JP2012145408A - Engine rotation speed display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly display a range of a red zone by distinguishing between a state of an engine which has a high possibility of receiving damage and a state of the engine which has a low possibility of receiving the damage.SOLUTION: An engine rotation speed display device includes: a red zone display part S11 which displays the red zone showing that the engine rotation speed is in a region close to its limit; and a red zone switching part S17 which automatically discriminates the magnitude of load applied to an engine when the detected engine rotation speed is equal to or more than a predetermined one, and automatically switches a display form regarding the red zone in accordance with the magnitude of the load applied to the engine. The magnitude of the load on the engine is distinguished by detecting at least one of presence/absence of connection of a clutch and the duration in the state where the engine rotation speed exceeds a threshold Rth.

Description

  The present invention relates to an engine rotation speed display device that is mounted on a vehicle, sequentially detects the rotation speed of an engine that drives the vehicle, and displays information on the detected engine rotation speed in real time, and particularly for red zone display. Regarding technology.

  In many cases, a tachometer that displays the current engine speed (rpm) is mounted on the instrument panel of a vehicle such as an automobile. Further, an area called a red zone, which is usually colored in red, is provided at a location near the upper limit of the scale of the dial of the tachometer.

  Such a tachometer red zone is provided to represent the engine's limiting rotational speed. In other words, if the engine is operated with the engine speed in the red zone, the engine may be destroyed. Accordingly, the driver refers to the indicated value of the tachometer as necessary, and performs the driving operation while paying attention so that the engine speed does not enter the red zone as much as possible.

  Further, the red zone of the tachometer naturally changes according to the difference in the type and specification of the engine mounted on the vehicle. For example, the engine rotational speed in the red zone changes to, for example, 5000 rpm or more, 6000 rpm or more, or 7000 rpm or more depending on the engine type such as a SOHC engine, a DOHC engine, or a DOHC turbo engine.

  Thus, for example, Patent Document 1 discloses a technique that enables a common tachometer to be used for various vehicles equipped with engines of different formats. Specifically, the display range of the red zone is divided into a plurality of display units, and whether or not each display unit is assigned to the actual red zone is switched by turning on / off illumination light of the plurality of light emitting diodes. Also, the red zone is switched by changing the connection state of the connector terminal in response to the difference in the target vehicle type and engine type.

JP-A-6-336127

  However, the conventional tachometer as described above does not necessarily display the red zone range appropriately. In other words, in a general tachometer, the normal driving state of the corresponding vehicle is assumed, and the red zone range is determined in advance according to the specifications of the mounted engine. The red zone range may not be appropriate.

  For example, when the driver depresses the accelerator and increases the engine rotation speed with the clutch provided in the vehicle drive system disconnected, the drive system is not connected to the engine output shaft. Therefore, the load on the engine becomes very small. Therefore, in this case, even if the engine speed is increased to the range of the red zone assumed in the normal running state, the engine is unlikely to be damaged. Therefore, in this case, the red zone range is not appropriate.

  Further, even when the vehicle is driven with the clutch engaged, it is normal that no problem arises even if the engine speed is increased to the range of the red zone only for a short time. Therefore, for example, a motorsport enthusiast or racer who races on a circuit field, a driver who is familiar with the characteristics of the vehicle and the engine can set the engine speed within a range that does not place a heavy burden on the engine. In many cases, the driving operation is performed up to the red zone. Therefore, in this case as well, the range of the red zone is not always appropriate from the viewpoint of the driver.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to appropriately display the range of the red zone by distinguishing between a state where the engine is likely to be damaged and a state where the engine is likely to be damaged. An engine rotational speed display device is provided.

