JP2016200207A - Vehicle automatic transmission control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle automatic transmission capable of ensuring that a vehicle turns into a restartable state at an intended shift position during sudden deceleration of the vehicle, and appropriately preventing two shift gears belonging to the same input shaft from being simultaneously synchronized with the input shaft during the sudden deceleration at which tires are locked, or so-called synchronous engagement.SOLUTION: When a vehicle turns into a sudden deceleration state, a corresponding synchronization mechanism is controlled to forcibly, synchronously engage a shift gear of the other shaft for enabling restart with the other shaft (perform pre-shifting) and changes over clutches at arbitrary timing in a tire locked state, so as to turn the vehicle into a restartable state. When the tire locked state is cancelled, a synchronous control is restarted to enable the vehicle to be safely restarted. Furthermore, when the sudden deceleration state is cancelled, a normal shift gear switching control is restarted to enable the vehicle to safely travel.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a control device for an automatic transmission for a vehicle, and more particularly, to an automatic transmission for a vehicle that can reliably bring the vehicle to a re-startable state at a target shift stage when the vehicle suddenly decelerates. The present invention relates to a control device.

In recent years, a twin-clutch transmission (DCT) with a torque converter having both functions of an automatic transmission and a manual transmission has become widespread.
The skeleton of the twin-clutch transmission has two input shafts, an odd-numbered input shaft that synchronizes odd-numbered transmission gears and an even-numbered input shaft that synchronizes even-numbered transmission gears, and the clutch mechanism is odd-numbered. One stage input shaft and one even stage input shaft are provided. A plurality of transmission gears belonging to each input shaft are grouped by a pair of two gears (for example, a first gear, a third gear, a second gear, a fourth gear, etc.), and one sync for each group. A mechanism is provided. The speed change process includes “shift preparation (pre-shift)”, “clutch switching”, and “shift release”. Shift preparation refers to the next shift speed (hereinafter referred to as “target shift speed”) when the transmission gear of the current shift speed is synchronized with an input shaft (hereinafter also referred to as “current travel axis”) that contributes to the current travel. Is also synchronized with an input shaft (hereinafter also referred to as “other shaft”) that does not contribute to the current travel. The clutch switching means releasing the clutch of the current traveling shaft (hereinafter also referred to as “current stage clutch”) and engaging the clutch of the other shaft (hereinafter also referred to as “next stage clutch”) to set the target shift speed. It is to be established as the current shift stage. Further, the release of the shift means that the gear shift stage (hereinafter referred to as the “old gear stage”) immediately before the current gear stage synchronized with the other shaft by returning the synchro mechanism (shift fork) to the neutral position after the clutch is switched. .) Is to release the synchronous engagement of the transmission gear.

  In particular, because of the pre-shift, the shift is basically a shift from the shift gear of the current travel shaft to the shift gear of the other shaft, for example, from the second gear of the even-numbered input shaft to the third gear of the odd-numbered input shaft, or odd Shift from the 3rd speed gear of the stage input shaft to the 4th speed gear of the even speed stage input shaft, etc., and a coaxial shift, for example, a shift from the 2nd speed gear of the even speed input shaft to the 4th speed gear, or 3 of the odd speed input shaft It is not possible to change gears from a high-speed gear to a 5-speed gear. As described above, in the twin clutch type transmission, the target shift speed (next shift speed) is limited, and further, the shift speed is increased, so that when the vehicle decelerates suddenly, the current shift speed reaches the target shift speed. The speed change process (pre-shift, clutch switching, shift release) of each speed cannot follow the deceleration of the vehicle, and the speed may not be lowered to the low speed (target speed) when the vehicle stops. In this case, it is conceivable that when the vehicle re-starts, the engine speed decreases and the engine stalls in the worst case.

  Although details will be described later, FIG. 8 and FIG. 9 show an example of a hydraulic pressure supply circuit of a twin clutch transmission of forward eighth speed. As shown in FIG. 8, in the pre-shift from the 8th gear to the 7th gear, the spool of the servo shift valve 70t moves to the left and the piston chamber of the 7th gear of the other shaft and the outlet port (output) of the servo shift valve 70q. Port) will communicate. The outlet port (output port) is closed by the spool of the servo shift valve 70q and does not communicate with the oil passage 70r. On the other hand, the outlet port (output port) of the servo shift valve 70q that communicates with the piston chamber of the second gear belonging to the current traveling shaft communicates with the oil passage 70r. Note that the oil passage 70r is not yet supplied with hydraulic pressure (hydraulic oil) that moves the piston to the right side of the second gear. In this case, the shift fork of the 2-speed-4 speed synchro mechanism 60 is in the neutral position. Thus, the shift stage in which both the servo shift valve 70q and the servo shift valve 70t are in communication with the second speed gear and the second speed / fourth speed sync mechanism 60 is in a neutral state, particularly the second speed neutral pre-shift or It may be called a 2nd speed N pre-shift.

  Here, as shown in FIG. 9, when the linear solenoid valve (L / Sol D) 70j is turned on, the hydraulic pressure is supplied to the oil passage 70r. However, if the servo shift valve 70q is locked on the left side or the on / off solenoid valve Sol C that drives it fails and the spool is in its original position, the hydraulic pressure is supplied to the piston chamber of the second gear. Is done. When the tire is locked, both the output shaft of the transmission and the current traveling shaft are locked in rotation, so the second speed gear is synchronized with the current traveling shaft with which the eighth speed gear is synchronized. Biting occurs. When the tire lock is released and the vehicle re-starts, the current traveling shaft is interlocked by synchro biting, and in the worst case, the synchro mechanism and the like may be damaged.

