JPH03185211A - Cooling water temperature control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To facilitate temperature adjustment by providing a main cooling water passage connected to a radiator inlet passage and a bypass cooling water passage branching from the main cooling water passage, and providing, in the main cooling water passage, a butterfly valve whose opening is by a step motor. CONSTITUTION:In a cooling water temperature control device 11, a main body 12 thereof is composed of a main cooling water passage 12a connected to the radiator inlet passage of a cooling device, a pipe part 12c having a bypass cooling water passage 12b branching from the passage 12a in the main body, and is connected to a bypass passage, and a nearly square cylindrical gear box 12d having its bottom and provided integratedly on the pipe part 12c. A butterfly valve 13 is provided rotatably in the main cooling water passage 12a, and a worm wheel is fixed on a part facing to the inside of the gear box 12d of the valve shaft 13a of the butterfly valve 13. A worm gear 16 is engaged with the worm wheel so as to communicate rotation of the output shaft 14a of a step motor 14 to the worm gear 16 through a gear column 17.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cooling water temperature control device used in an internal combustion engine such as an automobile engine.

[Conventional technology]

Conventionally, in order to cool internal combustion engines such as automobile engines,
A water-cooled cooling system using a radiator was used. In this type of cooling system, a thermostat is used to control the temperature of the cooling water, and if the cooling water is lower than a predetermined temperature, it is routed to a bypass passage and circulated without passing through the radiator. It was a structure that allowed A conventional cooling device of this type will be explained with reference to FIG.

FIG. 4 is a schematic configuration diagram showing a conventional cooling system. In the same figure, 1 is a cooling water passage of a cylinder block in an engine, and 2 is a cylinder head that communicates with the cooling water passage 1 of the cylinder block in the engine. Cooling water passage 3 indicates a radiator.

The cooling water inlet of the radiator 3 is communicated with the cooling water passage 2 of the cylinder head via the radiator artificial passage 4, and the cooling water outlet of the radiator 3 is communicated with the cooling water passage 2 of the cylinder head via the radiator outlet passage 5. water passage 1
is communicated with. 6 is a cooling water pump, and this cooling water pump 6 is interposed in the middle of the radiator outlet passage 5. Reference numeral 7 denotes a thermostand for controlling the flow rate of cooling water flowing into the radiator 3 according to the temperature of the cooling water, and this thermostat 7 is interposed in the middle of the radiator artificial passage 4. Further, the thermostat 7 is configured to be fully closed when the temperature of the cooling water is below a set temperature (-80° C. for boat fishing). Reference numeral 8 denotes a bypass passage for circulating the cooling water bypassing the radiator 3 when the cooling water is lower than a predetermined temperature.
It is connected to the upstream side of the throat 7 via a cooling water branch 9, and the other end is connected to the cooling water pump 6.

In the conventional cooling system configured as described above, when the temperature of the cooling water is low, such as immediately after starting the engine, the cooling water supplied from the cooling water pump 6 to the cooling water passage 1 of the cylinder block is The water flows from the cooling water passage 2 of the cylinder head to the cooling water branch part 9, and the thermostat 7
Since the water is in a fully closed state, the water is not flown to the radiator 3 side, but is returned to the cooling water pump 6 via the bypass passage 8. In this way, at low temperatures, cooling water is circulated without cooling. When the temperature of the cooling water rises above the set temperature of the thermostat 7, the thermostat 7 opens and the cooling water flows from the cooling water passage 2 of the cylinder head to the cooling water branch 9. It flows into the radiator 3 through the radiator artificial passage 4. The cooling water cooled by the radiator 3 is returned to the cooling water pump 6 from the radiator outlet passage 5, and is again supplied to the cooling water passage 1 of the cylinder block. By supplying the cooling water cooled by the radiator 3 to the engine in this manner, the engine is cooled.

[Problem to be solved by the invention]

However, in conventional cooling systems, the temperature of the cooling water is controlled by the set temperature of the thermostat 7, so the temperature remains approximately constant in winter and summer (-80°C for boat fishing).
is maintained. For this reason, it has been difficult to optimally control the temperature of the cooling water depending on the outside temperature and the operating state of the engine. For example, if you set the coolant temperature high in the winter to improve heater performance and fuel efficiency, the coolant temperature tends to rise in the summer when outside temperatures are high, reducing the engine cooling effect. , a problem arises in that the temperature of the lubricating oil increases. Additionally, thermostats used to control the flow rate of cooling water have a large pressure loss, so there is a limit to how much the flow rate of cooling water can be increased.

