JP7467868B2 - Lubrication control device for automatic transmission - Google Patents

Description

The present invention relates to a lubrication control device for an automatic transmission mounted on a vehicle such as an automobile, and in particular belongs to the technical field of lubrication structures for frictional fastening elements of an automatic transmission.

Automatic transmissions installed in vehicles such as automobiles are configured to achieve a predetermined gear ratio according to the driving state of the vehicle by selectively engaging a power transmission path consisting of a planetary gear set or the like through multiple frictional engagement elements consisting of clutches, brakes, etc.

The clutch used in such an automatic transmission generally includes a clutch drum, a clutch hub, multiple friction plates arranged between the clutch drum and the clutch hub, a piston that presses the multiple friction plates, an engagement hydraulic chamber to which hydraulic oil is supplied to urge the piston toward the friction plates, and a centrifugal balance chamber that prevents the piston from pressing the friction plates when the clutch is not engaged.

This centrifugal balance chamber addresses the problem that if hydraulic oil remains in the hydraulic chamber when the clutch is not engaged, centrifugal force acts on the remaining hydraulic oil, causing the hydraulic oil to press the piston toward the friction plate, resulting in the clutch being engaged.

Specifically, this centrifugal balance chamber is provided on the axially opposite side of the hydraulic chamber across from the piston, and hydraulic oil supplied as lubricating oil to the transmission is introduced into this chamber. Centrifugal force acts on the hydraulic oil in this centrifugal balance chamber, and the hydraulic oil presses the piston in the direction opposite the friction plate. This solves the problem of the clutch becoming engaged when the clutch is not engaged due to hydraulic oil remaining in the hydraulic chamber.

The centrifugal balance chamber is filled with hydraulic oil, for example, supplied from an oil pump through a lubricating oil passage for lubricating the friction plates of each clutch. By generating centrifugal hydraulic pressure in the centrifugal balance chamber, the force due to the centrifugal hydraulic pressure generated in the engagement hydraulic pressure chamber is cancelled.

In a clutch having such a centrifugal balance chamber, for example, hydraulic oil is drained from the centrifugal balance chamber when the engine is stopped. Also, the specified engagement oil pressure for engaging a clutch having a centrifugal balance chamber is usually set to a pressure that assumes that the centrifugal balance chamber is sufficiently filled with hydraulic oil.

Therefore, if a gear shift is performed in a short time immediately after starting in a state in which hydraulic oil has been drained from the centrifugal balance chamber and hydraulic oil is not fully filled in the centrifugal balance chamber immediately after starting, the timing of engagement of the clutch for low gears, such as second and third gears, which are engaged after starting, will be premature, causing the clutch to be abruptly engaged and resulting in gear shift shock.

In response to this, Patent Document 1 discloses a configuration in which the volume of the centrifugal balance chamber is reduced, thereby filling the centrifugal balance chamber of the clutch with hydraulic oil in a short time. With this configuration, the centrifugal balance chamber of the clutch is filled with hydraulic oil in a short time, suppressing the above-mentioned unexpected shock when starting the engine.

JP 2018-15525 A

However, there is a limit to the reduction in the volume of the centrifugal balance chamber of the clutch described in Patent Document 1 due to the constraints imposed on the ability to cancel the centrifugal oil pressure generated in the engagement oil pressure chamber when the clutch is disengaged. In addition, reducing the volume of the centrifugal balance chamber of the clutch may require design changes to the powertrain related to the structure of the clutch. Therefore, there is room for improvement in shortening the time it takes to fill the centrifugal balance chamber with hydraulic oil.

Incidentally, one way to shorten the time it takes for hydraulic oil to fill the centrifugal balance chamber is to increase the amount of hydraulic oil supplied. However, if the source pressure (line pressure) of the hydraulic circuit is increased as a way to increase the amount of hydraulic oil supplied, the load on the oil pump increases, which may lead to a deterioration in the fuel efficiency of the drive source that drives the oil pump.

The present invention aims to suppress the shock caused by hydraulic oil not being filled in the centrifugal balance chamber of the clutch while suppressing the deterioration of fuel efficiency in a lubrication control device for an automatic transmission.

First, the present invention provides a lubrication control device for an automatic transmission, comprising:
A piston that presses the plurality of friction plates;
a fastening hydraulic chamber to which hydraulic oil is supplied for urging the piston toward the friction plate;
A lubrication control device for an automatic transmission having a clutch that is engaged when starting and has a centrifugal balance chamber to which hydraulic oil is supplied to urge the piston in a direction opposite to the friction plate direction,
a hydraulic control circuit for controlling the supply of lubricating oil to each lubrication portion in the automatic transmission;
the hydraulic control circuit includes a first lubrication circuit that is branched off midway through the hydraulic control circuit and that is capable of changing a flow rate of lubricating oil that communicates with the centrifugal balance chamber , and a second lubrication circuit that is separate from the first lubrication circuit,
The second lubrication circuit is configured to be able to change a flow rate of lubricating oil,
and a control means for controlling the flow rate of the first lubrication circuit to be increased and the flow rate of the second lubrication circuit to be limited during a predetermined period immediately after starting of the drive source.

The invention described in claim 2 is the invention described in claim 1,
The control means increases a flow path of the first lubricating circuit, thereby increasing a flow rate of the first lubricating circuit.

The invention described in claim 3 is the invention described in claim 1 or claim 2 ,
The automatic transmission includes a starting brake that is engaged when starting, and a brake other than the starting brake,
The starting brake and the other brakes are connected to a lubrication circuit separate from the first lubrication circuit in the hydraulic control circuit .

The invention described in claim 4 is the invention described in claim 3 ,
The hydraulic control circuit further includes a third lubrication circuit separate from the first and second lubrication circuits,
The starting brake is supplied with lubricating oil from the second lubrication circuit,
The other brakes are supplied with lubricating oil from the third lubricating circuit.

According to the invention described in claim 1, immediately after starting the drive source, the flow rate of hydraulic oil supplied to the first lubrication circuit communicating with the centrifugal balance chamber of the clutch is increased, so that hydraulic oil is quickly supplied to the centrifugal balance chamber.

As a result, when a gear shift (engagement operation) is performed in a state where the lubricating oil in the centrifugal balance chamber has been drained and is stored in the oil pan, such as immediately after starting the vehicle, the timing of engagement can be prevented from being accelerated even if an engagement oil pressure set at a pressure that assumes that lubricating oil is being supplied to the centrifugal balance chamber is supplied.

In this way, the flow rate of hydraulic oil in the first lubrication circuit, which requires an increase in hydraulic oil, is increased, thereby suppressing a deterioration in fuel efficiency while suppressing the shock caused by the centrifugal balance chamber not being filled with hydraulic oil when the clutch is engaged.
In addition, by limiting the flow rate of the second lubrication circuit, the proportion of lubricating oil flowing into the first lubrication circuit can be increased compared to when the flow rate of the lubricating oil in the second lubrication circuit is not limited, and therefore the flow rate of the hydraulic oil supplied to the centrifugal balance chamber can be increased, so that the hydraulic oil can be supplied to the centrifugal balance chamber in a shorter time.

According to the invention described in claim 2, by increasing the flow path, the flow path resistance of the first lubrication circuit is reduced, so that, for example, the flow rate of the first lubrication circuit can be increased without increasing the source pressure (line pressure) of the hydraulic circuit. This allows lubricating oil to be supplied to the centrifugal balance chamber in a short time while reducing the load on the oil pump. As a result, it is possible to suppress the shock caused by the centrifugal balance chamber not being filled with hydraulic oil when the clutch is engaged while suppressing deterioration of fuel efficiency.

According to the invention described in claim 3 , since the starting brake and the other brakes are connected to a lubrication circuit different from the first lubrication circuit that communicates with the centrifugal balance chamber of the clutch, when the flow rate of the first lubrication circuit is increased, only the amount of lubricating oil supplied to the centrifugal balance chamber of the clutch connected to the first lubrication circuit is increased. As a result, the hydraulic oil can be supplied to the centrifugal balance chamber in a shorter time than when the starting brake and the other brakes are connected to the first lubrication circuit.

According to the fourth aspect of the present invention, the starting brake is connected to the second lubrication circuit, and the other brakes are connected to the third lubrication circuit, so that when the flow rate of the first lubrication circuit is increased, only the amount of lubricating oil supplied to the centrifugal balance chamber of the clutch connected to the first lubrication circuit is increased. As a result, the hydraulic oil can be supplied to the centrifugal balance chamber in a shorter time than when the starting brake and the other brakes are connected to the first lubrication circuit.

1 is a schematic diagram of an automatic transmission according to an embodiment of the present invention. 2 is a timing chart for the automatic transmission of FIG. 1; FIG. 4 is a cross-sectional view of a second brake portion in the automatic transmission of the present invention. 2 is a cross-sectional view of a first brake and first to third clutches in the automatic transmission of the present invention. FIG. 1 is a circuit diagram showing a portion of a hydraulic circuit of an automatic transmission according to the present invention. FIG. 4 is a circuit diagram showing the remaining part of the hydraulic circuit of the automatic transmission according to the present invention. 1 is a system diagram of an automatic transmission according to the present invention. 4 is a table showing a lubricant supply pattern of an automatic transmission according to the present invention. 4 is a map showing an example of cooling characteristics of the temperatures of each frictional engagement element in the automatic transmission of the present invention. 4 is a flowchart of a lubricating oil supply control for an automatic transmission according to the present invention. 11 is a flowchart showing the contents of a lubricant supply pattern determination step in the flowchart of FIG. 10 .

The following describes in detail the automatic transmission 10 according to an embodiment of the present invention.

Figure 1 is a schematic diagram showing the configuration of an automatic transmission 10 according to this embodiment. This automatic transmission 10 is connected to a drive source such as an engine without going through a fluid transmission device such as a torque converter. The automatic transmission 10 has an input shaft 12 connected to the drive source and arranged on the drive source side (left side of the figure) and an output shaft 13 arranged on the opposite drive source side (right side of the figure) within a transmission case 11. The automatic transmission 10 is a longitudinally mounted type for front-engine, rear-drive vehicles in which the input shaft 12 and output shaft 13 are arranged on the same axis.

On the axial center of the input shaft 12 and the output shaft 13, from the drive source side, the first, second, third and fourth planetary gear sets (hereinafter simply referred to as the "first, second, third and fourth gear sets") PG1, PG2, PG3 and PG4 are arranged.

