JP2004124980A - Transmitting mechanism for automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a constitution where a clutch piston of an auxiliary transmission for enabling the start control under the increase of torque, does not receive the returning force from lubricant pressure inside of the auxiliary transmission. <P>SOLUTION: In starting, the auxiliary transmission 20 is kept in a low-speed stage (decelerating stage) selecting state by releasing a clutch 24, and the start is performed by controlling the connection of a forward clutch 4a from a neutral state where both of the forward clutch 4a and a backward brake 4b are released. As a piston 24p of the clutch 24 is pressed to the right in a drawing by the lubricant pressure in an auxiliary transmission case 21, the piston working pressure α to the piston chamber 46 should be determined to be higher for the same, which worsens the fuel consumption in a conventional mechanism, but by mounting a back chamber 53 in a state of being kept into contact with the piston 24p at a side farther from the piston chamber 46, the piston pressing force by lubricant pressure in the auxiliary transmission case 21 is reduced, and further as the piston working pressure α is not determined to be higher, the worsening of the fuel consumption can be prevented. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a transmission mechanism for an automatic transmission including a continuously variable transmission.
[0002]
[Prior art]
Automatic transmissions are usually provided with a torque converter in a transmission system for absorbing and mitigating torque fluctuations during operation of an engine at a preceding stage as described in Patent Document 1, for example, and for the purpose of increasing torque. It is common to provide.
[0003]
[Patent Document 1]
JP-A-9-112672
[0004]
[Problems to be solved by the invention]
By the way, even if the torque converter is a lock-up type torque converter that enables direct connection between input and output elements with the aim of improving transmission efficiency under operating conditions that do not require a torque fluctuation absorption function or a torque increase function, lock-up In the non-lock-up state (converter state) in which the clutch is released, fluid transmission is performed, so that it is not possible to avoid the problem that transmission efficiency is deteriorated due to slippage between input and output elements.
[0005]
On the other hand, if an electromagnetic clutch is used instead of the torque converter, the torque increasing function useful in the torque converter cannot be obtained, and the power performance including the deterioration of the starting performance is deteriorated.
[0006]
SUMMARY OF THE INVENTION It is an object of the present invention to propose a transmission mechanism for an automatic transmission that can avoid the above-described problem as a configuration that does not require the use of a torque converter or an electromagnetic clutch.
[0007]
[Means for Solving the Problems]
To this end, the transmission mechanism of the automatic transmission according to the first invention has the following configuration. The main transmission is configured to be in a neutral state, and a subtransmission having a low speed stage for reducing the input rotation and outputting and a high speed stage capable of higher speed transmission is provided at the preceding stage.
[0008]
Here, the sub-transmission is filled with lubrication and cooling oil flowing from the main transmission and returning to the main transmission, and the sub-transmission case to which the input rotation is transmitted,
It is assumed that the clutch includes a clutch drum in the auxiliary transmission case, which is drivingly connected thereto, and a clutch having a clutch piston slidably fitted in the clutch drum.
The clutch is engaged or released by the clutch piston which responds to the operating oil pressure to the piston chamber, so that the sub-transmission can be set to the state in which the high-speed stage or the low-speed stage is selected.
[0009]
Also, a rear chamber is defined in contact with the side surface of the clutch piston to prevent the intrusion of the lubrication / cooling oil so that the pressure of the lubrication / cooling oil does not act on the side surface of the clutch piston far from the piston chamber.
Further, in the start control, the start control is enabled by controlling the engagement progress of a friction element for changing the main transmission from the neutral state to the power transmission state in the low speed stage selection state of the auxiliary transmission.
[0010]
【The invention's effect】
When starting, the sub-transmission is set to the low speed stage, which is the deceleration stage, and the start control is enabled by controlling the engagement progression of the friction element that changes the main transmission at the subsequent stage of the sub-transmission from the neutral state to the power transmission state. To
Therefore, in the present invention, even when the vehicle is started, the same starting operation as that of the manual transmission can be employed while being an automatic transmission. Therefore, since a torque converter is not necessary, the conventional torque converter is used. In addition, it is possible to solve the problem regarding the transmission efficiency of the automatic transmission.
[0011]
Further, in the first invention, since the sub-transmission is set to the low-speed stage selection state which is the reduction stage at the time of starting, the sub-transmission exhibits the same function as the torque increasing operation of the torque converter, and the electromagnetic clutch is used. There is no problem that the power performance is deteriorated.
