JP2014085005A - Hydraulic control apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic control device capable of reducing cost and size and simultaneously increasing the use range of an accumulator.
A switching valve provided between an accumulator and a control circuit, a signal pressure is supplied to a signal pressure port of the switching valve, and the switching valve is opened and closed according to the signal pressure. A signal pressure communication passage 16 and a bypass oil passage 17 for allowing the accumulator 8 to communicate with the control circuit 1 in a state in which the switching valve 9 operates so as to shut off the accumulator 8 from the control circuit 1. The minimum opening diameter of the oil passage 17 is set smaller than the minimum opening diameter of the oil passage via the switching valve 9 between the accumulator 8 and the control circuit 1 in a state where the switching valve 9 communicates the accumulator 8 with the control circuit 1. Has been.
[Selection] Figure 1

Description

  The present invention relates to an apparatus for controlling a hydraulic pressure for operating a hydraulic actuator, and relates to a hydraulic control apparatus including an accumulator that stores hydraulic pressure and supplies the hydraulic pressure to the actuator as the hydraulic pressure.

  2. Description of the Related Art Conventionally, in various industrial devices and vehicles, devices that are operated by hydraulic pressure and that control the operation by hydraulic pressure are used. For example, an automatic transmission for a vehicle is configured such that an operation state is changed by hydraulic pressure to change a gear ratio, or a transmission torque capacity is changed according to the level of hydraulic pressure. The hydraulic pressure is generated by driving an oil pump with a driving force source of the vehicle, and the generated hydraulic pressure is adjusted to an original pressure called line pressure by a pressure adjusting valve, and the line pressure is adjusted as required. The pressure is supplied to an actuator in a transmission mechanism, a clutch or a brake. One example thereof is described in Patent Document 1.

  An example of the hydraulic control device described in Patent Document 1 is a device intended for a belt-type continuously variable transmission, and is a high-pressure hydraulic circuit for controlling the hydraulic pressure of a pulley that is wound around a belt and performs shifting. And a low pressure hydraulic circuit for controlling the hydraulic pressure to be supplied to the torque converter and various lubrication points, and the hydraulic pressure generated by the hydraulic pump driven by the engine is required in the high pressure hydraulic circuit by the first regulator valve. The hydraulic pressure adjusted by the first regulator valve is adjusted to a lower pressure by the second regulator valve and supplied to the torque converter, and the drain hydraulic pressure generated from the first regulator valve is lubricated. It is comprised so that it may supply to a location.

  The high-pressure hydraulic circuit is equipped with an accumulator that accumulates high-pressure hydraulic pressure to the extent that it can be used in the high-pressure hydraulic circuit, and the oil pump is connected to the accumulator by a switching valve that is an electromagnetic valve connected to the input side. Alternatively, the oil pump is configured to be connected to a high pressure hydraulic circuit. An electric oil pump capable of generating high pressure is connected to the inflow side of the switching valve. And as said 1st regulator valve or 2nd regulator valve, the valve by which a pressure regulation level is set according to the signal pressure generated from a predetermined electromagnetic valve can be used. Further, in the configuration described in Patent Document 1, the switching valve is configured to operate by the electromagnetic force of the solenoid, and the hydraulic pressure in each pulley on the driving side and the driven side is provided corresponding to each pulley. Control is performed by a solenoid valve for supply and a solenoid valve for discharge.

JP 2010-151240 A

  The switching valve described in the above-mentioned Patent Document 1 is configured by a solenoid valve that can be electrically controlled in order to quickly supply a high pressure and a large amount of hydraulic pressure to the pulley at the time of sudden shift or the like. ing. Therefore, the control response of the hydraulic pressure in a controlled object such as a pulley is improved. However, in addition to the pressure regulation by each regulator valve and the supply / discharge of the hydraulic pressure to each pulley described in Patent Document 1, the communication between the accumulator and the oil pump and the shutoff thereof are performed by a solenoid. For this reason, the number of locations and solenoids to be electrically controlled increases, which increases the cost of the entire device and may increase the size of the entire device.

  Note that it is conceivable that the switching operation of the switching valve is performed by a predetermined signal pressure instead of the electromagnetic force. For example, when a large amount of pressure oil is required in a high-pressure hydraulic circuit, it is a time when the accelerator pedal, such as sudden acceleration, is greatly depressed, so the throttle pressure linked to the accelerator opening (set the pressure regulation level of the primary regulator valve) It is conceivable that the above-described switching valve is operated by hydraulic pressure. However, in such a configuration, although a solenoid is not required, the switching valve is switched on / off by a signal pressure such as a throttle pressure, so that the pressure can be accumulated when the signal pressure is below a predetermined value. It will be limited to. Therefore, the pressure range in which the accumulator communicates with the high-pressure hydraulic circuit or the line pressure oil passage becomes narrow, and there arises a problem that the accumulator cannot be used effectively.

  The present invention has been made paying attention to the above technical problem, and an object of the present invention is to provide a hydraulic control device capable of reducing the cost and size and simultaneously increasing the use range of the accumulator. Is.

  In order to achieve this object, the invention according to claim 1 is directed to a pressure regulating valve for regulating the hydraulic pressure generated by the oil pump to the operating hydraulic pressure required by the control circuit, and a signal for determining the hydraulic pressure to be set by the pressure regulating valve. A hydraulic pressure control device comprising a signal pressure generating valve for supplying pressure to the pressure regulating valve, and an accumulator for storing hydraulic pressure to be supplied to the control circuit, provided between the accumulator and the control circuit; and A switching valve that causes the accumulator to communicate with the control circuit by opening and closing, and that shuts off the accumulator from the control circuit, and the signal pressure generated by the signal pressure generating valve is a signal of the switching valve. A signal pressure communication path that supplies the pressure port to open and close the switching valve according to the signal pressure, and the switching valve A bypass oil passage that communicates the accumulator with the control circuit in a state where the accumulator is operated to shut off the control circuit, and the switching valve has a minimum opening diameter of the bypass oil passage. It is set to be smaller than the minimum opening diameter of the oil passage that passes through the switching valve between the accumulator and the control circuit in a state where it is communicated with the control circuit.

