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 adjusts an optical axis of a headlamp unit 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, an operation information acquisition part 116 which acquires operation information indicating an operation state of a cooling device for the engine, and an optical axis adjusting part 117 which adjusts the optical axis of the headlamp unit on the basis of the displacement amount and the operation information.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 Art

[0002] The optical axis of a vehicle headlamp is adjusted so as to be located within a range defined by regulations. As an optical axis adjusting device for adjusting the optical axis of a vehicle headlamp, for example, an auto leveling device that adjusts the optical axis according to the inclination angle when the angle of the vehicle body in the longitudinal direction is inclined with respect to the horizontal direction is known (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, during the running of a vehicle, the temperature around and inside the vehicle headlamp changes depending on the surrounding environment and the running condition of the vehicle, and the optical axis may be displaced due to the temperature change. Specifically, due to the temperature change, thermal expansion occurs in the housing of the vehicle headlamp, causing the vehicle headlamp itself to be displaced with respect to the vehicle body, or thermal expansion occurs in the light source unit housed inside the housing of the vehicle headlamp, causing the light source unit to be displaced with respect to the housing. Due to such displacement, the optical axis of the vehicle headlamp may deviate from within a predetermined range.

[0005] However, in the auto leveling device of Patent Document 1 described above, adjustment of the optical axis displacement due to temperature change is not assumed. In recent years, with the high definition of light sources (LEDs) used in vehicle headlamps and the spread of high - performance vehicle headlamps such as ADB (Adaptive Driving Beam), more accurate optical axis adjustment has been desired.

[0006] The present invention aims to address such a situation. That is, it aims to calculate and adjust the deviation of the optical axis caused by temperature changes around the vehicle headlamp, etc.

Means for Solving the Problem

[0007] To solve such problems, the optical axis adjustment device according to the present invention has the following configuration. That is, one aspect of the present invention is an optical axis adjustment device for adjusting the optical axis of a headlamp unit mounted on a vehicle, comprising an engine temperature acquisition unit that acquires the temperature in the engine room of the vehicle, a displacement amount calculation unit that calculates the displacement amount of the optical axis based on the temperature, an operation information acquisition unit that acquires operation information indicating the operation status of the cooling device for the engine, and an optical axis adjustment unit that adjusts the optical axis of the headlamp unit based on the displacement amount and the operation information. An optical axis adjustment device for a vehicle headlamp is provided.

Effects of the Invention

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

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Best Mode for Carrying Out the Invention

[0010] 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 indicate parts having the same function, and duplicate descriptions in each drawing will be omitted as appropriate.

[0011] As shown in FIG. 1, the optical axis adjustment device mounted on the vehicle according to the embodiment of the present invention functions as a part of the vehicle control system 1 and is provided in the vehicle 100. The vehicle control system 1 includes various electronic devices necessary for the running of the vehicle 100 and a plurality of in-vehicle ECUs (Electronic Control Units) that control these electronic devices. Each electronic device and each in-vehicle ECU, etc. are communicably connected to each other by an in-vehicle network 3 such as CAN (Controller Area Network) or LIN (Local Interconnect Network), and are connected to a central gateway (CGW) 4 as a relay device to constitute the vehicle control system 1.

[0012] Each in-vehicle ECU can be configured to include a processor such as a CPU (Central Processing Unit) or MPU (Micro Processing Unit), an electric circuit, and a storage element such as a RAM (Random Access Memory) or ROM (Read Only Memory). Also, part or all of the operations executed by the in-vehicle ECU can be realized by hardware such as an ASIC (application specific integrated circuit), an FPGA (field-programmable gate array), or a GPU (Graphics Processing Unit). In the following description, detailed explanations and illustrations of electronic devices, etc. that are not directly related to the optical axis adjustment device (optical axis adjustment ECU 11) according to the present embodiment will be omitted.

[0013] As shown in FIG. 1, the vehicle control system 1 includes, as in-vehicle ECUs, an optical axis adjustment ECU 11, an engine ECU 21, a brake ECU 31, a steering ECU 41, an air-conditioning ECU 51, and a wiper ECU 61. Each in-vehicle ECU is connected to an electronic device that is the control target of the in-vehicle ECU, and controls the operation of the electronic device to which it is connected based on information (data) acquired from the in-vehicle network 3. Further, each in-vehicle ECU outputs information indicating a state such as the operation state of the connected electronic device to the in-vehicle network 3.

[0014] The optical axis adjustment ECU 11 is connected to a headlight unit 13 provided in front of the vehicle and a drive unit 12 that drives the headlight unit 13, and functions as an optical axis adjustment device that adjusts the optical axis of the headlight unit. Details of the optical axis adjustment ECU 11 will be described 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. Then, the engine ECU 21, the brake ECU 31, and the steering ECU 41 control the running of the vehicle based on the information acquired from the in-vehicle network 3.