It should be noted that keeping the sub-transmission in the low-speed gear selection state, which is the reduction gear, as described above at the time of starting means that when the friction element that brings the main transmission from the neutral state to the power transmission state is controlled to advance in engagement at the time of starting, This means that the input rotation of the friction element can be reduced, and the durability of the friction element can be improved, and the engagement progress control at the time of starting can be facilitated, which is a great advantage.
[0012]
The sub-transmission for the above operation and effect is a clutch having the clutch drum and the clutch piston in a sub-transmission case filled with lubrication and cooling oil flowing from the main transmission and returning to the main transmission. The auxiliary transmission is switched between a high speed selection state and a low speed selection state when the clutch is engaged or released by a clutch piston that responds to the operating oil pressure to the piston chamber.
[0013]
By the way, since the auxiliary transmission is used in place of the torque converter as described above, the above-mentioned lubrication / cooling oil diverts the operating oil used for the shift control of the main transmission, flows in from the main transmission, and also receives the main transmission. The auxiliary transmission case is filled with lubrication and cooling oil returning to the transmission to provide lubrication and cooling for the auxiliary transmission.
As a result, the lubricating / cooling oil in the auxiliary transmission case has a pressure, and this pressure acts on the side surface of the clutch piston far from the piston chamber to try to urge the clutch piston toward the piston chamber.
[0014]
The urging force of the clutch piston due to the pressure of the lubrication / cooling oil in the auxiliary transmission case acts as a resistance to the operation of the clutch piston by the operating oil pressure to the piston chamber, and it is necessary to set the operating oil pressure to the piston chamber high. Occurs.
For this reason, it becomes necessary to determine the source pressure of the operating oil pressure to be higher by that amount, and the driving load of the oil pump that generates the source pressure increases, leading to deterioration of fuel efficiency.
Further, the urging force of the clutch piston due to the pressure of the lubrication / cooling oil impairs the operation response of the clutch piston, that is, the engagement response of the clutch, thereby deteriorating the shift feeling.
[0015]
By the way, in the present invention, as described above, since the rear chamber for preventing the pressure of the lubrication / cooling oil from acting on the side of the clutch piston far from the piston chamber is defined,
The pressure of the lubricating / cooling oil acts on the side of the clutch piston far from the piston chamber and does not urge the clutch piston toward the piston chamber, or at least the urging can be reduced. This eliminates the need to set the operating oil pressure to the piston chamber high.
For this reason, the source pressure of the working oil pressure can be determined to be lower by that amount, and the driving load of the oil pump that generates the source pressure is reduced, so that fuel efficiency can be improved.
[0016]
According to the configuration of the present invention in which the pressure of the lubrication / cooling oil can reduce the urging of the clutch piston toward the piston chamber, the operating response of the clutch piston by the operating oil pressure to the piston chamber, that is, The shift response can be improved by increasing the clutch engagement response.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a toroidal type continuously variable transmission in which a torque converter is replaced with an auxiliary transmission 20 according to an embodiment of the present invention.
First, the transmission path will be briefly described. The rotation of the engine (motor) 1 is transmitted to the forward / reverse switching mechanism 4 via the auxiliary transmission 20 and the main transmission (transmission) input shaft 3.
[0018]
When the vehicle is traveling forward in the automatic transmission (D) range, the forward / reverse switching mechanism 4 transmits the engine rotation from the auxiliary transmission 20 as it is by engaging the forward clutch 4a, and travels backward in the reverse traveling (R) range. When the reverse brake 4b is engaged, the engine rotation from the auxiliary transmission 20 is decelerated and transmitted in the reverse direction. When the vehicle is parked or stopped in the parking (P) range or the neutral (N) range, the forward clutch 4a and the reverse Both of the brakes 4b are released to prevent transmission of the engine rotation from the auxiliary transmission 20 to the subsequent stage.
[0019]
Two toroidal transmission units (a front-side toroidal transmission unit 5 and a rear-side toroidal transmission unit 6) are provided at the rear stage of the forward / reverse switching mechanism 4 in coaxial back-to-back relation.
Each of the toroidal transmission units 5 and 6 includes an input disk 7, an output disk 8 coaxially opposed thereto, and a pair of power rollers 9 interposed between the corresponding input and output disks 7, 8. The configuration is the same.
[0020]
The two toroidal transmission units 5 and 6 are arranged coaxially so that the respective output disks 8 are back-to-back. In this arrangement, the respective input disks 7 are rotationally engaged with the main shaft 10 and the forward and backward switching mechanism 4 is used. The rotation is commonly input, and each output disk 8 is rotatably supported on a main shaft 10.
