JPH028132Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a butterfly valve that can withstand excessive pressure and can be used for a long period of time.

(Prior Art) Butterfly valves, which have been widely used in the food and cosmetics industries, have a disk-shaped valve body attached to the lower end of the valve shaft, which is housed in a valve box, and which rotates. A cylindrical hard body with a channel-shaped cross section is provided in the part of the valve box that comes into contact with the valve body, so that the valve body is always brought into close contact with the inside of the valve box. However, with this butterfly valve,
Since the lower end of the valve body is not supported, when the valve body is closed, the weight of the fluid is applied to the entire surface of the valve body.
In particular, when the diameter of the fluid flow path is large and the valve body is also large, the total load applied to the valve body increases in proportion to the square of the diameter. Therefore, this load is supported only by the connecting portion between the valve stem and the valve body, which causes the valve body to curve, resulting in a poor sealing quality and ultimately rendering the valve unusable.

In order to eliminate this drawback, an engagement hole was drilled at the lower end of the valve body, and a through hole was drilled at the corresponding part of the valve body.
A structure has been proposed in which the lower end of the valve body is fixed to the valve body by inserting a screw or the like from the outside of the valve body to eliminate the above-mentioned drawback (Japanese Patent Application Laid-open No. 132618/1983). However, with this structure that fixes the lower end of the valve body,
In order to form the engagement hole, a bulge is essential, and in the normal molding method, the bottom surface of the bulge is flat, and furthermore, in the normal molding method, the fluid flow path in the valve box is also arcuate. As a result, a gap is formed between the valve body and the valve box, which should be in close contact with each other, causing fluid leakage and impairing the original function of the valve body.

In order to eliminate this drawback, it is conceivable to form the lower surface of the bulge in an arc shape or to form the flow path in a flat shape, but in reality, from a technical point of view, It is almost impossible to mold into such a shape without causing fluid leakage, and even if it could be formed, the cost of the mold etc. would be very high, which would be very disadvantageous economically.

(Purpose of the invention) An object of the invention is to provide a butterfly valve that has a simple structure and can withstand large fluid pressure without impairing the original function of the valve body.

(Means for Solving the Problems) The present invention has a disc-shaped valve shaft that is housed in a valve box at one end of the valve shaft, and has an engaging hole formed at key points in the lower part with a planar lower surface around the valve shaft. A hard body is provided at a portion connecting the valve body and in contact with the inner surface of the valve body and the valve body, the hard body having through holes aligned with the engagement holes at key points in the lower part. In a butterfly valve comprising an engaging body that engages with a through hole and an engaging hole to fix the valve body within the valve box, the diameter of at least a portion of the engaging body that contacts the hard body is set to a diameter of the hard body. is made larger than the inner diameter of the through hole, and the engaging body deforms a part of the hard body to close the space between the lower surface of the valve body and the valve box, and forcefully bites into the engaging hole. This is a butterfly valve that is characterized by

The present invention will be explained in detail below.

The present invention is intended to solve the problem of fluid leakage in the structure of fixing the lower part of the valve body and the valve box using an engaging member such as a screw.

When the diameter of the valve body is small, that is, when the fluid flow rate is small, the load applied to the valve body is small and there is almost no problem of fluid leakage, but as the diameter of the valve body increases, in other words, as the fluid flow rate increases, The load on the valve body increases, and in some cases, the valve body may become deformed, and fluid leakage becomes impossible to ignore.

As mentioned above, the conventional solution to this problem is to drill an engagement hole in the lower part of the valve body, insert a screw, etc. into the engagement hole from outside the valve body, and adjust the positional relationship between the valve body and the valve body. This is a method of fixing. However, in this method, a space is almost inevitably created between the valve body and the valve body, and in order to ensure the function of the valve body to prevent fluid leakage, it is necessary to simply close this space. suffice, and means are required to contain the large fluid pressures.

In the present invention, the elasticity of the hard body having elasticity is utilized to close the space and ensure close contact between the valve body and the valve box. In other words, by making the inner diameter of the through hole of the hard body into which the engaging body is inserted smaller than the outer diameter of the engaging body,
When the engaging body is inserted into the through hole, the hard body around the through hole deforms and closes the space, and a portion of the hard body deforms and closes the space, and a portion of the hard body is inserted into the engaging hole between the engaging body and the valve body. It also enters the space and elastically seals the space between the valve body and the valve box.

The hard body used in the present invention is preferably made of a material that has elasticity and deforms at room temperature or under heat, such as synthetic resin such as Teflon (registered trademark), or metal such as stainless steel. It is preferable that the insertion of the combination into the through hole and the engagement hole is carried out in a state where the hard body under heating is easily deformed.

Next, the present invention will be explained based on an embodiment of the illustrated butterfly valve, but this embodiment is not intended to limit the present invention.

FIG. 1 is a longitudinal sectional view showing one embodiment of the butterfly valve according to the present invention, and FIG. 2 is a longitudinal sectional view showing the butterfly valve of FIG. 1 before insertion of an engaging body.

