JP6471365B2 - Control device for automatic transmission - Google Patents

Description

  The present invention relates to a control device for an automatic transmission.

  As a control device for an automatic transmission, a technique described in Patent Document 1 is known. In this publication, during the downshift accompanying the depression of the accelerator pedal from the 5th speed to the 4th speed, the engagement preparation hydraulic pressure (hereinafter referred to as the piston) is compensated for the loss stroke of the piston in the friction engagement element that is engaged at the 3rd speed and 2nd speed. (Referred to as pre-charge pressure) at the same time, thereby ensuring responsiveness when a request for another gear is made.

JP 2008-223939 A

  In recent years, stepped automatic transmissions have been further multi-staged, and if the number of shift stages to be precharged at the same time increases, the amount of oil may become insufficient and shift shocks and shift response may decrease. It was.

  The present invention has been made paying attention to the above problems, and an object of the present invention is to provide a control device for an automatic transmission that can suppress a shift shock and a decrease in shift response.

  In order to achieve the above object, in the automatic transmission control device of the present invention, if it is determined that there is a possibility of shifting during traveling at a predetermined shift stage, the shift is performed before the target shift stage is determined. Estimate the amount of oil required for precharging to stroke the pistons of all frictional engagement elements that are engaged at all gear positions that can be moved from the release position to the engagement position, and the estimated required oil amount is the oil pump Whether or not discharge is possible, and if discharge is possible, precharge all frictional engagement elements that are engaged at all gears that can be shifted. The frictional engagement elements that are engaged at a certain speed are precharged, and then the frictional engagement elements that are engaged at other speeds that are likely to be shifted are precharged.

  In other words, because the number of friction engagement elements that precharge is changed according to the oil pump discharge flow rate, engine blow-up and shift shock due to insufficient precharge are suppressed, and reduction in shift response due to precharge delay is also suppressed. it can.

1 is a skeleton diagram showing a configuration of an automatic transmission that achieves FR type 7 forward speed 1 reverse speed according to Embodiment 1; FIG. FIG. 3 is a circuit diagram illustrating a hydraulic circuit of the control valve unit according to the first embodiment. It is a figure which shows the fastening operation | movement table | surface of the forward 7 speed reverse speed 1 in the automatic transmission of Example 1. FIG. It is a figure showing the action | operation table | surface of solenoid valve SOL1-SOL7 in each gear stage of Example 1. FIG. It is a figure which shows a downshift line among the shift maps of Example 1. FIG. FIG. 3 is a control block diagram illustrating precharge control according to the first embodiment. 3 is a flowchart illustrating a precharge control process according to the first embodiment. As a comparative example, it is a time chart at the time of precharging all the frictional engagement elements in a state where the discharge flow rate of the oil pump is insufficient. As a comparative example, it is a time chart at the time of performing a precharge sequentially to one friction engaging element. 7 is a time chart when a sufficient oil pump discharge flow rate is ensured when downshifting from the seventh speed in the precharge control process of the first embodiment. 7 is a time chart when the oil pump discharge flow rate is Qc ≦ Qb <Qa when downshifting from the seventh speed in the precharge control process of the first embodiment. FIG. 6 is a time chart when the target shift speed is determined during precharge when downshifting from the seventh speed in the precharge control process of Embodiment 1. FIG.

  FIG. 1 is a skeleton diagram showing the configuration of an automatic transmission that achieves the first forward speed and the reverse speed of the FR type according to the first embodiment, and an overall system diagram showing a control configuration of the automatic transmission. The automatic transmission according to the first embodiment is connected to the engine Eg via a torque converter TC to which a lockup clutch LUC is attached. The rotation output from the engine Eg rotationally drives the pump impeller and the oil pump OP of the torque converter TC. The oil stirred by the rotation of the pump impeller is transmitted to the turbine runner through the stator, and drives the input shaft Input.

  Further, an engine controller (hereinafter referred to as ECU) 10 that controls the drive state of the engine Eg, an automatic transmission controller (hereinafter referred to as ATCU) 20 that controls the shift state of the automatic transmission, and the like, based on output signals of the ATCU 20 And a control valve unit CVU that performs hydraulic control of the fastening element. The ECU 10 and the ATCU 20 are connected via a CAN communication line or the like, and share sensor information and control information with each other by communication.

  The ECU 10 is connected to an APO sensor 1 that detects the amount of accelerator pedal operation by the driver and an engine speed sensor 2 that detects the engine speed. The ECU 10 controls the fuel injection amount and the throttle opening based on the engine speed and the accelerator pedal operation amount, and controls the engine output speed and the engine torque.

  The ATCU 20 includes a first turbine rotation speed sensor 3 that detects the rotation speed of the first carrier PC1 described later, a second turbine rotation speed sensor 4 that detects the rotation speed of the first ring gear R1, and the rotation speed of the output shaft Output. Is connected to an output shaft speed sensor 5 and an inhibitor switch 6 for detecting the shift lever operating state of the driver. The shift lever is an engine brake in which an engine brake acts in addition to P, R, N, and D. A range position and a normal forward travel range position where the engine brake does not act are provided.

