JP4930480B2 - Lubrication device using microbubbles - Google Patents

Description

  The present invention relates to a lubrication apparatus using microbubbles, which can generate microbubbles by mixing air into lubricating oil.

  Conventionally, a lubrication device that lubricates and cools components provided inside a transmission when the transmission is operated by the operation of the internal combustion engine is known, and an example thereof is described in Patent Document 1. In this patent document 1, a mission oil circulation path for lubricating and cooling the inside of a transmission is provided, and a microbubble generator for generating microbubbles from air as a gas is provided. Furthermore, an oil pump for pressurizing oil in the circulation path is provided. Then, the temperature of the mission oil is detected, and it is determined whether or not the temperature of the mission oil is equal to or lower than a predetermined value. The predetermined value is a temperature at which it is difficult to start the internal combustion engine due to the friction of the transmission. When the temperature of the mission oil supplied to the transmission is equal to or lower than a predetermined value, microbubbles are generated by operating the microbubble generator, and the microbubbles are mixed into the mission oil. The mission oil mixed with microbubbles can reduce viscosity, heat transfer rate, and heat capacity compared to oil not mixed with microbubbles. As a result, friction in the transmission can be reduced, and when starting an internal combustion engine connected to the transmission, the startability can be improved. Patent Documents 2 to 4 describe inventions in which microbubbles are mixed in the fuel of an internal combustion engine.

JP 2007-24011 A Japanese Patent Laid-Open No. 2007-24012 JP 2007-224815 A Japanese Utility Model Publication No. 5-61446

  By the way, although the degree of drag may vary depending on the state of the rotating element provided in the transmission, the lubricating device described in Patent Document 1 determines whether or not to generate microbubbles based on the temperature of the mission oil. The drag state of the rotating element provided in the transmission is not considered, and there is room for improvement in this respect.

  The present invention has been made paying attention to the above technical problem, and is a lubricating device using microbubbles capable of changing the viscosity of the lubricating oil in accordance with the specific drag state of the rotating element. Is intended to provide.

  In order to achieve the above object, an invention according to claim 1 is configured such that a transmission gear ratio between an input rotating member and an output rotating member can be changed, and a transmission provided in the casing, A microbubble having a lubricating oil supply device that supplies lubricating oil to a portion to be lubricated and a microbubble generator that generates microbubbles by mixing air in the lubricating oil before being supplied to the lubricated portion In the lubricating device using the above, the lubricated portion is attached to the casing so as not to rotate, and stops a rotating element provided in a power transmission path from the input rotating member to the output rotating member of the transmission. A difference in rotational speed between the brake and the rotating element is determined in advance as bubbles are generated in the lubricating oil due to relative rotation between the brake and the rotating element. A rotational speed difference determining means for determining whether or not a predetermined rotational speed difference is exceeded, and when it is determined that the rotational speed difference between the brake and the rotating element exceeds a predetermined rotational speed difference A first supply means for supplying the lubricating oil to the brake without mixing air in the lubricating oil by the microbubble generator, and a rotational speed difference between the brake and the rotating element is predetermined. And a second supply means for supplying the brake with the lubricating oil in which the microbubbles are generated by the microbubble generator when it is determined that the difference in rotational speed is not exceeded. Is.

  According to a second aspect of the present invention, in addition to the structure of the first aspect, a heating device is provided to warm the air before the microbubble generator is mixed with the lubricating oil. Before the air is mixed into the lubricating oil by the microbubble generator, and the oil temperature detecting means for detecting the oil temperature of the lubricating oil and the oil temperature detecting means. Comparing means for determining whether or not the oil temperature is equal to or lower than a predetermined value that is determined in advance as dragging between the brake and the rotating element, and the oil temperature of the lubricating oil by the comparing means. When it is determined that the temperature is less than or equal to a predetermined value, the air heated by the heating device is supplied to the lubricating oil to warm the lubricating oil and generate microbubbles. Supply to brake A third supply unit, and the rotation speed difference determination unit determines whether the oil temperature of the lubricating oil is not lower than a predetermined value by the oil temperature determination unit. It is characterized by including means for determining whether or not the rotational speed difference exceeds a predetermined rotational speed difference.

  According to a third aspect of the present invention, in addition to the configuration of the second aspect, when it is determined that the temperature of the lubricating oil is not lower than a predetermined value, the transmission gear ratio is controlled by the brake. The first supply means includes a gear ratio determining means for determining whether or not the gear ratio is achieved when power is generated, and the first supply means is configured such that the gear ratio of the transmission is controlled by the brake. And a means for supplying the lubricating oil to the brake without making a determination of the rotational speed difference determining means when it is determined that the transmission ratio is achieved. When the speed ratio of the transmission is determined not to be a speed ratio achieved by generating a braking force with the brake, the speed difference between the brake and the rotating element is a predetermined speed. Including means for determining whether the difference is exceeded, The third supply means, when it is determined that the oil temperature of the lubricating oil is equal to or lower than a predetermined value, does not make the determination of the gear ratio determination means, and the rotation speed difference determination means Without the determination of the above, characterized in that there is provided means for supplying air warmed by the heating device to the lubricating oil to generate a microvalve, and supplying the lubricating oil generated by the microbubbles to the brake Is.

