JPS58121350A - Controller for direct coupled type clutch in automatic speed change gear - Google Patents

Abstract

PURPOSE:To make a titled device so that a shock resulting from a speed shift does not become big and to prevent power performance at the time of low loading from deteriorating, by providing widely a buffer zone where a direct coupled type clutch does not actuate on a low load side of a boundary between two speed ratios. CONSTITUTION:Areas B1 and B2 are buffer zones where a direct coupled have been interrupted and a shock resulting from a speed shift to be generated at the time of each shifting up and shifting down between a first speed and a second speed and a second speed and a third speed can be made to absorb by a torque converter Tc. The direct coupled clutch can be kept at an interrupted state until an increasing vehicle speed (V) arrives at V1 or V2 even after shifting up of the vehicle speed to either a second speed or a third speed as the areas B1 and B2 are expanded on a lower side of an opening (theta) of a throttle valve. Then, torque can be amplified by the torque converter.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention operates an automatic transmission for a vehicle, particularly a hydraulic torque converter, and a gear train of multiple stages with different speed ratios selectively connected to the output side of the converter. An automatic transmission comprising: an auxiliary transmission having a plurality of hydraulically actuated friction engagement means for providing a hydraulically actuated frictional engagement; and a hydraulically actuated direct-coupled clutch capable of directly connecting a pump impeller and a turbine impeller of the torque converter; The clutch is activated in a timely manner.
The present invention relates to a control device for a direct coupling clutch.

When the direct coupling clutch operates, it directly connects the pump impeller and turbine impeller of the torque converter, which eliminates slip loss between the two impellers, which greatly contributes to quieter cruising and improved fuel efficiency. Therefore, it is desirable to widen the range of use of this method as much as possible, but various problems arise when trying to use it over two speed ratios.

The first problem is that if the speed ratio is selected while the direct clutch is operating, the shock during gear shifting is likely to be larger than that of conventional gears, and the purpose of the direct clutch is to achieve quietness. This goes against the idea of a comfortable drive.

Therefore, the first object of the present invention is to provide a buffer zone where the direct-coupled clutch is not operating at the boundary between at least two speed ratios where the direct-coupling clutch is to be used, so that gear changes can be performed with the direct-coupling clutch operating. An object of the present invention is to provide the control device that prevents the above.

The second problem is that when the direct coupling clutch operates, the torque converter's inherent torque amplification function is lost, resulting in a reduction in power performance. For example, if a direct clutch operating range is provided for 2nd (2ND) and 3rd (rop) of an automatic transmission with 3 front speeds, the power performance immediately after shifting up to 3rd speed will drop by the difference in speed ratio. Since the engine's output torque curve is generally low at low speeds, the lack of power performance is especially strong when the engine is under light load and requires early upshifts.

Therefore, the second object of the present invention is to solve this problem by making the buffer zone wide at low loads, rather than having a constant width, and by activating the direct coupling clutch after the engine speed has recovered to a certain extent. It's about trying.

This reduction in power performance also occurs when the engine is throttled down, such as when a vehicle attempts to enter the flow of traffic on a highway from a ramp, or when it is necessary to overtake on a highway. This is not preferable when driving with the engine close to fully open (particularly when driving with a gear train in a relatively high speed gear such as when driving in TOP, this reduction in power performance is significant, and under such special conditions the quiet It is preferable to disable the direct clutch even if it sacrifices performance and fuel efficiency.

Therefore, a third object of the present invention is to solve this problem of reduced power performance by releasing the direct coupling clutch when high output is required.

Having said that, there are times when high power is being transmitted, such as when cruising near the maximum speed, but quietness and low fuel consumption are required, so the fourth objective of the present invention is to The objective is to satisfy this requirement by continuing to operate the direct coupling clutch when the vehicle speed exceeds the speed set by the gear train.

