JPS58193953A - Automatic transmission of vehicle - Google Patents

Abstract

PURPOSE:To improve the fuel consumption ratio of a vehicle with a torque converter by providing a single creep preventing device capable of controlling engaging forces of a plurality of forwarding clutches, and throttling the throttle opening degree to the necessary minimum limit upon idle driving. CONSTITUTION:The operating oil pressure at two positions R and L combined with an oil groove 58 is supplied by changeover to clutches C2, C1 and C3 by a manual valve 50. A branch groove 59 short-circuiting to a tank 46 is provided in the oil groove 58. In the branch groove 59 is provided a spool valve 60 opened and closed by a solenoid valve of a pilot type. When a solenoid 74 is excited, the pressure of the oil groove 58 extends a predetermined value, the branch groove 59 is opened by the spool valve 60. If the pressure is set to a valve less than the engaging pressure of the clutch, creeping is prevented. Creeping is also prevented upon not only first speed forwarding but second speed starting or retracting.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic transmission for a vehicle equipped with a creep prevention device.

In a vehicle equipped with a hydraulic torque converter, if the shift lever is placed in the D position (forward position) and the shift lever is stopped to wait for a traffic signal, etc., the oil in the torque converter is agitated and the shift lever is moved against the driver's will. This causes a phenomenon called creep, where the car tries to move forward.

This creep phenomenon has not been considered a problem in the past because the pedal force required for braking is not so great in cars with power brake V-keys, but originally when this creep occurs, the engine ~200 rI
This imposes such a burden that it causes the rotation of Nll to drop, and it is necessary to increase the throttle opening during idling operation to compensate for this rotation reduction, which increases the fuel consumption rate and increases the torque. This was a contributing factor to the poor fuel consumption rates of vehicles equipped with converters.

Also, to reduce the engine speed, we created two different idle speeds when putting the lever in the tN position (neutral position) and the D position, so we created a mount that satisfies both of these two idle speeds. This required a rubber system design, which was difficult in practice, and the rotation speed of one side was inevitably included in the resonance region of the mount system, which was disadvantageous in terms of vibration countermeasures.

As a solution to this problem, a method has been proposed in which the engine speed is detected and the starting clutch is disengaged. Although it is clear that this method is effective in solving the above problem, in ordinary vehicles with two or more starting clutches, it is already sufficiently complex to apply this method to each starting clutch. This results in further complication of the control system, which is not practical.

Even in the case of a fully automatic transmission, the starting clutch has two types, one for forward movement and one for reverse movement, and in the case of a semi-automatic transmission in which gears are changed manually, all of the gears correspond to this starting clutch. do.

Therefore, the object of the present invention is to provide a single creep prevention device capable of controlling the engagement force of a plurality of starting clutches,
An object of the present invention is to provide an automatic transmission for a vehicle that improves the fuel consumption rate of a vehicle equipped with a torque converter by limiting the throttle opening degree to the necessary minimum during idling operation.

A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a configuration diagram of a power train with three forward speeds and one reverse speed suitable for application of the present invention, and FIG. 2 is a control circuit diagram of an automatic transmission.

In FIG. 1, the output of the engine E is transmitted to the pump 12 of the fluid torque converter 10, and further hydrodynamically transmitted to the turbine 14 side. When torque is amplified in converter 10, stator 16 bears the reaction force. This stator 16 is fixed to a case (not shown) via a one-way clutch 17 and a hollow shaft 18.
2 and the turbine 14 are allowed to rotate only in the same direction.

The turbine 14 is integrally connected to the main shaft 20 of the auxiliary transmission, and on the main shaft 20 are 3-speed (top) drive gears 2 in order from the left.
2. A second speed (second) clutch C2 and a first speed (low) clutch C1 are integrally assembled. Furthermore, this main shaft 20
As shown in the figure, a second speed drive gear 24 and a first speed drive gear 26, which rotate together with the main shaft 20 when the clutches C2 and CI are engaged, are loosely fitted so as to be relatively rotatable, and the second speed drive gear 2
4 is integrally provided with a reverse drive gear 25.

On the subshaft (countershaft) 30 parallel to the main shaft 20, splines S that can selectively engage with the final drive gear 32, third speed clutch C3, second speed writhing gear 64, and reverse driven gear 35 are arranged in order from the left. , l-speed driven gear 66 are integrally assembled.

