JP2008128444A - Parking device for automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a parking device for an automatic transmission, which reliably holds a parking released condition. <P>SOLUTION: The parking device for the automatic transmission comprises: a parking rod 12 for engaging/disengaging a parking pole 33 with/from a parking gear 37; a parking lock spring 40 for energizing the parking pole 33 in the direction of engaging it with the parking gear 37 to move the parking rod 12; a hydraulic cylinder 15 for moving the parking rod 12 against the energizing force of the parking lock spring 40 in the direction of releasing the parking pole 33 from the parking gear 37; and a holding solenoid 21 for preventing the axial movement of the parking rod 12. The holding solenoid 21 prevents the axial movement of the parking pole 33 so as to hold the parking pole 33 released from the parking gear 37. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a parking device for an automatic transmission, and more particularly to a parking device suitable for a shift-by-wire automatic transmission.

  In an automatic transmission of an automobile, a range in which a necessary line pressure circuit is switched among a parking range (P range), a reverse range (R range), a neutral range (N range), a forward range (D range), etc. A switching valve is provided. This range switching valve is generally switched manually by a shift lever in the driver's seat.

  In this type of automatic transmission, a parking mechanism is provided for locking the rotation of the output shaft of the automatic transmission by switching the range switching valve to the P range. Such a parking mechanism comprises a parking gear provided on the output shaft and a parking pole that is detachably engaged with the parking gear. When the shift lever is switched to the P range, the parking rod is connected via a link mechanism or the like. Is to be slid. By sliding the parking rod, the parking pole is rotated via the parking cam, and the parking pole is engaged with the parking gear to lock the rotation of the output shaft.

  By the way, in the so-called shift-by-wire automatic transmission in which the range switching valve described above is switched by the operation of a selector switch or a shift button provided in the driver's seat, a separate drive means is used to slide the parking rod of the parking mechanism. Must be used. For example, Patent Literature 1 describes a device using a hydraulic cylinder as drive means.

  In the above-described Patent Document 1, when the shift lever is switched to the parking range, the hydraulic oil in the oil chamber (253) is discharged and the parking piston (252) is moved by the action of the spring (251). It moves to the left direction of FIG. 3, and it will be in a parking lock state.

When the shift lever is switched to a range other than the parking range, hydraulic oil is supplied to the oil chamber (253), the parking piston (252) is moved to the right in FIG. 3, and the parking release state is established.
JP 57-57944 A (6th page, FIG. 3)

  However, in the one described in Patent Document 1 described above, at the time of parking release, the parking piston is pressed by the action of the hydraulic oil against the urging force of the spring, so that sudden shifting is repeated and the amount of oil consumption increases rapidly. In some cases, the parking piston may move in the parking direction during traveling due to a pressure reduction phenomenon that occurs when the oil pump sucks air.

  The present invention has been made to solve the above-described conventional problems, and an object thereof is to provide a parking device for an automatic transmission that can reliably maintain a parking release state.

    In order to solve the above problems, the parking device for an automatic transmission according to claim 1 is characterized in that a vehicle is provided by engaging a detachable parking pole with a parking gear provided on an output shaft of the automatic transmission. A parking rod that moves in the axial direction in a parking device that restricts the movement of the parking rod, and a parking rod that engages and disengages the parking pawl with the parking gear, and urges the parking rod to engage the parking pawl with the parking gear. A parking lock spring that urges the parking rod in a direction and a predetermined operating oil pressure are supplied, and the parking pole is released from the parking gear against the urging force of the parking lock spring. A hydraulic cylinder for moving the parking rod; and an axial direction of the parking rod. Holding electromagnetic drive means for preventing movement, the holding electromagnetic drive means for preventing the parking pole from moving in the axial direction so as to keep the parking pole released from the parking gear. is there.

  According to a second aspect of the present invention, there is provided a parking device for an automatic transmission according to the first aspect, wherein the holding electromagnetic driving means is a solenoid, and the holding shaft is movable in the axial direction when the solenoid is driven and not driven. The roller has a roller rotatably provided at the tip of the holding shaft, and the solenoid is engaged with a recess provided in the parking rod during driving.

    According to a third aspect of the present invention, there is provided a parking device for an automatic transmission according to the first or second aspect, wherein the holding electromagnetic driving means is configured such that the predetermined operating oil pressure is supplied to the hydraulic cylinder and the shaft of the parking rod is provided. It is driven to prevent movement in the direction.

