Hydraulic control device for automatic transmission and vehicle

Abstract

To provide a hydraulic control device for an automatic transmission that can appropriately adjust the feeling when shifting gears. [Solution] The hydraulic control device 1 of the automatic transmission disclosed herein comprises an electromagnetic proportional valve 10 that adjusts the pressure of the hydraulic oil, a pressure sensor 31 that detects the hydraulic oil pressure, and a control device 32 that outputs a pulsed control current of a predetermined current value and a predetermined application time to the electromagnetic proportional valve 10 in accordance with a pre-stored control map 32a, thereby transitioning the hydraulic clutch 11 from an open state to an engaged state, and when the control device 32 outputs the pulsed control current to the electromagnetic proportional valve 10, it performs a correction process to correct the predetermined current value and the predetermined application time so that the hydraulic oil pressure of the hydraulic oil supplied to the hydraulic clutch 11 is within a predetermined target pressure range.

Description

[Technical Field]

[0001] The present disclosure relates to a hydraulic control device for an automatic transmission and a vehicle. [Background technology]

[0002] Generally, a vehicle's automatic transmission has multiple hydraulic clutches that are selectively engaged or disengaged to change gears. The hydraulic clutches are connected to a hydraulic pump via an electromagnetic proportional valve, and hydraulic oil is supplied to the hydraulic clutches by passing an electric current through the electromagnetic proportional valve. When hydraulic oil fills the cylinder of the hydraulic clutch, the hydraulic clutch is engaged and power is transmitted from the engine to the wheels.

[0003] At this time, if the hydraulic oil pressure (hereinafter referred to as "output hydraulic pressure") supplied from the hydraulic pump to the hydraulic clutch is inappropriate, gear shift shock or gear shift delay may occur. In light of this background, various hydraulic control devices or hydraulic control methods have been proposed to improve the control accuracy of the output hydraulic pressure. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-256987 Summary of the Invention [Problem to be solved by the invention]

[0005] In an automatic transmission mounted on a vehicle, components such as a hydraulic clutch and an electromagnetic proportional valve generally have individual differences between vehicles due to variations in dimensions during manufacturing, etc. Therefore, in such an automatic transmission, there may be individual differences between vehicles in terms of the hydraulic pressure when engaging the hydraulic clutch and the filling completion time for filling of hydraulic oil.

[0006] These individual differences cause variations in the time lag between the shift operation and the engagement of the hydraulic clutch in an automatic transmission. These individual differences can also cause delays in shifting. Furthermore, depending on the state of the hydraulic clutch or the electromagnetic proportional valve, there is a risk of torque shock occurring during shifting.

[0007] As described above, in the automatic transmission according to the prior art, there are cases where a delay in gear shifting occurs and the feeling when shifting gears varies between vehicles.

[0008] Additionally, the condition of components such as hydraulic clutches and proportional solenoid valves typically deteriorates over time, which means that automatic transmissions according to conventional technology may experience shift delays or a change in the feel of shifting gears over time.

[0009] The present invention has been made in consideration of the above problems, and aims to provide a hydraulic control device for an automatic transmission and a vehicle that make it possible to appropriately adjust the feeling when shifting gears. [Means for solving the problem]

[0010] The present disclosure mainly solves the above-mentioned problems by: A hydraulic control device for an automatic transmission that performs vehicle gear shifting by engaging and disengaging a hydraulic clutch, an electromagnetic proportional valve disposed in the hydraulic circuit for adjusting the pressure of hydraulic oil supplied to the hydraulic clutch; a pressure sensor for detecting the hydraulic pressure of the hydraulic oil supplied to the hydraulic clutch; a control device that outputs a pulsed control current of a predetermined current value and a predetermined application time to the electromagnetic proportional valve in accordance with a pre-stored control map, thereby filling the hydraulic oil into the hydraulic clutch and transitioning the hydraulic clutch from a released state to an engaged state; Equipped with When the control device outputs the pulsed control current to the electromagnetic proportional valve, the control device performs a correction process to correct the predetermined current value and the predetermined application time stored in the control map at a predetermined timing so that the hydraulic pressure of the hydraulic oil supplied to the hydraulic clutch falls within a predetermined target pressure range. It is a hydraulic control device.

[0011] In other respects, A vehicle equipped with the above hydraulic control device. [Effects of the Invention]

[0012] According to the hydraulic control device of the present invention, it is possible to appropriately adjust the feeling when shifting gears. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a hydraulic control device for an automatic transmission. [Figure 2] FIG. 10 is a diagram illustrating the operation of the hydraulic control device when the hydraulic clutch is changed from a released state to an engaged state. [Figure 3] FIG. 10 is a diagram showing an example of an operation flow of a control map correction process performed by an ECU. [Figure 4] FIG. 10 is a diagram showing an example of a change in pulse-shaped control current before correction and a behavior of the output hydraulic pressure of the hydraulic oil. [Figure 5] FIG. 10 is a diagram showing an example of a change in pulse-shaped control current after the current value of the control current is corrected, and an example of the behavior of the output hydraulic pressure of the hydraulic oil. [Figure 6] FIG. 10 is a diagram showing an example of a change in pulse-shaped control current after correction of the application time of the control current, and a behavior of the output hydraulic pressure of the hydraulic oil. [Figure 7] FIG. 10 is a diagram showing an example of data related to the applied current and application time of a pulsed control current stored in a control map. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functions are designated by the same reference numerals, and redundant description will be omitted.

