JP4100057B2 - Shift control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shift control device for a vehicle equipped with an exhaust brake device.
[0002]
[Prior art]
For example, in a large vehicle, an exhaust brake device may be equipped as an auxiliary brake. The exhaust brake device is mainly composed of an exhaust brake valve provided in the exhaust path of the engine, and applies a braking force by closing the throttle path to some extent by closing the valve.
[0003]
For example, if the exhaust brake device is used when the vehicle is going down a long downhill, the vehicle can be decelerated without stepping on the brake pedal, preventing the brake disc from becoming hot, Can be improved.
[0004]
[Problems to be solved by the invention]
However, in a vehicle equipped with a shift control device that automatically shifts the transmission, when the exhaust brake device is used when the vehicle speed is relatively high, for example, when the exhaust brake device is used while traveling on a highway, etc. In general, since the gear stage of the transmission is located at a relatively high speed stage, the reduction ratio on the wheel side (driven side) with respect to the engine side (driving side) is small, and the braking force by the exhaust brake device cannot be obtained sufficiently. There is a case.
[0005]
Therefore, in order to secure a larger braking force, a shift control device has been devised that automatically shifts down the transmission as the exhaust brake device operates when the vehicle speed is relatively high.
[0006]
For example, a shift control device described in Japanese Patent Laid-Open No. 10-246321 has a shift down interlock switch separately from the exhaust brake operation switch, and the driver turns on both the exhaust brake operation switch and the shift down interlock switch. In this case, the exhaust brake device is operated and the shift down control of the transmission according to the vehicle speed is executed.
[0007]
However, in Japanese Patent Laid-Open No. 10-246321, the transmission control is performed when the downshift control is released (the downshift interlock switch is turned off) after the transmission is downshifted together with the operation of the exhaust brake device. Has not been proposed.
[0008]
An object of the present invention is to provide a transmission control device having means for downshifting the transmission when the exhaust brake device is operated, so that the driver can obtain a good feeling when the downshift control is released. An object of the present invention is to provide a shift control device that performs optimal control.
[0009]
[Means for Solving the Problems]
  In order to achieve the above object, the present invention is provided in a vehicle equipped with an exhaust brake device, and is a gear shift that automatically shifts a transmission according to a shift control means that basically determines the gear stage of the transmission based on the driving state of the vehicle. An exhaust brake device switching means for switching between operation and non-operation of the exhaust brake device, and for shifting down the transmission regardless of the shift control means when the exhaust brake device is operated. Downshift control means;StrangeGear position detecting means for detecting the gear stage of the speed machine, means for storing the gear stage before the downshift by the downshift control means, and after the downshift by the downshift control means has been executed,UpShift up control means for shifting up the transmission to the stored gear position before downshifting when the exhaust brake device switching means is switched to the non-operating side.The shift-up control means stores the gear stage determined by the shift control means based on the driving state of the vehicle at that time even when the exhaust brake device switching means is switched to the non-operating side. The above upshift is not executed if the gear is not in the gear position before the downshift.Is.
[0010]
  Also,Means for storing the gear stage after the downshift by the downshift control means;The shift up control means includes:UpEven when the exhaust brake device switching means is switched to the non-operating side,When the gear stage of the transmission is not the gear stage after the downshift stored aboveIt is preferable not to execute the above-mentioned upshift.
[0011]
  Also, the downshift by the downshift control meansShift down control switching to switch between execution and non-executionMeans for further upshifting,After the downshift by the downshift control means is executed, when the downshift control switching means is switched to the non-execution side, the transmission is shifted up to the stored gear stage before the downshift, AndWhen the shift down control switching means is switched to the non-execution sideKidEven if there isWhen the gear stage determined by the shift control means based on the driving state of the vehicle is other than the gear stage before the downshift stored.It is preferable not to execute the above-mentioned upshift.
  The shift-down control means further comprises means for storing the gear stage after the downshift by the downshift control means, and the upshift control means is operable even when the downshift control switching means is switched to the non-execution side. It is preferable not to execute the upshift when the gear stage of the transmission is not the gear stage after the stored downshift.
[0012]
Further, the shift down control means includes means for calculating an engine rotation speed after the downshift based on the driving state of the vehicle at the time before executing the downshift, and the calculated engine rotation speed is a predetermined value. It is preferable not to execute downshifting when the overrun rotational speed is higher than.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
[0014]
This embodiment is applied to the automatic transmission disclosed by the present applicant in Japanese Patent Laid-Open No. 2001-263472. First, an outline of the automatic transmission will be described.