In the transmission case 11, a first clutch CL1 is disposed on the drive source side of the first gear set PG1, a second clutch CL2 is disposed on the drive source side of the first clutch CL1, and a third clutch CL3 is disposed on the drive source side of the second clutch CL2. In addition, a first brake BR1 is disposed on the drive source side of the third clutch CL3, and a second brake BR2 is disposed on the drive source side of the third gear set PG3 and the opposite drive source side of the second gear set PG2.

The first, second, third and fourth gear sets PG1, PG2, PG3 and PG4 are all single pinion types in which a pinion supported by a carrier directly meshes with a sun gear and a ring gear. The first, second, third and fourth gear sets PG1, PG2, PG3 and PG4 have sun gears S1, S2, S3 and S4, ring gears R1, R2, R3 and R4 and carriers C1, C2, C3 and C4 as rotating elements.

The first gear set PG1 is a double sun gear type in which the sun gear S1 is split into two in the axial direction. The sun gear S1 has a first sun gear S1a arranged on the drive source side in the axial direction, and a second sun gear S1b arranged on the opposite drive source side. The first and second sun gears S1a, S1b have the same number of teeth and mesh with the same pinion supported by the carrier C1. As a result, the first and second sun gears S1a, S1b always rotate in the same direction.

In the automatic transmission 10, the sun gear S1 of the first gear set PG1, specifically the second sun gear S1b, and the sun gear S4 of the fourth gear set PG4 are always connected, the ring gear R1 of the first gear set PG1 and the sun gear S2 of the second gear set PG2 are always connected, the carrier C2 of the second gear set PG2 and the carrier C4 of the fourth gear set PG4 are always connected, and the carrier C3 of the third gear set PG3 and the ring gear R4 of the fourth gear set PG4 are always connected.

The input shaft 12 is constantly connected to the carrier C1 of the first gear set PG1 through the gap between the first sun gear S1a and the second sun gear S1b, and the output shaft 13 is constantly connected to the carrier C4 of the fourth gear set PG4. Specifically, the input shaft 12 is connected to the first carrier C1 through a power transmission member 14 that passes between the pair of first sun gears S1a, S1b, and the fourth carrier C4 and the second carrier C2 are connected through a power transmission member 15.

The first clutch CL1 is disposed between the input shaft 12 and the carrier C1 of the first gear set PG1 and the sun gear S3 of the third gear set PG3, and is adapted to connect and disconnect them. The second clutch CL2 is disposed between the ring gear R1 of the first gear set PG1 and the sun gear S2 of the second gear set PG2 and the sun gear S3 of the third gear set PG3, and is adapted to connect and disconnect them. The third clutch CL3 is disposed between the ring gear R2 of the second gear set PG2 and the sun gear S3 of the third gear set PG3, and is adapted to connect and disconnect them.

The first brake BR1 is disposed between the transmission case 11 and the sun gear S1 of the first gear set PG1, specifically the first sun gear S1a, to connect and disconnect them. The second brake BR2 is disposed between the transmission case 11 and the ring gear R3 of the third gear set PG3, to connect and disconnect them.

With the above configuration, the automatic transmission 10 is able to achieve 1st to 8th gears in the D range and a reverse gear in the R range by combining the engagement states of the first clutch CL1, the second clutch CL2, the third clutch CL3, the first brake BR1, and the second brake BR2, as shown in FIG. 2.

The structures of the first and second brakes BR1, BR2 and the first to third clutches CL1, CL2, CL3 will be explained using Figures 3 and 4.

As shown in FIG. 3, the first brake BR1 has a drum member 71a that is integral with the vertical wall portion 11a that extends radially inward from the transmission case 11, a hub member 71b that is provided radially inward of the drum member 71a, a plurality of friction plates 71c that are arranged in the axial direction between the hub member 71b and the drum member 71a, and a piston 71d that is arranged on the opposite side of the drive source to the plurality of friction plates 71c and fastens the plurality of friction plates 71c.

The first brake BR1 is equipped with a return spring 71e that biases the piston 71d toward the opposite side of the drive source on the radially inner side of the hub member 71b.

Between the piston 71d and the vertical wall portion 11a, a fastening hydraulic chamber (hereinafter also referred to as the "fastening chamber") P11 is formed, to which hydraulic oil is supplied to urge the piston 71d in the fastening direction. The vertical wall portion 11a is provided with a fastening supply oil passage (hereinafter "fastening oil passage") L11 for supplying hydraulic oil to the fastening chamber P11 of the first brake BR1. When hydraulic oil is supplied to the fastening chamber P11 from a valve body (not shown) via the fastening oil passage L11, the multiple friction plates 71c are fastened, and the hub member 71b of the first brake BR1 is coupled to the transmission case 11.

The hub member 71b of the first brake BR1 has a cylindrical portion 71f on the radially outer side and a vertical wall portion 71g extending radially inward from the end of the cylindrical portion on the drive source side. The hub member 71b of the first brake BR1 is connected to the sun gear S1a via the power transmission member 16 at the radially inner end of the vertical wall portion 71g. The input shaft 12 is disposed radially inward of the power transmission member 16.

The power transmission member 16 and the input shaft 12 are provided with a lubricating oil passage L12 for supplying lubricating oil to the first brake BR1. The lubricating oil passage L12 has an axial oil passage 12a1 provided in the input shaft 12 that communicates with the valve body, and radial oil passages 12a2, 16a provided in the input shaft 12 and the power transmission member 16. The lubricating oil supplied from the valve body is supplied to the first brake BR1 via the lubricating oil passage L12.

As shown in FIG. 4, the second brake BR2 has a hub member 72a that is connected to the transmission case 11, a drum member 72b that is disposed on the anti-drive source side of the hub member 72a and is connected to the ring gear R3 of the third gear set PG3, a plurality of friction plates 72c that are arranged in the axial direction between the hub member 72a and the drum member 72b, and a piston 72d that is disposed on the anti-drive source side of the plurality of friction plates 72c and fastens the plurality of friction plates 72c.

The second brake BR2 has hydraulic chambers P21, P22 to which hydraulic oil is supplied that biases the piston 72d radially inward of the friction plate 72c. The hydraulic chambers P21, P22 each have a fastening chamber P21 to which fastening hydraulic oil is supplied that biases the piston 72d in the fastening direction, and a release chamber P22 to which release hydraulic oil is supplied that biases the piston 72d in the release direction.

The second brake BR2 also has a spring 72e that applies a biasing force to the piston 72d in the tightening direction on the radially inner side of the friction plate 72c.

The hub member 72a of the second brake BR2 comprises a first hub member 72f to which the friction plate 72c is splined and which is splined to the transmission case 11, a second hub member 72g which is disposed on the drive source side of the first hub member 72f and fitted to the transmission case 11 and extends radially inward from the first hub member 72f, a third hub member 72h which is connected to the anti-drive source side of the second hub member 72g radially inward from the first hub member 72f, and a fourth hub member 72i which is connected to the anti-drive source side of the third hub member 72h radially inward from the first hub member 72f.

The first hub member 72f has a vertical wall portion 72f1 that is formed in a substantially disk-like shape and extends in a direction perpendicular to the axial direction of the transmission case 11, and a cylindrical portion 72f2 that extends in a substantially cylindrical shape from the vertical wall portion 72f1 toward the opposite side to the drive source on the radially inner side of the vertical wall portion 72f1.

The first hub member 72f is connected to the transmission case 11 by a spline portion (not shown) formed on the outer circumferential surface of the vertical wall portion 72f1 being spline-engaged with a spline portion (not shown) of the transmission case 11. A friction plate 72c is spline-engaged with a spline portion provided on the outer circumferential surface of the cylindrical portion 72f2 of the first hub member 72f.

The second hub member 72g has a vertical wall portion 72g1 formed in a substantially disk shape extending in a direction perpendicular to the axial direction of the transmission case 11. The vertical wall portion 72g1 of the second hub member 72g is formed with a fastening oil passage L21 that supplies fastening hydraulic oil to the fastening chamber P21 described below, a release oil passage L22 that supplies release hydraulic oil to the release chamber P22, and a lubricating oil passage L23 that supplies lubricating hydraulic oil to the friction plate 72c.

The fastening oil passage L21, the release oil passage L22, and the lubricating oil passage L23 are arranged in a circumferential line on the lower side of the transmission case 11, and the second hub member 72g is formed so that the fastening oil passage L21, the release oil passage L22, and the lubricating oil passage L23 are each connected to the valve body 5.

The third hub member 72h includes a vertical wall portion 72h1 that extends in a direction perpendicular to the axial direction of the transmission case 11 and is formed in a substantially disk-like shape, a first cylindrical portion 72h2 that extends in a substantially cylindrical shape from the radial outside of the vertical wall portion 72h1 toward the non-driving source side, and a second cylindrical portion 72h3 that extends in a substantially cylindrical shape from the radial inside of the vertical wall portion 72h1 toward the non-driving source side.

The first cylindrical portion 72h2 of the third hub member 72h is provided radially inward of the cylindrical portion 72f2 of the first hub member 72f. The first cylindrical portion 72h2 of the third hub member 72h has a flange portion 72h2' that extends radially outward so as to abut against the inner circumferential surface of the cylindrical portion 72f2 of the first hub member 72f on the side opposite the driving source, and is provided to form a lubrication supply oil passage L21 between the first cylindrical portion 72h2 of the first hub member 72f. Hydraulic chambers P21 and P22 are formed on the outer circumferential side of the second cylindrical portion 72h3 of the third hub member 72h.

The fourth hub member 72i is formed in a generally disk-like shape extending in a direction perpendicular to the axial direction of the transmission case 11, and is disposed on the opposite side of the third hub member 72h from the driving source. The fourth hub member 72i is formed to extend radially outward from the second cylindrical portion 72h3 of the third hub member 72h, and the outer peripheral surface of the fourth hub member 72i is fitted to the piston 72d.

The piston 72d is disposed between the cylindrical portion 72f2 of the first hub member 72f and the drum member 72b, and is slidably fitted to the outer peripheral surface of the second cylindrical portion 72h3 of the third hub member 72h. The piston 72d is formed in an annular shape and includes a pressing portion 72d1 provided on the outer peripheral side to press the friction plate 72c, and a hydraulic chamber forming portion 72d2 provided on the inner peripheral side to form the hydraulic chambers P21 and P22.

The hydraulic chamber forming portion 72d2 extends radially inward from the anti-drive source side of the friction plate 70 and is fitted to the outer peripheral surface of the fourth hub member 72i and is also fitted to the outer peripheral surface of the second cylindrical portion 72h3 of the third hub member 72h. As a result, a fastening chamber P21 is formed by the anti-drive source side surface of the hydraulic chamber forming portion 72d2, the outer peripheral surface of the third hub member 72h, and the drive source side surface of the fourth hub member 72i. A notch portion 72d3 is provided at the radially inner end of the hydraulic chamber forming portion 72d2, and a release chamber P22 is formed between the second cylindrical portion 72h3 and the notch portion 72d3.