In order to achieve the above-described object, an engine speed display device according to the present invention is characterized by the following (1) to (4).
(1) An engine rotation speed display device that is mounted on a vehicle, sequentially detects the rotation speed of an engine that drives the vehicle, and displays information on the detected engine rotation speed in real time,
A red zone display for displaying a red zone indicating that the engine speed is close to the limit;
When the detected engine rotation speed is equal to or higher than a predetermined value, the magnitude of the load on the engine is automatically identified, and the red zone is automatically switched according to the magnitude of the load on the engine. And a zone display switching unit.
(2) The engine speed display device according to (1) above,
The red zone display switching unit monitors at least one of a state of a clutch connecting the drive system of the vehicle and a length of elapsed time when the detected engine rotation speed is equal to or higher than a predetermined value, and is applied to the engine. Automatically identify the magnitude of the burden.
(3) The engine speed display device according to (1) above,
The red zone display switching unit automatically switches at least one of the hue, lightness, and saturation of the display color relating to the display of the red zone according to the burden on the engine.
(4) The engine speed display device according to (1) above,
The red zone display unit graphically displays an area in a predetermined range on the engine speed scale displayed on the graphic display screen as the red zone in a display form different from other areas.

According to the engine rotation speed display device having the configuration (1), the user can grasp to some extent the load on the engine from the relationship between the detected engine rotation speed and the displayed display form of the red zone. Is possible. That is, since it is possible to distinguish whether or not the engine is highly likely to be damaged, the red zone can be displayed in an appropriate state as viewed from the user.
According to the engine rotation speed display device having the configuration (2), the magnitude of the load on the engine can be automatically identified. That is, if the clutch is not connected, the load is small and the possibility of damage is low even if the engine speed is higher than a predetermined speed. Even if the engine speed becomes higher than a predetermined speed when the clutch is connected, if the state is only for a very short time, the possibility of damage is low.
According to the engine rotation speed display device having the configuration (3), the user can easily identify the magnitude of the load on the engine by the difference in the display color of the red zone.
According to the engine rotation speed display device having the configuration (4), the red zone is displayed by graphic display, so that the display form such as the display color of the red zone can be easily changed.

  According to the engine rotation speed display device of the present invention, on the dial of a tachometer mounted on a vehicle, the range of the red zone is appropriately displayed by distinguishing between a state where the engine is likely to be damaged and a state where the engine is likely to be damaged. It becomes possible.

  The present invention has been briefly described above. Further, details of the present invention will be further clarified by reading through the modes for carrying out the invention described below with reference to the accompanying drawings.

It is a flowchart showing the red zone display control of the engine speed display apparatus of embodiment. It is a flowchart showing the modification of the control shown in FIG. It is a front view which shows the specific example of the state transition of the engine speed display of embodiment. It is a block diagram which shows the structural example of the hardware of the meter panel display apparatus containing the engine speed display apparatus shown in FIG.

  Specific embodiments relating to the engine speed display device of the present invention will be described below with reference to the drawings.

  An outline of the red zone display control of the engine rotation speed display device in the present embodiment is shown in FIG. 1, and a specific example of the state transition of the engine rotation speed display in the present embodiment is shown in FIG. A modification of the control shown in FIG. 1 is shown in FIG.

  The engine rotation speed display device of the present embodiment is arranged on a dashboard of a vehicle as a part of a meter panel display device 10 having a configuration as shown in FIG. 4, for example, and the engine rotation speed (rpm: The measured value (generally called engine speed) is always displayed.

  As shown in FIG. 4, the meter panel display device 10 includes a read only memory (EEPROM) 11, an interface 12, an interface 13, a CPU power supply unit 14, a microcomputer (CPU: Central Processing Unit) 20, A graphic controller 21, a frame memory 22, an X driver 23, a Y driver 24, an LCD (Liquid Crystal Display) power supply unit 25, and a liquid crystal display (TFT-LCD: Thin Film Transistor Liquid Crystal Display) 26 are provided.

  The microcomputer 20 executes a program prepared in advance and performs various processes necessary for realizing the function of the meter panel display device 10. For example, the microcomputer 20 also executes the processing shown in FIGS.

  The read-only memory 11 holds the contents of a program executed by the microcomputer 20 and fixed data prepared in advance. For example, fixed data representing a threshold value referred to by the microcomputer 20 in steps S13 and S16 in FIG. 1 may be held on the read-only memory 11.

  The interface 12 inputs a signal (IGN +) indicating the state of the ignition switch on the vehicle side to the microcomputer 20.

