JPH06249160A - Cooling water pump structure for outboard motors - Google Patents

Abstract

(57) [Summary] [Purpose] To achieve commonality of press-molding dies for cooling water pump plates, thereby reducing man-hours and manufacturing costs. [Structure] A cylindrical case body 12 in which a pump case 10 of a cooling water pump 4 is housed in a state where a rubber impeller 11 is fitted into a drive shaft 3, and a case lid fixed to an upper portion of the case body 12. The body 13, the disk-shaped lower plate 14 fixed to the lower portion of the case body 12, the disk-shaped upper ceramics plate 15 fixed to the lower surface of the case lid 13, and the upper surface of the lower plate 14. It is composed of a fixed disk-shaped lower ceramics plate 16, and the upper ceramics plate 15 and the lower ceramics plate 16 are formed in the same shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling water pump structure for an outboard motor, and is particularly suitable for sharing a plate incorporated in a cooling water pump so as to use a common die for press molding of the plate. Cooling water pump structure for various outboard motors.

[0002]

2. Description of the Related Art Conventionally, in an outboard motor, an impeller disposed inside a cooling water pump is rotated by a drive shaft connected to an engine so that a cooling water suction port is formed in a housing of the outboard motor. The structure is such that seawater, lake water, etc. are introduced into the cooling water pump, and the cooling water pump supplies the cooling water to the engine to cool the engine. The cooling water pump 50 is shown in FIG.
Also, as shown in FIG. 5, a pump case 51 and a rubber impeller 5 fitted to the drive shaft 52 inside the pump case.
3, a lower plate 55 having a cooling water intake 54 arranged at the lower end of the pump case, and a cooling water outlet 56 arranged at the side of the pump case. When supplying cooling water to the engine, use the impeller 53 as the pump case 5.
1 and the lower plate 55 are slidably rotated in the space defined by the lower plate 55.

A detailed structure of the inside of the pump case 51 will be described with reference to FIGS. 6 to 8. In the lower surface of the pump case 51 of the cooling water pump 50, a hole 57 through which the drive shaft 52 passes is formed.
A metal plate 58 having an eccentricity and having abrasion resistance is fixed, and a hole 59 through which the drive shaft 52 penetrates is formed at the center of the upper surface of the lower plate 55, and a cooling water intake 54 and A wear-resistant metal plate 61 having a communicating hole 60 formed on the outer peripheral edge side is fixed. In this case, by making the drive shaft 52 penetrating the inside of the pump case 51 eccentric with respect to the inner circumference of the pump case 51, the tip end of the rubber impeller 53 is inside the pump case 51. Because it extends on the cooling water inlet 54 side and bends on the cooling water outlet 56 side (see FIG. 5),
Inside the pump case 51, the pressure (volume) on the cooling water intake 54 side is small and the pressure (volume) on the cooling water outlet 56 side is large, so that cooling water is taken in and sent out.

[0004]

However, in the conventional cooling water pump for the outboard motor, as described above, among the two plates respectively disposed on the upper and lower inner peripheral surfaces of the pump case, A hole for the drive shaft is formed in an eccentric state in the upper plate, and a hole for the drive shaft is formed in the center of the lower plate and a hole for the cooling water intake is formed on the outer peripheral side. (See FIGS. 7 and 8), it is necessary to prepare two molds when press-molding two plates having different shapes, which increases the manufacturing cost of the molds and also requires the mold replacement. The number of man-hours associated with setup change increases,
There has been a problem that it takes a lot of time to perform adjustment work for die replacement.

[0005]

It is an object of the present invention to improve the disadvantages of the above-mentioned conventional examples, and in particular, by sharing a plate incorporated in a cooling water pump, a die for press-molding a plate can be shared and the number of steps can be reduced. It is an object of the present invention to provide a cooling water pump structure for an outboard motor that achieves a reduction in manufacturing cost.

