JPS60139955A - Controller for automatic speed change gear - Google Patents

Abstract

PURPOSE:To prevent the resonance of a driving system by installing an electromagnetic means for duty-controlling the supply of pressurized fluid into a fluidic actuator which switches the transmission passages of a driving-force transmission mechanism and varying the cycle for duty-control according to the speed- change stage. CONSTITUTION:The first and the second input shafts 2 and 3 are rotatably arranged onto a driving shaft 1b which extends from a crankshaft 1a, and can be connected with the driving shaft 1b through the first and the second clutches 5 and 6, which are operated through operating levers 7 and 9 by actuators 8 and 10, respectively, which are controlled by controlling solenoid valves 35 and 36. The ports 35c and 36c of the solenoid valves 35 and 36 are connected to an electromagnetic cut valve 37. The connection for each clutch 5, 6 is performed by controlling the solenoid valve 36 and the cut valve 37 according to the duty cycle which is varied according to the speed-change stage by a control circuit 42.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for an automatic transmission that prevents resonance of a drive system due to duty control.

(Prior art) For example, some automatic transmissions that utilize a torque converter and an auxiliary transmission consisting of a planetary gear mechanism include a so-called lock-up clutch that directly connects the engine output shaft and the input shaft of the auxiliary transmission without going through the torque converter. I have something prepared. As shown in Japanese Utility Model Application No. 57-150655, the lock-up clutch is gradually engaged by controlling the duty of the electromagnetic means for controlling the supply of pressure fluid to the lock-up clutch. Some proposals have been made to reduce shock during lock-up.

Furthermore, some automatic transmissions that do not use a torque converter have two input shafts arranged coaxially, and each input shaft is provided separately, as shown in Japanese Patent Laid-Open No. 56-94050, for example. The clutch is connected to the crankshaft as the engine output shaft, and one input shaft has 1st and 3rd speed gears, and the other input shaft has 2nd and 4th gears. For example, when one input shaft is connected to a crankshaft and a transmission gear on that shaft, for example, a first speed or third speed transmission gear, is in a meshed state, a clutch on the other input shaft is disconnected. Cut off,
During this time, the speed change gear on this input shaft, for example 2nd speed or 4th speed.
After the meshing of the speed change gears is completed, the clutch of the one input shaft is disengaged and the clutch of the other input shaft is connected at an appropriate time. Theoretically, the number of input shafts is not limited to two, but may be three or more, in which case the same number of clutches as input shafts are provided, and the clutches are provided on each input shaft. It is sufficient that the transmission gears used in the transmission are not adjacent to each other in the transmission stage.

In gear transmissions of the type described above, in order to eliminate shift shock, the clutch on the power transmission side (the clutch that was previously transmitting power) and the clutch on the non-power transmission side (the clutch that will now transmit power) are Consideration is being given to the timing of disengagement and engagement of the clutch, or to the setting of the clutch engagement speed.

That is, when a shift command is issued to shift up the gear to a higher gear, the clutch on the non-power transmission side is engaged at the first connection speed, and after a first period has elapsed from the time of the shift command, the engagement speed of the clutch is changed. The above first connection speed is slower than the second
After the first period has elapsed and the second period has elapsed, - the speed of connection of the non-power transmission clutch is changed to the second connection speed. If the speed is returned to the first connection speed, a load is applied to the engine during the first period and the rotational speed decreases, and during the second period the non-power transmission side (high speed side)
The shift shock when the clutch is engaged is alleviated.

Also, when commanding a gear shift to downshift to a lower gear,
If you disengage the clutches on the power transmission side to temporarily create a state in which all clutches are disengaged, and then turn on the clutches on the non-power transmission side, the engine will start when all clutches are disengaged. Since the rotation speed increases, the shift shock when the non-power transmission side (low gear side) clutch is engaged is alleviated.

As one means for controlling the two clutches as described above, it is possible to perform duty control of the electromagnetic means for controlling the supply of pressure fluid to the two clutches, similar to the lock-up clutch described above.