[0015]
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 rotational speed and the engine load from the outputs of the engine rotational sensor 7 that detects the rotational speed of the engine and the accelerator opening sensor 8 that detects the accelerator opening, and based on these, the fuel The electronic governor 1d of the injection pump 1a is controlled to control the fuel injection timing and the fuel injection amount. On the other hand, during the speed change of the transmission 3, 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.
[0016]
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 (rotation speed).
[0017]
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.
[0018]
As shown in FIG. 2, the clutch 2 is a mechanical friction clutch, a flywheel 1b on the input side, a driven plate 2a on the output side, and a pressure plate 2b that frictionally contacts or separates the driven plate 2a from the flywheel 1b. Consists of The clutch 2 operates the pressure plate 2b in the axial direction by the clutch actuator 10 (see FIG. 1), 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 (see FIG. 1) is also possible here. This is a configuration of a so-called selective auto clutch. As shown in FIG. 1, 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 (depression amount) of the clutch pedal 11 are provided. It is connected to the.
[0019]
As clearly shown in FIG. 3, the clutch actuator (clutch booster) 10 is connected to the air tank 5 through two systems of pneumatic 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 actuator 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.
[0020]
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 blocked 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, OFF when 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 actuator 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 actuator 10 is discharged from the MVC 2 and the clutch is connected.
[0021]
However, if an abnormality occurs in the electromagnetic valve MVC1 or MVC2 during clutch separation 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 actuator 10 to maintain the clutch disengaged state and prevent sudden clutch engagement.
[0022]
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 actuator 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 actuator 10. When the automatic connection / disconnection of the clutch 2 interferes with the manual connection / disconnection, the manual connection / disconnection is prioritized.
[0023]
As shown in detail in FIG. 2, the transmission 3 is a multi-stage transmission that is basically meshed with a main shaft (main shaft) 33 and a counter shaft (counter shaft) 32, and has 16 forward speeds and 2 reverse speeds. Shifting is possible. 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.
[0024]
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 actuator 10 and controlled by the TMCU 9. The current position (current gear position) of each gear 17, 18, 19 is detected by a gear position switch 23 (see FIG. 1). The rotational speed of the secondary shaft 32 is detected by the secondary shaft rotation sensor 26, and the rotational speed of the output shaft 4 is detected by the output shaft rotation sensor 28. These detection signals are sent to TMCU9.
[0025]
The TMCU 9 calculates the current vehicle speed based on the current output shaft rotation speed detected by the output shaft rotation sensor 28, and displays this on the speedometer.
[0026]
In this automatic transmission, a manual mode is set, and a manual shift based on a driver's shift change operation is also 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 change device 29 provided in the driver's seat as a signal. That is, when the driver shifts the shift lever 29a of the shift change device 29, the shift switch built in the shift change device 29 is activated (ON), and a shift instruction signal is sent to the TMCU 9, based on which the TMCU 9 The clutch actuator 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.
[0027]
In the shift change device 29 shown in FIG. 1, R means reverse, N means neutral, D means drive, UP means manual shift up position, and DOWN means manual shift down position. 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 the manual shift mode and the automatic shift mode, and a skip switch 25 for switching whether the shift is performed step by step or step skipping.
[0028]
When the shift lever 29a is positioned in the D range in the automatic transmission mode, the transmission 3 basically follows a shift-up map and a shift-down map (hereinafter sometimes referred to simply as a shift map). Automatic shifting is performed. If the driver manually operates the shift lever 29a to the manual shift-up position (UP) or the manual shift-down position (DOWN) during the automatic shift mode, the transmission 3 according to the driver's manual operation regardless of the shift map. Are shifted up or down. At this time, if the skip switch 25 is OFF (normal mode), the shift is performed step by step by one operation 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 shift is performed by skipping one step. This is effective when the trailer is not towed or when the load is light.
[0029]
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 shift is performed, 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 shift is performed one step at a time, and if the skip switch 25 is ON, the shift is skipped by one step. In this mode, the D range is an H (hold) range that holds the current gear stage.
[0030]
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.
[0031]
As shown in FIG. 2, in the transmission 3, the input shaft 15, the main shaft 33, and the output shaft 4 are arranged coaxially, and the sub 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.
[0032]
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. Gear MR is always meshed with idle reverse gear IR, and idle reverse gear IR is always meshed with counter gear CR fixed to countershaft 32.
