JP2009052638A - Hydraulic fluid supply device in automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic fluid supply device in an automatic transmission, reducing the capacity of an electric motor by supplying pressure oil discharged from a first oil pump driven by an engine to an inlet port of a second oil pump to discharge low-temperature hydraulic fluid in low-temperature starting. <P>SOLUTION: This hydraulic fluid supply device in the automatic transmission includes: an electromagnetic switching valve 18 for communicating the inlet port 12b of the second oil pump 12 to one of the oil pressure source side and the discharge port 11a of the first oil pump 11, and communicating and interrupting the discharge passage 15 of the first oil pump and an inlet passage 23 of the second oil pump; and a switching control means 108 for switching the electromagnetic switching valve at the low temperature starting of the engine and communicating the inlet port of the second oil pump to the discharge port of the first oil pump. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a hydraulic oil supply device in an automatic transmission including an oil pump driven by an engine and an oil pump driven by an electric motor.

Conventionally, as described in, for example, Patent Document 1, an oil pump drive for a transmission including a first oil pump that is always driven by an engine and a second oil pump that is arbitrarily driven and controlled by an electric motor. The device is known. According to such an oil pump drive device, the required amount of discharged oil is reduced by driving the electric motor to drive the first and second oil pumps until the engine reaches a predetermined rotational speed. Can be secured. In addition, when the engine exceeds a predetermined number of revolutions, by stopping the electric motor, an excessive amount of discharged oil can be reduced in the high engine speed region, and the oil pump driving loss can be reduced.
Japanese Patent Laid-Open No. 6-193711 (paragraphs 0028 to 0032, FIG. 3)

  However, in the oil pump drive apparatus configured as described in Patent Document 1 described above, the first oil pump 11 is forcibly driven by the engine, particularly when the viscosity of the hydraulic oil becomes high, particularly at low temperatures. Although there is no problem, there has been a problem that the driving torque of the electric motor that drives the second oil pump is increased due to the viscous resistance, and the load torque at the time of low temperature start is increased. For this reason, it is necessary to obtain a motor output sufficient to overcome the load torque, resulting in a problem that the motor capacity is increased, the electric pump unit is enlarged, and the vehicle mounting property is deteriorated.

  The present invention has been made to solve the above-described conventional problems, and supplies the pressure oil discharged from the first oil pump driven by the engine to the suction port of the second oil pump at the time of cold start. It is an object of the present invention to provide a hydraulic oil supply device in an automatic transmission that can reduce the capacity of an electric motor by allowing low-temperature hydraulic oil to be discharged.

  In order to solve the above-mentioned problems, the invention according to claim 1 is characterized in that hydraulic oil from a hydraulic source is connected to a hydraulic circuit of an automatic transmission which is connected to a drive shaft driven by an engine and includes a friction engagement element and the like. In the hydraulic oil supply device for an automatic transmission, comprising: a first oil pump that discharges oil; and a second oil pump that is driven by an electric motor and discharges hydraulic oil from the hydraulic power source to the hydraulic circuit. The suction port of the oil pump communicates with one of the hydraulic power source side and the discharge port side of the first oil pump, and the discharge passage of the first oil pump and the suction passage of the second oil pump are cut off. And switching the electromagnetic switching valve when the engine is started at a low temperature so that the suction port of the second oil pump is connected to the discharge of the first oil pump. It is to have a switch control means communicates with the over-up side.

  A feature of the invention according to claim 2 is that, in claim 1, the electric motor is driven when idling is stopped.

  According to the first aspect of the present invention, the suction port of the second oil pump communicates with one of the hydraulic power source side and the discharge port side of the first oil pump, and the discharge passage of the first oil pump and the second oil pump side. An electromagnetic switching valve for communicating and shutting off the suction passage of the oil pump, and a switching control means for switching the electromagnetic switching valve at a low temperature start of the engine and communicating the suction port of the second oil pump to the discharge port side of the first oil pump. Therefore, when starting the engine at a low temperature, the second oil pump is forcibly driven by the pressure oil discharged from the first oil pump driven by the engine, and the low-temperature hydraulic oil in the second oil pump is supplied. The electric motor can be discharged quickly, and the driving torque of the electric motor required to drive the second oil pump can be reduced. Accordingly, since the motor capacity of the electric motor can be made unnecessary to have a large motor output that overcomes the viscous resistance at the time of low temperature start, the electric pump can be reduced in size and the vehicle mountability can be improved.

