Hydraulic control device for automatic transmission and vehicle

Abstract

The invention provides a hydraulic control device for an automatic transmission and a vehicle. The hydraulic control device for an automatic transmission can appropriately adjust the driving feeling at the time of shifting. To this end, this hydraulic pressure control device for an automatic transmission is provided with: an electromagnetic proportional valve for regulating the pressure of hydraulic oil; a pressure sensor that detects the hydraulic pressure of the hydraulic oil; and a control device that outputs a pulse-shaped control current having a predetermined current value and a predetermined application time to the electromagnetic proportional valve on the basis of a pre-stored control map, thereby shifting the hydraulic clutch from the disengaged state to the engaged state. The control device corrects the predetermined current value and the predetermined application time so that the hydraulic pressure of the hydraulic oil supplied to the hydraulic clutch is within a predetermined target pressure range when the pulse-shaped control current is output to the electromagnetic proportional valve.

Description

Technical Field

[0001] This disclosure relates to a hydraulic control device for an automatic transmission and a vehicle thereof. Background Technology

[0002] Generally, automatic transmissions in vehicles have multiple hydraulic clutches, and gear shifting is performed by selectively engaging or disengaging these clutches. The hydraulic clutches are connected to a hydraulic pump via electromagnetic proportional valves, and hydraulic fluid is supplied to the clutches by applying current to these valves. By filling the cylinders of the hydraulic clutches with this fluid, the clutches engage, thereby transmitting power from the engine to the wheels.

[0003] At this point, if the hydraulic pressure (hereinafter referred to as "output hydraulic pressure") supplied from the hydraulic pump to the hydraulic clutch is inappropriate, shift shock and shift delay will occur. Against this backdrop, various hydraulic control devices or methods have been proposed to improve the control accuracy of the output hydraulic pressure.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2011-256987 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] However, in automatic transmissions installed in vehicles, there are often individual differences in components such as hydraulic clutches and electromagnetic proportional valves, which vary from vehicle to vehicle, such as dimensional errors caused during manufacturing. Therefore, in such automatic transmissions, the time required for the hydraulic pressure to engage the hydraulic clutch and for the filling of the working fluid, i.e., the filling completion time, may vary from vehicle to vehicle.

[0009] These individual variations can cause differences in the time delay between the shift operation and the engagement of the hydraulic clutch in an automatic transmission. These individual variations can also lead to shift delays. Furthermore, depending on the state of the hydraulic clutch and the solenoid proportional valve, torque surges may occur during shifts.

[0010] In this case, in existing automatic transmissions, there may be shift delays, or the driving feel during shifts may vary depending on the vehicle.

[0011] Furthermore, components such as hydraulic clutches and electromagnetic proportional valves typically age over time. Therefore, in existing automatic transmissions, shift delays or changes in the driving feel during shifts may occur during use.

[0012] The present invention was made in view of the above-mentioned problems, and its object is to provide a hydraulic control device and vehicle for an automatic transmission that can appropriately adjust the driving feel during gear shifting.

[0013] Solution to the problem

[0014] The main solution to the above problems is a hydraulic control device for an automatic transmission that performs gear shifting by engaging and disengaging a hydraulic clutch, characterized in that it comprises:

[0015] An electromagnetic proportional valve, installed in the hydraulic circuit, regulates the pressure of the working oil supplied to the hydraulic clutch.

[0016] A pressure sensor detects the hydraulic pressure of the working oil supplied to the hydraulic clutch; and

[0017] The control device performs the filling of the hydraulic clutch with working oil by outputting a pulse-shaped control current with a specified current value and a specified application time to the electromagnetic proportional valve according to a pre-stored control map, thereby transferring the hydraulic clutch from a disengaged state to an engaged state.

[0018] The control device performs a correction process on the specified current value and the specified application time stored in the control map at a specified time interval, so that when the pulse-shaped control current is output to the electromagnetic proportional valve, the hydraulic pressure of the working oil supplied to the hydraulic clutch is within a specified target pressure range.

[0019] Another aspect of this disclosure is a vehicle equipped with the aforementioned hydraulic control device.

[0020] Invention Effects

[0021] The hydraulic control device according to the present invention can appropriately adjust the driving feel during gear shifting. Attached Figure Description

[0022] Figure 1 This is a diagram illustrating an example of the structure of the hydraulic control unit of an automatic transmission.

[0023] Figure 2 This diagram illustrates the operation of the hydraulic control device when changing the hydraulic clutch from a disengaged state to an engaged state.

[0024] Figure 3 This is a diagram illustrating an example of the action flow of control mapping correction processing performed by the ECU.

[0025] Figure 4This diagram illustrates an example of the change in the pulsed control current before the correction and the behavior of the output hydraulic pressure of the working oil.

[0026] Figure 5 This diagram illustrates an example of how the pulsed control current is changed after the control current value is corrected, as well as the behavior of the output hydraulic pressure of the working oil.

[0027] Figure 6 This diagram illustrates an example of how the pulsed control current changes after the application time of the control current is corrected, as well as the behavior of the output hydraulic pressure of the working oil.

