JPH04331881A - Three-way solenoid valve - Google Patents

Abstract

PURPOSE:To provide a three-way solenoid valve which increase a rate of flow from a discharge port to a drain port, which enhances the operation responsiveness at the drain port, and which is miniature and is of a low cost and a less power consumption. CONSTITUTION:There are provided a solenoid part 3 and a valve part 2 composed of a cylindrical base 7 and a cylindrical valve seat 8 inserted in the base 7. A suction port 4 communicated with an oil pump is formed in the front end wall 7 of the base 7 while a discharge port 5 communicated with a load is formed in the peripheral wall 72 of the base 7, and a ball valve 10 is disposed between the front end wall 71 and the valve seat 8 which is formed at its center with a small diameter communication passage 83 and a large diameter passage 84 coaxial with each other. The communication passage 83 is communicated with the discharge port 5 through a passage 86. A drain port 6 communicated with an oil tank is formed in a connection part between the valve part 2 and the solenoid part 3. The drain port 6 is communicated with the communication passage 84. A suction port seat 81 for the ball valve 10 is formed at the front end of the valve seat 8, and a drain port seat 82 for the shaft 9 in the solenoid part 3 is formed at the rear end thereof.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a three-way solenoid valve used in hydraulic equipment such as electronically controlled automatic transmissions for automobiles.

0002

2. Description of the Related Art In vehicles such as automobiles, switching from two-way valves to three-way valves is required in order to reduce oil consumption. However, since the three-way valve has a complicated structure, for example, in the three-way solenoid valve disclosed in Japanese Unexamined Patent Publication No. 64-69875, the cross-sectional area of the passage that communicates the oil inlet and outlet is set to be relatively large. The cross-sectional area of the passage communicating the oil discharge port and the drain port is set small. Therefore, the flow rate characteristics of the valve are large when oil flows from the suction port to the discharge port, and small when oil flows from the discharge port to the drain port.

0003

[Problem to be Solved by the Invention] When a piston load is connected to the discharge port of the three-way solenoid valve as described above, the suction port side is maintained at a constant high pressure by the fluid pump provided on the upstream side. Since the side receives extrusion pressure due to the piston load, the pressure may be low, and there is a difference in the operational response of the suction port when the current is applied and the operational response of the drain port when the current is cut off, and it is said that the operational response of the drain port is poor. There's a problem.

If an attempt is made to improve the operational response of this drain port, the overall size of the three-way solenoid valve increases, power consumption increases, and a small, low-cost solenoid valve cannot be obtained.

An object of the present invention is to provide a three-way solenoid valve in which the operational response of the drain port is as good as that of the suction port, and which is compact, low cost, and consumes little power.

[0006]

[Means for Solving the Problems] In order to solve the above problems, the three-way solenoid valve of the present invention consists of a valve part and a solenoid part connected to the valve part, and the valve part has a fluid intake port and a fluid discharge port. A drain port is provided at the connection between the valve part and the solenoid part, and the cross-sectional area of the passage in the valve part that communicates the discharge port and the drain port is equal to the cross-sectional area of the passage in the valve part that communicates the suction port and the discharge port. It has a configuration larger than the cross-sectional area of .

[0007]

[Operation] Due to the above configuration, the flow rate of oil is higher when going from the discharge port of the valve to the drain port than when going from the suction port to the discharge port, so when a piston load is attached to the discharge port of the valve, The operational responsiveness of the drain port is improved, and the difference in operational responsiveness between the suction port and the drain port is almost eliminated.

[0008]

EXAMPLES The present invention will be explained below with reference to FIGS. 1 to 3 showing examples. The three-way solenoid valve 1 is composed of a valve section 2 and a solenoid section 3. The valve part 2 has a cylindrical valve seat 8 within a cylindrical base 7, and the front end wall 71 of the base 7 is provided with an inlet 4, and the peripheral wall 72 is provided with an outlet 5. ing. The suction port 4 is connected to an oil pump (not shown), and the discharge port 5 is connected to a load (not shown). The internal hole of the valve seat 8 consists of a small-diameter communication passage 83 on the front side and a large-diameter communication passage 84 on the rear side connected to this through a step. Communication path 84
A flow path 86 is provided that communicates with the. A ball valve 10 is inserted into the base 7 between the front end wall 71 of the base 7 and the valve seat 8, and an inlet seat 81 with which the ball valve 10 comes into contact is formed at the front end of the valve seat 8. A drain port sheet 82 is formed at the rear end. The drain port seat 82 comes into contact with a drain valve section 91 of the shaft 9 due to movement of the shaft 9 of the solenoid section 3, which will be described later. 17, 18
is an O-ring.

