Control device for vehicle power transmission

Abstract

To provide a control device for a vehicle power transmission, which can more accurately resolve engagement failure caused by meshing of a dog clutch having a synchromesh mechanism.SOLUTION: In the case where engagement failure caused by meshing of a sleeve 50 and a gear piece 52 in a dog clutch D1 is detected and the engagement failure caused by meshing of the dog clutch D1 is not resolved even when the dog clutch D1 is operated to a release side, a forward clutch C1 or a reverse brake B1 is engaged in response to a shift operation to forward or reverse travelling to relatively rotate the sleeve 50 side and the gear piece 52 side of the dog clutch D1, so that the engagement failure caused by meshing can be resolved. Since control for re-engaging the dog clutch D1 is executed after a phase shift of meshing of the sleeve 50 and the gear piece 52 is performed, even in an initial state where engagement failure caused by meshing is likely to occur due to insufficient fitting in a synchromesh mechanism, it is possible to more accurately resolve engagement failure of the dog clutch.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a control device for a vehicle power transmission device equipped with a dog clutch having a synchromesh mechanism. [Background technology]

[0002] A power transmission device is known that includes a first power transmission path having a gear mechanism and a second power transmission path having a continuously variable transmission, which are arranged in parallel between an input shaft to which engine power is transmitted and an output shaft to which the power is transmitted to drive wheels. A dog clutch having a synchromesh mechanism is inserted in the first power transmission path, and when the power is transmitted using the first power transmission path during starting of the vehicle or low-speed driving, the dog clutch is engaged.

[0003] In the above-mentioned vehicle power transmission device, if the mesh clutch fails to engage, the vehicle cannot start. To deal with this situation, Patent Document 1 discloses a technique for maintaining the engaged state even when the engine is stopped, and Patent Document 2 discloses a technique for releasing the mesh clutch when a failure to engage occurs and retrying to re-engage it. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-50617 A [Patent Document 2] JP 2018-132151 A Summary of the Invention [Problem to be solved by the invention]

[0005] One type of engagement failure in a dog clutch is when the engagement between the sleeve and gear piece of the dog clutch does not reach the complete position and stops halfway. This type of engagement is likely to occur in the initial stage after manufacture due to insufficient compatibility of the friction material of the synchromesh mechanism, and even the techniques disclosed in Patent Documents 1 and 2 have had problems in accurately resolving the engagement.

[0006] The present invention has been made against the background of the above circumstances, and its object is to provide a control device for a vehicle power transmission device that can more accurately eliminate engagement failure caused by meshing of a mesh clutch having a synchromesh mechanism. [Means for solving the problem]

[0007] The gist of the present invention is a control device for a vehicle power transmission device, which (a) includes a first power transmission path having a gear mechanism and a second power transmission path having a continuously variable transmission, which are arranged in parallel between an input shaft to which engine power is transmitted and an output shaft to which the power is transmitted to drive wheels, and which includes a first clutch for forward driving, a first brake for reverse driving, and a mesh clutch having a synchromesh mechanism provided on the output shaft side of the first clutch and the first brake, in the first power transmission path, and (b) when a misengagement due to meshing between a sleeve and a gear piece of the mesh clutch is detected and the misengagement due to the meshing is not eliminated even when the mesh clutch is operated to the release side, the control device engages the first clutch or the first brake in response to a shift operation to forward driving or reverse driving, and rotates the sleeve side and the gear piece side of the mesh clutch relative to each other to eliminate the misengagement due to the meshing and shift the phase of the meshing between the sleeve and the gear piece, and then executes control to re-engage the mesh clutch. Effect of the Invention

[0008] According to the present invention, if a misengagement due to the meshing between the sleeve and the gear piece of the meshing clutch is detected, and the misengagement due to the meshing is not resolved even when the meshing clutch is operated to the release side, the first clutch or the first brake is engaged in response to the shift operation to the forward driving or the reverse driving, and the sleeve side and the gear piece side of the meshing clutch are rotated relative to each other to resolve the misengagement due to the meshing and shift the phase of the meshing between the sleeve and the gear piece, and then control is executed to re-engage the meshing clutch, so that the misengagement of the meshing clutch can be more accurately resolved even in an initial state where misengagement due to the meshing is likely to occur due to insufficient fit of the synchromesh mechanism.

