JP2005299708A - Parallel shaft transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a parallel shaft transmission capable of smoothly and swiftly changing speed and avoiding an enlargement of a roller rotation speed synchronization control mechanism even in low-speed gear transmission in which a large transmission shock occurs during speed change. <P>SOLUTION: In the parallel shaft transmission, constant engagement gears to respective gear stages are provided on a parallel shaft. The transmission is equipped with a multistage transmission mechanism achieving transmission by changing a torque transmission passage of the constant engagement gear, two-way clutches 301, 302 for first and second speeds for fastening/releasing of a second output shaft 23 of the parallel shaft and transmission gears 201, 202 for first and second speed drive of the constant engagement gear. A torque limiter 410 for transmitting the prescribed torque only is provided on the torque transmitting passage between the second-third driven transmission gear 212 of the constant engagement gear and the output shaft 25. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is a continuously meshing transmission used in a vehicle, and particularly belongs to the technical field of a parallel shaft transmission.

  Conventionally, in a transmission, at the time of shifting, the clutch is disengaged and then shifted to the next transmission gear. However, due to changes in the gear position, the rotational speed of the input shaft and the output shaft before and after shifting are changed. Since the rotation speed ratio of the rotation speed changes, if a shift is performed without setting the rotation speed ratio corresponding to the gear position after the shift, a great shift shock occurs.

Therefore, a rotation speed synchronization control clutch means for synchronizing the rotation speeds of the input and output shafts is used, and a two-way clutch that absorbs a shift shock generated when the transmission gear is engaged is used (see, for example, Patent Document 1 and Patent Document 2). ).
JP-A-5-338471 JP-A-8-128462

  However, in the above prior art, if the two-way clutch is engaged in a state where the rotation speed synchronization is not sufficiently performed, a great shift shock occurs. In particular, this effect is significant because the transmission torque is large at the time of shifting in the first gear and the second gear. For this reason, it is necessary to increase the engagement capacity of the two-way clutch so as to withstand a shift shock, which hinders downsizing of the apparatus. Although it is possible to reduce the size of the two-way clutch by accurately performing the rotation speed synchronization, it takes time for the rotation synchronization with high accuracy, and it is not preferable because a feeling of idling occurs at the time of shifting. .

  The present invention has been made paying attention to the above-mentioned problems, and the object of the present invention is to achieve smoothness without increasing the size of the two-way clutch even in a low-speed gear shift that generates a large shift shock during a shift. It is an object of the present invention to provide a parallel shaft transmission capable of achieving a shift.

  In order to achieve the above-described object, in the present invention, a constant meshing gear is provided for each shift stage on a parallel shaft, the driving side rotational shaft and the driven side rotational shaft are arranged in parallel, and the torque of the constant meshing gear. A parallel shaft transmission comprising: a multi-stage transmission mechanism that achieves speed change by switching a transmission path; and a two-way clutch that engages and releases the drive-side rotation shaft of the parallel shaft and the drive-side gear of the constantly meshing gear. The torque limiter for transmitting only a predetermined torque is provided on the torque transmission path between the low-speed driven gear of the constantly meshing gear and the driven rotary shaft.

  That is, according to the present invention, since the power is transmitted between the low-speed gear and the driven-side rotating shaft via the torque limiter, smooth and quick gear shifting is possible even in the case of a low-speed gear shifting in which a large shift shock is generated at the time of shifting. It can be performed.

  Therefore, an increase in the size of the two-way clutch can be avoided, and a parallel shaft transmission that does not require accurate rotation speed synchronization can be provided.

  Hereinafter, the best mode for carrying out the present invention will be described based on Example 1 and Example 2.

First, the configuration will be described.
FIG. 1 is a schematic diagram illustrating the overall configuration of the parallel shaft transmission according to the first embodiment. The parallel shaft transmission includes an electromagnetic multi-plate clutch (starting clutch) 30 that connects and disconnects the rotation output from the engine 10, a multi-stage transmission 20 that shifts the input rotation, and the electromagnetic multi-plate clutch 30 and the multi-stage transmission 20. The control unit 500 is configured to output a control command.

[Configuration of electromagnetic multi-plate clutch 30]
FIG. 2 is a sectional view of the parallel shaft transmission. The electromagnetic multi-plate clutch 30 is housed in an input clutch housing 39 attached to the output shaft side of the engine 10. A front end portion of a transmission case 21 that houses the multi-stage transmission 20 is connected to a rear end portion of the input clutch housing 39.

  The electromagnetic multi-plate clutch 30 includes a pilot clutch 34 that is fastened by electromagnetic force of an electromagnet 37, a main clutch 33 that is disposed on the outer periphery of the pilot clutch 34, and a torque cam mechanism 35 that is disposed on the inner periphery of the pilot clutch 34. ing.