[0015] <Hydraulic control device for automatic transmission> An example of the configuration of a hydraulic control device for an automatic transmission according to one embodiment of the present invention (hereinafter referred to as "hydraulic control device 1") will be described below.

[0016] Although not shown, the automatic transmission according to this embodiment may be, for example, a multi-speed automatic transmission, which has a configuration similar to that of a conventionally known transmission that uses multiple gears to transmit power and change the gear ratio in stages. The automatic transmission is provided with a clutch as a friction element that operates in response to the output hydraulic pressure of the hydraulic oil supplied from a hydraulic control device.

[0017] FIG. 1 is a diagram showing an example of the configuration of a hydraulic control device 1 for an automatic transmission.

[0018] The hydraulic control device 1 adjusts the output hydraulic pressure of the hydraulic oil supplied to the hydraulic clutch 11 of the automatic transmission, thereby changing the engaged state and disengaged state of the hydraulic clutch 11 and causing the automatic transmission to shift gears.

[0019] 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 drain 4a, a relief valve 5, an electromagnetic proportional valve 10, a second drain 15, an oil temperature sensor 34, a pressure sensor 31, and an ECU 32.

[0020] One end of the conduit 3 is connected to a first drain 4a that stores hydraulic oil, and the other end is connected to a hydraulic clutch 11 to which the hydraulic oil is supplied, forming a flow path for the hydraulic oil. A hydraulic pump 2, a filter 4, and an electromagnetic proportional valve 10 are connected to the conduit 3 between the first drain 4a and the hydraulic clutch 11. A relief valve 5 is also provided in the conduit 3 in parallel with the filter 4.

[0021] The hydraulic pump 2 is operated by using the power of a pump drive motor 2 a to draw up hydraulic oil from a first drain 4 a and discharge the hydraulic oil, which has been adjusted to a high pressure, into a pipeline 3 .

[0022] The hydraulic clutch 11 is adapted to transmit power from an engine mounted on a vehicle to wheels by engaging the hydraulic clutch 11. Here, a wet-type multi-plate hydraulic clutch is used as the hydraulic clutch 11.

[0023] The hydraulic clutch 11 has a piston chamber 12, a clutch piston 13, and a return spring 14. The clutch piston 13 is slidably housed in the piston chamber 12 while being biased by the return spring 14.

[0024] The configuration of the hydraulic clutch 11 itself is similar to that of a known device. Hydraulic oil is supplied into the piston chamber 12 from the hydraulic control device 1 (hydraulic pump 2), and this hydraulic oil pushes the clutch piston 13 against the biasing force of the return spring 14. When the piston chamber 12 is filled with hydraulic oil, the clutch piston 13 pushes multiple clutch plates (not shown) of the hydraulic clutch 11 into contact with each other, thereby engaging the hydraulic clutch 11. When the hydraulic clutch 11 is engaged, power from the vehicle engine is transmitted to the wheels.

[0025] That is, the hydraulic clutch 11 switches from a released state to an engaged state when the clutch piston 13 is actuated by the hydraulic oil introduced into the piston chamber 12 from the hydraulic control device 1. The state of the hydraulic clutch 11 mainly depends on the hydraulic pressure output from the hydraulic control device 1. For example, when the hydraulic pressure output from the hydraulic control device 1 is equal to or greater than a predetermined threshold, the hydraulic clutch 11 is in an engaged state, and when the output hydraulic pressure is less than the predetermined threshold, the hydraulic clutch 11 is in a released state.

[0026] The hydraulic control device 1 may be provided with a plurality of hydraulic clutches in parallel with the hydraulic clutch 11. The gear ratio of the automatic transmission may be changed by changing the combination of engagement and release of each of the plurality of hydraulic clutches.

[0027] The electromagnetic proportional valve 10 is disposed between the hydraulic pump 2 and the hydraulic clutch 11 in the hydraulic circuit, and adjusts the output hydraulic pressure of the hydraulic oil supplied to the hydraulic clutch 11. The electromagnetic proportional valve 10 is driven, for example, by a solenoid 10a, and supplies hydraulic oil of an output hydraulic pressure corresponding to the operation of the solenoid 10a to the hydraulic clutch 11. The configuration of the electromagnetic proportional valve 10 is similar to that of a conventionally known valve, and therefore a detailed description thereof will be omitted here (see, for example, Patent Document 1).

