Optical axis adjustment device

Abstract

To calculate and adjust a deviation of an optical axis due to temperature variation around a vehicular headlamp.SOLUTION: An optical axis adjusting device 11 adjusts an optical axis of a headlamp unit 13 mounted on a vehicle. The optical axis adjusting device for a vehicular headlamp includes an engine temperature acquisition part 114 which acquires a temperature within an engine room of the vehicle, a displacement amount calculation part 115 which calculates a displacement amount of the optical axis based on the temperature, and an optical axis adjusting part 116 which adjusts the optical axis of the headlamp unit on the basis of the displacement amount.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an optical axis adjusting device for adjusting the optical axis of a vehicle headlamp provided on a vehicle. [Background technology]

[0002] Vehicle headlights are adjusted so that their optical axes are positioned within a legally defined range. As an optical axis adjusting device for adjusting the optical axis of a vehicle headlight, for example, an auto-leveling device is known that adjusts the optical axis in accordance with the angle of inclination when the angle of the front-to-rear direction of the vehicle body is inclined relative to the horizontal direction (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-234456 Summary of the Invention [Problem to be solved by the invention]

[0004] While a vehicle is traveling, the temperature around and inside the vehicle headlamp changes depending on the surrounding environment and the vehicle's traveling conditions, and temperature changes can cause a deviation in the optical axis. Specifically, temperature changes can cause thermal expansion in the housing of the vehicle headlamp, resulting in the vehicle headlamp itself being misaligned relative to the vehicle body, or thermal expansion in the light source unit housed inside the housing of the vehicle headlamp, resulting in the light source unit being misaligned relative to the housing. Such deviations can cause the optical axis of the vehicle headlamp to deviate from a predetermined range.

[0005] However, the auto-leveling device of Patent Document 1 does not anticipate adjusting the deviation of the optical axis due to temperature changes. In recent years, with the increasing definition of light sources (LEDs) used in vehicle headlights and the spread of high-performance vehicle headlights such as ADB (Adaptive Driving Beam), there is a demand for more accurate optical axis adjustment.

[0006] The present invention addresses such a situation by calculating and correcting the deviation of the optical axis caused by temperature changes around the vehicle headlamp. [Means for solving the problem]

[0007] In order to solve such problems, the optical axis adjusting device according to the present invention has the following configuration. That is, one aspect of the present invention provides an optical axis adjusting device for a vehicle headlamp that adjusts the optical axis of a headlamp unit mounted on a vehicle, the optical axis adjusting device including: an engine temperature acquiring unit that acquires a temperature inside an engine compartment of the vehicle; a displacement amount calculating unit that calculates a displacement amount of the optical axis based on the temperature; and an optical axis adjusting unit that adjusts the optical axis of the headlamp unit based on the displacement amount. [Effects of the Invention]

[0008] According to the optical axis adjusting device having such characteristics, it is possible to calculate the deviation of the optical axis caused by the temperature change around the vehicle headlamp and correct or adjust it with high precision. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is an explanatory diagram showing a schematic configuration of a vehicle control system including a light axis adjusting device according to an embodiment of the present invention; [Figure 2] 1 is an explanatory diagram showing a schematic configuration of an optical axis adjusting device according to an embodiment of the present invention; [Figure 3] 1 is an explanatory diagram showing a schematic configuration of a vehicle headlamp unit in which optical axis adjustment is performed by an optical axis adjusting device according to an embodiment of the present invention; [Figure 4] FIG. 4 is a cross-sectional view of the AA end of FIG. [Figure 5] 4 is an AA end view of FIG. 3, illustrating the movement of a bracket supporting the headlamp unit. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same reference numerals in different drawings denote parts with the same functions, and duplicated descriptions in each drawing will be omitted as appropriate.

