JP2009144876A - Lubricating oil control device for transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricating oil control device for a transmission promoting the oil temperature rise of the transmission when warming up an engine. <P>SOLUTION: This lubricating oil control device is provided with: a reflux circuit 4e returning surplus oil discharged from a C/V unit (hydraulic control valve unit) 6 to an oil pump 2; and means for suppressing a reduction in oil temperature when warming up the engine (a bypass circuit 8 and a controller 11), which, when engine water temperature is lower than a predetermined value α, restrict the amount of lubricating oil led to flow from the C/V unit 6 into a heating circuit 9 and a cooling circuit 10, and increase the flow rate of the reflux circuit 4e. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention belongs to the technical field of a lubricating oil control device for keeping lubricating oil for a transmission at an appropriate temperature.

In Patent Document 1, in order to keep the oil temperature of the transmission lubricating oil at an appropriate temperature, when the oil temperature in the transmission casing is lower than the lower limit value of the appropriate temperature range, the lubricating oil is supplied to the transmission via the oil warmer. A technique for supplying lubricating oil to a lubricated part via an oil cooler when the oil temperature is higher than the upper limit value of the appropriate temperature range is disclosed.
JP 2000-234669 A

  The oil warmer generally has a configuration in which the lubricating oil is heated by heat exchange with the engine cooling water. Therefore, in the technique described in Patent Document 1, an oil warmer is used before engine warm-up when the temperature of the engine cooling water is low. There was a problem that the oil temperature could not be raised due to.

  The present invention has been made paying attention to the above problem, and an object of the present invention is to provide a lubricating oil control device for a transmission that can promote an increase in the oil temperature of the transmission when the engine is warmed up. It is in.

  In order to achieve the above-described object, in the lubricating oil control device for a transmission according to the present invention, when the excess water discharged from the pressure adjusting means is returned to the oil pump, and the engine water temperature is equal to or lower than a predetermined temperature, Engine warm-up oil temperature lowering suppression means is provided for restricting the amount of lubricating oil flowing from the lubricant generating means to the heating circuit and cooling circuit and increasing the flow rate of the reflux circuit.

  In the present invention, when the engine water temperature is low before the engine warms up and the oil temperature rise by the heater cannot be expected, the amount of lubricating oil supplied to the lubricated part via the heating circuit and the cooling circuit is reduced. Limit and increase the flow rate in the reflux circuit. That is, by reducing the amount of oil sent to the outside of the transmission casing and increasing the amount of oil circulating inside the transmission casing, it is possible to promote an increase in the oil temperature of the transmission when the engine is warmed up.

  Hereinafter, the best mode for carrying out the present invention will be described based on the first embodiment.

FIG. 1 is a block diagram illustrating a configuration of a transmission lubrication control device according to a first embodiment.
An oil pump 2 and an automatic transmission (hereinafter referred to as “AT”) 3 are arranged in this order on the output side of the engine 1. An oil pan 5 for storing oil is provided at the bottom of the casing 4 of the AT 3.

  The oil pump 2 is driven according to engine rotation, and sucks oil stored in the oil pan 5 from a strainer (filter) 5a disposed in the oil pan 5 to the suction port 2a via the suction circuit 4a. After pressurization by means of, discharge from the discharge port 2b. As the oil pump 2, for example, an internal gear pump is used.

  The oil pump 2 supplies oil discharged from the discharge port 2b to a hydraulic control valve unit (hereinafter referred to as C / V unit) 6 provided in the casing 4 via the discharge circuit 4b.

  The C / V unit 6 generates a line pressure from the discharge pressure of the oil pump 2, generates hydraulic oil that supplies the line pressure to each element using a plurality of valves and solenoids, and supplies the hydraulic oil to each element. Here, since the configuration of the C / V unit is a well-known technique, the description thereof is omitted.

