JP2000257742A - Solenoid proportion valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the change of a valve characteristic by the dispersion of a spring for energizing a valve element in the valve close direction and further miniaturize the whole valve by not deforming the valve element and not changing the valve characteristic after adjusting, even when the valve element is pressed in the valve seat strongly at the valve adjusting time and pressed in slantingly. SOLUTION: In this valve, a valve element storage 17 and spring chamber 28 are provided on the lower end of a plunger 13, a valve spring 21 and valve element 18 are stored, a holder 12 is calked and fixed to the outer periphery of the plunger and the drop of the valve element 18 is prevented by the holder 12. A sheet spring 15 is arranged between the spring receiver 14 of the upper end of the holder 12 and the lower end surface of the upper cover 16 screwed to the valve main body 1 and the spring force of the sheet spring is adjusted by rotating the upper cover and the operation characteristic of the valve and the position of the valve element are adjusted. The lower end of a tube 26 at whose inside the plunger is slided is fixed to the upper cover and its upper end to a suction piece respectively by welding or soldering. When the plunger is pushed in at the adjusting time, the valve element is pushed inside the valve element storage 17 against the valve spring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic proportional valve for use in an apparatus for supplying a predetermined amount of a small amount of fluid at a low pressure to an analyzer such as a chromatography.

[0002]

2. Description of the Related Art In an analyzer such as a chromatography, it is required to supply a very small amount of a low-pressure fluid accurately. Therefore, while accurately measuring the flow rate of the supplied fluid, it is necessary to supply the fluid to a flow path accordingly. Opening and closing control of a provided electromagnetic valve is performed. In this case, in order to accurately supply a predetermined flow rate, an electromagnetic proportional valve that opens and closes in proportion to the supply current is often used as the electromagnetic valve.

In such an electromagnetic valve, a plunger is slidably provided in an electromagnetic coil, a valve element provided at a tip of the plunger is opposed to a valve seat, and a valve spring is always provided by a coil spring provided on a back surface of the plunger. A valve closing force is applied in the direction in which the valve is pressed against the valve seat, and by energizing the coil, the attraction force generated in accordance with the supply current at that time causes the valve body to open together with the plunger against the coil spring by the attraction force. And the valve is opened in proportion to the supply current.

As shown in FIG. 6, for example, a valve body and a valve seat portion of such an electromagnetic proportional valve have an upper portion urged in a valve closing direction by a coil spring (not shown).
A valve body accommodating recess 52 is formed at the lower end of the valve body, a valve body 53 is accommodated in the valve body accommodating recess 52, and an inner peripheral surface 56 of a holder 55 is press-fitted into a lower peripheral surface 54 of the plunger 51 and fixed. The valve body holding portion 56 at the lower end of the holder 55
By extending to the lower end surface 57 of the valve 3, the valve element 53 is stored so as not to fall from the valve element storage recess 52.
The valve seat 58 facing the valve body 53 is provided with a valve body 6.
0 protrudes upward from the bottom surface 59 and has a fluid inflow hole 61 at the center thereof.
The valve hole 62 is closed by contacting the valve hole 3.

[0005]

In the above-mentioned electromagnetic proportional valve, when the valve is to be adjusted for initial setting at the time of assembling the valve, or when it is necessary to readjust the valve after long-term use of the valve, the valve is closed. Plunger 51 for valve position setting
Is pushed to the maximum position on the valve-closing side, and the pushing force at that time sometimes pushes further than the normal valve-closing position, that is, so-called pushing-in may be performed. At this time, since the valve element 53 is immovably fixed in the valve element accommodating recess 52, the lower end surface 63 of the holder 55 is fixed to the bottom surface around the valve seat 58 of the valve body 60 as shown in FIG. In some cases, the contact portion of the valve body 53 with the valve seat portion 58 is pushed by the valve seat portion 58 to deform as shown in the drawing. May be.

