JPH0635750U - Check valve - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a non-return valve in which foreign matter in a fluid does not enter between the valve shaft and the guide hole to cause malfunction of the valve body. [Structure] A plurality of inward projections 4c are provided in a hole 4a formed in a holder 4 by providing a sufficient gap 4b between the valve shaft 2b and the valve shaft 2b.
Is provided, and the valve shaft 2b is guided by the protrusion 4c. In addition, the cross-sectional shape of the ridge 4c is substantially arcuate.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a check valve that is attached to a pipe for water, oil, gas or the like to prevent backflow.

[0002]

[Prior art]

 FIG. 4 is a vertical cross-sectional view showing an example of a conventional check valve, and FIG. 5 is a cross-sectional view showing a BB cross section of FIG. This check valve is a lift check valve with a built-in spring. In FIGS. 4 and 5, 11 is a check valve, 12 is a valve body, 13 is a valve box, 14 is a holder, 15 is a spring, 16 is a seat ring, and the valve body 12 is an elastic force of the spring 15. 4 is pushed to the right in FIG. 4, and the stopper portion 12a of the valve body 12 is in contact with the stopper portion 13a of the valve box 13. In this state, the elastic seat ring 16 mounted on the valve body 12 is crimped to the valve seat portion 13b formed on the valve box 13 to seal the space between the valve box 13 and the valve body 12 and to prevent the reverse flow of fluid. (Flow from left to right in Fig. 4) is blocked.

During normal flow of the fluid (flow from the right to the left in FIG. 4), the valve body 12 is pushed by the fluid and moves to the left while compressing the spring 15, and the seat ring 16 moves to the valve seat portion. The fluid flows away from 13b. Further, the valve shaft 12b of the valve body 12 is inserted into the guide hole 14a of the holder 14, thereby guiding the lateral movement of the valve body 12 and controlling the posture of the valve body 12. For this reason, the gap between the valve shaft 12b and the guide hole 14a is made small so that the valve body 12 does not tilt and the seat ring 16 is properly crimped to the valve seat portion 13a for reliable sealing.

With such a structure, foreign matter in the fluid may get into the gap between the valve shaft 12b and the guide hole 14a, and the operation of the valve body 12 may become defective. In addition, the elastic force of the spring 15 may be increased so that the malfunction does not occur even if a small amount of foreign matter enters, and in this case, the fluid resistance during forward flow increases.

[0005]

[Problems to be solved by the device]

 The check valve of the present invention is for solving the malfunction of the valve element due to the foreign matter in the fluid, which occurs in the conventional check valve as described above.

[0006]

[Means for Solving the Problems]

 The check valve of the present invention has the following structure in order to solve the above problems. A sufficient gap is provided between the valve shaft and the valve shaft to provide a plurality of inward protrusions in the hole formed in the holder, and the protrusions guide the axial movement of the valve shaft. In this case, the projection may be a projection in the axial direction of the hole, and the cross section of the projection may be substantially arcuate.

[0007]

[Action]

 Since the check valve of the present invention is configured as described above, even if foreign matter in the fluid enters between the hole of the holder and the valve shaft, a sufficient gap is provided for the foreign matter. The valve body does not malfunction. For this reason, the elastic force of the spring is not increased to increase the fluid resistance during normal flow. Also, the hole is provided with a plurality of inward projections, which guide the movement of the valve shaft in the axial direction, so that the posture of the valve body is correctly controlled and the valve body tilts when the valve is closed. The seal will not be defective.

When the protrusion is a protrusion in the axial direction of the hole, processing is easy, foreign matter that has entered the gap easily flows out, and the guide of the valve shaft becomes smooth and reliable. Further, when the ridge has a substantially arcuate cross-sectional shape, it is difficult for foreign matter in the fluid to enter between the ridge and the valve shaft, and the frictional resistance between the ridge and the valve shaft is small.

