JP2016079991A - Transmission, control method of transmission and vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transmission which can suppress the generation of an energy loss.SOLUTION: A hydraulic control circuit comprises: a first oil passage and a second oil passage which circulate hydraulic pressure to a gear change mechanism; an oil pump which supplies the hydraulic pressure to the first oil passage; an unload valve which is arranged in the first oil passage, and unloads oil in the first oil passage on the basis of set pressure; a check valve which can make the oil pass to only the second oil passage from the first oil passage; and an accumulator which is connected to the second oil passage, and accumulates the hydraulic pressure of the second oil passage. In the gear change mechanism, a gear change ratio is controlled by the hydraulic pressure which is supplied from the second oil passage, and a control part variably controls the set pressure of the unload valve on the basis of a gear change state of the gear change mechanism.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a transmission whose gear ratio is controlled by hydraulic pressure supplied by a hydraulic control circuit, a control method therefor, and a vehicle including the transmission.

  The transmission is shifted by supplying hydraulic pressure to the hydraulic chamber. The hydraulic pressure generated by the oil pump is supplied to the hydraulic chamber through the oil passage. In order to suppress the fluctuation of the hydraulic pressure generated by the oil pump, the oil passage may be provided with an accumulator. Patent Document 1 discloses that an accumulator is provided in a high-pressure oil passage communicating with a hydraulic chamber, and the hydraulic pressure discharged from the oil pump is stored in the accumulator.

JP 2011-163367 A

  In the prior art described in Patent Document 1, the hydraulic pressure generated by the oil pump is stored in the accumulator. However, when the hydraulic pressure is supplied exceeding the upper limit of the accumulator capacity, the excess hydraulic pressure is discharged by the relief valve.

  In such a configuration, the oil pressure generated by the oil pump is discharged by the relief valve, resulting in a loss of energy for driving the oil pump. When the drive source of the oil pump is an engine, fuel consumption is deteriorated. When the drive source of the oil pump is a motor, the power consumption increases.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a transmission that suppresses the generation of energy loss and a control method thereof in a transmission that includes an accumulator in an oil passage.

  According to an embodiment of the present invention, a transmission includes a hydraulic control circuit, a transmission mechanism, and a control unit that controls the operation of the hydraulic control circuit, and the hydraulic control circuit distributes hydraulic pressure to the transmission mechanism. A first oil passage, a second oil passage, an oil pump that supplies hydraulic pressure to the first oil passage, and an unload valve that is disposed in the first oil passage and unloads the oil in the first oil passage based on a set pressure. A check valve capable of passing oil only from the first oil passage to the second oil passage, and an accumulator connected to the second oil passage and accumulating the oil pressure of the second oil passage, The transmission ratio is controlled by the hydraulic pressure supplied from the second oil passage, and the control unit variably controls the set pressure of the unload valve based on the shift state of the transmission mechanism.

  According to the present invention, when the oil pressure in the first oil passage reaches the set pressure, the unload valve is unloaded, the oil pressure in the first oil passage is drained, and the oil pump is driven with no load. As a result, an interval time during which the oil pump is operated without load can be obtained, so that energy loss due to friction during rotation of the oil pump can be reduced, and fuel efficiency of the driving force source can be improved.

It is explanatory drawing which shows the structure of the vehicle carrying the transmission of 1st Embodiment of this invention. It is explanatory drawing which shows the structure of the hydraulic control circuit of 1st Embodiment of this invention. It is explanatory drawing which shows the structure of the hydraulic control circuit of 2nd Embodiment of this invention. The flowchart in the state which the accelerator pedal is ON and the vehicle is powering of 2nd Embodiment of this invention is shown. The flowchart in 2nd Embodiment of this invention in the state in which the brake pedal is set to ON and the vehicle decelerates while the vehicle is drive | working. The flowchart of the second embodiment of the present invention in the idle stop state when the brake pedal is ON and the vehicle stops. It is explanatory drawing which shows the structure of the hydraulic control circuit of 3rd Embodiment of this invention. It is explanatory drawing which shows an example of a structure of the oil pump of 3rd Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is an explanatory diagram showing the configuration of a vehicle equipped with a transmission 4 according to a first embodiment of the present invention.

  The vehicle includes an engine 1 as a power source. The output rotation of the engine 1 is transmitted to drive wheels via a torque converter 2 with a lock-up clutch, an automatic transmission (hereinafter simply referred to as “transmission 4”), and a final reduction gear 6.

  The vehicle is driven by using a part of the power of the engine 1 to generate a hydraulic pressure, adjust the generated hydraulic pressure and supply the hydraulic pressure to each part of the transmission 4, and the hydraulic control circuit 11 A controller 12 is provided as a control unit for controlling the operation.