[0006] When the valve closing portion of the valve body 53 is deformed in this way, the initial position at which the valve body starts to open becomes unstable, and the lower end surface of the valve body is not flat. The state of the gap between the lower end face 57 of the valve body 53 and the valve seat changes due to displacement, inclination, etc., and especially in the vicinity of the valve closing position, the proportional characteristic of the flow rate to the supply current to the valve body changes depending on the state of the valve. Therefore, accurate flow control cannot be performed. Further, when the valve is closed, the contact pressure between the valve seat and the valve body is reduced, and a leak may occur from the high pressure primary side to the low pressure secondary side. In particular, as shown in FIG. 8, when the plunger is tilted and pressed during the run-in, the deformation of the valve-closing portion of the valve body becomes indefinite, as shown in FIG. There was a problem.

Further, since a valve closing force is applied by a coil spring provided on the upper end side of the plunger, and the coil is energized, the valve is opened against the valve closing force of the coil spring. Larger load scales often result in variations in free length and load, which can lead to unstable flow characteristics of the valve.
When a coil spring is used, the size of the spring is increased, and there is a disadvantage that the entire valve is increased in size.

Therefore, the present invention is not limited to the case where the valve is strongly pushed into the valve seat when the valve is adjusted, or even when the valve is inclined and pushed in, the valve is not deformed, and the valve after adjustment is adjusted. It is an object of the present invention to prevent the characteristics from changing, prevent the characteristics of the valve from changing due to a variation in a spring that biases the valve body in a valve closing direction, and further reduce the size of the entire valve. .

[0009]

According to the present invention, there is provided an electromagnetic proportional valve according to the present invention, comprising: a plunger that slides in response to an electric current of an electromagnetic coil; and a valve body provided at an end of the plunger. A valve element that is loosely fitted in the storage section and is slidably provided in the axial direction of the plunger, a valve spring that presses the valve element toward the end of the plunger in the valve element storage section, and fixed to the outer periphery near the lower end of the plunger. The valve body includes a holder for preventing the valve body from coming off, and a valve seat protruding into a valve storage chamber disposed at a portion communicating the inflow port and the outflow port of the valve body and abutting on the valve body.

In addition, the holder is fixed to the outer periphery of the plunger by caulking, and a V-shaped groove having a pressing surface inclined inward and abutting a caulking tool is formed in the upper end edge of the holder in advance. Was done,
Further, a leaf spring is provided between the upper part of the holder and the upper lid screwed to the valve body, so that the screw characteristics of the upper lid are adjusted to adjust the valve characteristics and adjust the positions of the valve element and the valve seat. In addition, a member provided with an engagement hole for fitting into a projection formed on the forked arm of the turning tool on the upper surface of the upper lid, and a cutout groove for fitting to the forked arm of the rotary tool, which is integrated with the upper lid. A groove into which a minus screwdriver type rotating part of a rotary tool is fitted is provided on the top of a member integrated with the upper lid, and the leaf spring is cut into a corrugated washer. A leaf spring, the lower end of which is fixed to the upper lid screwed to the valve body, the upper end of which is fixed to the suction element of the electromagnetic coil part by welding or brazing, respectively, and a plunger is slidably provided inside. And lubricated around the plunger. It is those, also those fixed by press-fitting the valve seat body to form a valve seat in the valve body.

[0011]

Embodiments of the present invention will be described with reference to the drawings. The valve body 1 is provided with an inflow port 2 and an outflow port 3 for a fluid, and a communicating portion thereof is formed with a valve storage chamber 4 that opens upward. A valve seat 6 is fixed to the valve body 1, and a valve seat portion 7 of the valve seat 6 is provided so as to protrude from a bottom surface 5 of the valve storage chamber 4. A passage 8 is formed, and this flow passage 8 penetrates up to the upper end of the valve seat 7, and an opening at the tip forms a valve seat 10. When the valve seat 6 is fixed to the valve body 1, it is fixed by press-fitting to accurately position the valve seat and prevent fluid leakage from the inflow port 2 side to the outflow port 3 side.

