JPH01262377A - High pressure seal - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to high-pressure seals, and particularly to high-pressure seals suitable for use in high-pressure seals such as high-pressure water pumps that generate ultra-high pressure fluids of several thousand kg/cm2. Regarding seals.

[Conventional technology] Conventionally, as a means of sealing fluids in general.

There are self-sealing type seals and gland packing type seals. The former self-seal type seal mainly uses a U-shaped or ■-shaped (Fig. 5) lip seal, and by crushing this lip, force is obtained for initial tightening, and further fluid pressure is applied. This creates contact pressure on the sealing surface and seals the high-pressure fluid (for example, the
0-40938). On the other hand, the latter gland packing type seal obtains contact pressure to the sealing surface by compressing the packing from the low pressure side.

[Problems to be Solved by the Invention] However, such conventional seals have problems in high pressure resistance and life expectancy. To explain this in detail next, in the case of a self-sealing type lip seal, the seal is performed at the lip, but if water is used, the lubricating film is easily broken, so the lip will wear out quickly. As a result, there is a disadvantage that leakage occurs because contact pressure to the sealing surface cannot be obtained. Also, because a relatively soft material is used for the sealing material, gaps will form when the pressure is high.

There were also some inconveniences such as the sticker sticking out from here. On the other hand, in the case of the gland packing type, the possible sealing pressure is proportional to the tightening force, so when the pressure is as high as several thousand kg/cm2, large tightening torque is required, making it difficult to seal in practice. there were.

The present invention has focused on the above-mentioned conventional problems, and aims to provide a high-pressure seal that is resistant to high pressure and has a long service life.

[! ! ! Means for Solving the Problem] In order to achieve the above object, the high pressure seal according to the present invention will be explained based on FIG. In the circumscribed seal ring, a space and two cylindrical rings 2 for fixing the outer circumference of the circumscribed seal ring provided between the cylinder and the plunger, and this cylindrical ring 2.
An elastic seal ring 3° having a substantially wedge-shaped cross section is supported by two elastic seal rings 4a and 4b that sandwich both wedge surfaces 13 and 14 of the substantially wedge-shaped elastic seal ring, and two elastic seal rings 4a and 4b are supported by the elastic seal rings 4a and 4b. The plunger is provided with a circumscribing seal ring of the plunger consisting of a support ring 5, and an adjusting ring 6 that is in back contact with the support ring 5 and applies a tension force to the circumscribed seal ring of the plunger. Through adjustment, the circumferential seal ring of the plunger is brought into pressure contact with the cylinder and the plunger to seal high-pressure fluid.

[Function] According to the above configuration, the initial contact pressure between the sealing surfaces of the circumscribed seal ring and the cylinder and plunger compresses the substantially wedge-shaped elastic seal ring through adjustment of the adjustment ring, without providing any particular lip. This compressive force is obtained by acting on the two elastic seal rings via both wedge surfaces of the wedge-shaped elastic seal rings. In order to reduce the sealing effect due to a decrease in contact pressure caused by sliding wear on the sealing surfaces of these two, in other words, two-part elastic seal rings, the sealing effect can be improved by readjusting the adjustment ring. It has the effect of restoring.

[Examples] Examples according to the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the entire embodiment, FIG. 2 is an enlarged view of section P in FIG. 1, and FIG. 3 is a diagram showing the effects of this embodiment.

Further, FIG. 5 is a diagram showing the effect of a conventional high-pressure seal for comparison with the effect of the present embodiment. 1 and 2, a metal cylindrical ring 2 is mounted on the surface 11 of a metal spacer 8 provided on the high pressure side of the cylinder 1. In FIGS.

Next, the circumscribed seal ring will be described. On the other surface 12 of the metal cylindrical ring 2, an elastic seal ring 3 made of rubber and having a substantially wedge-shaped cross section is attached. On the wedge surfaces 13 and 14 of the substantially wedge-shaped elastic seal ring 3, elastic seal rings 4a and 4b, each having a substantially trapezoidal cross-sectional shape, are arranged so as to sandwich the substantially wedge-shaped elastic seal ring 3 therebetween. And these elastic seal rings 4a and 4b
The elastic seal ring 4a is in close contact with the resin support ring 5 on the low-pressure side 15, and the elastic seal ring 4b is in contact with the cylinder to form a seal surface 10, while the elastic seal ring 4b is in contact with the branyer 7 and forms a seal surface. 20. As described above, the circumscribed seal ring is composed of the wedge-shaped elastic seal ring 3, two types of substantially trapezoidal elastic seal rings 4a and 4b, and the support ring 5. and the support ring 5
is further supported from the low-pressure side surface 16 on the right side of the figure by a metal adjustment ring 6. As described above, the high-pressure seal has a structure in which the nine cylindrical rings 2, the circumscribed seal ring, and the adjustment ring 6 are fixedly installed in the space provided between the cylinder 1 and the plunger.