  The interface 13 is used for communication between the microcomputer 20 and various control devices (ECU: Electric Control Unit) on the vehicle side. Specifically, data representing various current vehicle conditions such as vehicle speed, engine speed, fuel remaining amount, cooling water temperature, and whether or not a clutch is connected is input to the microcomputer 20 from the vehicle side as almost real-time data. .

  The CPU power supply unit 14 receives the DC power supplied from the vehicle-side plus-side power supply line (+ B) and generates a DC voltage (Vcc) necessary for the operation of the microcomputer 20. Further, a reset signal is generated as necessary, and an operation for suppressing power supply in accordance with a sleep signal output from the microcomputer 20 is also performed.

  The liquid crystal display 26 has a color two-dimensional display screen in which a large number of minute display cells constituted by liquid crystal devices are arranged in the X direction and the Y direction. By individually controlling the display state of a large number of minute display cells for each cell, desired information such as graphics, characters, images, and the like can be graphically displayed on the two-dimensional display screen.

  The scanning position in the Y direction on the display screen of the liquid crystal display 26 is sequentially switched by the output of the Y driver 24. The Y driver 24 sequentially switches the scanning position in the Y direction in synchronization with the vertical synchronization signal output from the graphic controller 21.

  The X driver 23 sequentially switches the scanning position in the X direction on the display screen of the liquid crystal display 26 in synchronization with the horizontal synchronization signal output from the graphic controller 21. In addition, the X driver 23 gives the RGB image data output from the graphic controller 21 to the display cell at the scanning position to control the display contents on the screen.

  The graphic controller 21 displays various graphic elements on the screen of the liquid crystal display 26 in accordance with various instructions input from the microcomputer 20. Actually, the microcomputer 20 or the graphic controller 21 writes the display data to the frame memory 22 that holds the display contents for each pixel and draws the graphic. In addition, a vertical synchronizing signal and a horizontal synchronizing signal for two-dimensional scanning of the screen of the liquid crystal display 26 are generated, and display data stored at a corresponding address on the frame memory 22 at a timing synchronized with these synchronizing signals. Is applied to the liquid crystal display 26.

  In the present embodiment, the image data written to the frame memory 22 for display is managed as different layer data for each type. That is, the image data is divided into warning image data D1, background image data D2, scale display image data D3, and pointer image D4 shown in FIG. 4 and is assigned to different layers.

  The LCD power supply unit 25 inputs DC power supplied from the vehicle-side plus-side power supply line (+ B) and generates predetermined DC power required for display on the liquid crystal display 26.

  A graphic display screen 30 as shown in FIG. 4 is displayed by the two-dimensional screen display of the liquid crystal display 26. In this example, display areas of a speedometer 31, an engine tachometer 32, a fuel gauge 33, a thermometer 34, and an odometer 35 are provided in the graphic display screen 30. That is, the speed (km / h) of the vehicle is displayed in the area of the speedometer 31, the engine speed (rpm) is displayed in the area of the engine tachometer 32, the remaining fuel is displayed in the area of the fuel gauge 33, The coolant temperature is displayed in the area of the thermometer 34, and the accumulated traveling distance of the vehicle is displayed in the area of the odometer 35.

  Further, in the present embodiment, since the graphic display is performed on the screen of the liquid crystal display 26 capable of color display and the display of the contents (30) of the meter panel is realized, the display form of each instrument to be displayed can be easily changed. . For example, the hue, brightness, saturation, etc. of the display color of the red zone displayed on the scale of the engine tachometer 32 can be easily changed.

  The engine rotation speed display device of this embodiment controls the display of the engine tachometer 32 displayed on the graphic display screen 30 of the meter panel display device 10. A specific example of the display state transition in the engine tachometer 32 is shown in FIG.

  As shown in FIG. 3, the engine tachometer 32 includes a scale 32a, a pointer 32b, and a red zone 32c as graphic display elements.

  The scale 32a shows the engine rotation speed values and the division positions for each of a plurality of representative positions determined by dividing the predetermined display range of the engine tachometer 32 (in this example, 0 to 8000 rpm) into constant values. This is an image represented as information, and is included in the scale display image data D3.

