JP2005325879A - Hydraulic control device for automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To continue operation of a motor-driven oil pump and promptly release a friction clutch when it is not determined that an engine start condition is achieved, to stop the operation of the motor-driven oil pump and operate a starter motor independently immediately after it is determined that the engine start condition is achieved, and in particular to improve engine startability at the time of low temperature and battery consumption, in a hydraulic control device for an automatic transmission. <P>SOLUTION: This hydraulic control device for the automatic transmission is provided with a shift position switch for detecting a shift position; a transmission oil temperature sensor for detecting transmission oil temperature; a starter switch turned on/off so as to operate/non-operate the starter motor communicating with a starter of the engine; and a control means for determining the engine start condition based on the shift position, the transmission oil temperature and the on/off state of the starter switch and performing stop control of the motor-driven oil pump when the engine start condition is achieved. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a hydraulic control device for an automatic transmission, and in particular, prevents an electric oil pump that supplies hydraulic oil to a friction clutch (starting clutch) from operating simultaneously with an engine starter motor to deteriorate engine startability. The present invention relates to a hydraulic control device for an automatic transmission.

  As a friction clutch (starting clutch) of a manual transmission of a vehicle, a diaphragm type is often adopted, and an automatic one operated by hydraulic pressure, a motor or the like has been proposed. An automatic transmission provided with such a friction clutch is provided between the engine and the transmission, and is normally maintained in an engaged state and is released by a hydraulically operated release mechanism. A hydraulic circuit comprising: a hydraulic circuit communicating through a switching valve; an electric oil pump that supplies hydraulic oil to the hydraulic circuit; an accumulator that holds the hydraulic pressure of the hydraulic circuit; and a hydraulic sensor that detects the hydraulic pressure of the hydraulic circuit. When the engine is started at an oil pressure of less than a predetermined value, the electric oil pump is operated by switching the switching valve so that the hydraulic circuit communicates with the release mechanism.

2. Description of the Related Art Conventionally, there are automatic clutch control devices that operate a hydraulic pump to the minimum necessary to cut off the automatic clutch before starting the engine, thereby reducing discomfort and suppressing battery consumption.
In addition, the automatic transmission control device is provided with a mechanical oil pump that is operated by an engine and an electric oil pump that is operated by electric power in a vehicle that performs automatic stop and restart, and the conditions for automatic engine stop are established. In some cases, it is possible to start an agile vehicle by starting the operation of the electric oil pump and holding it in a state where the hydraulic pressure is raised within a delay time from when the engine is actually stopped. .
JP 2000-88008 A JP 2001-41067 A

  By the way, in the conventional friction clutch of an automatic transmission, when the friction material of the clutch disk is worn out due to long-term use, the pressing load of the friction clutch changes depending on the wear amount, and the release bearing moves. Since the position moves, as a result, the release piston stroke detected in the control and the torque characteristics of the friction clutch change.

  Since the release load is not a linear characteristic due to the characteristics of the diaphragm spring, the release piston is stroked by controlling the flow rate, not the hydraulic oil pressure, and the piston stroke is feedback controlled to control the friction clutch torque. The change makes appropriate torque control difficult.

  In addition, the hydraulic circuit for operating the friction clutch is provided with an electric oil pump and pressure accumulating means such as an accumulator so that the friction clutch can be released even when the engine is stopped.

  When the engine is started from a state where the hydraulic pressure in the hydraulic circuit is below a predetermined value, the electric oil pump is driven to supply hydraulic oil to the release piston to release the friction clutch. Later, since the hydraulic oil was accumulated in the accumulator, the electric oil pump was driven, and the engine startability deteriorated.

  In other words, in a hydraulic control device for an automatic transmission having such a diaphragm friction clutch, when the engine is started when the hydraulic pressure in the hydraulic circuit is below a predetermined value, the hydraulic circuit is switched to communicate with the release mechanism. The electric oil pump is operated by switching the valve. First, the friction clutch is released. Even after the friction clutch is released, the electric oil pump is continuously operated until the hydraulic pressure in the hydraulic circuit exceeds a predetermined value. The In this case, the operation of the electric oil pump is overlapped with the operation of the stark motor for starting the engine, and therefore, the engine startability is deteriorated particularly when the temperature is low or the battery is consumed.