[0033]
The gears SH, M4,... Attached to the input shaft 15 and the main shaft 33 are integrally provided with a dog gear 36 so that the gear can be selected, and the input shaft 15 and the main shaft 33 are first adjacent to the dog gear 36. -The 4th hubs 37-40 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 at the same time as the input shaft 15 or the main shaft 33, and slide back and forth to selectively engage / disengage the dog gear 36. That is, the hub 37 and the dog 36 in the splitter 17 and the dog 36 on the countershaft 32 side and the hubs 37 to 40 on the main shaft 33 side in the main gear 18 are engaged and disengaged by the sleeves 42 to 45, so that gear-in / gear-out is achieved. Done. 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.
[0034]
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. Further, the splitter 17 has a normal mechanical sync mechanism in its spline part, but each gear stage of the main gear 18 is a non-synchronous gear stage in which no sync mechanism exists in each spline part. For this reason, when a shift with a shift of the main gear 18 is executed, a sync control described later is performed to synchronize (synchronize) the dog gear rotation speed on the auxiliary shaft 32 side with the sleeve rotation speed on the main shaft 33 side. It is possible to shift without any. 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).
[0035]
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 rearmost 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 engaged with the outer periphery of the planetary gear 66. . 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.
[0036]
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.
[0037]
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) greater than 1. This is the low position.
[0038]
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.
[0039]
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.
[0040]
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.
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.
[0041]
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. The pneumatic cylinder 48 is provided with three solenoid valves MVC, MVD and MVE, and the pneumatic cylinder 49 is provided with two solenoid valves MVB and MVA.
[0042]
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.
[0043]
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.
[0044]
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.
[0045]
By the way, a countershaft (counter shaft) brake means 27 is provided on the subshaft 32 in order to decelerate and brake the subshaft 32 in the synchro control described later. The countershaft brake means 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, the air pressure is supplied to the countershaft brake means 27, and the countershaft brake means 27 is activated. When the solenoid valve MV BRK is OFF, the air pressure is discharged from the countershaft brake means 27, and the countershaft brake means 27 is deactivated.
[0046]
Next, the contents of the sync control in the case of performing a shift with gear-in of each gear stage of the main gear 18 that is a non-synchronized gear stage will be described.
[0047]
As shown in FIGS. 4 and 5, 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 determines the dog gear at the gear stage (target main gear stage) of the main gear 18 as the next shift destination based on the number of gear teeth of the main gear 18 and the countershaft rotation speed (rpm) detected by the countershaft rotation sensor 26. Calculate the number of revolutions (rpm). Further, the TMCU 9 rotates the sleeve in 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 speed (rpm) detected by the output shaft rotation sensor 28. Calculate the number (rpm). Here, since the sleeve is fitted to the hub of the main shaft, naturally, the number of rotations of the sleeve is equal to the number of rotations of the hub.
[0048]
In the left column of the table of FIG. 5, 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.
[0049]
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”.
[0050]
The right column of the table in FIG. 5 shows a formula for calculating the dog gear rotation speed (rpm) on the sub shaft 32 side. For example, if the target main gear stage is “1st”, the gear ratio Z_C1/ Z₁ Is a rotation of the dog gear 36 fixed to the gear M1, that is, a dog gear rotation speed (rpm). At the target main gear stage “Rev”, the reduction ratio C is added to the countershaft rotation speed (rpm)._Rev The value multiplied by is the dog gear rotation speed (rpm).
[0051]
On the other hand, the lower part of FIG. 5 shows a calculation formula for the rotation of the sleeves 43, 44, 45 on the main shaft 33 side, that is, the sleeve rotation speed (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 speed (rpm)) becomes the sleeve rotation speed (rpm) as it is. When the target range gear is Low, the reduction ratio is C_RG= 4.5, so the output shaft rotation speed (rpm) and the reduction ratio C_RGThe value multiplied by is the sleeve rotation speed (rpm).
[0052]
In the synchro control, control is performed so that the dog gear rotation speed interlocked with the sub-shaft 32 and the sleeve rotation speed (hub rotation speed) on the main shaft 33 side are brought within a gear-in range. Specifically, a rotation difference Δ = (dog gear rotation speed−sleeve rotation speed) is calculated, and control is performed to put this value in a gear-in range. For example, when the gear speed of the gear shift destination is greater than the number of rotations of the sleeve, such as during upshifting, after disengaging the clutch 2 and releasing the gear, the countershaft brake means (hereinafter referred to as CSB) is used. ), The countershaft 32 is decelerated and braked to reduce the dog gear rotation speed and synchronize. On the other hand, when the gear speed of the shift destination is smaller than the number of rotations of the sleeve, such as when shifting down, double clutch control is performed to increase the dog gear rotation and synchronize.
