JPH10176533A - Engine cooling device - Google Patents

Abstract

(57) [Problem] To provide an engine cooling device capable of minimizing flow resistance in a cooling air discharge passage and preventing a decrease in fan efficiency. A radiator (6) is provided in an engine room (1) in which an engine (5) is installed and cools a cooling water of the engine (5).
c and the heat exchangers 6a to 6c
A centrifugal fan 4 that is driven by the power of the cooling air to induce cooling air that cools the heat exchanger 6, and that is provided upstream of the centrifugal fan 4 and downstream of the heat exchanger 6, In the engine cooling device having the radiator shroud 8 introduced to the suction side of the centrifugal fan 4, a spiral cover 18 that covers the centrifugal fan 4 together with the radiator shroud 8 and guides the cooling air blown out from the centrifugal fan 4 upward is provided. Diameter D1 of the suction side end
Is smaller than the diameter D2 of the downstream end of the impeller 4b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an engine cooling device for cooling an engine, and more particularly to an engine cooling device provided with a centrifugal fan.

[0002]

2. Description of the Related Art Conventionally, as a known technique relating to this type of engine cooling device, there is one disclosed in Japanese Utility Model Laid-Open No. 2-64799, for example. This known technique uses a centrifugal fan as a fan for supplying cooling air in a cooling device of an automobile engine, and fixes a cover for accommodating the centrifugal fan to a baffle plate (radiator shroud), thereby forming a cooling air discharge passage. By exhausting the cooling air smoothly to the outside while minimizing the flow path resistance, the exhaust duct required when the axial fan is used as the cooling fan is eliminated.

[0003]

The above-mentioned known techniques have the following problems. Generally, in an engine cooling device equipped with a centrifugal fan, the cooling air that has cooled a heat exchanger such as a radiator is reduced in its flow passage area by a radiator shroud, and then the centrifugal fan is positioned near the downstream end of the radiator shroud. Is introduced axially to the suction side of the impeller, and is further blown out radially by the rotation of the impeller. Here, in the above-mentioned known technology, it is not considered that the cooling air squeezed by the radiator shroud is smoothly introduced to the suction side end of the impeller of the centrifugal fan, and the cooling air squeezed by the radiator shroud is The projections of the cover are attached to the radiator shroud and are disturbed by collision with the projections or the like, and are introduced into the suction side end of the impeller of the centrifugal fan in the disturbed state. For this reason, there is a problem that the loss increases and the fan efficiency represented by (flow rate × pressure) / (power input to the fan rotation shaft) decreases, thereby increasing noise. An object of the present invention is to solve the above-described problems, and an object of the present invention is to provide an engine cooling device capable of minimizing a flow path resistance in a cooling air discharge passage and preventing a decrease in fan efficiency. It is in.

[0004]

According to the present invention, there is provided, in accordance with the present invention, at least one heat exchanger including a radiator provided in an engine room in which an engine is provided and cooling a cooling water of the engine. An exchanger and a centrifugal fan that induces cooling air for cooling the heat exchanger by driving a rotating shaft by the power of the engine, and an upstream side of the centrifugal fan and a downstream side of the heat exchanger. Provided,
An engine cooling device having a baffle plate for introducing the cooling air to the suction side of the centrifugal fan, wherein the engine cooling device covers the centrifugal fan together with the baffle plate and guides the cooling air blown from the centrifugal fan in a predetermined direction. An engine cooling device is provided, wherein a cover is provided, and a diameter of a suction side end of the centrifugal fan is smaller than a diameter of a downstream end of the air guide plate. Preferably, in the engine cooling device, an engine cooling device is provided, wherein the suction side end of the centrifugal fan is arranged to enter inside the downstream end of the air guide plate. That is, the cooling air that has cooled the heat exchanger including the radiator is introduced into the centrifugal fan by the air guide plate located downstream of the heat exchanger, and is blown out in the radial direction of the fan by the rotation of the fan. The cooling air blown out from the fan is guided in a predetermined direction by a cover that covers the centrifugal fan, so that the cooling air is smoothly discharged to the outside while minimizing the flow path resistance in the cooling air discharge passage. At this time, a part of the air guide plate covers the centrifugal fan together with the cover,
The diameter of the downstream end of the baffle plate is larger than the diameter of the suction side end of the centrifugal fan, for example, such that the suction side end of the centrifugal fan enters inside the downstream end of the baffle plate. Placed in As a result, the vicinity of the suction side end of the centrifugal fan is disposed in the baffle plate, so that the cooling air squeezed by the baffle plate is directed to the baffle plate near the downstream end of the baffle plate. The flow can be smoothly introduced into the centrifugal fan from the suction side end of the centrifugal fan without being disturbed at the boundary between the cover and the cover. Therefore, unlike the conventional structure in which the cover is attached to the air guide plate and disturbed, it is possible to prevent a decrease in fan efficiency.

