JPS598512A - Room heating device of car mounted with water-cooled engine - Google Patents

Abstract

PURPOSE:To promptly obtain a sufficient degree of room heating temperature at cold time of an engine, by heating cooling water taken out from a high temperature part in a cooling water jacket of the engine through a heat exchange with exhaust gas and then guiding the water to a heater core for room heating. CONSTITUTION:Cooling water in a water jacket 1a of a cylinder head part partitioned by a partition P flows in through a radiator circulative passage 4 interposing a radiator 5 by driving of a water pump 8 and is cooled, and then returned from a flow inlet 2 again into the water jacket 1a. Here the second flow outlet 11 of cooling water is formed to said water jacket 1a, and this flow outlet 11 is connected to a bypass passage 6 by a cooling water circulative passage 12 for a heater. A heat exchanger 18 heating the cooling water by a heat exchange with exhaust gas flowing in an exhaust passage 17 and a heater core 13 performing room heating through a heat exchange between the cooling water heated in the exchanger 18 and air conditioning air are interposed in said circulative passage 12, and at cold time of an engine, the cooling water is circulated in said passage 12.

Description

[Detailed description of the invention] do.

BACKGROUND ART In vehicles, especially automobiles, heating the interior of the vehicle is essential to provide good comfort during winter operation. Currently, as this heating device, if the vehicle is equipped with a water-cooled engine, a hot water type device that utilizes the heat of engine cooling water is used.

However, in conventional hot water heating systems, the temperature of the cooling water does not rise sufficiently, especially when the engine is cold, and therefore the heating does not work satisfactorily. This is because when the engine is cold, the head of the engine is quite hot, but the block is at a low temperature, so the cooling water flowing through the entire cooling water mantle of the engine body is on average. This is thought to be because the temperature becomes low due to

Therefore, in Japanese Patent Application Laid-open No. 3ll-202llg, an engine cooling water flow mechanism was proposed in which when the engine is cold, the cooling water is flowed only to the head section where the temperature is high to keep the cooling water as high as possible. has been done. According to this water passage mechanism, the temperature of the cooling water can be raised to some extent, but even with this, it may not be possible to obtain a sufficient heating temperature.

In addition, as another method, there is a method in which cooling water that has been heated to a certain degree is further heated using the heat of the exhaust gas, and the further heated cooling water is used for heating. Even with this, there were cases in which a sufficient heating temperature could not be obtained. The above-mentioned drawbacks of conventional heating devices are particularly noticeable in diesel engines with good combustion efficiency, and improvements have been desired.

Therefore, in view of the above-mentioned drawbacks of hot water type heating devices that utilize the heat of cooling water, the present invention aims to further heat the cooling water heated in the high temperature section of the cylinder using the heat of exhaust gas. It is an object of the present invention to provide a heating device for a vehicle equipped with a water-cooled engine that can supply water to a heater core and thereby obtain a sufficient heating temperature.

That is, the heating device for a vehicle equipped with a water-cooled engine according to the present invention extracts cooling water only from the high-temperature part of the cooling water jacket of the engine body, is installed in the exhaust passage, and heats the cooling water by heat exchange with exhaust gas. A heater cooling water circulation path is provided for returning the cooling water to the high temperature section of the cooling water sleeve through the exchanger and the heater core for heating the vehicle interior, and the cooling water is circulated through the circulation path at least when the engine is cold. This is a characteristic feature. Note that, for example, a cooling water cannula of a cylinder head may be used as the high temperature part of the cooling water cannula.

The heating system for a vehicle equipped with a water-cooled engine of the present invention having the above structure extracts cooling water from the part of the cooling water mantle that is relatively high temperature even when the engine is cold, and uses the heat of the exhaust gas to make this cooling water. Since the cooling water thus sufficiently heated is sent to the heating heater core, a sufficient heating temperature can be obtained even when the engine is cold.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A heating device for a vehicle equipped with a water-cooled engine according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of a heating system for a vehicle equipped with a water-cooled engine according to a first embodiment of the present invention.

