JPS6117753A - Mechanism for preventing hydraulic transmission from creep - Google Patents

Abstract

PURPOSE:To hold hydraulic engaging elements under the pressurized condition below the engaging pressure without any special adjustment by providing a main pressure receiving surface and an auxiliary pressure receiving surface on an actuator to supply working oil only to the auxiliary pressure receiving surface in idling. CONSTITUTION:On an actuator 2 for operating an engaging element 1 are provided a main pressure receiving surface S1 and an auxiliary pressure receiving surface S2 for operatively engaging the engaging element 1 to supply working oil only to said surface S2 by a control means 4 in idle running. Thus, the engaging element 1 can be held under the pressurized condition below the engaging pressure by an extremely simple constitution yet without any special adjustment.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a creep prevention mechanism for a hydraulically operated transmission equipped with a torque converter.

(Prior art) In general, in a hydraulically operated transmission equipped with a torque converter, when idling is performed with the shift lever shifted to the driving range, the engine torque is transferred to the drive via the torque converter or transmission system. This is transmitted to the wheels, causing a so-called creep phenomenon in which the vehicle moves.
In order to prevent the occurrence of this creep phenomenon, a creep prevention mechanism is provided that cuts off oil supply to hydraulic engagement elements such as a hydraulic clutch in the transmission during idling, and when idling, even if the shift lever is
A system has been developed in which the mechanism releases the engagement of the hydraulic engagement element and automatically returns the transmission to the neutral state even when the transmission is shifted to the driving range. In some cases, when the hydraulic engagement element is refueled during a start operation, there is a time lag before the hydraulic engagement element engages, which may cause the engine to rev up or even cause a start shock. Ta.

Therefore, in the past, as shown in, for example, Japanese Patent Application Laid-Open No. 58-21047, a pressure holding means for holding the hydraulic engagement element in a pressurized state below the engagement pressure during idling has been provided to the creep prevention device. In particular, a system has been developed in which the hydraulic engagement element is immediately engaged when the vehicle is assembled and started from idling.

(Problems to be Solved by the Invention) However, in the above system, not only a special regulating valve is required as the pressure holding means, but also the pressure holding means controls the hydraulic pressure acting on the hydraulic engagement element. It was difficult to adjust the pressurized state to below the engagement pressure.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention detects engine idling and uses hydraulically actuated engagement elements in a hydraulically actuated transmission equipped with a torque converter. In the device in which creep is prevented by controlling engagement, an actuator for hydraulically operating the engagement element,
A soil pressure receiving surface that engages and operates the engagement element and an auxiliary pressure receiving surface are provided, and during idling operation, hydraulic oil is supplied only to the auxiliary pressure receiving surface so that the actuator is engaged and operated by the engagement element. A control means is provided to control the pressing force to be less than or equal to the pressing force.

(Function) According to the present invention, the hydraulic engagement element can be maintained in a pressurized state below the engagement pressure with an extremely simple configuration and without requiring any special adjustment.

(Example ) Embodiments of the present invention will be described below with reference to the drawings.

The embodiment shown in the drawings is used for an automatic transmission equipped with a torque converter and a planetary gear device, and as is known, the planetary gear device of this automatic transmission includes a drive clutch, a reverse clutch, etc. These engaging elements are actuated via an actuator that is connected to a cylinder and a piston having a hydraulic operating length to switch to, for example, a neutral range or a drive range.

In the figure, (1) is a multi-plate drive clutch which is one of the engaging elements of the planetary gear system described above, and as is known, this drive clutch (1) has a reciprocating mechanism inside a cylinder (2o). Piston with freely movable interior (21)
and a return spring (22) for reciprocating the piston (21), the drive flange (1) is engaged or disconnected by the operation of the piston (21) of the actuator (2). It is done as it is done.

Further, a piston (21) constituting the actuator (2)
), the soil pressure receiving surface (sl) and the soil pressure receiving surface (Sl)
The hydraulic oil supply passage (3) extending from the manual valve (not shown) is divided into first and second oil passages (31) and (32).
is provided, and the first oil passage (31) is connected to the cylinder (20
) of the piston (21) in the soil pressure receiving surface (Sl)
Also on the side is the second ura passage (32) and the cylinder (20).
) of the piston (21) in the auxiliary pressure receiving surface (S2
) side respectively.