  Conventionally, there has been known a shift control device for an automatic transmission configured to prevent an overrun of the engine by preventing the gear stage from being changed immediately by stopping the drive system when the tire is locked ( For example, see Patent Document 1.)

JP 63-6260 A

As described above, the shift of the twin clutch type transmission is basically a shift from the transmission gear of the current traveling shaft to the transmission gear of the other shaft, and before the shift (clutch switching), the transmission gear of the next shift stage is set in advance. It is necessary to perform pre-shifting synchronized with other shafts (the target shift speed is limited), and when the vehicle decelerates suddenly due to the multi-stage transmission, each stage from the current shift speed to the target shift speed There is a case where the speed change process (pre-shift, clutch switching, shift release) cannot follow the deceleration of the vehicle, and the speed is not lowered to the low speed (target speed) when the vehicle stops. In this case, it is conceivable that when the clutch is engaged and the vehicle re-starts, the engine speed decreases and the engine stalls in the worst case. Further, when the tire is locked, a servo shift valve (servo shift valve 70q in FIGS. 8 and 9) that selectively supplies hydraulic pressure to either the synchro mechanism belonging to the current traveling shaft or the synchro mechanism belonging to another shaft. Due to one spool lock failure of the on / off solenoid valve Sol C), so-called synchro-co-meshing occurs in which two transmission gears belonging to the same input shaft are simultaneously synchronized with the same input shaft. When the tire lock is released, the driving force is transmitted to the tire, and the vehicle re-starts, the current traveling shaft is interlocked by synchro-engagement, and in the worst case, the synchro mechanism and the like may be damaged.
Accordingly, the present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to ensure that the vehicle can be re-started at the target shift stage and the tire is locked when the vehicle is suddenly decelerated. An object of the present invention is to provide a control device for an automatic transmission for a vehicle that can suitably prevent so-called synchro-co-meshing, in which two transmission gears belonging to the same input shaft are simultaneously synchronized with the same input shaft during sudden deceleration. .

  In the control apparatus for an automatic transmission for a vehicle according to the present invention for achieving the above object, a driving force from the driving source (1) is received, and gears for a plurality of gear stages are provided so as to be relatively rotatable. One input shaft (2a) and a second input shaft (2b), an output shaft (2c) for outputting the shifted driving force to the wheel side, and one gear stage selected from the plurality of gear stages The first transmission mechanism (GR1) and the second transmission mechanism (GR2) that engage the gears on the first input shaft (2a) or the second input shaft (2b), respectively, and the first transmission mechanism (GR1) ), The first clutch (CL1) for engaging the first input shaft (2a) and the output shaft (2c), and the second transmission mechanism (GR2). , The second input shaft (2b) and the output shaft (2 ), A target shift speed is determined from a shift map according to the accelerator opening (AP) and the vehicle speed (V), and the first and second shift speeds are determined based on the target shift speed. In a control device for an automatic transmission comprising a speed change mechanism and a speed change control means (3a) for performing a shift speed change control by the first and second clutches, the absolute value of the deceleration of the vehicle has a first threshold value. A sudden deceleration determining means for determining a sudden deceleration state of the vehicle when exceeding, and a lock state of the wheel when the absolute value of the deceleration of the vehicle exceeds a second threshold value larger than the first threshold value. Tire lock determination means for determining, when the sudden deceleration determination means determines that the vehicle is in a sudden deceleration state, the first or second clutch (CL1, CL2) relating to the released clutch The first or second input shaft (2a, Among the plurality of gear stages belonging to 2b), the gear on which the vehicle can restart is pre-engaged with either the first or second input shaft (2a, 2b), while the tire lock determination When the means determines that the wheel is in a locked state, the shift speed switching control is prohibited.

  In the above configuration, the control device usually determines the target shift speed based on the shift map, and sets the target shift speed in order while pre-shifting the gear position of the other shaft one stage below the current shift speed. While switching control (current shift stage → current shift stage-1 → current shift stage-2 → current shift stage-3 →... → target shift stage) is performed, when the vehicle is in a sudden deceleration state, The above-described switching control of the shift speed is prohibited, and instead, a forced preshift is performed in which a gear stage that can be restarted by the vehicle is previously engaged with the other shaft among a plurality of gear stages that belong to the other shaft with the clutch released. In other words, before the tire locks, the control device forcibly pre-shifts from the current gear position to the gear position (target gear position) where the vehicle can re-start, thereby releasing the tire lock state and controlling the normal gear position switching. After the (synchronized control) is resumed, the vehicle is surely brought into a state where the vehicle can restart at the target shift stage. Further, the control device prohibits the normal shift speed switching control (synchronized control) in the tire lock state, thereby preventing the synchronous co-engagement and thereby the transmission from being interlocked.

  A second feature of the control device for an automatic transmission for a vehicle according to the present invention is that the clutch in the released state is engaged and the clutch in the engaged state is released while the shift speed change control is prohibited. It is configured to be.

  In the above configuration, since the gear stage on the other shaft where the clutch is disengaged can be re-shifted, the shift stage switching control by the transmission means is prohibited (during the tire lock state). In addition, by switching the clutches to each other, the vehicle is brought into a state where the vehicle can be restarted at the gear stage. That is, by switching the clutches to each other, the vehicle can be restarted at the gear stage as soon as the driving force is transmitted to the tires.

  A third feature of the control apparatus for an automatic transmission for a vehicle according to the present invention is that the normal shift speed switching control is resumed after the tire lock state is released.