  The present invention provides a friction clutch provided between an engine and a transmission and normally maintained in an engaged state and released by a hydraulically operated release mechanism, and a hydraulic pressure communicating with the release mechanism via a switching valve. Circuit, an electric oil pump that supplies hydraulic oil to the hydraulic circuit, an accumulator that holds the hydraulic pressure of the hydraulic circuit, and a hydraulic sensor that detects the hydraulic pressure of the hydraulic circuit, and the hydraulic pressure of the hydraulic circuit is a predetermined value In the hydraulic control device for an automatic transmission that operates the electric oil pump by switching the switching valve so that the hydraulic circuit communicates with the release mechanism when the engine is started below, A shift position sensor for detecting a shift position; a transmission oil temperature sensor for detecting a transmission oil temperature of the automatic transmission; A starter switch that is turned on / off to activate / deactivate a starter motor that communicates with the starter is provided, and the shift position of the automatic transmission, the transmission oil temperature of the automatic transmission, and the on / off state of the starter switch The engine starting condition is determined based on the above, and when it is determined that the engine starting condition is satisfied, there is provided control means for stopping the operation of the electric oil pump.

  The hydraulic control device for an automatic transmission according to the present invention determines an engine start condition based on a shift position of an automatic transmission, a transmission oil temperature, and an on / off state of a starter switch during operation of an electric oil pump. If it is not determined that the start condition is satisfied, the operation of the electric oil pump is continued to quickly release the friction clutch, and if it is determined that the engine start condition is satisfied, the electric oil is immediately By stopping the pump operation and operating the starter motor alone, it is possible to improve the startability of the engine, particularly when the temperature is low or the battery is consumed.

The present invention achieves the purpose of improving the startability of the engine at low temperatures or when the battery is exhausted by avoiding the operation of the electric oil pump that supplies hydraulic oil for the friction clutch simultaneously with the starter motor of the engine. is there.
Embodiments of the present invention will be described in detail and specifically with reference to the drawings.

  1 to 8 show an embodiment of the present invention.

  In FIG. 6, 2 is an engine mounted on a vehicle (not shown), 4 is a crankshaft, and 6 is an automatic transmission that automates shifting based on a manual transmission. The automatic transmission 6 includes a diaphragm spring type friction clutch (start clutch) 10, a transmission gear mechanism 12 having a transmission gear train, and a differential mechanism 14 in a transmission case 8. The friction clutch 10 is interposed between the crankshaft 4 of the engine 2 and the transmission gear mechanism 12 of the automatic transmission 6 and is normally maintained in an engaged state and is released by a later-described release mechanism 52 that is hydraulically operated. Is.

  As shown in FIG. 7, the transmission case 8 includes a clutch case 8-1 on the engine 2 side, a center case 8-2 connected to the clutch case 8-1, and a side case connected to the center case 8-2. 8-3.

  In the clutch case 8-1, as shown in FIG. 6, an input shaft 16 is disposed coaxially with the crankshaft 4, and an output shaft 18 is disposed in parallel with the input shaft 16. .

  A flywheel 22 fixed by a wheel fixing bolt 20 is provided on the end surface of the crankshaft 4.

  The input shaft 16 is supported by a pilot bearing 24 held at one end by the flywheel 22 and supported at the other end by an input bearing 28 held by the case wall 26 of the clutch case 8-1.

  A clutch cover 34 is fixed to the outer edge portion of the flywheel 22 by a cover fixing bolt 32 so as to constitute the clutch portion 30. An outer edge portion of the diaphragm spring 36 is disposed in the clutch cover 34. An annular pressure plate 38 is held on the outer edge of the diaphragm spring 36.

  A clutch disk 40 is provided between the pressure plate 38 and the flywheel 22. The clutch disc 40 includes a disc hub 42 provided on the input shaft 16 so as to be movable in the axial direction, a disc connecting portion 44 connected to the disc hub 42, a pressure plate 38 and a flywheel connected to the disc connecting portion 44. The clutch plate 46 is disposed between the wheels 22. The clutch plate 46 includes a wheel-side facing 48 fixed to the flywheel 22 side and a plate-side facing 50 fixed to the pressure plate 38 side, and is engaged (clamped) between the flywheel 22 and the pressure plate 38. ) ・ It will be released.