  According to the invention of claim 2, since the electric motor is driven when idling is stopped, the electric motor is driven even when the first oil pump is stopped by idling stop. The hydraulic oil discharged from the second oil pump can be supplied to the hydraulic circuit, and the fastening state of the friction engagement element of the automatic transmission can be maintained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 11 denotes a first oil pump that is driven by the engine 10 and discharges a discharge flow rate proportional to the rotational speed of the engine 10, and 12 is driven by the electric motor 13 and is proportional to the rotational speed of the electric motor 13. The 2nd oil pump which discharges discharge flow volume is shown. These first and second oil pumps 11 and 12 are constituted by constant discharge type pumps such as gear pumps, trochoid pumps or vane pumps.

  A discharge passage 15 is connected to the discharge port 11a of the first oil pump 11, and a suction passage 17 connected to an oil pan 16 as a hydraulic source of the automatic transmission is connected to the suction port 11b. The discharge passage 15 is connected to the hydraulic circuit 20 via the electromagnetic switching valve 18. The hydraulic circuit 20 includes a friction engagement element (hydraulic servo) such as a clutch and a brake of an automatic transmission, a torque converter and its cooler piping, a lubrication passage leading to a lubrication part of the automatic transmission, and the like, and is supplied to the hydraulic circuit 20 The frictional engagement element and the torque converter are controlled by a hydraulic fluid comprising ATF (automatic transmission fluid), and the lubricating portion is lubricated.

  When the first oil pump 11 is driven by the engine 10, the hydraulic oil stored in the oil pan 16 is sucked up from the suction port 11b through the suction passage 17, and is operated in proportion to the engine speed from the discharge port 11a. Oil is discharged into the discharge passage 15.

  An auxiliary discharge passage 21 connected to the discharge passage 15 is connected to the discharge port 12a of the second oil pump 12, and in the auxiliary discharge passage 21 from the discharge passage 15 to the discharge port 12a side of the second oil pump 12. A check valve 22 is inserted to prevent reverse flow of the air. A suction passage 23 is connected to the suction port 12 b of the second oil pump 12, and the suction passage 23 is connected to either the discharge port 11 a side or the suction passage 17 side of the first oil pump 11 by an electromagnetic switching valve 18. It has become so.

  The electromagnetic switching valve 18 is a two-position four-way switching valve having two ports on the inlet side and two ports on the outlet side, and is on the discharge passage 15 of the first oil pump 11 and the suction passage of the second oil pump 12. 23. One inlet port of the electromagnetic switching valve 18 is connected to the discharge port 11a side of the first oil pump 11, and the other inlet port is connected to the suction passage 17 side. Further, one outlet port of the electromagnetic switching valve 18 is connected to the hydraulic circuit 20 side, and the other outlet port is connected to the suction port 12 b side of the second oil pump 12.

  The electromagnetic switching valve 18 is normally held at the original position shown in FIG. 1 by the urging force of a spring, and is switched to the switching position shown in FIG. 4 by a solenoid. In a state where the electromagnetic switching valve 18 is held in the original position, one inlet port connected to the discharge port 11a of the first oil pump 11 communicates with one outlet port connected to the hydraulic circuit 20. The other inlet port connected to the suction passage 17 is communicated with the other outlet port connected to the suction port 12b of the second oil pump 12.

  In this state, the first and second oil pumps 11 and 12 are connected in parallel between the oil pan 16 and the hydraulic circuit 20. In a state where the electric motor 13 is stopped, the hydraulic oil discharged from the first oil pump 11 driven by the engine 10 is supplied to the hydraulic circuit 20 through the discharge passage 15. When the electric motor 13 is driven in this state, the hydraulic oil discharged from the first oil pump 11 driven by the engine 10 and the hydraulic oil discharged from the second oil pump 12 driven by the electric motor 13. Are merged on the discharge passage 15 and supplied to the hydraulic circuit 20.

  With such a configuration, the pump capacity of the first oil pump 11 can be reduced as much as possible, and the electric motor 13 is driven during the shift control of the automatic transmission that requires a large flow rate, whereby the insufficient flow rate is reduced to the second. It can be supplemented by the oil pump 12. As a result, the driving torque required to drive the first oil pump 11 can be reduced, and useless power loss can be reduced.

  When the electromagnetic switching valve 18 is switched to the switching position, one inlet port connected to the discharge port 11a of the first oil pump 11 is connected to the suction port 12b of the second oil pump 12, as shown in FIG. The other outlet port connected to the suction passage 17 side and the one outlet port connected to the hydraulic circuit 20 side are closed. Thus, a series circuit of the first oil pump 11 and the second oil pump 12 is configured, and the hydraulic oil discharged from the first oil pump 11 is supplied to the hydraulic circuit 20 via the second oil pump 12 and the auxiliary discharge passage 21. To be supplied.

