JP2008180302A - Hydraulic control device for vehicular automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic control device 10 for an automatic transmission having a continuously variable transmission and a multi-stage transmission 4, having a simple and easy-to-control auxiliary pump for reducing the energy loss during normal travel with the shifting operation of a torque converter. <P>SOLUTION: First and second check valves 16, 32 are provided on a connection passage 13 in a supply port 18 of a shift valve 17, and an electromagnetic pump 30 is provided for reciprocating a piston 33 to be moved in and out of a cylinder chamber 36 therebetween with electromagnetic force to suck/deliver oil. At a timing when supplying pressure oil to a friction engaging device 8 selected by the shift valve 17, a first hydraulic pump 11 supplies the pressure oil which the friction engaging device requires to be held at predetermined pressure. Then, the friction engaging device is held by pressure oil from the electromagnetic pump. The pressure of the first hydraulic pump is controlled to be lower than pressure which the friction engaging device requires and not lower than pressure as which the pressure of a pressure control valve 20 can be kept. The friction engaging device is set at a drive position, and otherwise the electromagnetic pump is stopped. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to energy saving of a hydraulic control device for an automatic transmission for a vehicle including a continuously variable transmission such as a torque converter, a pulley type (CVT), and an automobile having a multi-stage transmission such as a gear.

  Conventional automatic transmissions for automobiles include neutral, 1st, 2nd, drive by changing the gear ratio and meshing with torque converters, lubrication devices, cooling devices, etc. that transmit the output from the engine via hydraulic pressure The multi-stage transmission performs a shift operation such as reverse rotation. A hydraulic control device is provided for supplying hydraulic pressure to the torque converter, the lubrication device, the cooling device, etc., controlling the hydraulic pressure of the multi-stage transmission, and supplying hydraulic pressure. The multi-stage transmission is provided with various hydraulic engagement devices by selectively supplying or discharging hydraulic pressure with a manual shift valve, and further via a shift valve or a solenoid valve provided downstream of the manual shift valve. The desired shift state and gear position can be selected by combining these. For example, in a manual shift valve, neutral, first speed, second speed, drive, and reverse rotation are selected. Furthermore, in addition to the selected shift state, the frictional shift device is further selected according to the accelerator and the vehicle speed while hydraulically or electrically controlling the shift valve and solenoid valve in the subsequent stage, and the first, second, third, A smooth automatic transmission is possible by selecting the number of steps, four steps, or a finer number of steps.

  The hydraulic control device is provided with a hydraulic pump for supplying hydraulic pressure to a torque converter, a lubrication unit, a friction engagement device, and the like. The hydraulic oil of the hydraulic pump is adjusted by a pressure adjusting valve (referred to as a primary valve or the like), and is supplied to or discharged from the friction engagement device via a manual shift valve, a shift valve, a solenoid valve, or the like. On the other hand, pressure oil having a pressure lower than that of the hydraulic pump is supplied to other hydraulic devices such as a torque converter and an oil cooler via a pressure regulating valve (referred to as a secondary valve or the like). The solenoid valve is an electromagnetic switching valve that moves the spool and poppet by turning the electromagnetic coil on and off, a duty valve that controls the electromagnetic coil by turning it on and off in minute time units, and the flow rate and pressure according to the electrical command signal Various things such as an electromagnetic proportional valve that can be controlled by using the above are known.

  However, when the hydraulic pressure is supplied by one hydraulic pump, the pressure on the lubrication / cooling device / torque converter side may be low, and the flow rate needs to be increased as the speed increases. High pressure is required on the side, and the holding force of the friction engagement device must be increased by increasing the speed, and the pressure needs to be increased. Therefore, the hydraulic pump is loaded with high pressure and large capacity, and the engine There was a problem that driving loss was large.