[0053]
Double clutch control is as follows. As shown in FIG.₁ When 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.₁ Start with. For engine control, the clutch position is p₁ From that point, control is shifted to the control based on the pseudo accelerator opening away from the actual accelerator opening. At this time, the ECU 6 sets the target engine speed X corresponding to the target countershaft speed Y required to synchronize the dog gear speed on the countershaft 32 side and the sleeve speed on the main shaft 33 side in the gear stage of the speed change destination. The actual engine speed is increased to the target engine speed X and held constant. In the present embodiment, the target engine rotational speed X is the actual output shaft rotational speed, the gear of the target gear stage of the shift destination (the gear stage in the entire transmission, one of 1 to 16 speeds). The target engine speed X is calculated by multiplying the ratio. Thus, if the target engine speed X is calculated directly from the output shaft speed, the calculation becomes easy and the control can be simplified.
[0054]
After the gear is disengaged, the clutch is momentarily connected, whereby the rotation speed of the countershaft 32 rises to the vicinity of the target countershaft rotation speed Y, and the rotation difference between the dog gear rotation speed and the sleeve rotation speed falls within a gear-in range. 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.₂ Starts 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 the countershaft rotation speed shift to rotation according to the actual accelerator opening.
[0055]
The shift control device controls the transmission 3, the engine 1, and the clutch 2 at the time of shifting. In the present embodiment, the shift control device includes an ECU 6, a TMCU 9, a clutch actuator 10, a gear shift unit GSU, and the like. The contents of control by this shift control device will be described below.
[0056]
As shown in FIGS. 7 and 8 respectively, the TMCU 9 stores a shift-up map and a shift-down map that predetermine the range of each gear stage of the transmission 3 based on the driving state of the vehicle. In the automatic transmission mode, the transmission 3 is basically shifted according to these shift maps. Therefore, the “shift control means” in “Claims” is this shift map in this embodiment.
[0057]
For example, in the shift-up map of FIG. 7, the shift-up line from the gear stage n (n is an integer from 1 to 15) to n + 1 is determined by a function of the accelerator opening (%) and the output shaft rotational speed (rpm). ing. On the map, only one point is determined from the actual accelerator opening (%) detected by the accelerator opening sensor 8 and the actual output shaft rotation speed (rpm) detected by the output shaft rotation sensor 28. During vehicle acceleration, the rotational speed 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 shift-up line, the gear is shifted up by one step. At this time, in the skip mode, the upshift lines are alternately skipped one by one, and the upshift is performed by two stages.
[0058]
Similarly, in the downshift map of FIG. 8, the downshift line 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 speed (rpm). It has been decided. On the map, only one point is determined from the actual accelerator opening (%) and the output shaft speed (rpm). Since the rotation speed of the output shaft 4 gradually decreases during deceleration of the vehicle, in the normal automatic transmission mode, the gear is shifted down by one step each time the current point exceeds each shift down line. In the skip mode, the downshift lines are alternately skipped one by one and shifted down by two stages.
[0059]
Now, the shift control device of the present invention is applied to a vehicle equipped with an exhaust brake device, and the exhaust brake device will be described with reference to FIG.
[0060]
As shown in FIG. 9, the exhaust brake device 71 is mainly configured by an exhaust brake valve 72 provided in an engine exhaust path 70 and an exhaust brake actuator 73 that opens and closes the exhaust brake valve 72. The exhaust brake actuator 73 is actuated by a signal from the ECU 6.
[0061]
When the exhaust brake device 71 is not operated, the exhaust brake valve 72 is fully opened by the exhaust brake actuator 73. On the other hand, during operation, the exhaust brake valve 72 is operated in the closing direction, and the exhaust passage 70 is closed (throttle). As a result, a braking force is generated.
[0062]
The driver's cab is provided with an exhaust brake operating lever 74 that can be manually operated by a driver. By operating the lever 74, the exhaust brake device 71 can be switched between operation and non-operation. The exhaust brake operating lever 74 is provided so as to be able to reciprocate in the front-rear direction. Position A is pushed in most, position B is pulled one position before from position A, and position is pulled one position before from position B. It can be operated in three positions with C. A lever switch 75 provided on the exhaust brake operation lever 74 outputs a signal corresponding to the current position of the exhaust brake operation lever 74 to the ECU 6 or TMCU 9.
