JP5273570B2 - Hydraulic control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic controller which shortens time required for engagement control to the extent possible even if there is "variations" in ineffective strokes. <P>SOLUTION: Command signal calculation of engagement control is determined (S100). Entry of a hydraulic control spool into an overlap region is determined (S120). A return time is calculated (S130). When the return time exceeds a specified lower limit time (S140), the magnitude and period of an initial driving current are increased (S150). <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to a hydraulic control device used in an automatic transmission.

  For example, in an automatic transmission, shifting is performed by selectively engaging or releasing a plurality of friction elements such as clutches and brakes. In the hydraulic multi-plate clutch, the clutch disks alternately stacked as the above-described friction elements are used, and these clutch disks are pressure-bonded by a clutch piston to create an engaged state. The clutch piston is operated by hydraulic oil supplied from the output port of the electromagnetic hydraulic control valve.

  On the other hand, the release of the friction element moves the clutch piston in the direction opposite to that at the time of engagement, thereby separating the clutch disk. At this time, an “invalid stroke” is set for the clutch piston in order to completely open the clutch piston.

  The invalid stroke refers to a period immediately before the clutch piston comes into contact with the clutch disk and engages with the clutch disk. Due to the presence of such an invalid stroke, if the time required for the clutch piston to contact the clutch disk and engage the clutch disk becomes long, the shift response is deteriorated.

  Therefore, at the time of engagement, so-called “gap filling (elimination of invalid stroke)” is performed in which the clutch piston is moved at a relatively high speed by increasing the amount of hydraulic oil supplied in the initial stage.

  However, the time required for “packing” varies depending on the line pressure to which hydraulic oil is supplied. Thus, a technique for setting a control parameter based on the engine speed and the operating oil temperature that affects the line pressure has been disclosed (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 10-184887

  However, even in the invention described in Patent Document 1, the following points are insufficient. That is, the above-mentioned invalid stroke has “variation”. Therefore, the conventional engagement control process has a problem that the shift response is deteriorated.

  Here, in order to facilitate understanding of the following invention, a conventional engagement control process will be described. FIG. 2 is a timing chart showing spool displacement, command signal and actual hydraulic pressure, and clutch piston displacement in the engagement control process.

  First, at time t1, the microcomputer calculates a command signal. Based on this command signal, a drive current is output. Here, the magnitude of the command signal (hereinafter referred to as “command value”) represents the target hydraulic pressure value.

  First, in a period b from time t1 to time t3, a command signal having a relatively large command value a is calculated. At time t3, a command signal having a command value d smaller than the command value a is calculated.

  The reason why the command signal having a relatively large command value a is calculated in the first period b of the engagement control as described above is to perform so-called “backlash” as described above. That is, the time required for the clutch piston to contact the clutch disc is shortened. This improves the shift response. In the present specification, a relatively large drive current output in the first period due to “packing” is referred to as “initial drive current”.

  Then, as shown in FIG. 2, “packing” is completed in a period c from time t3 to time t5. In FIG. 2, “packing” is completed at time t4 when the actual hydraulic pressure value matches the command value d.

  From time t5, a command signal is calculated so that the command value increases linearly to deepen the engagement, and during the period from time t6 to time t7, a command signal having a constant command value is calculated according to the inertia torque of the engine. At time t7, a command signal having a larger command value is calculated so as to maintain the complete engagement state.

  At this time, if the completion timing of “packing” becomes earlier than time t3, the clutch piston collides with the clutch disk. Further, when the completion timing of “packing” is delayed in time from time t5, a shift shock is caused by an increase in the command value.

  Therefore, conventionally, the period b is set according to the minimum invalid stroke, and the period c is set according to the maximum invalid stroke (see “clutch piston displacement” in FIG. 2). In this way, even if there is “variation” of invalid strokes, “gap filling” is always completed in the period c.

  However, in this case, since the period b is set in accordance with the minimum invalid stroke, if the invalid stroke is larger than that, the period required for completion of “packing” becomes long. There is a fear.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a hydraulic control device that shortens the time required for engagement control as much as possible even if there is "variation" of invalid strokes. It is to provide.

  The hydraulic control apparatus according to claim 1, which has been made to achieve the above-described object, is used in an automatic transmission that performs engagement control by supplying hydraulic oil to a friction element. The hydraulic control device includes a linear solenoid valve and a control unit.