[0011] 1, an optical axis adjusting device mounted on a vehicle according to an embodiment of the present invention functions as a part of a vehicle control system 1, and is provided on a vehicle 100. The vehicle control system 1 includes various electronic devices required for driving the vehicle 100, and a plurality of on-board ECUs (Electronic Control Units) that control these electronic devices. The electronic devices and on-board ECUs are connected to each other via an on-board network 3 such as a CAN (Controller Area Network) or a LIN (Local Interconnect Network) so as to be able to communicate with each other, and are also connected to a central gateway (CGW) 4 as a relay device, thereby constituting the vehicle control system 1.

[0012] Each in-vehicle ECU may be configured to include, for example, a processor such as a central processing unit (CPU) or a micro processing unit (MPU), electrical circuits, and storage elements such as a random access memory (RAM) or a read-only memory (ROM). In addition, some or all of the operations performed by the in-vehicle ECU may be realized by hardware such as an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or a graphics processing unit (GPU). In the following description, detailed description and illustration of electronic devices and the like that are not directly involved in the optical axis adjustment device (optical axis adjustment ECU 11) according to this embodiment will be omitted.

[0013] 1, the vehicle control system 1 includes, as on-board ECUs, a light axis adjustment ECU 11, an engine ECU 21, a brake ECU 31, and a steering ECU 41. Each on-board ECU is connected to an electronic device that is the control target of that on-board ECU, and controls the operation of the connected electronic device based on information (data) acquired from an on-board network 3. Furthermore, each on-board ECU outputs information indicating the operating state and other status of the connected electronic device to the on-board network 3.

[0014] The optical axis adjustment ECU 11 is connected to a headlamp unit 13 provided at the front of the vehicle and a drive unit 12 that drives the headlamp unit 13, and functions as an optical axis adjustment device that adjusts the optical axis of the headlamp unit. The optical axis adjustment ECU 11 will be described in detail later.

[0015] The engine ECU 21 is connected to the engine, the brake ECU 31 is connected to the brake, and the steering ECU 41 is connected to the steering. The engine ECU 21, the brake ECU 31, and the steering ECU 41 control the running of the vehicle based on information acquired from the in-vehicle network 3.

[0016] In particular, the engine ECU 21 is connected to an oil temperature sensor 22 and a coolant temperature sensor 23. The oil temperature sensor 22 detects the oil temperature of the engine while the vehicle is running and outputs the detected value to the engine control ECU 21. The coolant temperature sensor 23 detects the temperature of the engine coolant while the vehicle is running and outputs the detected value to the engine control ECU 21.

[0017] In addition, the engine ECU 21, brake ECU 31 and steering ECU 41 acquire status information indicating the status of the electronic devices connected to them (for example, information regarding engine speed, torque, accelerator opening, vehicle running speed and running time, fuel consumption, foot brake depression amount, side brake on / off, steering angle and steering amount, etc.), and output the acquired information to the in-vehicle network 3.

[0018] (About the optical axis adjustment device) The following describes the optical axis adjustment device, the optical axis adjustment ECU 11. The optical axis adjustment ECU 11 controls the drive unit 12 by referring to information acquired from each of the above-mentioned on-board ECUs via the on-board network 3, and adjusts the optical axis of the light emitted from the headlamp unit 13 so that it is located within a predetermined range.

[0019] As shown in FIG. 2, the optical axis adjustment ECU 11 includes a CPU (Central Processing Unit) 111, a ROM 112, and a RAM 113. The CPU 111 executes various processes based on programs stored in the ROM 112. In this embodiment, the CPU 111 loads the programs stored in the ROM 112 into a memory such as the RAM 113 and executes them, thereby functioning as the engine temperature acquisition unit 114, the displacement amount calculation unit 115, and the optical axis adjustment unit 116 shown in Fig. 2. The engine temperature acquisition unit 114, the displacement amount calculation unit 115, and the optical axis adjustment unit 116 will be described below.

[0020] The engine temperature acquisition unit 114 acquires the engine oil temperature detected by the oil temperature sensor 22 or the engine coolant temperature detected by the coolant temperature sensor 23 as the temperature inside the engine compartment via the engine control ECU 21 and the in-vehicle network 3.