[0028] In the electromagnetic proportional valve 10, when a solenoid 10a is driven, an internal spool valve disposed integrally with the solenoid 10a moves, and the amount of hydraulic oil supplied to the hydraulic clutch 11 is adjusted according to the position of the spool valve. Specifically, when a control current is supplied to the solenoid 10a, the solenoid 10a is driven, causing the internal spool valve to move to one side, increasing the amount of hydraulic oil supplied from the hydraulic pump 2 to the hydraulic clutch 11, thereby increasing the output hydraulic pressure of the hydraulic oil supplied to the hydraulic clutch 11. On the other hand, when a control current is not supplied to the solenoid 10a, the solenoid 10a is not driven, and the internal spool valve moves to the other side due to the biasing force of a return spring 10b provided on the opposite side of the solenoid 10a, reducing the amount of hydraulic oil supplied from the hydraulic pump 2 to the hydraulic clutch 11, thereby decreasing the output hydraulic pressure of the hydraulic oil supplied to the hydraulic clutch 11.

[0029] Furthermore, when no control current is flowing through the solenoid 10a, the electromagnetic proportional valve 10 connects the hydraulic clutch 11 to the second drain 15, and discharges the hydraulic oil in the piston chamber 12 into the second drain 15.

[0030] The electromagnetic proportional valve 10 (solenoid 10a) is electrically connected to the ECU 32 and is controlled by a control current supplied from the ECU 32. Basically, the solenoid 10a generates a driving force corresponding to the current value of the supplied control current, and moves an internal spool valve by an amount corresponding to the current value of the control current. In other words, the electromagnetic proportional valve 10 adjusts the amount of hydraulic oil supplied from the hydraulic pump 2 to the hydraulic clutch 11 so as to achieve an output hydraulic pressure corresponding to the current value of the supplied control current.

[0031] The pressure sensor 31 is provided in the pipeline 3 between the electromagnetic proportional valve 10 and the hydraulic clutch 11. The pressure sensor 31 is capable of detecting the pressure in the piston chamber 12 of the hydraulic clutch 11, i.e., the output hydraulic pressure of the hydraulic oil supplied from the hydraulic pump 2 to the hydraulic clutch 11. The pressure sensor 31 is electrically connected to the ECU 32, and transmits the detected output hydraulic pressure to the ECU 32.

[0032] The oil temperature sensor 34 is disposed in the first drain 4a and detects the temperature of the hydraulic oil (i.e., the oil temperature). The oil temperature sensor 34 is electrically connected to the ECU 32 and transmits the detected oil temperature to the ECU 32.

[0033] The ECU 32 (corresponding to a control device of the present invention) is composed of, for example, a microcomputer, a drive circuit, etc., and executes gear 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 electromagnetic proportional valve 10, and controls the operation of the electromagnetic proportional valve 10 by controlling the current flowing through the solenoid 10a. The ECU 32 then controls the operation of the electromagnetic proportional valve 10 to adjust the output hydraulic pressure of the hydraulic oil supplied to the hydraulic clutch 11 (i.e., adjust the amount of output oil), thereby controlling the operation of the hydraulic clutch 11.

[0034] Based on the control map 32a, the ECU 32 supplies a control current (described later with reference to FIG. 2A) having a predetermined waveform to the electromagnetic proportional valve 10, thereby controlling the operation of the electromagnetic proportional valve 10. The data of the control map 32a is stored in advance in a storage unit (e.g., a ROM) included in the ECU 32, for example.

[0035] The ECU 32 is configured to be able to acquire detection signals from the pressure sensor 31 and the oil temperature sensor 34 in order to obtain information on the state of the hydraulic oil. The ECU 32 is also configured to be able to acquire detection signals from various sensors 40 (for example, a shift lever sensor, a throttle opening sensor, an engine rotation speed sensor, a vehicle speed sensor, and an acceleration sensor) provided in the vehicle in order to obtain various types of vehicle operating information required for executing the gear shift control process.

[0036] <Regarding the engagement operation of the hydraulic clutch 11> Hereinafter, with reference to FIG. 2, the operation of the hydraulic control device 1 (the ECU 32 and the electromagnetic proportional valve 10) when the hydraulic clutch 11 is changed from the released state to the engaged state will be described.

[0037] 2A is a diagram showing an example of the control current output from the ECU 32 to the electromagnetic proportional valve 10 when engaging the hydraulic clutch 11. In FIG. 2A, the horizontal axis represents time, and the vertical axis represents the current value [A] of the control current output to the electromagnetic proportional valve 10.

[0038] Fig. 2B is a diagram showing an example of the behavior of the output hydraulic pressure of the hydraulic oil supplied to the hydraulic clutch 11 corresponding to the operation of the electromagnetic proportional valve 10 in Fig. 2A. In Fig. 2B, the horizontal axis represents time, and the vertical axis represents the output hydraulic pressure [Pa] of the hydraulic oil supplied to the hydraulic clutch 11. Note that Fig. 2A and Fig. 2B are drawn with the time axes aligned.

[0039] A vehicle is provided with, for example, a shift lever for changing gears in an automatic transmission. When the driver operates the shift lever, the ECU 32 sends a control current to the electromagnetic proportional valve 10 in response to the operation, and the hydraulic clutch 11 is engaged.

