Transmission control unit

Abstract

The present invention provides a transmission control device that can prevent the gear shifting period from becoming unnecessarily long. [Solution] The electronic control device 150 of the transmission 26 (a) when it outputs two preceding and succeeding transmission instruction signals Stm, namely learning transmission instruction signals Sstd1 and Sstd2, to the shift actuator 100, it pre-learns a predetermined interval period Tintv, which is the shortest period between the output time of learning transmission instruction signal Sstd1 and the output time of learning transmission instruction signal Sstd2, so that the transmission caused by the later output learning transmission instruction signal Sstd2 does not fail; and (b) after pre-learning the interval period Tintv, it waits for the output of the second transmission instruction signal Stm2 that follows the first transmission instruction signal Stm1 until the interval period Tintv has elapsed from the time the first transmission instruction signal Stm1 is output, and outputs the second transmission instruction signal Stm2 after the interval period Tintv has elapsed.

Description

Technical Field

[0001] The present invention relates to a control device for a transmission including a shift barrel shaft that selectively establishes gear stages and an actuator that rotates the shift barrel shaft.

Background Art

[0002] There are provided a plurality of types of gear pairs meshing with each other provided on a first rotating shaft and a second rotating shaft parallel to each other, a shift fork that operates a plurality of dog clutches between the gear on the second rotating shaft side of the gear pairs and the second rotating shaft, and a shift barrel shaft having a plurality of shift grooves with which the base ends of the shift forks are respectively engaged and selectively establishing a plurality of gear stages for each predetermined rotation angle, and a transmission that rotates the shift barrel shaft by linearly moving in the longitudinal direction a longitudinal rack (= tooth row) having teeth meshing with a pinion provided on the shift barrel shaft is known. For example, the transmission described in Patent Document 1 is such. In the transmission described in Patent Document 1, when the rack moves in one direction in the longitudinal direction, it is upshifted, and when the rack moves in the other direction in the longitudinal direction, it is downshifted.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] For example, in the transmission described in Patent Document 1, instead of a longitudinal rack, the shift device configuration may include an actuator that rotates the shift barrel shaft by linearly moving a ratchet pawl from a predetermined reference position, and a biasing member that biases the ratchet pawl to the reference position. The ratchet pawl engages with one of a plurality of engagement pins arranged at equal intervals in the circumferential direction of the shift barrel shaft. In this case, a considerable amount of time is required for the ratchet pawl to return to the reference position due to the biasing force of the biasing member, but this considerable amount of time will differ for each shift device due to manufacturing variations of the biasing member, etc. When outputting two consecutive shift instruction signals to the actuator, if the interval period between the two shift instruction signals is made too long, for example, the shift period may become unnecessarily long. For example, if the interval period is made too short, the shift may fail, requiring the shift control to be executed again, which may actually prolong the shift period.

[0005] This invention was made against the above circumstances, and its objective is to provide a transmission control device that can suppress the shifting period from becoming unnecessarily long. [Means for solving the problem]

[0006] The gist of the present invention is a shift barrel shaft having multiple gear pairs of mutually meshing types provided on a first and second rotational shaft which are parallel to each other, a shift fork that acts on multiple dog clutches between the gear on the second rotational shaft and the second rotational shaft, a shift barrel shaft having multiple shift grooves that engage with the base ends of the shift forks and selectively setting multiple gear stages at predetermined rotational angles, an actuator that rotates the shift barrel shaft by linearly moving a ratchet pawl that engages with one of a plurality of engagement pins arranged at equal intervals in the circumferential direction of the shift barrel shaft from a predetermined reference position, and the ratchet pawl is positioned as a reference A control device for a transmission including a biasing member that biases the position, wherein (a) when two preceding and succeeding gear shift instruction signals are output to the actuator, the control device pre-learns a predetermined interval period which is the shortest period between the output times of the two gear shift instruction signals such that the gear shift caused by the later of the two gear shift instruction signals does not fail, and (b) after the interval period has been pre-learned, the control device waits for the output of a second gear shift instruction signal that follows the first gear shift instruction signal until the interval period has elapsed from the time of output of the first gear shift instruction signal, and outputs the second gear shift instruction signal after the interval period has elapsed. [Effects of the Invention]

