Vehicle transmission

Abstract

To provide a vehicle transmission capable of preventing a power transmission shaft from rotating abruptly using an oil pump during release of a parking lock, to prevent drivability of a vehicle from deteriorating.SOLUTION: A transmission 3 comprises a parking gear 32 provided on a counter shaft 11, and a parking pole 33 that restricts rotation of the counter shaft 11 by engaging with the parking gear 32 and allows the rotation of the counter shaft 11 when disengaged from the parking gear 32. An oil pump 40 is attached to the counter shaft 11, and when the parking gear 32 and parking pole 33 are disengaged, the oil pump 40 serves as resistance to the rotation of the counter shaft 11.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a vehicle transmission.

Background Art

[0002] A parking lock mechanism mounted on a vehicle has a parking gear on a power transmission shaft in a power transmission path from a drive source to drive wheels, and engages a parking pole with teeth of the parking gear to restrict rotation of the power transmission shaft, thereby restricting rotation of the drive wheels.

[0003] In this parking lock mechanism, when the drive wheels ride over a wheel stopper, or when switching from another shift position to the parking position on a slope and operating the parking lock mechanism to release the foot brake, the drive shaft is twisted by the rotational force applied to the drive shaft of the drive wheels.

[0004] Therefore, the twist of the drive shaft is transmitted to the power transmission shaft having the parking gear, and the drive system from the drive shaft to the power transmission shaft is twisted, and a state where the torsional torque is accumulated is formed.

[0005] Therefore, when switching the shift position from the parking position to another shift position and releasing the parking lock mechanism at the time of starting, the torsional torque of the drive system is released and the vehicle vibrates, or a knocking sound due to play in the transmission occurs, which may deteriorate the drivability of the vehicle.

[0006] Conventionally, as a means for suppressing deterioration of the drivability of a vehicle when releasing the parking lock state, a vehicle transmission described in Patent Document 1 and a control device for an automatic transmission described in Patent Document 2 are known.

[0007] When the parking lock is released by selecting the parking release range in the parking lock state in the transmission for a vehicle described in Patent Document 1, if the slope of the parking road of the vehicle is large and the detection angle of the slope sensor exceeds a predetermined threshold value, after establishing the gear train, the lock of the parking lock mechanism is released.

[0008] Therefore, when the parking lock state is released when the slope of the parking road of the vehicle is large and a large twist occurs between the drive wheel and the output element, the reaction force due to the release of the twist is reduced by the friction of the established gear train.

[0009] Therefore, when the parking lock state is released, the knocking sound generated in the play part in the transmission can be suppressed, and the deterioration of the drivability of the vehicle can be suppressed.

[0010] In the control device of the automatic transmission described in Patent Document 2, when the parking range is selected, the locking means operates to stop the rotation of the output shaft, and at the same time, the friction engagement device (brake) engages to stop the rotation of the output shaft.

[0011] In this control device of the automatic transmission, when shifting from the parking range to another range, the locking means disengages, but since the friction engagement device is gradually released, the output shaft is not immediately released. As a result, even when torsional torque is accumulated in the power transmission system including the output shaft, the output does not rotate suddenly, and shocks and vibrations caused by the torsional torque can be prevented, and the deterioration of the drivability of the vehicle can be suppressed.

Prior Art Documents

Patent Documents

[0012]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0013] However, in the vehicle transmission described in Patent Document 1, when releasing the parking lock state, after establishing the gear train, the lock of the parking lock mechanism is released. Therefore, there is a risk of gear wear and the like, and it is necessary to operate the clutch to establish the gear train.

[0014] Also, in the control device for an automatic transmission described in Patent Document 2, when shifting from the parking range to another range, the friction engagement device is gradually released. Therefore, it cannot be used for transmissions other than automatic transmissions having a clutch or a brake.

