Foreign object detection device

Abstract

To provide a foreign matter capture device that can capture foreign matter (contamination) more accurately regardless of the condition of the oil passage (lubrication circuit). [Solution] The foreign object capturing device 1 includes an electromagnet 30 disposed in an oil passage 10 through which oil flows, various sensors (such as a rotation speed sensor 51, an oil temperature sensor 52, and an acceleration sensor 72) that detect the state of the oil passage 10 (for example, oil flow rate and vibration), and a TCU 50 that controls (variable) the strength of the magnetic force of the electromagnet 30 according to the state of the oil passage 10.

Description

Technical Field

[0001] The present invention relates to a foreign matter capturing device that captures foreign matter (contamination) in oil.

Background Art

[0002] For example, in a transmission or a rear differential, when power is transmitted by gears or variators made of metal, wear powder (foreign matter: contamination) is generated from the metal contact parts. The metal-based wear powder mixes into the oil (flows with the oil flow) and diffuses, and may, for example, enter functional parts such as gears, bearings, and control valves, thereby reducing the durability reliability of the functional parts or deteriorating the vibration and noise performance.

[0003] In order to capture such foreign matter (contamination), for example, Patent Document 1 discloses a technique (adsorbent) having a permanent magnet and a capture body made of a weakly magnetic material that is magnetized by the magnetic force of the permanent magnet and adsorbing foreign matter in lubricating oil.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the above-described technique, for example, when the oil flow rate changes (especially increases) due to the rotational speed of the gear, the oil temperature, etc., or when vibration is applied, depending on the state of the oil passage (lubrication circuit), there is a risk that foreign matter (contamination) cannot be sufficiently captured.

[0006] The present invention was made to solve the above-mentioned problems, and aims to provide a foreign matter capture device that can capture foreign matter (contamination) more accurately regardless of the condition of the oil passage (lubrication circuit). [Means for solving the problem]

[0007] A foreign object capturing device according to one aspect of the present invention is characterized by comprising an electromagnet disposed in an oil passage through which oil flows, a detection means for detecting the state of the oil passage, and a control unit for controlling the strength of the magnetic force of the electromagnet according to the state of the oil passage detected by the detection means.

[0008] According to one aspect of the present invention, the state of the oil passage is detected, and the strength of the magnetic force of the electromagnet is controlled (variable) according to the state of the oil passage. Therefore, foreign matter (contamination) in the oil can be captured more accurately in accordance with the state of the oil passage. [Effects of the Invention]

[0009] According to the present invention, it becomes possible to capture foreign matter (contamination) more accurately regardless of the condition of the oil passage (lubrication circuit). [Brief explanation of the drawing]

[0010] [Figure 1] This is a diagram showing the configuration of a foreign object capture device according to an embodiment. [Figure 2] (a) This figure shows the relationship between gear rotation speed, oil temperature, and oil flow rate, and (b) the relationship between gear rotation speed, oil temperature, and the strength of the electromagnet's magnetic force (target magnetic force). [Figure 3] This flowchart shows the processing procedure for foreign object capture control (magnetic force control) by the foreign object capture device according to the embodiment. [Figure 4] This flowchart shows the processing procedure for stopping the operation of an electromagnet by a foreign object capture device according to an embodiment. [Figure 5] This figure shows another example of the arrangement of the electromagnets that constitute the foreign object capturing device according to the embodiment. [Modes for carrying out the invention]

[0011] Preferred embodiments of the present invention will be described in detail below with reference to the drawings. In the drawings, the same or corresponding parts will be denoted by the same reference numerals. In addition, in each drawing, the same elements will be denoted by the same reference numerals, and redundant explanations will be omitted.

[0012] First, the configuration of the foreign object capturing device 1 according to the embodiment will be described using Figure 1. Figure 1 is a diagram showing the configuration of the foreign object capturing device 1.

