JP2005273880A - Hydraulic oil adjusting device of transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic oil adjusting device for a transmission to adjust the oil level in an oil pan, capable of suppressing the drop of the oil level. <P>SOLUTION: A hydraulic circuit 4000 includes a control valve 4600 which allows the hydraulic oil having passed an oil cooler 4500 to flow out to a reserver when the oil temperature is higher than the predetermined temperature and a bypass valve 4700 which allows the working oil to flow out to an oil pan upon bypassing the oil cooler 4500 and the control valve 4600 when the oil temperature is lower than the predetermined temperature. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a hydraulic fluid adjustment device for a transmission, and more particularly to a hydraulic fluid adjustment device for a transmission that adjusts an oil level in an oil pan.

  Transmissions such as AT (Automatic Transmission) and CVT (Continuously Variable Transmission) are operated by hydraulic pressure of hydraulic oil. The hydraulic oil is stored in the oil pan, sucked out from the oil pan by the oil pump, circulated in the transmission, and then returned to the oil pan. The volume of hydraulic oil decreases as the temperature decreases. Therefore, when the temperature of the hydraulic oil is low, the oil level in the oil pan is lowered as compared with the case where the temperature is high. If the oil level drops, the oil pump may inhale air. On the other hand, when the temperature of the hydraulic oil is high, the volume of the hydraulic oil expands, and the oil level in the oil pan increases. If the oil level rises too much, hydraulic fluid may spill from the transmission case breather. Therefore, it is necessary to adjust the oil level in the oil pan.

  Japanese Patent Laid-Open No. 5-33853 (Patent Document 1) discloses an oil adjusting device capable of controlling oil level fluctuation. The oil adjusting device described in Patent Document 1 is a distribution system that is provided in a part of a cooler circuit and operates so as to distribute oil by branching from the circuit in an oil pan that receives hydraulic oil and an oil cooler. A valve, an oil reservoir connected to the distribution valve, to which hydraulic oil is sent when the distribution valve is operated, a return valve that operates to return the hydraulic oil in the reservoir at a low temperature, and hydraulic oil in response to an increase in oil temperature or oil level. And a control device for controlling the distribution valve so as to be discharged to the oil reservoir.

According to the oil adjusting device described in this publication, the distribution valve that distributes oil by branching from the circulation system cooler circuit having an oil pan and an oil cooler increases the oil temperature or the liquid level under the control of the control device. In response, hydraulic oil is delivered to the oil reservoir, while the return valve operates to return the oil in the reservoir when the temperature is low. Thereby, the oil level in the oil pan can be adjusted.
JP-A-5-33853

  However, in the oil adjusting device described in the above publication, when the hydraulic oil temperature is low, the hydraulic oil in the reservoir is returned to the oil pan. However, when the hydraulic oil temperature is low, the hydraulic oil temperature at the start is particularly high. If the hydraulic oil is supplied to the oil cooler when the oil pressure is low, the oil level in the oil pan may be lowered. Therefore, there is a problem that the oil pump may suck air.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a hydraulic fluid adjustment device for a transmission that can suppress a decrease in the oil level in the oil pan. is there.

  A hydraulic fluid adjustment device for a transmission according to a first invention adjusts hydraulic fluid supplied to the transmission. This hydraulic oil adjusting device is connected to an oil pan in which hydraulic oil is accumulated, a reservoir in which hydraulic oil is accumulated at a position different from the oil pan, an oil cooler that cools hydraulic oil, and an oil cooler. A supply oil passage through which hydraulic oil supplied to the cooler flows, a discharge oil passage connected to the oil cooler and through which hydraulic oil discharged from the oil cooler flows, and a discharge oil passage connected to the discharge oil passage. A control valve that flows out to at least one of the oil pan and the reservoir according to the hydraulic oil temperature, and a supply oil path, and the hydraulic oil in the supply oil path is supplied to the oil cooler and the hydraulic oil according to the hydraulic oil temperature. And a bypass valve that flows out to the oil pan while avoiding the control valve.

  According to the first aspect of the present invention, the control valve connected to the discharge oil passage through which the hydraulic oil discharged from the oil cooler flows causes the hydraulic oil in the discharge oil passage to pass through at least the oil pan and the reservoir according to the hydraulic oil temperature. Let it flow out to either one. For example, when the hydraulic oil temperature is high, the oil is allowed to flow out to the reservoir to suppress an excessive increase in the oil level in the oil pan. When the hydraulic oil temperature is low, the oil is allowed to flow out to the oil pan. The oil level in the oil pan can be suppressed and the oil level can be adjusted. Further, a bypass valve connected to the supply oil passage causes the hydraulic oil in the supply oil passage to flow out to the oil pan, avoiding the oil cooler and the control valve, according to the operating oil temperature. Thereby, when the hydraulic oil temperature is low, the hydraulic oil can be returned to the oil pan by bypassing the oil cooler and the control valve. Therefore, the hydraulic oil can be returned to the oil pan without being supplied to the oil cooler and the reservoir, and a decrease in the oil level can be suppressed. As a result, it is possible to provide a hydraulic fluid adjusting device for a transmission that can suppress a decrease in the oil level in the oil pan.