[0015] The present invention has been made paying attention to the above circumstances, and an object thereof is to provide a vehicle transmission that can suppress the rapid rotation of the power transmission shaft by using an oil pump when releasing the parking lock and can suppress the deterioration of the drivability of the vehicle.

Means for Solving the Problems

[0016] The present invention includes a parking gear provided on a power transmission shaft, and a parking pole that restricts the rotation of the power transmission shaft by engaging with the parking gear and allows the rotation of the power transmission shaft when the engagement with the parking gear is released. When the parking pole is engaged with the parking gear, it is a vehicle transmission that restricts the rotation of a drive wheel via a drive shaft interlocked with the power transmission shaft, and an oil pump is attached to the power transmission shaft. When releasing the engagement between the parking gear and the parking pole, the oil pump becomes a resistance to the rotation of the power transmission shaft.

Effects of the Invention

[0017] According to the present invention as described above, when releasing the parking lock, it is possible to suppress the sudden rotation of the power transmission shaft by using the oil pump, and it is possible to suppress the deterioration of the drivability of the vehicle.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0019] A transmission for a vehicle according to an embodiment of the present invention includes a parking gear provided on a power transmission shaft, and a parking pole that restricts the rotation of the power transmission shaft by engaging with the parking gear and allows the rotation of the power transmission shaft when the engagement is released from the parking gear. When the parking pole is engaged with the parking gear, it is a transmission for a vehicle that restricts the rotation of a drive wheel via a drive shaft interlocked with the power transmission shaft. An oil pump is attached to the power transmission shaft, and when releasing the engagement between the parking gear and the parking pole, the oil pump becomes a resistance to the rotation of the power transmission shaft.

[0020] Thereby, the transmission for a vehicle according to an embodiment of the present invention can suppress the sudden rotation of the power transmission shaft by using the oil pump when releasing the parking lock, and can suppress the deterioration of the drivability of the vehicle.

Example

[0021] Hereinafter, a transmission for a vehicle according to an embodiment of the present invention will be described with reference to the drawings. FIGS. 1 to 4 are diagrams showing a transmission for a vehicle according to an embodiment of the present invention.

[0022] First, the configuration will be described. In FIG. 1, an engine room 2 of a vehicle 1 is provided with an engine as an internal combustion engine (not shown) and a transmission 3 connected to the engine. The transmission 3 of this embodiment constitutes a transmission for a vehicle.

[0023] The power of the engine is transmitted from the transmission 3 to the left and right drive wheels 25L and 25R via the left and right drive shafts 24L and 24R.

[0024] The transmission 3 includes a transmission case (not shown), a single-plate clutch (not shown) respectively housed in the transmission case, a transmission mechanism 9, and a differential device 50.

[0025] The differential device 50 is installed behind the transmission mechanism 9. The transmission 3 inputs the power of the engine to the transmission mechanism 9 via a single-plate clutch, performs speed change in the transmission mechanism 9 by the operation of a shift shaft (not shown), and transmits the changed rotation to the drive wheels 25L and 25R via the drive shafts 24L and 24R by the differential device 50.

[0026] The transmission mechanism 9 is connected to a crankshaft (not shown) of the engine via a single-plate clutch, and includes an input shaft 10 to which power is transmitted from the engine, a counter shaft 11 and a reverse shaft 12 installed in parallel with the input shaft 10.

[0027] A plurality of speed change gears 13 are provided on the input shaft 10, and the speed change gears 13 include a first-speed input gear 14A, a second-speed input gear 14B, a third-speed input gear 14C, a fourth-speed input gear 14D, and a fifth-speed input gear 14E.

[0028] The 1st-speed input gear 14A and the 2nd-speed input gear 14B are fixed to the input shaft 10, and the 3rd-speed input gear 14C, the 4th-speed input gear 14D, and the 5th-speed input gear 14E are provided rotatably with respect to the input shaft 10.