  In the above configuration, since the vehicle is already in a state where the clutch is switched and can be restarted, when the tire lock state is released and the normal shift speed switching control (synchronized control) is resumed, the driving force is applied to the tire. Then, the vehicle is safely restarted at the above-described gear position where the vehicle can restart, and travels safely while being automatically controlled based on a predetermined shift map.

  According to the control apparatus for an automatic transmission for a vehicle of the present invention, when the vehicle is suddenly decelerated, the vehicle can be reliably put into a state where the vehicle can be restarted at the target shift stage and the tire is locked. It is possible to suitably prevent so-called biting in which two transmission gears are simultaneously synchronized with the input shaft.

It is a block diagram which shows the automatic transmission containing the control apparatus of the automatic transmission of this invention. It is a skeleton figure which shows the transmission which concerns on this invention. 1 is a hydraulic circuit diagram showing a configuration of a hydraulic pressure supply circuit according to the present invention. It is explanatory drawing which shows the shift map of the transmission which concerns on this invention. It is a flowchart which shows the synchro control of the transmission which concerns on this invention. It is a time chart which shows the switching control of the gear stage in the normal time. It is a time chart which shows the switching control of the gear stage at the time of sudden deceleration. It is explanatory drawing which shows the hydraulic pressure supply circuit of the twin clutch type transmission in a 2nd speed N pre-shift state. It is explanatory drawing which shows the hydraulic pressure supply circuit of the twin clutch type transmission in a synchro co-biting state.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an automatic transmission 100 including a control device for an automatic transmission according to the present invention.
The automatic transmission 100 includes an engine 1 that generates driving force, an automatic transmission 2 that changes the rotational speed of the driving force transmitted from the engine 1 to a desired rotational speed, and a speed change that will be described later based on sensor information. The electronic control unit 3 that executes each process related to the stage control and the sync control (shift stage switching control), and the difference that distributes the driving force transmitted from the automatic transmission 2 to the left and right drive shafts D / SL, D / SR It is transmitted from the left and right drive shafts D / SL, D / SR and the left and right drive shafts D / SL, D / SR that transmit the driving force to the moving device D / G and the left and right wheels (tires, drive wheels) WL, WR. The left and right wheels WL and WR are used to transmit the driving force to the road surface and to move the vehicle forward or backward by the reaction force. Hereinafter, each configuration will be further described.

  The engine 1 is not particularly limited as long as it outputs a rotational driving force. An example is an electric engine or a hybrid engine in addition to an internal combustion engine such as a gasoline engine. A brake pedal sensor 200 is provided in the vicinity of a brake pedal (not shown) for detecting an operation amount BP of the brake pedal by the driver. Further, an engine torque sensor 201 and an engine rotation sensor 202 for detecting the torque Te and the rotation speed Ne of the engine 1 are provided in the vicinity of the crankshaft 1a of the engine 1, respectively.

  Further, the primary shaft 2a (FIG. 2) and the counter shaft 2c (FIG. 2) of the automatic transmission 2 have a primary shaft rotation sensor 203 and counter shaft rotation for detecting the rotational speeds Np and Nc of the primary shaft 2a and the counter shaft 2c. Each sensor 204 is provided. Note that the rotational speed Ns of the secondary shaft 2b (FIG. 2) is calculated based on, for example, the rotational speed Nc of the countershaft 2c and the gear ratio of each stage.

  A wheel speed sensor 205 for detecting a vehicle speed V (wheel rotation speed) is provided on one or both of the left and right wheels (tires) WR and WL. In addition, one or both of the left and right drive shafts D / SL and D / SR connected to the left and right wheels (tires) WR and WL have a foot shaft for detecting the foot shaft torque Td of the left and right drive shafts D / SL and D / SR. A torque sensor 206 is provided. Note that “foot shaft torque” is used interchangeably with “axle torque” throughout.

FIG. 2 is a skeleton diagram showing the automatic transmission 2 according to the present invention.
The automatic transmission 2 includes a torque converter T / C with a lockup clutch L / C to which a driving force from the crankshaft 1a of the engine 1 is input. The automatic transmission 2 includes a primary shaft (first input shaft) 2a, a sub-primary shaft (first sub-input shaft) S2a that is concentrically parallel to the primary shaft (first input shaft) 2a, and a secondary shaft (second input shaft). An input shaft 2b and a sub-secondary shaft (second sub-input shaft) S2b having a concentric parallel structure therewith, a counter shaft (output shaft) 2c and a reverse idle shaft 2d are provided. The automatic transmission 2 includes a first clutch CL1 that engages (engages) the primary shaft 2a and the sub-primary shaft S2a, and a second clutch CL2 that engages (engages) the secondary shaft 2b and the sub-secondary shaft S2b. And a third clutch CL3 for synchronizing the reverse idle gear Grv with the reverse idle shaft 2d.

  Primary shaft 2a is coupled to torque converter T / C. A primary intermediate gear Gpm is fixed to the primary shaft 2a. The primary intermediate gear Gpm meshes with the reverse intermediate gear Grm or the secondary intermediate gear Gsm. On the sub-primary shaft S2a, the first speed gear G1, the third speed gear G3, the seventh speed gear G7, and the fifth speed gear G5 (hereinafter, these plural gears are collectively referred to as an “odd number gear group”). Is provided rotatably. Further, the first-speed / third-speed sync mechanism 64 that synchronizes either the first speed gear G1 or the third speed gear G3 with the sub primary shaft S2a, and either the fifth speed gear G5 or the seventh speed gear G7. Is synchronized with the sub-primary shaft S2a and a 5-speed-7-speed sync mechanism 66 is fixed on the sub-primary shaft S2a.

