JPS6053289A - Double-seat solenoid valve - Google Patents

Abstract

PURPOSE:To increase the oil tightness of a doubleseat solenoid valve which is, however, constructed simply, by setting the valve seat of a tank connection port to have a large diameter with respect to the diameter of the valve seat of a pump connection port. CONSTITUTION:The valve seat 11d of a tank port is set to have a substantially large diameter with respect to the diameter of the valve seat 12b of a pump port. When a solenoid device 2 is fed with a current to attract a plunger 21, a ball valve body 23 comes apart from the valve seat 12d of the pump port and is pressed against the valve seat 11d of the tank port. When the ball valve body 23 is seated on the valve seat 11d, the stability thereon is ensured since the ball valve body 23 may be subjected to a working pressure increased as high as corresponding to the incremented area of the valve seat resulting from the increase in diameter of the valve seat 11d with respect to the valve seat 12b of the pump port. Furthermore, the passage resistance to which working fluid is subjected when it is returned from an actuator into an oil tank may be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a double-seated solenoid valve with a simple structure and good oil tightness.

It has either a pump connection boat (hereinafter referred to as P boat 1), an actuator connection port (hereinafter referred to as A port), and a tank connection boat (hereinafter referred to as T port), and the valve body connects to either P boat or T boat. For example, Japanese Patent Publication No. 49-10371 is used for a double-seated solenoid valve that is closed and communicates between the A port and the T port, or the P port and the A boat.
There is a pulse-controlled double-seat solenoid valve J disclosed in No.

In this solenoid valve, working fluid pressure is simultaneously applied directly to the valve body disposed between both seats from one direction and via a plunger from the opposite direction to balance out the working fluid pressure acting on the valve body. A weak spring acts on the body to close one valve hole, improving the responsiveness of opening and closing the valve. In such a double-seat solenoid valve, a passage must be provided in the valve outer casing to guide the working fluid toward the plunger, and a recess for applying high-pressure working fluid to the plunger and a return passage for low-pressure working fluid must be provided. Even though it must be completely oil-tight, the push rod penetrates the member that defines both parts, and the push rod must slide smoothly against the defining member, so the sliding part must be extremely tight. requires high machining accuracy.

In view of the above, an object of the present invention is to provide a double-seated solenoid valve that has a simple structure, does not require high processing accuracy, and has good oil tightness, and can be used within a predetermined working fluid pressure range.
For this reason, it has a P boat, an A port, and a T port, and the valve body closes either the P boat or the T boat and communicates between the A boat and the T port, or the P boat and the A boat. In a double-seated solenoid valve, there is a spring that suppresses the valve body and always closes the P boat against the pressure of the working fluid, and a spring that is actuated by the excitation of the solenoid to press the valve body against the spring force and close the T boat 1-. The above objective is achieved by having a plunger for closing the valve and by setting the diameter of the valve seat of the T boat to be slightly larger than that of the valve seat of the P boat.

An embodiment of the present invention will be described below with reference to the drawings. A cylindrical valve holder 1 is equipped with a solenoid M from one end along the axis.
A large-diameter hole 3 with a female thread for holding the valve seat 2, a medium-diameter hole 5 for accommodating the valve seat block 4, and a small-diameter hole 7 with a bottom for accommodating the valve spring [; are installed in series,
P bow 1” P p at the step 8 between the large diameter hole 3 and the medium diameter hole 5
However, the stepped portion 9 between the medium diameter hole 5 and the small diameter hole 7 has an A bow h P
A, and a T-boat PT are bored in the axial direction at the bottom 10 of the small diameter hole 7 and penetrated through the other end surface of the valve holder 1.

The valve seat block 4 is connected to the valve seat block 11 on the T-bow 1 side and P
It is divided into valve seat block 12 on the port 1 side and the valve seat block 12 on the side. The valve seat block 11 on the T-boat side has a disk-shaped portion +1a that fits into the medium-diameter hole 5, and a boss portion 111 that fits into the small-diameter hole 7).
are formed along the axis from the end surface of the disc-shaped part +1a, a delivery chamber 11c, a valve hole IIc having a valve seat lad, and a boss part 11.
A central hole 11f is formed in sequence in the valve chamber 11c and communicates with an annular groove 11h on the circumferential side of the disc-shaped portion +Ia through a diametrical passage 11g.