  In the ATCU20, together with a rotation speed calculation unit for calculating the rotation speed of the input shaft Input, and at the normal time, based on the vehicle speed Vsp and the accelerator pedal opening APO, an optimum command shift speed from the shift map of the seventh forward speed shown in FIG. And a control unit for outputting a control command for achieving the command shift speed to the control valve unit CVU.

(About automatic transmission configuration)
Next, the configuration of the automatic transmission will be described. The first planetary gear set GS1 and the second planetary gear set GS2 are arranged in this order from the input shaft Input side to the axial output shaft Output side. In addition, a plurality of clutches C1, C2, C3 and brakes B1, B2, B3, B4 are arranged as friction engagement elements. A plurality of one-way clutches F1 and F2 are arranged.

The first planetary gear G1 is a single pinion type planetary gear having a first sun gear S1, a first ring gear R1, and a first carrier PC1 that supports a first pinion P1 that meshes with both gears S1 and R1.
The second planetary gear G2 is a single pinion planetary gear having a second sun gear S2, a second ring gear R2, and a second carrier PC2 that supports a second pinion P2 meshing with both gears S2 and R2.
The third planetary gear G3 is a single pinion planetary gear having a third sun gear S3, a third ring gear R3, and a third carrier PC3 that supports a third pinion P3 that meshes with both gears S3 and R3.
The fourth planetary gear G4 is a single pinion planetary gear having a fourth sun gear S4, a fourth ring gear R4, and a fourth carrier PC4 that supports a fourth pinion P4 that meshes with both gears S4 and R4.

The input shaft Input is connected to the second ring gear R2 and inputs the rotational driving force from the engine Eg via the torque converter TC or the like.
The output shaft Output is connected to the third carrier PC3, and transmits the output rotational driving force to the driving wheels via a final gear or the like not shown.

The first connecting member M1 is a member that integrally connects the first ring gear R1, the second carrier PC2, and the fourth ring gear R4.
The second connecting member M2 is a member that integrally connects the third ring gear R3 and the fourth carrier PC4.
The third connecting member M3 is a member that integrally connects the first sun gear S1 and the second sun gear S2.

The first planetary gear set GS1 is configured by connecting a first planetary gear G1 and a second planetary gear G2 with a first connecting member M1 and a third connecting member M3, and includes four rotating elements. In addition, the second planetary gear set GS2 includes a third planetary gear G3 and a fourth planetary gear G4 connected by a second connecting member M2 and configured by five rotating elements.
The first planetary gear set GS1 has a torque input path that is input from the input shaft Input to the second ring gear R2. The torque input to the first planetary gear set GS1 is output from the first connecting member M1 to the second planetary gear set GS2.
The second planetary gear set GS2 has a torque input path that is input from the input shaft Input to the second connecting member M2, and a torque input path that is input from the first connecting member M1 to the fourth ring gear R4. The torque input to the second planetary gear set GS2 is output from the third carrier PC3 to the output shaft Output.
When the H & LR clutch C3 is released and the rotation speed of the fourth sun gear S4 is larger than that of the third sun gear S3, the third sun gear S3 and the fourth sun gear S4 generate independent rotation speeds. Therefore, the third planetary gear G3 and the fourth planetary gear G4 are connected via the second connecting member M2, and each planetary gear achieves an independent gear ratio.

The input clutch C1 is a clutch that selectively connects and disconnects the input shaft Input and the second connecting member M2.
The direct clutch C2 is a clutch that selectively connects and disconnects the fourth sun gear S4 and the fourth carrier PC4.
The H & LR clutch C3 is a clutch that selectively connects and disconnects the third sun gear S3 and the fourth sun gear S4. A second one-way clutch F2 is arranged between the third sun gear S3 and the fourth sun gear.
The front brake B1 is a brake that selectively stops the rotation of the first carrier PC1. The first one-way clutch F1 is disposed in parallel with the front brake B1.
The low brake B2 is a brake that selectively stops the rotation of the third sun gear S3.
The 2346 brake B3 is a brake that selectively stops the rotation of the third connecting member M3 (the first sun gear S1 and the second sun gear S2).
The reverse brake B4 is a brake that selectively stops the rotation of the fourth carrier PC4.

(About the configuration of the control valve unit)
FIG. 2 is a circuit diagram showing a hydraulic circuit of the control valve unit CVU. The circuit configuration will be described below. The hydraulic circuit according to the first embodiment includes an oil pump OP as a hydraulic source driven by an engine, a manual valve MV that switches an oil passage that supplies a line pressure PL in conjunction with a driver's shift lever operation, and a line A pilot valve PV for reducing the pressure to a predetermined constant pressure is provided.

