JPH0369877A - Electromagnetically controlled spool valve - Google Patents

Abstract

PURPOSE:To prevent a temperature rise of oil in a spool valve disposed in the air, which is caused by discharged oil, by connecting an oil discharge pipe to an opening in the intermediate section between the spool valve which is communicated with a discharge passage of a control valve upon energization and a drive linear solenoid, and by positioning the front end opening thereof above the solenoid. CONSTITUTION:Oil from a hydraulic drive section flows through an outlet passage 24 and annular grooves 17, 31 so as to be restricted, and then flows into a center hole 35 by way of an annular groove 33 and a communication hole 37. The oil is then discharged from a drain passage opening 20 in an intermediate part between a spool valve 1 and a linear solenoid 2 by way of a communication hole 36. The opening 20 is connected thereto with an oil discharge pipe 2 having its forward end port positioned above a linear solenoid part 2. Accordingly, oil discharged from the drain passage opening 20 is poured onto the linear solenoid part 2, and accordingly, even though the solenoid part 2 which generates heat upon application of an energizing current is in the air, it is cooled by the discharged oil, thereby it is possible to smoothly slide the spool 12.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to an electromagnetically controlled spool valve, particularly an electromagnetic pressure control valve for an automatic transmission of a motor vehicle.

[Prior art] A conventional electromagnetic pressure control valve for an automatic transmission of a car is disclosed in Utility Model Application No. 10520/1983.
As shown in No. 7, in order to cool the linear solenoid part, the linear solenoid part is installed so as to be located in oil within the transmission housing. This prevents the temperature inside the linear solenoid from rising.

[Problem to be solved by the invention]

Depending on design requirements, the electromagnetic pressure control valve may be installed above the oil level in the transmission housing.

In this case, the electromagnetic pressure control valve, ie, the linear solenoid, will operate in air, which has low thermal conductivity. Therefore, the temperature inside the linear solenoid rises and exceeds the permissible temperature of the coil enamelled wire and resin material, and the temperature of the oil inside the electromagnetic pressure control valve also rises, causing the oil to deteriorate and reduce its viscosity. As a result, the sliding of the spool of the electromagnetic pressure control valve is inhibited.

[Means to solve the problem]

The electromagnetically controlled spool valve according to the present invention is an electromagnetically controlled spool valve installed in the air, the spool valve communicating with a discharge passage in the electromagnetically controlled spool valve at least during excitation operation, and an intermediate portion between the spool valve and a linear solenoid that operates the spool valve. An oil outflow pipe is connected to the opening of the oil outflow pipe, and the tip end of the oil outflow pipe is located above the solenoid portion.

[For production]

When the solenoid of the electromagnetically controlled spool valve is energized, oil flowing out from the discharge passage of the valve is poured into the solenoid portion of the electromagnetically controlled spool valve through an oil spill pipe.

In this way, the solenoid section that generates heat when the excitation current is applied and the electromagnetic control spool valve itself that is heated thereby,
Cooled by spilled oil.

〔Example〕

Embodiments of the invention will be described with reference to the drawings.

The electromagnetic pressure control valve for an automatic transmission of an automobile shown in FIG. 1 as an example of an electromagnetically controlled spool valve is composed of a spool valve 1 and a linear solenoid 2 for operating the spool valve. The spool valve 1 is embedded in a hollow horizontal hole formed in the mission housing H, and a linear solenoid 2 coaxial with the spool valve 1 has its base end fixed to the exposed end of the spool valve 1. It protrudes into the air above the oil level in the oil tank T formed between the mission housing H and the mission case C.

In the spool valve 1, a sliding hole 11 is formed passing through the spool housing 10 made of a non-magnetic material in the axial direction, and is fitted into a hollow horizontal hole of the mission housing H. is fitted so as to be slidable in the axial direction. The rear end (the left end in FIG. 1) of the slide hole 11 is hermetically closed by a screw plug 13 that is adjustably screwed into the slide hole 11. Further, on the inner circumferential surface of the sliding hole 11, a large diameter hole 14, a first annular groove 15, a second annular groove 16, a third annular groove 17, and a third annular groove 17 are formed at intervals from the exposed end side of the spool housing 10. A first drain passage 20 in which four annular grooves 18 and a fifth annular groove 19 are formed, and which faces upward from the inner circumferential surface of the large diameter hole 14 is a feedback passage provided with a throttle 21 from the bottom of the first annular groove 15. 22, a supply passage 23 is formed from the bottom of the second annular groove 16, and a second drain passage 25 is formed from the bottom of the fifth annular groove 19 in the radial direction toward the outer peripheral surface of the spool housing 10, respectively. Incidentally, recessed portions 16' and 23' of small protrusions are formed in the second annular groove 16 and the supply passage 23 on the third annular groove 17/output passage 24 side.