  Further, the C / V unit 6 reduces the excess of the line pressure to generate lubricating oil for lubricating the lubricated portion of the AT 3, and the first lubricating circuit 4 c that extends the lubricating oil to the outside of the casing 4. To the switching valve (route switching means) 7 (lubricating oil generating means). The excess line pressure generated when the C / V unit 6 generates lubricating oil is returned to the suction port 2a of the oil pump 2 through the reflux circuit 4e.

  The switching valve 7 switches the connection destination of the first lubrication circuit 4c to any of the bypass circuit 8, the heating circuit 9, and the cooling circuit 10. As the switching valve 7, any linear solenoid valve or the like can be used as long as it can selectively switch the communication state with any one of the three output ports with respect to one input port. .

  The bypass circuit 8 is provided with an orifice (flow rate limiting means) 8a in the middle of the circuit. The inner diameter of the orifice 8a is set so that the minimum amount of lubricating oil can be supplied to the lubricated portion of the AT3.

The heating circuit 9 is provided with an oil warmer (heater) 9a in the middle of the circuit. The oil warmer 9a heats the lubricating oil by heat exchange with the engine coolant.
The cooling circuit 10 is provided with an oil cooler (heat radiator) 10 in the middle of the circuit. The oil cooler 10a cools the lubricating oil by heat exchange with the atmosphere.

  The bypass circuit 8, the heating circuit 9, and the cooling circuit 10 are connected to the second lubricating circuit 4d, respectively. The second lubricating circuit 4d extends to the inside of the casing 4 and communicates with an axial oil passage (not shown) of the AT 3 and the like. Lubricating oil supplied to the shaft center oil passage or the like is sent to the lubricated part and returns to the oil pan 5 by its own weight.

The controller (path switching control means) 11 controls the switching valve 7 according to the engine water temperature and the oil temperature in the casing 4. The controller 11 bypasses the connection destination of the first lubricating circuit 4 c based on the engine water temperature from the engine water temperature sensor 12 provided in the engine 1 and the oil temperature from the oil temperature sensor 13 provided in the oil pan 5. Lubrication control processing for switching to one of the circuit 8, the heating circuit 9, or the cooling circuit 10 is executed.
In the first embodiment, the controller 11 and the bypass circuit 8 constitute an engine warm-up oil temperature decrease suppressing means.

  In the first embodiment, a part of the first lubricating circuit 4 c, a part of the second lubricating circuit 4 d, the switching valve 7, the bypass circuit 8, the heating circuit 9, and the cooling circuit 10 are connected to the casing 4. Although arranged outside, other components are arranged inside the casing 4. The arrangement position of the controller 11 is arbitrary, and may be arranged inside the C / V unit 6, for example.

[Lubrication control processing]
FIG. 2 is a flowchart showing the flow of the lubrication control process of the first embodiment, and each step will be described below. This control process is repeatedly executed at a predetermined calculation cycle from when the ignition key switch is turned on until it is turned off.

  In step S1, the engine water temperature from the engine water temperature sensor 12 is input, and the process proceeds to step S2.

  In step S2, the oil temperature from the oil temperature sensor 13 is input, and the process proceeds to step S3.

  In step S3, whether or not the engine water temperature is low is determined based on whether or not the engine water temperature input in step S1 is equal to or lower than a predetermined value α. If YES, the process moves to step S8, and if NO, the process moves to step S4.

  In step S4, whether or not the oil temperature is low is determined based on whether or not the oil temperature input in step S2 is less than a predetermined value β. If YES, the process proceeds to step S6. If NO, the process proceeds to step S5. Here, the predetermined value β is the minimum value in the appropriate temperature range of the oil temperature.

  In step S5, whether or not the oil temperature is high is determined by whether or not the oil temperature input in step S2 exceeds a predetermined value γ. If YES, the process proceeds to step S7. If NO, the process proceeds to step S6. Here, the predetermined value γ is the maximum value in the appropriate temperature range of the oil temperature.

