2, the following actions can be obtained by the above means.

That is, when the reciprocating motion of the sliding member 2 causes the ultra high pressure water to enter the seal ring 11 and the ultra high pressure to act on the elastic seal member (for example, an O ring) 12, the elastic seal member 12 has a radius. Seal ring 1 by elastically deforming in the direction
The inner and outer peripheral wall portions 11b and 11a of 1 are brought into pressure contact with the outer peripheral surface of the sliding member 2 and the inner peripheral surface of the fixed member 1, respectively, so that sealing performance is ensured. Moreover, at this time, the elastic seal member 12 is smoothly deformed along the inner peripheral surface of the seal ring 11, and the elastic seal member 1 as in the conventional example.
From the place where partial deformation of 2 does not occur, the seal ring 1
Even if the pressure in 1 repeats ultrahigh pressure and low pressure, the "peeling phenomenon" due to partial wear does not occur.

According to the third aspect of the invention, the following actions can be obtained by the above means.

That is, since the surface of the O-ring 12 on which the ultra-high pressure liquid enters is flat, the pressure-receiving area of the ultra-high pressure acting on the O-ring 12 increases, and the seal ring 11 slides due to elastic deformation of the O-ring 12. Adhesion to the moving member 2 and the fixed member 1 is significantly improved.

[0016]

According to the first or second aspect of the present invention, there is provided between the cylindrical fixing member 1 and the sliding member 2 slidably inserted into the fixing member 1 through the spacer 3. A sealing device for an ultra-high pressure liquid that seals the ultra-high pressure liquid invading between the fixed member 1 and the sliding member 2,
The outer peripheral wall 11a that abuts the inner peripheral surface of the
The seal ring 11 having a U-shaped cross section, which has an inner peripheral wall portion 11b that abuts the outer peripheral surface of the seal member, and an annular elastic seal member 12 fitted in the seal ring 11 are slidable. When the ultra high pressure water enters the seal ring 11 due to the reciprocating motion of the member 2 and the ultra high pressure acts on the elastic seal member (for example, O ring) 12, the elastic seal member 12 is elastically deformed in the radial direction. Since the inner and outer peripheral wall portions 11b and 11a of the seal ring 11 are brought into pressure contact with the outer peripheral surface of the sliding member 2 and the inner peripheral surface of the fixed member 1, respectively, the sealing property between the sliding member 2 and the fixed member 1 is improved. Has an excellent effect that it can be surely held.

Further, according to the invention of claim 1 or 2, since the elastic seal member (for example, the O-ring) 12 is smoothly deformed along the inner peripheral surface of the seal ring 11, the elastic seal member 12 in the conventional example is used. As described above, the elastic seal member 12 is not partially deformed, and even if the pressure inside the seal ring 11 is repeatedly super-high pressure and low pressure, the "peeling phenomenon" due to partial wear does not occur, and the elastic seal member 12 is prevented.
Has an excellent effect that the life can be extended and the sealing property can be maintained for a long period of time.

According to the invention of claim 3, in the sealing device for ultra-high pressure liquid according to claim 2, the super-high-pressure liquid intruding side of the O-ring 12 is made flat so that it acts on the O-ring 12. Since the high pressure receiving area is increased, the adhesion of the seal ring 11 to the sliding member 2 and the fixed member 1 due to the elastic deformation of the O-ring 12 is significantly improved, and the sealing property is further improved. It has the excellent effect of being able to.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

The superhigh pressure liquid sealing device according to each of the following examples is applied to the superhigh pressure water generating part of the pressure booster in the water jet cutting system. The structure of the superhigh pressure water generating part is as follows: Since it is the same as the conventional one, the structure shown in FIG. 4 which has already been described is used here. The members common to those shown in FIGS. 4 and 5 are designated by the same reference numerals and the description thereof will be omitted.

Embodiment 1 FIG. 1 shows an ultrahigh pressure liquid sealing device according to Embodiment 1 of the present invention. The present embodiment corresponds to the inventions of claims 1 and 2.

The ultrahigh-pressure liquid sealing device of this embodiment includes a cylinder 1 which is a cylindrical fixing member, and a plunger 2 which is a sliding member slidably inserted into the cylinder 1 via a spacer 3. Between the cylinder 1 and the plunger 2, which is used to seal the extra-high pressure liquid, and which is in contact with the inner peripheral surface of the cylinder 1 and the outer peripheral wall portion 11a and the plunger 2. A seal ring 11 having a U-shaped cross section having an inner peripheral wall portion 11b that abuts on the outer peripheral surface, and an annular elastic seal member (O ring in this embodiment) 12 fitted in the seal ring 11. It is composed by.