  According to the first aspect of the present invention, when the brake is released, it is determined whether or not the rotational speed difference between the brake and the rotating element exceeds a predetermined rotational speed difference, and the brake and the rotating element are determined. When it is determined that the rotational speed difference exceeds the predetermined rotational speed difference, the microbubble generator supplies the lubricating oil to the brake without mixing air into the lubricating oil. On the other hand, if it is determined that the rotational speed difference between the brake and the rotating element does not exceed a predetermined rotational speed difference, the lubricating oil in which microbubbles are generated by the microbubble generator is applied to the brake. To supply. Therefore, only under conditions where dragging occurs in the brake due to the viscous resistance of the lubricating oil, the microbubble generator generates microbubbles in the lubricating oil to reduce the viscosity of the lubricating oil, and the lubricating oil whose viscosity has decreased Can be supplied to the brake.

  According to the invention of claim 2, in addition to obtaining the same effect as that of the invention of claim 1, it is determined whether or not the oil temperature of the lubricating oil is equal to or lower than a predetermined value. Here, when it is determined that the oil temperature of the lubricating oil is equal to or lower than a predetermined value, the lubricating oil is warmed and microbubbles are generated by supplying the air heated by the heating device to the lubricating oil. Later, the lubricant is supplied to the brake. In addition, when it is determined that the temperature of the lubricating oil is not lower than a predetermined value, it is determined whether or not the rotational speed difference between the brake and the rotating element exceeds a predetermined rotational speed difference.

  According to the invention of claim 3, in addition to obtaining the same effect as that of the invention of claim 2, when it is determined that the temperature of the lubricating oil is not lower than a predetermined value, the transmission is predetermined. It is determined whether or not the brake is engaged in order to achieve the transmission gear ratio. When it is determined that the brake is engaged, lubricating oil that is not mixed with air is supplied to the brake without making the determination of the rotational speed difference determining means. When it is determined that the brake is released, it is determined whether or not the rotational speed difference between the brake and the rotating element exceeds a predetermined rotational speed difference. When it is determined that the temperature of the lubricating oil is equal to or lower than a predetermined value, a determination is made by the rotation speed difference determination means without determining whether the brake is engaged. Without performing, the air heated by the heating device is supplied to the lubricating oil to generate micro bubbles, and the lubricating oil in which the micro bubbles are generated is supplied to the brake.

  In the present invention, lubricating oil is supplied to the brake to lubricate and cool the rotating and stationary elements. Thereby, the temperature rise of a rotation element and a fixed element is suppressed, seizure and wear are suppressed, and durability improves. The input rotation member, the output rotation member, and the rotation element in the present invention are elements that constitute a power transmission path, and the input rotation member, the output rotation member, and the rotation element are connected to each other by connecting a rotation shaft, a gear, and the rotation elements. Includes drums. The lubricating oil supply apparatus according to the present invention includes an oil pump that gives kinetic energy to the lubricating oil, an oil passage that is a passage of the lubricating oil, and a valve. The heating device according to the present invention includes a device for warming the lubricating oil by using heat generated by the generation of power from a driving force source mounted on the vehicle, or a dedicated device provided for warming the lubricating oil. .

  Next, a specific example when the present invention is used in a vehicle will be described with reference to FIG. An engine 3 is mounted on a vehicle 1 as an object of the present invention as a driving force source that generates power to be transmitted to wheels 2. The engine 2 is a power unit that outputs power by burning fuel, and an internal combustion engine such as a gasoline engine, a diesel engine, or an LPG engine can be used as the engine 2.

  The engine 2 has a configuration in which heat energy generated by fuel combustion is converted into rotational motion of the crankshaft 4, and a fluid transmission device 5 is provided so as to be able to transmit power to the crankshaft 4. This fluid transmission device 5 is a device that can transmit power by the kinetic energy of fluid. Specifically, a hollow casing 6 is fixed to the outer wall of the engine 3, and the fluid transmission device 5 is provided inside the casing 6. The fluid transmission device 5 includes a pump impeller 7 and a turbine runner 8, and the pump impeller 7 is connected to the crankshaft 4 so as to be able to transmit power, specifically, to rotate integrally. Further, an oil pump 9 is provided inside the casing 6. The oil pump 9 is driven by the power of the pump impeller 7 and sucks oil from an oil pan (not shown) and discharges the sucked oil.

