JP2023087364A - transportation vehicle - Google Patents

Abstract

To make front surface wind speed distribution of cooling air as uniform as possible even in a grid box configured such that a discharge port center of a centrifugal blower and the center of the air channel front surface of a cooling air passage provided with a resistor are dislocated.SOLUTION: A current plate is disposed in a duct connecting a discharge port of a centrifugal blower and an inlet port of a cooling air passage of a housing frame, and thus a drift current is introduced to bring the flow closer to a more uniform flow. A current plate is provided introducing air for variations in wind speed distribution in each of a flow passage width direction and a flow passage height direction of the discharge port of the centrifugal blower. In a dump truck (transportation vehicle) for mine with the centrifugal blower, variations in wind speed distribution in the discharge port of the centrifugal blower are reduced, and thermal dissipation (cooling performance) of a resistor is improved.SELECTED DRAWING: Figure 8

Description

TECHNICAL FIELD The present invention relates to a transportation vehicle such as a dump truck for mining, which uses an electric motor (hereinafter also referred to as an electric motor) as a traveling device, and includes a grid box that accommodates a resistor for electric brakes and cools the resistor with a blower.

BACKGROUND ART Patent Document 1, for example, discloses the following content as a dump truck equipped with an electrically driven traveling device that uses an electric motor as a drive source. Dump trucks are used, for example, to transport a large amount of ore and earth and sand at a mining site of a mine using an open pit mining method or the like.

A dump truck equipped with an electrically driven traveling device drives a generator with the shaft output of the engine, and the electric power generated by the generator (generated power) excites an electric motor via a control device such as an inverter. It drives the tires, which are the wheels. For example, the electric motors are mounted near the inner sides of the left and right rear tires in order to drive the rear tires, which are driving wheels (also called running wheels) of a dump truck. Together with the speed reducer, it constitutes a traveling device.

In a dump truck using such an electric motor as a traveling device, an electric brake resistor is installed on the vehicle body. That is, the braking force is generated by discharging and consuming the regenerated electric power of the electric motor through the resistor.

When discharging to such a resistor, the temperature of the resistor increases due to the heat generated in the resistor. In order to prevent the temperature rise of the resistor, the resistor is housed within the housing frame of the grid box, and a blower is installed on one end side of the grid box. By operating the blower, the resistor is cooled by blowing air. Such a device is installed on the vehicle body.

JP 2015-223927 A

Dump trucks such as those described above tend to increase in loading weight and vehicle weight in order to improve transportation efficiency. As the weight of cargo and vehicles increases, the amount of electric power generated during braking of dump trucks increases. The grid box needs to have a higher output as the size of the vehicle increases. On the other hand, the grid box mounting space on the deck is limited. Therefore, it is difficult to significantly increase the size of the grid box. Therefore, the grid box is required to have a high output and a small size.

Resistors must be densely arranged in order to achieve high output miniaturization of the grid box. High-density arrangement of resistors leads to increased pressure loss during forced air cooling by a blower. Therefore, a high-pressure centrifugal blower equipped with a centrifugal impeller and a scroll casing forming a spiral flow path is generally used as a blower for generating cooling air. The air flow at the discharge port of a high-pressure centrifugal blower (hereinafter also referred to as a centrifugal blower) tends to be complicated, and the velocity distribution may be biased. If the biased velocity distribution flows into the resistor without being rectified, the temperature of the resistor may become uneven. If the local maximum temperature of the temperature unevenness exceeds the allowable temperature value of the resistor material, the resistor may be damaged or broken down, leading to a problem of reduced productivity at the mining site.

The grid box of the dump truck described in Patent Document 1 has a blower on one end side of an air passage (hereinafter also referred to as a cooling air passage) provided in the housing frame, and a resistor is arranged and installed on the downstream side. This structure is used as one grid box, and a plurality of grid boxes are arranged according to the output of the dump truck. These grid boxes are installed in a state in which multiple bases are stacked in the height direction due to restrictions on the installation area on the vehicle body deck. This installation method increases the height dimension of the entire grid box. In addition, in this installation method, it is expected that the height of the entire grid box will increase as the output of the dump truck increases. On the other hand, there is a driver's seat (also referred to as a cabin) of the dump truck on the opposite side of the deck from where the grid box is installed. If the height of the grid box is increased, there is a concern that visibility of surroundings from the driver's seat will be deteriorated.

In addition, by stacking the grid boxes in the height direction, for example, if the grid box located in the lowest stage fails for some reason, the grid box in the upper stage that is operating normally is temporarily removed and replaced with another grid box. After storing it in a place, it becomes a procedure to perform repair work, and there is a concern that maintainability will deteriorate.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and its object is to realize a high-power miniaturization of the grid box without deteriorating the heat dissipation (cooling) of the resistor, and to To provide a transport vehicle capable of suppressing deterioration of visibility and maintainability of a dump truck that may occur due to miniaturization and high output of a dump truck.

In order to solve the above problems, a transportation vehicle according to the present invention includes an engine, a generator driven by the engine, a deck, and a deck installed on the deck, and discharges power generated by the generator when braking the vehicle body. A resistor for an electric brake that allows the cooling air to flow from the centrifugal blower, a centrifugal blower that sends cooling air to the resistor, a discharge port of the centrifugal blower and an inlet of a cooling air passage where the resistor is arranged are connected. and a grid box containing a duct for introducing the cooling air into the resistor of the air passage, wherein the exhaust port of the grid box for discharging the cooling air to the outside air is connected to the deck. The outlet of the centrifugal blower is opened toward the side opposite to the installation side of the other device so as not to blow into the other device installed above, and the outlet of the centrifugal blower is the lower end of the centrifugal impeller of the centrifugal blower. , and the outlet of the centrifugal blower and the inlet of the cooling air passage are arranged to face each other while being offset in the width direction of the passage. The duct connecting to the inlet has a shape that is inclined in the width direction of the flow path, and is provided along the width direction of the flow path from the discharge port of the duct to the inlet to direct the cooling air to the height of the flow path. A first straightening vane for straightening in the vertical direction and a second straightening vane for straightening the cooling air in the width direction of the flow passage are arranged so as to intersect with each other, and The starting end of the first straightening plate is located below a position corresponding to the lower end of the centrifugal impeller of the centrifugal blower in the flow path height direction of the discharge port, and the terminal end of the first straightening plate is Positioned above the center position of the inlet in the flow channel height direction, the terminal end of the second current plate is located at the center position of the flow channel width direction of the inlet or above it in the flow channel width direction of the discharge port. It is characterized in that it is located on the side opposite to the center position side of the

According to the present invention, it is possible to suppress the generation of local high-temperature parts of the resistor, realize a high-power miniaturization of the grid box without deteriorating the heat dissipation (cooling) of the resistor, and at the same time, reduce the size and height of the grid box. It is possible to prevent deterioration of the visibility and maintainability of the dump truck that may occur due to increased output.

Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

1 is an external view (side view) showing a schematic configuration of a dump truck (transportation vehicle) according to the present invention; FIG. FIG. 2 is an external view (perspective view) showing a part of the dump truck (transportation vehicle) shown in FIG. 1 ; FIG. 4 is a diagram showing the main configuration of the grid box and the flow direction of the cooling air; FIG. 4 is a view showing the cross section AA shown in FIG. 3 and the flow direction of the cooling air; FIG. 4 is a diagram showing an example of the main configuration of the grid box and the wind speed distribution of the cooling air; A diagram showing an example of the cross-section taken along line BB shown in FIG. 5 and the wind speed distribution of the cooling air. FIG. 4 is a diagram showing the main configuration of the grid box and the flow direction of the cooling air according to the first embodiment; FIG. 8 is a view showing the cross section along line CC shown in FIG. 7 and the flow direction of the cooling air; FIG. 4 is a diagram showing in detail the main configuration of the grid box and the flow direction of the cooling air according to the first embodiment; FIG. 8 is a diagram showing in detail the CC cross section arrow view shown in FIG. 7 and the flow direction of cooling air; FIG. 8 is a view showing the cross-sectional configuration of the main parts of the grid box and the flow direction of the cooling air according to the second embodiment; FIG. 8 is a diagram showing in detail the cross-sectional configuration of the main parts of the grid box and the flow direction of the cooling air according to the second embodiment; FIG. 10 is a view showing the cross-sectional configuration of the main parts of the grid box and the flow direction of the cooling air according to the third embodiment; The figure which looked at an example of the current plate which concerns on Example 3 from the discharge port of the centrifugal blower. The figure which looked at the other example of the current plate which concerns on Example 3 from the discharge port of the centrifugal blower. FIG. 11 is a view of still another example of the rectifying plate according to the third embodiment, viewed from the discharge port of the centrifugal blower;

An embodiment of the present invention will be described below with reference to the drawings and the like. The following description provides specific examples of the subject matter of the present invention. However, the present invention is not limited to these descriptions, and various changes and modifications can be made by those skilled in the art within the scope of the technical ideas disclosed in this specification. In addition, in all the drawings for explaining the present invention, parts having the same functions are denoted by the same reference numerals, and repeated explanations thereof may be omitted.