  According to a second aspect of the present invention, in the first aspect of the invention, the bypass oil passage is provided in the middle of the communication passage that communicates the accumulator and the control circuit, and the minimum of the bypass oil passage. The hydraulic control device includes an orifice having a hole diameter set.

  According to a third aspect of the present invention, in the first aspect of the invention, the switching valve is configured such that the first port communicated with the control circuit, the second port communicated with the accumulator, and the first port in the closed position. And a valve body that shuts off one of the first port and the second port in a valve open position, and the bypass oil passage has the valve body in a valve closed position. The hydraulic control device is characterized in that the valve body is formed so that the first port and the second port communicate with each other.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the accumulator and the control circuit are provided in parallel to the bypass oil passage, and the accumulator is directed to the control circuit. The hydraulic control apparatus further includes a check valve that allows the supply of the hydraulic pressure and that blocks the supply of the hydraulic pressure from the control circuit to the accumulator.

  According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, when the signal pressure generating valve generates the signal pressure that increases the operating hydraulic pressure in the control circuit. When the signal pressure generating valve generates the signal pressure for closing the accumulator with respect to the control circuit by closing the signal pressure, and lowering the hydraulic pressure in the control circuit, the signal pressure is generated. The hydraulic control device is configured to open the valve to communicate the accumulator with the control circuit.

  According to a sixth aspect of the present invention, in the first aspect of the present invention, when the required pressure for the operating hydraulic pressure required by the control circuit is higher than the hydraulic pressure of the accumulator, the required pressure is adjusted by the pressure adjustment. The hydraulic pressure is characterized in that a valve is generated and the switching valve is closed to output a first signal pressure for shutting off the accumulator from the control circuit from the signal pressure generating valve. It is a control device.

  The invention of claim 7 is the invention according to any one of claims 1 to 6, wherein when the required pressure for the operating oil pressure required by the control circuit is less than or equal to the oil pressure of the accumulator, the request is less than or equal to the oil pressure of the accumulator. The pressure regulating valve generates pressure, and the switching valve is opened to output a signal pressure from the signal pressure generating valve to communicate the accumulator with the control circuit. The hydraulic control device.

  According to an eighth aspect of the present invention, in the seventh aspect of the invention, the signal pressure is when the required pressure is equal to or lower than the hydraulic pressure of the accumulator and the accumulator pressure is reduced to a predetermined pressure at which pressure accumulation is to be performed. The pressure control valve includes a second signal pressure of a pressure that generates a hydraulic pressure higher than that of the accumulator and opens the switching valve.

  The invention of claim 9 is the invention of claim 7 or 8, wherein the signal pressure is when the required pressure is less than or equal to the hydraulic pressure of the accumulator and the pressure of the accumulator is greater than or equal to a pressure in a predetermined range in which pressure accumulation is to be performed. In addition, the pressure control valve includes a third signal pressure of a pressure that generates a hydraulic pressure equal to or lower than that of the accumulator and opens the switching valve.

  According to the hydraulic control apparatus of the present invention, when the signal pressure generating valve outputs a signal pressure, the operating hydraulic pressure in the control circuit is controlled to a hydraulic pressure corresponding to the signal pressure, and at the same time, the signal pressure is connected to the signal pressure link. It is led to the signal pressure port of the switching valve through the passage, and the switching valve is set to the open state or the closed state according to the signal pressure. Therefore, according to the present invention, the adjustment control of the hydraulic pressure and the opening / closing control of the switching valve, which are performed in parallel, can be executed based on the signal pressure output from the signal pressure generating valve. In other words, the signal pressure generating valve can be used for both the hydraulic pressure adjustment control and the switching valve opening / closing control, so the number of necessary valves can be reduced, and the cost and size of the hydraulic control device can be reduced. Can be planned. Further, when the accumulator and the control circuit are shut off by the switching valve, the hydraulic pressure generated by the oil pump is mainly supplied to the control circuit, but the control circuit and the accumulator are connected via a bypass oil passage having a small opening diameter. Because of the communication, a part of the hydraulic pressure generated by the oil pump is supplied to the accumulator, and pressure accumulation can be performed. Alternatively, the hydraulic pressure of the accumulator can be supplied to the control circuit. Therefore, in the present invention, even when the switching valve is in a state of shutting off the accumulator and the control circuit, even if the accumulator and the control circuit are communicated with each other by the bypass oil passage, the hydraulic pressure is circulated between the two. Therefore, the use range of the accumulator or the opportunity for use can be increased.

  The bypass oil passage can be constituted by a communication path provided separately from the switching valve and an orifice in the middle thereof. Instead, if the bypass oil passage is formed in the valve body of the switching valve, the number of oil passages can be reduced, and the overall configuration of the apparatus can be simplified or miniaturized.

  Furthermore, if the check valve is provided, the hydraulic pressure generated by the oil pump is restricted from flowing to the accumulator when the required hydraulic pressure in the control circuit is large. Not only can this be satisfied, but also the flow rate of pressure oil from the accumulator to the control circuit can be increased, so that the hydraulic pressure stored in the accumulator can be used effectively and the range of use can be increased.

  On the other hand, in the present invention, the switching valve is closed when the pressure adjustment value is large, that is, when the hydraulic pressure is increased, and conversely, when the pressure adjustment value is small, that is, when the hydraulic pressure is low, the switching valve is opened. Can be configured. With such a configuration, it is possible to prevent or suppress a part of the pressure oil from being sent to the accumulator and causing a delay in the increase of the hydraulic pressure in the control circuit when the hydraulic pressure is increased. In other words, it is possible to improve the control response when the operating hydraulic pressure is increased.

