JPH0432928B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a supercharged air temperature regulating device installed in a diesel engine or the like equipped with a supercharger and suitable for use when controlling the temperature of air supplied from the supercharger.

Supercharged air from a supercharger is supplied to a combustion chamber of a diesel engine or the like after passing through a cooler or a heater and being brought to an appropriate temperature. In this case, low-temperature cooling water and high-temperature cooling water are supplied to the cooler and heater, respectively, and by adjusting the amounts of these water, the temperature of the supercharged air is adjusted.

Conventionally, in order to adjust the temperature of this supercharged air,
The temperature sensor detects the temperature of the supercharged air, and based on this temperature information, the opening of the hydraulic servo temperature control valve is adjusted, thereby controlling the amount of water flowing to the cooler. It's on.

However, in conventional temperature adjustment devices, the number of parts is large and the configuration is complicated.
It has the drawbacks of being expensive and requiring complicated maintenance. Furthermore, in conventional temperature control devices, the relationship between the load of the diesel engine and the supercharging air temperature is constant regardless of the load because the supercharging air temperature is detected and controlled to be constant. .
There was a problem in that the supercharged air temperature was low at high loads, and the optimum relationship was not established, with the supercharged air temperature increasing as the load decreased.

This invention was made in view of the above-mentioned circumstances, and it is possible to reduce the number of parts and space required, as well as reduce costs and simplify maintenance. It is an object of the present invention to provide a temperature adjustment device for supercharging air that can accurately control and optimize the relationship between load and supercharging air temperature.

In order to solve the above-mentioned problems, the present invention provides a cooler for cooling air supplied from a supercharger to a diesel engine, a pipe line for passing cooling water to the cooler, and a pipe provided in the pipe line. and a flow control valve that controls the flow rate of cooling water in the pipe, the flow control valve receiving a predetermined spring force from one side and supercharging air pressure from the other side to control the flow rate of these forces. It is characterized by having a piston that moves to a balance point, a valve body connected to this piston, and a control passage whose flow passage cross-sectional area of the pipe is changed by this valve body.

In this case, since the supercharging air pressure changes in response to the load on the diesel engine, the flow rate control by the above-mentioned flow control valve corresponds to the load on the diesel engine, and thereby the load on the diesel engine and the supercharging air temperature change. relationship can be optimized.

Moreover, the flow rate of cooling water in the pipe is controlled by directly moving the piston using supercharged air pressure and moving the valve body connected to the piston to change the cross-sectional area of the control flow path. There is no need for a sensor for detecting supercharging air pressure and a control device for operating a flow control valve based on information from this sensor.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing the structure of an embodiment of the present invention, and 1 is a flow control valve having a three-way valve 2 at the bottom and a cylinder 3 at the top. The three-way valve 2 is
Outlet ports 5 and 6 are formed on the upper and lower right sides of the valve body 7, respectively, and an inlet port 4 is formed on the left side of an intermediate portion between the outlet ports 5 and 6.
The valve body 7 is attached to the rod 8 and serves to distribute water flowing from the inlet 4 to the respective outlet ports 5 and 6. This valve body 7 has two truncated cones formed by tapering the contact surface 7a with the valve seat 2a with a larger diameter near the inlet 4 and a smaller diameter near each outlet 5 and 6. It is a shape that is made by butting together.

When the valve seat 2a and the contact surface 7a come into contact, the delivery 5 or 6 is brought into a fully closed state. Further, the valve body 7 moves up and down together with the rod 8, and the distribution ratio of water to the outlets 5 and 6 is determined by its position.
The rod 8 is integrally joined to the lower surface of the piston 9 that slides up and down within the cylinder 3, and moves up and down smoothly without lateral wobbling due to the valve guide 2b. Further, the upper surface of the piston 9 is pressed by a spring 10, and the upper end of this spring 10 is pressed by a spring pressing member 11.
It is fixed by. The lower end of an adjustment bolt 12 is in contact with the upper part of the spring holding member 11, and the adjustment bolt 12 is screwed into a screw hole 15 bored approximately at the center of a cap 14 that closes the upper end opening of the cylinder 3. There is. In this case, adjustment bolt 1
2, the spring holding member 11 slides in the vertical direction, thereby changing the spring force acting on the piston 9. In this way, the upper part of the cylinder 3 serves as a spring chamber 15. Further, the lower part of the cylinder 3 is a pressure chamber 16, and is provided with a supercharging air pressure intake port 17 for taking in supercharging air pressure. The spring chamber 15, pressure chamber 16 and three-way valve 2 are
The sliding parts are sealed with a sealing material to prevent water and supercharged air from leaking.

In the above-described configuration, when supercharging air pressure is taken into the pressure chamber 16, the piston 9 receives the spring force of the spring 10 on the axis of the rod 8 and the supercharging air pressure receiving pressure surface 9a of the piston 9 on the opposite side of the piston 9 that is in contact with the spring 10. Since the piston 9 stands still at a position balanced with the applied supercharging air pressure, when the supercharging air pressure is high, the piston 9 is balanced at the upper position, and when the supercharging air pressure is low, the piston 9 is balanced at the downward position. Since the valve body 7 is integrated with the piston 9 via the rod 8, the ratio of the delivery amounts of the delivery ports 5 and 6 depends on the supercharging air pressure taken in from the supercharging air pressure intake port 17, and the supercharging air pressure is higher. When the supercharging air pressure is low, the amount delivered to the delivery port 6 is large, and when the supercharging air pressure is low, the amount delivered to the delivery port 5 is large.