  The inner edge of the diaphragm spring 36 is in contact with a release bearing 54 constituting the release mechanism 52 so as to be able to contact and separate. The clutch portion 30 is urged in the engagement direction via a diaphragm spring 36. The release mechanism 52 operates the clutch unit 30 in the release direction.

  The release bearing 54 is slidably provided on a tubular sleeve 56 connected to the case wall portion 26. Further, a spring contact / separation portion 58 where the inner end of the diaphragm spring 36 contacts / separates is provided on one end side of the release bearing 54.

  One end side of the release lever 60 is engaged with the other end side of the release bearing 54. The other end of the release lever 60 is connected to a release shaft 62 rotatably supported by the clutch case 8-1, and moves the release bearing 54 in the axial direction.

  As shown in FIG. 7, one end side of the release arm 64 is connected to the release shaft 62 by an arm mounting bolt 66 outside the clutch case 8-1. The other end of the release arm 64 is connected to a hydraulic cylinder (start clutch actuator) 68 that operates the release mechanism 52. The hydraulic cylinder 68 is fixed to the outer surface of the center case 8-2 with a cylinder mounting bolt 70.

  As shown in FIG. 8, the hydraulic cylinder 68 is provided with an operating body 78 in which a piston 74 and a rod 76 are integrated with each other on an axial center in a cylinder body 72 so as to be axially movable. ing.

  Further, a blind plug 82 is provided in the cylinder main body 72 via an end seal material 80 on one end side on the piston 74 side. The blind plug 82 is held by a stop ring 84.

  Further, in the cylinder main body 72, a spring hole 86 is formed on the piston 74 on the axial center. In addition, the tip end side is located in the deep part of the spring hole 86 in the spring hole 86, and A piston spring 88 whose end side is in contact with the inner surface of the blind plug 82 is contracted.

  A piston sealing material 94 is provided between the inner peripheral surface of the piston sliding portion 90 on one end side of the cylinder main body 72 and the outer end stepped portion 92 of the piston 74. Thus, a hydraulic chamber 96 is formed between the inner surface of the blind plug 82 and the piston seal material 94. The hydraulic chamber 96 communicates with a hydraulic oil inlet / outlet 98 formed on the outer surface of the cylinder main body 72 so as to introduce hydraulic oil of control hydraulic pressure.

  The rod 76 of the operating body 78 is slidably supported by the rod sliding portion 100 on the other end side of the cylinder body 72. The rod 76 is connected to an arm connecting shaft 102 that is connected in the axial direction to the other end of the release arm 64. A rubber material boot 104 fixed to the outer peripheral surface of the rod sliding portion 100 of the cylinder body 72 is provided on the distal end side of the arm connecting shaft 102.

  The hydraulic cylinder 68 is provided with a piston stroke sensor 106 that detects the stroke amount of the axial movement of the piston 74 so as to determine the released state of the friction clutch 10.

  The piston stroke sensor 106 is connected to a pair of engaging flanges 110 and 110 forming an engaging groove 108 at a substantially central portion of the rod 76, an engaging element 112 engaged with the engaging groove 108, and the engaging element 112. The connecting arm 114, the sensor shaft 116 connected to the connecting arm 114, and the stroke sensor portion 122 connected to the sensor shaft 116 and fixed to the protruding sensor mounting portion 118 of the cylinder body 72 with the sensor fixing bolt 120. Become.

  As shown in FIG. 8, when the piston 74 moves to one end side (leftward in FIG. 8), the hydraulic cylinder 68 engages the clutch portion 30 of the friction clutch 10, while the piston 74 is connected to the other end side (FIG. 8). When the rod 76 is pushed forward by moving in the right direction, the clutch portion 30 of the friction clutch 10 is released.

  As shown in FIG. 5, the hydraulic cylinder 68 is operated by the control hydraulic pressure of the hydraulic oil generated from the hydraulic unit 124 and operates the release mechanism 52.