When the shift lever is shifted to the drive range during idling operation, hydraulic oil is supplied only to the auxiliary pressure receiving surface (S2-) side of the piston (21), so that the piston (21) The piston (21) is brought into contact with the clutch (1) at a pressure lower than the pressing force required to engage the trough clutch (1).
) by supplying hydraulic oil to the soil pressure receiving surface (S, ) side of the piston (21), the piston (21) is brought into contact with the clutch (1) with a pressing force that causes the drive clutch (1) to engage.
has been completed.

Moreover, (4) is the main receiving pressure (Sl) of the piston (21).
first and second shift valves (4) and (5) that selectively communicate the side and the auxiliary pressure receiving surface (S2) side with the supply passage (3) or the tank line (45) (55);
, the first and second shift valves (4) and (5) that control the second shift valves (4) and (5).
It consists of solenoid valves (6) and (7).

The first shift valve (4) shown in the figure has the first and second lands (
41a) A two-land type spool (41) with (4l b,) is used, and a pressure control chamber (42) is provided on the negative side of the spool (41), and a spring chamber (43) is provided on the other side.
A coil spring (
44), while a tank line (45) is installed between the first land (41a) and the second land (4l b) a.
and connects the downstream side passage (31a) and the secondary side passage (31b,) of the first oil passage (31), and is normally 1)? 1. The second land (4l b) connects the downstream passageway (31a) and the secondary passageway (3l b) of the first oil passageway (31).
b) At the same time, the secondary passageway (3) is cut off.
l b) is connected to the tank line (45), and as the spool (41) moves forward, the first land (41a) closes the tank line (45) and at the same time closes the tank line (45) to the next side journey. (3'la) to the secondary passageway (3l b
).

Further, the second shift valve (5) is connected to the first soft valve (4).
), a spool (51) equipped with first and second lands (51a) (5l b) is used, and the - of the spool (51) is used.
There is a pressure control chamber (52) on one side and a spring chamber (52) on the other side.
53), and a coil spring (54) is interposed in the spring chamber (53), while the first land (51a
) and the second land (51b), there is a tank line (55
) and the downstream side passage (32a) and the secondary side passage (32b) of the second oil passage (32) are connected, and the second oil passage (32) is normally connected to the second land (51b). 32)-
The structure is configured such that communication between the next side passage (32a) and the second side passage (32b) is cut off, and at the same time, the second side passage (32b) is made to communicate with the tank line (55). As the movement occurs, the tank line (55) is closed at the first land (51'a) and the next passageway ('32'a) is closed.
a) to communicate with the secondary passageway (32b).

Further, orifices (33a) (34) are provided in the supply passage (3).
a) are provided, and the first branch passage (33) is connected to the pressure control chamber (41) of the first shift valve (4), and The second branch passage (34) is connected to the pressure control chamber (51) of the second shift valve (5), while the first branch passage (34) is connected to the pressure control chamber (51) of the second shift valve (5).
33), and the second solenoid valve (7) is interposed in the middle of the second branch passage (84).

However, the first solenoid valve (6) shown in the figure is connected to the tank line (
61) and the first branch passageway (33) are connected to each other.
60), a solenoid (62) that is energized as the accelerator pedal is depressed, and a solenoid (62) that moves due to the energization of the solenoid (62) to cut off communication between the tank line (61) and the first branch passage (33). The second solenoid valve (7) is also provided with a valve body (θ3) that is similar to the first solenoid valve (θ3).
Similarly to 6), a valve body (70) connecting the tank line (71) and the second branch passageway (34) is filled with a valve that connects the tank line (71) and the second branch passage (34).
I and the solenoid (72) is energized as the shift lever is shifted to the drive range CD), and the solenoid (72) is energized to move and move the tank line (
70) and a valve body (73) that cuts off communication between the second branch passageway (34) and the second branch passageway (34).

Next, the operation of the creep prevention mechanism constructed as above will be explained.