[0016] In particular, the engine ECU 21 is connected to an oil temperature sensor 22, a cooling water temperature sensor 23, an engine rotation sensor 24, and a cooling device 25. The oil temperature sensor 22 detects the oil temperature of the engine during running and outputs it to the engine ECU 21. The cooling water temperature sensor 23 detects the temperature of the engine cooling water during running and outputs it to the engine ECU 21. The engine rotation sensor 24 detects the rotation speed of the engine from, for example, an ignition pulse or the like and outputs it to the engine ECU 21. The engine ECU 11 is connected to the cooling device 25, and the cooling device 25 outputs the operating state of the cooling device 25 to the engine ECU 11. In the present embodiment, the cooling device 25 is, for example, a radiator fan that cools the engine, an active grille shutter that reduces running resistance, etc., and refers to a device that causes a temperature change in the engine compartment by operating even if the main purpose is not to cool the engine.

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

[0018] The air-conditioning ECU 51 is connected to an outside air temperature sensor 52 attached to the outside of the vehicle, and controls an air-conditioning unit (not shown) based on the outside air temperature acquired from the outside air temperature sensor 52 and the information acquired from the in-vehicle network 3. That is, the air-conditioning ECU 51 controls the air-conditioning unit so that the temperature inside the vehicle compartment becomes the desired temperature set by the user while referring to the outside air temperature acquired from the outside air temperature sensor 52.

[0019] The wiper ECU 61 is connected to, for example, a raindrop sensor 62 that detects the amount of rainfall by the amount of raindrops adhering to the windshield, and operates the wiper at predetermined time intervals according to the amount of raindrops acquired from the raindrop sensor 62. Alternatively, the wiper ECU 61 operates the wiper according to information based on an operation by an occupant of the vehicle acquired via the in-vehicle network 3.

[0020] (Regarding the optical axis adjustment device) Hereinafter, the optical axis adjustment ECU 11 as the optical axis adjustment device will be described. The optical axis adjustment ECU 11 controls the drive unit 12 with reference to the information acquired from each of the above-described in-vehicle ECUs via the in-vehicle network 3, and adjusts the optical axis of the light irradiated from the headlight unit 13 so as to be positioned within a predetermined range.

[0021] 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 the programs stored in the ROM 112. In this embodiment, the CPU 111 reads 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, displacement amount calculation unit 115, operation information acquisition unit 116, and optical axis adjustment unit 117 shown in FIG. 2. Hereinafter, the engine temperature acquisition unit 114, displacement amount calculation unit 115, operation information acquisition unit 116, and optical axis adjustment unit 117 will be described.

[0022] The engine temperature acquisition unit 114 acquires, as the temperature inside the engine room, the engine oil temperature detected by the oil temperature sensor 22 or the coolant temperature of the engine detected by the coolant water temperature sensor 23 via the engine ECU 21 and the in-vehicle network 3. The engine temperature acquisition unit 114 may predict the temperature inside the engine room based on the engine speed acquired from the engine rotation sensor 24.

[0023] The displacement amount calculation unit 115 calculates the displacement amount (deviation amount) of the optical axis of the headlight unit based on the temperature inside the engine room acquired by the engine temperature acquisition unit 114. For example, the displacement amount calculation unit 115 stores, in advance, in the ROM 112 or the like, a calculation formula for calculating the displacement amount corresponding to the temperature inside the engine room or a table in which the temperature inside the engine room and the displacement amount are associated with each other, and calculates based on this. It is preferable to acquire the calculation formula or the table in advance by simulation or the like for each vehicle.

[0024] The operation information acquisition unit 116 acquires operation information indicating the operation status of the cooling device 25. The cooling device 25 is a device that causes a temperature change inside the engine room by operating, for example, a radiator fan that cools the engine, an active grille shutter that reduces running resistance, or the like.

[0025] When the cooling device 25 operates, it is difficult to predict the temperature around the headlight unit only from the engine room temperature estimated from the temperature obtained from the oil temperature sensor 22 or the cooling water temperature sensor 23, or from the engine room temperature predicted from the engine speed obtained from the engine speed sensor 24. In such a case, since it is necessary to consider the operating state of the cooling device 25, the operating information acquisition unit 116 acquires the operating information indicating the operating situation of the cooling device 25.

[0026] For example, when the cooling device is a radiator fan, the rotation speed, rotation speed, operating time, etc. of the radiator fan are included in the operating information. When the cooling device 25 is an active grille shutter, the opening degree of the active grille shutter, the time for maintaining the open state, etc. are included in the operating information. The acquired operating information is output to the optical axis adjustment unit 117.