  In step S6, a command to connect the first lubricating circuit 4c to the heating circuit 9 is output to the switching valve 7, and the process proceeds to return.

  In step S7, a command to connect the first lubricating circuit 4c to the cooling circuit 10 is output to the switching valve 7, and the process proceeds to return.

  In step S8, a command to connect the first lubricating circuit 4c to the bypass circuit 8 is output to the switching valve 7, and the process proceeds to return.

Next, the operation will be described.
[Heating capacity of oil warmer before engine warm-up]
In vehicles equipped with automatic transmissions, not limited to stepped or continuously variable, the lubricating oil in the transmission is difficult to increase due to heat dissipation from the oil pan and cooling by the oil cooler when cold. There is a concern. For this reason, a measure for warming the lubricating oil as quickly as possible is required by adding an oil warmer or the like. Further, when the oil temperature is high, it is necessary to supply sufficient cooled oil to ensure the transmission function and durability.

  However, since the engine water temperature is low before the engine warms up, the oil warmer that heats the lubricating oil by exchanging heat with the engine water temperature cannot sufficiently heat the lubricating oil. Therefore, when the lubricating oil is returned into the transmission via the oil warmer, the lubricating oil is sent to the outside of the transmission casing and then returned to the oil pan, so that the temperature of the lubricating oil is lowered. .

[Oil warming action before engine warm-up]
On the other hand, in the lubricating oil control device for a transmission according to the first embodiment, when the engine water temperature is low before the engine warms up and an increase in the oil temperature by the oil warmer 9a cannot be expected, that is, the engine water temperature is a predetermined value α or less. In this case, in the flowchart of FIG. 2, the flow proceeds from step S 1 → step S 2 → step S 3 → step S 8, and the lubricating oil is supplied to the lubricated part via the bypass circuit 8.

At this time, surplus oil returned from the C / V unit 6 to the suction port 2a of the oil pump 2 through the recirculation circuit 4e is increased by the orifice 8a of the bypass circuit 8. That is, the amount of oil circulating between the oil pump 2 and the C / V unit 6 is increased, and the amount of oil sent to the outside of the casing 4 is reduced, so that the oil that has risen with the pressure increase of the oil pump 2 The temperature can be kept warm and the oil temperature can be raised early.
The orifice 8a of the bypass circuit 8 is set to a throttle amount that can secure a minimum amount of oil necessary for lubrication. In addition, since the AT 3 is in the neutral state while the engine is warming up, problems such as seizure of the clutch and gear due to insufficient lubrication do not occur.

  If the oil temperature falls below the appropriate temperature range after the engine is warmed up, that is, if the engine water temperature is larger than the predetermined value α and the oil temperature is lower than the predetermined value β, Step S1 → Step S2 → Step S3 → Step S4 → The flow proceeds to step S6, and the lubricating oil is supplied to the lubricated part via the heating circuit 9. After the engine is warmed up, the engine water temperature is sufficiently high, so the oil warmer 9a promotes the increase in the oil temperature and raises the oil temperature to an appropriate temperature, thereby reducing friction and improving the fuel efficiency of the vehicle. Can do.

  If the oil temperature exceeds the appropriate temperature range after the engine is warmed up, that is, if the engine water temperature is larger than the predetermined value α and the oil temperature exceeds the predetermined value γ, Step S1 → Step S2 → Step S3 → Step S4 → The flow proceeds from step S5 to step S7, and the lubricating oil is supplied to the lubricated part via the cooling circuit 10. When the oil temperature is high, all the lubricating oil can be cooled by the oil cooler 10a, and the heating of the oil temperature can be suppressed and both the function maintenance and durability improvement of the AT 3 can be achieved.

Next, the effect will be described.
In the lubricating oil control device for a transmission according to the first embodiment, the following effects can be obtained.