  Therefore, in Patent Document 1, an engine-driven low-pressure hydraulic pump is provided exclusively for the torque converter side, and a high-pressure electric hydraulic pump is provided exclusively for the friction engagement device side, systematized according to the purpose of use, and engine driving Loss is reduced and fuel efficiency is improved. In addition, the electric hydraulic pump can perform fine control, and can easily secure the necessary hydraulic pressure and flow rate on the friction engagement device side. Although not disclosed in Patent Document 1, for example, a high pressure and high flow rate can be set during shifting, and a high pressure and low flow rate can be set during holding. Further, in Patent Document 1, the supply path of the low-pressure hydraulic pump is further bypass-supplied to the supply path of the electric hydraulic pump via a check valve, so that the hydraulic pressure of the engine drive when the electric hydraulic pump fails. Hydraulic pressure is supplied from the pump to the friction engagement device.

On the other hand, Patent Document 2 discloses a configuration in which pressure oil from two hydraulic pumps is supplied to a friction engagement device via a check valve. In this system, the pressure oil of the first hydraulic pump driven by the engine is controlled by the pressure control valve, and the clutch pressure circuit controlled by the pressure control valve integrated with the pressure control valve is supplied by the manual shift valve. The port is connected. Further, a first check valve is provided in the clutch circuit so as to prevent backflow from the supply port. Further, pressure oil is supplied to the connection path between the first check valve and the supply port from the second hydraulic pressure (pump) source including the electric hydraulic pump, the accumulator, and the accumulator control circuit via the second check valve. Connected as possible. As a result, when the vehicle is stopped, the engine is stopped by idling stop to save energy, while pressure oil is supplied from the second hydraulic power source to the frictional engagement device such as a clutch to ensure the engaged state during traveling, and when the engine is restarted To prevent shock.
JP 2001-74130 A JP 11-159366 A

  However, since the thing of patent document 1 performs supply and a holding | maintenance to a friction engagement apparatus only by an electric (2nd) hydraulic pump, control of a large capacity | capacitance needs a small capacity | capacitance. An efficient pump is needed. Further, when the rotational speed is constant, a variable pump is used, but the structure is complicated. Further, when changing the rotation speed, the motor control circuit becomes complicated. In addition, a large flow rate is required when moving from an open or pressure-holding state to another state by adding pressure oil, but there are problems such as poor response in variable pumps and electric motors.

  Further, pressure oil is supplied from the first hydraulic pump to the friction engagement device when the electric (second) hydraulic pump fails. However, in this case, since the torque converter supply pressure is lower than the pressure of the friction engagement device, there is a problem that the holding pressure is low, high speed operation cannot be performed, and normal operation becomes impossible. In preparation for this, in order to increase the pressure of the first hydraulic pump in the event of a failure, the pump performance and valve performance should be higher than the normal specifications originally used, and the function to set the pressure to a high pressure at the time of failure. There was a problem such as having to add.

  On the other hand, in Patent Document 2, when the vehicle is stopped or during energy recovery, the engine is stopped, the first hydraulic pump is also stopped, and pressure oil of the friction engagement device is held by an electric hydraulic pump or the like to save energy. I am trying. However, during normal driving, the first hydraulic pump is always in operation and pressure oil continues to be supplied to the pulley transmission, and is set to a value higher than the pressure of the second hydraulic source even during idling. The surplus oil is only distributed to the friction engagement device, and there is a problem that the driving energy is not different from the conventional one. Further, there is no disclosure regarding the supply of pressure oil to the low pressure side to the torque converter or lubricating oil. Furthermore, the second hydraulic pump requires an accumulator and an accumulator control circuit, and there is a problem that the structure is complicated and large.

  In view of the above-described problems, an object of the present invention is to provide a small, simple and easily controlled auxiliary pump (second hydraulic pump) in a hydraulic control device for an automatic transmission for a vehicle including a continuously variable transmission and a multi-stage transmission. ). Furthermore, in a vehicular multi-stage transmission using a multi-stage transmission and a torque converter without using a CVT, the energy loss during normal running is reduced.