[0040] The operation of the hydraulic control device 1 for engaging the hydraulic clutch 11 consists of a filling step t1, a pressure reduction step t2, and a pressure increase step t3. That is, the engagement operation of the hydraulic clutch 11 starts from the filling step t1. Note that in Fig. 2A, the reason that a control current is supplied from a stage prior to the filling step t1 is to maintain the output hydraulic pressure of the working oil supplied to the hydraulic clutch 11 at a constant level even when the hydraulic clutch 11 is in a released state, and to shorten the rise time when the hydraulic clutch 11 is changed from a released state to an engaged state.

[0041] The filling step t1 is a step of filling hydraulic oil into the hydraulic clutch 11. That is, when the shift lever is operated, the ECU 32 first supplies a control current to the electromagnetic proportional valve 10 according to the control map 32a in order to fill hydraulic oil into the hydraulic clutch 11. In the filling step t1, the ECU 32 supplies a pulsed control current to the electromagnetic proportional valve 10.

[0042] Here, the pulsed control current is set to a relatively high current value Ip in order to shorten the time required for the hydraulic oil to be completely filled. Also, the application time (i.e., pulse width) Δt1 of the pulsed control current is set to an appropriate time width (e.g., several tenths of a second) so that the hydraulic clutch 11 (i.e., the piston chamber 12) can be completely filled with the hydraulic oil by this pulsed control current.

[0043] During the filling step t1, a large flow of hydraulic oil is supplied from the electromagnetic proportional valve 10 to the hydraulic clutch 11. During this time, the output hydraulic pressure increases as soon as the electromagnetic proportional valve 10 opens, and then becomes a constant pressure determined by the biasing force of the return spring 14 of the hydraulic clutch 11. When the filling of hydraulic oil is complete, the hydraulic clutch 11 engages, and the power of the vehicle engine is transmitted to the wheels. However, in this state immediately after the filling is complete, the pressing force that brings the multiple clutch plates into contact with each other in the hydraulic clutch 11 is small, so the multiple clutch plates slip relative to each other (i.e., a half-clutch state).

[0044] The pressure reducing step t2 is a step in which the control current that the ECU 32 passes to the electromagnetic proportional valve 10 is significantly reduced from the current value in the filling step t1, thereby reducing the output hydraulic pressure of the hydraulic oil flowing from the electromagnetic proportional valve 10 to the hydraulic clutch 11. In the pressure reducing 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 hydraulic oil becomes a predetermined specified pressure.

[0045] In this way, the output hydraulic pressure of the hydraulic oil flowing to the hydraulic clutch 11 is temporarily reduced, thereby suppressing shock of the hydraulic clutch 11 that occurs when the clutch is engaged. In the pressure reduction step t2, the output hydraulic pressure of the hydraulic oil is maintained at a substantially constant pressure. The duration of the pressure reduction step t2 may be a short time (for example, several tenths of a second to several seconds) after the output hydraulic pressure of the hydraulic oil flowing to the hydraulic clutch 11 has decreased from the hydraulic pressure in the filling step t1 to a predetermined pressure.

[0046] The pressure increasing step t3 is a step in which the ECU 32 significantly increases the control current flowing to the electromagnetic proportional valve 10 from the current value in the pressure reducing step t2, thereby increasing the output hydraulic pressure of the hydraulic oil flowing from the electromagnetic proportional valve 10 to the hydraulic clutch 11. In the pressure increasing step t3, the ECU 32 gradually increases the control current flowing to the electromagnetic proportional valve 10 from the current value in the pressure reducing step t2, thereby increasing the output pressure of the hydraulic oil supplied from the electromagnetic proportional valve 10 to the hydraulic clutch 11. In this pressure increasing step t3, the current value of the control current flowing to the electromagnetic proportional valve 10 is controlled so that it is ultimately greater than the current value of the pulsed control current in the filling step t1.

[0047] This pressure increasing step t3 increases the pressing force to fully engage the hydraulic clutch 11. This allows the power of the vehicle engine to be fully transmitted to the wheels, completing the gear change.

[0048] In the above description, the influence of the oil temperature of the hydraulic oil on the operation of the hydraulic clutch 11 was explained while ignoring it. However, in reality, depending on the oil temperature of the hydraulic oil, changes occur in the viscous resistance of the hydraulic oil, etc., and the operation mode of the hydraulic clutch 11 changes slightly. Therefore, it is preferable that the ECU 32 stores a control map 32a for each oil temperature of the hydraulic oil in the memory in advance, and determines the control map 32a to be read out based on the oil temperature of the hydraulic oil detected by the oil temperature sensor 34 (see FIG. 5).

[0049] <Regarding the correction function of the control map in the ECU 32> As described above, the hydraulic clutch 11 is engaged. In order to shorten the time until the completion of gear shifting in the automatic transmission and improve the gear shifting feeling, it is important to adjust the output hydraulic pressure when filling the hydraulic oil into the hydraulic clutch 11 to the semi-clutch state, that is, the output hydraulic pressure of the hydraulic oil in the filling process t1.

