JP4637996B2 - Automatic transmission for vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an automatic transmission for a vehicle that is applied to a large vehicle such as a tractor.
[0002]
[Prior art]
Recently, in order to reduce the burden on the driver, there are many examples in which an automatic transmission is employed even in a large vehicle such as a tractor or a truck. In such a large vehicle, in addition to the main gear, a multi-stage transmission having a splitter and a range gear as auxiliary transmissions is equipped. In this case, in order to reduce the number of parts and the cost, it can be considered that the mechanical sync mechanism is omitted from the main gear, and the sync control is performed instead to synchronize at the time of gear-in. Here, the synchro control mainly means that counter shaft brake control is performed when shifting up, and double clutch control is performed when shifting down. The synchronized state means that the dog gear rotation and the sleeve rotation substantially coincide with each other at the next main shift target gear stage.
[0003]
[Problems to be solved by the invention]
By the way, in the countershaft brake control, the countershaft brake is operated to reduce the countershaft rotation to the target rotation. However, if the rotation is reduced too much due to overshoot, the synchro state is lost and gear-in is not possible, and the countershaft rotation must be increased again by double clutch control, which is not preferable.
[0004]
Accordingly, an object of the present invention is to perform optimum brake force adjustment in countershaft brake control.
[0005]
[Means for Solving the Problems]
  An automatic transmission for a vehicle according to the present invention includes a transmission including a main gear that does not have a mechanical synchronization mechanism, and a shift control unit that executes a shift control of the transmission, and a predetermined speed is set when the main gear is shifted. A countershaft brake for braking the countershaft of the transmission, and a countershaft brake control means for controlling the operation of the countershaft brake. At this time, a first predetermined value M in which the rotational speed difference ΔN obtained by subtracting the sleeve rotation from the dog gear rotation at the target main gear stage is a positive set value.₁Is exceeded, the synchro control is set to a predetermined countershaft brake control, and the countershaft brake control is operated intermittently so that the brake force of the countershaft brake can be adjusted in two stages. In addition, the counter shaft brake operating time ratio can be selected from a large value and a small value, and the counter shaft brake control means is configured to start and end the counter shaft brake control.For each time interval smaller than the operation time of the small value of the operation time ratio of the counter shaft brake,The rotation speed difference ΔN is the first predetermined value M.₁Second predetermined value ΔN set to a larger value than₁Whether the rotational speed difference ΔN is equal to or greater than the second predetermined value ΔN.₁At this time, the operation time ratio of the countershaft brake is set to the large value, and the rotational speed difference ΔN is set to the second predetermined value ΔN.₁Less than the first predetermined value M₁Is exceeded, the operating time ratio of the countershaft brake is set to the small value.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
[0009]
FIG. 1 shows an automatic transmission for a vehicle according to this embodiment. Here, the vehicle is a tractor that pulls the trailer, and the engine is a diesel engine. As shown in the figure, a transmission 3 is attached to the engine 1 via a clutch 2, and an output shaft 4 (see FIG. 2) of the transmission 3 is connected to a propeller shaft (not shown) to drive a rear wheel (not shown). It is supposed to be. The engine 1 is electronically controlled by an engine control unit (ECU) 6. That is, the ECU 6 reads the current engine speed and the engine load from the outputs of the engine rotation sensor 7 and the accelerator opening sensor 8, and controls the fuel injection pump 1a mainly based on these to control the fuel injection timing and the fuel injection. Control the amount.
[0010]
On the other hand, during the shift, the engine control is executed based on the pseudo accelerator opening processed by the ECU 6 independently of the actual accelerator opening detected by the accelerator opening sensor 8. This is particularly necessary in the double clutch control described later.
[0011]
As shown in FIG. 2, the flywheel 1b is attached to the crankshaft of the engine, the ring gear 1c is formed on the outer periphery of the flywheel 1b, and the engine rotation sensor 7 outputs a pulse each time the teeth of the ring gear 1c pass, The ECU 6 counts the number of pulses per unit time and calculates the engine speed.
[0012]
As shown in FIG. 1, here, the clutch 2 and the transmission 3 are automatically controlled based on a control signal of a transmission control unit (TMCU) 9. That is, the automatic transmission device includes an automatic clutch device and an automatic transmission. The ECU 6 and the TMCU 9 are connected to each other via a bus cable or the like and can communicate with each other.
[0013]
As shown in FIGS. 1, 2, and 3, the clutch 2 is a mechanical friction clutch. The flywheel 1b that forms the input side, the driven plate 2a that forms the output side, and the driven plate 2a are in frictional contact with the flywheel 1b. Or it is comprised from the pressure plate 2b made to separate. The clutch 2 operates the pressure plate 2b in the axial direction by a clutch booster (clutch actuator) 10 and is basically automatically connected / disconnected, thereby reducing the burden on the driver. On the other hand, in order to enable delicate clutch work at the time of very low speed back and sudden clutch disconnection in an emergency, manual connection / disconnection by the clutch pedal 11 is also possible here. This is a configuration of a so-called selective auto clutch. A clutch stroke sensor 14 for detecting the clutch position (that is, the position of the pressure plate 2b) and a clutch pedal stroke sensor 16 for detecting the position of the clutch pedal 11 are provided, and are connected to the TMCU 9 respectively.