Further, a third-speed driven gear 68, a second-speed driven gear 64, and a reverse driven gear 35, which rotate together with the third-speed clutch C3 when the third-speed clutch C3 is engaged, are loosely fitted onto the subshaft 30, allowing relative rotation. There is. The two reverse gears 25 and 35 mesh with each other via the idle gear I.

Then, the torque of the final drive gear 32 is transmitted to the gear 40, and the differential device 42 is further assembled integrally with the gear 40.
The power is transmitted to the left and right front wheels WL and WR via the front wheels WL and WR, and these front wheels WL and WR are driven to rotate.

In the above, when the clutches CL, C2, or C3 are pressurized by the action of the switching valve of the control mechanism, which will be described later, the clutches are engaged and the speed ratio of the first, second, or third speed is established, respectively.

When reversing, the selector knob H=i on the subshaft 60 is moved to the right to engage the subshaft 30 and the reverse driven gear 65, and the clutch C2f is engaged to adjust the reverse torque to the front wheels WL,
Tell WR.

In order to obtain hydraulic pressure to pressurize the clutches C1, C2, C3f and move the selector hub Hi, a hydraulic pop is driven by the engine E via a spline S provided in the torque converter input member.

In FIG. 2, a hydraulic pump 44 pumps up oil in a tank 46, regulates the pressure once with a pressure regulating valve 48, and then sends the pressure oil to a manual valve 50. Pressure regulating valve 48 (1 is a known one,
The spring 48-A is trying to close the spool 48-1, but the pressure oil is flowing through the throttle 48-Ct- to the spool 48-1.
Since the oil is introduced into the chamber Sl formed at the left end of the pump, the pump discharge pressure acts on the opening side of the spool 48-B, and the oil flows into the oil passage 48-B, and is eventually adjusted to the pressure determined by the spring 48-A. be pressured.

The oil overflowing into the oil passage 48-D is further pressure-regulated by the regulator valve 47, and then circulated to lubricate each part.

A part of the oil discharged from the hydraulic pump 44 is sent to the torque controller 10 via the throttle 10-B' in the oil passage 10-A, and after cooling this part 10, it is sent to the oil passage 10-C and the check valve. 1
0-D and oil cooler 49ff: Returned to tank 46 via.

The manual valve 50 is manually operated from the N position shown, 2, 3. When shifted to the R position, the hydraulic pump 44
The discharge pressures of the clutches CI, C2, C3, and C2 are introduced and pressurized, respectively, but the configuration is such that none of the clutches is pressurized at the N position and the 2 position shown in the figure.

The manual valve 50 simultaneously functions to move the servo 52 by introducing pressure oil into either of its left-end piston chambers 82, 83. The servo 52 is connected to a yoke (not shown) that moves the selector hub H by a screw 54, and pressurizes the piston chamber S3i only when the selector hub H is moved to the R position, and moves the screw 54 from the 9 position shown to the R position. This completes the reverse gear train. manual valve 5
0 gari.

When in the 2.3 position, the chamber 82 is pressurized and the servo 52 is held in the illustrated position by communicating with the chamber 5a (H tank 46).In addition, in the N and P positions, both piston chambers S2 and S3 are pressurized by the tank 46. , but remains in the position shown due to the resilient force of spring 56.

The rond part of servo 52 is group 57-A.

Together with 57-B, it constitutes a switching valve, and at the L, 2°3 position, the pressure oil led to the piston chamber S2 is transferred to the group 57-B.
The pressure oil is also guided to the oil passage 58 through Ak, and in the R position, the pressure oil guided to the chamber S3 is also introduced into the oil passage 58 through the hole provided in the shaft 1 and the group 57-Bk. It is designed to be guided.

Therefore, the hydraulic pressure at the R, L, and 2 positions, once integrated into the oil passage 58, is again guided by the manual valve 50 to the respective clutches, that is, clutches C2, CI, and C2. In addition, there is a throttle 5 in the oil passage 58 as shown in the figure.
8-A is provided, and a branch path 59 that short-circuits to the tank 46 is also provided.

A spool valve 60 that is opened and closed by a pilot type solenoid valve is interposed in the branch path 59.