[0063]
When the exhaust brake operating lever 74 is positioned at the position A, the exhaust brake device 71 is in an inoperative state (released state). Therefore, it can be said that the position A is an exhaust brake non-operation position.
[0064]
When the exhaust brake operation lever 74 is positioned at the position B, the exhaust brake 71 is operated. That is, a signal is output from the lever switch 75 to the ECU 6, and the exhaust brake actuator 73 closes the exhaust brake valve 72 by the signal from the ECU 6. In this position B, the downshift control described later is not executed. Therefore, it can be said that the position B is an exhaust brake operation + shift down control non-execution position.
[0065]
When the exhaust brake operating lever 74 is positioned at the position C, the exhaust brake device 71 is operated, and the transmission 3 is shifted by a predetermined stage (in this embodiment, one stage) in order to ensure a larger braking force. Down. That is, when the exhaust brake lever 74 is positioned at the position C, the exhaust brake device 71 is operated in the same manner as at the position B, and a signal is output from the lever switch 75 to the TMCU 9 so that the transmission 3 becomes the shift map. Are shifted down one stage independently. Therefore, it can be said that the position C is an exhaust brake device operation + shift down control execution position.
[0066]
As described above, in the present embodiment, the exhaust brake operating lever 74 can be used to switch between operation / non-operation of the exhaust brake device 71 and execution / non-execution of shift down control linked to the operation of the exhaust brake device 71. It has become. Therefore, the exhaust brake operating lever 74 also has a function as a shift down control switching means. However, the present invention is not limited in this respect. For example, the exhaust brake operation lever 74 may simply be configured to switch between operation and non-operation of the exhaust brake device 71, and a switch for switching execution / non-execution of the shift down control may be provided separately.
[0067]
Even if the exhaust brake operating lever 74 is positioned at the position B or the position C and switched to the operating side of the exhaust brake device 71, the exhaust brake device 71 is not operated when the depression of the accelerator pedal by the driver is detected. It is said. This is because it is difficult to think that the driver wants a big deceleration. In short, the exhaust brake device 71 operates only when the two conditions that the exhaust brake operating lever 74 is switched to the operating side (position B or C) and the accelerator is not depressed are satisfied.
[0068]
When the exhaust brake operating lever 74 is located at the position B and the position C, the driver is notified by means such as a lamp (not shown) provided at the driver's seat.
[0069]
In the present invention, when the transmission 3 is downshifted in accordance with the operation of the exhaust brake device in order to ensure a larger braking force of the exhaust brake device, the shift down control is subsequently released (not executed). Improvements have been made to improve the feeling when the exhaust brake device 71 is released (or deactivated).
[0070]
As basic control, the gear stage before the downshift is stored when the transmission 3 is downshifted in accordance with the operation of the exhaust brake device 71, and then when the downshift control is released, or the exhaust When the brake device 71 is released, the transmission 3 is shifted up to the gear stage before the shift down stored. As a result, the feeling felt by the driver returns to almost the same as before the shift-down control. Since the driver will remember the feeling before executing the downshift control as a sensation, it can be reassured by returning to the same feeling when the downshift control is stopped.
[0071]
To explain with an example, it is assumed that the vehicle is currently running with the exhaust brake device 71 in an inoperative state (lever position A). After that, when the vehicle slowly descends and the driver positions the lever 74 at the position B, the exhaust brake device 71 is activated and a braking force (deceleration force) is applied to the vehicle. Then, when the vehicle approaches a steep downhill, the driver positions the lever 74 at the position C in order to secure a larger braking force. As a result, the transmission 3 is automatically shifted down, and a large braking force acts on the vehicle. Subsequently, when a steep slope is finished and an attempt is made to travel on a gentle downhill again, the driver returns the lever 74 to the position B because it is not necessary to secure a large braking force. At this time, the transmission 3 is shifted up to the same gear stage (gear stage before downshifting) as when traveling in the position B before. Therefore, the deceleration feeling felt by the driver is the same as when traveling in the position B before.
[0072]
This will be described below with reference to the flowchart of FIG. Note that the flowchart described below is repeatedly executed by the TMCU 9 every predetermined time (ex. 32 msec).
[0073]
First, the downshift control will be described.
