JP2005127485A - Engine speed control device of hybrid transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine speed control device of a hybrid transmission, preventing overspeed of an engine, and securing the mechanical durable reliability of a differential gear transmission. <P>SOLUTION: The hybrid transmission includes: a differential gear transmission having a planetary gear train in which a first motor generator MG1 and a second motor generator MG2 are disposed on both end positions of a lever on an alignment chart, an engine E and an output shaft OUT are disposed in the lever inside position and an engagement element for selecting two or more running modes; an engine clutch EC provided in the midway position of an input route from the engine E and connected by frictional force. The hybrid transmission includes: an engine speed sensor for detecting the speed of the engine E; and an engine speed control means for performing semi-clutch control for making sliding connection of the engine clutch EC when the engine speed Ne in the highest speed range is detected by the engine speed sensor 9. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an engine speed control device for a hybrid transmission having an engine clutch on an engine output shaft.

Conventionally, in a hybrid transmission using a differential gear transmission that uses one engine and two motor generators as power sources, there are four sun gears S1, ring gear R, carrier C, and second sun gear S2 on the collinear diagram. It constitutes a four-element, two-degree-of-freedom planetary gear mechanism in which input / output elements are arranged. One of two elements (ring gear R and carrier C) arranged on the inner side is input In from the engine, and the other is a drive system. Is assigned to each of the two outer elements (first sun gear S1 and second sun gear S2). As a result, the torque on the motor generator side with respect to the engine output can be reduced to reduce the size, and the energy passing through the motor generator can be further reduced, so that the transmission efficiency as a drive device is improved (for example, patents) Reference 1).
JP 2003-32808 A

  However, in a conventional hybrid transmission, in a traveling scene in which the maximum vehicle speed is obtained with the high-side continuously variable transmission ratio mode selected, the engine speed is the highest and the second motor generator speed is high. For example, in a driving scene where the vehicle speed further increases due to inertia by shifting from a flat road to a downhill, the engine speed and the second motor generator speed exceed the allowable speed. There was a problem that the mechanical durability of the planetary gear became severe.

  The present invention has been made by paying attention to the above problems, and provides an engine speed control device for a hybrid transmission that prevents engine over-rotation and ensures the mechanical durability reliability of a differential gear transmission. The purpose is to provide.

In order to achieve the above object, according to the present invention, a power source having an engine, at least a first motor generator and a second motor generator, and each of the power source and the output member are coupled to a rotating element, respectively. A planetary gear train in which a first motor generator and a second motor generator are disposed at both lever positions on the diagram, and an engine and an output member are disposed at lever inner positions; and an engagement element for selecting a plurality of travel modes; An engine clutch that is provided at a midway position in an input path that connects an output shaft of the engine and an engine input rotation element of the differential gear transmission, and is fastened by a frictional force; In a hybrid transmission with
Engine speed detecting means for detecting the engine speed, and engine speed for performing half-clutch control for slidingly engaging the engine clutch when the engine speed in the maximum speed range is detected by the engine speed detecting means. And a number control means.

  Therefore, in the engine speed control device of the hybrid transmission of the present invention, when the engine speed control means detects the engine speed in the maximum speed range, the half-clutch control for slidingly engaging the engine clutch is performed. Therefore, even if the output speed increases due to a driving scene in which the vehicle speed further increases, even if the apparent engine speed increases due to lever displacement in the nomograph, the actual engine speed The engine speed is not increased, and the maximum engine speed allowed is maintained. As a result, it is possible to prevent the engine from over-rotating and to ensure the mechanical durability reliability of the differential gear transmission.

  Hereinafter, the best mode for realizing an engine speed control device for a hybrid transmission according to the present invention will be described based on Examples 1 to 3 shown in the drawings.

First, the configuration will be described.
[Hybrid transmission drive system]
FIG. 1 is an overall system diagram showing a hybrid transmission to which an engine speed control device of Embodiment 1 is applied.

  As shown in FIG. 1, the drive system of the hybrid transmission in the first embodiment has an engine E, a first motor generator MG1, and a second motor generator MG2 as power sources. A differential gear transmission in which these power sources E, MG1, MG2 and an output shaft OUT (output member) are coupled includes a first planetary gear PG1, a second planetary gear PG2, and a third planetary gear PG3. It has an engine clutch EC, a low brake LB (engagement element), a high clutch HC (engagement element), and a high / low brake HLB (engagement element).