Preferably, in the engine cooling device, the cover is integrated with the baffle plate. More preferably, in the engine cooling device, an engine cooling device is provided, wherein the cover has a structure that can be divided into a plurality of covers. This allows
When assembling the engine cooling device, first install the air guide plate and the heat exchanger in which a part of the divided pieces of the cover are integrated, and then install the engine and the centrifugal fan driven by it. Then, the remaining divided pieces of the cover can be assembled so as to cover the fan. Since the assembling work can be performed in such a smooth procedure, assemblability can be improved.

Preferably, in the engine cooling device, the cover is provided with an exhaust port for discharging cooling air blown from the centrifugal fan facing upward. . As a result, when the exhaust port is provided in the upper part of the engine compartment, the cooling air can be exhausted from the upper exhaust port to the outside of the engine compartment. Can be planned.

Preferably, in the engine cooling device, the lower portion of the cover has a substantially arc shape along the outer shape of the centrifugal fan. Thereby, when the centrifugal fan rotates in the circumferential direction, the flow path area around the fan becomes substantially constant in the circumferential direction. Therefore, since the cooling air is smoothly guided in the rotation direction of the fan, the flow path resistance in the cooling air discharge path can be further reduced.

[0008]

An embodiment of the present invention will be described below with reference to the drawings. This embodiment is an embodiment of an engine cooling device provided in an engine room of a hydraulic shovel. FIG. 1 is a sectional view illustrating the structure of the engine cooling device according to the present embodiment, and FIG. 2 is an enlarged view of a main part of FIG. 1 and 2, an engine cooling device is provided in an engine room 1 in which an engine 5 is provided, and includes an intercooler 6a for pre-cooling intake air for combustion of the engine 5, and a hydraulic oil for a hydraulic shovel. Cooler 6b that cools the cooling water of the engine 5, a radiator 6c that cools the cooling water of the engine 5, a cooling fan 4 that induces cooling air to cool the intercooler 6a, the oil cooler 6b, and the radiator 6c, and a cooling fan that cools the cooling air. A radiator shroud 8 to be introduced into a suction port of the cooling fan 4 and a spiral cover 18 that covers the cooling fan 4 together with the radiator shroud 8 are provided. In addition, a cooling air inlet 7 for taking in outside air is provided on an upper wall surface of the engine room 1.
And an outlet 9 for exhaust.

The radiator shroud 8 includes a cooling fan 4
And on the downstream side of the radiator 6 c, and is supported on the wall surface of the engine room 1 via the shielding plate 11. The cooling fan 4 is a centrifugal fan and has a rotating shaft 4a.
And an impeller 4b attached to the rotating shaft 4a. The engine 5 is driven by transmitting power from the crankshaft 2 of the engine 5 to the rotating shaft 4a via the fan belt 3. The impeller 4b has a core plate 4b1 formed on the engine 1 side, a plurality of blades 4b2, and a rotary shroud 4b3 formed on the radiator 6c side. As shown in FIG. 2, the cooling fan 4 has a diameter D1 at the suction side end of the impeller 4b, and the radiator shroud 8
The diameter is smaller than the diameter D2 of the downstream end of the radiator 4b, and the suction end of the impeller 4b is disposed inside the downstream end of the radiator shroud 8.

FIG. 3 is a view showing the detailed structure of the spiral cover 18 as viewed from the III-III plane in FIG. 1 to 3
In the spiral cover 18, the three pieces 18
a, 18b, 18c. The piece 18a closest to the radiator 6c is fixed to the radiator shroud 8 by, for example, inner circumferential welding 50 (see FIG. 2). Seven nuts 14 are welded to this piece 18a, and the remaining pieces 18b, 18c
Are attached to the nuts 14 by fastening the bolts 12 respectively. Thus, the spiral cover 18 has a structure integrated with the radiator shroud 8. An exhaust port 13 for exhausting the cooling air blown from the cooling fan 4 is formed above the pieces 18a and 18c so as to face upward, and is provided with a wire net 13A. Also the pieces 18a and 18b
Has a substantially arc shape along the outer shape of the impeller 4b of the cooling fan 4, as shown in FIG. At this time, the exhaust port 9 of the engine room 1 is located substantially above the exhaust port 13.

