JP3064602B2 - Outboard 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 water pump for an outboard motor.

[0002]

2. Description of the Related Art A conventional water pump for an outboard motor comprises a metal water pump case and a rubber impeller rotatably housed in the water pump case and fitted into a drive shaft. The impeller driven by the drive shaft eccentrically rotates while strongly sliding inside the water pump case,
The mechanism is such that cooling water is pumped to the engine.

[0003]

However, in the above-mentioned conventional water pump for an outboard motor, seawater or lake water is used as engine cooling water.
Since sand and mud in seawater and lake water are sucked together with water, the mixed sand and mud act as abrasive particles between the water pump case and the sliding surface of the impeller, and the metal water pump case There was a problem that the inner wall surface was abnormally worn and the function of the water pump was reduced in a very short time.

The present invention has been made in view of such circumstances, and has as its object to fix a ceramic plate provided to reduce wear of a sliding portion in a water pump case at low cost, An object of the present invention is to provide a water pump for an outboard motor capable of improving the performance by effectively utilizing the excellent wear resistance of ceramics.

[0005]

According to the present invention, a rubber impeller is rotatably provided inside a water pump case.
A water pump for an outboard motor in which a ceramic plate is fixed to an inner wall surface of a water pump case on which the impeller slides with a resinous adhesive, wherein 2 to 70% by weight of carbon powder is mixed as the resinous adhesive. Is used.

[0006]

[Operation] In the water pump of the outboard motor according to the present invention,
Since a predetermined amount of carbon powder is mixed in the resinous adhesive for fixing the ceramics plate, it is possible to mount the ceramics plate having excellent wear resistance in the water pump case at low cost. At the same time, the thermal conductivity of the resinous adhesive is improved, and it is possible to sufficiently radiate frictional heat generated by the rotation and rotation of the rubber impeller in the water pump case while sliding.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

1 to 3 show an embodiment of the present invention. In the drawings, reference numeral 1 denotes an outboard motor, and the outboard motor 1 is mounted on a hull (not shown) via a mounting bracket 2. It has become. An engine 4 is mounted on an upper part of the casing 3 of the outboard motor 1, and the engine 4 drives the drive shaft 5, the gear unit 6 and the propeller shaft 7.
The propeller 8 is configured to be driven to rotate via the.

An engine 4 is provided inside the casing 3.
A water pump 9 for cooling the water is provided.
The water pump 9 includes a substantially cylindrical water pump case 10 made of metal. Inside the water pump case 10, a rubber impeller 11 eccentrically driven and rotated by the drive shaft 5 is rotatable. Is provided. Further, the water pump case 10 is provided with a discharge port 13 for sending out the cooling water introduced from the water intake port 12 to the outside. The water inlet 12 is formed on the side surface of the submerged portion of the casing 3 and communicates with the water pump 9 via a water suction pipe (not shown). In addition,
The discharge port 13 communicates with a water jacket (not shown) of the engine 4 via a water discharge pipe 14.

That is, the water pump 9 is driven in conjunction with the rotation of the drive shaft 5 accompanying the operation of the engine 4, and is rotated by the rotation of the impeller 11.
The cooling water taken into the water pump case 10 from the engine 4 is discharged from the discharge port 13 through the water discharge pipe 14 to the engine 4.
Of the engine 4
It is designed to cool down.

On the other hand, on the upper surface side of the impeller 11, the water pump case 1 on which the impeller 11 slides.
A disk-shaped ceramic plate 15 having excellent abrasion resistance is attached to the inner wall surface. The ceramic plate 15 is fixed to the inner wall surface of the water pump case 10 with a resin adhesive, and an insertion hole 16 through which the drive shaft 5 is inserted is formed at a position near the center. The ceramic plate 15 is formed of a material such as silicon nitride or alumina, and has a thickness of about 2 mm.

As the above resinous adhesive, 2-70% by weight of carbon powder is contained in a two-part curable epoxy resin adhesive.
Is used. As shown in Table 1 below, the thermal conductivity of the epoxy resin is two orders of magnitude lower than that of ceramics, so the frictional heat generated by the rubber impeller 11 rotating while sliding is the presence of the epoxy resin. This will hinder heat dissipation. However,
The carbon powder has a very high thermal conductivity, as is clear from Table 1, and therefore, as shown in FIG.
It can be seen that the thermal conductivity of the resinous adhesive is improved only by adding the amount by weight. However, if the carbon powder is mixed into the epoxy resin in an amount of 70% by weight or more, the adhesive force is greatly reduced, and the epoxy resin is not suitable for practical use. FIG.
, The solid line shows the change in the thermal conductivity of the epoxy resin when the mixing ratio of the carbon powder was changed, and the broken line shows the change in the adhesiveness of the epoxy resin when the mixing ratio of the carbon powder was changed.

