JP2006010401A - Fuel consumption display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel consumption display apparatus capable of determining fuel consumption degradation due to the pneumatic pressure of tires among causes of fuel consumption degradation. <P>SOLUTION: The fuel consumption display apparatus for vehicles is provided with tire pneumatic pressure sensors 10-13 for detecting the pneumatic pressure of tires and a fuel consumption computing part 1 for computing the amount F<SB>rd</SB>of fuel consumption degradation due to reductions in the pneumatic pressure of tires at least on the basis of pneumatic pressure values P<SB>fr</SB>, P<SB>fl</SB>, P<SB>rr</SB>, and P<SB>rl</SB>of the tires detected by the tire pneumatic pressure sensors 10-13. The fuel consumption display apparatus for vehicles is provided with a fuel consumption display part 2 for displaying the state of fuel consumption degradation of vehicles on the basis of output of the fuel consumption computing part 1. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel consumption display device for a vehicle.

  The following are known as conventional fuel consumption display devices.

A fuel efficiency calculation unit that selectively sets multiple types of fuel consumption measurement conditions and measures vehicle fuel consumption under the measurement conditions, a reference setting unit that sets reference values under the fuel consumption measurement conditions, fuel consumption measurement results, and Display means for displaying the reference value is provided. For example, by using the fuel efficiency estimated from the known characteristics of the vehicle and the fuel efficiency information of the same type of competitors received via communication means as the reference fuel efficiency, and comparing this with the fuel efficiency measured in the driving state corresponding to the fuel measurement conditions The deterioration of fuel consumption is judged (for example, refer to Patent Document 1).
JP 2001-108503 A

  However, in the above-described background art, there is a problem in that only the fuel consumption in the current vehicle state is displayed, and the driver cannot grasp the cause of the deterioration in fuel consumption and cannot take improvement measures. .

  In view of the above problems, an object of the present invention is to provide a fuel consumption display device that can determine fuel consumption deterioration due to tire air pressure among causes of fuel consumption deterioration.

  The present invention relates to an air detection means for detecting tire air pressure in a fuel consumption display device for a vehicle, and a fuel consumption deterioration amount calculating means for calculating a fuel consumption deterioration amount due to tire air pressure based on at least the air pressure detected by the air detection means. And a display means for displaying a fuel consumption deterioration state of the vehicle based on the output of the fuel consumption deterioration amount calculation means.

  By displaying the fuel consumption deterioration state of the vehicle based on the output from the fuel consumption deterioration amount calculating means for calculating the fuel consumption deterioration amount due to the tire air pressure, the driver can recognize the fuel consumption deterioration due to the decrease in the air pressure. By replenishing the tire air, it is possible to take an improvement measure against fuel consumption deterioration.

  The configuration of the control system of the fuel consumption display device used in the present embodiment will be described with reference to FIG.

From the fuel injection amount, vehicle speed, mileage information, tire pressure values P _fr , P _fl , P _rr , P _rl, etc., the fuel consumption value F _n , the fuel consumption deterioration amount F _rd due to a decrease in tire air pressure, and the tire pressure warning information are output. A calculation unit 1 is provided. Note that the tire air pressure values of the front right wheel, the front left wheel, the rear right wheel, and the rear left wheel are P _fr , P _fl , P _rr , P _rl . The fuel consumption calculating section 1 comprises a storage device, fuel economy regulations to determine fuel economy pneumatic proper value P _ref, coefficient rolling during pressure proper value P _ref mu _ref, air replenishment required pressure P _ng, due to tire pressure drop The quantity F _rdref is set and stored in advance. Further, a map of the tire rolling coefficient μ with respect to the vehicle tire pressure average value P _av as shown in FIG. 3 is stored in advance. Further, a gear loss L _g corresponding to the operating state is stored.

Also it controls the engine 7 and the fuel injection unit 8 comprises an engine control unit 3 for calculating the engine losses L _e from the engine torque T _e and the engine speed n _e. The engine control unit 3 includes a storage device, and stores an engine efficiency map in advance. Further, a vehicle speed sensor 9, a brake control unit 4 that recognizes the vehicle speed from information from the vehicle speed sensor 9, and a meter / odometer unit 5 that calculates and displays a travel distance from the vehicle speed information from the brake control unit 4 are provided. Further, the air pressure sensor 10-13 for each tire and the air pressure for recognizing the air pressure values P _fr , P _fl , P _rr , P _rl of each tire (front left and right wheels, rear left and right wheels) by the signals of the tire pressure sensors 10-13. alarm tuner 6, the fuel consumption value F _n from the fuel efficiency calculation unit 1, fuel economy amount F _rd by decreased air pressure of the tire, the tire pressure warning information, and a fuel efficiency indicator 2 for displaying the contents.