  More specifically, if the required pressure for the working hydraulic pressure is higher than the accumulator hydraulic pressure at that time, the hydraulic pressure stored in the accumulator cannot satisfy the demand, and the hydraulic pressure generated by the oil pump In this case, the hydraulic pressure in the control circuit is prevented from flowing into the accumulator, or the hydraulic pressure in the control circuit or a predetermined value connected to the control circuit is controlled. The operating hydraulic pressure of the actuator rises quickly. That is, the responsiveness to the pressure increase request is improved.

1 is a schematic hydraulic circuit diagram for explaining an example of a hydraulic control device according to the present invention. FIG. It is a hydraulic circuit diagram which shows the control circuit more concretely. It is a flowchart for demonstrating an example of the control by the hydraulic control apparatus. It is a figure which shows the relationship between the 1st thru | or 3rd signal pressure in the hydraulic control apparatus, and the open / close state of a switching valve. It is a figure for demonstrating the example which made the groove part formed in the land of the spool the bypass oil path, Comprising: (a) is a front view of the land, (b) is a part of spool valve used as a switching valve FIG. It is a figure which shows the opening area characteristic in the structure shown in FIG. FIG. 6 is a schematic hydraulic circuit diagram showing another example of the present invention in which a check valve is further used.

  The present invention will be described below based on the specific examples shown in the drawings. FIG. 1 schematically shows an example in which the present invention is applied to a hydraulic control apparatus including a control circuit 1 having a relatively high hydraulic pressure and a low pressure circuit 2 having a relatively low hydraulic pressure. The oil pump 3 is driven by an engine or an electric motor (not shown) to generate hydraulic pressure. The oil pump 3 and the control circuit 1 are connected to each other by an oil passage 4. A pressure regulating valve 5 that regulates the hydraulic pressure discharged from the oil pump 3 or the hydraulic pressure in the oil passage 4 to a predetermined operating hydraulic pressure is communicated with the oil passage 4. An example of the working oil pressure is a line pressure that becomes a source pressure as a whole of the hydraulic control device. The pressure regulating valve 5 is a valve for setting the hydraulic pressure (that is, the hydraulic pressure) in the oil passage 4 to a pressure corresponding to the signal pressure. For example, conventionally, the line pressure of an automatic transmission for a vehicle is set. The primary regulator valve used for this purpose and the regulator valve described in the aforementioned Japanese Patent Application Laid-Open No. 2010-151240 correspond to the pressure regulating valve 5 described above.

  A specific configuration of the pressure regulating valve 5 will be described. A spool having a land which communicates an input port communicated with the oil passage 4 and a drain port and which shuts off these ports is provided. Is provided with an elastic body for pressing the spool in the axial direction and a signal pressure port, and a feedback port for applying the oil pressure of the oil passage 4 to the spool is provided at the opposite end. Therefore, a load that is a sum of the elastic force of the elastic body and the pressing force of the signal pressure input to the signal pressure port acts on the spool, and a load based on the hydraulic pressure acting on the feedback port acts against this. Works. When the spool moves according to these loads and the drain port opens, the oil pressure in the oil passage 4 is discharged to the drain port and decreases. When the spool moves and the drain port is closed accordingly, the oil passage 4 is closed. The operating hydraulic pressure of increases. Eventually, the pressure regulating valve 5 operates so that the above loads are balanced, and the hydraulic pressure of the oil passage 4 is set to a pressure corresponding to the signal pressure. In such a configuration, the hydraulic pressure of the oil passage 4 is increased by increasing the signal pressure, and the hydraulic pressure of the oil passage 4 is decreased if the signal pressure is decreased.

  Since the operating hydraulic pressure required by the control circuit 1 that performs gear shifting or the like needs to be changed according to the operating state of the hydraulic control device or an external request, the signal pressure supplied to the pressure regulating valve 5 is appropriately changed. It is configured to be able to. Specifically, a signal pressure generating valve 6 is provided. The signal pressure generating valve 6 is constituted by, for example, a linear solenoid valve, and is configured to output a signal pressure corresponding to an electric signal such as a current flowing through the solenoid. And the signal pressure is supplied to said pressure regulation valve 5, Therefore, the pressure regulation level of the pressure regulation valve 5 is comprised by the signal pressure.

  Further, an electronic control unit (ECU) 7 for controlling the signal pressure generating valve 6 is provided. The electronic control unit 7 is mainly composed of a microcomputer, and performs a calculation based on input data or data stored in advance, and outputs a control signal to the signal pressure generating valve 6. It is configured. If the hydraulic control circuit shown in FIG. 1 is mounted on a vehicle, the data input to the electronic control device 7 is the accelerator opening, vehicle speed, oil temperature, and the like.

  The pressure regulating valve 5 regulates the pressure by discharging a part of the hydraulic pressure discharged from the oil pump 3 from the drain port, so that the drain pressure of a predetermined pressure is generated from the pressure regulating valve 5. The drain hydraulic pressure is supplied to the low pressure circuit 2 as the original pressure or the low pressure operating hydraulic pressure.

  Further, an accumulator 8 for storing hydraulic pressure is communicated to the control circuit 1 via an oil passage 4. More specifically, an accumulator 8 is connected to the oil passage 4 through a switching valve 9. The accumulator 8 houses a piston held by an elastic body such as a spring, or a member that is inflated and contracted elastically by containing gas, so that the internal volume of the container is elastically increased or decreased. This is a known configuration, and is configured to store the pressure oil at a predetermined pressure when the pressure oil is pushed in.

  The switching valve 9 is a so-called opening / closing valve that allows the accumulator 8 and the control circuit 1 to communicate with each other and to be shut off, and is configured to open and close according to the hydraulic pressure supplied as the signal pressure. Therefore, the switching valve 9 may be a valve having an appropriate configuration such as a poppet type valve, a needle valve, or a butterfly valve, and FIG. 1 shows a spool type valve. Describing the structure, a spool 10 in which a land portion and a valley portion are integrally formed is accommodated in the cylinder portion 11 so as to be movable in the axial direction. An input port (first port) 12 that is opened / closed by the input port 12 and an output port (second port) 13 that communicates with the input port 12 and is shut off are formed.