[0050] However, as described above, components such as the hydraulic clutch 11 and the electromagnetic proportional valve 10 generally have individual differences for each vehicle, such as variations in dimensions during manufacturing. There may be individual differences for each vehicle in the output hydraulic pressure when the electromagnetic proportional valve 10 is operated. In addition, due to the aging deterioration of the hydraulic clutch 11, the electromagnetic proportional valve 10, etc., the operation mode of the electromagnetic proportional valve 10 when the same control current is supplied also changes slightly.

[0051] Therefore, the ECU 32 according to the present embodiment corrects the current value and the application time of the pulsed control current stored in the control map 32a so that the filling mode of the hydraulic oil into the hydraulic clutch 11 in the filling process t1 becomes appropriate.

[0052] As the timing for the ECU 32 to perform such correction, for example, when a control map correction command is given by the driver, or when a change in the gear shifting feeling is detected from the detection signals of various sensors provided in the vehicle (see the modified example described later), etc. can be mentioned.

[0053] As a method for the ECU 32 to adjust the output hydraulic pressure of the hydraulic oil, a method in which the ECU 32 feedback-controls the control current of the electromagnetic proportional valve 10 based on the pressure detected by the pressure sensor 31 when the automatic transmission is shifting gears may be considered. However, there is a response delay between when the control current applied to the electromagnetic proportional valve 10 is changed and when the electromagnetic proportional valve 10 actually operates and the output hydraulic pressure of the hydraulic oil supplied to the hydraulic clutch 11 changes. The filling process t1 is a process in which a pulse-like control current is applied for an extremely short period of time. Therefore, it is practically difficult for the ECU 32 to feedback-control the control current of the electromagnetic proportional valve 10 based on the pressure detected by the pressure sensor 31 when the automatic transmission is shifting gears, taking into account this response delay, so as to provide an appropriate shift feeling.

[0054] From this perspective, the ECU 32 according to this embodiment uses this correction function to observe the behavior of the output hydraulic pressure of the hydraulic oil according to the control current of the electromagnetic proportional valve 10 and correct the control map 32a.

[0055] Fig. 3 is a diagram showing an example of an operation flow of a control map correction process by the ECU 32 according to this embodiment. The process of the flowchart shown in Fig. 3 is, for example, a process executed by the ECU 32 in accordance with a computer program. The ECU 32 starts the process of the flowchart in Fig. 3, for example, upon receiving a control map correction command from the driver.

[0056] 4, 5 and 6 are diagrams showing an example of the change in pulse-like control current and the behavior of the output hydraulic pressure of the hydraulic oil before and after each correction process during the control map correction process according to this embodiment.

[0057] Fig. 4 is a diagram showing an example of the pulsed control current (Fig. 4A) and the behavior of the output hydraulic pressure of the hydraulic oil (Fig. 4B) before the control map correction process. Fig. 5 is a diagram showing an example of the pulsed control current (Fig. 5A) and the behavior of the output hydraulic pressure of the hydraulic oil (Fig. 5B) after the applied current is increased (i.e., S6) from the state of Fig. 4. Fig. 6 is a diagram showing an example of the pulsed control current (Fig. 6A) and the behavior of the output hydraulic pressure of the hydraulic oil (Fig. 6B) after the application time is increased (i.e., S8) from the state of Fig. 5.

[0058] FIG. 7 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 (the applied current and application time in the filling step t1).

[0059] The processing of the flowchart in Fig. 3 will now be described in order. The processing of the flowchart in Fig. 3 is primarily aimed at minimizing the application time of the pulsed control current in order to shorten the time it takes to complete a gear shift in an automatic transmission. Therefore, the processing of the flowchart in Fig. 3 is a procedure for minimizing the application time of the pulsed control current while adjusting the applied current of the pulsed control current to an appropriate value.

[0060] In step S1, the ECU 32 receives a detection signal from the oil temperature sensor 34 and detects the temperature of the hydraulic oil.

[0061] In step S2, the ECU 32 determines the application time and current value of the pulsed control current based on the control map 32a.

[0062] In step S3, the ECU 32 outputs to the electromagnetic proportional valve 10 a pulsed control current having the application time and current value determined in step S3.

[0063] In step S4, the ECU 32 receives a detection signal from the pressure sensor 31 and detects the output hydraulic pressure of the hydraulic oil.

[0064] In order to shorten the time it takes to complete a gear shift in an automatic transmission and to improve the gear shift feeling, the output oil pressure when hydraulic oil is filled into the hydraulic clutch 11 to put it in a half-clutch state, i.e., the output oil pressure of the hydraulic oil when the filling step t1 is completed, is important. Also, there is usually a response delay from the time a pulse-shaped control current is output until the electromagnetic proportional valve 10 operates and the amount of hydraulic oil supplied to the hydraulic clutch 11 follows the pulse output.