  An input shaft 10 is connected to the turbine runner 8 so that power can be transmitted. Further, a transmission 11 is provided in the power transmission path from the input shaft 10 to the wheels 2. This transmission 11 is also provided inside the casing 6. The transmission 11 has a plurality of sets of planetary gear mechanisms. Specifically, it has a first planetary gear mechanism 12 and a second planetary gear mechanism 13. The first planetary gear mechanism 11 constitutes an auxiliary transmission unit, and is constituted by a single pinion type planetary gear mechanism. The first planetary gear mechanism 12 has a sun gear 14 and a ring gear 15 that are arranged coaxially with each other, and a carrier 17 that holds the pinion gear 16 meshed with the sun gear 14 and the ring gear 15 so as to be capable of rotating and revolving. is doing. The sun gear 14 is coupled to rotate integrally with the input shaft 10.

  A second planetary gear mechanism 13 is disposed on the outer peripheral side of the input shaft 10. The second planetary gear mechanism 13 constitutes a main transmission unit, and is constituted by a Ravigneaux planetary gear mechanism. The second planetary gear mechanism 13 includes a first sun gear 18 and a ring gear 19 arranged coaxially, a short pinion gear 20 meshed with the first sun gear 18, and a long pinion gear meshed with the short pinion gear 20 and the ring gear 19. 21, a carrier 22 that holds the short pinion gear 20 and the long pinion gear 21 so as to rotate and integrally revolve, and a second sun gear 23 meshed with the long pinion gear 21. The first sun gear 18 and the second sun gear 23 are disposed so as to be relatively rotatable and coaxial. Further, the number of teeth of the first sun gear 18 is configured to be smaller than the number of teeth of the second sun gear 23.

  Next, a clutch for connecting and releasing the rotating elements of the first planetary gear mechanism 12 and the second planetary gear mechanism 13 and a brake for selectively stopping (fixing) each rotating element will be described. First, a first clutch C1 for selectively connecting and releasing the second sun gear 23 and the input shaft 10 is provided. Further, a second clutch C2 for selectively connecting and releasing the ring gear 19 and the input shaft 10 is provided. Further, a first brake B1 for stopping both the carrier 17 and the first sun gear 18 is provided. Further, a second brake B2 for stopping the ring gear 19 is provided. Further, a third brake B3 for stopping the ring gear 15 is provided.

  In this specific example, a description will be given by taking as an example a case where a friction engagement device such as each clutch and brake is a hydraulically controlled friction engagement device in which engagement and release are controlled by hydraulic pressure. Each brake is a multi-plate brake in which a plurality of annular disks are coaxially arranged in a direction along the axis of the input shaft 10. An annular disk is supported by the casing 6 so as not to rotate, and is configured to be operable in a direction along the axis. A plurality of plates that rotate integrally with the power transmission member of the transmission 11 and that can operate in the direction along the axis are arranged in the direction along the axis. In particular, the brake B2 has a plurality of discs 50 that are supported by the casing 6 so as not to rotate. On the other hand, the ring gear 19 stopped by the engagement of the brake B2 is formed on the annular member 51, and a plurality of plates 52 are attached to the annular member 51.

  The plate 52 is configured to be operable in a direction along the axis. A friction material is attached to the disk 50 and the plate 52 along the circumferential direction. In the brake B2, when the hydraulic pressure in the hydraulic chamber is increased, the disc 50 is pressed against the plate 52 and the braking force increases. This is the engagement of the brake B2. On the other hand, when the hydraulic pressure in the hydraulic chamber is reduced, the brake 50 is separated from the plate 52 and the braking force is reduced. This is the release of the brake B2. Each clutch is a multi-plate clutch in which annular plates and annular disks are alternately arranged in the direction along the axis of the input shaft 10. An annular disk and an annular plate are separately provided on the rotating elements to be connected, and are configured to be operable in a direction along the axis. Each of these friction engagement devices is a friction engagement device configured to be lubricated and cooled by being supplied with lubricating oil, that is, a wet friction engagement device.

  Here, a lubrication apparatus that lubricates and cools the lubricated portion provided inside the casing 11 will be described. In this embodiment, the lubricating device is configured to lubricate and cool the lubricated portion by supplying lubricating oil (oil) to the lubricated portion. Specifically, a lubricating oil supply device 24 as shown in FIG. 3 is provided to supply the lubricating oil to the lubricated portion in the casing 11. The lubricating oil supply device 24 includes an oil passage 25 for supplying the oil discharged from the oil pump 9 to the lubricated portion, a passage, a hole, an opening, a pipe, a valve 26, and the like. In addition to each brake and each clutch, the lubricated portion includes a meshing portion of gears constituting the transmission 11, a bearing that rotatably supports a power transmission member of the transmission 11, and the like.