  In addition, a first pressure regulating valve CV1 for regulating the engagement pressure of the low brake B2, a second pressure regulating valve CV2 for regulating the engagement pressure of the input clutch C1, a third pressure regulating valve CV3 for regulating the engagement pressure of the front brake B1, A fourth pressure regulating valve CV4 for regulating the engagement pressure of the H & RL clutch C3, a fifth pressure regulating valve CV5 for regulating the engagement pressure of the 2346 brake B3, and a sixth pressure regulating valve CV6 for regulating the engagement pressure of the direct clutch C2 are provided. Yes.

  In addition, the second switching valve SV2 that switches the supply oil path of the D range pressure and the R range pressure to the direct clutch C2 and the hydraulic pressure supplied to the reverse brake B4 are switched to the sixth pressure regulating valve CV6. The third switching valve SV3 that switches between the supply hydraulic pressure from the R range pressure and the supply hydraulic pressure from the R range pressure, and the fourth switching that switches the hydraulic pressure output from the sixth pressure regulating valve CV6 between the oil passage 123 and the oil passage 122 Valve SV4 is provided.

  Further, based on a control signal from the ATCU 20, a first solenoid valve SOL1 that outputs a pressure regulating signal to the first pressure regulating valve CV1, and a second solenoid valve SOL2 that outputs a pressure regulating signal to the second pressure regulating valve CV2; The third solenoid valve SOL3 that outputs a pressure regulation signal to the third pressure regulation valve CV3, the fourth solenoid valve SOL4 that outputs the pressure regulation signal to the fourth pressure regulation valve CV4, and the pressure regulation to the fifth pressure regulation valve CV5 A fifth solenoid valve SOL5 that outputs a signal, a sixth solenoid valve SOL6 that outputs a pressure regulation signal to the sixth pressure regulating valve CV6, and a seventh solenoid valve SOL7 that outputs a switching signal to the third switching valve SV3 are provided. It has been.

  Each of the solenoid valves SOL2, SOL5, SOL6 is a three-way proportional solenoid valve having three ports, the first port is supplied with pilot pressure described later, the second port is connected to a drain oil passage, Each port is connected to a pressure receiving portion of a pressure regulating valve or a switching valve. The solenoid valves SOL1, SOL3, and SOL4 are two-way proportional solenoid valves having two ports, and the solenoid valve SOL7 is a three-way on / off solenoid valve having three ports.

  The first solenoid valve SOL1, the third solenoid valve SOL3, and the seventh solenoid valve SOL7 are normally closed types (closed when not energized). On the other hand, the second solenoid valve SOL2, the fourth solenoid valve SOL4, the fifth solenoid valve SOL5, and the sixth solenoid valve SOL6 are of a normally open type (open state when not energized).

(About oil passage configuration)
The discharge pressure of the oil pump OP driven by the engine is adjusted to the line pressure and then supplied to the oil passage 101 and the oil passage 102. The oil passage 101 includes an oil passage 101a connected to a manual valve MV that operates in conjunction with the driver's shift lever operation, an oil passage 101b that supplies the original pressure of the fastening pressure of the front brake B1, and an H & LR clutch C3. An oil passage 101c for supplying the original pressure of the fastening pressure is connected.

  The manual valve MV is connected to an oil passage 105 and an oil passage 106 that supplies an R range pressure selected during reverse travel, and switches between the oil passage 105 and the oil passage 106 in accordance with a shift lever operation.

  In the oil passage 105, there are an oil passage 105a that supplies the original pressure of the engagement pressure of the low brake B2, an oil passage 105b that supplies the original pressure of the engagement pressure of the input clutch C1, and an original pressure of the engagement pressure of the 2346 brake B3. An oil passage 105c for supplying, an oil passage 105d for supplying the original pressure of the engagement pressure of the direct clutch C2, and an oil passage 105e for supplying a switching pressure of a second switching valve SV2 described later are connected.

  In the oil passage 106, an oil passage 106a that supplies the switching pressure of the second switching valve SV2, an oil passage 106b that supplies the original pressure of the engagement pressure of the direct clutch C2, and an oil passage that supplies the engagement pressure of the reverse brake B4 106c is connected.

  An oil passage 103 for supplying pilot pressure is connected to the oil passage 102 via a pilot valve PV. The oil passage 103 has an oil passage 103a for supplying pilot pressure to the first solenoid valve SOL1, an oil passage 103b for supplying pilot pressure to the second solenoid valve SOL2, and an oil for supplying pilot pressure to the third solenoid valve SOL3. Passage 103c, an oil passage 103d for supplying pilot pressure to the fourth solenoid valve SOL4, an oil passage 103e for supplying pilot pressure to the fifth solenoid valve SOL5, and an oil passage 103f for supplying pilot pressure to the sixth solenoid valve SOL6 And an oil passage 103g for supplying a pilot pressure to the seventh solenoid valve SOL7.