[0065] From this perspective, when determining the magnitude of the output oil pressure of the hydraulic oil in the subsequent steps S5 and S7, the ECU 32 uses the output oil pressure detected by the pressure sensor 31 as a reference at a timing a predetermined time after the rising timing of the pulse-shaped control current, for example, at the falling timing.

[0066] In step S5, the ECU 32 determines whether the output hydraulic pressure of the hydraulic oil is equal to or greater than the lower limit of the target pressure range. If the output hydraulic pressure of the hydraulic oil is equal to or greater than the lower limit of the target pressure range (S5: YES), the process proceeds to step S7. If the output hydraulic pressure of the hydraulic oil is not equal to or greater than the lower limit of the target pressure range (S5: NO), the process proceeds to step S6.

[0067] Here, the target pressure range is a predetermined pressure range set based on the pressure resisting the biasing force of the return spring 14 of the hydraulic clutch 11. In Figures 4B, 5B, and 6B, the pressure resisting the biasing force of the return spring 14 is shown as the target pressure.

[0068] In step S6, the ECU 32 increases the current value of the pulsed control current stored in the control map 32a by a predetermined amount. If the output hydraulic oil pressure is not equal to or greater than the lower limit of the target pressure range (S5: NO), this is because the output hydraulic oil pressure of the hydraulic oil is not able to resist the biasing force of the return spring 14 of the hydraulic clutch 11 to a sufficient degree, preventing the hydraulic oil from smoothly filling the clutch 11 (see FIG. 4).

[0069] In Figure 4, the output hydraulic pressure of the hydraulic oil fluctuates up and down because the output hydraulic pressure of the hydraulic oil is smaller than the biasing 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 is completed, the hydraulic clutch 11 is still not completely filled with hydraulic oil (i.e., the half-clutch state is not yet complete). In this state, if the pressure-reducing step t2 and the pressure-increasing step t3 on the control map 32a are performed, the actual hydraulic clutch 11 will be forced to engage from a state in which the half-clutch state is not yet complete, resulting in a large gear shift shock. Furthermore, in this case, it will take a longer time than usual for the hydraulic clutch 11 to fully engage.

[0070] In step S6, by increasing the current value of the pulsed control current stored in the control map 32a by a predetermined amount, the port width of the port in the electromagnetic proportional valve 10 that connects the hydraulic pump 2 and the hydraulic clutch 11 is widened. This increases the amount of high-pressure hydraulic oil sent from the pump 2 to the hydraulic clutch 11, and increases the output hydraulic pressure of the hydraulic oil. In this state, hydraulic oil is smoothly filling the hydraulic clutch 11 against the biasing force of the return spring 14 of the hydraulic clutch 11, so the output hydraulic pressure of the hydraulic oil detected by the pressure sensor 31 remains approximately constant during the filling process t1.

[0071] However, if the current value of the pulsed control current is increased to some extent in order to minimize the application time of the pulsed control current, the application time of the pulsed control current becomes slightly longer. As a result, the output oil pressure of the hydraulic oil increases after the hydraulic clutch 11 is completely filled with hydraulic oil. This is why, in Figure 5, the output oil pressure of the hydraulic oil detected by the pressure sensor 31 increases sharply after the filling step t1 on the control map 32a is completed.

[0072] After step S6, the ECU 32 returns to step S1 to execute the update process again in order to confirm that the output hydraulic pressure of the hydraulic oil has fallen within the target pressure range.

[0073] The lower limit of the target pressure range is set to an appropriate value based on the biasing force of the return spring 14. Therefore, the ECU 32 repeatedly executes steps S1 to S6 as necessary to adjust the applied current of the pulsed control current on the control map 32a to an appropriate value.

[0074] In step S7, the ECU 32 determines whether the output hydraulic pressure of the hydraulic oil is equal to or less than the upper limit of the target pressure range. If the output hydraulic pressure of the hydraulic oil is equal to or less than the upper limit of the target pressure range (S7: YES), the process of the flowchart in Fig. 4 ends without performing any particular process. If the output hydraulic pressure of the hydraulic oil is not equal to or less than the upper limit of the target pressure range (S7: NO), the process proceeds to S8.

[0075] In step S8, the ECU 32 reduces the application time of the pulsed control current stored in the control map 32a by a predetermined amount.

[0076] As described above, when the output hydraulic oil pressure of the hydraulic oil is equal to or higher than the upper limit of the target pressure range, as shown in Fig. 5, it is presumed that the application time of the pulsed control current stored in the control map 32a is too long, and the state in which the amount of high-pressure hydraulic oil sent to the hydraulic clutch 11 is increased continues even after the hydraulic oil has completely filled into the clutch 11. In this state, in the actual hydraulic clutch 11, the hydraulic clutch 11 is forced to transition from the half-clutch state to the clutch-engaged state in the filling step t1, which is a preparatory stage (i.e., the clutch is engaged without going through the pressure reduction step t2), resulting in a large gear shift shock.