[0021] The displacement amount calculation unit 115 calculates the amount of displacement (deviation) of the optical axis of the headlamp unit based on the temperature inside the engine compartment acquired by the engine temperature acquisition unit 114. For example, the displacement amount calculation unit 115 performs calculations based on a formula for calculating the amount of displacement according to the temperature inside the engine compartment or a table in which the temperature inside the engine compartment and the amount of displacement are associated, which is stored in advance in the ROM 112 or the like. It is preferable that the formula or table be acquired in advance for each vehicle by simulation or the like.

[0022] The optical axis adjustment unit 116 adjusts the optical axis of the headlamp unit based on the amount of displacement calculated by the displacement amount calculation unit 115. Specifically, the optical axis adjustment unit 116 determines the amount of adjustment of the headlamp unit 13 according to the amount of displacement of the headlamp unit, and outputs a drive signal indicating the amount of adjustment to the drive unit 12.

[0023] (Headlamp unit) Next, the headlamp unit 13, which is the target of the optical axis adjustment by the optical axis adjustment ECU 11, will be described with reference to FIGS.

[0024] A pair of headlamp units 13 are normally provided on the left and right sides of the front of the vehicle, but only one is shown as a representative example in Figures 3 to 5. As shown in Figures 3 to 5, headlamp unit 13 is configured by accommodating, in a housing, for example, a light source (not shown), a reflector that guides light emitted from the light source to the front of the vehicle, a lens that distributes the light emitted from the light source over a predetermined range, and the like.

[0025] The headlamp unit 13 is fixed to a bracket 14 and attached to the vehicle body 80 via the bracket 14. The bracket 14 is attached to the vehicle body 80 by a ball joint 141 provided on the upper part of the bracket 14, an aiming screw 142 for left-right adjustment, and an aiming screw 144 for up-down adjustment provided on the lower part of the bracket 14 via a retainer 143.

[0026] Ball joint 141 is attached to bracket 14 so that ball portion 141A at one end serves as the swing center (fulcrum) of bracket 14, and threaded portion 141B at the other end is attached to vehicle body 80.

[0027] One end of the vertical adjustment aiming screw 144 is attached to the bracket 14 via a retainer 143, and the other end is attached to a vertical aiming adjustment gear 146 of a leveling unit 145 on the vehicle body 80 side.

[0028] In this way, the headlamp unit 13 is supported so as to be tiltable up and down together with the bracket 14 relative to the vehicle body 80, with the ball portion 141A at one end of the ball joint 141 as a fulcrum, as the vertical adjustment aiming screw 144 or the retainer 143 moves in the fore-and-aft direction of the vehicle.

[0029] In other words, by rotating the vertical adjustment aiming screw 144, the retainer 143 moves in the fore-and-aft direction of the vehicle, and the lower part of the bracket 14 also moves in the fore-and-aft direction of the vehicle in conjunction with the movement of the retainer 143. As a result, the headlamp unit 13 rotates and tilts around the ball portion 141A of the ball joint 141.

[0030] When adjusting the optical axis of the headlamp unit 13, the adjustment can be performed manually by an operator or automatically by the optical axis adjustment ECU 11. In the case of manual adjustment by an operator, when the operator rotates the vertical adjustment aiming screw 144 with a screwdriver, the retainer 143 moves in the fore-and-aft direction of the vehicle at the threaded portion of the vertical adjustment aiming screw 144. As the retainer 143 moves, the lower part of the bracket 14 also moves in the fore-and-aft direction of the vehicle. As a result, the headlamp unit 13 together with the bracket 14 rotates and tilts around the ball portion 141A of the ball joint 141.

[0031] In the case of automatic adjustment by the optical axis adjustment ECU 11, the drive unit 12 (for example, a motor) included in the leveling unit 145 is driven to rotate the vertical adjustment aiming screw 144 together with the vertical aiming adjustment gear 146. When the drive unit 12 rotates the vertical adjustment aiming screw 144, the vertical adjustment aiming screw 144 moves in the fore-and-aft direction of the vehicle, and accordingly the retainer 143 also moves in the fore-and-aft direction of the vehicle. As a result, the headlamp unit 13 together with the bracket 14 rotates and tilts around the ball portion 141A of the ball joint 141.

