JP2000104761A - Solenoid valve and hydraulic pressure control device for clutch mechanism using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solenoid valve physically small to detect malfunction. SOLUTION: A solenoid valve 30 is a hydraulic pressure control valve to adjust pressure of working oil pumped up from a tank 56 by a pump 55 and to apply it on a clutch 20. A spool 37 stops at a position where energizing force of a spring 38, electromagnetic force generated on a coil 47 by an electric current supplied to the coil 47 and force which the spool 37 receives from pressure of a feedback chamber 39 are balanced. When a plunger 42 makes contact with a stopper 50, an electric potential of a terminal 51 becomes an earth electric potential, and when the plunger 42 aparts from the stopper 50, the electric potential of the terminal 51 becomes an electric power source electric potential. It is possible to speedily detect completion of filling as an ECU 54 detects from pressure rise the feedback chamber 39 in filling control that the plunger 42 aparts from the stopper 50 and the electric potential of the terminal 51 becomes the electric power source electric potential.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve for controlling an output pressure according to the position of a movable member, and more particularly to a hydraulic control valve for controlling a pressure of a clutch mechanism.

[0002]

2. Description of the Related Art In a conventional solenoid valve, it is common to detect a malfunction (fail) due to disconnection of a coil or twisting of a movable member by providing a fail detecting means separately from the solenoid valve.

[0003] Further, the position of the movable member is defined by the electromagnetic force generated by the coil, the urging force of the spring, and the force received by the movable member from the pressure obtained by feeding back the output pressure.
2. Description of the Related Art An electromagnetic valve that adjusts an output pressure according to a position of a movable member is known. For example, if such an electromagnetic valve is used for a hydraulic control valve used in an automatic transmission, the hydraulic pressure applied to friction elements such as a clutch and a brake can be controlled with high accuracy. When shifting control is performed using such an electromagnetic valve, the time (filling time) until hydraulic oil is supplied to the clutch chamber of the friction element and the piston actually presses the clutch plate with hydraulic pressure is set in the timer. It is known that the filling time is shortened and the shift control is performed quickly by maximizing the amount of hydraulic oil supplied to the clutch chamber until immediately before the hydraulic oil is filled.

[0004]

However, if fail detecting means is provided separately from the solenoid valve, there is a problem that the size of the entire apparatus including the solenoid valve becomes large.

The charging time set in the timer is determined by the difference in clearance between the clutch plate and the piston, the difference in the volume of the clutch chamber, the difference in oil temperature, the difference in the amount of air mixed in the working oil, etc., depending on the type of vehicle and the specifications of the friction elements. The hydraulic fluid may be filled in the clutch chamber beforehand. Then, the piston starts to push the clutch plate while the supplied hydraulic oil amount is maximum, and the friction element is suddenly engaged, so that a shift shock may occur.

[0006] By providing a hydraulic switch for detecting the hydraulic pressure of the clutch chamber, the completion of filling the clutch chamber is detected,
It is also conceivable to control the friction element with a predetermined pressure after detecting the filling. However, if the hydraulic pressure for detecting the end of filling differs depending on the clutch, it is necessary to set the detected hydraulic pressure for each clutch. Further, if a hydraulic switch is provided separately from the hydraulic control valve, the physical size of the hydraulic control device becomes large and the manufacturing cost increases.

It is an object of the present invention to provide a small-sized solenoid valve for detecting a malfunction. It is another object of the present invention to provide a hydraulic control device that performs filling control optimally irrespective of a difference in a clutch structure and an operation environment, and shortens a shift time.

[0008]

According to the solenoid valve of the present invention, the movement of the movable member in the direction of increasing the output pressure of the solenoid valve is regulated, and the movable member is brought into contact with the movable member. A stopper electrically connected to the movable member is provided,
The movable member and the stopper constitute an electric switch for detecting the presence or absence of contact between the movable member and the stopper. ON of the electric switch indicates that the movable member and the stopper are in contact, and OFF of the electric switch indicates that the movable member and the stopper are apart.

Therefore, it is possible to detect that the movement of the movable member has become impossible due to disconnection, twisting of the movable member, or the like by continuing the ON or OFF state of the electric switch. Furthermore, since the electric switch is provided integrally with the solenoid valve, the size of the solenoid valve having the electric switch can be reduced. Further, since the movable member is used as a part of the electric switch, an increase in the number of parts can be prevented and the manufacturing cost can be reduced.