[0013] The foreign matter capture device 1 captures foreign matter (contamination) in the oil that lubricates a lubricated part, such as a transmission. Here, the present invention will be explained using the example of its application to a lubrication circuit (oil passage) 10 for agitation lubrication by gears. This lubrication circuit (oil passage) 10 is provided with, for example, a gear 20 that circulates the oil and an oil guide 21 that rectifies the oil flow and assists in oil circulation, for example, by being formed in an arc shape and having a concave radial cross-section. In the example shown in Figure 1, the oil flows in from the top of the drawing and is sent out to the lower left side of the drawing as the gear 20 rotates.

[0014] In particular, the foreign matter capture device 1 has the function of capturing foreign matter (contamination) more accurately regardless of the condition of the oil passage (lubrication circuit) 10, such as oil flow rate and vibration, and suppressing foreign matter from entering functional parts.

[0015] Therefore, the foreign object capturing device 1 mainly comprises an electromagnet 30 placed in the oil passage (lubrication circuit) 10, various sensors (corresponding to the detection means described in the claims, details of which will be described later) that detect the state of the oil passage (lubrication circuit) 10 (for example, oil flow rate, vibration, etc.), and a TCU 50 (corresponding to the control unit described in the claims) that controls the electromagnet 30 (variable magnetic force) according to the detected state of the oil passage (lubrication circuit) 10.

[0016] The electromagnet 30 is disposed within an oil passage (lubrication circuit) 10 through which oil flows. Further, the electromagnet 30 is preferably disposed upstream of functional components that can be affected by foreign matter (contamination) (i.e., on the side where foreign matter flows in). More specifically (in this embodiment), the electromagnet 30 is, for example, arranged (disposed) along the circumferential direction on the outer periphery of the above-described arc-shaped oil guide 21.

[0017] The electromagnet 30 is configured to have, for example, a core made of a magnetic material (such as an iron core) and a coil wound around the outer periphery of the core. The size and magnetic force (rated current value and number of turns of the coil) of the electromagnet 30 are set according to requirements such as the oil flow rate at the installation location and the amount of foreign matter (contamination) to be captured, for example. Note that the electromagnet 30 may be composed of a plurality of electromagnets, that is, it may be divided into a plurality of electromagnets.

[0018] When the electromagnet 30 is turned on (energized), metallic foreign matter (contamination) is captured (adsorbed) by its magnetic force. The drive (on, off, and magnetic force strength) of the electromagnet 30 is controlled by the TCU 50.

[0019] Here, the TCU 50 comprehensively controls the control of the transmission (not shown) (such as shift control, etc.). Further, the TCU 50 controls the drive of the electromagnet 30 (on, off, variable magnetic force).

[0020] Connected to the TCU 50 are, in addition to various sensors for detecting the operating state of the transmission, a rotation speed sensor 51 for detecting the rotational speed of the gear 20 and an oil temperature sensor 52 for detecting the oil temperature (temperature of the oil), etc. Further, the TCU 50 is communicably connected to an ECU 60 that comprehensively controls the engine (not shown), a vehicle dynamics control unit (hereinafter referred to as "VDCU") 70, a driving support device 80, a car navigation system 90, etc., via, for example, a CAN (Controller Area Network) 100.

[0021] The ECU 60 is connected to various sensors such as, for example, a crank angle sensor, an air flow meter, an accelerator sensor 61, a LAF (linear air-fuel ratio) sensor, a water temperature sensor, etc. Based on the detection signals input from the various sensors described above, the ECU 60 acquires various information such as engine speed, intake air volume, accelerator operation amount, air-fuel ratio of the air-fuel mixture, and water temperature. Then, based on these various pieces of information acquired, the ECU 60 comprehensively controls the engine by controlling various devices such as fuel injection amount, ignition timing, and throttle valve.

[0022] The ECU 60 transmits information such as engine speed, engine shaft torque, and accelerator operation amount to the TCU 50 via the CAN 100.

