JP2005282618A - Hydraulic controller for transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To share a valve requiring large capacity in a hydraulic controller by combining the valve with a valve sufficient to have small capacity, and thereby reduce the size and weight of a hydraulic circuit. <P>SOLUTION: This hydraulic controller for a transmission is provided with a flow rate control valve comprising an orifice 2 and a relief valve 3 and controlling the amount of drain which returns from an upstream side oil passage of the orifice 2 to a suction side oil passage (a) of an oil pump 1 in accordance with pressure difference before and after the orifice 2, between a discharge side oil passage (b) of the oil pump 1 and a hydraulic-activated circuit (c). A signal pressure selector valve 4 for controlling application and release of signal pressure with respect to the flow rate control valve is interposed in a signal pressure oil passage (e) applying hydraulic pressure in the orifice downstream side to the flow rate control valve. Due to this, the flow rate control valve can be operated also as an unloader valve with large capacity for releasing a pump drive load, and compared with the case where the unloader valve is actually mounted, reduction of the size and weight of the circuit is attained. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a transmission hydraulic control device, and more particularly to a technique for controlling a discharge flow rate of a base pressure circuit of a transmission hydraulic control device using an oil pump as a hydraulic pressure generation source.

  One example of a device that uses a hydraulic control device is an automatic transmission. The hydraulic control device in an automatic transmission is equipped to supply hydraulic pressure for the operation of hydraulic servos for clutches and brakes for shift control, lubrication and cooling of each part of the mechanism, and for the circulation of hydraulic oil to the torque converter. In general, an oil pump mechanically driven by a rotary member on the pump side of a torque converter that rotates at the same speed as the engine speed is used as a hydraulic pressure generation source. In this way, using the hydraulic energy of the hydraulic pressure generation source, long-time high pressure that requires little flow rate for maintaining a specific shift stage (maintaining clutch and brake engagement) and shifting (clutch and brake) Hydraulic operation circuit that requires a high flow rate for a short time without requiring a very high hydraulic pressure, and a lubrication that requires a substantially constant flow rate at a lower pressure than this hydraulic operation circuit. In order to supply oil to the circuit, it is necessary to use an oil pump having a capacity that can sufficiently cope with these conditions.

  In such a hydraulic circuit using an engine-driven oil pump, when the engine speed is higher than the flow rate required by the hydraulic operation circuit and the lubrication circuit, the oil discharged from the oil pump is drained to drain the hydraulic pressure due to excessive flow rate. Therefore, it is reasonable to control the flow rate of the oil discharged from the oil pump, which changes according to the engine speed, to a predetermined amount, so that no unnecessary increase in hydraulic pressure occurs. Conventionally, there are techniques described in Patent Document 1 and Patent Document 2 as techniques for performing such flow rate control.

In addition, when the hydraulic operation circuit is equipped with an accumulator, the circuit operation can be performed using the accumulated pressure in the accumulator, so it is possible to create a state that does not require the output of the oil pump when the accumulator is accumulated. At this time, the energy loss can be reduced by rotating the oil pump in a no-load state. An unloader valve is used as means for releasing the load of such an oil pump. There exists a technique of patent document 3 as what discloses such a technique.
Japanese Utility Model Publication No. 2-39655 Japanese Patent Laid-Open No. 11-30320 Japanese Patent Laid-Open No. 11-280643

  By the way, the flow rate control valve and the unloader valve as described above require a drain capacity of a large flow rate corresponding to the discharge flow rate of the oil pump. Therefore, when these valves are provided in the hydraulic circuit, two large capacity valves are used. The hydraulic circuit becomes larger with the arrangement. Such an increase in the size of the circuit is not preferable because it is a factor that hinders mounting on a vehicle for an on-vehicle transmission.

  The present invention has been devised in view of the circumstances as described above, and a valve that requires a large capacity in a hydraulic control device for a transmission is shared by a combination with a valve that requires a small capacity, thereby a hydraulic circuit. The main purpose is to reduce the size and weight as much as possible. Moreover, this invention makes it the further objective to reduce the energy loss which concerns on the drive of an oil pump.

  The present invention is interposed between a discharge-side oil passage (b) and a hydraulic operation circuit (c) of an oil pump (1), and includes an orifice (2) and a pressure regulating valve (3). A flow rate control valve for controlling the drain amount returning from the upstream oil passage of the orifice to the suction side oil passage (a) according to the pressure is provided, and the flow rate of oil flowing to the hydraulic operation circuit is controlled by adjusting the drain amount. In the transmission hydraulic control device, a signal pressure switching valve (4) for controlling application and release of signal pressure to the flow control valve is provided in a signal pressure oil passage (e) for applying hydraulic pressure downstream of the orifice to the flow control valve. The main feature is the insertion.