According to the third aspect of the present invention, during the charging control, the current supplied to the coil is adjusted so that the movable member and the stopper are kept in light contact with each other. I have. Therefore, when the feedback pressure increases, the movable member is quickly separated from the stopper, and the electric switch is turned off. The control device detects that the electric switch has been turned off in a state where the movable member and the stopper are in light contact with each other, so that the clutch mechanism can be hydraulically controlled at a predetermined pressure immediately after the filling is completed, so that the speed change control can be performed quickly. Will be

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention. FIG. 2 shows a hydraulic control apparatus for an automatic transmission using an electromagnetic valve as a hydraulic control valve according to an embodiment of the present invention.

The automatic transmission 1 transmits engine torque to the axle through a torque converter 2 and an auxiliary transmission 3. The auxiliary transmission 3 includes a planetary gear 10, a brake 1
And a solenoid element 30 as a hydraulic control valve for hydraulically controlling the friction element.

The planetary gear 10 includes a ring gear 11, a pinion gear 12, and a sun gear 13. In this embodiment, the sun gear 13 is connected to the input shaft, and the pinion gear 12 is connected to the output shaft. The sun gear 13 can be connected to the housing 15 via a brake 19 and can be connected to an output shaft via a clutch 20. The shift speed is low when hydraulic oil is supplied to the brake 19 and hydraulic oil is discharged from the clutch 20, and is high when hydraulic oil is discharged from the brake 19 and hydraulic oil is supplied to the clutch 20.

The input housing 21 of the clutch 20 shown in FIG. 1 is connected to the sun gear 13, that is, the input shaft, and the output housing 23 is connected to the output shaft. A plurality of disk-shaped clutch plates 22 and 24 are arranged alternately. The clutch plates 22 and 24 are respectively assembled in annular grooves formed in the inner peripheral walls of the input housing 21 and the output housing 23, and are restricted from moving in the rotation direction. The snap ring 25 is used to hold the clutch plate 24 between the input housing 21 and the clutch plate 22.
It is attached to.

The piston 26 is axially assembled between the input housing 21 and the clutch plate 22, and a clutch chamber 27 is formed between the piston 26 and the input housing 21 in the axial direction. When hydraulic oil is supplied to the clutch chamber 27, the piston 26 receives a force on the clutch plate 24 in the direction of pressing the clutch plate 22. The spring 28 is locked by a stopper 29 fixed to the input housing 21, and moves the piston 2 away from the clutch plate 22.
6 are energized. When the operating oil is not supplied to the clutch chamber 27, the piston 26 and the clutch plate 22
And a gap d is formed in the axial direction.

The solenoid valve 30 is a hydraulic control valve that adjusts the pressure of the hydraulic oil sucked from the tank 56 by the pump 55 and applies it to the clutch 20. The housing 31 is grounded, and supports a spool 37 as a movable member in a reciprocating manner. The housing 31 has an input port 32,
An output port 33, a discharge port 34, and a feedback port 35 are formed. The output port 33 is connected to the input port 21 provided in the input housing 21 of the clutch 20.
a, and supplies hydraulic oil to the clutch chamber 27. The output port 33 and the feedback port 35 communicate with each other through a communication port 36, and the feedback chamber 3
9 communicates with the feedback port 35. The discharge port 34 is a port for discharging hydraulic oil to the tank 56.

On the spool 37, large-diameter lands 37a, 37b and small-diameter lands 37c are formed in this order from the left in FIG. The small diameter land 37c is the large diameter land 37a, 37b.
Smaller in diameter than The spool 37 is always in contact with a plunger 42 described later, and reciprocates with the plunger 42.

The spring 38 as the urging means is provided in FIG.
Is urged to the right in FIG. Since the feedback chamber 39 is formed between the large-diameter land 37b and the small-diameter land 37c, the hydraulic pressure in the feedback chamber 39 acts to press the spool 37 to the left in FIG.