An engine cooling water temperature control device for an internal combustion engine that eliminates such problems is disclosed in Japanese Patent Publication No. 60-20563. In this system, a cooling water passage is provided in parallel with a cooling water passage having a high temperature thermostat and a cooling water passage having a low temperature thermostat, and a flow control valve is connected to one of the cooling water systems. Using two thermostuffs in this way allows you to double the conditions for cooling water temperature control, but since the cooling water systems are in parallel, it occupies more space inside the engine, making it even more difficult to control the flow rate. The disadvantage was that it required a valve, making it larger. Furthermore, a thermostat with a large pressure loss was used in the cooling water passage, and the structure ensured a large flow rate with two thermos valve throats, resulting in low efficiency.

In addition, in the cooling system shown in Fig. 4, since a branching pipe joint and a connecting rubber hose are normally used in the cooling water branching section 9, there are many places where the rubber hose can be attached and detached during assembly or maintenance inspection. becomes complicated. Furthermore, in the cooling system shown in FIG. 4, even if the temperature of the cooling water rises above the set temperature and the thermostat 7 is fully opened, a portion of the cooling water is flowed through the bypass passage 8. All the cooling water cannot flow to the radiator 3. Therefore, the cooling efficiency of the cooling water from the perspective of the entire cooling system was low.

[Means to solve the problem]

A cooling water temperature control device for an internal combustion engine according to a first aspect of the present invention includes a main body having a main cooling water passage and a bypass cooling water passage branched from the main cooling water passage, and a flow rate for opening and closing the main cooling water passage. It is equipped with a control butterfly valve and a stepper motor connected to the butterfly valve via a speed reducer having a worm gear, and a branch part between the main cooling water passage and the bypass cooling water passage of the main body is connected within the main body. It is installed upstream from the butterfly valve.

Further, in the cooling water temperature control device for an internal combustion engine according to the second aspect of the present invention, in the first cooling water temperature control device for an internal combustion engine, the bypass cooling water passage of the main body is connected to the butterfly valve of the main cooling water passage. The relative angle is set perpendicular to the opening and closing direction,
A bypass side butterfly valve is provided which is opened and closed in accordance with the opening and closing operations of the butterfly valve.

[For production]

According to the first aspect of the present invention, by adjusting the butterfly valve to a predetermined opening degree using a stepper motor, the flow rate of cooling water flowing into the radiator can be controlled according to its temperature. Moreover, the main body can be used as a substantial branching pipe joint.

According to the second aspect of the present invention, since it is possible to suppress the cooling water from flowing into the bypass cooling water passage when the temperature of the cooling water exceeds the set temperature, it is possible to prevent all the cooling water from flowing to the radiator. can.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIGS. 1(a) to Td) and FIG.

FIGS. 1(a) to 1(d) are diagrams showing a cooling water temperature control device for an internal combustion engine according to the first aspect of the present invention, and FIG. 1(a) is a front view with main parts cut away; FIG. ('b) is a left side view, (fc) is a plan view showing the gearbox with the cover removed, and (d) is a sectional view taken along line I-1 in (a). FIG. 2 is a schematic configuration diagram showing a cooling device equipped with a cooling water temperature control device for an internal combustion engine according to the present invention. In these figures, the same or equivalent members as those explained in FIG. 4 are given the same reference numerals and detailed explanations will be omitted. In these figures, reference numeral 11 indicates a cooling water temperature control device according to the present invention, and this cooling water temperature control device 11 includes a main body 12, a butterfly valve 13, and a stepper motor 14.
It consists of 8.

The main body 12 includes a main cooling water passage 12a connected to the radiator artificial passage 4 of the cooling device, and a main cooling water passage 12a connected to the radiator artificial passage 4 of the cooling device.
A gear box having a tube portion 12c having a bypass cooling water passage 12b branched from a in the main body 12 and connected to the bypass passage 8, and a gear box having a substantially bottomed rectangular tube shape integrally provided with the tube portion 12C. 12d. Further, a shaft hole 12e into which a butterfly valve 13, which will be described later, is inserted is bored in the pipe portion 12c and the gear box 12d. This shaft hole 12e is connected to the main cooling water passage 12.
The bypass cooling water passage 12b is disposed downstream of the branching point between the cooling water passage 12a and the bypass cooling water passage 12b.

