JP5742708B2 - Hydraulic control device and vehicle control device - Google Patents

Description

  The present invention relates to a hydraulic control device and a vehicle control device.

  2. Description of the Related Art Conventionally, a configuration is known in which each component of a power transmission device for transmitting power from a vehicle power source (engine) to a drive wheel is controlled by hydraulic pressure using a mechanical mechanical pump operated by engine power as a supply source. ing.

  On the other hand, in recent years, for the purpose of reducing fuel consumption and the like, an increasing number of vehicles have a technique for stopping the engine during vehicle operation, that is, a so-called idling stop function. In such a vehicle, during execution of the idling stop function, the mechanical pump is also stopped when the engine is stopped. Therefore, a hydraulic pressure supply source different from the mechanical pump for controlling the power transmission device is required.

  For this reason, conventionally, in a vehicle having an idling stop function, a configuration has been proposed in which a motor-driven electric pump and an accumulator that accumulates hydraulic pressure during normal travel are used as a hydraulic pressure supply source when the engine is stopped. For example, Patent Document 1 discloses a configuration in which the hydraulic pressure held in the accumulator is supplied to the forward clutch when the engine is restarted from the idling stop.

JP 2010-151226 A

  The configuration of the conventional hydraulic control device as described in Patent Document 1 is intended to improve the controllability of the power transmission device (clutch) when the engine is restarted after executing the idling stop function mainly when the vehicle is stopped. belongs to.

  Here, if the idling stop function is to be executed when the vehicle is decelerating, there may be a situation where a larger hydraulic pressure is required for controlling the power transmission device than when the vehicle is stopped. Specifically, for example, in a vehicle including a belt-type continuously variable transmission mechanism as one element of a power transmission device, sudden braking, rough road traveling, road surface change, etc. while the idling stop function is being executed when the vehicle is decelerating. The disturbance is input to the power transmission device from the drive wheel side.

  In such a situation, torque fluctuations may occur due to disturbance input from the drive wheel side, and the belt of the belt-type continuously variable transmission mechanism may slip. Since the required belt clamping pressure is increased so as to prevent such belt slippage, the hydraulic pressure for controlling the belt clamping pressure is required to have a high level. In the configuration of the conventional hydraulic control device as described in Patent Document 1, it is necessary to increase the size of the electric pump in order to cope with the belt clamping pressure required during the execution of the idling stop function at the time of deceleration traveling. .

  The present invention has been made in view of the above, and an object of the present invention is to provide a hydraulic control device and a vehicle control device that can suppress an increase in size of an electric pump that operates when an idling stop function is executed.

  In order to solve the above-described problems, a hydraulic control device according to the present invention operates a power transmission device including a belt-type continuously variable transmission provided in a vehicle capable of executing an idling stop function for stopping an engine while the vehicle is running. In the hydraulic control apparatus for controlling the hydraulic pressure of the oil supplied to drive the engine, a mechanical pump that supplies oil to the power transmission device via a hydraulic path by driving the engine, and the hydraulic path via the hydraulic path by driving a motor. An oil pump that supplies oil to the power transmission device and an oil passage that is branched from the hydraulic path and supplies oil only to a sheave that controls the belt clamping pressure of the belt-type continuously variable transmission mechanism. A boost check valve that prevents backflow of the vehicle, and is connected to the oil passage between the boost check valve and the sheave, and Oil and accumulator from the oil passage during travel, characterized in that the accumulator is oil in traveling the idling stop function is performed and a accumulator supplied to the sieve.

  Further, in the above hydraulic control device, when the hydraulic pressure supplied to the sheave is equal to or lower than a required hydraulic pressure during traveling while the idling stop function is being executed, the idling stop function is stopped and the engine is stopped. It is preferable to start up.

  In the above hydraulic control apparatus, it is preferable that the accumulator cut off the communication with the oil passage when the execution of the idling stop function is stopped.

  Similarly, in order to solve the above-described problem, a vehicle control device according to the present invention includes an engine, a power transmission device including a belt-type continuously variable transmission mechanism, and the above-described hydraulic control device. .

  In the hydraulic control device and the vehicle control device according to the present invention, the oil accumulated in the accumulator is supplied to the sheave that controls the belt clamping pressure of the belt-type continuously variable transmission mechanism during the traveling in which the idling stop function is executed. Therefore, the hydraulic pressure can be increased and supplied to the continuously variable transmission mechanism so as to ensure the belt clamping pressure that can prevent the belt from slipping. On the other hand, the electric pump is mainly used for control of a continuously variable transmission mechanism during slow deceleration other than when a disturbance occurs, and for control of a clutch having a lower required hydraulic pressure than the belt clamping pressure. Thus, since the hydraulic control device according to the present invention uses an accumulator to secure the belt clamping pressure of the continuously variable transmission mechanism, the hydraulic level that can be supplied by the electric pump can be reduced. There exists an effect that enlargement of an electric pump can be controlled.

FIG. 1 is a schematic diagram showing the configuration of a vehicle equipped with a hydraulic control device according to an embodiment of the present invention. FIG. 2 is a diagram showing a schematic configuration of the hydraulic control apparatus shown in FIG. FIG. 3 is a flowchart showing a pressure accumulation process and a discharge process of the accumulator in the hydraulic control apparatus according to the embodiment of the present invention. FIG. 4 is a diagram showing an example of the necessary belt clamping pressure Pd ^* corresponding to the vehicle speed used in the processing shown in FIG.

  Hereinafter, embodiments of a hydraulic control device and a vehicle control device according to the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will not be repeated.

  First, with reference to FIG. 1, the structure of the vehicle 2 carrying the hydraulic control apparatus 1 which concerns on this embodiment is demonstrated. As shown in FIG. 1, the vehicle 2 includes an engine 3 as a power source during driving, a drive wheel 4, a power transmission device 5, a hydraulic control device 1, and an ECU (Electronic Control Unit) as a control device. Electronic control unit) 7.