[0023] The VDCU 70 is connected to a brake switch that detects whether the brake pedal is depressed or not, and a brake hydraulic pressure sensor 71 that detects the master cylinder pressure (brake hydraulic pressure) of the brake actuator. The VDCU 70 is also connected to a vehicle speed sensor 73 that detects the rotational speed (vehicle speed) of each wheel of the vehicle, an acceleration sensor 72 that detects the acceleration (G) acting on the vehicle, a stroke sensor 74 that detects the suspension stroke, etc.

[0024] The VDCU 70 drives the brake actuator according to the operation amount (depression amount) of the brake pedal to brake the wheels (vehicle), and detects vehicle behavior by various sensors (for example, vehicle speed sensor 73, steering angle sensor, acceleration sensor 72, yaw rate sensor, etc.), and suppresses skidding and ensures vehicle stability during turning by brake control by automatic pressurization and torque control of the engine.

[0025] Furthermore, the VDCU70 incorporates an anti-lock braking function (ABS function) that prevents wheel lock-up during sudden braking or braking on slippery surfaces, maintains the appropriate slip ratio of each wheel to ensure directional stability and steering performance during braking, and obtains optimal braking force, as well as a traction control function (TCS function) that suppresses wheelspin of the drive wheels caused by slippery surfaces or excessive driving force, ensuring vehicle stability and acceleration during starting and acceleration.

[0026] The VDCU70 transmits braking information (brake operation information) such as detected brake switch and brake fluid pressure, as well as ABS information, wheel speed (vehicle speed), acceleration (G), suspension stroke, etc., to the TCU50 via the CAN100.

[0027] The driver assistance system 80 has functions to detect the external environment of the vehicle (for example, the driving environment in front of the vehicle) and to provide warnings and automatic braking (automatic braking) for obstacles ahead (automatic braking function / pre-collision braking function). In addition, the driver assistance system 80 also has functions to support the driver's driving operations by performing follow control and warning control for detected preceding vehicles.

[0028] The driver assistance system 80 processes image data captured by a stereo camera 81, which consists of, for example, a pair of cameras, to detect, for example, the road conditions and the external driving environment (external environment) such as preceding vehicles and obstacles.

[0029] Furthermore, the driver assistance device 80 recognizes, for example, whether the road surface is wet, covered in snow, or paved or unpaved (rough road) based on road surface reflectivity information. The driver assistance device 80 then transmits this detected external environmental information (for example, whether the road is paved or unpaved (rough road)) to the TCU 50 via the CAN 100.

[0030] The car navigation system 90 detects the vehicle's position based on GPS satellite signals received by the GPS (Global Positioning System). It also calculates the distance traveled based on vehicle speed information and detects the vehicle's direction of travel according to signals from the gyro sensor. Furthermore, the car navigation system 90 acquires road information (including road surface information such as whether it is a paved road or an unpaved road (rough road)) of the road the vehicle is traveling on from a map information storage device such as a built-in hard disk or DVD disc.

[0031] The car navigation system 90 transmits acquired road information (such as road surface information, including whether it is a paved road or an unpaved road (rough road)) to the TCU 50 via the CAN 100.

[0032] The TCU50 consists of a microprocessor that performs calculations, an EEPROM that stores programs for the microprocessor to execute various processes, a RAM that stores various data such as calculation results, a backup RAM whose contents are maintained by a battery, and an input / output interface. The TCU50 also includes a driver circuit that drives the electromagnet 30.

[0033] The TCU50 receives various information from the ECU60, VDCU70, driver assistance device 80, and navigation system 90 via CAN100, in particular information for determining the state of the oil passage (lubrication circuit) 10, namely, accelerator operation amount, braking information such as brake fluid pressure (brake operation information), ABS information, wheel speed (vehicle speed), acceleration (G), suspension stroke, and external environmental information (for example, road surface information such as whether it is an unpaved road (rough road)).

