JP2010071351A - Hydraulic system and method of controlling the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic system which reduces loss of an oil pump and simultaneously is capable of supplying a part of working fluid as lubricating oil at the time of low rotation of an engine. <P>SOLUTION: The hydraulic system 1 is provided with the oil pump 11 which is driven by rotation of an engine, at least one actuator 14 which is actuated through oil supplied by the oil pump 11 and the first control valve 13 which is disposed in front of the actuator 14 and controls supply of oil to the actuator 14. The hydraulic system 1 is also provided with a relief valve 12 which is disposed in the first oil passage between the oil pump 11 and the first control valve 13 and makes oil from the first oil passage flow out so as to keep hydraulic pressure to the actuator 14 at a predetermined hydraulic pressure or below, a tank 15 which stores oil having flowed out of the relief valve 12, a gear change element 17 in a transmission and the second control valve 16 which is disposed in the second oil passage supplying oil from the tank 15 to the gear change element 17 and controls supply of oil stored in the tank 15 to the gear change element 17. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a hydraulic system used for supplying hydraulic oil and lubricating oil in an automobile, for example, a hydraulic system used for an automated manual transmission.

In an automobile transmission, an actuator that performs a shift operation and a clutch operation is operated by hydraulic oil supplied from, for example, an oil pump that is driven by engine rotation. In such a hydraulic oil passage, in order to maintain the discharge pressure from the oil pump at a predetermined pressure, a relief valve is provided inside the shaft that drives the oil pump, and the hydraulic oil that has flowed out of the relief valve is transferred to the transmission element. 2. Description of the Related Art An automobile transmission that supplies oil as lubricating oil is known (see Patent Document 1).
JP 2002-21987

  The following analysis is given from the perspective of the present invention.

  When an oil pump is driven by driving an engine, an oil pump that supplies hydraulic oil to an actuator is usually designed to be driven even when the engine is running at a low speed. Therefore, when the engine rotates at a high speed, a discharge pressure more than necessary is generated. In such a state, the power of the engine cannot be used efficiently, which causes a reduction in fuel consumption.

  In the automobile transmission described in Patent Document 1, the discharge pressure from the oil pump is maintained at a predetermined pressure, but when the engine has a low discharge pressure of the oil pump, the hydraulic oil is used as the lubricating oil from the relief valve when the engine rotates at a low speed. It cannot be supplied.

  An object of the present invention is to provide a hydraulic system capable of reducing a loss of an oil pump and supplying a part of hydraulic oil as lubricating oil when the engine is running at a low speed.

  According to the first aspect of the present invention, an oil pump that is driven by rotation of an engine, at least one actuator that is operated by oil supplied by the oil pump, and an actuator that is disposed in front of the actuator to supply oil to the actuator. A first control valve to be controlled, and a relief valve which is disposed in a first oil passage between the oil pump and the first control valve, and causes the oil to flow out from the first oil passage so that the hydraulic pressure to the actuator is equal to or lower than a predetermined hydraulic pressure And a tank for storing oil flowing out from the relief valve, at least one transmission element in the transmission, and a second oil passage for supplying oil from the tank to the transmission element, to the transmission element for the oil stored in the tank And a second control valve for controlling the supply of the hydraulic system.

  According to a preferred form of the first aspect, the second control valve opens when the engine is driven and closes when the engine is stopped.

  According to a preferred embodiment of the first aspect, the hydraulic system further includes a casing that houses at least one transmission element. The at least one transmission element is lubricated by scooping up the oil when it accumulates at the bottom of the casing.

  According to the preferred form of the first aspect, the oil stored in the tank is also supplied to the clutch as lubricating oil.

  According to a preferred embodiment of the first aspect, the hydraulic system further includes a third oil passage that allows oil to escape to at least one of the transmission element and the clutch so that the storage amount of the tank does not exceed a predetermined amount.

  According to a preferred mode of the first aspect, at least one actuator performs at least one of a shift operation and a clutch operation.