  The engine 3 is a driving source (prime mover) that drives the vehicle 2, and generates power that consumes fuel and acts on the driving wheels 4 of the vehicle 2. The engine 3 can generate mechanical power (engine torque) on the crankshaft 8 that is an engine output shaft as the fuel burns, and can output this mechanical power from the crankshaft 8 toward the drive wheels 4. .

  The power transmission device 5 transmits power from the engine 3 to the drive wheels 4. The power transmission device 5 is provided in a power transmission path from the engine 3 to the drive wheel 4 and is operated by the pressure (hydraulic pressure) of oil as a liquid medium.

  More specifically, the power transmission device 5 includes a torque converter 9, a forward / reverse switching mechanism 10, a continuously variable transmission mechanism 11, a speed reduction mechanism 12, a differential gear 13, and the like. In the power transmission device 5, the crankshaft 8 of the engine 3 and the input shaft 14 of the continuously variable transmission mechanism 11 are connected via a torque converter 9, a forward / reverse switching mechanism 10, and the like, and an output shaft 15 of the continuously variable transmission mechanism 11 is connected. It is connected to the drive wheel 4 via the speed reduction mechanism 12, the differential gear 13, the drive shaft 16, and the like.

  The torque converter 9 is disposed between the engine 3 and the forward / reverse switching mechanism 10, and amplifies (or maintains) the power torque transmitted from the engine 3 and transmits it to the forward / reverse switching mechanism 10. it can. The torque converter 9 includes a pump impeller 9a and a turbine runner 9b that are rotatably arranged to face each other, and the pump impeller 9a is coupled to the crankshaft 8 through a front cover 9c so as to be integrally rotatable, and the turbine runner 9b is switched forward and backward. It is configured to be connected to the mechanism 10. As the pump impeller 9a and the turbine runner 9b rotate, a viscous fluid such as hydraulic fluid interposed between the pump impeller 9a and the turbine runner 9b circulates and flows. It is possible to amplify and transmit torque while allowing

  The torque converter 9 further includes a lock-up clutch 9d that is provided between the turbine runner 9b and the front cover 9c and is coupled to the turbine runner 9b so as to be integrally rotatable. The lock-up clutch 9d is operated by oil pressure supplied from a hydraulic control device 1 described later, and is switched between an engaged state (lock-up ON) and an open state (lock-up OFF) with the front cover 9c. In a state where the lockup clutch 9d is engaged with the front cover 9c, the front cover 9c (that is, the pump impeller 9a) and the turbine runner 9b are engaged, and the relative rotation between the pump impeller 9a and the turbine runner 9b is restricted, Since the differential between the input and the output is prohibited, the torque converter 9 transmits the torque transmitted from the engine 3 to the forward / reverse switching mechanism 10 as it is.

  The forward / reverse switching mechanism 10 can shift the power (rotation output) from the engine 3 and can switch the rotation direction. The forward / reverse switching mechanism 10 includes a planetary gear mechanism 17, a forward / reverse switching clutch (forward clutch) C1 as a friction engagement element, a forward / reverse switching brake (reverse brake) B1, and the like. The planetary gear mechanism 17 is a differential mechanism that includes a sun gear, a ring gear, a carrier, and the like as a plurality of rotational elements that can rotate differentially with each other. The forward / reverse switching clutch C1 and the forward / reverse switching brake B1 It is an engagement element for switching the operating state of the gear mechanism 17 and can be constituted by, for example, a frictional engagement mechanism such as a multi-plate clutch. Here, a hydraulic wet multi-plate clutch is used.

  In the forward / reverse switching mechanism 10, the forward / reverse switching clutch C1 and the forward / reverse switching brake B1 are operated by the pressure of oil supplied from the hydraulic control device 1 described later, and the operating state is switched. When the forward / reverse switching clutch C1 is in the engaged state (ON state) and the forward / reverse switching brake B1 is in the released state (OFF state), the forward / reverse switching mechanism 10 rotates the power from the engine 3 in the normal rotation (vehicle 2). Is transmitted to the input shaft 14 in the direction in which the input shaft 14 rotates as the vehicle advances. When the forward / reverse switching clutch C1 is in the released state and the forward / reverse switching brake B1 is in the engaged state, the forward / reverse switching mechanism 10 rotates the power from the engine 3 in reverse rotation (when the vehicle 2 moves backward, the input shaft 14 In the direction of rotation). At the time of neutral, the forward / reverse switching mechanism 10 is in a released state for both the forward / reverse switching clutch C1 and the forward / reverse switching brake B1. In the present embodiment, such a control system that controls the engagement / release of the forward / reverse switching clutch C1 and the forward / reverse switching brake B1 is collectively referred to as a “C1 control system” 18.

  The continuously variable transmission mechanism 11 is a transmission that is provided between the forward / reverse switching mechanism 10 and the drive wheel 4 in the power transmission path from the engine 3 to the drive wheel 4 and that can output the power of the engine 3 by shifting the power. is there. The continuously variable transmission mechanism 11 is operated by the pressure of oil supplied from a hydraulic control device 1 described later.

  The continuously variable transmission mechanism 11 changes the rotational power (rotational output) from the engine 3 transmitted (input) to the input shaft 14 at a predetermined speed ratio and transmits it to the output shaft 15 that is a transmission output shaft. The power shifted from the output shaft 15 toward the drive wheel 4 is output. More specifically, the continuously variable transmission mechanism 11 includes a primary pulley 20 connected to an input shaft (primary shaft) 14, a secondary pulley 21 connected to an output shaft (secondary shaft) 15, a primary pulley 20 and a secondary pulley 21. It is a belt-type continuously variable transmission (CVT) comprised including the belt 22 etc. which were spanned between. In the following description of the present embodiment, the continuously variable transmission mechanism 11 is also expressed as a “belt-type continuously variable transmission mechanism”.

