JP2000145454A - Installing mechanism of water glow plug - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an installation mechanism of a water glow plug with improved radiating efficiency for cooling water. SOLUTION: A water glow plug 1 is installed outside a bent portion 12a of an engine cooling-water pipe so that a heating portion 1a of thereof is inserted into the bent portion 12a. As a result, the heating portion 1a is positioned in a farther area 16 of the corner within the bent portion 12a. The flow velocity of cooling water running inside the bent portion 12a of the cooling- water pipe 12 is higher in the farther area 16 of the corner than closer area 18. Therefore, by positioning the heating portion 1a of the water glow plug 1 in the farther area 16 of the corner within the bent portion 12a where cooling- water runs faster, quantity of cooling-water contacting the heating portion 1a per unit time is increased. Thereby, radiating efficiency for cooling water is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure for a water draw plug which is mounted on a cooling water pipe of an engine to heat cooling water.

[0002]

2. Description of the Related Art A water draw plug is attached to a cooling water pipe of an engine (diesel or gasoline) by inserting a heat-generating portion of the plug into the pipe, and heating the cooling water to increase the water temperature after the engine is started. Is to speed up. With such a water draw plug, the effect of the heater is improved early after starting and the engine is stabilized early.

FIGS. 7 and 8 show a mounting structure of a conventional water draw plug 1 to a cooling water pipe 2. FIG. As shown in the figure, a plurality of cooling water pipes 2 (3
The water draw plug 1 of the present invention is attached to the straight pipe portion of the pipe 2 so that the heat generating portion 1a of each plug 1 is inserted into the pipe 2 so as to match its radial cross section.

[0004]

In the conventional mounting structure of the water draw plug 1, the viewpoint of layout to make the appearance after mounting compact and the viewpoint of securing a space for inserting a tool at the time of mounting. The mounting structure for improving the heat radiation efficiency to the cooling water is not particularly provided.

An object of the present invention, which has been made in view of the above circumstances, is to provide a mounting structure of a water draw plug with improved heat radiation efficiency to cooling water.

[0006]

According to a first aspect of the present invention, there is provided a mounting structure for a water draw plug, wherein a heat generating portion is provided outside a curved pipe portion of an engine cooling water pipe. A water draw plug is attached so as to be positioned outside the corner of the above.

[0007] The flow rate of the cooling water flowing in the curved pipe portion of the cooling water pipe is faster at the outside of the corner than at the inside. Therefore,
By arranging the heat generating portion of the water draw plug outside the corner in the curved pipe portion having a high flow velocity, the amount of cooling water contacting the heat generating portion per unit time increases, and the heat radiation efficiency to the cooling water improves.

[0008] A mounting structure for a water draw plug according to a second aspect of the present invention is such that a water draw low plug is attached to a cooling water pipe of an engine such that a heat generating portion is obliquely inserted into the cooling water pipe.

In this case, since the length of the heat generating portion inserted into the cooling water pipe can be increased, the contact surface area of the heat generating portion with the cooling water increases, and the heat radiation efficiency to the cooling water improves. Also,
Existing water flow plugs can be used for thin cooling water piping.

It is preferable that the length of the heat generating portion of the water draw plug is set to be larger than the inner diameter of the cooling water pipe.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the first invention will be described below with reference to FIGS.

FIG. 3 shows an outline of a cooling water circuit of an engine (diesel or gasoline). As shown in the figure, the cooling water discharged from the water pump 3 flows to the cylinder head 5 through the cylinder block 4. A part of the cooling water of the cylinder head 5 flows to the oil cooler 7 (water cooling type) via the thermo valve 6, and the rest flows to the cooling water gallery 8. The thermo valve 6 is closed when the temperature of the cooling water or the oil temperature of the lubricating oil is lower than a predetermined temperature, and is opened when the temperature is higher than the predetermined temperature.

A part of the cooling water in the cooling water gallery 8 flows to the heater 10 through the cooling water pipe 9, and the rest flows to the thermostat 11. The cooling water of the heater 10 returns to the water pump 3 via a cooling water pipe 12 and a cooling water pipe 13 (hereinafter, referred to as a bypass pipe 13). The thermostat 11 opens the gallery 8 when the cooling water is below a predetermined temperature.
The cooling water in the water pump 3
And when the cooling water is higher than a predetermined temperature, the radiator 14
To the water pump 3 via

According to the above-mentioned cooling water circuit, the cooling water circuit of the heater 10 is composed of the water pump 3 → the cylinder block 4 →
Cylinder head 5 → Cooling water gallery 8 → Cooling water pipe 9 →
Heater 10 → cooling water pipe 12 → bypass pipe 13 → water pump 3. The cooling water gallery 8 is connected to a reservoir tank 15 which is also connected to the radiator 14. The reservoir tank 15 separates the cooling water introduced from the cooling water gallery 8 and the radiator 14 into gas and liquid, and guides the liquid to the water pump 3.

The cooling water pipe 12 constituting the cooling water circuit of the heater 10 has a curved pipe portion 12a. The curved pipe part 1
As shown in FIGS. 1 and 2, the water draw plug 1 has a heat generating portion 1a outside the bent portion 12a.
It is attached so that it can be inserted into. In the present embodiment, three water draw plugs 1 are attached with their phases shifted in the flow direction A of the cooling water.

The heat generating portion 1a of each of the water draw plugs 1 inserted into the curved tube portion 12a is located in a corner outer region 16 in the curved tube portion 12a. That is, the heat-generating portion 1a formed in a rod shape is inserted into the curved tube portion 12a from outside the corner of the curved tube portion 12a, and is disposed such that the front end 1b substantially coincides with the center line 17 of the curved tube portion 12a. ing.

The operation of this embodiment having the above configuration will be described.