[0074]
First, in step S1, it is determined whether or not the exhaust brake operating lever 74 is located at the position C. That is, it is determined whether the exhaust brake device 71 is switched to the operating side and the shift down control is switched to the execution side.
[0075]
If it is determined in step S1 that the exhaust brake operating lever 74 is located at the position C, the process proceeds to step S2 where the accelerator opening detected by the accelerator opening sensor 8 is greater than the set value (here 1%). It is determined whether or not it is small. This set value is set to the same value as the value for releasing the operation of the exhaust brake device 71.
[0076]
If it is determined that the accelerator opening is smaller than the set value, the process proceeds to step S3 and whether or not nothing is stored in the memory area of the storage stage 1 provided in the TMCU 9 (memory stage 1 = 0). Determine. If any gear stage is already stored as the storage gear stage 1 when the previous flow is executed, it is not necessary to store the gear stage, and the process ends.
[0077]
When it is determined in step S3 that the storage stage 1 = 0, the process proceeds to step S4, and the temporary target gear stage 1 is set to a gear stage that is one stage lower than the current gear stage. Here, description will be made assuming that the current gear stage is 12th. Accordingly, 11th is set as the temporary target gear stage 1.
[0078]
Next, the process proceeds to step S5, and the engine rotation speed when the transmission 3 is shifted down to the temporary target gear stage 1 is calculated based on the current output shaft rotation speed and the gear ratio of the temporary target gear stage 1 (11th). Then, it is determined whether the calculated engine speed is equal to or higher than a predetermined overrun speed. The overrun rotation speed is 90% of the maximum engine rotation speed, for example.
[0079]
If it is determined in step S5 that the calculated engine speed is equal to or higher than the overrun speed, the process ends. That is, even if the exhaust brake operating lever 74 is located at the position C, if it is determined that the engine is in an overrun state after the downshift, the downshift is not executed.
[0080]
If it is determined in step S5 that the calculated engine rotational speed is smaller than the overrun rotational speed, the process proceeds to step S6, and the temporary target gear stage 1 (11th) is set as the target gear stage.
[0081]
Next, the process proceeds to step S7, where the current gear stage (12th) is stored as the storage stage 1, and then the process proceeds to skip S8, where the target gear stage (11th) is stored as the storage stage 2, and the process ends.
[0082]
Thereafter, the transmission 3 is shifted down to the target gear stage (11th) regardless of the shift map. As a result, the reduction ratio on the wheel side with respect to the engine side is increased, and the braking force by the exhaust brake device 71 can be increased.
[0083]
As described above, when performing the downshift control, the TMCU 9 stores the gear stage before the downshift as the storage stage 1 and stores the gear stage after the downshift as the storage stage 2.
[0084]
Next, after the downshift is performed, the downshift control or the upshift control when the exhaust brake device is released will be described.
[0085]
When the downshift control or the exhaust brake device is released means that the position of the exhaust brake operating lever 74 is determined not to be position C in step S1 of FIG. 10, or the accelerator opening is greater than or equal to the set value in step S2. In this case, the process proceeds to step S9 to determine whether the storage stage 1 of the TMCU 9 is 0 or not.
[0086]
In step S9, when the storage stage 1 = 0, that is, when no gear stage is stored as the storage stage 1, this means that the shift-down by the above-described shift-down control has not been performed, and the process ends. This is the case, for example, when it is determined that the engine speed calculated in step S5 is equal to or higher than the overrun speed. In step S9, the storage stage 2 may be used instead of the storage stage 1.
[0087]
If it is determined in step S9 that one of the gear stages (here, 12th) is stored in the storage stage 1, the process proceeds to step S10, and the current gear stage of the transmission 3 is stored in the storage stage 2 stored in step S8. It is determined whether it is the same as (11th).
[0088]
If the current gear stage is not equal to the storage stage 2, the process proceeds to step S12, the storage stage 1 is reset (storage stage 1 = 0), and then the storage stage 2 is reset in step S13 (storage stage 2 = 0) to finish. The fact that the current gear stage is not equal to the storage stage 2 is, for example, a case where a shift change is performed by manual operation of the driver after the above-described shift down control is performed. Since shifting up to the previous gear stage is not preferable, the process ends.
[0089]
On the other hand, when it is determined in step S10 that the current gear stage of the transmission 3 is the storage stage 2 (11th), the process proceeds to step S11, and the storage stage 1 (12th) stored in step S7, that is, before the shift down. Is set as the target gear stage.