  In the present invention, a continuously variable transmission, a multi-stage transmission that performs shifting by selectively coupling and releasing a plurality of friction engagement devices, and selection of supply / discharge of pressure oil to the friction engagement devices A shift valve for switching, a first hydraulic pump configured to supply pressure oil to the continuously variable transmission and the friction engagement device, and pressure oil from the first hydraulic pump to a supply port of the shift valve In a hydraulic control device for an automatic transmission for a vehicle, comprising: a connection path for supplying pressure oil; and a first and a second in series provided in a direction in which pressure oil is supplied to the connection path toward a supply port to the shift valve. An electromagnetic pump comprising: a second check valve; a cylinder chamber communicating between the first and second check valves; a piston that expands and contracts the cylinder chamber; and an electromagnetic coil that reciprocates the piston. With a second hydraulic pump And solve the problems described above by providing a hydraulic control device for an automatic transmission for a vehicle.

  That is, the second hydraulic pump as an auxiliary pump that supplies pressure oil to the friction engaging device side line to the first hydraulic pump similar to the conventional one, and the first and second check valves, An electromagnetic pump comprising a cylinder chamber communicating between the two check valves, a piston that expands and contracts the cylinder chamber, and an electromagnetic coil that reciprocates the piston, and is provided in a connection path between the first hydraulic pump and the shift valve . As a result, when the electromagnetic coil is not applied, the first hydraulic pump passes through the first check valve, the cylinder chamber, and the second check valve, and is frictionally engaged as in the conventional case via the shift valve. The device can supply pressure oil. On the other hand, when the first hydraulic pump is at a low pressure, an ON-OFF current is applied to the electromagnetic coil to reciprocate the piston, thereby generating a pressure and enabling the friction engagement device to maintain the pressure.

  The second hydraulic pump may have a small capacity that compensates for leakage of a valve, a friction engagement device, etc., and the flow rate accuracy is not so high as long as the pressure is controlled, and such an electromagnetic pump structure is sufficient. Further, the electromagnetic pump may be integrated, or each component may be incorporated into a valve assembly to which shift valves are attached.

  Further, if the first and second check valves and the cylinder chamber are large, the pump performance may be reduced, and if it is small, the pressure loss of the first hydraulic pump increases. Therefore, in the invention described in claim 2, a third check valve is provided in the same direction in parallel with the first and second check valves. According to this, the size of the check valve can be selected regardless of the second hydraulic pump, and pressure oil can be supplied to the shift valve without excessive pressure loss.

  Further, in a transmission having a CVT, a high pressure is required even during normal traveling operation. For example, in a combination of a torque converter and a multi-stage transmission without a CVT as described in Patent Document 1, the torque converter is not used in normal traveling. The friction engagement device supplies a high pressure. However, the friction engagement device only needs to maintain pressure.

  Therefore, in the invention described in claim 3, the continuously variable transmission is a torque converter, and a pressure control valve for controlling a pressure of the first hydraulic pump and a pressure of the friction engagement device, and the torque converter A pressure regulating valve that controls the pressure of the pressure oil supplied to the pressure control valve below the pressure of the pressure control valve, the shift valve is a manual shift valve, and the pressure oil passing through the manual shift valve is the friction When it is selected to be supplied to any one of the engagement devices, the pressure control valve is configured so that the selected friction engagement device is in the supply timing of the pressure oil to the selected friction engagement device. It is set to supply the required pressure oil, and at least after the pressure to the selected friction engagement device reaches and maintains a predetermined pressure, the selection is performed by the pressure oil from the electromagnetic pump. And the pressure control valve reduces the pressure during operation of the first hydraulic pump to be lower than the pressure required for the selected friction engagement device, and adjusts the pressure of the pressure regulating valve. It was made to be controllable to a pressure higher than the pressure that can be maintained.