[0034] In this context, the rotation speed sensor 51, oil temperature sensor 52, accelerator sensor 61, brake fluid pressure sensor 71, acceleration sensor 72, vehicle speed sensor 73, stroke sensor 74, stereo camera 81, and car navigation system 90 described above function as detection means as described in the claims.

[0035] The TCU50 controls the electromagnet 30 (variable magnetic force control) to more accurately capture foreign matter (contamination) regardless of the state of the oil passage (lubrication circuit) 10, such as oil flow rate and vibration, and to suppress foreign matter (contamination) from entering functional components. In the TCU50, this function is realized by the execution of a program stored in EEPROM or the like by a microprocessor.

[0036] The TCU 50 controls (variables) the strength of the magnetic force of the electromagnet 30 according to the detected state of the oil passage (lubrication circuit) 10. The TCU 50 controls (variables) the strength of the magnetic force of the electromagnet 30 by varying the current (or voltage) applied to the electromagnet 30 based on the difference.

[0037] More specifically, the TCU 50 controls (varies) the strength of the magnetic force of the electromagnet 30 according to the detected oil flow rate, or to indicator values ​​correlated with the oil flow rate, such as the rotational speed of the gear 20 or the oil temperature. The oil flow rate may be detected (measured) directly, or it may be detected (estimated) indirectly from, for example, the rotational speed of the gear 20 or the oil temperature. Furthermore, the TCU 50 controls (varies) the strength of the magnetic force of the electromagnet 30 according to the magnitude (degree) of vibration (acceleration) applied to the oil passage (lubrication circuit) 10.

[0038] In this process, the TCU50 increases the magnetic force of the electromagnet 30 as the oil flow rate increases, that is, as the rotational speed of gear 20 and the oil temperature increase. Furthermore, the TCU50 increases the magnetic force of the electromagnet 30 as the magnitude (degree) of vibration (acceleration) increases.

[0039] Here, Figure 2(a) shows the relationship between the rotational speed of gear 20, oil temperature, and oil flow rate. Also, Figure 2(b) shows the relationship between the rotational speed of gear 20, oil temperature, and the magnetic force strength (target magnetic force) of electromagnet 30.

[0040] As shown in Figure 2(a), the higher the rotational speed of gear 20 and the higher the oil temperature, the greater the oil flow rate and the greater the amount of foreign matter (contamination) that enters. Therefore, as shown in Figure 2(b), the TCU 50 increases the magnetic force of the electromagnet 30 as the rotational speed of gear 20 and the oil temperature increase, thereby increasing the trapping force (amount of trapping) of foreign matter (contamination).

[0041] In this process, the TCU 50 pre-stores, for example, a map (target magnetic force map) that defines the relationship between the rotational speed of the gear 20, the oil temperature, and the target magnetic force (target current or target voltage). Using the detected rotational speed of the gear 20 and the oil temperature, it searches this target magnetic force map and sets the target magnetic force (target current or target voltage).

[0042] On the other hand, the greater the vibration acting on the oil passage (lubrication circuit) 10, the greater the amount of foreign matter (contamination) re-diffused. In other words (more specifically), when vibrations from driving on rough roads or acceleration from sudden acceleration or deceleration act on the vehicle, there is a risk that captured foreign matter (contamination) will re-diffuse, or that settled foreign matter (contamination) will be released and diffused.

[0043] Therefore, the TCU 50 detects (and estimates) vibrations acting on the oil passage (lubrication circuit) 10 based on, for example, acceleration, accelerator pedal input (rapid acceleration), brake fluid pressure (rapid deceleration), suspension stroke, etc., and increases the magnetic force of the electromagnet 30 as the vibrations acting on the oil passage (lubrication circuit) 10 increase, thereby increasing the ability to capture foreign matter (contamination) (capture amount). In addition, the TCU 50 may predict the road surface conditions (changes in vibration) ahead based on, for example, road surface information from the driver assistance device 80 or the car navigation system 90, and may increase the magnetic force of the electromagnet 30 (for example, maximize it) if it is predicted that vibrations will occur (increase), such as when the road ahead becomes rough (unpaved).

