JP2892473B2 - Solenoid control valve - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electromagnetic control valve used for controlling an unloader circuit in, for example, a variable displacement compressor.

[Conventional technology]

Conventionally, as a control valve used in an unloader circuit of a compressor for a refrigerator, etc., the suction side pressure of the compressor is received on one side of a pressure responsive member such as a diaphragm, and the opening degree of a valve body is changed to thereby control the suction. There is a configuration in which the amount of fluid returning from the discharge side to the suction side is increased or decreased according to a change in the side pressure. Furthermore, in order to adjust the operating point in the automatic adjustment function of such a control valve, there is a method of changing the pressure of the heat-sensitive working medium applied to the other side of the pressure responsive member or the mechanical pressing force by a rotary motor or the like. Because the actuator for generating the pressing force is small and the control is simple, the electromagnetic coil operation method is also preferably used.

As such an electromagnetically operated control valve, there is one having a structure as shown in FIG. 5, for example. In this valve, the force of the operating spring e, the fluid pressure from the operating pressure inlet f, and the force of the valve spring i work together from below the pressure responsive member a such as a diaphragm, and the plunger spring from above the pressure responsive member a. The power of c works and is balanced as a whole. When the fluid pressure decreases in this state, the valve element h moves away from the valve seat g to increase the flow rate. When the plunger b is sucked by the suction element d, the force of the plunger spring c is canceled in accordance with the suction force. Therefore, the valve body h approaches the valve seat g to reduce the flow rate.

In such a conventional electromagnetic control valve, since the moving distance of the plunger b is small, the plunger b and the suction element d
Is usually made flat as shown in FIG. 2 (a). Accordingly, the suction force changes in inverse proportion to the distance between the suction element and the plunger as shown by the curve A in FIG. 3, so that the suction force is calculated from the total value of the spring constants of the used springs c, e, i, and the like. Unless the force is within a small range, there is a problem that accurate valve opening control cannot be performed.

On the other hand, the facing surface between the suction element and the plunger is
As shown in FIG. 3 (b), there is known a method of reducing the change in the attraction force between the suction element and the plunger by forming a conical shape as shown in FIG. In addition, since the change in the attraction force is small but the attraction force is also weak, it is necessary to use a large and powerful electromagnetic coil j, which is disadvantageous in cost.

[Problems to be solved by the invention]

An object of the present invention is to provide an electromagnetic control valve with an automatic adjustment function that can improve the above-mentioned disadvantages of the prior art and perform accurate proportional control using a small electromagnetic coil. .

[Means for solving the problem]

SUMMARY OF THE INVENTION An object of the present invention as described above is an electromagnetic valve for pressure control that changes the position of a valve body by a pressure responsive member that receives pressing by a plunger for operating an electromagnetic coil from one side and receives working fluid pressure from the other side. The opposing surfaces of the fixed attraction element provided on the electromagnetic coil and the plunger are each formed of a conical surface having the same apex angle (α) and a plane perpendicular to the axis. The distance B is: Is within a range of 1 ± 0.2, and the closest position of the plunger to the fixed suction element is set farther from the contact position with the fixed suction element. Can be achieved.

In the present invention, the conical surface of the apex angle (α) formed on the opposing surface of the fixed suction element and the plunger has an angle of α / 2 between the generatrix and the axis, and the plunger can move only parallel to the axis. From the above, if the distance between the conical surfaces is A, the distance that the plunger moves in the axial direction until it contacts the fixed suction element is A co
sec α / 2. This distance is 0.8 to 0.8 of the distance B between the opposing planes of the fixed suction element and the plunger.
It should be within 1.2 times. The value of the above formula is 1 ± 0.2
When the plunger is out of the range, a change in the suction force due to a change in the position of the plunger is large or the suction force is weak. In any case, the advantages of the present invention are lost.

Further, since the ratio between the area of the flat portion and the cross-sectional area of the plunger in the opposing surface of the fixed suction element and the plunger is within the range of 0.55 ± 0.2, the change in the suction force depending on the position of the plunger is further reduced.

Furthermore, the axial height H of the conical surface and the outer diameter d of the plunger
Is within the range of 0.2 ± 0.1, so that a stronger attractive force is exhibited as compared to the size of the electromagnetic coil.