  That is, a solenoid valve which is a first hydraulic pump and a second hydraulic (auxiliary) pump is arranged, and the supply timing when the pressure oil passing through the manual shift valve is supplied to the selected friction engagement device, that is, the friction engagement When operating one of the combined devices, the pressure control valve is set to supply the pressure oil required by the friction engagement device, that is, the first hydraulic pump is set to high pressure, and the friction engagement device is the same as before. To operate. Further, at least after the pressure to the friction engagement device reaches a predetermined pressure and is held, the friction engagement device is held by pressure oil from a small capacity electromagnetic pump, that is, held at a high pressure. At this time, the pressure control valve can control the pressure during the operation of the first hydraulic pump to a pressure lower than the pressure required for the selected friction engagement device and higher than the pressure capable of maintaining the pressure of the pressure regulating valve, that is, torque It is operated at the pressure required for converters.

  As a result, the friction engagement device is held at a high pressure by the electromagnetic pump during normal operation, and the first hydraulic pump is operated at a low pressure. Therefore, energy is wasted compared to operating the first hydraulic pump at a high pressure. The occurrence of is reduced. Further, the operation is similar to that of the conventional hydraulic control device, and the conventional control system can be applied almost as it is. In addition, the capacity of the electromagnetic pump is more effective for energy saving, but the selected friction engagement device is necessary to compensate for leakage of manual shift valve, downstream valve, friction engagement device, etc. It is necessary to have a capacity that can be maintained at a predetermined pressure. The pressure of the first hydraulic pump when holding the electromagnetic pump is preferably as low as possible. Further, since the electromagnetic pump is connected to the supply port of the manual shift valve, the pressure oil can be efficiently distributed to the selected friction engagement device regardless of the path of the subsequent valve and the complexity of the operation.

  As described above, some multi-stage transmissions perform finer automatic shift control by selecting a friction engagement device more finely by using not only a main manual shift valve but also a rear shift valve or solenoid valve. Therefore, in the invention described in claim 4, a shift valve provided on the downstream side of the manual shift valve and configured to selectively switch supply / discharge of hydraulic pressure to the friction engagement device and / or A solenoid valve, and when the manual shift valve or the shift valve or the solenoid valve is selected to supply pressure oil to any of the friction engagement devices, to the selected friction engagement device The pressure control valve is set so as to supply the pressure oil required by the selected friction engagement device, and at least the pressure to the selected friction engagement device is predetermined. After reaching and holding the pressure, the selected friction engagement device is held by pressure oil from the electromagnetic pump, and the pressure control valve is The pressure in the pump operation lower than the pressure required for the selected friction engagement device, and a hydraulic control system for an automatic transmission for a controllable vehicle pressure higher than the pressure capable of maintaining the pressure of the pressure regulating valve.

  That is, when the selection of the friction engagement device is performed not only with the manual shift valve but also with a shift valve or a solenoid valve downstream of the manual shift valve, as described above, the selected friction engagement device is compressed with pressure oil. Is supplied from the first pump, and after reaching a predetermined pressure, the pressure of the first hydraulic pump is reduced to hold the pressure oil of the friction engagement device selected by the electromagnetic pump. did. Accordingly, the present invention can be applied not only to a manual shift valve but also to a hydraulic control device for an automatic transmission for a vehicle having a shift valve and a solenoid valve capable of finer gear shift control at a later stage.

  Further, when the manual shift valve is in the neutral position, it is not necessary to supply pressure oil to the friction engagement device. Therefore, the first hydraulic pump is controlled to a low pressure and the second hydraulic pump is stopped as in the conventional case. In the back position, the operation time is short. In addition, a low speed gear such as a low gear has a short time, requires a large output, or is in an engine brake state, so that the influence of drive loss is small. Therefore, in the invention described in claim 5, the selected friction engagement device is set to a drive position. Even if the manual shift valve is in the drive position, the shift valve and solenoid valve in the subsequent stage are operated by the accelerator, the vehicle speed, etc., and each shift stage (first speed, second speed, third speed, fourth speed, The friction engagement device corresponding to the overdrive or the like is selected, and pressure oil is supplied and discharged.

  In addition, the electromagnetic pump has a small capacity and can always be operated, but it is preferable to stop when the pressure of the friction engagement device is not required. Therefore, in the invention according to claim 6, the electromagnetic pump is operated at a position or drive position other than when the manual shift valve is neutral, and is stopped at other times.

