JP2011214593A - Power transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent problems produced due to the leakage of oil from a differential chamber for storing a differential mechanism to a coupling chamber for storing a coupling mechanism in a power transmission device of a vehicle in which the differential mechanism is formed integrally with the coupling mechanism for variably controlling a transmission torque to the differential mechanism.SOLUTION: The oil for lubricating the differential mechanism, the bearings 47, 48 of a drive pinion shaft 20, and the like is stored in the differential chamber X. An oil seal 52 for inhibiting the inflow of the oil from the differential chamber X into the coupling chamber Y is installed between the differential chamber X and the coupling chamber Y. An oil leakage sensor 61 for detecting the oil flowing into the coupling chamber Y through the oil seal 52 is disposed at the bottom of the coupling chamber Y. The signal detected by the oil leakage detection sensor is output to a control device on the outside of a housing via conductors 61a, 61a.

Description

  The present invention relates to a power transmission device mounted on a vehicle, and more particularly to a power transmission device including a torque distribution coupling mechanism for a four-wheel drive vehicle, and belongs to the field of vehicle power transmission technology.

  In a four-wheel drive vehicle in which the engine is disposed in the front part of the vehicle body, the torque distribution between the front and rear wheels is variably controlled between the power transmission shaft that transmits power to the rear wheel side and the rear wheel differential mechanism. The coupling mechanism may be provided, and the differential mechanism may be driven via the drive pinion shaft by the output of the coupling mechanism, in which case, for example, as disclosed in Patent Document 1, A housing for housing the coupling mechanism and a housing for housing the drive pinion shaft and the differential mechanism are coupled, and the coupling mechanism and the differential mechanism are integrated to form a power transmission device for driving the rear wheels. It is customary.

  In this type of power transmission device, oil that lubricates the meshing portions of the gears and the bearing portion of the drive pinion shaft, etc. in the differential mechanism is stored in the housing on the differential mechanism side. During the operation, the oil is scraped and supplied to the respective parts.

  In that case, in the power transmission device disclosed in Patent Document 1, an oil seal is provided in the vicinity of a mating portion between the drive pinion shaft and the housing that houses the differential mechanism and the housing that houses the coupling mechanism. After the oil stored in the space in the housing (hereinafter referred to as “the differential chamber”) lubricates each part of the differential mechanism and the bearing of the drive pinion shaft, the space in the latter housing (hereinafter referred to as the “coupling chamber”). ")" To prevent inflow.

  According to this, the oil for lubricating the differential mechanism, the bearing of the drive pinion shaft, etc., compared with the configuration in which the differential chamber and the coupling chamber communicate with each other and the oil in the differential chamber flows into the coupling chamber. It is possible to reduce the amount of oil, and the resistance when the oil stored in the bottom of the differential chamber is lifted is reduced, the weight of the vehicle is reduced, and the fuel efficiency is improved.

  Further, when the member constituting the outer shell of the coupling mechanism is formed of a material that can be corroded by oil, the oil in the differential chamber is prevented from flowing into the coupling chamber as described above. As a result, the cost can be reduced, for example, it is not necessary to apply a coating for preventing corrosion to the member.

Japanese Patent Laid-Open No. 10-281266

  However, as described above, even if the differential chamber and the coupling chamber are partitioned by the oil seal, a slight or small amount of leakage from the oil seal may occur, and the oil in the differential chamber may flow into the coupling chamber. In that case, the following problems may occur.

  That is, for example, in the case of an oil leak from a seal portion or the like where the axle projects from the left and right from the differential mechanism, the oil leaks to the outside of the housing, so it is possible to visually confirm the leak from the outside. Although it is possible, the oil leak from the differential chamber to the coupling chamber is a leak into the housing that houses the coupling mechanism, so it cannot be visually confirmed from the outside and may be overlooked. is there.