[0014]
As clearly shown in FIG. 3, the clutch booster 10 is connected to the air tank 5 through two air pressure passages a and b indicated by solid lines, and operates with the air pressure supplied from the air tank 5. One passage a is for automatic clutch connection / disconnection, and the other passage b is for clutch manual connection / disconnection. One of the passages a is bifurcated, one of which is provided with a series of solenoid valves MVC1 and MVC2 for automatic connection / disconnection, and the other is provided with an emergency solenoid valve MVCE. A double check valve DCV1 is provided at the branch junction. A hydraulically operated valve 12 attached to the clutch booster 10 is provided in the other passage b. A double check valve DCV2 is also provided at the junction of both passages a and b. The double check valves DCV1, DCV2 are differential pressure actuated three-way valves.
[0015]
The solenoid valves MVC1, MVC2, and MVCE are ON / OFF controlled by the TMCU 9. When ON, the upstream side communicates with the downstream side, and when OFF, the upstream side is shut off and the downstream side is opened to the atmosphere. First, the automatic side will be described. The electromagnetic valve MVC1 is simply turned ON / OFF in accordance with the ON / OFF of the ignition key. The ignition key is OFF, that is, it is OFF while the vehicle is stopped, and the air pressure from the air tank 5 is shut off. The electromagnetic valve MVC2 is a proportional control valve and can freely control the amount of supply or exhaust air. This is to control the clutch connection / disconnection speed. When the solenoid valves MVC1 and MVC2 are both ON, the air pressure in the air tank 5 is switched to the double check valves DCV1 and DCV2 and supplied to the clutch booster 10. As a result, the clutch is disconnected. When the clutch is connected, only the MVC 2 is turned OFF, whereby the air pressure of the clutch booster 10 is discharged from the MVC 2 and the clutch is connected.
[0016]
However, if an abnormality occurs in the electromagnetic valve MVC1 or MVC2 during clutch disconnection and either of them is turned OFF, the clutch is suddenly engaged against the driver's intention. Therefore, when such an abnormality is detected by the abnormality diagnosis circuit of the TMCU 9, the solenoid valve MVCE is immediately turned on. Then, the air pressure that has passed through the electromagnetic valve MVCE is switched to the reverse of the double check valve DCV1 and supplied to the clutch booster 10 to maintain the clutch disengaged state and prevent sudden clutch engagement.
[0017]
Next, the manual side will be described. The hydraulic pressure is supplied / discharged from the master cylinder 13 in response to the depression / return operation of the clutch pedal 11, and this hydraulic pressure is supplied to the hydraulic valve 12 via a hydraulic passage 13a indicated by a broken line. As a result, the hydraulic valve 12 is opened and closed, the pneumatic pressure is supplied to and discharged from the clutch booster 10, and the clutch 2 is manually connected and disconnected. When the hydraulically operated valve 12 is opened, the air pressure passing through the hydraulically operated valve 12 switches the double check valve DCV2 to reach the clutch booster 10.
[0018]
As shown in detail in FIG. 2, the transmission 3 is basically a multi-stage transmission that is always meshed, and can shift to 16 forward speeds and 2 reverse speeds. The transmission 3 includes a main gear 18 and a splitter 17 and a range gear 19 as auxiliary transmissions on the input side and the output side, respectively. Then, the engine power transmitted to the input shaft 15 is sent to the splitter 17, the main gear 18, and the range gear 19 in order and output to the output shaft 4.
[0019]
A gear shift unit GSU is provided to automatically shift the transmission 3, and is composed of a splitter actuator 20, a main actuator 21, and a range actuator 22 that are responsible for shifting the splitter 17, the main gear 18, and the range gear 19. These actuators are also pneumatically operated like the clutch booster 10 and controlled by the TMCU 9. The current positions of the gears 17, 18 and 19 are detected by a gear position switch 23 (see FIG. 1). The rotation speed of the counter shaft 32 is detected by the counter shaft rotation sensor 26, and the rotation speed of the output shaft 4 is detected by the output shaft rotation sensor 28. These detection signals are sent to TMCU9.
[0020]
In this automatic transmission, a manual mode is set, and a manual shift based on a driver's shift change operation is possible. In this case, as shown in FIG. 1, the connection / disconnection control of the clutch 2 and the shift control of the transmission 3 are performed with a shift instruction signal from a shift lever device 29 provided in the driver's seat as a signal. In other words, when the driver shifts the shift lever 29a of the shift lever device 29, the shift switch built in the shift lever device 29 is activated (ON), and a shift instruction signal is sent to the TMCU 9, based on which the TMCU 9 The clutch booster 10, the splitter actuator 20, the main actuator 21 and the range actuator 22 are appropriately operated to execute a series of gear shifting operations (clutch disengagement → gear disengagement → gear engagement → clutch engagement). The TMCU 9 displays the current shift stage on the monitor 31.
[0021]
In the illustrated shift lever device 29, R means reverse, N means neutral, D means drive, UP means shift up, and DOWN means shift down. The shift switch outputs a signal corresponding to each position. The driver's seat is provided with a mode switch 24 for switching the shift mode between automatic and manual and a skip switch 25 for switching whether the shift is performed step by step or step skipping.
[0022]
If the shift lever 29a is put in the D range in the automatic shift mode, the shift is automatically performed according to the vehicle speed. Even in the automatic transmission mode, if the driver operates the shift lever 29a to UP or DOWN, manual upshifting or downshifting is possible. In this automatic shift mode, if the skip switch 25 is OFF (normal mode), the shift is performed step by step by one operation of UP or DOWN of the shift lever 29a. This is effective when the loaded load is relatively large, such as when trailer is pulled. If the skip switch 25 is ON (skip mode), the gear shift is performed by skipping one step. This is effective when the trailer is not towed or when the load is light.