  Further, on one end side of the spool 10 that is a valve body, a spring 14 that presses the spool 10 in the axial direction (lower side in FIG. 1) is disposed. A signal pressure port 15 is formed at the other end of the spool 10 to apply a hydraulic pressure to the spool 10 in a direction in which the spring 14 is compressed. The oil passage 4 or the control circuit 1 is communicated with the input port 12, and the accumulator 8 is communicated with the output port 13. Further, the signal pressure port 15 is connected to the signal pressure generating valve 6 via the signal pressure communication path 16 so as to supply the signal pressure output from the signal pressure generating valve 6 described above. The area of the face that receives the elastic force and signal pressure of the spring 14 is set so that the spool 10 operates as described later and the switching valve 9 opens and closes according to the level of the signal pressure.

  A bypass oil passage 17 is provided between the accumulator 8 and the control circuit 1 in parallel with the switching valve 9. The bypass oil passage 17 in the example shown in FIG. 1 includes a communication path 18 that allows the accumulator 8 and the control circuit 1 to communicate with each other, and an orifice 19 provided in the middle of the communication path 18. The orifice 19 is for setting the minimum opening diameter of the path through the bypass oil path 17 between the accumulator 8 and the control circuit 1, and the opening diameter is the above-described valve opening state. It is set smaller than the minimum opening diameter in the path between the control circuit 1 and the accumulator 8 via the switching valve 9. That is, the orifice 19 is configured to restrict the flow of hydraulic pressure between the control circuit 1 and the accumulator 8 rather than the flow through the switching valve 9.

  In the configuration shown in FIG. 1, a hydraulic pressure sensor 20 that detects the hydraulic pressure stored in the accumulator 8 and outputs a signal is provided. In addition, a check valve 21 is provided between the oil path 4 and the location where the accumulator 8 is connected to the oil pump 3 to prevent the hydraulic pressure of the accumulator 8 from flowing back to the oil pump 3 side. Yes.

  As described above, the present invention can be applied to a hydraulic control circuit in a vehicle transmission, and the control circuit 1 described above can be a hydraulic circuit having the configuration shown in FIG. FIG. 2 schematically shows an example of the control circuit 1 in the belt type continuously variable transmission. The continuously variable transmission 30 shown here includes a driving pulley (primary pulley) 31 and a driven pulley (a pulley that is wound around the belt). Secondary pulley) 32, and by changing the groove width of these pulleys 31 and 32 wide and narrow, the wrapping radii of the belts around the respective pulleys 31 and 32 are changed to be large and small so that a predetermined gear ratio is obtained. It is configured to set and change the gear ratio. That is, each of the pulleys 31 and 32 includes a fixed sheave integrated with the rotating shaft, and a movable sheave that moves in the axial direction on the rotating shaft to approach and separate from the fixed sheave. Are provided with hydraulic chambers (or hydraulic actuators) 31A and 32A for supplying hydraulic pressure for pressing the cylinder toward the fixed sheave. Therefore, the groove width is changed by the hydraulic pressure (or the amount of pressure oil) supplied to one pulley 31 (or 32), and the belt clamping pressure is set by the hydraulic pressure supplied to the other pulley 32 (or 31). The transmission torque capacity according to the hydraulic pressure is configured. And it is comprised so that a torque may be transmitted from the driven pulley 32 to the drive wheel which is not illustrated.

  An oil passage 33 branched from the oil passage 4 corresponding to the line pressure oil passage communicates with the hydraulic chamber 31A of the drive pulley 31, and a supply solenoid valve 34 is provided in the oil passage 33. The oil passage 33 is opened and closed by the solenoid valve 34 for the pressure, and the pressure oil is selectively supplied to the hydraulic chamber 31A in the drive pulley 31. Further, the hydraulic chamber 31A in the drive pulley 31 is connected to a discharge pressure solenoid valve 36 for discharging the hydraulic pressure of the hydraulic chamber 31A to a drain location such as an oil pan 35. In the example shown in FIG. 2, the exhaust pressure solenoid valve 36 is connected to the oil passage 33 between the supply solenoid valve 34 and the hydraulic chamber 31A. The solenoid valve for supply 34 and the solenoid valve for exhaust pressure 36 are valves that are electrically controlled to open and close the port, and close the port with almost no leakage of hydraulic pressure in a non-energized state (off state). It is configured as follows. This is because the hydraulic pressure is closed in the hydraulic chamber 31A to ensure a predetermined gear ratio and transmission torque capacity even when the energization is interrupted.

  The hydraulic pressure supply / discharge mechanism for the hydraulic chamber 32A in the driven pulley 32 that sets the clamping pressure for clamping the belt is configured similarly to the hydraulic pressure supply / discharge mechanism for the hydraulic chamber 31A in the input pulley 31 described above. That is, a supply solenoid valve 38 is provided in an oil passage 37 that branches off from the oil passage 4 and reaches the hydraulic chamber 32A of the driven pulley 32. The supply solenoid valve 38 opens and closes the oil passage 37 to follow. The pulley 32 selectively supplies hydraulic pressure to the hydraulic chamber 32A. Further, the hydraulic chamber 32A in the driven pulley 32 is connected to a solenoid valve 39 for exhaust pressure that discharges the hydraulic pressure of the hydraulic chamber 32A to a drain location such as the oil pan 35. In the example shown in FIG. 2, the exhaust pressure solenoid valve 39 is connected to the oil passage 37 between the supply solenoid valve 38 and the hydraulic chamber 32A.

  The supply solenoid valve 38 and the exhaust pressure solenoid valve 39 are electrically controlled valves that open and close the ports, and close the ports with almost no hydraulic leakage in a non-energized state (off state). It is configured as follows. This is because the hydraulic pressure is closed in the hydraulic chamber 32A to ensure a predetermined gear ratio and transmission torque capacity even when energization is interrupted.