Furthermore, when cruising, the engine throttle opening is reduced to adjust the distance to the vehicle in front, or when the engine is not required, such as when adjusting speed on a downhill slope, a direct clutch is used. If this is activated, engine braking will be applied more strongly, which is unfavorable in terms of fuel efficiency. Particularly in a region where the engine rotates at a high rotational speed, it is preferable to release the operation of the direct coupling clutch in order to prevent such unnecessary engine braking from being applied.

Therefore, the fifth object of the present invention is to make the engine brake stronger (in such a region, the direct coupling clutch is released from operation and the engine braking can be maintained with the same effect as an automatic transmission without a direct coupling clutch). , thereby preventing deterioration of fuel efficiency.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. First, in FIG. 1, the output of the engine E is transmitted to the pump impeller P of the hydraulic torque converter Tc, and then hydrodynamically transmitted to the turbine impeller T. It will be done. When there is a relative speed between the impellers P and T and there is a torque amplification effect, the stator S receives the reaction force. The output torque of the turbine impeller T is transmitted to the driving wheels W of the automobile via the auxiliary transmission G and the differential gear. The auxiliary transmission G is
Three forward speed gear trains and one reverse speed gear train (both not shown) with different speed ratios, and friction engagement means such as hydraulically operated clutches and brakes for operating these gear trains respectively. C1, C,.

It is equipped with C3 and C'r.

A direct coupling clutch 1)c is provided between the pump impeller P and the turbine impeller T, which mechanically directly couples both P and T, and this direct coupling clutch Dc is connected to the first and second switching valves as will be described later. 1. ．． 1. Hydraulically operated via.

The pump impeller P drives a hydraulic pump 3 which is a hydraulic pressure source through a gear mechanism or other suitable transmission means 2, and pressure-feeds the hydraulic oil in an oil tank 4 to a speed ratio selection means 5. A pressure regulating valve 6 is provided in an oil passage connecting the discharge side of the hydraulic pump 3 and the oil tank 4 in order to regulate the discharge pressure of the hydraulic pump 3 to a predetermined pressure.

The speed ratio selection means 5 detects the vehicle speed and the throttle valve opening representing the magnitude of the output of the engine E, and changes the discharge oil pressure of the hydraulic pump 3 every time these two detected values exceed a predetermined reference value. The frictional engagement means C□, C2°C3, and Cr are supplied. Therefore, the frictional engagement means CI r C
,t C1l (1'?'' operates the corresponding gear train when hydraulic pressure is supplied, thereby setting forward 1st speed, forward 2nd speed,
Establish the speed ratio of 3rd gear (TOP) and reverse.

The above configuration is publicly known and does not constitute a basic part of the present invention, so further detailed explanation will be omitted.

2nd speed frictional engagement means C2 or 3rd speed frictional engagement means Cs
In order to introduce the working hydraulic pressure into the working piston of the direct coupling clutch Dc and release the working hydraulic pressure to the oil tank 4,
The hydraulic oil %L, which connects the 2nd speed frictional engagement means C2 and the speed ratio selection means 5, and the first branch oil passage t, and also connects the 3rd speed frictional engagement means C1 and the speed ratio selection means 5. A second branch oil passage is extended from the hydraulic oil passage, and the first branch oil passage is extended from the hydraulic oil passage.
Branch oil path, oil tank 4 and intermediate oil path L77! and a second switching valve 1m between the intermediate oil passage Lm and the first branch oil passage L3 and the hydraulic oil passage Ld of the direct coupling clutch DC.
Switching valve 1. Interpose each.

First switching valve1. is configured electromagnetically and connects between a first position (the illustrated position) where the intermediate oil passage Lm communicates with the oil tank 4 and a second position where the intermediate oil passage Lm communicates with the first branch oil passage t. It is normally held in the first position by the biasing force of a spring 7, and is operated by a solenoid 8.
When 1 is excited, the excitation force causes it to switch to the second position.