  The transmission 4 includes a torque converter 2, a transmission mechanism 5, a hydraulic control circuit 11, and a controller 12 that controls these operations. The speed change mechanism 5 is a continuously variable speed change mechanism (hereinafter referred to as “variator 20”) and a stepped speed change mechanism (hereinafter referred to as “sub transmission mechanism”) that is disposed downstream of the variator 20 and provided in series with the variator 20. 30 ”).

  The variator 20 is a belt-type continuously variable transmission mechanism that includes a primary pulley 21, a secondary pulley 22, and a V-belt 23 that is wound around the pulleys 21 and 22. Each of the pulleys 21 and 22 includes a fixed conical plate, a movable conical plate that is arranged with a sheave surface facing the fixed conical plate, and forms a V-groove between the fixed conical plate, and the movable conical plate. The hydraulic cylinders 23a and 23b are provided on the back surface of the movable cylinder to displace the movable conical plate in the axial direction. When the hydraulic pressure supplied to the hydraulic cylinders 23a, 23b is adjusted, the width of the V groove changes, the contact radius between the V belt 23 and each pulley 21, 22 changes, and the speed ratio vRatio of the variator 20 changes steplessly. To do.

  The subtransmission mechanism 30 is a transmission mechanism having two forward speeds and one reverse speed. The subtransmission mechanism 30 includes a planetary gear mechanism and a plurality of frictional engagement elements 31 (for example, a Low brake, a High clutch, and a Rev brake) that change the linkage state of the planetary gear mechanism.

  When the hydraulic pressure supplied to the frictional engagement elements 31 is adjusted to change the engagement / release state of the frictional engagement elements 31, the gear position of the auxiliary transmission mechanism 30 is changed. For example, if the low brake is engaged and the high clutch and the rev brake are released, the shift stage of the auxiliary transmission mechanism 30 is the first speed. If the High clutch is engaged and the Low brake and Rev brake are released, the gear position of the subtransmission mechanism 30 becomes the second speed having a gear ratio smaller than the first speed. Further, if the Rev brake is engaged and the Low brake and the High clutch are released, the shift speed of the subtransmission mechanism 30 is reverse.

  The controller 12 outputs an output signal of an accelerator opening sensor 41 that detects the opening of the accelerator pedal (hereinafter referred to as “accelerator opening APO”), the input rotational speed of the transmission 4 (= the rotational speed of the primary pulley 21, hereinafter). , “Primary rotational speed Npri”), an output signal from the rotational speed sensor 42, an output signal from the vehicle speed sensor 43, which detects the traveling speed of the vehicle (hereinafter referred to as “vehicle speed VSP”), and the oil of the transmission 4. An output signal of the oil temperature sensor 44 that detects the temperature, an output signal of the inhibitor switch 46 that detects the position of the select lever 45, an output signal of the brake switch 47 that detects that the brake pedal is depressed, and the like are input.

  The controller 12 determines a target speed ratio based on these input signals, and the speed change recorded in advance so that the overall speed ratio (through speed ratio) of the transmission 4 follows this target speed ratio. With reference to a map or the like, a shift control signal for controlling the gear ratio of the variator 20 and the shift speed of the auxiliary transmission mechanism 30 is generated, and the generated shift control signal is output to the hydraulic control circuit 11.

  Based on the shift control signal from the controller 12, the hydraulic control circuit 11 adjusts the necessary hydraulic pressure from the hydraulic pressure generated by the oil pump 10 m (see FIG. 2) rotated by driving the engine 1, and the adjusted hydraulic pressure is transmitted to the transmission 4. Supply to each site. As a result, the gear ratio of the variator 20 and the gear position of the auxiliary transmission mechanism 30 are changed, and the transmission 4 is shifted.

  FIG. 2 is an explanatory diagram showing the configuration of the hydraulic control circuit 11 according to the first embodiment of the present invention.

  The hydraulic control circuit 11 is provided in an oil pump 10 m that rotates by driving the engine 1, a first oil passage 101 and a second oil passage 102 that serve as a supply passage of oil pressure discharged from the oil pump, and a second oil passage 102. And an accumulator 70 for storing hydraulic pressure. The second oil passage 102 supplies hydraulic pressure to the high pressure system 100 of the transmission 4.

  The hydraulic control circuit 11 further includes a motor M and an electric oil pump 10e that is rotated by driving the motor M to generate hydraulic pressure. The hydraulic pressure generated by the electric oil pump 10 e is supplied to the low pressure system 200 of the transmission 4.

  The high pressure system 100 of the transmission 4 is supplied with the hydraulic cylinder 23a, the hydraulic cylinder 23b of the variator 20, the friction engagement element 31 of the auxiliary transmission mechanism 30, and the like, and the hydraulic pressure for generating transmission torque mainly for transmitting power. The system to be supplied.

