JPH0612144B2 - Lockup clutch controller - Google Patents

Description

The present invention relates to a lockup clutch control device.

(B) Conventional Technique As a conventional lockup clutch control device, there is, for example, one disclosed in Japanese Patent Laid-Open No. 60-241570. The torque converter of the automatic transmission shown therein has a lock-up clutch, and this lock-up clutch is engaged at two or more gear stages. When shifting from a state in which a lockup clutch of a predetermined shift stage is engaged to a state in which a lockup clutch of another shift stage is engaged, the lockup clutch is temporarily released. That is, the lockup clutch is released a predetermined time after the shift command signal is output, and the lockup clutch is reengaged a predetermined time after this. The shift is completed while the lockup clutch is released. This is intended to mitigate the shock when shifting.

(C) Problems to be Solved by the Invention However, in the conventional lockup clutch control device as described above, the engine rotation speed is increased because the lockup clutch is disengaged at the same time when the lockup clutch is released during gear shifting. There is a problem that a feeling of idling of the engine is generated, and conversely, the engine rotation speed is reduced at the time of re-engagement, which causes a shock. In particular, during gentle operation with a small throttle opening, the above-mentioned feeling of idling or shock is noticeable and causes discomfort.

It should be noted that Japanese Patent Laid-Open No. 62-194068 discloses that the lockup clutch is always in the engaged state at the time of the 3-4 irregularity, which is the shift stage on the high speed side. Excessive shift shock will occur when the engine torque is high.

The present invention aims to solve such problems.

(D) Means for Solving the Problems The present invention solves the above problems by holding the lock-up clutch engaged state during gear shifting with a small throttle opening. That is, the control device for the lock-up clutch according to the present invention includes a throttle opening degree determination means for determining whether the throttle opening degree is larger or smaller than a predetermined value, and a predetermined gear shift stage when the throttle opening degree is equal to or smaller than a predetermined value. When the gear is shifted from the lock-up operating region to the lock-up operating region of another gear, the lock-up holding means for holding the lock-up operating state during the shift is provided and a predetermined value when the throttle opening is larger than a predetermined value. And a lockup releasing means at the time of a large throttle opening for temporarily releasing the lockup clutch during the shift when shifting from the lockup operating region of the shift stage to the lockup operating region of another shift stage. ing.

(E) Action Due to the action of the lockup holding means at the small throttle opening, the operating state of the lockup clutch is maintained as it is in the case of the shift at the small throttle opening. Since the operating condition is a small throttle opening degree, a large shift shock is not generated, and conversely, the operating state of the lockup clutch does not change, so that a shock due to a change in engine speed is prevented. On the other hand, in a gear shift other than the above, the lockup clutch is temporarily released during the gear shift as in the conventional gear shift shock is reduced.

(F) Embodiment An embodiment of the present invention is shown in FIG. Torque converter 10
Has a lockup clutch 18 in addition to the pump impeller 12, the turbine runner 14, and the stator 16. An apply chamber 20 in which the pump impeller 12, the turbine runner 14, etc. are arranged is formed on the right side of the lockup clutch 18 in the drawing, and a release chamber 22 is formed on the left side of the lockup clutch 18 in the drawing. The oil passage 24 is connected to the apply chamber 20, and the release chamber 22 is also connected.
The oil passage 26 is connected to. The lockup clutch 18 has a facing 30 that comes into contact with the friction surface of the cover 28 of the torque converter 10. The supply state of the hydraulic pressure to the oil passage 24 and the oil passage 26 is controlled by the lockup control valve 32. The lockup control valve 32 has a spool 34, a sleeve 36, a plug 38, and a spring 40. Further, the oil passage 42, the oil passage 44, and the oil passage 4 other than the oil passage 24 and the oil passage 26 described above.
6, the oil passage 48 and the oil passage 50 are also connected as shown. The torque converter relief valve 5 is provided in the oil passage 42.
A constant pressure is supplied from 2. The torque converter relief valve 52 performs a pressure adjusting action using the hydraulic pressure of the oil passage 54 to which the hydraulic pressure is supplied from a pressure regulator valve (not shown). The oil passage 44 is connected to an oil cooler 56, and the oil exiting the oil cooler 56 is used for lubrication. The oil passage 50 is supplied with a constant pressure regulated by a pressure regulating valve (not shown). The oil passage 46 branched from the oil passage 50 via the orifice 56 is connected to a lockup solenoid 58. The lockup solenoid 58 is provided with a plunger 62 that closes the opening 60 of the oil passage 46 in the non-energized state. The energized state of the lockup solenoid 58 is duty ratio controlled by a signal from the control unit 64. That is, the lock-up solenoid 58 is repeatedly turned on and off at a predetermined cycle, opens the opening 60 according to the ratio of the on-time, and thereby adjusts the hydraulic pressure of the oil passage 46 so as to be inversely proportional to the on-time. The control unit 64 includes an idle switch 66, a vehicle speed sensor 68 and a throttle opening sensor 7
Signals from 0 are input, and the control unit 64 controls the operation of the lockup solenoid 58 based on these signals as described later. The idle switch 66 is a switch that turns on when the throttle opening is fully closed.