Tokoro! As mentioned above, when controlling the duty of the electromagnetic means, the natural frequency of the drive system varies depending on the gear shift because the equivalent moment of inertia differs depending on the gear, and therefore, if the duty frequency is set to a certain value, 4. At some gears, the vibration during gear shifting is reduced, but at other gears, the duty frequency and the natural frequency of the drive system almost match, causing large vibrations due to resonance. A problem like this arises. Of course, in order to avoid such problems, the duty frequency can be made larger or smaller than the natural frequency of the drive system in all gears, and a special electromagnetic system that can handle this large or small duty frequency can be used. It is conceivable to use means. However, increasing the duty frequency can be achieved by special electromagnetic means such as high-speed 0N-O
Since a device capable of FF must be used, not only does it increase the cost, but it also tends to be insufficient in terms of durability and reliability. Also, reducing the duty frequency requires the use of special electromagnetic means for low speed; in this case, 1. This results in poor control accuracy and problems with shift feeling.

(Object of the Invention) The present invention has been made in consideration of the above circumstances, and is capable of preventing the resonance phenomenon caused by the duty frequency without using special electromagnetic means for high-speed or low-speed use. The purpose of the present invention is to provide a control device for an automatic transmission.

(Structure of the Invention) In order to achieve the above-mentioned object, in the present invention, the duty frequency is made to differ by 1 step depending on the gear position. 5. In other words, the natural frequency of the drive system is determined at a certain gear within a predetermined duty frequency range that satisfies the durability, reliability, control accuracy, etc. of the electromagnetic elements. In this case, a duty frequency that is far different from that is used.

Specifically, as shown in FIG. 1, the transmission path of the driving force transmission mechanism connected to the engine output shaft is switched by a hydraulic actuator, and the pressure fluid is supplied to the hydraulic actuator. The duty is controlled by electromagnetic means. The duty frequency adjusting means changes the frequency for duty control of the electromagnetic means according to the gear position.

(Example) FIG. 2 is a schematic diagram showing the entire transmission, in which a first input shaft 2 is mounted on the drive shaft lb extending from the crankshaft 1a of the engine 1.
and a second input shaft 3 are rotatably arranged, and an output shaft 4 is provided parallel to these input shafts 2.3. The first input shaft 2 is connected by the first clutch 5, and the second input shaft 3 is connected by the second clutch 5.
Each of the clutches 6 is connected to the engine drive shaft 1b. The first clutch 5 is preferably a dry clutch with a large torque transmission capacity, and in order to control the connection and disconnection of the first clutch 5,
A clutch operating lever 7 is provided. The operating lever 7 is actuated by a hydraulic first clutch actuator 8, and when fluid pressure is supplied to the clutch actuator 8, the operating lever 7 actuates the first clutch 5 in the connecting direction. The second clutch 6 is preferably a relatively small wet type clutch, and a second clutch operating lever 9 is provided to control the engagement and engagement of the clutch 6. The control lever 9 is actuated by a second hydraulic actuator 10, and when the actuator 10 is supplied with fluid pressure, the control lever 9 actuates the second clutch 6 in the connecting direction.

A first speed drive gear 11a and a third speed drive gear 12a are rotatably arranged on the first input shaft 2, and these drive gears 11a and 12a are fixedly connected to the output shaft 4. First speed and third speed driven gears 11b provided,
12b, respectively. Furthermore, the first input shaft 2
A reverse drive gear 13a is rotatably disposed above, and this gear 13a meshes with a reverse driven gear 13b on the output shaft 4 via an intermediate gear 13c. Second input shaft 3
A second speed drive gear 14a and a fourth speed drive gear 15a are rotatably arranged on the top, and these gears 14a and 15a are connected to the second speed driven gear 14 on the output shaft 4.
b and the fourth speed driven gear 15b, respectively.

A transmission hub 16 is provided on the first input shaft 2 between the gears 11a and 12a. This hub 16 is connected to the first input shaft 2
The first input shaft 2 rotates integrally with the first input shaft 2, but is arranged so as to be movable in the axial direction. hub 1
6 are formed with meshing teeth 17b and 18b that mesh with meshing teeth 17a and 18a formed on the hub portions of the gears 11a and 12a, respectively. By moving the hub 16, the gear 11a
, 12a, and the first human power shaft 2 is connected to the gear 1.
It can be bonded to one of 1a and 12a. A shift fork 19 is provided to operate the transmission hub 16, and this shift fork 19 is connected to the first transmission cylinder 20.
The piston 20a is connected to the piston 20a. Similarly, on the second input shaft 3, the transmission hub 1 is disposed between the gears 14a and 15a.
A transmission hub 21 having the same configuration as 6 is disposed, and this hub 21
is the second shift cylinder 2 via the shift fork 22.
It is operated by the piston 23a of No. 3. A transmission hub 24 for the reverse gear 13a is further provided on the first input shaft 2, and this hub 24 is operated by a piston 26a of a third transmission cylinder 26 via a shift fork 25.