  On the other hand, a secondary intermediate gear Gsm is fixed to the secondary shaft 2b. The secondary intermediate gear Gsm meshes with the primary intermediate gear Gpm. On the sub-secondary shaft S2b, the second speed gear G2, the fourth speed gear G4, the eighth speed gear G8, and the sixth speed gear G6 (hereinafter, these multiple gears are collectively referred to as an “even-numbered gear group”). Is provided rotatably. Furthermore, either the second speed / fourth speed gear G4 or the fourth speed gear G4 is synchronized with the sub-secondary shaft S2b, and either the sixth speed gear G6 or the eighth speed gear G8. Is synchronized with the sub-secondary shaft S2b and a 6-speed-8-speed sync mechanism 62 is fixed on the sub-secondary shaft S2b.

On counter shaft 2c, counter 1st-2nd gear C1 / 2G, counter 3rd-4th gear C3 / 4G, counter 7th-8th gear C7 / 8G, counter 5th-6th gear C5 / 6G (Hereinafter, the plurality of gears may be collectively referred to as a “counter gear group”.) And a final drive gear Gfd are fixed.
The counter gear group meshes with the odd-numbered gear group and the even-numbered gear group. The final driven gear Gfn meshes with the differential device D / G.

  The odd-numbered gears (the first, third, fifth and seventh gears) are established by the odd-numbered gear group and counter gear group and the first-speed to third-speed sync mechanism 64 and the fifth-speed to seventh-speed sync mechanism 66. Therefore, a first transmission mechanism GR1 is configured. Further, the even-numbered gears (2, 4, 6, and 8th gears) are established by the even-numbered gear group and the counter gear group, and the second-speed / four-speed sync mechanism 60 and the sixth-speed-8-speed sync mechanism 62. Therefore, a second speed change mechanism GR2 is configured.

  A reverse idle gear Grv is rotatably provided on the reverse idle shaft 2d. A reverse intermediate gear Grm that meshes with the primary intermediate gear Gpm is fixed to the reverse idle shaft 2d.

  Primary shaft 2a and sub-primary shaft S2a are engaged by engagement of first clutch CL1. Secondary shaft 2b and sub-secondary shaft S2b are engaged by engagement of second clutch CL2. Further, the reverse idle gear Grv is engaged with the reverse idle shaft 2d by the engagement of the third clutch CL3.

  Therefore, when the first speed is established with the automatic transmission 2 having the above-described configuration, the first-speed / third-speed sync mechanism 64 is driven to cause the first speed gear G1 to be synchronously engaged with the sub-primary shaft S2a. 1 clutch CL1 is engaged. As a result, the driving force from the engine 1 is as follows: torque converter T / C → primary shaft 2a → first clutch CL1 → sub-primary shaft S2a → first speed-3 speed sync mechanism 64 → first speed gear G1 → counter 1st speed− 2nd gear C1 / 2G → Counter shaft 2c → Final drive gear Gfd → Final driven gear Gfn → Differential gear D / G → Left and right drive shaft D / SL, D / SR to left and right drive wheels WL, WR Each is transmitted.

  On the other hand, when the second speed stage is established with the automatic transmission 2 having the above-described configuration, the second speed / fourth speed sync mechanism 60 is driven to cause the second speed gear G2 to be synchronously engaged with the sub-secondary shaft S2b. 2 clutch CL2 is engaged. Thus, the driving force from the engine 1 is as follows: torque converter T / C → primary shaft 2a → primary intermediate gear Gpm → secondary intermediate gear Gsm → secondary shaft 2b → second clutch CL2 → sub-secondary shaft S2b → second speed-4th speed. Synchro mechanism 60 → second speed gear G2 → counter first speed−second speed gear C1 / 2G → counter shaft 2c → final drive gear Gfd → final driven gear Gfn → differential device D / G → left / right drive shaft D / SL, D / It is transmitted to the left and right drive wheels WL and WR along the transmission path of SR.

FIG. 3 is a hydraulic circuit diagram showing a configuration of the hydraulic pressure supply circuit 70.
In the hydraulic pressure supply circuit 70, the discharge pressure (hydraulic pressure) of the hydraulic oil ATF pumped from the reservoir (oil pan formed at the bottom of the transmission case) 70a by the oil pump (oil feed pump) 70c through the strainer 70b is a regulator. The line pressure is regulated (depressurized) by a valve (pressure regulating valve) 70d.

  Although not shown, the oil pump 70c is connected to the pump impeller of the torque converter T / C via a gear, and thus the oil pump 70c is configured to be driven by the engine 1 and operate.

  The regulated line pressure is sent to the input port of the linear solenoid valve (L / SolA) 70g via an oil passage (first oil passage) 70f branched from the oil passage (first oil passage) 70e, The oil passage 70e is sent to input ports of a linear solenoid valve (L / SolB) 70h, a linear solenoid valve (L / SolC) 70i, and a linear solenoid valve (L / SolD) 70j.

  Linear solenoid valves 70g, 70h, 70i, and 70j are hydraulic control valves (electromagnetic control valves), and have a characteristic of linearly changing the output pressure from the output port by moving the spool in proportion to the energization amount. Then, it is configured as an N / C (normally closed) type in which the spool moves to the open position.