  The first planetary gear PG1, the second planetary gear PG2, and the third planetary gear PG3 that constitute the differential gear transmission are all single-pinion type planetary gears. The first planetary gear PG1 includes a first sun gear S1, a first pinion carrier PC1 that supports the first pinion P1, and a first ring gear R1 that meshes with the first pinion P1. The second planetary gear PG2 includes a second sun gear S2, a second pinion carrier PC2 that supports the second pinion P2, and a second ring gear R2 that meshes with the second pinion P2. The third planetary gear PG3 includes a third sun gear S3, a third pinion carrier PC3 that supports the third pinion P3, and a third ring gear R3 that meshes with the third pinion P3.

  The first sun gear S1 and the second sun gear S2 are directly connected by a first rotating member M1, and the first ring gear R1 and the third sun gear S3 are directly connected by a second rotating member M2, and the second pinion carrier PC2 And the third ring gear R3 are directly connected by a third rotating member M3 (engine input rotating element). Accordingly, the three planetary gears PG1, PG2, and PG3 include the first rotating member M1, the second rotating member M2, the third rotating member M3, the first pinion carrier PC1, the second ring gear R2, and the third pinion carrier PC3. 6 rotation elements.

  A connection relationship among the power sources E, MG1, MG2, the output shaft OUT, the engine clutch EC, and the engagement elements LB, HC, HLB for the six rotating elements of the differential gear transmission will be described. The second rotating member M2 is in a free state that is not connected to any of these, and the remaining five rotating elements are connected as follows.

  The engine output shaft of the engine E is connected to the third rotating member M3 via the engine clutch EC. That is, when the engine clutch EC is engaged, the second pinion carrier PC2 and the third ring gear R3 are set to the engine speed via the third rotation member M3.

  The first motor generator output shaft of the first motor generator MG1 is directly connected to the second ring gear R2. Further, a high / low brake HLB is interposed between the first motor generator output shaft and the transmission case TC. That is, when releasing the high / low brake HLB, the second ring gear R2 is set to the rotation speed of the first motor generator MG1. When the high / low brake HLB is engaged, the rotation of the second ring gear R2 and the first motor generator MG1 is stopped.

  The second motor generator output shaft of the second motor generator MG2 is directly connected to the first rotating member M1. Further, a high clutch HC is interposed between the second motor generator output shaft and the first pinion carrier PC1, and a low brake LB is interposed between the first pinion carrier PC1 and the transmission case TC. Is done. That is, when only the low brake LB is engaged, the first pinion carrier PC1 is stopped, and when only the high clutch HC is engaged, the first sun gear S1, the second sun gear S2, and the first pinion carrier PC1 are connected to the second motor generator MG2. Set the rotation speed. Further, when the low brake LB and the high clutch HC are engaged, the first sun gear S1, the second sun gear S2, and the first pinion carrier PC1 are stopped.

  The output shaft OUT is directly connected to the third pinion carrier PC3. A driving force is transmitted from the output shaft OUT to the left and right driving wheels via a propeller shaft, a differential, and a drive shaft (not shown).

  As a result, as shown in FIGS. 4 and 5, the first motor generator MG1 (R2), the engine E (PC2, R3), the output shaft OUT (PC3), the second motor generator MG2 (S1) , S2, PC1), and a rigid lever model that can simply represent the dynamic behavior of the planetary gear train can be introduced.

  Here, the “collinear diagram” is a velocity diagram used in a simple and easy-to-understand method of drawing instead of the method of obtaining by equation when considering the gear ratio of the differential gear. Take the number of rotations (rotation speed) of the rotating elements, take each rotating element such as ring gear, carrier, sun gear, etc. on the horizontal axis, and set the spacing between each rotating element to the gear ratio of the sun gear and ring gear (α, β, δ) It is arranged to become. 4A is a collinear diagram of the first planetary gear PG1, (2) is a collinear diagram of the second planetary gear PG2, and (3) is a third planetary gear PG3. FIG.

  The engine clutch EC is a multi-plate friction clutch that is fastened by oil pressure and cooled by oil, and is arranged at a position that coincides with the rotational speed axis of the engine E on the collinear charts of FIGS. As a result of the engagement, the rotation and torque of the engine E are input to the third rotating member M3 which is an engine input rotating element of the differential gear transmission.

  The low brake LB is a multi-plate friction brake that is fastened by hydraulic pressure, and is disposed at a position outside the rotational speed axis of the second motor generator MG2 on the alignment chart of FIGS. As shown in (a) and (b) of FIG. 5 and (a) and (b) of FIG.