From the opening 11 located at the upper end of the valve storage chamber 4 in the valve body 1, a holder 1 to be described later in detail is attached to the lower end.
The lower end of the plunger 13 to which the valve body 2 is fixed is inserted. A spring receiver 14 is provided on the upper end of the holder 12, and a leaf spring 15 is disposed thereon. It is contracted between the lower end surface of the upper lid 16 screwed into the opening 11 and the spring receiver 14. The upper lid 16 has a male screw portion 23 on the outer periphery of the upper end screwed into a female screw portion 24 on the upper end of the opening 11 of the valve body 1, and the pressing force of the leaf spring 15 is adjusted by the screwing amount of the screwed portion, and The characteristic value can be set, and the position of the valve body and the valve seat can be adjusted. After such an adjustment is made, an adhesive is applied so that the adjustment value does not shift, to prevent loosening, and to prevent rotation. An O-ring 25 is provided on the outer periphery of the upper lid 16 to prevent the fluid in the valve storage chamber from leaking to the outside.

The lower end of the plunger 13 is provided with a valve housing 17.
The valve element 18 is vertically movably fitted and accommodated therein, and the valve element accommodating portion 17 of the plunger 13 is formed therein.
A valve spring 21 made of a coil spring is housed in a spring chamber 20 formed at the upper part of the valve body 1.
The upper surface of the valve holding plate 22 provided on the upper surface 8 is pressed. When the valve is closed, the lower end surface of the valve body 18 is closed.
Abuts on the valve seat 10 at the tip of the valve, and the valve seat is closed by the force of the valve spring 21.

The lower end fixing portion 19 of the tube 26 is fixed to the upper portion of the upper lid 16 by brazing or welding, and the upper end fixing portion 29 of the tube 26 is attached to the attraction element 28 of the coil portion 27 disposed above the upper lid 16. Fixed by welding or brazing to the outer periphery of. The suction element 28 is the coil part 2
The coil portion 27 and the valve body 1 are connected via the tube 26 in a state where the coil portion 27 and the valve main body 1 are in contact with each other by protruding from the upper surface 31 of the outer box 30 of 7 and stopping the protruding portion by the retaining ring 32. Thus, the lower end of the tube 26 is fixed to the upper lid 16 by brazing or welding, and the upper end is
8 is fixed by welding or brazing, so that leakage of the internal fluid from this portion can be prevented. The plunger 13 is disposed inside the tube 26 so as to be movable up and down, and the outer periphery of the plunger 13 is lubricated to improve the sliding performance in the tube.

A core 33 is disposed at the center of the inside of the outer case 30 of the coil part 27, and an electromagnetic coil 34 is wound around the core 33. A magnetic force is generated in the attraction element 28 according to the amount of current supplied to the electromagnetic coil 34, and the lower end surface 3 of the attraction element 28
The valve body 18 held by the holder 12 is moved upward by sucking the upper end surface of the plunger 13 arranged at a distance from the valve body 5 and moving the plunger 13 upward.
8 is separated from the valve seat 10 to open the valve.

In the electromagnetic proportional valve having the above-described overall structure, when the holder 12 holding the valve element 18 is fixed, a groove 36 is previously formed on the outer periphery of the lower end of the plunger 13 as shown in FIG. At the time of assembly, the valve spring 21 is housed in the spring chamber 20 of the plunger 13, and the valve holding plate 22 and the valve body 18 are housed from below into the valve body housing portion 17 at the lower end of the plunger 13 from below. Then, the holder 1 is moved from the lower end of the plunger 13 in this state.
Put 2 on. Then, as shown in FIG. 2B, the holder 12 is placed on the base 38, and a ring-shaped or divided edge 41 is formed at the lower end on the inner peripheral side of the upper edge 40 of the holder 12. 2C, the inner peripheral end 43 of the upper edge 40 of the holder 12 is fallen inward as shown in FIG. 2C, and the plunger 13 located here is hit. Groove 3
Press into 6 and caulk.