  The present invention also provides an orifice (2) interposed between a discharge side oil passage (b) of the oil pump (1) and a hydraulic operation circuit (c), an oil passage upstream of the orifice, and an oil pump. Is inserted into an oil passage (d) communicating with the suction side oil passage (a), and the oil pressure upstream of the orifice and the oil pressure downstream of the orifice are applied to face each other, and the oil passage on the suction side of the oil pump from the oil passage upstream of the orifice And a pressure regulating valve (3) for controlling the drain amount to return to the hydraulic pressure control apparatus for controlling the amount of oil flowing through the hydraulic operation circuit by adjusting the drain amount. It is further characterized by comprising a signal pressure switching valve (4) for controlling application and release.

  In any case, it is effective that the signal pressure switching valve is composed of a solenoid-operated solenoid valve. The signal pressure switching valve may be a normally closed valve or a normally open valve. Further, it is effective that the hydraulic operation circuit includes output means (5, 6) for applying a signal pressure to the signal pressure switching valve by increasing the hydraulic pressure of the circuit. In this case, the output means includes a hydraulic pressure sensor (5) and an electronic control device (6) that outputs a solenoid drive signal to the signal pressure switching valve based on a signal from the hydraulic pressure sensor. The hydraulic operation circuit preferably includes an accumulator (7), and a check valve (8) for preventing back flow of oil is interposed between the accumulator and the orifice.

  According to the present invention, by combining the flow control valve and the signal pressure switching valve, the flow control valve can be operated as an unloader valve, as compared with the case where the flow control valve and the unloader valve are mounted in parallel. Therefore, the valve can be reduced in size by replacing the unloader valve with the signal pressure control valve. As a result, the hydraulic control device can be reduced in size and weight.

  The present invention is particularly effective when applied to a hydraulic control apparatus in which a hydraulic operation circuit is provided with an accumulator. By this, when the accumulation of pressure in the accumulator is completed, the flow control valve is switched to an unloaded state, thereby reducing the load on the oil pump. The release state can be lengthened to reduce energy loss.

  FIG. 1 shows a circuit configuration of an embodiment of a hydraulic control apparatus according to the present invention. This circuit constitutes a base pressure circuit that supplies oil pressure to the hydraulic operation circuit c using the oil pump 1 as a hydraulic energy source. The hydraulic operation circuit c in this example lubricates each part of the speed change mechanism by supplying oil, and if necessary, the hydraulic servo (C) 11 for each clutch and the hydraulic servo (B) 12 for the brake for speed change control. The circuit which operates is comprised. This circuit further includes an accumulator 7 that accumulates the supplied oil and supplies it to the hydraulic servos 11 and 12 as necessary.

  The base pressure circuit is interposed between the discharge-side oil passage b of the oil pump 1 and the hydraulic operation circuit c, and includes an orifice 2 and a pressure regulating valve 3. A flow rate control valve for controlling the drain amount returning from the upstream oil passage (discharge side oil passage b of the oil pump 1) to the suction side oil passage a of the oil pump 1 is arranged, and adjustment of the drain amount by this flow control valve Thus, the flow rate of the oil flowing through the hydraulic operation circuit c is controlled. In accordance with the characteristics of the present invention, a signal pressure switching valve 4 for controlling the application and release of the signal pressure to the pressure regulating valve 3 is provided in the signal pressure oil passage e for applying the hydraulic pressure downstream of the orifice 2 to the pressure regulating valve 3 of the flow control valve. It is inserted. In this example, the orifice 2 is inserted between the discharge side oil passage b of the oil pump 1 and the hydraulic operation circuit c, and the pressure regulating valve 3 is connected to the upstream side oil passage of the orifice 2 and the suction side oil of the oil pump 1. In the oil passage d communicating with the passage a, the oil pressure upstream of the orifice 2 and the oil pressure downstream of the orifice are applied oppositely to control the amount of drain returning from the oil passage upstream of the orifice 2 to the suction oil passage a of the oil pump 1. It is inserted as much as possible. The signal pressure switching valve 4 controls application and release of the hydraulic pressure downstream of the orifice 2 to the pressure regulating valve 3.