  The high clutch HC is a multi-plate friction clutch that is engaged by hydraulic pressure, and is disposed at a position that coincides with the rotational speed axis of the second motor generator MG2 on the alignment charts of FIGS. 4 (d), (e) and (d), (e) of FIG. 5 realize the high side gear ratio mode for sharing the high side gear ratio.

  The high / low brake HLB is a multi-plate friction brake that is fastened by hydraulic pressure, and is arranged at a position that coincides with the rotational speed axis of the first motor generator MG1 on the collinear charts of FIGS. The gear ratio is fixed to the low gear ratio on the underdrive side by fastening together with the high gear ratio, and the gear ratio is fixed to the high gear ratio on the overdrive side by fastening with the high clutch HC.

[Control system for hybrid transmission]
As shown in FIG. 1, the control system in the hybrid transmission of the first embodiment includes an engine controller 1, a motor controller 2, an inverter 3, a battery 4, a hydraulic control device 5, an integrated controller 6, an accelerator opening. Degree sensor 7, vehicle speed sensor 8 (vehicle speed detection means), engine speed sensor 9 (engine speed detection means), first motor generator speed sensor 10, and second motor generator speed sensor 11 (motor generator) (Rotational speed detection means), a third ring gear rotational speed sensor 12, and a brake controller 13 (cooperative brake control means).

  The engine controller 1 responds to an engine operating point (hereinafter referred to as an engine operating point) according to a target engine torque command from an integrated controller 6 that inputs an accelerator opening AP from an accelerator opening sensor 7 and an engine speed Ne from an engine speed sensor 9. The “operating point” refers to an operating point specified by the rotational speed and torque.), For example, is output to a throttle valve actuator (not shown).

  The motor controller 2 operates the first motor generator MG1 in response to a target motor generator torque command or the like from the integrated controller 6 that inputs the motor generator rotation speeds N1 and N2 from both the motor generator rotation speed sensors 10 and 11 by the resolver. A command for independently controlling the point and the operating point of the second motor generator MG2 is output to the inverter 3. The motor controller 2 outputs information on the battery S.O.C representing the state of charge of the battery 4 to the integrated controller 6.

  The inverter 3 is connected to the stator coils of the first motor generator MG1 and the second motor generator MG2, and generates respective drive currents according to commands from the motor controller 2. The inverter 3 is connected to a battery 4 that is discharged during power running and charged during regeneration.

  The hydraulic control device 5 receives a hydraulic command from the integrated controller 6 and performs engagement hydraulic pressure control and release hydraulic pressure control of the engine clutch EC, the low brake LB, the high clutch HC, and the high / low brake HLB. The engagement hydraulic pressure control and the release hydraulic pressure control include half-clutch / half-brake control by slip engagement control and slip release control.

  The integrated controller 6 includes an accelerator opening AP from the accelerator opening sensor 7, a vehicle speed VSP from the vehicle speed sensor 8, an engine speed Ne from the engine speed sensor 9, and a first motor generator speed sensor 10. Information of the first motor generator rotational speed N1, the second motor generator rotational speed N2 from the second motor generator rotational speed sensor 11, the third ring gear rotational speed ωin from the third ring gear rotational speed sensor 12, and the like. Input and perform predetermined arithmetic processing. Then, a control command is output to the engine controller 1, the motor controller 2, the hydraulic control device 5, and the brake controller 13 according to the calculation processing result. Here, when a coordinated brake command is output from the integrated controller 6 to the brake controller 13, the drive command is output from the brake controller 13 to, for example, an ABS / TCS / VDC actuator having a brake hydraulic pressure source, and the brake hydraulic pressure is output. To the wheel cylinder.

  The integrated controller 6 and the engine controller 1, and the integrated controller 6 and the motor controller 2 are connected to each other by bidirectional communication lines 14 and 15 for information exchange.

[Driving mode]
Since the hybrid transmission of the first embodiment can coaxially match the output shaft OUT of the transmission with the engine output shaft, the hybrid transmission is not limited to an FF vehicle (front engine / front drive vehicle) but also an FR vehicle (front engine It can be installed in a rear drive vehicle), and the continuous gear ratio range is not covered by one mode as a continuously variable gear ratio mode. Instead of a continuously variable gear ratio mode on the low side and a continuously variable gear ratio mode on the high side. Since the common gear ratio range is covered by sharing, the output sharing ratio of the two motor generators MG1 and MG2 can be suppressed to about 20% or less of the output generated by the engine E.