As a result, as shown in FIG. 2D, the holder 12 is firmly fixed to the lower end of the plunger 13. At this time, the valve body 18 is moved by the valve body pressing portion 39 of the holder 12 to the valve body inside the plunger 13. The retaining is performed in a state of being stored in the storage unit 17. Further, the valve element 18 stored in the valve element storage section 17 is held by a valve spring 21 with its lower surface in contact with the bottom surface of the holder 12. In this manner, since the holder 12 is fixed to the plunger 13 by swaging, the displacement of the holder 12 and the accompanying displacement and drop of the valve element 18 are prevented, and stable operation can be performed for a long period of time. In particular, when the surface of the plunger 13 is subjected to a lubrication treatment, there is a risk that the holder 12 may come off during use only by press-fitting and fixing the same. However, by fixing the holder 12 by caulking as described above, a reliable You can keep it from falling off.

As means for caulking the holder 12 to the lower end of the plunger 13, other than the above, for example, means shown in FIG. 3 can be considered. That is, as shown in FIG. 3A, a V-shaped groove 70 having a relatively sharp angle is formed in the upper end edge 40 of the holder 12 in advance, and the pushing surface inclined inward with respect to the V-shaped groove 70 is formed. 71, the inner portion of the V-shaped groove 70 is pushed into the groove 36 of the plunger 13 by hitting the caulking tool 72 having no inclined surface on the outside from above, as shown in FIG. Perform caulking. In this way, the holder 12
The spring receiver 14 can be stably mounted on the upper end edge 40 without giving a large deformation outside the upper end edge 40 as shown in FIG.

As the leaf spring 15, various types can be used. For example, a disc-shaped leaf spring 43 as shown in FIG. 4A, or the above-mentioned disc-shaped leaf spring as shown in FIG. A notched disc-shaped leaf spring 45 having cuts 44 alternately formed from the outer periphery and the inner periphery of the spring can also be used. When the notched disc-shaped leaf spring 45 as shown in FIG. 4B is used, even if a disc-shaped leaf spring having the same thickness is used, an arbitrary spring characteristic can be obtained depending on the interval, width and length of the notches. Can be set.

As a leaf spring, a corrugated washer-type leaf spring 46 formed in a corrugated washer shape as shown in FIG. 4C can be used. When such a corrugated washer-type leaf spring is used, The contact portion between the upper surface of the spring receiver 14 and the lower surface of the upper lid 16 can be in a radial line contact, so that the holder 12 can be pressed evenly and the plunger 13
Can operate stably without tilting.
Further, as shown in FIG. 4 (d), a cut-in wave washer-type leaf spring 47 or the like in which cuts 48 are alternately formed from the outer periphery and the inner periphery of the above-mentioned wave washer-type plate spring can also be used. When such a notched wave washer-type leaf spring 47 is used, as in the case of the notched disc-shaped leaf spring 45 shown in FIG. The spring characteristics can be freely set according to the interval, width, length, etc. As described above, by using a leaf spring as a spring for pressing the plunger portion downward, it is possible to reduce the overall size as compared with a conventional spring using a coil spring, and to prevent variations in spring characteristics. be able to.

Before the current is supplied to the electromagnetic coil 34 in the operation of the electromagnetic proportional valve constructed as described above, as shown in FIG. 14, via the holder 12, the plunger 13 fixed by the holder 12 and the caulking portion is pressed downward and moves to the lowest position. At this time, the valve element 18 is pressed downward by the valve spring 21, and the bottom surface of the valve element 18 is located at the upper end of the valve seat 1.
0, the flow passage 8 is closed and the valve is closed. At this time, assuming that the spring force of the leaf spring 15 is much larger than the spring force of the valve spring 21 and the spring force of the valve spring 21 is small, the valve spring 21 includes the plunger 13, the valve body 18, the holder 12, and the like. , And is balanced and stopped at a position corresponding to the spring force of the valve spring 21. At this time, if the spring force of the valve spring 21 is extremely small,
Is largely compressed, and the holder 12 contacts the bottom surface 5 of the valve body 1.

