JPH0599186A - Self-priming pump - Google Patents

Abstract

PURPOSE:To improve workability of screwing of a drain tap and reliability of a seal for a self-priming pump. CONSTITUTION:A protruded drain nozzle 31 with a male screw 32 on the outer dia. at the end, an O-ring 34 attached to the outer dia. at the bottom and a drain hole 33 at the center is provided at the bottom of the casing 21 of a pump. Also, a drain tap 35 which has a female screw 36 fitted to the male screw 32 of the drain nozzle 31 and a drain through-hole 37 smaller in dia. than the female screw 36 and has a plane packing 39 fitted in a level difference between the female screw 36 and the through-hole 37 so as to be held in a hollow with a rib 38 is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reheating device for boiling water in a bath, a boiler for supplying hot water to a floor heating panel, or the like, or a self-priming pump water used for circulating hot water. The present invention relates to the structure of the stopper.

[0002]

2. Description of the Related Art Conventionally, a self-priming pump of this type is provided with a drain port 3 having a female screw 1 and a drain hole 2 in a lower portion of a casing 4 as shown in FIG. 5 and a T-shaped through hole 6, and a water drain plug 11 having O-rings 9 and 10 attached to the tip 7 and the root 8, respectively. When the drain plug 11 is screwed into the drain port 3, the drain hole 2 is sealed by the O-ring 9 at the tip 7 of the drain plug 11, and when the drain plug 11 is loosened from the drain port 3, FIG. As shown in FIG. 4, a gap is formed between the O-ring 9 of the tip portion 7 of the water drain plug 11 and the drain hole 2, so that the water in the casing 4 is injected and drained from the T-shaped through hole 6 of the water drain plug 11. Is what you can do.

[0003]

However, in the conventional structure as described above, the water drain plug 11 is screwed into the drain port 3 again after the water in the casing 4 of the self-priming pump is injected and drained. In this case, since the drainage hole 2 is sealed by the O-ring 9, the compression margin is small, a large force is required to screw the screw sufficiently, and the sealing becomes insufficient when screwed with a small force. there were.

Therefore, the present invention solves the above-mentioned problems and provides a self-priming pump which can improve the workability of screwing a drain plug of a self-priming pump into a drain port and can reliably seal the drain port. The purpose is to do.

[0005]

In order to achieve the above object, the present invention has a male thread on the outer diameter of the tip portion, an O ring attached to the outer diameter of the root portion, and a convex shape having a drainage hole at the center portion. It has a drain nozzle at the bottom of the casing of the pump, and has a female thread that fits the male thread of the drain nozzle and a through hole with a diameter smaller than the outer diameter of the female thread. It is equipped with a drain plug in which a flat packing is fitted.

[0006]

According to the present invention, when the drain plug is loosened from the drain nozzle, a gap is formed between the flat packing and the end face of the drain nozzle, so that the inside of the casing is filled with water through the through hole of the drain plug. If you can drain water, and then screw the drain plug back into the drain nozzle, the flat packing will seal the drain hole on the end face of the drain nozzle.
Since the compression margin is larger than that of the O-ring seal, the sealing performance can be sufficiently secured even if screwed with a slight force, and the workability and the reliability of the seal can be significantly improved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 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 self-priming pump according to an embodiment of the present invention, and FIG. 2 is a vertical cross-sectional view showing the self-priming pump with a water drain plug loosened. In FIG. 1, reference numeral 21 denotes a casing of a pump having an inlet 22 and an outlet 23, which is partitioned by a separating plate 24 into a front chamber 25 and a rear chamber 26.
The separating plate 24 has a suction hole 27 in the center and a return hole 28 in the upper part. An impeller 29 is rotated by a motor 30. Reference numeral 31 is a convex drainage nozzle provided in the lower portion of the casing 21.
Has a drainage hole 33 in the center, and an O-ring 34 is attached to the outer diameter of the root portion. Reference numeral 35 is a drain plug, which is a female screw 36 that fits into the male screw 32 of the drainage nozzle 31.
Further, a through hole 37 having a diameter smaller than that of the female screw 36 is provided, and a flat packing 39 is fitted in a step portion of the female screw 36 and the through hole 37 so as to be held hollow by a rib 38.

The operation of the above configuration will be described. This self-priming pump is incorporated in a reheating device (not shown) for boiling water in a bath to circulate water or hot water, and the water flowing from the suction port 22 flows from the front chamber 25 to the suction hole 27. After passing through, it enters the rear chamber 26 and is discharged from the discharge port 23 by the rotation of the impeller 29. When air flows in through the suction port 22, the water in the front chamber 25 circulates again from the rear chamber 26 through the return hole 28 to the front chamber 25, and only air is discharged from the discharge port 23 during this time. It is possible to perform a so-called self-priming action of sucking water having a low water level by the action.

The antechamber 2 is used to carry out these water transport operations.
5 and the rear chamber 26 require priming water in advance, but this operation can be performed by rotating the water drain plug 35, loosening the screw from the drainage nozzle 31, and injecting water from the through hole 37. When it is necessary to drain the priming water due to freezing or the like, it can be performed by loosening the water drain plug 35 from the drain nozzle 31 and draining the water from the through hole 37.

In this way, the drain plug 35 is attached to the drain nozzle 31.
As shown in FIG. 2, when loosened, a gap is formed between the flat packing 39 and the end face of the drain nozzle 31, and the through hole 37 of the water drain plug 35, the drain hole 33 of the drain nozzle 31, and the casing 21. In the front chamber 25, water can be conducted, and the O-ring 34 can prevent water leakage from the root of the drainage nozzle 31.

On the other hand, when the water drain plug 35 is screwed into the drainage nozzle 31, the flat packing 39 hits the end face of the drainage nozzle 31 to seal the drain hole 33, but the flat packing 39 is different from the O-ring seal. Since it is possible to take a larger compression allowance, it is possible to secure a sufficient sealing property even if screwed in with a slight force, and as a result, it is possible to greatly improve the workability and the reliability of the seal.

[0012]

As apparent from the above embodiments, according to the present invention, when the water in the casing of the self-priming pump is injected and drained, and then the drain plug is screwed into the drain nozzle again, Since sealing is performed with a flat packing that has a larger compression margin than the O-ring, it is possible to secure sufficient sealing performance even if screwed in with a slight force, and it is possible to greatly improve workability and reliability of sealing. ..

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a self-priming pump according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a case where a water drain plug of the self-priming pump is loosened.

FIG. 3 is a vertical sectional view showing a conventional self-priming pump.

FIG. 4 is a vertical sectional view showing a case where a water drain plug of a conventional self-priming pump is loosened.

[Explanation of symbols]

 21 Casing 31 Drain Nozzle 32 Male Thread 33 Drain Hole 34 O-ring 35 Drain Plug 36 Female Thread 37 Through Hole 38 Rib 39 Flat Packing

Claims (1)

[Claims] 1. A convex drainage nozzle having a male thread at the tip, an O-ring attached to the outer diameter of the base, and a drainage hole at the center is provided at the bottom of the casing of the pump. It has a female screw to be fitted and a through hole having a diameter smaller than the outer diameter of the female screw, and a drain plug formed by fitting a flat packing so as to be held hollow by a rib in the step portion of the female screw and the through hole. When the drain plug is screwed into the drain nozzle, a flat packing contacts the drain nozzle end face to seal the drain hole, and when the drain plug is loosened from the drain nozzle, the flat packing and drain nozzle A self-priming pump that forms a gap between the end face and allows water to be injected and drained from the casing through the through hole of the water drain plug.