An output gear 27 is further provided on the output shaft 4, and this output gear 27 is engaged with an input gear 28a of the differential gear 28. An oil pump 29 is provided at the end of the drive shaft 1b, and hydraulic oil discharged from the oil pump 29 is sent to a pressure line 31 via a pressure regulator 30.

0 FIG. 3 shows a hydraulic circuit for speed change control.
A second speed change solenoid valve 33 is provided so that the speed change solenoid valve 32 controls the supply of hydraulic pressure to the second speed change cylinder 23 . The first speed change solenoid valve 32 consists of a valve hole 3.2a and a plunger 32b that slides inside the valve hole 32a.
A boat 32C connected to the forward pressure line 34 is formed near the center of the side of the valve hole 32a, and cylinders 20 are provided on both sides of the boat 32C on both sides of the piston 20a.
Bows 32d and 32e are formed to communicate with each other. Plunger 32b connects boat 32c to one of boats 32d or 32e by moving axially. The plunger 32b is pushed in one direction by a spring 32f, and in that position the boat 32C is
2d, and the piston 20a is connected to the first speed gear 11a.
is held in a position where it is connected to the first human power shaft 2. Solenoid valve 3
When an antimagnetic current is applied to 2, the plunger 32b is moved against the spring 32f, connecting the 1 boat 32C to the boat 32e. In this position, the piston 20a is moved in the opposite direction and the third gear gear 1
2a is coupled to the first human power shaft 2.

The second speed change solenoid valve 33 has the same configuration as the first speed change valve 32, and corresponding parts are indicated with the same suffixes. When the solenoid valve 33 is not energized, the boat 33c
communicates with the boat 33d, and the fourth speed gear 15a is coupled to the second human power shaft 3.

When the solenoid valve 33 is energized, the boat 33c
e, and the second speed gear 14a is connected to the second human power shaft 3.

A first control solenoid valve 35 and a second control solenoid valve 36 are provided to control the engagement and engagement of the clutch 5.6. 1st
The control solenoid valve 35 has a valve hole 35a and a plunger 35b.
A bow 35c is formed on the side of the valve hole 35a, which communicates with a cut valve 37 that functions as a pressure regulating valve. This cut valve 37 will be explained in detail later.

Furthermore, a boat 35d is formed in the valve hole 35a, and this boat 35d is connected to one pressure receiving surface Q of the first actuator 8 for operating the first valve 2 through the passage 38.
It communicates with the i side. A spring 35e is arranged at two ends of the plunger 35b, and this spring 35e causes the brush jar to
5□b is pushed toward one end, cutting off the communication between bonini) 35c and 3"5d. When the solenoid valve 35 is energized, the plunger 3
5b is moved against the spring 35e, and the bow) 35c, 3
5d is brought into communication. ” □The second control solenoid valve 36 has the same configuration as the first control solenoid valve 35, and the same parts are indicated with the same suffixes. 36 d' is connected to one pressure receiving surface 10a of the second actuator 10 for actuating the second clutch by the passage 38a.
It is connected to the.

The cut valve 37 consists of a valve hole 37a and a plunger 37b, and a boat 37C communicating with the pressure line 34a is formed on the side of the valve hole 37a. Furthermore, valve hole 3
A boat 37d is formed at 7a, and this boat 37d is connected to the valve hole 35a of the first control solenoid valve 3'5.
ft-t and the second control electric valve 36 (bow) 36c of the valve hole 36a of the solenoid valve 36.

