SE518332C2 - Power units for motor vehicles - Google Patents

Abstract

Drive unit for motor vehicles, comprising an internal combustion engine (1) and a gearbox (9) connected to the engine via an automated clutch (3), said gearbox (9) consisting of a non-synchronized stepped main group and thereafter a two-range synchronized range group with a free position between its range positions. The clutch and the gearbox are controlled by an electronic control unit (45), to which there are fed signals representing the selected gear from a gear selector (46) and signals representing various engine and vehicle data. The control unit is disposed, when the vehicle is standing still and the gear selector in the free position, to keep the clutch engaged and the range group in the free position. When a gear is selected, the clutch is first disengaged, whereafter the range group is moved to one of the engaged positions to brake the intermediate shaft and make possible engagement of the gear in the main group. After engagement in the main group, the clutch is engaged.

Description

Ivan; 10 15 20 25 30 518 332. . . . - - u. ~ ø sn ø II '"2 ring means make it possible to make the gearbox shorter or alternatively to make the gears wider with a given length than in a synchronized gearbox with a corresponding length in order to thereby enable the transmission of higher torques .

When the vehicle is stationary and the gear selector is in the neutral position, the clutch is nominally engaged, so that torque is transmitted from the engine via the clutch to the input shaft of the gearbox and thereby also to its intermediate shaft. This is often used to drive the gearbox lubricating oil pump, which means that the gearbox bearing is in this way supplied with lubricating oil even in the neutral position of the gearbox when the clutch is engaged. When starting the vehicle, the clutch must first be fi engaged before a starting gear can be engaged. If the gear to be engaged is an asynchronous gear, the interlocking gears on the main axle and the intermediate axle must first be decelerated to at least almost stationary before The gearbox of the type in question usually has very small losses, which means that it would take too long from the time the clutch fi was engaged until the rotating parts of the gearbox stopped, unless the rotating parts were actively braked. somehow.

A known way is to use an intermediate shaft brake, which quickly decelerates the intermediate shaft to a standstill when the clutch is disengaged.

The object of the present invention is to provide a gearbox of the type stated in the introduction, which is designed in such a way that the intermediate shaft can be braked without the use of separate means, which only have the task of braking the intermediate shaft.

This is achieved according to the invention in that the control unit is arranged to - on the basis of zero vehicle speed, the clutch engaged and the gear selector in a neutral position - when moving the gear selector to the selected gear first disengage the clutch and then engage a synchronized gear to brake the intermediate shaft thereby enabling the insertion of an asynchronous gear.

In a gearbox which lacks a shift gear, the synchronized gear may be any of the forward gears of the gearbox, preferably any of its lower gears, 1:11: 30. , i. t. 518 332 3 which can be used as a starting gear. The control unit is arranged to, when selecting a starting gear which is unsynchronized, after decelerating the intermediate shaft with the synchronized gear, disengage it and then load the selected unsynchronized gear.

In a preferred embodiment of the drive unit according to the invention, the gearbox comprises a base part with a number of gears and a range part with a low gear and a high gear for each gear in the base part. The range part has coupling means with synchronizing function, which in addition to a low gear position and a high gear position has an intermediate neutral position. The control unit is hereby arranged to - on the basis of fi without zero vehicle speed, the clutch engaged and the gear selector in neutral position involving the gear unit coupling means in neutral position - when fl moving the gear selector to the selected gear first fi- engage the clutch, then insert the part of the gear and finally, as needed depending on the gear position in the base part, load the gear in the base part, which gives the selected total gear.

The invention is described in more detail with reference to exemplary embodiments shown in the accompanying drawings, in which fi g. 1 shows a schematic representation of a drive unit according to the invention and fig. 2 shows the clutch and gearbox in fi g. 1 on an enlarged scale.

