JPH0353088Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an eccentric butterfly valve in which a valve stem is attached to a boss on the back side of the valve body. Regarding the alignment mechanism.

[Conventional technology]

In the conventional eccentric butterfly valve, as shown in FIG. A boss portion 4a on the back side of the valve body 4 is fixed with a bolt 5, and a seat ring 6 that seals the entire outer circumference of the valve body 4 in the fully closed state is attached to the inner circumference of the main body 1. attached to the edge of the surface.

A threaded portion 3a is formed at the lower end of the valve rod 3, and a thrust collar 7 is screwed into the threaded portion 3a.
The lower surface of the main body 1 is supported by an inner bottom surface 8a of a bottom cover 8 attached to the bottom of the main body 1. In addition, in the figure, 5a is a seal washer, 9 is a pin that fixes the thrust collar 7 and the valve stem 3, and 10 is an O-ring.

The assembly order (procedure) of the conventional butterfly valve described above is as follows.

(i) Fit the upper and lower bearings 2, 2 into the main body 1.

(ii) Insert the valve body 4 into the main body 1.

(iii) Insert the valve stem 3 into the main body 1 up to the lower bearing 2.

(iv) Fix the boss portion 4a of the valve body 4 and the valve stem 3 with bolts 5. Note that bolt holes are pre-drilled.

(v) Place the valve body 4 in the half-open position and attach the seat ring 6 to the main body 1.

(vi) Set the valve body 4 to the fully closed position. Centering is done at this time. This minute misalignment due to centering is absorbed by "pin hole alignment" between the thrust collar 7 and pin 9 for each unit. The center of the valve body 4 is determined based on the inner circumferential circle of the seat ring 6.

(vii) Screw the thrust collar 7 onto the lower end of the valve stem 3 and set it at the optimal mounting position.

(viii) Drill a pin hole in the thrust collar 7 and insert the pin 9 to secure the thrust collar 7 and the valve stem 3.

(ix) Attach the bottom cover 8.

[Problem that the invention attempts to solve]

In the conventional eccentric butterfly valve described above, vertical centering of the valve body 4 is performed by adjusting the optimal vertical position of the thrust collar 7 attached to the lower end of the valve stem 3. The sealing of the gland portion between the valve stem through hole 1 and the valve stem 3 was performed by a gland packing (not shown).

As mentioned above, the vertical centering of the valve body and the sealing of the gland were performed using separate parts, which resulted in the problem of an increase in the number of component parts and a high cost for parts and assembly. .

This invention reduces the number of parts, simplifies the structure, and reduces production costs by using a common member (collar) to perform the vertical centering of the valve body and the sealing action of the gland part. An object of the present invention is to provide an eccentric butterfly valve that reduces the

[Means for solving problems]

In order to achieve the above object, the present invention provides an eccentric butterfly valve with a collar penetrated by the valve stem in the space between the inner peripheral surface of the main body and the outer peripheral surface of the boss section on the back side of the valve body. is inserted, and a grease groove consisting of an O-ring and a number of independent grooves on the outside thereof is provided on the contact surfaces of the collar, main body, and valve body boss, respectively.

In addition, in practice, it is desirable that the grease groove formed of a large number of independent grooves is formed such that the outer groove is small and the inner groove is large.

[Effect]

Since the present invention is constructed as described above, the upper and lower circumferential surfaces of the valve body through which the valve stem passes are in contact with the inner circumferential surface of the main body via two collars, and the The vertical centering is determined based on the inner surface of the main body, that is, the contact surface with the collar, so the collar aligns the valve body in the vertical direction, and when assembling the valve, the valve body is aligned in the vertical direction. No particular centering work is required.

In addition, when the valve is operated, the O-ring provided on the sliding surface of the collar prevents fluid from flowing out from the valve stem, and the O-ring is provided on the sliding surface in parallel on the outside. When fluid enters the grease groove made up of a large number of grooves, the grease flows out onto the sliding surface and lubricates the sliding surface.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a vertical cross-sectional view of a main part of a butterfly valve equipped with a valve body alignment mechanism showing an embodiment of the present invention.
In the figure, the same reference numerals as those shown in FIG. 3 indicate the same or similar parts.

In the figure, collars 11, 11, which are penetrated by the valve rod 3, are interposed between the inner circumferential surface of the main body 1 and the outer circumferential surface of the boss portion 4a of the valve body 4. is supported on the inner circumferential surface of the holder via the two collars 11, 11.

The collar 11 includes a main body 1, a valve stem 3, and a valve body 4.
Two of the three contact surfaces with the main body 1 and the valve body 4 are sliding surfaces,
As shown in the enlarged sectional view of the main part in FIG. 2, both of these sliding surfaces have an O-ring groove 12a in which the O-ring 12 is fitted, and a plurality of grease grooves 13a and 13b on the outside thereof. These grease grooves 13 are formed smaller on the outside and larger on the inside. In addition, in the figure, 5 is a bolt and 6 is a seat ring.

The assembly order of the butterfly valve described above is as follows.

(i) Insert the valve stem 3 into each valve stem through hole of the valve body 4 and the upper and lower collars 11, 11.

(ii) Secure the valve body 4 and valve stem 3 with bolts 5. Note that the bolt holes are pre-drilled.