In this specification, a mining dump truck will be described as an example. A mine dump truck is, for example, a dump truck used for transporting a large amount of ore, earth and sand, etc. at a mining site of a mine by an open pit mining method or the like. The present invention also targets dump trucks other than mining dump trucks. In addition, electric drive vehicles other than dump trucks are also covered.

[Example 1]
<Description of the entire dump truck>
The entire dump truck will be described with reference to FIGS. 1 and 2. FIG. 1 and 2 are external views showing a schematic configuration of an electrically driven dump truck according to the present invention, where FIG. 1 is a side view and FIG. 2 is a perspective view. FIG. 2 omits a loading platform for loading materials such as ore and sand.

Dump truck 1000 has a vehicle body frame 410 extending in the longitudinal direction. Front wheels (steering wheels) 510 are mounted on the left and right sides of the front portion of the vehicle body frame 410 to enable the dump truck 1000 to be steered in the left and right direction. Front wheel 510 includes rubber tire 511 and tire wheel 512 assembled inside the tire, and supports the front portion of vehicle body frame 410 . At the rear portion of body frame 410, two rear wheels (driving wheels), a rear outer wheel 520 and a rear inner wheel, are arranged on both left and right sides in parallel in the vehicle width direction to enable forward and backward movement of dump truck 1000. 530 is installed. A rear outer wheel 520 and a rear inner wheel 530 are respectively composed of rubber tires 521 and 531 mounted on a tire wheel 522 and support the rear part of the vehicle body frame 410 .

A loading platform 420 for loading objects such as ore and earth and sand is mounted above the center to rear portion of the vehicle body frame 410 . The rear part of the loading platform 420 is rotatably supported by the body frame 410 through a connecting portion (not shown), and hydraulic cylinder devices ( (not shown) are connected, and by the expansion and contraction of the hydraulic cylinder device, the cargo bed 420 is driven to rise and fall with the connecting portion at the rear of the cargo bed 420 as a fulcrum.

An electric drive power unit for driving the dump truck 1000 is mounted on the front portion of the dump truck 1000 . The main devices that make up this power unit are an engine 330 for power generation, a generator 320 connected to the output shaft of the engine 330, and control devices such as an inverter (not shown). Of these, engine 330 and generator 320 are assembled to the front portion of vehicle body frame 410 . In addition, the control equipment is installed inside the cabinet 310 installed on either side of the front deck 430 in the left or right direction on the front portion of the body frame 410, which is assembled above the body frame 410. Installed with a heat sink (not shown). On one side of the front deck 430 in the left-right direction, on the side where the cabinet 310 is not installed, various devices necessary for driving the dump truck 1000 (steering wheel, accelerator pedal, brake pedal, body operation unit, instrument panel, etc.) , an operator seat, etc.) is provided. A grid box 1001 is provided on the opposite side of the cabin 440 with the cabinet 310 interposed therebetween. The grid box 1001 is generally composed of a resistor, a housing frame and a duct containing the resistor, and a centrifugal blower. The cooling air generated by the centrifugal blower is blown toward the resistors, and the cooling air used for heat dissipation is discharged from the exhaust port 1001a of the grid box 1001 to the outside air after cooling. The exhaust port 1001a is provided on the right side of the vehicle body so as to open toward the opposite side of the cabinet 310 and the cabin 440 installed on the front deck 430, and exhausts the hot air into the cabinet 310 and the cabin 440. avoid

An electric motor (also called a traveling motor) (not shown) that constitutes a traveling device is installed near the inside of the left and right rear tires of the dump truck 1000 together with a speed reducer (not shown) mounted on the inside of the rear tire wheel. ) are installed respectively. The dump truck 1000 equipped with an electrically driven traveling device using such an electric motor as a drive source drives the generator 320 with the shaft output of the engine 330, and the power generated by the generator 320 (generated power) An electric motor is excited via a control device such as an inverter to drive rear wheels 521 and 531, which are driving wheels (running wheels).

Dump truck 1000 using such an electric motor as a traveling device accommodates an electric brake resistor in the housing frame of grid box 1001 installed on front deck 430, and regenerates electric power from the electric motor. By discharging and consuming with a resistor (discharging the power generated by the generator 320 when braking the vehicle body, or converting the electricity generated by the generator 320 when braking the vehicle body into heat and exhausting the heat), the braking force is increased. generate. In order to prevent the temperature of the resistor from rising due to the heat generated by the resistor when discharging to such a resistor, the centrifugal blower installed at one end of the grid box 1001 is driven to generate the Cooling air is sent to the resistor to cool it.

<Explanation of grid box>
The basic structure of the grid box will be described with reference to FIGS. 3 and 4. FIG. FIG. 3 shows a plan view of the main configuration of the grid box. FIG. 4 shows a cross-sectional configuration diagram of the main part along the line AA in FIG. Note that FIG. 3 shows a cross section of a housing frame (resistor unit) portion (the same applies to FIGS. 5 and 7 below).

The grid box 1001 includes a centrifugal blower 3001, a double-axis motor 3002 for driving it, a resistor 3003, a resistor unit 3004 consisting of a frame for fixing the resistor 3003, and a resistor unit 3004 (resistor 3003), an insulating member 4001 for electrically insulating and fixing the resistor unit 3004 and the housing frame 3005, and the resistor unit Cooling air passage 3006 formed by arranging 3004 in series (or in parallel), and duct 3007 connecting outlet 3001a of centrifugal blower 3001 and inlet 3006a of cooling air passage 3006 are provided. The same grid boxes are arranged symmetrically with respect to the motors 3002 (symmetrically with respect to a plane passing through the center of the motors 3002 and perpendicular to the axial direction).

Specifically, the centrifugal blowers 3001 are installed on both front and rear sides of the left portion of the grid box 1001 (near the center of the vehicle body). A double-shaft motor 3002 is installed, in which a rotating shaft for driving protrudes back and forth (toward the front-rear direction). A rectangular housing frame 3005 is installed on the right side of the grid box 1001 (closer to the side of the vehicle body). They are arranged side by side (as a pair) in front and behind. Approximately in the center of each resistor unit 3004 in the front-rear direction, there is a cooling air passage 3006 for blowing cooling air to the resistor 3003. is formed toward the opposite side and downstream). The left and right portions of each resistor unit 3004 constitute the inlet 3006a and outlet 3006b of the cooling air passage 3006, respectively. A cooling air passage 3006 of each resistor unit 3004 has a plurality of (eight in the illustrated example) resistors 3003 arranged in the horizontal direction and fixed. The insulating member 4001 electrically insulates between the lower portion of each resistor unit 3004 and the lower portion of the housing frame 3005 and fixes them.

A discharge port 3001a of each centrifugal blower 3001 opens from the bottom of the centrifugal blower 3001 toward the right side. Specifically, the discharge port 3001a of the centrifugal blower 3001 (which rotates around a rotation axis provided along the longitudinal direction) opens tangentially to the right from the lower end of the centrifugal impeller 5001 of the centrifugal blower 3001. there is On the other hand, the inlet 3006a of the cooling air passage 3006 of each resistor unit 3004 opens toward the left side (the side of the housing frame 3005 and the centrifugal blower 3001 arranged in the horizontal direction).

In the central part of the grid box 1001, on both front and rear sides, that is, between the front centrifugal blower 3001 and the front resistor unit 3004, and between the rear centrifugal blower 3001 and the rear resistor unit 3004, Duct 3007 is installed. In other words, a pair of ducts 3007 are arranged side by side in the front-rear direction at the central portion of the grid box 1001, like the centrifugal blower 3001 and the resistor unit 3004 (cooling air passage 3006). The front duct 3007 connects the discharge port 3001a of the front centrifugal blower 3001 and the inlet 3006a of the cooling air passage 3006 of the front resistor unit 3004, and flows the cooling air from the centrifugal blower 3001 to the resistor 3003 of the cooling air passage 3006. Let The rear duct 3007 connects the outlet 3001a of the rear centrifugal blower 3001 and the inlet 3006a of the cooling air passage 3006 of the rear resistor unit 3004, and cools from the centrifugal blower 3001 to the resistor 3003 of the cooling air passage 3006. let the wind in.