  The primary pulley 20 is formed by coaxially disposing a movable sheave 20a (primary sheave) that can move in the axial direction of the primary shaft 14 and a fixed sheave 20b. The movable sheave 21a (secondary sheave) and the fixed sheave 21b that are movable in the axial direction are coaxially arranged opposite to each other. The belt 22 is stretched around a V-shaped groove formed between the movable sheaves 20a and 21a and the fixed sheaves 20b and 21b.

  In the continuously variable transmission mechanism 11, the oil pressure (primary pressure and secondary pressure) supplied from the hydraulic control device 1 described later to the primary sheave hydraulic chamber 23 of the primary pulley 20 and the secondary sheave hydraulic chamber 24 of the secondary pulley 21 is adjusted. Accordingly, the force (belt clamping pressure) that sandwiches the belt 22 between the movable sheaves 20a and 21a and the fixed sheaves 20b and 21b can be individually controlled by the primary pulley 20 and the secondary pulley 21. Thereby, in each of the primary pulley 20 and the secondary pulley 21, the V-shaped width can be changed to adjust the rotation radius of the belt 22, and the input rotation speed (primary rotation speed) corresponding to the input rotation speed of the primary pulley 20 can be adjusted. ) And the output shaft rotation speed (secondary rotation speed) corresponding to the output rotation speed of the secondary pulley 21 can be changed steplessly. Further, the belt clamping pressure of the primary pulley 20 and the secondary pulley 21 is adjusted, so that power can be transmitted with a torque capacity corresponding to this.

  The speed reduction mechanism 12 reduces the rotational speed of the power from the continuously variable transmission mechanism 11 and transmits it to the differential gear 13. The differential gear 13 transmits the power from the speed reduction mechanism 12 to each drive wheel 4 via each drive shaft 16. The differential gear 13 absorbs the difference in rotational speed between the center side of the turning, that is, the inner driving wheel 4 and the outer driving wheel 4 that occurs when the vehicle 2 turns.

  The power transmission device 5 configured as described above drives the power generated by the engine 3 via a torque converter 9, a forward / reverse switching mechanism 10, a continuously variable transmission mechanism 11, a speed reduction mechanism 12, a differential gear 13, and the like. 4 can be transmitted. As a result, the driving force [N] is generated on the contact surface of the driving wheel 4 with the road surface, and the vehicle 2 can travel by this.

  The hydraulic control device 1 uses a hydraulic pressure of oil as a fluid to lock up the clutch 9d of the torque converter 9, the forward / reverse switching clutch C1 and the forward / reverse switching brake B1, and the primary sheave 20a of the continuously variable transmission mechanism 11. The power transmission device 5 including the secondary sheave 21a is operated. The hydraulic control device 1 includes, for example, various hydraulic control circuits that are controlled by the ECU 7. The hydraulic control device 1 is configured to include a plurality of oil passages, an oil reservoir, an oil pump, a plurality of electromagnetic valves, and the like, and according to a signal from the ECU 7 described later, the oil supplied to each part of the power transmission device 5 Control the flow rate or hydraulic pressure. The hydraulic control device 1 also functions as a lubricating oil supply device that lubricates predetermined portions of the power transmission device 5.

  The ECU 7 controls driving of each part of the vehicle 2. The ECU 7 is physically an electronic circuit mainly composed of a known microcomputer including a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and an interface. The function of the ECU 7 is to load an application program held in the ROM into the RAM and execute it by the CPU, thereby operating various devices in the vehicle 2 under the control of the CPU and reading out data from the RAM or ROM. And writing. In the present embodiment, the ECU 7 controls each part of the power transmission device 5 such as the torque converter 9, the forward / reverse switching mechanism 10, and the continuously variable transmission mechanism 11 by controlling the hydraulic control device 1 described above. Note that the ECU 7 is not limited to the above functions, but also includes various other functions used for various controls of the vehicle 2.

  The ECU 7 includes an engine ECU that controls the engine 3, a T / M ECU that controls the power transmission device 5 (hydraulic control device 1), and an idling stop (S & S (start & stop)) control. The configuration may include a plurality of ECUs such as S & S ECUs.

  Next, the configuration of the hydraulic control apparatus 1 according to the present embodiment will be described with reference to FIG.

  As shown in FIG. 2, the hydraulic control device 1 is a mechanical type driven by driving an engine 3 (hereinafter also referred to as “Eng.”) As an oil supply source that supplies oil to each part of the power transmission device 5. Two hydraulic pumps, a mechanical pump (mechanical pump) 31 and an electric pump 33 driven by driving of an electric motor 32 are provided. The mechanical pump 31 and the electric pump 33 filter the oil stored in the drain 34 in the hydraulic control device 1 through the strainer 35, suck and compress the oil, and supply the oil to the power transmission device 5 through the hydraulic path 36. be able to.

  Note that the vehicle 2 of the present embodiment is provided with a function of stopping the engine 3 while the vehicle 2 is stopped or traveling, that is, a so-called idling stop function in order to improve fuel efficiency. When the predetermined condition is satisfied during the traveling, the idling stop traveling that travels with the engine 3 stopped can be performed. The electric pump 33 supplies the hydraulic oil (oil) as an alternative to the mechanical pump 31 when the idling stop function is executed, that is, when the engine 3 is stopped. In the present embodiment, the control for performing idling stop traveling is also referred to as “deceleration S & S control”.

  The electric pump 33 is communicated with the hydraulic path 36 via an outlet channel 37 connected to the discharge port. A check valve 38 is provided on the outlet channel 37 to prevent backflow of oil from the hydraulic path 36 to the electric pump 33.

  A primary regulator valve 39 is provided in the hydraulic path 36. The primary regulator valve 39 adjusts the hydraulic pressure generated by the mechanical pump 31 and the electric pump 33. A control pressure is supplied to the primary regulator valve 39 by the SLS linear solenoid 40. The SLS linear solenoid 40 is an electromagnetic valve that generates a control pressure according to a current value determined by a duty signal (duty value) transmitted from the ECU 7.

  The primary regulator valve 39 adjusts the hydraulic pressure in the hydraulic path 36 according to the control pressure by the SLS linear solenoid 40. The hydraulic pressure in the hydraulic path 36 adjusted by the primary regulator valve 39 is used as the line pressure PL.

