JP2566665Y2 - Drain structure of water pump - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drain pump for discharging water (drain) in a casing leaking from an impeller chamber to a water pump for sending out cooling water for cooling an engine or the like. It is.

[0002]

2. Description of the Related Art FIG. 6A is a sectional view of a main part of an ordinary water pump 10 for an automobile. A shaft 21 that rotates by receiving power from an engine (not shown) is disposed in a casing 11 in which a body 12 and a cover 13 are joined, and an impeller 24 is mounted on the shaft 21 in a so-called cantilever state. Attached to. That is, axis 2
1 is supported in the body 12 via a bearing 22 or the like,
The impeller 24 is provided at a position earlier than the bearing portion 15. The periphery of the impeller 24 is covered with a cover 13 (not shown, to which a suction pipe and a discharge pipe for cooling water are connected), thereby forming an impeller chamber 16 therein. Seal member 2 between
3 is attached.

[0003] When the sealing member 23 is made to be completely watertight, it causes wear between members, loss of rotational power, and an undesired phenomenon of stick-slip.
It is not possible to completely prevent the water in the impeller chamber 16 from leaking to the side of the bearing portion 15. Therefore, the water pump 10
As shown in the figure, a space 31 is provided between the seal member 23 and the bearing portion 15 and a water (drain) drain hole 32 is formed downward from the space 31 to the outside. The water pump is provided with such a drain hole,
For example, it is described in Japanese Utility Model Laid-Open Publication No. 59-64428. As shown in FIG. 6 (a) and the above-mentioned publication, the drain hole 32 conventionally has an opening 32o exposed outside the casing 11.

[0004]

[Problem to be Solved by the Invention] Opening 3 of drainage hole 32
When 2o is exposed to the outside, it is inconvenient to mount the water pump 10 as it is on an off-road vehicle (a vehicle running on a road other than a paved road). This is because, during traveling, if splashed muddy water or the like enters the opening 32o, it may flow backward through the drainage hole 32 and enter the inside of the water pump 10. If the pump 10 is flooded from the outside in this way, particles such as mud and sand enter between the sealing members 23, impairing the original sealing performance, or inviting inconvenience such as aggressive wear of the members.

[0005] Then, the inventors have hitherto shown in FIG.
-Attempts were made to prevent inundation from outside by means such as those shown in (c) and (d). That is, first, FIG.
In this example, a hollow pin (metal spring pin) 52 having a C-shaped cross section is press-fitted from the outside into the opening 32o of the second tube 32o, and a longer tube 53 is connected to the protruding end. FIG. 3C shows a state in which a cover 54 for preventing muddy water from covering the opening 32 o of the drain hole 32 is attached to the lower part of the outside of the water pump 10. Again
(d) is a drain hole 3 that is connected straight into the pump 10.
This is an example in which a plug 56 is plugged into the second original opening 32o, and a new opening 57 is provided at a position where muddy water and the like are less likely to be applied and the path is made maze to prevent inundation.

However, any of the examples shown in FIG.
Depending on the use condition of the vehicle during off-road or the like, it was not possible to completely prevent infiltration of muddy water into the water pump 10. The reason is that, in the example of FIGS. 6C and 6D, the space which is not sealed is the opening 32 of the drain hole 32.
o or 57, particles of the muddy water scattered during running of the vehicle pass through the space to form the openings 32o · 57.
It is thought that it is because it enters. In the example of FIG. 6B,
This is because muddy water infiltrates from the cut (open portion of the letter C) of the hollow pin 52.