Here, the inlet 3006a of the cooling air passage 3006 of each resistor unit 3004 (arranged in the front-rear direction) is closer to the center in the front-rear direction than the discharge port 3001a of the centrifugal blower 3001 arranged in the front-rear direction (both shafts provided near the center of the motor 3002). In other words, the outlet 3001a of the centrifugal blower 3001 and the inlet 3006a of the cooling air passage 3006 face each other in the left-right direction and are offset in the front-rear direction (explained later). Further, the inlet 3006a of the cooling air passage 3006 is set to have a larger opening area (here, corresponding to the dimension (width) in the front-rear direction) than the outlet 3001a of the centrifugal blower 3001 . Therefore, the duct 3007 connecting the discharge port 3001a of the centrifugal blower 3001 and the inlet 3006a of the cooling air passage 3006 has a central axis inclined in the front-rear direction with respect to the left-right direction, and the flow passage area (here, the dimension in the front-rear direction (width ) expands from upstream (outlet 3001a of centrifugal blower 3001 on the left) to downstream (inlet 3006a of cooling air passage 3006 on the right).

The outlet 3006b of the cooling air passage 3006 opens toward the right side (opposite to the side of the centrifugal blower 3001 arranged in the horizontal direction with the housing frame 3005), and constitutes the exhaust port 1001a of the grid box 1001. are doing.

With this configuration, the cooling air generated by the centrifugal blower 3001 driven by the dual-axis motor 3002 flows from the outlet 3001a provided at the bottom of the centrifugal blower 3001 through the duct 3007 (inclining in the front-rear direction with respect to the left-right direction). direction) passes through the cooling air passage 3006 from the inlet 3006a (horizontal direction) and is blown toward the resistor 3003. The air is discharged from the exhaust port 1001a of the grid box 1001 to the outside air (toward the right side of the vehicle body).

Resistors 3003 of each resistor unit 3004 arranged from upstream to downstream of cooling air passage 3006 are electrically connected via bus bar 3008 . In this embodiment, it is assumed that eight resistor units 3004 are connected in series.

When dissipating heat in grid box 1001, a high voltage (for example, several hundred volts) is applied between bus bar 3008a on the one end side of the first row and bus bar 3008b on the other end side of the eighth row. Therefore, an insulating spatial distance 3009 (hereinafter also referred to as an insulating distance) is provided between the resistor unit 3004 and the bus bar 3008 and the housing frame 3005 . If a sufficient insulation distance 3009 is provided while the grid box installation area is restricted, the center of the width direction (front-back direction) of the resistor unit 3004 (cooling air passage 3006) arranged side by side on the right side of the grid box 1001 The position and the center position in the width direction (front-rear direction) of the discharge ports 3001a of the centrifugal blowers 3001 arranged side by side on the left front and back of the grid box 1001 are offset. Therefore, (the central axis of) the duct 3007 connecting the outlet 3001a of the centrifugal blower 3001 and the inlet 3006a of the cooling air passage 3006 formed by the resistor unit 3004 and the housing frame 3005 is oblique in the width direction (front-rear direction). It becomes an inclined shape (Fig. 3). With the above structure, the centrifugal blower 3001 draws in air from the atmosphere, pressurizes (compresses) it, and then blows it through the obliquely inclined duct 3007 to the resistors 3003 in the first row. The air that has passed through the cooling air passage 3006 and is blown to the eighth row resistor 3003 to be cooled is discharged from the exhaust port 1001a that is the outlet 3006b provided in the housing frame 3005 .

<Description of cooling air flow inside the grid box>
The flow of cooling air inside the grid box will be described with reference to FIGS. 5 and 6. FIG. FIG. 5 is a plan view showing the main configuration of the grid box and the flow of cooling air. FIG. 6 is a diagram showing the cross-sectional configuration of the main part along the line BB in FIG. 5 and the flow of the cooling air. Here, the flow of cooling air inside the grid box will be described in the case where the straightening vane, which is a feature of the present invention, is not provided in the duct. Further, hereinafter, the longitudinal direction and the vertical direction of the vehicle body may be referred to as the flow channel width direction and the flow channel height direction of the duct, respectively.

Centrifugal blower 3001 pressurizes air sucked from the atmosphere by rotating centrifugal impeller 5001 (hereinafter also referred to as impeller) and blows the pressurized air (cooling air) toward resistor 3003 . On the way, in the obliquely inclined duct 3007, the flow passage area expands from upstream to downstream, and there is a partial sharply expanded shape in the width direction of the flow passage (enlarged portion 5002 offset from the discharge port 3001a). , the flow separates greatly at its enlarged portion 5002 . Separated downstream flows tend to be unstable and have reduced airflow. Furthermore, sufficient cooling air does not flow in a partial area 5003 of the resistor 3003 located downstream of the enlarged portion 5002 (FIG. 5).

The air pressurized by the rotation of the centrifugal impeller 5001 passes through the spiral flow path 6001 from the impeller outlet and is sent to the discharge port 3001a of the centrifugal blower 3001 while recovering the static pressure. In order to match the height dimension of the outlet 3001a of the centrifugal blower 3001 to the height of the resistor 3003 to be cooled, the height dimension of the outlet 3001a of the centrifugal blower 3001 is set at the lower side (peripheral side) of the outlet 3001a of the centrifugal blower 3001 in the flow path height direction. The air volume tends to be large, and the air volume tends to be small on the upper side (closer to the center). Furthermore, the downstream side of the discharge port 3001a is affected by this, and sufficient cooling air does not flow in a region 6002 of a part (upper portion) of the resistor 3003 (FIG. 6).

In the structure of the grid box 1001 for small size and high output, the wind speed distribution tends to be biased in the width direction and the height direction of the flow path in front of the resistor to be cooled.

That is, to outline the device configuration of the grid box 1001 assumed in this embodiment, two entire grid boxes are provided in order to secure visibility from the cabin (driver's seat) 440 of the dump truck 1000 and to improve maintainability of the grid box 1001. are arranged adjacent to each other in a plane without stacking them in the height direction. One centrifugal blower 3001 is provided for each unit (two units in total). A dual-axis motor 3002 is adopted as the motor for driving the centrifugal blower due to restrictions on the installation area.

A plurality of resistors 3003 are arranged in the cooling air passage 3006 in the grid box 1001 from the windward side to the leeward side, and electrically connected in series or parallel. A centrifugal blower 3001 is provided upstream of the resistor 3003 to generate high-pressure cooling air. The centrifugal blower 3001 has a centrifugal impeller 5001 and a scroll casing forming a spiral flow path 6001 on the outer peripheral side thereof. Also, between the air passage inlet of the grid box housing housing the resistor 3003 (inlet 3006a of the cooling air passage 3006) and the air passage outlet of the scroll casing (discharge port 3001a of the centrifugal blower 3001), each air passage A duct 3007 matching the cross-sectional shape is used for connection, and a cooling air passage is formed so that the resistor 3003 can be cooled.

Due to restrictions on the installation area, the housing frame 3005 of the grid box 1001, the duct 3007, the centrifugal blower 3001, and the double shaft motor 3002 are arranged at high density. Therefore, the shape of the duct partially expands rapidly from the scroll casing outlet (discharge port 3001a of the centrifugal blower 3001) toward the air passage inlet of the housing frame 3005 (the inlet 3006a of the cooling air passage 3006) (enlarged portion 5002). , and the wind speed distribution of the cooling air is biased in one direction. The bias in the wind speed distribution causes a decrease in heat dissipation (cooling) of resistor 3003 .

In this embodiment, the duct 3007 has a shape (enlarged portion 5002), but a shape that partially increases or a shape that increases gradually (stepwise) may be used.

Therefore, the present embodiment realizes a high-output miniaturization of the grid box 1001 without deteriorating the heat dissipation (cooling) of the resistor 3003, and at the same time, a cooling airflow that secures the visibility and maintainability of the dump truck 1000. The following structure is adopted as the road structure.

<Description of Current Plate Structure in Example 1 and Cooling Air Flow Inside Grid Box Adopting the Current Plate Structure>
The shape of the rectifying plate according to the first embodiment and the cooling air flow inside the grid box will be described with reference to FIGS. 7 and 8. FIG. FIG. 7 is a diagram (plan view) illustrating the main configuration of the grid box according to the first embodiment and the flow direction of the cooling air. FIG. 8 is a view (front view) showing the cross section along line CC shown in FIG. 7 and the flow direction of the cooling air.