13 is a butterfly valve for controlling the flow rate of cooling water flowing through the main cooling water passage 12a of the main body 12;
A valve shaft 13a that is inserted into the main cooling water passage 12a and crosses the main cooling water passage 12a.
and a valve body 13b fixed to a portion of the valve shaft 13a inside the main cooling water passage 12a,
It is rotatably supported by the main body 12. The end of the gear box 12d of the valve shaft 13a is pivotally supported by a cover 12f fixed to the gear box 12d, and a worm wheel 13c is fixed to a portion facing into the gear box 12d.

14 is a stepper motor for opening and closing the butterfly valve 13, and this stepper motor 14 is connected to a sensor (not shown) and a control device (not shown) for detecting the temperature of the cooling water. The gearbox 12d is attached to the side of the gearbox 12d. Further, as shown in FIG. 1(C), the output shaft 14a of this stepper motor 14 is attached to the gear box 12 so that its tip faces into the gear box 12d.
d, and a stepper motor side spur gear 15 is fixed to its tip. Reference numeral 16 denotes a worm for transmitting the driving force of the stepper motor 14 to the butterfly valve 13. This worm 16 has a spur gear 17 that meshes with the stepper motor side spur gear 15 fixed to one end thereof. It is rotatably supported by a gear box 12d in a state where it is meshed with a worm wheel 13c fixed to the valve 13. That is, this worm 16 and the worm wheel 13C constitute a reduction gear, and when the stepper motor 14 is driven and the stepper motor side spur gear 15 rotates together with the output shaft 14a, the worm 16 rotates together with the spur gear 17, and the worm wheel 13C rotates. The worm wheel 13c meshing with the worm wheel 16 rotates in a decelerated state, and the butterfly valve 13 is driven.

As shown in FIG. 2, the cooling water temperature control device 11 configured in this manner connects the main cooling water passage 12a in the main body 12 to the radiator inlet passage 4 instead of the conventional thermostat.
At the same time, the bypass cooling water passage 12b is connected to the bypass passage 8 and used. Note that when making this connection, the orientation of the main body 12 is set so that the branching portion between the main cooling water passage 12a and the bypass cooling water passage 12b is on the upstream side of the butterfly valve 13.

When the temperature of the cooling water is equal to or higher than the set temperature, the stepper motor 14 is driven by the control device and the butterfly valve 13 is opened. At this time, the driving force of the stepper motor 14 is transmitted from the output shaft 14a to the stepper motor side spur gear 15.
．． It is transmitted to the worm 16 via the spur gear 17, and from the worm 16 to the butterfly valve 13 via the worm wheel 13C. By opening the butterfly valve 13 in this manner, the cooling water passes through the main cooling water passage 12a, flows from the radiator artificial passage 4 to the radiator 3, and is cooled.

When the temperature of the cooling water is below the set temperature, the stepper motor 14 is driven by the control device to close the butterfly valve 13. By closing the butterfly valve 13, the cooling water does not flow toward the radiator 3, but instead passes through the bypass cooling water passage 12b of the main body 12, and flows into the radiator outlet passage 5 via the bypass passage 8. Become.

In addition to functioning as a thermostat by fully closing and fully opening the butterfly valve 13 as described above, the cooling water temperature control device 11 according to the present invention also performs cooling at different set temperatures depending on various conditions of the engine. The flow rate of water can be controlled, and the opening degree of the butterfly valve 13 can also be set arbitrarily to control the flow rate. For example, in winter when the outside temperature is relatively low, the temperature of the cooling water can be increased by keeping the butterfly valve 13 at an intermediate opening degree and slightly constricting the radiator inlet passage 4. Furthermore, in the summer when the outside temperature is relatively high, the temperature of the cooling water can be maintained at a low temperature by fully opening the butterfly valve 13.

Therefore, the cooling water temperature control device 11 according to the present invention can control the flow rate of cooling water flowing into the radiator 3 according to its temperature by adjusting the butterfly valve 13 to a predetermined opening degree using the stepper motor 14. .