When the spool 37 moves rightward in FIG. 1, the opening area of the input port 32 increases, and the output port 3
Since the communication between the port 3 and the discharge port 34 is interrupted, the amount of hydraulic oil supplied from the output port 33 to the clutch chamber 27 increases, and the hydraulic pressure at the output port 33 increases. Output port 33
Represents the output pressure of the solenoid valve 30. When the spool 37 moves to the left in FIG. 1, the input port 32 is closed,
Since the output port 33 and the discharge port 34 communicate with each other and the opening area of the discharge port 34 increases, the amount of hydraulic oil discharged from the clutch chamber 27 to the tank 56 via the output port 33 and the discharge port 34 increases, thereby increasing the output port. The oil pressure at 33 drops.

The yoke 40 is formed in a cylindrical shape, and is provided at an end of the housing 31. The end plate 41 is caulked and fixed by the yoke 40. The plunger 42 is fixed to the movable core 43 and the movable core 4
Reciprocates with 3. The plunger 42 and the movable core 43 together with the spool 37 constitute a movable member. The movable core 43 is supported by the end plate 41 so as to be able to reciprocate. One end of the plunger 42 is supported by a bearing 44, and the other end is supported by a bush 45. The diaphragm 46 separates the space between the electromagnetic drive side and the spool side. The coil 47 is wound around the outer periphery of the movable core 43. When a current is supplied to the coil 47, an electromagnetic force is generated, and the movable core 43 is attracted to the facing portion 40a of the yoke 40. Thus, the spool 37 moves to the left in FIG. 1 against the urging force of the spring 38.

The terminal 48 is electrically connected to the coil 47 and supplies a current to the coil 47. The connector housing 49 is formed of a non-conductive material such as a resin, and insulates the stopper 50 and the terminal 51 from other conductive members. The stopper 50 is a member that regulates the rightward movement of the plunger 42 in FIG. 1.
2 and the stopper 50 are electrically connected. The terminal 51 is electrically connected to the stopper 50 through a conductive member 50a integrated with the stopper 50.

A resistor 53 is connected in series between the terminal 51 and the power supply 52. Engine control unit (EC
U) 54 detects the potential on the terminal 51 side of the resistor 53 and controls the current value supplied to the coil 47. The detection device for detecting the potential on the terminal 51 side and the control device for controlling the current value supplied to the coil 47 may be separate devices. By controlling the current supplied to the coil 47 and adjusting the position of the spool 37, the pressure applied from the solenoid valve 30 to the clutch 20 is adjusted.

The spool 37 stops at a position where the biasing force of the spring 38, the electromagnetic force generated in the coil 47 by the current supplied to the coil 47, and the force received by the spool 37 from the pressure in the feedback chamber 39 are balanced.

For example, when these three forces are balanced and the current supplied to the coil 47 is increased with the spool 37 stopped, the spool 37 temporarily moves to the left in FIG.
Then, the discharge port 34 and the output port 33 communicate with each other,
The input port 32 is closed. Then, since the output pressure decreases and the pressure in the feedback chamber 39 decreases before the current is increased, the spool 37 returns to the right direction, that is, the pressure increasing direction, and stops at the position where the three forces are balanced.

When the three forces received by the spool 37 are balanced and the current supplied to the coil 47 is reduced in a state where the spool 37 is stopped, the spool 37 is temporarily moved rightward in FIG. Then
The discharge port 34 is closed, and the input port 32 is opened. Then, since the output pressure increases and the pressure in the feedback chamber 39 increases before the current is reduced, the spool 37
Returns to the left direction, that is, returns to the decompression direction, and stops at a position where the three forces are balanced.

When the current supply to the coil 47 is cut off or the current value is greatly reduced, the spool 37 and the plunger 42 are forced by the spring 38 so that the plunger 42
Moves to a position where it contacts the stopper 50. In this state, the input port 32 is fully opened and communicates with the output port 33, and the discharge port 34 is closed.

Next, the operation of the hydraulic control device shown in FIG. 1 will be described. The following description substantially corresponds to the period shown in FIG. Also switch (SW)
The signal is turned on and off when the plunger 42 is in contact with the stopper 50 and the plunger 42 is
A state apart from 0 indicates off.