In this embodiment, the duct 3007 is provided with a straightening vane to straighten the cooling air flowing into the resistor 3003 . A specific structure of the rectifying plate will be described below.

A first rectifying plate 801 and a second rectifying plate 802 are provided inside a duct 3007 that is obliquely inclined in the width direction of the flow path. The shape of each rectifying plate may be flat or moderately curved.

The installation positions of the first rectifying plate 801 and the second rectifying plate 802 will be described. First, in order to explain the position of the rectifying plate, each plane (line segment when viewed in plan view or front view) is drawn as follows.
A plane H is a plane passing through substantially the center of the height direction of the resistor 3003 (cooling air passage 3006) (FIG. 8),
A plane W is a line plane (FIG. 7) that passes through substantially the center of the width direction of the resistor 3003 (cooling air passage 3006),
Plane a is a plane that is almost parallel to plane H and touches the impeller outer diameter circle from near the center point in the height direction of the outlet of the centrifugal blower (discharge port 3001a) (FIG. 8),
A plane b is a plane drawn vertically downward from the tongue portion 803 of the centrifugal blower 3001, and corresponds to the discharge port 3001a defined by the area vertically below the tongue portion 803 (FIG. 8).
Plane c is a plane that is substantially parallel to plane W and passes through the vicinity of the center point in the width direction of tongue 803 of centrifugal blower 3001, and the plane that passes through the vicinity of the center point in the width direction of discharge port 3001a (FIG. 7). .

The first straightening plate 801 is composed of a plate-like member arranged in parallel (along the flow channel width direction) with the rotation axis of the centrifugal blower 3001 (double-shaft motor 3002) inside the duct 3007 (especially Figure 8).

The second current plate 802 is arranged inside the duct 3007 in parallel (along the flow path height direction) with the axis (vertical direction) perpendicular to the rotation axis of the centrifugal blower 3001 (double-shaft motor 3002). It is composed of a flat plate-shaped member that has been pressed (especially FIG. 7).

The first rectifying plate 801 and the second rectifying plate 802 are provided from the upstream end to the downstream end of the duct 3007 in the flow direction, that is, from the outlet 3001a of the centrifugal blower 3001 to the inlet 3006a of the cooling air passage 3006. 3007 are arranged so as to intersect.

A starting end 801a of the first rectifying plate 801 is positioned on the plane b (on the discharge port 3001a) and below the plane a in the height direction (FIG. 8).

A terminal end 801b of the first rectifying plate 801 is located downstream of the starting end 801a in the flow direction and above the plane H in the height direction (FIG. 8).

The starting end 802a of the second straightening plate 802 is positioned vertically below the tongue 803 (above the discharge port 3001a) and near the center in the width direction of the centrifugal blower outlet (discharge port 3001a of the centrifugal blower 3001). (Fig. 7).

A terminal end 802b of the second rectifying plate 802 is located downstream of the starting end 802a in the flow direction and closer to the double shaft motor 3002 than the plane W (FIG. 7).

Next, a method for determining the installation positions of the first rectifying plate 801 and the second rectifying plate 802 will be specifically described.

It can be said that the bias of the wind speed distribution at the inlet 3006a of the cooling air passage 3006 is determined by the inclination angle of the duct 3007 connected thereto and the wind speed distribution at the outlet 3001a of the centrifugal blower 3001. However, the bias of the wind speed distribution at the discharge port 3001a of the centrifugal blower 3001 varies depending on the shape of the impeller 5001 and the shape of the spiral flow path 6001 of the scroll casing. Therefore, in determining the installation positions of the first straightening vane 801 and the second straightening vane 802, it is necessary to first grasp the wind speed distribution. As a method of grasping, it is preferable to use a flow prediction result obtained by carrying out a fluid analysis on the centrifugal blower 3001 and the duct 3007 or an actual measurement result using an anemometer. In the case of fluid analysis, three-dimensional flow path shape analysis is performed. On the other hand, in the case of actual measurement, multiple measurement points are provided in the width direction and the height direction of the air passage so that the speed can be grasped respectively. The wind speed evaluation cross section should be the duct entrance (outlet 3001a of the centrifugal blower 3001) and the duct exit (inlet 3006a of the cooling air passage 3006). By doing so, it is possible to obtain a measure of rectification, such as how much wind speed distribution exists at the entrance of the duct 3007 and how much the flow is biased in the oblique flow path of the duct 3007 .

The installation positions of the first rectifying plate 801 and the second rectifying plate 802 described in the first embodiment will be specifically described with reference to FIGS. 9 and 10. FIG. FIG. 9 shows the wind speed distribution in the width direction (longitudinal direction) of the centrifugal blower 3001 and the inlet 3006a of the cooling air passage 3006 (in other words, at the inlet and the outlet of the duct 3007), and the second current plate. The positions of the beginning 802a and the end 802b of 802 are shown. FIG. 10 shows the wind speed distribution in the height direction (vertical direction) of the centrifugal blower 3001 and the inlet 3006a of the cooling air passage 3006 (in other words, at the inlet and outlet of the duct 3007), and the first rectification The positions of the start 801a and end 801b of the plate 801 are shown.

First, the first straightening plate 801 will be described (FIG. 10). Plane a and plane H in the figure are as described above. Additional plane a1 and plane H1 are added there. A plane that halves the distance m between the plane a (≈lower end surface of impeller 5001) and bottom surface 6001a of spiral flow path 6001 (≈lower end surface of outlet 3001a of centrifugal blower 3001 or inlet 3006a of cooling air passage 3006) draw a1. Plane H (≈ the center of the outlet 3001a of the centrifugal blower 3001 or the inlet 3006a of the cooling air passage 3006) and the upper wall surface 904 of the duct 3007 (≈ the upper end surface of the outlet 3001a of the centrifugal blower 3001 or the inlet 3006a of the cooling air passage 3006) Draw a plane H1 that bisects the distance n between The wind speed distribution 3007v3 in the height direction at the discharge port 3001a (the inlet of the duct 3007) of the centrifugal blower 3001 becomes faster in the region between the plane a and the bottom surface 6001a of the spiral flow path 6001, that is, in the region formed by the distance m, A bias is formed such that the speed is lower in the upper direction in the height direction. On the other hand, the wind speed distribution 3007v4 in the height direction at the inlet 3006a (exit of the duct 3007) of the cooling air passage 3006 has almost no effect of the inclination of the duct 3007 on the flow (wind speed distribution 3007v3) at the outlet 3001a of the centrifugal blower 3001. , little change from the wind speed distribution 3007v3.

In order to achieve rectification in such a wind speed distribution, the positions of the leading edge 801a and the trailing edge 801b of the first rectifying plate 801 in the height direction of the air passage are determined as follows. That is, the starting end 801a of the first current plate 801 is placed between the plane a1 and the bottom surface 6001a of the spiral flow path 6001. As shown in FIG. In other words, the starting end 801a of the first rectifying plate 801 is placed within a range of about 1/4 from the lower end of the discharge port 3001a of the centrifugal blower 3001 in the height direction. A terminal end 801b of the first current plate 801 is placed between the plane H and the plane H1. In other words, the end 801b of the first rectifying plate 801 is placed within a range of about 1/4 upward from the center position of the inlet 3006a of the cooling air passage 3006 in the height direction.

Next, the second current plate 802 will be described (FIG. 9). Plane c and plane W in the figure are as described above. The plane c divides the widthwise distance k of the outlet 3001a of the centrifugal blower 3001 into two. The plane W divides the widthwise distance L of the inlet 3006a of the cooling air passage 3006 into two. The widthwise wind speed distribution 3007v1 at the discharge port 3001a of the centrifugal blower 3001 has almost no deviation and is nearly uniform. On the other hand, the widthwise wind speed distribution 3007v2 at the inlet 3006a of the cooling air passage 3006 becomes faster on the left side of the plane W in the widthwise direction (the front side in the figure, the side that overlaps the outlet 3001a of the centrifugal blower 3001), The speed becomes lower on the right side (the rear side in the figure, the side offset from the outlet 3001a of the centrifugal blower 3001). The air flowing from the outlet 3001a of the centrifugal blower 3001 tries to flow along the (front) inclined surface of the duct 3007 while maintaining its inertial force, and stagnates on the opposite (rear) inclined surface 5004. is generated, the wind speed distribution 3007v2 as described above is formed.