However, when the spring force of the valve spring 21 is set to a predetermined value, the weight of the plunger 13 and the like is supported, the pressing force of the leaf spring 15 is supported, and the lower end surface of the holder 12 is compressed in a compressed state. It can be held at a position away from the bottom surface 5 of the main body 1 by H1. Due to such characteristics of the valve spring 21, in the embodiment shown in FIG. 1, the valve spring 21 is made constant and the spring force of the leaf spring 15 is adjusted by adjusting the upper lid 16, contrary to the above. The valve is held at a position where the weight of the plunger 13 and the like and the spring force of the valve spring 21 are balanced. Therefore, by adjusting the upper lid 16, the holder 12
The distance H1 between the lower end surface of the valve body 1 and the bottom surface 5 of the valve body 1 can be set arbitrarily.

When the electromagnetic coil 34 is energized and a predetermined current is supplied from such a state, it operates with the characteristics shown in the graph of FIG. That is, in a graph in which the X-axis is the valve displacement and the Y-axis is the force applied to the plunger, the attractive force according to the current supplied to the electromagnetic coil corresponds to the combined force of the plunger's own weight F0 and the pressing force of the leaf spring. In terms of balance, the solenoid proportional valve operates. Therefore, when a current of 20 mA is supplied to the electromagnetic coil, the force applied to the plunger balances at the point of F1, and this point is set to the opening start position of the valve when there is no supply fluid and when there is no pressure, and the valve displacement L0 Position. Further, for example, when a current of 70 mA is supplied to the electromagnetic coil, the force applied to the plunger is balanced at the point F2, the valve is at the position L1, and the distance from L0 to L1 is the valve movement distance of the valve opening. In addition, as described above, the upper lid 1
By rotating 6, the above characteristics can be changed by adjusting the setting of the leaf spring, and the valve opening start position L0 of the valve can be arbitrarily set.

As described above, the valve is displaced along the straight line of the resultant force C in accordance with the current supplied to the electromagnetic coil, and the proportional valve is actuated. The flow rate of the fluid flowing through the valve has the characteristics shown in FIG. That is, this graph shows that the electromagnetic proportional valve is 20 m
FIG. 5 is a graph when the valve is set to start to be opened at A. When it is measured in advance that a fluid flows with such characteristics, a current supplied to an electromagnetic coil for obtaining a predetermined flow rate is obtained. It is also possible to control the current supplied to the electromagnetic coil by measuring the flow rate of the fluid flowing through the flow path, so that the flow rate is always kept at a predetermined flow rate.

In the normal use of the electromagnetic proportional valve of the present invention, as shown in FIG. 5A, a gap D1 is formed between the lower surface of the valve body 18 and the upper surface of the valve body pressing portion 39 of the holder 12.
And a gap D2 exists between the lower surface of the holder 12 and the bottom surface 5 of the valve storage chamber 4 of the valve body 1. When adjusting the solenoid proportional valve, the plunger 13 is moved to the position shown in FIG.
As shown in (b), when the lower surface of the holder 12 and the bottom surface 5 of the valve body 1 are pushed in firmly until they come into contact with each other, the valve element 18 moves the valve spring 21 in the valve element storage portion 17 of the plunger 13.
To move upwards. At this time, the gap between the bottom surface and the upper surface of the valve body holding portion 39 of the holder 12 is obtained by adding a gap D2 between the bottom surface of the holder 12 and the bottom surface 5 of the valve body 1 to the normal gap D1. The gap becomes D3.
At this time, since the valve holding plate 22 provided on the upper part of the valve element 18 is set so as not to abut on the upper part of the valve element housing part 17 of the plunger 13, the valve element 18 simply reduces the pressing force of the valve spring 21. Figure 6
As in the conventional electromagnetic proportional valve shown in (1), the valve body is not deformed by receiving a large force.