[0027] The optical axis adjustment unit 117 determines the adjustment amount of the headlight unit 13 based on the displacement amount calculated by the displacement amount calculation unit 115, and outputs a drive signal indicating the adjustment amount to the drive unit 12. In addition, when there is the operating information acquired by the operating information acquisition unit 116, the optical axis adjustment unit 117 corrects the displacement amount calculated by the displacement amount calculation unit 115, and determines the adjustment amount of the headlight unit 13 according to the corrected displacement amount, and outputs a drive signal indicating the adjustment amount to the drive unit 12.

[0028] In addition, when the operating information includes the operating time of the cooling device and indicates that a predetermined time has elapsed since the start of operation, the optical axis adjustment unit 117 does not output a drive signal to the drive unit 12 so as not to adjust the optical axis of the headlight unit 13. This is considered in view of the fact that when the cooling device 25 has operated for a certain period of time or more, the periphery of the headlight unit 13 is sufficiently cooled and there is no need for optical axis adjustment. Therefore, it is preferable to predetermine the time for sufficiently cooling the periphery of the headlight unit 13 as the predetermined time.

[0029] In addition, when the operation information indicates during the operation of the cooling device, the optical axis adjustment unit 117 does not output a drive signal to the drive unit 12 so as not to adjust the optical axis of the headlight unit 13. This is considered in view of the fact that when the cooling device 25 is operating, the adjustment amount of the optical axis adjustment and the necessity of the optical axis adjustment may change depending on how long the operating state continues thereafter.

[0030] (Regarding the headlight unit) Subsequently, the headlight unit 13, which is the object of optical axis adjustment by the optical axis adjustment ECU 11, will be described with reference to FIGS. 3 to 5.

[0031] Normally, a pair of headlight units 13 are provided on the left and right in front of the vehicle. However, only one of them is shown as a representative example in FIGS. 3 to 5. As shown in FIGS. 3 to 5, the headlight unit 13 is configured by housing, for example, a light source (not shown), a reflector that guides the light emitted from the light source to the front of the vehicle, a lens for distributing the light emitted from the light source within a predetermined range, etc. inside a housing.

[0032] The headlight 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 at 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 via a retainer 143 at the lower part of the bracket 14.

[0033] The ball joint 141 has one end ball portion 141A attached to the bracket 14 so as to be the swing center (fulcrum) of the bracket 14, and the other end screw portion 141B attached to the vehicle body 80.

[0034] The aiming screw 144 for up - down adjustment has one end attached to the bracket 14 via a retainer 143 and the other end attached to the up - down aiming adjustment gear 146 of the leveling unit 145 on the vehicle body 80 side.

[0035] In this way, the headlight unit 13 is supported so as to be tiltable vertically together with the bracket 14 with respect to the vehicle body 80 with the ball portion 141A at one end of the ball joint 141 as a fulcrum as the aiming screw 144 for vertical adjustment or the retainer 143 moves in the longitudinal direction of the vehicle.

[0036] That is, by rotating the aiming screw 144 for vertical adjustment, the retainer 143 moves in the longitudinal direction of the vehicle, and the lower part of the bracket 14 also moves in the longitudinal direction of the vehicle as the retainer 143 moves. As a result, the headlight unit 13 rotates and tilts about the ball portion 141A of the ball joint 141.

[0037] When adjusting the optical axis of the headlight unit 13, it can be manually performed by an operator or automatically performed by the optical axis adjustment ECU 11. In the case of manual adjustment by an operator, when the operator rotates the aiming screw 144 for vertical adjustment with a driver, the retainer 143 moves in the longitudinal direction of the vehicle at the screw portion of the aiming screw 144 for vertical adjustment. The lower part of the bracket 14 also moves in the longitudinal direction of the vehicle as the retainer 143 moves. As a result, the headlight unit 13 together with the bracket 14 rotates and tilts about the ball portion 141A of the ball joint 141.

[0038] 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 aiming screw 144 for vertical adjustment together with the vertical aiming adjustment gear 146. By the drive unit 12 rotating the aiming screw 144 for vertical adjustment, the aiming screw 144 for vertical adjustment moves in the longitudinal direction of the vehicle, and accordingly, the retainer 143 also moves in the longitudinal direction of the vehicle. As a result, the headlight unit 13 together with the bracket 14 rotates and tilts about the ball portion 141A of the ball joint 141.

[0039] The optical axis adjustment ECU 11 according to this embodiment performs optical axis adjustment on the headlight unit 13 configured as described above as follows. Since the headlight unit 13 is attached near the engine of the vehicle body 80, it is likely to experience thermal expansion and the like due to the influence of temperature changes in the engine compartment during driving. Therefore, in the optical axis adjustment ECU 11, the engine temperature acquisition unit 114 acquires the engine oil temperature detected by the oil temperature sensor 22 or the cooling water temperature of the engine detected by the cooling water temperature sensor 23 as the temperature in the engine compartment, and estimates the temperature around the headlight unit near the engine.