In FIG. 1, reference numeral E indicates a water-cooled engine mounted on an automobile (not shown), and a cooling water mantle 1 is provided outside the combustion chamber of this engine E. This cooling water cannula 1 is divided into upper and lower parts by a partition wall P, and constitutes a cylinder head part water cannula la and a cylinder block part water cannula 1b. The partition wall P is an incomplete partition wall, and allows a certain amount of cooling water to flow therethrough.

A cooling water inlet 2 is provided at the bottom of the cylinder head water cannula 1a.
is formed, and a first cooling water outlet 3 is formed in the upper part. The inlet 2 and the outlet 3 are communicated by a radiator circulation passage 4, and a radiator 5 for cooling the cooling water is interposed in the circulation passage 4. A bypass passage 6 that bypasses the radiator 5 is formed in the circulation passage 4 . A thermostatic valve 7 that closes the passage toward the radiator 5 when the cooling water temperature is lower than a predetermined temperature is disposed at the branch port 6a of the bypass passage 6.

A water pump 8 driven by the engine E is provided between the outlet 6b of the bypass passage 6 of the circulation passage 4 and the second inlet 2. A downstream portion of the circulation passage 4 from the pump 8 is formed with a branch 1 passage 9 for diverting the cooling water to the cylinder block water sleeve 1b. This branch passage 9 is provided with a thermostatic valve 10 that opens the branch passage 9 when the temperature of the cooling water in the cylinder block water jacket becomes higher than a predetermined temperature.

The cylinder head water cannula 1aK has a second cooling water outlet 1
1 is formed, and this cooling water outlet 11 and the bypass passage 6 are communicated by a heater cooling water circulation path 12. A heater core 13, which is a heat exchanger, is interposed in this circulation passage 12. This heater core 13 heats the air sent by the blower 14 by heat exchange with the heated cooling water passing through the heater core 13. This heated air is introduced into the vehicle interior for heating purposes. The above blower 14 is 0EFX L
Manual blower switch 1 with range OWl Hl
Operated by 5.

In the figure, reference numeral 16 indicates an exhaust manifold, and an exhaust passage 17 is connected to the exhaust manifold 16.

In the middle of this exhaust passage 17, the second part of the circulation passage 12
A heat exchanger 18 is provided between the outlet 11 of the heater core 13 and the heater core 13 through the circulation passage 12.
The cooling water sent to is heated by the exhaust gas in this heat exchanger 18. A heat exchanger 1 is installed in the exhaust passage 1γ.
Pi/F2 passage 19 bypassing the part where 8 is provided
is formed. This bypass passage 19 is connected to the outlet 1
When the temperature of the cooling water flowing into the circulation passage 12 from 1 is sufficiently high and there is no need to heat the cooling water with the heat exchanger 18, or when the heating device is not used, It is something. For this reason, exhaust passage 1
A switching valve 20 is installed at the branch of the pi/F2 passage 19 from 7.
is provided to allow the exhaust gas to flow in a controlled manner between the exhaust passage (17) in which the heat exchanger 18 is provided and the bypass passage 19.

The downstream side 1 of the heater core 13 in the circulation passage 12 is provided with an on-off valve 21. This on-off valve 21 is closed when the heating device is not needed to prevent cooling water from being sent to the heater core 13. On the other hand, an on-off valve 22 is also provided at the first cooling water outlet 3 of the cylinder head water cannula 1a.
The opening/closing valve 22 is opened when the heating device is not needed, and the cooling water is sent to the radiator 5 for cooling.

), the cylinder head water mantle 1a is provided with a water temperature sensor 23 that detects the temperature of the cooling water in this part, and the output end of this water temperature sensor 23 is connected to seven inputs of a control circuit 24 consisting of a microcomputer. connected to the end.

The other input terminal of this control circuit 24 includes a blower switch 1.
5 is connected, and the control circuit 24 receives the heating device ON/OFF signal S/ from the blower switch 15 and the water temperature signal S2 from the water temperature sensor 23, and controls the switching valve 20 and the opening/closing operation. Control valves 21.22.