  The electromagnetic switching valve 18 is switched based on a switching command from the control device 30 when the engine 10 is started at a low temperature, and is discharged from the discharge port 11a of the first oil pump 11 by switching of the electromagnetic switching valve 18. The compressed pressure oil is supplied to the suction port 12b of the second oil pump 12.

  The electric motor 13 that drives the second oil pump 12 is driven based on a start command from the control device 30 when idling is stopped, that is, when the engine is stopped by detecting the stop of the vehicle. ing. Moreover, the electric motor 13 is driven based on a command from the control device 30 even during the shift control of the automatic transmission.

  FIG. 2 shows a flowchart for switching control of the electromagnetic switching valve 18 executed by the control device 30. The program shown in FIG. 2 is processed by interruption at regular intervals. First, in step 100, it is determined whether or not the ignition of the vehicle is turned on. If it is turned on, the determination result is Y (YES), and the routine proceeds to step 102. If it is not ON, the determination result is N (NO), and the program is returned. In step 102, it is determined whether or not the shift lever range is in the P (parking) range or the N (neutral) range, and if it is in the P range or N range, that is, if the vehicle is in a stopped state. The determination result is Y, and the routine proceeds to step 104. If the travel range is other than the P range or the N range, the determination result is N and the program is returned.

  In step 104, it is determined whether the battery capacity is at a high level or a low level. If the battery capacity is at a high level, the determination result is H (HIGH), and the process proceeds to step 106. If it is at the low level, the determination result is L (LOW) and the program is returned. Further, in step 106, it is determined whether the temperature of the hydraulic oil stored in the oil pan 16, that is, the ATF temperature is higher or lower than a predetermined temperature. If it is transferred and is higher, the determination result is H and the program is returned. In step 108, a switching command for switching the electromagnetic switching valve for a predetermined time is output. Based on this switching command, the electromagnetic switching valve 18 is controlled to be switched to the state shown in FIG. 4 for a predetermined time. Such step 108 constitutes a switching control means in the claims.

  Thus, when the ignition is turned on, the electromagnetic switching valve 18 is switched when the vehicle is stopped, the battery capacity is sufficient, and the ATF temperature is low. In other words, the electromagnetic switching valve 18 is switched when the engine is started at a low temperature, forcibly discharging the low-temperature working oil in the second oil pump 12 by the discharge pressure of the first oil pump 11, and the second oil pump 12. Is actuated to forcibly drive the hydraulic oil at an early stage.

  FIG. 3 is a diagram showing the discharge characteristics of the two oil pumps 11 and 12 described above. Diagram A shows the discharge characteristics of the first oil pump 11, and diagram B shows the discharge characteristics of the second oil pump 12. The solid line C indicates the flow rate when the discharge flow rates of the first and second oil pumps 11 and 12 are merged.

  Next, the operation in the above configuration will be described. Normally, the electric motor 13 is stopped, and the electromagnetic switching valve 18 is held in the original position shown in FIG. In this state, the first oil pump 11 driven by the engine 10 sucks the hydraulic oil from the oil pan 16 and discharges the hydraulic oil to the discharge passage 15, and the discharged hydraulic oil is supplied to the hydraulic circuit 20. The

  In this state, when the engine 10 is idling stopped, this is detected by the control device 30, and a start command for starting the electric motor 13 is sent from the control device 30. As a result, the electric motor 13 is started and the second oil pump 12 is driven. By driving the second oil pump 12, the hydraulic oil is sucked up from the oil pan 16, and a constant flow rate of hydraulic oil is discharged into the auxiliary discharge passage 21. The discharged hydraulic oil passes through the check valve 22 and the discharge passage 15. It is supplied to the hydraulic circuit 20.

  Thereby, even when the driving of the first oil pump 11 is stopped by the idling stop, the hydraulic oil discharged from the second oil pump 12 driven by the electric motor 13 is supplied to the hydraulic circuit 20, so that the idling is performed. The engaged state of the frictional engagement element (clutch) of the automatic transmission that is in the engaged state at the time of stop can be maintained.

  When the idling stop is released, the electric motor 13 is stopped based on a command from the control device 30, and the discharge of the hydraulic oil from the second oil pump 12 is stopped. As a result, only the hydraulic oil discharged from the first oil pump 11 driven by the engine 10 is supplied to the hydraulic circuit 20.

  In addition, when shift control is performed in the automatic transmission while the vehicle is running, this is detected by the control device 30, the electric motor 13 is started, and the second oil pump 12 is driven. As a result, the hydraulic oil discharged from the first oil pump 11 and the hydraulic oil discharged from the second oil pump 12 are merged and supplied to the hydraulic circuit 20, so that a large flow rate is required at the time of shift control. In this case, the second oil pump 12 can compensate for the insufficient flow rate in the first oil pump 11, and there is no need to increase the pump capacity of the first oil pump 11.