[0023]
On the other hand, in the manual shift mode, the shift completely follows the driver's intention. When the shift lever 29a is in the D range, no speed change is performed, and the current gear is held, and the shift up or down is possible only when the shift lever 29a is operated to UP or DOWN with the driver's positive intention. At this time, similarly to the above, if the skip switch 25 is OFF, the gear shift is performed one step at a time, and if the skip switch 25 is ON, the gear shift is skipped by one step. In this mode, the D range is an H (hold) range that holds the current gear stage.
[0024]
An emergency shift switch 27 is provided in the driver's seat so that when the GSU solenoid valve or the like breaks down, the gear can be shifted by manual switching of the switch 27.
[0025]
As shown in FIG. 2, in the transmission 3, the input shaft 15, the main shaft 33, and the output shaft 4 are coaxially arranged, and the counter shaft 32 is arranged in parallel below them. The input shaft 15 is connected to the driven plate 2a of the clutch 2, and the input shaft 15 and the main shaft 33 are supported so as to be relatively rotatable.
[0026]
First, the configuration of the splitter 17 and the main gear 18 will be described. An input gear SH is rotatably attached to the input shaft 15. Gears M4, M3, M2, M1, and MR are also rotatably attached to the main shaft 33 in order from the front. The gears SH, M4, M3, M2, and M1 except for the MR are always meshed with counter gears CH, C4, C3, C2, and C1 fixed to the countershaft 32, respectively. The gear MR is always meshed with the idle reverse gear IR, and the idle reverse gear IR is always meshed with a counter gear CR fixed to the counter shaft 32.
[0027]
The gears SH, M4... Attached to the input shaft 15 and the main shaft 33 are integrally provided with dog gears 36 so that the gears can be selected, and the input shafts 15 and the main shaft 33 are adjacent to the dog gears 36. The first to fourth hubs 37 to 40 are fixed. First to fourth sleeves 42 to 45 are fitted to the first to fourth hubs 37 to 40. Splines are formed in the outer peripheral portions of the dog gear 36 and the first to fourth hubs 37 to 40 and the inner peripheral portions of the first to fourth sleeves 42 to 45, and the first to fourth sleeves 42 to 45 are the first ones. The first to fourth hubs 37 to 40 are always engaged to rotate simultaneously with the input shaft 15 or the main shaft 33, and slide back and forth to selectively engage / disengage the dog gear 36. By this engagement / disengagement, gear-in / gear-out is performed. The first sleeve 42 is moved by the splitter actuator 20, and the second to fourth sleeves 43-45 are moved by the main actuator 21.
[0028]
As described above, the splitter 17 and the main gear 18 have a constant meshing configuration that can be automatically shifted by the actuators 20 and 21. In particular, although a normal mechanical sync mechanism exists in the spline portion of the splitter 17, no sync mechanism exists in each spline portion of the main gear 18. For this reason, the synchro control described later is performed to synchronize the dog gear rotation and the sleeve rotation so that the gear can be shifted without the sync mechanism. Here, in addition to the main gear 18, the splitter 17 is also provided with a neutral position so as to take a so-called rattling sound (see Japanese Patent Application No. 11-319915).
[0029]
Next, the configuration of the range gear 19 will be described. The range gear 19 employs a planetary gear mechanism 34 and can be switched to either a high or low position. The planetary gear mechanism 34 includes a sun gear 65 fixed to the rear end of the main shaft 33, a plurality of planetary gears 66 meshed with the outer periphery thereof, and a ring gear 67 having internal teeth meshed with the outer periphery of the planetary gear 66. Become. Each planetary gear 66 is rotatably supported by a common carrier 68, and the carrier 68 is connected to the output shaft 4. The ring gear 67 integrally has a pipe portion 69, and the pipe portion 69 is fitted on the outer periphery of the output shaft 4 so as to be relatively rotatable and constitutes a double shaft together with the output shaft 4.
[0030]
The fifth hub 41 is provided integrally with the pipe portion 69. An output shaft dog gear 70 is integrally provided on the output shaft 4 adjacent to the rear of the fifth hub 41. A fixed dog gear 71 is provided on the transmission case side adjacent to the front of the fifth hub 41. A fifth sleeve 46 is fitted to the outer periphery of the fifth hub 41. The fifth hub 41, the output shaft dog gear 70, the fixed dog gear 71, and the fifth sleeve 46 are similarly splined, and the fifth sleeve 46 is always engaged with the fifth hub 41 and slides back and forth. Then, the output shaft dog gear 70 or the fixed dog gear 71 is selectively engaged / disengaged. The movement of the fifth sleeve 46 is performed by the range actuator 22. A mechanical sync mechanism exists in the spline portion of the range gear 19.
[0031]
When the fifth sleeve 46 moves forward, it engages with the fixed dog gear 71, and the fifth hub 41 and the fixed dog gear 71 are connected. As a result, the ring gear 67 is fixed to the transmission case side, and the output shaft 4 is rotationally driven at a relatively large reduction ratio (here, 4.5) larger than 1. This is the low position.
[0032]
On the other hand, when the fifth sleeve 46 moves rearward, this engages with the output shaft dog gear 70, and the fifth hub 41 and the output shaft dog gear 70 are connected. As a result, the ring gear 67 and the carrier 68 are fixed to each other, and the output shaft 4 is directly driven at a reduction ratio of 1. This is the high position. In such a range gear 19, the reduction ratio between high and low is relatively different.