A spring 37e is arranged at one end of the plunger 37b,
□The spring 37e pushes the planar rear 37.b toward the other end, causing the bow) 37c and 37d to communicate,
There is. When the cut valve 37 is energized, the plunger 37b is moved against the spring 37e, cutting off communication between the boats 37C and 37d. □ - A reverse pressure line 3'9 is connected to the first shift cylinder 20 for reverse control, and this line 39 is provided with a □ check valve 40 with an orifice. This check valve 4
0 is closed when supplying supplementary injection to cylinder 26,
Hydraulic pressure is directed through the orifice, which is opened when hydraulic pressure is removed from the cylinder 26. oil pump 2
The pressure line 31 from 9 is connected to the lines 34, 39 through the shift valve 41, and when the shift valve 4"1 is in the position D', 3.2i, the line 31 is connected to line 3υ', and line 31 is connected to line 39' when in the R position.

Reference numeral 42 indicates a control circuit composed of, for example, a microcomputer, and a shift valve position detector 43, a vehicle speed sensor 44, and an engine load sensor 45 are connected to this control circuit 42. The control circuit 42 receives a shift valve position signal S from a shift valve position detector 43.
1, a vehicle speed signal S2 from the vehicle speed sensor 44 and an engine load signal S3 from the engine load sensor 45 are input, and these signals 31. S2. According to S3, the solenoid valves 32, 33, 35, 3 are
6 and the supply of current to the solenoid of the cut valve 37.

5 Next, the control contents of the control circuit 42 will be explained with reference to FIGS. 4 to 9. When the shift valve 41 is in the D position, the shift valve 41 is in the 1st to 4th gears, and in the 3rd position, the shift valve 41 is in the 1st to 4th gears. is between 1st and 3rd speeds, and when in 2nd position, automatic gear shifting is performed as appropriate between 1st and 2nd speeds, but the drive gears 11a and 13a for 1st speed and 3rd speed are Because it is located on the first input shaft 2, there is no direct gear change between 1st and 3rd gears, and for the same reason, there is no direct gear change between 2nd and 4th gears. It has become. Also, Figure 7,
Q, ~Q5 in Figure 8 are valves 32.33.35.36.37
Indicates the supply current for

Based on the above, we will sequentially explain overall control, control during upshifts, and control during downshifts, and after these explanations, we will explain the duty frequency control. do. Note that in the following explanation, P indicates a step.

In this initialization, the first and second clutches 5.6 are both disengaged, and the first clutch 5.6 is released in preparation for starting, as shown in FIG. A speed gear and a second speed gear are each meshed (with respect to the input shaft).

Next, in P2, it is determined whether the vehicle is to start (vehicle speed is 0), and when it is determined that the vehicle is to start, it is determined in P3 whether or not the shift valve 41 is in the R position. This P
If it is determined at step 3 that the position is not the R position, then the first and second gears are engaged at step P4 (the same applies below the one integrated with the input shaft 2 or 3). After that, in P5, it is determined whether the shift valve 41 is in the D, 3 or 2 position as one of the prerequisites for indicating the intention to start, and if it is not in the D, 3 or 2 position, this determination is repeated. If it is determined that the position is D, 3 or 2, the process moves to P6. In this P6, the accelerator is on (
It is determined whether the accelerator pedal is depressed (the accelerator pedal is depressed),
If the accelerator is not on, this determination is repeated, and if the accelerator is on, indicating an intention to start, the process moves to P7 and the first clutch 5 is connected to start the vehicle.

Then, a loop is made to P7 until the start at P8 is completed, and once the start is completed, the process returns to P2 again (control is completed).

When controlling the first clutch 5 for the above-mentioned start,
1st, cut valve 3 in the middle of clutch 5 connection stroke
7, the excitation current Qs is applied as shown in FIG.
The clutch 5 is temporarily disconnected in the half-clutch state, and then the excitation current of the rear shut valve 37 is cut off, thereby completing the connection of the first clutch. This latching connection operation will result in
It is possible to perform a smooth start without any impact.

If the R position is determined at P3, the vehicle moves to P6 without passing through P4 and P5 (starting in the backward direction).

On the other hand, when it is determined that it is not a start in P2,
Move to P9 and check whether to stop here (vehicle speed is lokm/
If it is determined that the vehicle is stopped, the first and second clutches 5.6 are disengaged at PIO, and then the process moves to P4 in preparation for the next start. (See Figure 8).