  Therefore, when oil leakage from the differential chamber to the coupling chamber cannot be completely prevented by the oil seal, particularly when reducing the amount of oil stored in the differential chamber for weight reduction as described above, This results in insufficient lubrication of the differential mechanism and the drive pinion shaft bearing. In addition, when the outer shell constituent member of the coupling mechanism is formed of a material that can be corroded by oil, if the amount of leakage into the coupling chamber increases, the member may be corroded.

  The present invention has the above-described problems in a power transmission device for a vehicle having a structure in which a differential mechanism and a coupling mechanism are integrated, and a differential chamber and a coupling chamber each housing both mechanisms are partitioned by an oil seal. It is an issue to avoid the problem.

  In order to solve the above problems, a power transmission device according to the present invention is configured as follows.

  First, the invention according to claim 1 of the present application includes a differential mechanism and a coupling mechanism that variably controls torque transmitted to the differential mechanism, and is provided in a housing in which the coupling mechanism is accommodated. The coupling chamber and the differential chamber in the housing in which the differential mechanism is accommodated are disposed adjacent to each other through an oil seal that prevents the oil stored in the differential chamber from flowing into the coupling chamber. An oil leakage detecting means for detecting oil leaked from the differential chamber to the coupling chamber, and oil leaked from the differential chamber to the coupling chamber based on the detection result of the oil leak detecting means And an oil leakage judging means for judging this.

  According to a second aspect of the present invention, in the power transmission device according to the first aspect, the coupling mechanism includes a solenoid that controls a transmission torque, and the housing of the coupling mechanism or the differential mechanism. The housing is provided with an opening for leading the conducting wire for energizing the solenoid to the outside, and the conducting wire connected to the oil leakage detecting means is led to the outside of the housing through the opening. It is characterized by.

  According to a third aspect of the present invention, in the power transmission device according to the first aspect, the coupling mechanism includes a solenoid that controls transmission torque, and the oil leakage detection means is connected to the solenoid. The detection signal of the detection means is output through a conducting wire that energizes the solenoid.

  Further, the invention according to claim 4 is the power transmission device according to claim 3, wherein the current supplied to the solenoid is ON / OFF controlled current, and the current is identified as ON / OFF. And power supply means for supplying the solenoid and the oil leak detection means in superimposition on a high frequency carrier wave capable of identifying the detection signal of the oil leak detection means.

  With the above configuration, according to the invention of each claim of the present application, the following effects can be obtained.

  First, according to the first aspect of the present invention, the oil that is stored in the differential chamber and lubricates each gear meshing portion of the differential mechanism and the bearing portion of the drive pinion shaft that transmits power to the differential mechanism. However, when leaking from the differential chamber to the coupling chamber through the oil seal, the oil leak detecting means detects the leaked oil, and the oil leak determining means is based on the detection signal from the oil leak detecting means. Oil leakage from the differential chamber to the coupling chamber is determined.

  Therefore, since the oil leaked from the differential chamber flows into the housing of the coupling mechanism, it is possible to accurately confirm the occurrence of oil leakage even if visual confirmation from the outside is impossible.

  Then, for example, based on the determination result of the oil leak determination means, it is possible to promptly cope with this by notifying the occupant of the vehicle of the occurrence of oil leak, and thereby the oil for the differential mechanism Even when the amount of the oil is reduced, it is possible to avoid inadequate lubrication with respect to each gear meshing portion or the like in the differential mechanism, and the material that corrodes the outer shell component of the coupling mechanism with oil. Even in the case of using, it is possible to prevent the corrosion in advance.

  According to a second aspect of the present invention, the coupling mechanism has a solenoid, and an opening for guiding a conducting wire for energizing the solenoid to the part is a housing or a differential mechanism of the coupling mechanism. In this case, the opening connected to the oil leak detection means is led out to the outside by using this opening as well. There is no need to further provide a through-hole or the like in the housing, and an increase in processing man-hours and a decrease in strength are avoided.