  A front cover 38 is attached to the input clutch housing 39 in a liquid-tight manner by bolts, thereby defining a first storage chamber 38 a that is open to the atmosphere for storing the torsional damper 40. The transmission case 21, a part of the input clutch housing 39 and the front cover 38 define a second storage chamber 21 a in which oil lubrication is performed.

  The first input drum 31 of the main clutch 33 has a bottomed cylindrical shape, and a torsional damper 40 is connected to the bottomed side end portion by meshing. The second input drum 32 of the main clutch 33 has a bottomed double cylinder shape, and the outermost cylinder surface can rotate integrally with the first input drum 31 by spline fitting, and the shaft of the second input drum 32 can be rotated. It is configured to be movable in the direction. A pilot clutch 34 is provided on the inner cylinder inner diameter of the second input drum 32. The second input drum 32 is spline-fitted with the main clutch 33, and an input clutch hub 36 is disposed outside the inner cylinder outer diameter portion of the second input drum 32.

  The torque cam mechanism 35 has a cam mechanism between the driven side member of the pilot clutch 34 and the input clutch hub 36, and fastens the main clutch 33 by converting a rotational force into an axial thrust.

  The power of the engine 10 is transmitted from the torsional damper 40 to the first input drum 31 and the second input drum 32, and is transmitted to the drive side of the pilot clutch 34. When the pilot clutch 34 is engaged, axial torque is generated by the torque cam mechanism 35, and the main clutch 33 is engaged. Therefore, the power of the engine 10 is transmitted from the electromagnetic multi-plate clutch 30 to the first input shaft 22.

[Configuration of multi-stage transmission]
Shifting in the multi-stage transmission is performed by a shift actuator. A first input shaft 22, a second input shaft 23, and an output shaft 25 are provided in the transmission case 21. These three axes are provided in parallel, and the first input shaft 22 and the second input shaft 23 are connected to each other via an idle gear 24 at the rear end portion.

  The first input shaft 22 has drive speed change gears 203, 204, 205 for 3rd to 5th speeds, 3rd-5th speed switching synchro 405, and 4th speed switching synchro 404. These gears are arranged in order of transmission gears 204, 205, and 203 for fourth speed, fifth speed, and third speed in order from the engine 10 side of the first input shaft 22.

  The second input shaft 23 includes first-speed, second-speed drive transmission gears 201 and 202, and a reverse drive transmission gear 206. These gears are second-speed, first-speed, and reverse drive in this order as viewed from the idle gear 24. Arranged in the order of gears. The first-speed and second-speed drive transmission gears 201 and 202 have a first-speed two-way clutch 301 and a second-speed two-way clutch 302, respectively.

  These first-speed and second-speed two-way clutches 301 and 302 have an outer ring that rotates integrally with the drive gear, and an inner ring that rotates integrally with the second input shaft 23. The outer ring and inner ring are fastened and released by movement in the axial direction.

  The output shaft 25 is provided between the first and second input shafts 22 and 23, and the first-speed driven transmission gear 211, the second-third speed driven transmission gear 212, and the fourth and fifth-speed driven transmission gears 214, 215. And a reverse driven transmission gear 216b that meshes with the reverse counter gear 216a, a reduction gear 217, and an output shaft integrated sleeve 411. These driven gears are provided at positions corresponding to the driving transmission gears of the respective shift stages.

  Here, the 2-3 speed driven transmission gear 212 is engaged with both the 3rd speed driving transmission gear 203 of the first input shaft 22 and the 2nd speed driving transmission gear 202 of the second input shaft 23. The output shaft integrated sleeve 411 is provided between the 2-3 speed driven transmission gear 212 and the 5th speed driven transmission gear 215 of the output shaft 25 and rotates integrally with the output shaft 25.

  A dog-tooth engaging spline 212a is provided on the engine 10 side of the 2-3rd driven gear shift gear 212. The dog-tooth engagement spline 212a is engaged with the dog clutch 420, thereby being fastened to the output shaft 25 via the output shaft integrated sleeve 411, and the 2-3 speed driven transmission gear 212 and the output shaft 25 are completely fastened. .

  Further, a torque limiter 410 is provided on the idle gear 24 side of the 2-3 speed driven transmission gear 212, and this torque limiter 410 is fitted to the 2-3 speed driven transmission gear 212 and the output shaft 25 so that both Torque is transmitted.