[0009] Preferably, the determination as to whether the meshing of the mesh clutch has been released is made by determining whether the difference in rotational speed between the sleeve side and the gear piece side of the mesh clutch is equal to or greater than a predetermined value. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram illustrating a schematic configuration of a vehicle power transmission device according to an embodiment of the present invention; [Diagram 2] 11A and 11B are diagrams illustrating an engaged state of a dog clutch during an engagement transition period. [Diagram 3] 4 is a flowchart illustrating a main part of a control operation of the electronic control device when the dog clutch is engaged at engine start. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that in the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios and shapes of the various parts are not necessarily drawn accurately. EXAMPLES

[0012] 1 is a schematic diagram for explaining the general configuration of a power transmission device 10 for a vehicle (hereinafter, referred to as the power transmission device 10) according to one embodiment of the present invention, and is a diagram showing a plurality of parallel shafts laid out in one plane. The power of an engine 12, which is a driving force source for running, is transmitted to a differential gear device 18 via a torque converter 14 and an automatic transmission 16, and is further distributed to left and right driving wheels 20.

[0013] The torque converter 14 is a well-known fluid transmission device having a lock-up clutch LU. The torque converter 14 is a well-known technique, and therefore a description thereof will be omitted.

[0014] The automatic transmission 16 is configured with a first power transmission path PT1 and a second power transmission path PT2 arranged in parallel between the input shaft 22 and the output shaft 30. The first power transmission path PT1 is configured to include a forward / reverse switching device 26 and a gear mechanism 28. The forward / reverse switching device 26 is configured to include a double pinion side planetary gear device 32, a forward clutch C1, and a reverse brake B1. The forward / reverse switching device 26 is a known technique, so a description thereof will be omitted.

[0015] The gear mechanism 28 includes a small diameter gear 42, a large diameter gear 46 that is non-rotatably mounted on the counter shaft 44 and meshes with the small diameter gear 42, and a small diameter idler gear 48 that is coaxially mounted on the counter shaft 44 and rotatable relative to the counter shaft 44. A mesh clutch D1 having a synchromesh mechanism S1 (hereinafter, synchro mechanism S1) is provided between the counter shaft 44 and the idler gear 48. The mesh clutch D1 connects and disconnects the counter shaft 44 and the idler gear 48.

[0016] The synchronizing mechanism S1 is a well-known synchronizing mechanism including a synchronizer ring 55. When the clutch hub sleeve 50 (hereinafter, sleeve 50) is operated to the left side of the drawing by the hydraulic actuator 34, the idler gear 48 is synchronized with the countershaft 44 by the action of the synchronizer ring 55, and when the sleeve 50 is further moved to the left side of the drawing, meshing teeth formed on the inner peripheral surface of the sleeve 50 mesh with a gear piece 52 formed integrally with the idler gear 48. At this time, the idler gear 48 is connected to the countershaft 44 via the meshing clutch D1 so as not to rotate relative to the countershaft 44. The idler gear 48 is also meshed with a large diameter gear 62 provided integrally with the output shaft 30 of the automatic transmission 16.

[0017] The second power transmission path PT2 is configured to include a belt-type continuously variable transmission 24. The belt-type continuously variable transmission 24 is a known technique, and therefore a description thereof will be omitted. A belt running clutch C2 is interposed between the belt-type continuously variable transmission 24 and the output shaft 30 to connect and disconnect the two.

[0018] In the power transmission device 10 configured as described above, when the forward clutch C1 and the mesh clutch D1 are engaged, the power of the engine 12 is transmitted to the drive wheels 20 via the first power transmission path PT1, enabling forward running, and when the reverse brake B1 and the mesh clutch D1 are engaged, reverse running is enabled via the same transmission path. Also, when the belt running clutch C2 is engaged, the power of the engine 12 is transmitted to the drive wheels 20 via the second power transmission path PT2, enabling forward running.

[0019] The hydraulic control circuit 70 is provided to be capable of adjusting the hydraulic pressure Pc1 of the hydraulic oil supplied to the hydraulic actuator 36 of the forward clutch C1, the hydraulic pressure Pb1 of the hydraulic actuator 38 of the reverse brake B1, the hydraulic pressure Pd1 of the hydraulic actuator 34 of the dog clutch D1, as well as the hydraulic actuator (not shown) of the belt running clutch C2, the hydraulic actuator 56 constituting the primary pulley 54 of the belt type continuously variable transmission 24, the hydraulic actuator 60 constituting the secondary pulley 58 of the belt type continuously variable transmission 24, and the hydraulic pressure (not shown) of the hydraulic oil supplied to the lock-up clutch LU. The hydraulic control circuit 70 is provided with a plurality of solenoid valves (not shown), and the hydraulic pressure of the hydraulic oil supplied to each of the hydraulic actuators is controlled by controlling the control pressures output from the various solenoid valves based on command signals from the electronic control device 80.

[0020] The electronic control device 80 executes various controls related to the power transmission device 10. In addition, various detection signals and the like (for example, the operating position Psh which is the operating position of the shift lever 76, the rotational speed Ndi [rpm] of the sleeve 50 side and the rotational speed Ndo [rpm] of the gear piece 52 side of the dog clutch D1, the stroke amount ST of the hydraulic actuator 34, etc.) are input to the electronic control device 80 by various sensors 82, 84, 86, 92 and the like provided on the vehicle. In addition, the electronic control device 80 functionally includes a first power control section 100 which performs control related to the first power transmission path PT1.