The two output disks 8 are integrally connected to each other via a hollow output shaft 11, and an output gear 12 is fixed on the hollow output shaft 11.
[0021]
The output gear 12 meshes with a counter gear 14 at the front end of the counter shaft 13, and the rear end of the counter gear 14 is drivingly connected to a transmission output shaft 16 coaxially arranged behind the main shaft 10 via an output gear set 15.
[0022]
The rotation from the forward / reverse switching mechanism 4 is transmitted to both input disks 7 in common, and the rotation of the input disk 7 reaches the output disk 8 via the corresponding power roller 9, and the rotation is transmitted from the common output gear 12 to the output disk 12. The gear is taken out of the transmission output shaft 16 through the counter gear 14 and the counter shaft 13 meshing with the gears and the output gear set 15 in order.
[0023]
At the time of shifting, if the power roller 9 is offset in the same phase in synchronization with the neutral position where its own rotation axis intersects with the rotation axis of the input / output disks 7, 8, the power roller 9 is rotated by the component force during rotation. It is tilted in phase in synchronism with the rotation axis which is orthogonal to the rotation axis, so that the contact trajectory arc diameter of the power roller 9 with respect to the input / output disks 7 and 8 changes continuously to perform a predetermined stepless speed change. It can be carried out.
When the speed ratio reaches the commanded speed ratio, the power roller 9 is returned to the initial stroke position at which the offset is 0, whereby the power roller 9 does not self-tilt and the commanded speed ratio can be maintained.
[0024]
In the present embodiment, the sub-transmission 20 has an actual configuration shown in FIG. 2, and includes an auxiliary transmission case 21, which is connected to a crankshaft of the engine 1 via a drive plate 22. At the same time, the following components are incorporated into the sub-transmission case 21 to form the sub-transmission 20.
That is, the input shaft (the input shaft of the main transmission) 3 of the forward / reverse switching mechanism 4 constituting the main transmission with the toroidal transmission units 5 and 6 is inserted into the sub-transmission case 21, and the input shaft 3 is inserted. A simple planetary gear set 23 is mounted on the end, and the carrier 23c of the simple planetary gear set 23 is drive-coupled to the input shaft 3 on the side far from the engine, and the clutch hub 24h of the high-speed stage selection clutch 24 on the side near the engine. Also drive coupled.
[0025]
The ring gear 23r of the simple planetary gear set 23 rotates therewith, but extends radially inward along the side of the simple planetary gear set 23 far from the engine, and a one-way as a low-speed step selecting brake. It is mounted on the hollow fixed shaft 26 via the clutch 25 sequentially.
The internal plate 41 is rotatable while being fixed in the axial direction while being sandwiched between the thrust bearings 42 and 43. The one-way clutch 25 causes the internal plate 41 and the ring gear 23r to rotate in the opposite direction to the rotation of the engine 1 (input rotation). It shall not be able to rotate in any direction.
[0026]
The high speed stage selection clutch 24 includes a clutch drum 24d housed in the auxiliary transmission case 21 in addition to the clutch hub 24h described above, and drives the clutch drum 24d to the auxiliary transmission case 21 via the high speed stage damper 27. Join.
The clutch drum 24d is further drivingly connected to a sun gear 23s of the simple planetary gear set 23 via a low speed gear damper 28.
[0027]
As shown in FIG. 2, the high-speed gear selecting clutch 24 further includes a clutch piston 24p fitted slidably in the axial direction within the clutch drum 24d, and the clutch drum 24d and the clutch drum 24d A liquid-tight seal is provided between the clutch pistons 24p.
The inner periphery of the clutch piston 24p is fitted to the outer periphery of a shaft portion 41a provided on the internal plate 41 so as to extend in a direction away from the simple planetary gear set 23, and a seal member 45 is interposed in the fitted portion. Perform liquid tight sealing.
Thus, a piston chamber 46 is defined between the end wall of the clutch drum 24d and the clutch piston 24p, and an oil passage 47 for supplying and discharging the working oil pressure α to and from the piston chamber 46 is connected to the auxiliary transmission case 21. And a hollow space between the drive shaft 48 of the pump O / P and the hollow fixed shaft 26.
[0028]
When the clutch operating oil pressure α is supplied from the oil passage 47 to the piston chamber 46, the clutch piston 24p strokes leftward in FIG. 2 against a return spring 49 contracted between the clutch piston 24p and the internal plate 41. At this time, the high speed stage selection clutch 24 couples the clutch drum 24d and the clutch hub 24h by fastening as shown in FIG. 3, and at this time, the rotation from the high speed stage damper 27 passes through the low speed stage damper 28. And transmitted directly to the input shaft 3 via the carrier 23c (in a high-speed stage selection state).