In order to achieve rectification in such a wind velocity distribution, the positions of the starting end 802a and the terminating end 802b of the second rectifying plate 802 are determined as follows. That is, the starting end 802a of the second straightening plate 802 is placed near the plane c. In other words, the starting end 802a of the second rectifying plate 802 is placed near the widthwise central position of the outlet 3001a of the centrifugal blower 3001 (the line of intersection with the plane c at the outlet 3001a). The end 802b of the second straightening plate 802 is placed near the plane W. FIG. In other words, the terminal end 802b of the second baffle plate 802 is placed near the widthwise center position of the inlet 3006a of the cooling air passage 3006 (the line of intersection with the plane W at the inlet 3006a).

As shown in FIG. 8, the first rectifying plate 801 (the starting end 801a thereof) pushes a part of the air biased toward the lower side (peripheral side) of the discharge port 3001a of the centrifugal blower 3001, and moves up and down in the height direction. Distribute. The air distributed above the first rectifying plate 801 flows along the wall surface of the first rectifying plate 801 and is guided to the upper side of the resistor 3003 in the height direction (region 6002 side in FIG. 6). On the other hand, the air distributed to the lower side of the first straightening plate 801 is guided downward in the height direction of the resistor 3003 through the lower side of the first straightening plate 801 .

As shown in FIG. 7, the second current plate 802 pushes the cooling air discharged from the discharge port 3001a of the centrifugal blower 3001 and distributes it in the width direction. Since the second baffle plate 802 guides the cooling air to the rear side of the duct internal flow path (FIGS. 5 and 7), it is possible to suppress the separation flow at the locally enlarged portion 5002 shown in FIG.

As described above, in this embodiment, as the device configuration of the grid box 1001 assumed in this embodiment, the field of view from the cabin (driver's seat) 440 of the dump truck 1000 is secured and the maintainability of the grid box 1001 is improved. , The entire grid box is composed of two units, which are not stacked in the height direction and are arranged adjacent to each other in the plane. One centrifugal blower 3001 is provided for each unit (two units in total). A dual-axis motor 3002 is adopted as the motor for driving the centrifugal blower due to restrictions on the installation area.

A plurality of resistors 3003 are arranged in the cooling air passage 3006 in the grid box 1001 from the windward side to the leeward side, and electrically connected in series or parallel. A centrifugal blower 3001 is provided upstream of the resistor 3003 to generate high-pressure cooling air. The centrifugal blower 3001 has a centrifugal impeller 5001 and a scroll casing forming a spiral flow path 6001 on the outer peripheral side thereof. Also, between the air passage inlet of the grid box housing housing the resistor 3003 (inlet 3006a of the cooling air passage 3006) and the air passage outlet of the scroll casing (discharge port 3001a of the centrifugal blower 3001), each air passage A duct 3007 matching the cross-sectional shape is used for connection, and a cooling air passage is formed so that the resistor 3003 can be cooled.

Due to restrictions on the installation area, the housing frame 3005 of the grid box 1001, the duct 3007, the centrifugal blower 3001, and the double shaft motor 3002 are arranged at high density. Therefore, the shape of the duct partially expands rapidly from the scroll casing outlet (discharge port 3001a of the centrifugal blower 3001) toward the air passage inlet of the housing frame 3005 (the inlet 3006a of the cooling air passage 3006) (enlarged portion 5002). , and the wind speed distribution of the cooling air is biased in one direction. The bias in the wind speed distribution causes a decrease in heat dissipation (cooling) of resistor 3003 .

Therefore, the present embodiment realizes a high-output miniaturization of the grid box 1001 without deteriorating the heat dissipation (cooling) of the resistor 3003, and at the same time, a cooling airflow that secures the visibility and maintainability of the dump truck 1000. provide road structure.

That is, the duct 3007 connecting the outlet 3001a of the centrifugal blower 3001 and the air passage inlet of the housing frame 3005 (the inlet 3006a of the cooling air passage 3006) has a rapidly expanding passage shape due to the restriction of the installation area of the grid box 1001. , the wind speed distribution of the cooling air becomes uneven. Therefore, straightening vanes (the first straightening vane 801 and the second straightening vane 802) are installed in the duct 3007 to guide the uneven flow to bring it closer to a more uniform flow. Straightening plates (first A rectifying plate 801 and a second rectifying plate 802) are provided.

More specifically, this embodiment is an electrically driven mining dump truck equipped with a traveling motor, and a front deck 430 extending in the longitudinal direction and the lateral direction of the dump truck 1000 is provided at the front of the dump truck 1000. , On the front deck 430 are the cabin (driver's seat) 440 of the dump truck 1000, the cabinet 310 that controls the running of the vehicle body, and the grid box 1001 that converts the electricity generated when braking the vehicle body into heat and exhausts the heat. , a boarding route to the cabin (driver's seat) 440, a space for operating and maintaining the cabinet 310 and the grid box 1001, and the cooling air outlet (exhaust outlet 1001a) of the grid box 1001 is , the grid box 1001 has a plurality of resistor units 3004, a housing frame 3005 containing them, and the resistor units 3004. An insulating member 4001 for electrically insulating the housing frame 3005, an insulating space distance 3009 necessary for insulating the resistor unit 3004 and the housing frame 3005, a centrifugal blower 3001 for blowing air, and a duct. 3007, one centrifugal blower driving double-axis motor 3002, the resistor unit 3004, the housing frame 3005, the insulating member 4001, the insulating space distance 3009, the air blowing centrifugal blower 3001, A duct 3007 is arranged at a symmetrical position in the axial direction of the double shaft motor 3002 for driving the centrifugal blower.

Then, a plane H (FIG. 8, etc.) passing through approximately the center of the resistor 3003 in the height direction, a plane W (FIG. 7, etc.) passing through approximately the center of the width direction of the resistor 3003, and approximately parallel to the plane H, the centrifugal blower A plane a (e.g., FIG. 8) in contact with the outer diameter circle of the impeller from the vicinity of the center point in the height direction of the outlet (discharge port 3001a) is drawn vertically downward from the tongue portion 8003 of the centrifugal blower 3001 (corresponding to the discharge port 3001a). Plane b (FIG. 8, etc.) and plane c (FIG. 7, etc.) are drawn which are almost parallel to plane W and pass through the vicinity of the center point of the width direction of the tongue portion 8003 of the centrifugal blower 3001 (equivalent to the width direction of the discharge port 3001a). , a first straightening plate 801 and a second straightening plate 802 are provided at the outlet of the centrifugal blower, and the starting end 801a of the first straightening plate 801 is on the plane b (on the discharge port 3001a) and from the plane a is located below the height direction of the flow path, and the terminal end 801b of the first rectifying plate 801 is located downstream of the starting end 801a in the flow direction and above the plane H in the height direction (Fig. 8 , FIG. 10). In addition, the starting end 802a of the second straightening plate 802 is vertically below the tongue portion 803 (above the discharge port 3001a), and the terminal end 802b of the second straightening plate 802 is downstream of the starting end 802a in the flow direction. Moreover, it is located on the double shaft motor 3002 side of the plane W (FIGS. 7 and 9).

In other words, in this embodiment, the engine 330, the generator 320 driven by the engine 330, the deck 430, and the deck 430 installed on the deck 430 discharge the power generated by the generator 320 when braking the vehicle ( A resistor 3003 for an electric brake that converts the electricity generated by the generator 320 during vehicle braking into heat and exhausts the heat, a centrifugal blower 3001 that sends cooling air to the resistor 3003, and a discharge port of the centrifugal blower 3001 A grid accommodating a duct 3007 that connects 3001a and an inlet 3006a of a cooling air passage 3006 in which the resistor 3003 is arranged, and allows the cooling air to flow from the centrifugal blower 3001 to the resistor 3003 of the cooling air passage 3006. box 1001;

The exhaust port 1001a of the grid box 1001 for discharging the cooling air to the outside air is arranged so as not to blow into other devices (cabin 440, cabinet 310, etc.) installed on the deck 430. , and the outlet 3001a of the centrifugal blower 3001 is connected to the centrifugal blower 3001 (rotating around a rotation axis provided along the width direction of the flow path). The outlet 3001a of the centrifugal blower 3001 and the inlet 3006a of the cooling air passage 3006 face each other while being offset in the passage width direction ( The duct 3007 connecting the discharge port 3001a and the inlet 3006a has an oblique shape in the width direction of the flow path, and the discharge port 3001a of the duct 3007 extends from the inlet 3001a. 3006a, a first rectifying plate 801 is provided along the width direction of the flow path to straighten the cooling air in the height direction of the flow path, and a flow path is provided along the height direction of the cooling air to flow the cooling air. It is arranged so as to intersect with the second straightening plate 802 that straightens in the width direction.

