JP2021116856A - Clutch control device - Google Patents

Abstract

To provide a clutch control device capable of quickly releasing a wet-type multiple disc clutch when a vehicle stops at a high deceleration speed even at a low temperature, at which viscosity of a hydraulic fluid is high.SOLUTION: A clutch control device is mounted on a vehicle including: a wet-type multiple disc clutch for connecting/disconnecting a power transmission passage between a driving source and a driving wheel of the vehicle; a lubricant supply device capable of controlling a flow rate of a lubricant for cooling the wet-type multiple disc clutch; and a piston which is displaced according to a piston control hydraulic pressure as a pressure of a hydraulic oil in a hydraulic chamber, generates an engagement pressure of the wet-type multiple disc clutch when the piston control hydraulic pressure is increased so that the piston is pressed against the wet-type multiple disc clutch, and is increased in back pressure when the flow rate of the lubricant is increased. The clutch control device controls the lubricant supply device to increase the flow rate of the lubricant when a vehicle deceleration speed in stopping of the vehicle with the wet-type multiple disc clutch engaged is high, in comparison with a case when the vehicle deceleration speed is low.SELECTED DRAWING: Figure 1

Description

The present invention relates to a clutch control device mounted on a vehicle including a wet multi-plate clutch arranged between a vehicle drive source and drive wheels.

Patent Document 1 discloses a lubrication control method for a starting clutch, which is arranged between a transmission of a vehicle and an engine and includes a wet multi-plate clutch for transmitting power. According to this lubrication control method, the flow rate of the lubricating oil supplied to the wet multi-plate clutch is controlled according to the engagement pressure (engagement pressure) of the wet multi-plate clutch.

Japanese Unexamined Patent Publication No. 2008-281919 JP-A-2010-149630 Japanese Patent No. 44832420

In a vehicle equipped with a wet multi-plate clutch (hereinafter, also simply referred to as "clutch") arranged between the drive source of the vehicle and the drive wheels, the clutch is released when the vehicle is about to stop at a high deceleration. There is a demand to quickly disconnect the drive source from the drive wheels. In particular, when the drive source is an internal combustion engine, if the clutch release is delayed, the internal combustion engine may stall, so that the above requirement is high. In particular, when the viscosity of the hydraulic oil of the piston that operates the clutch is high and the temperature is low, the release of the clutch tends to be delayed.

The present invention has been made in view of the above-mentioned problems, and the wet multi-plate clutch is quickly released when the vehicle stops at a high deceleration even at a low temperature where the viscosity of the hydraulic oil is high. It is an object of the present invention to provide a clutch control device capable of performing the above.

The clutch control device according to the present invention is
A wet multi-plate clutch that connects / disconnects the power transmission path between the vehicle drive source and drive wheels,
A lubricating oil supply device that can control the flow rate of the lubricating oil that cools the wet multi-plate clutch,
It is displaced according to the piston control oil pressure, which is the pressure of the hydraulic oil in the hydraulic chamber, and when the piston control oil pressure rises and is pressed against the wet multi-plate clutch, the engagement pressure of the wet multi-plate clutch is generated, and the lubricating oil A piston whose back pressure increases as the flow rate increases,
It is installed in a vehicle equipped with.
In the clutch control device, when the vehicle deceleration is high when the vehicle is about to stop while the wet multi-plate clutch is engaged, the flow rate of lubricating oil is larger than when the vehicle deceleration is low. The lubricating oil supply device is controlled so as to be.

According to the present invention, when the vehicle deceleration is high when the vehicle is about to stop while the wet multi-plate clutch is engaged, the flow rate of the lubricating oil is higher than when the vehicle deceleration is low. Will be increased. As the flow rate of lubricating oil increases, the back pressure of the piston increases. As a result, the release pressure of the clutch that acts to release the wet multi-plate clutch in the engaged state becomes high. As a result, when the wet multi-plate clutch is released in response to the establishment of the sudden stop determination, the release property of the clutch can be improved. Therefore, the wet multi-plate clutch can be quickly released even at a low temperature in which the responsiveness of the piston control oil pressure is lowered due to the high viscosity of the hydraulic oil.