  The linear solenoid valve includes a sleeve, a hydraulic control spool that can move in the axial direction within the sleeve, an electromagnetic force generator that urges the hydraulic control spool with electromagnetic force, and a displacement that detects displacement of the hydraulic control spool. And a detection unit.

  In particular, the sleeve has an output port for outputting hydraulic oil to the friction element, a supply port for supplying hydraulic oil from the outside, and a discharge port for discharging the hydraulic oil to the outside.

  The hydraulic control spool is biased in the output direction by the electromagnetic force generated by the electromagnetic force generator. Here, the direction in which the supply port communicates with the output port is referred to as “output direction” for convenience. Further, the hydraulic control spool is biased in the discharge direction by at least the hydraulic pressure of the hydraulic oil output from the output port. Here, the direction in which the output port communicates with the discharge port is referred to as “discharge direction” for convenience. “At least” is intended to include a configuration that biases in the discharge direction not only by hydraulic pressure but also by a spring or the like.

As a result, the hydraulic control spool regulates the hydraulic oil output from the output port of the sleeve.
Under such a configuration, in the present invention, in particular, the control unit makes the magnitude and period of the initial drive current in the engagement control non-communication between the output port and the supply port at the displacement detection unit from the supply start timing. It is set based on the return time until the displacement of the hydraulic control spool is detected.

  Here, the “supply start timing” may be determined by the displacement of the hydraulic control spool by the displacement detector as shown in claim 5. The output timing of the initial drive current or the parameter calculation timing related to the output of the initial drive current may be used. That is, not only the timing for starting the supply of hydraulic fluid directly, but also the timing for outputting or calculating a signal prior to the start of the supply.

  For example, time t1 in FIG. 2 is a command signal calculation timing prior to the output of the initial drive current, and this timing can be considered as a “supply start timing”.

  In FIG. 2, the displacement of the hydraulic control spool that causes the output port and the supply port to communicate with each other is detected at time t4. At this time, the displacement of the hydraulic control spool enters the range OL in FIG. 2 (see symbol A). This range OL is an overlap region where hydraulic oil is neither supplied nor discharged.

  That is, in the present invention, for example, the “return time” from the time t1 to the time t4 is calculated, the magnitude a and the period b of the command signal are set, and the initial drive current is set accordingly. In this way, the time required for engagement control can be shortened as much as possible even if there is “variation” of invalid strokes.

  Specifically, as shown in claim 2, when the return time exceeds the set lower limit value, at least one of the magnitude and the period of the initial drive current is set to be large. An example of the “setting lower limit period” here is a period set in accordance with the minimum invalid stroke. For example, in FIG. 2, the period is b. That is, in this example, by increasing at least one of the magnitude a and the period b of the command signal, at least one of the magnitude and the period of the initial drive current is set large. In this way, the time required for engagement control can be shortened as much as possible even if there is “variation” of invalid strokes.

  By the way, in the example of FIG. 2, the period c is set in accordance with the maximum invalid stroke, so if the invalid stroke is smaller than that, the hydraulic pressure increases after completion of “packing”. There is a risk that the period until the start will be longer.

  In view of this, as shown in claim 3, the drive current increase start timing may be set based on the return time. More specifically, as shown in claim 4, the drive current increase start timing is set immediately after the return time elapses. In this way, it is possible to shorten the period until the hydraulic pressure begins to increase after completion of “packing”. As a result, it contributes to shortening the time required for the engagement control as much as possible.

It is explanatory drawing which shows the whole structure of a hydraulic control system. It is a timing chart which shows the relationship between the spool displacement, the command signal, the actual oil pressure, and the clutch piston displacement in the engagement control process. It is explanatory drawing which shows a mode that "stuffing" was completed. It is a flowchart which shows a period setting process.

  Hereinafter, a hydraulic control device of an embodiment is explained based on a drawing. FIG. 1 is an explanatory diagram schematically showing a configuration of a hydraulic control system including a hydraulic control device. As shown in FIG. 1, the hydraulic control device includes a linear solenoid valve 10 and a TCU (Transmission Control Unit) 20 and controls a clutch 30.

  First, the structure of the clutch 30 will be described. The clutch 30 functions as a friction element of the automatic transmission. Although an automatic transmission is usually composed of a plurality of clutches 30, only one clutch 30 is shown here for convenience.

  The clutch 30 is provided inside the automatic transmission and constitutes a multi-plate clutch. The clutch 30 has a plurality of clutch disks 31 and 32 that overlap in the axial direction. These clutch disks 31 and 32 create an engaged state.