  According to the second aspect of the present invention, the step of driving the oil pump by the rotation of the engine and supplying the oil as hydraulic oil to at least one actuator, the discharge pressure of the oil pump exceeds at least the pressure required for the operation of the actuator Control of the hydraulic system including a step of causing the oil to flow out from the oil passage to the actuator and storing it in the tank, and a step of supplying the oil stored in the tank to the at least one transmission element as lubricating oil when the engine is driven Provide a method.

  According to a preferred embodiment of the second aspect, at least when oil does not flow out from the oil passage to the tank, the oil stored in the tank is supplied to at least one transmission element, and at least one transmission element The oil accumulated in the casing is scraped by the transmission element to lubricate at least one transmission element.

  According to the preferred embodiment of the second aspect, the amount of oil stored in the tank is increased when the engine speed is equal to or higher than a predetermined speed.

  According to the preferred form of the second aspect, when the amount of oil flowing into the tank is larger than the amount of oil flowing out of the tank, the tank oil is removed from the transmission element and the clutch so that the amount of storage in the tank does not exceed a predetermined amount. Supply to at least one.

  The present invention has at least one of the following effects.

  According to the present invention, when the engine speed is high, the oil pump pressure exceeding the pressure necessary for the operation of the actuator is used as oil storage or lubricating oil supply, so that energy can be used efficiently. it can.

  According to the present invention, the transmission element can be lubricated using the oil stored in the tank even when the engine speed is low so that the oil does not flow out from the relief valve. Further, when the engine speed is low, the speed change element can also be lubricated by scooping up oil accumulated in the casing of the speed change element.

  An embodiment of the hydraulic system of the present invention will be described. In FIG. 1, the oil-path conceptual diagram of the hydraulic system which concerns on 1st Embodiment of this invention is shown. FIG. 2 shows a schematic diagram of the hydraulic system according to the first embodiment of the present invention. FIG. 3 shows a schematic partial cross-sectional view of a tank portion in the hydraulic system of the present invention. The hydraulic system 10 of the present invention includes an oil pump 11 that is driven by the rotation of the engine 20, at least one actuator 14 that operates predetermined elements using the oil 25 supplied from the oil pump 11 as hydraulic oil, and a front of the actuator 14. The first control valve 13 that controls the supply to the actuator 14 and the first oil passage between the oil pump 11 and the first control valve 13, and the oil pressure in the first oil passage is equal to or lower than a predetermined oil pressure The relief valve 12, the tank 15 for storing the oil 25 flowing out from the relief valve 12, the at least one transmission element 17 in the transmission, and the second oil passage 23 for supplying the oil 25 from the tank 15 to the transmission element 17. A second control valve 16 disposed to control the supply of oil stored in the tank 15 to the speed change element 17, and an actuator. Oil 25 recovered from 14 and transmission elements 17 comprises an oil pan 18a which stores as an oil that the oil pump 11 inhales, the.

  The oil pump 11 supplies oil 25 to the actuator 14 as hydraulic oil, and may supply oil 25 to the clutch 19 as lubricating oil.

  As the actuator 14, for example, an actuator 14 a that performs a shift operation, an actuator 14 b that performs a clutch operation, and the like can be applied.

  The relief valve 12 preferably discharges the oil 25 to the tank 15 at least when a hydraulic pressure higher than that required for the operation of the actuator 14 is generated. As the relief valve 12, a suitable type of valve can be used as appropriate. When there are a plurality of actuators 14 to which hydraulic oil is supplied from the oil pump 11, the relief valve 12 is preferably arranged for each actuator 14.

  The second control valve 16 may be a valve that opens when the engine 20 is driven and closes when the engine 20 is stopped, or may be a valve that can adjust the valve opening according to the rotational speed of the engine 20.