  This torque limiter 410 is composed of a driving side plate and a driven side plate, and the driving side plate is spline-fitted to the inner periphery of a hollow cylindrical portion provided on the inner periphery of the 2-3 speed driven transmission gear 212, The plate is splined to the outer periphery of the output shaft 25. These two plates are combined so that they can rotate relative to each other, and are always pressed with a constant force.

  When a torque exceeding the specified value is input between the 2-3 speed driven transmission gear 212 and the output shaft 25, the driving side plate and the driven side plate of the torque limiter 410 rotate relative to each other, and torque transmission exceeding the specified value is cut off. Is done. That is, excessive torque generated between the 2-3 speed driven transmission gear 212 and the output shaft 25 is absorbed by the torque limiter 410.

  FIG. 3 is a detailed sectional view of the vicinity of the reverse gear of the parallel shaft transmission. The reverse drive transmission gear 206 is always meshed with the reverse counter gear 216a, and the reverse counter gear 216a is always meshed with the reverse driven transmission gear 216b. The reverse counter gear 216a is supported by the transmission case 21 so as to be axially rotatable, and rotates in parallel with the first and second input shafts 22 and 23.

  The reverse counter gear 216 a is a spur gear and is provided on the outer periphery of the reverse drive transmission gear 206. The reverse counter gear 216a functions in the same manner as the synchro by moving in the axial direction.

[Configuration of control unit]
Next, the configuration of the control unit 500 shown in FIG. 1 will be described. The parallel shaft transmission includes a throttle sensor 511 (detection of the throttle opening), an engine speed sensor 512, a turbine sensor 513 (detection of the output shaft speed of the electromagnetic multi-plate clutch 30, that is, the input shaft speed of the multi-stage transmission), vehicle speed. A sensor 514, an oil temperature sensor 515 (detecting the lubricating oil temperature of the electromagnetic multi-plate clutch 30), and a current sensor 516 (detecting a supply current to the electromagnetic multi-plate clutch 30).

  The control unit 500 includes a normal control unit 501 and a cryogenic control unit 502. The normal control unit 501 determines an optimal gear position based on the input sensor signals and outputs a shift command to the shift actuator 60. At the same time, a control command is output to the engine 10 and an engagement control command is output to the electromagnetic multi-plate clutch 30.

  The cryogenic temperature control unit 502 is a control unit that executes control when it is determined that the detected lubricating oil temperature is an extremely low temperature. When the lubricating oil temperature is extremely low, a control command corresponding to the extremely low temperature is output to the shift actuator 60, the engine 10, and the electromagnetic multi-plate clutch 30.

[1-2 Upshift control action]
In the 1-2 upshift, first, the energization of the electromagnetic multi-plate clutch 30 is stopped, and the shift from the first gear to the second gear is performed. At this time, the rotation speed ratio of the rotation speed Nin of the second input shaft 23 and the rotation speed Nout of the output shaft 25 changes before and after the shift due to the change of the shift speed. A large load is applied to the speed change mechanism during the first speed and the second speed shift, and a large load is applied to the 2-way clutch for the second speed when the speed change is executed without sufficiently synchronizing the rotational speed. If the engagement capacity of the 2-way 2-way clutch is increased corresponding to this load, the size of the 2-way clutch will increase with the increase of the engagement capacity.

  Therefore, in the embodiment of the present application, the rotational speed control of the input shaft rotational speed Nin (engine rotational speed control, electromagnetic multi-plate clutch engagement control, etc.) is performed, the input / output shaft rotational speed ratio is controlled, and the shift shock generated at the time of shifting Reduce. Furthermore, a torque limiter is provided at a low speed stage, which is a gear stage with a large shift shock, to further reduce the shock during the shift. In this embodiment, a torque limiter is provided between the 2-3 speed driven transmission gear 212 and the output shaft 25.

  In the 1-2 shift, the electromagnetic multi-plate clutch 30 is first released according to a command from the normal control unit 501, and then the first-speed 2-way clutch 301 is released by the shift actuator 60. Next, the second-speed two-way clutch 302 is engaged, and the electromagnetic multi-plate clutch 30 is started to be engaged. At this time, the torque limiter 410 provided between the 2-3 speed driven transmission gear 212 and the output shaft 25 prevents a torque exceeding a certain level from being transferred between the second input shaft 23 and the output shaft 25. Prevents the occurrence of shift shock.

At this time, assuming that the rotation speed of the second input shaft 23 is Nin and the rotation speed Nout of the output shaft 25, the absolute value of the difference between both rotation speeds | Nin−Nout |
Is equal to or less than the specified value, the dog clutch 420 is engaged and the second gear is brought into a completely engaged state, assuming that sufficient rotational speed synchronization control has been performed.