The fastening oil passage L21 has a radial oil passage 72g2 provided in the second hub member 72g, an axial oil passage 72h4 provided in the third hub member 72h, and a groove portion 72i1 provided in the fourth hub member 72i. The hydraulic oil supplied from the valve body 5 is supplied to the fastening chamber P21 via the fastening oil passage L21.

The release oil passage L22 has a radial oil passage 72g3 provided in the second hub member 72g and an axial oil passage 72h5 provided in the third hub member 72h. The hydraulic oil supplied from the valve body 5 is supplied to the fastening chamber P21 via the fastening oil passage L21.

The lubricating oil passage L23 has a radial oil passage 72g4 provided in the second hub member 72g and a circumferential oil passage 72h6 formed between the outer circumferential surface of the first cylindrical portion 72h2 of the third hub member 72h and the inner circumferential surface of the cylindrical portion 72f2 of the first hub member 72f. The lubricating oil supplied from the valve body 5 is supplied to the friction plate 72c via the lubricating oil passage L23.

As shown in FIG. 3, the first to third clutches CL1, CL2, and CL3 each have a hub member 73a, 74a, and 75a, drum members 73b, 74b, and 75b, a plurality of friction plates 73c, 74c, and 75c arranged in the axial direction between the hub members 73a, 74a, and 75a and the drum members 73b, 74b, and 75b, and pistons 73d, 74d, and 75d arranged on the opposite side of the drive source to the plurality of friction plates 73c, 74c, and 75c to fasten the plurality of friction plates 73c, 74c, and 75c.

The fastening chambers P31, P41, P51 and the balance chambers P32, P42, P52 are provided radially inward from the friction plates 73c, 74c, 75c. Return springs 73e, 74e, 75e that bias the pistons 73d, 74d, 75d toward the release side are arranged in the balance chambers P32, P42, P52.

A power transmission member 17 that connects the hub member 73a of the second clutch CL2 and the hub member 75a of the third clutch CL3 is provided on the inner peripheral side of the hub member 73a of the second clutch CL2 and the hub member 75a of the third clutch CL3.

The power transmission member 17 has a cylindrical portion 17a extending in the axial direction on the radially inner side, and a vertical wall portion 17b extending radially outward from a position corresponding to the hub member 73a of the second clutch CL2 at the axially intermediate portion of the cylindrical portion 17a. A spline portion is formed on the outer peripheral surface of the vertical wall portion 17b, which fits into a spline portion formed on the inner peripheral surface of the hub member 74a of the second clutch CL2.

A thrust bearing 76 that allows relative rotation with the sun gear S1 of the first gear set PG1 is disposed at the end of the cylindrical portion 17a opposite the drive source.
A spline portion is formed on the outer circumferential surface of the cylindrical portion 17a at a location closer to the driving source than the vertical wall portion 17b. The spline portion is adapted to fit with a spline portion formed on the inner circumferential surface of a hub member 75a of the third clutch CL3, which will be described later.

The hub member 75a of the third clutch CL3 has a cylindrical spline portion 75a1 that engages multiple friction plates 75c on its outer circumferential surface, a vertical wall portion 75a2 that extends radially inward from the spline portion 75a1, and a first cylindrical portion 75a3 on the drive source side and a second cylindrical portion 75a4 on the non-drive source side that extend axially from the radially inner end of the vertical wall portion 75a2.

A spline portion is formed on the outer peripheral surface of the first cylindrical portion 75a3 and the inner peripheral surface of the second cylindrical portion 75a4. A power transmission member 18 for transmitting power to the sun gear S3 of the third gear set PG3 is spline-fitted to the spline portion of the first cylindrical portion 75a3. The spline portion of the second cylindrical portion 75a4 is spline-fitted to the spline portion on the outer peripheral surface of the power transmission member 17.

This allows the drum member 73b of the first clutch CL1, the hub member 74a of the second clutch CL2, the hub member 75a of the third clutch CL3, and the sun gear S3 of the third gear set PG3 to rotate integrally.

A sleeve member 19 formed integrally with the vertical wall portion 11a is disposed on the inner circumferential side of the power transmission member 17. The power transmission member 17 is rotatably supported by the sleeve member 19 via a bearing 77 provided on the inner circumferential surface of the cylindrical portion 17a at a position on the opposite side to the drive source than the vertical wall portion 17b. The sleeve member 19 is formed of a first sleeve member 19a extending in the axial direction and a second sleeve member 19b press-fitted radially outward of the first sleeve member 19a.

The sleeve member 19 is provided with fastening oil passages L30, L40, L50 and balance chamber oil passages L60, L70, L80 for supplying hydraulic oil to the fastening chambers P31, P41, P51 and balance chambers P32, P42, P52 of the first to third clutches CL1, CL2, CL3.

The fastening oil passages L30, L40, L50 of the first to third clutches CL1, CL2, CL3 include fastening chamber axial oil passages L31, L41, L51 that communicate with a control valve (not shown), and fastening radial oil passages L32, L42, L52 that connect the fastening chamber axial oil passages L31, L41, L51 to the fastening chambers P31, P41, P51.

The axial oil passages L31, L41, and L51 for the fastening chamber are formed between a first sleeve member 19a that is fixed to the transmission case 11 and has multiple grooves 19a1 that extend axially and open radially outwardly at different circumferential positions, and a second sleeve member 19b that is pressed into the radially outward side of the first sleeve member 19a.

The fastening radial oil passage L32 of the first clutch CL1 is formed by a radial oil passage that penetrates the second sleeve member 19b in the radial direction, and a radial oil passage that penetrates the power transmission member 17 in the radial direction so as to connect the radial oil passage to the fastening hydraulic chamber P31. As a result, the hydraulic oil for fastening the first clutch CL1 is supplied to the fastening chamber P31 of the first clutch CL1 via the fastening oil passage L30.

The fastening radial oil passage L42 of the second clutch CL2 is formed of a radial oil passage that passes radially through the second sleeve member 19b, a radial oil passage that passes radially through the power transmission member 17, and a radial oil passage that passes radially through the second cylindrical portion 75a4 of the hub member 75a of the third clutch CL3 so as to connect these radial oil passages to the fastening chamber P41. As a result, the hydraulic oil for fastening the second clutch CL2 is supplied to the fastening chamber P41 of the second clutch CL2 via the fastening oil passage L40.

The third clutch CL3 radial oil passage L52 for fastening is formed by a radial oil passage that passes radially through the second sleeve member 19b, a radial oil passage that passes radially through the power transmission member 17, and a radial oil passage that passes radially through the power transmission member 18 to connect these radial oil passages to the fastening chamber P51. As a result, the hydraulic oil for fastening the third clutch CL3 is supplied to the fastening chamber P51 of the third clutch CL3 via the fastening oil passage L50.

The balance chamber oil passages L60, L70, and L80, like the fastening oil passage P31, are provided with axial oil passages L61, L71, and L81 for the centrifugal balance chamber, which are connected to a control valve (not shown) provided in the transmission case 11, and radial oil passages L62, L72, and L82 for the centrifugal balance chamber, which are connected to the axial oil passages L61, L71, and L81 for the centrifugal balance chamber.

The axial oil passages L61, L71, and L81 for the centrifugal balance chamber of the first to third clutches CL1 to CL3 are formed at circumferential positions different from the axial oil passages L31, L41, and L51 for the fastening chamber of the sleeve member 19.

The balance chamber radial oil passage L62 of the first clutch CL1 is formed by a radial oil passage that penetrates the second sleeve member 19b in the radial direction, and a radial oil passage that penetrates the power transmission member 17 in the radial direction so as to connect the radial oil passage to the balance chamber P32. As a result, the hydraulic oil for the balance chamber of the first clutch CL1 is supplied to the balance chamber P32 of the first clutch CL1 via the balance chamber oil passage L60.

The balance chamber radial oil passage L72 of the second clutch CL2 is formed of a radial oil passage that penetrates the second sleeve member 19b in the radial direction, a radial oil passage that penetrates the power transmission member 17 in the radial direction, and a radial oil passage that penetrates the second cylindrical portion 75a4 of the hub member 75a of the third clutch CL3 in the radial direction so as to connect these fastening radial oil passages to the balance chamber P42. As a result, the fastening hydraulic oil of the second clutch CL2 is supplied to the balance chamber P42 of the second clutch CL2 via the balance chamber oil passage L70.

The radial oil passage L82 for the balance chamber of the third clutch CL3 is formed of a radial oil passage that penetrates the second sleeve member 19b in the radial direction, a radial oil passage that penetrates the power transmission member 17 in the radial direction, and a radial oil passage that penetrates the power transmission member 18 in the radial direction so as to connect these radial oil passages to the fastening chamber P81. As a result, the hydraulic oil for the balance chamber of the third clutch CL3 is supplied to the balance chamber P52 of the third clutch CL3 via the balance chamber oil passage L80.

In this embodiment, the axial oil passages L61, L71, and L81 for the balance chambers of the first, second, and third clutches CL1, CL2, and CL3 are formed by the same groove provided in the sleeve member 19. This allows hydraulic oil to be supplied simultaneously to the balance chambers of the first, second, and third clutches CL1, CL2, and CL3.

Next, we will explain the lubricating oil supply path for lubricating the multiple friction plates 73c, 74c, and 75c of the first, second, and third clutches CL1, CL2, and CL3.

The supply path of the lubricating oil supplied to the friction plate 73c of the first clutch CL1 is formed so as to communicate with the space Z1 between the centrifugal balance chamber P32 of the first clutch CL1 and the first gear set PG1 via the axial oil passage L61 for the balance chamber of the first clutch CL1, the radial oil passage formed in the second sleeve member 19b, the bearing 77, and the thrust bearing 76.

The lubricating oil that flows into the space Z1 is rectified by the baffle plate 78 provided between the first gear set PG1 and the balance chamber P32 of the first clutch CL1, and is supplied to the friction plate 73c of the first clutch CL1 and the bearing of the carrier C1 of the first gear set PG1.

The supply path of the lubricating oil supplied to the friction plate 74c of the second clutch CL2 is formed so that the axial oil passage L71 for the balance chamber of the second clutch CL1, the radial oil passage formed in the second sleeve member 19b, and the space Z2 between the centrifugal balance chamber P42 of the second clutch CL2 and the hub member 74a of the second clutch CL2 are connected via a notch provided at the end of the second cylindrical portion 75a4 of the hub member 75a on the side opposite the driving source. As a result, the lubricating oil that has flowed into the space Z2 is supplied to the friction plate 74c.

