JPS60196464A - Control unit of lock-up clutch for automatic speed change gear - Google Patents

Abstract

PURPOSE:To prevent a delay in the transit time and incompleteness in shifting to the engaging state by controlling a solenoid valve according to a pulse signal within a specified time and retaining the solenoid valve in the open or close state after the lapse of the specified time in case of switching a lock-up clutch to the engaging state. CONSTITUTION:In case of switching a lock-up clutch 28 from the disengaging state to the engaging state, within a specified time from the start time of engaging operation, a solenoid valve 34 is periodically opened and closed according to an electric pulse signal. After the lapse of the specified time, the solenoid valve 34 is retained in the open or close state. Thus, within the specified time, the control pressure of the lock-up clutch 28 is suitably limited to restrain a shock, and after the lapse of the specified time, the control pressure of the lock-up clutch 28 can be controlled to high or low enough to improve the transit time to the complete engagement and the engaging state.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a control device for a lock-up clutch used in an automatic heavy-duty automatic transmission.

BACKGROUND OF THE INVENTION A lock-up clutch is provided in parallel with a fluid torque converter and is held engaged under predetermined operating conditions to prevent power loss due to power transmission in the fluid torque converter. In the conventional control device for such a lock-up clutch, a solenoid valve is provided to control the control pressure of the lock-up clutch in relation to the duty (2) ratio of the electric human power pulse signal.
By sending an electric pulse signal with an appropriate decoupling ratio to the solenoid valve between j and weakening the engagement force of the Y1 pull-up clutch, the impact on the power transmission system when the lock-up clutch is switched from the released state to the engaged state is reduced. is being eased.

1 Note 1] When switching the pull-up clutch to the engaged state, variations in the engine torque, hydraulic control circuit, or its oil temperature may take a long time to fully engage the clutch, or the clutch may not fully engage. There is a possibility that the rym may not be properly engaged. These are undesirable because they cause deterioration in drivability and durability of the lock-up clutch.

DISCLOSURE OF THE INVENTION An object of the present invention is to prevent the occurrence of shock when switching the lock-up clutch to the engaged state, and to reduce the transition time and engagement time of the lock-up clutch to the redundantly engaged state. ρj
An object of the present invention is to provide a control device for a cock-up clutch for an automatic transmission that can improve the condition.

To achieve this object, the present invention provides that a lock-up clutch is provided in parallel to the driftwood converter, and that a solenoid valve is connected to the differential ratio of the electric manual pulse signal. A control device for the +1 pull-up clutch for white dynamic oil converters that controls the control pressure of the lock-up clutch? 1
In (-1), when changing the pull-up clutch from the released state to the engaged state, the solenoid valve is periodically opened and closed by an electric pulse signal within a predetermined time from the start time of the engagement operation. and a second control means (41j) for keeping the solenoid valve closed and closed after a predetermined period of time has elapsed.

When the lock-up clutch is switched to the engaged state, the first control means performs electric pulse signal control of the solenoid valve, and as a result, the control pressure of the lock-up clutch is limited (drops) and locked. Since the engagement force of the up clutch is adjusted appropriately, the rotational speed of the engine is gradually increased and the engine speed is controlled by 1fl.

Further, at a predetermined time, ifli tu, the solenoid valve is held either open or closed by the second control means, and the control pressure of the lock-up clutch becomes sufficiently high or low to cause the clutch of the lock-up clutch to engage. 6. Since JJ rises quickly, it may take a long time for the lock-up clutch to become fully engaged, or if it becomes fully engaged, 1. Prevents you from collapsing.

In a most practical example, the control II of the lock-up clutch is based on the engagement hydraulic pressure that increases the engagement force of the lock-up clutch and the release force FE that acts on the opposite body 1 of the engagement hydraulic pressure. The solenoid valve controls the spool position of the spool valve that controls the supply h1 of the hydraulic medium to the engagement pump L "generating port 1-" and the release side hydraulic pressure generating port 1.