[0007] According to the transmission control device of the present invention, (a) when two sequential gear shift instruction signals are output to the actuator, a predetermined interval period is pre-learned, which is the shortest period between the output times of the two gear shift instruction signals such that the gear shift caused by the later of the two gear shift instruction signals does not fail; and (b) after the interval period has been pre-learned, the output of the second gear shift instruction signal following the first gear shift instruction signal is kept on standby from the time of output of the first gear shift instruction signal until the interval period has elapsed, and the second gear shift instruction signal is output after the interval period has elapsed. In this way, the interval period such that the gear shift caused by the later of the two sequential gear shift instruction signals does not fail is pre-learned. Furthermore, after the interval period has been learned, the output of the second gear shift instruction signal is kept on standby from the time of output of the first gear shift instruction signal until the interval period has elapsed, and the second gear shift instruction signal is output after the interval period has elapsed. This prevents gear shifting failures and reduces the need for excessively long gear shifting times. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram illustrating the general configuration of a vehicle equipped with a transmission to which the present invention is applied. [Figure 2] This diagram shows the arrangement of the main shaft, sub-shaft, pair of drive shafts, and shift device in a view along the second axis of the transmission, and also explains the shifting mechanism of the shift device. [Figure 3] This is a diagram illustrating the mechanism for transmitting the operating force of the shift device. [Figure 4] This is an example flowchart illustrating the control operation for learning the interval period in an electronic control device. [Figure 5] This is an example of a flowchart illustrating the control operation of gear shift control after learning the interval period in an electronic control unit. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the drawings in the embodiments have been simplified or modified as appropriate, and the dimensional ratios and shapes of each part are not necessarily depicted accurately. [Examples]

[0010] Figure 1 is a schematic diagram illustrating the general configuration of a vehicle 10 equipped with a transmission 26 to which the present invention is applied. The vehicle 10 is equipped with a power transmission device 16 in the power transmission path between the engine 12 and a pair of drive wheels 14. The power transmission device 16 comprises, in order from the engine 12 side, a propeller shaft 18, a clutch K1, a bevel gear pair 24, a transmission 26, and a differential gear 58. Of the power transmission device 16, the bevel gear pair 24, the transmission 26, and the differential gear 58 are housed in a case 70. The clutch K1 connects and disconnects the propeller shaft 18 and one of the bevel gear pair 24. The other end of the bevel gear pair 24 is connected to the main shaft 28 of the transmission 26.

[0011] Clutch K1 is a friction engagement device, for example, a hydraulic type, installed between the engine 12 and the transmission 26. The control state (engaged state, released state) of clutch K1 is switched by control hydraulic pressure supplied from the hydraulic control circuit 22.

[0012] The transmission 26 is a so-called vehicle dog clutch type transmission that comprises a main shaft 28 and a sub-shaft 52 arranged parallel and horizontally to each other, and sets up multiple gear stages (gear stages) by reducing or increasing the rotation of the main shaft 28 by a predetermined gear ratio γ (also called the gear ratio γ) (= rotational speed of the main shaft 28 / rotational speed of the sub-shaft 52). The "main shaft 28" and "sub-shaft 52" correspond to the "first rotating shaft" and "second rotating shaft" in this invention, respectively. The main shaft 28 is rotatably arranged around the first axis C1, and the sub-shaft 52 is rotatably arranged around the second axis C2. The sub-shaft 52 and the differential gear 58 are connected by the meshing of an output gear 52g provided on the sub-shaft 52 and a final gear 58a provided on the differential gear 58. The differential gear 58 and a pair of drive wheels 14 are connected via a pair of drive shafts 20. A pair of drive shafts 20 are rotatably arranged around a third axis C3 that is parallel to the second axis C2.

[0013] The transmission 26 is equipped with multiple types of gear pairs 30. Each gear pair 30 has a drive gear 32 fixed to the main shaft 28 so as not to rotate relative to it, and a driven gear 34 that is always meshed with the drive gear 32, is rotatable relative to the sub-shaft 52, and is immovable in the direction of the second axis C2. In order from one direction of the first axis C1 (= second axis C2) to the other, the reverse gear pair 30a, second gear pair 30b, first gear pair 30c, fourth gear pair 30d, fifth gear pair 30e, sixth gear pair 30f, and third gear pair 30g are provided as multiple gear pairs 30. The reverse gear pair 30a has an intermediate gear 36 between the drive gear 32 and the driven gear 34 that meshes with both of them in order to reverse the direction of rotation. In the following, unless otherwise specified, the reverse gear ratio 30a to the 3rd gear ratio 30g will be referred to as "gear ratio 30".

