JPH10317998A - Hot water type heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the flow rate of hot water in a heater corresponding to the temperature of intake air led thereinto. SOLUTION: A hot water passage 42 is laid in which hot water for heating a throttle body 1 flows. The hot water passage 42 is provided therein with a thermo-valve 18 for controlling the hoot water flow rate through temperature sensing by its temperature sensing element 23, which is arranged in an intake passage 4 in which intake air flows. When the intake air temperature is lower, the valve 18 is opened so that the hot water flowing in the hot water passage 42 heats the throttle body 1 up to prevent icing. When the intake air temperature reaches a predetermined value, on the other hand, the valve 18 is closed to stop the heating of the throttle body 1 by the hot water so that the intake air that has been heated up by the heat of the throttle body 1 cools down and its volume reduces for improved charging efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water type heating device for heating a member forming an intake passage of an engine, for example, a throttle body with hot water.

[0002]

2. Description of the Related Art Conventionally, this type of hot water type heating apparatus is disclosed in, for example, Japanese Utility Model Laid-Open No. 2-103164 and Japanese Patent Laid-Open No. 6-185.
There is one disclosed in Japanese Patent Publication No. 415. In these conventional devices, a hot water passage through which hot water (corresponding to engine cooling water) for heating the throttle body is provided, and a thermo valve (or a thermostat) is provided in the hot water passage. The thermovalve controls the flow rate of the hot water by sensing the temperature of the hot water by the temperature sensing unit. That is, during the warm-up operation of the engine (when the temperature of the hot water is low), the throttle valve is heated by the hot water flowing through the hot water passage by opening the thermo valve to prevent icing (freezing).
After the engine is warmed up (when the temperature of the hot water is high), the thermo-valve closes to stop the heating of the throttle body by the hot water, thereby reducing the temperature of the intake air heated by the heat of the throttle body. To suppress the expansion of the intake air volume and improve the charging efficiency.

[0003]

According to the conventional hot water heating apparatus, the flow rate of the hot water is controlled by a thermo valve which operates based on the temperature of the engine cooling water. Therefore, hot water control according to the temperature condition of the intake air is not performed. Therefore, for example, even when the temperature is extremely low,
After the engine is warmed up, the thermo valve senses the temperature of the cooling water and closes the hot water passage. Then, even though the intake air is at a very low temperature, the throttle body is not heated, so that the throttle body temperature is lowered, and the problem that the icing prevention effect is reduced remains. As described above, there remains a problem that it is difficult to obtain an effective icing prevention effect and an improvement effect of intake air charging efficiency with the conventional device.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a hot water control apparatus capable of controlling a flow rate of hot water according to a temperature condition of intake air. An object of the present invention is to provide a heating device of the type.

[0005]

According to a first aspect of the present invention, there is provided a hot water heating apparatus provided with a hot water passage through which hot water for heating a throttle body flows as an icing prevention measure. A hot water type heating device characterized in that a thermo valve for controlling the flow rate of hot water is provided in the passage by sensing the temperature of the temperature sensing portion, and the temperature sensing portion of the thermo valve is arranged in the intake passage through which the intake air flows. .
According to the hot water heating device of the first aspect, when the temperature of the intake air is low, the thermo valve is opened to heat the throttle body with the hot water flowing through the hot water passage, thereby preventing icing. When the temperature of the intake air becomes higher than a predetermined value, the thermo valve closes to stop heating the throttle body, thereby lowering the temperature of the intake air heated by the heat of the throttle body. In addition, the expansion of the volume of the intake air is suppressed to improve the charging efficiency. Therefore, by controlling the flow rate of the hot water by the thermo valve that operates based on the temperature of the intake air, it is possible to control the flow rate of the hot water according to the temperature condition of the intake air. Thus, unlike the conventional hot water heating device, for example, if the air temperature is extremely low even after the engine is warmed up, the throttle body can be heated to obtain an icing prevention effect.

According to a second aspect of the present invention, there is provided the hot water heating apparatus according to the first aspect, wherein the wall member of the hot water flow path of the thermovalve is formed of a material having heat insulating properties. Device. According to the hot water heating device of the second aspect, it is possible to prevent the heat of the hot water flowing through the hot water flow path of the thermovalve from being transmitted to the temperature sensing portion through the wall member.

According to a third aspect of the present invention, there is provided the hot water type heating apparatus according to the first aspect, wherein the thermo valve is mounted on the member to be mounted in a thermally insulated state. According to the third aspect of the present invention, it is possible to prevent the heat of the attached member from being transmitted to the thermo valve.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. The hot water heating device of the present embodiment is provided on a throttle body 1 as shown in a sectional view in FIG. The throttle body 1 includes a body 2 and a throttle valve 3. The body main body 2 is made of aluminum die-cast and has a substantially cylindrical shape forming the intake passage 4. The throttle valve 3 opens and closes an intake passage 4 of the body 2 and is attached to a throttle shaft 5 rotatably provided on the body 2. The intake air flows through the intake passage 4 of the throttle body 1 from above to below in FIG. The intake passage 4 communicates with an intake manifold (not shown) and an intake passage of a cylinder head.