  Further, in the example shown in FIG. 2, a clutch 40 is provided. The clutch 40 is provided in the middle of a power train that transmits torque from the engine to the drive wheels, transmits torque when engaged, and interrupts transmission of torque when released. Therefore, it is configured to engage with high hydraulic pressure. A supply solenoid valve 42 is provided in an oil path 41 that branches from the oil path 4 and reaches the clutch 40. The supply solenoid valve 42 opens and closes the oil path 41 to provide a hydraulic pressure for the hydraulic chamber in the clutch 40. Is supplied selectively. In addition, an exhaust pressure solenoid valve 43 is connected to the hydraulic chamber of the clutch 40. This exhaust pressure solenoid valve 43 is configured to be electrically controlled to exhaust pressure from the clutch 40 to a drain location or the like, and these supply solenoid valves 42 and 43 leak hydraulic pressure in a non-energized state (off state). It is configured to close the port with almost no occurrence. This is because the clutch 40 is engaged to ensure a predetermined transmission torque capacity even when the energization is interrupted.

  On the other hand, the low-pressure circuit 2 is configured to operate at a lower hydraulic pressure than the control circuit 1 described above. The low-pressure circuit 2 includes a valve or a torque converter that regulates the drain hydraulic pressure from the pressure regulating valve 5 described above. Also included are lubrication points that require lubrication due to slippage, valves for opening / closing or switching the oil passages leading to these torque converters and lubrication points. The torque converter is provided between the engine and the transmission mechanism, as in the conventional automatic transmission for vehicles. Each solenoid valve 34, 36, 38, 39, 42, 43 shown in FIG. 2, each valve in the low-pressure circuit 2 and the like are configured to be controlled by the electronic control unit 7 described above, and the hydraulic sensor Reference numeral 20 is configured to input a detection signal to the electronic control unit 7.

  In the hydraulic control device described above, the hydraulic pressure is adjusted according to the required drive amount represented by the accelerator opening, the vehicle speed, and the like, and at the same time, the switching valve 9 is controlled to open and close. The hydraulic pressure is adjusted by setting the pressure adjustment level of the pressure adjusting valve 5 in accordance with the signal pressure output from the signal pressure generating valve 6. Specifically, as the signal pressure increases, the pressure adjustment level increases accordingly, so that the hydraulic pressure in the oil passage 4 increases. Therefore, for example, when the accelerator opening increases, the signal pressure generating valve 6 outputs a signal pressure corresponding to the accelerator opening in response to a command signal from the electronic control unit 7, and as a result, the hydraulic pressure of the oil passage 4, that is, the control circuit. The control hydraulic pressure at 1 is set to a hydraulic pressure corresponding to the accelerator opening (in other words, engine load or engine torque). In this case, the signal pressure is not only supplied to the pressure regulating valve 5 but also supplied to the signal pressure port 15 of the switching valve 9 via the signal pressure communication passage 16. Accordingly, the switching valve 9 is opened or closed by the signal pressure. The signal pressure output by the signal pressure generating valve 6 is controlled by the electronic control unit 7 as will be described below because the switching valve 9 is controlled to open and close in addition to the adjustment of the hydraulic pressure. .

  FIG. 3 is a flowchart showing an example of the control, and the routine shown here is repeatedly executed in the electronic control unit 7 every predetermined short time. In the control example shown in FIG. 3, it is first determined whether or not the hydraulic pressure (necessary hydraulic pressure or required pressure) Pt required by the control circuit 1 is higher than the accumulator pressure Pa (step S1). When the control circuit 1 includes, for example, the pulleys 31 and 32 shown in FIG. 2, the continuously variable transmission 30 needs to transmit a large torque as the accelerator opening increases. The required operating hydraulic pressure (control pressure) to be determined increases. Therefore, the hydraulic pressure Pt required by the control circuit 1 can be obtained based on data representing the traveling state of the vehicle such as the accelerator opening and the vehicle speed. More specifically, the required oil pressure corresponding to these data is prepared in advance as a map, and the required oil pressure Pt may be obtained from the map. The accumulator pressure Pa is the pressure of the pressure oil stored in the accumulator 8 and can be obtained by the hydraulic sensor 20 described above.

  If the required pressure Pt in the control circuit 1 described above is higher than the accumulator pressure Pa, and a positive determination is made in step S1, the signal pressure by the signal pressure generating valve 6 is set to the first signal pressure P1. (Step S2). Thereafter, the routine of FIG. 3 is once terminated. This first signal pressure P1 is higher than the minimum pressure (in other words, the maximum pressure that can be opened) Pclose that can make the switching valve 9 closed, and the control circuit. 1 is the signal pressure of the pressure that sets the pressure regulation level of the pressure regulating valve 5 so that the hydraulic pressure generated by the pressure regulating valve 5 becomes the required pressure Pt.

  Therefore, when the required pressure Pt is high, the operating hydraulic pressure (line pressure) rises to a high pressure, and the switching valve 9 is switched to the closed state, and the accumulator 8 is shut off from the oil passage 4 or the control circuit 1. On the other hand, since the control circuit 1 or the oil passage 4 is communicated with the accumulator 8 by the bypass oil passage 17 which is the communication passage 18 provided with the orifice 19, the oil pressure of the oil passage 4 adjusted to a high pressure is obtained. The pressure is supplied to the accumulator 8 through the bypass oil passage 17 and accumulated. That is, even in a high pressure state where the oil passage 4 and the accumulator 8 are blocked by the switching valve 9, the accumulator 8 can be accumulated, and the use range or the opportunity of use of the accumulator 8 can be increased. . In this case, the minimum opening diameter of the bypass oil passage 17 is smaller than the minimum opening diameter of the passage from the oil passage 4 via the switching valve 9 to the accumulator 8, so that the bypass oil passage 17 is supplied to the accumulator 8 via the bypass oil passage 17. The amount of hydraulic pressure is greatly limited. Therefore, since the amount of pressure oil flowing from the oil passage 4 into the accumulator 8 is small, the operating oil pressure quickly rises as the pressure regulation level in the pressure regulation valve 5 increases, and the control response of the oil pressure in the control circuit 1 is good. become. In the control shown in FIG. 3, regardless of the level of the accumulator pressure Pa, if the required pressure Pt is higher than the accumulator pressure Pa, the switching valve 9 is closed as the pressure regulation level in the pressure regulation valve 5 increases. Since the path from the oil path 4 through the switching valve 9 to the accumulator 8 is cut off, the control responsiveness when the operating hydraulic pressure is raised in the control circuit 1 becomes good regardless of the level of the accumulator pressure Pa.