  According to a third aspect of the present invention, when the coupling mechanism has a solenoid, the oil leakage detection means is connected to the solenoid, and the detection signal of the oil leakage detection means is transmitted through a conducting wire that energizes the solenoid. Since the output is made, the arrangement of the conductors outside the housing is simplified as compared with the case where the conductor of the oil leak detecting means is led out to the portion of the housing separately from the solenoid conductor.

  According to the fourth aspect of the present invention, in the configuration of the third aspect, when the current supplied to the solenoid is a current that is ON / OFF controlled, the current is turned ON / OFF. Since it is superimposed on a high-frequency carrier wave that can be identified and the detection signal of the oil leak detection means can be supplied, the solenoid can be turned off without affecting the operation of the solenoid or the oil leak detection means. Even during the control, it is possible to output the detection signal of the oil leak detection means, and when an oil leak occurs, it can be detected immediately.

It is a cross-sectional top view of the power transmission device which concerns on embodiment of this invention. It is a principal part expansion vertical side view of the power transmission device cut | disconnected by the aa line of FIG. FIG. 3 is an enlarged plan view of a lead wire take-out portion as viewed in the direction of arrow b in FIG. 2. It is a control system figure of the embodiment. FIG. 3 is a control flow diagram. It is an enlarged plan view of the conducting wire takeout part of the second embodiment. It is a principal part expansion vertical side view of 3rd Embodiment. It is an enlarged plan view of the conducting wire extraction part of the same embodiment. It is a control system figure in the embodiment. It is explanatory drawing at the time of using a carrier wave in the same embodiment.

  Hereinafter, embodiments of the present invention will be described.

  First, the overall configuration of the power transmission device 1 according to the present embodiment will be described with reference to FIG. 1. A coupling mechanism 10 connected to a rear end of a propeller shaft A extending rearwardly from the front of the vehicle body in the longitudinal direction of the vehicle body, and a drive pinion shaft (hereinafter referred to as “pinion”) for extracting output from the coupling mechanism 10 to the rear side Shaft 20) and a rear wheel differential mechanism 30 that is driven by the pinion shaft 20 and distributes and transmits torque to the left and right axles B, B. It is integrated.

  Here, the housing 40 is, from the front, a coupling housing 41 that houses the coupling mechanism 10, and a differential carrier (hereinafter referred to as “carrier”) as a housing that houses the pinion shaft 20 and the first half of the differential mechanism 30. ) 42 and an end cover 43 that houses the latter half of the differential mechanism 30.

  The coupling mechanism 10 includes a drum-shaped case 11 whose front end surface is closed and whose rear end surface is opened, a cover 12 that closes the rear end surface of the case 11, and the case 11 and the cover 12. A cylindrical output shaft 14 disposed in the center of the space, having a front end rotatably supported by the case 11 via a bearing 13, and a rear end extending through the center of the cover 12 and extending rearward. Have.

  And between the inner peripheral surface of the said case 11 and the outer peripheral surface of the said output shaft 14, the several friction board 15 ... 15 engaged with these alternately, and the cam mechanism which fastens these friction plates 15 ... 15 16 and a clutch mechanism 17 for operating the cam mechanism 16 by receiving a magnetic force from the outside. These mechanisms are accommodated in a space formed by the case 11 and the cover 12, and the whole unit In addition, the unit of the coupling mechanism 10 is accommodated in the coupling housing 41, and a case 11 constituting the front end portion thereof is rotatably supported by the coupling housing 41 via a bearing 44. Yes.

  Further, the coupling mechanism 10 has a solenoid 18 disposed behind the cover 12, and a plurality of friction plates 15... 15 through the clutch mechanism 17 and the cam mechanism 16 by energization control on the solenoid 18. Thus, the amount of torque transmitted from the propeller shaft A to the differential mechanism 20 side through the output shaft 14 and the pinion shaft 20, in other words, the torque distribution of the front and rear wheels is variably controlled. It has become.

  Here, the solenoid 18 is fixed to the front end portion of the carrier 42 via a cylindrical support member 45, and a boss extending rearwardly provided on the inner peripheral surface of the support member 45 and the cover 12. A bearing 46 is interposed between the outer peripheral surface of the portion 12 a and the rear part of the unit constituting the coupling mechanism 10 is rotatably supported by the carrier 42 via the bearing 46.