[0033]
After all, in this transmission 3, on the forward side, it is possible to shift to two stages of high and low by the splitter 17, four stages of the main gear 18, and two stages of high and low by the range gear 19, so that a total of 2 × 4 × 2 = The speed can be changed to 16 stages. On the reverse side, the speed can be changed to two stages by switching between high and low only by the splitter 17.
[0034]
Next, each actuator 20, 21, 22 will be described. These actuators are composed of a pneumatic cylinder that is operated by the air pressure of the air tank 5 and a solenoid valve that switches supply and discharge of air pressure to and from the pneumatic cylinder. These solenoid valves are selectively switched by TMCU 9 to selectively actuate the pneumatic cylinder.
[0035]
The splitter actuator 20 includes a pneumatic cylinder 47 having a double piston and three electromagnetic valves MVH, MVF, and MVG. When the splitter 17 is set to neutral, MVH / ON, MVF / OFF, and MVG / ON are set. When the splitter 17 is set to high, MVH / OFF, MVF / OFF, and MVG / ON are set. When the splitter 17 is set to low, MVH / OFF, MVF / ON, and MVG / OFF are set.
[0036]
The main actuator 21 includes a pneumatic cylinder 48 having a double piston and responsible for the operation on the select side, and a pneumatic cylinder 49 having a single piston and responsible for the operation on the shift side. A plurality of solenoid valves MVC, MVD, MVE and MVB, MVA are provided for each of the pneumatic cylinders 48 and 49.
[0037]
The select-side pneumatic cylinder 48 moves downward in the figure when MVC / OFF, MVD / ON, and MVE / OFF, and can select 3rd, 4th, or N3 of the main gear, and MVC / ON, MVD / OFF, MVE / When ON, it becomes neutral, and the 1st, 2nd or N2 of the main gear can be selected, and when it is MVC / ON, MVD / OFF, or MVE / OFF, it moves upward in the figure, and the main gear Rev or N1 can be selected.
[0038]
The shift side pneumatic cylinder 49 is neutral when MVA / ON, MVB / ON, and can select N1, N2 or N3 of the main gear, and moves to the left side of the figure when MVA / ON, MVB / OFF. 2nd, 4th or Rev can be selected, and when MVA / OFF or MVB / ON, it moves to the right side of the figure, and 1st or 3rd of the main gear can be selected.
[0039]
The range actuator 22 includes a pneumatic cylinder 50 having a single piston and two electromagnetic valves MVI and MVJ. The pneumatic cylinder 50 moves to the right side of the diagram when MVI / ON and MVJ / OFF, and moves the range gear to the high side when MVI / OFF and MVJ / ON, and sets the range gear to low.
[0040]
Incidentally, a counter shaft brake 27 is provided on the counter shaft 32 in order to brake the counter shaft 32 at the time of synchro control described later. The countershaft brake 27 is a wet multi-plate brake and is operated by the air pressure of the air tank 5. An electromagnetic valve MV BRK is provided to switch between supply and discharge of the air pressure. When the solenoid valve MV BRK is ON, pneumatic pressure is supplied to the countershaft brake 27, and the countershaft brake 27 is activated. When the solenoid valve MV BRK is OFF, the air pressure is discharged from the countershaft brake 27, and the countershaft brake 27 is deactivated.
[0041]
Next, the contents of the automatic shift control will be described. The TMCU 9 stores a shift-up map shown in FIG. 4 and a shift-down map shown in FIG. 5, and the TMCU 9 executes automatic shift according to these maps in the automatic shift mode. For example, in the shift-up map of FIG. 4, the shift-up diagram from gear stage n (n is an integer from 1 to 15) to n + 1 is determined by a function of accelerator opening (%) and output shaft rotation (rpm). ing. On the map, only one point is determined from the current accelerator opening (%) and output shaft rotation (rpm). During the acceleration of the vehicle, the rotation of the output shaft 4 connected to the wheels gradually increases. Therefore, in the normal automatic transmission mode, every time the current point exceeds each diagram, the upshift is performed by one step. At this time, if it is the skip mode, the diagram is alternately shifted one by one and shifted up by two stages.
[0042]
Similarly, in the shift down map of FIG. 5, the shift down diagram from the gear stage n + 1 (n is an integer from 1 to 15) to n is a function of the accelerator opening (%) and the output shaft rotation (rpm). It has been decided. On the map, only one point is determined from the current accelerator opening (%) and output shaft rotation (rpm). While the vehicle is decelerating, the rotation of the output shaft 4 gradually decreases. Therefore, in the normal automatic transmission mode, every time the current point exceeds each diagram, the output is shifted down by one step. In the skip mode, the diagram is alternately shifted one by one and shifted down by two stages.
[0043]
On the other hand, in manual mode, the driver can freely shift up and down regardless of these maps. In the normal mode, one shift can be achieved by one shift change operation, and in the skip mode, two shifts can be achieved by one shift change operation.
[0044]
The TMCU 9 converts the current vehicle speed from the current output shaft rotation value detected by the output shaft rotation sensor 28, and displays this on the speedometer. That is, the vehicle speed is indirectly detected from the output shaft rotation, and the output shaft rotation and the vehicle speed are in a proportional relationship.
[0045]
Next, the contents of the sync control will be described.