The seal ring 11 is integrally formed of a material having excellent wear resistance such as tungsten carbide.

With the above construction, the following operation can be obtained.

When the ultra-high pressure water enters the seal ring 11 due to the reciprocating movement of the plunger 2 and the O-ring 12 is subjected to the ultra-high pressure, the O-ring 12 is elastically deformed in the radial direction to cause the seal ring 11 to move. The inner and outer peripheral wall portions 11b and 11a are pressed against the outer peripheral surface of the plunger 2 and the inner peripheral surface of the cylinder 1, respectively. Therefore, the sealing property between the plunger 2 and the cylinder 1 is reliably maintained.

Further, since the O-ring 12 is deformed smoothly along the inner peripheral surface of the seal ring 11 when elastically deformed, the O-ring 12 is not partially deformed as in the conventional example. Even if the pressure inside the seal ring 11 repeats extremely high pressure and low pressure, there is no possibility of the "peeling phenomenon" due to partial wear. Therefore, the life of the O-ring 12 can be extended and the sealing property can be maintained for a long period of time.

Embodiment 2 FIG. 2 shows an ultrahigh pressure liquid sealing device according to Embodiment 2 of the present invention. The present embodiment corresponds to the inventions of claims 1 to 3.

In this embodiment, the O-ring 12 has a flat surface on the side where the ultra-high pressure water enters. By doing so, the pressure receiving area of the ultrahigh pressure acting on the O-ring 12 becomes large. Therefore, the adhesion of the seal ring 11 to the plunger 2 and the cylinder 1 due to the elastic deformation of the O-ring 12 is significantly improved, and the sealability can be further improved. Other configurations, functions and effects are the same as those of the first embodiment, and the description will be omitted to avoid duplication.

Embodiment 3 FIG. 3 shows an ultrahigh pressure liquid sealing device according to Embodiment 3 of the present invention. The present embodiment corresponds to the invention of claim 1.

In the case of this embodiment, as the elastic seal member 12, an elastic member having a substantially V-shaped cross section, which is convex toward the extra-high pressure water intrusion side, is adopted. By doing so, the pressure receiving area of the super high pressure acting on the elastic seal member 12 is increased, and the radial elastic deformation force of the elastic seal member 12 is increased. Therefore, the adhesion of the seal ring 11 to the plunger 2 and the cylinder 1 due to the elastic deformation of the elastic seal member 12 is further significantly improved.
The sealing property can be further improved. Other configurations, functions and effects are the same as those of the first embodiment, and the description will be omitted to avoid duplication.

The invention of the present application is not limited to the configuration of each of the above-described embodiments, and it goes without saying that the design can be appropriately changed without departing from the scope of the invention.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an ultrahigh pressure liquid sealing device according to a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing an ultrahigh pressure liquid sealing device according to Embodiment 2 of the present invention.

FIG. 3 is a vertical cross-sectional view showing an ultrahigh pressure liquid sealing device according to Embodiment 3 of the present invention.

FIG. 4 is a vertical sectional view showing a main part of a general pressure booster.

FIG. 5 is a vertical cross-sectional view showing a conventional sealing device for ultra-high pressure liquid.

[Explanation of symbols]

1 is a fixed member (cylinder), 2 is a sliding member (plunger),
3 is a spacer, 7 is a backup ring, 11 is a seal ring, 11a is an outer peripheral wall portion, 11b is an inner peripheral wall portion, 12 is an elastic seal member (O-ring), and A is a sealing device for ultrahigh pressure liquid.

Claims (3)

[Claims] 1. A cylindrical fixing member (1) and the fixing member (1)
The fixing member (1) and the sliding member (2) are provided between the fixing member (1) and the sliding member (2) which is slidably fitted and inserted through the spacer (3).
An ultrahigh pressure liquid sealing device for sealing an ultrahigh pressure liquid penetrating between the sliding member (2) and an outer peripheral wall portion (11a) which abuts an inner peripheral surface of the fixing member (1). From a seal ring (11) having a U-shaped cross section having an inner peripheral wall portion (11b) that abuts the outer peripheral surface of the ring, and an annular elastic seal member (12) fitted in the seal ring (11). A sealing device for an ultra-high pressure liquid, which is characterized in that 2. The sealing device for ultra-high pressure liquid according to claim 1, wherein an O-ring is adopted as the elastic sealing member (12). 3. The O-ring (12) according to claim 2, characterized in that a surface of the O-ring (12) into which the ultrahigh pressure liquid enters is flat.
The seal device for an ultrahigh pressure liquid described.