[0032] The optical axis adjustment ECU 11 according to this embodiment performs optical axis adjustment on the headlamp unit 13 configured as described above as follows. Since the headlamp unit 13 is attached near the engine of the vehicle body 80, it is susceptible to thermal expansion and the like due to the influence of temperature changes in the engine compartment while the vehicle is running. Therefore, in the light axis adjustment ECU 11, the engine temperature acquisition unit 114 acquires the engine oil temperature detected by the oil temperature sensor 22 or the engine coolant temperature detected by the coolant temperature sensor 23 as the temperature in the engine compartment, and estimates the temperature around the headlamp unit near the engine.

[0033] The displacement amount calculation unit 115 calculates the amount of displacement of the optical axis according to the acquired temperature inside the engine compartment using a calculation formula or the like stored in the ROM 112. The optical axis adjustment unit 116 calculates the amount of adjustment of the headlamp unit 13 based on the amount of displacement calculated by the displacement amount calculation unit 115, and outputs a drive signal indicating the amount of adjustment to the drive unit 12.

[0034] Based on the drive signal from the optical axis adjustment unit 116, the drive unit 12 rotates the vertical adjustment aiming screw 144 to move it in the front-to-rear direction relative to the vehicle body 80 by the adjustment amount. As the vertical adjustment aiming screw 144 moves, the retainer 143 also moves in the front-to-rear direction of the vehicle body 80 by the adjustment amount calculated by the displacement amount calculation unit 115, and the bracket 14 rotates and tilts around the ball portion 141A. As a result, the headlamp unit 13 supported by the bracket tilts up and down relative to the vehicle body 80, and the position of the optical axis can be adjusted according to the displacement amount of the optical axis calculated by the displacement amount calculation unit 115.

[0035] As described above, according to this embodiment, the displacement (deviation) of the optical axis of the headlight unit 13 caused by the temperature change in the engine compartment is calculated (estimated) based on the engine oil temperature or the engine coolant temperature, so that the deviation of the optical axis caused by the temperature change around the vehicle headlight can be calculated and adjusted in real time.

[0036] Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configurations are not limited to these embodiments, and the present invention also includes design changes within the scope of the present invention. Furthermore, the above-described embodiments can be combined by utilizing each other's technologies as long as there are no particular contradictions or problems in their purposes, configurations, etc. [Explanation of symbols]

[0037] 1: Vehicle control system, 3: In-vehicle network, 11: Optical axis adjustment ECU (optical axis adjustment device), 12: Drive unit, 13: Headlamp unit, 14: Bracket, 21: Engine ECU, 22: Oil temperature sensor, 23: Coolant temperature sensor, 31: Brake ECU, 41: Steering ECU, 80: Body, 100: Vehicle, 114: Engine temperature acquisition unit, 115: Displacement amount calculation unit, 116: Optical axis adjustment unit, 141: Ball joint, 141A: Ball portion, 141B: Screw portion, 142: Aiming screw for left and right adjustment, 143: Retainer, 144: Aiming screw for up and down adjustment, 145: Leveling unit 146: Up and down aiming adjustment gear

Claims

[Claim 1] An optical axis adjusting device for adjusting an optical axis of a headlamp unit mounted on a vehicle, an engine temperature acquisition unit that acquires a temperature inside an engine compartment based on an oil temperature of the engine of the vehicle or a water temperature of a cooling water that cools the engine; a displacement amount calculation unit that calculates a displacement amount of the optical axis caused by a temperature change around the headlamp unit based on the temperature; an optical axis adjusting unit that adjusts an optical axis of the headlamp unit based on the displacement amount, The displacement amount calculation unit calculates the displacement amount of the optical axis based on a formula for calculating the displacement amount of the optical axis according to the temperature inside the engine compartment, or a table in which the temperature inside the engine compartment and the displacement amount of the optical axis are associated with each other.

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