(1) When the clutch 20 is released When a current is supplied to the coil 47, the movable core 43 is attracted to the opposing portion 40a of the yoke 40 against the urging force of the spring 38, and from the position shown in FIG. Move further to the left. Then, the input port 32 is closed, and the output port 33 and the discharge port 34 communicate. As a result, the operating oil in the clutch chamber 27 of the clutch 20 is discharged to the tank 56. Since the piston 26 is pressed against the input housing 21 by the urging force of the spring 28, the engagement between the clutch plate 22 and the clutch plate 24 is released.

(2) When the clutch 20 is engaged When a gearshift command is issued and the clutch 20 is engaged, first, the current supply to the coil 47 is cut off as shown in FIG. The spool 37 is biased by a spring 38 as shown in FIG.
Move to the right. Then, the discharge port 34 is closed, the input port 32 is fully opened and communicates with the output port 33, and hydraulic oil is supplied to the clutch chamber 27. At this time, the maximum amount of hydraulic oil is supplied to the clutch chamber 27. The pressure in the clutch chamber 27 hardly increases until the clutch chamber 27 is filled with hydraulic oil and the piston 26 starts pressing the clutch plate 22. The plunger 42 that moves rightward in FIG. 1 together with the spool 37 comes into contact with the stopper 50 and stops, and the electric switch is turned on. The spool 37 is the housing 3
1 and the plunger 42 and the stopper 50
Is contacted, the terminal 51 is grounded via the stopper 50, the plunger 42, the spool 37, and the housing 31. Therefore, the potential of the terminal 51 becomes the ground potential.

When the ECU 54 detects the ground potential of the terminal 51, that is, detects the contact between the plunger 42 and the stopper 50, the ECU 54 gradually increases the current value supplied to the coil 47. And the spring 38
When the movable core 43 is attracted to the left side of FIG. 1 and the plunger 42 is separated from the stopper 50, the electric switch is turned off, and the potential of the terminal 51 becomes the power supply potential.

When the potential of the terminal 51 becomes the power supply potential, the ECU 54 slightly reduces the value of the current supplied to the coil 47. When the plunger 42 comes into light contact with the stopper 50 to turn on the electric switch and the potential of the terminal 51 becomes the ground potential, the current value at this time is maintained, and the state in which the plunger 42 comes into light contact with the stopper 50 is maintained.

While the hydraulic oil is being supplied to the clutch chamber 27, the pressure in the clutch chamber 27 hardly rises as shown in FIG. When the filling of the hydraulic oil into the clutch chamber 27 is completed and the piston 26 comes into contact with the clutch plate 22, the clutch chamber 27, the output port 33, the feedback chamber 39
Pressure starts to rise. Then, due to the difference in pressure receiving area between the large-diameter land 37b and the small-diameter land 37c, the spool 37 receives a force in the left direction in FIG.
By moving away from 0, the electric switch is turned off and the potential of the terminal 51 becomes the power supply potential. When the second power supply potential is detected by the ECU 54 after the shift command is issued, the current value supplied from the ECU 54 to the coil 47 is controlled to hydraulically control the clutch 20.

(Comparative Example) FIG. 4 shows a shift process of a comparative example in which the supply of current to the coil 47 is not controlled by the ECU 54 during the filling control and the state in which the plunger 42 and the stopper 50 are in light contact is not maintained. The configurations of the solenoid valve and the clutch of the comparative example are the same as those of the present embodiment. In FIG. 4, 100
Indicates a change in the clutch chamber pressure, and 101 indicates a displacement of the piston.

When a shift command is issued, the supply of current to the coil 47 is cut off, and the plunger 42 is pressed against the stopper 50 by the urging force of the spring 38 without receiving an electromagnetic force in a direction opposite to the urging force of the spring 38. Therefore, even if the filling of the hydraulic fluid into the clutch chamber 27 is completed, the plunger is required to increase the pressure in the feedback chamber 39 to a level at which the spool 37 can move to the left in FIG. 1 against the urging force of the spring 38. 42 does not separate from the stopper 50. Therefore, even if the filling of the hydraulic fluid into the clutch chamber 27 is completed, the hydraulic fluid is supplied to the clutch chamber 27 in the maximum amount, so that the pressure in the clutch chamber 27 excessively increases as shown in FIG. Then, an impact may occur when the clutch 20 is engaged.