In the above configuration, the cooling air from the outside of the engine room 1 enters the engine room 1 through the cooling air inlet 7 as shown by the arrows, and intercoolers 6a, oil coolers 6b, which are heat exchangers, After cooling the radiator 6c, the radiator 6c is throttled by the radiator shroud 8 and reaches the cooling fan 4. The cooling air blown in the radial direction of the cooling fan 4 is guided upward by a spiral cover 18 that covers the cooling fan 4, and the spiral cover 1
The exhaust gas is discharged from the upper part of the engine room 1 through the exhaust port 13 at the upper part of the engine room 1 through the outlet 9 at the upper part of the engine room 1.

The effects of the present embodiment configured as described above will be described below.

(1) Effects of the dimensions and positional relationship between the radiator shroud and the cooling fan As described above, the cooling air is supplied to the heat exchangers of the intercooler 6a, the oil cooler 6b, and the radiator 6c.
After cooling, the cooling fan 4 is throttled by the radiator shroud 8 and reaches the cooling fan 4. At this time, in the present embodiment, the diameter D1 of the downstream end of the radiator shroud 8 is set.
Is larger than the diameter D2 of the suction side end of the impeller 4b, and is arranged such that the suction side end of the impeller 4b enters inside the downstream end of the radiator shroud 8.
As a result, the cooling air squeezed by the radiator shroud 8 flows through the fixing structure (for example, the inner circumferential welding 50 in FIG. 1) between the radiator shroud 8 and the spiral cover 18 at the downstream end of the radiator shroud 8 so that the cooling air flows. Even if the protrusions are arranged or disturbed, they can flow into the impeller 4b smoothly from the suction side end of the impeller 4b without being affected by the arrangement or the protrusion shape. Therefore, it is possible to prevent the efficiency of the fan from being reduced as in the conventional structure in which the cover is attached to the radiator shroud and the disturbance occurs.

(2) Effect of Arrangement of Spiral Cover FIG. 4 shows a comparative example for explaining this effect. In FIG. 4, the spiral cover 18 is omitted,
The position of the discharge port 9 is particularly different from the structure of the present embodiment shown in FIG. That is, the cooling air blown in the radial direction of the cooling fan 4 is supplied to the engine 5 and the oil pan 1 below the engine 5.
While cooling them around the periphery of the engine room 1, they are discharged from outlets 9, 9 in the upper and lower parts of the engine compartment 1. In this comparative example, since the cooling air after passing through the cooling fan 4 is blown out in the radial direction, most of the cooling air hits the upper partition 1a and the frame 1b of the engine room 1 perpendicularly and is rapidly changed. Become. Therefore, the flow path resistance increases and the pressure loss increases.

On the other hand, in the cooling device of the present embodiment, the cooling air blown from the cooling fan 4 is smoothly guided upward by the spiral cover 18 covering the cooling fan 4, and It is discharged to the outside from the discharge port 9 of the engine room 1 arranged above the exhaust port 13. Thereby, the discharge resistance in the cooling air discharge passage is reduced, and the cooling air can be smoothly discharged to the outside. Further, since the lower portions of the pieces 18a and 18b of the spiral cover 18 have a substantially arc shape along the outer shape of the impeller 4b of the cooling fan 4, the impeller 4b of the cooling fan 4 rotates in the circumferential direction. In this case, the flow path area around the blade becomes substantially constant in the circumferential direction. Thus, the cooling air is smoothly guided in the rotation direction of the impeller 4b, so that the flow path resistance in the cooling air discharge passage can be further reduced. Since the flow resistance in the cooling air discharge passage is reduced as described above, a large amount of air can be supplied to the intercooler 6a, the oil cooler 6b, and the radiator 6c, so that the cooling performance can be improved. At this time, the cooling by the cooling air is not performed on the engine 5 and the oil pan 5 which have been performing the cooling by the cooling air in the comparative example, but the cooling capacity of the oil cooler 6b and the radiator 6c is described above. Can be covered.