  Even if there is more oil flowing into the tank 15 than the oil 25 flowing out from the tank 15, the tank 15 may be provided with a third oil passage 22 for releasing the oil so that the amount of oil stored in the tank 15 becomes a predetermined amount. Good. The third oil path 22 may be, for example, an oil path that supplies the oil 25 to the transmission element 17 as lubricating oil, an oil path that returns to the oil pan 18a, or a plurality of locations, for example, the transmission element 17 and the clutch. An oil passage for supplying oil 25 to 19 may be used. Further, when the third oil passage is not formed in the tank 15, the tank 15 may be configured to overflow the oil 25 to the oil pan 18 a. Or the tank 15 can also be made into the form which does not overflow in consideration of the whole oil amount and oil distribution.

  The transmission element 17 is accommodated in a casing 18, and the bottom of the casing 18 is an oil pan 18a. The oil pan 18a stores the oil 25 supplied from the tank 15 to the speed change element 17 when the rotational speed of the engine 20 is low (for example, when the oil 25 does not flow out from the relief valve 12 to the tank 15). It is preferable. Thereby, the oil accumulated in the casing by the rotation of the speed change element 17 can be lifted and lubricated, and the speed change element 17 can be lubricated even when the oil is no longer supplied from the tank 15.

  The speed change element 17 is at least one element included in the speed change mechanism. Examples of the speed change element 17 include a gear, a bearing, a synchronization device, and an oil seal.

  Next, the control method of the hydraulic system of the present invention will be described. First, when the engine 20 is started, the oil pump 11 is also driven, and the oil 25 is supplied to the actuator 14 as hydraulic oil. When the rotational speed of the engine 20 is low, the relief valve 12 is not opened, and all the oil 25 discharged from the oil pump 11 is supplied to the actuator 14. When the rotational speed of the engine 20 increases and the hydraulic pressure exceeds a predetermined hydraulic pressure (for example, when the hydraulic pressure exceeds the pressure required for the operation of the actuator 14), the relief valve 12 is opened and the oil 25 is supplied to the relief valve. 12 and flows into the tank 15 through the fourth oil passage 21 from the relief valve 12.

  For example, the second control valve 16 arranged at the outlet of the tank 15 is opened when the engine 20 is driven, and is closed when the engine 20 is stopped. When the second control valve 16 is opened, the oil 25 stored in the tank 15 is supplied as the lubricating oil to the transmission element 17 through the second oil passage 23. For example, in the embodiment shown in FIG. 3, oil 25 flows down or drops from the supply hole 23a formed in the second oil passage 23 to the gear 17a. Thus, even when the engine 20 has a low rotation speed and no oil 25 flows out from the relief valve 12, the oil 25 stored in the tank 15 at the time of high engine 20 rotation is supplied to the transmission element 17 as lubricating oil. Can do. By supplying the lubricating oil from the tank 15, the vehicle fuel efficiency can be improved as compared to the lubricating oil supply by scraping.

  The oil supplied from the tank 15 to the speed change element 17 is accumulated in the oil pan 18a because the oil pump 11 discharges less when the engine 20 is running at a low speed. At this time, even when the oil from the tank 15 is not supplied, the speed change element 17 is lubricated by scooping up oil accumulated in the bottom of the casing by the speed change element 17.

  The amount of oil flowing into the tank 15 and the amount of oil flowing out of the tank 15 are preferably adjusted so that the amount of oil stored in the tank 15 increases when the engine 20 rotates at a high speed. Further, when the storage amount of the tank 15 exceeds a predetermined amount or when the tank 15 is full, the oil flowing into the tank 15 or the oil overflowing from the tank 15 is changed to the transmission element 17, the clutch 19, the oil pan 18a, or a plurality of elements. It is preferable to supply to.

  According to the present invention, oil flowing out from the relief valve 12 is stored in the tank 15 and used for lubricating the speed change element 17 when the engine 20 is at a high speed, and stored in the tank 15 when the engine 20 is at a low speed. Oil can be supplied to the transmission element 17 as lubricating oil and re-lubricated in the transmission element 17.

  Next, a hydraulic system according to a second embodiment of the present invention will be described. FIG. 4 is a conceptual diagram of an oil passage of a hydraulic system according to the second embodiment of the present invention. In the first embodiment, the oil flowing out from the tank 15 through the second control valve is supplied to the speed change element. However, in the hydraulic system 30 according to the second embodiment, the oil from the tank 15 is further supplied to the clutch 19. Is also supplied as lubricating oil. Other forms are the same as in the first embodiment.