  On the other hand, the pinion shaft 20 is rotatably supported by the carrier 42 via bearings 47 and 48, and a front end portion thereof is spline-fitted to the output shaft 14 of the coupling mechanism 10 and is attached to a rear end portion. A drive pinion 21 for driving the differential mechanism 30 is provided.

  The differential mechanism 30 includes a ring gear 31 meshed with the drive pinion 21 at the front end of the pinion shaft, and is coupled to the ring gear 31. A differential case 32 rotatably supported around an axis, and a pair of pinions 34 and 34 rotatably supported by pinion pins 33 disposed in a direction perpendicular to the axis within the differential case 32; It has a pair of left and right side gears 35, 35 meshed with these pinions 34, 34.

  The left and right axles B and B, which are spline-fitted to the side gears 35 and 35, pass through the differential case 32 and pass through holes formed in the mating portion of the carrier 42 and the end cover 43. Extending in the direction, rear wheels (not shown) are respectively attached to the front ends thereof.

  Here, oil is stored in the differential chamber X formed by the carrier 42 in which the differential mechanism 30 is housed and the end cover 43, and the oil is swept up by the rotation of the ring gear 31, so that the differential mechanism 30, the meshing portions of the gears, the bearings 47 and 48 of the pinion shaft 20, and the like are lubricated. In this case, in order to prevent this oil from leaking to the outside, oil seals 51, 51 are mounted in the holes of the mating portion between the carrier 42 and the end cover 43 through which the axles B, B pass.

  Further, an oil seal 52 is attached to the front end portion of the carrier 42 so that the inner peripheral portion is in sliding contact with the outer peripheral surface of the rear end portion of the boss portion 12a provided on the cover 12 of the coupling mechanism 10. The seal 52 separates the differential chamber X from the coupling chamber Y, which is a space outside the coupling mechanism 10 in the coupling housing 41, and the oil in the differential chamber X enters the adjacent coupling chamber Y. It is designed to prevent inflow.

  The space formed by the case 11 and the cover 12 of the coupling mechanism 10 is filled with oil necessary for lubrication of the bearing 13, the friction plates 15 ... 15, the cam mechanism 16, the clutch mechanism 17, and the like. ing. Further, the bearing 44 that supports the case 11 of the coupling mechanism 10 is a grease-enclosed bearing, and rain water or the like from the outside to the bearing 44 or the coupling chamber Y is disposed in front of the bearing 44. An oil seal 53 for preventing the intrusion is attached.

  In addition to the above-described configuration, the power transmission device 1 includes an oil seal 52 from the inside of the differential chamber X at a lower portion in the vicinity of the joint Z between the coupling housing 41 and the carrier 42 as shown in FIG. An oil leakage sensor 61 that detects oil that has passed through the seal portion and flows into the coupling chamber Y and accumulated at the bottom of the chamber Y is provided. The oil leakage sensor 61 detects oil leakage from the differential chamber X to the coupling chamber Y by changing the resistance value by touching the oil.

  Then, the two conducting wires 61a and 61a (only one is shown) connected to the oil leakage sensor 61 are guided to the upper part of the mating portion Z between the coupling housing 41 and the carrier 42, and the coupling mechanism 10 The two lead wires 18a and 18a (only one is shown) for energizing the solenoid 18 are led out to the outside.

  That is, as shown in FIGS. 2 and 3, an opening 41a is formed in the upper portion of the mating portion Z of the coupling housing 41 by cutting the mating surface of the coupling housing 41 with the carrier 42 into a substantially semicircular shape. A rubber grommet 62 that closes the opening 41a is mounted, and the total of the four conducting wires 18a, 18a, 61a, 61a are led to the outside through the grommet 62. ing.