During the period when the electromagnetic valve is receiving the electrical input pulse signal, the engagement side oil pressure decreases appropriately, and the release side oil pressure increases appropriately.

By kneading, [the engagement force of the cock-up clutch should be properly adjusted!] The shock is softened.

Preferably, the time period during which the solenoid valve is controlled by an electric manual pulse signal is equal to f! of the control pressure medium. It! It is assumed to be a decreasing function of degree. If the control pressure medium has a low fertility (Iu), it has a high viscosity, and the control pressure that gradients to the same pump rotation V < speed is also high < 7.T.
Therefore, it is necessary to lengthen the time limit of the control pressure to suppress the 41II attack. By making the electric pulse control time a decreasing function of the degree of control pressure medium, it is possible to eliminate the influence of changes in control pressure due to the degree of control pressure medium.

Example The present invention will be described with reference to the embodiment shown in FIG.

FIG. 1 is an overall schematic diagram of an automatic transmission and its control device, and the automatic transmission 10 includes an engine-side fluid torque converter 12 and a gear device 14 coaxially connected thereto. The fluid 1 to lux converter 12 has a pump impeller +8 connected to the crankshaft 16, a stator 22 connected to the housing via a one-way clutch 20, and a tooth F (connected to the input shaft 24 of the i-device 14). The turbine runner 2+i, which is currently in use, is installed.

The lock-up clutch 28 is connected to the fluid torque converter 1
2, and when engaged, the crankshaft 16
The power is transferred to the input shaft 2 without passing through the fluid torque converter 12.
Transmits 10 tangents to 4. The microcomputer 30 for automatic transmission control receives input signals such as throttle opening, vehicle speed, oil temperature, and shift position, and controls the hydraulic control circuit 3.
2? Controls the solenoid valve 34 as the I[ia valve.

The solenoid valve 34 is provided for controlling the lock-up clutch 28, and controls the control pressure of the lock-up clutch 28.

FIG. 2 is a detailed hydraulic control circuit diagram of the lock-up clutch 28.

The lock-up signal pressure generating valve 36 is connected to an input boat 38 and an output boat 40 that are supplied with line pressure at high speeds of 2nd speed or higher.
It has a spool 44 selectively connecting it to an input boat 38 or a drain 42, and a hydraulically supplied chamber 48 opposing a spring 46. The oil passage 50 has an orifice 5
It is supplied with line pressure via 2 and connected to chamber 48 .

(7) The solenoid valve 34 has a solenoid 54 and a solenoid 5.
4, and the valve body 56 whose position is controlled by the oil passage 5.
0 and the drain 58.

When the solenoid 54 is energized, the valve body 56 is opened and the hydraulic medium in the blood path 50 is discharged to the drain 58. When the solenoid 54 is not energized, the valve body 56 is closed and the oil path 50 is maintained at line pressure.

The lock-up control valve 60 includes an input port 2 that is constantly supplied with line pressure PI, and a lock-up signal pressure generating valve 3.
A control chamber 64 connected to the output boat 40 of 6, a boat 66 connected to the oil cooler, an output port 8 connected to the hydraulic torque converter 12 and thus to the engagement side of the lock-up clutch 28, a lock-up Output port door 0 , drains 72 , 74 , control chamber 64 connected via clutch 28 to fluid torque converter 12 and thus to the release side of lock-up clutch 28
A spool 76 selectively connects the input port 2 to the output port 8 or 70 in relation to the oil pressure of the control chamber 78 (8), which urges the spool 76 toward the control chamber 64 in response to the in pressure. It has a spool 80.

The overall operation of this hydraulic control circuit will be explained.