The solenoid part 3 is coaxially attached to the rear end of the valve part 2, and a shaft 9 is disposed in the center of a cylindrical yoke 14 so as to be movable in the axial direction. The stator core 12 is
A coil 16 is disposed outside. The front end portion of the shaft 9 forms a push rod portion 92 having a smaller diameter than the shaft 9 via a diagonally stepped drain valve portion 91 . Push rod part 92
moves the shaft 9 to the left to push the ball valve 10 and open the inlet seat 81. A moving core 11 is fixed to the rear part of the shaft 9, and an air gap 19 is provided between the stator core 12 and the moving core 11. The moving core 11 is movably arranged within a ring-shaped plate 13 with a predetermined gap therebetween, and the plate 13 is prevented from falling off from the yoke 14 by a stopper 15. A drain port 6 is provided at the connection between the valve portion 2 and the solenoid portion 3, and this drain port 6 communicates with an oil tank (not shown).

In the above configuration, when the three-way solenoid valve 1 is not energized, the ball valve 10 presses the suction port seat 81 to close due to the oil pressure applied from the suction port 4, and the drain port seat 82 opens. Hold in valve state. When energized, the moving core 11 is attracted to the stator core 12 as shown in Figure 1.
The push rod portion 92 pushes the ball valve 10 to the left to open the suction port seat 81 of the valve seat 8, and the drain valve portion 91 of the shaft 9 opens the drain port seat 82 of the valve seat 8. Close the valve. Since the cross-sectional area of the communicating path 84 is larger than the cross-sectional area of the communicating path 83, (drain port flow rate)>(inlet port flow rate). Here, since (diameter of drain port seat 82)>(diameter of suction port seat 81), the valve closing force applied to the drain valve section 91 due to the solenoid suction force needs to be stronger than the valve opening force in the ball valve 10. However, since the push rod type solenoid section 3 was used as described above, the solenoid suction force characteristics and valve opening characteristics are as shown in FIG. The relationship between the valve closing force is established, and the valve closing force of the drain port seat 82 (suction part air gap position S2) shown at point (a) in FIG. Valve force (suction part air gap position S1)
Become bigger. Therefore, the solenoid suction force can be used effectively. As a result, it becomes possible to develop a compact, low-cost, large-flow three-way solenoid valve.

Another advantage of the present invention is that since the flow rate of oil at the suction port 4 is small, the amount of oil leaking from the suction port 4 to the drain port 6 when the valve is operated is reduced. Furthermore, when a piston load is connected to the discharge port 5, the difference in operational response between the suction port 4 and the drain port 6 is reduced, so that the linearity of hydraulic characteristics during pulse wide modulation operation is improved. Further, since the oil passage of the valve section 2 and the magnetic circuit of the solenoid section 3 are separated by the shaft 9, the function of preventing foreign matter from entering the solenoid section 3 is improved.

FIG. 4 shows an example of the use of the present invention, in which the oil pump 20 communicates with the suction port 4, the discharge port 5 communicates with the piston load 21, and the drain port 6 with the oil tank 2.
It is connected to 2. The other configurations are the same as those in FIG. 1, so explanations will be omitted. The action is also as described above.

Table 1 shows the test results of the three-way solenoid valve of the present invention and the conventional three-way solenoid valve. For the same current, the three-way solenoid valve of the present invention has a lower flow rate (
liters per minute) than conventional products, and hydraulic response is also excellent.

[0014]

[Table 1]

[0015]

[Effects] Since the present invention has the above structure, it has the following excellent effects. (a) The flow rate from the discharge port to the drain port increases, improving the operational response of the drain port. (b) Small size, low cost, and low power consumption.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view of one embodiment.

FIG. 2 is an enlarged longitudinal sectional front view of the valve portion.

FIG. 3 is a diagram showing the relationship between solenoid suction force and suction part air gap.

FIG. 4 is a front view of an example of use.

[Explanation of symbols]

1 Three-way solenoid valve 2 Valve part 3 Solenoid part 4 Inlet 5 Discharge port 6 Drain port 83 Communication path 84 Communication path

Claims (1)

[Claims] Claim 1: Consisting of a valve part and a solenoid part connected to the valve part, the valve part is provided with a fluid intake port and a fluid discharge port, and the connection part between the valve part and the solenoid part is provided with a drain port. ,
A three-way solenoid valve characterized in that the cross-sectional area of a passage in a valve part that communicates with a discharge port and a drain port is larger than the cross-sectional area of a passage in a valve part that communicates with a suction port and a discharge port.