JPH0543901B2 - - Google Patents

Description

[Detailed description of the invention]

TECHNICAL FIELD The present invention relates to a control device for an automatic transmission for a vehicle, and more particularly to a technique for eliminating shock when a shift lever is operated from a neutral range to a forward range, regardless of the rotational speed of the engine. Prior Art In automatic transmissions for vehicles, in order to prevent a shock that occurs when the shift lever is operated from the neutral range to the forward range, a temporary (about 1
A gear stage higher than the lowest speed gear stage (for example, the third gear stage) is engaged in a period of about 2 seconds). According to such control, since the gear ratio of the upper gear is smaller than that of the lowest gear, the shock when operating the shift lever is reduced. Problems to be Solved by the Invention However, in order to shift to the upper gear, it is necessary to operate the hydraulic actuator for switching to the lowest gear and other hydraulic actuators in addition to the hydraulic actuator for switching to the lowest gear. Since the discharge amount is affected by the engine rotation speed, or the engagement time of the upper gear stage varies depending on the engine rotation speed, the other hydraulic actuators mentioned above are controlled according to a fixed control time. However, there was an inconvenience in that a shift shock occurred depending on the rotational speed of the engine. That is,
For example, if the shift lever is switched from the neutral range to the forward range when the engine is running at a relatively high rotational speed, such as in the first idle rotation state at a cold start or in a state immediately after revving, the normal idle rotation Since the discharge amount of the hydraulic pump is larger than that of the hydraulic pump, when the hydraulic actuator for switching to the lowest speed gear is operated first, the engagement of the lowest speed gear may start first, or Even though the engagement time becomes longer as the engine rotation speed increases, the hydraulic fluid of other hydraulic actuators starts draining before the upper gear stage is sufficiently engaged. There was an inconvenience that the shift shock became large due to the engagement of the high gear stage. Means for Solving the Problems The present invention has been made against the background of the above-mentioned circumstances, and its gist is the operation of a hydraulic actuator and other hydraulic actuators for switching to the lowest speed gear. In a vehicle automatic transmission of the type that switches to a gear higher than the lowest gear, when the shift lever is operated from the neutral range to the forward range, the automatic transmission for switching to the lowest gear By supplying hydraulic fluid to the hydraulic actuator and supplying hydraulic fluid to the other hydraulic actuator in addition to the hydraulic actuator, the upper gear is temporarily shifted to the lowest gear prior to switching to the lowest gear. (1) lever operation detection means for detecting that the shift lever has been switched from a neutral range to a forward range; and (2) an engine rotation detection means for detecting a rotation speed of the vehicle engine. speed detection means; (3)
The present invention further includes a control time adjusting means for lengthening the time from when the shift lever is switched to when the discharge of hydraulic oil from the other hydraulic actuator is started in accordance with an increase in the rotational speed of the engine. Operation and Effects of the Invention With this arrangement, as shown in the claim correspondence diagram of FIG. 1, when the shift lever detection means detects the shift lever switching operation, the engine rotational speed detection means The time from when the shift lever is switched to when the hydraulic fluid of the other hydraulic actuator starts to be discharged is controlled by the control time adjusting means according to the increase in the engine rotation speed. long adjusted. This eliminates the problem of switching shock caused by operating the shift lever from the neutral range to the forward range even when the engine speed is high, such as during first idle or when revving. It is. In other words, if the time from when the shift lever is switched until the discharge of hydraulic fluid from other hydraulic actuators starts is adjusted to be longer depending on the engine rotation speed, the upper gear Since sufficient gear engagement time can be ensured, it is possible to eliminate the occurrence of a shift shock caused by the engagement of the lowest speed gear starting before the engagement of the upper gear has progressed sufficiently. Preferably, the control device of the