When it is determined that the vehicle is not stopped at P9, automatic gear shifting is performed when moving forward. In this case, first, P
It is determined whether or not the shift valve 41 is at the 0 position. If this Pit determines that it is in the 0 position, the MAX gear is set to 4th gear in PI3 (the gears that can be selected during upshifts and downshifts are 4th gear or lower, that is, 1st gear or 1st gear). PI3 determines whether or not the vehicle is currently in first gear. When the PI3 determines that the gear is not in the first gear, the PI3 determines that the shift control characteristic diagram is based on a predetermined shift control characteristic diagram (in the embodiment, it is created based on the relationship between the engine load and the vehicle speed). A check is made as to whether or not to shift down, and it is determined at PI3 whether or not to shift down. When it is determined in this PI3 that a shift should be downshifted, the shift is made to PIB9, and after this, a command for the gear shift gear position to be selected is issued in PLB, and then the determination in PI3.18.19 is made. Ru. In other words, there is no change in the gear position command (as determined by PI3), and the gear to be selected is less than or equal to the MAX gear (as determined by PI3).
If to seconds have elapsed since the gear position command (determination at PI3), the process shifts to P2O, and control for downshifting, which will be described later, is performed. Also, P16
At 100, there is a change in the gear position command (as determined by PI3), and it is not below the MAX gear (as determined by PIB).
If to seconds have not elapsed (determined by PI3), P2
The loop is passed to P2 without passing through O.

Furthermore, when it is determined in P13 that the current gear is 1st gear, or when it is determined in PI3 that downshifting is not necessary, the process moves to P21 and checks whether the current gear is 4th gear or not. is determined, and if it is not 4th speed, P22
, a check is made as to whether or not to shift up based on the shift control characteristic diagram for upshifting.
At P203, it is determined whether or not to shift up. Then, when it is determined that it is necessary to shift up, the P
16100 processing is performed, but in this case, when the process shifts to P2O, shift control for upshifting, which will be described later, is performed in this P2O. Note that when it is determined that p2x-@the current speed is 4th speed, or when it is determined that an upshift is not to be performed at P23, the control is completed as is.

When it is determined that the shift valve 41 is not in the 0 position in the above-mentioned Fi, the process moves to P25, and it is determined whether or not it is in the 3 position. If it is in the 3 position, the shift valve 41 is shifted to
After setting the AX gear position to the 3rd gear corresponding to the 3 positions (-the selectable gears are 1st gear to 3rd gear), it is determined in P 6 whether or not the current gear is 3rd gear or lower. . When it is determined in P26 that the current speed is 3rd speed or lower, the process moves to PI3 and the same processing as described above is performed. Also, when it is determined at P2O that the current gear is not lower than 3rd gear (in the example, it is 1 when the current gear is 4th gear), the shift goes to P27 and the predetermined gear (if shifted from P26) After the engine speed when downshifting to 3rd gear is calculated, the calculated engine speed is changed to a predetermined speed of 550 Or'pm in P28.
Whether or not tA* is equal to or less than tA* is determined. Then, in P28, if it is determined that the speed is 5500 rpm or less,
After shifting to P2O, a shift control for downshifting, which will be described later, is performed, and when it is determined that the speed is not below 5500 rpm, the shift is not downshifted and the speed is changed to P? to prevent the engine from overspeeding. The Q loop is turned and control is completed.

Furthermore, when it is determined in P24 that the shift valve 41 is not in the 3rd position, it means that it is in the 2nd position after all, so in P2O, after the MAX gear position is set to the 2nd position (selectable change □The speed is the first speed or the second speed), the shift to P2O is made, and it is determined here whether or not the current speed is the second speed or lower. When it is determined that the speed is lower than the second speed, the process moves to P13, and the current speed is lower than the second speed.
If the gear stage is higher than gear 2 (in the example, it is 3rd gear or 4th gear), it shifts to P27 (when shifting from P2O to P27, the gear shift when calculating the engine speed stage is second gear).

Shift Arp I'5.7 This control corresponds to the process of P2O in FIG. 4, but since it is the time of upshifting, it is the case where the shift has been made from P23 to P16.

During this upshift, 1st gear → 2nd gear, 1st gear
Speed → 4th gear, 3rd gear → 4th gear, 2nd gear → 3rd gear
The way the clutch is connected is different for shifting from 1st gear to 2nd gear (determined by P2O), and from 1st gear to 4th gear (P51). judgment)
, in the case of a shift from 3rd gear to 4th gear (judgment at Pb0), the transition goes to P54, and in the case of a 5th gear shift from 2nd gear to 3rd gear (judgment at Pb0), P55 Move to.