  And as shown in FIG. 4, the two conducting wires 18a, 18a for energizing the solenoid 18 and the two conducting wires 61a, 61a connected to the oil leakage sensor 61 are connected to the control device 70, The control device 70 performs energization control of the solenoid 18, that is, torque distribution control of the front and rear wheels, and a signal from the oil leakage sensor 61 is input to the control device 70 to perform control when oil leakage is detected.

  That is, as shown in the flowchart of FIG. 5, when the resistance value of the oil leakage sensor 61 changes from a reference value by a predetermined value or more and the state continues for a predetermined time, the warning lamp 71 provided in the driver's seat of the vehicle. Is lit to notify the occupant of oil leakage from the differential chamber X to the coupling chamber Y. Here, instead of turning on the warning lamp, a warning buzzer may be operated, or a warning display may be performed on a display provided in the driver's seat.

  According to the above configuration, the oil stored in the differential chamber X is lifted up by the ring gear 31 of the differential mechanism 30, and the meshing portions of the gears in the differential mechanism 30 and the bearings 47 and 48 of the pinion shaft 20. It is conceivable that this oil passes through the oil seal 52 disposed between the differential chamber X and the coupling chamber Y and flows into the coupling chamber Y.

  In this case, since the coupling chamber Y is a space inside the coupling housing 41, the inflow of oil into the chamber Y cannot be visually confirmed from the outside, and the oil in the differential chamber X is reduced. May be overlooked. However, when a predetermined amount of oil leaking into the coupling chamber Y accumulates at the bottom of the chamber Y, the oil leakage sensor 61 detects this, and the control device 70 leaks oil from the differential chamber X to the coupling chamber Y. Determine. Then, the warning lamp 71 is turned on to notify the occupant of this oil leak.

  This makes it possible to quickly take measures against the oil leakage, such as replenishing oil to the differential chamber X. In particular, each gear meshing portion of the differential mechanism 30 and the bearing 47 of the pinion shaft 20 for reducing the vehicle weight. Even when the amount of lubricating oil such as 48, 48 is reduced, insufficient lubrication of the differential mechanism 30 can be avoided.

  In addition, when oil leakage occurs, it is possible to quickly cope with it, so when using a material corroded by oil as a material of the case 11 and the cover 12 constituting the outer shell of the coupling mechanism 10, It is possible to prevent the corrosion without requiring a coating for preventing the corrosion.

  In particular, in the power transmission device 1, the two conductors 61 a and 61 a connected to the oil leakage sensor 61 are coupled together with the two conductors 18 a and 18 a that energize the solenoid 18 of the coupling mechanism 10. Since it is led out through the grommet 62 of the opening 41a provided in the mating part Z of the housing 41 and the carrier 42, in addition to the opening 41a for leading out the conducting wires 18a, 18a of the solenoid 18, There is no need to separately provide an opening for leading out the conducting wires 61a and 61a of the sensor 61.

  Thereby, compared with the case where two openings are provided, the processing man-hour of the coupling housing 41 is reduced, and a decrease in the strength of the housing 41 due to the provision of the openings is suppressed. By sharing the grommet 62, an increase in the number of parts can be avoided.

  In this embodiment, as the oil leak sensor 61, a sensor whose resistance value changes by touching oil is used, but a sensor whose capacitance changes may be used.

  In addition, the two conductors 18a and 18a connected to the solenoid 18 and the earth conductor of the two conductors 61a and 61a connected to the oil leakage sensor 61 are connected in the coupling chamber Y. If the number is unified, as shown in FIG. 6, the number of the conducting wires that pass through the grommet 62 ′ attached to the opening 41a can be made three, and the power transmission device is compared with the case where there are four conducting wires. 1 is simplified, and the opening 41a and the grommet 62 'can be miniaturized.

  In the embodiment shown in FIG. 7, conductive wires 61 a ′ and 61 a ′ (only one is shown) of the oil leak sensor 61 are connected to the solenoid 18. In this case, as shown in FIG. As a result, only two conductors are required to be led to the outside from the opening 41a, and the arrangement of the conductors outside the power transmission device 1 is further simplified, and the opening 41a and the grommet 62 "of the coupling housing 41 are further simplified. Can be further reduced in size.