[0028] Figure 7 This is a diagram representing an example of the applied current and application time data of the pulsed control current stored in the control map.

[0029] Explanation of reference numerals in the attached figures

[0030] 1: Hydraulic control device

[0031] 2: Hydraulic pump;

[0032] 2a: Pump drive motor;

[0033] 3: Piping;

[0034] 4: Filter;

[0035] 4a: First oil drainer;

[0036] 5: Pressure relief valve;

[0037] 10: Electromagnetic proportional valve;

[0038] 10a: Solenoid;

[0039] 10b: Return spring;

[0040] 11: Hydraulic clutch;

[0041] 12: Piston chamber;

[0042] 13: Clutch piston;

[0043] 14: Return spring;

[0044] 15: Second oil drainer;

[0045] 31: Pressure sensor;

[0046] 32: ECU (electronic control unit);

[0047] 32a: Control mapping;

[0048] 34: Oil temperature sensor. Detailed Implementation

[0049] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that in this specification and the accompanying drawings, components that actually have the same function are labeled with the same reference numerals to avoid redundant descriptions.

[0050] <Hydraulic control unit of automatic transmission>

[0051] Hereinafter, an example of the structure of a hydraulic control device (hereinafter referred to as "hydraulic control device 1") for an automatic transmission according to an embodiment of the present invention will be described.

[0052] It should be noted that, although not illustrated, the automatic transmission of this embodiment is, for example, a stepped automatic transmission, having the same structure as conventionally known automatic transmissions that use multiple gears to transmit force and periodically change the gear ratio. The automatic transmission includes a clutch as a friction element, which operates according to the output hydraulic pressure of the working oil supplied from the hydraulic control device.

[0053] Figure 1 This is a diagram showing an example of the structure of the hydraulic control device 1 of an automatic transmission.

[0054] The hydraulic control device 1 changes the engagement and disengagement states of the hydraulic clutch 11 by adjusting the output hydraulic pressure of the working oil supplied to the hydraulic clutch 11 of the automatic transmission, thereby enabling the automatic transmission to shift gears.

[0055] The hydraulic control device 1 includes: a hydraulic pump 2, a pump drive motor 2a, a pipeline 3 constituting a hydraulic circuit, a filter 4, a first oil drain 4a, a pressure relief valve 5, a solenoid proportional valve 10, a second oil drain 15, an oil temperature sensor 34, a pressure sensor 31, and an ECU 32.

[0056] One end of pipeline 3 is connected to a first drain valve 4a that stores working oil, and the other end is connected to a hydraulic clutch 11 that serves as the supply destination for the working oil, thus forming a flow path for the working oil. A hydraulic pump 2, a filter 4, and a solenoid proportional valve 10 are connected between the first drain valve 4a and the hydraulic clutch 11 in pipeline 3. In addition, a pressure relief valve 5 is connected in parallel with the filter 4 in pipeline 3.

[0057] The hydraulic pump 2 uses the power of the pump drive motor 2a to draw working oil from the first oil drainer 4a and discharge the working oil adjusted to high pressure into the pipeline 3.

[0058] The hydraulic clutch 11 is configured to transmit power from the engine of the vehicle to the wheels by engaging it. Here, a wet multi-plate hydraulic clutch is used as the hydraulic clutch 11.

[0059] The hydraulic clutch 11 has a piston chamber 12, a clutch piston 13, and a return spring 14. The clutch piston 13 is slidably accommodated within the piston chamber 12 under pressure applied by the return spring 14.

[0060] The hydraulic clutch 11 has the same structure as known structures. Working oil from the hydraulic control unit 1 (hydraulic pump 2) is supplied to the piston chamber 12, causing the clutch piston 13 to press against the force of the return spring 14. Furthermore, by filling the piston chamber 12 with working oil, the multiple clutch discs (not shown) of the hydraulic clutch 11 are pressed against each other by the clutch piston 13, thereby engaging the hydraulic clutch 11. With the hydraulic clutch 11 engaged, the power of the vehicle's engine is transmitted to the wheels.

[0061] That is, the hydraulic clutch 11 switches from the disengaged state to the engaged state by the action of the clutch piston 13 under the action of the working oil introduced from the hydraulic control device 1 into the piston chamber 12. The state of the hydraulic clutch 11 mainly depends on the output hydraulic pressure from the hydraulic control device 1. For example, when the output hydraulic pressure from the hydraulic control device 1 is above a predetermined threshold, the hydraulic clutch 11 enters the engaged state, and when the output hydraulic pressure is below the predetermined threshold, the hydraulic clutch 11 enters the disengaged state.

[0062] It should be noted that multiple hydraulic clutches can be connected in parallel with the hydraulic clutch 11 in the hydraulic control device 1. Furthermore, it can be configured such that the gear ratio of the automatic transmission can be changed by altering a combination of the engagement or disengagement of the multiple hydraulic clutches.