  Further, a microbubble generator 27 is provided that generates microbubbles (fine bubbles) by mixing air into the lubricating oil before being supplied to the lubricated part. Microbubbles are mixed in the oil discharged from the microbubble generator 27. The microbubble generator 27 can be provided, for example, inside the casing 6 or outside the casing 6. When the microbubble generator 27 is provided inside the casing 6, the oil passage 25 is configured such that oil discharged from the oil pump 9 provided inside the casing 6 is supplied to the microbubble generator 27. In addition, the oil passage can be configured so that the oil discharged from the microbubble generator 27 is supplied to the lubricated portion. On the other hand, when the microbubble generator 27 is provided outside the casing 6, an oil passage through which oil discharged from an oil pump (not shown) provided outside the casing 6 is supplied to the microbubble generator 27. (Not shown) can be provided, and an oil passage (not shown) can be configured such that the oil discharged from the microbubble generator 27 is supplied into the casing 6.

  As the microbubble generator 27, for example, a swirling flow type, a fine hole type, a supersaturated precipitation type or the like can be used. A swirling flow type microbubble generator is described in, for example, Japanese Patent Application Laid-Open No. 2007-447 and Japanese Patent Application Laid-Open No. 2007-209953. A micro-hole type microbubble generator is described in, for example, JP-A-9-207874. A supersaturated precipitation type microbubble generator is described in, for example, Japanese Patent Application Laid-Open No. 2007-844. In this embodiment, a swirl type microbubble generator 27 as shown in FIG. 3 is used. A casing 28 constituting a part of the microbubble generator 27 is provided, and the oil discharged from the oil pump 9 is supplied into the casing 28 via the oil passage 25 and the valve 26. Further, a supply path 29 for supplying air to the casing 28 is provided, and the air in the supply path 29 is supplied into the casing 28 through the air supply port 30. When air is supplied into the casing 28, rotational shearing of oil occurs, and microbubbles are generated by the rotational shearing. In FIG. 3, the flow of oil in the casing 28 is indicated by arrows. And it is the structure by which the oil containing a microbubble is supplied to the to-be-lubricated part in the casing 6. FIG.

  Furthermore, an example of an air supply mechanism for supplying air to the microbubble generator 27 will be described with reference to FIG. A switching valve 31 is connected to the supply path 29. The switching valve 31 is a mechanism that selectively connects the two supply paths 32 and 33 to the supply path 29. A part of the air used in the indoor air conditioner of the vehicle 1 is supplied to the supply path 32. On the other hand, a heat source 34 that warms the air passing through the supply path 33 is provided. The heat source 34 includes the engine 3 itself or an exhaust pipe connected to the engine 3. The heat of the heat source 34 is transmitted to the air and warms the air. The switching valve 31 is configured by a known solenoid valve, and includes an input port 35 connected to the supply path 32, an input port 36 connected to the supply path 33, and an output port 37 connected to the supply path 29. And have. When the energization current to the switching valve 31 is controlled, control for connecting one of the two input ports 35 and 36 to the output port 37 and control for blocking the two input ports 35 and 36 can be performed.

  Furthermore, a hydraulic control device 38 is provided to control the engagement and release of the friction engagement device. The hydraulic control device 38 includes a hydraulic circuit to which oil discharged from the oil pump 9 is supplied, a switching valve that switches a flow path of oil supplied to the hydraulic circuit, a pressure control valve that controls the hydraulic pressure of the hydraulic circuit, and a hydraulic circuit It is a well-known thing provided with the flow control valve etc. which control the flow volume of the oil which flows through. Then, by controlling the hydraulic pressure of the hydraulic chamber provided for each friction engagement device, the engagement and release of each friction engagement device can be controlled. In particular, in the brake B2, when the hydraulic pressure in the hydraulic chamber increases, the disc 50 is pressed against the plate 52, the frictional force increases, and the braking force applied to the ring gear 19 increases. That is, the brake B2 is engaged. On the other hand, in the brake B2, when the hydraulic pressure in the hydraulic chamber decreases, the disc 50 moves away from the plate 52, the frictional force decreases, and the braking force applied to the ring gear 19 decreases. That is, the brake B2 is released.