This high-pressure seal is installed by compressing the elastic seal rings 4a and 4b and the approximately wedge-shaped elastic seal ring 3 through the support ring 5 with the adjustment ring 6. At this time, a wedge action occurs, and the elastic seal rings 4a and 4b are compressed. and can be pressed against the respective sealing surfaces 10 and 20 to obtain an initial contact pressure. Furthermore, as fluid pressure is applied to the gaps A and B, the substantially wedge-shaped elastic seal ring 3 is further compressed and transmits compressive force to the elastic seal rings 4a and 4b, creating more efficient sealing surfaces 10 and 20. form.

Since the support ring 5 has a higher yield strength than the two elastic seal rings 4a and 4b, it is possible to prevent the elastic seal rings 4a and 4b from protruding when high pressure is generated. Due to long-term operation, the sealing surfaces of the elastic seal rings 4a and 4b will wear out and leakage will occur if initial contact pressure cannot be obtained, but in that case, tighten the nut by turning the nut provided on the adjustment ring 6. The original contact pressure is restored and the sealing effect is restored.

Next, a comparison of the measured effects between the two embodiments and the conventional high-pressure seal will be described.As shown in Fig. 3, the high-pressure seal of the present invention can be adjusted in response to an increase in the amount of leakage of high-pressure fluid from the seal. It can be seen that the additional tightening of the ring 6 is effective in restoring the contact pressure between the seal surfaces 10 and 20. As a result,
The sealing effect continues even after over 500 hours. Against this.

The self-sealing type Suppatskin with conventional configuration is
As shown in Figure 5, the sealing effect is quickly lost under high pressures such as 3000 kg/cm2.

It can also be seen that even if retightening is performed, the sealing effect is lost in a very short period of time. As can be seen from this comparison, it is clear that the high-pressure seal of the present invention has an effect of extending the life by at least 10 times as compared to the conventional high-pressure seal in the two examples.

[Effects of the Invention] As explained above, according to the present invention, it is possible to solve the problems of conventional seals with insufficient high pressure resistance and long life. As seen in the actual measurement result data of Examples 9, the high-pressure seal of the present invention has approximately 10 times longer lifespan than conventional seals. That is, it shows that it is also excellent in high pressure resistance.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing an embodiment of the present invention.
A detailed view of the P part in the figure, Figure 3 is a graph showing the measured effect of the example, Figure 4 is a diagram showing the main parts of the conventional self-sealing V-shaped snap packing, and Figure 5 is the conventional self-sealing type. It is a graph diagram showing the actually measured effect of V-shaped pop packing. 1...Cylinder 2...Cylindrical ring 3...
Approximately wedge-shaped elastic seal rings 4a, 4b...Elastic seal ring 5...Support ring 6...Adjustment ring 7...
Plunger 8...Spacer 10...Cylinder seal surface 20...Plunger seal surface 13.14...Wedge surface Patent applicant Komatsu Ltd. Representative (patent attorney) Oka 1) Kazu Kidai 1 Figure 2 Figure 4 Figure 5

Claims (1)

[Claims] In the circumscribed seal ring of the plunger 7 that reciprocates within the cylinder 1 to generate high-pressure fluid, a space is provided between the cylinder and the plunger for fixing the outer periphery of the circumscribed seal ring. , cylindrical ring 2
, an elastic seal ring 3 supported by the cylindrical ring 2 and having a substantially wedge-shaped cross section, and two elastic seal rings 4a that sandwich both wedge surfaces 13 and 14 of the substantially wedge-shaped elastic seal ring.
, 4b and a support ring 5 that is placed behind the elastic seal rings 4a and 4b, and an adjustment ring 6 that is in back contact with the support ring 5 and applies a tension force to the circumscription seal ring. and
This high-pressure seal is characterized in that by adjusting the adjustment ring 6, the outer seal ring of the plunger is brought into pressure contact with the cylinder and the plunger to seal high-pressure fluid.