  The transmission low pressure system 200 is a system that is supplied to the torque converter 2 and the lubrication of the transmission 4 and the like, and supplies hydraulic pressure to parts that can be covered with a lower hydraulic pressure than the high pressure system 100.

  A check valve 90 is provided between the first oil passage 101 and the second oil passage 102. The check valve 90 is configured as a check valve that supplies hydraulic pressure only from the first oil passage 101 to the second oil passage 102 and does not back flow from the second oil passage 102 to the first oil passage 101.

  The first oil passage 101 is provided with an unload valve 80. The unloading valve 80 is opened when the oil pressure of the second oil passage 102 is input and the oil pressure of the second oil passage 102 exceeds the unload pressure Psig set by the controller 12. Unload hydraulic pressure. When the unload valve 80 is opened, the hydraulic pressure discharged from the oil pump 10m is drained as it is, so that the oil pump 10m is operated without load. Thereby, friction is reduced and energy loss can be reduced. Hereinafter, the time during which the oil pump 10m is operated with no load is referred to as “interval time”.

  The unload pressure Psig is set higher than the set pressure of the accumulator 70, that is, the hydraulic pressure of the accumulator 70 and the second oil passage 102 when the accumulator 70 is accumulated to the maximum.

  The hydraulic control circuit 11 of the first embodiment configured as described above operates as follows.

  The hydraulic pressure generated by the oil pump 10 m is supplied to the high pressure system 100 of the transmission 4 via the first oil passage 101, the check valve 90, the accumulator 70, and the second oil passage 102. The accumulator 70 accumulates the hydraulic pressure of the second oil passage 102.

  The low pressure system 200 of the transmission 4 is supplied with hydraulic pressure generated by the electric oil pump 10e driven by the motor M.

  Here, the hydraulic pressure of the second oil passage 102, that is, the hydraulic pressure supplied to the accumulator 70 is supplied to the unload valve 80. When the oil pressure in the second oil passage 102 exceeds the unload pressure Psig, the unload valve 80 is unloaded and the oil pressure in the first oil passage 101 is drained. Since a check valve 90 is provided between the first oil passage 101 and the second oil passage 102, only the hydraulic pressure of the first oil passage 101 is reduced, and the accumulator 70 accumulates pressure in the second oil passage 102. The hydraulic pressure of the accumulator 70 is supplied to the high pressure system 100.

  Thereafter, when the hydraulic pressure of the accumulator 70 decreases and the hydraulic pressure of the second oil passage 102 falls below the unload pressure Psig, the unload valve 80 is closed and the unloading ends. In this case, the hydraulic pressure supplied by the oil pump 10m is supplied from the first oil passage 101 to the second oil passage 102 via the check valve 90, and the hydraulic pressure in the second oil passage 102 is increased. The hydraulic pressure of the second oil passage 102 supplied by the oil pump 10 m is supplied to the high pressure system 100.

  As described above, according to the first embodiment of the present invention, the transmission mechanism 5 including the variator 20 and the auxiliary transmission mechanism 30 that are variably controlled by the hydraulic pressure supplied by the hydraulic control circuit 11, and the hydraulic control circuit. And a controller 12 that controls the operation of the controller 11.

  The hydraulic control circuit is disposed in the first oil passage 101 and the second oil passage 102 that distribute the hydraulic pressure to the transmission mechanism 5, the oil pump 10 m that supplies hydraulic pressure to the first oil passage 101, and the first oil passage 101. An unload valve 80 for unloading the oil in the first oil passage 101 based on the set pressure, a check valve 90 capable of passing the oil only from the first oil passage 101 to the second oil passage 102, and a second oil passage 102 and an accumulator 70 that accumulates the hydraulic pressure of the second oil passage 102.

  The hydraulic control circuit 11 configured as described above variably controls the unload pressure Psig that is the set pressure of the unload valve 80 based on the shift state of the transmission mechanism 5.

  With such a configuration, the accumulator 70 in the second oil passage 102 is accumulated by the hydraulic pressure supplied from the oil pump 10m, and when the accumulator 70 is sufficiently accumulated, the unload valve 80 is unloaded and the first oil is accumulated. The oil pressure in the passage 101 is drained and the oil pump 10m is driven with no load.

  As a result, an interval time during which the oil pump 10m is operated without load can be obtained, so that energy loss due to friction during rotation of the oil pump 10m can be reduced, and fuel efficiency of the driving force source can be improved. . This effect corresponds to claim 1.

  Next, the hydraulic control circuit 11 according to the second embodiment of the present invention will be described.

  FIG. 3 is an explanatory diagram showing the configuration of the hydraulic control circuit 11 according to the second embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the structure same as 1st Embodiment, and the description is abbreviate | omitted.