The valve seat block 12 on the P port side is provided with an axial valve hole 12c having a valve seat 12b for the P port in the center of a disc-shaped portion +2a that directly enters the medium aperture hole 5.
The diameter of the valve seat lid of the T-bows 1 to 3 is set to be slightly larger than that of the valve seat lid.

The valve seat block 11 on the T-boat side is fitted into the medium-diameter hole 5 and the small-diameter hole 7 of the valve holder 1 through O-rings 13 and 14 on its circumferential side, and the valve seat block 11 on the P-port side is fitted on the upper end surface.
are joined via an O-ring 15.

In the solenoid device 2, a coil 2c wound around a bobbin 2b is fitted around the outer periphery of an iron core 2a, and the coil 20 is attached to the valve holder 1.
The coil 2c is housed in a cylindrical case 2d that is screwed into a female thread of a large diameter hole 3, and the lead wire 2e of the coil 2c is taken out from an insulating member 2f fitted to the head of the case 2d. A magnetic member 17 having an outer diameter equal to that of the large diameter hole 3 of the valve holder 1 and having an O-ring 16 fitted on the circumferential surface is attached to the opening end surface of the case 2d, and is connected to the iron core 2a via a non-magnetic member 18 that blocks magnetic lines of force. A center hole 19 is bored in the shaft center portion from the iron core 2a to the magnetic member 17. This center hole 19 is located in the case 2d.
The head side of the valve seat block 4 is closed, and a concave seat portion 17a having approximately the same diameter as the outer diameter of the valve seat block 4 is formed on the end surface side of the magnetic member 7. Also, in the center hole 194- there is a plunger 2 that can slide inside the center hole 19, which is pressed against the opening side of the center hole 19 by a weak plunger spring 20.
1, and a concave seat + with an end surface slightly protruding from the concave seat 17a.
A magnetic pole 22 made of a magnetic phase and having a flange portion 22a that fits into the flange portion 7a is inserted.

By screwing the case 2d of this solenoid device 2 into the large diameter hole 3 of the valve boulder 1, the flange portion 22 of the magnetic pole 22
The end face of a is pressed against the upper end face of the valve seat block 12 on the P port side, and the valve seat block 4 is integrated in an oil-tight manner. In this state, the valve seat 12h of the P port and the valve seat 11d of the T boat are connected to each other. The ball valve body 23, which faces both sides of the chamber 1+,c and is housed in the valve chamber 11c, is movable with a small distance between both valve seats 121) and Ild. The valve hole 12c of the P port is formed by a cross-shaped diametrical groove 2211 (only one direction is shown in the figure) bored in the end surface of the flange portion 22a of the magnetic pole 22, and between the end surface of the magnetic member 17 and the valve holder 1.
P through the annular gap 24 formed between the stepped portion 8 of
The valve chamber 11c communicates with the A port PA via a diametrical passage 11g and an annular groove 11h on the outer periphery of the valve seat block 11 on the T port side, and the valve hole 11e of the T port communicates with the boss portion. 11b center hole 1.1f and small diameter hole 7
It communicates with T port PT via. An axial groove 22c is cut in the outer circumferential portion of the magnetic pole 22 to allow the hydraulic pressure on the P boat Pp side to freely flow to the plunger 21 side, thereby facilitating the operation of the plunger 21. Plunger 21 has magnetic pole 2
The ball valve body 23 in the valve chamber 11C is inserted into the valve seat 1. The valve spring 6 compressed into the small diameter hole 7 of the one-way valve holder 1 overcomes the weak spring force of the plunger spring 20 with a strong spring force, and the spring receiver 25
The ball valve body 23 is separated from the valve seat lid of the T port and pressed against the valve seat 12b of the P boat. In this state, the distance between the end faces of the plunger 21 and the magnetic pole 22 is set to be slightly larger than the distance of the ball valve body 23 between the valve seat lid of the T port and the valve seat L2b of the P port. The spring force of the valve spring 6 is set to be slightly stronger than the sum of the working fluid pressure acting on the ball valve body 23 through the area of the valve seat 12b of the P port and the spring force of the plunger spring 20.

In the double-seated solenoid valve having the above configuration, pipes for a hydraulic pump, an actuator, and an oil tank (not shown) are connected to the P boat PP, A port PA, and T boat PT, respectively, and the P port 1''
A working fluid pressure of a predetermined pressure is introduced to P p. Here, if the solenoid device 2 is not energized, the solenoid device 2 is demagnetized, and the valve spring 6 is activated by the working fluid pressure acting on the ball valve body 23 through the area of the valve seat 12h of the P bow 1- and the spring of the plunger spring 20. The ball valve body 23 is pressed against the valve seat 12b of the P boat against the sum of the forces, thereby closing the valve hole 12c of the P port and closing the valve hole 1 of the T boat. ],
e is opened to communicate the A boat PA and the T port PT. Therefore, hydraulic oil does not flow to the actuator and the actuator does not operate.