The supply path of the lubricating oil supplied to the friction plate 75c of the third clutch CL3 is formed so as to communicate with the space Z3 between the centrifugal balance chamber of the third clutch CL3 and the vertical wall portion of the hub member of the second clutch CL2 via the axial oil passage L81 for the balance chamber of the third clutch CL3, the radial oil passage formed in the second sleeve member 19b, the spline fitting portion between the hub member 75a of the second clutch CL2 and the power transmission member 18, and the notch provided at the end of the power transmission member 18 on the radially inner side opposite the drive source. As a result, the lubricating oil flowing into the space Z3 is supplied to the friction plate 75c.

As described above, in this embodiment, the balance chamber axial oil passages L61, L71, and L81 of the first, second, and third clutches CL1, CL2, and CL3 are formed by the same groove provided in the sleeve member 19. This allows lubricating oil to be supplied simultaneously to the friction plates 73c, 74c, and 75c of the first, second, and third clutches CL1, CL2, and CL3.

The automatic transmission 10 has a hydraulic control device 2 that realizes the gear stages by engaging and disengaging the above-mentioned frictional engagement elements BR1, BR2, CL1, CL2, and CL3. This hydraulic control device 2 will now be described in detail.

As shown in Figures 5 and 6, the hydraulic control device 2 includes, as hydraulic sources, a mechanical pump (MOP) 21 (hereinafter referred to as a "mecha pump") with a relief valve that is driven by an engine (not shown), and an electric pump (EOP) 22 (hereinafter referred to as an "electric pump") that is driven electrically mainly when the engine is stopped.

The hydraulic control device 2 adjusts the hydraulic oil discharged from these pumps 21 and 22, generates operating pressures for forming gear stages such as engagement pressure and release pressure supplied to each frictional engagement element BR1, BR2, CL1, CL2, and CL3 for gear shift control, and is equipped with a hydraulic control circuit 20 that controls the supply of lubricating oil to each lubricated part in the transmission including the frictional engagement elements BR1, BR2, CL1, CL2, and CL3. Note that the hydraulic control circuit 20 in Figures 5 and 6 is mainly shown as a lubrication circuit. In this embodiment, the hydraulic control device 2 also has the function of a lubrication control device in the claims.

The hydraulic control circuit 20 has a number of spool valves that operate with hydraulic pressure and spring force to switch oil paths and adjust hydraulic pressure, a number of on-off solenoid valves (hereafter referred to as "on-off valves") that operate with electrical signals to connect and disconnect oil paths, and a number of linear solenoid valves (hereafter referred to as "linear valves") that also operate with electrical signals to supply and discharge and adjust operating pressure, and the circuit is configured so that the hydraulic source, these valves, and frictional fastening elements are connected via oil paths to perform shift control, lubricating oil supply control to control the supply of lubricating oil, etc.

The valves constituting the hydraulic control circuit 20 include a regulator valve 31 that adjusts the discharge pressure of the mechanical pump 21 to a predetermined line pressure, a pump shift valve 32 that switches between the line pressure and the discharge pressure of the electric pump 22 and selectively supplies the line pressure to the frictional fastening element side as the base pressure for the shift control operating pressure, and a lubrication switching valve 33 for the electric pump 22 that supplies the discharge oil of the electric pump 22 as lubricating oil. The control ports 331 and 332 of the lubrication switching valve 33 are connected to the line pressure oil passage a that supplies the line pressure and the discharge oil passage b of the electric pump 22, respectively.

When the force due to the line pressure is greater than the discharge pressure of the electric pump 22 and the force due to the spring, the spool 333 is located on the left side of the drawing (hereinafter the same) and the discharge oil passage b of the electric pump 22 is connected to the lubricating oil additional oil passage c. In the opposite case, the spool 333 is located on the right side and the discharge oil passage b of the electric pump 22 is connected to the pump shift valve 32 via the lubrication switching valve 33.

The control ports 321, 322 at both ends of the pump shift valve 32 are connected to a line pressure oil passage a that supplies line pressure and a discharge oil passage b of the electric pump 22 via the lubrication switching valve 33, respectively.

When the force of the line pressure and the spring (not shown) is greater than the force of the discharge pressure of the electric pump 22, the spool 323 is located on the right side of the drawing (hereinafter the same) and the line pressure oil passage a is connected to the shift source pressure oil passage d. In the opposite case, the spool 323 is located on the left side and the discharge oil passage b of the electric pump 22 is connected to the shift source pressure oil passage d.

The shift control source pressure is supplied from the shift source pressure line d through multiple shift source pressure branch lines (not shown) to multiple shift linear valves 60 (see FIG. 7) that generate the engagement pressures for the first and second brakes BR1 and BR2 and the first to third clutches CL1, CL2, and CL3. The engagement pressures generated by the linear valves 60 are supplied to the engagement chambers of the frictional engagement elements according to the gear position, and the corresponding frictional engagement elements are engaged.

The line pressure oil passage a is led to a reducing valve 41, which reduces the line pressure to a predetermined pressure to generate a control pressure. This control pressure is supplied to the first and second on/off valves 51 and 52, respectively, via the first and second branch control pressure oil passages e1 and e2 branched from the control pressure oil passage e.

When the first on/off valve 51 is on, the control pressure is supplied to the lubricating oil increase valve 34 for the second brake through the first branch control pressure oil line e1.
When the second on/off valve 52 is on, the control pressure is supplied to the lubricating oil quantity increasing valve 35 for the first to third clutches through the second branch control pressure oil passage e2.
The lubricant amount increasing action of the first and second on/off valves 51, 52 and the lubricant amount increasing valves 34, 35 will be described later.

The control pressure generated by the reducing valve 41 is also guided to the line pressure control linear valve 61 and supplied to the regulator valve 31 to generate a line pressure adjustment pressure for adjusting the set line pressure to a predetermined pressure according to the vehicle's operating state. The control ports 311 and 312 of the regulator valve 31 are respectively connected to the line pressure oil passage a and the control pressure oil passage e via the line pressure control linear valve 61.

When the control pressure of the line pressure control linear valve 61 and the force of the spring (not shown) are smaller than the force of the line pressure, the spool 313 is positioned on the right side of the drawing (hereinafter the same) and the line pressure oil passage a is connected to the main lubricating oil passage f. In the opposite case, the spool 313 is positioned on the left side and the line pressure oil passage a is connected to the drain port in addition to the main lubricating oil passage f.

The hydraulic control circuit 20 is equipped with a lubrication reducing valve 42 that adjusts the lubrication pressure in the main lubrication oil passage f. For fail-safe purposes, the line pressure oil passage a is connected to the main lubrication oil passage f downstream of the lubrication reducing valve 42 via an orifice 80. The orifice 80 is formed with a small diameter of, for example, φ0.8 mm, so that the line pressure oil passage a is connected to the main lubrication oil passage f when a pressure difference occurs due to a sudden drop in the lubrication pressure in the main lubrication oil passage f.

The main lubricating oil passage f passes through an oil cooler 91 and then branches into first to third lubricating oil passages f1, f2, and f3, which supply lubricating oil to the first and second brakes BR1 and BR2, the first to third clutches CL1, CL2, and CL3, and the main shaft D in the transmission via fixed orifices 81, 82, and 83, respectively. In this embodiment, the third lubricating circuit in the claims is constituted by the third lubricating oil passage f3.

The main lubricating oil passage f is provided with a bypass oil passage f' that bypasses the oil cooler 91, and the bypass oil passage f' is provided with a lubricating oil relief valve 92 to protect the oil cooler 91.

The main lubricating oil passage f branches off from the upstream side of the oil cooler 91, and the fourth lubricating oil passage f4 is connected to the lubricating oil increase valve 34 for the second brake described above. The main lubricating oil passage f also branches off from the downstream side of the oil cooler 91 to the fifth lubricating oil passage f5, which is connected to the lubricating oil increase valve 35 for the first to third clutches.

When the first on-off valve 51 is on, the spool 341 of the second brake lubricant oil increase valve 34 is positioned to the right by the control pressure supplied from the first branch control pressure oil line e1, and the fourth lubricant oil branch line f4 is connected to the second brake lubricant oil increase oil line g. Lubricant oil is supplied to the second brake BR2 via the second brake lubricant oil increase valve 34 and the increase orifice 84. In this embodiment, the second lubricant circuit in the claims is composed of the first lubricant oil branch line f1 and the second brake lubricant oil increase oil line g.

When the second on/off valve 52 is on, the spool 351 of the lubricating oil increase valve 35 for the first to third clutches is positioned to the right by the control pressure supplied from the second branch control pressure oil passage e2, and the fifth lubricating oil branch passage f5 is connected to the lubricating oil increase passage h for the first to third clutches CL1, CL2, CL3. Lubricating oil is supplied to the first to third clutches CL1, CL2, CL3 through the lubricating oil increase valve 35 for the first to third clutches and the increase orifice 85. In this embodiment, the first lubricating circuit in the claims is composed of the second lubricating oil branch passage f2 and the lubricating oil increase passage h for the first to third clutches CL1, CL2, CL3.

In addition, in this embodiment, by opening the lubricant oil boost valve 35 for the first to third clutches, in addition to the second lubricant branch oil passage f2, the lubricant oil boost oil passage h for the first to third clutches CL1, CL2, CL3 is connected to the centrifugal balance chambers of the first to third clutches CL1 to CL3. This increases the flow path of the first lubricant circuit. By closing the lubricant oil boost valve 34 for the second brake, the second brake lubricant oil boost oil passage g is blocked, and the flow path of the second lubricant circuit is limited to the first lubricant branch circuit f1.

The hydraulic control circuit 20 is further provided with a lubrication switching valve 33 for the electric pump 22 to supply the discharge oil of the electric pump 22 as lubricating oil for the second brake BR2. The line pressure is supplied as a control pressure from the line pressure oil passage a to the lubrication switching valve 33 for the electric pump 22, and when the spool 371 is positioned to the left due to this control pressure, the discharge oil passage b of the electric pump 22 is connected to the lubricating oil additional oil passage c, and when the electric pump 22 operates in this state, the discharge oil is supplied as lubricating oil to the second brake BR2 via the lubricating oil additional oil passage c.

As shown in FIG. 7, the automatic transmission 10 includes the aforementioned valve 60 for shift control, valves 51, 52, and 61 for lubrication control, and a control unit 200 as a control device for controlling the electric pump 22. Various external signals used for controlling the vehicle are input to the control unit 200.