  According to a fourth aspect of the present invention, there is provided a parking device for an automatic transmission according to any one of the first to third aspects, wherein the driver is requested to release the parking pole from the parking gear. Is stopped, the electric oil pump is driven based on a signal from the control unit of the vehicle, and predetermined hydraulic oil supplied from the electric oil pump is supplied to the hydraulic cylinder.

  In the parking device for the automatic transmission according to the first aspect, when the parking is released, the hydraulic cylinder moves the parking rod in a direction to release the parking pole from the parking gear against the urging force of the parking lock spring. Further, the holding electromagnetic drive means prevents the parking pole from moving in the axial direction so as to keep the parking pole released from the parking gear. Thereby, even if a pressure reduction phenomenon occurs, it is possible to prevent the parking rod from being moved by the biasing force of the parking lock spring. Therefore, according to the parking device for the automatic transmission, the parking release state can be reliably maintained.

  In the automatic transmission parking device according to the second aspect of the present invention, since the roller provided rotatably at the tip of the holding shaft of the solenoid is disposed, the parking rod is attached to the parking rod when engaged with the parking gear. Since the roller rotates at the corners of the disposed recesses and is accurately engaged with the recesses, the parking rod can be held accurately. In addition, when the parking pole is engaged with the parking gear by the parking lock spring, the roller rotates to reduce friction between the parking rod and the solenoid holding shaft, so only the parking lock spring is urged. Thus, the parking pole can be accurately engaged with the parking gear.

  In the automatic transmission parking device according to the third aspect, the parking rod can be prevented from moving in the axial direction in a state where the parking gear is released from the parking pole, and the restriction on the movement of the vehicle can be accurately canceled. Can do.

  In the automatic transmission parking device according to the fourth aspect, when the driver is requested to release the parking pole from the parking gear, and when the vehicle engine is stopped, the control unit of the vehicle Since the electric oil pump is driven based on the signal and the predetermined hydraulic oil supplied from the electric oil pump is supplied to the hydraulic cylinder, the parking rod can be moved to keep the parking pole released from the parking gear. . Therefore, the vehicle can be pulled while the engine is stopped.

  An embodiment of a parking device for an automatic transmission according to the present invention will be described below with reference to the drawings. FIG. 1 shows an outline of a parking device 10 for an automatic transmission. The parking rod 12 is supported by the support portions 13 and 14 so as to be movable in the axial direction. A parking cam 31 is slidably fitted at one end of the parking rod 12, that is, the right end in FIG. 1, and the parking cam is inserted by a spring 32 inserted between the parking cam 31 and the parking rod 12. 31 is urged to the right in FIG. 1 with respect to the parking rod 12 and is prevented from coming off at a predetermined position on the parking rod 12. In addition, 39 is a guide member which guides the front-end | tip part of the parking rod 12 so that sliding is possible.

  As shown in FIG. 2, the parking pole 33 is configured such that one end 34 is rotatably supported and the other end 35 is engaged with the parking cam 31. An engaging portion 36 that removably engages with a parking gear 37 that is mounted on the output shaft of the automatic transmission is provided at the center of the parking pole 33. The parking pole 33 is rotated in a direction in which the engaging portion 36 is disengaged from the parking gear 37 by the urging force of the spring 38, whereby one end portion 35 is always in contact with the parking cam 31.

  As shown in FIG. 1, a hydraulic cylinder 15 is provided at the center of the parking rod 12. The hydraulic cylinder 15 has a cylinder tube 16 fixed to the case body 11, a piston 17 that can slide in the cylinder tube 16, and an oil chamber 18 to which hydraulic oil for pressing the piston 17 is supplied. ing. The parking rod 12 penetrates the cylinder tube 16 and is fixed to the piston 17. Further, a parking lock spring 40 is inserted between the cylinder tube 16 and the piston 17, and the parking rod 12 is biased rightward in FIG. 1 by the parking lock spring 40. The parking lock spring 40 has a spring load necessary for engaging the parking pole 33 with the parking gear 37 via the parking cam 31.