[1-2 Upshift control processing]
Next, 1-2 upshift control will be described as a specific shift control example. FIG. 4 is a flowchart showing the flow of a shift control process executed by the normal control unit 501 during a 1-2 upshift in the control unit 500 of the parallel shaft transmission. Hereinafter, each step will be described.

  In step S1, the energization of the electromagnetic multi-plate clutch 30 is stopped to be in a non-engaged state, and the process proceeds to step S2.

  In step S2, it is determined whether or not the dog clutch 420 is in a released state. If YES, the process proceeds to step S4, and if NO, the process proceeds to step S3.

  In step S3, the dog clutch 420 is released, and the process proceeds to step S4.

  In step S4, the first-speed two-way clutch 301 is released, and the process proceeds to step S5.

  In step S5, energization of the electromagnetic multi-plate clutch 30 is resumed, and the process proceeds to step S6.

  In step S6, the engine speed is used to perform rotational speed synchronization control of the first and second input shafts 22 and 23, and the process proceeds to step S7.

  In step S7, it is determined whether or not the absolute value of the input / output shaft rotational speed difference Nin−Nout is less than the specified value. If YES, the process proceeds to step S8, and if NO, the process returns to step S6 to rotate again. Performs number synchronization control.

  In step S8, the 2-speed 2-way clutch 302 is engaged, and the process proceeds to step S9.

  In step S9, the dog clutch 420 is engaged, and the process proceeds to step S10.

  In step S10, the electromagnetic multi-plate clutch 30 is brought into a completely engaged state and the control is terminated.

[1-2 Time-dependent change of upshift control]
FIG. 5 is a time chart of the shift control from the first speed to the second speed in the first embodiment. Fig. 5 (a) shows a shift command, Fig. 5 (b) shows the engine speed Ne, Fig. 5 (c) shows an engagement command and an engagement force for the electromagnetic multi-plate clutch 30, and Fig. 5 (d) shows first and second speeds. FIG. 5 (e) shows an engagement command and an engagement state for the dog clutch 420, and FIG.

At time t ₁ , a shift command from the first speed to the second speed is issued, a non-energization command is output to the electromagnetic multi-plate clutch 30, and a release command is output to the first-speed 2-way clutch 301. At this time, the rotational speed of the engine 10 and the fastening force of the electromagnetic multi-plate clutch 30 gradually decrease.

In time t _2, the electromagnetic multiple disk clutch 30 and the first-speed two-way clutch 301 is completely released position. At this time, the 2-speed 2-way clutch 302 and the dog clutch 420 are still in the non-engaged state, and the engine speed continues to decrease.

At time t ₃ , the energization of the electromagnetic multi-plate clutch 30 is resumed to be in the engaged state, and the rotational speed synchronization control of the input shaft by the rotation of the engine 10 is started. In order to smoothly perform the rotational speed synchronization control, the electromagnetic multi-plate clutch 30 is not completely engaged, and the rotational speed of the engine 10 is gradually reduced to approach the rotational speed at the second speed. At the same time, the second-speed two-way clutch 302 starts to be engaged.

At time t ₄ , the second-speed two-way clutch 302 is completely engaged, and the dog clutch 420 starts to be engaged on the assumption that the rotational speed synchronization control of the input shaft has been sufficiently performed. If the rotational speed ratio of input and output shafts by the rotation speed synchronization control is not completely synchronized, the rotation speed decreases rapidly at t _4, shift shock occurs. As described above, the torque limiter 410 reduces the shift shock when the second gear is engaged.

At time t _5, the dog clutch 420 is completely engaged state, and thus the shift is completed the electromagnetic multiple disk clutch 30 as a complete engagement state.

[General shift control action]
In the parallel shaft transmission of the present invention, not only the 1-2 upshift, but also the entire shift control involving the second speed or the third speed, such as the 2-3 upshift and the 4-3 downshift, is obtained. It is done. Hereinafter, each case will be described.

[(1) Shift control action from 1, 4, 5 speed to 2 or 3 speed]
During a shift such as a 1-2 upshift or a 4-3 downshift, the dog clutch 420 is in a disengaged state at the shift stage before the shift. Therefore, at the start of shifting, the electromagnetic multi-plate clutch 30 is first released, the gear stage before the shifting (first speed, fourth speed or fifth speed) is released, and the rotational speed synchronization control of the input / output shaft is performed. After sufficiently synchronizing the rotational speed, the gear stage after the shift (second speed or third speed) is engaged.

  Since the gear stage after the shift is the 2-3 speed driven transmission gear 212 provided with the torque limiter 410, when the gear stage after the gear shift (second speed or third speed) is engaged, the gear is first entered via the torque limiter 410. Transmits torque between output shafts. After the shift shock reduction by the torque limiter 410 is completed, the dog clutch 420 is engaged and the electromagnetic multi-plate clutch 30 is fully engaged.