  Next, the configuration of the power transmission path from the carrier 22 to the wheel 2 will be described. The carrier 22 is disposed on the outer periphery of the input shaft 10 so that the carrier 22 and the input shaft 10 can rotate relative to each other. A counter drive gear 39 is formed on the carrier 22. The input shaft 10 is supported so as to be rotatable about an axis, and a countershaft 40 is provided that is rotatable about an axis parallel to the axis of the input shaft 10. A counter driven gear 41 is formed on the counter shaft 40, and the counter drive gear 39 and the counter driven gear 41 are engaged with each other. A drive pinion gear 42 is formed on the counter shaft 40. Further, a differential case 43 is provided in the casing 6, and a ring gear 44 is formed on the outer periphery of the differential case 43. The ring gear 44 and the drive pinion gear 42 are meshed with each other. The ring gear 44 and the drive pinion gear 42 constitute a final reduction gear. Further, a pinion gear 48 and a side gear 45 are provided inside the differential case 43, and a drive shaft 46 is connected to the side gear 45. A wheel (front wheel) 2 is connected to the drive shaft 46 so that power can be transmitted.

  Furthermore, a control system for controlling a system mounted on the vehicle 1 will be described. An electronic control unit 47 is provided as a controller for controlling the system mounted on the vehicle 1. The electronic control unit 47 includes a request for starting the engine 3, an accelerator opening degree indicating the depression state of the accelerator pedal, Sensor and switch detection signals that detect the depressed state, shift position, vehicle speed, engine speed, etc., and sensor signals that detect the temperature (oil temperature) of the oil (oil pan oil) before being supplied to the lubricated part A signal of a sensor for detecting the rotational speed of the input shaft 10 is input. The electronic control unit 47 stores data for controlling the engine output, data for controlling the gear position of the transmission 11, and data for controlling the switching valve 31. Based on a signal input to the electronic control unit 47 and data stored in the electronic control unit 47, a signal for controlling the engine speed and the engine torque, a signal for controlling the hydraulic control unit 38, and the switching valve 31. A signal for controlling is output.

  In the above vehicle, when the engine 3 is operated, the engine torque is transmitted to the input shaft 10 via the fluid transmission device 5. On the other hand, a driver operates a shift position selection device (not shown) provided in the vehicle 1 to set a parking (P) position, a reverse (R) position, a neutral (N) position, and a drive (D) position. Selectable. The transmission 11 is controlled by switching the shift positions. An operation state of the clutch and the brake when the drive position and the reverse position are selected will be described with reference to FIG. The electronic control unit 38 stores a shift map for controlling the shift stage of the transmission 11, and at the drive position, the shift stage of the transmission 11 is controlled based on the shift map. This shift map defines a region for selecting each shift stage using the vehicle speed and the accelerator opening as parameters.

  Specifically, the first speed (1st), the second speed (2nd), the third speed (3rd), the fourth speed (4th), the fifth speed (5th), and the sixth speed as the speed stages of the transmission 11. The (6th) gear position can be selectively switched. That is, the transmission 11 is a stepped transmission that can switch the gear ratio stepwise. In FIG. 4, “◯” mark means that the clutch or the brake is engaged. Furthermore, the blank in FIG. 4 means that the clutch or brake is released. Although not shown in FIG. 4, when the parking position is selected or when the neutral position is selected, all the brakes and clutches are released. When the drive position or the reverse position is selected, the engine torque is transmitted to the wheels 2 via the transmission 11 to generate driving force.

  Next, an example of control performed in this embodiment will be described based on the flowchart of FIG. First, the input signal is processed in the electronic control unit 47, and various controls are performed based on the data and the input signal stored in the electronic control unit 47 (step S1). In step S1, for example, a sensor signal for detecting the vehicle speed, the opening degree of the aquacel, the oil temperature of the oil stored in the oil pan, the shift position, the engine speed, and the like is processed. Various controls include obtaining a required driving force based on the vehicle speed and the accelerator opening, and controlling the engine output from the required driving force. Thus, when the engine 3 is operated, the oil pump 9 is driven by the engine torque and the oil in the oil pan is sucked, and a part of the oil discharged from the oil pump 9 is covered in the casing 6. Supplyed to the lubrication part, the lubricated part is lubricated and cooled. Various controls include obtaining a target gear position of the transmission 11 based on the vehicle speed, the accelerator opening, and the shift map. A part of the oil discharged from the oil pump 9 is supplied to the hydraulic control device 38, and in order to achieve the target shift speed in the transmission 11, the hydraulic chamber for engaging and releasing the friction engagement device. Hydraulic pressure is controlled.

  Following this step S1, it is determined whether or not the oil temperature of the oil (that is, the oil in the oil pan) before being supplied to the lubricated part is below a predetermined value (step S2). The predetermined value used for the determination in step S2 is the responsiveness of the hydraulic control system and the power by dragging when the rotating element of the transmission 11 rotates when the viscosity of the oil supplied to the transmission 11 is relatively high. It is a predetermined value from the loss, and is a value obtained by experiment or simulation.

