JP5360553B2 - Air resistance reduction structure for vehicles equipped with signage devices - Google Patents

Description

  The present invention relates to an air in a vehicle equipped with a marking device in which a marking device for alerting or displaying a warning to surrounding traveling vehicles such as a patrol car used by a manager of a highway is attached to a roof of a normal automobile. The present invention relates to a resistance reduction structure. In the present invention, an ordinary automobile is a four-wheeled vehicle having a total vehicle weight of less than 5000 kg, a maximum loading capacity of less than 3000 kg, and a passenger capacity of 10 or less in the Road Traffic Law, and corresponds to a so-called passenger car.

  In a freight vehicle, when a trailer having a load box higher than the cabin of a tractor is connected, air resistance increases due to a step between the tractor and the trailer. Since the increase in air resistance has problems such as adversely affecting fuel consumption, a deflector for reducing this air resistance is mounted on the roof of the tractor. This deflector is provided with an inclined surface that increases in height toward the rear of the vehicle body, and the air above the tractor flows along the inclined surface when the freight vehicle travels. Resistance can be reduced.

  Recently, a method for improving the performance and function of the deflector has been studied. For example, Japanese Patent Application Laid-Open No. 6-329053 discloses a wind guide posture for reducing air resistance during traveling and an escape space outside the cabin. A deflector that can be changed to a posture at the time of escape to ensure the above is disclosed. Japanese Patent Application Laid-Open No. 2002-154462 discloses a deflector in which a canvas is attached to a frame member made of a metal bar that regulates the shape to reduce the weight. Furthermore, Japanese Patent Application Laid-Open No. 2007-1545 discloses a panel body that can be tilted with respect to a roof about a front end portion that is supported rotatably about a rotation axis along the vehicle width direction, and a roof and a panel body. And an angle adjusting unit that adjusts the inclination angle of the panel main body with respect to the upper surface of the roof within a predetermined angle range, and aims to reduce air resistance in a state where the trailer is pulled and a state where the trailer is not pulled. A possible deflector is disclosed.

JP-A-6-329053 JP 2002-154462 A JP 2007-1545 A

  On the other hand, ordinary automobiles (so-called passenger cars) that are not supposed to pull a trailer or the like can reduce air resistance by optimizing the vehicle body shape without attaching a device such as a deflector. However, in order to perform patrol monitoring of expressways, it is necessary to alert the surrounding traveling vehicles and display warnings while traveling at the same speed as ordinary vehicles traveling on the expressway. In addition, when a sign device is attached to the roof of an ordinary automobile, an increase in air resistance that is not expected at the stage of designing the vehicle body shape occurs.

  Therefore, an object of the present invention is to provide a structure for reducing the air resistance of a vehicle equipped with a marking device, which is configured by attaching a marking device to the roof of a normal automobile.

In the air resistance reduction structure for a vehicle with a marking device according to the present invention, in the vehicle with a marking device that is configured by attaching the marking device to a roof of a normal automobile, the height of the roof is increased to the rear of the vehicle at the front position of the marking device. An inclined part is provided. The ratio of the width of the inclined portion to the width of the marker device is 0.75. When an air flow from the front is generated, a vortex is formed between the inclined portion and the marking device, and an air flow passing near the upper end of the inclined portion and the upper end of the marking device is formed above the vortex. .

The inclined portion, the relative roof, preferably has an inclination angle of 45 degrees, also the height of the front Symbol inclined portion, the ratio of the height of the labeling device to be 0.5 preferable. Furthermore, it is preferable to have translucency.

  In addition, the inclined portion is configured by a base that is fixed on the roof by passing the top of the roof in the width direction and fixing both end edges thereof to the edge of the roof, and an inclined plate that is attached to the base so as to be adjustable in angle. May be. In this case, the inclined plate preferably has translucency.

