JPH032673Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Purpose of the Invention] (Field of Industrial Application) The present invention relates to an engine cooling device that can be applied to a cooled internal combustion engine.

(Prior Art) A cooling water pump for a water-cooled internal combustion engine discharges cooling water in an amount proportional to the engine speed, but in many cases, the water pump flow rate in a high speed range is a little excessive. This has caused disadvantages to the engine, such as loss of water pump shaft horsepower, overcooling in cold weather, cavitation due to reduced water pump suction pressure, or excessive pressurization of the thermostat valve.

A cooling device for a cooled internal combustion engine that eliminates the above-mentioned disadvantages has been proposed in Japanese Utility Model Application Publication No. 184318/1983. This cooling device is shown in Figures 10 to 12.
As shown in the figure, a water jacket 2 of the engine 1, a passage 4 for discharging cooling water from the water jacket 2 of the engine 1 to the radiator 3, a return passage 5 leading from the radiator 3 to the thermostat section 6, and the discharge passage. Bypass passage 7 leading from 4 to thermostat section 6
and a suction passage 9 leading from the thermostat section 6 to the cooling water pump 8, the bypass passage 10 guiding the cooling water discharged from the water jacket 2 directly to the suction passage 9.
and a negative pressure control bypass valve 11 interposed in the bypass passage 10, and when the suction negative pressure in the suction passage 9 increases, the bypass valve 11 is opened to supply cooling water to the suction passage 9. The suction negative pressure is reduced by supplying the suction negative pressure. In addition, 12 is a water heater, 13 is a valve body, 14 is a spring, and 15 is a rotating shaft.

However, the bypass valve 11 has the following drawbacks. That is, FIG. 11 and FIG. 12a
As shown in the figure, there is a gap between the bypass passage 10 and the valve body 13 even when the valve is closed, and a small amount of water flows into the passage 1.
It had the drawback of flowing through 0. In addition, since the cooling water pump 8 has a structure that opens and closes slightly even in a low rotational speed range, there is a drawback that the flow rate of cooling water to the radiator 3 is low in low and medium speed ranges that require a large cooling capacity. The circuit flow rate also decreases (9th
figure). In addition, QM in Figure 9 is the main circuit flow rate, QR
is the relief circuit flow rate. Furthermore, there is a possibility that the valve body 13 may operate due to engine vibration, and there is also a risk that the valve body 13 may not operate if a foreign object intervenes between the rotary shaft 15 and the valve body 13. These are serious drawbacks that lead to overheating, and in particular, it was necessary to increase the capacity of the cooling water pump 8 to compensate for the decrease in the amount of cooling water.

(Problems to be Solved by the Invention) The present invention aims to solve problems in the conventional cooling system for internal combustion engines when the amount of cooling water to the radiator is insufficient, the valve body malfunctions due to vibration, or the valve body malfunctions due to the intervention of foreign objects. The aim is to solve the following problems:

[Structure of the idea]

(Means for Solving the Problem) Therefore, the present invention includes a water pump that forcibly sends cooling water to the internal combustion engine, a passage that projects the cooling water from the head of the internal combustion engine to the radiator, and a passage that projects the cooling water from the radiator to the water pump. a return passage for guiding cooling water; a first branch conduit located between the discharge passage and the return passage and short-circuited without passing through the radiator;
a second branch conduit disposed in parallel with the branch conduit and having a one-way valve; and at least a second branch conduit on the protruding passage between the first and second branch conduits and the radiator, or at a confluence of the first branch conduit and the return passage. In the engine cooling device having a thermostatic valve, the one-way valve includes a conical valve seat, a conical or spherical valve body made of resin or an elastic body, and a valve body that is moved toward the valve seat. It consists of a biasing spring and a bearing that supports the spring and the valve body, and a slight gap is formed between the valve body support part of the bearing and the valve body when the valve is opened (at maximum stroke). It is formed into a conical shape and is used as a means to solve problems.

(Operation) The valve body is closed by being pressed against the sealing surface of the housing by a spring, but when the pressure in the water circuit reaches the set pressure, the valve opens and water flows. This flowing water is recirculated to the water pump.