present invention further includes an oil temperature sensor that detects the temperature of the hydraulic oil supplied to the hydraulic actuator, and the control time adjusting means is configured to adjust the control time from the time of the switching operation of the shift lever to the time of the switching operation of the shift lever. The time required to start discharging the hydraulic fluid from other hydraulic actuators is corrected based on the temperature of the hydraulic fluid. In this case, changes in the response characteristics of the hydraulic actuator due to changes in the viscosity of the hydraulic oil are suitably compensated for. Embodiment In FIG. 2, a stepped transmission gear system 14 is connected to a vehicle engine 10 via a fluid coupling 12 with a direct clutch such as a fluid coupling or a torque converter. The output shaft 16 of the transmission gear device 14 is connected to drive wheels of the vehicle via a differential device (not shown) or the like. Speed change gear device 14
For example, a plurality of sets of planetary gear devices and a ring gear, a planet gear, and a sun gear that constitute each of the planetary gear devices are coupled to each other, or,
The device includes a plurality of friction devices, such as a plurality of clutches and brakes, coupled to a fixed casing to selectively prevent rotation, and a one-way clutch. By selectively operating these friction devices by a plurality of hydraulic actuators, as shown in Table 1, the first gear (lowest gear), the second gear, and the third gear gear, overdrive gear, or reverse gear. A hydraulic circuit 18 is provided to operate each hydraulic actuator of the transmission gear system 14. The hydraulic circuit 18 includes electromagnetic valves MV1, MV2, and MV3 that are operated by command signals from a microcomputer (ECU) 20. The solenoid valves MV1 and MV2 are used exclusively to control the hydraulic actuator for changing gears of the transmission gear 14, and the solenoid valve MV3 is used exclusively to control the direct coupling clutch of the fluid coupling 12. Therefore, the fluid coupling 12, transmission gear device 14, and hydraulic circuit 18 constitute an automatic transmission that automatically changes the gear ratio according to a drive signal from the microcomputer 20. Since the fluid coupling 12, transmission gear device 14, and hydraulic circuit 18 are well known, a detailed explanation thereof will be omitted. It is constructed similarly to that described. Therefore, as shown in Table 1, when only the solenoid valve MV1 is operated while the shift lever is switched from the neutral range to the forward range (for example, drive range), hydraulic oil is supplied to the hydraulic actuator C1. , the transmission gear device 14 shifts to the lowest speed gear (first gear).
(speed gear). In addition, solenoid valve MV
1 and MV2 are operated simultaneously, the hydraulic actuator B2 is supplied with hydraulic oil in addition to the hydraulic actuator C1, and is switched to the second gear. Further, when only the solenoid valve MV2 is operated, hydraulic oil is further supplied to the hydraulic actuator C2, and the gear is switched to the third gear. In addition,
When the shift lever is switched to the forward range, hydraulic oil is always supplied to the hydraulic actuator CO except for overdrive (OD), so a description thereof will be omitted. Also, solenoid No. in Table 1.
No. 1 and No. 2 actuate the solenoid valves MV1 and MV2, respectively, so when the solenoid indicated by a circle is activated, the solenoid valve corresponding to that solenoid is activated.

[Table] A throttle opening sensor 24 is provided in the intake pipe of the engine 10, and a throttle opening signal Sθ representing the opening θ of the throttle valve is supplied from the throttle opening sensor 24 to the microcomputer 20. Ru. Further, the engine 10 is provided with an engine rotation sensor 26, and an engine rotation speed signal SR representing the rotation speed Ne of the engine 10 is supplied from the engine rotation sensor 26 to the microcomputer 20. Further, a rotation sensor 28 is provided to detect the rotation speed of the output shaft 16 of the transmission gear device 14, and a vehicle speed signal SV representing the vehicle speed V is supplied from the rotation sensor 28 to the microcomputer 20. The hydraulic circuit 18 is provided with an oil temperature sensor 30 that detects the temperature of the hydraulic oil, and an oil temperature signal SY representing the oil temperature To of the hydraulic oil is supplied from the oil temperature sensor 30 to the microcomputer. . Further, a pattern select signal SP representing, for example, "power", "normal", or "economy" is sent from the operation pattern select switch 32 to the water temperature sensor 34.