[0063] The electromagnetic proportional valve 10 is disposed between the hydraulic pump 2 and the hydraulic clutch 11 in the hydraulic circuit, and regulates the output hydraulic pressure of the working oil supplied to the hydraulic clutch 11. The electromagnetic proportional valve 10 is driven, for example, by the solenoid 10a, and supplies the hydraulic clutch 11 with working oil whose output hydraulic pressure corresponds to the operation of the solenoid 10a. Since the structure of the electromagnetic proportional valve 10 is the same as that of conventionally known electromagnetic proportional valves, its detailed description is omitted here (for example, see Patent Document 1).

[0064] The electromagnetic proportional valve 10 is configured such that an internal slide valve integrally mounted with the solenoid 10a moves when driven by the solenoid 10a, thereby adjusting the amount of working oil supplied to the hydraulic clutch 11 in accordance with the position of the slide valve. Specifically, when a control current is supplied to the solenoid 10a, the solenoid 10a is driven, causing the internal slide valve to move to one side, increasing the amount of working oil supplied from the hydraulic pump 2 to the hydraulic clutch 11, thereby increasing the output hydraulic pressure of the working oil supplied to the hydraulic clutch 11. On the other hand, when the control current is not supplied to the solenoid 10a, the solenoid 10a is not driven, and under the action of the return spring 10b located on the opposite side of the solenoid 10a, the internal slide valve moves to the other side, decreasing the amount of working oil supplied from the hydraulic pump 2 to the hydraulic clutch 11, thereby reducing the output hydraulic pressure of the working oil supplied to the hydraulic clutch 11.

[0065] It should be noted that the electromagnetic proportional valve 10 is configured to connect the hydraulic clutch 11 to the second oil drain 15 when the control current does not flow through the solenoid 10a, thereby discharging the working oil in the piston chamber 12 to the second oil drain 15.

[0066] The electromagnetic proportional valve 10 (solenoid 10a) is electrically connected to the ECU 32, and its operation is controlled by the control current supplied by the ECU 32. Essentially, the solenoid 10a generates a driving force corresponding to the value of the supplied control current, causing the internal spool valve to move by an amount corresponding to that control current value. That is, the electromagnetic proportional valve 10 regulates the amount of working oil supplied from the hydraulic pump 2 to the hydraulic clutch 11 to obtain an output hydraulic pressure corresponding to the value of the supplied control current.

[0067] A pressure sensor 31 is installed in the pipeline 3 between the electromagnetic proportional valve 10 and the hydraulic clutch 11. The pressure sensor 31 is configured to detect the pressure inside the piston chamber 12 of the hydraulic clutch 11, that is, the output hydraulic pressure of the working oil supplied from the hydraulic pump 2 to the hydraulic clutch 11. The pressure sensor 31 is electrically connected to the ECU 32 and sends the detected output hydraulic pressure to the ECU 32.

[0068] An oil temperature sensor 34 is installed in the first oil drainer 4a to detect the temperature of the working oil (i.e., oil temperature). The oil temperature sensor 34 is electrically connected to the ECU 32 and sends the detected oil temperature to the ECU 32.

[0069] The ECU 32 (equivalent to the control device of the present invention) is composed of, for example, a microcomputer and a drive circuit, and performs shift control processing by controlling the operation of the hydraulic clutch 11. Specifically, the ECU 32 is electrically connected to the solenoid 10a of the solenoid proportional valve 10, and controls the operation of the solenoid proportional valve 10 by controlling the current flowing through the solenoid 10a. Moreover, the ECU 32 controls the operation of the hydraulic clutch 11 by controlling the operation of the solenoid proportional valve 10 to regulate the output hydraulic pressure of the working oil supplied to the hydraulic clutch 11 (i.e., regulate the output oil quantity).

[0070] ECU 32 supplies a specified waveform of control current to solenoid proportional valve 10 based on control mapping 32a (see below). Figure 2 (As explained in section A), thereby controlling the operation of the electromagnetic proportional valve 10. The data for controlling the mapping 32a is, for example, pre-stored in a storage unit (e.g., a read-only memory (ROM)) of the ECU 32.

[0071] It should be noted that the ECU 32 is configured to acquire detection signals from the pressure sensor 31 and the oil temperature sensor 34 to obtain working oil status information. Additionally, the ECU 32 is configured to acquire detection signals from various sensors installed in the vehicle (e.g., shift lever sensor, throttle opening sensor, engine speed sensor, vehicle speed sensor, and acceleration sensor) 40 to obtain various driving information of the vehicle required for performing shift control processing.

[0072] Engagement of hydraulic clutch 11

[0073] Below, refer to Figure 2 The operation of the hydraulic control device 1 (ECU 32 and solenoid proportional valve 10) when changing the hydraulic clutch 11 from the disengaged state to the engaged state will be explained.

[0074] Figure 2 Figure A is an example of how the control current is output from the ECU 32 to the solenoid proportional valve 10 when the hydraulic clutch 11 is engaged. Figure 2 In A, the horizontal axis represents the time axis, and the vertical axis represents the current value [A] of the control current output to the electromagnetic proportional valve 10.