[0077] In step S8, the application time of the pulsed control current stored in the control map 32a is reduced by a predetermined amount, thereby matching the port width expansion time of the port connecting the pump 2 and the hydraulic clutch 11 in the electromagnetic proportional valve 10 with the timing at which the hydraulic oil is completely filled into the hydraulic clutch 11. In other words, as shown in Fig. 6, this eliminates the state in which the output hydraulic pressure of the hydraulic oil increases sharply after the hydraulic clutch 11 is completely filled with the hydraulic oil, and therefore the output hydraulic pressure of the hydraulic oil can be kept within the target pressure range.

[0078] After step S8, the ECU 32 returns to step S1 to execute the update process again in order to confirm that the output hydraulic pressure of the hydraulic oil has fallen within the target pressure range.

[0079] The upper limit of the target pressure range is set to an appropriate value based on the biasing force of the return spring 14. Therefore, the ECU 32 repeatedly executes steps S1 to S5 and S7 to S8 as necessary, and adjusts the application time of the pulsed control current on the control map 32a to an appropriate value.

[0080] By performing the above-described steps S1 to S8, the ECU 32 can adjust the output hydraulic pressure of the hydraulic oil so that it falls within the target pressure range during the filling step t1. This allows the control map 32a to be updated so that a good shift feeling can be obtained while shortening the shift time when actually performing the shift process.

[0081] [effect] As described above, according to the hydraulic control device for an automatic transmission according to this embodiment, an electromagnetic proportional valve disposed in the hydraulic circuit for adjusting the pressure of hydraulic oil supplied to the hydraulic clutch; a pressure sensor for detecting the hydraulic pressure of the hydraulic oil supplied to the hydraulic clutch; a control device that outputs a pulsed control current of a predetermined current value and a predetermined application time to the electromagnetic proportional valve in accordance with a pre-stored control map, thereby filling the hydraulic oil into the hydraulic clutch and transitioning the hydraulic clutch from a released state to an engaged state; Equipped with When the control device outputs the pulsed control current to the electromagnetic proportional valve, it performs a correction process to correct the specified current value and the specified application time stored in the control map at a specified timing so that the hydraulic pressure of the hydraulic oil supplied to the hydraulic clutch falls within a specified target pressure range.

[0082] This makes it possible to appropriately adjust the shift feeling even when the state of the operating object (e.g., hydraulic clutch and electromagnetic proportional valve) changes due to deterioration over time, or when there are individual variations in the operating object (e.g., hydraulic clutch and electromagnetic proportional valve) during manufacturing.

[0083] In particular, according to the hydraulic control device for the automatic transmission of this embodiment, the electromagnetic proportional valve can be operated with a pulsed control current whose current value and application time are appropriately set, and hydraulic oil can be filled into the hydraulic clutch in a short time, making it possible to achieve constant, short-time gear shifting operations.

[0084] <Modification> In the above embodiment, the control map update process shown in FIG. 3 is executed in response to a control map correction command from the driver of the vehicle.

[0085] In this regard, as mentioned above, the components that make up the hydraulic clutch 11, the electromagnetic proportional valve 10, etc. deteriorate over time, and this deterioration may cause the gear shift feeling to become poor without the driver realizing it.

[0086] Taking such viewpoints into consideration, the hydraulic control device 1 (ECU 32) according to this modified example determines whether the vehicle's gear shifting operation is abnormal based on the acceleration fluctuation of the vehicle or the rotation fluctuation of the vehicle's axle detected during the gear shifting operation of the automatic transmission, and if the vehicle's gear shifting operation is abnormal, performs the above-mentioned correction processing (see FIG. 3) to resolve the abnormal state.

[0087] Normally, during a gear shift operation of an automatic transmission, after the filling step t1 is completed, the hydraulic clutch 11 is in a half-clutch state, and the engine receives a load from the output shaft, which causes the engine speed to decrease.

[0088] Thereafter, during the pressure reduction step t2, the hydraulic clutch 11 remains in a half-clutch state. Then, during the pressure increase step t3, the hydraulic clutch 11 is released from the engaged state, and a large load is applied to the engine from the output shaft. Accordingly, the engine speed is further reduced.

[0089] If the characteristics of the hydraulic clutch 11, the electromagnetic proportional valve 10, etc. change, the behavior of the engine speed will change.

[0090] For example, if the output hydraulic pressure of the hydraulic oil supplied to the hydraulic clutch 11 is too low during the filling step t1, the half-clutch state will not be completed even when the filling step t1 is completed, and the engine speed will hardly change. In this case, the hydraulic clutch 11 will be forcibly engaged during the pressure increase step t3, and the engine speed will suddenly decrease during the pressure increase step t3.

[0091] On the other hand, for example, if the output oil pressure of the hydraulic oil supplied to the hydraulic clutch 11 is too high during the filling step t1, the hydraulic clutch 11 will be forced to enter an engaged state during the filling step t1, causing the engine speed to drop sharply during the filling step t1.

[0092] Moreover, under such circumstances, torque shock (that is, acceleration fluctuation) occurs in the filling step t1 and the pressure increasing step t3.