[0046]
As shown in FIGS. 6 and 7, TMCU 9 has a number of teeth Z of each gear in splitter 17 and main gear 18._SH, Z₁~ Z_Four, Z_R, Z_CH, Z_C1~ Z_C4, Z_CRAnd the high / low reduction ratio in the range gear 19 are stored in advance. Therefore, the TMCU 9 rotates the dog gear at the gear stage of the main gear 18 (target main gear stage) as the next shift destination (target main gear stage) based on the number of gear teeth of the main gear 18 and the counter shaft rotation (rpm) detected by the counter shaft rotation sensor 26. rpm). The TMCU 9 also rotates the sleeve (rpm) of the main gear 18 based on the reduction ratio of the gear stage (target range gear stage) of the range gear 19 that is the next shift destination and the output shaft rotation (rpm) detected by the output shaft rotation sensor 28. ) Is calculated.
[0047]
In the left column of the table of FIG. 7, the words “1st”, “2nd”... “Rev” written at the left end indicate the target main gear stage. In addition, the words “1st”, “2nd”,... In parentheses indicate the target gear stage of the entire transmission that each target main gear stage is responsible for. For example, “1st” (gear M1) of the main gear 18 is assigned to “1st”, “2nd”, “9th”, and “10th”. The words in the parentheses are divided into the first two and the latter two by the low and high of the range gear 19. For example, when the main gear is “1st”, “1st” and “2nd” are range gear low, and “9th” and “10th” are range gear high. Then, in the first two or the latter two, the front and rear are separated by the low and high of the splitter 17. For example, if the main gear is “1st” and the range gear is low, the transmission is “1st” when the splitter is low, and the transmission is “2nd” when the splitter is high. When the main gear is “1st” and the range gear is high, the transmission is “9th” at splitter low, and the transmission is “10th” at splitter high. The same applies to “2nd”, “3rd”, and “4th” of the target main gear stage.
[0048]
In the target main gear stage “Rev”, separation by the range gear 19 is not performed, and separation is performed only by the splitter 17. When the splitter is high, reverse is “high”, and when the splitter is low, reverse is “low”.
[0049]
The right column of the table of FIG. 7 shows a formula for calculating the dog gear rotation (rpm). For example, in the case of the target main gear stage “1st”, the value detected by the counter shaft rotation sensor 26 (counter shaft rotation (rpm)) is set to the gear ratio Z._C1/ Z₁The value obtained by multiplying is the rotation of the dog gear 36 fixed to the gear M1, that is, the dog gear rotation (rpm). At the target main gear stage “Rev”, the gear ratio C is included in the countershaft rotation (rpm)._RevThe value multiplied by (0.45 here) is the dog gear rotation (rpm).
[0050]
On the other hand, the lower part of FIG. 7 shows a calculation formula for the rotation of the sleeves 43, 44, 45 of the main gear 18, that is, the sleeve rotation (rpm). When the target range gear position of the next shift destination is High, the reduction ratio is 1, so the value detected by the output shaft rotation sensor 28 (output shaft rotation (rpm)) becomes the sleeve rotation (rpm) as it is. When the target range gear is low, the reduction ratio is C_RG= 4.5, so the output shaft rotation (rpm) and the reduction ratio C_RGThe value multiplied by is the sleeve rotation (rpm).
[0051]
In the synchro control, the dog gear rotation and the sleeve rotation are controlled so as to be within a range where gear-in is possible. Specifically, a rotation difference ΔN = (dog gear rotation−sleeve rotation) is calculated, and control is performed to put this value in a gear-in range. In the shift-up, since dog gear rotation> sleeve rotation immediately before normal gear-in, counter shaft brake (hereinafter referred to as CSB) control is performed to reduce dog gear rotation. On the contrary, in the downshift, since the dog gear rotation is less than the sleeve rotation just before the normal gear-in, double clutch control is performed to increase the dog gear rotation.
[0052]
Double clutch control is as follows. As shown in FIG.₁When there is a shift instruction signal, the clutch is first disengaged and the gear is released. The gear release is the position immediately after the clutch starts to be disengaged, in other words, the position p immediately after entering the half-clutch region.₁Start with. For engine control, the clutch position is p₁From that point on, the control shifts to the control based on the pseudo accelerator opening that is away from the actual accelerator opening. At this time, the engine rotation is increased to a rotation (target engine rotation) that is sufficient to accelerate the countershaft and can substantially match the dog gear rotation with the sleeve rotation at the target main gear stage. The rotation is kept constant.
[0053]
After the gear is released, the clutch is momentarily connected, whereby the dog gear rotation is increased to a rotation that allows gear-in. Immediately after this, the clutch is disengaged again and gear-in is executed. The gear-in is a position immediately before the end of clutch disengagement, in other words, a position p immediately before exiting the half-clutch region.₂Starts from. Immediately after the gear-in is completed, the clutch is reconnected, and when the clutch is completely engaged, the double clutch control is terminated, and the engine and countershaft rotation shifts to the rotation according to the actual accelerator opening.
[0054]
By the way, when the entire transmission is downshifted, both the downshift of the range gear and the double clutch control may be executed. In the table of FIG. 7, the cases are 9th → 7th, 9th → 8th, 10th → 8th. At this time, if the order of these is not properly determined, the overall shift time will be lengthened.
[0055]
That is, the range gear has a relatively large reduction ratio between high and low, and therefore it takes time to shift down even if it has a mechanical synchro mechanism. The double clutch control also takes a relatively long time because the clutch is engaged once during the gear disengagement / gear-in operation and rotated. Therefore, if these operations are performed in order, the overall shift time becomes longer.