  As shown in FIG. 2, the traveling mode includes a low fixed speed ratio mode (hereinafter referred to as “Low mode”), a low-side continuously variable speed ratio mode (hereinafter referred to as “Low-iVT mode”), and 2-speed fixed mode (hereinafter referred to as “2nd mode”), high-side continuously variable gear ratio mode (hereinafter referred to as “High-iVT mode”), and high fixed gear ratio mode (hereinafter referred to as “High mode”). And 5) driving modes.

  As shown in FIG. 2, the Low mode is obtained by engaging the low brake LB, releasing the high clutch HC, and engaging the high / low brake HLB. The Low-iVT mode is obtained by engaging the low brake LB, releasing the high clutch HC, and releasing the high / low brake HLB. The 2nd mode is obtained by engaging the low brake LB, engaging the high clutch HC, and releasing the high / low brake HLB. The High-iVT mode is obtained by releasing the low brake LB, engaging the high clutch HC, and releasing the high / low brake HLB. The High mode is obtained by releasing the low brake LB, engaging the high clutch HC, and engaging the high / low brake HLB.

  Regarding these five driving modes, the electric driving mode (hereinafter referred to as “EV mode”) in which only the motor generators MG1 and MG2 are driven without using the engine E, and the engine E and both motor generators MG1 and MG2 are used. And a hybrid driving mode (hereinafter referred to as “HEV mode”). Therefore, as shown in FIG. 3, when the EV mode and the HEV mode are combined, ten travel modes are realized. Figure 4 shows the EV-Low mode collinear diagram, EV-Low-iVT mode collinear diagram, EV-2nd mode collinear diagram, EV-High-iVT mode collinear diagram, EV-High A collinear chart of each mode is shown. Fig. 5 shows HEV-low mode collinear diagram, HEV-Low-iVT mode collinear diagram, HEV-2nd mode collinear diagram, HEV-High-iVT mode (hybrid vehicle high side continuously variable transmission) The nomogram of the ratio mode) and the nomogram of the HEV-High mode are shown.

  Here, the integrated controller 6 is preset with a travel mode map in which the 10 travel modes are allocated in a three-dimensional space defined by the accelerator opening AP, the vehicle speed VSP, and the battery SOC. The travel mode map is searched based on the detected values of the accelerator opening AP, the vehicle speed VSP, and the battery SOC, and the optimal travel mode map corresponding to the driving point of the vehicle and the battery charge determined by the accelerator opening AP and the vehicle speed VSP is selected. The

  When the mode is changed between the “EV mode” and the “HEV mode” by selecting the travel mode map, the engine clutch EC engagement control and the engine clutch EC Release control, or in addition, engagement / release control of engagement elements such as clutches and brakes is executed. In addition, when performing mode transition between the five modes of “EV mode” and mode transition between the five modes of “HEV mode”, the engagement / release control of the engagement elements such as clutches and brakes is executed. Is done. These mode transition controls are performed by sequence control according to a predetermined procedure so that the operating points are transferred smoothly.

  Next, the operation will be described.

[Engine speed control processing]
FIG. 6 is a flowchart showing the flow of the engine speed control process executed by the integrated controller 6 of the first embodiment. Each step will be described below (engine speed control means). This process is executed during traveling in the HEV-High-iVT mode.

  In step S1, it is determined whether or not the engine speed from the engine speed sensor 9 is in the maximum speed range. If YES, the process proceeds to step S2, and if NO, the process returns to START.

  In step S2, it is determined whether or not the vehicle speed VSP (= output shaft rotational speed No) from the vehicle speed sensor 8 exceeds the maximum vehicle speed. If YES, the process proceeds to step S3, and if NO, the process returns to START.

In step S3, based on the determination that both the engine speed condition in step S1 and the vehicle speed condition in step S2 are satisfied, half-clutch control is performed to turn the engine clutch EC into a half-clutch by sliding engagement. The process proceeds to S4.
Here, the “half-clutch control of the engine clutch EC” is performed by sliding engagement that ensures the operation of the engine brake without changing the engine speed Ne.

In step S4, the rotational speed N2 of the second motor generator MG2 is decreased, and the process proceeds to step S5.
Here, the “decrease amount of the second motor generator rotational speed N2” is determined based on the second pinion limit rotational speed from the viewpoint of ensuring the durability of the second pinion P2, and the rotational speed of the second pinion P2 is limited. The amount of decrease is less than the rotation speed.

  In step S5, a command to apply cooperative braking is output to the brake controller 13, and the process proceeds to return.