The starting end 801a of the first rectifying plate 801 is below the position (line of intersection with the plane a) corresponding to the lower end of the centrifugal impeller 5001 of the centrifugal blower 3001 in the flow path height direction of the discharge port 3001a. (Figs. 8 and 10). More preferably, the starting end 801a of the first straightening plate 801 is located within a range of about 1/4 from the lower end of the discharge port 3001a in the flow channel height direction (FIG. 10). The terminal end 801b of the first rectifying plate 801 is located above the center position of the inlet 3006a in the flow channel height direction (the line of intersection with the plane H) (FIGS. 8 and 10). More preferably, the terminal end 801b of the first rectifying plate 801 is positioned within a range of about 1/4 upward from the center position in the height direction of the inlet 3006a (FIG. 10).

The starting end 802a of the second rectifying plate 802 is located near the center position (line of intersection with the plane c) of the discharge port 3001a in the width direction of the flow path (FIGS. 7 and 9). The terminal end 802b of the second rectifying plate 802 is located at the center position of the inlet 3006a in the flow channel width direction (the line of intersection with the plane W) or the center position of the discharge port 3001a in the flow channel width direction (the plane c line of intersection with ) (Figs. 7 and 9).

In addition, the inlet 3006a of the cooling air passage has a dimension (width) in the width direction of the passage larger than the outlet 3001a of the centrifugal blower 3001, and the duct 3007 is located upstream (the outlet 3001a of the centrifugal blower 3001). ) to the downstream side (inlet 3006a of the cooling air passage 3006), it has a shape (enlarged portion 5002) that becomes larger wholly or partially (and continuously or stepwise).

In addition, the centrifugal blower 3001, the cooling air passage 3006 in which the resistor 3003 is arranged, and the duct 3007 are arranged in a pair in the width direction of the passage, and the pair of centrifugal blowers 3001 are driven at the same time. A single dual-axis motor 3002 is provided for driving.

In addition, the centrifugal blower 3001, the cooling air passage 3006 in which the resistor 3003 is arranged, and the duct 3007 are arranged at symmetrical positions in the axial direction of the dual shaft motor 3002. As shown in FIG.

In addition, the grid box 1001 has a housing frame 3005 that encloses the resistor 3003, and a space between the resistor 3003 and the housing frame 3005 is provided between the resistor 3003 and the housing frame 3005. An insulating member 4001 or an insulating clearance 3009 is provided for electrical isolation between them.

According to the present embodiment, it is possible to suppress the generation of local high temperature parts of the resistor 3003, to realize high output miniaturization of the grid box 1001 without deteriorating the heat dissipation (cooling) of the resistor 3003, and to realize the grid box 1001 It is possible to prevent the visibility and maintainability of the dump truck 1000 from deteriorating as the box 1001 becomes smaller and more powerful.

[Example 2]
<Description of Current Plate Structure in Embodiment 2 and Cooling Air Flow Inside Grid Box Adopting the Current Plate Structure>
The shape of the rectifying plate according to the second embodiment and the flow of cooling air inside the grid box will be described with reference to FIG. 11 . FIG. 11 is a diagram (front view) showing the cross-sectional configuration of the main part of the grid box and the flow direction of the cooling air according to the second embodiment.

In the second embodiment, a straightening vane is provided in the duct 3007 to straighten the cooling air flowing into the resistor 3003 as in the first embodiment. A specific structure of the rectifying plate will be described below.

The second straightening plate 802 for straightening in the width direction of the flow path is the same as in the first embodiment. Only the rectifying plate structure provided for rectifying in the flow channel height direction will be described. In this embodiment, a structure in which two rectifying plates are provided for rectifying in the flow channel height direction will be described, but the number of rectifying plates is of course not limited to two.

The installation positions of the third flow straightening vane 901 and the fourth straightening vane 902 for straightening the cooling air in the flow path height direction will be described. Each plane for explaining the position of each current plate is the same as that described in the first embodiment.

Both the third rectifying plate 901 and the fourth rectifying plate 902 are flat plates arranged inside the duct 3007 parallel to the rotational axis of the centrifugal blower 3001 (double-shaft motor 3002) (along the flow channel width direction). It consists of a shaped member.

The third straightening plate 901 and the fourth straightening plate 902 are provided from the upstream end to the downstream end of the duct 3007 in the flow direction, that is, from the outlet 3001a of the centrifugal blower 3001 to the inlet 3006a of the cooling air passage 3006. Inside 3007, the third straightening vane 901 is located on the lower side and the fourth straightening vane 902 is located on the upper side so as to intersect the second straightening vane 802 .

The starting end 901a of the third straightening plate 901 is located on the plane b (on the discharge port 3001a) and below the plane a in the height direction.

The terminal end 901b of the third rectifying plate 901 is positioned above the starting end 901a, downstream of the starting end 901a in the flow direction, and below the plane H in the height direction.

A starting end 902a of the fourth rectifying plate 902 is located on the plane b (on the discharge port 3001a) and below the plane a in the height direction.

The terminal end 902b of the fourth rectifying plate 902 is located above the starting end 902a, downstream of the starting end 902a in the flow direction, and above the plane H in the height direction.

That is, the fourth rectifying plate 902 described in the second embodiment corresponds to the first rectifying plate 801 described in the first embodiment.

The height direction distance h1 between the bottom wall surface 903 of the duct 3007 (≈the lower end surface of the discharge port 3001a of the centrifugal blower 3001 or the inlet 3006a of the cooling air passage 3006) and the starting end 901a of the third straightening plate 901, and the third straightening The distance h2 in the height direction between the starting end 901a of the plate 901 and the starting end 902a of the fourth straightening plate 902, the starting end 902a of the fourth straightening plate 902 and the upper wall surface 904 of the duct 3007 (≈ the discharge port 3001a of the centrifugal blower 3001 to In the height direction distance h3 from the upper end surface of the inlet 3006a of the cooling air passage 3006, the distance dimensions of h1, h2, and h3 are unequal intervals (h1<h2<h3 in the illustrated example).

The installation positions of the third rectifying plate 901 and the fourth rectifying plate 902 described in the second embodiment will be specifically described with reference to FIG. FIG. 12 shows the wind speed distribution in the height direction (vertical direction) of the centrifugal blower 3001 and the inlet 3006a of the cooling air passage 3006 (in other words, at the inlet and outlet of the duct 3007), and the third rectification The positions of the start 901a and end 901b of the plate 901 and the start 902a and end 902b of the fourth current plate 902 are shown.

Plane a and plane H in the figure are as described above. Additional planes a2, a3 and planes H2, H3 are appended there. A plane that divides the distance p between the plane a (≈lower end surface of the impeller 5001) and the bottom surface 6001a of the spiral flow path 6001 (≈lower end surface of the outlet 3001a of the centrifugal blower 3001 or the inlet 3006a of the cooling air passage 3006) into three equal parts Draw a2, plane a3. A plane H2 and a plane H3 that divide the height direction distance q of the inlet 3006a of the cooling air passage 3006 into three are drawn. The explanation of the wind speed distributions 3007v5 and 3007v6 at the outlet 3001a (entrance of the duct 3007) of the centrifugal blower 3001 and the inlet 3006a (exit of the duct 3007) of the cooling air passage 3006 is the same as the distribution explained in FIG. omitted.

In order to achieve further rectification in the presence of such a wind speed distribution, the height of the air passages of the start end 901a and the end 901b of the third straightening plate 901 and the start end 902a and the end 902b of the fourth straightening plate 902 are Determine the position of the direction as follows. That is, the starting end 901a of the third straightening plate 901 is positioned near the surface of the plane a3, or between the plane a3 and the bottom surface 6001a of the spiral flow path 6001 (and below the starting end 902a of the fourth straightening plate 902). put. The terminal end 901b of the third current plate 901 is placed near the surface of the plane H3 (and below the terminal end 902b of the fourth current plate 902). Also, the starting end 902a of the fourth straightening plate 902 is placed near the surface of the plane a2 or between the planes a2 and a3 (and above the starting end 901a of the third straightening plate 901). The terminal end 902b of the fourth straightening plate 902 is placed near the surface of the plane H2 (and above the terminal end 901b of the third straightening plate 901).

Next, the flow of cooling air will be described. As shown in FIG. 11, the starting ends (901a, 902a) of the third rectifying plate 901 and the fourth rectifying plate 902 push through the flow biased downward (outer peripheral side) at the discharge port 3001a of the centrifugal blower 3001. , distributing the cooling air. The distributed cooling air flows downstream along the wall surfaces of the third rectifying plate 901 and the fourth rectifying plate 902, and flows into the resistor 3003 in a more uniform state.

The second embodiment is considered to have a higher rectifying effect than the first embodiment.