The second switching valve 12 is also configured to be electromagnetic, and the direct coupling clutch D
The first branch oil passage t connects the hydraulic oil passage Ld of C to the second branch oil passage t.
It can be operated to switch between the position (the illustrated position) and the second position where the hydraulic oil passage Ld is communicated with the intermediate oil passage Lm, and is normally operated by a spring 7. is held in the first position by the biasing force of solenoid 8. When excited, the excitation force causes the switch to switch to the second position. Furthermore, the second switching valve 1. The end face opposite to the side receiving the biasing force of the spring T communicates with the intermediate oil passage Lm via the oil passage Lm',
The solenoid 8 receives the hydraulic pressure of the intermediate oil passage Lm on its end face.
．． It is designed to switch to the second position regardless of whether the magnet is demagnetized or magnetized.

Therefore, the second switching valve 1. When is held at the first position shown in the figure, regardless of the position of the first switching valve 11, the hydraulic oil passage Ld of the direct coupling clutch Dc is connected to the third-speed hydraulic oil passage via the second branch oil passage t. Since communication is lost, speed ratio selection means 5
Only when hydraulic pressure is supplied to the third-speed frictional engagement means C3, the direct coupling clutch DC receives the hydraulic pressure and enters the connected state. In addition, both switching valves 1. ．． 1. When both are switched to the second position, the hydraulic oil path L of the direct coupling clutch Dc
d communicates with the 2nd speed hydraulic oil path via the intermediate oil path Lm and the first branch oil path t, so the speed ratio selection means 5
Only when hydraulic pressure is supplied to the coupling frictional engagement means C3, the direct coupling clutch Da receives the hydraulic pressure and enters the connected state. Further, when only the second switching valve 1□ is switched to the second position, the hydraulic oil passage Ld of the direct coupling clutch Dc communicates with the oil tank 4 via the intermediate oil passage Lm and the first switching valve 11, so the direct coupling Clutch Dc is in a disconnected state.

Thus, during two-way driving when the second frictional engagement means C1 is operating, the direct coupling clutch D is activated by energizing the first switching valve 1m.
c can be freely controlled and is not affected by whether or not the second switching valve 12 is energized. Furthermore, while the third frictional engagement means C8 is operating in the third speed (rop), no hydraulic pressure is supplied to the second speed hydraulic oil path, so the second switching valve 1
．． The operation of the direct coupling clutch DC can be freely controlled by energizing the first switching valve 1□, and is not affected by whether or not the first switching valve 1□ is energized. In other words, both switching valves 1t and 1t are independently set to 2nd speed without being affected by each other.

This controls the operation of the direct coupling clutch Dc in the third speed region.

First and second switching valves 1□, 1. Solenoid 8. .

8□ is a control circuit 10 that controls these demagnetization and excitation.
This control circuit 1o includes a vehicle speed sensor 11, a throttle valve opening sensor 12, a vehicle speed detection circuit 13, and a logic circuit 14.
and 1st. The second output amplification circuit is composed of 1st and 1st.

Next, the control circuit 1o will be explained in detail with reference to FIG. 2.The vehicle speed sensor 11 is connected to a reed switch 21 fixed at a suitable position on the vehicle body, and a member that rotates in conjunction with the wheels, such as a speedometer cable 16. It is composed of a magnetic rotor 17. This rotor 1T is equipped with a permanent magnet 17α on the outer periphery, and the speedometer cable 1
Each time the magnet 17α passes in front of the reed switch 21 as the motor 6 rotates, the switch 21 is closed and an output signal is sent to the vehicle speed detection circuit 13. Therefore, the frequency of its output signal is speedometer cable 1
6, that is, it is proportional to the vehicle speed V.

The vehicle speed detection circuit 13 includes resistors 22 and 23, a capacitor 24,
Inverter 25, capacitor 26, resistor 21, inverter 28, NAND circuit 29, capacitor 30, resistor 31
, an inverter 32, a resistor 33, a transistor 34, resistors 35, 36, 38, capacitors 37, 39, and a comparator 40 are connected as shown in the figure. This is smoothed and the voltage υ proportional to the vehicle speed V is output to the first . The signal is output to the second and third comparators 45 and 50°55.