  As the primary regulator valve 39, for example, a spool valve in which a valve body (spool) slides in the axial direction in the valve body to open or close a flow path can be applied, and a hydraulic path 36 is connected to an input port. The SLS linear solenoid 40 is connected to the pilot port for inputting the pilot pressure, and the excess flow generated by regulating the line pressure PL can be discharged from the output port.

  The mechanical pump 31 and the electric pump 33 are connected to the C1 control system 18 (the forward / reverse switching clutch C1 and the forward / reverse switching brake B1) of the forward / reverse switching mechanism 10 and the continuously variable transmission mechanism 11 (of the primary sheave 20a) via the hydraulic path 36. The primary sheave hydraulic chamber 23 and the secondary sheave hydraulic chamber 24 of the secondary sheave 21a are connected so that the hydraulic pressure adjusted to the line pressure PL by the primary regulator valve 39 can be supplied.

  Although not shown in FIG. 2, a hydraulic control circuit capable of adjusting the hydraulic pressure supplied to the C1 control system 18 is provided between the hydraulic path 36 and the C1 control system 18. Are controlled by the ECU 7.

  The hydraulic path 36 connected to the continuously variable transmission mechanism 11 (primary sheave 20a and secondary sheave 21a) includes a first oil path 36a that supplies hydraulic pressure to the primary sheave hydraulic chamber 23 of the primary sheave 20a, and a secondary sheave of the secondary sheave 21a. A branch is made to a second oil passage 36b for supplying hydraulic pressure to the hydraulic chamber 24.

  Among these, on the 2nd oil path 36b, LPM (Line Pressure Modulator) No. One valve (pressure regulating valve) 41 is provided. LPM No. The 1 valve 41 outputs a hydraulic pressure adjusted with the line pressure PL as a source pressure. LPM No. A control pressure is supplied to the one valve 41 by an SLS linear solenoid 42. Similarly to the SLS linear solenoid 40 of the primary regulator valve 39, the SLS linear solenoid 42 is an electromagnetic valve that generates a control pressure in accordance with a current value determined by a duty signal (duty value) transmitted from the ECU 7.

  LPM No. The 1 valve 41 is, for example, a spool valve, and outputs a reduced oil pressure using the output oil pressure of the SLS linear solenoid 42 duty-controlled by the ECU 7 as a pilot pressure and the line pressure PL introduced into the valve as an original pressure. LPM No. The hydraulic pressure output from the one valve 41 is used as the secondary pressure Pd and supplied to the secondary sheave hydraulic chamber 24. The thrust of the secondary sheave 21a changes according to the secondary pressure Pd supplied to the secondary sheave hydraulic chamber 24, and the belt clamping pressure of the continuously variable transmission mechanism 11 is increased or decreased.

  Note that the LPM No. on the second oil passage 36b. A pressure sensor 43 that detects the secondary pressure Pd is provided between the one valve 41 and the secondary sheave hydraulic chamber 24, and is configured to transmit information on the detected secondary pressure Pd to the ECU 7.

  In the present embodiment, the LPM No. of the second oil passage 36b is preferably provided on the second oil passage 36b of the hydraulic passage 36. An accumulator 44 is connected upstream of the one valve 41. The accumulator 44 accumulates and holds (accumulates) the hydraulic pressure supplied from the mechanical pump 31 when driving the mechanical pump 31 during normal traveling of the vehicle, and stores the held hydraulic pressure in the secondary sheave 21a as necessary. It is configured to supply. “Vehicle traveling” means that the vehicle is traveling and the idling stop function is not executed.

  The accumulator 44 can be realized by a known configuration. For example, in the case of a gas type accumulator, a piston is arranged inside, and an internal space sealed by the piston is filled with gas. During pressure accumulation, the piston is pushed in and oil is stored inside. At this time, the gas is compressed, and the pressure of the compressed gas is balanced with the pressure of the stored oil. Further, at the time of discharge, the piston is pushed out by utilizing the expansion force of gas, whereby the accumulated oil is discharged from the inside and supplied to the secondary sheave 21a.

  The accumulator 44 can change the internal gas volume between the minimum value Va_min and the maximum value Va_max according to the sliding of the piston. When the gas volume is the minimum value Va_min, the gas pressure becomes the maximum value Pa_max. When the gas volume is the maximum value Va_max, the gas pressure is configured to be the minimum value Pa_min. Here, the minimum value Pa_min of the gas pressure corresponds to the secondary pressure Pd required to ensure the minimum belt clamping pressure that can prevent the belt 22 of the continuously variable transmission mechanism 11 from slipping during idling stop traveling. In addition, the maximum value Pa_max of the gas pressure is set in advance as a pressure that can maintain the secondary pressure Pd at least at Pa_min when discharging accumulated pressure from the accumulator 44.

  Accumulation and discharge of the accumulator 44 are controlled by a pressure accumulation control valve 45 provided between the accumulator 44 and the second oil passage 36b. When the pressure accumulation control valve 45 is closed, the oil is accumulated in the accumulator 44, and when the pressure accumulation control valve 45 is opened, the accumulated oil is discharged. The opening / closing operation of the pressure accumulation control valve 45 is controlled by the ECU 7. The pressure accumulation control valve 45 is, for example, an electromagnetic poppet valve, and can be opened and closed by adjusting a supply current by the ECU 7. In addition, a spool valve or a pilot check valve may be applied as the pressure accumulation control valve 45, and the ECU 7 may be configured to switch between opening and closing by adjusting the pilot pressure.

  Between the accumulator 44 and the pressure accumulation control valve 45, a pressure sensor 46 for detecting the pressure (accumulator pressure) Pacc of the oil accumulated in the accumulator 44 is provided, and information on the detected accumulator pressure Pacc is transmitted to the ECU 7. It is configured.