  As shown in FIG. 3, the first oil passage 101 is provided with a switching valve 120.

  The switching valve 120 supplies the hydraulic pressure supplied by the oil pump 10m from the first oil passage 101 to the high-pressure system 100 via the oil passage 101a and the second oil passage 102, or from the first oil passage 101 to the oil passage. Whether to supply to the high-pressure system 100 via 101b and the bypass oil passage 103 is switched. The switching valve 120 switches the oil passage when a command is given to the solenoid by the controller 12.

  A bypass oil passage (third oil passage) 103 communicates the switching valve 120 and the second oil passage 102. The bypass oil passage 103 is provided with a relief valve 130. The relief valve 130 discharges the hydraulic pressure to the relief oil passage 14 when the hydraulic pressure of the second oil passage 102 communicating with the bypass oil passage 103 becomes equal to or higher than a predetermined pressure. The relief oil passage 14 is connected to the low pressure system 200 of the transmission 4 and supplies hydraulic pressure to the low pressure system 200.

  An ON-OFF valve 140 is provided between the accumulator 70 and the high pressure system 100 in the second oil passage 102. The ON-OFF valve 140 switches whether to supply the hydraulic pressure accumulated in the accumulator 70 to the high pressure system 100 via the second oil passage 102. The ON-OFF valve opens and closes the second oil passage 102 when a command is given to the solenoid by the controller 12.

  The hydraulic control circuit 11 of the second embodiment configured as described above operates as follows.

  Also in the second embodiment, similarly to the first embodiment, the unload valve 80 is controlled by the unload pressure Psig of the unload valve 80 and the oil pressure of the second oil passage 102.

  When the oil pressure in the second oil passage is lower than the unload pressure Psig, the oil pressure generated by the oil pump 10 m is supplied to the second oil passage 102 and accumulated in the accumulator 70. When the oil pressure in the second oil passage 102 exceeds the unload pressure Psig, the unload valve 80 is unloaded, and the oil pressure accumulated in the accumulator 70 is supplied to the second oil passage 102.

  The controller 12 can change the setting of the unload pressure Psig. For example, when the vehicle is traveling at a reduced speed, the input torque of the transmission 4 is small and the transmission torque in the transmission 4 is small, so the hydraulic pressure required for the high-pressure system 100 is relatively small.

  In such a case, the controller 12 controls to increase the unload pressure Psig so that a large amount of hydraulic pressure is accumulated in the accumulator 70. Further, when the unload valve 80 is unloaded, the unload pressure Psig is decreased (for example, near the set pressure of the accumulator 70), thereby extending the time during which the unload state is maintained.

  As a result, the interval time during which the oil pump 10m operates without load can be increased, and the energy efficiency of the vehicle can be improved.

  On the other hand, when kickdown occurs due to the driver greatly depressing the accelerator pedal, the transmission torque of the transmission 4 increases, so the high pressure system 100 is required to have high hydraulic pressure.

  In such a case, the controller 12 switches the switching valve 120 to the side where the oil pump 10m and the bypass oil passage 103 communicate with each other, and switches the ON-OFF valve 140 to the closed side. By setting in this way, the hydraulic pressure generated by the oil pump 10 m is directly supplied from the bypass oil passage 103 to the second oil passage 102 and the high-pressure system 100. Thereby, when the hydraulic pressure in the accumulator 70 is less than the predetermined hydraulic pressure, it is possible to prevent the responsiveness of the hydraulic pressure in the first oil passage 101 from being lowered (time lag) until the hydraulic pressure is accumulated in the accumulator 70. .

  Furthermore, during idle stop when the engine 1 is stopped when the vehicle is stopped, the transmission 4 does not transmit torque, so that no hydraulic pressure is required for the high-pressure system 100. At this time, since the engine 1 is stopped, the oil pump 10m does not generate hydraulic pressure.

  In such a case, the controller 12 closes the ON-OFF valve 140 in order to prevent the hydraulic pressure accumulated in the accumulator 70 from gradually decreasing. As a result, the second oil passage 102 between the ON-OFF valve 140 and the check valve 90 is closed, and the hydraulic pressure accumulated in the accumulator 70 is maintained until the ON-OFF valve 140 is opened again. Thereafter, for example, when the depression of the brake pedal is released, the controller 12 opens the ON-OFF valve 140 and supplies the hydraulic pressure accumulated in the accumulator 70 to the high pressure system 100 via the second oil passage 102. To do.

  4 to 6 are flowcharts of the control of the hydraulic control circuit 11 executed by the controller 12 according to the second embodiment of the present invention.

  These flowcharts are executed in a predetermined cycle (for example, every 10 ms) in parallel with other processing executed in the controller 12.