  The pointer 32b is a needle-like image pattern extending in the circumferential direction from the rotation center position of the engine tachometer 32, and is included in the pointer image D4. That is, according to the latest engine rotation speed obtained by the measurement, an image pattern of the pointer oriented in a direction in which the tip of the pointer 32b indicates the position of the corresponding scale is drawn.

  The red zone 32c is visible information that represents an area close to the limit of the engine speed in the display range of the scale 32a (0 to 8000 rpm in this example). In the example shown in FIG. 3, an area exceeding 7000 rpm is assigned as a red zone in consideration of the type and characteristics of the engine mounted on the target vehicle.

  In the present embodiment, the display form of the red zone 32c changes into two types. That is, even when the engine speed has reached the red zone, in a state where the burden on the engine is small and the possibility of being damaged is low, a light red red zone 32c (A ) Is displayed in the corresponding area on the scale 32a. Further, in a state where there is a high possibility of receiving damage, a dark red red zone 32c (B) is displayed like the engine tachometer 32B shown in FIG. That is, the shade of the red zone 32c displayed on the engine tachometer 32 is switched according to the possibility of the engine being damaged. This switching is automatically performed by the microcomputer 20 executing the process shown in FIG.

  In addition, about the difference in the some display form of the red zone 32c, it can also display as a difference by any one of the hue of a display color, lightness, and saturation, or these combination. Alternatively, a plurality of types of display forms can be expressed by switching the display density and pattern shape of a large number of pixels constituting the image pattern of the red zone 32c.

  Next, the red zone display control shown in FIG. 1 will be described. In addition to the processing shown in FIG. 1, the microcomputer 20 also needs processing for displaying the scale 32a and the background of the dial, and processing for displaying the pointer 32b in a direction corresponding to the engine rotational speed obtained by the measurement. Run on demand or periodically.

  In step S11, the microcomputer 20 displays the red zone 32c with a light red image pattern like the red zone 32c (A) of the engine tachometer 32A shown in FIG. If a timer described later is operating, it is stopped and the time is cleared.

  In step S12, the microcomputer 20 inputs information representing the state of the vehicle via the interface 13, and detects the latest engine speed Rp and the state of clutch engagement.

  In step S13, the microcomputer 20 compares the engine speed Rp detected in step S12 with a predetermined threshold value Rth. When switching control as shown in FIG. 3 is performed, it is assumed that 7000 rpm which is the lower limit of the red zone is adopted as the threshold value Rth. When the condition of “Rp> Rth” is satisfied, the process proceeds to the next step S14, and otherwise, the process returns to step S11.

  In step S14, the microcomputer 20 identifies whether or not the clutch state detected in step S12 is in the connected state. If the clutch is in the engaged state, the process proceeds to the next step S15, and otherwise, the process returns to step S11.

  In step S15, the microcomputer 20 starts the operation of the internal timer in order to measure the elapsed time. This process is omitted when the timer has already started.

  In step S16, the microcomputer 20 monitors the measurement time of the internal timer started in step S15, and identifies whether or not a predetermined time has elapsed. As a time threshold in this case, “10 seconds” can be assumed as a realistic representative example. If this time has elapsed, the process proceeds to the next step S17, and if not, the process returns to step S12.

  In step S17, the microcomputer 20 switches the display of the red zone 32c from a light red color to a dark red color like the red zone 32c (B) of the engine tachometer 32B shown in FIG. Also, the operation of the internal timer is stopped and the time is cleared.

  In step S18, the microcomputer 20 inputs information representing the state of the vehicle via the interface 13 and detects the latest engine speed Rp. Then, the latest engine speed Rp is compared with a threshold value Rth. If the condition of “Rp <Rth” is satisfied, the process proceeds to step S11, and otherwise, the process of step S18 is repeated.

  Therefore, even when the engine speed is increased by the driver's accelerator operation and the latest engine speed reaches the red zone (in this case, a range exceeding 7000 rpm), the clutch is not connected or When the duration of this state is equal to or shorter than the predetermined time, the image representing the red zone is displayed in a light red color as in the red zone 32c (A) of FIG. When the engine speed reaches the red zone when the clutch is in the engaged state and the duration of this state exceeds a predetermined time, the image representing the red zone is dark as in the red zone 32c (B) of FIG. The display automatically changes to red. In addition, after the red zone is switched to a dark red display, the display of the red zone is automatically switched to a light red when the engine speed decreases below the red zone.