  Hereinafter, details of the basic pressure circuit and each element constituting the circuit will be described in detail. This circuit constitutes an open circuit similar to a normal automatic transmission that draws up oil from the oil reservoir 10 by the oil pump 1 and drains the oil supplied to each part and returns it to the oil reservoir 10. First, the oil pump 1 as a hydraulic pressure generating source that sucks up oil from the oil reservoir 10 and discharges it to a circuit is for a normal automatic transmission in which the engine is always in an operating state during vehicle operation. In this case, it is desirable to use an oil pump that is mechanically driven by an engine, and in the case of a drive device with a built-in motor for an electric vehicle or a hybrid vehicle in which the engine is stopped even when the vehicle is operated, It is desirable to be done.

  The orifice 2 constituting the flow control valve is of an appropriate type such as a plate type having an opening or a choke type having a slot on a cylindrical peripheral surface. The pressure regulating valve 3 is a spring-returned spool type two-port valve, and the hydraulic pressure downstream of the orifice 2 is applied to the spool end on the spring load side, and upstream of the other spool end (oil pump discharge side oil passage b). The hydraulic pressure is applied. Further, the flow capacity when the pressure regulating valve 3 is fully opened is a capacity capable of flowing the entire discharge flow rate when the oil pump rotates at the highest speed. The import of the pressure regulating valve 3 is connected to the oil passage b on the upstream side of the orifice, and the outport is connected to the suction side oil passage a of the oil pump 1. Therefore, when the differential pressure across the orifice is small, the pressure regulating valve 3 operates mainly in the port closing direction due to the spring load to reduce the amount of return oil to the oil pump suction side, and when the differential pressure increases, When the applied signal pressure wins, it operates in the port opening direction to increase the amount of return oil. The operation of the pressure regulating valve 3 keeps the oil flow rate through the orifice 2 substantially constant.

  The signal pressure switching valve 4 is a solenoid-operated spring return type normally closed three-port spool valve. The import of the signal pressure switching valve 4 is connected to the oil passage on the downstream side of the orifice, and the out port is connected to the spring load load side spool end of the pressure regulating valve 3. Accordingly, the signal pressure switching valve 4 is switched to the communication state between the import and the outport when the solenoid signal is applied, and the hydraulic pressure downstream of the orifice is applied to the spring load load side spool end of the pressure regulating valve 3, and the spring is not applied when the solenoid signal is not applied. The connection between the import and the outport is cut off at the return, and the outport is switched to the drain communication. In connection with the operation of the signal pressure control valve 4, when the signal pressure is applied by the signal pressure switching valve 4, the pressure regulating valve 3 operates as a flow control valve in cooperation with the orifice 2, and when the signal pressure is released, the pressure regulating valve 3 Operates as an unloader valve that releases the compression load of the oil pump 1.

  An output means provided in the hydraulic operation circuit c to release the signal pressure switching valve 4 by increasing the hydraulic pressure of the circuit is driven by a solenoid to the signal pressure switching valve 4 by a signal from the hydraulic sensor 5 and the hydraulic sensor 5. It consists of an electronic control unit (ECU) 6 that outputs signals. The hydraulic sensor 5 is a hydraulic switch that operates by detecting the hydraulic pressure of the hydraulic operation circuit c, and the electronic control unit 6 detects an operation of the hydraulic switch 5 and outputs a solenoid drive signal, A control unit for controlling the drive device is used. In addition, the structure which has the same effect can be implement | achieved even if it uses a transducer instead of a hydraulic switch.

  Further, the hydraulic operation circuit c is provided with an accumulator 7 for accumulating the hydraulic pressure supplied to the circuit, and accordingly, in order to prevent the accumulated hydraulic pressure from returning to the pump discharge side, the accumulator 7 and the orifice 2 In the meantime, a check valve 8 for preventing the backflow of oil is inserted.

The hydraulic control apparatus having the above configuration is controlled as shown in the time chart of FIG. In this time chart, the horizontal axis is time, the vertical axis is the pressure upstream of the orifice (pump discharge pressure: indicated by a solid line in the figure), and the flow rate through the orifice (output flow rate: indicated by a dotted line in the figure). Represents. As shown in the figure, in the flow control state by the ON operation of the signal pressure switching valve (denoted as a solenoid valve in the figure), the flow rate through the orifice is kept constant by the flow control, assuming that the pump discharge flow rate itself is constant, As the pump discharge pressure increases, the accumulator pressure accumulation (accumulator pressure: indicated by broken lines in the figure) also gradually increases. If the solenoid valve is turned off when the accumulator pressure rises to a predetermined upper limit (P _H ) pressure, the circuit is switched to the unloaded state, and the flow rate through the orifice becomes 0. And then keep a constant value. On the other hand, the accumulator pressure gradually decreases due to flow consumption for lubrication on the hydraulic operation circuit side, leakage from the circuit, and the like. When the accumulator pressure is thus reduced to the predetermined lower limit (P _L ), when the solenoid valve is turned on, the flow rate through the orifice is restored, the pump discharge pressure starts to rise, and the accumulator pressure is again increased accordingly. The increase starts toward the upper limit value (P _H ). This time chart shows the case where there is no operation of the clutch or brake that suddenly consumes accumulator pressure on the hydraulic operation circuit side, and when there is such operation, the accumulator pressure decreases in the unloaded state Becomes more rapid and the duration of unloading is shorter.