[0029]
However, when the high-speed stage selection clutch 24 is disengaged as shown in FIG. 1 without the operating oil pressure α to the piston 24p, the rotation from the high-speed stage damper 27 passes through the low-speed stage damper 28 to rotate the simple planetary gear. The sun gear 23s of the gear set 23 is reached.
Here, the sun gear 23s rotates the carrier 23c in the same direction while reducing the speed because the high-speed stage selection clutch 24 is released and the one-way clutch 25 prevents the ring gear 23r from rotating in the opposite direction to the engine 1. It is driven and power is transmitted to the input shaft 3 in the low speed stage selection state.
[0030]
The damper characteristics of the high speed gear damper 27 are set to the characteristics required in the high speed gear selection state, and the low speed damper 28 is set to the characteristics required in the low speed gear selection state.
[0031]
In order to supplementally describe the actual configuration of the forward / reverse switching mechanism 4 shown in FIG. 2, the forward / reverse switching mechanism 4 includes a simple planetary gear set 4c in addition to the forward clutch 4a and the reverse brake 4b.
When the forward clutch 4a is engaged by the oil pressure β, the sun gear 4d and the ring gear 4e of the simple planetary gear set 4c are connected to rotate the input shaft 3 and the toroidal transmission units 5, 6 downstream of the sun gear 4d as shown in FIG. 1) to enable forward travel in the D range,
When the reverse brake 4b is engaged by the hydraulic pressure γ, the carrier 4f of the simple planetary gear set 4c is fixed, the rotation from the input shaft 3 is reduced, and the reverse rotation is transmitted to the toroidal transmission units 5, 6 downstream from the sun gear 4d. Enables reverse travel in the R range.
Thus, when the vehicle is parked or stopped in the P, N range, both the forward clutch 4a and the reverse brake 4b are released, and the rotation from the input shaft 3 is not transmitted to the toroidal transmission units 5 and 6 at the subsequent stage.
[0032]
By the way, the sub-transmission 20 needs lubrication and cooling of the simple planetary gear set 23, the high-speed stage selection clutch 24, and the one-way clutch 25 inside. Therefore, the sub-transmission case 21 is always filled with lubrication and cooling oil. It is necessary to circulate while circulating.
As described above, since the auxiliary transmission 20 is used instead of the torque converter as described above, the lubricating / cooling oil uses the operating oil used for the shift control of the toroidal type continuously variable transmission that is the main transmission, This hydraulic oil flows from the main transmission into the sub-transmission case 21 through an oil passage 51 drilled in the input shaft 3, and also flows into the sub-transmission case 21 through an oil passage 53 drilled in the input shaft 3. To the main transmission.
Therefore, the working oil described above is filled in the sub-transmission case 21 as lubrication and cooling oil for the sub-transmission 20, so that the sub-transmission 20 can be lubricated and cooled.
[0033]
However, the lubricating / cooling oil in the sub-transmission case 21 has a pressure for returning to the main transmission, and this pressure acts on the side of the clutch piston 24p far from the piston chamber 46 to direct the clutch piston 24p toward the piston chamber 46. Try to energize.
The urging force of the clutch piston 24p due to the pressure of the lubricating / cooling oil in the auxiliary transmission case 21 acts as a resistance to the above-described operation of the clutch piston 24p by the operating oil pressure α to the piston chamber 46, and the operation to the piston chamber 46 It is necessary to set the hydraulic pressure α to be high.
For this reason, it is necessary to determine the source pressure of the working oil pressure α to be higher by that amount, and the driving load of the oil pump O / P that generates the source pressure increases, which causes deterioration of fuel efficiency.
Further, the urging force of the clutch piston 24p due to the pressure of the lubrication / cooling oil impairs the operation response of the clutch piston 24p, that is, the engagement response of the clutch 24, thereby deteriorating the shift feeling.
[0034]
By the way, in the present embodiment, the rear chamber 53 is defined in contact with the side of the clutch piston 24p far from the piston chamber 46 so that the pressure of the lubricating / cooling oil does not act on the side face.
For this reason, the outer periphery of the internal plate 41 is slidably fitted to the clutch piston 24p under liquid-tight sealing by the seal member 54, thereby defining a rear chamber 53 between the internal plate 41 and the clutch piston 24p. I do.