  As shown in FIG. 5, the hydraulic unit 124 has a hydraulic circuit 126 that communicates with the hydraulic chamber 96 of the hydraulic cylinder 68. The hydraulic circuit 126 includes a communication oil passage 130 having one end communicating with the hydraulic chamber 96 of the hydraulic cylinder 68 and a switching valve (flow control solenoid) 128 provided on the other end, and a supply-side oil branched from the switching valve 128. It comprises a path 132 and a discharge side oil path 134.

  Further, in the hydraulic unit 124, as shown in FIG. 5, the leading end side of the supply side oil passage 132 communicates with an oil tank 136 that stores hydraulic oil, and the supply side oil passage 132 is sequentially formed from the oil tank 136 side. , An electric oil pump 138 as hydraulic pressure generating means for supplying hydraulic oil to the communication oil passage 130 side, a one-way valve 140 that allows the flow of the hydraulic oil only to the switching valve 128 side, and dust of the hydraulic oil is removed. An oil filter 142, a hydraulic pressure sensor 144 for detecting the hydraulic pressure of the hydraulic oil, and an accumulator 146 as a pressure accumulating means for holding the hydraulic pressure of the hydraulic oil are provided, and a supply between the electric oil pump 138 and the one-way valve 140 is provided. A relief oil passage 148 communicating with the oil tank 136 is connected to the side oil passage 132. Relief valve 150 is interposed, the leading end side of the discharge-side oil passage 134 is connected to the relief oil passage 148 of the oil tank 136 side of the relief valve 150 to.

  In the hydraulic unit 124, an oil pump motor 164 (described later) that operates the electric oil pump 138 is operated within the base pressure range by the hydraulic sensor 144, and the operation oil is stored in the accumulator 146 by the operation of the electric oil pump 138. Do.

  As shown in FIG. 5, the switching valve 128 includes a first on-off valve 154 that opens and closes the supply-side oil passage 132, a second on-off valve 156 that opens and closes the discharge-side oil passage 134, and an axial direction. A spool valve 158-1 and a solenoid 158-2 are provided so as to be slidably inserted. The switching valve 128 controls the flow rate (volume) of the hydraulic oil supplied to and discharged from the hydraulic cylinder 68, thereby operating the release mechanism 52 by stroke-operating the piston 74 of the operating body 78 of the hydraulic cylinder 68. Yes, it communicates with the control means 160 and the duty is controlled by a signal from the control means 160. Further, the stroke sensor unit 122 of the piston stroke sensor 106 and the hydraulic pressure sensor 144 communicate with the control means 160.

  Further, as shown in FIG. 4, the control means 160 is connected to an oil pump motor 164 that operates an electric oil pump 138 via an oil pump motor relay 162, and is connected to a starter switch 168 via a starter permission relay 166. Connected to the starter relay 170 via the starter permission relay 166. The starter relay 170 is connected to a starter motor 172 as engine starting means of the engine 2. The starter switch 168 is turned on / off by the control means 160 so as to activate / deactivate the starter motor 172. The starter switch 168 is turned on when the driver turns an ignition key (not shown) to the starter position. It will be.

  In the control means 160, as shown in FIG. 4, the operation of the oil pump motor 164 is performed by turning on the oil pump motor relay 162, and is arranged in series with the starter relay 170 when an engine start condition described later is satisfied. The engine 2 is started by turning on the starter permission relay 166.

  A shift position switch 174 for detecting the shift position of the automatic transmission 6 and a transmission oil temperature sensor 176 for detecting the transmission oil temperature of the automatic transmission 6 are connected to the control means 160. A gear position sensor 178 for detecting the gear position of the transmission 6 is connected.

  As a result, the control means 160 switches the switching valve 128 so that the hydraulic circuit 126 communicates with the release mechanism 52 when the engine 2 is started when the hydraulic pressure of the hydraulic circuit 126 is equal to or less than a predetermined value (T). The oil pump 138 is operated.

  Further, the control means 160 includes a determination unit 160A that determines an engine start condition based on the shift position of the automatic transmission 6, the transmission oil temperature of the automatic transmission 6, and the on / off state of the starter switch 168. When the part 160A determines that the engine start condition is satisfied, the operation of the electric oil pump 138 is controlled to stop.