The flow rate of the cooling water flowing through the curved pipe portion 12a of the cooling water pipe 12 is faster in the outer region 16 of the corner than in the inner region 18, as indicated by the arrow in FIG. Therefore, by arranging the heat generating portion 1a in the corner outer region 16 having a high flow velocity, the amount of cooling water contacting the heat generating portion 1a per unit time increases. As a result, the efficiency of radiating heat to the cooling water circulating in the cooling water circuit of the heater 10 is improved.

That is, the heat release amount Q from the heat generating portion 1a of the water draw plug 1 to the cooling water is represented by C, the specific heat of the cooling water,
Assuming that V is the flow rate of the cooling water and T is the temperature of the heat generating portion 1a, Q
= CVT, so that as V increases, the amount of heat dissipation Q increases, and the heat dissipation efficiency increases.

Therefore, after the engine is started, the cooling water circulating in the cooling water circuit of the heater 10 is heated at an early stage, and the effectiveness of the heater 10 is improved at an early stage. Further, since the cylinder block 4 and the cylinder head 5 warm up early, the engine is stabilized early. Further, since a cooling water channel which is not obstructed by the heat generating portion 1a is secured in the corner inner region 18 in the curved pipe portion 12a, a large pressure loss does not occur.

Further, since the water draw plug 1 of this embodiment is mounted with a phase shift in the flow direction A of the cooling water as shown in FIG. 2, it is different from the conventional type shown in FIGS. The resistance to the cooling water is smaller than that of the three mounted in the same plane. This also contributes to a reduction in pressure loss.

That is, in the conventional type shown in FIG. 7 and FIG.
In contrast, according to the water draw plug 1 of the present embodiment shown in FIG. 2, the cross-sectional area of the flow path of the cooling water is reduced to only one heat generating portion 1a. Therefore, the pressure loss due to the attachment of the water draw plug 1 is smaller in the present embodiment than in the conventional type.

The mounting position of the water draw plug 1 is not limited to the cooling water pipe 12, and any pipe may be used as long as it forms a cooling water circuit of the heater 10 and has a curved pipe portion. . For example, in FIG. 3, the cooling water pipe 9 may be attached to the outside of the corner of the curved pipe section 9a of the cooling water pipe 9 or the curved pipe section 13a of the bypass pipe 13.

The number of the water draw plugs 1 is not limited to three as shown in the figure, but may be one, two or four or more. However, in the present embodiment, since the heat radiation efficiency of the heat generating portion 1a is increased as described above, the same heat radiation amount as before can be ensured even if the number of attachments is reduced.

Next, an embodiment of the second invention will be described with reference to FIGS.

The cooling water circuit of the engine shown in FIG. 6 has basically the same configuration as that of the cooling water circuit shown in FIG. 3, so that the same components are denoted by the same reference numerals and description thereof is omitted. I do.

The feature of this embodiment is that the water draw plug 1 is connected to the cooling water pipe 19 connected to the cooling water gallery 8 constituting the cooling water circuit of the heater 10 with respect to the radial cross section of the pipe 19. The heat generating part 1a of the water draw plug 1 is inserted obliquely into the cooling water pipe 19 as shown in FIG. Heating part 1
The length of “a” is set to be larger than the inner diameter of the cooling water pipe 19.

In this case, since the length L of the heat generating portion 1a inserted into the cooling water pipe 19 can be increased, the contact surface area of the heat generating portion 1a with the cooling water increases, and the heat radiation efficiency to the cooling water improves. Therefore, the effect of the heater 10 is improved early after the engine is started, and the engine is warmed up early.
The existing water draw plug 1 (the length of the heat generating portion 1a is longer than the inner diameter of the pipe 19) can also be used for the thin cooling water pipe 19.

When a plurality of the water draw plugs 1 are attached, it is preferable to attach them out of phase in the flow direction A of the cooling water as shown in FIG. In the present embodiment, since the length L of the heat generating portion 1a can be increased as described above, the same heat radiation amount as before can be ensured even if the number of mounting portions is reduced.

The mounting position of the water draw plug 1 is not limited to the cooling water pipe 9 but may be any pipe as long as it is a pipe (9, 12, 13) constituting a cooling water circuit of the heater 10. .

[0031]

As described above, according to the mounting structure of the water draw plug according to the present invention, the efficiency of radiating heat to the cooling water can be improved.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a mounting structure of a water draw plug according to an embodiment of the first invention.

FIG. 2 is a plan view showing a mounting structure of the above water law plug.

FIG. 3 is an explanatory diagram of a cooling water circuit to which the above water draw plug is attached.

FIG. 4 is a side sectional view showing a mounting structure of a water draw plug according to an embodiment of the second invention.

FIG. 5 is a plan view showing a mounting structure of the above water law plug.

FIG. 6 is an explanatory diagram of a cooling water circuit to which the above water draw plug is attached.

FIG. 7 is a cross-sectional view showing a mounting structure of a water draw plug showing a conventional example.

FIG. 8 is a plan view showing an attachment structure of the above water law plug.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Water draw plug 1a Heating part 12 Cooling water pipe 12a Curved pipe part 19 Cooling water pipe L Length of heat generating part

Claims (3)

[Claims] 1. A wart draw plug, wherein a water draw low plug is attached to an outside of a curved pipe portion of an engine cooling water pipe such that a heat generating portion is located outside a corner in the curved pipe portion. Mounting structure. 2. A mounting structure for a water draw plug, wherein a water draw low plug is attached to a cooling water pipe of an engine such that a heat generating portion is inserted obliquely into the cooling water pipe. 3. The length of the heat generating portion of the water draw plug is set to be larger than the inner diameter of the cooling water pipe.
Mounting structure of the described water draw plug.