  In the clutch 30, the shaft portion 33 is assembled so as to pass through the cylindrical base portion 34. The base portion 34 is provided with a disk-shaped bottom portion 34a extending radially outward. The above-described clutch disks 31 and 32 are arranged inside the outer portion 34b which is an outer portion continuous to the bottom portion 34a. Yes.

  A disc-shaped clutch piston 35 is supported on the base portion 34 so as to be reciprocally movable in the axial direction. Here, a piston chamber 36 is formed between the clutch piston 35 and the bottom 34a.

  A disc-shaped locking portion 34c is formed at the end of the base portion 34 opposite to the bottom portion 34a. The locking portion 34c is located just inside the clutch disks 31 and 32 in the radial direction. A spring 37 is provided between the locking portion 34 c and the clutch piston 35. As a result, the clutch piston 35 is urged toward the bottom 34a.

  The above-described piston chamber 36 is supplied with hydraulic oil via an oil passage 33 a formed in the shaft portion 33. As a result, when the hydraulic pressure in the piston chamber 36 rises and the urging force of the spring 37 is overcome, the clutch piston 35 moves away from the bottom 34a. When the clutch piston 35 comes into contact with the clutch disk 31 and presses the clutch disk 31, the clutch disks 31 and 32 are engaged.

  The linear solenoid valve 10 supplies hydraulic oil to such a clutch 30. Next, the linear solenoid valve 10 will be described. Although a plurality of linear solenoid valves 10 are usually provided, only one linear solenoid valve 10 is shown here corresponding to the clutch 30.

  The linear solenoid valve 10 includes a sleeve 11 and an electromagnetic force generator 12. The sleeve 11 is formed with a discharge port 11a, an output port 11b, a supply port 11c, and a self-regulating port 11d from the electromagnetic force generator 12 side.

  A supply pipe 41 is connected to the supply port 11c. The supply pipe 41 is a pipe that supplies hydraulic oil from the oil pan 42 to the linear solenoid valve 10, and an oil pump 43 is connected to the supply pipe 41. A discharge pipe 44 is connected to the discharge port 11a. The discharge pipe 44 discharges hydraulic oil from the linear solenoid valve 10 to the oil pan 42.

  An output pipe 45 is connected to the output port 11b. The output pipe 45 is connected to an oil passage 33 a formed in the shaft portion 33 of the clutch 30. As a result, the hydraulic oil is supplied from the output pipe 45 to the piston chamber 36 via the oil passage 33a. A branch pipe 46 is formed in the middle of the output pipe 45 so as to branch. The branch pipe 46 is connected to the self-pressure regulating port 11d.

  The sleeve 11 accommodates a hydraulic control spool 13 that can reciprocate in the axial direction. The hydraulic control spool 13 communicates a predetermined port among the plurality of ports 11a to 11d described above by axial displacement.

  Specifically, when displaced in a direction away from the electromagnetic force generator 12 (hereinafter referred to as “output direction”), the supply port 11c and the output port 11b communicate with each other. In addition, when displaced in a direction close to the electromagnetic force generator 12 (hereinafter referred to as “discharge direction”), the output port 11b and the discharge port 11a communicate with each other. At the intermediate position, there is an overlap region where neither the supply port 11c nor the discharge port 11a communicates with the output port 11b.

  A return spring 14 is provided on the front end side of the hydraulic control spool 13, and the hydraulic control spool 13 is biased in the discharge direction by the return spring 14. Further, the hydraulic oil from the output port 11b is supplied to the self-pressure adjusting port 11d via the branch pipe 46, and the hydraulic control spool 13 is biased in the discharge direction by the hydraulic pressure of the hydraulic oil from the output port 11b.

  The electromagnetic force generating unit 12 includes a movable unit 15, a fixed unit 16, a coil 17, a connector 18, and the like. The movable part 15 is supported inside the cylindrical fixed part 16 so as to be movable in the axial direction. The coil 17 is arranged around the fixed portion 16. Further, the TCU 20 is electrically connected through the connector 18.

  A drive current based on the command signal is sent from the TCU 20. When the coil 17 is energized by this drive current, an electromagnetic attractive force in the output direction acts on the movable portion 15. As a result, the movable portion 15 biases the hydraulic control spool 13 in the output direction via the rod-shaped connecting portion 19 supported by the fixed portion 16.