  Therefore, when a positive determination is made in step S2, the operation of the switching valve 31 is controlled so that the oil can be warmed and the viscosity can be lowered (step S3), and this control routine is ended. When the process proceeds to step S3, the supply path 29 and the supply path 33 are connected by the operation of the switching valve 31, and the input port 35 is shut off. For this reason, air is heated by the heat of the heat source in the process of passing through the supply path 33, and the warmed air is supplied to the microbubble generator 27 via the supply path 29. A part of the oil discharged from the oil pump 9 is supplied to the container 28 via the oil passage 25, and microbubbles are mixed in the oil. In this way, the oil is warmed by the air, and the oil mixed with the microbubbles is discharged from the discharge port 28A of the container 28, and the oil is supplied to the lubricated portion in the casing 6. Thus, since the viscosity of the oil supplied to the hydraulic chamber that controls the engagement and release of the friction engagement device is relatively reduced, the response of engagement and operation of the friction engagement device is reduced. Can be avoided. Further, since the viscosity of the oil is relatively lowered, when the oil is supplied to the lubricated portion, the drag torque of the oil generated by the rotation of the rotating element can be reduced, and the increase in power loss can be avoided.

  On the other hand, if a negative determination is made in step S2, the gear position of the transmission 11 at the drive position is calculated (step S4). This may be obtained using the vehicle speed, the accelerator opening, and the shift map, or may be obtained from the engaged and released states of all the friction engagement devices. Following this step S4, it is determined whether or not the first speed (1st) is selected in the transmission 11 and the brake B2 is engaged (step S5). If the determination in step S5 is affirmative, it means that the disk 50 and the plate 52 do not rotate relative to each other. That is, in the brake B2, drag torque due to oil viscosity resistance is not generated. This means that it is not necessary to further reduce the viscosity of the oil supplied to the brake B2. Therefore, if a positive determination is made in step S5, the operation of the switching valve 31 is controlled to shut off both the input ports 35 and 36 (step S6), and this control routine is terminated. As a result, the oil discharged from the oil pump 9 is supplied to the lubricated part in the casing 6 via the microbubble generator 27, but the microbubble generator 27 does not generate microbubbles.

  On the other hand, if a negative determination is made in step S5, the input rotational speed Nin of the transmission 11 (the rotational speed of the input shaft 10) is calculated (step S7), and the rotational speed between the disk 50 and the plate 52 is calculated. It is determined whether or not the difference is less than a predetermined value (step S8). This predetermined value is a predetermined value as a reference for determining that aeration (bubble) is generated in the lubricating oil existing in the vicinity of the brake B2 due to the relative rotation of the disk 50 and the plate 52. This is the calculated value. If a negative determination is made in step S8, that is, if the relative rotational speed difference is large, the oil existing in the vicinity of the brake B2 is agitated by the relative rotation between the disc 50 and the plate 52, and aeration (bubbles) is generated. And the viscosity of the oil decreases. For this reason, the drag torque generated by the relative rotation between the disk 50 and the plate 52 becomes relatively low. This means that the microbubble generator 27 does not need to artificially generate microbubbles. Therefore, if a negative determination is made in step S8, the process proceeds to step S6.

  On the other hand, if the determination in step S8 is affirmative, even if the disk 50 and the plate 52 rotate relative to each other, aeration does not occur in the oil existing in the vicinity of the brake B2, and drag is generated in the brake B2. Torque can be relatively large. Therefore, when a positive determination is made in step S8, the switching valve 31 is controlled to connect the supply path 32 and the supply path 29 and control to shut off the input port 36 (step S9). The control routine ends. By the processing in step S9, the air (without warm air) in the supply path 32 is supplied to the microbubble generator 27, the microbubbles are mixed into the oil, and the oil is supplied to the brake B2. Therefore, generation of drag torque by the brake B2 can be avoided, and reduction in fuel consumption of the engine 3 can be suppressed. Further, since the oil pump 9 is not configured to mix and discharge air into the oil, pressure loss due to the air mixed into the oil by the oil pump 9 can be reduced.

  Note that the negative determination in step S2 basically means that the oil viscosity is relatively low, but even when the oil viscosity needs to be further reduced (determined affirmative in step S8). Further, the temperature of the oil cannot be raised (for example, it causes deterioration of the oil), or the viscosity does not change even if the temperature of the oil is raised. In step S9, the temperature of the oil is raised. Without generating microbubbles, the viscosity of the oil is reduced.

  Here, the correspondence between the functional means shown in FIG. 1 and the configuration of the present invention will be described. Step S8 corresponds to the rotational speed difference determining means of the present invention, and step S6 is the first of the present invention. Step S9 corresponds to the second supply means of the present invention, Step S1 corresponds to the oil temperature detecting means of the present invention, Step S2 corresponds to the comparison means of the present invention, Step S3 corresponds to the third supply means of the present invention, and step S5 corresponds to the speed ratio determining means of the present invention.