[0014] In the direction of the second axis C2, the transmission 26 is equipped with a switching mechanism 40 between one side of the driven gear 34 of the reverse gear pair 30a, between the driven gears of the second gear pair 30b and the first gear pair 30c, between the driven gears of the fourth gear pair 30d and the fifth gear pair 30e, and between the driven gears of the sixth gear pair 30f and the third gear pair 30g. Each switching mechanism 40 is mounted on the sub-shaft 52 so as to be immobile relative to it and movable in the direction of the second axis C2. Each of the switching mechanisms 40 has switching meshing teeth 42 at a position facing the driven gear 34 in the direction of the second axis C2. Each of the driven gears 34 has gear-side meshing teeth 44 that can mesh with the switching meshing teeth 42 at a position facing the switching mechanism 40 in the direction of the second axis C2. A switching mechanism 40 equipped with switching meshing teeth 42 and a driven gear 34 equipped with gear-side meshing teeth 44 constitute a dog clutch 50. The dog clutch 50 is a dog clutch between the driven gear 34, which is the gear on the sub-shaft 52 side of the gear pair 30, and the sub-shaft 52. The driven gear 34 corresponds to the "gear on the second rotating shaft side" in this invention.

[0015] The shift mechanism 60 comprises a shift fork 62, a shift barrel shaft 66, an engagement pin 72, and a shift device 74. The shift barrel shaft 66 is rotatably mounted about a fourth axis C4 parallel to the second axis C2. The shift barrel shaft 66 has a plurality of shift grooves 64 into which the base ends of the shift forks 62 each engage. The plurality of shift grooves 64 are formed to selectively establish a plurality of gears for each predetermined rotation angle of the shift barrel shaft 66 by defining the movement position of the shift fork 62 in the direction of the second axis C2 via the shift fork 62. The shift forks 62 are supported so as to be movable in the direction of the fourth axis C4 (= direction of the second axis C2) and each engages with the switching mechanism 40 to switch the engagement state of their dog clutches 50. That is, the shift forks 62 operate each of the plurality of dog clutches 50 to either an engaged state (= connected state) or an unengaged state (= disconnected state). The engagement pins 72 are fixed between a pair of flanges 68 fixed to one end of the shift barrel shaft 66, and are arranged at equal intervals (e.g., 45-degree intervals) in the circumferential direction and are parallel to the fourth axis C4, forming a number of pins (e.g., 8). The shift device 74 is fixed to the case 70 and shifts the gear of the transmission 26 by rotating the shift barrel shaft 66 at predetermined rotation angles (e.g., 45 degrees) using the engagement pins 72. The transmission 26 shifts gears by switching the engagement and disengagement states of the dog clutch 50, respectively, as the switching mechanism 40 is moved to predetermined positions in the direction of the second axis C2 according to the rotation position of the shift barrel shaft 66. In other words, the shift barrel shaft 66 selectively establishes multiple gear stages of the transmission 26 at predetermined rotation angles.

[0016] Figure 2 shows the arrangement of the main shaft 28, sub-shaft 52, pair of drive shafts 20, and shift device 74 in view along the second axis C2, and also illustrates the gear shifting mechanism of the shift device 74. Figure 3 illustrates the force transmission mechanism of the shift device 74. The case 70 is constructed by integrally assembling multiple case members with fasteners such as bolts. In Figure 2, only the outer edge of the case 70, where the fasteners are tightened, is shown. Figure 2 specifically illustrates the mechanism of the shift device 74 that operates by rotating the shift barrel shaft 66 at predetermined rotation angles (e.g., 45 degrees).

