JPH076589U - Discharge pump discharge piping structure - Google Patents

Abstract

(57) [Summary] [Purpose] Even if the metal pipe side has a drop with respect to the connection part between the hose connected to the drainage pump side and the metal pipe connected to the downstream end of the hose, the downstream end of the hose It suppresses the occurrence of pressure pulsation in the vicinity of the section, smoothes the flow, and prevents damage to the hose. [Structure] An orifice portion 12 having a through hole 11 having a diameter r smaller than the inner diameter R of the metal tube 4 is provided at the connection portion between the hose 2 and the metal tube 4 so that the internal pressure at the connection portion is positive. I have to.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a discharge pipe structure of a drainage pump installed from a drainage pump at a drainage pump station to a discharge destination such as a river.

[0002]

[Prior art]

 Conventionally, as this type of piping structure, as shown in FIG. 4, the upstream end 2a is connected to the discharge port of the drainage pump 1, for example, the downstream end 2b of the hose 2 having a diameter of about 500 mm. The hose joint 3 is attached, and the flange 5 of the upstream end 4a of the steel pipe 4 as a metal pipe is connected and fixed to the flange 3a of the hose joint 3 with bolts 6 as shown in FIG. It is known that a steel pipe 4 which is lowered with a drop H is buried under the ground S and extended, for example, and a downstream end 4b thereof is opened toward a discharge destination such as a river L. In FIG. 4 and FIG. 5, 7 is a tightening band for fixing the hose joint.

[0003]

[Problems to be solved by the device]

 In the discharge piping structure of the conventional drainage pump having the above-described configuration, the connecting portion between the hose 2 and the steel pipe 4 is located at a level higher than the downstream portion of the steel pipe 4 by the drop H. During a predetermined drainage operation, the downstream side end 2b of the hose 2 has a negative pressure -P (see FIG. 5), and that portion repeatedly contracts and expands as shown by the chain line in FIG. 5 to cause pressure pulsation. Occurs. As a result, there is a problem that the flow of the drainage Q is likely to be hindered and the hose 2 is easily damaged by the repeated contraction and expansion deformation as described above.

The present invention has been made in view of the above circumstances, and suppresses the occurrence of pressure pulsation even if there is a drop between the hose and the metal connected to the downstream side of the hose, and smooth drainage. The purpose of the present invention is to provide a drainage pump discharge piping structure that can prevent damage and hose damage.

[0005]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the discharge piping structure of the drainage pump according to the present invention has a hose connected to the drainage pump side, at the downstream end of the hose, which is provided with a drop relative to the hose. In the discharge piping structure of the drainage pump, in which the upstream end of the pipe is connected, the connecting portion between the hose and the metal pipe has an outflow hole having a diameter smaller than the inner diameter of the metal pipe, It is provided with an orifice part that makes the inside of the downstream end part a positive pressure.

[0006]

[Action]

 According to the present invention, the water discharged from the drainage pump reaches the metal pipe through the hose and is discharged from the downstream end of the metal pipe to the discharge destination such as a river. Here, even if the downstream side of the metal pipe is located at a low position with respect to the connection part between the hose and the metal pipe and there is a head drop between the two, the downstream end of the hose will be A pipe loss corresponding to the above-mentioned head is given to the inside of the hose, and the inside of the downstream end of the hose is maintained at a positive pressure. Therefore, pressure pulsation due to contraction and expansion deformation of the hose is less likely to occur, the flow is smooth, and damage to the hose can be prevented as much as possible.

[0007]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical cross-sectional view showing a main part of a discharge pipe structure of a drainage pump according to an embodiment of the present invention. In FIG. 1, the same parts as those of the conventional example shown in FIG. The description thereof will be omitted.