The throttle valve opening sensor 12 is composed of a cam 56 connected to the accelerator pedal 18 that is depressed by the driver inside the vehicle, and a normally closed switch 57 that is disposed opposite to the cam 56. Engine throttle valve opening θ
is smaller than the predetermined value θ1, and when the value θ is greater than the larger predetermined value θ2, the switch 57 is released from the cam 56 and closes its contact, and the throttle valve opening θ is the predetermined value θ, and θ, the switch 57 is pressed by the cam 56 to open its contact, and when the contact is opened, it sends a high-level output signal to the inverter 61 of the logic circuit 14. .

1 of the logic circuit 14. 2nd and 3rd comparator 4
5, 50.55 compares the output voltage V of the vehicle speed detection circuit 13 with a predetermined reference voltage, and each reference voltage is set vehicle speed Vt -Vx,'s (however, Vl < Vz
Voltage v1 corresponding to <Vs>.

j'l, IJs (however, v, <El, riv,), and these settings are resistors 41, 42; 4B, 4v;
51°52. Therefore, when the output voltage V of the vehicle speed detection circuit 13 is larger than the reference voltage υl*vfi+υ, each output of the comparator 45°50.55 becomes a high level, and when it is smaller, each output becomes a low level. Become.

In the logic circuit 14, the output of the first comparator 45 is sent to the first human gate 64a of the NAND circuit 64, and the output of the second comparator 50 is sent to the first gate 64a of the NAND circuit 66.
The output of the third comparator 55 is input to the human power gate 66α, and the output of the third comparator 55 is inputted to the second human power gates 65h and 67A of the NAND circuits 65 and 67, respectively.
NAND circuit 64. 66 second human power game) 64b, 66
The output of the inverter 61 is input to h via the inverter 62. In addition, the first manual gates 65α and 67α of the NAND circuits 65 and 67 are connected to the NAND circuits 64 and 66.
The outputs of each are input. And NAND circuit 6
The output of the other NAND circuit 6.1 is inputted directly to the first output amplifier circuit 15°, and the output of the other NAND circuit 6.1 is inputted via the inverter 68 to the second output amplifier circuit 15□.

First output amplifier circuit 15. is a resistor 701 and an NPN transistor 71. When the output of the NAND circuit 65 is at a high level, the transistor 71 becomes conductive, and the first switching valve 1. The second output amplification circuit 152 is configured to close the energizing circuit of the resistor 70.
and an NPN transistor γ1□, and when the output of the inverter 68 is at a high level, the transistor γ1□ becomes conductive and closes the energizing circuit of the second switching valve 12.

If now, v (v, then the outputs of the first to third comparators 45, 50, and 55 all show a low level, so
NA where the low level output of the first comparator 45 is input
The output of the ND circuit 64 becomes high level, which is the NAND
input to the first human power gate 65α of the circuit 65;
The low level output of the third comparator 55 is input to the human power gate 65b (01, ``amplifier circuit 15, f)) 57'
), <fi71· remain in the cutoff state, and the first switching valve 11 is demagnetized.

Similarly, the output of the KHAND circuit 61 also shows a low level, but it is inverted to a high level by the inverter 68 and input to the second output amplifier circuit 152, so the transistor γ1. becomes conductive, and the second switching valve 1. is excited.

Also, if vl υ ν, the second comparator 50
, the outputs of the NAND circuit 66.6γ and the inverter 68 are the same as in the case of ν(v , so the second switching valve 1□ is excited. On the other hand, the output of the first comparator 45 is at a high level, which is the output of the NAND circuit 66.6γ and the inverter 68. 64, the output level of the HAND circuit 64 is determined by the input level of the second human-powered gate 64b.