[Engine speed control action]
FIG. 7 is an alignment chart at the maximum vehicle speed in the HEV-High-iVT mode, and the engine speed Ne and the second motor generator speed N2 are maintained in the maximum speed range.
If the vehicle speed further increases due to inertia when traveling from the maximum vehicle speed shown in FIG. 7, for example, when going downhill, the vehicle speed (= output shaft rotational speed No) increases as shown by the dotted line → solid line in FIG. Along with this, the lever representing the second planetary gear PG2 is pushed up as it is, the engine speed Ne exceeds the maximum engine speed, and the second motor generator speed N2 (= NMG2) is the second. The motor generator exceeds the maximum number of revolutions, resulting in overspeed.

  When the engine E and the second motor generator MG2 are in an over-rotation state and the second planetary gear PG2 is focused, the second sun gear S2 is rotated by the second motor generator MG2 and the second pinion carrier PC2 is rotated by the engine E. Since the second ring gear R2 is rotated by the first motor generator MG1 and the rotation directions are the same, the pinion P2 supported by the second pinion carrier PC2 reaches, for example, about 20000 rpm. Over-rotation. Therefore, if driving is continued with the over-rotation of the pinion P2 left untreated, the deterioration and damage of the pinion P2 progresses and the durability of the pinion P2 decreases, and as a result, the mechanical durability reliability of the hybrid transmission is impaired. It will be.

  Therefore, it is conceivable that when the engine E2 reaches the maximum speed range, the cooperative brake is immediately activated to prevent the engine E from over-rotating. However, the engine over-rotation prevention control by the cooperative brake is performed during traveling at the maximum vehicle speed. If this happens, the vehicle will suddenly decelerate despite the fact that neither the accelerator return operation nor the brake operation is performed, which gives the driver a sense of incongruity.

  On the other hand, in the first embodiment, when traveling at the maximum vehicle speed in the HEV-High-iVT mode, the engine speed Ne is in the maximum speed range and the vehicle speed VSP is in the maximum vehicle speed range. In step S1, the process proceeds from step S1 to step S2 to step S3 to step S4. In step S3, the second motor that is in the maximum speed range in step S4 is executed while performing half-clutch control for slidingly engaging the engine clutch EC. Control is performed to reduce the generator rotational speed N2.

  A collinear diagram representing the second planetary gear PG2 as shown by the dotted line → solid line in FIG. 9 simply by lowering the second motor generator rotational speed N2 in the maximum rotational speed range by half clutch control of the engine clutch EC. The lever can change the lever inclination by rotating around the output shaft position with an increase in the apparent engine speed Ne. Therefore, an increase in the output shaft rotational speed No (= vehicle speed) is allowed while maintaining the engine rotational speed Ne and the second motor generator rotational speed N2 below the maximum rotational speed.

  Therefore, the engine speed Ne and the second motor generator speed N2 are maintained at the maximum speed or less by performing the control to decrease the second motor generator speed N2 while executing the half clutch control of the engine clutch EC. As a result, the mechanical durability reliability can be ensured by preventing the second pinion P2 from over-rotating.

  Further, in the flowchart of FIG. 6, after the second motor generator rotation speed N2 is controlled to be reduced in step S4, the process proceeds to step S5. In step S5, the cooperative brake is applied, so that the dotted line in FIG. As shown by the solid line, the lever in the collinear chart representing the second planetary gear PG2 is pushed down as the output shaft rotational speed No decreases, and both motor generator rotational speeds N1 and N2 decrease. That is, the vehicle speed is reduced by the cooperative brake operation while maintaining the engine speed Ne at the maximum speed by the half-clutch control.

  Here, the reason why the cooperative brake (mechanical type) is used in order to prevent the vehicle speed from increasing excessively is that the vehicle speed can be surely reduced. For example, when the regenerative brake is used, regeneration is possible when the battery S.O.C is low, but regeneration is possible when the battery S.O.C is high. Also, when relying on foot brakes, the fade phenomenon becomes a problem.

  Then, when the vehicle speed is sufficiently reduced by the cooperative brake operation and the engine speed Ne is on the lever of the collinear diagram representing the second planetary gear PG2, the half-clutch control of the engine clutch EC is stopped, and the engine clutch EC is By fully engaging, the half clutch control time of the engine clutch EC can be shortened.

Next, the effect will be described.
In the engine speed control device of the hybrid transmission according to the first embodiment, the following effects can be obtained.