  Furthermore, the pressure of the electromagnetic pump may hold the pressure oil of the friction engagement device, but the holding pressure changes depending on the operation speed or the like. Therefore, in the invention described in claim 7, the pressure oil of the electromagnetic pump is controlled to the maximum pressure necessary for holding the friction engagement device or the necessary pressure.

  As described above, in the present invention, communication between the first and second check valves and the first and second check valves is an auxiliary pump that supplies pressure oil to the line on the friction engagement device side. An electromagnetic pump comprising a cylinder chamber that performs expansion, a piston that expands and contracts the cylinder chamber, and an electromagnetic coil that reciprocates the piston, and is provided in the connection path between the first hydraulic pump and the shift valve. There is no need to provide a line. In addition, there is no risk of poor suction and the structure is simple and control is easy. In addition, the change of the conventional hydraulic control device is very small, the technical hurdle is small, and the design is easy. Even if the electromagnetic pump breaks down, the pressure oil can be supplied from the first hydraulic pump, and the same operation as before can be performed.

  Further, in the invention described in claim 2, since a third check valve is provided in parallel with the electromagnetic pump and the pressure loss to the shift valve is not excessive, energy saving is not hindered and the same as in the conventional case. Can be operated.

  Further, in the invention described in claim 3, in the hydraulic control device for an automatic transmission for a vehicle including a torque converter and a multi-stage transmission instead of a CVT operated at a high pressure, friction engagement is performed by an electromagnetic pump during normal operation. The device is held at high pressure, and the first hydraulic pump supplies low-pressure oil to the torque converter and lubrication line to reduce drive loss, thus saving energy. Further, since the first hydraulic pump only controls the pressure, there is no problem with responsiveness. Furthermore, since the configuration may be almost the same as that of the conventional hydraulic control device, a small improvement of the conventional hydraulic control device for an automatic transmission for a vehicle effectively reduces the drive energy loss. In addition, although this invention reduces the drive energy loss in normal driving | operation, it can be applied also at the time of idling stop like the case of the patent document 2 mentioned above.

  Further, in the invention described in claim 4, not only a manual shift valve but also a high-speed automatic transmission that can automatically select a friction engagement device by a vehicle speed, an accelerator, etc. not only in a shift valve and a solenoid valve in the subsequent stage. Therefore, even with a hydraulic control device for a vehicle automatic transmission having a complicated structure, the same effect as described above can be obtained.

  Further, in the invention described in claim 5, since it is limited to the most effective drive position in each position, energy saving can be achieved by simple control. In addition, the first hydraulic pump and the electromagnetic pump work according to the automatic shift while traveling, and the driving feeling is the same as in the conventional case. In addition, since the electromagnetic pump is stopped when not required, no noise or energy loss occurs. Furthermore, if the pressure is controlled, an appropriate holding force corresponding to the speed and load can be obtained.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram of an automobile automatic transmission according to the present invention, and FIG. 2 is a system diagram of a hydraulic control device of the automobile automatic transmission. In the present embodiment, a conventional hydraulic control device for an automatic transmission for automobiles uses an electromagnetic pump as a second hydraulic pump on the connection path (main circuit) between the first hydraulic pump and the supply port of the manual shift valve. It is arranged to supply pressure oil to the supply port of the manual shift valve. As shown in FIG. 1, an automatic transmission 1 for an automobile according to the present embodiment has a torque converter 3 connected to a drive shaft of an engine 2, a multi-stage transmission 4 connected to an output shaft of the torque converter, and a terminal deceleration. The wheel 6 is driven via the machine 5.

  The multi-stage transmission has a planetary type, etc., and controls a plurality of brakes 81 and clutches 82, that is, friction engagement devices 8 that actuate a large number of gears by hydraulic pressure, to fix the gears or connect the gears. Thus, it is possible to obtain a shift range such as selection of forward and reverse, 1st speed, 2nd speed, 3rd speed, 4th speed, direct connection, overdrive and the like. Many such multi-stage transmissions are known and will not be described.