  FIG. 4 shows a flowchart in a state where the accelerator pedal is ON and the vehicle is powering in the second embodiment of the present invention.

  In step S100, the controller 12 determines whether or not the driver depresses the accelerator pedal and the vehicle is in a power running state. If it is not in the power running state, the process according to this flowchart is terminated and the process returns to other processes.

  When it determines with it being a power running state, the controller 12 acquires the present line command pressure PL1 in the high voltage | pressure system 100 in step S110.

  Next, in step S120, the controller 12 determines that the time change rate (time differential value) of the difference between the previous line command pressure PL0 (accumulator pressure Paccm) and the acquired line command pressure PL1 is the upper limit of the line pressure increase rate. It is determined whether or not the value is greater than dPLmax.

  For example, at the time of kickdown in which the accelerator pedal is greatly depressed by the driver, the line command pressure of the high pressure system 100 is suddenly increased to prevent the V belt 23 of the variator 20 from slipping. In such a case, the response of the hydraulic pressure supplied to the high pressure system 100 for accumulating in the accumulator 70 is delayed.

  Therefore, when the time change rate of the line command pressure is large, such as when the command pressure to the high pressure system 100 suddenly increases, the controller 12 disconnects the accumulator 70 from the oil passage as will be described below, and the oil pump 10m Is controlled to supply hydraulic pressure directly to the high pressure system.

  As a result of the determination in step S120, when the time differential value of the line command pressure PL1 is larger than the upper limit value dPLmax of the line pressure increase rate, the process proceeds to step S130, and the controller 12 sets the switching valve 120 to ON, that is, The oil pump 10m is switched to the supply side to the oil passage 101b, the oil pump 10m and the bypass oil passage 103 are switched to the communication side, and the ON-OFF valve 140 is switched to the closed side.

  Thus, the hydraulic pressure supplied by the oil pump 10 m is directly supplied from the first oil passage 101 to the high-pressure system 100 via the switching valve 120, the oil passage 101 b, the relief valve 130, and the oil passage 103, and the time lag by the accumulator 70 is Can be prevented.

  As a result of the determination in step S120, when the time differential value of the line command pressure PL1 is less than the upper limit value dPLmax of the line pressure increase rate, the process proceeds to step S140, and the controller 12 sets the switching valve 120 to OFF, that is, While switching from the oil pump 10m to the oil passage 101a, the ON-OFF valve is switched to the open side.

  Next, in step S150, the controller 12 sets a value obtained by adding the predetermined value Δp to the line command pressure PL1 acquired in step S120 as a new unload pressure Psig. The predetermined value Δp is a set value for making the pressure accumulated in the accumulator 70 slightly larger than the line command pressure PL1 so that the hydraulic pressure can be appropriately supplied to the high-pressure system 100.

  In step S160, the controller 12 measures the current accumulator pressure Paccm and compares it with the unload command pressure Psig. When the accumulator pressure Paccm is larger than the unload command pressure Psig, the process proceeds to step S170, and the controller 12 changes the unload command pressure Psig to the line command pressure PL1, and then proceeds to step S200. When the accumulator pressure Paccm is smaller than the unload pressure Psig, the process proceeds to step 180, and the controller 12 compares the accumulator pressure Paccm with the line command pressure PL1.

  When the accumulator pressure Paccm is smaller than the line command pressure PL1, the process proceeds to step S190, and the controller 12 sets the unload command pressure Psig to a pressure obtained by adding the predetermined pressure ΔP to the line command pressure PL1, and step S200. Migrate to In step S200, the accumulator pressure Paccm, which is the current hydraulic pressure of the accumulator 70, is set as the line command pressure PL0, the processing according to this flowchart is terminated, and the processing returns to other processing.

  In this way, the hydraulic pressure is supplied to the high pressure system 100 while accumulating the hydraulic pressure of the oil pump 10 m in the accumulator 70. On the other hand, when a large hydraulic pressure is required, the accumulator 70 can be disconnected from the second oil passage 102, and the hydraulic pressure can be supplied directly from the oil pump 10m to the high pressure system 100. Therefore, the time lag due to pressure accumulation in the accumulator 70 is reduced. Can be prevented.

  FIG. 5 is a flowchart in the second embodiment of the present invention in a state where the brake pedal is turned on and the vehicle is decelerating while the vehicle is traveling.

  In step S210, the controller 12 determines whether or not the driver depresses the brake pedal and the vehicle is in a decelerating running state. If the vehicle is not in the decelerating running state, the process according to this flowchart is terminated and the process returns to the other process.

  When it is determined that the vehicle is in the decelerating running state, the controller 12 acquires the current line command pressure PL1 in the high pressure system 100 in step S220.