[0013]

[Table 1]

The water pump 9 of the present embodiment and the water pump of the comparative example were incorporated in the outboard motor 1, respectively, and the engine 4 was started without running cooling water, and idling was performed for 1-2 minutes. This is because there is a high possibility that the outboard motor 1 will be run idling depending on the situation, and therefore, the conventional metal water pump is designed so that no abnormality occurs even if the idling operation is performed for 2 minutes. is there. Here, the water pump 9 according to the present embodiment has a carbon-containing adhesive formed by adding 40% by weight of carbon powder to each of the main component and the curing agent of the two-component curable epoxy resin adhesive and kneading them sufficiently with three rolls. A silicon nitride ceramic plate 15 is fixed to the inner wall surface of the water pump case 10 using an agent. The thickness of the resinous adhesive of this embodiment after being cured is about 0.5.
It is 2 mm. In the water pump of the comparative example, a ceramic plate 15 of the same material as that of the present embodiment is fixed to the inner wall surface of the water pump case using a two-component curing type epoxy resin adhesive.

In this embodiment, the outboard motor 1 is operated for 2 minutes without running, the engine 4 is stopped, the water pump 9 is disassembled, and the water pump case 10 and the rubber impeller 11 are collected. When the state was confirmed, no abnormality had occurred. On the other hand, in the comparative example, the outboard motor 1 was run idle for one minute, and then the engine 4 was stopped, the water pump was disassembled, and the state of the water pump case and the rubber impeller was confirmed, as in the above embodiment. As a result, the temperature of the rubber impeller increased due to insulated frictional heat, so that the portion in contact with the ceramic plate was melt-ruptured.

In the water pump 9 of the present embodiment,
Since the ceramic plate 15 is fixed to the inner wall surface of the water pump case 10 using a resin adhesive mixed with carbon powder having improved thermal conductivity, the ceramic plate 15 can be easily and inexpensively assembled. In addition, the frictional heat generated by the idling operation of the outboard motor 1 is not insulated and stored by the presence of the resinous adhesive, but is sufficiently radiated.

As described above, one embodiment of the present invention has been described.
The present invention is not limited to the embodiments described above, and various modifications and changes can be made based on the technical idea of the present invention.

For example, in the above-described embodiment, the ceramic plate 15 is provided only on the upper surface side of the impeller 11, but
In the present invention, the ceramic plate 15 is connected to the impeller 11.
It is needless to say that the present invention can be applied to a water pump of a type arranged also on the lower surface side of the water pump.

[0019]

As described above, in the water pump of the outboard motor according to the present invention, a rubber impeller is rotatably provided inside a water pump case, and the inner wall surface of the water pump case on which the impeller slides is provided. Since the ceramic plate is fixed by a resinous adhesive containing carbon powder mixed in an amount of 2 to 70% by weight, it is ensured that the ceramic plate is bonded to a metal material which is a problem in using a ceramic material having excellent wear resistance. The ceramic plate can be easily assembled to the water pump case, and the effective use of the excellent wear resistance of the ceramics and the efficiency of the assembling work can be improved. In addition, since the thermal conductivity of the resinous adhesive for fixing the ceramic plate is improved and increased, frictional heat generated by sliding of the rubber impeller is insulated.
It is possible to dissipate heat sufficiently without storing heat,
As a result, the rubber impeller does not melt and break, and the reliability and performance of the cooling system in the outboard motor can be improved.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a structure of an outboard motor to which a water pump according to one embodiment of the present invention is assembled.

FIG. 2 is a sectional view showing the water pump.

FIG. 3 is a plan view of the water pump as viewed from below.

FIG. 4 is a characteristic diagram showing the relationship between the amount of carbon mixed and the thermal conductivity and adhesiveness of an epoxy resin.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outboard motor 3 Casing 4 Engine 5 Drive shaft 9 Water pump 10 Water pump case 11 Rubber impeller 15 Ceramics plate 16 Insertion hole

Claims (1)

(57) [Claims] 1. A water pump for an outboard motor in which a rubber impeller is rotatably provided inside a water pump case, and a ceramics plate is fixed to an inner wall surface of the water pump case on which the impeller slides with a resinous adhesive. A carbon powder as the resinous adhesive,
A water pump for an outboard motor, wherein a water pump containing 0% by weight is used.