Next, when the solenoid (device 2) is energized, the magnetic pole 22 is excited and attracts the plunger 21 made of magnetic material. 7- Separate from 12b and press against the valve seat lid of the T boat to close the valve hole IIs of the T port and close the valve hole 12 of the P port.
e to communicate between P port Pp and A boat P person.

Accordingly, the actuating fluid flows to the actuator and the actuator is actuated. Here, the spring force of the valve spring 6 is set to be only slightly stronger than the sum of the working fluid pressure acting on the ball valve body 23 through the area of the valve seat 12b of the P port and the spring force of the plunger spring 20. Therefore, the operation of opening the valve hole 12c of the P boat by the ball valve body 23 is performed with extremely good responsiveness. In addition, since the valve seat lid of the T boat is set to have a slightly larger diameter than the valve seat 12b of the P boat, when the ball valve body 23 is seated on the valve seat lid, the ball valve body 23 is attached to the valve seat 12b of the P port. On the other hand, it is possible to receive a large hydraulic pressure corresponding to the area of the valve seat whose diameter has been increased, and to counteract the increase in spring force caused by the compression of the valve spring 6 without increasing the excitation force of the solenoid device 2. The body 23 is securely seated on the valve seat lid of the T port, and the flow path resistance when the working fluid returns from the actuator to the oil tank is reduced.

As described above, according to the present invention, the pump connection port,
It has an actuator connection port and a tank connection boat, and the valve body closes either the pump connection port or the tank connection port 1-, and communicates the actuator connection port and the tank connection port, or connects the pump connection port and the actuator. In the double-seated solenoid valve that communicates with the boat,
A spring that presses the valve body and constantly closes the pump connection port against the working fluid pressure, and a plunger that is actuated by the excitation of the solenoid to suppress the valve body against the spring force and close the tank connection port 1. Because of this structure, there is no high-pressure fluid passage in the valve holder to balance the working fluid pressure in the valve body, and therefore the valve body does not require high machining precision in the cylinder, and is small and easy to assemble, making it suitable for mass production. A solenoid valve can be realized.

In addition, the diameter of the valve seat on the tank connection boat is set to be slightly larger than the valve seat on the pump connection port, so when the valve is opened, the return passage of the working fluid is reliably blocked without increasing the excitation force of the solenoid device. When the actuator is closed, the flow path resistance of the working fluid returning from the actuator to the oil tank can be reduced.

[Brief explanation of drawings]

The drawing is a longitudinal sectional view showing an embodiment of the present invention. 2... Solenoid device, 6... Valve spring, 11
, d... Valve seat of tank connection port, 12b... Valve seat of pump connection port, 21... Plunger, 23...
・Ball valve body, pp...pump connection port, PA...
・Actuator connection port, PT...Tank connection port. Applicant: Diesel Kiki Co., Ltd. Agent Patent Attorney: Toshihiko Watanabe 28 2 Pp PT PA 11- Procedural amendment (voluntary) 1. Indication of the case 1982 Patent Application No. 161.159 2. Name of the invention Double-seated solenoid valve 3 , Relationship with the case of the person making the amendment Patent applicant address 3-6-7, Shibuya, Shibuya-ku, Tokyo Name (33
3) Diesel Kiki Co., Ltd. Representative: Mochizuki - 4, Agent address: 301 Sunshine Koken Plaza, 3-2-4 Higashiikebukuro, Toshima-ku, Tokyo -

Claims (1)

[Claims] ■. It has a pump connection port 1-, an actuator connection port and a tank connection boat, and the valve body closes either the pump connection boat or the tank connection boat and communicates the actuator connection port and the tank connection boat, or In a double-seated solenoid valve that communicates between a pump connection boat and an actuator connection port, there is a spring that presses the valve body and constantly closes the pump connection port 1- against the working fluid pressure, and a spring that is activated by the excitation of the solenoid to close the valve body. and a plunger that presses against the spring force to close the tank connecting boat, and the valve seat of the tank connecting boat is set to have a slightly larger diameter than the valve seat of the pump connecting boat. Double seated solenoid valve.