  2 and FIG. 3 and the configuration of the present invention will be described. The transmission 11 corresponds to the transmission of the present invention, and the input shaft 10 is the input rotation of the present invention. The ring gear 19 corresponds to the power transmission member of the present invention, the counter drive gear 39 corresponds to the output rotating member of the present invention, the casing 6 corresponds to the casing of the present invention, and the brake B2 The plate 52 corresponds to the rotating element of the present invention, the microbubble generator 27 corresponds to the microbubble generator of the present invention, the oil passage 25, the valve 26, and the oil pump 9 Is equivalent to the lubricating oil supply device of the present invention, and the heat source 34 is equivalent to the heating device of the present invention.

  Next, another specific example of the heating device used in the vehicle 1 of FIG. 2 will be described based on FIG. In FIG. 5, a heater 41 that warms the air passing through the supply path 40 is provided. When the heater 41 is turned on, the air passing through the supply path 40 is warmed, and when the heater 41 is turned off, the air is not warmed through the supply path 40. A switching valve 42 is provided between the supply path 40 and the supply path 29. The switching valve 42 has an input port 43 and an output port 44, a supply path 40 is connected to the input port 43, and a supply path 29 is connected to the output port 44. The supply path 29 and the supply path 40 are connected or blocked by the operation of the switching valve 42. A known solenoid valve can be used as the switching valve 42. The operation of the switching valve 42 and ON / OFF of the heater 41 are controlled by a signal from the electronic control unit 47. The heating device shown in FIG. 5 can be used in place of the heating device shown in FIG.

  A control example when the heating device of FIG. 5 is used in the vehicle 1 of FIG. 2 will be described based on the flowchart of FIG. In the flowchart of FIG. 6, steps that perform the same processing as in the flowchart of FIG. 1 are assigned the same step numbers as in the flowchart of FIG. 1. In the flowchart of FIG. 6, when a negative determination is made in step S <b> 2, the heater 41 is turned on, the air in the supply path 40 is warmed (step S <b> 11), and the supply path 29 and the supply are controlled by the control of the switching valve 42. The path 40 is connected (step S12), and this control routine is terminated. Thereby, the warmed air is supplied to the microbubble generator 27, and the same effect as the case where the process of step S3 of FIG. 1 is performed can be obtained.

  On the other hand, when a positive determination is made in step S2, the heater 41 is turned off (step S13), and the process proceeds to step S5. If the determination in step S5 is affirmative, it is not necessary to mix microbubbles in the oil supplied to the brake B2 for the same reason as described above. Therefore, when a positive determination is made in step S5, the switching valve 42 is controlled to shut off the supply path 40 and the supply path 29 (step S14), and this control routine is ended. When the control in step S14 is performed, the air in the supply path 40 is not supplied to the microbubble generator 27. For this reason, the same effect as the case where the process of step S6 is performed in the flowchart of FIG. 1 can be obtained.

  On the other hand, if a negative determination is made in step S5, the process proceeds to step S8 via step S7. If a positive determination is made in step S8, the process proceeds to step S12. That is, unwarmed air is supplied to the microbubble generator 27, and microbubbles are mixed into the oil. For this reason, when it progresses to step S12 via step S8, the effect similar to the case where it progresses to step S9 from step S8 in FIG. 1 is acquired. Further, if a negative determination is made in step S8, the process proceeds to step S14. As described above, when the process proceeds from step S8 to step S14, the same effect as when the process proceeds from step S8 to step S6 in the flowchart of FIG. 1 can be obtained.

  Here, the correspondence between the functional means shown in FIG. 6 and the configuration of the present invention will be described. Step S8 corresponds to the rotational speed difference determining means of the present invention, and step S14 is the first of the present invention. 1 corresponds to the first supply means, step S12 corresponds to the second supply means of the present invention, step S2 corresponds to the oil temperature determination means of the present invention, and steps S11 and S12 correspond to the third supply of the present invention. Corresponds to means. Further, the correspondence between the configuration shown in FIG. 5 and the configuration of the present invention will be described. The heater 41 corresponds to the heating device of the present invention.

  In the flowcharts of FIGS. 1 and 6, the oil temperature detecting means is described as step S1 and the comparing means is step S2. However, the oil temperature detecting means and the comparing means are the same steps. There may be. Further, the gear stage of the transmission 11 may be performed in step S1. Further, the determination in step S7 may be made in step S1. The friction engagement devices described in the above specific examples are all configured to be controlled in engagement and release by hydraulic control. However, the actuator that controls the engagement and release of the friction engagement device is a hydraulic type. In addition, an electromagnetic actuator or a mechanical actuator may be used. Moreover, although the transmission has a planetary gear mechanism, it may be a transmission having a planetary roller mechanism. Further, a transmission is constituted by a planetary mechanism having differentially rotatable input elements and reaction force elements and output elements, and the speed ratio between the input elements and the output elements is controlled by controlling the rotational speed of the reaction force elements. The control shown in FIGS. 1 and 6 can be executed even in a vehicle having a transmission capable of changing the speed continuously. Further, in the vehicle shown in FIG. 2, the engine 3 is shown as a driving force source. However, the control shown in FIGS. 1 and 6 can be executed even in a vehicle using an electric motor instead of the engine 3. . Furthermore, the control shown in FIGS. 1 and 6 can be executed even in a vehicle provided with both the engine 3 and the electric motor as driving force sources.