Next, the operation of this embodiment will be described. First, control of the disengaged state, the half-clutched state, and the completely engaged state of the lockup clutch 18 will be described.

The released state of the lockup clutch 18 is realized as follows. That is, the lock-up solenoid 58 has a duty ratio of 0, and the opening 60 has the plunger 62.
Completely closed by. Therefore, the same hydraulic pressure as the oil passage 50 is generated in the oil passage 46, and this acts on the left end portion of the spool 34 of the lockup control valve 32. Therefore, the spool 34 is in the state shown in the figure, and the oil pressure of the oil passage 42 is transmitted through the oil passage 26 to the release chamber 22.
To the cover 2 and the hydraulic pressure in the release chamber 22 is supplied to the cover 2
8 through the clearance between the friction surface and the facing 30 into the apply chamber 20 side, then through the oil passage 24 and back to the lockup control valve 32, and then the oil passage 44.
Is discharged to. That is, hydraulic pressure is supplied from the oil passage 26 to the release chamber 22, and then from the apply chamber 20 to the oil passage 24.
Is discharged to. Therefore, the hydraulic pressure in the release chamber 22 and the hydraulic pressure in the apply chamber 20 become the same (strictly speaking, since the apply chamber 20 side is on the downstream side, the apply chamber 20 side is slightly lower due to the flow path loss). As a result, the lockup clutch 18 is released. That is,
The torque converter 10 is in a torque converter state in which the rotational force is transmitted only via the fluid.

When controlling the lockup clutch 18 from the above state to the half-clutch state, the following operation is performed. That is, when the duty ratio given from the control unit 64 to the lockup solenoid 58 is gradually increased, oil is discharged from the opening 60 according to this duty ratio, and the oil pressure in the oil passage 46 is reduced. Therefore, the hydraulic pressure acting on the left end portion of the spool 34 of the lockup control valve 32 decreases, and the spool 34 and the plug 38 move leftward in the drawing. Spool 34 and plug 3
When 8 moves to the left by a predetermined amount, the oil passage 26 is slightly communicated with the drain port 72, and at the same time, the oil passage 4
2 is in communication with the oil passage 24. Since the oil pressure of the oil passage 26 is fed back to the right end portion of the plug 38 via the oil passage 48, the lockup control valve 32
Is adjusted, and the oil pressure in the oil passage 26 is adjusted according to the oil pressure acting on the left end portion of the spool 34 from the oil passage 46. That is, in this state, the torque converter 1
0 is supplied with oil pressure from the oil passage 24 to the apply chamber 20,
The hydraulic pressure in the apply chamber 20 enters the release chamber 22 through the clearance between the lockup clutch 18 and the cover 28, and is discharged from the oil passage 26. This oil passage 26
Oil pressure of the oil passage 46, that is, the oil pressure adjusted in inverse proportion to the duty ratio of the lockup solenoid 58,
Will be controlled by. Since the hydraulic pressure on the release chamber 22 side is lower than the hydraulic pressure on the apply chamber 20 side, the facing 30 of the lockup clutch 18 is pressed against the friction surface of the cover 28. The force pressing the lockup clutch 18 is controlled by the lockup solenoid 58 as described above.

Next, the duty ratio of the lockup solenoid 58 is set to 1
At 00%, the opening 60 is completely released. Therefore, the oil pressure in the oil passage 46 becomes 0, and the spool 34 is completely switched to the left side in the drawing. In this state, the hydraulic pressure is supplied from the oil passage 24 to the apply chamber 20 and the lockup clutch 18 is completely engaged, so that almost no oil flows into the oil passage 26.