[0029] A plurality of speed change gears 15 are provided on the counter shaft 11. The speed change gears 15 include a 1st-speed counter gear 16A, a 2nd-speed counter gear 16B, a 3rd-speed counter gear 16C, a 4th-speed counter gear 16D, and a 5th-speed counter gear 16E.

[0030] The speed change gears 15 are always meshed with the speed change gears 13 that constitute each same speed stage. The 1st-speed counter gear 16A and the 2nd-speed counter gear 16B are provided rotatably on the counter shaft 11. The 3rd-speed counter gear 16C, the 4th-speed counter gear 16D, and the 5th-speed counter gear 16E are fixed to the counter shaft 11.

[0031] A reverse idler gear 17 is provided on the reverse shaft 12 so as to be axially movable. A reverse input gear 14F is fixed to the input shaft 10, and a reverse counter gear 16F is fixed to the counter shaft 11.

[0032] The reverse idler gear 17 meshes with the reverse input gear 14F provided on the input shaft 10 and the reverse counter gear 16F provided on the counter shaft 11 by moving axially.

[0033] The transmission mechanism 9 includes engagement clutches 18 to 20. The engagement clutches 18 to 20 are provided between the 1st-speed counter gear 16A and the 2nd-speed counter gear 16B, between the 3rd-speed input gear 14C and the 4th-speed input gear 14D, and to the left of the 5th-speed input gear 14E, respectively.

[0034] The transmission mechanism 9 performs a shift operation, moves the engagement clutches 18 to 20 axially, and appropriately meshes the speed change gears 13 and 15 that constitute each speed stage, thereby establishing each speed stage.

[0035] The transmission mechanism 9 meshes the reverse idler gear 17 with the reverse input gear 14F of the transmission gear 13 and the reverse counter gear 16F of the transmission gear 15 to form a reverse gear stage.

[0036] A final drive gear 16G is fixedly provided at the right end of the countershaft 11, and a large-diameter final driven gear 23 meshes with the final drive gear 16G.

[0037] The differential device 50 includes a differential case 51 to which the final driven gear 23 is fixed, a pinion shaft 52, a pair of pinion gears 53A and 53B rotatably supported by the pinion shaft 52, and a pair of side gears 54A and 54B meshing with the pinion gears 53A and 53B.

[0038] The side gears 54A and 54B are connected to the left and right drive shafts 24L and 24R. The final driven gear 23 meshes with the final drive gear 16G, and the differential device 50 transmits the rotation of the final drive gear 16G to the left and right drive wheels 25L and 25R while allowing differential of the left and right drive wheels 25L and 25R.

[0039] The transmission 3 is provided with a parking lock mechanism 31. The parking lock mechanism 31 includes a parking gear 32, a parking pole 33, a parking rod 34, and a parking cam 35.

[0040] The parking gear 32 is provided on the left end side of the countershaft 11 and rotates integrally with the countershaft 11. As shown in FIG. 2, a plurality of convex portions 32A and concave portions 32B are provided at equal intervals in the circumferential direction on the outer peripheral portion of the parking gear 32.

[0041] The parking pole 33 is rotatably supported by a parking pole shaft 36. A claw portion 33A is formed on the parking pole 33. When the parking pole 33 rotates counterclockwise (leftward in FIG. 2) about the parking pole shaft 36, the claw portion 33A engages with a recess 32B of the parking gear 32.

[0042] When the parking pole 33 rotates clockwise (rightward in FIG. 2) about the parking pole shaft 36, the engagement between the claw portion 33A and the recess 32B is released.

[0043] Thus, the parking pole 33 rotates between an engagement position where the claw portion 33A engages with the recess 32B and a release position where the engagement between the claw portion 33A and the recess 32B is released.

[0044] When the claw portion 33A engages with the recess 32B, the rotation of the parking gear 32 is restricted, and the rotation of the countershaft 11 is restricted.