  On the other hand, if a negative determination is made in step S1, that is, if the required pressure Pt in the control circuit 1 is less than or equal to the accumulator pressure Pa, whether or not the accumulator 8 needs to be accumulated, that is, the pressure Pa of the accumulator 8 is accumulated. It is determined whether or not the pressure has decreased to a predetermined pressure to be performed (step S3). Specifically, it is determined whether or not the accumulator pressure Pa detected by the hydraulic pressure sensor 20 is lower than the upper limit pressure Pa0 within a predetermined range. Accumulation by the accumulator 8 is performed in order to maintain a predetermined gear ratio even when the oil pump 3 does not generate oil pressure by stopping the engine or the like, or to secure the oil pressure to such an extent that shifting can be executed. Therefore, the accumulated pressure upper limit Pa0 is determined in advance by experiments or simulations so as to enable the maintenance of the gear ratio or the execution of the gear shift.

  If the accumulator pressure Pa is less than the above-mentioned accumulated pressure upper limit Pa0, if the determination in step S3 is affirmative, the signal pressure by the signal pressure generating valve 6 is set to the second signal pressure P2 (<P1). Then, the routine of FIG. 3 is once ended. This second signal pressure P2 is lower than the above-mentioned minimum pressure Pclose capable of closing the switching valve 9 and is generated by the hydraulic pressure in the control circuit 1, that is, the pressure regulating valve 5. This is the signal pressure of the pressure that sets the pressure regulation level of the pressure regulating valve 5 so that the hydraulic pressure becomes higher than the accumulator pressure Pa. Therefore, in this case, the switching valve 9 is opened when the second signal pressure P2 supplied to the signal pressure port 15 is lower than the minimum pressure Pclose, and the switching valve 9 operates in the oil passage 4. Since the hydraulic pressure becomes higher than the accumulator pressure Pa, the hydraulic pressure generated by the oil pump 3 and regulated by the pressure regulating valve 5 is supplied to the control circuit 1 while being supplied to the accumulator 8 to accumulate pressure. That is, the hydraulic pressure is adjusted by the signal pressure generated by the signal pressure generating valve 6 and at the same time, the control for accumulating is executed. Since the accumulator 8 is always in communication with the oil passage 4 or the control circuit 1 via the bypass oil passage 17 described above, if the oil pressure of the oil passage 4 or the control circuit 1 is higher than the oil pressure of the accumulator 8, the bypass oil passage The hydraulic pressure is supplied to the accumulator 8 through 17 to accumulate pressure.

  On the other hand, if a negative determination is made in step S3, that is, if the hydraulic pressure Pa of the accumulator 8 detected by the hydraulic sensor 20 is equal to or higher than the pressure required for accumulating, the accumulator pressure Pa is equal to or higher than the required pressure in the control circuit 1 and is high enough not to accumulate pressure. In this case, the hydraulic pressure stored in the accumulator 8 is supplied to the control circuit 1. That is, the signal pressure by the signal pressure generating valve 6 is set to the third signal pressure P3 (<P2) (step S5), and then the routine of FIG. 3 is temporarily terminated. The third signal pressure P3 is a signal pressure lower than the second signal pressure P2, and is sufficiently lower than the minimum pressure Pclose that can close the switching valve 9 described above. That is, the pressure is such that the switching valve 9 can be opened. In this case, since the hydraulic pressure required by the control circuit 1 is lower than the accumulator pressure Pa, and the accumulator 8 can be used as the hydraulic pressure source of the control circuit 1, the third signal pressure P3 is required by the control circuit 1. The pressure determined based on the hydraulic pressure required by the low-pressure circuit 2 is used regardless of the hydraulic pressure. Specifically, the pressure of the third signal pressure P3 is determined so as to set the pressure regulation level at which the drain hydraulic pressure from the pressure regulating valve 5 becomes the pressure required in the low pressure circuit 2.

  Therefore, in this case, the switching valve 9 is opened when the third signal pressure P3 supplied to the signal pressure port 15 is sufficiently lower than the minimum pressure Pclose, and the oil passage 4 Is lower than the accumulator pressure Pa, the hydraulic pressure stored in the accumulator 8 is supplied to the control circuit 1 via the switching valve 9 and the bypass oil passage 17. For this reason, the hydraulic pressure regulated by the pressure regulating valve 5 is considerably low, but the pressure regulating level of the pressure regulating valve 5 is set so that the drain hydraulic pressure accompanying pressure regulation is equal to or higher than the pressure required by the low pressure circuit 2. It is set by the third signal pressure P3, and the working oil pressure is a pressure corresponding to the pressure regulation level. That is, also in this case, the hydraulic pressure stored in the accumulator 8 is controlled at the same time as the hydraulic pressure is adjusted by the signal pressure generated by the signal pressure generating valve 6.

  FIG. 4 shows the relationship between the first to third signal pressures P1, P2, and P3, the open / close state of the switching valve 9, and the pressure accumulation range. As shown in FIG. 4, the switching valve 9 is closed when the signal pressure supplied to the signal pressure port 15 is equal to or higher than the minimum pressure Pclose for closing the valve. Therefore, when the signal pressure generating valve 6 outputs the first signal pressure P 1 described above, the switching valve 9 is closed and the accumulator 8 is shut off from the oil passage 4 or the control circuit 1. As a result, a relatively high hydraulic pressure regulated according to the first signal pressure P1 is quickly generated and supplied to the control circuit 1. That is, it is possible to improve the control response when increasing the hydraulic pressure in the oil passage 4 and the control circuit 1. Even in this state, the oil pressure in the oil passage 4 is supplied to the accumulator 8 via the bypass oil passage 17 and accumulated.