Therefore, in this case, if θ<θ2 or θ>θ2, the output of the switch 57 is at a low level, so the input to the second human power gate 64A of the HAND circuit 64 also indicates a low level, and therefore the 1 switching valve 11 is demagnetized in the same way as in the case of v (v, but if ul<θ and θ8, NA
First and second manual gates 64α, 64b of the ND circuit 64
Since the inputs to both are high level, the output of the circuit 64 is low level, and therefore the output of the NAND circuit 65 is high level, transistor γ11 is conductive and the first switching valve 11 is excited.

Also, if v, (II< v, the outputs of the first comparator 45 and the NAND circuits 64 and 65 are v,
Since this is the same as in the case of θ1 and θ>θ2, the first switching valve 11 is demagnetized when θ1 and θ>θ2. In addition, the second comparator V-Yu 5G
The output states of the HAND circuits [66 and 67 are also the same as those of the first comparator 45 and the NAND circuits 64 and 65, but since the output of the NAND circuit 67 is inverted by the inverter 68, the second switching valve 11 is θ, or θ〉θ,
It is magnetized when θ1×θ×θ, and is demagnetized when θ1×θ×θ.

Finally, if v〉υ, the output of the third comparator 55 becomes high level, which is inverted to low level by the inverter 63 and inputted to each second human power gate 65b#67h of the NAND circuit 65.67. Therefore, the first switching valve 1. is excited, and the second switching valve 1. is demagnetized.

First and second switching valves based on the above operations 1. .

The state of No. 1 is shown in graphs as shown in FIGS. 4 and 5, in which the shaded area is the excitation area of each switching valve, and the other area is the demagnetization area. As a result, a schedule map for controlling the direct coupling clutch Dc as shown in FIG. 3 is obtained, where the shaded area is the connection area of the direct coupling clutch Dc and the other areas are the disconnection areas. Further, dotted lines X and Y are transmission characteristic lines; the left side of dotted line

As is clear from Figures 3 to 5, υ〈vl, that is, V
In the case of , the second switching valve 1. Since only the
Direct coupling clutch Dc is not connected.

v,<rr<v, that is, in the case of Vt<'<'t, the second switching valve 1-3 is always in the excited state, and the first
Since the switching valve 11 is excited when θ1, θ, and θ2, only in the 2nd speed region, that is, the 2nd speed friction image combining means C
Direct coupling clutch Dc only when 1 digit hydraulic pressure is supplied
is connected. This area is A in FIG.

If 9g<υ<υ8, that is, Vt<V<”s, θ<
If θ1 or θ>θ2, the first switching valve 11 is demagnetized and the second switching valve 1. is excited, so the direct coupling clutch Dc is kept in the disconnected state. However, if θ1 × θ × θ, the first □ switching valve 11 is energized and the second
Therefore, in the second speed region, the second switching valve 1. is also switched to the second position, and as a result, the direct coupling clutch Dc is switched to the second gear hydraulic oil path L! In the 3rd speed (TOP) region, the hydraulic pressure in the intermediate oil passage Lm disappears and the second switching valve 1. returns to the first position, so the direct coupling clutch Dry receives more oil pressure through the third-speed hydraulic oil path and becomes connected (area As in FIG. 3).

In this manner, the direct coupling clutch Dc can be operated as needed in the second speed or TOP driving state, resulting in significant improvements in fuel efficiency and quietness.

The region BteBt in Fig. 3 is a buffer zone where the direct coupling clutch DC is disconnected, and here the shift shock that occurs when upshifting and downshifting between 1st and 2nd gears, 2nd and 3rd gears is transferred to the torque converter Tc. It can be absorbed.

In addition, when driving in a general city, the smaller the throttle valve opening θ (the weaker the engine output), the earlier the upshift will be performed, resulting in a reduction in power performance. Although it is necessary to compensate with the torque amplification function of the torque converter Tc, the above regions Bi and B extend to the lower throttle valve opening θ, so even after shifting up to 2nd or 3rd gear, the vehicle speed V remains constant. The direct coupling clutch Dc can be kept in the disconnected state until it increases and reaches V or V2, and therefore the above request can be met.