  The hydraulic pressure sent to the linear solenoid valve 70g is adjusted (decreased) to the clutch pressure (odd number clutch pressure), sent from the output port to the input port of the servo shift valve 70m via the oil passage 70k, and sent from the output port to the odd number. It is supplied to the first clutch CL1 on the stage side.

  Similarly, the hydraulic pressure sent to the linear solenoid valve 70h is adjusted to the clutch pressure (even clutch pressure), sent from the output port to the input port of the servo shift valve 70o via the oil passage 70n, and even from the output port. It is supplied to the second clutch CL2 on the stage side.

  When the clutch pressure is supplied to the first or second clutch CL1, CL2, the sub primary shaft S2a or the sub secondary shaft S2b is engaged (engaged) with the primary shaft 2a or the secondary shaft 2b, while the hydraulic pressure is discharged. The connection (fastening) between the sub-primary shaft S2a or sub-secondary shaft S2b and the primary shaft 2a or secondary shaft 2b is cut off (released).

  The hydraulic pressure sent to the linear solenoid valve 70i is adjusted (reduced pressure) to the synchro pressure, sent from the output port to the input port of the servo shift valve 70q via the oil passage 70p, and sent to the linear solenoid valve 70j. The hydraulic pressure thus adjusted is also adjusted to the synchro pressure, and is sent from the output port to the servo shift valve 70q via the oil passage 70r.

  In the figure of the servo shift valve 70q, the output from one of the pair of left and right output ports is sent to the servo shift valve 70s, and either one of the first and third speed sync mechanisms 64 (1-3) is sent from the pair of left and right output ports in the figure. The piston chamber and any one of the 6-speed-8-speed sync mechanism 62 (6-8) are sent.

  Similarly, in the figure of the servo shift valve 70q, the output from the other of the pair of left and right output ports is sent to the servo shift valve 70t, and in the figure, the second and fourth speed synchronization mechanisms 60 (2-4) are sent from the pair of left and right output ports. Are sent to any one of the piston chambers and any one of the piston chambers of the 5-speed-7-speed sync mechanism 66 (5-7).

  Although not shown, the synchro mechanisms 60, 62, 64, and 66 include a cylinder and a piston disposed in the left and right sides of the cylinder, and the piston corresponds to the supply direction of the synchro pressure from the servo shift valves 70s and 70t. Configured to move left and right in the figure.

  Servo shift valves 70m 70o, 70q, 70s and 70t are connected to on / off solenoid valves (hydraulic control valves (electromagnetic control valves)) (Sol A, Sol B, Sol C, Sol D, Sol E), respectively. The left and right output ports in the figure are switched by excitation and demagnetization of the solenoid, and hydraulic pressure input from the linear solenoid valve 70g or the like is output.

  Further, according to the excitation of the corresponding on / off solenoid valve, the other output port of the servo shift valves 70m, 70o is connected (drained) to the reservoir 70a as shown by the broken line.

  In the twin clutch type automatic transmission 2 shown in FIG. 2, the hydraulic pressure is supplied to any of the synchro mechanisms 60, 62, 64, 66 corresponding to the next shift stage, and the sub primary shaft S2a, sub primary One of the shafts S2b is fastened (engaged, pre-shifted), then the hydraulic pressure is discharged from the clutches CL1 and CL2 corresponding to the current gear, and the other clutch CL1 and CL2 corresponding to the next gear is Speed is changed by supplying hydraulic pressure and fastening (engaging) to the primary shaft 2a or the secondary shaft 2b.

  Shifting is basically performed alternately between odd-numbered stages (first speed, third speed, fifth speed, and seventh speed) and even stages (second speed, fourth speed, sixth speed, and eighth speed). Although not shown, each cylinder of the synchro mechanism 60, 62, 64, 66 is connected to a shift fork, and the shift fork is connected to a detent mechanism having a concavo-convex surface so as to be at an opposite gear stage or at a neutral position therebetween. When driven, it is configured to be held in the driven position even when the supply of hydraulic pressure is stopped.

  Returning to the description of the vicinity of the regulator valve 70d in FIG. 3, the oil passage 70f connected to the linear solenoid valve 70g is connected to the oil passage 70u. The oil passage 70u is connected to an accumulator (ACM) 70x that stores hydraulic pressure via a branch oil passage 70v (second oil passage) and 70w on the downstream side.

  An on / off solenoid valve (switching valve, Sol ACM) 70y is inserted in the oil passage 70v, a first check valve 70z1 is inserted in the oil passage 70f, and a second check valve 70z2 is inserted in the oil passage 70w. The on / off solenoid valve 70y is configured such that the spool moves between an on position and an off position in accordance with excitation / demagnetization, in the same manner as the valve connected to the above-described servo shift valve 70m.

  In addition to the above, the hydraulic pressure supply circuit 70 includes a plurality of linear solenoid valves, and the engagement / release operation of the lock-up clutch L / C of the torque converter T / C through excitation and demagnetization thereof. However, since it is not directly related to the present invention, the description thereof is omitted.

  Returning to FIG. 1 again, the electronic control unit 3 has, for example, a shift map shown in FIG. 4 as the shift speed control means 3a, and includes an accelerator operation amount sensor (not shown), an engine torque sensor 201, an engine rotation sensor. 202, an accelerator pedal operation amount AP, a vehicle speed V, and a shift position (current shift) generated by detection signals output from the primary shaft rotation sensor 203, the counter shaft rotation sensor 204, the wheel speed sensor 205, and the foot shaft torque sensor 206, respectively. ) To determine the target gear position (gear ratio) and the timing related to the downshift or upshift to reach the gear position, or the engagement (ON) / release of the lockup clutch L / C ( OFF) or lockup clutch L / C The lip ratio is determined, and control commands relating to these are transmitted to the hydraulic pressure supply circuit 70, and the corresponding linear solenoid valves 70g, 70h, 70i, 70j and the on / off solenoid valves Sol A, Sol B, Sol C, Sol D, Sol E are driven, and the corresponding clutch mechanism and synchro mechanism are engaged or driven by hydraulic pressure.

