JPS6121542Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a flow rate control device for an engine cooling water passage for improving the heating performance of a car heater.

Generally, cooling water is supplied to the car heater by branching the cooling water from the engine's cooling water system and guiding it to the car heater. As shown in Fig. 1, the cooling water system of an automobile engine generally includes a main circulation path 3 that connects the engine 1 and the radiator 2 and circulates the cooling water, and the cooling water bypasses the radiator and flows through this circulation path. A bypass flow path 4 is provided, and further,
Generally, a car heater cooling water channel 6 is provided which branches off from the main circulation path 3 and returns cooling water to the main circulation path 3 via the car heater 5. A thermostat 7 is provided in the main circulation path 3 on the upstream side of the radiator 2, and the thermostat 7 is closed while the cooling water temperature is low. Therefore, the cooling water circulates through the bypass path 4, but when the water temperature is low, the thermostat 7 is closed. When the temperature rises, the thermostat 7 opens and cooling water circulates through the radiator 2. When the car heater 5 is operated, the cooling water from the main circulation path 3 branches through the car heater cooling water passage 6 and flows to the car heater 5, where the car heater 5 exchanges heat with, for example, the air in the driver's cabin. The cooling water is returned to the main circulation path 3.

In a cooling water system with such a configuration, when heating is performed using a car heater while the cooling water is at a low temperature and is circulating through the bypass passage, the flow resistance of the car heater and the car heater cooling water passage will increase the flow resistance of the bypass passage. Since it is considerably larger than the excessive resistance, the amount of cooling water flowing to the bypass passage increases. Especially when the engine speed is low and the amount of circulating water in the entire cooling water system is small, such as when idling, the amount of cooling water flowing to the car heater will affect the heating performance. There was a risk that a sufficient amount could not be obtained and the heating performance would deteriorate.

In order to improve this problem, conventional bypass passages were equipped with an on-off valve (thermostat) 8 that operated by sensing the temperature of the cooling water flowing through the bypass passage. There is a large time delay in operation, and since the operation is simply on and off, it is not possible to precisely control the amount of cooling water supplied to the car heater. In particular, when the flow rate of cooling water changes significantly due to a sudden change in engine speed, for example, when the engine speed suddenly increases and the amount of cooling water increases significantly, a simple temperature-sensitive type cannot keep up with the change. The amount of cooling water flowing through the car heater is far greater than the amount of cooling water required by the car heater to ensure its heating performance, and as a result, the cooling water pressure upstream of the car heater (upstream of the on-off valve in the bypass path) increases significantly. There was a fear that it would have a negative impact.

Therefore, in view of the above circumstances, this invention eliminates the drawbacks of conventional ones by providing an on-off valve that senses and responds to the pressure on the upstream side of the car heater.
It is an object of the present invention to provide a device that can better control the amount of cooling water and improve heating performance.

In response to this purpose, the engine cooling water passage flow rate control device of this invention includes a main circulation path that circulates cooling water between the engine and the radiator, and a main circulation path that is attached to the main circulation path and cools the water by bypassing the radiator. A temperature sensing member that senses the temperature of the engine coolant and operates in an engine coolant passage that includes a bypass passage that circulates water and a car heater cooling water passage that is attached to the main circulation passage and that supplies the cooling water to the car heater. and a pressure valve that changes valve opening pressure by actuation of the temperature-sensitive member provided in the bypass passage, and controls the flow rate of cooling water flowing into the car heater cooling water passage by opening and closing the pressure valve. It is characterized by being configured to do so.

The details of this invention will be explained below with reference to the drawings showing one embodiment.