On the other hand, in the present embodiment, by controlling the value of the current supplied to the coil 47 during the charging control, the charging of the hydraulic oil into the clutch chamber 27 is completed and the pressure in the feedback chamber 39 slightly increases. , Stopper 50
The plunger 42 and the stopper 50 are in contact with each other so that the plunger 42 is separated from the plunger 42. Therefore, when the plunger 42 separates from the stopper 50, the ECU 54
Quickly detects the end of filling. As a result, it is possible to promptly shift to the hydraulic control after the filling is completed, so that the shift can be promptly processed.

Further, if the plunger 42 becomes immovable due to disconnection or twisting of the plunger 42, the terminal 5
1 is fixed to the ground potential or the power supply potential. E
The CU 54 can detect such a malfunction of the solenoid valve by detecting the potential of the terminal 51. Furthermore, since the electric switch for detecting malfunction is provided integrally with the solenoid valve, the size of the solenoid valve for detecting malfunction can be reduced.

In this embodiment, the electromagnetic valve is used to connect the input port 32 and the output port 33 to supply the hydraulic oil to the clutch chamber 27 when the current supply to the coil 47 is interrupted. Time, input port 32 and output port 3
A configuration of an electromagnetic valve that communicates with the clutch chamber 3 and supplies hydraulic oil to the clutch chamber 27 may be used. In the present embodiment, the solenoid valve of the present invention is used as a hydraulic control valve for hydraulically controlling a friction element of an automatic transmission, but may be used as a pressure control valve of another clutch mechanism.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a hydraulic control apparatus for an automatic transmission using an electromagnetic valve as a hydraulic control valve according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing an automatic transmission according to the embodiment.

FIG. 3 is a characteristic diagram showing a shift process according to the embodiment.

FIG. 4 is a characteristic diagram showing a shift process according to a comparative example.

[Explanation of symbols]

 Reference Signs List 1 automatic transmission 19 brake (clutch mechanism) 20 clutch (clutch mechanism) 30 solenoid valve (hydraulic control valve) 32 input port 33 output port 35 feedback port 37 spool (movable member, electric switch) 38 spring (biasing means) 39 Feedback chamber 40 Yoke 41 Movable core (movable member) 42 Plunger (movable member, electric switch) 47 Coil 50 Stopper (electric switch) 51 Terminal 52 Power supply 53 Resistor 54 ECU (Control device)

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hitoshi Tanaka 1-1-1, Showa-cho, Kariya-shi, Aichi F-term in DENSO Corporation (reference) 3J057 AA04 BB04 EE07 GA11 GA51 GB18 GB21 GB22 GE01 GE10 JJ02

Claims (3)

[Claims] A movable member for adjusting an output pressure according to a reciprocating position; a coil for generating an electromagnetic force when energized; and a coil in a direction opposite to a force received by the movable member from the electromagnetic force generated in the coil. An urging means for urging the movable member, wherein the position of the movable member is defined by an electromagnetic force generated by the coil, an urging force of the urging means, and a force received from a feedback pressure obtained by feeding back an output pressure. An electromagnetic valve that restricts movement of the movable member in a direction to increase output pressure, and includes a stopper that is electrically connected to the movable member by coming into contact with the movable member. An electromagnetic valve, wherein the stopper constitutes an electric switch for detecting the presence or absence of contact between the movable member and the stopper. 2. The solenoid valve according to claim 1, wherein engagement and disengagement of the clutch mechanism are hydraulically controlled. 3. An electromagnetic valve according to claim 2, further comprising: a control device that detects whether the electric switch is on or off and controls a current supplied to the coil. When the engagement command is generated, the movable member is moved in a direction in which the current supplied to the coil is increased or decreased in one direction to increase the output pressure so that the hydraulic oil supply amount to the clutch mechanism is maximized. When the electric switch is turned on, the current supplied to the coil is gradually increased or decreased in the other direction to turn off the electric switch, and the current value when the electric switch is turned off is increased or decreased in one direction. The output pressure applied to the clutch mechanism when the movable member is kept in light contact with the stopper and the electric switch is turned off by the increase of the feedback pressure Hydraulic control apparatus for a clutch mechanism and sets the predetermined pressure.