  The hydraulic fluid adjustment device for a transmission according to the second invention further includes an orifice provided in the supply oil passage between the oil cooler and the bypass valve in addition to the configuration of the first invention.

  According to the second invention, an orifice is provided in the supply oil passage between the oil cooler and the bypass valve. Thereby, the hydraulic fluid supplied to the oil cooler can be suppressed, and more hydraulic fluid can be returned from the bypass valve to the oil pan.

  In the hydraulic fluid adjusting device for a transmission according to the third aspect, in addition to the configuration of the first or second aspect, the bypass valve is provided in the supply oil passage when the hydraulic fluid temperature is lower than a predetermined temperature. Operating means for operating the oil so as to flow out to the oil pan while avoiding the oil cooler and the control valve.

  According to the third invention, the bypass valve causes the hydraulic oil in the supply oil passage to flow out to the oil pan while avoiding the oil cooler and the control valve when the hydraulic oil temperature is lower than a predetermined temperature. Actuating means are provided for actuating. As a result, the bypass valve can be operated without providing a separate solenoid valve for controlling the bypass valve.

  In the hydraulic fluid adjusting device for a transmission according to the fourth aspect of the invention, in addition to the configuration of the first or second aspect, the control valve is provided in the exhaust oil passage when the hydraulic fluid temperature is higher than a predetermined temperature. Actuating means for actuating the hydraulic oil to flow into the reservoir.

  According to the fourth invention, the control valve is provided with an operating means for operating the hydraulic oil in the discharge oil passage to flow out to the reservoir when the hydraulic oil temperature is higher than a predetermined temperature. It has been. As a result, the control valve can be operated without providing a separate solenoid valve for controlling the control valve.

  In the hydraulic fluid adjusting device for a transmission according to the fifth invention, in addition to the configuration of the third or fourth invention, the operating means is a shape memory spring.

  According to the fifth invention, a shape memory spring is used as the actuating means. Thereby, a bypass valve and a control valve can be operated according to hydraulic oil temperature, without performing electrical control.

  In the hydraulic fluid adjusting device for a transmission according to the sixth aspect of the invention, in addition to the configuration of the third or fourth aspect of the invention, the operating means is a bimetal.

  According to 6th invention, the bimetal is used for the operation means. Thereby, a bypass valve and a control valve can be operated according to hydraulic oil temperature, without performing electrical control.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  With reference to FIG. 1, a vehicle equipped with a hydraulic fluid adjustment device for a transmission according to the present embodiment will be described. This vehicle is an FF (Front engine Front drive) vehicle. The vehicle equipped with the automatic transmission control device according to the present embodiment may be a vehicle other than FF.

  The vehicle includes an engine 1000, a transmission 2000, a planetary gear unit 3000 that forms part of the transmission 2000, a hydraulic circuit 4000 that forms part of the transmission 2000, a differential gear 5000, a drive shaft 6000, and front wheels. 7000 and ECU (Electronic Control Unit) 8000.

  Engine 1000 is an internal combustion engine that burns a mixture of fuel and air injected from an injector (not shown) in a combustion chamber of a cylinder. The piston in the cylinder is pushed down by the combustion, and the crankshaft is rotated. An external combustion engine may be used instead of the internal combustion engine. Further, a rotating electrical machine or the like may be used instead of the engine 1000.

  Transmission 2000 changes the rotational speed of the crankshaft to a desired rotational speed by forming a desired gear stage. The output gear of transmission 2000 is meshed with differential gear 5000. Instead of planetary gear unit 3000, a pair of pulleys and a belt may be used, and transmission 2000 may be configured as a CVT. Further, the transmission 2000 may be configured as an automatic MT (Manual Transmission). The hydraulic circuit 4000 will be described in detail later.

  A drive shaft 6000 is connected to the differential gear 5000 by spline fitting or the like. Power is transmitted to the left and right front wheels 7000 via the drive shaft 6000.

  The ECU 8000 displays signals sent from a vehicle speed sensor (not shown), a position switch (not shown), an accelerator opening sensor (not shown), etc., a map and a program stored in a ROM (Read Only Memory). Based on this, the devices are controlled so that the vehicle is in a desired running state.