Next, the operation of the heating device having the structure described above will be explained.

First, the operation of the heating system when Ennon E is in a cold operating state will be explained. Heating device blower switch 15
is moved from the OFF state to the ON state, LOW or Hl range, and the signal S/ indicating this and the signal s2 from the water temperature sensor 23 are input to the control device 24, this control circuit 24 switches the switching valve 2o. Set the bypass passage 19 to the closed position, open the on-off valve 21, and close the on-off valve 2.
Close 2. Thermostat valves 7 and 10 are in a closed state because the temperature of the cooling water is low. When the water pump 8 is driven by the engine E with the valves in the above state, the cooling water is introduced into the cylinder head water cannula 1a through the inlet 2, and is heated by the cylinder head of the engine E here. The cooling water heated by the cylinder head E flows into the circulation passage 12 from the outlet 11 and is further heated by the exhaust gas flowing through the exhaust passage 17 in the lower heat exchanger 8. This further heated cooling water is sent to the heater core 13. The heater core 13 heats the air sent from the blower 14 and sends it into the vehicle interior to heat the vehicle interior. The cooling water that has passed through the heater core 13 passes through a portion of the circulation passage 12 on the downstream side of the heater core 13, and then returns to the cylinder head water cannula 1a via the bypass passage 6 and a portion of the circulation passage 12.

When the rotational speed of the engine E gradually increases and the water temperature sensor 2β detects that the temperature of the cooling water in the cylinder/rad section water jacket a has exceeded a predetermined temperature, the control circuit 24 turns the changeover switch 2o on. , the bypass passage 19 is opened and the exhaust passage 17 on the heat exchanger 18 side is closed. Thus, heating of the cooling water by the exhaust gas in the heat exchanger 18 is stopped, and heating of the cooling water and the engine is prevented. At this time, as mentioned above, the cooling water temperature is high, so
Thermostat valve 7 also detects this and opens.
Therefore, a portion of the cooling water returning from the heater core 13 is
It flows into the circulation passage 4, is cooled by the radiator 5, is returned to the cylinder head water cannula 1aK, and is circulated again. Thus, from this point as well, overheating of the cooling water and the engine E is prevented. Furthermore, when the temperature of the cooling water in the cylinder block water jacket becomes high, the thermostat valve 1o is also opened, and a portion of the cooling water being circulated by the water pump 8 is also transferred to the cylinder block water jacket 1b via the branch passage 9. It also prevents the cylinder block from overheating.

In the embodiment described above, the partition wall P that separates the high-temperature part and the low-temperature part of the cooling water cannula 1 is an incomplete partition wall so that some cooling water can pass through this wall, but as shown in FIG. It may also be a complete partition wall P'. In this case, the cylinder block water jacket 1b is also provided with a cooling water outlet 31 for the circulation passage 30 communicating with the walk pump 4. Alternatively, the circulation passage 12 may be branched as shown in FIG. 2 to form the circulation passage 4 for a radiator. A switching pulp 32 is provided at this branch part so that the cooling water flows to the circulation passage 12 side when the heating device is in use, and the cooling water flows to the radiator circulation passage 4 side when the heating apparatus is not in use.

This switching valve 32 is also controlled by the control circuit 24.

Next, a heating device according to a fourth embodiment of the present invention will be described with reference to FIG. 3 and subsequent figures. In this example, the first
Components and members that are the same as those in the embodiment will be given the same reference numerals and their explanations will be omitted.

The cylinder block water cannula 1b of the cooling water cannula 1 has a radiator cooling water circulation passage 4' similar to the radiator cooling water circulation passage 4 of the first embodiment, and the cylinder spatula 1 part water cannula 1a has a radiator cooling water circulation passage 4' similar to the radiator cooling water circulation passage 4 of the first embodiment. Heater cooling water circulation passages 12' similar to the heater cooling water circulation passages 12 of the first embodiment are communicated with each other.