It is a schematic diagram which showed an example of the structure around the wet multi-plate clutch 10 of the vehicle which mounted the clutch control device which concerns on Embodiment 1 of this invention. It is a flowchart which shows the routine of the process concerning the control of the clutch control device which concerns on Embodiment 1 of this invention. It is a schematic diagram which showed an example of the structure of the power train system of the vehicle which mounted the clutch control device which concerns on Embodiment 2 of this invention. It is a flowchart which shows the routine of the process concerning the control of the clutch control device which concerns on Embodiment 2 of this invention.

When the number, quantity, quantity, range, etc. of each element is referred to in the embodiment shown below, the number mentioned is not specified unless otherwise specified or clearly specified in principle. However, the present invention is not limited. In addition, the structures, steps, and the like described in the embodiments shown below are not necessarily essential to the present invention, unless otherwise specified or clearly specified in principle.

1. 1. Embodiment 1
The first embodiment of the present invention will be described with reference to FIGS. 1 and 2.

1-1. An example of a system configuration FIG. 1 is a schematic view showing an example of a configuration around a wet multi-plate clutch 10 of a vehicle 1 on which the clutch control device 50 according to the first embodiment is mounted.

The vehicle 1 provided with the wet multi-plate clutch (hereinafter, also simply referred to as “clutch”) 10 shown in FIG. 1 includes an internal combustion engine (not shown) as an example of a drive source and an automatic transmission combined with the internal combustion engine (not shown). (Not shown). The clutch 10 is provided as a starting clutch for this automatic transmission. Specifically, the clutch 10 is arranged between these internal combustion engines and an automatic transmission, and connects / disconnects a power transmission path between the internal combustion engine (drive source) and drive wheels (not shown).

As shown in FIG. 1, the clutch 10 is housed in the outer shell 12. The outer shell 12 rotates integrally with the input shaft 14 connected to the crankshaft (not shown) of the internal combustion engine. The clutch 10 includes a plurality of substantially annular separator plates 16 which are friction engagement elements on the input side (drive source side) and a plurality of annular clutch discs which are friction engagement elements on the output side (drive wheel side). Includes 18 and. As shown in FIG. 1, the separator plate 16 and the clutch disc 18 are alternately arranged in the axial direction of the input / output shafts 14 and 20.

The separator plate 16 on the input side is spline-coupled to the outer shell 12 located on the outer diameter side thereof. The clutch disc 18 on the output side is spline-coupled to the inner shell 22 located on the inner diameter side thereof. The inner shell 22 rotates integrally with the output shaft 20 connected to the input shaft (not shown) of the automatic transmission.

A piston 24 is arranged inside the outer shell 12. The piston 24 is interposed between one end of the clutch 10 and the side wall 12a of the outer shell 12 on the side facing the one end. A hydraulic chamber 26 is formed between the side wall 12a and the piston 24. The hydraulic oil is supplied to the hydraulic chamber 26 via the oil passage 28 formed in the input shaft 14. The piston 24 is displaced according to the pressure of the hydraulic oil (hereinafter, also referred to as “piston control oil pressure”).

More specifically, the piston 24 is urged toward the side wall 12a by the return spring 30. Further, the pressure in the internal space 32 of the outer shell 12 located on the opposite side of the hydraulic chamber 26 via the piston 24 acts on the piston 24 as back pressure. When the piston control oil pressure becomes high, the force for moving the piston 24 toward the clutch 10 becomes large. When this force overcomes the force of the return spring 30 and the force based on the back pressure, the piston 24 is displaced toward the clutch 10. The piston 24 creates an engaging pressure on the clutch 10 when pressed against the clutch 10. The higher the piston control oil pressure, the stronger the force pressing the piston 24 against the clutch 10, and the higher the engagement pressure.

When the piston control oil pressure rises and the engaging pressure of the clutch 10 rises to a predetermined value, the clutch 10 starts to engage. When the engagement pressure further increases, the clutch 10 is in a completely engaged state. As a result, the power transmission path between the drive source and the drive wheels is connected. On the other hand, if the piston control oil pressure is lowered in this fully engaged state, the engaging pressure is lowered. When the engagement pressure falls below the above-mentioned predetermined value, the clutch 10 is released. As a result, the power transmission path is cut off. When the internal combustion engine is stopped, the clutch control device 50 controls the piston control oil pressure so that the clutch 10 is in the released state in order to avoid the stall of the internal combustion engine.