[(2) Shift control action in 2-3 upshift or 3-2 downshift]
In the 2-3 upshift and the 3-2 downshift, the dog clutch 420 is in the engaged state at the gear stage (second speed or third speed) before the shift. Therefore, at the start of the shift, the electromagnetic multi-plate clutch 30 is first released, the gear stage before the shift (second speed or third speed) is released, and the dog clutch 420 is further released. Since the torque limiter 410 always has a constant fastening force, the input / output shaft is in a state of torque transmission via the torque limiter 410. In this state, the rotational speed synchronization control of the input / output shaft is performed, and then the gear stage after the shift is fastened.

  Since the gear stage after the shift is also the second gear or the third gear, torque transmission is performed via the torque limiter 410 simultaneously with the gear stage after the gear shift. When the shift shock reduction by the torque limiter 410 is completed, the dog clutch 420 is engaged and the electromagnetic multi-plate clutch 30 is completely engaged.

[(3) Shift control action from 2nd or 3rd speed to 1, 4 and 5th speed]
In shift control from 2nd or 3rd speed such as 3-4 upshift or 2-1 downshift to 1st speed, 4th speed, or 5th speed, dog clutch 420 is operated at the shift stage before the shift (2nd speed or 3rd speed). Fastened state. At the start of gear shifting, the electromagnetic multi-plate clutch 30 is first released, the gear stage before the gear shifting (second gear or third gear) is released, and the dog clutch 420 is further released. In this state, the rotational speed synchronization control of the input / output shaft is performed, and then the gear stage after the shift (first speed, fourth speed or fifth speed) is engaged, and the electromagnetic multi-plate clutch 30 is completely engaged.

[General shift control processing]
FIG. 6 is a flowchart illustrating the flow of a general shift control process executed by the normal control unit 501 during a shift in the control unit 500 of the parallel shaft transmission according to the first embodiment. Hereinafter, each step will be described.

  In step S11, the energization of the electromagnetic multi-plate clutch 30 is stopped and brought into a non-engaged state, and the process proceeds to step S12.

  In step S12, it is determined whether the dog clutch 420 is in the released state. If YES, the process proceeds to step S14, and if NO, the process proceeds to step S13.

  In step S13, the dog clutch 420 is released, and the process proceeds to step S14.

  In step S14, the current gear position is released and the process proceeds to step S15.

  In step S5, energization of the electromagnetic multi-plate clutch 30 is resumed, and the process proceeds to step S16.

  In step S16, Nin is rotationally synchronized by the electromagnetic multi-plate clutch 30 so that the input shaft rotational speed Nin and the output shaft rotational speed Nout after shifting are the same, and the process proceeds to step S17.

In step S17, the absolute value of the difference between the input shaft speed Nin and the output shaft speed Nout
| Nin-Nout |
It is determined whether or not the value is equal to or less than the specified value. If YES, the process proceeds to step S18, and if NO, the process returns to step S16.

  In step S18, the desired gear position is fixed to the input shaft, and the process proceeds to step S19.

  In step S19, it is determined whether or not the speed after the shift is the second speed or the third speed. If YES, the process proceeds to step S20, and if NO, the process proceeds to step S21.

  In step S20, the dog clutch 420 is engaged, the 2-3 speed driven transmission gear 212 is fixed to the output shaft 25, and the process proceeds to step S11.

  In step S21, the electromagnetic multi-plate clutch 30 is completely engaged and the shift control is terminated.

[Effect of the embodiment of the present application]
(1) The 2-3 speed driven transmission gear 212 is provided with the torque limiter 410, and the 2-3 speed driven transmission gear 212 transmits power to the output shaft 25 via the torque limiter 410. In addition, first-speed and second-speed two-way clutches 301 and 302 were used for fastening the first-speed and second-speed drive transmission gears 201 and 202 and the second input shaft 23, respectively.
As a result, when shifting to the second speed or the third speed, such as 1-2 upshift, the dog clutch 420 is released and torque transmission is performed only by the torque limiter 410. It becomes possible to block. Therefore, even in the case of a 1-2 shift in which a large shift shock occurs during a shift, an increase in the size of the device due to an increase in the engagement capacity of the 2-way clutch 302 for the second speed is avoided, and accurate rotation speed synchronization is not performed. Both can perform smooth and quick gear shifting (corresponding to claim 1).