The example shown in FIG. 6B is different from the ordinary water pump 10 shown in FIG.
However, the hollow pin 52 having a C-shaped cross section having insufficient waterproofness is used for the following reasons a) to e). ing. That is, a) The impeller chamber 16 of the water pump 10 is formed by joining a separate cover 13 to the body 12 having the bearing portion 15 so that the shaft 21 and the impeller 24 can be assembled. b) Drain hole 3
Since 2 is located beside the impeller chamber 16, it generally penetrates just beside the joining surfaces 12 a and 13 a of the casing 11 as shown in FIG. c) Thus, the joining surface 12a
When a metal pipe having a closed cross section is press-fitted into the drain hole adjacent to 13a in a general manner, the fitting surface (in the illustrated case, the joining surface 12a) is deformed due to a strong reaction force of fitting (outside). Inflate). d) If the joint surface 12a is deformed, the casing 11 (the body 12 and the cover 13) will not be tightly joined, causing inconvenience such as water leakage. e)
Therefore, in order to prevent such deformation, a spring pin 52 having a C-shaped cross section, which is surely connected by press-fitting even if the fitting reaction force is weak, is used. In other words, since the configuration of the casing 11 of the water pump 10 is as shown in FIG. 6A, it is impossible to press-fit a metal pipe having an annular cross section having a high waterproof effect conventionally. It is.

An object of the present invention is to provide a drain structure of a water pump which does not infiltrate water from the outside through a drain hole and does not cause the above-mentioned inconvenience on a joint surface of a casing.

[0009]

SUMMARY OF THE INVENTION The present invention relates to a water pump in which a casing is provided with an impeller chamber and a bearing portion through a seal member, and water (drain) leaking from the impeller chamber beyond the seal member. Is a drain structure for discharging metal to the outside, and a metal pipe (a general pipe having an annular cross section) is press-fitted into a drain hole provided near the joint surface of the casing (fitted in a so-called interference fit state). ), And a device for preventing water from entering from outside is connected to the metal pipe (the end protruding outside the casing).
However, the inner diameter of the drain hole is set to be larger than the outer diameter of the metal pipe in a range close to the joint surface, and the metal tube is sized so as to be press-fittable in a portion away from the joint surface .

[0010] As the water immersion preventing device, a one-way valve in which a long tube as described in claim 2 (about 10 cm or more as a guide) or a rubber bag according to claim 3 is cut. Alternatively, it is possible to connect a check valve of a type in which the valve body is pressed against the valve seat by a spring as described in claim 4 .

[0011]

The drain structure of the water pump according to the present invention has the following operation.

1) Since a metal pipe is press-fitted into the drainage hole and an external water intrusion prevention tool is connected to the tip of the metal pipe, muddy water cannot enter the drainage hole. The connection between the drainage hole and the metal pipe is joined by strong metal-to-metal contact and prevents water intrusion, but the metal pipe part prevents water from entering by a closed wall around the entire circumference. In addition, since a means for preventing water from entering from the outside is connected to the tip of the metal tube, there is no path for water to enter the inside of the drain hole from outside.

2) Since it is only necessary to press-fit a metal pipe into the drain hole and attach a water immersion preventer to the tip of the metal pipe, a muddy water protection cover as shown in FIG. ), The configuration can be made very simple as compared with the case where another drainage hole is formed as in the case of) or the case where a screw portion is formed in the drainage hole and a metal tube is attached (not shown). Therefore, there is a great cost advantage especially in mass production.

3) Further, in this drain structure,
Despite the fact that there is a drain hole near the joint surface of the casing and the metal pipe is pressed into it, deformation of the joint surface that makes the joining incomplete does not occur. That is, the inner diameter of the drain hole is larger than the outer diameter of the metal pipe in the range close to the joint surface,
This is because only the portion distant from the joining surface has a size suitable for press fitting of the metal tube. In other words, the casing (water drainage hole) receives the reaction force in the radial direction (outward) due to the fitting (press-fitting) from the metal tube only in a portion away from the joint surface, and in a portion close to the joint surface in the drainage hole. Does not receive any force from the metal tube, and therefore does not deform the joint surface adversely.