Further, the vehicle 1 is provided with a lubricating oil supply device 34. The lubricating oil supply device 34 supplies the lubricating oil to the clutch 10 for cooling the clutch 10. The lubricating oil is supplied to the inside of the outer shell 12 through the lubricating oil path 36 shown in FIG. The lubricating oil that has cooled the clutch 10 is returned to the oil pan 40 via the oil cooler 38.

The lubricating oil supply device 34 is configured to be able to control the flow rate of the lubricating oil. More specifically, the lubricating oil supply device 34 includes, as an example, a linear solenoid 34a and a pressure regulating valve 34b. The linear solenoid 34a continuously changes the line pressure from the automatic transmission, and as a result, the flow rate of the lubricating oil is continuously changed. The pressure adjusting valve 34b adjusts the pressure of the lubricating oil supplied to the clutch 10 so as not to exceed a certain value. When the flow rate of the lubricating oil supplied to the clutch 10 is increased by controlling the linear solenoid 34a, the pressure in the internal space 32 described above increases. That is, the back pressure of the piston 24 increases.

Further, the vehicle 1 is equipped with a clutch control device 50. The clutch control device 50 includes an electronic control unit (ECU), and controls the lubricating oil supply device 34 together with a hydraulic control device (not shown) for controlling the piston control hydraulic pressure. The clutch control device 50 includes the operation of the vehicle 1 such as the throttle opening of the internal combustion engine, the engine speed, the input speed of the automatic transmission (transmission input speed), the presence / absence of depression of the brake pedal, and the vehicle deceleration. Sensors 52 for detecting the state are connected.

1-2. Control by the clutch control device In the vehicle 1 provided with the wet multi-plate clutch 10 arranged between the drive source (internal combustion engine) and the drive wheels, when the vehicle 1 tries to stop at a high deceleration (that is, sudden stop). There is a demand to release the clutch 10 and quickly disconnect the drive source from the drive wheels. The reason is that if the release of the clutch 10 is delayed, the internal combustion engine may stall. In view of such a problem, the clutch control device 50 of the present embodiment executes the routine processing shown in FIG. 2 below.

FIG. 2 is a flowchart showing a processing routine related to control of the clutch control device 50 according to the first embodiment. The processing of this routine is repeatedly executed while the vehicle is running.

In the routine shown in FIG. 2, the clutch control device 50 (ECU) first executes a sudden stop determination of the vehicle 1 in step S100. The sudden stop determination referred to here is to determine whether or not the time when the vehicle 1 is about to stop at a deceleration of a predetermined value or more (the vehicle stop process in which the vehicle speed is decreasing toward the stopped state) has arrived. To say. Such a sudden stop determination can be performed using any known determination method. As an example, the sudden stop determination can be made by using the throttle opening and the transmission input rotation speed (or engine rotation speed), and when the throttle opening is zero, the reduction rate is as high as a predetermined value or more. It is established when the transmission input speed drops below a predetermined value.

If a sudden stop determination is made in step S100, the process proceeds to step S102. In step S102, the clutch control device 50 increases the clutch cooling flow rate (that is, the flow rate of the lubricating oil) so that the clutch 10 is in the ON / OFF state (engaged state / released state). Controls the supply device 34. More specifically, as an example, the clutch control device 50 controls the lubricating oil supply device 34 (linear solenoid 34a) so that the higher the deceleration when the vehicle 1 is about to stop, the greater the deceleration.

On the other hand, if the sudden stop determination is not made in step S100, the process proceeds to step S104. In step S104, the clutch control device 50 adjusts the clutch cooling flow rate so that the clutch 10 has a predetermined small flow rate value when the clutch 10 is in the ON / OFF state. Further, in the case of a clutch slip state (clutch SLIP) other than the ON / OFF state, the clutch cooling flow rate is adjusted so as to have a predetermined large flow rate value larger than the above small flow rate value. In addition, even when the engine is stopped by the idling stop function, the clutch cooling flow rate is set to a predetermined small flow rate value in step S104.