  As described above in detail, according to this embodiment, the flow control valve and the signal pressure control valve 4 can be combined to operate the flow control valve as an unloader valve. Compared with the case where they are arranged in parallel, the unloader valve can be reduced in size by replacing the signal pressure control valve with a lower volume of the valve. When this is expressed by specific numerical values, for example, assuming an automatic transmission for an engine with a displacement of 1000 cc class, it is excessively discharged from the oil pump and drained into the oil sump without being consumed on the hydraulic operation circuit side. When the flow control valve and unloader valve corresponding to this are individually installed, it is necessary to flow a flow of 50 L / min or more with each valve. Therefore, it is only necessary that the flow rate control valve has a capacity capable of flowing a flow rate of 50 L / min or more, and the signal pressure switching valve 4 may have a flow capacity of about 1 L / min for applying the signal pressure. This leads to a reduction in size and weight of the hydraulic control device.

  In the first embodiment, the signal pressure switching valve 4 is a normally closed solenoid valve. However, the valve may be a normally open solenoid valve. Next, a circuit configuration of the second embodiment having such a configuration will be described.

  FIG. 3 shows a hydraulic circuit configuration of the second embodiment. Since this hydraulic circuit is basically the same as that of the first embodiment except for the configuration of the signal pressure switching valve 4, the illustration of the hydraulic operation circuit and the circuit of the output means is omitted. Corresponding portions are denoted by the same reference numerals instead of the description, and only differences will be described below. In this circuit, the signal pressure switching valve 4 is a solenoid-operated spring return-type normally open three-port spool valve. Therefore, the signal pressure switching valve 4 applies the oil pressure downstream of the orifice to the spring load load side spool end of the pressure regulating valve 3 by maintaining the communication state between the import and the out port by the spring return when no solenoid signal is applied, When the solenoid signal is applied, the import is cut off, the out port is switched to drain communication, and the application of the hydraulic pressure downstream of the orifice to the pressure regulating valve 3 is released. In connection with the operation of the signal pressure switching valve 4, when the signal pressure is applied by the signal pressure switching valve 4, the pressure regulating valve 3 operates as a flow control valve in cooperation with the orifice 2, and when the signal pressure is released, the pressure regulating valve 3 Operates as an unloader valve that releases the compression load of the oil pump 1.

  In the case of adopting the configuration of the second embodiment, the relationship between the flow control of the flow control valve and the switching of the unload state with respect to the application or non-application of the solenoid signal to the signal pressure switching valve 4 is reversed. In this example, the state in which the flow rate control valve achieves the flow rate control function is maintained when no solenoid signal is applied, so even if a failure such as accidental disconnection of the solenoid or loss of the solenoid drive signal occurs, The advantage is that the hydraulic supply to the operating circuit can be maintained.

  In the above two embodiments, the signal pressure switching valve 4 is constituted by an electromagnetic valve. However, it is also possible to adopt a configuration in which this valve is operated by using hydraulic pressure as a signal pressure, and the operation of the valve is performed by another electromagnetic valve. . Finally, a circuit configuration of the third embodiment having such a configuration will be described.

  FIG. 4 shows a hydraulic circuit configuration of the third embodiment. This hydraulic circuit is basically the same as that of the first embodiment except for the configuration of the signal pressure switching valve 4 and the newly added electromagnetic valve 9, so that the hydraulic operating circuit and the output means portion are the same. In the figure, the corresponding parts are denoted by the same reference numerals, and only the differences will be described below. In this circuit, the signal pressure switching valve 4 is a normally closed three-port spool valve of a hydraulically operated spring return type. Moreover, the electromagnetic valve 9 which operates this is a simple on / off open / close valve. In this circuit configuration, when the signal pressure is not applied, the signal pressure switching valve 4 shuts off the import by returning the spring, makes the out port drain communication, and releases the application of the hydraulic pressure downstream of the orifice to the pressure regulating valve 3. The import of the solenoid valve 9 is connected to an oil passage having a pressure lower than the accumulator pressure, such as a modulator pressure oil passage in the hydraulic control circuit, and the outport is defined as the spring load load side of the signal pressure switching valve 4. Connected to the opposite spool end. In this circuit, a signal pressure is output to the signal pressure switching valve 4 in a state where a solenoid signal is applied to the electromagnetic valve 9, thereby causing communication between the signal pressure switching valve 4 and the out port. Hydraulic pressure is applied to the spring load side spool end of the pressure regulating valve 3. In connection with the operation of the signal pressure switching valve 4, when the signal pressure is applied by the signal pressure switching valve 4, the pressure regulating valve 3 operates as a flow control valve in cooperation with the orifice 2, and when the signal pressure is released, the pressure regulating valve 3 Operates as an unloader valve that releases the compression load of the oil pump 1. Note that the solenoid valve 9 in this embodiment can also be a normally open on / off solenoid valve in the sense of maintaining the flow rate control function at the time of failure as in the case of the second embodiment.

