Electromagnetic drive pump

Abstract

To provide an electromagnetic driving pump capable of easily adjusting a discharge flow rate by using a simple configuration and highly accurately maintaining the discharge flow rate.SOLUTION: An electromagnetic driving pump 100 includes: an electromagnetic coil 102; a fixed iron core 106 disposed on the inner side of the electromagnetic coil; a plunger 110 moving on the inner side of the electromagnetic coil; and a cylindrical guide 108 guiding the movement of the plunger on the inner side of the electromagnetic coil. An end surface 126 of the plunger and an end surface 128 of the guide are disposed to oppose to an end surface 130 of the fixed iron core. The electromagnetic driving pump further includes: a metal spacer 132 disposed to abut on the end surface of the fixed iron core and adjusting a stroke of the plunger; and an elastic ring 134 sealing a space between the metal spacer and the end surface of the guide and energizing the metal spacer toward the end surface of the fixed iron core.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an electromagnetic drive pump that uses an electromagnetic coil as power.

Background Art

[0002] Conventionally, as a pump for transferring a fluid, an electromagnetic drive pump that uses an electromagnetic coil as power is known. The electromagnetic drive pump transfers the fluid by the reciprocation of a plunger (movable iron core) inside a housing.

[0003] Patent Document 1 describes an electromagnetic pump. This electromagnetic pump includes a cylindrical body, a cylindrical coil inserted into the body, a movable iron core that slides inside the coil, a fixed iron core provided inside the coil facing the movable iron core, a pump body, and an adjustment mechanism.

[0004] The pump body is attached to the body and has a suction port and a discharge port. Further, through holes communicating with the suction port and the discharge port are respectively formed in the pump body, and an inlet check valve and an outlet check valve are respectively provided in these through holes.

[0005] The adjustment mechanism is attached to the body and is a mechanism that presses the movable iron core to regulate the stroke of the movable iron core, and includes an adjustment screw capable of adjusting the stroke of the movable iron core and a nut member screwed onto the adjustment screw.

[0006] Furthermore, in this electromagnetic pump, the positions of the suction port and the discharge port of the pump body are arranged on one side of the movable iron core, and the adjustment mechanism is arranged on the opposite side facing the positions of the suction port and the discharge port. Patent Document 1 states that by arranging the suction port and the discharge port on the same side of the movable iron core and adjusting the stroke of the movable iron core by the adjustment mechanism, the discharge amount can be mechanically and easily adjusted.

Prior Art Documents

Patent Documents

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-47058 [Summary of the Invention] [Problems to be Solved by the Invention]

[0008] However, in the technology of Patent Document 1, after assembling the electromagnetic pump, it is necessary to adjust the discharge flow rate over time by an adjustment mechanism while measuring the discharge flow rate with high precision. In addition, the adjustment mechanism requires an adjustment screw and a nut member to adjust the stroke of the movable iron core, resulting in an increase in the number of parts.

[0009] Also, as an example, it is conceivable to regulate the stroke of the movable iron core by attaching rubber to the end face of the movable iron core, that is, the end face facing the fixed iron core. However, in this case, when the rubber deteriorates over time, the stroke of the movable iron core becomes longer and the discharge flow rate increases.

[0010] Furthermore, in an electromagnetic pump, when an air pocket is generated in the pump chamber and compression and expansion are repeated, it is impossible to obtain an appropriate discharge flow rate corresponding to the stroke of the movable iron core, the discharge flow rate decreases, and it becomes difficult to maintain the discharge flow rate.

[0011] In view of such problems, an object of the present invention is to provide an electromagnetic drive pump that can easily adjust the discharge flow rate with a simple structure and can maintain the discharge flow rate with high precision. [Means for Solving the Problems]

[0012] In order to solve the above problems, a typical configuration of the electromagnetic drive pump according to the present invention is an electromagnetic drive pump having an electromagnetic coil, which includes a fixed core disposed inside the electromagnetic coil, a plunger that moves inside the electromagnetic coil, and a cylindrical guide that guides the movement of the plunger inside the electromagnetic coil. The end face of the plunger and the end face of the guide are disposed opposite to the end face of the fixed core. The above electromagnetic drive pump further includes a metal spacer that is disposed in contact with the end face of the fixed core and adjusts the stroke of the plunger, and an elastic ring that seals between the metal spacer and the end face of the guide and biases the metal spacer toward the end face of the fixed core.