1-3. Effect According to the routine processing shown in FIG. 2 described above, the clutch control device 50 is a vehicle when the vehicle deceleration is high when the vehicle 1 is about to stop while the clutch 10 is engaged. The lubricating oil supply device 34 is controlled so that the clutch cooling flow rate (flow rate of the lubricating oil) is larger than that when the deceleration is low. As described above, as the flow rate of the lubricating oil increases, the back pressure of the piston 24 increases. As a result, the release pressure of the clutch 10 that acts to release the clutch 10 in the engaged state increases. As a result, the release property of the clutch 10 can be improved when the clutch 10 is released in response to the establishment of the sudden stop determination. In particular, the clutch 10 can be quickly released even at a low temperature at which the responsiveness of the piston control oil pressure is lowered due to the high viscosity of the hydraulic oil.

More specifically, according to the routine processing shown in FIG. 2, the clutch control device 50 cools the clutch as the vehicle deceleration when the vehicle 1 is about to stop while the clutch 10 is engaged is higher. Increase the flow rate (flow rate of lubricating oil). As a result, the higher the vehicle deceleration, the higher the back pressure of the piston 24 and the higher the release pressure of the clutch 10. That is, the higher the vehicle deceleration, the faster the clutch 10 can be released.

1-4. Another Example of Lubricating Oil Flow Control In the above-described first embodiment, if the vehicle deceleration is high when the vehicle 1 is about to stop while the clutch 10 is engaged, the vehicle deceleration is increased. As an example of control to increase the clutch cooling flow rate (lubricating oil flow rate) as compared with the case where the clutch cooling flow rate is low, the linear solenoid 34a is used, and the higher the vehicle deceleration, the higher the lubricating oil flow rate. In another example of this flow rate control, an on / off solenoid for switching the flow rate of the lubricating oil in two stages may be used instead of the linear solenoid 34a. Then, when the vehicle deceleration when the vehicle 1 is about to stop with the clutch 10 engaged is higher than the predetermined value, the lubricating oil is compared with the case where the vehicle deceleration is equal to or less than the predetermined value. Flow rate may be increased.

2. Embodiment 2
Next, a second embodiment of the present invention will be described with reference to FIGS. 3 and 4.

2-1. Example of System Configuration FIG. 3 is a schematic diagram showing an example of the configuration of the power train system of the vehicle 60 on which the clutch control device 70 according to the second embodiment is mounted. The vehicle 60 shown in FIG. 3 is a hybrid vehicle including an internal combustion engine 62 and a motor generator (MG) 64 as drive sources. The MG 64 is arranged coaxially with the output shaft (crankshaft) of the internal combustion engine 62 between the internal combustion engine 62 and the automatic transmission 66. A wet multi-plate clutch 10 (see FIG. 1) is incorporated between the MG 64 and the automatic transmission 66 as a so-called K0 clutch. As described above, also in the vehicle 60 of the present embodiment, the clutch 10 is arranged so as to connect / shut off the power transmission path between the drive source (internal combustion engine 62 and MG64) and the drive wheel 68.

The vehicle 60 includes a clutch control device 70 having the same function as the clutch control device 50. The clutch control device 70 controls the lubricating oil supply device 34 together with a hydraulic control device (not shown) for controlling the piston control hydraulic pressure.

2-2. Control by Clutch Control Device In this embodiment as well, as in the first embodiment, the higher the vehicle deceleration when the vehicle is about to stop with the clutch 10 engaged, the more the linear solenoid 34a is used. Therefore, the clutch cooling flow rate (flow rate of lubricating oil) is increased. In addition, also in this embodiment, the above-mentioned 1-4. When the vehicle deceleration is higher than the predetermined value when the vehicle is about to stop while the clutch 10 is engaged by using the on / off solenoid instead of the linear solenoid 34a as in the example described in the above. , The flow rate of the lubricating oil may be increased as compared with the case where the vehicle deceleration is equal to or less than the predetermined value.

Further, in the present embodiment, the clutch cooling flow rate is set to a predetermined large flow rate value even when the internal combustion engine 62 is stopped, the clutch 10 is released, and the brake pedal is not depressed (brake OFF). On the other hand, when the internal combustion engine 62 is stopped, the clutch 10 is released, and the brake pedal is depressed (brake ON), the clutch cooling flow rate is set to a predetermined small flow rate value.

FIG. 4 is a flowchart showing a processing routine related to control of the clutch control device 70 according to the second embodiment. The processing of steps S100 to S104 in this routine is as described above in the first embodiment.

In the routine shown in FIG. 4, if the sudden stop determination is not made in step S100, the process proceeds to step S200. In step S200, the clutch control device 70 determines whether or not the engine is stopped. As a result, if the engine is not stopped, the process proceeds to step S104.