[0044] On the other hand, when the TCU 50 stops (turns off) the operation of the electromagnet 30, it gradually reduces the magnetic force of the electromagnet 30. Also, if the electromagnet 30 consists of multiple electromagnets, the TCU 50 sequentially stops (turns off) the operation of the electromagnets 30, starting from the one located vertically above (upper side).

[0045] By the way, if the magnetic force of the electromagnet 30 is instantly reduced to zero when the vehicle is stopped or the power is turned off, there is a risk that the captured contaminants will disperse. For this reason (to prevent diffusion), it is preferable to gradually reduce the magnetic force of the electromagnet 30 when stopping its operation. Also, if the electromagnet 30 consists of multiple electromagnets, it is preferable to gradually reduce the magnetic force starting from the electromagnet 30 located vertically above (upper side), thereby preventing the re-diffusion of foreign matter (contamination) while guiding and discharging the foreign matter.

[0046] Furthermore, when the TCU 50 stops (turns off) the drive of the electromagnet 30, it sets a delay time (delay time) until the drive of the electromagnet 30 is stopped (turned off) according to the oil temperature at the time of stopping and the operating state (driving state) before stopping, and stops the drive of the electromagnet 30 after the delay time has elapsed.

[0047] For example, if the vehicle stops immediately after high-speed driving, that is, if the electromagnet 30 is turned off while the oil temperature is high, there is a risk that foreign matter (contamination) captured by the electromagnet 30 will disperse in the remaining oil flow (high-temperature, low-viscosity oil). Therefore, it is preferable to maintain the magnetic force for a while (until the delay time has elapsed) and then gradually weaken the magnetic force to prevent the diffusion of foreign matter (contamination).

[0048] Furthermore, after the electromagnet 30 is turned off, any foreign matter (contamination) that has moved away from the electromagnet 30 is preferably allowed to sink by its own weight into an oil pan located at the bottom of the transmission (gearbox), and then captured by a permanent magnet attached around the sinking point. Alternatively, when the engine is started again (when the oil pump is driven), the foreign matter (contamination) may be sucked into the oil strainer by the suction negative pressure of the oil pump and filtered out (captured) by the oil strainer.

[0049] Next, the operation of the foreign object capture device 1 will be explained with reference to Figures 3 and 4. Figure 3 is a flowchart showing the processing procedure for foreign object capture control (magnetic force control). Figure 4 is a flowchart showing the processing procedure for stopping the drive of the electromagnet 30. This process is mainly performed repeatedly at predetermined timings in the TCU 50.

[0050] First, we will explain the processing procedure for foreign object capture control (magnetic force control) using Figure 3.

[0051] In step S100, the rotational speed of gear 20 is read, and in the following step S102, a determination is made as to whether the rotational speed of gear 20 is equal to or greater than a predetermined rotational speed (i.e., whether or not to drive the electromagnet 30). If the rotational speed of gear 20 is equal to or greater than the predetermined rotational speed (i.e., oil is flowing and it is necessary to drive the electromagnet 30), the process proceeds to step S104. On the other hand, if the rotational speed of gear 20 is less than the predetermined rotational speed (i.e., it is not necessary to drive the electromagnet 30), the process is temporarily exited. In this way, by limiting the driving (operation) of the electromagnet 30 to when necessary, the power consumption of the electromagnet 30 can be suppressed.

[0052] In step S104, the target magnetic force (target current or target voltage) is provisionally set according to the rotational speed of gear 20 and the oil temperature (according to the oil flow rate). The method for setting the target magnetic force is as described above, so a detailed explanation is omitted here.