[0015] The flooding prevention tool, it is desirable configuration has a function of preventing entry of water from the outside to the inside while the drain from the water pump is simple, according to claims 2 to 4 Such a point is also excellent in the drain structure. First, in the case of the second aspect , since the above-mentioned tube is long, it is possible to prevent intrusion of muddy water or the like from the end to the drain hole (or the metal pipe), and it is naturally easy to manufacture and install. In the case of the third aspect , it is only necessary to cover the tip of the metal tube with a rubber bag and make a cut (or attach a commercially available valve having such a structure to the metal tube), so that the structure is also extremely simple. Although such a one-way valve emits water (drain) from the inside through the cut, it prevents water from flowing in from the outside due to the nature of the rubber that is naturally closed. Also
In the case of the fourth aspect , the structure of the waterlogging prevention device is slightly complicated and requires cost, but the waterlogging prevention device from the outside is particularly high. If this inundation prevention tool, whose valve body is pressed against the valve seat by the force of the spring, is connected to the metal pipe with the valve seat side near the drain hole, the path through which water enters from the outside is completely shut off, This is because the path is not opened even if the pressure on the outside increases. In addition, when water (drain) accumulates inside the drain hole or metal pipe, when the pressure of the water exceeds the force of the spring, the valve body is pushed and released from the valve seat, so that a drainage path is formed between the two and smooth. Is drained.

[0016]

1 to 3 show an embodiment of the present invention.
This example relates to a water pump 10 for cooling a water-cooled engine mounted in the four-wheeled working vehicle 1 shown in FIG. 3. FIG. 1 is a sectional view of a main part of the pump 10, and FIG. FIG. 4 is an external view (a detailed view of part II in FIG. 3).

The work vehicle 1 shown in FIG. 3 includes a water pump 10 shown in FIG. The water pump 10 is for sending the cooling water to the engine as described above. The cover 13 having the impeller chamber 16 therein has a suction pipe 13i and a discharge pipe 13o as shown in FIG. Are provided.

As shown in FIG. 1, the casing 11 of the water pump 10 is similar to that of FIG.
The shaft 21 is supported by a bearing 22 inside, and an impeller 24 is attached to an end of the shaft 13 in a cantilevered manner. The casing 11 is formed in a split type because of the convenience of assembling the shaft 21 and the impeller 24 and the like, but between the joint surfaces (the joint surface 12a on the body 12 side and the joint surface 13a on the cover 13 side). Has a sheet-like gasket 14. A seal member 23 is mounted on the shaft 21 as a water sealing means for preventing cooling water passing through the impeller chamber 16 from entering the bearing portion 15. The seal member 23 is, as shown in the figure, a ceramic ring 23d which is integrally attached to the impeller 24, a rubber seal ring 23c sliding between the ceramic ring 23d, and a rubber seal ring 23c pressed against the ceramic ring 23d. A rubber sleeve 23b with a spring, a rubber seal ring 23c and a sleeve 23b
And a retainer 23a for fixing it inside. However, a small amount of water leaks between the ceramic ring 23d and the rubber seal ring 23c of the seal member 23 due to the necessity of smooth sliding between them. The leaked water travels between the shaft 21 and the retainer 23a toward the bearing portion 15. Therefore, in this water pump 10 as well, a space 31 in which leakage water can accumulate is formed between the seal member 23 and the bearing portion 15, and a drain hole 32 is provided subsequently to the space 31. Drain hole 32
Penetrates the body 12 substantially vertically downward and opens to the outside.

The work vehicle 1 (FIG. 3) on which the water pump 10 is mounted often cuts grass and transports loads by running on the soil. Splashes. When splashed muddy water or the like enters the drain hole 32, it may travel upward due to capillary action, vehicle vibration, and the like, and may reach the seal member 23 along the shaft 21. When the seal member 23 is reached, mud particles adhere to the sliding surfaces of the ceramic ring 23d and the rubber seal ring 23c, and there is a possibility that the sealing performance and smoothness of sliding between the two may be reduced. Muddy water is also not preferable for the bearing 22. Therefore, in this embodiment, intrusion of muddy water or the like (water intrusion) from the outside into the drain hole 32 is prevented by the following means.