  (1) By connecting the power source having the engine E, at least the first motor generator MG1 and the second motor generator MG2, and the power sources E, MG1, MG2 and the output shaft OUT to the rotating elements, A planetary gear train in which the first motor generator MG1 and the second motor generator MG2 are arranged at both lever positions on the alignment chart, and the engine E and the output shaft OUT are arranged at the lever inner position, and a plurality of driving modes are selected. A differential gear transmission having an engaging element, and an intermediate position on an input path connecting the output shaft of the engine E and the engine input rotation element of the differential gear transmission, and is fastened by frictional force. In the hybrid transmission equipped with the engine clutch EC, the engine speed sensor 9 for detecting the speed of the engine E and the engine speed sensor 9 for maximum speed And an engine speed control means for performing half-clutch control for slidingly engaging the engine clutch EC when the engine speed Ne in several ranges is detected, thereby preventing over-rotation of the engine E and differential gear shifting. The mechanical durability reliability of the machine can be ensured.

  (2) The half-clutch control of the engine clutch EC by the engine speed control means is a sliding engagement that ensures the operation of the engine brake without changing the engine speed Ne, thus preventing over-rotation of the engine speed Ne. Therefore, it is possible to prevent the operation of the engine brake from being lost as in the case of controlling the release of the engine clutch EC.

  (3) When the engine speed Ne is detected by the engine speed sensor 9, the engine speed control means performs a half-clutch control for slidingly engaging the engine clutch EC, In order to control the second motor generator rotational speed N2 on the side where the rotational speed increases due to the lever tilt in the figure, the engine E is prevented from over-rotation and at the same time the second motor-generator MG2 is prevented from over-rotating. Can do.

  (4) A brake controller 13 that generates a braking force in response to an external command is provided, and the engine speed control means is configured to detect the engine speed Ne when the engine speed Ne in the maximum speed range is detected by the engine speed sensor 9. While executing the half-clutch control for sliding engagement of the clutch EC, the control is performed to reduce the second motor generator rotational speed N2 on the side where the rotational speed increases due to the lever inclination on the nomograph, and then the cooperative brake control is performed. As a result, the increase in the vehicle speed can be suppressed, the operating time of the half clutch control of the engine clutch EC can be shortened, and the durability of the engine clutch EC can be improved.

  (5) The vehicle speed sensor 8 for detecting the vehicle speed is provided, and the engine speed control means detects the engine speed Ne in the maximum engine speed range by the engine engine speed sensor 9, and the vehicle speed sensor 8 detects the maximum vehicle speed area. When the vehicle speed VSP is detected, control to prevent over-rotation of the engine E is executed, so that over-rotation of the engine E is prevented during traveling at the maximum vehicle speed, and the mechanical durability reliability of the differential gear transmission is Sex can be secured.

  (6) The differential gear transmission includes a planetary gear train connected so as to be arranged in the order of the first motor generator MG1, the engine E, the output shaft OUT, and the second motor generator MG2 on the alignment chart. As a combination element, it has a high clutch HC that changes the gear ratio to the high side gear ratio by engagement, and as the driving mode, the high clutch HC is engaged, and the engine E, the first motor generator MG1, and the second motor generator MG2 are the power source. HEV-High-iVT mode that travels with a high-side continuously variable transmission ratio, and the engine speed control means selects the engine when traveling in the maximum vehicle speed range when the HEV-High-iVT mode is selected. In order to execute control to prevent over-rotation of E, when HEV-High-iVT mode is selected and traveling at the maximum vehicle speed range, over-rotation of engine E is prevented and the mechanical durability of the differential gear transmission Reliability can be ensured.

  The second embodiment is an example in which the vehicle speed condition is eliminated with respect to the first embodiment and the cooperative braking is not performed.

  That is, as shown in the flowchart of FIG. 11, when it is determined in step S1 that the engine speed from the engine speed sensor 9 is in the maximum speed range, the process proceeds to step S3, and in step S3, step S1 Based on the determination that the engine speed condition is satisfied, the half-clutch control is executed to make the engine clutch EC a half-clutch by sliding engagement. In the next step S4, the speed N2 of the second motor generator MG2 is set. Control to decrease. Since the configuration and other actions are the same as those in the first embodiment, the description thereof is omitted.

  Therefore, in the engine speed control device for the hybrid transmission of the second embodiment, the effects (1), (2), (3), and (6) of the first embodiment can be obtained.

  The third embodiment is an example in which the vehicle speed condition is eliminated from the first embodiment, but the cooperative brake control is performed when the measured half-clutch control time exceeds the set time.