  In this case, as a mode of connecting the conducting wire of the oil leak sensor 61 to the solenoid 18, in the case of the resistance type sensor 61, as shown in FIG. In the case of 61 ′, the solenoid 18 is connected in parallel as shown in FIG. In either case, the solenoid 18 and the oil leakage sensors 61 and 61 ′ are connected to the control devices 70 ′ and 70 ″ by sharing the two conductors, and the conductors 18a and 18a for energizing the solenoids are connected. Through this, detection signals from the oil leakage sensors 61 and 61 'are input to the control devices 70' and 70 ".

  By the way, as shown in FIGS. 7-9, when the conducting wire for energizing the solenoid 18 and the conducting wire for inputting signals from the oil leakage sensors 61 and 61 'are shared, when the solenoid 18 is OFF. The sensors 61 and 61 'are not energized, and even if an oil leak occurs, it cannot be detected until the solenoid 18 is next turned on.

  Therefore, as shown in FIG. 10, the current ON / OFF signal energizing the solenoid 18 is configured to be superimposed on the high frequency carrier wave and output, and the frequency and amplitude of the carrier wave at that time are set to the solenoid signal ON, OFF and set so that the oil detection signals of the oil leak sensors 61 and 61 ′ can be identified. As a result, while the conducting wire for energizing the solenoid 18 and the conducting wire for inputting a signal from the oil leakage sensor 61, 61 ′ are shared, the sensor 61, 61 ′ can also be used when the solenoid 18 is OFF. A signal indicating oil leakage can be input, and oil leakage can always be detected promptly.

  As described above, according to the present invention, in a vehicle power transmission device in which a differential mechanism and a coupling mechanism that variably controls a transmission torque to the differential mechanism are integrated, the differential mechanism and the like are lubricated. It is possible to prevent poor lubrication with respect to the differential mechanism or the like while reducing the amount of oil. Therefore, the present invention may be suitably used in the manufacturing industry of vehicles equipped with this type of power transmission device. is there.

DESCRIPTION OF SYMBOLS 1 Power transmission device 10 Coupling mechanism 18 Solenoid 18a Conductor 30 Differential mechanism 41 Housing (coupling housing)
41a Opening 42 Housing (carrier)
52 Oil seal 61, 61 'Oil leak detection means 61a Conductor wire 70, 70', 70 "Oil leak judgment means, power supply means (control device)

Claims (4)

A differential mechanism; a coupling mechanism that variably controls torque transmitted to the differential mechanism; a coupling chamber in a housing in which the coupling mechanism is accommodated; and the differential mechanism is accommodated. A differential chamber in the housing is a power transmission device disposed adjacently via an oil seal that prevents the oil stored in the differential chamber from flowing into the coupling chamber;
Oil leakage detecting means for detecting oil leaking from the differential chamber to the coupling chamber;
A power transmission device comprising: an oil leakage determination unit that determines that oil has leaked from the differential chamber to the coupling chamber based on a detection result of the oil leakage detection unit. The coupling mechanism includes a solenoid that controls transmission torque,
An opening is provided in the housing of the coupling mechanism or the housing of the differential mechanism to lead the conducting wire for energizing the solenoid to the outside, and
The power transmission device according to claim 1, wherein a conducting wire connected to the oil leakage detection unit is led out of the housing through the opening. The coupling mechanism includes a solenoid that controls transmission torque,
The oil leak detection means is connected in series or in parallel to the solenoid,
The power transmission device according to claim 1, wherein a detection signal of the detection means is output through a conducting wire energizing the solenoid. The current flowing through the solenoid is a current that is ON / OFF controlled.
Power supply means for supplying the current to the solenoid and the oil leak detection means by superimposing the current on a high frequency carrier wave capable of identifying ON / OFF and the detection signal of the oil leak detection means is provided. The power transmission device according to claim 3.

Images