[0021] The first power control section 100 controls the engagement and release of the forward clutch C1 and the reverse brake B1, and controls the engagement, release, and determination of the engaged state of the mesh clutch D1. The forward clutch C1 is engaged and released by controlling and supplying a hydraulic pressure Pc1 to the forward clutch C1, a hydraulic pressure Pb1 to the reverse brake B1, and a hydraulic pressure Pd1 to the mesh clutch D1 to the hydraulic actuators described above that correspond to each of the hydraulic pressures. The first power control section 100 engages the mesh clutch D1 so that the power of the engine 12 is transmitted to the drive wheels 20 via the first power transmission path PT1 when the vehicle is starting or traveling at low speed, but controls the clutch D1 to be released when traveling at high speed.

[0022] Incidentally, it is known that in the dog clutch D1, engagement failure occurs when the sleeve 50 and the gear piece 52 formed on the idler gear 48 do not mesh properly. Fig. 2 shows the engagement state of the sleeve 50, the gear piece 52, and the synchronizer ring 55 of the dog clutch D1. In Fig. 2, states CA1 to CA3 respectively show states in which engagement failure has occurred in the dog clutch D1, and state CA4 shows a state in which engagement is complete.

[0023] State CA1 is a state in which frictional resistance between the chamfers formed on the sleeve 50 and the chamfers formed on the teeth of the synchronizer ring 55 causes a pushing failure in which the sleeve 50 cannot proceed to the left side of the paper. State CA2 is a state in which the tip of the sleeve 50 and the tip of the gear piece 52 collide, causing an uplock in which the sleeve 50 cannot proceed to the left side of the paper. State CA3 is a state in which frictional resistance between the chamfers of the sleeve 50 and the chamfers of the gear piece 52 causes the sleeve 50 to not proceed to the left side of the paper, causing so-called jamming. Jamming is an event that is likely to occur in the initial stage due to insufficient compatibility of the friction materials between the meshing chamfers.

[0024] Conventionally, when the meshing clutch D1 fails to engage, a retry is made to release and re-engage the meshing clutch D1. However, in the case of meshing, even if a retry is made, the frictional resistance is not improved and the meshing failure is not resolved because the meshing combination of the chamfer of the sleeve 50, where the lack of fit is occurring, and the chamfer of the gear piece 52 is the same.

[0025] Therefore, when meshing occurs, the electronic control device 80 rotates the sleeve 50 side to release the meshing, and then re-engages the meshing clutch D1 through a control operation described later in Fig. 3. Fig. 3 is a flowchart illustrating the control operation of the first power control section 100 in the electronic control device 80 when the meshing clutch D1 is engaged at engine start.

[0026] First, in step (hereinafter, step will be omitted) S10, the engine 12 while the vehicle is stopped is started.

[0027] Next, in S20, the hydraulic pressure Pd1 to the hydraulic actuator 34 is increased, and engagement of the dog clutch D1 begins.

[0028] Next, in S30, it is determined whether or not the engagement of the mesh clutch D1 has been completed. The determination is made based on whether or not the stroke amount ST of the hydraulic actuator 34 has exceeded a preset predetermined value L3 (see FIG. 2). The predetermined value L3 is set as a lower threshold value at which it can be determined that the engagement of the mesh clutch D1 has been completed. When the stroke amount ST exceeds the predetermined value L3, it is determined that the engagement has been completed, but when it is equal to or less than the predetermined value L3 even after the lapse of a prescribed predetermined time ts1 [sec], it is determined that the engagement has not been completed. When the determination in S30 is positive, i.e., when the engagement of the mesh clutch D1 has been completed, this routine is terminated.

[0029] If the determination in S30 is negative, that is, if the dog clutch D1 is disengaged, the hydraulic pressure Pd1 to the hydraulic actuator 34 is reduced in S40, and control for releasing the dog clutch D1 is performed.

[0030] Next, in S50, it is determined whether the mesh clutch D1 has been normally released. The determination is made positive if either of the following is true: whether the stroke amount ST of the hydraulic actuator 34 has returned to an initial value L1 (see FIG. 2) or less within a specified time ts2 [sec] from the start of the reduction in the hydraulic pressure Pd1, and whether the difference between the sleeve 50 side rotation speed Ndi [rpm] and the gear piece 52 side rotation speed Ndo [rpm] of the mesh clutch D1 is equal to or greater than a specified value Vd. The specified value Vd is a set value that is determined in advance by experiment or design and allows determination of the release of the meshing. If the determination in S50 is positive, i.e., if the mesh clutch D1 has been normally released, the process returns to S20, and the mesh clutch D1 is engaged again.