  (1) A recirculation circuit 4e that recirculates excess oil discharged from the C / V unit 6 to the oil pump 2, and when the engine water temperature is equal to or lower than a predetermined value α, the C / V unit 6 starts the heating circuit 9 and the cooling circuit. The engine warm-up oil temperature decrease suppressing means (bypass circuit 8, controller 11) is provided that restricts the amount of lubricating oil flowing to 10 and increases the flow rate of the reflux circuit 4e. Thereby, the oil temperature rise of the transmission at the time of engine warm-up can be promoted.

  (2) The engine warm-up oil temperature drop suppression means bypasses the heating circuit 9 and the cooling circuit 10 and supplies the lubricating oil to the lubricated part via the flow restriction means, and the engine water temperature is predetermined. When the value α is equal to or less than the value α, a controller 11 that outputs a command to connect the C / V unit 6 and the bypass circuit 8 to the switching valve 7 is provided. Thereby, it is possible to simultaneously realize the restriction of the flow rate of the lubricating oil and the increase of the flow rate of the reflux circuit 4e with a simple configuration in which the C / V unit 6 and the bypass circuit are connected. In addition, since the minimum necessary amount of lubricating oil can be supplied to the lubricated part, problems such as clutch and gear seizure due to insufficient lubrication can be avoided.

  (3) Since the flow rate limiting means is the orifice 8a, the flow rate of the lubricating oil passing through the bypass circuit 8 can be limited to a predetermined amount without performing complicated control.

It is a block diagram which shows the structure of the lubrication control apparatus of the transmission of Example 1. FIG. 3 is a flowchart illustrating a flow of a lubrication control process according to the first embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Oil pump 2a Suction port 2b Discharge port 3 Automatic transmission 4 Casing 4a Suction circuit 4b Discharge circuit 4c 1st lubrication circuit 4d 2nd lubrication circuit 4e Recirculation circuit 5 Oil pan 6 Control valve unit (lubricating oil production | generation means)
7 Switching valve (route switching means)
8 Bypass circuit (oil temperature drop suppression means when engine warms up)
8a Orifice 9 Heating circuit 9a Oil warmer (heater)
10 Cooling circuit 10a Oil cooler (radiator)
11 controller (oil temperature drop suppression means during engine warm-up, path switching control means)
12 Engine water temperature sensor 13 Oil temperature sensor

Claims (3)

An oil pump that pressurizes and discharges the stored oil in the transmission casing;
Lubricating oil generating means for generating lubricating oil with a reduced discharge pressure of the oil pump;
A heating circuit for supplying the lubricating oil to the lubricated part via a heater disposed outside the transmission casing;
A cooling circuit that bypasses the heating circuit and supplies the lubricating oil to a lubricated portion of the transmission via a radiator disposed outside the transmission casing;
When the oil temperature of the lubricating oil is below a predetermined value, the lubricating oil generating means and the heating circuit are connected, and when the oil temperature exceeds the predetermined value, the lubricating oil generating means and the heating A path switching means for connecting the circuit;
In a lubricating oil control device for a transmission comprising:
A recirculation circuit for recirculating surplus oil discharged from the pressure adjusting means to the oil pump;
When the engine water temperature is equal to or lower than a predetermined temperature, the engine warm-up oil temperature that limits the amount of lubricating oil flowing from the lubricating oil generating means to the heating circuit and the cooling circuit and increases the flow rate of the reflux circuit. Reduction suppression means,
A lubricating oil control device for a transmission, comprising: The lubricating oil control device for a transmission according to claim 1,
The engine warm-up oil temperature drop suppression means is:
A bypass circuit that bypasses the heating circuit and the cooling circuit, and supplies the lubricating oil to the lubricated portion via a flow rate limiting means;
A path switching control means for outputting a command to connect the lubricating oil generating means and the bypass circuit to the path switching means when the engine water temperature is equal to or lower than the predetermined temperature;
A lubricating oil control device for a transmission, comprising: The lubricating oil control device for a transmission according to claim 2,
A lubricating oil control device for a transmission, wherein the flow restriction means is an orifice.

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