  In the air resistance reduction structure for a vehicle with a sign device according to the present invention, the direction of the air flow from the front generated by traveling of the vehicle is changed at the inclined portion, and a vortex is formed between the inclined portion and the sign device, An air flow passing above the upper end of the inclined portion and above the upper end of the sign device is formed above the air flow, preventing the air flow from directly hitting the sign device and reducing the air resistance. Further, by changing the direction of the air flow from the front at the inclined portion, the air resistance in the vicinity of the roof front edge can be reduced at the same time. Furthermore, since the air flow passing above the upper end of the marking device is not disturbed and the streamline is horizontal, it is possible to prevent the generation of vortices behind the marking device and the generation of resistance due to negative pressure.

The inclined portion can be appropriately adjusted in arrangement and shape so as to form a vortex between the inclined portion and the marking device, but if the traveling speed of the vehicle equipped with the marking device is assumed to be 70 to 80 km, the roof The inclination angle is preferably 45 degrees. Further, it is preferable that the ratio of the height of the height and the labeling device inclined slope portion is 0.5. Furthermore, if the inclined portion has translucency, the visibility of the sign device from the front of the sign device-equipped vehicle can be improved.

  In addition, the inclined part is composed of a base that is fixed on the roof by passing it across the width in the width direction and fixing both ends of the roof to the edge of the roof, and an inclined plate that is attached to the noble base so that the angle can be adjusted. If there is, it can be easily applied to an existing vehicle equipped with a sign apparatus, and the adjustment to an angle optimum for the speed at which the vehicle equipped with the sign apparatus is assumed can be easily performed. In this case, if the inclined plate has translucency, the visibility of the sign device from the front of the sign device-equipped vehicle can be improved.

1 is a side view showing an overview of a sign apparatus-equipped vehicle to which an air resistance reduction structure for a sign apparatus-equipped vehicle according to the present invention is applied. It is a top view which expands and shows the air resistance reduction structure in the labeling device mounting vehicle. It is a side view which shows the area | region of numerical analysis. It is a three-dimensional flow velocity distribution map in the case of attaching an inclined part and a marking device. FIG. 5 is a flow velocity distribution diagram of a longitudinal section in which the Z coordinate is 0 in FIG. 4. It is a three-dimensional flow velocity distribution diagram in the case where neither an inclined part nor a marking device is attached. FIG. 7 is a flow velocity distribution diagram of a longitudinal section in which the Z coordinate is 0 in FIG. 6. It is a three-dimensional flow velocity distribution diagram in the case where only the marking device is not attached without attaching the inclined portion. FIG. 9 is a flow velocity distribution diagram of a longitudinal section in which the Z coordinate is 0 in FIG. 8. It is a side view which shows other embodiment of an inclination part. It is a top view of the embodiment.

An embodiment of an air resistance reduction structure for a vehicle equipped with a marking device according to the present invention is shown in the drawing. This structure is applied to a signage-equipped vehicle in which a signage device is fixed to the roof of a so-called recreational vehicle (RV) having a displacement of about 2000 cc.
On the roof 11 of the signage device-equipped vehicle 10, a signage device 1 is attached for alerting and displaying warnings on surrounding traveling vehicles. The sign device 1 includes a display board 2 for switching and displaying a plurality of predetermined character strings such as “running caution” on the back surface, and a rotating flashing lamp 3 on the top. Further, a guide portion 4 is provided on the front surface for directing the air flow direction from the front upward. The weight is about 300 kg, the width is 1060 mm, and the height from the roof 11 to the upper end of the rotary flashing lamp 3 is 1000 mm.

  Further, the roof 11 is provided with an inclined portion 5 that increases in height toward the rear of the vehicle at a position in front of the sign device 1. The material of the inclined portion 5 may be any material as long as it has sufficient strength, but if it has translucency, the visibility of the sign device 1 from the front of the sign device-equipped vehicle 10 can be improved. There is an advantage. In addition, the width | variety of the inclination part 5 is 800 mm, the height from the roof 11 to the front-end | tip part 6 is 500 mm, and the inclination angle with respect to the roof 11 of the front surface 7 is 45 degree | times.

  The air drag reduction effect by this structure will be described below with reference to the results of numerical analysis. The numerical calculation was performed by creating a three-dimensional shape (3D model) using the fluid simulation software Flow Simulation of SolidWorks and discretizing the time-dependent Navier-Stokes equations and solving them on a calculation mesh.