As described above, in this embodiment, the plane H (FIG. 8) passing through substantially the center of the resistor 3003 in the height direction, the plane W (FIG. 7 etc.) passing through substantially the center of the resistor 3003 in the width direction, A plane a (Fig. 8, etc.) that is almost parallel to the plane H and touches the impeller outer diameter circle from near the center point in the height direction of the centrifugal blower outlet (discharge port 3001a), pulls vertically downward from the tongue 8003 of the centrifugal blower 3001 Plane b (equivalent to discharge port 3001a) (FIG. 8, etc.) is substantially parallel to plane W and passes through the vicinity of the center point of the width direction of tongue 8003 of centrifugal blower 3001 (corresponding to the width direction of discharge port 3001a). A plane c (FIG. 7, etc.) is drawn, and a third rectifying plate 901 and a fourth rectifying plate 902 are provided. , is located below the plane a in the height direction, and the terminal end 901b of the third current plate 901 is above the starting end 901a, downstream of the starting end 901a in the flow direction, and higher than the plane H direction below (Fig. 11). In addition, the starting end 902a of the fourth straightening plate 902 is located on the plane b (on the discharge port 3001a) and below the plane a in the height direction, and the terminal end 902b of the fourth straightening plate 902 is , above the starting end 902a, downstream of the starting end 902a in the flow direction, and above the plane H in the height direction (FIG. 11).

In other words, the third rectifying plate 901 is provided along the flow path width direction from the discharge port 3001a to the inlet 3006a of the duct 3007 to rectify the cooling air in the flow path height direction. The starting end 901a of the third straightening plate 901 is located at the height direction of the flow path of the discharge port 3001a of the first straightening plate 801. It is located below the starting end 801a (the starting end 902a of the fourth current plate 902) (Fig. 11). The terminal end 901b of the third rectifying plate 901 is lower than the center position of the inlet 3006a in the flow channel height direction (the line of intersection with the plane H) and corresponds to the starting end 901a of the third rectifying plate 901. 11).

Also, the distance in the flow path height direction between the lower end of the discharge port 3001a and the starting end 901a of the third straightening plate 901 is h1, the starting end 901a of the third straightening plate 901 and the starting end of the first straightening plate 801 are 801a (starting edge 902a of the fourth flow straightening plate 902) is h2, the distance between the flow path height direction is h2, The distances h1, h2, and h3 are unequal, with h3 being the distance in the flow channel height direction from the upper end (Fig. 11).

Also preferably, h1<h2<h3 (FIG. 11).

Also, the distance in the flow path height direction between the lower end of the inlet 3006a and the terminal end 901b of the third straightening plate 901 is h4, the terminal end 901b of the third straightening plate 901 and the terminal end 801b of the first straightening plate 801 are h4. (the terminal end 902b of the fourth straightening plate 902) is h5, and the distance between the terminal end 801b of the first straightening plate 801 (the terminal end 902b of the fourth straightening plate 902) and the upper end of the inlet 3006a is Assuming that the distance in the height direction of the flow path is h6, the distance dimensions of h4, h5, and h6 are equidistant (q/3) (Fig. 12).

According to this embodiment, as in the first embodiment, the generation of local high temperature parts of the resistor 3003 is suppressed, and the heat radiation (cooling performance) of the resistor 3003 is suppressed. In addition, it is possible to prevent deterioration of the visibility and maintainability of the dump truck 1000 that may occur due to the miniaturization and high output of the grid box 1001 .

[Example 3]
<Description of Current Plate Structure in Example 3 and Cooling Air Flow Inside Grid Box Adopting the Current Plate Structure>
13, 14, 15, and 16, the current plate shape and the flow of cooling air inside the grid box according to the third embodiment will be described. FIG. 13 is a diagram (front view) showing the cross-sectional configuration of the main parts of the grid box and the flow direction of the cooling air according to the third embodiment.

14, 15 and 16 are views of the current plate according to the third embodiment, viewed from the discharge port 3001a of the centrifugal blower 3001 toward the inlet 3006a of the cooling air passage 3006. FIG. Figures 14, 15 and 16 are used to show the difference in communication holes.

In the third embodiment, a rectifying plate 1010 is provided in the duct 3007 to rectify the cooling air flowing into the resistor 3003 as in the first and second embodiments. A specific structure of the rectifying plate will be described below.

The second straightening plate 802 for straightening in the width direction of the flow path is the same as in the first and second embodiments. Only the rectifying plate structure provided for rectifying in the flow channel height direction will be described. In this embodiment, the structure of the rectifying plate that rectifies in the height direction of the flow path will be described, but it is a matter of course that the same structure (communication hole) can be applied to the rectifying plate that rectifies in the width direction of the flow path.

From the upstream end to the downstream end of the duct 3007 in the flow direction, that is, from the discharge port 3001a of the centrifugal blower 3001 to the inlet 3006a of the cooling air passage 3006, and inside the duct 3007 so as to intersect the second straightening plate 802. , a fifth current plate 1010 is provided.

The starting end 1010a of the fifth rectifying plate 1010 is located on the plane b (on the discharge port 3001a) and below the plane a in the height direction.

The terminal end 1010b of the fifth rectifying plate 1010 is located downstream of the starting end 1010a in the flow direction and above the plane H in the height direction.

That is, the fifth rectifying plate 1010 described in the third embodiment corresponds to the first rectifying plate 801 described in the first embodiment.

At least one, preferably a plurality of communication holes are provided in a portion of the fifth straightening plate 1010 . In the present Example 3, the case where two communication holes (1011, 1012) are opened will be described as an example (FIG. 13). The communication hole is perforated so as to communicate the upstream side wall surface 1013 of the fifth current plate 1010 (the wall surface on the side of the discharge port 3001a of the centrifugal blower 3001) and the downstream side wall surface 1014 (the wall surface on the side of the inlet 3006a of the cooling air passage 3006). do.

The rectifying plate distributed in the flow channel height direction, for example, the terminal end 801b of the first rectifying plate 801 is above the plane H in the flow channel height direction, and the higher position extends to the upper part of the resistor 3003. Cooling air can be distributed. However, the installation angle with respect to the flow becomes large, and there is a possibility that the flow will stagnate on the downstream side wall surface of the current plate.

Therefore, by piercing the communication holes (1011, 1012) like the fifth straightening plate 1010, part of the flow guided upward by the fifth straightening plate 1010 passes through the communication holes (1011, 1012) to the fifth flow. from the upstream side wall surface 1013 of the current plate 1010 to the downstream side wall surface 1014. By doing so, the stagnation described above can be suppressed, and the wind speed distribution in the flow path height direction of the cooling air flowing into the resistor 3003 can be made nearly uniform.

The shape of the communication holes (1011, 1012) provided in the fifth straightening plate 1010 may be circular, rectangular, slit-like, etc., as long as it can bypass part of the flow. However, when a plurality of communication holes are provided, it is more effective to provide them so that the cross-sectional area of the air duct increases toward the downstream side when viewed from the centrifugal blower 3001 side, regardless of the hole shape. be. The form is shown in FIG. For example, in the communication hole shown in FIG. 14, the air passage cross-sectional area (S1) of the communication hole 1012 positioned on the upper downstream side is larger than that of the communication hole 1011 positioned on the lower upstream side (S2 ). Alternatively, the air passage cross-sectional area for each communication hole may be made equal, and the overall air passage cross-sectional area may be adjusted by the number of installations. The form is shown in FIG. A plurality of communication holes 1012 located on the upper downstream side and communication holes 1011 located on the lower upstream side are provided in the width direction and the height direction respectively, and the number of the communication holes 1012 is provided more than the number of the communication holes 1011. By adjusting the air passage cross-sectional area (S1, S2), the same effect can be obtained even if the bypass air volume is adjusted by the communication hole. Alternatively, the shape of one communication hole may be adjusted so that the size of the cross-sectional area of the air passage increases toward the downstream side when viewed from the centrifugal blower 3001 side. The form is shown in FIG. A similar effect can be obtained by adjusting the bypass air volume by means of the communication hole 1015 having a shape in which the cross-sectional area of the air passage (corresponding to the dimension in the width direction in the illustrated example) increases from the upstream side to the downstream side.