  On the second oil passage 36b, LPM No. A check valve (pressure increase check valve) 57 is provided upstream of the one valve 41. That is, the accumulator 44 is connected to the check valve 57 on the second oil passage 36b of the hydraulic passage 36 and the LPM No. Between the first valve 41 and the second oil passage 36b. By installing the check valve 57 in this way, the first oil connected to the primary sheave 20a or the reverse flow of the oil discharged from the accumulator 44 to the upstream side (mechanism pump 31, electric pump 33, C1 control system 18 side). The inflow into the passage 36a can be prevented, and the secondary pressure Pd can be efficiently increased by the accumulator 44.

  Further, a check valve 58 and an orifice 59 are installed in parallel between the pressure accumulation control valve 45 and the second oil passage 36b. The check valve 58 is disposed so as to prevent the flow of oil from the second oil passage 36b to the accumulator 44 and to allow the oil to flow from the accumulator 44 to the second oil passage 36b.

  With such a configuration, oil flows only through the orifice 59 during the pressure accumulation process of the accumulator 44, and through both the check valve 58 and the orifice 59 during the discharge process. Therefore, the introduction path to the accumulator 44 during pressure accumulation is more than that during the discharge. The opening area can be reduced. Thereby, excessive oil inflow from the second oil passage 36b can be prevented during pressure accumulation, and the line pressure PL and secondary pressure Pd during pressure accumulation can be suppressed. For example, excessive oil inflow to the accumulator 44 can be prevented even when a failure (failure) occurs while the pressure accumulation control valve 45 is open during the pressure accumulation process. Furthermore, since the opening area increases at the time of discharge, it is possible to improve the hydraulic response at the time of discharge. As a result, it is possible to simultaneously improve the pressure drop prevention performance of the secondary pressure Pd during accumulator 44 pressure accumulation and the hydraulic pressure response during discharge.

  A first shift control valve 47 and a second shift control valve 48 are provided on the first oil passage 36a. The first shift control valve 47 adjusts the oil supply to the primary sheave hydraulic chamber 23 in accordance with the drive of the first duty solenoid (DS1) 49 that is duty-controlled by the ECU 7. The second shift control valve 48 adjusts the oil discharge from the primary sheave hydraulic chamber 23 in accordance with the driving of the second duty solenoid (DS2) 50 that is duty-controlled by the ECU 7.

  That is, when the first duty solenoid 49 is actuated, oil is introduced from the first shift control valve 47 into the primary sheave hydraulic chamber 23, and the primary sheave 20a moves in the direction of narrowing the groove width of the primary pulley 20, as a result. The applied diameter of the belt 22 increases and upshifts. When the second duty solenoid 50 is actuated, the oil is discharged from the primary sheave hydraulic chamber 23 by the second shift control valve 48, and the primary sheave 20a moves in the direction of widening the groove width of the primary pulley 20. As a result, the belt 22 The hanging diameter decreases and downshifts. Thus, the gear ratio of the continuously variable transmission mechanism 11 can be controlled by operating the first duty solenoid 49 and the second duty solenoid 50.

  A secondary regulator valve 51 is connected to the output port of the primary regulator valve 39. The secondary regulator valve 51 is also a spool valve, like the primary regulator valve 39, and adjusts the hydraulic pressure of the excess flow discharged from the primary regulator valve 39 in accordance with the control pressure of the SLS linear solenoid 52 that is duty-controlled by the ECU 7. Pressure.

  An L / U control system 53 for controlling the engagement / release of the lockup clutch 9d of the torque converter 9 is further connected to the output port of the primary regulator valve 39, and when an excess flow is generated from the primary regulator valve 39 The surplus flow is regulated by the secondary regulator valve 51, and the regulated surplus flow is supplied to the L / U control system 53 (or the low pressure control system that can be controlled at a lower pressure than the continuously variable transmission mechanism 11). Has been.

  Further, the secondary regulator valve 51 is configured to be able to supply a further surplus flow generated by regulating the surplus flow from the output port to each part lubrication at a predetermined location in the power transmission device 5. Although not shown in FIG. 2, an oil passage is formed so that the surplus flow supplied to the L / U control system 53 and each part lubrication is finally returned to the drain 34.

  The SLS linear solenoid 40 of the primary regulator valve 39, the SLS linear solenoid 52 of the secondary regulator valve 51, and the LPM No. The SLS linear solenoid 42 of the one valve 41 may be a single linear solenoid and may be configured to control the line pressure PL and the secondary pressure Pd (belt clamping pressure) in conjunction with each other. Alternatively, each may be a separate linear solenoid, which can be individually controlled by the ECU 7, and may be configured to independently control the line pressure PL and the secondary pressure Pd (belt clamping pressure).

  The SLS linear solenoid 40, the SLS linear solenoid 42, and the SLS linear solenoid 52 are connected to the primary regulator valve 39, LPM No. The pilot pressure input to the first valve 41 and the secondary regulator valve 51 can be generated using the line pressure PL in the hydraulic path 36.

  In this embodiment, among the components of the vehicle 2 described above, at least the engine 3, the power transmission device 5 (especially the continuously variable transmission mechanism 11 and the C1 control system 18, the hydraulic control device 1 (especially the mechanical pump 31, electric motor) The pump 33, the accumulator 44), and the ECU 7 function as the vehicle control device according to the present embodiment.

Next, the operation of the hydraulic control apparatus 1 according to this embodiment will be described with reference to FIGS. FIG. 3 is a flowchart showing a pressure accumulation process and a discharge process of the accumulator 44 in the hydraulic control device 1 of the present embodiment. FIG. 4 is a diagram showing an example of the necessary belt clamping pressure Pd ^* corresponding to the vehicle speed used in the processing shown in FIG.

  A series of processing shown in the flowchart of FIG. 3 is performed by the ECU 7 at predetermined time intervals, for example, using the pressure sensors 43 and 46 of the hydraulic control device 1, the pressure accumulation control valve 45, various sensor information of the vehicle 2, and the like.