[Action]

In the electromagnetic control valve of the present invention, the opposing surfaces of the fixed suction element and the plunger are each formed by a conical surface and a plane,
Neither the conical surface portion nor the planar portion can contact each other. Since the area of the plane portion occupies a large proportion of the cross-sectional area of the plunger, as shown in a curve C in FIG. 3, the magnetic force is small and the attractive force is large. Even if the plunger interval changes, the change in suction force is small.

〔Example〕

 FIG. 1 shows an example of the electromagnetic control valve of the present invention.

In the figure, a ball-shaped valve body 2 is urged by a valve spring 3 toward a valve seat 11 formed at a lower portion of a valve body 1, and movement of a bellows-shaped pressure responsive member 4 penetrates a partition wall portion 12. The pressure is transmitted to the valve body 2 by the pressing rod 41. The fluid pressure introduced from the working pressure introduction port 13 is applied to the outside of the pressure responsive member 4 and acts to compress the fluid pressure. When the fluid pressure decreases, the valve body 2 moves away from the valve seat 11. .

A pressure member 52 connected to the plunger 5 by a connecting rod 51 provided through the fixed suction element 7 is inserted inside the pressure responsive member 4, and the pressure responsive member 4 is pushed by the plunger spring 6. Working to stretch.

As shown in FIG. 2 (C), the opposing surfaces of the fixed suction element 7 and the plunger 5 are formed of a conical surface portion having an apex angle (α) of about 60 ° and an annular plane portion perpendicular to the axis. And the height H in the axial direction of the conical surface portion is about the outer diameter d of the plunger 5.
It is 0.2 times. The width of the annular planar portion around the plunger 5 is about 0.05 times d, the diameter of the central planar portion is about 0.65 times d, and the area of the planar portion is
About 61% of the cross-sectional area. Here, since cosec 30 ° is 2, the axial movement distance of the plunger 5 required to reduce the interval A between the conical surfaces is substantially equal to A × 2,
The interval B between the plane portions is also twice as large as A.

Furthermore, when the plunger 5 approaches the fixed suction element 7, the end face of the pressure responsive member 4 abuts on the surface of the partition wall 12, and the connecting rod 51 connecting the plunger 5 and the pressing member 52 contacts the plunger 5. The length is precisely adjusted and fixed so that the fixed suction element 7 cannot contact with the fixed suction element 7. At this time, the valve opening is maximized.

With the electromagnetic control valve of the present invention configured as described above, when the electromagnetic coil 8 is energized, the suction force between the conical surfaces formed between the plunger 5 and the opposed surface of the fixed suction element 7 and between the flat portions is well balanced. In operation, the plunger 5 cooperates with the plunger spring 6 to move in the axial direction in proportion to the amount of electric current, and works to push and extend the pressure responsive member 4, so that the valve body 2 moves away from the valve seat 11, The operating point moves to the larger flow rate.

When assembling such a control valve of the present embodiment, it is necessary to accurately adjust the length of the connecting rod 51, but it is better to use a procedure as shown in FIG. That is, first, the pressure responsive member 4 is attached to the valve body 1, the pressing member 52 is inserted therein, and then the electromagnetic coil 8 in which the fixed suction element 7 is incorporated is attached. Next, the connecting rod 51 is inserted into the hole of the fixed suction element 7, and the lower end thereof is inserted into the hole of the pressing member 52,
Further, a dimensioning jig 9 for defining the distance between the opposing surfaces of the plunger 5 and the fixed suction element 7 is placed on the fixed suction element 7,
The hole of the plunger 5 is applied to the upper end of the connecting rod 51, and the plunger 5 is pressed by the press-fitting jig 10 to be fitted and fixed. At this time, since the end surface of the pressure responsive member 4 is in contact with the surface of the partition wall portion 12, the distance between the opposing surfaces of the plunger 5 and the fixed suction element 7 is accurately dimensioned and equal to the thickness of the jig 9. .