  That is, as shown in the flowchart of FIG. 12, when it is determined in step S1 that the engine speed from the engine speed sensor 9 is in the maximum speed range, the process proceeds to step S3, and in step S3, step S1 Based on the determination that the engine speed condition is satisfied, the half-clutch control is executed to make the engine clutch EC a half-clutch by sliding engagement. In the next step S4, the speed N2 of the second motor generator MG2 is set. Control to decrease. In step S6, the continuation time of the half clutch control of the engine clutch EC is calculated (half clutch control time measuring means), and in the next step S7, the half clutch control is continued until the half clutch control time reaches the set time. If the half-clutch control time exceeds the set time, the process proceeds to the next step S5, where the cooperative brake is applied. After applying this cooperative brake, as in the first embodiment, when the engine speed Ne is on the lever of the collinear diagram representing the second planetary gear PG2, the half-clutch control of the engine clutch EC is stopped, and the engine Fully engage the clutch EC.

  Here, the “half-clutch control time setting time” is set to a time during which the engine clutch EC stays at a temperature increase level that does not promote deterioration of durability of the clutch facing portion. Since the configuration and other actions are the same as those in the first embodiment, the description thereof is omitted.

  Therefore, in the engine speed control device for the hybrid transmission of the third embodiment, in addition to the effects of (1), (2), (3), (4), (6) of the first embodiment, An effect can be obtained.

  (7) A half-clutch control time measuring step S6 for measuring the duration of half-clutch control of the engine clutch EC is provided, and the engine speed control means performs control to reduce the second motor generator speed N2. When the measured half-clutch control time exceeds the set time, the coordinated brake control is performed, so that the half-clutch control operation time of the engine clutch EC can be managed, and the durability reliability of the engine clutch EC can be secured. .

  As mentioned above, although the engine speed control apparatus of the hybrid transmission of the present invention has been described based on the first to third embodiments, the specific configuration is not limited to these embodiments, and Design changes and additions are permitted without departing from the spirit of the invention according to each claim of the scope.

  Although the example when the hybrid vehicle high-side continuously variable gear ratio mode is selected is shown in the first embodiment, the present invention can be applied in exactly the same manner when the hybrid vehicle low-side continuously variable gear ratio mode is selected.

  The engine speed control device for a hybrid transmission according to the present invention shows an application example to a hybrid transmission having a differential gear transmission with three simple planetary gear trains using one engine and two motor generators as power sources. However, as shown in the conventional example, in the hybrid transmission, four input / output elements in which four input / output elements of the first sun gear S1, the ring gear R, the carrier C, and the second sun gear S2 are arranged on the collinear diagram. A planetary gear mechanism having a degree of freedom is configured, and an input In from the engine is assigned to one of two elements (ring gear R and carrier C) arranged inside, and an output Out to the drive system is assigned to the other. It can be applied to a hybrid transmission having a differential gear transmission in which motor generators MG1 and MG2 are connected to the two outer elements (first sun gear S1 and second sun gear S2), respectively. Kill.

1 is an overall system diagram showing a hybrid transmission to which an engine speed control device of Embodiment 1 is applied. It is a figure which shows the fastening / release state of three engagement elements in each driving mode in the hybrid transmission of Example 1. FIG. In the hybrid transmission of the first embodiment, the operation tables of the engine, the engine clutch, the motor generator, the low brake, the high clutch, and the high / low brake in the five traveling modes in the electric vehicle mode and the five traveling modes in the hybrid vehicle mode are shown. FIG. FIG. 5 is a collinear diagram illustrating five travel modes in an electric vehicle mode in the hybrid transmission according to the first embodiment. FIG. 5 is a collinear diagram illustrating five travel modes in a hybrid vehicle mode in the hybrid transmission according to the first embodiment. 3 is a flowchart showing a flow of an engine speed control process executed by the integrated controller of the first embodiment. It is a collinear diagram showing the maximum vehicle speed when the HEV-High-iVT mode is selected. It is a collinear diagram showing when the engine speed is in an overspeed state at the maximum vehicle speed with the HEV-High-iVT mode selected. FIG. 5 is a collinear diagram showing an engine overspeed prevention state when half clutch control and second motor generator rotation speed reduction control are used together at the maximum vehicle speed with the HEV-High-iVT mode selected. FIG. 5 is a collinear diagram showing a cooperative brake operation in an engine overspeed prevention state when a half clutch control and a second motor generator rotation speed reduction control are used together at the maximum vehicle speed with the HEV-High-iVT mode selected. 6 is a flowchart illustrating a flow of an engine speed control process executed by an integrated controller according to a second embodiment. 12 is a flowchart illustrating a flow of an engine speed control process executed by an integrated controller according to a third embodiment.