A cooling oil pipe 26 is connected to the opening of the first drain passage 20, and the tip of the cooling oil pipe 26 is located close to and above the linear solenoid 2. The feedback passage 22 and the output passage 24 are connected to the hydraulic operating section A, and the supply passage 2
3 to the pump P, the second drain passage 25 to the oil tank T,
They communicate with each other via communication passages formed in the mission housing H, respectively.

The valve spool 12 has a tip small diameter portion 27 and a first land portion 2.
8, first annular groove 29, second land 30, second annular groove 31. The third land portion 32, the third annular groove portion 33, and the fourth
Land portions 34 are sequentially formed, and a center hole 35 that is open only at the rear end of the fourth land portion 34 is bored in the central axis direction. Note that the first land portion 28 is different from the other land portions 3.
The diameter is slightly smaller than 0.32.34. Therefore, there is a difference in area between both end faces of the first annular groove portion 29.

The center hole 35 is a communication hole 36 that communicates with the outer peripheral surface of the small diameter portion 27 in the radial direction, and a communication hole 37 that communicates with the third annular groove portion 33 in the radial direction.
They communicate with each other.

A spring holding piece 38 is fitted into the opening step of the center hole 35 of the valve spool 12, and the spring holding piece 38 and the screw stopper 13 are fitted together.
A compression coil spring 39 is fitted between the two. Therefore, the opening of the center hole 35 (the left end in FIG. 1) is closed by the spring holding piece 38.

In the linear solenoid 2, a flange portion 41 is provided on the base end side.
A solenoid 42 is fitted onto the outer peripheral surface of a first solenoid housing 40 made of a magnetic material and is a cylindrical member formed with a cylindrical member, and a flange portion 41 is fixed to the exposed end of the spool housing 10.

A second solenoid housing 44 made of a magnetic material and a cup-shaped member with a cylindrical protrusion 43 on the inside covers the outer periphery of the solenoid 42, and its mouth edge is connected to the flange 41 of the first solenoid housing 40 and the spool. The cylindrical protrusion 43 is fixed to the exposed end of the housing 10 and has a first
It faces the yoke portion 40' at the tip of the solenoid housing 40 with an appropriate distance therebetween. A support fitting 44a that supports the cooling oil pipe 26 is fixed to the outer peripheral surface of the second solenoid housing 44 (see FIG. 2).

A non-magnetic valve rod 47 is fitted into the hollow hole of the first solenoid housing 40 via a sleeve 45 and rolling bearings 46, 46 so as to be slidable in the axial direction. A magnetic plunger 48 is attached, and the plunger 48 is loosely fitted into the hollow hole 49 of the cylindrical protrusion 43 with a small gap.

The valve spool 12 is biased and displaced by the spring force of the compression coil spring 39, and its tip is always in contact with the rear end of the valve rod 47, and in turn, the valve stem 47 has its tip brought into contact with the second solenoid housing 44. is biased toward the bottom of the hollow hole 49 of the cylindrical protrusion 43.

As a result, if the solenoid 42 is not energized,
The tip of the valve stem 47 is in contact with the bottom of the hollow hole of the cylindrical protrusion 43 1, and the rear end surface of the plunger 48 is opposed to the yoke part 40' of the first solenoid housing 40 with an appropriate distance therebetween. .

The upper half of the valve spool 12 and valve stem 47 in FIG. 1 shows a state in which the solenoid 42 is not energized, and the lower half shows a state in which an exciting current is applied to the solenoid 42 according to a control signal.

The operation of the above electromagnetic pressure control valve will be explained.

When the solenoid 42 is not energized, the spring force Fs of the compression coil spring 39 acts on the valve spool 12, and the valve spool 12 (moving to the right in FIG. 1) is attached to the tip of the valve stem 47 of the linear solenoid 2. is in a protruding state until it contacts the bottom of the hollow hole 49, and the supply passage 23 is connected to the second land portion 3.
At the same time, the third annular groove 17 and the fourth annular groove 18 are blocked by the third land portion 32 (the upper half state in FIG. 1). Therefore, the pressure oil supplied from the pump P to the supply passage 23 is
3', the second annular groove 31 and the third annular groove 17 are supplied to the output passage 24, that is, to the hydraulic operating part A, which approaches the pump pressure.

At that time, from the feedback passage 22 to the throttle 21 and the first
The hydraulic actuating portion A is also connected to the first annular groove portion 29 via the annular groove 15.
Pressure oil is supplied from a communication passage to the first annular groove portion 29, and a force p·ΔA obtained by multiplying the area difference ΔA between both end surfaces of the first annular groove portion 29 by the feedback pressure p acts against the spring force Fs of the compression coil spring 39. That is, the force of Fs-p・ΔA causes the valve spool 12 to
is pressed until the tip of the valve stem 47 comes into contact with the bottom of the hollow hole 49.