[0090]
Subsequently, the storage stage 1 is reset in step S12, and the storage stage 2 is reset in step S13. Thereafter, the transmission 3 is shifted up to the gear stage (12th) before the shift-down control. Therefore, the feeling felt by the driver is the same as before the shift down control is executed. Thereafter, the transmission 3 is automatically shifted by the TMCU 9 according to the shift map.
[0091]
Here, when the driving state of the vehicle greatly changes after executing the downshift control, it is not preferable to shift up to the gear stage before the downshift when the downshift control or the exhaust brake device is released. There is.
[0092]
Therefore, in order to prevent shifting up to an inappropriate gear stage with respect to the driving state of the vehicle, a flowchart shown in FIG. 11 is provided between step S10 and step S12 shown in FIG. Also good.
[0093]
That is, when it is determined in step S10 of FIG. 10 that the current gear stage is the storage stage 2 (11th), the process proceeds to step S11a of FIG. 11, and the storage stage 1 (12th) stored in step S7 of FIG. That is, the gear stage before the downshift is set as the temporary target gear stage 2.
[0094]
Next, proceeding to step S14, one point on the shift map determined from the current driving state of the vehicle (output shaft rotation speed and accelerator opening) is the temporary target gear stage 2 (12th) set in step S11a. Determine if it is within range. The range of the gear stage on the shift map will be described later. In short, it is determined here whether or not the temporary target gear stage 2 is a (suitable) gear stage that matches the current driving state of the vehicle.
[0095]
When it is determined in step S14 that one point on the shift map based on the driving state of the vehicle at that time is within the range of the temporary target gear stage 2, the process proceeds to step S15, and the temporary target gear stage 2 (12th) is set. Set as the target gear. Next, the process proceeds to step S12 shown in FIG. 10, the storage stage 1 is reset, and the process proceeds to step S13, where the storage stage 2 is reset and the process ends. Therefore, the transmission 3 is shifted up to the gear stage (12th) before the downshift.
[0096]
On the other hand, if it is determined in step S14 of FIG. 11 that one point on the shift map based on the current driving state of the vehicle is outside the range of the temporary target gear stage 2, the process proceeds to step S16 and the target gear stage is shifted. Set the gear according to the map. Then, the storage stage 1 is reset in step S12 shown in FIG. 10, the storage stage 2 is reset in step S13, and the process ends. Therefore, the transmission 3 is shifted to the gear stage according to the shift map. That is, when the gear stage before the downshift control is not commensurate with the current driving state of the vehicle, the shift is performed according to the shift map. This prevents shifting to a gear stage that is inappropriate for the driving state of the vehicle.
[0097]
Here, the gear range on the shift map will be described with reference to FIG. In FIG. 12, the horizontal axis represents the output shaft rotation speed of the transmission (corresponding to the vehicle speed), and the vertical axis represents the accelerator opening.
[0098]
FIG. 12 shows the shift-up line shown in FIG. 7 and the shift-down line shown in FIG. 8 as one shift map. As shown in FIG. The range of each gear stage of the transmission 3 is determined.
[0099]
For example, it is assumed that the vehicle is traveling at the 11th gear stage (A). Thereafter, when the vehicle accelerates and crosses the shift-up line from 11 to 12th, the transmission 3 is shifted up to 12th (B). Similarly, if the shift up line from 12 to 13th is exceeded, the shift is further shifted up to 13th (C).
[0100]
When the vehicle that has been shifted up to 13th decelerates, the transmission 3 is shifted down to 12th when the shift down line from 13 to 12th is exceeded (D). Similarly, when the shift down line of 12 → 11th is exceeded, the shift down is performed to 11th (E).
[0101]
Here, it can be seen that the transmission 3 always becomes 11th in the region between the shift-up line from 10 → 11th and the shift-down line from 12 → 11th. Therefore, this area is the 11th area. The region between the 12 → 11th shift-down line and the 11 → 12th shift-up line is the 11th or 12th region, and the 11 → 12th shift-up line and 13 → 12th shift-down. A region between the lines is a 12th region, and a region between the 13 → 12th shift-down line and the 12 → 13th shift-up line is a 12th or 13th region. Thus, the range of the gear stage is determined by each shift up line and shift down line.
[0102]
Therefore, for example, the range of the gear stage 12th is a region between the shift-down line L1 from 12 to 11th and the shift-up line L2 from 12 to 13th, as indicated by hatching in FIG. This is because when the shift is performed according to the shift map, the transmission 3 is not positioned at 12th except in the shaded area (12th is an area that cannot exist). After all, the “gear range” means a range or a region where the gear stage can exist on the shift map.