FIG. 1 shows a state in which the transmission is shifted to the neutral range and the engine is in idling operation without the accelerator pedal being depressed. At this time, the supply passage (
3) is shut off by a manual valve, and each solenoid (82) (72) of the first and second solenoid valves (6) and (7) is also closed.

Therefore, the piston (2) in the actuator (2)
Hydraulic oil is not supplied to the soil pressure receiving surface (Sl) and the auxiliary pressure receiving surface (S2) of 1), so the drive clutch (1) is disconnected.

Next, when starting, if you perform Ai Trig operation with the shift lever shifted to the drive range,
While hydraulic oil is sent into the supply passage (3) via the manual valve, only the solenoid (72) of the second solenoid valve (7) is energized, and the tank connected to the second solenoid valve (7) is energized. Line (71) is closed, and along with this,
The hydraulic oil in the supply passage (3) is transferred to the second branch passage (34a).
) of the 27th foot valve (5).
52), the spool (51) of the second soft valve (5) moves forward.

As shown in FIG. 2, the forward movement of the spool (51) causes the secondary passage (32b) of the second ura passage (32) to communicate with the secondary passage (32a), and the piston in the actuator (2) Hydraulic oil is supplied to the auxiliary pressure receiving surface (S,) of (21), and as a result, the piston (21)
The shift lever moves leftward from the position shown in the figure to press the drive clutch (1), but the pressing force is less than the force required for the drive clutch (1) to engage. Even though the engine is shifted to \, the engine torque is not transmitted to the drive wheels, so no creep phenomenon occurs.

However, when the accelerator pedal is pressed to start from the levered state, solenoid 11 (62) of the first solenoid valve (6)
is also excited, the tank line (61) connected to the first solenoid valve (6) is closed, and as a result, the hydraulic oil in the supply passage (3) marked 11 is supplied to the first shift valve (4) marked θη. ), the spool (41) of the first lift valve (4) moves forward. The forward movement of the spool (41) causes the secondary side passage (3l b) of the first oil passage (31) to open as shown in FIG.
1a), hydraulic oil is also supplied to the earth pressure receiving surface (S,) of the piston (21) in the actuator (2), but the piston (21) is connected to the drive clutch (1). Since the drive clutch (1) is in contact with the clutch (1) at a pressure lower than the pressing force that causes the engagement operation, the drive clutch (1) is immediately engaged as hydraulic oil is supplied to the soil pressure receiving surface (S). Therefore, a smooth start is achieved without causing the engine to rev up due to a delay in engagement of the clutch (1).

Although the above embodiment has been described using the drive clutch (1) as the engagement element in the automatic transmission, a reverse clutch may also be used.

(Effects of the Invention) As described above, according to the present invention, the auxiliary pressure receiving surface of the actuator can prevent the occurrence of creep phenomenon during idling operation with the shift lever shifted to the driving range, and can smoothly start from the idling operation. This can be done by simply controlling the flow of hydraulic oil to the soil pressure receiving surface, and therefore it has become possible to omit special adjusting means for adjusting the pressure of the hydraulic oil and adjustment of the pressure of the hydraulic oil.

[Brief explanation of drawings]

Fig. 1 is a hydraulic circuit diagram showing one embodiment of the device of the present invention;
3 and 3 are hydraulic circuit diagrams showing the operating state of the device of the present invention. (1) Drive clutch (locking element) (2
)...Actuator (S,)...Soil pressure receiving surface (S2)...Auxiliary pressure receiving surface (4)...Control means

Claims (1)

[Claims] An actuator that hydraulically operates the engagement element in a hydraulically operated transmission equipped with a torque converter that detects idling of the engine and controls engagement of the engagement element by hydraulic operation to prevent creep. a main pressure receiving surface that engages and operates the engagement element;
In addition to providing an auxiliary pressure receiving surface, during idling operation,
A creep prevention mechanism for a hydraulically operated transmission, characterized in that a control means is provided for supplying hydraulic oil only to the auxiliary pressure receiving surface and controlling the actuator to a pressure lower than the pressing force at which the engagement element engages. .