  The case main body 11 is provided with a holding solenoid 21. The holding solenoid 21 can move the mover 23 upward in FIG. 1 against the urging force of the spring 24 by energizing the coil 22, and the mover 23 slides on the case body 11. It is connected to a holding shaft 25 that is supported. A roller 26 is supported at the tip of the holding shaft 25 so as to be rotatable around an axis center in the direction perpendicular to the paper surface of FIG. Further, a recess 12a that engages with the roller 26 is provided on the other end side of the parking rod 12, that is, on the left side in FIG.

  When hydraulic oil is supplied to the oil chamber 18 of the hydraulic cylinder 15, the parking rod 12 is moved to the left in FIG. 1 against the urging force of the parking lock spring 40, whereby the parking cam 31 is moved to the parking pole. Departed from 33. As a result, the parking pole 33 is disengaged from the parking gear 37 by the urging force of the spring 38, and the parking release state is set. When a holding current is supplied to the coil 22 of the holding solenoid 21, the holding shaft 25 is moved together with the mover 23 in FIG. 1, and the roller 26 and the recess 12 a are engaged. This prevents the parking rod 12 from moving in the parking lock direction even when a pressure drop occurs during parking release.

  Further, as shown in FIG. 3, when the supply of the holding current to the coil 22 of the holding solenoid 21 is stopped, the holding shaft 25 is moved downward along with the mover 23 in FIG. Is disengaged. When the supply of hydraulic oil to the oil chamber 18 of the hydraulic cylinder 15 is stopped, the parking rod 12 is moved to the right in FIG. 3 by the biasing force of the parking lock spring 40. Accordingly, the parking pawl 33 is rotated by the parking cam 31 pressed by the spring 12, the parking pawl 33 is engaged with the parking gear 37, the rotation of the output shaft of the automatic transmission is prevented, and the parking lock state is set. The

  In FIGS. 1 and 3, reference numeral 45 denotes a position sensor that detects the position of the parking pole 33 and detects that the parking pole 33 is engaged with the parking gear 37. Based on the detection signal of the position sensor 45, The holding solenoid 21 is controlled. The position sensor 45 is a proximity switch, and is not limited to the parking pole 33, and detects that the parking pole 33 is engaged with the parking gear 37 by detecting the position of the parking cam 31 or the parking rod 12. Can do.

  As shown in FIG. 4, the shift lever 60 includes a P range (parking range) for requesting parking of the vehicle, an R range (reverse range) for requesting reverse travel, an N range (neutral range) for requesting stop, and a forward drive. Characters (P, R, N, D) representing the D range (drive range) requesting traveling are displayed. When the driver operates the shift lever 60, one required range is selected, and a shift signal corresponding to the selected required range is input to the control unit 61. In addition to the shift lever 60, the holding solenoid 21, the position sensor 45, and the electric oil pump 62 are connected to the control unit 61. In this embodiment, the shift lever 60 is employed. However, as long as the shift signal corresponding to the requested range selected by the driver can be generated, for example, a selector switch, a shift button, A voice input device or the like may be used.

  The parking device 10 of the automatic transmission configured as described above controls the hydraulic cylinder 15 and the holding solenoid 21 based on the selection operation of the shift lever 60 by the driver, and the parking device 10 is controlled by parking lock control or parking release. Control. The operation will be described below based on the flowcharts of FIGS.

  In the parking lock state shown in FIG. 3, when the D range, that is, the NotP range is selected by the operation of the shift lever 60 by the driver, the NotP drive flag is established, and the parking release program shown in FIG. 5 is executed. When the parking release program is executed, it is first determined in step S10 whether or not the engine is rotating. If the engine is rotating (YES), step S12 is executed. If the engine is stopped (NO), step S11 is executed.

  In step S11, the electric oil pump 62 is started. When the engine is stopped, hydraulic oil is supplied from the electric oil pump 62 to the oil chamber 18 of the hydraulic cylinder 15. In step S <b> 12, hydraulic oil is supplied to the oil chamber 18 of the hydraulic cylinder 15. As a result, the parking rod 12 is moved to the left against the urging force of the parking lock spring 40. Then, the parking cam 31 is detached from the parking pole 33, and the parking pole 33 is disengaged from the parking gear 37 by the biasing force of the spring 38.

  In step S <b> 13, a holding current is supplied to the coil 22 of the holding solenoid 21. Thereby, the holding shaft 25 is moved upward together with the mover 23, and the roller 26 and the recess 12a are engaged. In step S14, the timer is reset and the timer count is started. This timer detects a failure of the parking apparatus 10.