When the vehicle travels, the fuel consumption calculation unit 1 calculates the fuel consumption value F _n from the fuel injection amount transmitted from the engine control unit 3, the vehicle speed transmitted from the brake control unit 4, and the travel distance transmitted from the meter / odometer unit 5. To do. Further, the rolling coefficient μ is obtained from the average value P _av of the air pressure values P _fr , P _fl , P _rr , P _rl of each tire transmitted from the air pressure alarm tuner unit 6, and further the tire rolling loss L _r is obtained. Also, determine the air resistance loss L _a from the vehicle speed transmitted from the brake control unit 4. The total loss L _t is calculated from the tire rolling loss L _r , the air resistance loss L _a , the engine loss L _e transmitted from the engine control unit 3, and the gear loss L _g .

Further, the fuel efficiency deterioration amount F _r due to the tire rolling loss L _{r is} calculated from the fuel efficiency value F _n and the total loss L _t and the ratio R _r (= L _r / L _t ) of the tire rolling sentence loss L _{r to} the total loss L _t . calculate. Further, the fuel consumption deterioration amount F _rd due to the decrease in tire air pressure is calculated from the difference between the fuel consumption deterioration amount F _r and the current rolling coefficient μ and the rolling coefficient μ _ref when the air pressure is appropriate (predetermined state). Further, it is determined whether or not the tire pressure needs to be adjusted by comparing the fuel consumption deterioration amount F _rd with the fuel consumption deterioration specified amount F _rdref for determining the deterioration of the fuel consumption due to the decrease in the tire air pressure.

Outputs thus fuel consumption value F _n obtained by the fuel consumption calculating section 1, fuel economy amount F _rd, the tire air pressure adjustment request to fuel efficiency indicator 2, displays the state of fuel efficiency.

  Next, the flow of the fuel consumption display control method described above will be described with reference to FIG.

In step S1, each tire pressure signal is received from each tire pressure sensor 10-13, and each tire pressure P _fr , P _fl , P _rr , P _rl is detected by the air pressure alarm tuner unit 6.

Next, in step S2, it is determined whether or not each tire air pressure value P _fr , P _fl , P _rr , P _rl is greater than or equal to an appropriate air pressure value P _ref . When each tire air pressure value P _fr , P _fl , P _rr , P _rl is equal to or greater than the appropriate air pressure value P _ref , the process proceeds to step S13 and the normal fuel consumption display is performed. That is, the current fuel consumption value F _n is obtained from the fuel injection amount, the vehicle speed, and the travel distance, and this is displayed on the fuel consumption display unit 2. The state of the fuel consumption display unit 2 at this time is shown in FIG.

In step S2, if at least one of the tire air pressure values P _fr , P _fl , P _rr , P _rl is less than the appropriate air pressure value P _ref , the process proceeds to step S3 and each tire air pressure value P _fr , P _fl , It is determined whether P _rr and P _rl are _equal to or higher than the air replenishment required air pressure P _ng . The air replenishment required air pressure P _ng is a predetermined value for determining whether or not the tire air pressure adjustment is necessary, and is set in advance. When at least one tire air pressure value P _fr , P _fl , P _rr , P _rl is less than the air replenishment required air pressure P _ng , the process proceeds to step S14 and an air replenishment request display is performed on the fuel display unit 2. Here, the current fuel consumption F _n and the air replenishment request for the tire determined to be less than the air replenishment required air pressure P _ng are displayed on the fuel consumption display unit 2. The state of the fuel consumption display unit 2 at this time is shown in FIG.

If all the tire pressure values P _fr , P _fl , P _rr , P _rl are greater than or equal to the air replenishment required air pressure value P _ng , the process proceeds to step S4. In step S4, the vehicle tire pressure average value P _av is calculated from the tire pressure values P _fr , P _fl , P _rr , P _rl . That means
P _av = (P _fr + P _fl + P _rr + P _rl ) / 4
And

Next, in step S5, determining the tire rolling coefficient μ from the vehicle tire pressure average value P _av. Here, the rolling coefficient μ is obtained using a map of the rolling coefficient μ with respect to the vehicle tire air pressure average value P _av as shown in FIG. In addition, the rolling coefficient μ decreases as the vehicle tire air pressure average value P _av increases.

Next, in step S6, the engine control unit 3, the current engine torque T _e and the engine speed n _e, calculates the loss L _e by the engine using the previously stored engine efficiency map. Next, in step S7, a loss L _r due to tire rolling is calculated from the tire rolling coefficient μ. In step S8, the calculated loss L _a by the air resistance than the vehicle speed read from the brake control unit 4.

In step S9, the loss L _e, L _r, determine the total loss L _t than the sum of the gear loss L _g corresponding to L _a and the operating conditions, further, the loss rate of the tire rolling loss L _r R _r Is calculated. That means
L _t = L _e + L _g + L _r + L _a
R _r = L _r / L _t
Ask for.

Next, in step S10, the current fuel consumption value F _n, the percentage loss R _r of total loss L _t and the tire rolling loss L _r, calculates the fuel consumption deterioration amount F _r based on tire rolling loss.

F _r = F _n × (1 / (1-L _t ) −1) × R _r
Further, in step S11, the relative difference of the rolling coefficient mu _ref in a current rolling coefficient mu and a predetermined state (tire air pressure is proper pressure P _ref), and, from the fuel economy amount F _r based on the tire rolling loss Then, a fuel consumption deterioration amount F _rd due to a decrease in air pressure is calculated. That means
F _rd = F _r × (1− (μ _ref / μ))
Is calculated.