The solenoid 54 of the solenoid valve 34 is energized (
On), the hydraulic medium in the oil passage 50 is discharged to the drain 58 via the open valve element 56, so the oil pressure in the control chamber 48 of the lock-up signal pressure generating valve 36 is low. Therefore, the spool 44 moves toward the control room 48 and the output boat 40
The line pressure is guided to. Lockup control valve 60 is supplied with line pressure to control chamber 64 so that spool 76 moves toward spool 80 and input port 2 is connected to output port 8. As a result, line pressure is supplied to the engagement side of the lock-up clutch 28, and the lock-up clutch 28 becomes engaged.

When the solenoid 54 of the solenoid valve 34 is not energized (off), the valve body 56 is in a closed state, and the oil passage 50 and the control chamber 48 are maintained at line pressure. The spool 44 therefore moves towards the spring 46 (9) and the output boat 40 is connected to the drain 42. Since the oil pressure in the control chamber 64 of the lock-up control valve 60 is low, the spool 76 moves toward the control chamber 64 due to the biasing force from the spool 80, and the input port door 2 is connected to the output port door 0.

As a result, line pressure is applied to the release side of lock-up clutch 28, fluid torque converter 12, and output port 8.
The oil is then guided from Bo 1-66 to the oil cooler. As a result, the lock-up clutch 28 is held in a released state, and engine power is transmitted via the fluid torque converter 12.

FIG. 3 shows the effect of electric pulse signal control of the solenoid valve 34 (solid line) in comparison with the effect of no electric pulse signal control (broken line). During the period when electric pulse signal control is being performed, the valve body 56 of the solenoid valve 34 repeats opening and closing periodically, so the output boat 40 is connected to the input port 3.
8 and drain 42 alternately, the output boat 40
oil pressure, and therefore the control of the lock-up control valve 60 (10
) The oil pressure in the chamber 64 is lowered appropriately from the line pressure. As a result, the spool 76 is in the intermediate position, and the input port 2 is synchronously connected to the output ports h68 and 70. However, the connection circulation area to the input port 2 is larger for the output port 8 than for the output port 70. Therefore, the hydraulic pressure on the engaging side of the lock-up clutch 28 appropriately decreases, and the hydraulic pressure on the releasing side increases appropriately. Changes in the engine rotational speed when changing to the engaged state +IrJ become gentler, and fluctuations in the output shaft torque of the automatic transmission 10 are also suppressed, reducing the impact. In the case where electric pulse signal control is not carried out, the engaging side hydraulic pressure increases to the line pressure of the input coupler 1-62, and the disengaging side hydraulic pressure decreases to zero, so that the engaging force of the I pull-up clutch 28 is The l-lux deflection, and therefore the shock, increases. Note that even when electric pulse signal control is implemented, the reason why the solenoid valve 34 is continuously kept energized within a predetermined time Ti from the engagement operation start time 10 is because of the first time 1 (71 o'clock?■ This is to prevent a delay in the rise of the engagement side oil pressure due to the implementation of the i-pulse signal.

FIG. 4 shows the effect of the present invention (solid line) in which the electric pulse signal control is limited to a predetermined time '1'd from the engagement operation start time 10.
(The period 11i is continued ()) and the electric pulse signal section (broken line) is omitted compared to Sentence 1. The resultant force will be reduced appropriately, but if the engine torque is large, variations in the hydraulic control path, oil width, etc., the lock-up clutch 28 may not be fully engaged, causing the engine rotation speed and output shaft to decrease. Fluctuations may occur in the torque.Therefore, ?Tt pulse signal control is performed for a predetermined time T.
d, and the solenoid valve 34 is continuously kept energized after time t1. As a result, after time t1, the engagement side oil pressure and the release side oil pressure quickly reach the line pressure of input ports 1 to 02 and zero, respectively.
The lock-up clutch 28 is fully engaged. As a result, [the durability of the hook-up clutch 28 is reduced,
Also, delays in reaching the fully engaged state are prevented.

The lower the hot water temperature, the higher the viscosity of the hydraulic medium, and therefore the higher the oil pressure at the same pump drive speed.
In order to prevent shock at the initial stage of engagement of the lock-up clutch 28, it is advantageous to set the predetermined time Td as a function of decreasing oil pressure, and to lengthen the electric pulse signal control period as the oil pressure is lower. It is.