  In other words, even if the engine speed approaches the limit and reaches the red zone, if the engine is not likely to be damaged, the red zone will be displayed in a light red color. You can easily recognize that it is not. In addition, when the engine speed reaches the red zone and the engine is likely to be damaged, the red zone is displayed in dark red, making it easy for the driver to be in a dangerous situation. An operation for avoiding danger, that is, an operation for reducing the engine rotation speed can be performed.

  In the process shown in FIG. 1, the same threshold value Rth is referred to in step S13 and step S18, but mutually independent threshold values may be assigned. For example, if a value smaller than Rth is assigned to the threshold value in step S18, switching from a dark color to a light color in the red zone can be delayed.

  In the red zone display process shown in FIG. 1, it is assumed that two types of density are automatically selected as the display of the red zone 32c, but in the modification shown in FIG. 2, the display of the red zone 32c is performed. Assuming that a large number of concentrations can be selected.

  That is, when it is detected in step S16 in FIG. 2 that the predetermined time has elapsed, in the next step S17B, the microcomputer 20 gradually changes the display density of the red zone 32c as time elapses. Gradually switch to dark red display.

  Even when switching from light red to dark red, if the condition of “Rp <Rth” is satisfied, the processing of the microcomputer 20 returns from step S18 to S11, so that the display is switched to light red. .

  Note that the processing for switching the display of the red zone 32c from dark red to light red may be changed so that the display density is gradually switched, as in step S17B.

  In any case, even when the engine rotation speed is approaching the limit, the display state of the red zone 32c is automatically switched by distinguishing between a state in which the engine or the like is likely to be damaged and a state in which it is low. Therefore, the red zone can be displayed in an appropriate state as seen from the driver. That is, the driver can easily recognize whether or not the engine or the like is in a driving state in which the possibility of damage is high due to a difference in display form such as shading.

  As described above, it is assumed that the engine rotation speed display device of the present invention is used as a display of an engine tachometer (tachometer) mounted on a meter panel of a vehicle such as an automobile. By applying the present invention, the driver can easily recognize whether or not the engine is in a driving state in which there is a high possibility of damage.

DESCRIPTION OF SYMBOLS 10 Meter panel display apparatus 11 Read-only memory 12, 13 Interface 14 CPU power supply part 20 Microcomputer 21 Graphic controller 22 Frame memory 23 X driver 24 Y driver 25 LCD power supply part 26 Liquid crystal display 30 Graphic display screen 31 Speedometer 32, 32A 32B Engine tachometer 32a Scale 32b Pointer 32c Red zone 33 Fuel gauge 34 Thermometer 35 Odometer

Claims (4)

An engine rotation speed display device that is mounted on a vehicle, sequentially detects the rotation speed of an engine that drives the vehicle, and displays information on the detected engine rotation speed in real time,
A red zone display for displaying a red zone indicating that the engine speed is close to the limit;
When the detected engine rotation speed is equal to or higher than a predetermined value, the magnitude of the load on the engine is automatically identified, and the red zone is automatically switched according to the magnitude of the load on the engine. An engine rotation speed display device comprising: a zone display switching unit. The red zone display switching unit monitors at least one of a state of a clutch connecting the drive system of the vehicle and a length of elapsed time when the detected engine rotation speed is equal to or higher than a predetermined value, and is applied to the engine. The engine rotation speed display device according to claim 1, wherein the magnitude of the burden is automatically identified. The red zone display switching unit automatically switches at least one of a hue, brightness, and saturation of a display color related to the display of the red zone according to a magnitude of a burden on the engine. Item 4. The engine rotation speed display device according to Item 1. The red zone display unit graphically displays an area in a predetermined range on the engine speed scale displayed on the graphic display screen as the red zone in a display form different from other areas. The engine speed display device according to claim 1.

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