Therefore, the temperature of the cooling water can always be kept at an optimal temperature. Moreover, since the main body I2 can be used as a substantial branch pipe joint, the branch pipe joint used conventionally can be made unnecessary.

Next, a cooling water temperature control device according to a second aspect of the present invention will be explained with reference to FIGS.

3(a) to 3(C) are diagrams showing a cooling water temperature control device according to a second aspect of the present invention, in which FIG. 3(a) is a front view with main parts cut away, and FIG. Left side view (C) is +8
1 is a sectional view taken along the line ■-■ in FIG. In these figures, the same or equivalent members as those explained in FIGS. 1(a) to (d) and FIG. 2 are designated by the same reference numerals, and detailed explanations thereof will be omitted. In FIGS. 3(a) to (C1, 21 is a butterfly valve for controlling the flow rate of cooling water flowing through the main cooling water passage 12a and the bypass cooling water passage 12b of the main body 12, and this butterfly valve 2
1 is inserted into the shaft hole 12e of the main body 12 and is connected to the main cooling water passage 1.
2a and a valve shaft 21a that crosses the bypass cooling water passage 12b, and the main cooling water passage 1 in this valve shaft 21a.
It is composed of a main cooling water passage side valve body 21b fixed to a part inside the main cooling water passage 2a, and a bypass cooling water passage side valve body 21c fixed to a part inside the bypass cooling water passage 12b. freely supported. The end of the valve shaft 21a on the side of the gear box 12d of the main body 12 is pivotally supported by a cover 12f fixed to the gear box I2d.
The worm wheel 21d that meshes with the worm 16 is shown. Further, the bypass cooling water passage side valve body 21c
is set so that the relative angle with the main cooling water passage side valve body 21b is perpendicular to the opening/closing direction.

That is, the bypass cooling water passage side valve body 21c is opened and closed according to the opening/closing operation of the main cooling water passage side valve body 21b, and when the main cooling water passage side valve body 21b is fully opened, the bypass cooling The water passage side valve body 21C is completely closed.

As described above, in the cooling water temperature control device equipped with the bypass cooling water passage side valve body 21C, when the temperature of the cooling water reaches or exceeds the set temperature and the butterfly valve 21 is opened,
The main cooling water passage side valve body 21b is operated to open, and the bypass cooling water passage side valve body 21c is operated to close.

Then, when the main cooling water passage side valve body 21b is fully opened and the bypass cooling water passage side valve body 21c is fully closed, the cooling water is supplied to the main body 1.
2, the coolant water does not flow to the bypass cooling water passage 12b, but flows to the radiator 3 through only the main cooling water passage 12a. When the temperature of the cooling water is below the set temperature, the butterfly valve 21 is closed, the main cooling water passage side valve body 21b is fully opened, and the bypass cooling water passage side valve body 21c is fully open. In this state, the cooling water does not flow into the main cooling water passage 12a, but instead flows into the bypass cooling water passage 12b.
The cooling water is allowed to flow through the bypass passage 8 to the radiator outlet passage 5, thereby making it possible to raise the temperature of the cooling water while circulating an appropriate amount of the cooling water.

Therefore, in this way, the bypass cooling water passage side valve body 21
By providing c, it is possible to prevent the cooling water from flowing into the bypass cooling water passage 12b when the temperature of the cooling water exceeds the set temperature, so that all of the cooling water can flow to the radiator 3.

Although this embodiment shows an example in which the main cooling water passage side valve body 21b and the bypass cooling water passage side valve body 21c are attached to the same valve shaft 21a, the present invention is not limited to this. Instead, butterfly valves having separate valve shafts may be provided in the main cooling water passage 12a and the bypass cooling water passage 12b, and both butterfly valves may be opened and closed with a phase shift of 90'. Even in this case, the same effect as in the above embodiment can be obtained.

〔Effect of the invention〕

As described above, the cooling water temperature control device for an internal combustion engine according to the first aspect of the present invention includes a main body having a main cooling water passage and a bypass cooling water passage branched from the main cooling water passage, and a main cooling water temperature control device for an internal combustion engine according to the first invention. A branch part between the main cooling water passage and the bypass cooling water passage of the main body, comprising a flow control butterfly valve for opening and closing the passage, and a stepper motor connected to the butterfly valve via a reducer having a worm gear. is located upstream of the butterfly valve within the main body, so by adjusting the butterfly valve to a predetermined opening degree using a stepper motor, the flow rate of cooling water flowing into the radiator can be controlled according to its temperature. .