An ISC valve housing (not shown) of an idle speed control device (hereinafter referred to as an ISC valve) is provided on an outer surface of the body body 2 (FIG. 1 shows the body body 2).
Only the attachment part for is shown. ) 7 is attached. As is well known, the ISC valve controls the amount of intake air that bypasses the throttle valve 3. A hot water chamber 8 is formed on the mating surface between the body 2 and the ISC valve housing 7. The hot water chamber 8 is formed by a concave portion 9 formed on the outer surface of the body main body 2.
O between the body 2 and the ISC valve housing 7
A ring 13 is interposed. Also, the ISC valve housing 7 is formed with upper and lower pipe mounting holes 10 communicating between the inside and outside of the hot water chamber 8. Upper and lower connection pipes 11 and 12 are connected to the respective pipe mounting holes 10 by fitting.

A boss 15 is formed on the outer surface of the body 2 of the throttle body 1. The boss portion 15 is formed with a thermovalve mounting hole 14 penetrating into and out of the intake passage 4. A female screw (symbol is omitted) is formed in the thermovalve mounting hole 14. The thermo-valve mounting hole 14 is located slightly upstream from the closed position of the throttle valve 3.

FIG. 2 is a cross-sectional view of a thermo-valve 18 mounted in the thermo-valve mounting hole 14 of the body 2. In FIG. 2, a valve body 19 of the thermovalve 18 is made of brass and has a male screw 20 screwed into the thermovalve mounting hole 14 and a stepped surface 21 which comes into contact with the end face of the boss 15. The male screw 20 is covered with a coating 22 coated with a resin having a heat insulating property, for example, a nylon resin.

A metal case 23 containing a temperature-sensitive wax that expands and contracts in response to a change in the intake air temperature is attached to the tip (the left end in the figure) of the valve body 19. Since the case 23 containing the temperature-sensitive wax corresponds to the temperature-sensitive portion, the same reference numeral as that of the case 23 is given to the temperature-sensitive portion. A stainless steel rod 24 that moves axially by utilizing expansion and contraction of the temperature-sensitive wax of the temperature-sensitive portion 23 is provided at the axis of the valve body 19.

A hollow cup 26 forming a hot water flow path 27 is attached to the end face of the valve body 19 on the opposite end side (right side in the figure). The open end face of the cup 26 is closed by a plate 28. Cup 26
A hot water inlet connection port 29 is formed on an end face of the cup 26, and a hot water outlet connection port 30 is formed on a side surface of the cup 26. Inside the cup 26, a stainless steel rod 32 of a valve body 31 for opening and closing the hot water inlet connection port 29 is provided so as to be axially movable while penetrating the axis of the plate 28. A spring seat 33 is provided on an end surface of the plate 28 on the side of the hot water flow path 27. The spring seat 33 is pressed against the plate 28 by a first spring 34 interposed between the spring seat 33 and the end face in the cup 26 facing the spring seat 33.

A second spring 36 is provided between the spring seat 33 and the spring seat 35 provided on the valve body 31 to bias the valve body 31 in the opening direction (leftward in the figure). . By attaching the cup 26 to the valve body 19, the rod 32 of the valve body 31 is abutted against the rod 24 on the valve body 19 side.
The cup 26 and the plate 28 correspond to a wall member forming the hot water flow path 27, and are made of a material having a heat insulating property.
For example, it is formed of PPS resin. Also plate 28
May be press-fitted into the cup 26 or may be fitted into the gap, but the press-fitting into the cup 26 provides a greater heat insulating effect than the gap-fitting.

As shown in FIG. 1, the thermo valve 18 is mounted on the throttle body 1 by screwing a male screw 20 of a valve body 19 into a thermo valve mounting hole 14 of the body 2. Boss 1
The stepped surface 21 of the valve body 19 is in contact with the end face of the valve body 5. Thereby, the thermo valve 18 opens the valve body 31 when the temperature of the intake air sensed by the temperature sensing part 23 is low,
When the temperature of the intake air reaches a predetermined temperature (for example, 20 ° C.), the temperature-sensitive wax expands, and the valve element 31 is pushed via the rods 24 and 32 against the bias of the second spring 36. As a result, the valve element 31 is closed. Also, when the temperature of the intake air falls below a predetermined temperature, the temperature-sensitive wax shrinks,
Due to the elasticity of the second spring 36, the valve body 31
The valve element 31 is opened by being moved back together with 4, 32. Since the temperature sensing portion 23 of the thermo valve 18 is located upstream of the closed position of the throttle valve 3,
It is possible to prevent the measured value of the temperature of the intake air from becoming unstable due to the influence of the flow of the intake air.