These circulation passages 4' and 12'u are completely independent from each other. Therefore, a first water pump 50 is installed in the circulation passage 4', and a second water pump 51 is installed in the circulation passage 12', respectively. The operation of all of these water pumps is controlled by a control circuit 24.

The circulation passage 12' includes a heater core 13 and a heat exchanger 1.
A bypass passage 52 is provided to bypass 8.

This bypass passage 52 is provided with a radiator 53 that cools the cooling water flowing through the bypass passage 52.

This bypass passage 52 supplies cooling water to the heat exchanger 18 and the circulation passage 1 on the heater core 13 side when heating is not performed.
This is to prevent it from flowing into the 2'. For this reason, a switching valve 54 is provided at the branch part of the circulation passage 12' and the bypass passage 52, and the cooling water is adjusted between the circulation passage 12' where the heat exchanger 18 etc. are provided and the bypass passage 520. It is designed to flow. The cylinder block water jacket 1b detects the temperature of the cooling water therein and sends a signal S3.
A water temperature sensor 55 is provided that outputs the temperature to the degree control circuit 24.

On the other hand, a pipe/gas passage 56 that bypasses the radiator 5 is provided in the circulation passage 4'. This bypass passage 56 serves to circulate cooling water without passing through the radiator 5 when the engine is in a cold state, thereby helping to warm up the ennon.

To prevent this, a thermostatic pulp 57 is provided at the branching point between the circulation passage 4' and the bypass passage 56, so that the cooling water is allowed to flow through the bypass passage 56 until the engine is sufficiently warmed up.

Next, the operation of the heating device having the structure described above will be explained.

First, the operation of the heating system when the engine E is in a cold operating state will be explained. Heating equipment Glowis Isote 15
goes from OFF to ON state LOW'! or Hl range, and the signal S/ indicating this and the water temperature sensor 23
and signals S2 and U S 3 from 55 are sent to control device 2
4, this control circuit 24 switches the switching valve 2
o is set to a position that closes the bypass passage 19, the switching valve 54 is set to a position that closes the bypass passage 52, and the opening/closing pulp 21 is opened. The thermostatic pulp 51 is opened because the temperature of the cooling water is low, so that the cooling water flows through the bypass passage.

The water pumps 5o and 51 are started with the pulp in the above state. The water pump 5o is connected to the cylinder block 1 which is detected by a water temperature sensor 55 as shown in FIG.
The temperature of the cooling water in b is the first predetermined temperature 1. The control circuit 24 controls the rotation speed to increase in proportion to the rise in temperature from t2 to a predetermined temperature t2. When the temperature of the cooling water reaches the second predetermined temperature t2, the oak pump 050 is operated at a constant rotation speed. At this time, the thermopulp 57 opens to allow cooling water to flow into the lanoator. In addition, this walk pump 50 is
17 may be used so that it is driven by an engine.

The water pump 51 basically operates at a constant rotation speed when the heating system is in operation, and when the heating system is not in use, the temperature of the cooling water in the cylinder head water canopy a detected by the water temperature sensor 23 and the engine speed are controlled. The control may be performed according to the rotation speed, load, etc. of the engine. For example, when controlling the water pump 51 according to the temperature of the cooling water, the temperature of the cooling water detected by the water temperature sensor 23 is the first as shown in FIG.
The water pump 51 is operated at a constant low speed to prevent partial overheating until the predetermined temperature Tl is reached, and then the water pump 51 is operated at a constant low speed until the temperature of the coolant reaches a predetermined temperature T2. The number of rotations of the water pump 051 is increased, and thereafter it is rotated at a constant number of rotations. Note that when starting the engine, it is desirable to temporarily stop the operation of the water pump 51 in order to supply sufficient current to the starter.

In the above embodiment, the control circuit 2 uses a microcomputer to control the operation of the water pumps 50 and 51.
4 has been explained, but this control is performed by the fourth
It may also be carried out using an electric circuit as shown in FIGS.