(Example) The embodiment of the present invention will be explained below with reference to the drawings. Figures 1 to 7 show the embodiment of the present invention, and Figure 1 is the embodiment of the present invention. , shows an in-line type engine cooling device equipped with a one-way valve 20 shown in FIG. 7, etc., and FIG. 2 shows a bottom bypass type engine cooling device.

First, in FIG. 1, 21 is the head of the internal combustion engine, 22 is a water pump that forcibly supplies cooling water to the internal combustion engine, and 23 is a connection from the head 21 to the radiator 2.
4 is a passage for projecting cooling water, 25 is a radiator 2
26 is located between the discharge passage 23 and the return passage 25 and is short-circuited without passing through the radiator 24; 27 is arranged in parallel with the first branch conduit 26; 28 is a thermostatic valve provided on the discharge passage 23 between the first and second branch conduits 26, 27 and the radiator 24, and 29 is a heater circuit. A1 also includes the head 21, the discharge passage 23, the thermostat valve 28, the radiator 24, the return passage 25, and the water pump 2.
2 is the first circuit through which the cooling water flows, A2 is the head 2
1, a discharge passage 23, a first branch conduit 26, a return passage 25, and a second passage through which cooling water flows through the water pump 22;
Circuit A3 is a third circuit in which cooling water flows through the head 21, the one-way valve 20, the second branch conduit 27, and the water pump 22. In addition, QM in Fig. 1 is the main circuit flow rate, and QR is the relief circuit flow rate.

Next, FIG. 2 shows a case where a thermostatic valve 28 is provided at the confluence of the first branch conduit 26 and the return passage 25, but there is no difference in operation and effect from FIG. 1.

Next, the one-way valve 20 will be explained with reference to FIGS. 3 and 4. 30 is a conical valve seat formed in the housing 31 of the discharge passage 23, 32 is a conical valve body made of resin or an elastic body, 33 is the valve body 32
This spring is interposed between the valve body 32 and the bearing 34, and biases the valve body 32 against the valve seat 30.
The bearing 34 is fixed to the housing 31, and
A truncated cone shape 36 is formed which engages with a conical hole 35 of the valve body 32, and the valve body 32 opens as shown on the left side of FIG.
6, there is a small gap a between the conical hole 35 and the truncated conical shape 36 to prevent foreign matter from getting caught.
is beginning to form. The valve body 32 is made of a resin such as polyacetal or an elastic material such as nitrile rubber.

Next, the function of the embodiment shown in FIG. 3 will be explained.
3 to be pressed against the valve seat 30 of the housing 31. When the pressure of the cooling water flowing from the head 21 to the discharge passage 23 reaches a predetermined pressure, the valve body 32 is pushed down as shown on the left side of FIG. Cooling water flows between the body 32 and the valve seat 30 and is recirculated through the second branch conduit 27 to the water pump 22.

Next, to explain the flow of water when the valve body operates, in the inline method shown in Figure 1, [water pump low rotation] When the water temperature is low (thermostat valve closed) → circuit A
2 (one-way valve closed) When water temperature is high (thermostat valve open) → Circuit A
1+A2 (one-way valve closed) [Water pump high speed] When water temperature is low (thermostat valve closed) → Circuit A
2+A3 (one-way valve open) When water temperature is high (thermostat valve open) → Circuit A
1+A2+A3 (one-way valve open) Next, in the bottom bypass type shown in Figure 2, [water pump low rotation] When the water temperature is low (thermostat valve closed) → circuit A
2 (one-way valve closed) When water temperature is high (thermostat valve open) → Circuit A
1 (One-way valve closed) [Water pump high speed] When water temperature is low (thermostat valve closed) → Circuit A
2+A3 (one-way valve open) When water temperature is high (thermostat valve open) → Circuit A
1+A3 (one-way valve open) By branching water to circuit A3 in this way,
Reduces shaft horsepower (due to lower water flow resistance), prevents overcooling, prevents cavitation (alleviates suction negative pressure), and reduces pressure on the thermostat valve.