(2) A dog clutch 420 that is rigidly coupled to the output shaft 25 is provided in the 2-3 speed driven transmission gear 212, and power transmission between the 2-3 speed driven transmission gear 212 and the output shaft 25 is for 2nd speed 2 Torque is transmitted by the torque limiter 410 only for a predetermined time after the start of the engagement of the way clutch 302 or the third speed driving transmission gear 203, and then the dog clutch 420 is coupled to transmit torque to the output shaft 25.
As a result, at the time of shifting to the second speed or the third speed, it is possible to change the gear position while interrupting the torque transmission of a certain value or more by the torque limiter 410 and then completely engage the output shaft 25 by the dog clutch 420. Thus, reliable power transmission can be performed (corresponding to claim 2).

  (3) A torque limiter 410 and a dog clutch 420 are provided in parallel as fastening elements for the 2-3 speed driven transmission gear 212 and the output shaft 25. Thus, at the time of shifting to the second speed or the third speed, the input / output shaft can be completely fastened immediately after the shift shock is reduced (corresponding to claim 3).

  (4) When shifting to the second speed via the 2-3 speed driven transmission gear 212, after the torque transmission is performed by the torque limiter 410 for a certain time after the two-speed two-way clutch 302 is engaged. The torque transmission is performed by rigidly coupling the dog clutch 420. As a result, even when the two-speed two-way clutch 302 is abruptly engaged, the torque limiter 410 absorbs the shock associated with the engagement, and then the dog clutch 420 is engaged to rigidly connect the input and output shafts. It is possible to reduce the burden on the two-speed two-way clutch 302, thereby avoiding an increase in size due to an increase in fastening capacity (corresponding to claim 5).

[Start control at cryogenic temperatures]
Next, the start control process when the parallel shaft transmission is at a very low temperature will be described. At an extremely low temperature, the viscosity of the lubricating oil lubricated in the electromagnetic multi-plate clutch 30 increases. Therefore, even if the electromagnetic multi-plate clutch 30 is released, the power of the engine 10 may be transmitted as drag torque due to the lubricating oil having increased viscosity interposed between the clutch plates.

  When the cryogenic temperature is extremely low, the creep torque of the engine is lower than that at the normal time. If all the creep torque transmitted by the drag torque is transmitted to the drive wheels 53, the engine 10 may stall. In particular, in the electromagnetic multi-plate clutch 30 of the first embodiment of the present application, since the drag torque generated in the pilot clutch 34 is increased by the torque cam mechanism 35, the influence is great.

  Therefore, in the embodiment of the present application, in order to eliminate the drag torque at the start of cryogenic temperature, the electromagnetic multi-plate clutch 30 is relatively rotated by the creep torque of the engine 10 to generate heat, and the drag torque is eliminated. At extremely low temperatures, the creep torque of the engine is lower than normal, and it is often difficult to start the vehicle body. At this time, if all the creep torque transmitted by the drag torque is transmitted to the drive wheels 53, the engine 10 may stall. Therefore, the input / output shafts in the multi-stage transmission 20 are not completely fastened, and the torque limiter 410 absorbs the torque to avoid the engine 10 from stalling.

[Start control at cryogenic temperature]
When the oil temperature sensor 515 shown in FIG. 1 determines that the temperature is extremely low, the electromagnetic multi-plate clutch 30 is first released, and the second gear is engaged with the dog clutch 420 open. The creep torque transmitted by the drag torque is a constant value in the drive wheel 53 due to the torque absorbing action associated with the relative rotation of the torque limiter 410 provided in the 2-3 speed driven transmission gear 212 which is the gear stage in the 2nd speed. The above is not transmitted.

  Since the torque limiter 410 is a plurality of relatively rotatable plates pressed with a constant force, a reaction force is generated with the relative rotation. Since this reaction force acts on the electromagnetic multi-plate clutch 30, the creep torque from the engine 10 and the reaction force from the torque limiter 410 act on the electromagnetic multi-plate clutch 30 in a relative manner.

  When these two torques acting in the relative directions in the electromagnetic multi-plate clutch 30 exceed the value of the drag torque, the electromagnetic multi-plate clutch 30 in the released state starts relative rotation and generates frictional heat. By this frictional heat, the oil temperature in the electromagnetic multi-plate clutch 30 is raised to lower the viscosity of the lubricating oil, thereby eliminating the drag torque.

  The start control at the time of cryogenic temperature may be continued until the oil temperature is detected and the oil temperature becomes equal to or higher than a predetermined value, or may be continued for a preset predetermined time. In this embodiment, this time is measured by a counter 502a provided in the cryogenic temperature control unit 502, and if a certain time or more has elapsed, it is determined that the drag torque has been eliminated, and the normal control unit 501 performs normal torque transmission. Shall start.