When the connecting rod 51 and the plunger 5 are fitted, the connecting rod 51 and the pressing member 52 are preferably inserted so as to be freely inserted and removed, and conversely, the connecting rod 51 and the pressing member 52 are fitted. When this is done, the connecting rod 51 and the plunger 5 are preferably inserted so as to be freely inserted and removed. This is because the dimensioning jig 9 is removed after the fitting operation, and the fact that the plunger 5 and the pressing member 52 can rotate freely with each other is effective for making the operation of the control valve smoother.

The electromagnetic control valve of the present invention configured as described above operates such that the amount of fluid passing through the valve seat 11 decreases as the fluid pressure introduced from the working pressure introduction port 13 increases,
In addition, as the amount of current supplied to the electromagnetic coil 8 increases, the valve seat 11
The operating point can be moved so that the amount of fluid passing therethrough increases. The function of the electromagnetic coil 8 at this time is only to shift the position where the force is balanced by the valve spring 3, the pressure responsive member 4, and the plunger spring 6. Since the change in suction force when the interval changes is not so large,
The operation point can be adjusted smoothly and accurately in accordance with the amount of current supplied to the electromagnetic coil 8.

〔The invention's effect〕

The electromagnetic control valve of the present invention can perform smooth proportional control by adjusting the amount of current supplied to the electromagnetic coil, but can easily achieve high-precision fluid control using a small electromagnetic coil. The advantage is that the cost is low and the accuracy is high.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a closed state of an example of an electromagnetic control valve according to the present invention, and FIGS. 2 (a), (b) and (c) each show a shape of a surface facing a suction element and a plunger. FIG. 3 is a graph showing the relationship between the suction force and the distance between the suction element and the plunger in each case of FIG. 2, and FIG. 4 is a diagram showing a method of assembling an example of the electromagnetic control valve of the present invention. FIG. 5 is a sectional view of a conventional electromagnetic control valve. DESCRIPTION OF SYMBOLS 1 ... Valve body, 11 ... Valve seat, 12 ... Partition wall part, 13 ... Operating pressure introduction port, 2 ... Valve body, 3 ... Valve spring, 4 ... Pressure response member, 41 ... Pressing rod 5, a plunger, 51, a connecting rod, 52, a pressing member, 6, a plunger spring, 7, a fixed suction element, 8, an electromagnetic coil, 9, a dimensioning jig, 10
… Press-fitting jig, a… Pressure-responsive member, b… Plunger, c… Plunger spring, d… Suction element, e… Operation spring, f… Operation pressure introduction port, g… Valve seat , H ... valve body,
i: valve spring; j: electromagnetic coil.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kazuya Kimura 2-1-1, Toyota-cho, Kariya-shi, Aichi Prefecture Inside Toyota Industries Corporation (56) References JP-A-57-90475 (JP, A) JP-A Sho JP-A-2-76206 (JP, A) JP-A-58-69917 (JP, U) JP-A-60-153506 (JP, U) JP-A-61-1810 (JP, A) U) Japanese Utility Model Hei 2-92907 (JP, U) Japanese Utility Model 63-28576 (JP, Y2) Japanese Utility Model 55-31777 (JP, Y2) Japanese Utility Model 63-39934 (JP, Y2) (58) Survey Field (Int.Cl. ⁶ , DB name) F16K 31/00-31/11 H01F 7/16

Claims (3)

(57) [Claims] An electromagnetic valve for controlling a pressure, wherein a position of a valve body is changed by a pressure responsive member which receives pressure from a plunger for operating an electromagnetic coil from one side and receives working fluid pressure from the other side. The opposed surfaces of the provided fixed suction element and the plunger are each formed of a conical surface having the same apex angle (α) and a plane perpendicular to the axis. The distance A between the conical surfaces and the distance B between the planes are as follows. formula: Is within a range of 1 ± 0.2, and the closest position of the plunger to the fixed suction element is set farther from a contact position with the fixed suction element. 2. The electromagnetic control valve according to claim 1, wherein the ratio of the area of the plane portion to the cross-sectional area of the plunger is within a range of 0.55 ± 0.2. 3. The electromagnetic control according to claim 1, wherein the ratio between the axial height H of the conical surface and the outer diameter d of the plunger is in the range of 0.2 ± 0.1. valve.