Generally, the noise of the engine room 1 is
It is known that the case where the cooling air is discharged from the upper part is the lowest. This is because noise is less likely to reach workers near the engine room 1 than when exhausting from the side or lower part of the engine room, for example. In the present embodiment, the exhaust port 13 of the spiral cover 18 faces upward,
By exhausting from the exhaust port 9 in the upper part of the engine room 1,
Noise can be reduced. In addition, although there are two outlets 9 in the comparative example, noise reduction can be achieved by using only one outlet 9. Further, by covering the entire surface of the cooling fan 4 with the spiral cover 18, there is also an effect of blocking sound emitted from the cooling fan 4 itself.

Further, since the impeller 4b of the cooling fan 4 is a rotating body in the engine room 1, in the comparative example, some other means is provided so that a worker or the like does not touch the body when performing inspection and maintenance. Although it is necessary, in the present embodiment, the spiral cover 18 fulfills its role, and safety can be ensured. The spiral cover 18
By closing the exhaust port 13 with the wire mesh 13, the safety is further improved.

(3) Effect of Split Structure of Spiral Cover In this embodiment, the spiral cover 18 has a structure that can be split into three pieces 18a, 18b, and 18c. Thus, when assembling the engine cooling device, first, the radiator shroud 8 to which the piece 18a is fixed and the heat exchanger 6 are mounted in the engine room 1, and then the engine 5 and the cooling fan integrated therewith are integrated. 4 and then the remaining pieces 18 are inserted so as to sandwich the rotation shaft 4a of the cooling fan 4 (see FIG. 3).
b and 18c may be attached with bolts 12. Thus, assembling work can be performed in a smooth procedure,
The assemblability can be improved.

In the above embodiment, the intercooler 6a, the oil cooler 6b,
And the radiator 6c are shown as an example, but the invention is not limited to this, and another heat exchanger such as a condenser of an air conditioner in a hydraulic shovel cab may be provided, and in these cases, the same effect is obtained. Furthermore, the above embodiment has described the engine cooling device of the hydraulic shovel,
The present invention is not limited to this, and can be applied to other various construction machines, agricultural machines, and the like, and in these cases, the same effects can be obtained.

[0020]

According to the present invention, the cooling air blown from the fan is guided in a predetermined direction by the cover covering the centrifugal fan, so that the cooling air can be smoothly reduced while minimizing the flow path resistance in the cooling air discharge passage. Is released to the outside. Further, at this time, since the vicinity of the suction side end of the centrifugal fan is disposed in the air guide plate, the cooling air can flow into the centrifugal fan smoothly. Therefore, unlike the conventional structure in which the cover is attached to the air guide plate and disturbed, it is possible to prevent a decrease in fan efficiency.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a structure of an engine cooling device according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is a view showing the detailed structure of the spiral cover shown in FIG. 1 as viewed from an arrow III-III in FIG. 1;

FIG. 4 is a cross-sectional view illustrating a structure of an engine cooling device according to a comparative example.

[Explanation of symbols]

 Reference Signs List 1 engine room 4 cooling fan (centrifugal fan) 5 engine 6c radiator (heat exchanger) 8 radiator shroud (wind guide plate) 9 exhaust port 18 spiral cover (cover) 18a-c split piece of spiral cover D1 cooling fan impeller Diameter at suction end D2 Diameter at downstream end of radiator shroud

Claims (6)

[Claims] An at least one heat exchanger including a radiator provided in an engine room in which an engine is provided, and cooling a cooling water of the engine, and a rotating shaft driven by the power of the engine, A centrifugal fan for inducing cooling air for cooling the heat exchanger; and a wind guide provided upstream of the centrifugal fan and downstream of the heat exchanger for introducing the cooling air to a suction side of the centrifugal fan. An engine cooling device having a plate and a cover that covers the centrifugal fan together with the baffle plate and guides cooling air blown out of the centrifugal fan in a predetermined direction, and a suction-side end of the centrifugal fan. An engine cooling device, wherein the diameter is smaller than the diameter of the downstream end of the air guide plate. 2. The engine cooling device according to claim 1, wherein the suction side end of the centrifugal fan is disposed so as to enter inside the downstream end of the air guide plate. . 3. The engine cooling device according to claim 1, wherein said cover is integrated with said air guide plate. 4. The engine cooling device according to claim 3, wherein said cover has a structure that can be divided into a plurality of covers. 5. The engine cooling device according to claim 1, wherein an exhaust port for exhausting cooling air blown from the centrifugal fan of the cover faces upward. 6. The engine cooling device according to claim 1, wherein the lower portion of the cover has a substantially arc shape along the outer shape of the centrifugal fan.