  Further, the control means 160 is a determination unit 160A in which the shift position of the automatic transmission 6 is the parking (P) range or the neutral (N) range, the starter switch 168 is on, and the shift of the automatic transmission 6 is changed. When the machine oil temperature is equal to or lower than the predetermined value and the friction clutch 10 is released, it is determined that the engine start condition is satisfied.

  Furthermore, the control means 160 is the determination unit 160A, in which the shift position of the automatic transmission 6 is the parking range or the neutral range, the starter switch 168 is on, and the transmission oil temperature of the automatic transmission 6 is a predetermined value. When the above is true and the gear position of the automatic transmission 6 is the neutral position, it is determined that the engine start condition is satisfied.

  In addition, the control unit 160 is a determination unit 160A in which the shift position of the automatic transmission 6 is the parking range or the neutral range, the starter switch 168 is on, and the transmission oil temperature of the automatic transmission 6 is equal to or higher than a predetermined value. When the gear position of the automatic transmission 6 is not the neutral position and the friction clutch 10 is released, it is determined that the engine start condition is satisfied.

  Next, the operation of this embodiment will be described.

  When the engine 2 is started, the electric oil pump 138 is operated so as to release the engaged friction clutch 10 by turning on an ignition switch (not shown).

  As shown in FIG. 1, in the hydraulic control of the automatic transmission 6, when the program starts (step 202), it is first determined whether the hydraulic flag is “0” or “1” (step 204). As shown in FIG. 2, the hydraulic pressure flag is “1” when the hydraulic pressure is equal to or higher than the maximum value (Pmax), and is “0” when the hydraulic pressure is lower than the minimum value (Pmin) that is lower than the maximum value (Pmax). There is a hysteresis h between the hydraulic pressure flags “0” and “1”.

  In this step 204, when the hydraulic pressure flag = 0, the accumulator 146 does not have enough pressure accumulation, so it is necessary to continue the operation of the electric oil pump 138. In this case, whether or not the engine start condition is satisfied. Is determined (step 206).

  The determination as to whether or not the engine start condition is satisfied is performed as shown in FIG.

  That is, as shown in FIG. 3, in the engine start condition determination process, when the program starts (step 302), it is first determined whether or not the shift position is in the parking (P) range or neutral (N) range ( Step 304).

  In step 304, if the shift position is the parking (P) range or neutral (N) range and YES, it is determined whether the starter switch 168 is on (ON) or off (OFF) (step 306).

  If the starter switch 168 is on in step 306, it is determined whether the transmission oil temperature is equal to or lower than a predetermined value (T) (step 308). That is, when the transmission oil temperature is extremely low, the vehicle moves due to the operation of the starter motor 172 even if the gear position is neutral unless the friction clutch 10 is released, but the transmission oil temperature is a predetermined value (T In the above case, the starter motor 172 can be operated if the gear position is in the neutral position.

  In this step 308, if the transmission oil temperature is equal to or higher than a predetermined value (T) and NO, it is determined whether or not the gear position is a neutral position (step 310). This is because it is already determined in step 304 that the shift position is in the parking range or neutral range, but the shift position operated by the driver and the gear position of the automatic transmission 6 are guaranteed to match. Not to confirm that.

  In step 310, if the gear position is other than the neutral position and NO, and in step 308, the transmission oil temperature is equal to or lower than a predetermined value (T), and if YES, the friction clutch 10 is released. It is determined whether or not (step 312).

  In step 312, the friction clutch 10 is disengaged and if YES, and if the gear position is neutral in step 310, it is determined that the engine start condition is satisfied (YES in step 314). ).

  On the other hand, if the shift position is other than the parking (P) range or the neutral (N) range in step 304, and NO, the friction is determined in step 306, the starter switch 168 is OFF, and in step 312. If the clutch 10 has not been released and the determination is NO, the engine start condition is not satisfied (step 316).

  Then, after the engine start condition is established in step 314 and after the engine start condition is not established in step 316, the program is terminated (step 318).