This spool valve 60 throttles the pressure in the branch passage 59 62.6
3'i to the upper and lower end surfaces of the valve 60, respectively, and normally the branching passage 59 is closed as shown in the figure by the elastic force of the spring 64. A valve seat 68 having a diaphragm 66 having a larger opening area than the diaphragm 62 in the center is incorporated in the upper part of the nozzle 64, and a spring chamber 65 is formed in the lower part of the valve seat 68.

The throttle 66 of the valve seat 68 is closed by the movable iron core 72 energized by the second bolt 70 as shown in the figure, and the solenoid 7
4 is energized, the diaphragm 66 is opened and the spring chamber 6 is
5 is communicated with the tack 46 through the throttle 66 and the communication hole 69. As a result, the pressure in the chamber 65 decreases, and the spool 60 is lifted upward by the force of the pressure oil acting on its lower end surface. , branch road 59'f! :open. The pressure in the oil passage 58 at this time, in other words, the pressure in the pressure clutch at that time is
The strength of the screw 64 and the effective cross-sectional area of the spool valve 60 are decisive, so if this pressure is set below the clutch engagement pressure,
A clean ° will allow β wrestlers to do so.

- force, which causes the electrical circuit 80 to actuate the solenoid 74;

In the figure, 85 is a vehicle speed sensor, and a reed switch 8 is connected to it.
6 and magnet 8 installed on the speedometer cable
7, and a lead switch 86 detects when the cable rotational speed is 0. The output of the vehicle speed sensor 85 is set by the vehicle speed detection circuit 81 to a low level when the set vehicle speed (the set rotational speed of the speedometer cable) is set to L, and a low level when set to a high level.
It is sent to the D circuit 82.

In addition, 88 is the idling detection switch for engine/engine E, and when the throttle pedal 89 is not depressed, it outputs a high level and a low level output of 1AN when it is depressed, respectively.
It is sent to the D circuit 82.

Also, as will be described later, in this embodiment, the creep prevention mechanism does not work when starting in 3rd gear, so the operation of the solenoid 74 is controlled by the soft lever. It is better to have it performed when it is in the R position,
For this reason, the output signal of the shift lever position switch 90 is received, and the output signal 94 is at a high level when it is in the 2°R position, and is at a low level at other times.
A shift position detection circuit 92 is provided to send data to the shift position detection circuit 92.

The output of the AND circuit 82 is connected to the base of a power transistor 84 via a resistor 86, one emitter is grounded, and the collector is connected to the solenoid 74. Although the other end 96 of the solenoid 74 is not shown, it is connected to the positive terminal of the battery via an ignition switch.

Next, to explain the operation, when the shift lever is in the iL or 2 position and the vehicle is stopped waiting for a signal,
As mentioned above, the servo 52 is in the position shown in the figure with high pressure being supplied to the piston chamber S2, and the pressure oil is sent to the oil passage 58 through the throttle 58-A. , [SeLme-U +il ilL power train is formed.

While waiting for the signal, all three inputs to the A N I) circuit 82 are at high level, and the solenoid 74 is energized, so the pressure in the oil line 58 is maintained at a low pressure below the setting 111. Then, the manual valve 50 is connected to the clutch C1 or C.
2, no matter which position is pressurized, the clutch will not engage.

At this point, when the traffic light turns green and the throttle pedal 89 is depressed, this output goes to a low level, so the solenoid 7
4 is demagnetized, the throttle 66 is closed, and the branch path 59 is also closed, so that the relevant clutch recovers its engagement force and the vehicle starts moving.

After starting, when the vehicle speed reaches a certain set value or higher, the vehicle speed (No. 13) changes to a low level, so the creep prevention mechanism does not operate.
Engine braking function is restored.

In addition, when the driver tries to exit from a narrow road onto a wide road by placing the driver lever 1 in the position, the piston chamber S3 is pressurized due to the position of the manual valve 1, and this causes the servo 52 to shift to the position shown in FIG. Move center right to selector hub Hi 1st
In the figure, the power train is moved to the right in the figure, thereby forming a power train for reversing, and the pressure in the piston chamber S3 is increased by group 57-B.
, is also transmitted to clutch C2 via throttle 58-A and manual valve 501.

However, when the driver pauses to check for other cars on the wide street, all three inputs of the Fi, AND circuit 82 are at a high level, still preventing creep.