The input signals to the control unit 200 include a vehicle speed sensor 201 that detects the vehicle's traveling speed, an accelerator opening sensor 202 that detects the accelerator opening (amount of depression of the accelerator pedal), an engine speed sensor 203 that detects the engine speed as the input speed input to the automatic transmission 10, an output speed sensor 204 that detects the output speed output from the automatic transmission 10, an oil temperature sensor 205 that detects the temperature (ATF temperature) of the lubricating oil stored in the oil storage section at the bottom of the transmission case 11 of the automatic transmission 10, an input torque sensor 206 that detects the engine output torque as the input torque input to the automatic transmission 10, and detection signals from an oil pressure sensor 207 that detects the oil pressure of the hydraulic oil supplied to each frictional engagement element.

The control unit 200 includes a shift control means 210 that controls shifting by outputting a control signal to the hydraulic control device 2 of the automatic transmission 10 based on detection values from various sensors including a vehicle speed sensor 201, an accelerator opening sensor 202, an engine speed sensor 203, and an output speed sensor 204, a lubricant supply control means 220 described below, and a frictional engagement element temperature calculation means 230 that serves as a frictional engagement element detection means.

The lubricant supply control means 220 has a plurality of lubricant supply patterns in which the lubricant supply destinations and the supply amount of lubricant to each supply destination are set. The lubricant supply control means 220 performs the following lubricant supply control by outputting a control signal to the hydraulic control device 2 based on input signals from the input rotation speed sensor 203, the output rotation speed sensor 204, the oil temperature sensor 205, the input torque sensor 206, and the hydraulic pressure sensor 207.

The lubricant supply control controls the switching of the supply pattern of lubricant supplied to each frictional fastening element according to the vehicle condition in order to reduce the agitation resistance and drag resistance of the lubricant in each frictional fastening element and the discharge loss of the oil pump while suppressing the thermal load of each frictional fastening element BR1, BR2, CL1, CL2, and CL3, thereby improving fuel efficiency.

As shown in FIG. 8, the lubricant supply control means 220 has a plurality of lubricant supply patterns that switch the lubricant supply destinations and the amount of lubricant supplied to each supply destination. The plurality of lubricant supply patterns are switched according to the cooling requirement level for the second brake BR2 and the cooling requirement level for the first to third clutches CL1, CL2, and CL3 (specifically, low cooling requirement level L, high cooling requirement level H, and maximum cooling requirement level HH).

The cooling requirement level is determined based on whether the parameters related to the temperature of each frictional engagement element are equal to or greater than a threshold value. Here, we will explain the parameters that determine the cooling requirement level for switching between multiple lubricant supply patterns and the threshold value set for each parameter.

The parameters used to determine the cooling requirement level for switching between multiple lubricant supply patterns are values that contribute to the temperature rise (heat generation) of each frictional engagement element. Specifically, the input torque detected by the input torque sensor 206, the input rotation speed detected by the input rotation speed sensor 203, and the temperatures of the second brake B2 and the first to third clutches CL1, CL2, and CL3 calculated by the frictional engagement element temperature calculation means 230 are used.

The input torque is proportional to the temperature of each frictional engagement element, so the temperature rise of each frictional engagement element can be estimated. As the input rotation speed increases, the differential rotation ΔN increases. As this differential rotation ΔN is proportional to the temperature of each frictional engagement element, the temperature rise of each frictional engagement element can be estimated, just like the input torque. The temperature rise of each frictional engagement element can be detected directly.

In this embodiment, the temperature of each frictional engagement element, which serves as a parameter for switching the destination and amount of lubricating oil supplied to each frictional engagement element, is calculated by each frictional engagement element temperature calculation means 230. The temperature of each frictional engagement element is calculated based on the input rotation speed, output rotation speed, input torque, oil pressure of the oil passage communicating with each frictional engagement element, and the cooling temperature of each frictional engagement element due to heat dissipation to the surrounding atmosphere and lubricating oil, which will be described later.

Specifically, the temperature T1 of each frictional engagement element calculated by each frictional engagement element temperature calculation means 230 is calculated from each frictional engagement element temperature T0 calculated in the immediately preceding cycle, the absorbed energy E of each frictional engagement element, the heat capacity Q of the friction plates of each frictional engagement element, the cooling temperature (Tc×tc) calculated from the heat dissipation rate (frictional engagement element temperature drop rate) Tc from each frictional engagement element to the surrounding atmosphere and lubricating oil and the cycle time (time required for one calculation) tc, and the following equation 1. Note that the ATF temperature detected by the oil temperature sensor 205 is used as the initial value of each frictional engagement element temperature T0 calculated in the immediately preceding cycle.

The absorbed energy E of each frictional engagement element is calculated from the differential rotation ΔN between the input side and the output side of each frictional engagement element, the transmission torque Trq of each frictional engagement element, and the following equation 2.

The differential rotation ΔN is calculated based on the input rotation speed detected by the input rotation speed sensor 203, the output rotation speed detected by the output rotation speed sensor 204, the gear stage, and the speed diagram. The differential rotation ΔN is calculated based on the rotation difference that occurs between the drum member and hub member of the frictional engagement element that is in a disengaged state in the current gear stage and will be in an engaged state in the next gear stage.

The transmission torque Trq is calculated from the number n of friction surfaces, the piston return spring set load Fr, the friction coefficient μ, the operating oil pressure Pa detected by the oil pressure sensor 207, the piston major diameter Dpo, the piston minor diameter Dpi, the friction surface major diameter Do of each frictional fastening element, and the friction surface minor diameter Di of each frictional fastening element, and the following equation 3.

The cooling temperature Tc of each frictional engagement element in Equation 1 is calculated from the temperature T1 of each frictional engagement element (the value calculated in the previous cycle), the heat generation temperature ΔT of each frictional engagement element calculated from the ATF temperature (the temperature of each frictional engagement element - the ATF temperature), and a map (Figure 9) showing the relationship between the heat generation temperature ΔT of each frictional engagement element and the cooling temperature Tc of each frictional engagement element (the rate at which the temperature of each frictional engagement element drops). Specifically, as shown in Figure 9, the cooling temperature Tc of the frictional engagement element is calculated by reading the value of the cooling temperature Tc1 of the frictional engagement element when the frictional engagement element has a heat generation temperature ΔT1.

The map of the cooling temperature Tc of each frictional fastening element versus the heat generation temperature ΔT of each frictional fastening element in FIG. 9 is calculated by an approximation formula derived based on experimental values of the temperature drop rate (cooling temperature) of a specific frictional fastening element when a specific flow rate of lubricating oil is supplied to the specific frictional fastening element engaged in a specific gear shift state. Note that a map of the cooling temperature Tc of each frictional fastening element versus the heat generation temperature ΔT of each frictional fastening element is provided for each frictional fastening element engaged in multiple gear shift states.

The thresholds of the above parameters (input torque, input speed, and temperature of each frictional engagement element) are set to conditions when the heat generation of each frictional engagement element is relatively small and an increase in lubricant is required. For example, the input torque threshold Tq1 is set to 250 Nm, the input speed threshold Nin is set to 3000 rpm, the temperature thresholds Tcl1, Tcl2, and Tcl3 of the first to third clutches CL1, CL2, and CL3 are set to 150°C, and the first threshold Tlow of the second brake temperature is set to 150°C. Note that for the temperature of the second brake, a second threshold Thigh is set that is higher than the first threshold. For example, the second threshold Thigh is set to 180°C.

As shown in FIG. 8, multiple lubricant supply patterns are set as pattern 1 to pattern 5. Here, we will explain the multiple lubricant supply patterns, the parameter conditions for switching between each lubricant supply pattern, and an example of a scene (vehicle state) assumed for each lubricant supply pattern.

The multiple lubricant supply patterns are switched according to the cooling requirement level for the second brake BR2 and the cooling requirement level for the first to third clutches CL1, CL2, and CL3. For example, the cooling requirement level is set to a low cooling requirement level L, which is a cooling requirement level that ensures durability by cooling each frictional engagement element with the amount of lubricant constantly supplied to each frictional engagement element, a high cooling requirement level H, which is a cooling requirement level higher than the low cooling requirement level L, and a maximum cooling requirement level HH, which is a cooling requirement level higher than the high cooling requirement level H for the second brake BR2.

When the cooling requirement level for the second brake BR2 is low L and the cooling requirement level for the first to third clutches CL1, CL2, and CL3 is low L, pattern 1 is executed as the first lubricant supply pattern.

The conditions for each parameter are that the temperature of the second brake BR2 is less than the first threshold value Tlow, and that all of the parameters for determining the amount of lubricant supplied to the first to third clutches CL1, CL2, CL3 (input torque, input speed, and temperatures of the first to third clutches CL1, CL2, CL3) are less than their respective threshold values Tq1, Nin, Tcl1, Tcl2, Tcl3.

In pattern 1, the second brake BR2 is supplied with a first predetermined flow rate (small) of lubricating oil through the first lubricating oil branch passage f1. The first to third clutches CL1 to CL3 are supplied with a second predetermined flow rate (small) of lubricating oil through the second lubricating oil branch passage f2.

Expected scenarios include situations where there is no need to increase the amount of lubricating oil supplied to each frictional engagement element, such as under light load, during fuel-efficient driving, coasting down (when the transmission is decelerating), before engine start (for example, when the engine speed is less than 500 rpm), etc. In this way, when the thermal load of each frictional engagement element is not high (cooling requirement level is low L), the amount of lubricating oil is suppressed, thereby suppressing the agitation resistance and drag resistance caused by the lubricating oil of each frictional engagement element and the discharge loss of the oil pump.

When the cooling requirement level for the second brake BR2 is low (L) and the cooling requirement level for the first to third clutches CL1, CL2, and CL3 is high (H), pattern 2 is executed as the second lubricant supply pattern.

The conditions for each parameter are that the temperature of the second brake BR2 is less than the first threshold value Tlow, and one or more of the parameters for determining the amount of lubricant supplied to the first to third clutches CL1 to CL3 (input torque, input speed, temperature of the first to third clutches CL1 to CL3) is equal to or greater than a predetermined value.

In pattern 2, the second brake BR2 is supplied with a first predetermined flow rate (small) of lubricating oil through the first lubrication branch oil passage f1. The first to third clutches CL1 to CL3 are supplied with a third predetermined flow rate (large) of lubricating oil, which is greater than the second predetermined flow rate, through the first to third clutch lubrication increase oil passages h in addition to the second lubrication branch oil passage f2.