Explanation of symbols

E engine
MG1 1st motor generator
MG2 Second motor generator
OUT Output shaft (output member)
PG1 1st planetary gear
PG2 2nd planetary gear
PG3 3rd planetary gear
EC engine clutch
LB Low brake (engagement element)
HC high clutch (engagement element)
HLB High / Low brake (engagement element)
DESCRIPTION OF SYMBOLS 1 Engine controller 2 Motor controller 3 Inverter 4 Battery 5 Hydraulic control apparatus 6 Integrated controller 7 Accelerator opening degree sensor 8 Vehicle speed sensor (vehicle speed detection means)
9 Engine speed sensor (Engine speed detector)
10 1st motor generator rotation speed sensor 11 2nd motor generator rotation speed sensor (motor generator rotation speed detection means)
12 Third ring gear rotation speed sensor 13 Brake controller (cooperative brake control means)

Claims (7)

A power source having an engine and at least a first motor generator and a second motor generator;
By connecting each power source and output member to a rotating element, the first motor generator and the second motor generator are arranged at both lever positions on the alignment chart, and the engine and the output member are arranged at lever inner positions. A differential gear transmission having a planetary gear train to be engaged and an engagement element for selecting a plurality of travel modes;
An engine clutch provided at an intermediate position of an input path connecting the output shaft of the engine and an engine input rotation element of the differential gear transmission, and fastened by frictional force;
In a hybrid transmission with
Engine speed detecting means for detecting the engine speed;
An engine speed control means for performing half-clutch control for slidingly engaging the engine clutch when the engine speed in the maximum speed range is detected by the engine speed detection means;
An engine speed control device for a hybrid transmission characterized by comprising: In the engine speed control device for a hybrid transmission according to claim 1,
The engine speed control device for a hybrid transmission is characterized in that the half-clutch control of the engine clutch by the engine speed control means is slip engagement that ensures the operation of the engine brake without changing the engine speed. In the engine speed control device for a hybrid transmission according to claim 1 or 2,
The engine speed control means performs a half-clutch control for slidingly engaging the engine clutch when the engine speed in the maximum speed range is detected by the engine speed detection means, An engine rotation speed control device for a hybrid transmission, characterized in that control is performed to reduce the motor generator rotation speed on the side where the rotation speed increases due to lever inclination. In the engine speed control device for a hybrid transmission according to claim 1 or 2,
Coordinated brake control means that generates braking force in response to an external command is provided.
The engine speed control means performs a half-clutch control for slidingly engaging the engine clutch when the engine speed in the maximum speed range is detected by the engine speed detection means, An engine rotation speed control device for a hybrid transmission, which performs cooperative brake control after performing control to reduce the motor generator rotation speed on the side where the rotation speed increases due to lever tilt. In the engine speed control device for a hybrid transmission according to claim 4,
Providing a half-clutch control time measuring means for measuring a duration of half-clutch control of the engine clutch;
The engine rotational speed control means performs cooperative brake control when the measured half-clutch control time exceeds a set time after performing control to reduce the motor generator rotational speed. Number control device. The engine speed control device for a hybrid transmission according to any one of claims 1 to 5,
Vehicle speed detecting means for detecting the vehicle speed is provided;
The engine speed control means detects engine overspeed when the engine speed in the maximum speed range is detected by the engine speed detection means and the vehicle speed in the maximum vehicle speed range is detected by the vehicle speed detection means. An engine rotation speed control device for a hybrid transmission, characterized by executing control to prevent. The engine speed control device for a hybrid transmission according to any one of claims 1 to 6,
The differential gear transmission has a planetary gear train connected so as to be arranged in the order of the first motor generator, the engine, the output member, and the second motor generator on the collinear diagram, and the engagement element is used to change the speed by fastening. Has a high clutch that sets the ratio to the high gear ratio,
A hybrid vehicle high-side continuously variable gear ratio mode in which a high clutch is engaged as a traveling mode and the engine, the first motor generator, and the second motor generator are driven as a power source at a high-side continuously variable gear ratio;
The hybrid engine is characterized in that the engine speed control means executes control for preventing over-rotation of the engine when traveling in a maximum vehicle speed range with the hybrid vehicle high-side continuously variable gear ratio mode selected. Engine speed control device.

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