  If the signal pressure is lower than the above-mentioned minimum pressure Pclose, the spool 10 in the switching valve 9 is pushed by the spring 14 and moves to the signal pressure port 15 side, and the input port 12 and the output port 13 are communicated. That is, the switching valve 9 is opened. In this state, the accumulator 8 and the oil passage 4 or the control circuit 1 communicate with each other. Therefore, pressure accumulation is performed according to the accumulator pressure Pa, the oil pressure in the oil passage 4 or the control circuit 1, or the oil pressure is output from the accumulator 8. Is done. That is, when the signal pressure is set to the above-described second signal pressure P2, the operating oil pressure in the oil passage 4 or the control circuit 1 becomes higher than the accumulator pressure Pa, so that pressure accumulation is performed. At the same time, hydraulic pressure is supplied to the accumulator 8 through the bypass oil passage 17 and accumulated. Therefore, in the configuration including the bypass oil passage 17 described above, if the oil pressure in the oil passage 4 (so-called line pressure) is higher than the oil pressure in the accumulator 8, pressure can be accumulated in the accumulator 8 regardless of whether the switching valve 9 is open or closed. FIG. 4 shows the range as an “accumulator pressure accumulation range” that reaches the maximum value Pmax of the signal pressure.

  On the other hand, when the third signal pressure P3 is set, the hydraulic pressure in the oil passage 4 or the control circuit 1 becomes lower than the accumulator pressure Pa, so that the hydraulic pressure is supplied from the accumulator 8 to the switching valve 9 and the bypass oil passage. The oil is supplied to the oil passage 4 or the control circuit 1 through 17. In other words, the accumulator 8 functions as a hydraulic pressure source for the control circuit 1. At the same time, the required hydraulic pressure in the low pressure circuit 2 is supplied from the pressure regulating valve 5 to the low pressure circuit 2.

  In the hydraulic control apparatus according to the present invention, as described above, the hydraulic pressure in the oil passage 4 or the control circuit 1 is set by the signal pressure output from the signal pressure generating valve 6, and the accumulator 8 is combined therewith. Is controlled to communicate with or cut off from the control circuit 1. Accordingly, the signal pressure generating valve 6 serves as a control means for simultaneously executing control for adjusting the hydraulic pressure and switching control for connecting / blocking the accumulator 8 to the control circuit 1. The generation valve 6 is shared by the control executed in parallel. For this reason, in the hydraulic control apparatus according to the present invention, it is possible to reduce the cost by reducing the number of necessary parts in accordance with the sharing of the components, particularly the sharing of the necessary parts in the control executed in parallel. In addition, the overall configuration of the apparatus can be reduced in size. Further, the supply and accumulation of hydraulic pressure to the accumulator 8 via the switching valve 9 is limited to the case where the switching valve 9 is set to an open state, but the bypass oil path 17 is an oil path that restricts the flow rate of pressure oil. 4 is always in communication with the accumulator 8, so that if the oil pressure in the oil passage 4 is higher than the oil pressure in the accumulator 8, the pressure can always be accumulated via the bypass oil passage 17. Therefore, the use range of the accumulator 8 or the opportunity to use it can be increased.

  As described above, in the hydraulic control apparatus according to the present invention, the bypass oil passage 17 that constantly communicates the accumulator 8 with the oil passage 4 or the control circuit 1 by reducing the cross-sectional area of the flow passage regardless of the open / close state of the switching valve 9. It has. The bypass oil passage 17 is not limited to the configuration shown in FIG. 1 and may be provided inside the switching valve 9 as shown in FIGS. 5A and 5B, for example. Explaining the configuration, the spool 10 in the switching valve 9 is provided with a land portion 10A that opens the input port 12 at the lowered position and closes the input port 12 at the raised position. The groove portion 10B is formed.

  The groove portion 10B is formed so as to reach the intermediate portion in the axial direction of the land portion 10A from the upper face in FIG. 5 of the land portion 10A, and the length of the spool 10 (that is, the land portion 10A) is closed. Even when the position is raised, the length is set so as to communicate with the input port 12. Further, the sectional area of the groove 10B (that is, the minimum opening diameter) or the area where the groove 10B opens to the input port 12 in a state where the spool 10 is raised to the valve closing position is determined by the switching valve 9 in the valve open state. It is set to be smaller than the minimum opening diameter in the path through which the oil path 4 and the accumulator 8 communicate with each other. Therefore, the groove 10 </ b> B constitutes the bypass oil passage 17.

  FIG. 6 shows the relationship between the stroke amount of the spool 10 and the opening area of the path from the oil path 4 to the accumulator 8 when the configuration shown in FIG. 5 is adopted. In FIG. 6, the stroke amount of the spool 10 in the valve open state is set to “0”. When the spool 10 gradually strokes (rises) from this state (when the spool 10 strokes in the valve closing direction), the land portion 10 </ b> A opens the input port 12. Since it gradually closes, the opening area gradually decreases. When the land portion 10A completely covers the open end of the input port 12, the input port 12 and the output port 13 are in communication with each other through the groove portion 10B (bypass oil passage 17). In that case, since the length of the portion opened to the input port 12 in the groove portion 10B is long, the area obtained by multiplying the length by the width of the groove portion 10B is the opening area. When the spool 10 is further raised, the length of the groove portion 10B that opens to the input port 12 is shortened, so that the opening area is reduced. Eventually, the groove portion 10B slightly opens to the input port 12 and opens. The hole diameter (opening area) is as small as the opening diameter of the orifice 19 described above. Therefore, even when the bypass oil passage 17 is configured as shown in FIG. 5, the use range of the accumulator 8 can be increased and a high hydraulic pressure or a large hydraulic pressure is required by the control circuit 1. The control response can be improved.