  The first pressure regulating valve CV1 has a first port to which the oil passage 105a is connected, a second port connected to the drain circuit, a third port to which the oil passage 115a connected to the low brake B2 is connected, The fourth port to which the signal pressure of the first solenoid valve SOL1 is supplied, the fifth port to which the oil passage fed back from the oil passage 115a as the counter pressure of this signal pressure is connected, and the hydraulic pressure supplied to the fourth port There is provided a spring that acts oppositely. In FIG. 2, when the first pressure regulating valve CV1 moves upward, the oil passage 105a communicates with the oil passage 115a, while when moved downward, the oil passage 115a communicates with the drain. Similarly, the second pressure regulating valve CV2 to the sixth pressure regulating valve CV6 are provided with the same configurations as the first port to the fifth port and the spring, and thus description thereof is omitted.

  The second switching valve SV2 has a first port connected to the oil passage 105d for supplying the D range pressure, a second port connected to the oil passage 106d for supplying the R range pressure, and the sixth pressure regulating valve CV6. A third port connected to an oil passage 120 for supplying hydraulic pressure, a fourth port connected to an oil passage 105e for supplying D range pressure, and an oil passage 106a for supplying an R range pressure as a counter pressure of the fourth port. And a spring acting opposite to the hydraulic pressure supplied to the fourth port. In FIG. 2, when the second switching valve SV2 moves to the right, the oil passage 106b communicates with the oil passage 120, while when moved to the left, the oil passage 105d communicates with the oil passage 120.

  The third switching valve SV3 includes a first port connected to an oil passage 122 that supplies hydraulic pressure from the fourth switching valve SV4, a second port connected to an oil passage 106c that supplies R range pressure, and reverse. The third port connected to the oil passage 130 for supplying hydraulic pressure to the brake B4, the fourth port connected to the oil passage 140a for supplying the signal pressure of the seventh solenoid valve SOL7, and the fourth port d4 are supplied. A spring is provided to act against the hydraulic pressure. In FIG. 2, when the third switching valve SV3 moves to the right, the oil passage 106c and the oil passage 130 are communicated, and when moved to the left, the oil passage 122 and the oil passage 130 are communicated.

  The fourth switching valve SV4 has a first port connected to the oil passage 121 for supplying hydraulic pressure from the sixth pressure regulating valve CV6, a second port and a third port connected to the drain circuit, and an R range pressure. The fourth port to be supplied, the fifth port to which the D-range pressure is supplied, the spring acting opposite to the fourth port, the seventh port connected to the oil passage 122, and the oil passage 123 are connected. An eighth port is provided. In FIG. 2, when the fourth switching valve SV4 moves to the right, the oil passage 121 and the oil passage 123 communicate with each other and the oil passage 122 and the drain circuit communicate with each other. On the other hand, when the fourth switching valve SV4 moves to the left, the oil passage 121 and the oil passage The oil passage 123 and the drain circuit are in communication with each other.

Next, the operation will be described.
[Shifting action]
FIG. 3 is a diagram showing a fastening operation table of forward 7-speed backward 1-speed in the gear transmission for an automatic transmission according to the first embodiment, and FIG. 4 is a diagram showing operation tables of solenoid valves SOL1 to SOL7 at each gear stage. . When the clutches C1, C2, C3 and brakes B1, B2, B3, B4 are in a normal state, as shown in the engagement operation table of FIG. ) And release pressure (no mark).

<First gear>
In the first speed, different fastening elements act when the engine brake is applied (when the engine brake range position is selected) and when the engine brake is not applied (normally when the forward travel range position is selected). When the engine brake is actuated, it is obtained by engaging the front brake B1, the low brake B2, and the H & LR clutch C3 as shown in FIG. The first one-way clutch F1 provided in parallel with the front brake B1 and the second one-way clutch F2 provided in parallel with the H & LR clutch C3 are also involved in torque transmission. When the engine brake is not applied, the front brake B1 and the H & LR clutch C3 are released, only the low brake B2 is engaged, and torque is transmitted by the first one-way clutch F1 and the second one-way clutch F2.
At this time, as shown in the solenoid valve operation table of FIG. 4, the first to third solenoid valves SOL1 to SOL3 and the sixth and seventh solenoid valves SOL6 and SOL7 are turned on, and the others are turned off. The fastening pressure is supplied to the fastening elements.

<Second gear>
In the second speed, different engagement elements are engaged when the engine brake is applied (when the engine brake range position is selected) and when the engine brake is not applied (when the normal forward travel range position is selected). When the engine brake is actuated, it is obtained by engaging the low brake B2, the 2346 brake B3, and the H & LR clutch C3 as shown in FIG. The second one-way clutch F2 provided in parallel with the H & LR clutch C3 is also involved in torque transmission. When the engine brake is not operated, the H & LR clutch C3 is released, the low brake B2 and the 2346 brake B3 are engaged, and torque is transmitted by the second one-way clutch F2.
At this time, as shown in the solenoid valve operation table of FIG. 4, by turning on the first, second, fifth to seventh solenoid valves SOL1, SOL2, SOL5, SOL6, SOL7, A fastening pressure is supplied to the desired fastening element.