  As shown in FIG. 3, first, it is confirmed whether or not deceleration S & S control (idling stop traveling) is being executed (S101). The deceleration S & S control is executed by judging from the vehicle speed, completion of accumulator 44 pressure accumulation, vehicle deceleration state, battery state, oil temperature, engine coolant temperature, and the like. The execution period of the deceleration S & S control can be a period from an engine stop instruction at the start of control to an engine start completion determination at the end of control. When the deceleration S & S control is not executed (No in S101), the process proceeds to step S102. When the deceleration S & S control is being executed (Yes in S101), the process proceeds to step S111.

  If it is determined in step S101 that the deceleration S & S control is not being executed, it is assumed that the engine 3 is operating, and it is determined whether or not the engine 3 that is currently operating has elapsed for a predetermined time after completion of startup. Confirmed (S102). If the predetermined time has not elapsed after the start of the engine 3 (No in S102), in order to ensure the responsiveness of the belt clamping pressure Pd required at the start of the engine, the oil flow from the hydraulic path 36 to the accumulator 44 is prevented. In order to shut off and prevent oil consumption due to the pressure accumulation process of the accumulator 44, the pressure accumulation control valve 45 is closed (closed) (S103), and the process ends. On the other hand, when the predetermined time has elapsed after the start of the engine 3 (Yes in S102), the process proceeds to step S104.

  If it is determined in step S102 that the engine 3 that is currently operating has passed a predetermined time after the completion of startup, whether or not the accumulator pressure Pacc detected by the pressure sensor 46 is equal to or greater than a predetermined value Pa_max. Confirmed (S104). Here, the predetermined value Pa_max is the magnitude of the hydraulic pressure required for the oil accumulated in the accumulator 44, and as described above, the belt 22 of the continuously variable transmission mechanism 11 during the deceleration S & S control (during idling stop travel). This is the hydraulic pressure required to maintain the secondary pressure Pd at the level of the hydraulic pressure Pa_min that can ensure the minimum belt clamping pressure that can prevent the occurrence of slippage. When the accumulator pressure Pacc is smaller than the predetermined value Pa_max (No in S104), the process proceeds to step S105. On the other hand, when the accumulator pressure Pacc is equal to or higher than the predetermined value Pa_max (Yes in S104), it is assumed that the oil is sufficiently accumulated in the accumulator 44, and the accumulator control valve 45 is closed (closed) (S103). The oil pressure in the oil 44 is maintained at Pa_max, and the process is terminated.

  If it is determined in step S104 that the accumulator pressure Pacc is smaller than the predetermined value Pa_max, it is next checked whether or not the line pressure PL is equal to or higher than the predetermined value Pa_max (S105). The line pressure PL is detected by a pressure sensor (not shown) connected on the hydraulic path 36.

  When the line pressure PL is equal to or higher than the predetermined value Pa_max (Yes in S105), the process proceeds to step S106. On the other hand, when the line pressure PL is smaller than the predetermined value Pa_max (No in S105), if the current line pressure PL is accumulated in the accumulator 44, the secondary sheave 21a is controlled based on the line pressure PL. Assuming that the sufficient secondary pressure Pd cannot be maintained, the line pressure PL is increased (boosted) (S110). As a specific method for increasing the line pressure PL, for example, the SLS linear solenoid 40 of the primary regulator valve 39 is operated to adjust the control pressure of the primary regulator valve 39, thereby adjusting the pressure by the primary regulator valve 39. Increasing the line pressure PL can be mentioned. After step S110 is performed, the process ends.

If it is determined in step S105 that the line pressure PL is greater than or equal to the predetermined value Pa_max, the surplus flow rate of the mechanical pump 31 is subsequently calculated (S106). The surplus flow rate of the mechanical pump 31 can be calculated by the following equation (1), for example.
Mechanical pump surplus flow = Mechanical pump volume × Engine speed Ne × Volume efficiency −Hydraulic circuit oil leakage amount−Shift flow rate (1)
Here, “volumetric efficiency” is a parameter that varies due to oil temperature, and “hydraulic circuit oil leakage amount” is a parameter that varies due to oil temperature and line pressure. The “transmission flow rate” is an oil flow rate required for changing the speed ratio γ of the continuously variable transmission mechanism 11 and is a value obtained by multiplying the change amount (dγ / dt) of the speed ratio γ by the sheave area.

Next, the consumption flow rate at the time of execution of the pressure accumulation process of the accumulator 44 is calculated (S107). The consumption flow rate when accumulator 44 is accumulated can be calculated by, for example, the following equation (2).
Consumption flow rate = flow rate coefficient C × channel area × {(PL-Pacc) / oil density ρ} ^ 0.5 (2)
Here, the “flow path area” is a cross-sectional area of the hydraulic path 36 and the oil introduction path to the accumulator 44.

  Then, the “mechanical pump surplus flow rate” calculated in step S106 is compared with the “consumer flow rate during accumulator pressure accumulation” calculated in step S107, and the “mechanical pump surplus flow rate” is greater than or equal to “consumption flow rate during accumulator pressure accumulation”. It is confirmed whether or not a certain condition (surplus flow rate ≧ consumed flow rate) is satisfied (S108).

  When the condition of surplus flow rate ≧ consumption flow rate is satisfied (Yes in S108), even if the mechanical pump 31 discharges a surplus flow rate larger than the oil flow rate necessary for the pressure accumulation process and the accumulator 44 performs the pressure accumulation process, Assuming that the influence on the pressure Pd is small, the pressure accumulation control valve 45 is opened (opened), and the pressure accumulation process of the accumulator 44 is performed (S109).

  On the other hand, if the condition of surplus flow rate ≧ consumption flow rate is not satisfied (No in S108), the surplus flow rate of the mechanical pump 31 is less than the oil flow rate required for the pressure accumulation process, and the pressure of the secondary pressure Pd is obtained when the accumulator 44 is accumulated. The pressure accumulation control valve 45 is closed (S103), and the process is terminated, assuming that there is a risk of low.