  By the way, in the configuration including the bypass oil passage 17 in which the cross-sectional area of the flow path is reduced, the flow rate is limited even when hydraulic pressure is supplied from the accumulator 8 to the control circuit 1. In order to eliminate or relax such a restriction, a check valve 50 is provided between the accumulator 8 and the oil passage 4 or the control circuit 1 in parallel with the orifice 19 as shown in FIG. That's fine. The check valve 50 opens when the hydraulic pressure of the accumulator 8 is higher than the hydraulic pressure of the oil passage 4 or the hydraulic pressure of the control circuit 1, and on the contrary, the hydraulic pressure of the accumulator 8 is relative to the hydraulic pressure of the oil passage 4 or the control circuit 1. It is a valve that closes when it is low. Therefore, in the configuration shown in FIG. 7, the check circuit 50 is provided from the accumulator 8 to the control circuit 1 in addition to the bypass oil passage 17 having the orifice 19 and the switching valve 9 when the valve is open. The hydraulic pressure is supplied through. Therefore, the amount of hydraulic pressure supplied from the accumulator 8 to the control circuit 1 can be increased by the amount of the oil passage in which the check valve 50 is provided, so that the control responsiveness in the control circuit 1 can be improved.

  Note that the present invention is not limited to the above-described specific example, and the switching valve may be replaced with another type of valve instead of the spool type valve. Moreover, when employ | adopting the check valve mentioned above, you may form a bypass oil path in the check valve. For example, a bypass oil passage may be provided by penetrating a valve body in the check valve.

  DESCRIPTION OF SYMBOLS 1 ... Control circuit, 2 ... Low pressure circuit, 3 ... Oil pump, 4 ... Oil path, 5 ... Pressure regulation valve, 6 ... Signal pressure generation valve, 7 ... Electronic control unit (ECU), 8 ... Accumulator, 9 ... Switching Valves, 10 ... Spool, 12 ... Input port, 13 ... Output port, 15 ... Signal pressure port, 16 ... Signal pressure communication passage, 17 ... Bypass oil passage, 18 ... Communication passage, 19 ... Orifice, 21 ... Check valve, 30 ... Continuously variable transmission, 50 ... Check valve, Pt ... Hydraulic pressure (necessary or required pressure), Pa ... Accumulator pressure, P1 ... First signal pressure, Pclose ... Minimum pressure (in other words, open valve) Maximum pressure)), P2 ... second signal pressure, P3 ... third signal pressure.

Claims (9)

A pressure regulating valve that regulates the hydraulic pressure generated by the oil pump to the working hydraulic pressure required by the control circuit, and a signal pressure generating valve that supplies the pressure regulating valve with a signal pressure that determines the hydraulic pressure to be set by the pressure regulating valve; In the hydraulic control device comprising an accumulator for storing the hydraulic pressure to be supplied to the control circuit,
A switching valve that is provided between the accumulator and the control circuit and that opens and closes to connect the accumulator to the control circuit and shuts off the accumulator from the control circuit;
A signal pressure communication path for supplying the signal pressure generated by the signal pressure generating valve to a signal pressure port of the switching valve and opening and closing the switching valve according to the signal pressure;
A bypass oil passage that communicates the accumulator with the control circuit in a state in which the switching valve is operating to shut off the accumulator from the control circuit;
The minimum opening diameter of the bypass oil passage is smaller than the minimum opening diameter of the oil passage passing through the switching valve between the accumulator and the control circuit in a state where the switching valve communicates the accumulator with the control circuit. A hydraulic control device characterized by being set.   The bypass oil passage includes a communication passage that allows the accumulator and the control circuit to communicate with each other, and an orifice that is provided in the middle of the communication passage and sets the minimum opening diameter of the bypass oil passage. The hydraulic control device according to claim 1. The switching valve shuts off and opens one of the first port communicated with the control circuit, the second port communicated with the accumulator, and the first port and the second port at the closed position. A valve body communicating the first port and the second port at a valve position;
The said bypass oil passage is formed in the said valve body so that said 1st port and 2nd port may be connected in the state in which the said valve body exists in a valve closing position. Hydraulic control device.   Between the accumulator and the control circuit, it is provided in parallel to the bypass oil passage, and allows the supply of hydraulic pressure from the accumulator to the control circuit and allows the hydraulic pressure from the control circuit to the accumulator. The hydraulic control device according to any one of claims 1 to 3, further comprising a check valve for shutting off the supply.   The switching valve closes the accumulator from the control circuit by closing the signal pressure for increasing the hydraulic pressure in the control circuit when the signal pressure generating valve generates the signal pressure. And when the signal pressure generating valve generates the signal pressure that lowers the operating hydraulic pressure in the control circuit, the signal pressure is opened to open the accumulator in communication with the control circuit. The hydraulic control device according to claim 1, wherein the hydraulic control device is provided.   When the required pressure for the hydraulic pressure required by the control circuit is higher than the hydraulic pressure of the accumulator, the pressure regulating valve generates the required pressure and the switching valve is closed to control the accumulator. 6. The hydraulic control device according to claim 1, wherein the first signal pressure that is cut off from the circuit is output from the signal pressure generating valve.   When the required pressure for the hydraulic pressure required by the control circuit is equal to or lower than the hydraulic pressure of the accumulator, the pressure regulating valve generates the required pressure equal to or lower than the hydraulic pressure of the accumulator and opens the switching valve. 7. The hydraulic control device according to claim 1, wherein a signal pressure for communicating the accumulator with the control circuit is output from the signal pressure generating valve.   The signal pressure is set so that when the required pressure is equal to or lower than the accumulator oil pressure and the accumulator pressure is reduced to a predetermined pressure at which pressure accumulation is to be performed, the pressure regulating valve has a higher oil pressure than the accumulator oil pressure. The hydraulic control device according to claim 7, further comprising a second signal pressure that is generated and opens the switching valve.   The signal pressure is generated when the required pressure is equal to or lower than the pressure of the accumulator and the pressure control valve generates a hydraulic pressure equal to or lower than the pressure of the accumulator when the pressure of the accumulator is equal to or higher than a predetermined range of pressure to be accumulated. The hydraulic control device according to claim 7, further comprising a third signal pressure of a pressure for opening the switching valve.

Images