Reference numeral 1 denotes a valve box having a fluid passage 2 extending in the front-rear direction, and an enlarged diameter portion 3 is formed in the center of the valve box 1 . A valve shaft through hole 4 is bored in the upper part of the enlarged diameter portion 3, and a valve shaft 6 having a valve body 5 connected to its lower end is rotatably fitted into the through hole 4. Bulging portions 7 and 8 are formed on the upper and lower side edges, and the lower bulging portion 8 is provided with an engagement hole 9 facing downward. Around the valve body 5, a donut-shaped hard body 10, which is made of a hard synthetic resin such as Teflon, a metal such as stainless steel, or silicone rubber, and has a channel-shaped cross section, is positioned to form the fluid path 2. hand,
When the valve body 5 is in the closed state, the fluid path 2 is sealed to prevent liquid leakage, and wear of the hard body 10 itself due to contact with the valve body 5 is minimized. Reference numeral 11 denotes a donut-shaped cushion that is fitted into the channel portion of the hard body 10 and comes into contact with the inner wall of the valve box 1, and urges the hard body 10 inward to prevent liquid leakage due to wear of the hard body 10. is prevented. As shown in FIG. 2, a through hole 12 with the same diameter is bored in the center of the lower part of the hard body 10 and the cushion 11, and a through hole 12 with a larger diameter than the through hole 12 is formed in the lower part of the enlarged diameter part 3. A screw hole 13 is screwed. Reference numeral 14 denotes an engaging body consisting of a large-diameter head 15 and a small-diameter engaging portion 16, and the outer diameter of the engaging portion 16 matches the screw hole 13 and is larger than the through hole 12. It is smaller than the inner diameter of case 9.

In the state before the engagement body 14 is inserted in FIG.
4 into the engaging hole 9 and the through hole 12, the peripheral edge of the through hole 12 of the hard body 10, which is in a thermally deformable state, is pushed upward by the engaging portion 16, as shown in FIG. It is pushed and deformed to close the space, and also enters between the inner wall of the engagement hole 9 and the engagement portion 16 as indicated by reference numeral 10' to elastically close the valve body 1 and the valve body 5. Seal tightly.

In this embodiment, an engagement hole 9 is formed in the lower bulge 8 and a through hole 1 in the hard body 10 and the cushion 11 is provided.
2, and the engaging portion 16 of the engaging body 14 is engaged with the engaging hole 9, and the valve body 1 and the valve body 5 are fixed to each other. Therefore, a large load is applied to the valve body 5. Even in the past, the valve body 5 will never be deformed, causing liquid leakage or becoming unusable. Furthermore, hard body 1
0 and the inner diameter of the through hole 12 of the cushion 11 is connected to the engaging part 1.
Since the outer diameter of the engaging portion 16 is smaller than that of the engaging portion 16
In order to engage the engaging body 1 into the engaging hole 9,
4 must be forcibly pressed onto the hard body 10 and cushion 11 and screwed into place. Therefore, hard body 1
The peripheral edge of the through hole 12 of the cushion 11 deforms toward the valve body 5 side, blocks the space, and enters between the engagement hole 9 and the engagement portion 16 to firmly adhere, preventing liquid leakage. can be reliably prevented.

(Effect of the invention) In the present invention, the inner diameter of the through hole of the hard body is made smaller than the outside diameter of the engaging part of the engaging body, so when the engaging body is screwed in, the hard body around the through hole deforms. This closes the space between the lower part of the valve body and the inner wall of the arcuate valve body, and also enters between the inner wall of the engagement hole and the engagement portion to firmly adhere to the valve body. Therefore, the engaging body not only fixes the valve body and the valve body and provides resistance to large fluid pressure, but also reliably prevents liquid leakage that often occurs in conventional butterfly valves of this type.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing one embodiment of the butterfly valve according to the present invention, and FIG. 2 is a longitudinal sectional view showing the butterfly valve of FIG. 1 before insertion of an engaging body. 1... Valve box, 2... Fluid path, 3... Expanded diameter part, 4
... Valve stem through hole, 5... Valve body, 6... Valve stem, 7...
...Upper bulge, 8...Lower bulge, 9...Engagement hole, 10, 10'...Hard body, 11...Cushion, 12...Through hole, 13...Threaded hole, 14... Engaging body, 15... head, 16... engaging portion.

Claims (1)

[Scope of utility model registration request] A disk-shaped valve body housed in a valve body and having an engagement hole whose peripheral lower surface is formed into a flat shape at key points in the lower part is connected to one end of the valve shaft, and the inner surface of the valve body and the valve body are connected to each other. A hard body is provided in the part that comes into contact with the valve body, and the hard body is provided with a through hole at a lower key point that is aligned with the engaging hole, and is further engaged with the through hole and the engaging hole from below the valve body. In the butterfly valve, the diameter of at least a portion of the engaging body that contacts the hard body is made larger than the inner diameter of the through hole of the hard body, and the engaging body fixes the A butterfly valve characterized in that a part of the hard body is deformed to close a space between the lower surface of the valve body and the valve box and to forcefully bite into the engagement hole.