[0017] The shift device 74 comprises a ratchet pawl 82, a plunger spring 84, a shift member 86, a position return spring 88, a plunger 90, a cylinder 92, a spring housing 94, and a spring fixing part 96. The ratchet pawl 82 has an engagement recess 76 that receives two of the eight engagement pins 72, and inclined portions 78a and 78b provided on the front and rear sides of the engagement recess 76, respectively, and is rotatably mounted around the pins 80. The plunger spring 84 biases the ratchet pawl 82 in a direction that constantly presses it against the engagement pins 72. The shift member 86 is a member with a circular cross-section that can move linearly in the tangential direction of the flange 68 within the cylinder 92. When the shift member 86 is moved linearly in its axial direction within the cylinder 92, the plunger 90 pushes or pulls the ratchet pawl 82 linearly. In this way, when the ratchet pawl 82 is pushed or pulled, the engagement pins 72 are moved one by one in the circumferential direction of the flange 68. This ensures that the shift barrel shaft 66 is rotated and stopped reliably, for example, in increments of 45 degrees, without over-rotating the shift barrel shaft 66. The position return spring 88 has one end housed in the spring housing 94 and the other end fixed to the spring fixing part 96.

[0018] The shift device 74 includes a shift actuator 100, a bell crank 102, a connecting link 104, a connecting joint 108, a ball joint 110, and a ball shaft 114. The shift actuator 100 is, for example, a so-called pneumatic valve actuator, and includes a pneumatic compressor that generates compressed air as a driving source, a pneumatic cylinder, a regulating valve, and pipes that connect these components respectively. The shift actuator 100 corresponds to the "actuator" in the present invention. The bell crank 102 is rotatable about a fifth axis C5 that is orthogonal to a fourth axis C4. One end of the shift actuator 100 is fixed, and the other end is connected to one end of the bell crank 102. The connecting portion between the other end of the shift actuator 100 and one end of the bell crank 102 is connected so as to be relatively rotatable. The other end of the bell crank 102 is connected to one end of the connecting link 104 via a connecting joint 108 that is relatively rotatable about a pin 106 parallel to the fifth axis C5. The other end of the connecting link 104 is connected to the shift member 86 via the ball joint 110 so as to be rotatable about the center (center of the sphere) of the spherical portion 112 of the ball joint 110. The shift actuator 100 can apply a rotational force so that one end of the bell crank 102 connected to the shift actuator 100 rotates in one direction or the other direction about the fifth axis C5, and can release the applied rotational force. The position return spring 88 constantly applies a biasing force to return the ratchet pawl 82 to the reference position. The "reference position" is the position of the ratchet pawl 82 when the shift actuator 100 is not applying a rotational force to one end of the bell crank 102 and the engagement recess 76 receives the two engagement pins 72. The position return spring 88 corresponds to the "biasing member" in the present invention.

[0019] The shift control of the transmission 26 is executed according to the following procedure. First, the shift actuator 100 applies a rotational force that causes one end of the bell crank 102 to rotate in one direction or the other about the fifth axis C5. As a result, the rotation of the bell crank 102 is converted into a motion that pushes or pulls the ratchet pawl 82 from the reference position via the shift member 86. For example, when the ratchet pawl 82 is pushed from the shift member 86, in FIG. 2, the engagement pin 72 engaged with the ratchet pawl 82 is sent counterclockwise, causing the flange 68 to rotate counterclockwise. For example, when the ratchet pawl 82 is pulled from the shift member 86, in FIG. 2, the engagement pin 72 engaged with the ratchet pawl 82 is sent clockwise, causing the flange 68 to rotate clockwise. As the flange 68 rotates, the shift barrel shaft 66 is rotated. When the shift barrel shaft 66 rotates, the disengagement / engagement states of the plurality of dog clutches 50 are switched by the shift fork 62 and the switching mechanism 40, respectively, to effect a gear shift.

[0020] When the shift control is completed, the shift actuator 100 releases the rotational force applied to one end of the bell crank 102. As a result, the ratchet pawl 82 is returned to the reference position by the biasing force of the position return spring 88, and is moved in the direction of pressing against the engagement pin 72 by the biasing force of the plunger spring 84. Thereby, the engagement recess 76 of the ratchet pawl 82 is brought into a state of receiving two new engagement pins 72.

[0021] Return to FIG. 1. The vehicle 10 includes an electronic control unit 150. The electronic control unit 150 is configured to include, for example, a so-called microcomputer, and executes various controls of the vehicle 10 by performing signal processing according to a program stored in advance. The electronic control unit 150 corresponds to the "control device" in the present invention.