FIG. 2 is a block diagram showing a case where the flow rate control valve 1 described above is used to control the amount of water flowing to the air cooler, and parts corresponding to those in FIG. 1 are given the same reference numerals. .

In the figure, reference numeral 20 denotes low-temperature cooling water, which flows in from the inlet 4 of the flow control valve 1 and then is sent out from the outlets 5 and 6 at a ratio determined by the position of the valve body 7.
The low-temperature cooling water 20 sent out from the outlet 6 flows into the air cooler 21 to be cooled, and then flows into the return path 22. On the other hand, the low-temperature cooling water 20 sent out from the outlet 5 directly flows into the return path 22 via the bypass path 23 and does not contribute to cooling. 25
is a supercharger, and supercharged air from this supercharger 25 is supplied to a diesel engine 26 via an air cooler 21. Reference numeral 27 denotes a pipe line that guides the supercharging air pressure to the supercharging air pressure intake port 17.

According to the above-described configuration, when the load on the diesel engine becomes large and the supercharging air pressure increases, the piston 9 is balanced above, so the proportion of the outflow amount on the outlet port 6 side increases, contributing to cooling. The amount of low-temperature cooling water 20 to be used increases, and the cooling effect on the supercharged air increases. On the other hand, when the engine load becomes small and the supercharged air pressure decreases, contrary to the above case, the amount of low-temperature cooling water 20 that does not contribute to cooling increases, and the cooling effect on the supercharged air weakens. FIG. 4 is a graph showing an example of the relationship between the load of the diesel engine and the supercharging air temperature, in which the broken line is for the conventional device and the solid line is for this embodiment. As shown in this graph, according to this embodiment, the supercharging air temperature becomes high during low load, improving the efficiency of the diesel engine.

FIG. 3 is a block diagram when the flow rate control valve 1 is used to control the amount of water flowing to the air heater. In FIG. 3, parts corresponding to those in FIG. 1 and FIG. 2 are given the same reference numerals. The difference between this figure and FIG. 2 is that an air heater 3 is installed after the air cooler 21.
1 and high temperature cooling water 30
is supplied to the air heater 31 via the outlet 5 and to the bypass path 23 via the outlet 6. According to such a configuration,
When the load on the diesel engine becomes large and the piston 9 is balanced upward, the ratio of the delivery amount on the delivery port 6 side becomes large, and the amount of high-temperature cooling water that contributes to heating decreases, causing heating of the supercharged air. The effect decreases. On the other hand, when the load on the diesel engine becomes small,
Contrary to the above case, the amount of high-temperature cooling water that contributes to heating increases, and the heating effect on the supercharged air increases. FIG. 5 is a graph showing the relationship between the load of the diesel engine and the supercharging air temperature in this case, where the broken line is for the conventional device and the solid line is for this embodiment. As can be seen from this graph, according to the configuration shown in FIG. 3, the supercharged air temperature rises, especially during low load, and the efficiency of the diesel engine is improved in this region.

In addition, in the embodiment described above, the pressure chamber 16
Although the supercharging air pressure is introduced as is in the above, instead of this, for example, the supercharging air pressure may be converted into oil pressure and this oil pressure may be introduced to the pressure chamber 16.

Further, this mechanism can be applied not only as a three-way valve but also as a two-way valve. However, in the case of the embodiment described above, the outlet 6 to the air cooler 21
Alternatively, the outlet 5 to the air heater 31 should be the outlet of a two-way valve, and the bypass 23 needs to be provided with a separate two-way valve or a throttle plate.

In addition, in the above embodiment, by adjusting the adjustment bolt 12 to change the spring force, it is possible to change the relationship between the supercharging air pressure and the water flow rate that contributes to temperature adjustment, and to adjust the spring force to suit each system. Can be set in relationship.

As explained above, according to the present invention, when the load on the diesel engine increases and the supercharging air pressure increases, the supercharging air temperature is lowered, and conversely, when the engine load decreases, the supercharging air pressure decreases. In this case, since the supercharged air temperature can be increased, the relationship between the engine load and the supercharged air temperature can be optimized.

Moreover, the flow rate of cooling water in the pipe is controlled by directly moving the piston using supercharged air pressure and moving the valve body connected to the piston to change the cross-sectional area of the control flow path. There is no need for a sensor to detect supercharging air pressure or a control device for operating a flow rate control valve based on the information from this sensor, resulting in an extremely simple configuration that reduces costs and equipment layout. The required space can be reduced, and maintenance can also be simplified. Furthermore, the control is completely mechanical, and durability and reliability against temperature changes can be improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the configuration of an embodiment of the present invention, and FIGS. 2 and 3 are system configurations in which the temperature of supercharged air is controlled using the flow control valve 1 shown in FIG. 1. Figures 4 and 5 are graphs showing the relationship between the diesel engine load and the supercharged air temperature when the supercharged air temperature is adjusted using the configurations shown in Figs. 2 and 3, respectively. It is. 1...Flow rate control valve, 2...Three-way valve, 3...Cylinder, 5, 6...Outlet port (control flow path), 7...Valve body, 9...Piston, 10...Spring, 16... pressure chamber.

Claims (1)

[Scope of Claims] 1. A cooler for cooling air supplied from a supercharger to a diesel engine, a pipe line for passing cooling water to the cooler, and a pipe line provided in the pipe line. In a supercharged air temperature adjustment device comprising a flow control valve that controls the flow rate of cooling water, the flow control valve receives a predetermined spring force from one side and receives supercharged air pressure from the other side to balance these forces. A supercharged air supply system characterized by having a piston that moves to a point, a valve body connected to the piston, and a control flow path in which the cross-sectional area of the pipe is changed by the valve body. Temperature control device.