  The electronic control unit 3 controls the engagement / release of the four synchro mechanisms 60, 62, 64, 66 as the sync control means 3b. As the synchronization control of this embodiment, “normal synchronization control” and “synchronization control during sudden deceleration (forced preshift)” are performed. “Normal sync control” means that the gear stage (the next gear stage) below the other shaft is synchronously engaged (preshifted) with the shaft so that the gear stage becomes the target gear stage, and the clutch is switched. This means that the sync mechanism corresponding to each gear stage is controlled so that the gear stage (old gear stage) that is one stage higher than the current gear stage is released (shift released) from the synchronous engagement with the shaft. .

  In contrast, “synchronous control during sudden deceleration (forced preshift)” refers to a gear that can be re-started belonging to another shaft when the vehicle is determined to be in a sudden deceleration state at the current gear. This means that the corresponding synchro mechanism is controlled so as to be synchronously engaged (forced preshift).

  Further, the electronic control unit 3 drives the linear solenoid valves 70g and 70h and the on / off solenoid valves Sol A and Sol B as the clutch control means 3c, and after the pre-shift to the target shift stage, the first clutch CL1 And the engagement / release state of the second clutch CL2 is switched.

FIG. 4 is an explanatory diagram showing a shift map of the transmission. The automatic transmission 2 shown in FIG. 2 has the eighth forward speed, but for the sake of simplicity of explanation, the forward transmission having the first to sixth speeds is more general instead of the shift map for the eighth forward speed. The shift characteristics and the slip ratio control region relating to the shift map of the 6-speed automatic transmission are respectively shown.
This shift map is an example of a shift map for a flat road, and an upshift line is displayed as a solid line and a downshift line is displayed as a thick line. Further, the slip control start line of the lockup clutch T / C is displayed by a dotted line. Furthermore, the lockup clutch slip control area is locked up when downshifting from 6th gear to 5th gear, downshifting from 5th gear to 4th gear, and downshifting from 2nd gear to 1st gear. Clutch slip control areas 76, 78, and 80 are set, respectively.

  The electronic control unit 3 determines the optimum shift speed (target shift speed) for the vehicle driving situation from the accelerator operation amount (accelerator opening) AP and the vehicle speed V. For example, in the vehicle driving situation at point A, the fourth gear is selected as the target gear for an upshift, and the fifth gear is selected as the target gear for a downshift.

  In the lockup clutch slip control regions 76, 78, and 80, the electronic control unit 3 slips the lockup clutch T / C at the dotted line position before the downshift line, thereby increasing the engine speed and driving force. On the other hand, by fully engaging the lockup clutch T / C on the downshift line, the responsiveness of the shift and the fuel efficiency are improved. Note that the slip control of the lockup clutch T / C is not directly related to the present invention, and the description thereof is omitted here.

FIG. 5 is a flowchart showing the synchro control of the automatic transmission 2 according to the present invention.
In step S1, it is determined whether or not the tire lock determination flag is “1”. If the tire lock determination flag is “1” (YES), the process of step S5 is executed. On the other hand, when the tire lock determination flag is not “1” (NO), the process of step S2 is executed. The “tire lock determination flag” is a flag indicating whether or not the tire is in a locked state, and “1” means that the tire is locked (tire locked state). "" Means that the tire is not locked. The determination of the tire lock state is performed based on whether or not the absolute value of the vehicle deceleration G (= change amount ΔV / ΔT of the vehicle speed V per unit time) exceeds the tire lock determination threshold (FIG. 7).

  In step S2, it is determined whether or not the rapid deceleration determination flag is “1”. If the rapid deceleration determination flag is “1” (YES), the process of step S3 is executed. On the other hand, when the rapid deceleration determination flag is not “1” (NO), the process of step S4 is executed. The “sudden deceleration determination flag” is a flag indicating whether or not the vehicle is in a sudden deceleration state, and “1” means that the vehicle is suddenly decelerating (sudden deceleration state). “0” means that the vehicle is not decelerating rapidly. The determination of the sudden deceleration state is made based on whether or not the absolute value of the deceleration G of the vehicle exceeds the rapid deceleration determination threshold (FIGS. 6 and 7).

  In step S3, synchronization control during sudden deceleration is performed. Specifically, the gear stage in which the other shaft can restart is synchronously engaged (forced preshift) with the other shaft at the current gear position. The “restartable gear stage” referred to here is a gear stage belonging to another shaft such as one, three, or five (odd) below the current gear, and the clutch of the other shaft is engaged. For example, a gear that does not exceed the rev limit when the engine is engaged. For example, when the current shift speed is 8th speed, it is desirable that the gear stage capable of restarting is 7th speed, 5th speed or 3rd speed. When the current gear stage is the fifth speed stage, the gear stage that can be restarted is the fourth speed stage or the second speed stage. When the current gear stage is the third speed stage, the gear stage that can be restarted is the second speed stage. The sync control at the time of sudden deceleration will be described later with reference to FIG.