[0075] Figure 2 B represents the relationship with Figure 2 Figure A shows an example of the behavior of the output hydraulic pressure supplied to the hydraulic clutch 11, corresponding to the operation of the electromagnetic proportional valve 10. Figure 2 In B, the horizontal axis represents the time axis, and the vertical axis represents the output hydraulic pressure [Pa] of the working oil supplied to the hydraulic clutch 11. It should be noted that... Figure 2 A and Figure 2 B is drawn in a time-axis aligned manner.

[0076] The vehicle is equipped with, for example, a gear shift lever for switching gears in an automatic transmission. When the driver operates the gear shift lever, the ECU 32 applies a control current to the electromagnetic proportional valve 10, thereby engaging the hydraulic clutch 11.

[0077] The operation of the hydraulic control device 1 for engaging the hydraulic clutch 11 includes a filling step t1, a depressurization step t2, and a pressurization step t3. That is, the engagement of the hydraulic clutch 11 begins from the filling step t1. It should be noted that in... Figure 2 In step A, the reason for supplying control current from the pre-filling step t1 is that even when the hydraulic clutch 11 is in the disengaged state, the output hydraulic pressure of the working oil supplied to the hydraulic clutch 11 is maintained at a certain level, thereby preventing the working oil in the piston chamber 12 from being completely emptied, so as to shorten the response time from when the hydraulic clutch 11 changes from the disengaged state to the engaged state until the filling step t1 actually begins.

[0078] The filling step t1 is the step of filling the hydraulic clutch 11 with working oil. That is, when the shift lever is operated, the ECU 32 first applies a control current to the solenoid proportional valve 10 according to the control mapping 32a to fill the hydraulic clutch 11 with working oil. In the filling step t1, the ECU 32 supplies pulsed control current to the solenoid proportional valve 10.

[0079] Here, the pulsed control current is set to a relatively high current value Ip to shorten the filling completion time until the working oil is filled. In addition, in order to complete the filling of the working oil into the hydraulic clutch 11 (i.e., piston chamber 12) by means of the pulsed control current, the application time (i.e., pulse width) Δt1 of the pulsed control current is set to an appropriate time width (e.g., a fraction of a second).

[0080] During the filling step t1, a large flow of working oil is supplied from the electromagnetic proportional valve 10 to the hydraulic clutch 11. During this period, the output hydraulic pressure increases as the electromagnetic proportional valve 10 opens, and then becomes a constant pressure determined by the force of the return spring 14 of the hydraulic clutch 11. When the working oil filling is complete, the hydraulic clutch 11 engages, and the vehicle's engine power is transmitted to the wheels. However, in this newly filled state, due to the small pressing force required to engage the multiple clutch plates within the hydraulic clutch 11, slippage occurs between the clutch plates (i.e., a semi-engaged state).

[0081] The decompression step t2 is a step of significantly reducing the control current applied by the ECU 32 to the electromagnetic proportional valve 10, thereby decompressing the output hydraulic pressure of the working oil flowing from the electromagnetic proportional valve 10 to the hydraulic clutch 11. In the decompression step t2, the current value of the control current is set to be significantly smaller than the current value in the filling step t1, so that the output hydraulic pressure of the working oil reaches a predetermined specified pressure.

[0082] In this way, by temporarily reducing the output hydraulic pressure of the working oil flowing to the hydraulic clutch 11, the impact generated when the hydraulic clutch 11 engages is suppressed. In the decompression step t2, the output hydraulic pressure of the working oil is maintained at a substantially constant pressure. It should be noted that the time width of the decompression step t2 can be a short period (for example, from a few tenths of a second to several seconds) after the output hydraulic pressure of the working oil flowing to the hydraulic clutch 11 is reduced from the hydraulic pressure in the filling step t1 to the specified pressure.

[0083] The pressurization step t3 is a step in which the ECU 32 significantly increases the control current applied to the electromagnetic proportional valve 10 from the current value in the decompression step t2, thereby increasing the output hydraulic pressure of the working oil flowing from the electromagnetic proportional valve 10 to the hydraulic clutch 11. In the pressurization step t3, the ECU 32 gradually increases the control current applied to the electromagnetic proportional valve 10 from the current value in the decompression step t2 to increase the output hydraulic pressure of the working oil supplied from the electromagnetic proportional valve 10 to the hydraulic clutch 11. In this pressurization step t3, the current value of the control current applied to the electromagnetic proportional valve 10 is controlled so as to finally become a value greater than the current value of the pulsed control current in the filling step t1.

[0084] Through this pressurization step t3, the hydraulic clutch 11 is fully engaged by increasing the pressure. As a result, the power of the vehicle's engine is completely transmitted to the wheels, and thus the gear shift is completed.