  The hydraulic circuit 4000 will be described with reference to FIG. Hydraulic circuit 4000 includes a valve body 4100, a strainer 4200, an oil pump 4300, and an oil cooler 4500. The valve body 4100 is provided in an oil pan 2004 attached below the transmission case 2002. The hydraulic oil stored in the oil pan 2004 is supplied to each friction engagement element of the planetary gear unit 3000 via the valve body 4100.

  The strainer 4200 is attached below the valve body 4100. The hydraulic oil stored in the oil pan 2004 is supplied from the strainer 4200 into the valve body 4100. The supplied hydraulic oil circulates in the hydraulic circuit 4000 via the oil pump 4300 and is returned to the oil pan 2004.

  Oil pump 4300 is connected to a crankshaft (not shown) of engine 1000. The oil pump 4300 is driven by the rotation of the crankshaft. When the oil pump 4300 is driven, hydraulic pressure of the hydraulic oil is generated.

  The reservoir 4400 is provided in the upper part of the transmission case 2002 so as to be positioned above the oil level in the oil pan 2004 (oil level of the working oil). Oil cooler 4500 is provided outside transmission case 2002. The hydraulic oil circulating in the hydraulic circuit 4000 is supplied from the valve body 4100 to the oil cooler 4500 through the supply oil passage 4502. The hydraulic oil supplied to the oil cooler 4500 is heat-exchanged with cooling water or air of the engine 1000 and cooled. The cooled hydraulic oil is returned from the oil cooler 4500 to the valve body 4100 via the discharge oil passage 4504. The hydraulic oil returned from the oil cooler 4500 to the valve body 4100 is caused to flow out to the reservoir 4400 by the control valve 4600 when the temperature of the hydraulic oil (hydraulic oil temperature) is higher than a predetermined temperature. When the hydraulic oil temperature is lower than a predetermined temperature, the hydraulic oil is returned to the vicinity of the strainer 4200 inside the oil pan 2004.

  The hydraulic circuit 4000 will be further described with reference to FIG. Control valve 4600 includes a drain port 4602, a first spring 4604, and a second spring 4606. The drain port 4602 communicates with the oil pan 2004. The hydraulic oil flows out from the drain port 4602 to the oil pan 2004.

  The first spring 4604 is a shape memory spring whose elastic coefficient changes according to the hydraulic oil temperature. The control valve 4600 is actuated by the balance of the urging forces of the first spring 4604 and the second spring 4606. When the hydraulic oil temperature is higher than a predetermined temperature, the urging force of the first spring 4604 exceeds the urging force of the second spring 4606, and the control valve 4600 is in the left side state in FIG. In this state, the drain oil passage 4504 and the reservoir 4400 are communicated. Accordingly, the hydraulic oil cooled by the oil cooler 4500 is not discharged from the oil cooler 4500 to the oil pan 2004 and is supplied to the reservoir 4400.

  When the hydraulic oil temperature is lower than a predetermined temperature, the urging force of the second spring 4606 exceeds the urging force of the first spring 4604, and the control valve 4600 is in the right state in FIG. In this state, the drain oil passage 4504 is disconnected from the reservoir 4400 and communicated with the drain port 4602. As a result, the hydraulic oil cooled by the oil cooler 4500 is returned to the oil pan 2004 without being supplied to the reservoir 4400.

  A bypass valve 4700 is connected to the supply oil passage 4502. Bypass valve 4700 includes a spring 4702. The spring 4702 is a shape memory spring whose elastic coefficient changes according to the hydraulic oil temperature. When the hydraulic oil temperature is lower than a predetermined temperature, the load (biasing force) of the spring 4702 becomes low, so the hydraulic pressure of the hydraulic oil supplied to the supply oil passage 4502 from a lockup relay valve (not shown). As a result, the bypass valve 4700 is opened. When the bypass valve 4700 is opened, the hydraulic oil in the supply oil passage 4502 is discharged from the bypass valve 4700 directly in the oil pan 2004 to the vicinity of the strainer 4200.

  When the hydraulic oil temperature is higher than a predetermined temperature, the biasing force of the spring 4702 is increased. In this case, hydraulic oil is supplied to the oil cooler 4500 at a hydraulic pressure determined by the urging force of the spring 4702.

  An orifice 4800 is provided in the supply oil passage 4502 between the oil cooler 4500 and the bypass valve 4700. The orifice 4800 increases the resistance of the supply oil passage 4502, so that when the bypass valve 4700 is opened, the flow rate of hydraulic oil supplied to the oil cooler 4500 decreases below a predetermined temperature. The flow rate of the hydraulic oil discharged from the bypass valve 4700 to the oil pan 2004 increases.

  The operation of the hydraulic oil adjustment device according to the present embodiment that is expressed based on the above configuration will be described.

