JPH0571564U - Solenoid valve for fluid control - Google Patents

Abstract

(57) [Summary] [Purpose] To improve the motion responsiveness of the push rod. The push rod 4 for urging the pilot valve in the valve closing direction reciprocates in the longitudinal direction when a movable member 5 integrated with the push rod 4 is driven by a solenoid device. The periphery of the movable member 5 is filled with the working oil of the intake / exhaust valve control device. A plurality of escape paths (through holes) 5a are provided so that the oil does not hinder the reciprocating movement of the movable member 5. Further, a relief valve 9 which is deformed by a temperature change is attached to an arbitrary hole of the plurality of escape paths 5a. The relief valve 9 closes the escape passage 5a when the oil temperature is high, and opens the escape passage 5a when the oil temperature is low. In this way, a substantially constant good operating response is obtained which is independent of the oil temperature.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a fluid control solenoid valve, and more particularly to a fluid control solenoid valve that opens and closes a main valve by opening and closing a pilot valve and performs fluid control by opening and closing the main valve. is there.

[0002]

[Prior Art]

 In a 4-cycle engine or the like (hereinafter referred to as an engine), it is known that the timing of opening and closing the intake and exhaust valves of the engine is shifted according to the engine speed to improve the output.

In such an intake / exhaust valve control device, oil or the like is interposed between the intake / exhaust valve and the lifting cam of the valve, and its pressure is controlled by using a solenoid valve. There is a type in which the opening / closing timing of the intake / exhaust valve is adjusted by substantially changing the shape and size of the cam (for example, the solenoid valve disclosed in Japanese Utility Model Laid-Open No. 60-173773). ..

FIG. 4 is a diagram showing an example of an intake / exhaust valve control device. In this figure, the coil 2 of the solenoid valve 100 is energized, the movable member 5 is adsorbed to the end surface 1P of the inner cylindrical portion of the housing 1, and the main valve 13 closes the fluid inlet 12A. It is shown. That is, the solenoid valve 100 has a configuration of ON (valve open) when not energized and OFF (closed valve) when energized.

In the figure, 100 is a solenoid valve, 101 is a pump, 102 and 103 are check valves, 104 is a cylinder, 105 is a tappet arranged in the cylinder 104, and 106 is an operating part (piston) of the cylinder. An intake / exhaust valve arranged in 104, 107 is a cam that contacts the tappet 105, and 108 is an accumulator.

Oil discharged from the pump 101 is introduced into the cylinder 104 via the check valves 102 and 103. The cylinder 104 is connected to the fluid inlet 12A of the solenoid valve 100. The fluid discharge port 12B of the solenoid valve 100 is connected to the accumulator 108 and the check valves 102 and 103 by a fluid passage 109.

In such an intake / exhaust valve control device, when the coil 2 is not energized, that is, the main valve 13 is retracted, and the fluid inlet 12A and the fluid outlet 12B are in communication ( When the solenoid valve 100 is turned on), the oil pressure in the cylinder 104 is absorbed by the accumulator 108 when the cam 107 is rotated and the tappet 105 descends. Therefore, the oil pressure does not rise much. As a result, the distance between the tappet 105 and the working part of the cylinder 104 becomes shorter.

On the contrary, as shown in FIG. 4, when the coil 2 is energized and the main valve 13 closes the fluid inlet 12A (the solenoid valve 100 is off). When the tappet 105 rises, the pressure in the cylinder 104 becomes lower than the pressure in the fluid passage 109. As a result, oil is introduced into the cylinder 104 via the check valve 103.

On the other hand, when the tappet 105 descends, the oil pressure in the cylinder 104 is not absorbed by the accumulator 108, and therefore becomes higher than when the solenoid valve 100 is on. Therefore, the distance between the tappet 105 and the operating portion of the cylinder 104 becomes longer, and the shape and size of the cam 107 are substantially changed, and the intake / exhaust timing of the intake / exhaust valve 106 is changed. To be done.