[0053] Next, in step S106, the magnitude of the vibration applied to the oil passage (lubrication circuit) 10 is read (or predicted). Then, in the following step S108, a determination is made as to whether the magnitude of the vibration is greater than or equal to a predetermined value. If the magnitude of the vibration is greater than or equal to the predetermined value, the process proceeds to step S108. On the other hand, if the magnitude of the vibration is less than the predetermined value, the process proceeds to step S110.

[0054] In step S110, the target magnetic force (target current or target voltage) is provisionally set according to the magnitude of the vibration.

[0055] Next, in step 112, a provisional target magnetic force set according to the rotational speed of gear 20 and oil temperature (according to the oil flow rate) is compared with a provisional target magnetic force set according to the magnitude of vibration, and the larger of the two target magnetic forces is determined (adopted) as the final target magnetic force.

[0056] Then, in the following step S114, the magnetic force of the electromagnet 30 is controlled (variable) based on the determined target magnetic force. After that, the process is temporarily exited.

[0057] Next, the procedure for stopping the drive of the electromagnet 30 will be explained using Figure 4. In step S200, if the vehicle is stopped and the engine is turned off, in step S202, a delay time is set for stopping the drive of the electromagnet 30 (turning it off) according to the oil temperature at the time of stopping and the driving state before stopping.

[0058] Next, in step S204, a determination is made as to whether or not the delay time has elapsed. If the delay time has not elapsed, this step is repeated until the delay time has elapsed. On the other hand, if the delay time has elapsed, the process moves on to step S206.

[0059] In step S206, the drive of the electromagnet 30 is stopped (turned off). After that, the process is temporarily exited. The method for stopping the electromagnet 30 is as described above, so a detailed explanation is omitted here.

[0060] As described in detail above, according to this embodiment, the state of the oil passage (lubrication circuit) 10 is detected, and the strength of the magnetic force of the electromagnet 30 is controlled (variable) according to the state of the oil passage 10. Therefore, foreign matter (contamination) in the oil can be captured more accurately in accordance with the state of the oil passage 10.

[0061] As a result, regardless of the condition of the oil passage (lubrication circuit) 10, foreign matter (contamination) can be captured more accurately, and it becomes possible to suppress the entry of foreign matter (contamination) into functional components such as gears, bearings, and control valves. This makes it possible to prevent a decrease in the durability and reliability of these functional components, as well as a deterioration in vibration and noise performance.

[0062] In particular, according to this embodiment, the state of the oil passage (lubrication circuit) 10 is detected, which includes indicator values ​​correlated with the oil flow rate, such as the rotational speed of the gear 20, the oil temperature, and the magnitude (degree) of vibration (acceleration). The strength of the magnetic force of the electromagnet 30 is controlled (variable) according to the detected rotational speed of the gear 20, the oil temperature, and the magnitude of vibration. As a result, foreign matter (contamination) can be accurately captured in accordance with the oil flow rate (i.e., the amount of foreign matter (contamination) flowing in). Furthermore, the re-diffusion of foreign matter can be accurately prevented in accordance with the magnitude (degree) of vibration.

[0063] More specifically, according to this embodiment, the magnetic force of the electromagnet 30 is strengthened as the rotational speed of the gear 20 and the oil temperature increase (i.e., as the oil flow rate increases), and as the magnitude (degree) of vibration (acceleration) increases. Therefore, even when the rotational speed of the gear 20 and the oil temperature increase, and the oil flow rate increases, and the amount of foreign matter (contamination) entering increases, the foreign matter (contamination) can be accurately captured. Furthermore, even when the vibration acting on the oil passage (lubrication circuit) 10 increases, the re-diffusion of foreign matter (contamination) due to vibration can be accurately prevented.