  In step S4, normal sync control is performed. Note that “normal sync control” specifically refers to shifting the shift fork of the sync mechanism corresponding to the next shift stage, which is one step lower in the current shift stage, from the synchro-neutral position. The pre-shift is performed to synchronize with the shaft, and after the clutches CL1 and CL2 are switched, the old fork shift is performed by returning the shift fork of the synchro mechanism engaged with the shift gear of the old gear to the synchro neutral position. This means that the shift is released to release the gear of the stage from the synchronous engagement with the shaft. The normal sync control will be described later with reference to FIG.

  In step S5, all sync control is prohibited. The sync control includes in-gear shift and shift release (neutral pre-shift) in addition to pre-shift. Note that clutch control is not prohibited. Therefore, although details will be described later with reference to FIG. 7, the engagement / release state of the first clutch CL1 and the second clutch CL2 is switched at an arbitrary timing while the tire is locked (during the tire lock state). The vehicle is placed in a state where it can restart.

FIG. 6 is a time chart showing the shift control of the shift speed from the 8th speed to the 5th speed in a normal state. The normal time means a time when the vehicle deceleration G does not exceed a preset sudden deceleration determination threshold.
At time t1, a shift fork (not shown) at the synchro neutral position (synchro N position) of the 5th-7th sync mechanism 66 is moved to the 7th gear G7 side which is the next shift stage. When the shift fork is further moved, the synchro sleeve with which the shift fork is engaged and the seventh speed gear G7 start to engage synchronously.

  At time t2, the synchro sleeve and the seventh speed gear G7 are completely synchronously engaged, and the pre-shift to the seventh speed stage is completed. Note that the position of the shift fork when the synchro sleeve and the seventh speed gear G7 are completely synchronously engaged is called a gear-in position.

  Almost simultaneously with the completion of the pre-shift to the seventh gear, clutch switching is executed. In this case, the second clutch CL2 starts to be released and the first clutch CL1 starts to be engaged. At time t3, clutch switching is completed. When the clutch switching is completed, the seventh speed is established as the current gear, the first input shaft 2a becomes the current traveling shaft that contributes to the traveling of the vehicle, and the second input shaft 2b does not contribute to the traveling of the vehicle. It becomes.

  At the time t3 when the clutch switching is completed, the synchro sleeve (shift fork) that has been engaged with the 8-speed gear G8, which is the old gear, is returned to the synchro-neutral position. At time t4, the shift fork is returned to the neutral position, and the eighth gear G8 is released from the synchronous engagement with the shaft. The shift process from time t3 to t4 is called a shift release, and here, the state where the shift fork is returned to the neutral position is called an 8-speed N pre-shift.

  At time t5, the shift fork in the synchro-neutral position of the 6-speed-8-speed sync mechanism 62 is moved to the 6th-speed gear G6 side that is the next shift. When the shift fork is further moved, the synchro sleeve with which the shift fork is engaged and the sixth speed gear G6 start to engage synchronously.

  At time t6, the synchro sleeve and the sixth speed gear G6 are completely synchronously engaged, and the preshift to the sixth speed stage is completed.

  Almost simultaneously with the completion of the pre-shift to the sixth gear, clutch switching is executed. In this case, the first clutch CL1 starts to be released and the second clutch CL2 starts to be engaged. At time t7, clutch switching is completed. When the clutch switching is completed, the sixth gear is established as the current gear, and this time, the second input shaft 2b becomes the current traveling shaft that contributes to the traveling of the vehicle, and conversely, the first input shaft 2a becomes the traveling of the vehicle. Other axes that do not contribute.

  At the time t7 when the clutch switching is completed, the synchro sleeve (shift fork) that has been engaged with the seventh gear G7, which is the old gear, is returned to the synchro neutral position. At time t8, the shift fork is returned to the neutral position, and the seventh speed gear G7 is released from the synchronous engagement with the shaft (7th speed N pre-shift).

  At time t9, the shift fork at the synchro-neutral position of the 5th-7th synchro mechanism 66 is moved to the 5th gear G5, which is the next gear. When the shift fork is further moved, the synchro sleeve with which the shift fork is engaged and the fifth speed gear G5 start to engage synchronously.

  At time t10, the synchro sleeve and the fifth gear G5 are completely synchronously engaged, and the preshift to the fifth gear is completed.

  Almost simultaneously with the completion of the pre-shift to the fifth gear, clutch switching is executed. In this case, the second clutch CL2 starts to be released and the first clutch CL1 starts to be engaged. At time t11, clutch switching is completed. When the clutch switching is completed, the fifth gear is established as the current gear, and this time, the first input shaft 2a becomes the current traveling shaft that contributes to the traveling of the vehicle, and conversely the second input shaft 2b becomes the traveling of the vehicle. Other axes that do not contribute.

  At the time t11 when the clutch switching is completed, the synchro sleeve (shift fork) that has been engaged with the sixth speed gear G6, which is the old gear, is returned to the synchro neutral position. At time t12, the shift fork is returned to the neutral position, and the sixth gear G6 is released from the synchronous engagement with the shaft (sixth gear stage N pre-shift).

  As described above, in the normal state, the electronic control unit 3 synchronizes the shift gear of the next shift stage with the shaft by moving the shift fork of the sync mechanism corresponding to the next shift stage one step lower than the neutral position at the current shift stage. Pre-shift to the next gear stage to be engaged is performed, and then the engagement / release state of the clutches CL1 and CL2 is switched, and the shift fork of the synchro mechanism that has been engaged with the transmission gear of the old gear stage is returned to the synchro neutral position. Thus, the synchronization control and the clutch control of performing the shift release for releasing the shift gear of the old shift stage from the synchronous engagement with the shaft are performed for each shift stage from the current shift stage to the target shift stage.