[Start control process at cryogenic temperature]
FIG. 7 is a flowchart showing the flow of the start control process executed by the cryogenic temperature control unit 502 when starting at an extremely low temperature. Hereinafter, each step will be described.

  In step S101, the energization of the electromagnetic multi-plate clutch 30 is stopped to be in a non-engaged state, and the process proceeds to step S102.

  In step S102, the dog clutch 420 is released, and the process proceeds to step S5.

  In step S103, the 2-way 2-way clutch 302 is engaged with the output shaft 25, and the process proceeds to step S105.

  In step S104, time measurement is started by the counter 502a, and the process proceeds to step S105.

  In step S105, it is determined whether the time measured by the counter 502a has passed a predetermined time. If YES, the process proceeds to step S107, and if NO, the process proceeds to step S106.

  In step S106, it is determined whether or not the accelerator is ON. If YES, the process proceeds to step S107, and if NO, the process returns to step S105.

  In step S107, the 2-way 2-way clutch 302 is released, and the process proceeds to step S108.

  In step S108, the first-speed two-way clutch 301 is engaged, and the process proceeds to step S109.

  In step S109, the electromagnetic multi-plate clutch 30 is energized, and the process is terminated as a normal engagement state.

[Time-dependent change of start control at cryogenic temperatures]
FIG. 8 is a time chart of start control at an extremely low temperature. FIG. 8 (a) shows a shift command, FIG. 8 (b) shows the engine speed Ne, FIG. 8 (c) shows the fastening force of the electromagnetic multi-plate clutch 30, and FIG. The engaged state of the two-way clutch 302 for speed is shown.

When a shift command from neutral to first speed is issued at time t ₁ , the first-speed two-way clutch 301 is disengaged and the second-speed two-way clutch 302 is started to be engaged. Further, in consideration of an increase in engine load accompanying an increase in the viscosity of the lubricating oil, the rotational speed Ne of the engine 10 is increased. At this time, the electromagnetic multi-plate clutch 30 is not engaged, but the power of the engine 10 is transmitted to the output shaft 25 via the torque limiter 410 by the drag torque.

In time t _2, the the second speed two-way clutch 302 is completely engaged state, and starts counting up the counter 502a for measuring the predetermined time. When the drag torque of the electromagnetic multi-plate clutch 30 is large, the engine stall is prevented by the relative rotation of the torque limiter 410.

  Due to the relative rotation of the torque limiter 410, a creep torque by the engine 10 and a reaction force by the torque limiter 410 are generated in the electromagnetic multi-plate clutch 30. When the torque acting in the two relative directions exceeds the drag torque, the electromagnetic multi-plate clutch 30 rotates relative to generate frictional heat, and the drag torque is eliminated by increasing the lubricating oil temperature. On the other hand, when the drag torque of the electromagnetic multi-plate clutch 30 is small, relative rotation of the electromagnetic multi-plate clutch 30 occurs and raises the lubricating oil temperature.

At time t ₃ , counting up by the counter 502 a is completed, and energization of the electromagnetic multi-plate clutch 30 is started on the assumption that a predetermined time for the oil temperature to rise has elapsed. Simultaneously with the release of the 2-speed 2-way clutch 302, the first-speed 2-way clutch 301 starts to be engaged.

At time t _4, 2-speed two-way clutch 302 is completely released, two-way clutch 301 is fully engaged for the first speed. As a result, the rotation of the engine 10 is constrained by the first speed gear, and the rotation speed corresponding to the gear ratio increases.

The electromagnetic multiple disk clutch 30 is completely engaged at time t _5, to achieve complete first speed.

[Effect of starting control at cryogenic temperature]
(5) The electromagnetic multi-plate clutch 30 is used as a starting clutch, and an oil temperature sensor 515 for detecting the lubricating oil temperature is provided. When the oil temperature is lower than a predetermined oil temperature, the cryogenic temperature control unit 502 causes the electromagnetic multi-plate clutch 30 to be The creep torque of the engine 10 is transmitted by the torque limiter 410 for a predetermined time.
As a result, a creep torque generated by the engine 10 and a reaction force generated by the torque limiter 410 are generated in the electromagnetic multi-plate clutch 30, and the electromagnetic multi-plate clutch 30 is relatively rotated by the torques acting in the two relative directions. Therefore, it is possible to generate frictional heat in the lubricating oil and the clutch plate that restrains the clutch plate, and to raise the oil temperature to eliminate the drag torque. Can be started (corresponding to claim 4).

(Other examples)
Although the best mode for carrying out the present invention has been described based on the first embodiment, the specific configuration of the present invention is not limited to each embodiment and does not depart from the gist of the present invention. Any changes in the design of the range are included in the present invention.