Next, in step S12, it is determined whether or not the fuel deterioration value F _rd due to the decrease in air pressure is equal to or less than the fuel efficiency deterioration prescribed value F _rdref . When the fuel deterioration value F _rd is _{equal to} or less than the fuel consumption deterioration specified value F _rdref , the process proceeds to step S15, and the display of the tire rolling fuel consumption deterioration is performed. Here, the current fuel consumption value F _n and the fuel consumption deterioration amount F _rd due to a decrease in tire air pressure are displayed on the fuel consumption display unit 2. The state of the fuel consumption display unit 2 at this time is shown in FIG.

On the other hand, in step S12, fuel deterioration value F _rd is, when fuel economy prescribed value F _Rdref larger, the process proceeds to step S16, the current fuel economy value F _n, fuel economy amount F _rd and pneumatic adjustment by the decreased tire pressures The request is displayed on the fuel consumption display unit 2. The state of the fuel display unit 2 at this time is shown in FIG.

Thus, in the present embodiment, the fuel consumption deterioration amount F _rd due to a decrease in tire air pressure is obtained and displayed, and when the fuel consumption deterioration amount F _rd is larger than the fuel consumption deterioration specified value F _rdref , the tire Displays the air pressure adjustment request.

  Next, the effect of this embodiment will be described.

In the vehicle fuel consumption display device, tire pressure sensors 10-13 for detecting tire pressure, and at least tire pressure values P _fr , P _fl , P _rr , P _rl detected by the air pressure sensors 10-13 are used to determine the tire pressure. A fuel consumption calculation unit 1 that calculates a fuel consumption deterioration amount F _rd due to a decrease in air pressure is provided. Moreover, the fuel consumption display part 2 which displays the fuel consumption deterioration state of a vehicle based on the output of the fuel consumption calculating part 1 is provided. As a result, the driver can recognize the deterioration in fuel consumption due to the decrease in air pressure, and can take improvement measures against the deterioration in fuel consumption by replenishing tire air.

Fuel consumption calculating portion 1, a tire air pressure value P _fr detected by the tire air pressure sensor 10 to 13, given the state of the P _fl, P _rr, sets the loss L _r rolling according to P _rl, rolling loss L _r Based on the increase amount with respect to (the tire pressure is in the appropriate value _Pref ), the fuel consumption deterioration amount F _rd due to the decrease in the air pressure is calculated. Here, the fuel consumption display unit 2 displays the fuel consumption deterioration amount F _rd calculated by the fuel consumption calculation unit 1. As a result, the driver can grasp the fuel consumption deterioration amount _Frd corresponding to the decrease amount of the tire air pressure.

Further, based on the fuel consumption deterioration amount F _rd calculated by the fuel consumption calculation unit 1, a means (S12) for determining whether or not the tire air pressure needs to be adjusted, and the driver adjusts the air pressure according to the determination result. Notification means (S16) for prompting. As a result, the driver can recognize the time when the improvement treatment is performed when the fuel consumption is significantly deteriorated.

  The present invention is not limited to the best mode for carrying out the invention, and it goes without saying that various modifications can be made within the scope of the technical idea described in the claims. Absent.

  The present invention relates to a fuel consumption display device. In particular, the present invention relates to a fuel consumption display device that determines the cause of deterioration in fuel consumption of a vehicle.

It is a block diagram of the control system of the fuel consumption display apparatus in this embodiment. It is a flowchart of the control system of the fuel consumption display apparatus in this embodiment. It is a relationship figure of vehicle tire air pressure average value Pav and rolling coefficient μ. It is a figure which shows the state of the fuel consumption display part in this embodiment.

Explanation of symbols

1 Fuel consumption calculation unit (fuel consumption deterioration amount calculation means)
2 Fuel consumption display part 10-13 Tire air pressure sensor (air pressure detecting means)
S12 determination means S13 notification means

Claims (4)

In a fuel consumption display device for a vehicle,
Air pressure detecting means for detecting tire air pressure;
A fuel consumption deterioration amount calculating means for calculating a fuel consumption deterioration amount due to a decrease in tire air pressure based on at least the air pressure detected by the air pressure detection means;
A fuel consumption display device comprising: display means for displaying a fuel consumption deterioration state of the vehicle based on an output of the fuel consumption deterioration amount calculating means. The fuel consumption deterioration amount calculating means includes
Determine the loss due to tire rolling according to the air pressure detected by the air pressure detection means,
The fuel consumption display device according to claim 1, wherein a fuel consumption deterioration amount due to a decrease in air pressure is calculated based on an increase amount of the rolling loss with respect to a predetermined state.   The fuel consumption display device according to claim 1, wherein the display unit displays the fuel consumption deterioration amount calculated by the fuel consumption deterioration amount calculation unit. Means for determining whether or not the tire air pressure needs to be adjusted based on the fuel consumption deterioration amount calculated by the fuel consumption deterioration amount calculating means;
The fuel consumption display device according to any one of claims 1 to 3, further comprising notification means for prompting a driver to adjust air pressure in accordance with the determination result.

Images