[0085] It should be noted that although the influence of the oil temperature of the working oil on the operation of the hydraulic clutch 11 is ignored in the above description, in fact, the viscous resistance of the working oil and the like change due to the oil temperature of the working oil, so that the operation mode of the hydraulic clutch 11 changes slightly. Therefore, preferably, the ECU 32 pre-stores the control map 32a corresponding to each oil temperature of the working oil in the memory, and determines the control map 32a to be read based on the oil temperature of the working oil detected by the oil temperature sensor 34 (see Figure 5 )

[0086] <The correction function of the control map 32a in the ECU 32>

[0087] The engagement method of the hydraulic clutch 11 is as described above. In order to improve the shift feel while shortening the time until the automatic transmission completes the shift, the key is to adjust the output hydraulic pressure when filling the hydraulic clutch 11 with working oil to enter the semi-clutch state, that is, to adjust the output hydraulic pressure of the working oil in the filling step t1.

[0088] However, as mentioned above, there are often individual differences in the components constituting the hydraulic clutch 11 and the electromagnetic proportional valve 10, depending on the vehicle, such as dimensional errors caused during manufacturing. Therefore, the output hydraulic pressure when the electromagnetic proportional valve 10 is actuated may vary from vehicle to vehicle. In addition, due to the aging of the hydraulic clutch 11 and the electromagnetic proportional valve 10, the operation mode of the electromagnetic proportional valve 10 may change slightly when the same control current is supplied.

[0089] Therefore, the ECU 32 of this embodiment makes the filling method of filling the hydraulic clutch 11 with working oil in the filling step t1 appropriate by modifying the current value and application time of the pulse-shaped control current stored in the control map 32a.

[0090] The timing for the ECU 32 to perform this correction is, for example, when the driver issues a control mapping correction command, or when a change in shift feel is detected based on detection signals from various sensors installed in the vehicle (see the variants described later).

[0091] It should be noted that, as a method for the ECU 32 to adjust the output hydraulic pressure of the working oil, one approach is for the ECU 32 to perform feedback control on the control current of the electromagnetic proportional valve 10 based on the pressure detected by the pressure sensor 31 when the automatic transmission shifts gears. However, there is a response delay from the time the control current applied to the electromagnetic proportional valve 10 changes until the electromagnetic proportional valve 10 actually actuates, thus changing the output hydraulic pressure of the working oil supplied to the hydraulic clutch 11. Moreover, the filling step t1 is a step in which a pulse-like control current is applied within a very short time. Therefore, it is practically difficult to achieve the following control: the ECU 32 performs feedback control on the control current of the electromagnetic proportional valve 10 based on the pressure detected by the pressure sensor 31 when the automatic transmission shifts gears, taking into account this response delay, to ensure an appropriate shift feel.

[0092] From this perspective, the ECU 32 of this embodiment observes the behavior of the output hydraulic pressure of the working oil corresponding to the control current of the electromagnetic proportional valve 10, and corrects the control mapping 32a through this correction function.

[0093] Figure 3 This diagram illustrates an example of the operation flow of the control mapping correction process performed by the ECU 32 in this embodiment. It should be noted that... Figure 3 The flowchart shown illustrates, for example, the processing performed by ECU 32 according to a computer program. ECU 32, for instance, begins processing upon receiving a control mapping correction command from the driver. Figure 3 The process is shown in the flowchart.

[0094] Figure 4 , Figure 5 and Figure 6 This diagram illustrates an example of the change in pulse-shaped control current and the behavior of the output hydraulic pressure of the working oil before and after each correction process during the control mapping correction process of this embodiment.

[0095] Figure 4 This is a way of representing the pulsed control current before the control mapping correction process. Figure 4 (A) and the behavior of the output hydraulic pressure of the working oil ( Figure 4 A diagram of an example of B). Figure 5 This indicates that the applied current is from Figure 4 The pulsed control current method after the addition of the method (i.e., S6) Figure 5 (A), and the behavior of the output hydraulic pressure of the working oil ( Figure 5 A diagram of an example of B). Figure 6 It means from Figure 5 The method of shortening the application time (i.e., S8) by using a pulsed control current ( Figure 6 (A), and the behavior of the output hydraulic pressure of the working oil ( Figure 6 A diagram of an example of B).

[0096] Figure 7 This is a diagram showing an example of data related to the applied current and application time of the pulsed control current stored in the control map 32a (filling in the applied current and application time in step t1).

[0097] Here, we will explain in turn. Figure 3 The flowchart shown illustrates the processing. It should be noted that, from the perspective of shortening the time until the automatic transmission completes a gear shift, Figure 3 The key to the process shown in the flowchart is to minimize the application time of the pulsed control current. Therefore, Figure 3 The flowchart shown illustrates the process of adjusting the applied pulsed control current to an appropriate value while minimizing the application time.

[0098] In step S1, the ECU 32 obtains a detection signal from the oil temperature sensor 34 and detects the oil temperature of the working oil.

[0099] In step S2, the ECU 32 determines the application time and current value of the pulsed control current based on the control mapping 32a.

[0100] In step S3, the ECU 32 outputs a pulsed control current to the electromagnetic proportional valve 10, which has the application time and current value determined in step S2.