Note that the liquid-tightly sealed portion by the seal member 54 has a diameter such that the pressure receiving area of the piston 24p in the rear chamber 53 is smaller than the pressure receiving area of the piston 24p in the piston chamber 46.
[0035]
Preferably, the rear chamber 53 is successively communicated with a drain passage 55 formed in the internal plate 41 and an annular drain passage 56 set between the hollow fixed shaft 26 and the input shaft 3. Even if hydraulic oil enters, it can be reliably eliminated.
In the present embodiment, since these drain passages 55 and 56 are adjacent to the lubricating / cooling oil supply oil passage 51, the carrier center boss portion 57 that controls the coupling of the carrier 23c to the input shaft 3 to isolate the two. The seal member 58 is interposed between the outer periphery of the inner plate and the inner periphery of the internal plate 41.
[0036]
By providing the rear chamber 53 as described above, the pressure receiving area in which the pressure of the lubricating / cooling oil in the auxiliary transmission case 21 acts on the side surface of the clutch piston 24p far from the piston chamber 46 can be reduced. The pressure of the cooling oil can reduce the urging force for urging the clutch piston 24p toward the piston chamber, and it is not necessary to set the operating oil pressure α to the piston chamber 46 high in anticipation of this urging force.
Therefore, the source pressure of the operating oil pressure α can be determined to be lower by that amount, and the driving load of the oil pump O / P that generates the source pressure can be reduced, and the fuel efficiency of the engine can be improved.
[0037]
According to this embodiment which can reduce the pressure of the lubrication / cooling oil urging the clutch piston 24p toward the piston chamber 46, the clutch piston 24p can be further reduced by the operating oil pressure α to the piston chamber 46. , Ie, the engagement response of the clutch 24, can be improved to improve the shift feeling.
[0038]
Further, when the rear chamber 53 is defined, the rear chamber 53 is defined by fitting the axial fixing member (in the drawing, the internal plate 41) and the clutch piston 24p, so that the piston 24p makes a stroke. Even so, the rear chamber 53 can be easily defined,
In particular, when the internal plate 41 is used as the axial fixing member as shown in the figure, since the internal plate 41 is an existing component indispensable for the attachment of the ring gear 23r, the rear chamber 53 can be inexpensively manufactured without adding a dedicated component. Advantageously, it can be defined as
[0039]
Further, since the pressure receiving area of the piston 24p in the rear chamber 53 is determined to be smaller than the pressure receiving area of the piston 24p in the piston chamber 46, as described above, the diameter of the liquid-tight sealing portion by the seal member 54 is determined.
Even if hydraulic oil enters the rear chamber 53 and the intruded oil pushes the piston 24p toward the piston chamber 46, the reverse force to the piston 24p by the hydraulic oil in the piston chamber is more reliable than this pushing force. And the situation where the intruding oil pushes the piston 24p back toward the piston chamber 46 can be avoided.
If the rear chamber 53 is communicated with the drain passages 55 and 56 as in the present embodiment, even if hydraulic oil enters the rear chamber 53, it can be reliably eliminated. It can be assured.
[0040]
The control for engaging and disengaging the forward clutch 4a and the reverse brake 4b of the forward / reverse switching mechanism 4 as described above, the above-described shift control of the toroidal transmission units 5 and 6, and the engagement of the high speed stage selection clutch 24 in the auxiliary transmission 20, Each release control is executed by the transmission controller 32 via the control valve body 31 as shown in FIG.
Therefore, a signal from an engine rotation sensor 33 that detects the engine rotation speed Ne is transmitted to the transmission controller 32,
A signal from a throttle opening sensor 34 for detecting a throttle opening TVO of the engine 1;
A signal from an idle switch 35 that is turned on when the accelerator pedal is released to detect an idle operation state;
A signal from a brake switch 36 which is turned on when the brake pedal is depressed to detect a braking state;
A signal from a vehicle speed sensor 37 for detecting the vehicle speed VSP is input.
[0041]
The operation of the toroidal type continuously variable transmission according to the above embodiment will be described below.
First, the transmission operation will be described. The engine rotation to the auxiliary transmission case 21 reaches the clutch drum 24d via the high speed damper 27.
Here, when the high-speed stage selection clutch 24 is released, the rotation to the clutch drum 24d reaches the sun gear 23s via the low-speed stage damper 28, and the rotation to the sun gear 23s is reduced to the low-speed stage by the action of the simple planetary gear set 23. In the selected state, the signal is transmitted to the input shaft 3 under deceleration.