At P54, a command to connect the second clutch 6 is issued (
The connection speed at this time is the first connection speed (3rd), and then in P56, an overlap time (both the first and second clutches 5.
6 are connected together) to. Then,
At P57, the overlap time t. It is determined whether or not t has elapsed, and if to has not elapsed, the loop continues and waits for 1a to elapse, and if tfl has elapsed, the process moves to P58 and the first clutch 5 is disengaged. In P59, the second clutch 6 is commanded to have its connection speed, that is, the second connection speed, and this second connection speed is slower than the first connection speed and is proportional to the accelerator opening. (Duty control of cut valve 37). After this, in P2O, it is determined whether or not the connection time at the second connection speed has passed for 11 seconds, and if 11 seconds have not elapsed, the loop to P59 is turned and waits for 18 seconds to elapse, and the 11 seconds When the time has elapsed, move to PO2. At PO2, the connection speed command (second connection speed command) for the second clutch 6 is cleared, and a connection command based on the first connection speed by 4 is issued. Then, in PO2, the third
It is determined whether or not the shift is from 3rd to 4th speed.
If the shift is not from 3rd gear to 4th gear, the 3rd gear gear is engaged 12 seconds later in P63, and then the 3rd gear gear is engaged in P63.
4, it is determined whether or not the shift is from 1st speed to 2nd speed, and if it is a shift from 1st speed to 2nd speed, P65
Clear the gear position command at If it is determined at PO2 that the shift is from 3rd gear to 4th gear, the process goes through P65, and when it is determined at P64 that the shift is not from 1st gear to 2nd gear, the process goes through P65. Each control is completed without any trouble.

On the other hand, when it is determined at Pb0 that the shift is from 2nd speed to 3rd speed, the process shifts to P55 and the first clutch 5
After the command to connect is given (first connection speed),
At P2O, an overlap time corresponding to the accelerator opening degree, that is, a time to when both the first and second clutches 5.6 are both connected is set. After this, on P67,
It is determined whether or not the overlap time to has elapsed. If to has not elapsed, the loop continues and waits until to has elapsed. When to has elapsed, the process moves to P68 and the process starts. A command is issued to disconnect the second clutch 6, and at PO2, a command is given for the connection speed of the first clutch 5 (a second connection speed that is slower than the first connection speed).
(duty control of cut valve 37). Then, in P2O, it is determined whether 11 seconds have passed since the connection at the second connection speed was started, and 11
If seconds have not passed, a loop is passed to PO2 and 11 seconds have passed.
Wait for seconds to pass, 1. When seconds have elapsed, the process moves to P71, where the connection command at the second connection speed of the first clutch 5 is cleared, and a connection command at the first connection speed is issued.

Thereafter, in P72, a command to engage the fourth gear is given after t3 seconds have elapsed in preparation for further upshifting, and then in P73, the gear position command is cleared, and the control is completed. Note that if it is determined in P57 that the shift is not from the second speed to the third speed, the control is completed as is.

Here, due to the half-connection of the second clutch 6 at time to, a load is applied to the engine and the engine speed decreases, but when the first clutch 5 is disengaged, the engine speed tries to rise again. While the engine speed is about to rise, the connection of the second clutch 6 is decreased inversely corresponding to the degree of accelerator opening as described above.
Although this is done at the connection speed, the tendency for the engine speed to rise is naturally more rapid as the accelerator opening is greater. Therefore, as mentioned above, when the accelerator opening is large, the degree of decrease is small, so it is quick, and when the accelerator opening is small, the degree of decrease is large, so the second
Since the clutch 6 is now engaged, the synchronization between the engine and the gear transmission can be achieved more accurately, and the shift shock can be suppressed even further. This kind of control to reduce the second connection speed of the latch inversely corresponding to the magnitude of the accelerator opening may be performed at every upshift, but in this embodiment, the shock is less likely to occur during shift 7. This is not done when upshifting from 2nd to 3rd gear.

Further, the time t has elapsed since the connection operation of the second clutch 6 started.
0, the excitation current Q5 is intermittently applied to the cut valve 37 for the time t1 as described above, but during this time, for example, the second clutch 6 is in a half-connected state, and the second clutch 6 is not connected to the engine. What is necessary is to predetermine the time at which the load starts to be applied via the .