[0040] The displacement amount calculation unit 115 calculates the displacement amount of the optical axis according to the acquired temperature in the engine compartment from the calculation formula stored in the ROM 112 and outputs the calculated displacement amount to the optical axis adjustment unit 117. The operation information acquisition unit 116 outputs the operation information of the cooling device 25 acquired from the cooling device 25 to the optical axis adjustment unit 117.

[0041] The optical axis adjustment unit 117 calculates the adjustment amount of the headlight unit 13 based on the displacement amount calculated by the displacement amount calculation unit 115 and outputs a drive signal indicating the adjustment amount to the drive unit 12. At this time, if there is operation information, the displacement amount is corrected according to the operation information, the adjustment amount of the headlight unit 13 based on the corrected displacement amount is calculated, and a drive signal indicating the adjustment amount is output to the drive unit 12.

[0042] Also, when the operation information indicates that the cooling device 25 has been operating for a predetermined time or more, or is currently operating, etc., the optical axis adjustment unit 117 does not output a drive signal to the drive unit 12 and does not perform optical axis adjustment. Note that the optical axis adjustment unit 117 may correct the displacement amount according to the outside air temperature acquired from the outside air temperature sensor 52 and the rainfall amount acquired from the raindrop sensor 62 as needed.

[0043] The drive unit 12 rotates the vertical adjustment aiming screw 144 based on the drive signal from the optical axis adjustment unit 117, and moves it in the front-rear direction relative to the vehicle body 80 by the amount of adjustment. As the vertical adjustment aiming screw 144 moves, the retainer 143 also moves in the front-rear direction of the vehicle body 80 by the amount of adjustment calculated by the displacement calculation unit 115, and the bracket 14 rotates and tilts about the ball portion 141A. As a result, the headlight unit 13 supported by the bracket tilts vertically with respect 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 calculation unit 115.

[0044] As described above, according to the present embodiment, the temperature inside the engine room is estimated, and the displacement (shift) of the optical axis of the headlight unit 13 due to the temperature rise is predicted in consideration of the temperature change by the cooling device provided inside the vehicle. Therefore, the shift of the optical axis caused by the temperature change around the vehicle headlight can be calculated in advance or in real time and adjusted with high accuracy.

[0045] Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and design changes and the like within the scope not departing from the gist of the present invention are also included in the present invention. In addition, the above-described embodiments can be combined by diverting each other's technologies as long as there are no particular contradictions or problems in their purposes and configurations.

Explanation of Reference Numerals

[0046] 1: Vehicle control system, 3: In-vehicle network, 11: Optical axis adjustment ECU (optical axis adjustment device), 12: Driving unit, 13: Headlight unit, 14: Bracket, 21: Engine ECU, 22: Oil temperature sensor, 23: Cooling water temperature sensor, 24: Engine rotation sensor, 25: Cooling device, 31: Brake ECU, 41: Steering ECU, 51: Air conditioning ECU, 52: Outside air temperature sensor, 61: Wiper ECU, 62: Raindrop sensor, 80: Vehicle body, 100: Vehicle, 114: Engine temperature acquisition unit, 115: Displacement calculation unit, 116: Operation information acquisition unit, 117: Optical axis adjustment unit, 141: Ball joint, 141A: Ball part, 141B: Screw part, 142: Left and right adjustment aiming screw, 143: Retainer, 144: Up and down adjustment aiming screw, 145: Leveling unit, 146: Up and down aiming adjustment gear

Claims

1. An optical axis adjustment device for adjusting the optical axis of a headlight unit mounted on a vehicle, an engine temperature acquisition unit that acquires the temperature inside the engine room of the vehicle; a displacement amount calculation unit that calculates the displacement amount of the optical axis based on the temperature; an operation information acquisition unit that acquires operation information indicating the operation status of a cooling device for the engine; and an optical axis adjustment unit that adjusts the optical axis of the headlight unit based on the displacement amount and the operation information. An optical axis adjustment device for a vehicle headlight.

2. The optical axis adjustment device according to claim 1, wherein the optical axis adjustment unit corrects the displacement amount based on the operation information and adjusts the optical axis of the headlight unit based on the corrected displacement amount.

3. The optical axis adjustment device according to claim 1, wherein the optical axis adjustment unit does not adjust the optical axis of the headlight unit when the operation information indicates that a predetermined time has elapsed since the start of operation of the cooling device.

4. The optical axis adjustment device according to claim 1, wherein the optical axis adjustment unit does not adjust the optical axis of the headlight unit when the operation information indicates that the cooling device is in operation.

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