[0006]

SUMMARY OF THE INVENTION According to the present invention, holes for penetrating a drive shaft for transmitting an engine driving force are formed at both end portions, and a cooling water inlet provided at the one end portion. And a hollow cylindrical pump case having a cooling water outlet arranged at the other side end portion and on the side opposite to the cooling water inlet with respect to the drive shaft, and the inside of the pump case. An impeller that is fixed to the drive shaft, rotates while sliding on the inner wall of the pump case, takes in seawater, lake river water, etc. as cooling water from the cooling water inlet, and sends it to the engine side from the cooling water outlet. Equip. Further, an inner wall portion of the pump case on the side of the cooling water intake is formed of a first ceramic member having a hole communicating with the cooling water intake and a through hole of the drive shaft are formed. A second hole in which an inner wall portion of the case on the cooling water delivery port side is formed with a hole communicating with the cooling water delivery port and a through hole of the drive shaft.
It is composed of a ceramic member. Further, the first and second ceramic members are formed in the same shape, and the center of the inner circumferential circle formed by the cylindrical surface of the pump case is eccentric to the cooling water intake side. ing. This is intended to achieve the above-mentioned object.

[0007]

According to the present invention, the inner wall portion of the pump case on the cooling water intake side is formed of the first ceramic member having the hole communicating with the cooling water intake and the through hole of the drive shaft. The inner wall portion of the pump case on the cooling water delivery port side is formed of a second ceramic member having a hole communicating with the cooling water delivery port and a through hole of the drive shaft, and the first and second ceramics. Since the members are formed in the same shape and the center of the inner circumference circle formed by the cylindrical surface of the pump case is eccentric to the cooling water intake side, the first and second ceramic members are pressed. When manufacturing by molding, it is possible to use a common mold. Therefore, as in the conventional case where two plates having different shapes are arranged on the inner surface of the pump case, the setup change when exchanging the two molds for each plate at the time of press-molding both plates is possible. Since it is unnecessary, the number of manufacturing steps and the manufacturing cost can be significantly reduced. Further, since the portion on which the impeller slides is formed of a ceramic member, it is possible to improve the wear resistance inside the pump case and improve the reliability of the cooling performance of the cooling water pump.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment to which the outboard motor cooling water pump structure of the present invention is applied will be described below with reference to the drawings.

First, the structure of the outboard motor equipped with the cooling water pump of this embodiment will be described with reference to FIG. 3. The drive shaft 3 connected to the crankshaft (not shown) of the engine 2 of the outboard motor 1 will be described.
A cooling water pump 4 is disposed in the middle of the drive shaft 3, and a propeller shaft 6 is connected to an end of the drive shaft 3 via a bevel gear 5. During operation of the outboard motor 1, the propeller 7 is rotated via the drive shaft 3 and the propeller shaft 6, while the impeller inside the cooling water pump 4 is rotated via the drive shaft 3. In the cooling water pump 4, the seawater, the lake water, etc. introduced from the cooling water inlet 8 formed in the housing of the outboard motor are pumped from the cooling water inlet 17 to the pump case 10 (which will be described later) as the impeller rotates. After being taken in, the cooling water is sent out from the cooling water outlet 9 in the direction of the arrow in the figure and supplied to the engine 2 for cooling.

Next, the structure of the cooling water pump of this embodiment will be described with reference to FIGS. 1 and 2. The pump case 10 of the cooling water pump 4 is made of rubber fitted into the drive shaft 3 (see FIG. 3). A cylindrical case body 12 that houses the impeller 11 and has a cylindrical surface 12A, a case lid body 13 fixed to the upper part of the case body 12, and a disk-shaped lower plate fixed to the lower part of the case body 12. 14, a disk-shaped upper ceramics plate 15 fixed to the lower surface of the case lid 13, and a disk-shaped lower ceramics plate 16 fixed to the upper surface of the lower plate 14. .