I fi g. 1 denotes a six-cylinder internal combustion engine, for example a diesel engine, the crankshaft 2 of which is coupled to a single-disc dry single-clutch clutch generally designated 3, which is enclosed in a clutch housing 4. The crankshaft 2 is inextricably connected to the clutch housing 5 of the clutch 3, while its lamella plate 6 with an input shaft 7, which is rotatably mounted in the housing 8 of a gearbox generally designated 9. In the housing 8, a main shaft 10 and an intermediate shaft 11 are rotatably mounted.

As most clearly shown by fi g. 2, a gear 12 is rotatably mounted on the input shaft 7 and lockable on the shaft by means of a coupling sleeve 13 provided with synchronizing means, which is rotatably but axially displaceably mounted on one with the znsi 10 10. . 30 .. 0,, ~ I. . ; . - | . .- 51 s sszgægz; 4 is rotatably connected to the hub 14. By means of the coupling sleeve 13, a gear 15 rotatably mounted on the main shaft 10 is also lockable relative to the input shaft 7. The gears 12 and 15 engage with gears 16 and 17, respectively, which are rotatably connected to the intermediate shaft 11. Additional gears 18, 19 and 20 are rotatably arranged on the intermediate shaft 11, which engage with gears 21, 22 and 23, respectively, rotatably mounted on the main shaft 10, which are lockable on the main shaft by means of coupling sleeves 24 and 25, respectively, which in the case shown On the main shaft 10, a further gear 28 is rotatably mounted and engages with an intermediate gear 30 rotatably mounted on a separate shaft 29, which in turn engages with an intermediate shaft gear 20. The gear shaft 28 is axially lockable. by means of a coupling sleeve 26.

The gear pairs 12, 16 and 15, 17 and the clutch sleeve 13 form a split gear with a low gear stage LS and a high gear stage HS. The pair of gears 15, 17 together with the pair of gears 21, 18, 22, 19, 23, 20 and 28, 30 also form a basic gearbox with four forward gears and a reverse gear. At the output end of the main shaft 10, a gear 31 is arranged rotatably, which forms the sun gear in a planetary type two-speed gearbox designated 32, whose planet gear carrier 33 is rotatably connected to a shaft 34 which forms the output shaft of the gearbox. The planetary gear 35 of the range gear 32 engages with a ring gear 36, which by means of a coupling sleeve 37 can be locked relative to the gearbox housing 8 for low-range LR and relative to the planet gear carrier 33 for high-range HR. The coupling sleeve 37 also has a neutral position NR lying between the gear positions LR and HR, in which the output shaft 34 is disengaged from the main shaft 10.

The coupling sleeves 13, 24, 25, 26 and 37 are slidable as the arrows show in fi g. 2, whereby the gear steps shown in connection with the arrows are obtained. The displacement is achieved with fi g. 2, schematically indicated servos 40, 41, 42, 43 and 44, which may be pneumatically actuated piston-cylinder devices of the type used in a gearbox of the type described above, which is marketed under the name Geartronic®. The servo unit is controlled by an electronic control unit 45 (fi g. 1), comprising a rush: 10 15 20 =}: ß, _m 518 332 n. . | -. ~ nvnuu of 5 microcomputer, depending on the control unit input signals representing different engine and vehicle data, which include at least engine speed, vehicle speed, clutch and accelerator pedal position and, where applicable, engine brake on-off, when an electronic selector 46 connected to the controller 45 is in its automatic mode. When the selector is in the position for manual shifting, the shifting takes place at the driver's command via the shift selector 46. The control unit 45 also controls the fuel injection, ie the engine speed, depending on the accelerator pedal position and the air supply to a pneumatic piston-cylinder device 47, by which the clutch 3 is engaged and disengaged.