[0103]
Therefore, in step S14 in FIG. 11, it is determined whether or not the current one point is within the range indicated by hatching in FIG. If the current point is within the hatched range (for example, P1), the temporary target gear stage 2 (12th) is set as the target gear stage as shown in step S15 of FIG. . That is, if the current point is within the hatched range, the transmission 3 is always shifted up to 12th. On the other hand, if the current point is outside the hatched range (for example, P2 or P3), it can be determined that the temporary target gear stage 2 (12th) is an inappropriate gear stage that does not match the driving state of the vehicle. As shown in step S16 of FIG. 11, the target gear is set to a gear (11th or 13th) according to the shift map.
[0104]
So far, the shift-down control has been described as shifting the transmission 3 down by one stage, but the present invention is not limited in this respect, and may be shifted down by two or more stages.
[0105]
Further, the present invention is not limited to the shift control device described so far, and can naturally be applied to other shift control devices.
[0106]
【The invention's effect】
As described above, according to the present invention, in the speed change control device having means for controlling the downshift of the transmission when the exhaust brake device is operated, the fee when the downshift control is released or when the exhaust brake device is released. The excellent effect of improving the ring is exhibited.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an automatic transmission for a vehicle according to an embodiment of the present invention.
FIG. 2 is a configuration diagram showing an automatic transmission.
FIG. 3 is a block diagram showing an automatic clutch device.
FIG. 4 shows the number of teeth of each gear in the transmission.
FIG. 5 shows calculation formulas for dog gear rotation and sleeve rotation.
FIG. 6 is a time chart showing the contents of double clutch control.
FIG. 7 is a shift-up map.
FIG. 8 is a downshift map.
FIG. 9 is a schematic view of an exhaust brake device.
FIG. 10 is a flowchart showing a downshift control that accompanies the operation of the exhaust brake device and an upshift control when the downshift control is released.
FIG. 11 is a flowchart for determining whether or not the gear stage before the downshift is a gear stage commensurate with the driving state of the vehicle.
FIG. 12 is a diagram for explaining a range of a gear stage determined by a shift map.
[Explanation of symbols]
3 Transmission
6 Engine control unit
8 Accelerator position detection means
9 Transmission control unit
71 Exhaust brake device
74 Exhaust brake operating lever

Claims (4)

A shift control device that is provided in a vehicle equipped with an exhaust brake device and that automatically shifts the transmission according to a shift control means that basically determines the gear stage of the transmission based on the driving state of the vehicle,
Exhaust brake device switching means for switching between operation and non-operation of the exhaust brake device;
Downshift control means for shifting down the transmission independently of the shift control means when the exhaust brake device is operated;
And the gear position detection means for detecting a gear stage of the speed change machine,
Means for storing the gear stage before downshift by the downshift control means;
After shift down by the downshift control means is executed, the upper Symbol exhaust brake system switching means when it is switched to the non-actuating side, to shift up the transmission to the gear before the shift-down that the storage Shift up control means ,
The shift up control means includes:
Even when the exhaust brake device switching means is switched to the non-operating side, the gear stage determined by the shift control means based on the driving state of the vehicle at that time is other than the stored gear stage before the downshift. In some cases, the shift control apparatus does not execute the upshift . Means for storing the gear stage after the downshift by the downshift control means;
The shift up control means includes:
Claims above Stories exhaust brake system switching means even when switched into the inactive side, which does not perform the shift-up when the gear position of the transmission at that time is not the gear stage after downshifting that the storage The shift control device according to 1. Further comprising shift down control switching means for switching execution / non-execution of the downshift by the downshift control means,
The shift up control means includes:
After the downshift by the downshift control means is executed, when the downshift control switching means is switched to the non-execution side, the transmission is shifted up to the stored gear stage before the downshift, and even-out bets the shift down control switching means is switched to the non-execution side, except the gear stage before shifting down the gear stage to be determined is the storage by the shift control means based on the operating condition of the vehicle at that time shift control device according to claim 1 Symbol placement not perform the shift-up when it is. Means for storing the gear stage after the downshift by the downshift control means;
The shift up control means includes:
4. The shift-up is not executed even when the shift-down control switching means is switched to the non-execution side when the gear stage of the transmission at that time is not the gear stage after the stored downshift. Shift control device.

Images