On the other hand, if the engine is stopped in step S200, the process proceeds to step S202. In step S202, the clutch control device 70 determines whether or not the clutch 10 is being released (a state in which the piston control oil pressure is controlled so that the clutch 10 is in the released state). As a result, if the clutch 10 is not being released, the process proceeds to step S204. In step S204, the clutch control device 70 sets the clutch cooling flow rate to a predetermined small flow rate value.

On the other hand, when the clutch 10 is being released in step S202, the clutch control device 70 determines whether or not the brake pedal is depressed (whether or not the brake is ON). As a result, when the brake is ON, the clutch control device 70 sets the clutch cooling flow rate to a small flow rate value in step S204.

On the other hand, when the brake pedal is not depressed (brake OFF state), the process proceeds to step S208. Examples of the process proceeding to step S208 in this way include an example in which the vehicle 60 is coasting in a state where the engine is stopped (a state in which the rotation shaft on the input side of the clutch 10 is not rotating) and the clutch 10 is released. It includes an example in which EV traveling is performed using another MG (not shown). In step S208, the clutch control device 70 sets the clutch cooling flow rate to a predetermined large flow rate value.

2-3. Effect Also by the routine processing shown in FIG. 4 of the second embodiment, the release property of the clutch 10 is improved when the clutch 10 is released in response to the establishment of the sudden stop determination as in the first embodiment. Can be improved.

Further, according to the routine processing shown in FIG. 4, a large clutch is also satisfied when the conditions that the internal combustion engine 62 is stopped, the clutch 10 is released, and the brake pedal is not depressed (brake OFF) are satisfied. The cooling flow rate is secured. If the clutch 10 is not sufficiently released and the drag torque of the clutch 10 is high during the above-mentioned EV running or coasting when this condition is satisfied, fuel consumption may deteriorate. Further, if the drag torque of the clutch 10 is high when the internal combustion engine 62 is restarted by using the torque of the MG 64 during EV traveling or coasting, the torque of the MG 64 is canceled by the drag torque and the restart is performed. Sex may worsen. In addition, these problems become remarkable at low temperatures when the viscosity of the hydraulic oil is high, similar to the problems at the time of sudden stop determination described above. In response to such a problem, in the present embodiment, when the above conditions are satisfied, a large clutch cooling flow rate (flow rate of lubricating oil) is secured, and the back pressure of the piston 24 is increased. As a result, the drag torque during EV traveling or coasting can be reduced to suppress deterioration of fuel efficiency, and the restartability from EV traveling or coasting can be improved.

Further, according to the routine processing shown in FIG. 4, when the conditions that the internal combustion engine 62 is stopped, the clutch 10 is released, and the brake pedal is depressed (brake ON) are satisfied, the clutch is cooled. The flow rate is reduced and the back pressure of the piston 24 is reduced. As a result, the drag torque of the clutch 10 can be used to assist the braking force.

The examples described in the above-described embodiments and the other modifications may be appropriately combined within a possible range other than the specified combinations, and various modifications may be made without departing from the spirit of the present invention. You may.

1, 60 Vehicle 10 Wet multi-plate clutch 24 Piston 26 Hydraulic chamber 30 Return spring 32 Internal space 34 Lubricating oil supply device 50, 70 Clutch control device 52 Sensors 62 Internal combustion engine 66 Automatic transmission 68 Drive wheels

Claims (1)

A wet multi-plate clutch that connects / disconnects the power transmission path between the vehicle drive source and drive wheels,
A lubricating oil supply device capable of controlling the flow rate of the lubricating oil that cools the wet multi-plate clutch, and
It is displaced according to the piston control oil pressure which is the pressure of the hydraulic oil in the hydraulic chamber, and when the piston control oil pressure rises and is pressed against the wet multi-plate clutch, the engagement pressure of the wet multi-plate clutch is generated. A piston whose back pressure increases as the flow rate of the lubricating oil increases,
It is a clutch control device mounted on a vehicle equipped with
When the vehicle deceleration is high when the vehicle is about to stop while the wet multi-plate clutch is engaged, the clutch control device lubricates the vehicle as compared with the case where the vehicle deceleration is low. A clutch control device characterized in that the lubricating oil supply device is controlled so that the flow rate of oil increases.

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