From is a water temperature signal SW representing the water temperature of the engine 10.
However, a brake operation signal SB indicating that a foot brake pedal (not shown) has been operated is sent from the brake switch 36 to the handbrake switch 38.
A side brake operation signal SSB indicating that the side brake lever has been manually operated is supplied to the microcomputer 20, and a shift lever position signal SL indicating the operation position of the shift lever is supplied from the shift lever position sensor 40 to the microcomputer 20. It's becoming like that. The microcomputer 20 is a so-called CPU,
It is composed of ROM, RAM, etc., and the CPU processes the signals supplied to the microcomputer 20 while using the temporary storage function of the RAM according to the program stored in advance in the ROM, and processes the signals supplied to the microcomputer 20.
Outputs a drive signal to operate MV2 and MV3. Next, the operation of the control device for a vehicle automatic transmission constructed as described above will be explained according to the flowchart shown in FIG. First, step S1 is executed and the contents of flag F are reset to zero. This flag F is used to determine that the shift lever is being operated from the neutral range to the forward range (eg, drive range). Then step S2 is executed and the contents of the timer are reset to zero. Then, the main routine of step S3 is executed, and the vehicle speed signal SV is determined from the pre-stored shift pattern represented by the pattern select signal SP.
The number of gears is determined based on the vehicle speed V and the throttle opening θ expressed by the throttle opening signal Sθ. Then, in step S4, it is determined whether the content of the flag F is 1, in other words, whether the shift lever has already been operated from the neutral range to the forward range. If the vehicle is already running, the shift lever has already been operated to the forward range, so steps S11 to S13 are executed to determine whether or not the brake is being operated, in other words, the brake operation signal. SB or handbrake operation signal
It is determined whether SSB has occurred, and whether the vehicle speed represented by the vehicle speed signal SV is zero or not.
Then, it is determined whether the throttle opening degree θ represented by the throttle opening degree signal Sθ is zero. If any one of the determinations in steps S11 to S13 is negative, step S14 is executed, flag F and timer are reset, and the solenoid drive control routine of step S21 is executed. In the solenoid drive control routine, the microcomputer 20 outputs a drive signal to operate a predetermined solenoid valve according to Table 1 in order to realize the number of gears determined by the execution of the steps up to that point. It is. If the vehicle is stopped, it is determined in step S4 that the shift lever has not been operated from the neutral range to the forward range, so step S5 is executed, in which the shift lever is changed from the neutral range to the forward range. It is determined whether the shift lever position signal SL has been operated from the normal range to the forward range. If it is determined in step S5 that the solenoid has not been operated yet, the solenoid drive control routine in step S21 is immediately executed. In such a case, the number of gears determined in step S3,
Normally, the solenoid valve is controlled to be neutral. If it is determined in step S5 that the shift lever has been operated from the neutral range to the forward range, the content of flag F is set to 1 in step S6, and a timer is started in step S7. And step S8
and S9 are executed, and the engine rotation speed signal is
Actual engine 10 rotational speed Ne based on SR
At the same time, the actual temperature To of the hydraulic oil in the hydraulic circuit 18 is read based on the oil temperature signal SY. Next, in step S10,
From the relationship determined in advance based on the actual engine speed Ne and oil temperature To, the control time t1 and
t2 is set. The relationships determined in advance are those shown in FIGS. 4 and 5, for example, and these relationships are stored in the ROM in the microcomputer 20 in the form of functional formulas or data maps. Here, the control time t1 is the time from the switching operation from the neutral range to the forward range until, for example, the start of supply of hydraulic oil to the hydraulic actuators C2 and B2 for engaging the third gear stage, As the engine rotational speed Ne increases, the discharge amount of the oil pump rotationally driven by the engine 10 increases. Therefore, before the engagement of the first gear stage by the hydraulic actuator C1 is realized, the hydraulic oil is supplied to the hydraulic actuators C2 and B2. Shorten the time to start supplying. Note that the control time t1 is mainly determined by the engine rotation speed Ne,
Corrected based on the temperature of the hydraulic oil. Since the viscosity of the hydraulic oil is high when the temperature is low, the delay time (time lag) until the start of engagement of each gear stage tends to become large. Therefore, as shown by the broken line, the lower the temperature of the hydraulic oil, the smaller the control time t1 is corrected. The relationship in Figure 4 is that the control time t1 is the oil temperature.