Therefore, the temperature of the cooling water can be kept at the optimum temperature regardless of the outside temperature, so the cooling water can be controlled at a high temperature in winter to improve heater performance.

It is possible to improve fuel efficiency, and by controlling the cooling water to a low temperature in the summer, it is possible to reliably prevent the cooling effect of the engine from decreasing and the temperature of the lubricating oil from increasing. In addition, since the cooling water temperature control device according to the present invention can be configured as one control valve, it can be implemented without increasing the size of the cooling water system. In addition, since a butterfly valve is used to control the flow rate of cooling water, the only pressure loss factors in the cooling water passage are the valve stem and the projection of the valve body thickness, and a thermostat is used for cooling water. The flow direction will not change drastically as in the case where the water flows smoothly. Therefore, the pressure loss in the cooling water passage can be significantly reduced, so that the cooling water can flow at a large flow rate. Furthermore, since it is equipped with a reducer with a worm gear, it is possible to obtain a large reduction ratio with a small size, which reliably prevents the butterfly valve from malfunctioning due to the pressure of the cooling water without increasing the size of the device. be able to. Furthermore, by employing a worm gear, it is possible to prevent the butterfly valve from rotating in the opposite direction due to the pressure of the cooling water when the butterfly valve is held at an intermediate opening degree by the stem and the motor.

Further, since the main body can be used as a substantial branching pipe joint, the branching pipe joint used conventionally can be made unnecessary. Therefore, the number of parts can be reduced and the cooling water piping system can be simplified, so the number of places where rubber hoses are attached and detached can be reduced, and the number of work steps such as assembly work, maintenance and inspection work, etc. can be reduced.

A cooling water temperature control device for an internal combustion engine according to a second aspect of the present invention includes:
A bypass side butterfly valve is provided in the bypass cooling water passage of the main body, and the relative angle with the butterfly valve of the main cooling water passage is perpendicular to the opening/closing direction, and the bypass side butterfly valve is opened and closed according to the opening and closing operation of the butterfly valve. Since it is possible to prevent the cooling water from flowing into the bypass cooling water passage when the temperature of the cooling water exceeds the set temperature, all of the cooling water can flow to the radiator. Therefore, the cooling water can be efficiently and rapidly cooled during the summer season when the temperature of the cooling water tends to rise, thereby reliably preventing the engine cooling effect from decreasing and the temperature of the lubricating oil from rising. You can

[BRIEF DESCRIPTION OF THE DRAWINGS] FIGS. 1(a) to 1(d) are diagrams showing a cooling water temperature control device for an internal combustion engine according to a first aspect of the present invention, and FIG. 1(a) shows a main part cut away. (b) is a left side view, and (b) is a left side view.
C) is a plan view showing the gearbox with the cover removed, and dl is a sectional view taken along the line I-1 in FIG. FIG. 3 is a schematic configuration diagram showing a cooling device equipped with a cooling water temperature control device according to the second aspect of the present invention. 11 is a front view shown as a front view shown in FIG. ...Cooling water temperature control device, 12.0.-Main body, 1
2a...Main cooling water passage, 12b...Bypass cooling water passage, 13.21...Butterfly valve, 13
c, 21d=... Worm wheel, 14... Stepper motor, 16... Worm, 21b...
Main cooling water passage side valve body, 21C... Bypass cooling water passage side valve body.

Claims (2)

[Claims] (1) A main body having a main cooling water passage and a bypass cooling water passage branched from the main cooling water passage, a flow control butterfly valve for opening and closing the main cooling water passage, and a reduction gear having a worm gear in the butterfly valve. and a stepper motor connected to each other via a stepper motor, and a branching portion between the main cooling water passage and the bypass cooling water passage of the main body is provided within the main body on the upstream side of the butterfly valve. Cooling water temperature control device for internal combustion engines. (2) In the cooling water temperature control device for an internal combustion engine according to claim 1, the bypass cooling water passage of the main body is provided at a relative angle with respect to the butterfly valve of the main cooling water passage at right angles to the opening/closing direction;
A cooling water temperature control device for an internal combustion engine, comprising a bypass-side butterfly valve that opens and closes in accordance with the opening and closing operations of the butterfly valve.