The means for preventing inundation employed in this example is as follows:
A metal tube 33 is press-fitted into the drain hole 32 from the outside, and a rubber tube 34 is attached to the tip thereof as shown in FIGS.
Are connected. The metal pipe 33 is a seamless pipe having an annular cross section and having an outer diameter of several millimeters, and is hammered from the tip (the lower part in the figure) and pressed into the drain hole 32. The tube 34 is formed by a bulge 33 a of the metal tube 33.
And one end thereof is lowered downward, and is fixed to the vehicle rearward. Tube 34 is about 2
Since the length is set to 0 cm and the tip is directed downward, it functions as a drain, but prevents muddy water or the like from entering the metal pipe 33 from the opening at the lower end. In addition to the tube 34, there is no path at the seam between the tube 34 and the metal tube 33, nor on the wall surface of the metal tube 33 and the press-fitting portion of the metal tube 33 into the drain hole 32. Although the prevention means has a simple configuration that can be easily realized, intrusion from the outside up to the drain hole 32 is completely prevented.

However, when the metal pipe 33 is press-fitted into the drain hole 32 as shown in FIG. 1, care must be taken so that the body 12 and the cover 13 forming the casing 11 are joined without any trouble. Since the drainage hole 32 provided in the body 12 is formed right from the side of the impeller chamber 16 and penetrates a portion close to the joint surface 12a, the drainage hole 32 is formed from the metal pipe 33 at a portion close to the joint surface 12a.
When a strong fitting force (a force acting outward on the inner surface of the drain hole 32) acts on the body 12, a part of the joint surface 12a of the body 12 swells and cannot be tightly joined to the joint surface 13a of the cover 13. It is.

In view of the above, in this embodiment, a large-diameter portion 32a, an intermediate portion 32b, and a press-fit portion 32c are formed in a drain hole 32 provided in the body 12, as shown in the figure. The large diameter portion 32a is connected to the joining surface 12a as shown in the figure.
(The part to be joined to the joining surface 13 a) is in a position adjacent to the back to back, and the inside diameter of this part is larger than the outside diameter of the metal tube 33 by about 0.5 mm. The press-fit portion 32c is a metal tube 3
3 so as to form a so-called interference fit,
The inner diameter is slightly smaller than the outer diameter of the metal tube 33 and finished smoothly. Also, an intermediate portion 32 formed between both portions.
In b, the inner diameter is continuously reduced from the large diameter portion 32a to the press-fit portion 32c so that the tip of the metal tube 33 easily enters the press-fit portion 32c when the metal tube 33 is pushed from the outside (the large-diameter portion side). ing.

If the metal pipe 33 is inserted into the drain hole 32 from the side of the large-diameter portion 32a and is lightly tapped with a hammer or the like and press-fitted, the metal pipe 33 is tightly fitted into the press-fit portion 32c. It fits and is connected without gaps by strong force. At this time, the vicinity of the press-fitting portion 32c of the body 12 is pushed outward by a force equivalent to the force applied to the metal tube 33, so that it is slightly outward (including the direction closer to the cover 13).
However, there is no fear that the joining between the body 12 and the cover 13 will be inconvenient. This is because the press-fitted portion 32c bulging in this manner is separated from the joining surface 12a, and the large-diameter portion 32a near the joining surface 12a has a gap between itself and the metal tube 33 and does not receive a force. Therefore, in this embodiment, water can be drained from the inside of the water pump 10 and water from the outside can be prevented.
2 and the cover 13 can be joined without any trouble.

4 and 5 show another embodiment of the present invention. Large diameter portion 32a and press-fit portion 32
1 is the same as in the example of FIG. 1 up to the point where the metal pipe 33 is press-fitted into the drainage holes 32 formed in order from the outside. Connected.

That is, first, in the example of FIG.
, A rubber one-way valve 35 is attached. As the one-way valve 35, a commercially available product in which a cut 35b is formed at the tip of a rubber bag 35a is used.
3 over the downward end as shown. Such a one-way valve 35 discharges accumulated water from the inside by the action of gravity through the cut 35b, but prevents inflow from the outside to the inside based on the nature of rubber which is naturally closed. It is also preferable to attach a resin cylinder or the like to the outside of the one-way valve 35 in terms of protection of rubber and the like.