It is shown that it is a function of the engine rotation speed Ne with To as a parameter. The control time t2 is the third period from when the shift lever is switched from the neutral range to the forward range.
This is the time required to start discharging the hydraulic fluid in the hydraulic actuators C2 and B2, which are other hydraulic actuators for engaging the high gear stage. As this control time t2 increases as the engine rotational speed Ne increases, it is necessary to increase the operating oil pressure to achieve engagement of the lowest gear stage, so the time it takes to reach that oil pressure also increases. , the control time t2 is increased according to the engine rotational speed Ne.
Further, similarly to the control time t1, the control time t2 is also corrected so that the lower the temperature of the hydraulic oil, the smaller the control time t2 becomes. The relationship in Figure 5 is that the control time t2 is the oil temperature.
It shows that it is a function of the engine rotation speed Ne with To as a parameter. As described above, in step S10, the control time is
Once t1 and t2 are determined, step S4 is executed again, and it is determined whether the content of flag F is 1 or not. At this time, the flag F has already been set in step S6.
Since the content of is set to 1, steps S11 to S13 are executed to determine whether the brake is being operated, whether the vehicle speed is zero, or whether the throttle is fully closed. be done. If at least one of these determinations is negative, steps S14 and subsequent steps are executed; however, if all of the determinations are affirmative, the vehicle is in a state immediately before starting, and therefore steps S17 and subsequent steps are executed. In step S17, the timer coefficient time T
It is determined whether or not is greater than the control time t1, and if it is not, in other words, the elapsed time since the shift lever was operated from the neutral range to the forward range has not yet reached the control time t1. Then, step S15 is executed and the first gear is determined. Therefore, step S15
By executing the subsequent step S21, the solenoid valve MV1 is operated by the microcomputer 20 to start supplying hydraulic oil to the hydraulic actuator C1 for engaging the first gear. If it is determined in step S17 that the timer coefficient time T has become greater than the control time t1, step S18 is executed to determine whether or not it is greater than the control time t2. If T has not yet reached the control time t2, step S20 is executed and the third gear is determined, so that the hydraulic actuators C2 and B2 for engaging the third gear are activated. In order to supply the operation, solenoid valve MV1 is deactivated and solenoid valve MV2 is
Activate. That is, in this state, supply of hydraulic fluid to hydraulic actuators C2 and B2 is started in addition to hydraulic actuator C1. In step S18, the timer coefficient time T
When becomes larger than the control time t2, step S19 is executed to reset the flag F and the timer, and steps S15 and subsequent steps are executed to realize engagement of the first gear stage. solenoid valve is activated. That is, solenoid valve MV1 is activated and MV2 is deactivated. As a result, the hydraulic fluid of the hydraulic actuators C2 and B2, which had been supplied with hydraulic fluid and whose pressure was in the process of rising, is discharged and the pressure drops, and hydraulic fluid is exclusively supplied to the hydraulic actuator C1, and after a predetermined period of time, the hydraulic fluid is in the process of rising. Engagement of the first gear stage is completed. Figure 6 shows the output shaft torque and each hydraulic actuator C1, C2, when controlled as described above.