  As shown in FIG. 1, in step 204, when the oil pressure flag = 1, in the case of YES, the oil pressure is sufficiently high and the pressure accumulation amount of the accumulator 146 is sufficient, so that the operation of the oil pump motor 164 is performed. (Step 208), and the operation of the electric oil pump 138 is stopped.

  If it is determined in step 314 in FIG. 3 that the engine start condition is satisfied, it is determined in step 206 in FIG. 1 that the engine start condition is satisfied, and the operation of the oil pump motor 164 is stopped (step 208), the operation of the electric oil pump 138 is stopped. When the engine start condition is satisfied, the operation of the electric oil pump 138 is stopped. Even when the operation of the electric oil pump 138 is stopped, the switching valve (flow control solenoid) 128 is released from the clutch unit 30. If the operation is controlled, the friction clutch 10 is held in the disengaged state for the time determined by the leakage amount of the switching valve 128. Therefore, if it is determined that this engine start condition is satisfied, starter motor 164 is operated alone.

  However, if it is determined in step 316 in FIG. 3 that the engine start condition is not established, the engine start condition is not established in step 206 in FIG. 1, and the operation of the oil pump motor 164 is continued (step 210). The operation of the electric oil pump 138 is continued.

  After step 208 and step 210, the process returns to step 204.

  As a result, in this embodiment, during operation of the electric oil pump 138, the engine start condition based on the shift position of the automatic transmission 6, the transmission oil temperature of the automatic transmission 6, and the on / off state of the starter switch 168 is satisfied. When the engine start condition is satisfied, the operation of the electric oil pump 138 is stopped. When the engine start condition is not satisfied, the operation of the electric oil pump 138 is continued. When the engine start condition is satisfied, the electric oil pump 138 is immediately stopped and the starter motor 164 is operated alone. The startability of the engine 2 can be improved when the battery is exhausted.

  Further, the shift position of the automatic transmission 6 is the parking range or the neutral range, the starter switch 168 is on, the transmission oil temperature of the automatic transmission 6 is equal to or lower than a predetermined value (T), and the friction clutch 10 When it is necessary to release the friction clutch 10 as described above, it is determined that the engine start condition is satisfied when the friction clutch 10 is released. 138 is operated to quickly release the friction clutch 10, and when the friction clutch 10 is released, it is determined that the engine start condition is satisfied, the electric oil pump 138 is stopped, and the startability of the engine 2 is improved. be able to.

  Further, the shift position of the automatic transmission 6 is the parking range or the neutral range, the starter switch 168 is on, the transmission oil temperature of the automatic transmission 6 is equal to or higher than a predetermined value (T), and the automatic transmission Since it is determined that the engine start condition is satisfied when the gear position 6 is the neutral position, the engine 2 can be started immediately even if the friction clutch 10 is not released as described above. In addition, the electric oil pump 138 is stopped and the startability of the engine 2 can be improved.

  Furthermore, the shift position of the automatic transmission 6 is the parking range or the neutral range, the starter switch 168 is on, the transmission oil temperature of the automatic transmission 6 is equal to or higher than a predetermined value (T), and the automatic transmission is performed. When the gear position of the machine 6 is not the neutral position and the friction clutch 10 is disengaged, it is determined that the engine start condition is satisfied, and thus the friction clutch 10 needs to be disengaged as described above. Until the friction clutch 10 is released, the electric oil pump 138 is operated to quickly release the friction clutch 10, and when the friction clutch 10 is released, it is determined that the engine start condition is satisfied, and the electric oil pump 138 can be stopped and the startability of the engine 2 can be improved.

  In this embodiment, when the engine 2 is started and the friction clutch 10 is not released, the electric oil pump 138 is operated to increase the control oil pressure until the friction clutch 10 is released. Stops the electric oil pump 138 and operates the starter motor 170. That is, a hydraulic cylinder 68 is provided as an actuator that can control the friction clutch 10 with hydraulic pressure, and a hydraulic unit 124 that controls the base hydraulic pressure for control by the hydraulic sensor 144 is provided. The hydraulic cylinder 68 is controlled in the operating direction before, and the friction clutch 10 is released before the hydraulic pressure is accumulated in the accumulator 146 as the pressure accumulating means. When the engine start condition is satisfied, the electric oil pump 138 By stopping the operation, it is possible to prevent the electric oil pump 138 as the hydraulic pressure generating means and the starter motor 170 as the engine starting means from operating at the same time to lower the battery voltage and deteriorate the startability of the engine 2. Can do.