Shift down I'S, 8 In Figure 6, when shifting from 2nd speed to 1st speed (P
In the case of shifting from 4th gear to 1st gear (judgment at P81), the process moves to P82, and after the 1st gear meshing command is issued, 14 seconds have elapsed at P83. It is determined whether or not, and if 14 seconds have not elapsed, the loop continues and waits for 14 seconds to elapse.
When 12 seconds have elapsed, the process moves to P84, where a command to disconnect the second clutch 6 is issued. After that, it is determined in P85 whether the accelerator is on, and if the accelerator is on, it is determined in P2O whether the engine speed has increased to a set value corresponding to the downshift. When the set value is reached, a command is issued at P87 to connect the first clutch i. Then, at P2O, after the connection of the first clutch 5 is completed, it is determined whether or not the ti-axis has passed, and if ty$ has not elapsed, the loop is continued and 1. Wait for 7 seconds to elapse, and when 7 seconds have elapsed, the second arrest gear engagement command is issued at P89, and the gear position command is cleared at P2O, completing the control.' □ □When it is determined in P85 that the accelerator is not on, the first and second clutches 5.
After the command to disconnect 6 is issued, the process moves to P89.

In addition, if it is determined that the engine speed has not risen to the set value in section P□86, the process moves to P92, and t5 seconds after the command to disengage the first clutch 5 is issued in P84. It is determined whether or not the elapsed time has elapsed, and 1. If seconds have not elapsed, a loop is passed to P2O, and if 15 seconds have elapsed before the engine speed rises to the set value, a command to connect the first clutch 5 is issued in P93 (the connection speed is ), and P
At step 94, it is determined whether 11 seconds have elapsed since the command to connect the first clutch 5, and if t6 seconds have not elapsed, P
Returning to 93, if t6 seconds have elapsed, the connection speed command for the first clutch 5 is cleared in P95, and then the processes from P88 onwards are performed.

If it is determined in P80.81 that the shift is not from 2nd speed to 1st speed, nor from 4th speed to 1st speed, the shift from 1st speed to 2nd speed is determined in P9O. It is determined whether or not the speed is high, and if the shift is from 3rd speed to 2nd speed, tr, after a command to engage the 2n' gear is issued in p97, 18 seconds have elapsed since this command in p98. It is judged whether or not it is true, and when t8 seconds have almost elapsed, the enemy loop continues and 1. After waiting for the ulcer to occur and after ts seconds have elapsed, a command to disconnect the first clutch 5 is issued at P99.

After this, it is determined in Ploo whether or not the accelerator is on, and when the accelerator is on, it is determined in Plot whether the engine speed has increased to a set value corresponding to the downshift, and the set value If it has risen to , a command is issued to connect the second clutch 6 at P2O3. After the gear position command is cleared in P2O3, the control is completed.

Even when it is determined in P106 that the accelerator is not on, the control is completed as is. Also, if the engine speed does not rise to the set value in Plol,
At P2O3, it is determined whether t11 seconds have elapsed after the command to disengage the first clutch 5. If t@ seconds have not elapsed, the process returns to Plol, and when 13 seconds have elapsed before the engine speed rises to the set value. moves to P2O3 and the second
A command is issued to connect the clutch 6, and the connection speed at this time is proportional to the accelerator opening. Then, in P2O3, it is determined whether or not t seconds have elapsed since the command to connect the second clutch 6. If t0 seconds have not elapsed, the process returns to P2O3 and the connection is performed at the above-mentioned connection speed. When 10 seconds have elapsed, the connection speed command for the second clutch 6 is cleared in Plol, and then P2
The process moves to O3 and control is completed.

When it is determined in P96 that the shift is not from 3rd speed to 2nd speed, it is determined in P2O3 whether or not the shift is from 4th speed to 3rd speed, and from 4th speed to 3rd speed. If it is determined that the shift is to be performed, the processes from P84 described above are performed. Further, if it is determined at P2O3 that the shift is not from 4th gear to 3rd gear, a command to disengage both the first and second clutches 5.6 is issued at P2O3, and then at pHO the first and second clutches 5.6 are disengaged. The meshing command for the two gears is issued, and the control is completed.