[0022] The electronic control unit 150 receives various signals based on values ​​detected by various sensors (for example, engine speed sensor 120, vehicle speed sensor 122, accelerator pedal position sensor 124, barrel shaft rotation angle sensor 126, upshift switch 130, downshift switch 134, etc.). These signals include, for example, engine speed Ne [rpm], which is the rotational speed of the engine 12; vehicle speed V [km / h]; accelerator pedal position θacc [%], which is the amount of accelerator pedal operation representing the magnitude of the driver's acceleration operation; barrel shaft rotation angle θbrl [deg], which represents the rotational position of the shift barrel shaft 66; an upshift signal Sup, which indicates that the upshift paddle shift lever 128 has been operated; and a downshift signal Sdn, which indicates that the downshift paddle shift lever 132 has been operated. The barrel shaft rotation angle θbrl corresponds to the "rotation angle of the shift barrel shaft" in this invention. The upshift paddle shift lever 128 and the downshift paddle shift lever 132 are each provided on a steering wheel (not shown). The upshift paddle shift lever 128 and the downshift paddle shift lever 132 are shift-by-wire operating devices that allow the driver to request shift control of the transmission 26, and correspond to the "shift operating device" in the present invention.

[0023] The electronic control unit 150 outputs various control signals to each device installed in the vehicle 10 (for example, the engine 12, the hydraulic control circuit 22, the shift device 74, etc.), such as an engine control signal Se for controlling the operation of the engine 12, a K1 disengagement control signal Sk1 for controlling the engagement and disengagement of the clutch K1, and a gear shift instruction signal Stm for instructing the start of gear shift control of the transmission 26 by rotating the shift barrel shaft 66.

[0024] The electronic control unit 150 calculates the required drive torque Trdem [N·m] by applying, for example, the accelerator opening θacc and vehicle speed V to a predetermined drive request map. The electronic control unit 150 outputs an engine control signal Se that obtains the engine torque Te [N·m] necessary to achieve the required drive torque Trdem, taking into account the gear ratio γ of the transmission 26.

[0025] Incidentally, if two consecutive gear shift instruction signals Stm are output, gear shifting in the transmission 26 may fail. The reason for this is as follows:

[0026] Here, regarding the two sequential gear shift instruction signals Stm, the one output first will be referred to as the "first gear shift instruction signal Stm1," and the one output second will be referred to as the "second gear shift instruction signal Stm2."

[0027] When the first gear shift instruction signal Stm1 is output to the shift actuator 100, the shift member 86 pushes or pulls the ratchet pawl 82 to initiate gear shift control. Once the gear shift control based on the first gear shift instruction signal Stm1 is complete, the ratchet pawl 82 is returned to its reference position by the biasing force of the position return spring 88. However, due to manufacturing variations such as the spring constant of the position return spring 88 and the sliding resistance between the shift member 86 and the cylinder 92, the time it actually takes for the ratchet pawl 82 to return to its reference position varies from one shift device 74 to another. Therefore, if the period from the time the first gear shift instruction signal Stm1 is output to the shift actuator 100 to the time the second gear shift instruction signal Stm2 is output to the shift actuator 100 is short, the engagement pins 72 may start to be fed out before the ratchet pawl 82 has fully returned to its reference position, that is, before the engagement recess 76 has received the two new engagement pins 72. However, before the engaging recess 76 accepts the two engaging pins 72, the engaging pins 72 cannot be extended, resulting in a failure of the gear shifting indicated by the second gear shift instruction signal Stm2.

[0028] Next, we will explain the control of the electronic control unit 150, which can suppress the shifting period from becoming unnecessarily long when two sequential shift instruction signals Stm are output to the shift actuator 100.

[0029] First, the electronic control unit 150 learns a predetermined interval period Tintv [ms] in advance. The interval period Tintv is the shortest period between the first gear shift instruction signal Stm1 and the second gear shift instruction signal Stm2, when the first and second gear shift instruction signals Stm1 and Stm2 are output to the shift actuator 100, during which the gear shift caused by the second gear shift instruction signal Stm2, which is output later, will not fail. In other words, the interval period Tintv is the shortest period between the output time of the first gear shift instruction signal Stm1 and the output time of the second gear shift instruction signal Stm2, during which the gear shift caused by the second gear shift instruction signal Stm2 will not fail.

[0030] In the following, during the learning of the interval period Tintv, of the two preceding and succeeding gear shift instruction signals Stm, the one output first will be referred to as the "learning gear shift instruction signal Sstd1," and the one output second will be referred to as the "learning gear shift instruction signal Sstd2."