[0056]
Therefore, in the present apparatus, when the entire transmission is shifted down accompanied by the range gear downshifting, the range gear downshifting and the double clutch control are simultaneously performed to shorten the entire gear shifting time. This will be described below.
[0057]
In this apparatus, the shift pattern is divided between when the entire transmission is shifted down with a range gear shift down and when it is not. FIG. 9 shows a program for determining this shift pattern. When there is a shift instruction, the TMCU 9 first determines in step 101 whether or not there is a range gear shift. When there is no range gear shift, the routine proceeds to step 104 where the shift A pattern is selected. The shift A pattern is a pattern that shifts according to the chart of FIG. 10, and is a normal shift pattern. When the range gear shift is present, the routine proceeds to step 102, where it is determined whether or not the shift is downshift (H → L). If the shift is up, the routine proceeds to step 104 to select the shift A pattern, and if the shift is down, the routine proceeds to step 103 to select the shift B pattern. The shift B pattern is a pattern for shifting according to the chart of FIG. 11, and is a shift pattern performed in a relatively special case.
[0058]
10 and 11, there is a time axis from the top to the bottom of the figure, and the items shown side by side indicate that they are performed simultaneously or at the same time. For example, in FIG. 10, step 201 and step 202 are performed simultaneously.
[0059]
Shift A pattern without range gear downshift. As shown in FIG. 10, first, when the main gear shift is present, the routine proceeds to step 201 where the main gear is removed. At this time, if there is also a shift of the splitter, the process proceeds to step 202 to perform gear removal (shift removal) of the splitter. The condition at this time is that the clutch position is p.₁It is more on the other side. Note that this is indicated by “clutch position> p₁Is displayed. Of course, when only one of the main gear and the splitter shifts, one of both steps is omitted. There is no case of shifting only with the range gear. This is because, as shown in the table of FIG. 7, seven steps are skipped (ex. 2nd → 10th).
[0060]
Next, steps 203, 204 and 205 are performed simultaneously. In step 203, the main gear is selected in accordance with the gears M1, M2,. The condition is that the main gear is in neutral. In step 204, when there is a shift of the range gear, the gear removal and the gear-in are simultaneously performed. This is because, as shown in FIG. 2, due to the structure of the range actuator 22, removal and in are performed simultaneously. The condition at this time is that the clutch position is p.₂("Clutch position> p₂") Or the main gear is neutral. In step 205, a gear-in (shift-in) of the splitter is performed. Conditions are the same as in step 204, clutch position> p₂Or, main gear = N. As a result, the engine power can be transmitted to the countershaft 32 and the double clutch control can be performed. In the case of a shift using only the splitter, the shift is completed here.
[0061]
  In step 206, synchronization control is executed. The condition here is that the main gear is N and the splitter and the range gear have been shifted. Dog gear rotation-sleeve rotation> M₁(Positive setting valueFirst predetermined value), I.e., when shifting up, countershaft brake control is performed to reduce the dog gear rotation to near the sleeve rotation. On the other hand, dog gear rotation-sleeve rotation <M₂If it is (set value of 0 or less), double clutch control is performed to increase the dog gear rotation to the vicinity of the sleeve rotation.
[0062]
When synchronization of the main gear is thus completed, the routine proceeds to step 207 where the main gear is engaged. The conditions here are that the main gear has been selected (step 203), the absolute value of the difference between the target countershaft rotation and the current countershaft rotation is equal to or less than a value α that allows gear-in, and the clutch position> p₂It is that. Thus, the shift A pattern is completed.
[0063]
Next, the shift B pattern accompanied by the range gear downshift. As shown in FIG. 11, the shift of the main gear is essential here (see FIG. 7), so the routine proceeds to step 302 where the main gear is removed. Conditions are the same as in step 201, clutch position> p₁It is. At this time, when there is also a shift of the splitter, the gear of the splitter is released at step 301 prior to step 302, and the splitter is geared at step 303 simultaneously with step 302. The execution conditions of steps 301 and 303 are the same as those of steps 202 and 205.
[0064]
Next, steps 304, 305 and 306 are performed simultaneously. In step 304, the main gear is selected as in step 203. In step 305, as in step 204, the range gear is disengaged and gear-in, that is, downshifted. In step 306, the sync control is performed as in step 206.
[0065]
When these steps are completed, the main gear is engaged in step 307 as in step 207, and the shift B pattern is completed.
[0066]
In this way, the range gear shift down and the double clutch control, which require a relatively long time, are simultaneously performed here, so that the entire speed change time can be shortened.
[0067]
Here, how to obtain the target countershaft rotation will be described. First, the current output shaft rotation is obtained, and this is multiplied by the gear ratio of the target gear stage of the entire transmission to calculate the target engine rotation. Based on the target engine rotation and the high / low of the splitter at the target gear stage, the target countershaft rotation is obtained by the following conversion formula.
[0068]
N_C= (Z_SH/ Z_CH) × N_E  (When splitter high)
N_C= (Z_Four/ Z_C4) × N_E  (When splitter low)
N_E: Engine rotation, N_C: Counter shaft rotation
If the current counter shaft rotation (= the value detected by the counter shaft rotation sensor) is matched with the target counter shaft rotation, the dog gear rotation automatically matches the sleeve rotation at the target main gear stage. After all, α is the maximum value that allows gear-in.