In this case, when the impeller 11 inside the pump case 10 rotates, in order to prevent the inner surface portion of the pump case 10 on which the impeller 11 slides from being worn, the upper ceramic plate 15 is attached to the sliding portion of the impeller 11. ，
By arranging the lower ceramics plate 16,
Improves wear resistance.

A case cover 1 which constitutes the pump case 10.
3, lower plate 14, upper ceramic plate 1
5, holes 13A, 14A, 15A, 16A for fitting with the drive shaft 3 (see FIG. 3) are formed in the lower ceramic plate 16.
Are formed respectively. Further, holes 14B and 16B are formed in the lower plate 14 and the lower ceramic plate 16, respectively, and these holes 14B and 16B are taken into the outboard motor 1 through the cooling water inlet 8 (see FIG. 3). A cooling water inlet 17 for taking in seawater or lake water into the pump case 10 is configured. Furthermore, the case lid 13,
The upper ceramic plate 15 has holes 13B and 15B.
Are formed respectively, and these holes 13B, 15B constitute a cooling water outlet 9 (see FIG. 3) for sending the cooling water inside the pump case 10 to the engine 2.

The cylindrical case body 12 is formed such that its inner peripheral surface is eccentric with respect to its outer peripheral surface.
The upper ceramic plate 15 and the lower ceramic plate 16 are formed in exactly the same shape. In this case, FIG. 2 is a diagram showing the positional relationship among the case body 12, the upper ceramic plate 15, and the lower ceramic plate 16.

Next, the manufacturing process of the upper ceramic plate 15 and the lower ceramic plate 16 used in the cooling water pump of this embodiment will be described. First, with respect to 100 parts of powder which is a raw material of ceramics, 0.5 part of a decoking agent, 0.5 part of a binder, 0.2 part of an antifoaming agent, and 5 parts of water.
0 part is put into a nylon pot together with, for example, a nylon ball containing an iron core, and then wet mixed for a predetermined time (for example, 24 hours) to form a slurry.

Next, the slurry is spray-dried by a spray dryer (for example, a spray dryer) to form granules having good fluidity, and then the fluid granules are set in a press machine with a press die having a predetermined shape. It is designed to be molded. Then, the press-formed molded body is heated to a predetermined temperature by an electric furnace (for example, in the case of alumina ceramics, 1400 to
A ceramic plate is manufactured by sintering at 1700 ° C.

Next, the operation of the present embodiment constructed as described above will be described.

When the engine 2 of the outboard motor 1 is driven, the propeller 7 starts rotating via the drive shaft 3 and the propeller shaft 6, and the impeller 11 of the cooling water pump 4 starts rotating via the drive shaft 3. To do. The seawater and lake water introduced from the cooling water introduction port 8 formed in the housing of the outboard motor 1 flows from the cooling water intake port 17 of the cooling water pump 4 to the pump case 10.
After being taken inside, the impeller 11 of the cooling water pump 4
With the rotation of the cooling water, the cooling water is sent out from the cooling water sending port 9 and supplied to the engine 2.

In this case, the impeller 11 slides on the inner surface of the pump case 10 as the impeller 11 rotates.
Since the upper ceramics plate 15 and the lower ceramics plate 16 are arranged in a portion where the impeller 11 slides, when the seawater or lake river water taken into the pump case 10 is contaminated with earth and sand, the earth and sand are impellered. 11 and the upper ceramics plate 15 and the lower ceramics plate 16 are interposed, the upper ceramics plate 15 and the lower ceramics plate 16 have good wear resistance, so that the cooling water from the cooling water pump 4 to the engine side is cooled. Can be supplied accurately.

By the way, the upper ceramic plate 1 constituting the pump case 10 of the cooling water pump 4 of this embodiment.
Since the 5 and the lower ceramic plate 16 are formed in the same shape, when the fluid granules produced from the ceramic raw material are press-formed to form a formed body at the time of manufacturing these ceramic plates, it is used by a press machine. It is possible to use a common die for a ceramic plate. Therefore, unlike the conventional case, when two ceramic plates having different shapes are press-molded, it is not necessary to perform a setup change when exchanging the two molds for each plate. Can be significantly reduced.