[0045] The countershaft 11 is located downstream of the input shaft 10 and the reverse shaft 12 in the power transmission path from the engine to the differential device 50, and is interlocked with the drive wheels 25L, 25R via the drive shafts 24L, 24R.

[0046] Accordingly, when the rotation of the parking gear 32 is restricted, the rotation of the countershaft 11 and the final driven gear 23 of the differential device 50 is restricted. As a result, the rotation of the drive wheels 25L, 25R via the drive shafts 24L, 24R is restricted, and the parked state of the vehicle 1 is maintained.

[0047] As shown in FIG. 1, the parking rod 34 moves axially in accordance with an operation of a shift lever (not shown) for changing the shift position. When the shift position is switched from another shift position to the parking position by the shift lever, the parking cam 35 contacts the parking pole 33 as the parking rod 34 moves axially to one side, and rotates the parking pole 33 from the release position to the engagement position.

[0048] When the shift position of the parking cam 35 is switched from the parking position to another shift position by the shift lever, the parking cam 35 is pulled away from the parking pole 33 as the parking rod 34 moves axially to the other side, and rotates the parking pole 33 from the engaged position to the released position.

[0049] The transmission 3 is provided with a trochoid oil pump 40, and the oil pump 40 is attached to the left end portion of the countershaft 11.

[0050] As shown in FIG. 3, the oil pump 40 has a housing 41 formed in the transmission case, and an inner rotor 42 and an outer rotor 43 are rotatably accommodated inside the housing 41.

[0051] The inner rotor 42 rotates in conjunction with the countershaft 11. The outer rotor 43 is provided radially outward of the inner rotor 42 and rotates as the inner rotor 42 rotates.

[0052] In the trochoid oil pump 40, a plurality of working chambers 44 for accommodating oil are formed between the outer teeth 42A and the inner teeth 43A when a plurality of inner teeth 43A formed on the outer rotor 43 come into contact with a plurality of outer teeth 42A formed on the inner rotor 42.

[0053] The housing 41 is formed with a suction port 41a communicating with the working chamber 44, a suction passage 41b communicating with the suction port 41a, a discharge port 41c communicating with the working chamber 44, and a discharge passage 41d communicating with the discharge port 41c.

[0054] In the oil pump 40, when the power of the countershaft 11 is transmitted to the inner rotor 42, the inner rotor 42 and the outer rotor 43 rotate in one direction W (counterclockwise in FIG. 3).

[0055] At this time, as the volume increase and decrease in the working chamber 44 occur continuously, oil is sucked from the suction passage 41b through the suction port 41a into the working chamber 44, and the oil pressurized by the working chamber 44 is discharged from the discharge port 41c through the discharge passage 41d.

[0056] As shown in FIG. 1, an oil pipe 45 is connected to the oil pump 40, and the oil discharged from the discharge passage 41d is supplied to the lubricating part of the transmission 3 through the oil pipe 45.

[0057] A solenoid valve 46 is arranged on the oil pipe 45. As shown in FIG. 4, the solenoid valve 46 includes a solenoid body 46A provided in the transmission case, a spool valve 46B movably provided on the solenoid body 46A, a coil spring 46C that biases the spool valve 46B to one side, and an electromagnetic coil 46D that moves the spool valve 46B to the other side against the biasing force of the coil spring 46C when energized.

[0058] The solenoid body 46A is formed with an inlet portion 46a and an outlet portion 46b. When the spool valve 46B is biased by the coil spring 46C, the valve body 46c of the spool valve 46B opens the inlet portion 46a and the outlet portion 46b to the maximum extent, thereby increasing the opening degree of the oil pipe 45 and increasing the amount of oil discharged from the oil pump 40 (see the oil O1 in FIG. 4(a)).