  Also, the computational mesh was automatically reconstructed during the flow calculation under reliable conditions to obtain a more appropriate solution. In order to solve the stationary problem using a time-dependent equation, the calculation is terminated when a stationary solution that converges in a preset range (ie, a converged solution) is obtained. In this numerical analysis, it is necessary to determine the air resistance with respect to the direction of travel of the marking device, so it is necessary to set engineering goals such as pressure, speed, and force for the calculation region. Here, the engineering goal is to select the most important analysis result from which various results can be obtained. In this numerical analysis, the air drag acting in the direction of travel of the marking device is obtained as a result from the setting of the engineering goal. As general setting conditions, the analysis type is external flow, the fluid is air, the flow type is laminar and turbulent, and the vehicle traveling speed conditions are 70 km / h, 80 km / h, 90 km / h, and 100 km / h. did.

  As shown in FIG. 3, the range of the numerical analysis was set to a region R including the upper half of the vehicle 10 equipped with a marking device. The vertical direction is the X-axis, the horizontal direction is the Y-axis, the vehicle body width direction is the Z-axis, and the range of the coordinate values is -500 to 4000 with the X-axis being positive and the Y-axis being backward. Is positive from -50 to 1600, and with respect to the Z-axis, the right hand side (front side of the paper) toward the rear is positive and from -1000 to 1000. In the following description, in the region R, the vicinity of the boundary between the windshield and the roof is the A region, the region between the inclined portion 5 and the guide unit 4 of the sign device 1 is the B region, and the inclined portion 5 is located above the B region. A continuous region including the vicinity of the upper end and the vicinity of the upper end of the sign device 1, a region D immediately above the rotary flashing lamp 3, and a region in which the height from the ground is higher than the sign device 1 behind the upper end of the sign device 1. Is the E region, the region behind the sign device 1 where the height from the ground is lower than the sign 1 is the F region, and the back of the vehicle body is the G region.

  4 and 5 show the analysis results. As comparative reference examples, the analysis results in a state where neither the inclined portion 5 nor the marking device 1 is attached are shown in FIGS. 6 and 7, and the analysis results in the state where only the marking device 1 is attached are shown in FIGS. Shown in 4 to 9 all show the flow of air in the region R when the vehicle traveling speed is 70 km / h as the velocity, and FIGS. 5, 7, and 9 show the Z coordinate. It is a flow velocity distribution in a longitudinal section that becomes zero.

  First, as shown in FIG. 9, when only the sign device 1 is attached without providing the inclined portion 5, it can be seen that the air flow is disturbed in the F region behind the sign device. In this F region, since the speed approaches 0 km / h, the pressure decreases and a force acts in the direction opposite to the traveling direction, so that the vehicle is pulled backward. On the other hand, the speed is high in the area A which is the boundary area between the windshield and the roof. This is a characteristic of the shape of the vehicle body itself, which is apparent from the fact that the speed of the A region is high even when the sign device 1 is not attached, as indicated by 7. 7 and 9 show that the resistance of the A region increases. Moreover, in D area | region which is an area | region right above the rotation blinking light 3, since the passage of air becomes narrow, the flow velocity is quick. Further, in the G region behind the vehicle body, the air flows smoothly if the sign device 1 is not present (FIG. 7), but in the state where the sign device 1 is present, the flow rate rapidly increases behind the sign device 1. The resistance rises due to the rise of the partial vortex. In addition, since the case where the marking apparatus 1 is hollow in consideration of an actual product shape is assumed, the inside of the marking apparatus 1 is swirled.