[0093] From this perspective, the ECU 32 according to this modification detects changes in vehicle acceleration and axle rotation speed during gear shifting by the automatic transmission, and determines whether the vehicle's gear shifting is in an abnormal state based on the nature of the changes. Any sensor can be used for this purpose as long as it can detect vehicle acceleration or axle rotation speed. Examples of such sensors that can be used include a clutch output rotation speed sensor, a gear input rotation speed sensor, a transmission output rotation speed sensor, a propeller shaft rotation speed sensor, and an acceleration sensor mounted on the vehicle.

[0094] At this time, the ECU 32 may store in advance in a storage unit reference data relating to the standard behavior of the vehicle acceleration and the axle rotation speed during the gear shifting operation of the automatic transmission, and may determine whether there is an abnormality in the behavior of the vehicle acceleration and the axle rotation speed by comparing with the reference data.

[0095] As described above, the hydraulic control device 1 for an automatic transmission according to this modified example can automatically execute the control map update process at an appropriate timing.

[0096] Although specific examples of the present invention have been described above in detail, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and alterations of the specific examples exemplified above. [Industrial Applicability]

[0097] According to the hydraulic control device of the present invention, it is possible to appropriately adjust the feeling when shifting gears. [Explanation of symbols]

[0098] 1 Hydraulic control device 2 hydraulic pumps 2a Pump drive motor 3 conduit 4 Filters 4a First drain 5 Relief valve 10. Solenoid proportional valve 10a solenoid 10b Return spring 11 Hydraulic clutch 12 Piston chamber 13 Clutch piston 14 Return spring 15 Second drain 31 Pressure Sensor 32 ECU (control unit) 32a Control Map 34 Oil temperature sensor

Claims

1. A hydraulic control device for an automatic transmission that performs vehicle gear shifting by engaging and disengaging a hydraulic clutch, an electromagnetic proportional valve disposed in the hydraulic circuit for adjusting the pressure of hydraulic oil supplied to the hydraulic clutch; a pressure sensor for detecting the hydraulic pressure of the hydraulic oil supplied to the hydraulic clutch; a control device that outputs a pulsed control current of a predetermined current value and a predetermined application time to the electromagnetic proportional valve in accordance with a pre-stored control map, thereby filling the hydraulic oil into the hydraulic clutch and transitioning the hydraulic clutch from a released state to an engaged state; Equipped with When the control device outputs the pulsed control current to the electromagnetic proportional valve, the control device performs a correction process to correct the predetermined current value and the predetermined application time stored in the control map at a predetermined timing so that the hydraulic pressure of the hydraulic oil supplied to the hydraulic clutch falls within a predetermined target pressure range. Hydraulic control device.

2. The predetermined target pressure range is set based on the pressure that resists the biasing force of the return spring of the hydraulic clutch. The hydraulic control device according to claim 1 .

3. The correction process includes: a first process of increasing the predetermined current value stored in the control map so that the hydraulic pressure of the hydraulic oil detected by the pressure sensor becomes higher than a lower limit value of the predetermined target pressure range when the pulsed control current is output to the electromagnetic proportional valve; a second process of reducing the application time stored in the control map so that the hydraulic pressure of the hydraulic oil detected by the pressure sensor becomes smaller than an upper limit value of the predetermined target pressure range when the pulsed control current is output to the electromagnetic proportional valve; Including, In the correction process, the control device performs the first process and then the second process. The hydraulic control device according to claim 1 .

4. An oil temperature sensor is further provided to detect the temperature of the hydraulic oil supplied to the hydraulic clutch. The control map stores the predetermined current value and the predetermined application time of the pulsed control current in association with the temperature of the hydraulic oil, During the correction process, the control device acquires the temperature of the hydraulic oil detected by the oil temperature sensor, and corrects the predetermined current value and the predetermined application time corresponding to the temperature on the control map. The hydraulic control device according to claim 1 .

5. The control device determines whether the gear shifting operation of the automatic transmission is in an abnormal state based on acceleration fluctuations of the vehicle or rotation fluctuations of an axle of the vehicle detected during the gear shifting operation of the automatic transmission, and performs the correction process if the gear shifting operation of the automatic transmission is in an abnormal state. The hydraulic control device according to claim 1 .

6. When the hydraulic clutch is changed from a released state to an engaged state, the control device a filling step of filling the hydraulic oil into the hydraulic clutch by outputting the pulsed control current to the electromagnetic proportional valve; a pressure reducing step in which a current value of a control current output to the electromagnetic proportional valve is reduced to a value lower than that of the filling step, thereby reducing the hydraulic pressure of the hydraulic oil; a pressure increasing process in which the current value of the control current output to the electromagnetic proportional valve is increased to a value higher than that of the pressure reducing process, and a step-like or ramp-like control current is applied to increase the hydraulic pressure of the hydraulic oil to a value higher than that of the filling process, thereby completing the engagement state of the hydraulic clutch; Execute the following in order: The hydraulic control device according to claim 1 .

7. A vehicle comprising the hydraulic control device according to claim 1.

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