  When the hydraulic oil temperature is lower than a predetermined temperature, the hydraulic oil supplied from the lock-up relay valve to the supply oil passage 4502 bypasses the oil cooler 4500 and the control valve 4600, and passes from the bypass valve 4700 to the oil pan 2004. To be discharged. As a result, when the hydraulic oil temperature is low, the hydraulic oil is not supplied to the oil cooler 4500, and the hydraulic oil is discharged in the vicinity of the strainer 4200 in the oil pan 2004. A decrease in oil level can be suppressed, the amount of hydraulic oil can be reduced, and mass and cost can be reduced. Further, since the hydraulic oil is not supplied to the oil cooler 4500, the hydraulic oil can be quickly raised to an appropriate temperature.

  When the hydraulic oil temperature is higher than a predetermined temperature, the bypass valve 4700 is closed, and the hydraulic oil in the supply oil passage 4502 is supplied to the oil cooler 4500 and cooled. If the temperature of the hydraulic oil cooled by the oil cooler 4500 is equal to or higher than a predetermined temperature, the hydraulic oil is supplied to the reservoir 4400 by the control valve 4600. Accordingly, since the hydraulic oil is held in the reservoir 4400, the oil level in the oil pan 2004 does not become higher than necessary. Therefore, it is possible to suppress the hydraulic oil from being blown from a breather (not shown) provided on the upper part of the transmission case 2002, and it is not necessary to deepen the oil pan 2004. Therefore, the transmission 2000 can be downsized.

  In the present embodiment, poppet valves are used for control valve 4600 and bypass valve 4700, but spool valves may be used instead of poppet valves. In the present embodiment, the first spring 4604 and the spring 4702 have been described as shape memory springs, but bimetals may be used instead of the shape memory springs.

  As described above, in the hydraulic oil adjustment device according to the present embodiment, when the hydraulic oil temperature is higher than the predetermined temperature, the control valve that causes the hydraulic oil to flow into the reservoir and the hydraulic oil temperature are predetermined. When it is lower than the temperature, it includes a bypass valve that bypasses the oil cooler and the control valve and causes the hydraulic oil to flow out to the oil cooler. Thereby, when hydraulic oil temperature is lower than predetermined temperature, it can suppress that hydraulic oil flows out into an oil pan and an oil level falls. Further, when the temperature of the hydraulic oil cooled by the oil cooler is higher than a predetermined temperature, the hydraulic oil can be prevented from flowing out into the reservoir and the oil level rising more than necessary.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a control block diagram which shows the vehicle carrying the hydraulic-oil adjustment apparatus which concerns on embodiment of this invention. It is sectional drawing of a transmission. It is a figure which shows a hydraulic circuit.

Explanation of symbols

  2000 Transmission, 4000 Hydraulic circuit, 4100 Valve body, 4200 Strainer, 4300 Oil pump, 4400 Reservoir, 4500 Oil cooler, 4600 Control valve, 4602 Drain port, 4604 1st spring, 4606 2nd spring, 4700 Bypass valve, 4702 Spring, 4800 orifice, 4502 supply oil passage, 4504 discharge oil passage.

Claims (6)

A hydraulic fluid adjusting device for a transmission,
An oil pan in which hydraulic oil accumulates;
A reservoir in which hydraulic oil is accumulated at a position different from the oil pan;
An oil cooler for cooling the hydraulic oil;
A supply oil path connected to the oil cooler and through which hydraulic oil supplied to the oil cooler flows;
A discharge oil passage connected to the oil cooler, through which hydraulic oil discharged from the oil cooler flows;
A control valve connected to the discharge oil passage, and causing the hydraulic oil in the discharge oil passage to flow out to at least one of the oil pan and the reservoir in accordance with a hydraulic oil temperature;
A bypass valve connected to the supply oil passage and including a bypass valve that causes the hydraulic oil in the supply oil passage to flow out to the oil pan while avoiding the oil cooler and the control valve according to the hydraulic oil temperature. Hydraulic oil adjustment device.   2. The hydraulic fluid adjustment device for a transmission according to claim 1, wherein the hydraulic oil adjustment device further includes an orifice provided in the supply oil passage between the oil cooler and the bypass valve.   The bypass valve operates to cause the hydraulic oil in the supply oil passage to flow out to the oil pan while avoiding the oil cooler and the control valve when the hydraulic oil temperature is lower than a predetermined temperature. The hydraulic fluid adjusting device for a transmission according to claim 1, further comprising an operating means for operating the transmission.   The control valve includes an operating means for operating the hydraulic oil in the exhaust oil passage to flow out to the reservoir when the hydraulic oil temperature is higher than a predetermined temperature. 3. The hydraulic fluid adjusting device for a transmission according to 2.   The hydraulic fluid adjusting device for a transmission according to claim 3 or 4, wherein the operating means is a shape memory spring.   The operating oil adjusting device for a transmission according to claim 3 or 4, wherein the operating means is a bimetal.

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