  On the other hand, according to the structure shown in FIGS. 1 and 2, as shown in FIG. 5, a vortex is formed in the B region between the inclined portion 5 and the marking device 1, and the inclined portion 5 is located above the B region. Since a smooth flow is formed in the C region in the continuous region including the vicinity of the upper end of the marking device and the vicinity of the upper end of the marking device 1, the air from the front flows upward of the marking device 1 and may directly hit the marking device 1. No. Therefore, the air resistance is reduced. Further, the smooth flow in the C region is not disturbed in the E region behind the sign device 1 (the streamline is kept horizontal in FIG. 5), and is also blocked by the inclined portion 5 in the G region. As a result, the air does not flow and no vortex is generated. As a result, the generation of the vortex behind the marking device is prevented and the vehicle is not pulled backward. Furthermore, it can be seen that the direction of the air flow from the front is changed by the inclined portion 5, and the air resistance in the region A is also reduced.

  4 to 9 show the flow velocity distribution, and Table 1 shows the results calculated as numerical values of the air resistance applied to the vehicle. In addition, the labeling device 1 is hollow as described above, but in order to confirm the influence of being hollow, the air calculated by performing the same numerical calculation when the hollow is closed without providing the inclined portion 5 is also calculated. The resistance values are also shown in Table 1 as “with bottom plate”. Further, FIGS. 4 and 5 show the results obtained when the angle of the front surface 7 of the inclined portion 5 is 45 degrees and the vehicle traveling speed is 70 km / h. The angle is set to 15 degrees or 30 degrees. The same numerical calculation was performed when the speed was 80 km / h, 90 km / h, or 100 km / h, and the calculated numerical values of air resistance are also shown in Table 1.

  In Table 1, “current shape” means a model that assumes that the marking device 1 has an actual product shape, that is, a model corresponding to FIGS. 8 and 9. From Table 1, it was confirmed that even if only the bottom plate for closing the hollow was attached, the overall air drag was hardly reduced. On the other hand, it was found that the air resistance is reduced by attaching the inclined portion 5. In particular, when the angle of the inclined portion 5 is 45 degrees, when the vehicle traveling speed is 70 to 80 km / h, a decrease in resistance by 70% of the air resistance of the current shape can be confirmed. However, when the traveling vehicle speed is 90 to 100 km / h, although a decrease of about 30 to 40% can be expected compared to the resistance value of the current shape, the resistance becomes larger than that when the traveling speed of the vehicle is 70 to 80 km / h. It was confirmed. Therefore, it is necessary to adjust the angle of the inclined portion 5 in consideration of the speed at which the sign apparatus-equipped vehicle 10 is supposed to travel. For example, an expressway where the traveling speed is assumed to be 70 to 80 km / h. If this is the case, 45 degrees is a suitable angle.

Next, the influence on fuel efficiency as an effect of reducing air resistance by this structure will be described below.
The impact on fuel consumption is the same as the road patrol vehicle equipped only with the signage device 1 and the same model as the road patrol vehicle without the signage device 1 (the weight is adjusted by mounting a block of about 300 kg). ) For ordinary vehicles, the mileage per unit fuel (hereinafter referred to as fuel efficiency) was measured and calculated based on these measured values.

Data necessary for measurement of fuel consumption was collected with a Diag Monitor HDM-30000 manufactured by Hitachi, Ltd., and the average fuel consumption was determined from the data. In addition, as reference data, data on general vehicles that are the same model as the road patrol vehicle and that do not include the marking device 1 and do not adjust the total weight were also collected. Table 2 shows the main data items acquired by the diagnostic monitor, and Table 3 shows the obtained results.

It was confirmed that there is a difference of 1.506 km / l in average fuel consumption between road patrol vehicles and general vehicles that have been adjusted in weight. Since the weights of both the vehicles are substantially the same and only the marking device has a difference in the vehicle body shape, the fuel consumption is deteriorated by 16.455% due to the air resistance of the marking device 1 in this state. On the other hand, when the air resistance reduction structure shown in FIG. 1 and FIG. 2 is adopted, the air resistance of the marking device 1 is reduced as described above, so that fuel efficiency is improved. And the fuel consumption at the time of employ | adopting this air resistance reduction structure is calculated | required with the following formula | equation.