1 is a schematic diagram illustrating an overall configuration of a parallel shaft transmission according to a first embodiment. It is sectional drawing of the parallel shaft transmission of Example 1. FIG. FIG. 3 is a detailed cross-sectional view of the vicinity of a reverse gear in the parallel shaft transmission of the first embodiment. 6 is a flowchart illustrating a flow of a shift control process executed by a normal control unit during a 1-2 upshift in the control unit in the parallel shaft transmission according to the first embodiment. 4 is a time chart of the shift control from the first speed to the second speed executed in the parallel shaft transmission of the first embodiment. 4 is a flowchart showing a flow of a general shift control process executed by a normal control unit at the time of shifting in the control unit of the parallel shaft transmission of the first embodiment. 6 is a flowchart illustrating a flow of a start control process executed by a cryogenic temperature control unit when starting at an extremely low temperature in the control unit provided in the parallel shaft transmission of the first embodiment. 3 is a time chart of start control at a cryogenic temperature in the parallel shaft transmission of the first embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Engine 20 Multistage transmission 21 Transmission case 21a 2nd storage chamber 22 1st input shaft 23 2nd input shaft 24 Idle gear 25 Output shaft 30 Electromagnetic multi-plate clutch 31 1st input drum 32 2nd input drum 33 Main clutch 34 Pilot clutch 35 Torque cam mechanism 36 Input clutch hub 37 Electromagnet 38 Front cover 38a First storage chamber 39 Input clutch housing 51 Axle 52 Differential gear 53 Drive wheel 60 Shift actuator 201 1st speed drive transmission gear 202 2nd speed drive transmission gear 202 203 3rd-speed drive transmission gear 204 4th-speed drive transmission gear 205 5th-speed drive transmission gear 206 Reverse drive transmission gear 211 1st-speed driven transmission gear 212 2-3rd-speed driven transmission gear 212a Dog-tooth engagement spline 214 For 4-speed driven High-speed gear 215 Five-speed driven transmission gear 216a Reverse counter gear 216b Reverse driven transmission gear 217 Reduction gear 220 First transmission gear 230 Second transmission gear 301 First-speed two-way clutch 302 Second-speed two-way clutch 401 Shift sleeve 404 4th speed switching sync 405 3-5th speed switching sync 410 Torque limiter 411 Output shaft integrated sleeve 420 Dog clutch 500 Control unit 511 Throttle sensor 501 Normal control unit 502 Cryogenic control unit 502a Counter 512 Engine speed sensor 513 Turbine sensor 514 Vehicle speed sensor 515 Oil temperature sensor 516 Current sensor

Claims (5)

A multi-stage shift is provided with a constant meshing gear for each shift speed on a parallel shaft, the drive-side rotation shaft and the driven-side rotation shaft are arranged in parallel, and a shift is achieved by switching the torque transmission path of the constant-meshing gear. Mechanism,
A two-way clutch that engages / releases the drive-side rotary shaft of the parallel shaft and the drive-side gear of the constantly meshing gear;
In a parallel shaft transmission comprising:
A parallel shaft transmission comprising a torque limiter for transmitting only a predetermined torque on a torque transmission path between a low-speed driven gear of the constantly meshing gear and the driven rotary shaft. The parallel shaft transmission according to claim 1, wherein
A rigid body coupling means capable of rigidly coupling the low-speed driven gear and the driven rotary shaft of the parallel shaft;
2. The parallel shaft transmission according to claim 1, wherein the rigid body coupling means is means for performing torque transmission by rigid body coupling after torque transmission by the torque limiter as a shift to the low speed driven gear. The parallel shaft transmission according to claim 2,
A parallel shaft transmission, wherein the torque limiter and the rigid body coupling means are arranged in parallel on the driven side rotating shaft. The parallel shaft transmission according to any one of claims 1 to 3,
A wet electromagnetic multi-plate clutch provided with a pilot clutch as a starting element, and a shift control means for performing shift control of the parallel shaft transmission,
Oil temperature detecting means for detecting the lubricating oil temperature of the electromagnetic multi-plate clutch is provided,
The parallel shaft transmission, wherein the shift control means performs torque transmission only by the torque limiter for a predetermined time when the detected oil temperature is lower than a predetermined oil temperature. The parallel shaft transmission according to claim 2 or 3,
When torque is transmitted via the low-speed driven gear by engaging the two-way clutch, torque is transmitted by the torque limiter for a predetermined time after the two-way clutch starts to be engaged, and then the rigid body coupling means is engaged. A parallel shaft transmission that performs torque transmission.

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