Expected scenarios include situations where the ATF temperature is relatively low (e.g., the temperature of the second brake BR2 is not likely to reach the first threshold value Tlow) and an increase in the amount of lubricant supplied to the second brake BR2 is not required, but an increase in the amount of lubricant supplied to the first to third clutches CL1 to CL3 is required, such as during medium loads (e.g., a load higher than a low load such as idling and lower than a high load such as when driving uphill), during acceleration, upshifts, and downshifts due to torque demands.

Specifically, as shown in FIG. 2, during acceleration, upshifting, and downshifting due to torque demand (e.g., downshifting from 6th gear to 3rd gear), the first to third clutches CL1 to CL3 undergo re-engagement (a state in which the clutches change between released and engaged states), and the cooling demand level for the first to third clutches CL1 to CL3 increases.

On the other hand, during acceleration and upshifting, the second brake BR2 is not gripped (changed from a released state to an engaged state), and there is no temperature rise in the second brake BR2 due to slipping, as occurs when starting off (first gear).

In addition, when downshifting due to the torque demand, the second brake BR2 is engaged (changed from a released state to an engaged state), but the temperature rise of the second brake BR2 in this case is lower than the temperature rise of the second brake BR2 when the second brake BR2 is in a slipping state, and the cooling demand level for the second brake BR2 is low.

In this way, when the thermal load of the first to third clutches CL1, CL2, CL3 is high and the thermal load of the second brake BR2 is not high, the amount of lubricating oil supplied to the first to third clutches CL1, CL2, CL3 is increased to ensure the durability of the first to third clutches CL1, CL2, CL3, and the amount of lubricating oil supplied to the second brake BR2 is reduced to reduce the agitation resistance and drag resistance caused by the lubricating oil in the second brake BR2 and the discharge loss of the oil pump.

In addition to the above-mentioned parameter conditions, pattern 2 is also applied when a certain period of time has passed since the engine was started (for example, within 3 seconds after the engine speed reaches 500 rpm or higher).

Specifically, usually, immediately after starting the vehicle, the lubricating oil in the centrifugal balance chambers P32, P42, and P52 may drain and remain in the oil pan. In this case, when the fastening operation is performed, hydraulic oil is supplied to the fastening hydraulic chambers P31, P41, and P51 without lubricating oil being supplied to the centrifugal balance chambers P32, P42, and P52.

The specified engagement oil pressure for engaging each frictional engagement element is set at a pressure that assumes that lubricating oil is supplied to the centrifugal balance chambers P32, P42, and P52. Therefore, if the specified engagement oil pressure is supplied when there is not enough lubricating oil supplied to the centrifugal balance chambers P32, P42, and P52, the timing of engagement will be accelerated, which may cause a shock to the occupants.

To solve this problem, immediately after starting, the amount of lubricating oil supplied to the first to third clutches CL1, CL2, and CL3 is increased (to the third predetermined flow rate) as described above, so that lubricating oil can be quickly supplied to the centrifugal balance chambers P32, P42, and P52.

Pattern 2 is also applied when another condition is that the ATF temperature is equal to or higher than a predetermined value Toil (e.g., 100°C).

Specifically, in this embodiment, when the ATF temperature is equal to or higher than a predetermined value Toil, the transmission control module (TCM) located in the oil pan may be damaged by heat due to the high oil temperature, so the ATF temperature must be lowered.

By changing the lubricant supply pattern to pattern 2, the resistance of the oil path passing through the oil cooler 91 (downstream of the oil cooler 91) can be reduced, so the amount of oil passing through the oil cooler 91 can be increased, effectively lowering the ATF temperature.

Specifically, in the second lubricating oil supply pattern (pattern 2), the second on/off valve 52 opens the lubricating oil increase valve 35 for the first to third clutches, so that the fifth lubricating oil branch passage f5, which branches off downstream of the cooler, communicates with the lubricating oil increase passage h for the first to third clutches. This allows the first to third branched lubricating oil supply passages f1 to f3, as well as the lubricating oil increase passage h for the first to third clutches to communicate, reducing resistance downstream of the oil cooler 91 and increasing the flow rate of lubricating oil flowing through the main lubricating oil passage f. As a result, the flow rate of lubricating oil cooled by the oil cooler 91 can be increased, and the ATF oil temperature can be reduced.

Furthermore, in pattern 2, the second brake lubricant oil boost valve 34 is closed by the first on/off valve 51, so that the fourth lubricant branch oil passage f4 branching off upstream of the oil cooler 91 is not connected to the second brake lubricant oil boost oil passage g that bypasses the oil cooler 91. As a result, in the hydraulic control circuit 20, lubricant oil is not supplied to the second brake BR2 from the second brake lubricant oil boost circuit g that does not pass through the cooler, and the amount of lubricant oil flowing through the oil passage that passes through the oil cooler 91 can be further increased.

When the cooling requirement level for the second brake BR2 is high H and the cooling requirement level for the first to third clutches CL1, CL2, and CL3 is low L, pattern 3 is executed as the third lubricant supply pattern.

The conditions for each parameter are that the temperature of the second brake BR2 is equal to or higher than the first threshold value Tlow, and that all of the parameters for determining the amount of lubricating oil supplied to the first to third clutches CL1 to CL3 (input torque, input speed, and temperatures of the first to third clutches CL1 to CL3) are less than predetermined values.

In pattern 3, the second brake BR2 is supplied with a fourth predetermined flow rate (large) of lubricant oil, which is greater than the first predetermined flow rate, through the second brake lubricant oil increase oil passage g in addition to the first lubricant oil branch passage f1. The first to third clutches CL1 to CL3 are supplied with a second predetermined flow rate (small) of lubricant oil through the second lubricant oil branch passage f2.

Expected scenarios include situations where an increase in the amount of lubricating oil supplied to the second brake BR2 is required, such as during high loads when going uphill, or during traffic jams, but an increase in the amount of lubricating oil supplied to the first to third clutches CL1 to CL3 is not required.

Specifically, when downshifting to go uphill, slippage occurs in the second brake BR2. In particular, the second brake BR2 is set with a larger number of friction plates than the other frictional fastening elements in order to ensure torque capacity when starting (see FIG. 4), so the amount of heat generated in a slipping state is also larger than that of the other frictional fastening elements. Therefore, the cooling requirement level for the second brake BR2 is high. In addition, when starting or holding the accelerator hill on an uphill road, the second brake BR2 slips under high load, so the temperature of the second brake BR2 is likely to exceed the first threshold value Tlow, and even in such a case, the cooling requirement level for the second brake BR2 is high.

When the vehicle is in a traffic jam, starting and stopping are repeated, which increases the frequency of slipping of the second brake BR2, and therefore increases the level of cooling required for the second brake BR2.

In this way, when the cooling requirement level for the second brake BR2 is high and the cooling requirement level for the first to third clutches CL1, CL2, and CL3 is low, the amount of lubricating oil supplied to the second brake BR2 is increased to ensure the durability of the second brake BR2, and the amount of lubricating oil supplied to the first to third clutches CL1, CL2, and CL3 is reduced to reduce the stirring resistance and drag resistance in the first to third clutches CL1, CL2, and CL3, as well as the discharge loss of the oil pump.

When the cooling requirement level for the second brake BR2 is high H and the cooling requirement level for the first to third clutches CL1, CL2, and CL3 is high H, pattern 4 is executed as the fourth lubricant supply pattern.

The conditions for each parameter are that the temperature of the second brake BR2 is equal to or higher than the first threshold value Tlow, and that one or more of the parameters for determining the amount of lubricant supplied to the first to third clutches CL1 to CL3 (input torque, input speed, temperature of the first to third clutches CL1 to CL3) is equal to or higher than a predetermined value.

In pattern 4, the second brake BR2 is supplied with a fourth predetermined flow rate (large) of lubricant oil that is greater than the first predetermined flow rate through the second brake lubricant oil increase passage g in addition to the first lubricant oil branch passage f1. The first to third clutches CL1 to CL3 are supplied with a third predetermined flow rate (large) of lubricant oil that is greater than the second predetermined flow rate through the first to third clutch lubricant oil increase passage h in addition to the second lubricant oil branch passage f2.

Expected scenarios include situations where the ATF temperature is relatively high (e.g., there is a risk that the temperature of the second brake BR2 may reach the first threshold value Tlow) and an increase in the amount of lubricant supplied to the second brake BR2 and an increase in the amount of lubricant supplied to the first to third clutches CL1 to CL3 are required, such as under medium load (e.g., a load higher than a low load such as idling and lower than a high load such as when driving uphill), during acceleration, upshifting, and downshifting due to torque demands.

Specifically, in a driving situation similar to pattern 2, if the ATF temperature is relatively high, the cooling requirement level for the second brake BR2 and the first to third clutches CL1 to CL3 is likely to be high.

In this way, when the cooling requirement level for the second brake BR2 and the first to third clutches CL1, CL2, and CL3 is high, the amount of lubricating oil supplied to the second brake BR2 and the first to third clutches CL1, CL2, and CL3 can be increased to prioritize ensuring the durability of the second brake BR2 and the first to third clutches CL1, CL2, and CL3.

In addition to the above parameter conditions, pattern 4 is also applied when the automatic transmission is in a failed state.

Specifically, for example, if any one of the following is true, a failure state is determined: an abnormality is detected in the input rotation speed sensor 203, an abnormality is detected in the oil temperature sensor 205, or an abnormality is detected in the input torque sensor 206 input from the engine to the transmission (if the input torque information signal is in a failed state status).

As a result, in a fail state, pattern 4 increases the flow rate of lubricating oil to the second brake BR2 and the first to third clutches CL1, CL2, and CL3, suppressing seizure and other problems in the frictional engagement elements and prioritizing reliability.

When the required cooling level for the second brake BR2 is at the highest HH, pattern 5 is executed as the fifth lubricant supply pattern.

The condition for each parameter is that the temperature of the second brake BR2 is equal to or greater than a second threshold Thigh (e.g., 180°C), which is higher than the first threshold Tlow.

In pattern 5, the second brake BR2 is supplied with a fifth predetermined flow rate (extra large) of lubricant oil, which is greater than the fourth predetermined flow rate (large), through the first lubricant branch oil passage f1, the second brake lubricant oil increase oil passage g, and the lubricant oil addition oil passage c connected to the discharge oil passage b of the electric pump 22. The first to third clutches CL1 to CL3 are supplied with a second predetermined flow rate of lubricant oil through the second lubricant branch oil passage f2.