  Hydraulic pressure is used for operating the torque converter 3, the lubrication cooling 7 of the multi-stage transmission, and the clutches and brakes that are the friction engagement devices 8. As shown in FIG. 2, the hydraulic control apparatus 10 is provided with a first hydraulic pump 11 driven by the engine 2, a pressure control valve 12 for controlling the pressure of the first hydraulic pump, and a connection path (main circuit). 13 pressures are controlled. The main circuit is branched and a relief valve 14 is provided as a safety valve. The pressure control valve 12 is an electromagnetic proportional pressure control valve whose pressure is controlled by an electrical command 42 from the controller 15. The connection path (main circuit) 13 is connected to the supply port 18 of the manual shift valve 17 via the first check valve 16. The manual shift valve 17 selects a predetermined position, and further selectively sends pressure oil to the brake or clutch friction engagement device 8 via a shift valve / solenoid valve 19 or the like at the subsequent stage. . The pressure applied to the frictional engagement device 8 is controlled to be low when the vehicle speed is low, and higher as the vehicle speed increases. In addition, for example, selecting a drive with a manual shift valve, and operating a subsequent shift valve or solenoid valve hydraulically or electrically according to the vehicle speed, etc., enables finer automatic shift control in the drive position state. Has been.

  On the other hand, the main circuit 13 is further branched and a low pressure line is provided via the pressure regulating valve 20. The output side of the pressure regulating valve 20 is lower than the required pressure to the friction engagement device 8 and is increased at a substantially constant pressure or in accordance with the speed. The torque converter 3 connected to the low pressure line 21 and other lubrication cooling systems 7 is supplied with low pressure oil. Further, the flow rate of the low-pressure oil is increased as the speed increases. The pressure regulating valve is called a secondary valve or the like.

  In particular, in the present embodiment, the pressure oil is serially connected to the connection path 13 that supplies the pressure oil from the first hydraulic pump 11 to the supply port 18 of the shift valve 17 toward the supply port to the shift valve. In addition, a first check valve 16 and a second check valve 32 are provided. Furthermore, a cylinder chamber 36 communicating between the first and second check valves 16, 32, a piston 33 that expands and contracts the cylinder chamber, and an electromagnetic coil 34 that reciprocates the piston are provided. ing. By supplying ON-OFF current 35 from the controller 15 to the electromagnetic coil 34 and reciprocating the piston 33, oil is sucked from the suction side check valve 31 and pressure oil is supplied from the discharge side check valve 32 to the supply port of the shift valve. 18 is supplied. Further, a third check valve 37 requiring bypass is provided in the same direction in parallel with the first and second check valves.

  The discharge amount of the electromagnetic pump 30 is controlled by an ON-OFF cycle, and the discharge pressure is controlled by an applied voltage or current. In brief, the discharge pressure is controlled to the maximum value of the required pressure of the friction engagement device 8, and more preferably, the pressure can be controlled according to the vehicle speed. Further, a pressure detector 40 that detects the pressure in the cylinder chamber 36 and outputs it as a signal is provided and input 41 to the controller 15. In addition, when it is applied even when the engine is stopped, such as an idling stop, there is a possibility that oil shortage may occur on the suction side of the electromagnetic pump 30. In such a case, the solenoid valve may be allowed to suck oil through a check valve 71 (indicated by a dotted line) connected to the tank or drain.

  The controller 15 is set with the position of the manual shift valve 17, the subsequent shift valve and the solenoid valve 19, and the pressure of the main circuit 13 in accordance with the accelerator and vehicle speed. The electric command is sent to the pressure control valve 12 according to the position of each valve. The given main circuit pressure is set to a predetermined pressure. The electromagnetic pump 30 is operated according to the position. Further, when the signal of the pressure detector 40 of the electromagnetic pump is fed back and the pressure of the electromagnetic pump becomes larger than a preset pressure, the main circuit pressure 13 is adjusted to be lower than the pressure required for the friction engagement device 8. An electric command 42 is given to the pressure control valve so that the pressure in the outlet side low pressure line 21 of the pressure valve 20 is higher than the pressure at which the pressure can be maintained.