(iii) Place the valve body 4 in the half-open position and attach the seat ring 6 to the main body 1.

(iv) Set the valve body 4 to the fully closed position. At this time, the valve body 4
The vertical center of is the inner surface of the main body 1, that is, the collar 8
It is determined based on the contact surface of , and no special centering work is required.

Furthermore, any vertical misalignment between the valve body 4 and the valve stem 3 during assembly is absorbed by the vertical movement of the valve stem 3, since the valve stem 3 is not fixed to the main body 1 in any way.

(v) Attach the bottom cover (corresponding to bottom cover 8 in Figure 3), not shown.

When the valve assembled as described above is operated, the O-ring 1 provided on the sliding surface of the collar 11
2 prevents the fluid from flowing out through the penetrating portion of the valve stem 3, and also prevents O from flowing on the sliding surface.
When fluid enters the outer grease groove 13a arranged in parallel with the ring 12, the grease filled in the groove 13a flows out onto the sliding surface, lubricates the sliding surface, and at the same time flows into the adjacent grease groove 13b. . At this time, change the shape of the grease groove 13 to the outside (the shape of the grease groove 13
a) is made small and the inside (grease groove 13b) is made large, so the pressure applied to the O-ring 12 provided on the inside is reduced due to the labyrinth effect in which the pressure of the fluid entering from the outside to the inside gradually decreases. Therefore, the durability of the O-ring 12 is improved.

According to this embodiment, the following effects are achieved.

(i) The valve body 4 has both upper and lower collars 11, 11.
Since it is supported in contact with the inner surface of the main body 1 through the
Automatic alignment is possible.

(ii) Since the valve stem 3 is sealed by an O-ring provided on the sliding surfaces of the collars 11, 11, there is no need to use a high-grade material with corrosion resistance in mind for the valve stem 3.

(iii) Since an O-ring is provided on the sliding surface of the collar 11 and a grease groove is provided on the outside of the O-ring, the grease flowing out through the grease groove maintains smooth opening and closing of the valve over a long period of time. It can lubricate and ensure long-term sealing performance.

(iv) The above grease groove is composed of a large number of independent grooves, with the outer side being smaller and the inner side being larger, so that the pressure of the fluid that enters from the outside to the inside along the sliding surface can be absorbed by the labyrinth effect. lowers blood pressure,
Since the pressure applied to the inner O-ring 12 can be reduced, the durability of the O-ring 12 is improved.

In the embodiment described above, the plurality of grease grooves 13
It is also possible to make the shape uniform. In this case as well, a pressure drop occurs due to fluid resistance due to a change in the cross-sectional area of the passage, which has the effect of increasing the durability of the O-ring 12.

[Effect of idea]

As explained above, according to the present invention, in an eccentric butterfly valve, a collar penetrated by the valve stem is inserted into the space between the inner peripheral surface of the main body and the outer peripheral surface of the boss portion on the back side of the valve body. However, by providing grease grooves each consisting of an O-ring and a number of independent grooves on the outside of the O-ring on the abutting surfaces of the collar, the main body, and the valve body boss, the following effects are achieved.

(i) The valve body supported by the boss on the back side of the valve body eliminates the need for vertical centering work and enables self-alignment.

(ii) Since the valve stem is sealed with an O-ring on the sliding surface of the collar, there is no need to use high-grade materials with corrosion resistance in mind for the valve stem, and there is no need to seal with a clamp seal, making work easier. High sealing performance and low torque can be obtained without variations depending on the member.

(iii) The sliding surface is lubricated by the grease flowing out from the grease groove, which is made up of many independent grooves arranged in parallel on the outside of the O-ring on the collar sliding surface, and the valve can be kept smoothly opened and closed over a long period of time. . Furthermore, the O-rings arranged in parallel can be lubricated by the flowing grease to ensure long-term sealing performance.

(iv) Since centering of the valve body and sealing of the valve stem can be performed at the same time using the collar, the number of parts can be reduced and the structure can be simplified compared to conventional systems in which these were performed separately. Production costs can be reduced.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of the main part of a butterfly valve equipped with a valve body alignment mechanism showing an embodiment of the present invention, Fig. 2 is an enlarged cross-sectional view of the main part of Fig. 1, and Fig. 3 shows a conventional example. FIG. 3 is a longitudinal cross-sectional view of the butterfly valve. 1...Main body, 3...Valve stem, 4...Valve body, 4a...
... Valve body boss, 6... Seat ring, 11...
Collar, 12... O-ring, 12a... O-ring groove, 13, 13a, 13b... Grease groove.

Claims (1)

[Claims for Utility Model Registration] 1. In an eccentric butterfly valve, a collar penetrated by the valve stem is inserted into the space between the inner peripheral surface of the main body and the outer peripheral surface of the boss section on the back side of the valve body, An eccentric butterfly valve characterized in that an O-ring and a grease groove consisting of a number of independent grooves are provided on the outside of the O-ring on the contact surfaces of the collar, the main body, and the valve body boss. Valve alignment device. 2 The grease groove consisting of a large number of independent grooves is
A valve alignment device for an eccentric butterfly valve according to claim 1, wherein the outer groove is small and the inner groove is large.