[0031] If the determination in S50 is negative, i.e., regardless of the operation of the hydraulic actuator 34 to the release side, the mesh clutch D1 is not normally released and is determined to be meshed, then in S60 it is determined whether or not the range is travelling, i.e., whether or not the operational position Psh of the shift lever 76 is in the forward travel position or the reverse travel position. If the determination in S60 is negative, i.e., the range is not travelling, the determination in S60 is repeated until the range is travelling.

[0032] If the determination in S60 is positive, in S70, when the operating position Psh is the forward drive position, the hydraulic pressure Pc1 to the hydraulic actuator 36 is increased to engage the forward clutch C1, and when the operating position Psh is the reverse drive position, the hydraulic pressure Pb1 to the hydraulic actuator 38 is increased to engage the reverse brake B1. With the forward clutch C1 or reverse brake B1 engaged, the sleeve 50 side of the dog clutch D1 is rotated while the hydraulic actuator 34 of the dog clutch D1 is operated to the release side, thereby releasing the dog clutch D1 from engagement.

[0033] Next, in S80, a determination is made as to whether or not the mesh clutch D1 has been normally released under the same determination conditions as in S50. If the determination in S80 is negative, that is, if the mesh clutch D1 has not been normally released, the determination in S80 is repeated until the mesh clutch D1 is released.

[0034] If the determination in S80 is positive, in S90, the hydraulic pressure Pc1 or hydraulic pressure Pb1 of the hydraulic actuator corresponding to the forward clutch C1 or reverse brake B1 engaged in S70 is reduced, and the forward clutch C1 or reverse brake B1 is released. This causes the sleeve 50 side of the mesh clutch D1 to stop, and the mesh (phase) with the gear piece 52 is shifted. Next, the process returns to S20, and the mesh clutch D1 is engaged again.

[0035] In this embodiment, the mesh clutch D1 is provided on the side where the sleeve 50 is connected to the forward clutch C1 and the reverse brake B1, but the gear piece 52 of the mesh clutch D1 may be provided on the side where the forward clutch C1 and the reverse brake B1 are connected. In this case, the gear piece 52 side is rotated to release the mesh with the sleeve 50 and to shift the mesh (phase).

[0036] As described above, according to this embodiment, when a misengagement due to meshing between the sleeve 50 and the gear piece 52 of the mesh clutch D1 is detected, and the misengagement due to meshing is not resolved even when the mesh clutch D1 is operated to the release side, the forward clutch C1 or the reverse brake B1 is engaged depending on the shift operation to forward or reverse driving, and the sleeve 50 side and the gear piece 52 side of the mesh clutch D1 are rotated relative to each other to resolve the misengagement due to meshing and shift the phase of the meshing between the sleeve 50 and the gear piece 52. After that, control is executed to re-engage the mesh clutch D1, so that the misengagement of the mesh clutch D1 can be resolved more accurately even in the initial state where misengagement due to meshing is likely to occur due to insufficient fit of the synchro mechanism S1.

[0037] Although the embodiment of the present invention has been described in detail above with reference to the drawings, the present invention can be applied to other embodiments.

[0038] For example, in the above embodiment, the power transmission device 10 is configured to include the first power transmission path PT1 and the second power transmission path PT2 in parallel, but the present invention is not necessarily limited to this. In short, the present invention can be applied as appropriate to any configuration that includes a mesh clutch having a synchromesh mechanism and a power transmission mechanism for forward travel or reverse travel.

[0039] It should be noted that the above is merely one embodiment, and the present invention can be embodied in various modified and improved forms based on the knowledge of those skilled in the art. [Explanation of symbols]

[0040] 10: Vehicle power transmission device 50: Sleeve 52: Gear piece 80: Electronic control device C1: Forward clutch B1: Reverse brake D1: Dog clutch S1: Synchromesh mechanism

Claims

[Claim 1] A control device for a vehicle power transmission device, comprising: a first power transmission path having a gear mechanism and a second power transmission path having a continuously variable transmission, which are arranged in parallel between an input shaft to which engine power is transmitted and an output shaft which transmits the power to drive wheels; and the first power transmission path is provided with a first clutch for forward travel, a first brake for reverse travel, and a mesh clutch having a synchromesh mechanism provided on the output shaft side of the first clutch and the first brake, When a malfunction of engagement due to meshing between the sleeve and the gear piece of the mesh clutch is detected, and the malfunction of engagement due to the meshing is not eliminated even when the mesh clutch is operated to the release side, the first clutch or the first brake is engaged in response to a shift operation to forward travel or reverse travel, and the sleeve side and the gear piece side of the mesh clutch are rotated relatively to eliminate the malfunction of engagement due to the meshing and to shift the phase of the meshing between the sleeve and the gear piece, and then the mesh clutch is controlled to be re-engaged. A control device for a vehicle power transmission device comprising:

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