[0009]

FIG. 1 is a vertical sectional view showing an embodiment of the check valve of the present invention, and FIG. 2 is a sectional view showing an AA cross section of FIG. This check valve is a built-in spring lift check valve. 1 and 2, 1 is a check valve, 2 is a valve body, 3 is a valve box, 4 is a holder, 5 is a spring, 6 is a seat ring, and the valve body 2 is an elastic force of the spring 5. In FIG. 1, the stopper portion 2a of the valve body 2 is pushed to the right and is in contact with the stopper portion 3a of the valve box 3. In this state, the elastic seat ring 6 mounted on the valve body 2 is pressure-bonded to the valve seat portion 3b formed on the valve box 3 to seal the space between the valve box 3 and the valve body 2 to prevent the reverse flow of fluid. (Flow from the left to the right in FIG. 1) is blocked.

During normal flow of the fluid (flow from the right side to the left side in FIG. 1), the valve body 2 is pushed by the fluid and moves to the left while compressing the spring 5, and the seat ring 6 moves toward the valve seat portion. Fluid flows away from 3b. FIG. 3 is a vertical cross-sectional view showing a valve open state, and arrows indicate the flow direction. Further, the valve shaft 2b of the valve body 2 is inserted into the hole 4a formed in the holder 4, and a sufficient gap 4b is provided between the hole 4a and the valve shaft 2b. The movement of the valve shaft 2b in the axial direction is guided by the protrusion 4c having a substantially arcuate cross section.

Next, the operation will be described with reference to FIGS. 1 and 2. Even if foreign matter in the fluid enters between the hole 4a of the holder 4 and the valve shaft 2b, a sufficient gap 4b is provided for foreign matter there, so that the valve body 2 does not malfunction. Therefore, it is not necessary to increase the elastic force of the spring 5, and the fluid resistance does not increase. Further, since the protrusion 4c guides the movement of the valve shaft 2b in the axial direction, the posture of the valve body 2 is properly controlled, and the valve body 2 does not tilt and close the seal when the valve is closed. Further, the foreign matter that has entered the gap 4b easily flows out along the protrusion 4c, the guide of the valve shaft 2b by the protrusion 4c is smooth and reliable, and the protrusion 4c has an arc-shaped cross section. It is difficult for foreign matter to enter between the strip 4c and the valve shaft 2b, and the frictional resistance between the projecting strip 4c and the valve box 2b is small. In the above-described embodiment, the holder is provided with the protrusion, but the present invention is not limited to this, and a protrusion may be formed on the valve shaft to provide a gap between the valve shaft and the holder. .

[0012]

[Effect of device]

 As described above, in the check valve of the present invention, even if foreign matter in the fluid enters between the hole of the holder and the valve shaft, the check valve does not malfunction. Therefore, it is not necessary to increase the elastic force of the spring, and the fluid resistance does not increase. In addition, foreign matter that has entered between the holder hole and the valve stem easily flows out, and it is difficult for foreign matter to enter between the ridge and the valve stem, and the frictional resistance between the ridge and the valve stem is small. . Further, the posture of the valve body is properly controlled, and the valve body does not tilt when the valve is closed, resulting in poor sealing.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of a check valve according to the present invention.

FIG. 2 is a sectional view showing an AA section of FIG.

FIG. 3 is a vertical sectional view showing a valve open state of the embodiment shown in FIG.

FIG. 4 is a vertical sectional view showing an example of a conventional check valve.

5 is a cross-sectional view showing a BB cross section of FIG. 4. FIG.

[Explanation of symbols]

 1 Check valve 2b Valve shaft 4 Holder 4a Hole 4b Clearance 4c Protrusion (projection)

Claims (3)

[Scope of utility model registration request] 1. A plurality of inward projections are provided in a hole formed in a holder with a sufficient gap between the valve shaft and the valve shaft, and the projections guide the axial movement of the valve shaft. A non-return valve that is characterized. 2. The check valve according to claim 1, wherein the protrusion is a protrusion in the axial direction of the hole. 3. The check valve according to claim 2, wherein the projection has a substantially arcuate cross-sectional shape.