When the high-speed stage selection clutch 24 is engaged by the hydraulic pressure α as shown in FIG. 3, the rotation to the clutch drum 24d is not passed through the low-speed stage damper 28, but is directly passed through the carrier 23c to the input shaft 3 in the high-speed stage selection state. Conveyed in.
[0042]
As described above, the low-speed damper 28 inserted in the transmission path used in the low-speed gear performs a predetermined damper function only when the low-speed gear is selected, and when the high-speed gear is selected, the low-speed damper 28 The power is transmitted through the high speed stage selection clutch 24 which bypasses the motor, so that the low speed stage damper 28 does not perform the damper function.
Therefore, the damper characteristics of the low-speed gear damper 28 can be set to the characteristics required in the low-speed gear selection state.
[0043]
On the other hand, when the high-speed gear is selected, only the high-speed gear damper 27 inserted in the transmission path shared by all the gears performs the damper function. , The characteristics required in the high-speed stage selection state can be set.
[0044]
The rotation that has been switched between high and low speeds by the sub-transmission 20 as described above and reached the input shaft 3 is caused by the forward / reverse switching mechanism while the forward clutch 4a of the forward / reverse switching mechanism 4 is engaged by the hydraulic pressure β as shown in FIG. 4 to the toroidal transmission units 5 and 6 at the subsequent stage as they are, and are taken out from the transmission output shaft 16 under the speed change by these toroidal transmission units 5 and 6.
While the reverse brake 4b of the forward / reverse switching mechanism 4 is engaged by the hydraulic pressure γ of FIG. 2, the rotation to the input shaft 3 is reversed to rotate in the reverse direction through the above-described operation of the forward / reverse switching mechanism 4, and the rear toroidal transmission unit 5 , 6 through the transmission output shaft 16 via the toroidal transmission units 5, 6.
While the forward clutch 4a and the reverse brake 4b of the forward / reverse switching mechanism 4 are both disengaged, the rotation to the input shaft 3 does not reach the toroidal transmission units 5 and 6 at the subsequent stage, and the toroidal type continuously variable transmission is neutralized. Can be kept in a state.
[0045]
Next, start control and shift control of the toroidal-type continuously variable transmission will be described.
At the time of starting, the transmission controller 32 sets the subtransmission 20 to the low speed (reduction speed) selection state by releasing the high speed selection clutch 24, and releases both the forward clutch 4a and the reverse brake 4b of the forward / reverse switching mechanism 4. From the previously set neutral state, the engagement progress control of the forward clutch 4a as a friction element for starting when the vehicle starts forward in the D range, and the engagement progress control of the reverse brake 4b as the friction element for starting when the vehicle starts backward in the R range. To start.
[0046]
Although the engagement progress control of the starting friction element is performed as shown in FIG. 4, the engagement progress control of the forward clutch 4a at the time of the preceding start will be representatively described below.
If the accelerator pedal has not yet been depressed in the D range, the idle switch 35 is ON, and the brake switch 36 is also ON due to the braking state in which the brake pedal is depressed.
If the vehicle speed VSP is less than 5 km / h, the forward clutch 4a is completely released to keep the toroidal type continuously variable transmission in a neutral state.
If the vehicle speed VSP is 5 km / h to 15 km / h, the forward clutch 4a is brought into a state in which the return spring 4g shown in FIG. 2 has finished contracting and the loss stroke of the clutch has been completed, that is, a state immediately before the start of engagement (initial control).
If the vehicle speed VSP is equal to or higher than 15 km / h, the forward clutch 4a is completely engaged, and in conjunction with the low speed selection state of the auxiliary transmission 20, the toroidal-type continuously variable transmission can perform normal power transmission at the D range and the low side gear ratio. Make it possible.
[0047]
If the accelerator pedal has not yet been depressed in the D range and the idle switch 35 is ON, but the brake switch 36 is OFF due to the brake release state in which the brake pedal is released,
From the stopped state where the vehicle speed VSP is less than 5 km / h, initial control is performed to change the forward clutch 4a to a state in which the return spring 4g shown in FIG.
If the vehicle speed VSP is 5 Km / h to 15 Km / h, the forward clutch 4a is subjected to a slip engagement control to gradually advance the engagement from the state immediately before the start of the engagement,
If the vehicle speed VSP is equal to or higher than 15 km / h, the forward clutch 4a is completely engaged, and in conjunction with the low speed selection state of the auxiliary transmission 20, the toroidal-type continuously variable transmission can perform normal power transmission at the D range and the low side gear ratio. Make it possible.