As mentioned above, if the throttle pedal 89 is depressed, the vehicle can be started.

The shift lever is in another shift position, ff1l, N.

When in the P,3 position, signal 94 is at a low level, so the anti-creep mechanism is not activated and the system operates as a normal automatic transmission.

As is clear from the above explanation, one set of the solenoid valve as a creep prevention mechanism and the electric circuit for controlling it can be applied not only to the first forward speed but also to multiple stages of clutches. The anti-creep mechanism can be applied easily and inexpensively when the driver takes off or when reversing, and since the fear of engine stalling is reduced accordingly, the throttle opening during idling can be reduced by that amount, which improves the fuel consumption rate. It can contribute to the improvement of

In the above embodiment, the pressure oil after exiting the servo 52 is throttled 5.
8-A to control the pressure in the oil passage 58 to il+1, but this is because the reverse power train IJ-bo 52
Since the discharge pressure of the pump 44 is not controlled by the creep prevention mechanism, the servo 5
2 to the right against the force of the spring 56 can be secured. If it is not necessary to create a power train for reversing the kneading gear by changing gears, the discharge pressure of the pump 44 itself may be directly controlled by the creep prevention mechanism, and in this case, the throttle 58-A is particularly controlled. unnecessary.

In addition, when changing speed between rt and D or 2, if the change is made by using the servo 52 as in this embodiment, the change cannot be performed if the overall pressure decreases, but by inserting a throttle, this change can be made. The problem will be resolved.

On the other hand, when the above-mentioned switching was performed without using the present invention, the shift shock was large because the clutch engagement and this switching were performed at the same time.However, according to the present invention, the clutch is engaged during the servo switching operation. Since no engagement occurs,
A side effect is that the above-mentioned shift-on yoke is avoided.

Various applications of the present invention are conceivable.

For example, among the signals input to the AND circuit 82, the shift position signal 94 is ANDed with the shift position detection circuit 92.
Manual switch interposed between circuit 82 (not shown)
You can set it to 0N-OFF with
By involving the signal from the water temperature sensor from the engine in the input signal of the circuit 82, the operation of the creep prevention mechanism can be interrupted during warm-up operation.

In the above embodiments, a semi-automatic transmission in which gears are changed manually was explained as an example, but even in the case of a fully automatic transmission, the pressure upstream of the switching valve that changes the speed ratio must be controlled. For example, two sets of clutches for determining speed ratios arranged downstream of the switching valve are placed under the control of the creep prevention mechanism, and a single creep prevention mechanism can adjust the speed ratios of multiple stages. On the other hand, since creep can be prevented, a simple and highly reliable system can be constructed.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a block diagram of a power train suitable for application of the present invention, and FIG. 2 is a control circuit diagram of an automatic transmission. In the drawing, 10 is a torque converter, 20 is a main shaft, 30 is a subshaft, 44 is a hydraulic pump, 46 is a tank, 48 is a pressure regulating valve, 50 is a manual valve, 52 is a servo, 60 is a spool valve, 74 is a lunoid, 81 is the vehicle speed detection circuit, 82 is the AN
D circuit, 86 is a resistor, 84 is a power transistor, 85
is the vehicle speed sensor, 86 is the reed switch, E is the engine,
CI, C2°C3 are clutches. Patent applicant: Honda Motor Co., Ltd. Agent: Patent attorney Yo Shimoda Patent attorney: Kunihiko Ohashi

Claims (2)

[Claims] (1) In an automatic transmission having a transmission system that is connected to a fluid torque converter and establishes a starting speed ratio of two or more stages, a hydraulic pump and two or more frictions that intervene in the transmission system to establish the speed ratio are used. an engagement element, a switching means for switching and supplying the discharge pressure of the hydraulic pump to either one of the frictional engagement elements; An automatic transmission for medium-sized vehicles, characterized in that it includes two creep prevention units [M+′] that reduce the pressure in the oil passage connecting the frictional engagement elements to a level below which releases the engagement of the frictional engagement elements. . (2) A throttle is interposed between the hydraulic ho/b and each of the cleave β horns, so that the discharge pressure of the hydraulic bonog can be maintained at a specified value or higher even when the creep prevention device is in operation. An automatic transmission for a vehicle according to claim 1.