For example, the fuel efficiency when the front surface 7 of the inclined portion 5 is inclined 45 degrees with respect to the roof 11 is 9.152 + ((141.117-43.644) /141.117) × (10.658-9. 152) is 10.192 km / l. For reference, the fuel consumption when R2 in the above formula (1) is the air resistance of the labeling device with a bottom plate is 9.152 + ((141.117-138.007) /141.117) × ( From 10.658-9.152), it is 9.185 km / l, which is almost the same as the average fuel consumption of road patrol vehicles, 9.152 km / l. The fuel efficiency calculated in the same manner in all cases shown in Table 1 is shown in Table 4, and the fuel efficiency improvement effect rate is shown in Table 5.

  In the structure shown in FIGS. 1 and 2, the inclined portion 5 is fixed to the roof 11 so that the front surface 7 forms a predetermined angle. However, as described above, the angle of the inclined portion 5 is preferably adjusted in accordance with the speed at which the traveling of the sign apparatus mounted vehicle 10 is assumed. Moreover, it is preferable that it is easily attached to a vehicle on which a sign device is already mounted. In such a case, as shown in FIG.10 and FIG.11, the inclination part 5 may be comprised with the base and the inclination board attached to this base so that angle adjustment was possible. 10 and 11, the same reference numerals are given to the substantially same parts as those shown in FIGS. 1 and 2, and the description thereof will be omitted.

  The base 16 constituting the inclined portion 15 shown in FIG. 10 and FIG. 11 can be fixed on the roof 11 by passing the top of the roof 11 in the width direction and hooking on both edges 16a and 16b of the roof 11 or the roof bar. ing. As a structure of such a base 16, the same thing as a well-known roof carrier is employable, for example. The inclined plate 17 is fixed to a support member 18 erected from the base 16 using screws 19. A plurality of insertion holes 20 for the screws 19 are formed at predetermined intervals along the longitudinal direction of the inclined plate 17, and angle adjustment is achieved by selectively using the insertion holes 20 through which the screws 19 are inserted. be able to. In addition, an elastic member 21 is attached to the edge of the inclined plate 17 in contact with the roof 11 so as to be in close contact with the roof 11. There is no restriction | limiting in the material of the elastic member 21, Rubber | gum, urethane, etc. can be used suitably.

  The material of the base 16 and the inclined plate 17 is not limited, and a material having sufficient strength can be used as appropriate. However, if the inclined plate 17 has translucency, it can be seen from the front of the signage device-equipped vehicle 10. There is an advantage that the visibility of the marking device 1 can be improved.

DESCRIPTION OF SYMBOLS 1 Marking apparatus 2 Display board 3 Flashing blinking lamp 4 Guide part 5, 15 Inclination part 6 Tip 7 Front surface 10 Labeling apparatus mounting vehicle 11 Roof 16 Base 17 Inclination board 18 Support member 19 Screw 20 Insertion hole 21 Elastic material

Claims (6)

In a vehicle equipped with a marking device that is constructed by attaching a marking device to the roof of a normal automobile,
An inclined portion that increases the height toward the rear of the vehicle is provided at the front position of the sign device on the roof, the ratio of the width of the inclined portion to the width of the sign device is 0.75, and when an air flow is generated from the front A vehicle equipped with a marking device, wherein a vortex is formed between the inclined portion and the marking device, and an air flow passing above the upper end of the inclined portion and above the upper end of the marking device is formed above the vortex flow. Air resistance reduction structure. The structure for reducing air resistance of a sign apparatus-equipped vehicle according to claim 1, wherein the inclined portion has an inclination angle of 45 degrees with respect to the roof. The air resistance reduction structure for a vehicle with a sign device according to claim 1 or 2 , wherein a ratio of a height of the inclined portion to a height of the sign device is 0.5. Air resistance reducing structure labeling system equipped vehicle according to claim 1, 2 or 3 wherein the inclined portion has a light-transmitting property. The inclined portion is composed of a base that is fixed on the roof by passing the top of the roof in the width direction and fixing both ends of the roof to the edge of the roof or the roof bar, and an inclined plate attached to the noble base so as to be adjustable in angle. The structure for reducing the air resistance of a signboard-equipped vehicle according to claim 1, 2 or 3 . The air resistance reducing structure for a vehicle equipped with a sign device according to claim 5 , wherein the inclined plate has translucency.