One anticipated scenario is when the second brake BR2 is subjected to an excessive thermal load during high loads such as accelerator hill hold or towing. For example, accelerator hill hold is when the vehicle is kept stopped on an uphill road using the required driving force generated by the driver depressing the accelerator pedal, without operating the brake pedal. In accelerator hill hold, the braking state is maintained by balancing the rolling torque caused by the vehicle's own weight on an uphill road and the required driving torque, so a differential rotation occurs between the driving source and the driving wheels. This differential rotation causes the second brake BR2 between the driving source and the driving wheels to slip, placing an excessive thermal load on the second brake BR2, which can easily reduce the durability of the second brake BR2.

In such a situation, the durability of the second brake BR2 is ensured by giving top priority to cooling the second brake BR2.

The first to fifth lubricant supply patterns in FIG. 8 and the map shown in FIG. 9 are pre-stored in a memory section (not shown) of the control unit 200.

An example of the operation of the above-mentioned lubricant supply control will be described in more detail with reference to the flowcharts in Figures 10 and 11.

In step S1 of FIG. 10, various information required for lubricant supply control is detected. In step S1, various detection values such as accelerator opening, oil temperature, input rotation, output rotation, input torque, and oil pressure are read.

In the next step S2, it is determined whether a failure has occurred. If a failure has occurred, the lubricant supply pattern is determined to be the fourth lubricant supply pattern, and the flow proceeds to step S30, where lubricant is supplied to the second brake BR2 and the first to third clutches CL1, CL2, and CL3 in pattern 4. In a failure state, the fourth lubricant supply pattern increases the flow rate of lubricant to both the second brake BR2 and the first to third clutches CL1, CL2, and CL3, thereby suppressing seizure of each frictional engagement element and prioritizing reliability.

As described above, in determining whether or not a failure has occurred in step S2, if an abnormality is detected in any one of the input rotation speed sensor, the oil temperature sensor 205, or the input torque sensor 206, then the failure is determined. If it is determined in step S2 that the failure has not occurred, the process proceeds to step S3.

In step S3, it is determined whether the temperature of the second brake (frictional engagement element for starting) BR2 is equal to or higher than a second threshold value Thigh (e.g., 180°C) based on the temperature of the second brake calculated by the second brake temperature calculation means 223.

If the temperature of the second brake BR2 is equal to or higher than the second threshold value Thigh, the lubricant supply pattern is determined to be the fifth lubricant supply pattern, the flow proceeds to step S30, and lubricant is supplied to the second brake BR2 and the first to third clutches CL1, CL2, and CL3 in pattern 5.

A scenario in which the temperature of the second brake BR2 becomes equal to or higher than the second threshold Thigh is, for example, when an excessive heat load is applied to the second brake BR2 during high load such as accelerator hill hold or towing. In this state in which an excessive heat load is applied to the second brake BR2, the amount of lubricant supplied to the second brake by the fifth lubricant supply pattern (pattern 5) is set to be extra large as described above, and the amount of lubricant supplied to the first to third clutches CL1, CL2, and CL3 is not increased. This allows the proportion of lubricant supplied to the second brake BR2 to be relatively increased, thereby allowing the second brake BR2 to be cooled more effectively.

If the temperature of the second brake BR2 is less than the second threshold value Thigh in step S3, the process proceeds to step S4. In step S4, it is determined whether the input rotation speed is equal to or greater than the idle rotation speed N0 (e.g., 500 rpm). If the input rotation speed is equal to or greater than the idle rotation speed N0 in step S4, the process proceeds to step S5, where the timer is counted up, and the process proceeds to step S6. On the other hand, if the input rotation speed is less than the idle rotation speed N0 in step S3, the process proceeds to step S7, where the timer is set to 0, and the process proceeds to step S6.

In step S6, it is determined whether the timer is 0. If it is determined in step S6 that the timer is 0, that is, before the engine is started (the period until the first explosion before idling), the lubricant supply pattern is determined to be the first lubricant supply pattern, the flow proceeds to step S30, and lubricant is supplied to the second brake BR2 and the first to third clutches CL1, CL2, CL3 in pattern 1, and the flow returns. Before the engine is started and lubrication is not required, the amount of lubricant supplied to the second brake BR2 and the first to third clutches CL1, CL2, CL3 is not increased, thereby improving fuel efficiency.

If the timer is not 0 in step S6, the process proceeds to step S8, where it is determined whether the timer is 3 seconds or more. If the timer is less than a predetermined time t1 (e.g., 3 seconds) (e.g., within the period from start-up until 3 seconds have elapsed), the lubricant supply pattern is determined to be the second lubricant supply pattern, the flow proceeds to step S30, and lubricant is supplied to the second brake BR2 and the first to third clutches CL1, CL2, and CL3 in pattern 2, and the flow returns. The amount of lubricant supplied to the second brake BR2 is reduced, while the amount of lubricant supplied to the first to third clutches CL1, CL2, and CL3 is increased.

In this way, immediately after starting, as described above, by increasing the amount of lubricating oil supplied to the first to third clutches CL1, CL2, and CL3 (third predetermined flow rate), lubricating oil is quickly supplied to the centrifugal balance chambers P32, P42, and P52, and shock to the occupants caused by the supply of a predetermined engagement oil pressure when there is not enough lubricating oil supplied to the centrifugal balance chambers P32, P42, and P52 can be suppressed.

If the timer is equal to or greater than the predetermined time t1 in step S8, the process proceeds to step S9. In step S9, it is determined whether a gear shift is in progress. Whether a gear shift is in progress is determined by detecting the start and end of the gear shift. For example, the start of the gear shift is determined by whether a gear shift command has been output by the gear shift command detection means, and the end of the gear shift is determined by whether the ratio of the input and output rotational speeds matches the reduction ratio after the gear shift, based on the input rotational speed, output rotational speed, and gear ratio.

If a gear shift is in progress in step S9, the current lubricant supply pattern is maintained and the flow proceeds to step S30. In other words, during a gear shift, the flow returns without switching the lubricant supply pattern. This makes it possible to suppress changes in the friction coefficient μ between the friction plates during precise engagement control during a gear shift, thereby suppressing gear shift shock caused by the engagement timing deviating from the optimal timing due to drag resistance caused by the viscosity of the lubricant when the frictional engagement element is engaged.

For example, when switching patterns to increase the amount of lubricating oil supplied during a gear shift operation, it is possible to suppress the occurrence of shocks caused by each frictional engagement element being engaged earlier than desired due to the viscosity of the lubricating oil.

If a gear shift is not in progress in step S9, the process proceeds to step S10. In step S10, it is determined whether the lubricant supply pattern is pattern 5. If the lubricant supply pattern is pattern 5 in step S10, a gear shift is prohibited even if a gear shift command is detected, and the flow proceeds to step S30, where control is executed and the flow returns.

In this way, in the fifth lubricant supply pattern (pattern 5), when lubricant is supplied to each frictional fastening element, even if a shift command is output from the shift control means 210 based on the accelerator opening and vehicle speed, the shift control by the shift control means 210 is suppressed. As a result, in vehicle conditions where the thermal load on the second brake BR2 is more severe (e.g., accelerator hill hold and towing, etc.), the lubrication of the second brake BR2 is prioritized over the shift operation, thereby ensuring the durability of the second brake BR2.

If the lubricant supply pattern is other than pattern 5 in step S10, the process proceeds to step S11. In step S11, it is determined whether the lubricant supply pattern is being switched. To determine whether the lubricant supply pattern is being switched, for example, a timer is counted up from the time when the lubricant supply pattern switching command is output, and if the timer is within a predetermined time t2 when the switching of the lubricant supply amount is thought to be completed, it is determined that the lubricant supply pattern switching operation is being performed.

If the lubricant supply pattern is being switched in step S11, the gear shift operation is prohibited even if a gear shift command is detected, and the flow advances to step S30, where control is executed and the flow returns.

This makes it possible to prohibit gear shifting during the lubricant supply pattern switching operation, thereby preventing changes in the friction coefficient μ between the friction plates during precise engagement control during gear shifting. As a result, for example, when pattern switching operations that increase the amount of lubricant supplied overlap during gear shifting, it is possible to suppress the occurrence of shocks caused by each friction engagement element being engaged earlier than desired due to the viscosity of the lubricant.

If the lubricant supply pattern is not being switched in step S11, the process proceeds to step S12, and shifting is permitted. In the following step S13, it is determined whether the ATF temperature detected by the oil temperature sensor 205 is equal to or higher than a predetermined value Toil (e.g., 100°C). If the ATF temperature is equal to or higher than the predetermined value Toil in step S13, the lubricant supply pattern is determined to be the second lubricant supply pattern, and the flow proceeds to step S30, where lubricant is supplied to the second brake BR2 and the first to third clutches CL1 to CL3 in pattern 2.

In this embodiment, if the ATF temperature is equal to or higher than a predetermined value Toil, the transmission control module (TCM) located in the oil pan may be damaged by heat due to the high oil temperature, so the ATF temperature must be lowered.

By using the second lubricant supply pattern (pattern 2), as described above, the resistance of the oil passage passing through the oil cooler 91 can be reduced, so the amount of oil passing through the oil cooler 91 can be increased, effectively lowering the ATF temperature.

If the ATF temperature is less than the predetermined value Toil in step S13, the process proceeds to step S14, where the lubricant supply pattern is determined according to the lubricant flow rate pattern determination flow shown in FIG. 11.

In step S15, it is determined whether the temperature of the second brake BR2 is equal to or greater than the first threshold value Tlow (e.g., 150°C). If the temperature of the second brake BR2 is less than the first threshold value Tlow, in step S16 it is determined whether the input speed is equal to or greater than a predetermined value Nin (e.g., 3000 rpm), in step S17 it is determined whether the input torque is equal to or greater than a predetermined value Tq1 (e.g., 250 Nm), in step S18 it is determined whether the temperature of the first clutch CL1 is equal to or greater than a predetermined value Tcl1 (e.g., 180°C), in step S19 it is determined whether the temperature of the second clutch CL2 is equal to or greater than a predetermined value Tcl2 (e.g., 180°C), and in step S20 it is determined whether the temperature of the third clutch CL3 is equal to or greater than a predetermined value Tcl3 (e.g., 180°C).

If the temperature of the second brake BR2 is less than the threshold Tlow, the input rotation speed is less than the predetermined value Nin, the input torque is less than the predetermined value Tq1, and the temperatures of the first to third clutches CL1, CL2, and CL3 are less than the predetermined values Tcl1, Tcl2, and Tcl3, the lubricant supply pattern is determined to be the first lubricant supply pattern, the flow proceeds to step S30, and lubricant is supplied to the second brake BR2 and the first to third clutches CL1, CL2, and CL3 in pattern 1, and the flow returns.