[0031] The electronic control unit 150 sequentially outputs the learning shift instruction signals Sstd1 and Sstd2, which are preceding and succeeding each other, with an interval of a set period Ts [ms], and determines whether the shift performed by the learning shift instruction signal Sstd2 was successful or not. After a predetermined execution period Texe [ms] has elapsed since the output of the learning shift instruction signal Sstd2, if the barrel axis rotation angle θbrl of the shift barrel axis 66 becomes the rotation angle corresponding to the learning shift instruction signal Sstd2, it is determined that the shift was successful; otherwise, it is determined that the shift failed. The "predetermined execution period Texe" is a period sufficient for the shift control to be completed. If the shift performed by the learning shift instruction signal Sstd2 is successful, the set period Ts is shortened and the same determination is made; if the shift performed by the learning shift instruction signal Sstd2 fails, the set period Ts is lengthened and the same determination is made. The setting period Ts is, for example, in the initial determination, a predetermined initial value Tinit[ms] which is expected to be near the boundary value between the setting period Ts in which the gear shift using the learning gear shift instruction signal Sstd2 is successful and the setting period Ts in which it fails. The electronic control unit 150 learns the interval period Tintv by adding a predetermined stabilization period Tstb[ms] to the boundary value between the setting period Ts in which the gear shift using the learning gear shift instruction signal Sstd2 is successful and the setting period Ts in which it fails. The "stabilization period Tstb" is a predetermined period that is designed in advance so that, for example, the gear shift based on the learning gear shift instruction signal Sstd2 is stably successful when the learned interval period Tintv is used.

[0032] Next, after the interval period Tintv has been learned in advance, the electronic control unit 150 waits to output the next gear shift instruction signal Stm from the time it outputs a certain gear shift instruction signal Stm to the shift actuator 100 until the interval period Tintv has elapsed, and then outputs the next gear shift instruction signal Stm to the shift actuator 100 after the interval period Tintv has elapsed.

[0033] Figure 4 is an example flowchart illustrating the control operation for learning the interval period Tintv in the electronic control unit 150. The flowchart in Figure 4 is executed when learning the interval period Tintv. The learning may be performed during the manufacturing of the vehicle 10 or during use after the vehicle 10 has been manufactured.

[0034] First, in step S10 (hereinafter, "step" will be omitted), the flag FLG is set to "0" and the setting period Ts is set to the initial value Tinit. The flag FLG represents the status in learning. Setting the flag FLG to "0" means that learning has just started, that is, each step from S20 onwards has not been executed. After the execution of S10, in S20, the learning gear shift instruction signal Sstd1 is output, and in S30, the learning gear shift instruction signal Sstd2 is output after the set period Ts has elapsed since the start of execution of S20. After the execution of S30, in S40, after a predetermined execution period Texe has elapsed since the output of the learning gear shift instruction signal Sstd2, it is determined whether the barrel axis rotation angle θbrl is the rotation angle corresponding to the learning gear shift instruction signal Sstd2.

[0035] If the determination in S40 is YES (i.e., the gear shift based on the learning gear shift instruction signal Sstd2 was successful), then in S50, it is determined whether the flag FLG is "+1". If the determination in S50 is NO, in S60, the set period Ts is reset to the value obtained by subtracting a predetermined step period ΔT [ms]. The "step period ΔT" is a predetermined period that is experimentally or design-wise determined in advance so that the interval period Tintv can be learned accurately and the number of learning iterations does not become excessively large. After the execution of S60, in S70, the flag FLG is set to "-1". A flag FLG of "-1" means that the gear shift based on the learning gear shift instruction signal Sstd2 was successful at least once, as determined in S40. If the determination in S40 is NO (i.e., the gear shift based on the learning gear shift instruction signal Sstd2 failed), then in S90, it is determined whether the flag FLG is "-1". If the result of S90 is NO, in S100 the set period Ts is reset to the set period Ts plus a predetermined step period ΔT. After the execution of S100, in S110 the flag FLG is set to "+1". A flag FLG of "+1" means that the gear shift based on the learning gear shift instruction signal Sstd2 has failed at least once, as determined in S40. After the execution of both S70 and S110, S20 is executed again.