When a controlled excitation current from an external control device (not shown) is applied to the solenoid 42, a magnetic field line circuit composed of the first solenoid housing 40, the second solenoid housing 44, and the plunger 48 is configured, and the excitation current is applied to the solenoid 42. Yoke 40° has a suction force that is proportional to the size.
and the plunger 48, the valve stem 47 presses the valve spool 12 against the spring force of the compression coil spring 39. As a result, the valve spool 12 receives the sum of the suction force Fm by the solenoid 42 and the hydraulic pressure p·ΔA, and the compression coil spring 39.
The supply passage 23 is at a position where the spring force Fs of
That is, the recessed portions 23' and 16' are constricted accordingly, and the constricted pressure oil is supplied to the communication passage to the hydraulic operating section A.

Therefore, depending on the magnitude of the excitation current, the aperture progresses, and the third annular groove 17 and the fourth annular groove 18 remain cut off by the third land part 32, and the recessed part 16 of the second annular groove 16 ' is also closed by the second land portion 30. In that case, the supplied oil leaks into the large diameter hole 14 from the fitting gap between the sliding hole 11 and the valve spool 12.

When the magnitude of the excitation current increases, the attraction force Fm by the solenoid 42 increases, and the valve rod 47 further presses the valve spool 12 against the spring force Fs of the compression coil spring 39. As a result, the second annular groove 16 including the recessed part 16'' is closed by the second land part 30, and the output passage 2
4 communicate with the fourth annular groove 18 and the third land portion 32 via the third annular groove 17 and the second annular groove portion 31 with a narrowed opening. The opening degree is maximum when the magnitude of the excitation current is maximum (lower half state in FIG. 1).

Therefore, oil from the hydraulic actuating part A passes through the output passage 24, the third annular groove 17, and the second annular groove 31, is squeezed, and passes through the fourth annular groove 18, the third annular groove 33, and the communication hole 37 to the center. It flows out into the cooling oil pipe 26 through the communication hole 36, the large-diameter hole 14 (intermediate part between the spool valve 1 and the linear solenoid 2), and the first drain passage 20, and the hydraulic operation part A , approaching tank pressure.

The oil that has leaked into the cooling oil pipe 26 is then poured onto the solenoid 42 from above the second solenoid housing 44 and discharged into the tank T.

Thus, the solenoid 4 which generates heat due to the application of the excitation current
2 and the electromagnetically controlled spool valve itself, which is heated thereby, is cooled by the spilled oil.

Furthermore, due to the movement of the valve spool 12 due to interruptions and changes in the excitation current, oil may flow out from the first drain passage 20 in the large diameter hole 14 of the sliding hole 11, or oil may flow out from the center hole 35 of the valve spool 12. The first
, the oil in the second solenoid housing 40.44 is replaced to prevent its deterioration.

The fitting area space of the compression coil spring 39 in the sliding hole 11 expands and contracts as the valve spool 12 advances and retreats, and performs a pumping action. Oil goes in and out of T.

[Effects of the Invention 1] According to the electromagnetic control spool valve of this invention, it is normally installed in oil in an oil tank! When the magnetically controlled spool valve is installed above the oil level in the oil tank due to design requirements, the electromagnetically controlled spool valve, i.e. the linear solenoid, cannot be installed separately even if it operates in air with low thermal conductivity. As a result, the oil flowing from the drain passage into the tank is cooled by being applied to the solenoid part without providing any cooling means.
This prevents an increase in oil temperature within the electromagnetically controlled spool valve, and also prevents an increase in the viscosity of the oil, which would cause the spool of the electromagnetically controlled spool valve to be inhibited from sliding.

[Brief explanation of drawings]

FIG. 1 is a sectional front view of an electromagnetic pressure control valve according to an embodiment of the invention, and FIG. 2 is a side view of the electromagnetic pressure control valve according to an embodiment of the invention. 1 Nisbourg valve 2: Linear solenoid lO
Varnish spool housing 11: sliding hole 12: valve spool 13: screw plug 14: large diameter hole 15: first annular groove 16: second annular groove 17: third annular groove 18: fourth annular groove
19; Fifth annular groove 20: First drain passage 21:
Throttle 22: Feedback passage 23: Supply passage 16°
, 23': recessed part 24: output passage 25: second
Drain passage 26: Cooling oil pipe 27: Small diameter tip
28: First land portion 29: First annular groove portion
30: Second land portion 31: Second annular groove portion 32
:Third land portion 33:Third annular groove portion 34:Fourth
Land portion 35: Center hole 36, 37: Communication hole 38: Spring holding piece 39: Compression coil spring 4
0: First solenoid housing 40゛: Yoke part 41:
Flange portion 42: Solenoid 43: Cylindrical protrusion 44:
Second solenoid housing 44a: Support fitting 45 Ni sleeve 46 Double rolling bearing 47: Valve stem 48 Ni plunger 4
9: Hollow hole A: Hydraulic operating part C: Mission case H
:Mission housing h:Hollow hole P:Pump T:Tank Figure 2

Claims (1)

[Claims] An oil spill pipe is coupled to an opening in the middle between a spool valve that communicates with a discharge passage in an electromagnetic control valve installed in the air at least during excitation operation, and a linear solenoid that operates the spool valve. Electromagnetic control spool valve located above the section