Next, FIGS. 5 and 6 show the one-way valve 20 of the present invention.
This shows a second embodiment of the invention. In this case, the supporting portion of the valve body 32a is formed into a truncated conical shape, the conical hole that engages with the supporting portion is provided in the bearing 34a, and the spring 32a is formed into a truncated conical shape.
Although 3a is a trapezoidal spring, there is no difference in the operation and effect. In addition, 37 in the figure is a roller crimping of the bearing 34, and by roller crimping in this way, water leakage is prevented. Further, it is convenient for manufacturing if the valve mechanism is assembled in advance in this manner and is attached as a unit to a part of the water circuit such as the housing 31.

Next, FIG. 7 shows a third embodiment of the one-way valve 20 of the present invention, in which the valve body 32b is shaped like a spherical head, but there is no difference in operation and effect.

[Effect of idea]

As explained in detail above, in the present invention, the valve body support portion of the bearing is formed in a conical shape, so that water can flow out along the tapered shaft without providing a drain hole in the valve body. Furthermore, since a slight gap is formed between the bearing and the conical support portion of the valve body when the valve is opened, foreign matter can be prevented from getting caught, and the valve will not become inoperable due to foreign matter getting caught. On the other hand, since the valve body is made of resin or an elastic body, there is no problem with the sealing surface getting caught.

Furthermore, by arbitrarily setting the mounting load of the spring that urges the valve body toward the valve seat, the valve opening pressure can be determined, and the valve can be prevented from opening below this pressure (FIG. 8). Furthermore, since the valve body is biased against the conical valve seat when the valve is closed, vibrations in the X and Z directions can be absorbed, and vibrations in the Y direction (the direction in which the valve opens) can be absorbed.
The valve body that receives vibration is made of a light material such as resin,
If the design is such that the value of (weight x vibration) does not exceed the mounting load of the spring, this operation will not occur.

[Brief explanation of the drawing]

1 and 2 are plan views of engine cooling systems according to different embodiments of the present invention, FIG. 3 is a side sectional view of a one-way valve according to the first embodiment of the present invention, and FIG.
An explanatory view showing the operating state of the valve body in the figure, FIG. 5 is a front view showing the second embodiment of the one-way valve of the present invention,
Figure 6 is a sectional view from A to A in Figure 5, Figure 7 is a side sectional view showing the third embodiment of the one-way valve of the present invention, and Figure 8 is the water pump rotation speed and main Diagram showing the relationship between the flow rate and the relief circuit flow rate, No. 9
The figure is a diagram showing the relationship between the conventional water pump rotation speed and the main and relief circuit flow rates, Figure 10 is a plan view of a conventional cooling system for a water-cooled internal combustion engine, and
Figure 1 is a front sectional view of the valve mechanism section in Figure 10, and Figure 12 is a front sectional view of the valve mechanism section in Figure 10.
Figures a and b are explanatory diagrams of the open and closed states of the valve body. Explanation of main parts of the figure, 20...One-way valve, 21
...Head, 22...Water pump, 23...
Discharge passage, 24...Radiator, 25...Return passage, 26...First branch conduit, 27...Second branch conduit, 28...Thermostat valve, 30...Conical valve seat, 31...Housing, 32...Valve body, 33
... Spring, 34 ... Bearing, 36 ... truncated cone.

Claims (1)

[Scope of utility model registration request] A water pump that forcibly sends cooling water to the internal combustion engine, a passage that discharges cooling water from the head of the internal combustion engine to the radiator, a return passage that leads the cooling water from the radiator to the water pump, and a passage between the discharge passage and the return passage. a first branch conduit which is short-circuited without passing through the radiator; a second branch conduit arranged in parallel with the first branch conduit and having a one-way valve; and the first and second branch conduits on the discharge passage. and a radiator, or at a confluence of the first branch conduit and the return passage, the one-way valve has a conical valve seat, a conical or spherical shape, and is made of a material. The valve body is made of resin or an elastic body, a spring that biases the valve body toward the valve seat, and a bearing that supports the spring and the valve body. An engine cooling device characterized by being formed in a conical shape such that a small gap is formed between the engine cooling device and the body when the valve is opened.