[0064] On the other hand, according to this embodiment, when the drive of the electromagnet 30 is stopped (turned off), the magnetic force of the electromagnet 30 is gradually reduced. Therefore, the re-diffusion of foreign matter (contamination) can be prevented. Also, if the electromagnet 30 consists of multiple electromagnets, the drive is stopped (turned off) sequentially in stages, starting from the electromagnet 30 located vertically above (upper side). Therefore, the re-diffusion of foreign matter (contamination) can be prevented while the foreign matter (contamination) is guided and discharged.

[0065] Furthermore, according to this embodiment, when the drive of the electromagnet 30 is stopped (turned off), a delay time is set until the drive of the electromagnet 30 is stopped, according to the oil temperature at the time of stopping and the operating state (driving state) before stopping, and the drive of the electromagnet 30 is stopped after the delay time has elapsed. Therefore, it is possible to prevent the re-diffusion of foreign matter (contamination) when the drive of the electromagnet 30 is stopped.

[0066] Although embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be modified in various ways. For example, in the above embodiments, the present invention was described as being applied to a lubrication circuit (oil passage) 10 for agitation lubrication by gear 20, but the present invention may be applied to other oil passages (lubrication circuits). For example, as shown in Figure 5, an electromagnet 30 may be arranged downstream of the permanent magnet 40 (or around the permanent magnet 40) in the oil passage (lubrication circuit) 10B through which oil flows. Figure 5 is a diagram showing another arrangement example of the electromagnet 30 that constitutes the foreign object capturing device 1.

[0067] Furthermore, the configuration of the lubrication circuit (oil passage) 10 for agitation lubrication according to the above embodiment is illustrative and can be applied to lubrication circuits (oil passages) for agitation lubrication with other configurations.

[0068] Furthermore, although the above embodiment described the application of the present invention to the oil passages of a transmission as an example, the present invention can also be applied to oil passages (lubrication circuits) of engines and the like. Also, although the electromagnet 30 was controlled by the TCU 50 in the above embodiment, it may be configured to be controlled by another control unit (for example, the ECU 60). [Explanation of Symbols]

[0069] 1 Foreign object capture device 10, 10B Oil path (lubrication circuit) 20 gears 21 Oil Guide 30 Electromagnets 40 permanent magnets 50 TCU 51 Rotation speed sensor 52 Oil temperature sensor 60 ECU 61 Accelerator sensor 70 VDCU 71 Brake fluid pressure sensor 72 Accelerometer 73 Vehicle speed sensor 74 Stroke Sensor 80 Driving assistance systems 81 Stereo Camera 90 Car Navigation System 100 CAN

Claims

1. An electromagnet is placed in an oil passage through which oil flows, A detection means for detecting the state of the oil passage, A foreign object capturing device comprising a control unit that controls the strength of the magnetic force of the electromagnet according to the state of the oil passage detected by the detection means.

2. The detection means detects the oil flow rate or an index value correlated with the oil flow rate, such as the gear rotation speed, oil temperature, and / or the magnitude of vibration, as the state of the oil passage. The foreign object capturing device according to claim 1, characterized in that the control unit controls the strength of the magnetic force of the electromagnet according to the detected oil flow rate or an index value correlated with the oil flow rate, such as the gear rotation speed, oil temperature, and / or the magnitude of vibration.

3. The foreign object capturing device according to claim 2, characterized in that the control unit increases the magnetic force of the electromagnet as the oil flow rate increases or as the gear rotation speed or oil temperature, which are index values ​​correlated with the oil flow rate, increases, and / or as the magnitude of vibration increases.

4. The foreign object capturing device according to claim 3, characterized in that the control unit gradually reduces the magnetic force of the electromagnet when stopping the driving of the electromagnet, or, if the electromagnet consists of multiple electromagnets, sequentially stops the driving of the electromagnets starting from the one located vertically above.

5. The foreign object capturing device according to claim 4, characterized in that the control unit sets a delay time to stop the driving of the electromagnet according to the oil temperature at the time of stopping and the operating state before stopping, and stops the driving of the electromagnet after the delay time has elapsed.

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