Here, when downshifting from 4th speed to 3rd speed, from 4th speed to 1st speed, or from 2nd speed to 1st speed, a predetermined time t
The clutch engagement after the predetermined time t9 has elapsed is performed at a constant reference speed as described in 2 above, but when downshifting from 3rd gear to 2nd gear, the clutch engagement after the predetermined time t9 has elapsed is performed at a constant reference speed as described in 2 above. The connection speed is proportional to the speed of the connection. In other words, in this downshift region from 3rd gear to 2nd gear, the difference between the set value of engine speed and the actual engine speed that does not reach this set value tends to vary greatly depending on the difference in accelerator opening. Therefore, when this difference is large and the accelerator opening degree is small, the connecting speed of the second clutch 6 is greatly reduced and the second clutch is connected slowly to enhance the energy absorption effect. Of course, it is better for the clutch itself to connect quickly, so if the difference between the actual engine speed and the set value is small, and the accelerator opening is large, then set the clutch engagement speed higher, contrary to the above. ing. In addition, such a second club 2
The connection speed of the chiro is controlled by duty-controlling the second control solenoid valve 36 (see FIG. 8es).

Dute, J' 3 Pb0 mentioned above (Fig. 7 e2, e4), 69 (Fig. 7 e
i), 105 (Fig. 8 es), I, N-(, the connection of clutch 5.6 is connected at a predetermined connection speed by duty control, respectively.
During this duty control, the magnitude of the frequency (duty frequency) is the gear position (the gear to be changed; for example, when changing from 2nd gear to 3rd gear, 3rd gear is different meanings). To explain this point in detail, Fig. 9 shows the influence of the vibration frequency on the car body vibration (the magnitude of acceleration in the longitudinal direction of the car body) for 1st to 4th speeds. In Fig. 9, the vibration frequency fA is the lower limit value taking into account the minimum required response of the second control solenoid valve 36 and the cut valve 37 as electromagnetic means, and the vibration frequency fB is the lower limit value of the second control solenoid valve 36 and the cut valve 37 as electromagnetic means. This is the maximum possible value considering fire resistance, reliability, etc. In this embodiment, when the gear position is 1st speed, 2nd speed, or 3rd speed, a frequency fB shifted from the peak point 4 is used as the duty frequency so that vibration in the longitudinal direction of the vehicle body is minimized.
Further, when the gear position is the fourth speed, a frequency fA shifted from the vibration peak point is used as the duty frequency.

In this way, the duty frequency when performing duty control is set to be shifted from the natural frequency of the drive system corresponding to each gear stage, so it is possible to reduce vibrations due to resonance that accompanies this duty control. .

Although the embodiments have been described above, the present invention can also be applied to an automatic transmission having a torque converter. In this case, for example, when the lock-up clutch is subjected to duty control, the duty frequency of the lock-up clutch is It may be changed depending on the gear position when the gear is locked up. Furthermore, when the control circuit 42 is configured by a microcomputer, it can be configured by either a digital type or an analog type.

(Advantages of the Invention) 5 As is clear from the above description, the present invention can prevent resonance of the drive system due to duty control, and is preferable for reducing shift shock. Also,
Since there is no need to use special electromagnetic means for high speed or low speed to prevent this resonance, durability, reliability, control accuracy, etc. can be sufficiently ensured as before.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of the present invention. FIG. 2 is a sectional view showing an example of an automatic transmission. FIG. 3 is an overall system diagram of the automatic transmission shown in FIG. 2. 4 to 6 are flowcharts showing an example of control contents of the present invention. 7 and 8 are graphs schematically showing the control contents shown in FIGS. 4 to 6. FIG. FIG. 9 is a diagram showing the relationship between the vibration frequency and the magnitude of vehicle body vibration for each gear stage. A-... Φ automatic transmission 5.6... clutch 36.37, duty-controlled electromagnetic means 42-...
・Control circuit 7 6

Claims (1)

[Claims] (1) a driving force transmission mechanism connected to the output shaft of the engine; a fluid actuator that switches the transmission path of the driving force transmission mechanism; an electromagnetic means that duty-controls pressure fluid supply to the hydraulic actuator; A control for an automatic transmission characterized by comprising: a duty frequency adjustment means for changing the frequency for duty control of the electromagnetic means according to the gear position.