The electric circuit 60Vi shown in FIG. 4 is a drive control circuit for the first water pump 50, and is composed of a differential amplifier 61 and a drive transistor 62 whose base is connected to the output terminal of the differential amplifier 61. . A water temperature sensor 55 is connected to one input terminal of the differential amplifier 61, and a constant voltage generator 6 that generates a constant voltage rl is connected to the other input terminal.
3 is connected. The differential amplifier 61Vi compares the constant voltage r1 with a signal S3 output by the water temperature sensor 55 detecting the temperature of the cooling water in the cylinder block water jacket 1b, and outputs a difference signal Sdl. The transistor 62 operates the water pump 50 with a current according to the difference signal Sd1.
The operation is controlled as shown in the figure.

On the other hand, the electric circuit 701d shown in FIG. 7 is a drive control circuit for the water pump 51, and includes a differential amplifier 71 and a drive transistor 72 whose base is connected to the output terminal of the differential amplifier 71. A water temperature sensor 23 is connected to one input terminal of the differential amplifier 71, and a constant voltage generator 7 that generates a constant voltage Vr2 is connected to the other input terminal.
3 is connected. The differential amplifier 11 operates at the constant voltage V
r2 is compared with a signal S2 which the water temperature sensor 23 outputs by detecting the temperature of the cooling water in the cylinder head water cannula a, and outputs a difference signal Sdz. When the cooling water temperature is T1 or higher, the I-Langistav 2 controls the operation of the water pump 51 using a current according to the difference signal Sdz as shown in the figure. As described above, it is desirable that the pump 51 rotates at a constant low speed until the cooling water reaches the first predetermined temperature TI. It is also connected to γ4. On the other hand, a switch 76 interlocked with the grower switch 15 is interposed at the base of the transistor fan 20, so that when the heating system is activated (when the grower switch is ON), regardless of the output of the water temperature sensor 23,
The transistor 12 is turned on and the pump 51 is rotated at a predetermined rotation speed. As described above, the pump 511d as a whole is driven as shown in FIG. It is desirable to provide a relay 75, which cuts off the operating circuit of the pump 51 when the starter St is turned on, before the starter St. It is assumed that the water temperature sensors 23 and 55 output the signals s, 2, and s3 only when the cooling water temperature reaches a certain predetermined temperature (for example, T+) or higher. Therefore, the differential amplifiers 61 and 71 do not output the difference signals Sd, .

[Brief explanation of drawings]

FIG. 7 is a schematic diagram of a heating device according to the first embodiment of the present invention, FIG. 2 is a modified example of a cooling water jacket, and FIG. 3 is a schematic diagram of a heating device according to the first embodiment of the present invention. 7 is a graph showing an example of operation of the first motor pump. FIG. 5 is a graph showing an example of operation of the first motor pump. FIG. 4 is a graph showing an example of operation of the first motor pump. Circuit Diagram Showing an Example of a Circuit FIG. 7 is a circuit diagram showing an example of an electric circuit that operates the first motor pump. E... Engine, 1... Cooling water mantle, 1a... Cylinder head water mantle, 1b... Cylinder block water mantle, 13... Heater core, 1γ... Exhaust passage, 18...
·Heat exchanger. Patent applicant: Toyo Kogyo Co., Ltd.

Claims (1)

[Claims] (1) Cooling water is supplied only from the high-temperature part of the engine body's cooling water jacket. Heat exchanger for heating the cooling water through heat exchange with the exhaust gas, which is installed in the exhaust passage and returns the cooling water to the high temperature section of the cooling water canister through the heater core for heating the interior of the vehicle. A heating device for a vehicle equipped with a water-cooled engine, which includes a cooling water circulation path and circulates cooling water through the circulation path at least when the engine is cold. (To) The heating device for a vehicle equipped with a water-cooled engine according to claim 1, wherein the high temperature portion of the cooling water canister is a cooling water cannula of a shilling head.