As shown in FIG. 5 (c), when the plunger is inclined, that is, when the lower surface of the holder 12 and the valve body 1
Is D4 on one side and D5 on the other side.
And when D5 is larger than D4,
8 can maintain a horizontal state in the figure due to the play around the inside of the valve housing 17, and the valve body is simply received by the pressing force of the valve spring 21 as in the case of FIG. Without receiving a force, the lower surface of the valve body is not deformed unlike the conventional electromagnetic proportional valve shown in FIG.

The adjustment of the electromagnetic proportional valve according to the present invention can be performed in various modes as shown in FIG.
That is, FIG. 6 (a) adjusts the solenoid proportional valve shown in the embodiment shown in FIG. 1, and has an engaging hole 74 formed in the upper surface 73 of the upper lid 16, while the engaging hole 74 Bifurcated arm 76 with an engagement projection 75 that can be fitted to 74
The adjustment is performed using the adjustment tool 77 that forms. When adjusting the proportional solenoid valve, first, a predetermined current is applied while the upper lid assembly is partially driven into the main body to compress the leaf spring. At this time, the valve is floating with respect to the valve seat. Then, when pressure is applied from the temporary side, the fluid flows out from the secondary side because the valve is in a floating state. afterwards,
While measuring the amount of granularity from the secondary side, the upper lid assembly is rotated to set a valve lift amount so as to have a predetermined flow rate with respect to the applied current.

As means for performing the above adjustment, means shown in FIG. 6B can be employed. That is, a notch 78 parallel to each other is formed in advance on the upper end of the suction element 28, while a forked arm 81 that fits into the notch 78 is formed on the adjustment tool 80. The above adjustment is performed by fitting the forked arm 81 of the adjustment tool 80 into the notch 78 and rotating it.

In addition to the adjusting means, FIG.
Means as shown in (c) can also be adopted. That is, the groove 82 is formed in the head of the suction element 28 in advance, while the adjusting tool 83 is formed with a minus driver type rotating portion 84 whose tip is narrower than the width of the groove 82. At the time of the above adjustment, the minus screwdriver type rotating part 84 of the adjustment tool 83 is fitted into the groove 82 of the suction element 28 and the tool is rotated. As this adjusting tool, a normal flathead screwdriver can be used as it is. In the above adjustment, various means for rotating the upper lid assembly from outside can be adopted in addition to the above embodiment.

[0030]

According to the first aspect of the present invention, the valve body which comes into contact with the valve seat protruding into the valve storage chamber is connected to the valve spring by the valve seat when the plunger is strongly pushed in at the time of valve adjustment or the like. Since the valve is only pushed into the valve storage chamber, excessive force is not applied to the valve, preventing deformation of the valve, and the valve is loosely fitted in the valve storage. So even when the plunger is tilted and pushed in,
Since the valve body does not follow the inclination of the plunger and the contact state between the valve body and the valve seat does not change, the deformation of the valve body can be prevented, and therefore, the electromagnetic element that operates stably for a long period of time It can be a proportional valve.

According to the second aspect of the present invention, since the holder is fixed to the outer periphery of the plunger by caulking, the holder can be securely fixed to the plunger. Therefore, the position of the valve body which is prevented from falling off by the holder does not shift due to the displacement of the holder, so that the electromagnetic proportional valve can be operated stably for a long period of time. According to the third aspect of the present invention, the V-shaped groove having an inwardly inclined press-in surface and contacting the caulking tool is formed in the upper end edge of the holder in advance, so that when caulking with the caulking tool, caulking is performed. The inside of the upper edge of the holder is caulked to the plunger by the pushing surface inclined to the inside of the tool, and the outer portion of the V-shaped groove at the upper edge of the holder is not affected by the caulking tool and is not deformed. There is no adverse effect on the members placed on top.