As described above, in this embodiment, the plane H (FIG. 8) passing through substantially the center of the resistor 3003 in the height direction, the plane W (FIG. 7 etc.) passing through substantially the center of the resistor 3003 in the width direction, A plane a (Fig. 8, etc.) that is almost parallel to the plane H and touches the impeller outer diameter circle from near the center point in the height direction of the centrifugal blower outlet (discharge port 3001a), pulls vertically downward from the tongue 8003 of the centrifugal blower 3001 Plane b (equivalent to discharge port 3001a) (FIG. 8, etc.) is substantially parallel to plane W and passes through the vicinity of the center point of the width direction of tongue 8003 of centrifugal blower 3001 (corresponding to the width direction of discharge port 3001a). A plane c (FIG. 7, etc.) is drawn and a fifth straightening plate 1010 is provided. Positioned below in the height direction, the terminal end 1010b of the fifth rectifying plate 1010 is positioned downstream of the starting end 1010a in the flow direction and above the plane H in the height direction. At least one or a plurality of communication holes (1011, 1012) are provided in a part of the fifth straightening plate 1010 so as to communicate the upstream side wall surface 1013 and the downstream side wall surface 1014 of the fifth straightening plate 1010 (Fig. 13).

In other words, the communication holes (1011, 1012) that communicate the upstream side wall surface 1013 and the downstream side wall surface 1014 of the first straightening plate 801 (fifth straightening plate 1010) are connected to the first straightening plate 801 (fifth straightening plate 1010). One or more of them are provided on a part of the rectifying plate 1010).

Further, the communication holes (1011, 1012) have an air passage cross-sectional area (flow passage area) that increases from the upstream side (discharge port 3001a of the centrifugal blower 3001) to the downstream side (the inlet 3006a of the cooling air passage 3006). .

Further, the cross-sectional area of the air passage of the communicating hole (1012) located downstream is larger than the cross-sectional area of the air passage of the communicating hole (1011) located upstream, or the communicating hole located downstream The number of (1012) is greater than the number of communication holes (1011) located on the upstream side.

Further, the communication hole (1015) has a shape in which the air passage cross-sectional area (flow passage area) increases from the upstream side (discharge port 3001a of the centrifugal blower 3001) to the downstream side (inlet 3006a of the cooling air passage 3006). have.

According to this embodiment, as in the first embodiment, the generation of local high temperature parts of the resistor 3003 is suppressed, and the heat radiation (cooling performance) of the resistor 3003 is suppressed. In addition, it is possible to prevent deterioration of the visibility and maintainability of the dump truck 1000 that may occur due to the miniaturization and high output of the grid box 1001 .

In addition, the present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the described configurations. Also, part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Moreover, it is possible to add, delete, or replace a part of the configuration of each embodiment with another configuration.

1000: Dump truck (transportation vehicle) for mining, 1001: Grid box, 1001a: Exhaust port, 3001: Centrifugal blower, 3001a: Discharge port of centrifugal blower, 3002: Double shaft motor, 3003: Resistor, 3004: Resistor Unit, 3005: Housing frame, 3006: Cooling air passage, 3006a: Cooling air passage inlet, 3006b: Cooling air passage outlet, 3007: Duct, 3008: Bus bar, 3009: Insulation space distance, 4001: Insulation member, 5001 : centrifugal impeller, 5002: expanded portion (locally expanded flow passage portion), 5003, 6002: region where cooling air is difficult to flow, 6001: spiral flow passage, 801: first rectifying plate, 801a, 802a, 901a , 902a, 1010a: starting end of current plate, 801b, 802b, 901b, 902b, 1010b: end of current plate, 802: second current plate, 803: tongue, 901: third current plate, 902: fourth 903: Bottom wall surface of duct 904: Upper wall surface of duct 1010: Fifth straightening plate 1011, 1012, 1015: Communication hole 1013: Upstream side wall surface of straightening plate 1014: Downstream of straightening plate Side wall surface, 3007v1: Wind speed distribution in the width direction of the flow passage at the outlet of the centrifugal blower, 3007v2: Wind speed distribution in the width direction of the flow passage at the inlet of the cooling air passage, 3007v3, 3007v5: Height direction of the flow passage at the outlet of the centrifugal blower , 3007v4, 3007v6: Wind speed distribution in the height direction at the inlet of the cooling air passage

Claims (13)

engine and
a generator driven by the engine;
a deck;
An electric brake resistor installed on the deck for discharging power generated by the generator when braking the vehicle body, a centrifugal blower for sending cooling air to the resistor, a discharge port of the centrifugal blower and the resistor. a grid box that houses a duct that is connected to the inlet of the arranged cooling air passage and allows the cooling air to flow from the centrifugal blower to the resistor of the cooling air passage,
The exhaust port of the grid box for discharging the cooling air to the outside air is opened toward the side opposite to the installation side of the other equipment installed on the deck so as not to blow into the other equipment installed on the deck. cage,
The discharge port of the centrifugal blower opens in a tangential direction from the lower end of the centrifugal impeller of the centrifugal blower, and the discharge port of the centrifugal blower and the inlet of the cooling air passage are aligned in the width direction of the passage. and the duct that connects the outlet and the inlet has a shape that is obliquely inclined in the width direction of the flow path,
a first straightening plate provided along the width direction of the flow path from the discharge port to the inlet of the duct for straightening the cooling air in the height direction of the flow path; arranged so as to intersect with a second straightening plate for straightening the cooling air in the width direction of the flow path,
the starting end of the first rectifying plate is located below a position corresponding to the lower end of the centrifugal impeller of the centrifugal blower in the flow path height direction of the discharge port;
the terminal end of the first rectifying plate is located above the center position of the inlet in the flow channel height direction,
The terminal end of the second rectifying plate is positioned at the center position of the inlet in the width direction of the flow path or on the side opposite to the center position side of the discharge port in the width direction of the flow path. transport vehicle. A transport vehicle according to claim 1,
the inlet of the cooling air passage has a dimension in the width direction of the passage larger than the outlet of the centrifugal blower;
The transport vehicle, wherein the duct has a shape that becomes larger wholly or partially from the upstream side to the downstream side. A transport vehicle according to claim 1,
The centrifugal blower, the cooling air passage in which the resistor is arranged, and the duct are arranged in a pair in the width direction of the passage,
A transportation vehicle comprising a single dual shaft motor for simultaneously driving the pair of centrifugal blowers. A transport vehicle according to claim 3,
The transportation vehicle according to claim 1, wherein the centrifugal blower, the cooling air passage in which the resistor is arranged, and the duct are arranged at symmetrical positions in the axial direction of the dual-shaft motor. A transport vehicle according to claim 1,
The grid box has a housing frame that encloses the resistor, and has a space between the resistor and the housing frame for electrically insulating the resistor and the housing frame. A transport vehicle, characterized in that it is provided with insulating members or insulating clearances. A transport vehicle according to claim 1,
A third straightening vane is provided along the width direction of the flow path from the outlet port to the inlet of the duct so as to straighten the cooling air in the height direction of the flow path so as to intersect the second straightening vane. further distributed to
the starting end of the third rectifying plate is positioned below the starting end of the first rectifying plate in the flow path height direction of the discharge port;
The terminal end of the third straightening vane is located below the center position of the inlet in the flow channel height direction and above the position corresponding to the starting end of the third straightening vane. transportation vehicle. A transport vehicle according to claim 6,
h1 is the distance in the flow channel height direction between the lower end of the discharge port and the start end of the third straightening plate, and the height direction distance between the start end of the third straightening plate and the start end of the first straightening plate is h2, and the distance in the flow path height direction between the start end of the first rectifying plate and the upper end of the discharge port is h3, and the distance dimensions of h1, h2, and h3 are unequal intervals. . A transport vehicle according to claim 7,
A transport vehicle characterized in that h1<h2<h3. A transport vehicle according to claim 6,
h4 is the flow channel height direction distance between the lower end of the inlet and the end of the third straightening plate, and the flow channel height direction distance between the end of the third straightening plate and the end of the first straightening plate is A transportation vehicle, wherein distances h4, h5, and h6 are equidistant, where h5 is the distance between the end of the first rectifying plate and the upper end of the inlet in the height direction of the flow path, h6. A transport vehicle according to claim 1,
A transportation vehicle, wherein one or a plurality of communication holes are provided in a part of the first straightening vane for communicating between the upstream side wall surface and the downstream side wall surface of the first straightening vane. A transport vehicle according to claim 10,
The transport vehicle, wherein the air passage cross-sectional area of the communication hole increases from the upstream side to the downstream side. A transport vehicle according to claim 11,
The air passage cross-sectional area of the communication hole located downstream is larger than the air passage cross-sectional area of the communication hole located upstream, or the number of the communication holes located downstream is greater than the number of the communication holes located upstream. A transportation vehicle characterized in that the number of said communication holes is greater than the number of said communication holes. A transport vehicle according to claim 11,
The transport vehicle, wherein the communication hole has a shape in which the cross-sectional area of the air passage increases from the upstream side to the downstream side.

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