[0036] If the result of S50 is YES (meaning that a gear change based on the learning gear change instruction signal Sstd2 has failed in the past but is successful this time), in S80, the set period Ts plus the stabilization period Tstb (=Ts+Tstb) is learned as the interval period Tintv. Preferably, the stabilization period Tstb is shorter than the step period ΔT. If the result of S90 is YES (meaning that a gear change based on the learning gear change instruction signal Sstd2 has succeeded in the past but is unsuccessful this time), in S120, the set period Ts plus the step period ΔT and the stabilization period Tstb (=Ts+ΔT+Tstb) is learned as the interval period Tintv. After the execution of both S80 and S120, the flowchart ends.

[0037] Figure 5 is an example flowchart illustrating the control operation of the gear shift control in the electronic control unit 150 after learning the interval period Tintv. The flowchart in Figure 5 is executed, for example, when the electronic control unit 150 receives a gear shift request from either the up paddle shift lever 128 or the down paddle shift lever 132.

[0038] First, in S200, it is determined whether the timer Ttimer[ms] is equal to or greater than the interval period Tintv. When the vehicle 10 is started, the timer Ttimer determined in S200 is pre-set to be equal to or greater than the interval period Tintv. Also, if gear shift control has already been performed after the vehicle 10 has been started, the timer Ttimer determined in S200 is reset to zero and measurement begins at the time the previous gear shift instruction signal Stm is output to the shift actuator 100 (see S210 below). If the determination in S200 is YES, in S210, the gear shift instruction signal Stm is output to the shift actuator 100 of the shift device 74, and the timer Ttimer is reset to zero and measurement begins. After the execution of S210, the program returns. If the determination in S200 is NO, in S220, the output of the gear shift instruction signal Stm is put into a waiting state. After the execution of S220, S200 is executed again.

[0039] According to this embodiment, (a) when two sequential gear shift instruction signals Stm, a first gear shift instruction signal Stm1 and a second gear shift instruction signal Stm2, are output to the shift actuator 100, an interval period Tintv is pre-learned, which is the shortest period between the output times of the first gear shift instruction signal Stm1 and the second gear shift instruction signal Stm2, so that the gear shift caused by the second gear shift instruction signal Stm2, which is the later of the two gear shift instruction signals Stm, does not fail; and (b) after the interval period Tintv has been pre-learned, the output of the second gear shift instruction signal Stm2, which follows the first gear shift instruction signal Stm1, is kept in a waiting state from the time of output of the first gear shift instruction signal Stm1 until the interval period Tintv has elapsed, and the second gear shift instruction signal Stm2 is output after the interval period Tintv has elapsed. In this way, the interval period Tintv, which prevents a gear shift failure when the second gear shift instruction signal Stm2 is issued, is pre-learned from the first gear shift instruction signal Stm1. Furthermore, after the interval period Tintv has been pre-learned, the output of the second gear shift instruction signal Stm2 is kept in a waiting state from the time the first gear shift instruction signal Stm1 is output until the interval period Tintv has elapsed. The second gear shift instruction signal Stm2 is then output after the interval period Tintv has elapsed. This prevents gear shift failures and suppresses the gear shift period from becoming unnecessarily long.

[0040] According to this embodiment, the output of the first gear shift instruction signal Stm1 and the second gear shift instruction signal Stm2 is required based on the driver manually operating either the up paddle shift lever 128 or the down paddle shift lever 132 of the shift-by-wire system. The electronic control unit 150 automatically performs gear shift control so that the gear shift period for the preceding and succeeding first gear shift instruction signal Stm1 and the second gear shift instruction signal Stm2 does not become unnecessarily long. As a result, the driver can manually operate the shift lever as needed without worrying about failing to shift gears, thus reducing the burden on the driver.

[0041] In this embodiment, during the learning of the interval period Tintv, whether or not the gear shift performed by the second gear shift instruction signal Stm2, which is the later of the two gear shift instruction signals Stm, was successful is determined based on the detection signal of a sensor that detects the barrel axis rotation angle θbrl. Determining whether or not the gear shift was successful based on the detection signal of a sensor that detects the barrel axis rotation angle θbrl is equivalent to determining it based on the position of the shift fork 62. This allows the learning to be performed by reducing the period from the time the shift fork 62 moves to the position corresponding to the learning gear shift instruction signal Sstd2 until each dog clutch 50 actually becomes engaged or disengaged. In other words, it is suppressed from learning the interval period Tintv to be longer than necessary. Note that if the barrel axis rotation angle θbrl corresponds to the learning gear shift instruction signal Sstd2, the shift fork 62 has moved to the desired position, and therefore the gear shift of the learning gear shift instruction signal Sstd2 will not fail thereafter.