In FIG. 2, 11 is an engine, 12 is a radiator, and the engine 11 and radiator 1
The engine 11 and the radiator 12 are connected to each other by a main circulation path 13, and therefore, cooling water circulates between the engine 11 and the radiator 12 through the main circulation path 13. A thermostat 17 is provided on the inlet side of the radiator 12 in the main circulation path 13 . Further, a bypass path 14 is provided in the main circulation path 13 so as to bypass the radiator 12 . Cooling water is pumped through the main circulation path 13 and the bypass path 14 by a water pump 19. A car heater cooling water channel 16 branches off from the main circulation path 13 . The car heater cooling water channel 16 branches from the engine downstream side of the main circulation path 13 to reach the car heater 15, exits from the car heater 15, and connects to the engine upstream side of the main circulation path 13. A pressure valve 21 is provided in the bypass path 14 . This pressure valve 21 is detected by a cooling water temperature sensing member 26 and a cable 30
(However, the cooling water temperature detection position of the cooling water temperature sensing member 26 is not shown in the figure.)
It does not operate only in response to an arbitrary position upstream of the car heater (for example, the position indicated by A, B or C), but also in response to the cooling water upstream of the car heater 15, for example, the upstream side of the pressure valve 21 of the bypass passage 14. For example, a butterfly valve 21' as shown in FIGS. 3 and 4 may be used, which opens and closes in response to the cooling water pressure. The butterfly valve 21' includes a valve plate 23 fixed to a shaft 22, and a coil spring 24 is attached to the shaft 22, and rotation of the shaft 22 of the valve plate 23 is elastically restrained by the coil spring 24. By adjusting the preset force of the coil spring 24, the opening pressure of the butterfly valve can be adjusted.

In the engine cooling water passage configured in this way, when the car heater is in use and the engine speed is low and the amount of circulating water is small, the pressure of the cooling water in the main circulation path 13 does not rise sufficiently. Since the pressure valve 21 is closed, most of the cooling water from the engine 11 does not pass through the bypass passage 14 and reaches the car heater 15 through the car heater cooling water passage 16, and the cooling water in the car heater cooling water passage reaches the car heater 15. It is possible to increase the flow rate and improve heating performance. Next, when the engine speed increases, the flow rate of the cooling water increases, and when the pressure of the cooling water in the main circulation path 13 rises and exceeds the set opening pressure of the pressure valve, the pressure valve 21 opens in accordance with the pressure. Since the cooling water is designed to flow into the bypass passage 14, the pressure valve 2
1, without the cooling water pressure upstream becoming abnormally high.
An appropriate amount of water flowing into the car heater 16 is ensured. That is, by opening and closing the pressure valve 21 according to the pressure of the bypass passage 14, the car heater cooling water passage 16
The amount of cooling water flowing through the system can always be controlled within an appropriate range.

As described above, according to the engine cooling water passage flow rate control device of this invention, when the cooling water is at a low temperature and the engine speed is low and the cooling water flow rate is small, the pressure valve 21 closes the bypass passage. By reducing the amount of cooling water and increasing the amount of cooling water sufficient for the car heater cooling waterway to improve heating performance, when the engine speed increases, the bypass passage 14 is set according to the pressure by the pressure valve.
Since the cooling water flow rate is opened and closed, it is possible to perform continuous and highly accurate flow rate control without time delay in response to fluctuations in the cooling water flow rate depending on the rotation speed, thereby providing more preferable heating performance. Note that after the thermostat 17 is opened, the cooling water passes through the main circulation path 13 and the radiator 12;
Since the cooling water flow resistance of No. 2 is quite large, the decrease in the flow rate to the car heater is small and the heating performance is not significantly impaired.