Next, the structure of the solenoid valve 100 will be described. First, a non-magnetic guide collar 3 is arranged in the housing 1, and a push rod 4 having a through hole 4A is slidably arranged in the guide color 3. A movable member 5 is caulked at a rear end portion 4B of the push rod 4. The push rod 4 is biased to the front of the solenoid valve 100 (on the main valve 13 side) by the coil spring 6 via the movable member 5.

The pilot valve 15 is biased to the rear of the solenoid valve 100 (on the side of the opening 1A) by a coil spring 16. Due to this biased arrangement, the push rod 4 and the movable member 5 are moved rearward when the power is not supplied, and a gap is formed between the inner cylinder end surface 1P of the housing 1 and the movable member 5. An opening 1A is formed in the rear part of the housing 1, and the through hole 4A communicates with the outside of the solenoid valve 100 by the opening 1A.

A coil 2 wound around a bobbin 19 is arranged around the push rod 4 in the housing 1. By energizing the coil 2 via the lead wire 2A, the movable member 5 is attracted to the end surface 1P so as to overcome the elastic force of the coil spring 16, and the push rod 4 slides forward.

A shim 10, a first cylinder 11 and a second cylinder 12 are arranged in a recess 1 B formed in the front portion of the housing 1, and the second cylinder 12 is located at the front end portion of the housing 1. It is fixed to the housing 1 by being caulked. The shim 10 is arranged between the recess 1 </ b> B of the solenoid valve 100 and the first cylinder 11 as shown in the drawing.

When the pilot valve 15 contacts the seat portion 21, it is desirable that the movable member 5 also contact the end surface 1P. Therefore, when assembling the solenoid valve 100, the shim 10 having an appropriate thickness is used to change the distance between the end face 1P and the seat portion 21 and the operation test is performed to operate the solenoid valve 100. The shim 10 that has desired characteristics and current consumption is adopted. Also in this example, the shim 10 defines the retracted position of the pilot valve 15.

A groove 11 B and a pilot orifice 11 A are formed at the tip of the first cylinder 11, and a pilot valve 15 and a coil spring 16 are arranged in the first cylinder 11. The pilot valve 15 is formed with a fluid passage 15A penetrating from its front portion to its rear end surface, and a large-diameter stopper 15B is formed at its rear end portion.

As described above, the coil spring 16 biases the pilot valve 15 rearward when not energized, and in this state, the pilot orifice 11A is open. When the coil 2 is energized, the pilot valve 15 moves forward, a gap is created between the stopper 15B and the shim 10 as shown in this figure, and the tip of the pilot valve 15 is The pilot orifice 11A is closed by coming into contact with the seat portion 21 of the pilot orifice 11A.

Between the first and second cylinders 11 and 12, a main valve 13 having a main orifice 13A formed in its front part is arranged. The main valve 13 is biased forward by a coil spring 14 arranged at the rear end thereof.

The operation of the solenoid valve 100 having the above configuration will be described below. First, when the coil 2 is energized, the movable member 5 is attracted to the end surface 1P as shown in the drawing, and the push rod 4 slides forward. As a result, the pilot valve 15 comes into close contact with the seat portion 21 and the pilot orifice 11A is closed.

As a result, the pressure of the main valve back pressure chamber R rises due to the oil flowing into the main valve back pressure chamber R through the main orifice 13A, and the pressure in this portion is equal to the pressure in the main valve front chamber F. Match.

Therefore, the main valve 13 is moved forward by the resilient force of the coil spring 14 to come into contact with the sheet portion 20, and the fluid inlet 12A is closed. That is, the solenoid valve 100 is turned off.

When the coil 2 is de-energized, the pilot valve 15, the push rod 4 and the movable member 5 are moved to the rear of the solenoid valve 100 by the elastic force of the coil spring 16.

As a result, the pilot valve 15 is retracted and the pilot orifice 11A is opened. The main valve back pressure chamber R communicates with the fluid passage 15A that is not affected by the compression force of the pump 101, and the pressure of the main valve back pressure chamber R becomes lower than the pressure of the main valve front chamber F.

As a result, the main valve 13 overcomes the elastic force of the coil spring 14 and retracts, so that the fluid inlet 12A and the fluid outlet 12B communicate with each other. That is, the solenoid valve 100 is turned on. After that, the oil in the cylinder 104 flows out from the fluid discharge port 12B through the fluid inflow port 12A, and the main valve 13 remains retracted due to the pressure of the oil.

The oil that has flowed into the first cylinder 11 from the pilot orifice 11A flows out of the solenoid valve 100 through the fluid passage 15A, the through hole 4A, and the opening 1A. The rattling of the push rod 4 and the movable member 5 in this case is absorbed by the elastic force of the coil spring 6. After that, when the coil 2 is energized again, the solenoid valve 100 is turned off.

[0025]

[Problems to be solved by the device]

 The above-mentioned conventional technique has the following problems. In the solenoid valve described above, it is necessary that the movable member 5 be attracted to or separated from the inner cylinder end surface of the housing 1, that is, the attraction surface 1P in quick response to the energization and de-energization of the coil 2.

By the way, when the movable member 5 reciprocates, the oil filled around the movable member 5 and in the front-back direction of the reciprocating motion acts so as to hinder the movement of the movable member 5. There was a problem that the operation response was delayed.

Further, the delay of the motion response is not always constant, and it is difficult to predict the delay of the motion response in advance and make a correction. That is, since the viscosity of oil changes according to the temperature, the delay of the operation response cannot be predicted.

The present invention has been made to solve the above-mentioned problems, and an object thereof is to reduce the resistance of oil that obstructs the movement of the movable member, and the movement of the movable member depends on the temperature of the oil. It is to provide a solenoid valve for fluid control which is not performed.

[0029]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the present invention provides a movable member with a plurality of through holes penetrating in the operation direction thereof, and opening and closing the through holes in at least a part of the plurality of through holes. It is characterized in that a relief valve is provided, and the relief valve is made of a temperature-sensitive material that deforms in the direction of closing the through hole as the temperature rises depending on the ambient temperature.

[0030]

[Action]

 In the present invention having the above characteristics, when the temperature of the oil covering the relief valve rises, the oil is deformed so as to close the through hole. On the other hand, when the temperature of the oil falls below a predetermined temperature, the oil deforms to open the through hole. As a result, the degree of opening and closing of the plurality of through holes is controlled by the relief valve according to the temperature of the oil, and the resistance of the oil that tries to hinder the movement of the movable member can be kept substantially constant.

[0031]

【Example】

 Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a vertical sectional view and a side view of a movable member and a push rod showing an embodiment of the present invention. This movable member and push rod are optimal for the solenoid valve shown in FIG. 3, but are not limited to this solenoid valve, and can be applied to other solenoid valves that employ the same operation method as this.

In FIG. 1, a push rod 4 is arranged behind a pilot valve (not shown), and when the movable member 5 is sucked by a housing (not shown), the push valve is pressed to seat the pilot valve. Block the pilot orifice.

The movable member 5 which is crimped and integrated with the push rod 4 is provided with four through holes 5 a which penetrate the movable member 5 in the reciprocating direction thereof, that is, the axial direction of the push rod 4. Has been done. Two of the through holes 5a are provided with relief valves 9 for opening and closing the through holes 5a. The relief valve 9 is fixed to one end surface of the movable member 5 with a screw 9a. Since the other surface of the movable member 5 is a surface facing the suction surface of the housing, the relief valve 9 is provided on the illustrated side. The relief valve 9 may be a bimetal in which materials having different thermal expansion coefficients are bonded together, or a plate made of a shape memory alloy designed to maintain a predetermined shape at a predetermined temperature.

The operation of the relief valve 9 will be described with reference to FIG. 2 showing the main part of the movable member 5. The state shown in FIG. 6A is a case where the ambient temperature of the relief valve 9 is high, and the relief valve 9 closes the through hole 5 a. Further, the state shown in FIG. 2B is a case where the ambient temperature of the relief valve 9 is low, and the relief valve 9 bends back to open the through hole 5a as shown in the figure.

First, when the ambient temperature of the relief valve 9 is high, two of the four through holes 5a are closed, so when the movable member 5 moves, the oil existing near the movable member 5 is moved. Passes through the remaining two through holes 5a and escapes toward the front and rear of the movable member 5.

On the other hand, when the ambient temperature of the relief valve 9 is low, all the four through holes 5a are open, so when the movable member 5 moves, the oil existing near the movable member 5 is released. It passes through the four through holes 5a provided and escapes in the front-back direction of the movable member 5.

As described above, the through hole 5 a is opened and closed according to the ambient temperature of the relief valve 9, that is, the temperature of the oil existing in contact with the movable member 5, so that the oil escapes before and after the movable member 5. The size of the passage is controlled. Therefore, even if the viscosity of the oil changes, that is, the fluidity due to the temperature change, the relief valve 9 is opened and closed to compensate for it, and the operation response performance of the movable member 5 is maintained substantially constant.

Although the relief valves 9 are provided in half of the through holes 5a in the present embodiment, the relief valves 9 may be provided in any number of through holes 5a. Further, the relief valves 9 need not all have the same or equivalent temperature-sensing characteristics, that is, a constant deformation amount with respect to a temperature change.

By using the relief valves 9 having different temperature-sensing characteristics, it is possible to finely control the opening / closing degree of the through hole 5a at a low cost against a slight temperature change of the oil. For example, it may be difficult in some cases in consideration of cost to request a material such as a bimetal or a shape memory alloy that has a high degree of precision in its deformation. In such a case, by using relief valves 9 having different temperature-sensing characteristics, the opening / closing number of the through holes 5a can be selected stepwise to control the size of the oil passage. The accuracy of individual temperature-sensing characteristics can be coarsened to some extent.

[0040]

[Effect of the device]

 As is clear from the above description, according to the present invention, when the oil surrounding the movable member is eliminated by the reciprocating movement of the movable member, the through hole is provided as an escape path for the movable member. , It responds quickly to the energization and de-energization of the coil.

Further, since the through-hole is provided with a relief valve that opens and closes according to a change in temperature around the through-hole, the relief valve compensates for a change in oil viscosity due to a change in temperature, so that it is substantially constant regardless of the temperature. The pilot valve can be opened and closed at the specified response speed.

[Brief description of drawings]

FIG. 1 is a vertical sectional view and a side view of a movable member and a push rod showing an embodiment of the present invention.

FIG. 2 is a sectional view of a main part of a movable member for explaining the operation of the embodiment.

FIG. 3 is a diagram showing an example of a conventional intake / exhaust valve control device.

[Explanation of symbols]

4 ... Push rod, 5 ... Movable member, 5a ... Through hole, 9 ... Relief valve

Claims (3)

[Scope of utility model registration request] 1. A fluid control solenoid valve for opening and closing a main valve by opening and closing a pilot valve with a solenoid device, and performing fluid control by opening and closing the main valve, comprising a push rod arranged behind the pilot valve, A movable member fixed to the push rod and driven by the solenoid device, a plurality of escape holes provided through the movable member in the operation direction thereof, and at least a part of the plurality of escape holes. And a relief valve that opens and closes the relief hole, the relief valve being formed of a temperature-sensitive material that deforms in a direction in which the relief hole is closed as the temperature of the relief valve increases depending on the ambient temperature. Solenoid valve for fluid control characterized by 2. The fluid control solenoid valve according to claim 1, wherein the relief valve is made of bimetal. 3. The solenoid valve for fluid control according to claim 1, wherein the relief valve is made of a shape memory alloy.