It is a flowchart which shows the example of control which can be performed with the lubricating device in this invention. It is a conceptual diagram which shows the structure of the vehicle which has a lubricating device of this invention. It is sectional drawing which shows the structural example of the microbubble generator shown by FIG. 3 is a chart showing an operation of a friction engagement device provided in the transmission of FIG. 2. It is a schematic diagram which shows the other structural example of the heating apparatus used for the vehicle shown by FIG. It is a flowchart which shows the other example of control which can be performed with the lubricating device in this invention.

Explanation of symbols

  6 ... casing, 9 ... oil pump, 10 ... input shaft, 11 ... transmission, 19 ... ring gear, 25 ... oil passage, 26 ... valve, 27 ... microbubble generator, 34 ... heat source, 39 ... counter drive gear, 41 ... Heater, 50 ... Disc, 52 ... Plate, B2 ... Brake.

Claims (3)

A transmission configured to change a gear ratio between the input rotating member and the output rotating member, and provided in the casing; and a lubricating oil supply device that supplies the lubricating oil to the lubricated portion in the casing; In a lubricating device using microbubbles, having a microbubble generating device that mixes air in the lubricating oil before being supplied to the lubricated part and generates microbubbles,
The lubricated portion is a brake that is attached to the casing in a non-rotatable manner and stops a rotating element provided in a power transmission path from an input rotating member to an output rotating member of the transmission,
It is determined whether the rotational speed difference between the brake and the rotating element exceeds a predetermined rotational speed difference that bubbles are generated in the lubricant due to relative rotation between the brake and the rotating element. A rotational speed difference judging means;
If it is determined that the rotational speed difference between the brake and the rotating element exceeds a predetermined rotational speed difference, the microbubble generator does not mix air into the lubricating oil. First supply means for supplying oil to the brake;
When it is determined that the rotational speed difference between the brake and the rotating element does not exceed a predetermined rotational speed difference, lubricating oil in which microbubbles are generated by the microbubble generator is supplied to the brake. And a second supply means for supplying the lubricating device using microbubbles. Before the air is mixed into the lubricating oil in the microbubble generator, a heating device that warms the air is provided,
Oil temperature detecting means for detecting the oil temperature of the lubricating oil before the lubricating oil is supplied to the brake and before air is mixed into the lubricating oil in the microbubble generator;
A comparing means for determining whether or not the oil temperature detected by the oil temperature detecting means is equal to or less than a predetermined value that is determined in advance as dragging occurs between the brake and the rotating element;
If it is determined by this comparison means that the oil temperature of the lubricating oil is below a predetermined value, the air heated by the heating device is supplied to the lubricating oil to warm the lubricating oil, and the microbubbles And a third supply means for supplying the lubricant to the brake after generating
The rotational speed difference determining means determines a rotational speed difference between the brake and the rotating element when the oil temperature determining means determines that the oil temperature of the lubricating oil is not lower than a predetermined value. The lubricating device using microbubbles according to claim 1, further comprising means for determining whether or not the rotational speed difference is exceeded. Whether or not the gear ratio of the transmission is a gear ratio achieved when a braking force is generated by the brake when it is determined that the oil temperature of the lubricating oil is not lower than a predetermined value. A gear ratio determining means for determining whether
When it is determined that the speed ratio of the transmission is a speed ratio achieved by generating a braking force with the brake, the first supply means does not perform the determination of the rotation speed difference determination means, Means for supplying the lubricant to the brake;
The rotational speed difference determining means determines that the rotational speed difference between the brake and the rotating element is determined when it is determined that the speed ratio of the transmission is not a speed ratio achieved by generating a braking force with the brake. Including means for determining whether or not a predetermined rotational speed difference is exceeded,
The third supply means does not make the determination of the gear ratio determination means and determines the rotation speed difference determination means when it is determined that the temperature of the lubricating oil is equal to or lower than a predetermined value. Without the determination of the above, characterized in that there is provided means for supplying air warmed by the heating device to the lubricating oil to generate a microvalve, and supplying the lubricating oil generated by the microbubbles to the brake A lubrication device using the microbubble according to claim 2.

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