In the example shown in FIG. 5, a check valve 36 of a general type in which a valve body 36b is pressed against a valve seat 36a by the force of a spring 36c is provided by using a metal pipe with the valve seat 36a side near the drain hole 32. 33 is connected to the end.
According to this check valve 36, the valve element 36b and the valve seat 3
No matter how much pressure is applied from the outside, a path through which water enters between them is not formed based on the positional relationship with 6a. on the other hand,
When water as a drain accumulates inside the drain hole 32 or the metal pipe 33, when the pressure of the water exceeds the force of the spring 36c, the valve body 36b is separated from the valve seat 36a, so that a drainage path is formed, and the drainage path is formed smoothly. Water is drained. In this example, the screw portion 33b is formed outside the distal end portion of the metal tube 33, and the check valve 36 is attached through the screw portion 33b.
For example, in the case of a check valve 36 having a metal pipe 33 part integrally, the part can be directly press-fitted into the drain hole 32 and connected to the water pump 10.

The drain structure of the water pump according to the present invention is not limited to the work vehicle 1 shown in FIG. 3, but may be various vehicles equipped with a water-cooled engine and used for applications where muddy water is likely to be applied, for example, a four-wheel buggy. It can be used in cars and off-road motorcycles.

[0028]

[Effect of the Invention] The drain structure of the water pump according to the present invention has the following effects.

1) Water (drain) in the water pump is discharged to the outside without any trouble, but muddy water cannot enter the inside from the outside. Since there is no intrusion of muddy water and the like, the original functions of the seal member and the like are maintained for a long time.

2) Since it is only necessary to press-fit a metal pipe into the drain hole and attach a water immersion preventer to the tip of the metal pipe, the construction can be made very simply and at low cost.

3) In this drain structure, no deformation occurs in the joint surface due to the press fitting of the metal tube.

4) The drain structures according to the second to fourth aspects have the further advantage that the respective structures are simple.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a main part of a water pump including a drain structure according to an embodiment of the present invention;

FIG. 2 is an external view of the water pump 10 of FIG.
FIG. 2 is a detailed view of part II.

FIG. 3 is a side view of the four-wheel working vehicle 1 on which the water pump 10 shown in FIGS. 1 and 2 is mounted.

FIG. 4 is a view showing another embodiment of the present invention, and is a cross-sectional view showing a main part of the water pump.

FIG. 5 is a cross-sectional view of a water pump according to another embodiment of the present invention.

FIG. 6 is a view showing a drain structure of a conventional water pump. FIG. 6 (a) is a sectional view of a main part of the water pump, and FIG.
(c) and (d) are sectional views or perspective views showing a conventional drain structure for which muddy water was tried.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Water pump 11 Casing 15 Bearing part 16 Impeller chamber 23 Seal member 32 Drain hole 32a Large diameter part 32c Press-fit part 33 Metal tube 34 Tube (water immersion prevention device) 35 One-way valve (water immersion prevention device) 36 Check valve ( Water flood prevention device)

Claims (4)

(57) [Scope of request for utility model registration] 1. A drain structure for discharging water leaked from an impeller chamber beyond the seal member to the outside, the water pump having an impeller chamber and a bearing portion provided in a casing via a seal member. The metal pipe was press-fitted into the drainage hole provided near the joint surface of the casing , and an external water intrusion prevention tool was connected to the metal pipe , and the inner diameter of the drainage hole was joined. In a range close to the surface
Is larger than the outer diameter of the metal tube, and
A drain pipe for the water pump, wherein the drain pipe has a dimension in which a metal pipe can be press-fitted . 2. A long tube as the above-mentioned inundation prevention tool.
The drain structure of the water pump according to claim 1, wherein
Build. 3. A rubber bag as the above-mentioned water intrusion prevention tool.
A one-way valve connected to an eyed type is described in claim 1.
Drain structure of the water pump described above. 4. A valve element as the above-mentioned water intrusion prevention tool,
Check valve that presses against valve seat
The drain structure of a water pump according to claim 1.