Next, the control of the lockup clutch 18 according to the present invention will be described. Lockup clutch 1 as described above
The control of 8 operations is performed in combination with the shift of the automatic transmission.
That is, the complete engagement area, the half clutch area, and the disengagement area are set in relation to the shift line as shown in FIG. FIG. 3 shows a shift pattern in the case of upshift shifting. In the case of the shift pattern shown in FIG. 3,
In the 4th speed, the lockup clutch is completely engaged in most of the region, and the half-clutch state is also set in the low vehicle speed range with a small throttle opening. Further, in the third speed, full engagement is performed in the large throttle opening / high speed range, and half-clutch control is performed only in the small throttle opening / low vehicle speed range. Further, in the second speed range, the half-clutch control is performed in the small throttle opening / low vehicle speed range. Code A
That is, the shift from the second speed to the third speed at the small throttle opening / low vehicle speed, and the shift from the third speed to the fourth speed at the small throttle opening / low vehicle speed indicated by symbol B At this time, the lockup clutch 18 is shifted while the half-clutch state is maintained. On the other hand, during the shift from the third speed fully engaged state to the fourth speed fully engaged state indicated by the symbol C, the lockup clutch 18 is released during the shift. Such control is performed according to the flowchart shown in FIG. That is, it is first determined whether or not the clutch is in the half-clutch control state (step 102), and then whether or not the clutch is in the completely-engaged state (step 104). When the complete engagement control is being performed, it is determined whether the current throttle opening θ is larger than a predetermined value θ _o (at 106).
If θ <θ _o , the routine continues as it is. If θ> θ _o , control is performed to temporarily release the lockup clutch 18 during gear shifting (at step 110). In this control, the lock-up solenoid 58 is turned on after a predetermined time has elapsed from the input of the shift command signal, and is turned off after a predetermined time. As a result, the lockup clutch 18 is released as described above. After all, by the control shown in FIG. 4, the lockup clutch 18 is temporarily released during the gear shift at the large throttle opening. On the contrary, when the throttle opening is small, the lockup clutch 18 is not temporarily released. As a result, the gear shifts A and B shown in FIG.
The gear shift is performed while the clutch 8 is in the half-clutch state, while the lock-up clutch 18 is temporarily released during the gear shift indicated by the symbol C shown in FIG. During the gear shift indicated by reference characters A and B, the gear shift is performed while the lock-up clutch 18 is in the half-clutch state as described above, but it is in a mild operating condition at a small throttle opening, and a large gear shift shock is generated. Rather, rather lockup clutch 18
Since the temporary release and re-engagement of the engine are not performed, it is possible to prevent a shock from occurring due to a change in the engine rotation speed. On the other hand, in the gear shift at the large throttle opening indicated by the symbol C, the lockup clutch 18 is temporarily released as in the conventional case,
Shift shock is reduced.

(G) Effect of the Invention As described above, according to the present invention, when the gear shift is performed with the small throttle opening, the gear shift is performed while the lock-up clutch is in the completely engaged state or the half-clutch state. It is possible to prevent a shift shock from occurring due to temporary disengagement and re-engagement of the clutch. Further, it is possible to prevent the occurrence of an excessive shift shock in the state where the engine torque is large, as compared with the case where the lock-up clutch is always engaged during the 3-4 shift.

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship between components of the present invention, FIG. 2 is a diagram showing an embodiment of the present invention, FIG. 3 is a diagram showing a shift pattern, and FIG. 4 is a diagram showing a control flow. . 18 ... Lockup clutch, 58 ... Lockup solenoid, 66 ... Idle switch.

Claims (1)

[Claims] 1. A lockup operating region in which the operating state of a lockup clutch capable of connecting a pump impeller side and a turbine runner side of a fluid transmission device is controlled by a solenoid, and the lockup clutch is in a completely engaged state or a half clutch state. In a control device for a lock-up clutch in which gear ratio is set to 2 or more, a throttle opening determination means for determining whether the throttle opening is larger or smaller than a predetermined position, and a state where the throttle opening is a predetermined value or less In the case of shifting from a lock-up operating region of a predetermined shift stage to a lock-up operating region of another shift stage, the lock-up holding means at a small throttle opening for holding the lock-up operating state during the shift and the throttle opening If the value is greater than the specified value, the lock-up operation area of a predetermined gear shifts to the lock of another gear. A lock-up clutch control device, comprising: a lock-up clutch release means at the time of a large throttle opening that temporarily releases the lock-up clutch during gear shifting when the gear is shifted to the up-actuation region.