<3rd speed>
As shown in FIG. 3, the third speed is obtained by engaging the 2346 brake B3, the low brake B2, and the direct clutch C2.
In this third speed, since the 2346 brake B3 is engaged, the rotation input from the input shaft Input to the second ring gear R2 is decelerated by the second planetary gear G2. This decelerated rotation is output from the first connecting member M1 to the fourth ring gear R4. Further, since the direct clutch C2 is engaged, the fourth planetary gear G4 rotates together. Further, since the low brake B2 is engaged, the rotation input to the third ring gear R3 via the second connecting member M2 from the fourth carrier PC4 that rotates integrally with the fourth ring gear R4 is the third planetary gear G3. And output from the third carrier PC3. As described above, the fourth planetary gear G4 is involved in torque transmission but not in deceleration.
At this time, as shown in the solenoid valve operation table of FIG. 4, turn on the first, second, fourth, fifth and seventh solenoid valves SOL1, SOL2, SOL4, SOL5, SOL7 and turn off the others. Thus, the fastening pressure is supplied to the desired fastening element.

<4th speed>
As shown in FIG. 3, the fourth speed is obtained by engaging the 2346 brake B3, the direct clutch C2, and the H & LR clutch C3.
At the fourth speed, since the 2346 brake B3 is engaged, the rotation input from the input shaft Input to the second ring gear R2 is decelerated only by the second planetary gear G2. This decelerated rotation is output from the first connecting member M1 to the fourth ring gear R4. Further, since the direct clutch C2 and the H & LR clutch C3 are engaged, the second planetary gear set GS2 rotates integrally. Therefore, the rotation input to the fourth ring gear R4 is output from the third carrier PC3 as it is.
At this time, as shown in the solenoid valve operation table of FIG. 4, by turning on the second and fifth solenoid valves SOL2 and SOL5 and turning off the other, the fastening pressure is supplied to a desired fastening element.

<5-speed>
As shown in FIG. 3, the fifth speed is obtained by engaging the input clutch C1, the direct clutch C2, and the H & LR clutch C3.
At the fifth speed, since the input clutch C1 is engaged, the rotation of the input shaft Input is input to the second connecting member M2. Further, since the direct clutch C2 and the H & LR clutch C3 are engaged, the third planetary gear G3 rotates integrally. Therefore, the rotation of the input shaft Input is output from the third carrier PC3 as it is.
At this time, as shown in the solenoid valve operation table of FIG. 4, by turning off all the solenoid valves SOL1 to SOL7, a fastening pressure is supplied to a desired fastening element.

<6th speed>
As shown in FIG. 3, the sixth speed is obtained by engaging the input clutch C1, the H & LR clutch C3, and the 2346 brake B3.
In the sixth speed, since the input clutch C1 is engaged, the rotation of the input shaft Input is input to the second ring gear and also to the second connecting member M2. Further, since the 2346 brake B3 is engaged, the rotation decelerated by the second planetary gear G2 is output from the first connecting member M1 to the fourth ring gear R4. Further, since the H & LR clutch C3 is engaged, the second planetary gear set GS2 outputs the rotation defined by the rotation of the fourth ring gear R4 and the rotation of the second connecting member M4 from the third carrier PC3.
At this time, as shown in the solenoid valve operation table of FIG. 4, the fifth and sixth solenoid valves SOL5 and SOL6 are turned on, and the other solenoid valves SOL1, SOL2, SOL3, SOL4, and SOL7 are turned off. The fastening pressure is supplied to the fastening elements.

<7th speed>
As shown in FIG. 3, the seventh speed is obtained by engaging the input clutch C1, the H & LR clutch C3, and the front brake B1 (first one-way clutch F1).
In the seventh speed, since the input clutch C1 is engaged, the rotation of the input shaft Input is input to the second ring gear and also to the second connecting member M2. Further, since the front brake B1 is engaged, the rotation decelerated by the first planetary gear set GS1 is output from the first connecting member M1 to the fourth ring gear R4. Further, since the H & LR clutch C3 is engaged, the second planetary gear set GS2 outputs the rotation defined by the rotation of the fourth ring gear R4 and the rotation of the second connecting member M4 from the third carrier PC3.
At this time, as shown in the solenoid valve operation table of FIG. 4, the third and sixth solenoid valves SOL3 and SOL6 are turned on, and the other solenoid valves SOL1, SOL2, SOL4, SOL5, and SOL7 are turned off. The fastening pressure is supplied to the fastening elements.

<Reverse speed>
As shown in FIG. 3, the reverse speed is obtained by engaging the H & LR clutch C3, the front brake B1, and the reverse brake B4.
At this time, as shown in the solenoid valve operation table of FIG. 4, turn on the second, third and sixth solenoid valves SOL2, SOL3, SOL6 and turn off the other solenoid valves SOL1, SOL4, SOL5, SOL7. Thus, the fastening pressure is supplied to the desired fastening element. The seventh solenoid SOL7 is turned on at the initial stage of R range switching and turned off after completion of the fastening.