  When the configuration of the third embodiment is adopted, the solenoid valve 9 can be a low-pressure operation and simple on / off operation valve than the solenoid valve used as the signal pressure switching valve 4 in the previous embodiment. Although the number increases, the cost of the solenoid valve, which is expensive in comparison with the hydraulically operated valve, can be reduced by lowering the capacity and turning on / off, so the cost and weight of the entire circuit can be reduced. Benefits are gained.

It is a circuit diagram which shows Example 1 of the hydraulic control apparatus of this invention. It is a time chart which shows the hydraulic control operation | movement of a hydraulic control apparatus. 6 is a circuit diagram of a hydraulic control apparatus according to Embodiment 2. FIG. FIG. 6 is a circuit diagram of a hydraulic control apparatus according to a third embodiment.

Explanation of symbols

1 Oil pump 2 Orifice (flow control valve)
3 Pressure regulating valve (Flow control valve)
4 Signal pressure switching valve 5 Hydraulic pressure sensor (output means)
6 Electronic control unit (output means)
7 Accumulator 8 Check valve a Suction side oil passage b Discharge side oil passage c Hydraulic operation circuit d Return oil passage e Signal pressure oil passage

Claims (8)

It is inserted between the discharge side oil passage (b) of the oil pump (1) and the hydraulic operation circuit (c), and consists of an orifice (2) and a pressure regulating valve (3), according to the differential pressure before and after the orifice. A hydraulic pressure for a transmission that includes a flow rate control valve that controls the amount of drain that returns from the upstream oil passage of the orifice to the suction-side oil passage (a) of the oil pump, and that controls the amount of oil flowing through the hydraulic operation circuit by adjusting the drain amount. In the control device,
The signal pressure oil passage (e) for applying the hydraulic pressure downstream of the orifice to the flow control valve is provided with a signal pressure switching valve (4) for controlling the application and release of the signal pressure to the flow control valve. Hydraulic control device for transmission. An orifice (2) interposed between the discharge side oil passage (b) of the oil pump (1) and the hydraulic operation circuit (c), an upstream oil passage of the orifice, and a suction side oil passage ( a) is inserted into the oil passage (d) communicating with the oil passage, and the oil pressure upstream of the orifice and the oil pressure downstream of the orifice are applied oppositely to control the amount of drain returning from the oil passage upstream of the orifice to the oil pump suction side oil passage. A hydraulic control device for a transmission that includes a pressure regulating valve (3) that controls the flow rate of oil flowing through the hydraulic operation circuit by adjusting a drain amount;
A transmission hydraulic control device comprising a signal pressure switching valve (4) for controlling application and release of hydraulic pressure downstream of an orifice to the pressure regulating valve.   The transmission hydraulic control device according to claim 1 or 2, wherein the signal pressure switching valve is configured by a solenoid-operated solenoid valve.   4. The transmission hydraulic control device according to claim 1, wherein the signal pressure switching valve is a normally closed valve.   4. The hydraulic control device for a transmission according to claim 1, wherein the signal pressure switching valve is a normally open valve.   The transmission hydraulic pressure according to any one of claims 1 to 5, wherein the hydraulic pressure operating circuit includes output means (5, 6) for applying a signal pressure to the signal pressure switching valve by increasing the hydraulic pressure of the circuit. Control device.   The said output means consists of a hydraulic pressure sensor (5) and the electronic control apparatus (6) which outputs a solenoid drive signal to a signal pressure switching valve by the signal of this hydraulic pressure sensor. Hydraulic control device for transmission.   The hydraulic operation circuit includes an accumulator (7), and a check valve (8) for preventing back flow of oil is interposed between the accumulator and the orifice. The hydraulic control apparatus for transmission as described.

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