[0042] The above-described examples are embodiments of the present invention, and the present invention can be implemented in various modified and improved forms based on the knowledge of those skilled in the art, without departing from its spirit.

[0043] In the embodiment described above, the shift direction of the learned interval period Tintv was not specifically mentioned, but for example, the interval period Tintv may be learned separately for upshifts and downshifts. If the time it takes for the ratchet pawl 82 to return to the reference position differs between upshifts and downshifts, it is possible to prevent the gear shift period from becoming unnecessarily long for each shift direction.

[0044] In the above-described embodiment, during learning of the interval period Tintv, whether or not the gear shift by the learning gear shift instruction signal Sstd2 was successful was determined based on the detection signal of a sensor that detects the barrel shaft rotation angle θbrl, but the present invention is not limited to this. For example, it may be determined based on whether or not the gear ratio γ of the transmission 26 corresponds to the second gear shift instruction signal Stm2.

[0045] In the above-described embodiment, the shift control of the transmission 26 was requested when either the up paddle shift lever 128 or the down paddle shift lever 132 was operated by the driver, but the present invention is not limited to this embodiment. For example, the shift control of the transmission 26 may be requested when a shift-by-wire type shift lever is operated by the driver. Furthermore, the present invention is also applicable when the transmission 26 is an automatic transmission. For example, the present invention is also applicable when the electronic control device 150 makes a shift decision using a well-known predetermined shift map and outputs two preceding and succeeding shift instruction signals Stm to the shift actuator 100. [Explanation of Symbols]

[0046] 26: Transmission, 28: Main shaft (first rotation axis), 30: Gear pair, 34: Driven gear (gear on the second rotation axis side), 50: Dog clutch, 52: Sub-shaft (second rotation axis), 62: Shift fork, 64: Shift groove, 66: Shift barrel shaft, 72: Engagement pin, 76: Engagement recess, 82: Ratchet pawl, 88: Position return spring (biasing member), 100: Shift actuator (actuator), 128: Up paddle shift lever (shift operation device), 132: Down paddle shift lever (shift operation device), 150: Electronic control unit (control unit), Tintv: Interval period, θbrl: Barrel shaft rotation angle (rotation angle of the shift barrel shaft)

Claims

1. A control device for a transmission, comprising: a plurality of pairs of gears of mutually meshing types provided on a first and second rotation axis parallel to each other; a shift fork that acts on a plurality of dog clutches between the gear on the second rotation axis and the second rotation axis; a shift barrel shaft having a plurality of shift grooves that engage with the base ends of the shift forks and selectively setting a plurality of gear stages at predetermined rotation angles; an actuator that rotates the shift barrel shaft by linearly moving a ratchet pawl that engages with one of a plurality of engagement pins arranged at equal intervals in the circumferential direction of the shift barrel shaft from a predetermined reference position; and a biasing member that biases the ratchet pawl to the reference position, When two sequential gear shift instruction signals are output to the actuator, a predetermined interval period is pre-learned, which is the shortest period between the output times of the two gear shift instruction signals such that the gear shift caused by the later of the two gear shift instruction signals does not fail. After the interval period has been learned in advance, the output of the second gear shift instruction signal, which follows the first gear shift instruction signal, is kept on hold from the time the first gear shift instruction signal is output until the interval period has elapsed, and the second gear shift instruction signal is output after the interval period has elapsed. A transmission control device characterized by the following features.

2. The aforementioned interval period is learned separately for cases where the shift direction is an upshift and cases where it is a downshift. A control device for a transmission according to feature 1.

3. During the learning interval, whether or not the gear shift performed by the later of the two gear shift instruction signals was successful is determined based on the detection signal from the sensor that detects the rotation angle of the shift barrel shaft. A control device for a transmission according to feature 1.

4. The output of the first gear shift instruction signal and the second gear shift instruction signal is required based on the fact that the shift-by-wire shift control device is manually operated by the driver. A transmission control device according to any one of claims 1 to 3.

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