  In step S15, whether or not the signal of the position sensor 45 that detects the position of the parking pole 33 has been switched from ON to OFF, that is, whether or not the parking pole 33 has been positioned at the unlocked position released from the parking gear 37. Is determined. When the signal of the position sensor 45 is switched from ON to OFF (YES), it is determined that the parking pole 33 is located at the unlocked position released from the parking gear 37, and Step S16 is executed. If the signal of the position sensor 45 is ON (NO), it is determined that the parking pole 33 is not positioned at the unlocked position released from the parking gear 37, and step S17 is executed.

  In step S16, the electric oil pump 62 is stopped and the execution of the parking release program is ended. In this case, the parking pole 33 is positioned at the unlocked position released from the parking gear 37, and the roller 26 and the concave portion 12a are engaged with each other, as shown in FIG.

  In step S17, it is determined whether or not a predetermined time has elapsed by the timer. If the predetermined time has not elapsed (NO), the process returns to step S15. Moreover, when predetermined time passes (YES), it determines with the parking apparatus 10 having failed, and step S18 is performed. In step S18, the electric oil pump 62 is stopped. In step S19, the driver is warned that the parking device 10 is out of order, and the execution of the parking release program is terminated.

  On the other hand, when the P range is selected by the driver operating the shift lever 60 in the parking release state shown in FIG. 1, the P drive flag is established, and the parking lock program shown in FIG. 6 is executed. When the parking lock program is executed, it is first determined in step S30 whether or not the engine is rotating. If the engine is rotating (YES), step S31 is executed. If the engine is stopped (NO), step S32 is executed.

  In step S31, the supply of hydraulic oil to the oil chamber 18 of the hydraulic cylinder 15 is stopped. In step S32, the supply of the holding current to the coil 22 of the holding solenoid 21 is stopped. As a result, the holding shaft 25 is moved downward together with the mover 23, and the engagement between the roller 26 and the recess 12a is released. The parking rod 12 is moved to the right by the urging force of the parking lock spring 40, the parking pawl 33 is rotated by the parking cam 31 pressed by the spring 12, and the parking pawl 33 is engaged with the parking gear 37. The rotation of the output shaft of the automatic transmission is prevented. In step S33, the timer is reset and the timer count is started. This timer detects a failure of the parking apparatus 10.

  In step S34, whether or not the signal of the position sensor 45 that detects the position of the parking pole 33 has been switched from OFF to ON, that is, whether or not the parking pole 33 is positioned at the locked position where the parking gear 37 is engaged. Is determined. When the signal of the position sensor 45 is switched from OFF to ON (YES), as shown in FIG. 3, it is determined that the parking pole 33 is positioned at the locked position engaged with the parking gear 37, and the parking lock program Execution is terminated. When the signal of the position sensor 45 is OFF (NO), it is determined that the parking pole 33 is not positioned at the lock position engaged with the parking gear 37, and step S35 is executed.

  In step S35, it is determined whether a predetermined time has elapsed by the timer. If the predetermined time has not elapsed (NO), the process returns to step S34. Moreover, when predetermined time passes (YES), it determines with the parking apparatus 10 having failed, and step S36 is performed. In step S36, an operation command is output to an unillustrated electric brake system, and the vehicle is held in a stopped state by the electric brake system. In step S37, the driver is warned that the parking apparatus 10 has failed, and the execution of the parking release program is terminated.

  Even when the parking rod 12 is moved to the right by the urging force of the parking lock spring 40 due to a failure or the like while the vehicle is running, the parking pole 33 is rebounded by the rotating parking gear 37. Therefore, the parking cam 31 is slid relative to the parking rod 12 against the urging force of the spring 32. When the vehicle is stopped, the parking pole 33 is engaged with the parking gear 37 by the urging force of the spring 32.

  In the parking device 10 of the automatic transmission according to the embodiment, when the parking release is performed, the parking cylinder 12 is moved in such a direction that the hydraulic cylinder 15 releases the parking pole 33 from the parking gear 37 against the urging force of the parking lock spring 40. Move. Further, the holding solenoid 21 prevents the parking pole 33 from moving in the axial direction so as to keep the parking pole 33 released from the parking gear 37. Thereby, even if a pressure reduction phenomenon occurs, the parking rod 12 can be prevented from being moved by the biasing force of the parking lock spring 40. Therefore, according to the parking device for the automatic transmission, the parking release state can be reliably maintained.