If it is determined in step S101 that the deceleration S & S control is being executed, a secondary pressure Pd ^* (hereinafter referred to as “necessary belt clamping pressure”) for generating the necessary belt clamping pressure corresponding to the current vehicle speed is calculated. (S111). Here, the necessary belt clamping pressure Pd ^* can be determined based on the current vehicle speed using, for example, a map relating to the vehicle speed and the necessary belt clamping pressure Pd ^{* as} shown in FIG. As shown in FIG. 4, the relationship between the vehicle speed and the necessary belt clamping pressure Pd ^* is, for example, that the necessary belt clamping pressure is constant in the ultra-low speed range of the vehicle speed, and the necessary belt clamping pressure also increases monotonously as the vehicle speed increases. When the vehicle speed reaches a predetermined value, the necessary belt clamping pressure can be set to a constant value again.

Next, it is confirmed whether or not the secondary pressure (belt clamping pressure) Pd detected by the pressure sensor 43 is equal to or less than the necessary belt clamping pressure Pd ^* calculated in step S111 (S112). When the belt clamping pressure Pd is larger than the required belt clamping pressure Pd ^* (No in S112), the pressure accumulation control valve 45 is opened (S113). When the pressure accumulation control valve 45 is opened, the oil accumulated from the accumulator 44 is discharged to the second oil passage 36b, and the belt clamping pressure Pd increases.

On the other hand, when the belt clamping pressure Pd is equal to or less than the necessary belt clamping pressure Pd ^* (Yes in S112), the belt clamping pressure Pd does not reach the necessary amount to continue the deceleration S & S control as it is, and the belt clamping pressure is sufficient. Therefore, the deceleration S & S control is stopped, the pressure accumulation control valve 45 is closed, and an engine start request is issued to the starter to restart the engine 3 (S114).

That is, in the present embodiment, the oil accumulated in the accumulator 44 is always discharged to the hydraulic path 36 during the execution of the deceleration S & S control. When the secondary pressure (belt clamping pressure) Pd becomes equal to or less than the required belt clamping pressure Pd ^* , the deceleration S & S control is stopped and the engine is started, and the pressure accumulation control valve 45 is closed and the discharge process of the accumulator 44 is also stopped. To do.

  Next, the effect of the hydraulic control apparatus 1 according to the present embodiment will be described.

  The hydraulic control device 1 according to the present embodiment is provided in a vehicle that can execute the idling stop function not only when the vehicle is stopped, but also when the vehicle is traveling, such as during deceleration.

  Conventionally, when the idling stop function is executed when the vehicle is stopped, it is sufficient that the belt-type continuously variable transmission mechanism 11 of the power transmission device 5 can secure a belt clamping pressure that is not affected by cranking when the engine is restarted. . Specifically, a hydraulic pressure of about 0.3 MPa is required as the secondary pressure Pd supplied to the secondary sheave 21a that controls the belt clamping pressure.

  On the other hand, when the idling stop function is executed while the vehicle is running as in the present embodiment, a situation in which a larger belt clamping pressure is required can be considered. For example, when rotational fluctuations due to disturbances such as sudden braking, rough road running, and road surface changes are input to the power transmission device 5 from the driving wheel 4 during idling stop running, torque fluctuations are generated by the disturbance input, and the belt type There is a possibility that the belt 22 slips in the continuously variable transmission mechanism 11, and the power transmission may be adversely affected. The belt clamping pressure to be secured in order not to be affected by such disturbance input is larger than that when the vehicle is stopped. Specifically, as the secondary pressure Pd, a hydraulic pressure of about 1.5 Mpa and an oil flow rate of about 6 (liters / minute) are required, and a hydraulic response in several tens of milliseconds is also required.

  In order to cover such belt clamping pressure mainly by the electric pump 33, the electric pump 33 needs to be very large. For example, as in the above example, in order to generate a hydraulic pressure that is five times that when the vehicle is stopped, the electric pump needs about 25 times the volume. In addition, an electric pump with a power consumption of several tens of watts is required for the idling stop function when the vehicle is stopped, whereas an electric pump with a kilowatt class power consumption is required for the idling stop function when the vehicle is running. It becomes. Such an increase in the size of the electric pump is concerned with problems such as an increase in cost and deterioration in mountability.

  Therefore, the hydraulic control device 1 according to the present embodiment is provided in the vehicle 2 capable of executing an idling stop function for stopping the engine 3 while the vehicle is running, and operates the power transmission device 5 including the belt type continuously variable transmission mechanism 11. The hydraulic control device 1 controls the hydraulic pressure of the oil supplied for the purpose, and includes a mechanical pump 31 that supplies oil to the power transmission device 5 through the hydraulic path 36 by driving the engine 3, and the hydraulic path 36 by driving the motor 32. An electric pump 33 that supplies oil to the power transmission device 5 through the second oil passage, and a second oil passage that branches from the hydraulic path 36 and supplies oil only to the secondary sheave 21a that controls the belt clamping pressure of the belt-type continuously variable transmission mechanism 11. 36b provided between the check valve 57 and the secondary sheave 21a, which is provided on 36b and prevents the backflow of oil upstream. The belt type continuously variable transmission mechanism 11 is connected to the second oil passage 36b, accumulates oil from the second oil passage 36b during normal traveling of the vehicle 2, and accumulates oil accumulated during traveling when the idling stop function is executed. And an accumulator 44 to be supplied.

  With the above configuration, the oil accumulated in the accumulator 44 is always supplied to the belt-type continuously variable transmission mechanism 11 during traveling while the idling stop function is executed. Even if a disturbance due to a change in the road surface or the like is input from the drive wheel 4 side, the secondary pressure Pd is increased by increasing the secondary pressure Pd so as to secure a belt clamping pressure that can prevent the belt 22 from slipping regardless of the disturbance input. Can be supplied to.

  On the other hand, the electric pump 33 is mainly used for control of the continuously variable transmission mechanism 11 at the time of slow deceleration other than when a disturbance occurs, and control of the C1 control system 18 having a required oil pressure lower than the belt clamping pressure.