According to a fourth aspect of the present invention, a leaf spring is provided between the upper portion of the holder and the upper lid screwed to the valve body, and the screw characteristics of the upper lid are adjusted to adjust the valve characteristics and the position of the valve body and the valve seat. Is performed, the pressing characteristics of the plunger are more stable than those using a coil spring, and the entire valve can be made smaller. In addition, the adjustment of the valve characteristics and the position of the valve element can be performed by adjusting the screwing of the upper lid, and various settings can be easily performed. According to the fifth aspect of the present invention, since the upper surface of the upper lid is provided with an engagement hole that fits into the protrusion formed on the forked arm of the turning tool, the upper lid that directly contacts the leaf spring can be rotated. , Reliable adjustment can be performed.

According to the sixth aspect of the present invention, since the notch groove for fitting into the forked arm of the rotary tool is provided on the top of the member integrated with the upper lid, the upper lid is integrated with the upper lid even when it is difficult to rotate. By rotating the member, the member can be easily rotated and adjusted. Further, since the member is fitted to the forked arm of the rotating tool, the rotation can be surely adjusted. Further, in the invention according to claim 7, since the groove in which the minus screwdriver type rotating portion of the rotary tool is fitted is provided on the top of the member integrated with the upper lid, the upper lid is rotated similarly to the above. Even when it is difficult to rotate, it can be easily rotated and adjusted by rotating the member integrated with the upper lid, and it is easy to adjust because it is fitted to the minus screwdriver type rotating part of the rotating tool. The structure can be adjusted with various conventional tools such as a flathead screwdriver, so that it can be made inexpensive, and even if a tool is lost, it can be easily replaced with another. can do. Furthermore, since it can be rotated with the coil part attached, it can be adjusted while observing the characteristics of the finished product, and can be automatically adjusted from the outside.

In the invention according to claim 8, since the leaf spring is a cut-in corrugated washer-type leaf spring, the plunger can be pressed evenly from the outer periphery thereof, so that the plunger is hardly inclined and stable operation is performed. In addition, the spring characteristics can be freely changed by arbitrarily setting the cut of the wave washer type leaf spring, and springs having various characteristics can be easily manufactured using the same wave washer. In the invention according to claim 9, the lower end is fixed to the upper lid screwed to the valve body, and the upper end is fixed to the suction element of the electromagnetic coil portion by welding or brazing, respectively, and a plunger is slidably provided inside. Therefore, it is possible to provide an electromagnetic proportional valve that operates stably for a long period of time without leakage of the internal fluid from these fixed portions.

According to the tenth aspect of the present invention, since the plunger outer periphery is lubricated, the plunger slides stably, and the opening and closing operation of the valve is stabilized. It can be a proportional valve. According to the eleventh aspect of the present invention, since the valve seat body having the valve seat formed therein is press-fitted into the valve body and fixed, the valve seat can be formed precisely, and relative positioning with the valve body can be performed. Accurately, the fluid can be prevented from leaking from the inflow side to the outflow side by bypassing the contact portion between the valve body and the valve seat.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of an electromagnetic proportional valve of the present invention.

FIGS. 2A and 2B are cross-sectional views showing a procedure for fixing a holder and a plunger in the same embodiment, where FIG. 2A shows a disassembled state of each part, and FIG. FIG. 7C is a view showing a state in which the caulking tool is used, and FIG. 7D is a view showing a state after being caulked.

FIGS. 3A and 3B are cross-sectional views illustrating a fixing procedure of another example of a fixing means of the holder and the plunger, wherein FIG. 3A shows a state before the swaging tool is applied to the groove, and FIG. 3B is swaged by the swaging tool. (C) shows a state in which the spring receiver is placed after caulking.

FIGS. 4A and 4B show various examples of leaf springs used in the embodiment, wherein FIG. 4A shows a disc spring, FIG.
(C) shows a corrugated washer leaf spring, and (d) shows a cut-in corrugated washer leaf spring.