  In the parking device 10 of the automatic transmission, the roller 26 is provided at the tip of the holding shaft 25 of the holding solenoid 21 so as to be rotatable. The roller 26 rotates at the corner of the concave portion 12a disposed in the parking rod 12 when engaged, and is accurately engaged with the concave portion 12a, so that the parking rod 12 can be accurately held. Furthermore, when the parking pole 33 is engaged with the parking gear 37 by the parking lock spring 40, the friction between the parking rod 12 and the holding shaft 25 can be reduced by the rotation of the roller 26. The parking pole 33 can be accurately engaged with the parking gear 37 only by urging the spring 40.

  Further, in the parking device 10 of this automatic transmission, the parking rod 37 can be prevented from moving in the axial direction while the parking gear 37 is released from the parking pole 33, and the restriction on the movement of the vehicle is accurately canceled. can do.

  Further, in this automatic transmission parking device 10, when the driver is requested to release the parking pole 33 from the parking gear 37 and the vehicle engine is stopped, the vehicle control unit In order to drive the electric oil pump 62 based on the signal from the motor and supply the predetermined hydraulic oil supplied from the electric oil pump 62 to the hydraulic cylinder 15, the parking pole 33 is parked so as to maintain the release from the parking gear 37. The rod 12 can be moved. Therefore, the vehicle can be pulled while the engine is stopped.

  The automatic transmission parking apparatus according to the present invention has been described with reference to the embodiments. However, the present invention is not limited to these embodiments, and may be modified as appropriate and applied as long as the technical idea of the present invention is not violated. Needless to say, it can be done.

Schematic diagram of parking device for automatic transmission of embodiment 1 is a perspective view showing a relationship between a parking pole and a parking gear, according to a parking device for an automatic transmission according to an embodiment. The schematic diagram which shows the operating state of the parking apparatus of the automatic transmission of embodiment. The block diagram of the parking apparatus of the automatic transmission of embodiment. The flowchart of the parking release program in connection with the parking apparatus of the automatic transmission of the embodiment. The flowchart of a parking lock program concerning the parking apparatus of the automatic transmission of embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 12 ... Parking rod, 15 ... Hydraulic cylinder, 21 ... Holding electromagnetic drive means (holding solenoid), 25 ... Holding shaft, 26 ... Roller, 12a ... Recess, 31 ... Parking cam, 33 ... Parking pole, 40 ... Parking lock Spring, 61 ... control unit, 62 ... electric oil pump.

Claims (4)

In a parking device for restricting movement of a vehicle by engaging a detachable parking pole with a parking gear provided on an output shaft of an automatic transmission,
A parking rod that engages and disengages the parking pole with the parking gear by moving in the axial direction, and biases the parking rod and biases the parking pole in a direction to engage the parking gear. A parking lock spring that moves the rod and a hydraulic cylinder that is supplied with a predetermined hydraulic pressure and moves the parking rod in a direction to release the parking pole from the parking gear against the biasing force of the parking lock spring And holding electromagnetic drive means for preventing the parking rod from moving in the axial direction,
The parking device for an automatic transmission, wherein the holding electromagnetic drive means prevents the parking pole from moving in the axial direction so as to keep the parking pole released from the parking gear. In claim 1,
The holding electromagnetic drive means is a solenoid, and has a holding shaft that can move in the axial direction when the solenoid is driven and not driven, and a roller that is rotatably provided at the tip of the holding shaft.
A parking device for an automatic transmission, wherein the solenoid is engaged with a recess provided in the parking rod when the solenoid is driven. In Claim 1 or Claim 2,
The parking apparatus for an automatic transmission, wherein the holding electromagnetic drive means is driven to prevent the parking rod from moving in the axial direction after a predetermined operating oil pressure is supplied to the hydraulic cylinder.   4. The vehicle control unit according to claim 1, wherein when the driver is requested to release the parking pole from the parking gear and the vehicle engine is stopped, the vehicle control unit is based on a signal. A parking apparatus for an automatic transmission, characterized in that an electric oil pump is driven and predetermined hydraulic oil supplied from the electric oil pump is supplied to the hydraulic cylinder.

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