  If there is an electrical command for operating the electromagnetic pump 30 but the electromagnetic pump pressure is lower than a predetermined pressure, the electrical command is sent to the pressure control valve 12 so that the main circuit pressure 13 is the same as the pressure commanded to the electromagnetic pump. Have been to give to. Here, for simplicity of explanation, the electromagnetic pump is set to operate only in the drive position. Note that the realization of such a controller can be easily obtained from a computer or various conventionally known electric circuits, and thus description thereof will be omitted.

  In such a hydraulic control device 10 for an automatic transmission for an automobile, the main circuit pressure 13 is set to a low pressure when the manual shift valve 17 is neutral during the operation of the engine 2. When the low, second, and back gears are selected, the main circuit pressure rises, and the friction engagement device 8 is operated with a pressure corresponding to the position to perform a desired gear combination. In this case, since the electromagnetic pump 30 is not operated, there is no difference from a conventional hydraulic control device for an automatic transmission for automobiles. Further, the bypass check valve 37 allows a large capacity of the first hydraulic pump to pass through with little pressure loss.

  Next, when the drive position is selected, the subsequent shift valve and solenoid valve are selected so as to have the first speed, and the friction engagement device 8 corresponding to the first speed is selected. Although the electromagnetic pump 30 is also activated, the signal of the pressure detector 40 is also low because the selected friction engagement device 8 is not activated. Accordingly, the main circuit 13 is raised, the friction engagement device is operated by the first hydraulic pump, and a desired gear combination is performed. When the engagement is completed and the pressure rises to a predetermined pressure, a signal is output from the pressure detector 40, and the main circuit pressure 13 is lowered. The friction engagement device 8 is pressure-held by the electromagnetic pump 30.

  Further, when the vehicle speed increases, the friction engagement device is selected so that the shift valve and the solenoid valve in the subsequent stage become the second speed, and the same operation is performed. Furthermore, automatic transmission such as 3rd speed and 4th speed is performed according to the speed. The main circuit pressure is increased at the start of each shift, the shift is completed, that is, the main circuit pressure is lowered after the pressure of the selected friction engagement device reaches a predetermined pressure, and the friction engagement selected by the electromagnetic pump The pressure of the apparatus is maintained as it is. As a result, the pressure of the main circuit 13 becomes low, and the driving loss of the engine 2 is reduced. When the drive position is released, the electromagnetic pump 30 is also stopped, and the pressure of the main circuit 13 becomes the same as that of a conventional hydraulic control device for an automobile automatic transmission.

  Furthermore, when the electromagnetic pump 30 fails, the signal from the pressure detector 40 also becomes low, so that the main circuit pressure 13 automatically increases and the friction engagement device 8 is held at the pressure of the first hydraulic pump 11. Is done. In addition, when the signal from the pressure detector 40 falls due to a failure of the solenoid valve 30 or the like, the pressure of the first hydraulic pump is introduced, so the pressure once drops and the first pump is restarted Take an electrical interlock so that the first pump does not interfere with the pressure detector. Thus, it becomes the same as the conventional one, and it can operate reliably even in the event of a failure, and can realize fail-safe. In addition, it can work effectively even when idling stops, contributing to energy saving.

  In addition, although electric control was demonstrated, control by oil_pressure | hydraulic is also possible. The electromagnetic pump is activated when a position is selected, but it may be delayed with a timer. The same applies to a transmission with a simple structure that does not have a shift valve or solenoid valve in the subsequent stage. Thus, it goes without saying that the invention can be applied to various hydraulic control devices for automatic transmissions for automobiles without departing from the gist of the present invention. Furthermore, in the embodiment, the description has been given for automobiles, but the present invention can also be applied to vehicles including railway vehicles such as diesel cars.