[0101] In step S4, the ECU 32 obtains a detection signal from the pressure sensor 31 and detects the output hydraulic pressure of the working oil.

[0102] To improve shift feel while shortening the time until the automatic transmission completes a shift, the key lies in the output hydraulic pressure when filling the hydraulic clutch 11 with working fluid to enter the semi-engaged state, i.e., the output hydraulic pressure of the working fluid when filling step t1 is completed. Furthermore, typically, after the output pulse-like control current, there is a response delay before the amount of working fluid supplied to the hydraulic clutch 11 follows the pulse output, thus starting to actuate the electromagnetic proportional valve 10.

[0103] From this perspective, in subsequent steps S5 and S7, when determining the magnitude of the output hydraulic pressure of the working oil, the ECU 32 uses the output hydraulic pressure detected by the pressure sensor 31 at a time (e.g., the falling edge time) after a predetermined time has elapsed from the rising edge time of the pulse-shaped control current as a reference.

[0104] In step S5, ECU 32 determines whether the output hydraulic pressure of the working oil is above the lower limit of the target pressure range. If the output hydraulic pressure of the working oil is above the lower limit of the target pressure range (S5: Yes), the process proceeds to step S7; if the output hydraulic pressure of the working oil is not above the lower limit of the target pressure range (S5: No), the process proceeds to step S6.

[0105] It should be noted that, here, the target pressure range is a specified pressure range set based on the pressure resisting the force of the return spring 14 of the hydraulic clutch 11. Figure 4 B, Figure 5 B and Figure 6 In section B, the pressure resisted by the force of the return spring 14 is described as the target pressure.

[0106] In step S6, ECU 32 increases the value of the pulsed control current stored in control map 32a by a predetermined amount. Here, if the output hydraulic pressure of the working oil is not above the lower limit of the target pressure range (S5: No), this is because the force generated by the output hydraulic pressure of the working oil, which resists the force of the return spring 14 of the hydraulic clutch 11, is small, thus failing to smoothly fill the hydraulic clutch 11 with working oil (see reference). Figure 4 ).

[0107] The output hydraulic pressure of the working oil is Figure 4The reason for the fluctuating behavior is that the output hydraulic pressure of the working oil is less than the force of the return spring 14 of the hydraulic clutch 11, causing the piston chamber 12 of the hydraulic clutch 11 to repeatedly expand and contract. Therefore, in this case, even after the filling step t1 on the control map 32a ends, the filling of the working oil into the hydraulic clutch 11 is not yet complete (i.e., the half-clutch state is not yet complete). In this state, if the depressurization step t2 is performed on the control map 32a and the pressurization step t3 is executed, the hydraulic clutch 11 is forcibly engaged from the incomplete half-clutch state, thus producing a large shift shock. Furthermore, in this case, the time required to complete the engagement of the hydraulic clutch 11 is longer than usual.

[0108] In step S6, by increasing the value of the pulsed control current stored in the control map 32a by a predetermined amount, the width of the port connecting the hydraulic pump 2 and the hydraulic clutch 11 in the electromagnetic proportional valve 10 increases accordingly. This increases the amount of high-pressure working oil supplied from the hydraulic pump 2 to the hydraulic clutch 11, and consequently increases the output hydraulic pressure of the working oil. In this state, the filling of the hydraulic clutch 11 with working oil proceeds smoothly due to the resistance of the return spring 14, thus maintaining a substantially constant output hydraulic pressure of the working oil detected by the pressure sensor 31 during the filling step t1.

[0109] However, if the pulsed control current value is increased to a certain extent in order to minimize the application time of the pulsed control current, the application time of the pulsed control current will be slightly longer. Therefore, after the hydraulic oil is filled into the hydraulic clutch 11, the output hydraulic pressure of the hydraulic oil will continue to increase. Figure 5 In the process, after the filling step t1 on the control map 32a is completed, the output hydraulic pressure of the working oil detected by the pressure sensor 31 increases sharply, which is due to this reason.

[0110] After step S6, ECU 32 returns to step S1 and performs the update process again to confirm that the output hydraulic pressure of the working oil is within the target pressure range.

[0111] It should be noted that the lower limit of the target pressure range is set to an appropriate value based on the force of the return spring 14. Therefore, as needed, the ECU 32 will repeat steps S1 to S6 to adjust the applied current of the pulsed control current on the control map 32a to an appropriate value.

[0112] In step S7, ECU 32 determines whether the output hydraulic pressure of the working oil is below the upper limit of the target pressure range. If it is determined that the output hydraulic pressure of the working oil is below the upper limit of the target pressure range (S7: Yes), no special processing is performed, and the process ends. Figure 3 The flowchart processing. If the output hydraulic pressure of the working oil is not below the upper limit of the target pressure range (S7: No), the processing proceeds to step S8.

[0113] In step S8, the ECU 32 reduces the application time of the pulsed control current stored in the control map 32a by a specified width.