(Shift pre-charge control process)
FIG. 5 is a diagram showing a downshift line in the shift map of the first embodiment. The gear position in the region to which the operating point defined by the vehicle speed VSP and the accelerator pedal opening APO belongs is set as the target gear position. The shift line shown in FIG. 5 is a downshift line. When the operating point moves from the high shift speed region to the low shift speed region, the downshift request is output when the downshift line is crossed. Note that an upshift line (not shown) is also set in the shift map in the same manner, and an upshift request is output when the operating point crosses the upshift line when moving from the low shift speed region to the high shift speed region. .

  For example, it is assumed that the current operating point is p1 in the seventh speed region. At this time, when the driver depresses the accelerator pedal, the driving point moves upward in FIG. 5 from p1, and there is a possibility of movement such as p2, p3, p4, and p5 (hereinafter, the possibility of movement occurs). (The shift stage is referred to as a temporary shift stage.) Here, how much the driver depresses the accelerator pedal cannot be determined when crossing the 7-6 downshift line. Therefore, normally, for example, an APO change rate representing a change in driving point is obtained until a predetermined time that is considered to be settled, or even before the predetermined time elapses. Until the predetermined value is reached, the determination of the target shift stage is prohibited. Then, after a predetermined time has elapsed after crossing the 7-6 downshift line, or before the predetermined time has elapsed and the APO change rate is equal to or less than a predetermined value, the target shift stage is determined and the downshift is executed. .

  At this time, if the precharge is not performed after the downshift request is output and the target shift speed is determined, and the precharge is started after the target shift speed is determined, the responsiveness is deteriorated. In particular, it takes time to precharge the piston of the friction engagement element from the release position to the engagement position, and torque cannot be transmitted during this period. Therefore, even before the target shift speed is determined, it is conceivable to secure shift response by precharging the friction engagement elements that are engaged at the temporary shift speed in advance.

  As a comparative example, FIG. 8 is a time chart in the case where all the frictional engagement elements are precharged in a state where the discharge flow rate of the oil pump is insufficient. When a downshift request is output at time t1, precharging is started for the frictional engagement element that is engaged at the temporary shift stage. At this time, there is a limit to the discharge flow rate of the oil pump OP, and when precharging is performed on a plurality of frictional engagement elements when the engine speed is relatively low, such as a downshift from a high gear, The charge rate representing the stroke rate of each frictional engagement element due to precharging is low due to insufficient amount. Then, even at the time t2, even if the target shift speed is determined and the downshift is started, a delay occurs in the engagement pressure increase due to the insufficient charge rate. Therefore, even if the precharge of the direct clutch C2 is completed at time t3, the charge rate of the low brake B2 becomes insufficient, and even at the time t4, even if the indicated pressure of the low brake B2 is increased, the engine rotation cannot be performed. There is a risk that the shift shock will be worsened by the increase in the number.

  FIG. 9 is a time chart in the case where one friction engagement element is sequentially precharged as a comparative example. At time t1, a downshift request is output, precharge is started, and when the target shift stage is determined at time t2, even if the discharge flow rate of the oil pump is secured, the precharge is performed sequentially. In particular, it takes time until the charge rate of the low brake B2 that starts precharging last increases, and there is a possibility that the shift response may be deteriorated due to insufficient progress speed of the inertia phase in which the gear ratio changes.

  In the first embodiment, therefore, the discharge flow rate of the oil pump OP is estimated from when the downshift request is output until the target shift speed is determined, and the estimated discharge flow rate is used to pre-apply the friction engagement element of the temporary shift speed. Judge whether or not charging is possible, and if possible, precharge all provisional gears, and if not possible, prioritize and precharge to ensure shift response It was.

  FIG. 6 is a control block diagram illustrating precharge control according to the first embodiment. The discharge flow rate estimation unit 201 estimates and calculates the discharge flow rate of the oil pump OP based on the engine speed Ne and the automatic transmission oil temperature Ta. The leak amount calculation unit 202 calculates the leak amount leaking from each friction engagement element, valve, and the like based on the line pressure PL and the automatic transmission oil temperature Ta. For example, in the friction engagement element that has already been engaged, the amount of oil that compensates for the leak is consumed, and thus that amount is estimated and calculated. The surplus flow rate calculation unit 203 calculates the surplus flow rate Qb by subtracting the leak amount from the estimated discharge flow rate.

  The required stroke flow rate calculation unit 204 individually calculates the precharge amount of the frictional engagement element that needs to be precharged based on the information on the provisional shift stage. Then, priorities are set in order from the smallest difference from the gear ratio of the current gear, and information on each precharge amount and priority is output. For example, as indicated by the operating points described in the shift map of FIG. 5, the current shift stage is the seventh speed, and the temporary shift stages are the sixth speed, the fifth speed, the fourth speed, and the third speed. In this case, the gear stage with the highest priority is the sixth speed, and the gear stage with the lowest priority is the third speed. In addition, as shown in the engagement table of FIG. 3, in order to shift from the 7th speed to the 6th speed, it is necessary to precharge the 2346 brake B3, and to shift from the 7th speed to the 5th speed, the direct clutch C2 is preloaded. It is necessary to charge, 2346 brake B3 and direct clutch C2 need to be precharged to shift from 7th gear to 4th gear, 2346 brake B3 and direct clutch C2 to shift from 7th gear to 3rd gear And it is necessary to precharge the low brake B2. Therefore, when the precharge priorities are arranged in descending order, 2346 brake B3, direct clutch C2, and low brake B2 are obtained. The precharge amount required for each of these frictional engagement elements is calculated individually.