  An Fe ring 13 a is provided at the end of the hydraulic control spool 13 on the electromagnetic force generating unit 12 side. Further, the sleeve 11 is provided with a hall IC 11e with a magnet corresponding to the Fe ring 13a. Thereby, the displacement of the hydraulic control spool 13 can be detected.

  The TCU 20 includes a microcomputer and a drive circuit. The TCU 20 includes a throttle opening sensor, an engine speed sensor, a turbine speed sensor, a range sensor, a vehicle speed sensor, an oil temperature sensor, etc. (all of which are used to acquire various operation information necessary for executing the engagement control). (Not shown) is connected.

  The microcomputer which comprises TCU20 calculates the command signal which makes a target hydraulic pressure value a command value by running various control programs. The drive circuit supplies a drive current for driving the electromagnetic force generator 12 based on the calculated command signal.

  Next, the period correction process by the TCU 20 will be described. FIG. 4 is a flowchart showing the period correction process. Here, FIG. 2 is also referred to as appropriate.

  In the first S100, it is determined whether or not a command signal has been calculated in the initial stage of engagement control. In the example shown in FIG. 2, it is determined that time t1 has come. If it is determined that the command signal has been calculated (S100: YES), the process proceeds to S110. On the other hand, as long as the command signal is not calculated, the subsequent processing is not executed and the period setting process is terminated.

  In S110, the timer is reset. As a result, the time is measured from the time t1 in FIG. For the timer, for example, a free-run counter of a microcomputer constituting the TCU 20 is used.

  In subsequent S120, it is determined whether or not the hydraulic control spool 13 has entered an overlap region (range OL in FIG. 2). This determination is made by detecting the displacement of the hydraulic control spool 13 by the Fe ring 13a and the hall IC 11e with magnet. In the example of FIG. 2, the time point indicated by the symbol A is determined. If it is determined that the overlap area has been entered (S120: YES), the process proceeds to S130. On the other hand, the determination process of S120 is repeated until the overlap area is not entered (S120: NO).

  In S130, the return time is calculated. In the example of FIG. 2, the period from time t1 to time t4 is calculated as the return time.

  In subsequent S140, it is determined whether or not the calculated return time exceeds a preset lower limit period. In the example of FIG. 2, the setting lower limit period is b. If it is determined that the return time exceeds the set lower limit period (S140: YES), the process proceeds to S150. On the other hand, if the return time does not exceed the set lower limit period (S140: NO), the subsequent process is not executed and the period setting process is terminated.

  In S150, the magnitude and period of the initial drive current are increased. In the example of FIG. 2, the magnitude a and period b of the command signal are increased, and the magnitude and period of the initial drive current are increased. In the next S160, the drive current increase timing is set. In the example of FIG. 2, the period c is decreased. For example, the increase timing of the drive current is set by setting the increase timing of the command signal immediately after time t4.

  As described above in detail, according to the present embodiment, the calculation of the engagement control command signal is determined (S100 in FIG. 4), and then it is determined that the hydraulic control spool 13 has entered the overlap region. (S120), and the return time is calculated (S130). And based on this return time, when it exceeds the setting minimum period (S140: YES), it sets so that the magnitude | size and period of an initial stage drive current may be increased (S150). As a result, the return time can be further shortened in the subsequent engagement control.

  In other words, in FIG. 2, the “return time” from time t1 to time t4 is calculated, the magnitude a and the period b of the command signal are set, and the initial drive current corresponding to this is set. In this way, the time required for engagement control can be shortened as much as possible even if there is “variation” of invalid strokes.

  Further, according to the present embodiment, the drive current increase timing is set in accordance with the return time (S160). In FIG. 2, immediately after the time t4 when the return time elapses, the increase timing of the drive current is set by setting the increase timing of the command signal. In this way, it is possible to shorten the period until the hydraulic pressure begins to increase after completion of “packing”. As a result, this point also contributes to shortening the time required for engagement control as much as possible.

  In this embodiment, the linear solenoid valve 10 corresponds to a “linear solenoid valve”, the sleeve 11 corresponds to a “sleeve”, the hydraulic control spool 13 corresponds to a “hydraulic control spool”, and the electromagnetic force generator 12 It corresponds to an “electromagnetic force generator”, and the Fe ring 13a and the hall IC 11e with magnet constitute a “displacement detector”. Further, the discharge port 11a of the sleeve 11 corresponds to a “discharge port”, the output port 11b corresponds to an “output port”, and the supply port 11c corresponds to a “supply port”. Furthermore, the TCU 20 corresponds to a “control unit”.