FIG. 7 is a time chart showing the shift speed switching control during sudden deceleration. The sudden deceleration means that the vehicle deceleration G exceeds a preset sudden deceleration determination threshold.
When the vehicle deceleration G exceeds the sudden deceleration determination threshold value (first threshold value) at time t1, the shift fork at the synchro-neutral position of the first-speed / third-speed sync mechanism 64 is a “restartable gear”. Move to the third gear G3 side. When the shift fork is further moved, the synchro sleeve with which the shift fork is engaged and the third speed gear G3 start to engage synchronously.

  At time t2, the synchro sleeve and the third gear G3 are completely synchronously engaged, and the preshift to the third gear is completed.

  When the vehicle deceleration G exceeds the tire lock determination threshold (second threshold) at time t3, all synchronization control is prohibited. As a result, the shift fork of the 1st to 3rd speed synchronization mechanism 64 and the shift fork of the 6th to 8th speed synchronization mechanism 62 are fixed at the gear-in position.

  Further, after time t3, clutch switching is executed at any time up to time t4 when the tire lock state is released. In this case, the second clutch CL2 starts to be released and the first clutch CL1 starts to be engaged. When the clutch switching is completed, the third speed stage is established as the current shift stage, and this time, the first input shaft 2a becomes the current traveling axis that contributes to the traveling of the vehicle, and conversely the second input shaft 2b contributes to the traveling of the vehicle. It will not be the other axis.

  Then, at time t4 when the tire lock state is released, the synchronization control at the time of sudden deceleration is resumed, and the synchronization sleeve (shift fork) engaged with the 8-speed gear G8, which is the old gear stage, is started to return to the synchronization neutral position. . At time t5, the shift fork is returned to the neutral position, and the 8-speed gear G8 is released from the synchronous engagement with the shaft (8-speed stage N pre-shift). In addition, the driving force is transmitted to the tire, and the vehicle restarts at the third speed.

  When the sudden deceleration state is canceled at time t6, normal sync control is resumed. Thus, the vehicle travels safely while being automatically shifted from the third gear based on a predetermined shift map.

In this way, the electronic control unit 3 forcibly pre-shifts the speed of the other shaft (third gear) that can re-start when the vehicle suddenly decelerates to the other shaft, and at any timing in the tire lock state. To change the clutch to make the vehicle ready for re-start. Then, when the tire lock state is released, the vehicle is safely restarted at the above-mentioned shift stage (third gear) that can restart. Then, when the sudden deceleration state is also released, the vehicle is safely driven while performing normal shift stage switching control based on a predetermined shift map.
In addition, the electronic control unit 3 prohibits all synchro control in the tire lock state, and prevents the occurrence of synchro-engagement, thereby preventing the transmission from interlocking.

1 Engine 2 Transmission 2a Primary shaft S2a Sub primary shaft 2b Secondary shaft S2b Sub secondary shaft 2c Counter shaft 2d Reverse idle shaft 64 1st speed-3 speed sync mechanism 60 2nd speed-4th speed sync mechanism 66 5th speed-7th speed sync mechanism 62 6-speed-8-speed sync mechanism CL1 1st clutch CL2 2nd clutch CL3 3rd clutch L / C Lockup clutch T / C Torque converter Gpm Primary intermediate gear Gsm Secondary intermediate gear Grm Reverse intermediate gear 3 Electronic control unit 70 Hydraulic supply Circuit 100 Automatic transmission 200 Brake pedal sensor 201 Engine torque sensor 202 Engine rotation sensor 203 Primary shaft rotation sensor 204 Countershaft rotation sensor 20 5 Wheel speed sensor 206 Foot axis torque sensor

Claims (3)

A first input shaft and a second input shaft, each of which receives a driving force from a driving source and is provided with a plurality of gears that are relatively rotatable,
An output shaft for outputting the shifted driving force to the wheel side;
A first speed change mechanism and a second speed change mechanism that respectively engage a gear applied to one gear stage selected from the plurality of gear stages with the first input shaft or the second input shaft;
A first clutch provided corresponding to the first speed change mechanism and engaging the first input shaft and the output shaft;
A second clutch provided corresponding to the second speed change mechanism and engaging the second input shaft and the output shaft;
Shift control for determining a target shift stage from a shift map according to the accelerator opening and the vehicle speed, and performing shift control of the shift stage by the first and second transmission mechanisms and the first and second clutches based on the target shift stage. A control device for an automatic transmission comprising:
Sudden deceleration determination means for determining a sudden deceleration state of the vehicle when the absolute value of the deceleration of the vehicle exceeds a first threshold;
Tire lock determination means for determining a locked state of the wheel when an absolute value of deceleration of the vehicle exceeds a second threshold value that is larger than the first threshold value,
When the sudden deceleration determining means determines that the vehicle is in a sudden deceleration state, the plurality of gear stages belonging to the first or second input shaft relating to the clutch in the released state among the first or second clutches. While the gear applied to the gear stage in which the vehicle can restart is pre-engaged with either the first or second input shaft,
The automatic transmission control device, wherein the shift control of the shift stage is prohibited when the tire lock determination means determines that the wheel is in a locked state.   2. The automatic operation according to claim 1, wherein the clutch in the released state is engaged and the clutch in the engaged state is released while the shift speed switching control is prohibited. Transmission control device.   3. The automatic transmission control according to claim 2, wherein the shift speed switching control is resumed after the determination of the locked state of the wheel by the tire lock determination unit is released. 4. apparatus.

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