  The flow rate combination calculation unit 205 calculates the first required flow rate Qa and the second required flow rate Qc based on each precharge amount and priority. For example, in the case of downshift from the seventh speed, the first required flow rate Qa is the sum of the precharge amount of 2346 brake B3, the precharge amount of direct clutch C2, and the precharge amount of low brake B2. The second required flow rate Qc is a flow rate obtained by combining the two in descending order of priority, and is the sum of the precharge amount of the 2346 brake B3 and the precharge amount of the direct clutch C2.

  The simultaneous charge availability determination unit 206 compares the excess flow rate Qb with the first required flow rate Qa and compares the excess flow rate Qb with the second required flow rate Qc, and if Qb ≧ Qa, all can be precharged simultaneously. If Qc ≦ Qb <Qa, it is determined that two of the higher priority levels can be precharged simultaneously, and if Qb <Qc, it is determined that precharge is sequentially performed individually.

  The precharge command calculation unit 207 outputs a precharge command based on the determination result of the simultaneous charge availability determination unit 206 and the priority order information of the stroke required flow rate calculation unit 204. For example, in the case of downshift from 7th gear, when Qb ≧ Qa, 2346 brake B3, direct clutch C2 and low brake B2 are all commanded to precharge at the same time, and when Qc ≦ Qb <Qa, 2346 Command to precharge brake B3 and direct clutch C2 at the same time, then output command to precharge low brake B2, and when Qb <Qc, individually 2346 brake B3 → direct clutch C2 → low brake B2 Outputs a precharge command.

FIG. 7 is a flowchart showing precharge control processing during downshifting according to the first embodiment.
In step S1, the possibility of a downshift request is determined. When it is determined that a downshift request is generated, the process proceeds to step S2, and in other cases, the control flow is terminated.
In step S2, friction engagement element determination is performed. Specifically, as described in the stroke required flow rate calculation unit 204, the friction engagement element that needs to be precharged based on the provisional shift stage is specified and the priority order is determined.

In step S3, the first required flow rate Qa is calculated.
In step S4, the surplus flow rate Qb is calculated.
In step S5, it is determined whether or not Qa−Qb ≦ 0. If negative, the process proceeds to step S6, and if positive, the process proceeds to step S7.
In step S6, all precharges are executed simultaneously.

In step S7, the second required flow rate Qc is calculated.
In step S8, it is determined whether or not Qb−Qc ≦ 0. If positive, the process proceeds to step S9, and if negative, the process proceeds to step S10.
In step S9, two of the higher priorities are precharged at the same time, and then the remaining precharge is executed.
In step S10, precharge is executed individually in order of priority.

In step S11, it is determined whether or not the target gear position is determined during precharge. If it is determined, the process proceeds to step S13, and otherwise, the process proceeds to step S12.
In step S12, it is determined whether or not all precharges are completed. If completed, this control flow is terminated. If not completed, the process returns to step S11 to continue the precharge.
In step S13, a precharge process after the target shift stage is determined is performed. For example, if 2346 brake B3 and direct clutch C2 are precharged simultaneously when a downshift is requested from 7th gear, if the target gear is determined to be 5th gear, precharge to 2346 brake B3 is immediately By canceling, the charge rate of the direct clutch C2 is quickly increased.

  Next, the operation based on the control flow will be described. FIG. 10 is a time chart when the oil pump discharge flow rate is sufficiently secured when downshifting from the seventh speed in the precharge control process of the first embodiment. By simultaneously precharging all the frictional engagement elements that require precharging based on the provisional shift stage, after the target shift stage is determined, a highly responsive shift can be performed without causing engine blow-up or shifting speed reduction. realizable.

  FIG. 11 is a time chart when the oil pump discharge flow rate is Qc ≦ Qb <Qa when downshifting from the seventh speed in the precharge control process of the first embodiment. Of the frictional engagement elements that need to be precharged based on the provisional shift stage, the 2346 brake B3 and the direct clutch C2 are precharged simultaneously, and then the low brake B2 is precharged. As a result, the charge rate of the 2346 brake B3 and the direct clutch C2 can be increased as compared with the case where all are precharged simultaneously. In addition, since two precharges are performed at the same time, the precharge of the 2346 brake B3 and the direct clutch C2 can be completed in a shorter time compared to the case of sequentially performing the precharge one by one.

  FIG. 12 is a time chart when the target shift speed is determined during precharge when downshifting from the seventh speed in the precharge control process of the first embodiment. At time t1, a downshift request is output, and all the frictional engagement elements based on the provisional shift stage are precharged. At time t12, when the change rate of the accelerator pedal opening APO of the driver becomes less than a predetermined value and the target shift speed is determined to be the fifth speed, precharging to the 2346 brake B3 and the low brake B2 is immediately terminated, and the direct clutch Only C2 precharge continues. As a result, quick precharge is possible, and a highly responsive shift can be realized without causing engine blow-up or a decrease in shift speed.