[0059] On the other hand, when the electromagnetic coil 46D is energized and the spool valve 46B moves to the other side against the biasing force of the coil spring 46C, the valve body 46c of the spool valve 46B reduces the opening degrees of the inlet portion 46a and the outlet portion 46b, thereby narrowing the opening degree of the oil pipe 45 and reducing the amount of oil discharged from the oil pump 40 (see the oil O2 in FIG. 4(b)). When reducing the amount of oil, the opening degree of the oil pipe 45 may be set to zero.

[0060] As shown in FIG. 1, the transmission 3 includes a shift position sensor 61 that detects the shift position of the shift lever, and a controller 62 to which a shift signal is input from the shift position sensor 61.

[0061] The shift position sensor 61 detects the shift position of the shift lever (not shown) and transmits a detection signal to the controller 62.

[0062] Specifically, when the shift position is switched from another shift position to the parking position, the shift position sensor 61 outputs a parking lock signal to the controller 62, and when the shift position is switched from the parking position to another shift position, the shift position sensor 61 outputs a parking lock release signal to the controller 62.

[0063] When the controller 62 receives a parking lock signal and a parking lock release signal from the shift position sensor 61, it energizes the electromagnetic coil 46D. When the electromagnetic coil 46D is energized, the spool valve 46B moves to the other side against the biasing force of the coil spring 46C, and the opening degree of the oil pipe 45 is narrowed.

[0064] That is, when shifting to the parking lock state and when the parking lock state is released, the solenoid valve 46 narrows the opening degree of the oil pipe 45, and the amount of oil flowing through the oil pipe 45 is reduced.

[0065] As a result, the amount of oil discharged from the working chamber 44 of the oil pump 40 is reduced compared to the case where the opening degree of the oil pipe 45 is large. For this reason, it becomes difficult for oil to be discharged from the working chamber 44, the rotation of the inner rotor 42 becomes difficult, and as a result, the rotational resistance of the countershaft 11 increases. That is, the oil pump 40 becomes a resistance to the rotation of the countershaft 11.

[0066] In this embodiment, the countershaft 11 constitutes a power transmission shaft, and the solenoid valve 46 constitutes an adjustment unit. Also, the oil pipe 45 constitutes a discharge oil passage.

[0067] Next, the effects of the transmission 3 of this embodiment will be described. When the shift position is switched from another shift position to the parking position, the parking pole 33 engages with the parking gear 32, so the rotation of the countershaft 11 is restricted.

[0068] And when the drive wheels 25L and 25R are in a state of riding on the wheel stoppers or when switching from another shift position to the parking position on a slope and the parking gear 32 and the parking pole 33 are engaged to release the foot brake, the drive shafts 24L and 24R of the drive wheels 25L and 25R are twisted by the rotational force applied to them.

[0069] Therefore, the twist of the drive shafts 24L and 24R is transmitted to the countershaft 11 having the parking gear 32 via the differential device 50, and the drive system from the drive shafts 24L and 24R to the countershaft 11 is in a state where the torsional torque is accumulated.

[0070] Therefore, when the shift position is switched from the parking position to another shift position at the start of the vehicle 1 and then the engagement between the parking gear 32 and the parking pole 33 is released, the torsional torque of the drive system is released and the vehicle 1 vibrates, or a knocking sound due to play in the transmission 3 occurs, which may deteriorate the drivability of the vehicle 1.

[0071] The transmission 3 of this embodiment includes a parking gear 32 provided on the countershaft 11 and a parking pole 33 that restricts the rotation of the countershaft 11 by engaging with the parking gear 32 and allows the rotation of the countershaft 11 when the engagement is released from the parking gear 32. When the parking pole 33 is engaged with the parking gear 32, the rotation of the drive wheels 25L and 25R is restricted via the drive shafts 24L and 24R interlocked with the countershaft 11.

[0072] An oil pump 40 is attached to the countershaft 11, and when the engagement between the parking gear 32 and the parking pole 33 is released, the oil pump 40 becomes a resistance to the rotation of the countershaft 11.