  The hydraulic system and the control method thereof according to the present invention have been described based on the above embodiment, but are not limited to the above embodiment, and are within the scope of the present invention and based on the basic technical idea of the present invention. It goes without saying that various modifications, changes, and improvements can be included in the embodiment. Further, various combinations, substitutions, or selections of various disclosed elements are possible within the scope of the claims of the present invention.

  Further problems, objects, and developments of the present invention will become apparent from the entire disclosure of the present invention including the claims.

  The hydraulic system and the control method thereof according to the present invention can be applied to, for example, an automobile transmission, and can be preferably applied to an automated manual transmission.

The conceptual diagram of the oil path of the hydraulic system which concerns on 1st Embodiment of this invention. 1 is a schematic diagram of a hydraulic system according to a first embodiment of the present invention. FIG. 3 is a schematic partial cross-sectional view of a tank portion in the hydraulic system of the present invention. The conceptual diagram of the oil path of the hydraulic system which concerns on 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,30 Hydraulic system 11 Oil pump 12 Relief valve 13 1st control valve 14 Actuator 14a Shift operation actuator 14b Clutch operation actuator 15 Tank 16 2nd control valve 17 Shift element 17a Gear 18 Casing 18a Oil pan 19 Clutch 20 Engine 21 Fourth oil passage 22 Third oil passage 23 Second oil passage 23a Supply hole 25 Oil

Claims (10)

An oil pump driven by the rotation of the engine;
At least one actuator operated by oil supplied by the oil pump;
A first control valve disposed in front of the actuator to control the supply of oil to the actuator;
A relief valve that is disposed in a first oil passage between the oil pump and the first control valve, and causes the oil to flow out of the first oil passage so that the oil pressure to the actuator is equal to or lower than a predetermined oil pressure;
A tank for storing oil flowing out from the relief valve;
At least one transmission element in the transmission;
And a second control valve disposed in a second oil passage for supplying oil from the tank to the transmission element and controlling supply of oil stored in the tank to the transmission element. system.   The hydraulic system according to claim 1, wherein the second control valve opens when the engine is driven and closes when the engine is stopped. A casing that houses the at least one transmission element;
3. The hydraulic system according to claim 1, wherein the at least one transmission element is lubricated by scooping up the oil when the oil is accumulated in the bottom of the casing.   The hydraulic system according to any one of claims 1 to 3, wherein the oil stored in the tank is also supplied to the clutch as lubricating oil.   5. The third oil passage according to claim 1, further comprising a third oil passage for allowing oil to escape to at least one of the transmission element and the clutch so that a storage amount of the tank does not exceed a predetermined amount. Hydraulic system.   The hydraulic system according to any one of claims 1 to 5, wherein the at least one actuator performs at least one of a shift operation and a clutch operation. Driving the oil pump by rotation of the engine and supplying the oil as hydraulic fluid to at least one actuator;
When the discharge pressure of the oil pump exceeds at least the pressure necessary for the operation of the actuator, the step of storing oil in the tank by letting the oil flow out from the oil passage to the actuator, and storing in the tank during engine driving A method for controlling a hydraulic system, comprising the step of supplying oil as lubricating oil to at least one transmission element.   At least when oil does not flow out from the oil passage to the tank, the oil stored in the tank is supplied to the at least one transmission element, and the oil collected in the casing of the at least one transmission element The hydraulic system control method according to claim 7, wherein the at least one speed change element is lubricated by lifting the speed change element with the speed change element.   The hydraulic system control method according to claim 7 or 8, wherein when the engine speed is equal to or higher than a predetermined speed, the amount of oil stored in the tank is increased.   When the amount of oil flowing into the tank is greater than the amount of oil flowing out of the tank, the tank oil is supplied to at least one of the transmission element and the clutch so that the amount of storage in the tank does not exceed a predetermined amount. The method for controlling a hydraulic system according to any one of claims 7 to 9.

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