Furthermore, even when driving in 2nd or 3rd gear while operating the direct coupling clutch Da, if the accelerator pedal is pressed in response to the need for sudden acceleration, the throttle valve opening θ may change to 0.
When the torque increases to 3 or more, the operation of the direct coupling clutch Dc is released (regions B3 and B4 in FIG. 3), so that the torque amplifying function of the direct coupling clutch Da can be obtained and good acceleration operation can be performed.

In addition, when decelerating during cruising (when the throttle valve opening θ is closed below θ, the operation of the direct coupling clutch DC is released, so slipping occurs in the direct coupling clutch DC and the effect of engine braking is reduced. This makes it possible to suppress an excessive increase in engine speed and prevent deterioration of fuel efficiency.

In the case of v>aa, since the second switching valve 1, which is related to θ, is demagnetized and is always in the third speed region, the direct coupling clutch D
c is always kept connected. This region is A4 in FIG. 3, where the direct coupling clutch Dc is connected and released, so even when driving on the Autobahn with the throttle valve fully open, you can enjoy quiet and economical high-speed cruising.

In the above, the direct coupling clutch Dc may be of a type that can transmit torque from either direction between the impellers P and T of the torque converter Tc during its operation, or a type that can transmit torque from either direction between the impellers P and T of the torque converter Tc, or
A type that can transmit torque only in one direction from the to the turbine impeller T can be applied, but when adopting a type with a one-way clutch function like the latter, θ, θ, There is almost no positive reason to release the operation of the direct coupling clutch Dc when this happens.In addition, configuring the switching valve ?, 1° as an electromagnetic type is effective for downsizing the device and increasing precision. However, it can also be configured to be hydraulically operated using throttle oil pressure and governor oil pressure, which are generally used to control the speed change valve of the auxiliary transmission G. However, the automatic transmission is not limited to a fully automatic transmission. () It may be a so-called semi-automatic transmission in which the speed ratio is manually selected.Furthermore,
Although the frictional engagement means Cr, C1, C2, and C are generally activated when hydraulic pressure is introduced to establish the gear ratio, they are normally released by the hydraulic pressure, and when the hydraulic pressure is applied. It is also possible to adopt a type in which the gear ratio is established by a spring force when the gear is removed.

Furthermore, the automatic transmission is not limited to the illustrated three forward speeds, but it is clear that it can be applied to the speed ratio of the top speed and the speed ratio immediately below it even in systems with four or more forward speeds. Even for the speed ratio of the adjacent 7!3 stages, the second
Switching valve 1. The switching valve corresponding to the second switching valve 1. It can be easily applied by inserting it between the clutch and the direct coupling clutch Dc. In other words, one switching valve may be provided each time the speed ratio to be applied increases.

The vehicle speed sensor 11 may use a Hall element or a Hall IC in place of the reed switch 21, or may be constructed from a combination of a photointerrupter and a shielding plate provided on the speedometer cable. As the throttle valve opening sensor 12, it is also possible to use a sensor made of a combination of a Niphoto interrupter and a shielding plate like the vehicle speed sensor 11, or a magnetic means made of a combination of a reed switch and a magnet. In the control circuit 10, the vehicle speed is processed in an analog manner, but it may also be processed digitally (Also, the configuration using logic elements can be programmed by a microcomputer. As described above, according to the present invention, one frictional engagement means First and second branch oil passages are extended from the hydraulic oil passage and the hydraulic oil passage of the other one frictional engagement means, and a first branch oil passage and a second branch oil passage are provided between the first branch oil passage and the oil tank and the intermediate oil passage. A first switching valve that selectively communicates the oil passage with the first branch oil passage or the oil tank is interposed, and between the second branch oil passage and the intermediate oil passage and the hydraulic oil passage of the direct coupling clutch. Since a second switching valve is installed to selectively communicate the hydraulic oil passage with the second branch oil passage or the intermediate oil passage, running at a predetermined speed ratio can be achieved by appropriately controlling the first and second switching valves. It is possible to automatically operate the direct-coupled clutch to ensure low fuel consumption and quietness.In addition, in consideration of the shifting characteristics, a buffer zone where the direct-coupling clutch does not operate is created at the boundary between the two speed ratios. This also prevents shock during gear shifting.Furthermore, the buffer zone becomes wider on the low load side, so even if an early shift is performed under light loads, the engine rotational speed will be reduced to some extent. The direct coupling clutch will not operate unless it recovers.
Therefore, a sufficient torque amplification function of the torque converter can be obtained, and there will be no feeling of insufficient power performance. Furthermore, when high output is required while driving at a relatively high speed ratio, the direct coupling clutch can be deactivated to obtain the torque amplification function of the torque converter. , when entering a predetermined high-speed state, the direct coupling clutch continues to operate to satisfy quietness and low fuel consumption, and to obtain a comfortable high-speed cruising state. There are also effects such as being able to prevent deterioration of fuel efficiency by releasing the operation of the direct coupling clutch.