[0114] As mentioned above, when the output hydraulic pressure of the working oil is above the upper limit of the target pressure range, the following can be inferred: Figure 5 As shown, the application time of the pulsed control current stored in the control map 32a is too long, resulting in a situation where the amount of high-pressure working oil supplied to the hydraulic clutch 11 continues even after the filling of the working oil into the hydraulic clutch 11 is completed. In this state, on the actual hydraulic clutch 11, since it is forcibly transferred from the semi-engaged state to the clutch engaged state in the filling step t1, which is a preparation stage (i.e., entering the clutch engaged state without going through the decompression step t2), a large shift shock is generated.

[0115] In step S8, by reducing the application time of the pulsed control current stored in the control map 32a by a predetermined width, the time for widening the port connecting the hydraulic pump 2 and the hydraulic clutch 11 in the electromagnetic proportional valve 10 can be matched with the time for filling the hydraulic clutch 11 with working oil. That is, as Figure 6 As shown, this eliminates the sharp increase in the output hydraulic pressure of the working oil after the working oil is filled into the hydraulic clutch 11, thus suppressing the output hydraulic pressure of the working oil within the target pressure range.

[0116] After step S8, ECU 32 returns to step S1 and performs the update process again to confirm that the output hydraulic pressure of the working oil is within the target pressure range.

[0117] It should be noted that the upper limit of the target pressure range is set to an appropriate value based on the force of the return spring 14. Therefore, as needed, the ECU 32 will repeat steps S1 to S5 and steps S7 to S8 to adjust the application time of the pulsed control current on the control map 32a to an appropriate value.

[0118] Through the processes described in steps S1 to S8, the ECU 32 can adjust the output hydraulic pressure of the working oil within the target pressure range during the filling step t1. That is, during actual gear shifting, the control mapping 32a is updated in a way that shortens the shifting time while providing a good shifting feel.

[0119] [Effect]

[0120] As described above, the hydraulic control device for the automatic transmission in this embodiment includes:

[0121] An electromagnetic proportional valve, installed in the hydraulic circuit, regulates the pressure of the working oil supplied to the hydraulic clutch.

[0122] A pressure sensor detects the hydraulic pressure of the working oil supplied to the hydraulic clutch; and

[0123] The control device performs the filling of the hydraulic clutch with working oil by outputting a pulse-shaped control current with a specified current value and a specified application time to the electromagnetic proportional valve according to a pre-stored control map, thereby transferring the hydraulic clutch from a disengaged state to an engaged state.

[0124] The control device performs a correction process on the specified current value and the specified application time stored in the control map at a specified time interval, so that when the pulse-shaped control current is output to the electromagnetic proportional valve, the hydraulic pressure of the working oil supplied to the hydraulic clutch is within a specified target pressure range.

[0125] Therefore, even when the condition of the operated objects (e.g., hydraulic clutches and electromagnetic proportional valves) changes due to aging, or when there are individual differences in the operated objects (e.g., hydraulic clutches and electromagnetic proportional valves) due to manufacturing defects, the shift feel can be adjusted appropriately.

[0126] In particular, the hydraulic control device of the automatic transmission according to this embodiment can drive the electromagnetic proportional valve by using a pulse-shaped control current with the current value and application time appropriately set, and fill the hydraulic clutch with working oil in a short time. Therefore, it can always achieve short-time shifting action.

[0127] <Variation Example>

[0128] In the above embodiment, it is shown that the control mapping correction command from the vehicle driver is used as an opportunity to execute... Figure 3 The control mapping update process is shown.

[0129] Regarding this, as mentioned above, the components that make up the hydraulic clutch 11 and the electromagnetic proportional valve 10, etc., will age over time, and this aging may cause the shifting feel to gradually deteriorate without the driver noticing.

[0130] Considering the above points, the hydraulic control device 1 (ECU 32) of this modified example determines whether the vehicle's shifting action is in an abnormal state based on the acceleration fluctuations or axle rotation fluctuations detected during the automatic transmission's shifting action, and performs the aforementioned correction processing when it is determined that the vehicle's shifting action is in an abnormal state (see reference). Figure 3 This will eliminate the abnormal state.

[0131] Normally, when an automatic transmission performs a gear shift, the hydraulic clutch 11 enters a semi-engaged state after completing the filling step t1, and the engine is subjected to a load from the output shaft. Therefore, the engine speed decreases accordingly.

[0132] Subsequently, in the decompression step t2, the hydraulic clutch 11 remains in a semi-engaged state. Then, in the pressurization step t3, the hydraulic clutch 11 is switched to an engaged state, and the engine bears a larger load from the output shaft. That is, the engine speed further decreases accordingly.

[0133] Here, assuming that the characteristics of the hydraulic clutch 11 and the electromagnetic proportional valve 10 change, the behavior of the engine speed will also change.

[0134] For example, in the filling step t1, if the output hydraulic pressure of the working oil supplied to the hydraulic clutch 11 is too low, the semi-clutch state will not be completed even after the filling step t1 is finished, and therefore the engine speed will remain almost unchanged. Moreover, in this case, since the hydraulic clutch 11 is forcibly engaged in the boosting step t3, the engine speed will decrease sharply in the boosting step t3.