In addition, if the temperature of the second brake BR2 is less than the first threshold value Tlow, and any one of the input rotation speed, input torque, and temperature of the first to third clutches CL1, CL2, and CL3 is equal to or greater than a predetermined value, the lubricant supply pattern is determined to be the second lubricant supply pattern, the flow proceeds to step S30, and lubricant is supplied to the second brake BR2 and the first to third clutches CL1, CL2, and CL3 in pattern 2, and the flow returns.

On the other hand, if the temperature of the second brake BR2 is equal to or greater than the first threshold Tlow in step S15, then in step S21 it is determined whether the input speed is equal to or greater than a predetermined value Nin (e.g., 3000 rpm), in step S22 it is determined whether the input torque is equal to or greater than a predetermined value Tq1 (e.g., 250 Nm), in step S23 it is determined whether the temperature of the first clutch CL1 is equal to or greater than a predetermined value Tcl1 (e.g., 180°C), in step S24 it is determined whether the temperature of the second clutch CL2 is equal to or greater than a predetermined value Tcl2 (e.g., 180°C), and in step S25 it is determined whether the temperature of the third clutch CL3 is equal to or greater than a predetermined value Tcl3 (e.g., 180°C).

If the temperature of the second brake BR2 is equal to or higher than the threshold value Tlow, the input rotation speed is less than the predetermined value Nin, the input torque is less than the predetermined value Tq1, and the temperatures of the first to third clutches CL1, CL2, and CL3 are less than the predetermined values Tcl1, Tcl2, and Tcl3, the lubricant supply pattern is determined to be the third lubricant supply pattern, the flow proceeds to step S30, and lubricant is supplied to the second brake BR2 and the first to third clutches CL1, CL2, and CL3 in pattern 3, and the flow returns.

In addition, if the temperature of the second brake BR2 is equal to or higher than the threshold value Tlow, and any one of the input rotation speed, input torque, and temperature of the first to third clutches CL1, CL2, and CL3 is equal to or higher than a predetermined value, the lubricant supply pattern is determined to be the fourth lubricant supply pattern, the flow proceeds to step S30, and lubricant is supplied to the second brake BR2 and the first to third clutches CL1, CL2, and CL3 in pattern 4, and the flow returns.

With the above configuration, the lubricant supply pattern can be switched depending on the temperature of the second brake BR2, the input torque, the input rotation speed, and the temperatures of the first to third clutches CL1, CL2, and CL3, so that an appropriate amount of lubricant can be supplied to the second brake BR2 and the first to third clutches CL1, CL2, and CL3 depending on the state of the vehicle.

This allows the amount of lubricating oil to the second brake BR2 and the first to third clutches CL1, CL2, and CL3 to be reduced, usually with an emphasis on fuel economy, while supplying the necessary amount of lubricating oil to the second brake BR2 and the first to third clutches CL1, CL2, and CL3 as needed. As a result, it is possible to achieve both improved fuel economy for the entire transmission while taking into account the state of the vehicle, and ensure the durability of each frictional engagement element.

In particular, when switching the amount of lubricant for the second brake BR2, which is sensitive to heat generation, the amount of lubricant supplied can be appropriately set by using the temperature of the second brake BR2, which is a parameter that is more directly related to the thermal load.

This allows the system to supply the necessary amount of lubricating oil to each frictional engagement element of the automatic transmission according to the vehicle's condition, without complicating the control content or control conditions, thereby improving fuel efficiency while ensuring the reliability of each frictional engagement element.

As mentioned above, during a predetermined period after the engine starts (for example, within 3 seconds from when the engine speed reaches 500 rpm or more), the lubricating oil increase oil passage h for the first to third clutches CL1 to CL3 is connected to the centrifugal balance chambers P32, P42, and P52 of the first to third clutches CL1 to CL3 in addition to the second lubricating oil branch passage f2, and the flow passage is increased, thereby reducing the flow passage resistance of the first lubricating circuit. This increases the flow rate of the first lubricating circuits f2 and h, and allows hydraulic oil to be quickly supplied to the centrifugal balance chambers P32, P42, and P52 without increasing the base pressure (line pressure) of the hydraulic circuit.

As a result, when a gear shift (engagement operation) is performed immediately after starting the vehicle, etc., while the lubricating oil in the centrifugal balance chambers P32, P42, and P52 has been drained and is stored in the oil pan, the timing of engagement can be prevented from being accelerated even if an engagement oil pressure set at a pressure that assumes that lubricating oil is being supplied to the centrifugal balance chambers P32, P42, and P52 is supplied.

This makes it possible to suppress the deterioration of fuel economy while also suppressing shocks caused by the centrifugal balance chambers P32, P42, and P52 not being filled with lubricating oil when the first, second, and third clutches CL1, CL2, and CL3 are engaged.

As described above, by blocking the second brake lubricating oil increase passage g that communicates with the second brake BR2 and restricting the flow rate of the second lubricating circuits f1, g, the proportion of lubricating oil flowing into the first lubricating circuits f2, h can be increased compared to when the flow rate of the lubricating oil in the second lubricating circuits f1, g is not restricted. This increases the flow rate of hydraulic oil supplied to the centrifugal balance chambers P32, P42, P52, so that hydraulic oil can be supplied to the centrifugal balance chambers in a shorter time.

The present invention is not limited to the illustrated embodiments, and various improvements and design changes are possible without departing from the spirit of the present invention.

For example, in this embodiment, the lubricating oil supplied to the first brake BR1 is described as being supplied from the lubricating oil passage L12 provided in the input shaft 12, but the lubricating oil supplied to the first brake BR1 may be supplied from the same supply path as the lubricating oil supply path for the first to third clutches CL1 to CL3. In this case, the amount of lubricating oil supplied to the first to third clutches CL1 to CL3 and the first brake BR1 may be configured such that a step is added to the steps following steps S20 and S25 in the flowchart of FIG. 11 to determine whether the temperature of the first brake BR1 is equal to or higher than a predetermined value (e.g., 180°C).

In addition, for example, in this embodiment, the lubricant supply pattern is determined based on whether the temperature of the second brake BR2, the input rotation speed, the input torque, and the temperatures of the first to third clutches CL1 to CL3 are equal to or greater than predetermined thresholds. However, the lubricant supply pattern may be determined based on the input torque and the temperature of the second brake BR2.

In addition, for example, in this embodiment, the lubricant supply pattern is determined based on whether the temperature of the second brake BR2, the input rotation speed, the input torque, and the temperatures of the first to third clutches CL1 to CL3 are equal to or greater than predetermined thresholds. However, the lubricant supply pattern may be determined based on the input torque, the input rotation speed, or the temperatures of the first to third clutches CL1 to CL3, and the temperature of the second brake BR2.

In addition, for example, in this embodiment, the temperature of each frictional fastening element is calculated by calculation, but as shown by the virtual lines in FIG. 7, the temperature of each frictional fastening element may be detected using a temperature sensor or the like for each frictional fastening element.

In addition, for example, in this embodiment, the determination of whether a gear shift is in progress in step S8 and the determination of when the gear shift is complete may be made based on whether each frictional engagement element is fully engaged.

In addition, for example, in this embodiment, a configuration has been described in which the switching operation of the lubricant supply pattern is restricted during a gear shift operation and the gear shift operation is prohibited during the gear shift operation, but it is also possible to only restrict the switching operation of the lubricant supply pattern during a gear shift operation or to prohibit the gear shift operation during the gear shift operation.

In addition, for example, in this embodiment, a configuration has been described in which an increase circuit (an increase orifice and an increase valve) for each frictional fastening element is provided to increase the amount of lubricating oil supplied to each frictional fastening element. However, as a configuration for increasing the amount of lubricating oil supplied to each frictional fastening element, instead of the increase orifices 84, 85, the lubricating oil increase valves 34, 35, and the fixed orifices 81, 82, 83, a variable orifice may be used to adjust the orifice diameter according to the operating state of the vehicle.

In this embodiment, an example has been described in which the third lubrication circuit in the claims is configured by the third lubrication branch oil passage f3, but the first brake BR1 may be connected to the second lubrication branch oil passage f2. In this case, the first brake BR1 is supplied with lubricating oil in the same way as the first to third clutches CL1 to CL3.

As described above, the present invention provides a lubrication control device for an automatic transmission that can suppress the deterioration of fuel economy while suppressing shocks caused by the clutch's centrifugal balance chamber not being filled with hydraulic oil, and therefore has the potential to be suitably used in the transmission manufacturing industry.

2. Hydraulic control device (lubrication control device)
10 Automatic transmission 73c Multiple friction plates 73d Piston 200 Lubricant supply control means (control device)
BR1 First brake (other brake)
BR2 Second brake (starting brake)
CL1, CL2, CL3 First, second, and third clutches (clutches)
P31 Fastening hydraulic chamber P32 Centrifugal balance chamber f1, g Second lubrication circuit f2, h First lubrication circuit f3 Third lubrication circuit t1 Predetermined period

Claims (4)

A piston that presses the plurality of friction plates;
a fastening hydraulic chamber to which hydraulic oil is supplied for urging the piston toward the friction plate;
A lubrication control device for an automatic transmission having a clutch that is engaged when starting and has a centrifugal balance chamber to which hydraulic oil is supplied to urge the piston in a direction opposite to the friction plate direction,
a hydraulic control circuit for controlling the supply of lubricating oil to each lubrication portion in the automatic transmission;
the hydraulic control circuit includes a first lubrication circuit that is branched off midway through the hydraulic control circuit and that is capable of changing a flow rate of lubricating oil that communicates with the centrifugal balance chamber , and a second lubrication circuit that is separate from the first lubrication circuit,
The second lubrication circuit is configured to be able to change a flow rate of lubricating oil,
and a control means for controlling the flow rate of the first lubrication circuit to be increased and the flow rate of the second lubrication circuit to be limited during a predetermined period immediately after starting of the drive source. The lubrication control device for an automatic transmission according to claim 1, characterized in that the flow rate of the lubricating oil in the first lubrication circuit is increased by increasing the flow path of the first lubrication circuit. The automatic transmission includes a starting brake that is engaged when starting, and a brake other than the starting brake,
3. The lubrication control device for an automatic transmission according to claim 1, wherein the starting brake and the other brakes are connected to a lubrication circuit separate from the first lubrication circuit in the hydraulic control circuit . The hydraulic control circuit further includes a third lubrication circuit separate from the first and second lubrication circuits,
The starting brake is supplied with lubricating oil from the second lubrication circuit,
4. The lubrication control device for an automatic transmission according to claim 3 , wherein the lubricating oil is supplied to the other brake from the third lubrication circuit.

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