  By the way, when the ignition is turned on, step 102 and the subsequent steps in the flowchart shown in FIG. 3 are executed. If it is determined in step 106 that the ATF temperature is lower than the predetermined temperature, the process proceeds to step 108. A switching command for switching the electromagnetic switching valve for a predetermined time is output. Based on this switching command, the solenoid of the electromagnetic switching valve 18 is excited, and the electromagnetic switching valve 18 is controlled to be switched to the switching position shown in FIG.

  By switching the electromagnetic switching valve 18, the pressure oil discharged from the first oil pump 11 is supplied to the suction port 12 b of the second oil pump 12 via the electromagnetic switching valve 18. At this time, the electric motor 13 is controlled so as to be able to rotate freely, and the second oil pump 12 is forcibly driven by the supply of pressure oil to the suction port 12 b of the second oil pump 12. As a result, the low temperature hydraulic oil in the second oil pump 12 is forcibly circulated, and the temperature of the hydraulic oil (ATF) is quickly raised by the forced drive of the second oil pump 12. When the electromagnetic switching valve 18 is switched and a certain time elapses, the solenoid of the electromagnetic switching valve 18 is demagnetized, and the electromagnetic switching valve 18 is returned to the original position shown in FIG.

  As described above, when the engine is started at a low temperature, the second oil pump 12 is forcibly driven by the pressure oil discharged from the first oil pump 11 driven by the engine, so that the operation at a low temperature in the second oil pump 12 is performed. Oil is discharged into the circulation. Therefore, even when the second oil pump 12 needs to be driven after the low temperature start, the driving torque of the electric motor 13 required to drive the second oil pump 12 can be reduced, and the motor of the electric motor 13 can be reduced. As a capacity, it is possible to eliminate the need for a large motor output that overcomes viscous resistance at low temperatures. As a result, the electric pump 13 can be reduced in size, and the vehicle mountability can be improved.

  In the above-described embodiment, the electric motor 13 that drives the second oil pump 12 is driven at the time of idling stop and the shift control of the automatic transmission. However, the electric motor 13 is driven only at the time of idling stop. In such a case, the first oil pump 11 driven by the engine 10 may be a pump having a pump capacity capable of discharging a flow rate required for the shift control.

  Further, in the above-described embodiment, the electromagnetic switching valve 18 is switched for a predetermined time at a low temperature start. However, the ATF temperature after switching the electromagnetic switching valve 18 is detected, and the ATF temperature is equal to or higher than a predetermined temperature. When it becomes, it may be controlled to return the electromagnetic switching valve 18 to the original position.

  Further, as a condition for switching the electromagnetic switching valve 18, for example, a fail-safe item such as the presence or absence of an abnormality in the coil temperature can be added.

  Thus, the specific configuration described in the above-described embodiment is merely an example of the present invention, and the present invention is not limited to such a specific configuration. Various embodiments can be adopted without departing from the scope.

1 is a hydraulic system diagram showing a hydraulic oil supply device in an automatic transmission showing an embodiment of the present invention. It is a figure which shows the flowchart which switches and controls an electromagnetic switching valve. It is a diagram which shows the discharge characteristic of two oil pumps. FIG. 2 is a hydraulic system diagram illustrating an operation state of FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Engine, 11 ... 1st oil pump, 11a ... Discharge port, 11b ... Suction port, 12 ... 2nd oil pump, 12a ... Discharge port, 12b ... Suction port, 13 ... Electric motor, 15 ... Discharge passage, 16 ... Oil pan, 18 ... electromagnetic switching valve, 23 ... suction passage, 30 ... control device, 108 ... switching control means.

Claims (2)

A first oil pump connected to a drive shaft driven by an engine and discharging hydraulic oil from a hydraulic power source to a hydraulic circuit of an automatic transmission having a friction engagement element and the like, and driven by an electric motor, A hydraulic oil supply device in an automatic transmission comprising a second oil pump that discharges hydraulic oil from the hydraulic circuit to the hydraulic circuit;
The suction port of the second oil pump communicates with either the hydraulic power source side or the discharge port side of the first oil pump, and the discharge passage of the first oil pump and the suction passage of the second oil pump. An electromagnetic switching valve that cuts off communication,
Switching control means for switching the electromagnetic switching valve at a low temperature start of the engine and communicating the suction port of the second oil pump to the discharge port side of the first oil pump;
A hydraulic fluid supply device for an automatic transmission, comprising: 2. The hydraulic oil supply device in an automatic transmission according to claim 1, wherein the electric motor is driven when idling is stopped.

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