[0135] On the other hand, for example, in the filling step t1, if the output hydraulic pressure of the working oil supplied to the hydraulic clutch 11 is too high, it will be forcibly transferred to the engaged state of the hydraulic clutch 11 in the filling step t1, and thus the engine speed will drop sharply in the filling step t1.

[0136] Furthermore, in this case, torque shocks (i.e. acceleration fluctuations) will occur in the filling step t1 and the pressurization step t3.

[0137] From this perspective, the ECU 32 in this modified example detects changes in vehicle acceleration and axle speed during automatic transmission shifting, and determines whether the vehicle shifting is in an abnormal state based on the manner of these changes. The sensor used can be any sensor capable of detecting vehicle acceleration or axle speed. Examples of such sensors include clutch output speed sensors, gear input speed sensors, transmission output speed sensors, driveshaft speed sensors, and acceleration sensors installed in the vehicle.

[0138] It should be noted that, in this case, the ECU 32 can store reference data related to the standard behavior of the vehicle's acceleration and axle speed during automatic transmission shifting in advance in the storage unit, and determine whether the vehicle's acceleration and axle speed behavior is abnormal by comparing it with the reference data.

[0139] As described above, the hydraulic control device 1 of the automatic transmission according to this modification is able to automatically perform control mapping update processing at appropriate timing.

[0140] The specific examples of the present invention have been described in detail above, but these are merely examples and not intended to limit the technical solutions. The claimed technology includes various modifications and variations to the specific examples described above.

[0141] Industrial applicability

[0142] The hydraulic control device according to the present invention can appropriately adjust the driving feel during gear shifting.

Claims

1. A hydraulic control device for an automatic transmission that shifts gears by engaging and disengaging a hydraulic clutch, characterized in that it comprises: An electromagnetic proportional valve, installed in the hydraulic circuit, regulates the pressure of the working oil supplied to the hydraulic clutch. A pressure sensor detects the hydraulic pressure of the working oil supplied to the hydraulic clutch; and The control device performs the filling of the hydraulic clutch with working oil by outputting a pulse-shaped control current with a specified current value and a specified application time to the electromagnetic proportional valve according to a pre-stored control map, thereby transferring the hydraulic clutch from a disengaged state to an engaged state. The control device performs a correction process on the specified current value and the specified application time stored in the control map at a specified time interval, so that when the pulse-shaped control current is output to the electromagnetic proportional valve, the hydraulic pressure of the working oil supplied to the hydraulic clutch is within a specified target pressure range.

2. The hydraulic control device as described in claim 1, wherein, The specified target pressure range is set based on the pressure that resists the force of the return spring of the hydraulic clutch.

3. The hydraulic control device as described in claim 1, wherein, The correction process includes the following first and second processes: In the first process, the predetermined current value stored in the control map is increased such that when the pulsed control current is output to the electromagnetic proportional valve, the hydraulic pressure of the working oil detected by the pressure sensor is above the lower limit of the predetermined target pressure range. In the second process, the predetermined application time stored in the control map is reduced such that when the pulsed control current is output to the electromagnetic proportional valve, the hydraulic pressure of the working oil detected by the pressure sensor is below the upper limit of the predetermined target pressure range. In the correction process, the control device performs the second process after performing the first process.

4. The hydraulic control device as described in claim 1, wherein, The hydraulic control device also includes an oil temperature sensor for detecting the temperature of the working oil supplied to the hydraulic clutch. The control map stores the specified current value and the specified application time of the pulsed control current in a manner associated with the temperature of the working oil. When performing the correction process, the control device acquires the temperature of the working oil detected by the oil temperature sensor, and corrects the specified current value and the specified application time corresponding to that temperature on the control map.

5. The hydraulic control device as described in claim 1, wherein, The control device determines whether the automatic transmission shifting action is in an abnormal state based on the acceleration fluctuations of the vehicle or the rotational fluctuations of the vehicle axle detected during the shifting action of the automatic transmission, and performs the correction process when it determines that the shifting action of the automatic transmission is in an abnormal state.

6. The hydraulic control device as claimed in claim 1, wherein, When the control device changes the hydraulic clutch from a disengaged state to an engaged state, it executes the following steps in sequence: The filling step involves filling the hydraulic clutch with working oil by outputting the pulsed control current to the electromagnetic proportional valve. The pressure reduction step involves lowering the control current output to the solenoid proportional valve to a value lower than that in the filling step, thereby reducing the hydraulic pressure of the working oil; and In the pressurization step, the hydraulic pressure of the working oil is increased to a higher pressure than that in the depressurization step by increasing the current value of the control current output to the electromagnetic proportional valve to a value greater than that in the depressurization step, and by applying a stepped or ramped control current, thereby completing the change of the hydraulic clutch to the engaged state.

7. A vehicle, characterized in that, The device comprises the hydraulic control device according to any one of claims 1 to 6.

Images