According to the invention, the control unit 45 is programmed so that the clutch 3 is engaged and the clutch sleeve 37 of the gear unit is in the neutral position, when the vehicle is stationary and the gear selector 46 is in the neutral position. This means that the motor drives the input shaft 7 and thus also the intermediate shaft 11, while the output shaft 34 is disengaged. Any attachments driven by the intermediate shaft, such as an oil pump for gearbox lubrication, are operated in this position. The control unit 45 is further programmed that, when the gear selector fl is moved n from the neutral position to a gear position, either to a position for automatic shifting or to a manual position with the starter gear selected by the driver, first disengage the clutch 3 and then set the gear in any of its gear positions LR or HR. In this case, the main shaft 10 is coupled to the stationary output shaft 34, which means that the main shaft 10 and with it also the intermediate shaft 11 are quickly decelerated to a standstill. If none of the gears 1-4 in the base gearbox are engaged or if any gear is engaged which does not give the selected total gear, the control unit now initiates shifting in the base gearbox to a gear which gives the automatic or the driver selected total gear, after which the clutch 3 is engaged again.

The invention has been described above with reference to a gearbox consisting of a base gearbox with a pre-engaged split gear and a geared gearbox, but is of course applicable to any unsynchronized gearbox which has at least one synchronized gear, which can be used as an intermediate axle brake. The control unit is hereby arranged to, regardless of which gear is selected as the starting gear, first load the synchronized gear in order to brake the intermediate shaft, then load the synchronous gear; 518 332 nu n | u n ø ø ~ | o ø n v '6 chronicled the gear in neutral (provided that the selected starting gear is not the synchronized gear) and finally put in the selected gear.

Claims (4)

: spur 10 15 20 25 518 332, n. . '. 'I,,,,,,. . a n v uu 7 Patentkrav Motor drive unit, comprising an internal combustion engine (1) and an input shaft (7) connected via an automated vane coupling (3) to the engine crankshaft (2) to a stepped gearbox (9) having at least one intermediate shaft mounted in a housing (11), which has at least one gear (16,17) in engagement with a gear (12,15) on the input shaft, a main shaft (10) mounted in the housing with gears (15,21,22, 23), which engages gears (17, 18, 19,20) on the intermediate shaft, the at least one gear in each pair of engaging gears on the intermediate shaft and the main shaft being rotatably mounted on its shaft and lockable by means of coupling means (13,24,25,26) , of which at least some forward gears (24,25,26) lack synchronizing function and at least one gear stage between an output shaft (34) and the intermediate shaft (1 1) has coupling means (37) with synchronizing function, and operating means cooperating with the coupling means (40,41,42,43), which are controlled by one with a gear selector (46) f connected control unit (45), in which signals representing the selected gear and various engine and vehicle data are input, which at least include engine speed, vehicle speed, clutch position and accelerator pedal position, characterized in that the control unit (45) is arranged to - based on zero vehicle speed, the clutch (3) engaged and the gear selector (46) in a neutral position - when moving the gear selector to the selected position, first disengage the clutch and then engage a synchronized gear (LR, HR) to brake the intermediate shaft (11) and thereby enable loading an unsynchronized gear. Drive unit according to claim 1, characterized in that the gearbox (9) comprises a base part with a number of gears (1-4, reverse) and a gear part with a low gear (LR) and a high gear (HR) for each gear in the base part and that the rank part has coupling means (37) with synchronizing function, which in addition to a low gear position and a high gear position has an intermediate neutral position (NR). : vina 10 518 332 ... . . . . . . .- 8 Drive unit according to Claim 2, characterized in that the control unit (45) is arranged so that - on the basis of zero vehicle speed, the clutch (3) is engaged and the gear selector (46) is in neutral position when the gear selector 'is moved to the selected position. disconnect the clutch, then insert the gear that depends on the selected total gear in the range part and then insert the gear in the base part, which gives the selected total gear. Drive unit according to Claim 2 or 3, characterized in that the main shaft (10) supports the sun gear (35) in a planetary gear (32) which has a planet gear carrier (33) which is connected to an output shaft (34) and planet gears (3 5), which engage with a ring wheel (36), which by means of the coupling means (37) is lockable relative to the housing or the output shaft.