[0069]
By the way, in steps 206 and 306, dog gear rotation-sleeve rotation> M₁That is, CSB control is performed when dog gear rotation> sleeve rotation. As described above, the CSB 27 is a wet multi-plate clutch and is effective. The counter shaft rotation can be instantaneously reduced, but oil dragging and the like are likely to overshoot. Therefore, there is a possibility that the rotation is reduced too much. In this case, not only is the synchro state broken, but also the necessity of double clutch control arises, which is not preferable.
[0070]
Therefore, in this apparatus, the following control is executed in order to perform the optimum brake force adjustment in the countershaft brake control.
[0071]
That is, in the CSB control, the CSB is intermittently operated, and the operation time ratio is changed according to the rotation difference between the dog gear rotation and the sleeve rotation. The operating time ratio is decreased as the rotation difference is smaller. In this embodiment, the operating time ratio is set to a small value when the rotation difference is less than a predetermined value, and a large value when the rotation difference is equal to or greater than the predetermined value.
[0072]
  This is specifically shown as follows. The operation / non-operation of the CSB 27 is switched by ON / OFF of the electromagnetic valve MV BRK. Here, the duty of the electromagnetic valve MV BRK is controlled by the TMCU 9 and the CSB 27 is operated intermittently. TMCU9 serves as a countershaft brake control means. At this time, the rotation difference ΔN between the dog gear rotation and the sleeve rotation (= dog gear rotation−sleeve rotation) is a predetermined value ΔN.₁ (Second predetermined value)In the above case, as shown in FIG. 14A, the first ON time TON1 is long and the first OFF time TOFF1 is short. On the other hand, the rotation difference ΔN is a predetermined value ΔN.₁If it is less, the second ON time TON2 is shortened and the second OFF time TOFF2 is lengthened as shown in FIG. 14 (b). TON1> TON2 and TOFF1 <TOFF2. Thus, when the rotation difference ΔN is large, the CSB operating time ratio is increased, and the countershaft can be decelerated quickly with a large braking force. On the other hand, if the rotation difference ΔN is small and the countershaft rotation approaches the target value, the CSB operating time ratio can be reduced, the braking force can be reduced, and overshoot can be prevented.
[0073]
Flows for executing such control are shown in FIGS. FIG. 12 is an ON time / OFF time setting flow, and FIG. 13 is an electromagnetic valve operation permission determination flow. These flows are repeatedly executed by the TMCU 9 every predetermined control time (ex. 32 ms). The flow of FIG. 12 is executed every time prior to the flow of FIG.
[0074]
About FIG. First, the TMCU 9 determines whether or not the current synchro control mode is set in step 401. If NO, the flow ends. If YES, the process proceeds to step 402. In step 402, the rotation difference ΔN = dog gear rotation−sleeve rotation is calculated. In the next step 403, it is determined whether or not the CSB operating condition is satisfied. As shown in step 206 in FIG. 10, the main gear = N, the range gear and the splitter shift are completed, and ΔN> M₁The condition is satisfied when all of the above are satisfied. If the condition is not satisfied, this flow is finished. If the condition is satisfied, the process proceeds to step 404.
[0075]
In step 404, the rotation difference ΔN is set to a predetermined value ΔN.₁Compare with ΔN₁A value of about 200 to 400 (rpm) is input. ΔN ≧ ΔN₁In this case, the routine proceeds to step 405, where the ON time of the solenoid valve MV BRK is set as the first ON time TON1. That is, the time during which the solenoid valve MV BRK is turned on is limited to TON1. In step 406, the OFF time of the solenoid valve MV BRK is set as the first OFF time TOFF1. That is, the electromagnetic valve MV BRK is forcibly turned off during TOFF1. As a result, the solenoid valve MV BRK is alternately turned ON / OFF for a long ON time and a short OFF time, and as a result of the CSB being intermittently operated at a large operating time ratio, the CSB comes to have a large braking force.
[0076]
On the other hand, in step 404, ΔN <ΔN₁In this case, the routine proceeds to step 407, where the ON time of the electromagnetic valve MV BRK is set to the second ON time TON2, and then in step 408, the OFF time of the electromagnetic valve MV BRK is set to the second OFF time TOFF2. As a result, the electromagnetic valve MV BRK is alternately turned ON / OFF with a short ON time and a long OFF time, and as a result of the CSB being intermittently operated at a small operating time ratio, the CSB brings about a small braking force.
[0077]
When the setting of the ON time and the OFF time is thus completed, this flow is finished, and the flow proceeds to the flow of FIG.
[0078]
In FIG. 13, TMCU 9 first determines whether or not the current synchro control mode is set in step 501. If NO, the process proceeds to step 512 to clear the ON timer, and in step 513, the OFF timer is fixed to the maximum value. If YES, the routine proceeds to step 502, where it is determined whether the CSB operating condition is satisfied. This is the same as step 403 in FIG. Next, in step 503, it is determined whether the electromagnetic valve MV BRK is ON, that is, whether the CSB is operating.
[0079]
If it is ON, the process proceeds to step 504 to increment (add) the ON timer, and in step 505, the OFF timer is cleared. Next, in step 506, the value of the ON timer is compared with TON * (* is 1 or 2, the same applies hereinafter). If the ON timer <TON *, the flow ends. If the ON timer ≧ TON *, the flow proceeds to step 507 to prohibit the operation (ON) of the solenoid valve MV BRK. On the other hand, since the solenoid valve MV BRK is turned on / off in a separate flow (not shown), the solenoid valve MV BRK is turned off in a separate flow by prohibiting the solenoid valve operation in this way.