As described above, the effects listed below can be obtained in the first embodiment.
(1) If it is determined that there is a possibility of a shift during traveling at a predetermined shift speed, it is engaged at a provisional shift speed (a shift speed at which all speeds can be changed) before the target shift speed is determined. Estimate the first required flow rate Qa, which is the amount of oil required for precharging to stroke the piston of the friction engagement element from the release position to the engagement position, and determine whether the first required flow rate Qa can be discharged from the oil pump OP. When discharging is possible, precharge is performed on all friction engagement elements (2346 Brake B3, Direct Clutch C2, Low Brake B2) of the provisional gears. The frictional engagement element that is engaged in step S1 is precharged, and then the frictional engagement element that is engaged in another shift stage where there is a possibility of shifting is precharged.
In other words, because the number of friction engagement elements that precharge is changed according to the oil pump discharge flow rate, engine blow-up and shift shock due to insufficient precharge are suppressed, and reduction in shift response due to precharge delay is also suppressed. it can.

  (2) In some of the shift speeds where there is a possibility of shifting, the difference in gear ratio from the predetermined shift speed among the temporary shift speeds is smaller than in other speeds where there is a possibility of shifting. In other words, since the friction engagement element that is engaged at a gear position close to the gear position at the start of gear shifting is precharged, for example, the change rate of the accelerator pedal opening APO becomes small after the accelerator pedal is operated, and a gear shift close at an early stage. Even when the speed is determined as the target shift speed, a highly responsive shift can be achieved.

  (3) When the amount of oil Qb that can be discharged from the oil pump OP is equal to or greater than the amount of oil necessary for precharging the plurality of frictional engagement elements, there are a plurality of shift stages that may be shifted. In other words, if Qc ≤ Qb <Qa, precharge multiple frictional engagement elements (2346 brake B3, direct clutch C2) simultaneously, and then precharge other frictional engagement elements (low brake B2) Thus, it is possible to realize a shift with higher responsiveness than in the case where sequential precharging is performed.

(4) After the target shift speed is determined, precharge for the frictional engagement elements other than the frictional engagement elements that are engaged at the determined shift speed is terminated.
Therefore, quick precharging can be performed for the determined shift stage, and a highly responsive shift can be realized without causing engine blow-up or a decrease in shift speed.

  The present invention has been described based on the first embodiment. However, the present invention is not limited to the above-described embodiment, and other configurations may be used. For example, in the first embodiment, the precharge control is performed when there is a downshift request, but may be performed when an upshift request is made. Further, in the first embodiment, the priority of the friction engagement elements is increased according to the gear position close to the gear position when the downshift request is output. For example, depending on the capacity of the friction engagement elements and the torque sharing ratio, Priorities may be determined.

  Further, in the first embodiment, the description has been given by taking the automatic transmission having seven forward speeds as an example. However, the automatic transmission may be applied to a multi-stage automatic transmission. In this case, if more than three precharges are required due to an increase in the provisional shift speed, the required flow rate associated with the combination of other friction engagement elements is calculated in addition to the second required flow rate Qc, and the combination From the optimal order. In addition, when there are four or more frictional engagement elements in the temporary shift stage, a plurality of precharges are performed at the first precharge, and after completion of the precharge, again based on the relationship between the discharge flow rate of the oil pump and the required flow rate. A plurality of precharges may be performed.

1 APO sensor 2 Engine speed sensor
10 Engine controller
20 Automatic transmission controller

Claims (4)

  If it is determined that there is a possibility of shifting during traveling at a predetermined shift speed, the pistons of all frictional engagement elements that are engaged at all shift speeds are determined before the target shift speed is determined. Estimate the amount of oil required for precharging to stroke from the release position to the fastening position, determine whether the estimated required amount of oil can be discharged from the oil pump, and if it can be discharged, there is a possibility of shifting Pre-charge all friction engagement elements that are engaged at all gears, otherwise pre-charge at some gears that may be geared, and then gears A control device for an automatic transmission that precharges a frictional engagement element that is engaged at any one of the shift speeds. The control apparatus for an automatic transmission according to claim 1,
Some of the gears that have the possibility of gear shifting are other gear speeds that have a gear ratio difference from the predetermined gear among all the gears that have the possibility of gear shifting. A control device for an automatic transmission characterized by being smaller than that. The control apparatus for an automatic transmission according to claim 1 or 2,
When the amount of oil that can be discharged from the oil pump is equal to or greater than the amount of oil necessary for precharging a plurality of frictional engagement elements, there are a plurality of shift stages that may be shifted. Control device for automatic transmission. The control apparatus for an automatic transmission according to any one of claims 1 to 3,
The automatic transmission control device according to claim 1, wherein after the target shift speed is determined, precharging of the friction engagement elements other than the friction engagement elements engaged at the determined shift speed is terminated.

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