In FIG. 1, a connection hole between the hose 2 and the steel pipe 4, for example, a flange 5 of the steel pipe 4, is formed with a through hole 11 having a diameter r smaller than the inner diameter R of the steel pipe 4, as shown in FIG. In addition, a loss corresponding to the drop H between the hose 2 and the steel pipe 4 is generated, and the orifice portion 12 that makes the inside of the downstream end 2b of the hose 2 a positive pressure + P is configured.

In the discharge piping structure of the drainage pump having the above structure, the drainage Q discharged from the drainage pump 1 reaches the steel pipe 4 via the hose 2 and is discharged from the downstream end 4b of the steel pipe 4 to a discharge destination such as a river. Is discharged. At this time, since the downstream side of the steel pipe 4 is located at a lower position with respect to the connection portion between the hose 2 and the steel pipe 4 and there is a drop H between the two, the inside of the downstream end 2b of the hose 2 becomes negative pressure. Even so, since the through hole 11 having the diameter r smaller than the inner diameter R of the steel pipe 4 is formed in the flange 5 of the steel pipe 4, the pipe loss corresponding to the above-mentioned drop H is caused to the steel pipe 4 here. Therefore, a positive pressure P is generated inside the downstream end 2b of the hose 2. Therefore, the hose 2 is suppressed from contracting and expanding and deforming in the vicinity of the connection portion with the steel pipe 4, and pressure pulsation does not occur and the flow of the drainage Q is maintained smoothly. Further, the hose 2 can be used for a long period of time without being damaged by repeated contraction and expansion deformation as described above.

By the way, in the above-mentioned embodiment, the orifice portion 12 has been described by forming the circulation hole 11 in the flange 5 of the steel pipe 4, but as shown in FIG. 3, it has a disc shape having the circulation hole 11. The member 13 may be clamped and fixed between the flange 3a of the hose joint 3 and the flange 5 of the steel pipe 4, and the orifice portion 12 may be constituted by the flow hole 11 of the disc-shaped member 13, and the hose joint 3 It is also possible to form the orifice portion by processing the flange 3a.

Further, although the steel pipe 4 is used as the metal pipe in the above embodiment, a hard synthetic resin pipe or an iron pipe may be used.

[0012]

[Effect of device]

 As described above, according to the present invention, the inner diameter of the metal between the hose on the drain pump side and the metal pipe located at a lower position with respect to the hose and connected to the downstream end of the hose is Since an orifice part with a smaller diameter circulation hole is provided, even if there is a drop between the hose and the downstream side of the metal, the internal pressure near the downstream end of the hose becomes positive pressure. The pressure pulsation can be prevented from being generated by maintaining it. Therefore, it is possible to smoothly maintain a predetermined drainage performance, suppress early damage due to repeated stress on the hose, and sufficiently extend the service life of one hose.

[Brief description of drawings]

FIG. 1 is an enlarged vertical sectional view showing a main part of a discharge pipe structure of a drainage pump according to an embodiment of the present invention.

FIG. 2 is an enlarged perspective view of a main part of the embodiment.

FIG. 3 is an enlarged vertical sectional view showing a main part of a discharge pipe structure of a drainage pump according to another embodiment of the present invention.

FIG. 4 is a side view showing an overall outline of a discharge pipe structure of a drainage pump to which the present invention is applied.

FIG. 5 is an enlarged vertical sectional view showing a main part of a discharge pipe structure of a conventional drainage pump.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drain pump 2 Hose 2b Downstream end of hose 4 Metal tube 4a Upstream end of metal tube 11 Flow hole 12,13 Orifice part R Inner diameter of metal tube r Diameter of flow hole

Claims (1)

[Scope of utility model registration request] 1. The discharge of a drainage pump, which comprises connecting a downstream end of a hose connected to the drainage pump side with an upstream end of a metal pipe arranged in a state of having a head with respect to the hose. In the piping structure, an outlet part having a diameter smaller than the inner diameter of the metal pipe is provided at a connection portion between the hose and the metal pipe, and an orifice part for making a positive pressure in the downstream end portion of the hose is provided. Discharge pump discharge pipe structure.