[0073] As a result, when the engagement between the parking gear 32 and the parking pole 33 is released, the oil pump 40 becomes a resistance to rotation, suppressing the countershaft 11 from rotating rapidly.

[0074] Therefore, when the torsional torque accumulated in the drive shafts 24L and 24R from the countershaft 11 via the differential device 50 is released, the countershaft 11 can absorb the torsional torque of the drive shafts 24L and 24R, suppressing the drive shafts 24L and 24R from rotating rapidly.

[0075] Accordingly, it is possible to suppress the vehicle 1 from vibrating due to the rapid rotation of the countershaft 11 and the drive shafts 24L and 24R, and to suppress the rapid rotation of the countershaft 11 to suppress knocking sounds caused by the meshing of the transmission gear 13 and the transmission gear 15. As a result, it is possible to suppress the deterioration of the drivability of the vehicle 1.

[0076] Further, according to the transmission 3 of the present embodiment, it has a solenoid valve 46 for adjusting the opening degree of the oil pipe 45 from which oil is discharged from the oil pump 40, and when releasing the engagement between the parking gear 32 and the parking pole 33, the solenoid valve 46 narrows the opening degree of the oil pipe 45.

[0077] As a result, the rotational resistance of the countershaft 11 can be increased using the existing oil pump 40, suppressing the countershaft 11 from rotating rapidly. As a result, it is possible to suppress the deterioration of the drivability of the vehicle 1 with a simple configuration.

[0078] Also, since the opening degree of the oil pipe 45 is narrowed by the solenoid valve 46 during parking lock, it is possible to prevent the lubrication of the lubrication parts of the transmission 3 from being hindered during normal operation.

[0079] Further, according to the transmission 3 of the present embodiment, when the parking pole 33 is engaged with the parking gear 32 (that is, at the time of parking lock), since the opening degree of the oil pipe 45 has already been restricted by the solenoid valve 46, it is possible to surely restrict the opening degree of the oil pipe 45 at the time of releasing the parking lock.

[0080] Note that when releasing the parking lock, the shift lever is operated with the brake pedal depressed. Therefore, after the parking lock is released, the energization of the electromagnetic coil 46D is stopped and the opening degree of the oil pipe 45 is increased after a predetermined time has elapsed after the depression of the brake pedal is released.

[0081] This predetermined time is set to the time required for the torsion of the drive system to be completely released. Further, instead of restricting the opening degree of the oil pipe 45 at the time of parking lock, the opening degree of the oil pipe 45 may be restricted only at the time of releasing the parking lock.

[0082] Although embodiments of the present invention have been disclosed, it is obvious that those skilled in the art can make changes without departing from the scope of the present invention. It is intended that all such modifications and equivalents be included in the following claims.

Explanation of Signs

[0083] 3 Transmission (vehicle transmission) 11 Countershaft (power transmission shaft) 24L, 24R Drive shaft 25L, 25R Driving wheel 32 Parking gear 33 Parking pole 40 Oil pump 45 Oil pipe (discharge oil passage) 46 Solenoid valve (adjusting unit)

Claims

1. a parking gear provided on a power transmission shaft; and a parking pawl that restricts rotation of the power transmission shaft by engaging with the parking gear and allows rotation of the power transmission shaft when the parking pawl is disengaged from the parking gear, A vehicle transmission that restricts rotation of a drive wheel via a drive shaft that is linked to the power transmission shaft when the parking pole is engaged with the parking gear, An oil pump is attached to the power transmission shaft, 4. A vehicle transmission comprising: a parking gear and a parking pole; a drive shaft for receiving the parking gear; a drive shaft for receiving the parking gear;

2. an adjustment unit that adjusts the opening of a discharge oil passage through which oil is discharged from the oil pump; 2. The vehicle transmission according to claim 1, wherein the adjustment portion reduces an opening degree of the discharge oil passage at least when the parking gear and the parking pole are disengaged from each other.

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