5A and 5B are diagrams showing a state when the plunger is pushed in at the time of adjustment and the like of the electromagnetic proportional valve in comparison with a normal operation state, wherein FIG. 5A is a cross-sectional view showing the normal operation state, and FIG. The state when the plunger is depressed is shown, and FIG. 3C shows the state when the plunger is depressed while inclined.

6A and 6B are perspective views showing a structure for adjusting the electromagnetic proportional valve of the present invention and a method for adjusting the same, wherein FIG. 6A shows the method for adjusting the electromagnetic valve of FIG. 1, and FIG. Another structure and its adjustment method are shown, and (c) shows still another structure for adjustment and its adjustment method.

FIG. 7 is a partially enlarged sectional view showing a deformed state of a valve body when a plunger is pushed in a conventional electromagnetic proportional valve.

FIG. 8 is a partially enlarged cross-sectional view showing a deformed state of the valve body when the plunger is pushed in with inclination in the conventional electromagnetic proportional valve.

FIG. 9 is an operation characteristic diagram when the supply current to the electromagnetic coil is changed in the electromagnetic proportional valve of the present invention.

FIG. 10 is a graph showing characteristics of a supply current to an electromagnetic coil of the electromagnetic proportional valve and a flow rate of the electromagnetic proportional valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Valve main body 2 Inflow port 3 Outflow hole 4 Valve storage chamber 6 Valve seat 7 Valve seat part 12 Holder 13 Plunger 14 Spring support 15 Leaf spring 16 Top lid 21 Valve spring 22 Valve presser plate 26 Tube 27 Coil part 28 Attractor 34 Electromagnetic coil

Continued on the front page F term (reference) 3H059 AA05 BB06 CB02 CD06 CD07 CE04 FF00 3H106 DA02 DA13 DA23 DB02 DB12 DB23 DB32 DC02 DC17 DD08 EE48 GB12 KK00

Claims (11)

[Claims] A plunger that slides in response to a current of an electromagnetic coil; a valve body that is loosely fitted in a valve body storage portion provided at an end of the plunger and that is slidably provided in an axial direction of the plunger; A valve spring that presses the valve element toward the end of the plunger in the valve element housing, a holder fixed to the outer periphery near the lower end of the plunger to prevent the valve element from coming off, and an inflow port and an outflow port of the valve body. And a valve seat protruding from a valve storage chamber disposed in a portion thereof and abutting against the valve body. 2. An electromagnetic proportional valve according to claim 1, wherein said holder is fixed to an outer periphery of a plunger by caulking. 3. The electromagnetic proportional valve according to claim 2, wherein a V-shaped groove provided with an inwardly inclined pushing surface and in which a caulking tool abuts is formed on an upper edge of the holder in advance. 4. A valve spring is provided between the upper part of the holder and the upper lid screwed to the valve body, and the valve characteristics are adjusted and the positions of the valve element and the valve seat are adjusted by adjusting the screwing of the upper lid. An electromagnetic proportional valve according to claim 3. 5. An electromagnetic proportional valve according to claim 4, wherein an engagement hole for fitting into a projection formed on the forked arm of the turning tool is provided on the upper surface of the upper lid. 6. A notch groove, which fits into a forked arm of a rotary tool, is provided on the top of a member integrated with the upper lid.
Electromagnetic proportional valve as described. 7. The electromagnetic proportional valve according to claim 4, wherein a groove in which the minus screwdriver type rotating part of the rotary tool is fitted is provided on the top of the member integrated with the upper lid. 8. The electromagnetic proportional valve according to claim 4, wherein said leaf spring is a cut-in wave washer type leaf spring. 9. A plunger is slidably provided in the upper cover, the lower end of which is fixed to the upper lid screwed to the valve body by welding or brazing, and the plunger is slidably provided therein. An electromagnetic proportional valve according to claim 8. 10. The proportional solenoid valve according to claim 1, wherein a lubrication process is performed on an outer periphery of the plunger. 11. The electromagnetic proportional valve according to claim 1, wherein a valve seat body having a valve seat is press-fitted into a valve body and fixed.