It is explanatory drawing of the automatic transmission for motor vehicles which shows the conventional and embodiment of this invention. 1 is a system diagram of a hydraulic control device for an automatic transmission for an automobile showing an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 Torque converter 4 Multistage transmission 8 Friction engagement apparatus 10 Hydraulic control apparatus of automatic transmission for vehicles 11 First hydraulic pump 12 Pressure control valve 13 Connection path (main circuit)
16 First check valve 17 (Manual) Shift valve 18 Shift valve supply port 19 Shift valve and / or solenoid valve 20 Pressure regulating valve 30 Electromagnetic pump (second hydraulic pump)
32 Second check valve 33 Piston 34 Electromagnetic coil 36 Cylinder chamber 37 Third check valve (bypass check valve)
40 Pressure detector

Claims (7)

A continuously variable transmission, a multi-stage transmission that performs shifting by selectively coupling and releasing a plurality of friction engagement devices, and a shift valve that selectively switches between supply and discharge of pressure oil to the friction engagement devices. A first hydraulic pump configured to supply pressure oil to the continuously variable transmission and the friction engagement device, and a connection path for supplying pressure oil from the first hydraulic pump to a supply port of the shift valve And a first check and a second check provided in series in a direction in which pressure oil is supplied to the connection path toward the supply port to the shift valve. A second hydraulic pump comprising an electromagnetic pump comprising a valve, a cylinder chamber communicating between the first and second check valves, a piston for expanding and contracting the cylinder chamber, and an electromagnetic coil for reciprocating the piston. With having as That a hydraulic control device for a vehicular automatic transmission. The hydraulic control device for an automatic transmission for a vehicle according to claim 1, wherein a third check valve is provided in the same direction in parallel with the first and second check valves. The continuously variable transmission is a torque converter, a pressure control valve for controlling the pressure of the first hydraulic pump and the pressure of the friction engagement device, and the pressure of the pressure oil supplied to the torque converter. A pressure control valve that controls the pressure at a pressure equal to or lower than the pressure of the pressure shift valve, and the shift valve is a manual shift valve so that the pressure oil that has passed through the manual shift valve is supplied to one of the friction engagement devices. In the selected case, the pressure control valve is set to supply the pressure oil required by the selected friction engagement device at the timing of supplying the pressure oil to the selected friction engagement device. At least after the pressure to the selected friction engagement device reaches and holds a predetermined pressure, the selected friction engagement device is held by pressure oil from the electromagnetic pump; and The force control valve is configured such that the pressure during operation of the first hydraulic pump is lower than the pressure required for the selected friction engagement device, and can be controlled to a pressure higher than a pressure capable of maintaining the pressure of the pressure regulating valve. The hydraulic control device for an automatic transmission for a vehicle according to claim 1 or 2. And a shift valve and / or a solenoid valve provided on the downstream side of the manual shift valve and capable of selectively switching between supply and discharge of hydraulic pressure to the friction engagement device. When the shift valve or the solenoid valve is selected to supply pressure oil to any of the friction engagement devices, the pressure control is performed at the supply timing of the pressure oil to the selected friction engagement device. The valve is set to supply the pressure oil required by the selected friction engagement device, and at least after the pressure to the selected friction engagement device reaches and maintains a predetermined pressure, The pressure engagement valve holds the selected friction engagement device, and the pressure control valve controls the pressure during operation of the first hydraulic pump. Device lower than the pressure necessary for the hydraulic control device according to claim 3 for a vehicle automatic transmission, wherein the being controllable to pressure higher than the pressure capable of maintaining the pressure of the pressure regulating valve. 5. The hydraulic control device for an automatic transmission for a vehicle according to claim 3, wherein the selected friction engagement device is a drive position. 6. The automatic transmission for a vehicle according to claim 3, wherein the electromagnetic pump is configured to operate at a position or drive position other than when the manual shift valve is neutral, and to stop at other positions. Hydraulic control device for the machine.   7. The vehicular automatic according to claim 3, wherein the pressure oil of the electromagnetic pump is controlled to a maximum pressure necessary for holding the friction engagement device or a necessary pressure. Hydraulic control device for transmission.

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