The present invention is not limited to the above-described embodiment, and can be implemented in various forms without departing from the gist thereof.
(A) In the period setting process of the above embodiment, the calculation timing of the command signal is “supply start timing”, but the drive current supply timing may be “supply start timing”, and the displacement of the hydraulic control spool 13 may be changed. The “supply start timing” may be determined by detection.

  (B) In the above embodiment, both the magnitude and the period of the command signal are increased (S150 in FIG. 4). However, at least one of the magnitude and the period may be increased.

  (C) The period setting process of the above embodiment may be executed only in the first engagement control by employing a flag, for example. Further, the period set by the period setting process may be repeatedly executed as the “set lower limit period” again.

  (D) In the above embodiment, a normally closed type valve, that is, a type of valve that outputs a low pressure when no drive current is applied to the linear solenoid valve 10 and outputs a high pressure when the drive current is applied is used. As described above, the present invention can be similarly applied to a known normally-open valve, that is, a type of valve that outputs a high pressure when no current is applied and outputs a low pressure when a current is applied. Needless to say. When the present invention is applied to a normally open linear solenoid valve, the same effect can be obtained by reversing the magnitude of the drive current in the description of the above embodiment.

DESCRIPTION OF SYMBOLS 10 ... Linear solenoid valve 11 ... Sleeve 11a ... Discharge port 11b ... Output port 11c ... Supply port 11d ... Self-regulation port 11e ... Hall IC with magnet
DESCRIPTION OF SYMBOLS 12 ... Electromagnetic force generation part 13 ... Hydraulic control spool 13a ... Fe ring 14 ... Return spring 15 ... Movable part 16 ... Fixed part 17 ... Coil 18 ... Connector 19 ... Connecting part 30 ... Clutch 31, 32 ... Clutch disk 33 ... Shaft part 33a ... Oil passage 34 ... Base part 34a ... Bottom part 34b ... Outer part 34c ... Locking part 35 ... Clutch piston 36 ... Piston chamber 37 ... Spring 41 ... Supply pipe 42 ... Oil pan 43 ... Oil pump 44 ... Drain pipe 45 ... Output pipe 46 ... Branch pipe

Claims (6)

A hydraulic control device for an automatic transmission that performs engagement control by supplying hydraulic oil to a friction element,
A sleeve, a hydraulic control spool capable of moving in the axial direction of the sleeve, an electromagnetic force generation unit that urges the hydraulic control spool by electromagnetic force, and a displacement detection unit that detects a displacement of the hydraulic control spool. A linear solenoid valve;
A controller that supplies a drive current to the electromagnetic force generator,
The sleeve has an output port that outputs hydraulic oil to the friction element, a supply port to which hydraulic oil is supplied from the outside, and a discharge port that discharges hydraulic oil to the outside.
The hydraulic control spool is urged in an output direction that causes the supply port and the output port to communicate with each other by an electromagnetic force generated by the electromagnetic force generation unit, and at least the output by the hydraulic pressure of hydraulic oil output from the output port. It is urged in the discharge direction to communicate the port and the discharge port, and is configured to regulate the hydraulic oil output from the output port,
The control unit detects the magnitude and period of the initial drive current in the engagement control based on the displacement of the hydraulic control spool that causes the output port and the supply port to be disconnected from the supply detection timing from the supply start timing. A hydraulic control device that is set based on a return time until detection. The hydraulic control device according to claim 1,
When the return time exceeds a setting lower limit period, the control unit sets at least one of the magnitude and period of the initial drive current to be larger. In the hydraulic control device according to claim 1 or 2,
The hydraulic control device, wherein the control unit sets an increase start timing of the drive current based on the return time. In the hydraulic control device according to claim 3,
The hydraulic control device, wherein the control unit sets an increase start timing of the drive current immediately after the return time has elapsed. In the hydraulic control device according to any one of claims 1 to 4,
The said control part judges the said supply start timing by the displacement of the said hydraulic control spool by the said displacement detection part. The hydraulic control apparatus characterized by the above-mentioned. In the hydraulic control device according to any one of claims 1 to 4,
The hydraulic control device, wherein the control unit sets the supply start timing as an output timing of an initial drive current or a calculation timing of a parameter related to the output of the initial drive current.

Images