[0080]
If it is determined in step 503 that the solenoid valve MV BRK is OFF, that is, CSB is not activated, the process proceeds to step 508 to clear the ON timer, and in step 509, the OFF timer is incremented. In step 510, the OFF timer value is compared with TOFF *. If the OFF timer <TOFF *, this flow is finished. If the OFF timer ≧ TOFF *, the operation of the solenoid valve MV BRK is permitted (that is, the operation prohibition is canceled) in step 511. As a result, the solenoid valve MV BRK can be turned on in a separate flow.
[0081]
As an actual CSB operation according to this flow, first, MV BRK is turned ON, and when CSB starts operation, the flow proceeds from step 503 to 504, and the ON timer starts incrementing. In the initial stage, ON timer <TON *, so steps 501,... 506 are repeated, but when ON timer ≧ TON *, the time is up and MVBRK is turned off and CSB is deactivated. When this happens, the process proceeds from step 503 to step 508, and the OFF timer starts incrementing. Initially, OFF timer <TOFF *, so steps 501,..., 510 are repeated, but when OFF timer ≧ TOFF *, the time is up. MV BRK ON prohibition is canceled.
[0082]
At this time, if the CSB is still necessary (CSB operation condition is satisfied), MV BRK is turned ON again in another flow, and the CSB is operated. While the CSB is necessary, this ON / OFF is repeated. When the CSB is no longer necessary, the MV BRK is turned off in another flow, and the CSB is deactivated.
[0083]
The flow of FIG. 12 is executed before this flow, and TON * and TOFF * are determined each time. Therefore, ON / OFF control (duty control) of MV BRK according to the rotation difference ΔN becomes possible, and the rotation difference ΔN The effect of CSB can be adjusted optimally according to
[0084]
As a result, the deceleration can be strengthened while the rotation difference ΔN is large, and the dog gear rotation can be ideally brought close to the sleeve rotation by decreasing the deceleration when the rotation difference ΔN becomes small. And overshoot can be prevented beforehand, and the necessity of a double clutch is also eliminated.
[0085]
  The embodiment of the present invention is not limited to the above. For example, in this embodiment, the countershaft braking force is adjusted in two stages..
[0086]
【The invention's effect】
According to the present invention, it is possible to achieve an excellent effect that optimum braking force adjustment can be performed during countershaft brake control.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a vehicle automatic transmission according to an embodiment.
FIG. 2 is a configuration diagram showing an automatic transmission.
FIG. 3 is a block diagram showing an automatic clutch device.
FIG. 4 is a shift-up map.
FIG. 5 is a shift-down map.
FIG. 6 shows the number of teeth of each gear in the transmission.
FIG. 7 shows calculation formulas for dog gear rotation and sleeve rotation.
FIG. 8 is a time chart showing the contents of double clutch control.
FIG. 9 is a flowchart showing a shift pattern determination program.
FIG. 10 is a flowchart showing the contents of a transmission A pattern.
FIG. 11 is a flowchart showing the contents of a shift B pattern.
FIG. 12 is a flowchart for setting ON time and OFF time.
FIG. 13 is a flowchart for determining solenoid valve operation permission.
FIG. 14 is a diagram showing a state of ON / OFF of a solenoid valve.
[Explanation of symbols]
2 Clutch
3 Transmission
6 Engine control unit
9 Transmission control unit
10 Clutch booster
17 Splitter
18 Main gear
19 Range gear
20 Splitter actuator
21 Main actuator
22 Range actuator
26 Countershaft rotation sensor
27 Countershaft brake
28 Output shaft rotation sensor
36 dog gear
43, 44, 45 Main gear sleeve
MV BRK solenoid valve
M₁  Set value
TON1 1st ON time
TON2 Second ON time
TOFF1 First OFF time
TOFF2 Second OFF time
ΔN rotation difference
ΔN₁  Predetermined value

Claims (1)

A transmission that includes a main gear that does not have a mechanical synchronization mechanism, and a shift control means that executes a shift control of the transmission, and that performs a predetermined synchronization control when shifting the main gear;
A countershaft brake for braking the countershaft of the transmission, and a countershaft brake control means for controlling the operation of the countershaft brake;
Upon the shifting of the main gear, the synchronous control by a predetermined countershaft brake control when the rotational speed difference by subtracting the sleeve rotates from Dogugiya rotation in the target main gear stage ΔN exceeds a first predetermined value M ₁ is a positive set value ,
In the counter shaft brake control, the counter shaft brake is operated intermittently, and the operation time ratio of the counter shaft brake is set to a large value and a small value so that the brake force of the counter shaft brake can be adjusted in two stages. And selectable from
The countershaft brake control means is configured such that, from the start to the end of the countershaft brake control , the rotation speed difference ΔN is reduced at every time interval smaller than the operation time of a small value of the operation time ratio of the countershaft brake . It is determined whether or not the second predetermined value ΔN ₁ is set to a value larger than the first predetermined value M ₁ , and when the rotational speed difference ΔN is the second predetermined value ΔN ₁ or more, The counter shaft brake operating time ratio is set to the above large value,
The automatic gear shifting of the vehicle, wherein when the rotational speed difference ΔN is less than the second predetermined value ΔN ₁ and exceeds the first predetermined value M ₁ , the operating time ratio of the countershaft brake is set to the small value. apparatus.

Images