A terminal portion of a pipe 38 for supplying cooling water for the engine is connected to the connection port 29 for hot water inlet of the thermo valve 18 by fitting. Thermo valve 1
One end of a relay pipe 39 is connected to the hot water outlet connection port 30 by fitting. The other end of the relay pipe 39 is connected to the lower connection pipe 12 of the ISC valve housing 7 by fitting. A terminal portion of an engine cooling water return pipe 40 is connected to the upper connection pipe 11 of the ISC valve housing 7 by fitting. Therefore, the cooling water supplied from the water jacket of the engine by the water pump (FIG. 1)
(See arrows in the middle). From the supply pipe 38, the hot water flow path 27 of the thermo valve 18, the relay pipe 39, the hot water chamber 8 of the ISC valve housing 7, and the return pipe 40 return to the engine water jacket. Circulates through a hot water passage (denoted by reference numeral 42).

According to the above-mentioned hot water heating apparatus, when the temperature of the intake air is as low as 20 ° C. or less, the thermo valve 1
When the valve 8 is opened, the body main body 2 of the throttle body 1 and the ISC valve housing 7 are heated by the hot water flowing through the hot water passage 42. This prevents icing.

When the temperature of the intake air becomes higher than 20 ° C., the thermo valve 18 closes,
The flow of the hot water in the hot water passage 42 is stopped, and the heating of the body 2 of the throttle body 1 and the ISC valve housing 7 by the hot water is stopped. Thereby, the intake passage 4 and the IS
The heating of the intake air passing through the intake passage of the C valve housing 7 is stopped, and the expansion of the volume of the intake air is suppressed to improve the charging efficiency.

As described above, the flow rate of the hot water can be controlled according to the temperature condition of the intake air by controlling the flow rate of the hot water by the thermo valve 18 which operates based on the temperature of the intake air. Thus, unlike the conventional hot water heating device, for example, if the air temperature is extremely low even after the engine is warmed up, the throttle body can be heated to obtain an icing prevention effect. Therefore, an effect of effectively preventing icing and an effect of improving the efficiency of charging the intake air can be obtained.

Further, since the cup 26 and the plate 28 of the thermovalve 18 are formed of a heat-insulating PPS resin, the heat of the hot water flowing through the hot water flow path 27 of the thermovalve 18 is transmitted through the cup 26 and the plate 28. 2
3 can be prevented.

The valve body 1 of the thermo valve 18
The thermo-valve body 19 of the thermo-valve 18 is attached to the body main body 2 of the throttle body 1 corresponding to a member to be mounted in a thermally insulated state by a coating 22 obtained by applying a heat-insulating resin, for example, a nylon resin, to the male screw 20 of the ninth embodiment. Thereby, it is possible to prevent the heat of the body 2 heated by the hot water from being transmitted to the temperature sensing portion 23 of the thermovalve 18.

The present invention is not limited to the above embodiment, but can be modified without departing from the scope of the present invention. For example, the thermo valve can be attached to an ISC valve housing, an intake manifold, a carburetor, etc. in addition to the body main body 2 forming the intake passage. Further, instead of the coating 22 provided on the male screw 20 of the valve body 19 of the thermo-valve 18, the female screw of the thermo-valve mounting hole 14 of the body main body 2 or at least one screw part of the male screw 20 is formed of a resin having heat insulating properties. Thereby, the thermo valve 18 and the member to be mounted (the body 2) can be mounted in a thermally insulated state. Further, it is desirable that the valve body 19 and the rods 24, 32 of the thermovalve 18 be made of a material having a heat insulating property as long as the strength can be secured.

[0023]

According to the hot water heating apparatus of the present invention, the flow rate of hot water can be controlled in accordance with the temperature condition of the intake air, so that the effective icing prevention effect and the improvement of the intake air filling efficiency can be achieved. Effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a hot water type heating device provided in a throttle body.

FIG. 2 is a partially cutaway side view of the thermovalve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Throttle body 2 Body main body 4 Intake passage 18 Thermo valve 23 Temperature sensing part 27 Hot water flow path 42 Hot water passage

Continuing on the front page (72) Inventor Kenji Mizoguchi 1-1-1, Kyowa-cho, Obu-shi, Aichi Prefecture Inside Ai San Kogyo Co., Ltd. (72) Inventor Nobuaki Kosaka 1-1-1, Kyowa-cho, Obu-shi, Aichi Prefecture Ai San (72) Inventor Akira Ii 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation

Claims (3)

[Claims] 1. A hot water type heating device provided with a hot water passage through which hot water for heating a throttle body flows as a measure for preventing icing, wherein a flow rate of the hot water is controlled by sensing a temperature of a temperature sensing part in the hot water passage. A hot-water heating device comprising: a thermovalve; and a thermosensitive portion of the thermovalve arranged in an intake passage through which the intake air flows. 2. The hot water heating apparatus according to claim 1, wherein the wall member of the hot water flow path of the thermovalve is formed of a material having heat insulating properties. 3. The hot water type heating device according to claim 1, wherein the thermo valve is attached to the member to be attached in a state of being thermally insulated.