[0048]
When the accelerator pedal is depressed in the D range, and the idle switch 35 is OFF, and the brake switch 36 is ON due to the braking state in which the brake pedal is depressed,
Even when the vehicle is stopped at a vehicle speed VSP of less than 5 km / h, slip engagement control is performed to gradually advance the engagement of the forward clutch 4a,
If the vehicle speed VSP is 5 km / h to 15 km / h, the above-described slip engagement control of the forward clutch 4a is continued to further advance the engagement of the forward clutch 4a,
If the vehicle speed VSP is equal to or higher than 15 km / h, the forward clutch 4a is completely engaged, and in conjunction with the low speed selection state of the auxiliary transmission 20, the toroidal-type continuously variable transmission can perform normal power transmission at the D range and the low side gear ratio. Make it possible.
[0049]
When the accelerator pedal is depressed in the D range, the idle switch 35 is OFF, and the brake switch 36 is also OFF due to the brake release state in which the brake pedal is released.
Slip engagement control is performed to gradually advance the engagement of the forward clutch 4a from a stopped state in which the vehicle speed VSP is less than 5 km / h,
If the vehicle speed VSP is 5 Km / h to 15 Km / h, the forward clutch 4a is completely engaged, and the toroidal type continuously variable transmission is operated in the D range and the low side gear ratio in combination with the low speed stage selection state of the auxiliary transmission 20. Power transmission is possible,
If the vehicle speed VSP is equal to or higher than 15 Km / h, the forward clutch 4a is kept in the fully engaged state to maintain the toroidal type continuously variable transmission in a state where normal power transmission in the D range and the low side gear ratio is possible.
[0050]
In the N and P ranges, regardless of the operation state of the accelerator pedal, that is, regardless of the ON / OFF state of the idle switch 35, and regardless of the operation state of the brake pedal, that is, regardless of the ON state or OFF state of the brake switch 36, The starting friction element (now in the D range, the forward clutch 4a) is completely released, and the other friction element (now in the D range, the reverse brake 4b) is released, and the toroidal-type continuously variable transmission is in the neutral state. To keep.
[0051]
To explain the shift control after the toroidal-type continuously variable transmission is set to the state where the normal power transmission in the D range is possible as described above, the transmission controller 32 uses a shift map to be exemplified in FIG. And the target input rotation speed Ne from the vehicle speed VSP and the throttle opening TVO. ^* And the engine speed Ne detected by the sensor 33 is calculated as the target input speed Ne. ^* The transmission control of the toroidal transmission units 5 and 6 is performed so as to coincide with the above.
Then, based on the vehicle speed VSP and the throttle opening TVO based on the map of FIG. 5, the transmission controller 32 determines whether the sub-transmission 20 is to be in the low-speed selection state or the sub-transmission 20 is in the high-speed selection state. Check if it is the high speed step selection area to be set.
[0052]
In the case of the low-speed gear selection range, the sub-transmission 20 is set to the low-speed gear selection state by releasing the high-speed gear selection clutch 24, and the above-described start control is executed. The sub-transmission 20 is brought into the high-speed stage selection state by the engagement of the high-speed stage selection clutch 24 shown in FIG. 3, and the shift control in accordance with FIG. 4 is enabled in conjunction with the engagement holding of the forward clutch 4a shown in FIG.
[0053]
By the way, in the present embodiment, at the time of starting, the sub-transmission 20 is set to the low-speed stage selection state which is the reduction stage, and the toroidal type continuously variable transmission which is the main transmission at the subsequent stage of the sub-transmission 20 is powered from the neutral state. Since the forward clutch 4a (during the D range) or the reverse brake 4b (during the R range), which is the starting frictional element to be in the transmission state, is controlled by performing the engagement progression as described above with reference to FIG.
Even at the time of the start, a start operation similar to that of a manual transmission can be adopted even though the transmission is an automatic transmission. Therefore, since a conventionally required torque converter is not required, there is a problem regarding the transmission efficiency of the automatic transmission. Can be eliminated.
[0054]
Further, in the present embodiment, since sub-transmission 20 is set to the low-speed stage selection state, which is the reduction stage, at the time of start, sub-transmission 20 exhibits the same function as the torque increasing operation of the torque converter. There is no problem that the power performance is reduced when the clutch is used.
Further, since the sub-transmission 20 is set to the low speed stage selection state as the deceleration stage at the time of starting, the forward clutch 4a (in the D range) or the reverse brake 4b (in the R range) is used as the starting friction element as described above. When used, the input rotation of the starting friction element can be reduced, its durability can be improved, and the above-described engagement progress control can be facilitated.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a transmission path of a toroidal type continuously variable transmission including a transmission mechanism according to an embodiment of the present invention.