This shows the oil pressure change characteristics of B2, and the output shaft rises smoothly regardless of changes in engine speed Ne, and when the engine speed is high, such as when the engine is revving or at first idle. The shift shock is also suitably eliminated. Note that the control time t1 is on the order of 2 to 300 msec, and t2 is on the order of 8 to 900 msec. Incidentally, FIG. 7 shows the change characteristics of the output shaft torque and the oil pressure in each actuator C1, C2, B2 when the control times t1 and t2 are constant regardless of the engine speed. In the figure, since the engine speed is high as during first idle, the control time t2 for engaging the third gear is relatively short, and after the control time t2 has elapsed, the shift shown in A is made. A shot is occurring. Although the embodiment of the present invention has been described above based on the drawings, the present invention can also be applied to other aspects. For example, in the embodiment described above, the control time
t1 was determined by the engine speed and oil temperature, but the control time t1 is always zero, that is, when the shift lever is changed from the neutral range to the forward range, immediately after the shift lever is operated, a gear other than 1st gear is selected. Even when hydraulic oil is supplied to the hydraulic actuator for engagement, a certain effect of preventing shift shock can be obtained by controlling the control time t2 based on the engine rotation speed and oil temperature. In addition, as shown in FIGS. 4 and 5, the control time t1 and the control time t2 are the engine rotational speed
It has been determined based on Ne and oil temperature, but some effect can be obtained even if it is determined based only on engine rotational speed Ne. In addition, in the above-described embodiment, after the control time t1 has elapsed and before the control time t2 has elapsed, the hydraulic actuators C2 and B2 for engaging the third gear stage are activated.
Although the supply of hydraulic oil is started in , the hydraulic oil may be supplied to the hydraulic actuator B2 for engaging the second gear stage. In short, any hydraulic actuator is sufficient as long as it engages a gear stage higher than the lowest speed gear stage. The above-mentioned embodiment is merely one embodiment of the present invention, and various modifications may be made to the present invention without departing from the spirit thereof.

[Brief explanation of the drawing]

FIG. 1 is a diagram corresponding to claims of the present invention. Second
The figure is an explanatory diagram showing the configuration of an embodiment of the present invention. FIG. 3 is a flowchart illustrating the operation of the embodiment shown in FIG. Figures 4 and 5 are
FIG. 6 is a diagram showing a predetermined relationship used to determine the control time in the flowchart of the figure. FIG. 6 is a time chart explaining the operation of the embodiment shown in FIG. FIG. 7 is a time chart showing the operation of the conventional control device. 26: Engine rotation sensor (engine rotation speed detection means), 30: Oil temperature sensor, 40: Shift lever position sensor (lever operation detection means), Steps S8, S9, S10: Control time adjustment means.

Claims (1)

[Scope of Claims] 1. In a vehicle automatic transmission of a type in which a gear is shifted to a gear higher than the lowest gear by operating a hydraulic actuator for switching to the lowest gear and another hydraulic actuator, When the shift lever is operated from the neutral range to the forward range, hydraulic oil is supplied to the hydraulic actuator for switching to the lowest speed gear, and hydraulic oil is supplied to the other hydraulic actuator in addition to the hydraulic actuator. A control device that temporarily switches to the upper gear prior to switching to the lowest gear by supplying the gear, and detects that the shift lever is operated to switch from the neutral range to the forward range. lever operation detection means for detecting the rotation speed of the engine of the vehicle; and engine rotation speed detection means for detecting the rotation speed of the engine of the vehicle; A control device for an automatic transmission for a vehicle, comprising: control time adjusting means that lengthens the control time according to an increase in the rotational speed of the engine. 2. The control device further includes an oil temperature sensor that detects the temperature of the hydraulic oil supplied to the hydraulic actuator, and the control time adjustment means adjusts the temperature of the hydraulic oil of the other hydraulic actuator from the time of the switching operation of the shift lever. 2. The control device for an automatic transmission for a vehicle according to claim 1, wherein the time required to start discharging the hydraulic fluid is corrected based on the temperature of the hydraulic fluid.