As described above, according to this embodiment, since the upper ceramic plate 15 and the lower ceramic plate 16 incorporated in the cooling water pump 4 have the same shape, the mold for manufacturing the ceramic plate can be shared. As a result, it is not necessary to perform setup change associated with die replacement, so that the number of manufacturing steps and the manufacturing cost can be reduced.

Further, according to this embodiment, the cooling water pump 4
Since the upper ceramics plate 15 and the lower ceramics plate 16 are arranged in the portion of the pump case 10 where the impeller 11 slides, wear resistance can be improved.

[0022]

As described above, according to the cooling water pump structure for the outboard motor of the present invention, the inner wall portion of the pump case on the cooling water inlet side is connected to the hole for communicating with the cooling water inlet and the drive shaft. And a through hole of the drive shaft, the inner wall portion of the pump case on the cooling water delivery port side is formed with a hole communicating with the cooling water delivery port. It is composed of a second ceramic member, the first and second ceramic members are formed in the same shape, and the center of the inner circumference circle formed by the cylindrical surface of the pump case is eccentric to the cooling water intake side. Due to this structure, it is possible to use a common mold when manufacturing the first and second ceramic members by press molding. As a result, the inner surface of the pump case has a similar shape to that of the conventional case. Different 2
As in the case of arranging one plate, it is not necessary to perform setup change when exchanging two molds for each plate at the time of press-molding both plates, so that man-hours and manufacturing cost can be significantly reduced. Also, because the part where the impeller slides is made of a ceramic member, it is possible to improve the wear resistance inside the pump case and increase the reliability of the cooling performance of the cooling water pump. That is, a remarkable effect can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a cooling water pump of this embodiment to which the present invention is applied.

FIG. 2 is an explanatory diagram showing a positional relationship between the upper and lower ceramic plates shown in FIG. 1 and a case body.

FIG. 3 is a schematic diagram of an outboard motor equipped with the cooling water pump of the present embodiment.

FIG. 4 is a sectional view of a conventional cooling water pump.

5 is an explanatory diagram showing a positional relationship between the respective parts shown in FIG.

6 is a detailed cross-sectional view of the cooling water pump shown in FIG.

FIG. 7 is a plan view of the upper ceramic plate shown in FIG.

FIG. 8 is a plan view of the lower ceramic plate shown in FIG.

[Explanation of symbols]

1 Outboard Motor 2 Engine 3 Drive Shaft 4 Cooling Water Pump 9 Cooling Water Outlet 10 Pump Case 11 Impeller 15 Upper Ceramics Plate as Second Ceramics Member 16 Lower Ceramics Plate as First Ceramics Member 17 Cooling Water Intake

Claims (1)

[Claims] 1. A hole for penetrating a drive shaft for transmitting an engine driving force is formed at both end portions, and a cooling water inlet provided at the one side end portion and the other side end portion are formed. And a hollow cylindrical pump case having a cooling water outlet arranged on the side opposite to the cooling water inlet with respect to the drive shaft, and fixed to the drive shaft in the pump case, Equipped with an impeller that rotates while sliding with the inner wall of the case and takes in seawater, lake river water, etc. as cooling water from the cooling water inlet and sends it out to the engine side from the cooling water outlet, the pump case The inner wall portion on the cooling water intake side is formed of a first ceramic member having a hole communicating with the cooling water intake port and a through hole of the drive shaft, and the cooling water delivery port of the pump case. Send the cooling water to the inner wall on the side A second ceramic member having a hole communicating with the mouth and a through hole of the drive shaft, the first and second ceramic members having the same shape, and a cylinder of the pump case. A cooling water pump structure for an outboard motor, wherein the center of an inner circumferential circle formed by the surfaces is eccentric to the cooling water intake side.