  Next, in Step S230, the controller 12 determines whether or not the time change rate (time differential value) between the previous line command pressure PL0 and the acquired line command pressure PL1 is larger than the upper limit value dPLmax of the line pressure increase rate. Determine whether. When the time change rate is larger than the upper limit value dPLmax of the line pressure increase rate, the process proceeds to step S240, and the controller 12 sets the switching valve 120 to ON, that is, on the side to supply the oil passage 101b from the oil pump 10m. Switching is performed so that the oil pump 10m and the bypass oil passage 103 communicate with each other, and the ON-OFF valve 140 is switched to the closed side. As a result, the hydraulic pressure generated by the oil pump 10 m is directly supplied to the high-pressure system 100 via the relief valve 130 without passing through the accumulator 70, so that time lag caused by accumulating the accumulator 70 can be prevented.

  In step S230, when the time change rate is smaller than the upper limit value dPLmax of the line pressure increase rate, the process proceeds to step S250, and the controller 12 sets the switching valve 120 to OFF, that is, supplies the oil path 10a from the oil pump 10m. And switching the ON-OFF valve to the open side. Thereby, the state in which the accumulator 70 and the oil passage 102 communicate with each other is set.

  Next, the process proceeds to step S260, where the controller 12 determines whether or not a value obtained by adding the previous value of the line command pressure PL0 and the upper limit value dPLmax of the line pressure increase rate is greater than the line hydraulic pressure upper limit value PMAX. If the added value exceeds the PMAX value, the process proceeds to step S270, the controller 12 sets the unload command pressure Psig to the hydraulic pressure upper limit value PMAX, and the process proceeds to step S290.

  If the added value is less than the PMAX value, the controller 12 sets the unload command pressure Psig to a value obtained by adding the line command pressure PL0 and the upper limit value dPLmax of the line pressure increase rate, and the process proceeds to step S290. .

  In step S290, the controller 12 sets the accumulator pressure Paccm, which is the current hydraulic pressure of the accumulator 70, to the line command pressure PL0, ends the processing according to this flowchart, and returns to other processing.

  By such control, the hydraulic pressure generated by the energy at the time of vehicle deceleration can be accumulated in the accumulator 70.

  FIG. 6 shows a flowchart in the idling stop state when the brake pedal is turned on and the vehicle is stopped in the second embodiment of the present invention.

  In step S310, the controller 12 determines whether or not the driver depresses the brake pedal, the engine 1 is in idle stop, and the vehicle is in a stopped state. If not in such a state, the process according to this flowchart is terminated and the process returns to the other process.

  When the brake pedal is depressed by the driver, the engine 1 is in idle stop, and the vehicle is in a stopped state, the controller 12 switches the ON-OFF valve 140 to the closed side in step S320. As a result, the second oil passage 102 is closed between the check valve 90 and the ON-OFF valve 140, and the hydraulic pressure accumulated in the accumulator 70 is maintained.

  Next, in step S330, the controller 12 determines whether or not the brake pedal is OFF, that is, whether or not the brake pedal has been released. When the brake pedal is depressed, the process according to this flowchart is terminated and the process returns to other processes.

  When it is determined that the brake pedal is turned off, the process proceeds to step S340, and the controller 12 restarts the engine 1.

  Next, in step S350, the controller 12 controls the ON-OFF valve 140 to the open side, ends the processing according to this flowchart, and returns to other processing.

  By such control, the hydraulic pressure accumulated in the accumulator 70 is supplied via the second oil passage 102 before the engine 1 is started and sufficient hydraulic pressure is supplied by the oil pump 10 m when the vehicle restarts after the vehicle stops. Since it can be supplied to the high-pressure system 100, by supplying sufficient hydraulic pressure to the transmission 4 when the vehicle restarts, the time lag at the start can be reduced, and the acceleration performance can be improved.

  In the second embodiment of the present invention configured as described above, the controller 12 is configured to change the setting of the unload pressure Psig. When the vehicle is traveling at a reduced speed, the controller 12 controls the accumulator 70 so that a large amount of hydraulic pressure is accumulated by increasing the unload pressure Psig. Thereby, the hydraulic pressure can be accumulated in the accumulator 70 and the load on the oil pump 10m can be reduced, so that the energy efficiency can be improved. This effect corresponds to claims 5 and 7.

  Further, when the unload valve 80 is unloaded, the controller 12 decreases the unload pressure Psig. As a result, the time during which the unloaded state is maintained is lengthened. As a result, the interval time during which the oil pump 10m operates without load can be increased, and the energy efficiency of the vehicle can be improved. This effect corresponds to claim 2.