FIG. 5 shows a control routine for the lock-up clutch solenoid valve 34. If it is determined from the input data such as the throttle opening degree O that the lock-up clutch 28 should be switched to the engaged state, electric pulse signal control is performed for a predetermined time Td, and after the predetermined time 'rd has passed, the solenoid valve 34 is is kept continuously energized (on). To describe each step, in step 86, input data necessary to determine whether the lock-up clutch 28 should be engaged is read, such as throttle opening (13) degree 0 and vehicle speed ■. In step 88, it is determined whether the lock-up clutch 28 should be engaged based on the data read in step 86. If the determination is negative, the process proceeds to step 90, and if it is not, the process proceeds to step 96. In step 90, the solenoid valve 3 is
4 and starts the operation of the elapsed time measurement timer. In step 92, the elapsed time 'I' measured by the elapsed time measuring timer is compared with Td, and when T>Td, the process proceeds to step 94. In step 94, the electric pulse signal control is turned off to keep the solenoid valve 34 on continuously. In step [ ] 6, the no. 1 tunoid valve' (4) is kept turned off continuously.

In the hydraulic control circuit of the embodiment, when the solenoid valve 34 is energized, the lock-up clutch 28 is engaged, and when the solenoid valve 34 is de-energized, the lock-up clutch CIA) 28 is engaged. The hydraulic control circuit has been described in which the lock-up clutch 28 is released when the solenoid valve 34 is energized, and the lock-up clutch 28 is engaged when the solenoid valve 34 is de-energized. It goes without saying that the present invention can also be applied to a hydraulic control circuit that is in a locked state (for example, the positions of the inlet port 1-38 and the drain 42 are reversed in the lock-up signal pressure generating valve 36).

[Brief explanation of the drawing]

Fig. 1 is a diagram schematically showing the entire automatic transmission and its control device, Fig. 2 is a detailed diagram of the hydraulic control circuit that controls the lock-up clutch, and Fig. 3 is a diagram showing the solenoid valve for controlling the lock-up clutch electrically. Figure 4 is a diagram showing the effect of controlling with a pulse signal. Figure 4 is a diagram showing the effect of limiting the period of electric pulse signal control of the solenoid valve for lock-up clutch control. Figure 5 is for lock-up clutch control. It is a flow chart of solenoid valve control ALJ rechin. (15) 10... automatic transmission, 12... fluid 1-lux converter, 28... lock-up clutch, 30... microphone r1 computer, 32... hydraulic control circuit, 34
...Solenoi) Kuben patent applicant 1 Heyota automatic 1i Stock company monthly fee RII Patent attorney Osamu Naka 4 ゛ (If)) 8

Claims (1)

[Claims] 1. For an automatic transmission in which a lock-up clutch is provided in parallel to a fluid torque converter, and a solenoid valve controls the control pressure of the lock-up clutch in relation to a duty 17 of an electrical input pulse signal. In a lock-up clutch control device, a first control means that periodically opens and closes a solenoid valve using an electric pulse signal within a predetermined time from the start time of engagement operation when switching the lock-up clutch from a released state to an engaged state. 1. A control device for a lock-up clutch for an automatic transmission, comprising: and second control means that holds the solenoid valve either open or closed after a predetermined period of time has elapsed. 2 The control pressure of the lock-up clutch consists of an engagement pressure (+) that increases the engagement force of the lock-up clutch and a disengagement hydraulic pressure that acts in the opposite direction to the engagement hydraulic pressure. Side oil pressure generation boat and release side 1
2. The control device according to claim 1, wherein the control device controls the spool position of a spool valve that controls the amount of hydraulic medium supplied to the pressure generating bow. 3. The control device according to claim 1, wherein the predetermined time is a decreasing function of the temperature of the control pressure medium.