According to the second invention, the intermediate oil passage is a second switching valve, and the hydraulic pressure generated in the intermediate oil passage switches the second switching valve to a position where the hydraulic oil passage of the direct coupling clutch and the intermediate oil passage communicate with each other. Therefore, even if the first switching valve is switched to the position where the intermediate oil passage and the first branch oil passage communicate with each other, there will be no difference whether hydraulic pressure is generated in the first branch oil passage or not. The positions of the second switching valves can be made different, thereby simplifying the input signal to the second switching valves, while still allowing the direct coupling clutch to be controlled in accordance with various requirements.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a system diagram of an automatic transmission equipped with the direct coupling clutch control device of the present invention;
Figure 2 is a detailed diagram of the electrical control circuit in Figure 1;
The diagram is the operation schedule map of the direct coupling clutch in Figure 1,
4 and 5 are excitation schedule maps of the first and second switching valves of FIG. 1.

Claims (2)

[Claims] (1) A hydraulic torque converter, a plurality of gear trains with different speed ratios selectively connected to the output side of the torque converter, and a plurality of hydraulically operated friction engagement means for operating these gear trains. and a hydraulically actuated direct coupling clutch capable of connecting between the pump impeller and the turbine impeller of the torque converter, wherein one of the hydraulic oil passages of the frictional engagement means and First and second branch oil passages extend from the hydraulic oil passage of the other one of the frictional engagement means, and the intermediate oil passage is provided between the first branch oil passage and the oil tank and the intermediate oil passage. A first switching valve that selectively communicates with the first branch oil passage or the oil tank is interposed between the second branch oil passage and the intermediate oil passage and the hydraulic oil passage of the direct coupling clutch. A control device for a direct clutch in an automatic transmission, which includes a second switching valve that selectively communicates an oil passage with a second branch oil passage or an intermediate oil passage. (2) A hydraulic torque converter, a plurality of gear trains with different speed ratios selectively connected to the output side of the torque converter, and a plurality of hydraulically operated friction engagement means for operating these gear trains. and a hydraulically actuated direct coupling clutch capable of connecting between the pump impeller and the turbine impeller of the torque converter, wherein one of the hydraulic oil passages of the frictional engagement means and The first and second hydraulic oil passages of the other one of the frictional engagement means
A first switching valve that extends branch oil passages respectively, and selectively communicates the intermediate oil passages with the first branch oil passage or the oil tank between the first branch oil passage and the oil tank and the intermediate oil passage. interposed between the second branch oil passage and the intermediate oil passage and the hydraulic oil passage of the direct coupling clutch, a first oil passage that selectively communicates the hydraulic oil passage with the second branch oil passage or the intermediate oil passage. A2 switching valve is interposed, and the intermediate oil passage is connected to the second switching valve, and the hydraulic pressure generated in the intermediate oil passage brings the A2 switching valve to a position where the hydraulic oil passage of the direct coupling clutch and the intermediate oil passage communicate with each other. A control device for a direct clutch in an automatic transmission, which is connected in a switching manner. Group