  In the present invention, when the ignition switch is turned on, the electric oil pump is first turned on, but the starter motor is turned off, and after the friction clutch is released, the electric oil is turned on. The pump and the starter motor can be prevented from being operated at the same time, and more reliable control can be performed.

  It can be applied to other controls to avoid operating the electric oil pump that supplies hydraulic oil for the friction clutch simultaneously with the starter motor of the engine.

It is a flowchart of the hydraulic control of an automatic transmission. It is a figure explaining a hydraulic flag. It is a flowchart of engine starting condition determination. It is an electric circuit diagram of the hydraulic control device of the automatic transmission. It is a block diagram of the hydraulic unit of the hydraulic control apparatus of an automatic transmission. It is sectional drawing of the friction clutch of an automatic transmission. It is a side view of the friction clutch site | part of an automatic transmission. It is sectional drawing of the hydraulic cylinder by the VIII-VIII line of FIG.

Explanation of symbols

2 Engine 6 Automatic transmission 10 Friction clutch 30 Clutch part 52 Release mechanism 68 Hydraulic cylinder 74 Piston 96 Hydraulic chamber 106 Piston stroke sensor 124 Hydraulic unit 126 Hydraulic circuit 128 Switching valve 130 Communication oil path 132 Supply side oil path 134 Discharge side oil path 138 Electric oil pump 144 Hydraulic sensor 146 Accumulator 160 Control means 164 Oil pump motor 168 Starter switch 172 Starter motor 174 Shift position switch 176 Transmission oil temperature sensor 178 Gear position sensor

Claims (4)

  A friction clutch provided between the engine and the transmission and normally maintained in an engaged state and released by a hydraulically operated release mechanism; a hydraulic circuit communicating with the release mechanism via a switching valve; An electric oil pump that supplies hydraulic oil to the hydraulic circuit; an accumulator that holds the hydraulic pressure of the hydraulic circuit; and a hydraulic sensor that detects the hydraulic pressure of the hydraulic circuit, wherein the engine has a hydraulic pressure equal to or lower than a predetermined value. When the engine is started, the shift position of the automatic transmission is detected in the hydraulic control device of the automatic transmission that switches the switching valve to operate the electric oil pump so that the hydraulic circuit communicates with the release mechanism. A shift position switch for detecting the transmission oil temperature of the automatic transmission, and a starter motor for the engine. An engine start condition based on a shift position of the automatic transmission, a transmission oil temperature of the automatic transmission, and an on / off state of the starter switch. A hydraulic control apparatus for an automatic transmission, comprising: a control means for stopping the operation of the electric oil pump when it is determined that the engine start condition is satisfied.   The control means includes a shift position of the automatic transmission in a parking range or a neutral range, the starter switch is on, a transmission oil temperature of the automatic transmission is equal to or lower than a predetermined value, and the friction clutch 2. The hydraulic control device for an automatic transmission according to claim 1, wherein when the engine is released, it is determined that the engine start condition is satisfied. 3.   The control means communicates with a gear position sensor for detecting a gear position of the automatic transmission, a shift position of the automatic transmission is a parking range or a neutral range, the starter switch is on, and the automatic transmission 2. The engine start condition is determined to be satisfied when a transmission oil temperature of the transmission is equal to or higher than a predetermined value and a gear position of the automatic transmission is a neutral position. Hydraulic control device for automatic transmission.   The control means communicates with a gear position sensor for detecting a gear position of the automatic transmission, a shift position of the automatic transmission is a parking range or a neutral range, the starter switch is on, and the automatic transmission When the transmission oil temperature of the transmission is equal to or higher than a predetermined value, the gear position of the automatic transmission is not in a neutral position, and the friction clutch is released, it is determined that the engine start condition is satisfied. The hydraulic control device for an automatic transmission according to claim 1.

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