FIG. 2 is a half vertical sectional side view showing an actual configuration of a subtransmission in the transmission mechanism together with a forward / reverse switching mechanism.
FIG. 3 is a schematic side view showing the auxiliary transmission in a high speed stage selection state and showing the forward / reverse switching mechanism in a forward rotation transmission state.
FIG. 4 is an explanatory diagram showing an engagement progress control mode of a starting friction element to be engaged in the start control in the embodiment.
FIG. 5 is a diagram illustrating a speed change pattern used for speed change control of the transmission mechanism in the embodiment.
[Explanation of symbols]
1 engine
3 Input shaft of main transmission
4 Forward / backward switching mechanism
5 Front toroidal transmission unit
6 Rear toroidal transmission unit
7 Input disk
8 Output disk
9 Power roller
10 Spindle
11 Hollow output shaft
12 Output gear
13 Counter shaft
14 Counter gear
15 Output gear set
16 Transmission output shaft
20 auxiliary transmission
21 Auxiliary transmission case
22 Drive plate
23 Simple planetary gear set
23c carrier
23r ring gear
23s sun gear
24 High speed gear selection clutch
24h clutch hub
24d clutch drum
24p clutch piston
25 One-way clutch (low speed gear selection brake)
26 Hollow fixed shaft
27 High Speed Damper
28 Low speed damper
31 Control valve body
32 Transmission controller
33 Engine rotation sensor
34 Throttle opening sensor
35 Idle switch
36 Brake switch
37 Vehicle speed sensor
41 Internal plate
44 Sealing member
45 Sealing member
46 piston chamber
47 Hydraulic oil supply passage for clutch operation
49 Return Spring
51 Lubrication / cooling oil supply oil passage
52 Lubrication / cooling oil return oil passage
53 rear room
54 Sealing member
55,56 drain passage
58 Sealing member

Claims (5)

A sub-transmission having a low-speed stage and a high-speed stage for reducing the input rotation and outputting is provided at a stage preceding the main transmission that can be in a neutral state,
The sub-transmission is filled with lubrication and cooling oil flowing from the main transmission and returning to the main transmission, and the sub-transmission case transmitted with the input rotation;
A clutch drum having a clutch drum in the auxiliary transmission case and drivingly coupled to the auxiliary transmission case, and a clutch piston slidably fitted in the clutch drum;
When the clutch is engaged or released by the clutch piston responsive to the operating oil pressure to the piston chamber, the auxiliary transmission can be set to the state in which the high speed stage or the low speed stage is selected,
In order that the pressure of the lubrication / cooling oil does not act on the side surface of the clutch piston far from the piston chamber, a rear chamber is defined in contact with the side surface of the clutch piston to prevent the intrusion of the lubrication / cooling oil,
A transmission mechanism for an automatic transmission, wherein starting control is enabled by controlling the engagement progress of a friction element that changes the main transmission from a neutral state to a power transmission state in a low speed stage selection state of the auxiliary transmission. . 2. The transmission mechanism according to claim 1, wherein an axial fixing member facing a side surface of the clutch piston remote from the piston chamber and a clutch piston are slidably fitted in a liquid-tight manner to define the rear chamber. A transmission mechanism for an automatic transmission, characterized in that: The transmission mechanism according to claim 1, wherein the auxiliary transmission is provided with a simple planetary gear set,
The carrier of the simple planetary gear set is coupled to the input shaft of the main transmission and can be coupled to the clutch drum by the clutch,
Coupled to the clutch drum to transmit the input rotation to a sun gear of a simple planetary gear set,
The ring gear of the simple planetary gear set is prevented from rotating in the opposite direction to the input rotation via an axially fixed internal plate facing the side surface of the clutch piston remote from the piston chamber,
A transmission mechanism for an automatic transmission, wherein the rear plate is defined by slidably fitting the internal plate and the clutch piston in a liquid-tightly sealed state. 4. The transmission mechanism according to claim 2, wherein a liquid-tightly sealed fitting portion between the axial fixing member or the internal plate and a clutch piston is provided, and a pressure receiving area of the clutch piston in the rear chamber is a clutch in the piston chamber. 5. A transmission mechanism for an automatic transmission, wherein the diameter is smaller than a pressure receiving area of a piston. The transmission mechanism according to any one of claims 1 to 4, wherein the rear chamber is communicated with a drain passage.

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