The preset of the coil spring 24 is adjusted according to the temperature of the cooling water. That is, Figures 5 and 6
Butterfly valve 2 as shown in Figure and Figure 7.
1'' includes a shaft 22 and a valve plate 23, the valve plate 23 is fixed to the shaft 22 at an eccentric position, and a coil spring 24 is attached to an extension of the shaft 22,
One end of the coil spring 24 is fixed to the shaft 22,
The other end is restrained and positioned by the temperature sensing member 25. Therefore, the rotation of the shaft 22 is elastically restrained by the coil spring 24, and by changing the preset force of the coil spring 24, the valve opening force of the valve plate 23 is also changed. The presetting force of the coil spring 24 is adjusted by operating the temperature sensing member 25. That is, the temperature sensing member 25 includes a temperature sensing member 26 and an operating rod 27, and is disposed at a fixed position. A thermo-pellet is used as the temperature sensing member 26, and is placed in a heat transfer relationship with the cooling water upstream of the car heater 15, for example, the cooling water upstream of the pressure valve 21 in the bypass passage 14, so that it responds to temperature changes in the cooling water. It expands and contracts. The actuating rod 27 is connected to the temperature sensing member 26 and moves forward and backward as the temperature sensing member 26 expands and contracts. That is, a change in volume of the temperature sensing member 26 is converted into a stroke of the actuating rod 27. The tip of the actuating rod 27 connects the end of the coil spring 24 to the coil spring 2.
4 in the circumferential direction, and therefore the actuating rod 2
7, the coil spring 24 is twisted and untwisted, and the preset force of the coil spring 24 changes, and the opening force of the butterfly valve 21'' changes.

In the pressure valve device configured in this way,
The temperature sensing member 26 undergoes a volume change due to thermal expansion,
As a result, the actuating rod 27 moves back and forth, changing the presetting force of the coil spring 24, and the valve plate 23
The valve opening pressure can be adjusted. In this case,
By setting the direction in which the actuating rod 27 restrains the coil spring 24 in the forward or reverse direction, the valve opening pressure is adjusted to increase as the temperature of the fluid increases, as shown by line A in FIG. Alternatively, as shown by line B, the valve opening pressure can be adjusted to decrease in accordance with the rise in fluid temperature.

According to this butterfly valve 21'', the opening pressure of the pressure valve can be automatically adjusted according to the temperature of the cooling water.Moreover, this butterfly valve 21'' has a simple structure and is inexpensive. It is inexpensive, and its operation is mechanical and highly reliable. The spring member is not limited to the coil spring shown in the above embodiments, but may be replaced with a leaf spring, for example. Further, as the temperature sensing member 25, in addition to the combination of the thermo pellet and the actuating rod described above, a bimetal 28 as shown in FIG. 8 can also be used.

[Brief explanation of the drawing]

FIG. 1 is a structural explanatory diagram showing a conventional flow rate control device for an engine cooling water passage, FIG. 2 is a structural explanatory diagram showing a flow rate control device for an engine cooling water passage according to an embodiment of this invention, and FIG. 4 is an explanatory plan view showing the butterfly valve, FIG. 5 is an explanatory plan view showing another butterfly valve, FIG. 6 is an explanatory front view showing another butterfly valve, and FIG. The figure is a graph showing the relationship between valve opening pressure and cooling water temperature, and FIG. 8 is a front explanatory view showing another example of the temperature sensing member. 11...Engine, 12...Radiator, 13
... Main circulation path, 14 ... Bypass path, 15 ... Car heater, 16 ... Car heater cooling water channel, 17 ...
...Thermostat, 19...Water pump, 2
1... Pressure valve, 21', 21''... Butterfly valve, 22... Shaft, 23... Valve plate, 24... Coil spring, 25... Temperature sensing member, 26... Temperature sensing member, 27... Operating rod, 28...bimetal.

Claims (1)

[Claims for Utility Model Registration] (1) A main circulation path that circulates cooling water between the engine and the radiator; a bypass path attached to the main circulation path that bypasses the radiator and circulates the cooling water; and a car heater cooling water passage that is attached to the main circulation path and that flows cooling water to the car heater, a temperature sensing member that operates by sensing the temperature of the engine cooling water, and a temperature sensing member that is provided in the bypass passage. A pressure valve is provided that changes the valve opening pressure by the operation of the temperature sensing member, and the flow rate of the cooling water flowing into the car heater cooling water passage is controlled by opening and closing the pressure valve. Features a flow rate control device for engine cooling water passages. (2) The pressure valve is provided with a temperature sensing member near the pressure valve that operates by sensing the temperature of the cooling water, and is configured to change the opening pressure of the pressure valve by the operation of the temperature sensing member. A flow rate control device for an engine cooling water passage according to claim 1, characterized in that: