JPH0710661U - 3-way solenoid valve - Google Patents

Abstract

(57) [Summary] [Purpose] To eliminate the temperature dependence of control characteristics. [Structure] The flow paths X and Y of the two paths consisting of the inflow hole 29, the discharge hole 30, and the discharge hole 31 are switched via the push rod 27 in accordance with the opening / closing operation of the ball valve body 34. First and second fixed orifices 40 and 41 are formed between the push rod 27 and the flow path forming member 33 by the first and second orifice forming portions 38 and 39. Both orifices 40 and 41 can equalize the flow rate balance of the flow paths X and Y of the two paths irrespective of the change in oil viscosity.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a three-way solenoid valve that alternately switches between two flow paths according to the opening / closing operation of a valve element.

[0002]

[Prior art]

 As is well known, as a three-way solenoid valve used in a hydraulic circuit such as an automatic transmission of an automobile, there is one shown in FIGS. 3 and 4 (see Japanese Patent Laid-Open No. 4-165173).

That is, this three-way solenoid valve is a normally open type (normally open type), and an electromagnetic actuator 2 is provided inside a housing 1. The electromagnetic actuator 2 is wound around a bobbin 3. Mounted electromagnetic coil 4, a core 5 provided inside the electromagnetic coil 4, a plunger 6 provided on the front end side of the core 5 and being an armature slidable back and forth, and the plunger 6 It has a push rod 7 fixed to one end in the sliding direction.

Further, the housing 1 is provided with an inflow hole 8 and a discharge hole 9 and a discharge hole 10 which are branched at the downstream end of the inflow hole 8, and the holes 8, 9, 10 are also provided. A columnar valve chamber 11 having a step is formed to communicate with each other. Inside the valve chamber 11, there is provided a substantially cylindrical flow path constituting member 12 arranged along the diameter direction of the valve chamber 11. This flow path forming member 12 has first and second through holes 13a and 13b formed through the center of the side wall along the diametrical direction, and a communication hole 14 formed at upper and lower positions in the internal axial direction. There is. Further, in the valve chamber 11, a first valve seat 15a provided at one end opening edge of the first through hole 13a is seated on and off to connect or disconnect the valve chamber 11 and the first through hole 13a. A ball valve body 16 is provided. The ball valve element 16 is biased in the closing direction by a return spring 17 in the valve chamber 11.

Further, in the push rod 7 of the electromagnetic actuator 2, the tip end portion 7 a loosely fits the first and second through holes 13 a and 13 b and is in contact with the ball valve body 16. When the electromagnetic coil 4 is demagnetized, the push rod 7 separates the ball valve body 16 from the first valve seat 15a by the spring force of the compression spring 18 mounted between the core 5 and the plunger 6, and at the same time, The root portion 7b of 7a operates so as to be seated on the second valve seat 15b of the second through hole 13b.

Therefore, at the time of demagnetizing the electromagnetic coil 4, the inflow hole 8, the first orifice 19 formed between the outer peripheral surface of the push rod 7 and the inner peripheral surface of the first through hole 13a, A first flow path X is formed by the communication hole 14 and the discharge hole 9, and the hydraulic pressure on the input side is supplied to the output side.

On the other hand, when the electromagnetic coil 4 is excited, the plunger 6 is attracted to the core 5 and the push rod 7 slides rearward, so that the ball valve body 16 uses the spring force of the return spring 17 to move the first valve. The seat portion 15a is seated and the first through hole 13a is closed, and at the same time, the root portion 7b of the push rod tip portion 7a is separated from the second valve seat 15b. Therefore, the second orifice Y formed between the discharge hole 9, the communication hole 14 and the outer peripheral surface of the push rod 7 and the inner peripheral surface of the second through hole 15a and the discharge hole 10 form the second flow path Y. Is formed to discharge the hydraulic pressure on the output side to the outside.

[0008]

[Problems to be solved by the device]

 By the way, in such a three-way solenoid valve, in order to ensure the accuracy of the control oil pressure, the control oil flowing through both flow paths X and Y should be taken into consideration, especially considering the oil temperature, that is, the viscous resistance of the control oil. The flow rates must be balanced and the flow resistance in both flow paths X and Y must be reduced.

However, in the above-described conventional three-way solenoid valve, the first orifice 19 and the second orifice 20 are formed according to the maximum forward / backward position of the push rod 7, and the opening areas of both orifices 19 and 20 are determined. It is like this. For this reason, if the machining accuracy of the push rod 7 varies, or if the root portion 7b is largely cut in the axial direction to prevent this variation, the maximum opening areas of both orifices 19 and 20 differ from each other. As a result, the balance of the control oil flowing through both flow paths X and Y is likely to be lost. Therefore, the flow resistance may change depending on the temperature, that is, the control characteristics may have temperature dependence.

Particularly, in recent years, when the solenoid valve is downsized in order to reduce the weight and save the installation space, each component forming each flow path X, Y is also small and complicated. Therefore, there is a tendency that the above-mentioned imbalance of the flow rate easily occurs.

The present invention has been made in view of the above conventional problems, and an object of the present invention is to provide a three-way solenoid valve that can reduce the temperature dependence of control characteristics while achieving miniaturization.

[0012]

[Means for Solving the Problems]

 In order to solve the above problems, in the present invention, a housing having three flow passages and a flow passage of two paths formed by the three flow passages, and the flow passage provided in the housing, A flow path forming member to be formed, a push rod that reciprocally slides in the flow path forming member by a relative pressure between a suction force of a solenoid and a spring force of a spring, and the one flow path according to the reciprocal sliding of the push rod. In a three-way solenoid valve having a valve body that opens and closes a hole to alternately switch between the two flow paths, a fixing that determines a passage cross-sectional area of each flow path between the push rod and the flow path constituent member. It is characterized by forming an orifice.

[0013]

[Action]

 In the above structure, the fluid does not flow through the orifice formed by the forward and backward movement of the push rod but through both fixed orifices formed in advance, so that both flow rates can be set uniformly and constant. Therefore, it is possible to easily secure the flow balance.

[0014]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a view showing a three-way solenoid valve according to the present invention. An electromagnetic actuator 22 provided inside a housing 21 includes an electromagnetic coil 24 wound around a bobbin 23 and a front end side of the bobbin 23. A yoke 25 provided on the inner periphery, a core (not shown) provided on the inner periphery on the rear end side, and an inner periphery of the yoke 25 are provided so as to be slidable back and forth and fixed to the tip of a plunger (not shown). And a guide member 26 for slidably supporting the pushed push rod 27. On the front end side of the push rod 27, a tip portion 27a having a smaller diameter than the other portions is formed.

In addition, an inflow hole 29 formed in the nozzle 28, a discharge hole 30 branched at a downstream end of the inflow hole 29, and a discharge hole 31 are provided inside the front end of the housing 21. A stepped columnar valve chamber 32 that communicates the holes 29, 30, 31 is provided. Inside the valve chamber 32, a substantially cylindrical flow path constituting member 33 is arranged along the valve chamber 32, and a ball valve body 34 for opening and closing a valve hole of the flow path constituting member 33 is provided. ing. As shown in FIG. 1, the flow path forming member 33 includes an annular valve seat 35 fitted and fixed in a fitting groove 28a of the nozzle 28, a fitting groove 28a of the fitting groove 28a and a yoke 25a. And a cylindrical portion 36 fixed between the valve chamber 32 and the discharge hole 30, or the communication holes 36a and 36a for connecting the discharge hole 30 and the discharge hole 31 to the peripheral wall of the cylindrical portion 36. Are formed.

The ball valve element 34 is seated on the tapered valve seat 35 a of the valve seat 35, and is biased in the seating direction by the spring force of the return spring 37.

Further, the push rod 27 has a tip end portion 27 a loosely fitted inside the flow path forming member 33 to come into contact with the ball valve element 34, and a spring of a compression spring (not shown) that biases the plunger forward. The force urges the ball valve element 34 in the opening direction against the spring force of the return spring 37.

An annular first orifice forming portion 38 is interposed between the valve seat 35 and the tubular portion 36, while the tubular portion 36 and the bottom surface of the fitting groove 25a are provided. An annular second orifice component 39 is interposed between the two. The inner diameters of the first and second orifice forming portions 38 and 39 are set to be the same, and the first fixed orifice 40 and the second fixed orifice 40 are provided between the inner peripheral surface and the outer peripheral surface 27b of the push rod tip portion 27a. The orifice 41 is formed.

Therefore, when the electromagnetic coil 24 is demagnetized, the push rod 27 holds the ball valve element 34 in the open position as shown in the upper half of FIG. The control oil pressure flowing into the valve chamber 32 is discharged from the discharge hole 30 to the output side through the relatively large clearance C1 between the ball valve element 34 and the valve seat 35a, the first fixed orifice 40 and the communication hole 36a. . That is, it is supplied to the output side through the first flow path X.

On the other hand, when the electromagnetic coil 24 is excited, the push rod 27 slides rearward through the plunger as shown in the lower half of FIG. 1, so that the ball valve element 34 is seated on the valve seat 35 a. To close the clearance C1. Therefore, the control oil pressure flows backward from the discharge hole 30 to compare the communication hole 36a with the second fixed orifice 41 and the root portion 27b of the yoke 25 push rod tip portion 27a. It is discharged from the discharge hole 31 to the outside through the relatively large clearance C2. That is, it is discharged through the second flow path Y.

As described above, in this embodiment, the clearances C1 and C2 are not used as control orifices as in the conventional case, but the first and second orifice components 38 and 39 and the push rod tip portion 27a are used. Since the first and second fixed orifices 40 and 41 between and are the control orifices, the passage cross-sectional areas of the first and second fixed orifices 40 and 41 are always the same and constant. Therefore, even if the processing accuracy of the push rod 27 or the like varies and the passage cross-sectional areas of the clearances C1 and C2 differ, the flow rate of the control oil passing through both the flow paths X and Y can be balanced. Therefore, the control oil pressure can always be controlled with high accuracy without being affected by the change in oil temperature, that is, the change in viscosity, and the temperature dependence of the control characteristic can be eliminated.

The present invention is not limited to the configuration of the above-described embodiment, and for example, the first and second orifice constituting portions 38 and 39 may be provided on the outer peripheral side of the tip portion 27a of the push rod 27. is there.

[0023]

[Effect of device]

 As is clear from the above description, according to the present invention, the flow rate of the control oil flowing through both flow paths is not determined by the orifice formed by the maximum sliding position of the push rod as in the conventional case. Since it is determined by the fixed orifice formed between the flow path forming member and the push rod, the flow rate of both flow paths can be balanced.

Therefore, the control oil pressure can be controlled with high accuracy regardless of the viscosity change, and the temperature dependence of the control characteristics can be eliminated.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of an essential part showing an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing a three-way solenoid valve of this embodiment.

FIG. 3 is a vertical cross-sectional view showing a conventional three-way solenoid valve.

FIG. 4 is an enlarged cross-sectional view of a conventional main part.

[Explanation of symbols]

 21 Housing 22 Electromagnetic Actuator 24 Electromagnetic Coil (Solenoid) 27 Push Rod 27a Tip Part 29 Inflow Hole 30 Discharge Hole 31 Discharge Hole 33 Flow Channel Component 34 Ball Valve 38 First Orifice Constituent 39 Second Orifice Constituent 40 First Fixed orifice 41 Second fixed orifice

Claims (1)

[Scope of utility model registration request] 1. A housing having three flow holes and a two-path flow path formed by the three flow holes, and a flow path forming member provided in the housing to form the flow path. A push rod that reciprocally slides in the flow path forming member by a relative pressure between a suction force of a solenoid and a spring force of the solenoid; In a three-way solenoid valve having a valve body that alternately switches flow passages, a fixed orifice that determines a passage cross-sectional area of each flow passage is formed between the push rod and the flow passage constituting member. 3 way solenoid valve.