  Further, when a high hydraulic pressure is required for the high-pressure system 100, such as when kickdown occurs, the controller 12 switches the switching valve 120 to the side where the oil pump 10m and the bypass oil passage 103 communicate with each other. -The OFF valve 140 is switched to the closed side. By setting in this way, the oil pressure generated by the oil pump 10 m is directly supplied from the bypass oil passage 103 to the second oil passage 102 and the high-pressure system 100 until the oil pressure is accumulated in the accumulator 70. It is possible to prevent the responsiveness of the hydraulic pressure of the passage 101 from being lowered (time lag). This effect corresponds to the third aspect.

  Further, when the vehicle is in an idle stop state, the oil pump 10m does not generate hydraulic pressure, so the controller 12 closes the ON-OFF valve 140 in order to prevent the hydraulic pressure accumulated in the accumulator 70 from gradually decreasing. To do. As a result, the second oil passage 102 between the ON-OFF valve 140 and the check valve 90 is closed, and the hydraulic pressure accumulated in the accumulator 70 is maintained until the ON-OFF valve 140 is opened again. Thereafter, for example, when the depression of the brake pedal is released, the controller 12 opens the ON-OFF valve 140 and supplies the hydraulic pressure accumulated in the accumulator 70 to the high pressure system 100 via the second oil passage 102. By doing so, the vehicle can be started immediately. This effect corresponds to claims 6 and 7.

  Next, the hydraulic control circuit 11 according to the third embodiment of the present invention will be described.

  FIG. 7 is an explanatory diagram showing the configuration of the hydraulic control circuit 11 according to the third embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the structure same as 1st or 2nd embodiment, and the description is abbreviate | omitted.

  As shown in FIG. 7, the oil pump 110m includes two discharge ports (a first discharge port 111 and a second discharge port 112), and is configured to be able to discharge hydraulic pressure from each discharge port. The first discharge port 111 supplies hydraulic pressure to the first oil passage 101. The second discharge port 112 supplies hydraulic pressure to the low pressure system 200 via the fourth oil passage 104.

  With this configuration, it is not necessary to separately provide a configuration such as an electric oil pump 10e for supplying hydraulic pressure to the low-pressure system 200. Therefore, it is possible to improve energy efficiency and reduce mounting space and weight by reducing the number of components. Can do.

  In addition, since the structure of the 1st oil path 101 and the 2nd oil path 102 is the same as that of 1st Embodiment, description is abbreviate | omitted.

  FIG. 8 is an explanatory diagram showing an example of the configuration of an oil pump 110m according to the third embodiment of the present invention.

  The oil pump 110m is configured as a vane pump, and has two discharge ports (first discharge port 111 and second discharge port 112) and two suction ports (first suction port 113 and second suction port) in the rotation direction of the rotor 115. 114).

  The rotor 115 that rotates together with the rotation shaft 116 is provided with a plurality of vanes 117. Oil sucked from the first suction port 113 is discharged from the second discharge port 112. The oil sucked from the second suction port 114 is discharged from the first discharge port 111. The second discharge port 112 and the second suction port 114 communicate with the fourth oil passage 104 of the low pressure system 200, and the hydraulic pressure generated at the second discharge port 112 and the second suction port 114 (this hydraulic pressure depends on the load of the low pressure system 200. To the low pressure system 200. The first discharge port 111 communicates with the first oil passage 101 and supplies hydraulic pressure to the first oil passage 101.

  With this configuration, the oil pump 110m outputs the first discharge port 111 that outputs the hydraulic pressure supplied to the high pressure system 100 via the first oil passage 101 and the second oil passage, and the hydraulic pressure supplied to the low pressure system 200. The second discharge port 112 can be provided.

  The second discharge port communicates with the second suction port 114 and outputs a hydraulic pressure determined by the load of the low pressure system 200. Therefore, the first discharge port 111 and the second discharge port 112 are rotated by the rotation of the rotor 115 of the oil pump 110m. The second discharge port 112 outputs a hydraulic pressure lower than that of the first discharge port 111.

  In the third embodiment of the present invention configured as described above, the oil pump 110m includes the first discharge port 111 that supplies hydraulic pressure to the first oil passage 101, and communicates with the low-pressure system 200. A second discharge port 112 for supplying hydraulic pressure to 104 is provided. With such a configuration, the oil pressure can be supplied to the two systems of the high pressure system 100 and the low pressure system 200 having different required hydraulic pressures by the single oil pump 110m, so that the oil pump or the oil pump is driven. The configuration of the drive source and the like can be reduced, and the weight and cost can be reduced. This effect corresponds to claim 4.

  The embodiment of the present invention has been described above, but the above embodiment is merely one example of application of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. is not.

  In the above embodiment, the variator 20 includes a belt-type continuously variable transmission mechanism. The variator 20 is a continuously variable transmission mechanism in which a chain is wound around pulleys 21 and 22 instead of the V-belt 23. There may be. Alternatively, the variator 20 may be a toroidal continuously variable transmission mechanism in which a tiltable power roller is disposed between the input disk and the output disk.

