JPH0322511Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of a cavitation erosion prevention device that mixes upper air in a water tank provided in an engine cooling system into cooling water.

The cavitation erosion prevention device of the above type is disclosed, for example, in Japanese Utility Model Application Publication No. 58-33729, etc., but this device conventionally has a structure in which the installation position of the air outlet part (outlet pipe) of the water tank is fixed. Because of this, there was a problem that the amount of air mixed into the cooling water would end due to changes in the cooling water temperature.

That is, as illustrated in FIG.
Since the cooling water d inside is in communication with the engine cooling water,
When the temperature of the engine cooling water increases due to engine operation, the volume of the engine cooling water expands, and the cooling water level c in the water tank a rises by the expanded volume.
In other words, the tank water level will rise. Therefore, as shown in FIG. 2, the distance between the air outlet b and the cooling water surface c is shortened to l', and the amount of air led out is reduced. The amount of air drawn out from water tank a is determined by air outlet b.
Since the volume of the water tank a is equal to the distance between the distance 1 and the cooling water surface c, the amount of air mixed into the cooling water decreases when the distance l in FIG. 1 changes to the distance l' in FIG. 2. For these reasons, the erosion prevention effect of conventional devices has been reduced.

Therefore, this invention provides a cavitation erosion prevention device that can solve the above-mentioned problems.

In addition, Utility Application No. 58-69784 (Utility Application No. 59-175628) is used to control the amount of mixed cooling water.
There is a technology proposed in

An embodiment of this invention will be described below with reference to FIGS. 3 and 4.

In the figure, 1 is a water tank (for example, a water subtank) provided in the engine cooling system. Top plate 2 located approximately in the center of this water tank 1
An outer cylinder 4 of the air outlet cylinder 3 is vertically disposed on the outer cylinder 4, and an inner cylinder 5 with a bottom is slidably fitted into the outer cylinder 4. The outer cylinder 4 and the inner cylinder 5 are seal members (O-rings).
6 and 7, and are airtight. At the bottom of the outer cylinder 4 is a vertical ellipse (length l'').
A hole 8 is formed in the inner cylinder 5, and a circular hole 9 that coincides with the hole 8 is formed in the inner cylinder 5. The holes 8 and 9 serve as air outlet portions. Further, a pipe 10 constituting an air flow passage is connected to the upper end of the outer cylinder 4, and the inner cylinder 5
A wax actuator 13 attached to a support 12 fixed on the bottom plate 11 of the water tank 1 is connected to the lower end of the tank.

The wax type actuator 13 has a structure similar to a known one, and includes a temperature sensing part (wax) that senses the temperature of the cooling water 14 in the water tank 1.
15, a piston 16 that expands and contracts depending on the condition of the temperature sensing portion 15, and a rod 17 that moves the inner cylinder 5 of the air outlet cylinder 3 in the vertical direction in response to the expansion and contraction of the piston 16. .

Because of this structure, when the temperature of the cooling water 14 in the water tank 1 rises, the wax-type actuator 13 expands as the temperature rises, causing the inner cylinder 5 to rise.
The hole 9 changes from position ○a to position ○a′, and the difference L
is equal to the difference L' between the position ○RO and the position ○RO' of the cooling water level 18 that changed due to the temperature rise, and the cooling water level 18
Even if there is a temperature change, the positional differences L and L' between the holes 9 and the cooling water surface 18 are always constant, and assuming that the amount of air mixed into the cooling water is constant, the amount of air mixed in decreases as the cooling water temperature rises. A predetermined erosion prevention effect is maintained without causing any damage.

5 and 6 show different embodiments;
The one shown in the figure is the one in which the air outlet tube 3 of the above-mentioned example is replaced with the outlet pipe 19, and a flexible part 20 is provided in a part of the outlet pipe 19, and the one shown in FIG. 6 is the wax in FIG. 5. The type actuator 13 is replaced with a bimetal (or shape memory alloy) 21, and both have the same effect and function as the above example.
You can expect good results.

In summary, the cavitation erosion prevention device according to this invention is a cavitation erosion prevention device that mixes upper air in a water tank provided in an engine cooling system into cooling water. , a temperature-sensitive expandable member is connected to the air outlet portion of the water tank that changes the air outlet portion in the height direction of the water tank in proportion to the temperature of the cooling water in the water tank. As the distance between the cooling water surface of the water tank and the air outlet can be kept constant regardless of the cooling water temperature, the amount of air mixed into the cooling water does not decrease, and the erosion effect is maintained. It has practical benefits that can be achieved.

[Brief explanation of the drawing]

1 and 2 are schematic sectional views showing a conventional cavitation erosion prevention device, and FIG.
The figure is a sectional view of an embodiment of this invention, FIG. 4 is an enlarged sectional view of the same essential part, and FIGS. 5 and 6 are schematic sectional views of different embodiments. In the figure, 1 is a water tank, 3 is an air outlet tube, 4 is an outer tube, 5 is an inner tube, 9 is a hole, 13 is a wax type actuator, 19 is a pipe, and 21 is a bimetal.

Claims (1)

[Scope of utility model registration request] In a cavitation erosion prevention device that mixes the upper air in a water tank provided in an engine cooling system into cooling water, the air outlet part of the water tank is provided with a cooling water temperature droplet in the water tank. 1. A cavitation erosion prevention device, characterized in that a temperature-sensitive elastic member is connected that proportionally changes the air outlet portion in the height direction of the water tank.