  As described above, the hydraulic control device 1 according to the present embodiment uses the accumulator 44 in order to secure the belt clamping pressure of the continuously variable transmission mechanism 11, thereby reducing the hydraulic level that can be supplied by the electric pump 33. Therefore, the enlargement of the electric pump 33 can be suppressed.

  Further, since the accumulator 44 is installed at a position where it can be directly discharged into the second oil passage 36b of the secondary pressure Pd, the oil leakage path can be minimized, and the accumulator 44 can be downsized. Furthermore, the seal prevention processing of the seal of the secondary sheave 21a, LPM No. By reducing the clearance of the one valve 41 and performing surface treatment to prevent thermal expansion of the valve body of the hydraulic control device 1, the leakage flow rate of the oil supplied to the secondary sheave 21a is reduced, and the accumulator 44 is further increased. It can be downsized.

  Further, since the electric pump 33 is provided, oil for controlling the C1 control system 18 can be supplied even when the engine 3 is stopped. Therefore, the C1 control system 18 (clutch C1) starts when returning from the idling stop. It is possible to control to a possible state (a state where stroke is possible), and it is possible to ensure control responsiveness when the engine 3 is restarted.

Further, in the hydraulic control device 1 according to the present embodiment, the supply hydraulic pressure (secondary pressure Pd) to the secondary sheave 21a is equal to or lower than the necessary hydraulic pressure (necessary belt clamping pressure Pd ^* ) during traveling in which the idling stop function is executed. If this is the case, stop the idling stop function and start the engine.

With this configuration, when the necessary belt clamping pressure Pd ^* cannot be secured, the secondary pressure Pd can be immediately increased by the mechanical pump 31 operated by the engine 3 in order to stop the execution of the idling stop function and start the engine 3. This makes it possible to secure the necessary belt clamping pressure Pd ^* . In other words, the accumulator 44 only needs to have a volume that can secure the necessary belt clamping pressure Pd ^* , and the accumulator 44 can be downsized.

  Further, in the hydraulic control device 1 of the present embodiment, the accumulator 44 is disconnected from the second oil passage 36b of the hydraulic passage 36 when the execution of the idling stop function is stopped.

  With this configuration, when the idling stop function is stopped and the engine is restarted, the pressure accumulation control valve 45 is closed, so that the inflow of oil from the second oil passage 36b to the accumulator 44 can be blocked. It is possible to prevent oil consumption due to accumulated pressure, and it is possible to avoid a decrease in the response of the secondary pressure (belt clamping pressure) Pd required when the engine is restarted.

  As mentioned above, although preferred embodiment was shown and demonstrated about this invention, this invention is not limited by these embodiment. The present invention may be configured by combining a plurality of the embodiments described above, and each constituent element of the embodiments can be easily replaced by a person skilled in the art, or substantially the same. It is possible to change to

  In the above embodiment, the C1 control system 18 (the forward / reverse switching clutch C1 and the forward / reverse switching brake B1) of the forward / reverse switching mechanism 10 is illustrated as a clutch hydraulically controlled together with the continuously variable transmission mechanism 11 by the hydraulic control device 1. However, this clutch can cut off the rotational torque between the engine 3 and the drive wheel 4 in the opened state, and can transmit the torque between the engine 3 and the drive wheel 4 in the engaged state. If present, a clutch other than the forward / reverse switching mechanism 10 may be used.

  Further, the accumulator 44 only needs to be connected to the hydraulic path 36 so as to be able to supply oil accumulated in the sheave that controls the belt clamping pressure of the continuously variable transmission mechanism 11. In the above embodiment, since the secondary sheave 21a exemplifies the configuration for controlling the belt clamping pressure, the accumulator 44 is connected to the second oil passage 36b that supplies oil to the secondary sheave 21a. In the configuration that controls the belt clamping pressure, the accumulator 44 can be connected to the first oil passage 36a that supplies oil to the primary sheave 20a.

DESCRIPTION OF SYMBOLS 1 Hydraulic control apparatus 2 Vehicle 3 Engine 4 Drive wheel 5 Power transmission apparatus 7 ECU
11 continuously variable transmission mechanism (belt type continuously variable transmission mechanism)
20a Primary sheave 21a Secondary sheave 31 Mechanical pump (mechanical pump)
32 motor 33 electric pump 36 hydraulic path 36a first oil path 36b second oil path 44 accumulator 45 accumulator control valve 57 check valve (check valve for boosting)
PL Line pressure Pd Secondary pressure (Supply hydraulic pressure)
Pd ^* Necessary belt clamping pressure (necessary hydraulic pressure)

Claims (4)

In a hydraulic control device that controls oil pressure of oil supplied to operate a power transmission device including a belt-type continuously variable transmission, which is provided in a vehicle capable of executing an idling stop function for stopping an engine while the vehicle is running,
A mechanical pump for supplying oil to the power transmission device via a hydraulic path by driving the engine;
An electric pump for supplying oil to the power transmission device via the hydraulic path by driving a motor;
A pressure increasing check valve that is provided on an oil passage that is branched from the hydraulic path and supplies oil only to a sheave that controls the belt clamping pressure of the belt-type continuously variable transmission mechanism, and prevents backflow of oil upstream;
Connected to the oil passage between the pressure check valve and the sheave, accumulates oil from the oil passage during normal traveling of the vehicle, and accumulates the pressure during traveling when the idling stop function is executed. An accumulator for supplying the oil to the sheave;
A hydraulic control device comprising:   During traveling in which the idling stop function is being performed, if the hydraulic pressure supplied to the sheave is less than or equal to the required hydraulic pressure, the idling stop function is stopped and the engine is started. The hydraulic control device according to claim 1.   The hydraulic control device according to claim 2, wherein the accumulator blocks communication with the oil passage when the execution of the idling stop function is stopped. Engine,
A power transmission device including a belt-type continuously variable transmission mechanism;
A hydraulic control device according to claims 1 to 3;
A vehicle control device comprising:

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