  In the above-described embodiment, the sub-transmission mechanism 30 is a transmission mechanism having two stages of first speed and second speed as the forward shift stage. A transmission mechanism having stages may be used.

DESCRIPTION OF SYMBOLS 1 Engine 2 Torque converter 4 Transmission 5 Transmission mechanism 10e Electric oil pump 10m Oil pump 11 Hydraulic control circuit 12 Controller (control part)
DESCRIPTION OF SYMBOLS 14 Relief oil path 20 Variator 30 Subtransmission mechanism 70 Accumulator 80 Unload valve 90 Check valve 100 High pressure system 101 1st oil path 102 2nd oil path 103 Bypass oil path (3rd oil path)
104 4th oil passage 110m Oil pump 111 1st discharge port 112 2nd discharge port 113 1st suction port 114 2nd suction port 120 Switching valve 130 Relief valve 140 OFF valve 200 Low pressure system

Claims (8)

A transmission comprising a hydraulic control circuit, a transmission mechanism, and a control unit that controls the operation of the hydraulic control circuit,
The hydraulic control circuit
A first oil passage and a second oil passage for circulating oil pressure to the speed change mechanism;
An oil pump for supplying hydraulic pressure to the first oil passage;
An unloading valve disposed in the first oil passage and unloading the oil in the first oil passage based on a set pressure;
A check valve capable of passing oil only from the first oil passage to the second oil passage;
An accumulator connected to the second oil passage and accumulating the oil pressure of the second oil passage;
With
The speed change mechanism is controlled by a hydraulic pressure supplied from the second oil passage,
The controller is
A transmission characterized in that the set pressure of the unload valve is variably controlled based on a shift state of the transmission mechanism. The transmission according to claim 1,
Setting the set pressure of the unload valve to a predetermined value;
When the unloading of the unloading valve is started when the hydraulic pressure of the second oil passage reaches the set predetermined value, the set pressure of the unloading valve is set to a smaller hydraulic pressure than the predetermined value. A transmission characterized by that. The transmission according to claim 1 or 2,
The hydraulic control circuit includes a third oil passage capable of supplying hydraulic pressure from the oil pump to the transmission mechanism,
The transmission is characterized in that when the hydraulic pressure accumulated in the accumulator is less than a predetermined hydraulic pressure, the hydraulic pressure is supplied from the third oil passage to the transmission mechanism. The transmission according to any one of claims 1 to 3,
The hydraulic control circuit includes a fourth oil passage capable of supplying hydraulic pressure from the oil pump to a low pressure system of the transmission mechanism,
The transmission includes: a first discharge port that discharges hydraulic pressure to the first oil passage; and a second discharge port that discharges hydraulic pressure to the fourth oil passage. A vehicle having the transmission according to any one of claims 1 to 4,
Changing the set pressure of the unload valve based on the running state of the vehicle,
When the vehicle is traveling at a reduced speed, the set pressure is largely changed as compared with a case where the vehicle is not at a reduced speed. A vehicle having the transmission according to any one of claims 1 to 4,
The hydraulic control circuit has a stop valve capable of stopping supply of hydraulic pressure from the accumulator to the speed change mechanism in the second oil passage,
When the vehicle is in an idle stop state, the vehicle controls the stop valve to stop the supply of hydraulic pressure from the accumulator to the transmission mechanism. A vehicle having the transmission according to any one of claims 1 to 4,
The hydraulic control circuit has a stop valve capable of stopping supply of hydraulic pressure from the accumulator to the speed change mechanism in the second oil passage,
Changing the set pressure of the unload valve based on the running state of the vehicle,
When the vehicle is traveling at a reduced speed, the set pressure is greatly changed as compared to when the vehicle is not at a reduced speed, and when the vehicle is in an idle stop state, the stop valve is controlled to control the shift from the accumulator. A vehicle characterized in that the supply of hydraulic pressure to the mechanism is stopped. A transmission control method comprising a hydraulic control circuit and a transmission mechanism,
The hydraulic control circuit
A first oil passage and a second oil passage for circulating oil pressure to the speed change mechanism;
An oil pump for supplying hydraulic pressure to the first oil passage;
An unloading valve disposed in the first oil passage and unloading the oil in the first oil passage based on a set pressure;
A check valve capable of passing oil only from the first oil passage to the second oil passage;
An accumulator connected to the second oil passage and accumulating the oil pressure of the second oil passage;
With
The speed change mechanism is controlled by a hydraulic pressure supplied from the second oil passage,
A transmission control method, wherein the set pressure of the unload valve is variably controlled based on a shift state of the transmission mechanism.

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