[0013] In the above configuration, a metal spacer for adjusting the stroke of the plunger is disposed in contact with the end face of the fixed core, the elastic ring biases the metal spacer toward the end face of the fixed core, and further seals between the metal spacer and the end face of the guide.

[0014] Therefore, when the electromagnetic coil is excited, due to the attractive force between the electromagnetic coil and the plunger, the plunger moves toward the metal spacer disposed in contact with the end face of the fixed core, and the movement stops when the end face of the plunger contacts the metal spacer. That is, the stroke dimension of the plunger can be set by the thickness dimension of the metal spacer. Thereby, at the time of assembling the electromagnetic drive pump, by simply selecting and assembling a metal spacer having an appropriate thickness dimension, the stroke dimension of the plunger can be set with high precision to, for example, a specified value.

[0015] Therefore, according to the above configuration, the discharge flow rate can be easily adjusted with a simple structure, and the accuracy of the discharge flow rate can be improved. Further, since the metal spacer is biased toward the end face of the fixed core by the elastic ring, it can be fixed so as not to move with respect to the end face of the fixed core, and the assemblability can be improved.

[0016] Furthermore, since the space between the metal spacer and the end face of the guide is sealed by an elastic ring, it is also possible to seal between the metal spacer, the guide, and the bobbin. Note that the bobbin is disposed outside the guide, and an electromagnetic coil is formed by winding a winding around it. Therefore, it is possible to prevent fluid from leaking to the bobbin side. Also, by sealing between the metal spacer, the guide, and the bobbin, for example, it is possible to block the air remaining around the guide and the pump chamber. As a result, it is possible to prevent an air pocket from forming in the pump chamber and maintain a proper discharge flow rate corresponding to the stroke of the plunger with high precision.

[0017] The above metal spacer is preferably made of a non-magnetic material.

[0018] As a result, when the electromagnetic coil is excited and the end face of the plunger is in contact with the metal spacer, a magnetic field gap (gap) corresponding to the thickness of the metal spacer made of a non-magnetic material is generated between the end face of the fixed core and the end face of the plunger. Therefore, when the current to the electromagnetic coil is turned off with the end face of the plunger in contact with the metal spacer, due to the magnetic gap, the end face of the plunger is likely to separate from the metal spacer, and it is easy to return the plunger to its initial position by, for example, a spring. That is, according to the above configuration, the responsiveness of the plunger when the current to the electromagnetic coil excited in the energized state is turned off and de-energized can be improved.

[0019] Inside the above plunger, a fluid passage through which a predetermined fluid passes is formed, and it is preferable that a groove communicating from the fluid passage to the gap between the plunger and the guide is formed on the end face of the plunger.

[0020] In this way, the groove formed on the end face of the plunger communicates with the gap between the plunger and the guide from the fluid passage. Therefore, air is dispersed through the groove to the fluid passage without staying in this gap. Thus, it is possible to avoid air staying in this gap.

[0021] Inside the plunger described above, a fluid passage through which a predetermined fluid passes is formed, and it is preferable that a hole communicating from the fluid passage to the gap between the plunger and the guide is formed in the plunger.

[0022] In this way, the hole formed in the plunger communicates from the fluid passage to the gap between the plunger and the guide. For this reason, air is dispersed through the hole to the fluid passage without staying in this gap. Therefore, it is possible to avoid air staying in this gap.

Advantages of the Invention

[0023] According to the present invention, it is possible to provide an electromagnetic drive pump that can easily adjust the discharge flow rate with a simple structure and can maintain the discharge flow rate with high precision.

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0025] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Dimensions, materials, and other specific numerical values shown in such embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals to omit duplicate description, and elements not directly related to the present invention are not shown.

[0026] FIG. 1 is a diagram showing an electromagnetic drive pump 100 according to an embodiment of the present invention. FIG. 2 is a diagram showing a main part of the electromagnetic drive pump 100 of FIG. 1. The electromagnetic drive pump 100 has an electromagnetic coil 102 shown in FIG. 1 and is a pump that transfers a fluid (for example, water) using the electromagnetic coil 102 as power. The electromagnetic coil 102 is disposed inside a housing 104.

[0027] Inside the electromagnetic coil 102, a fixed core 106, a cylindrical guide 108, and a plunger 110 guided by the guide 108 are disposed. The fixed core 106 is integrally formed with the housing 104.

[0028] The plunger 110 is disposed opposite to the fixed core 106 and is guided by the guide 108 so as to be movable inside the electromagnetic coil 102. Also, outside the guide 108, for example, a resin bobbin 112 is disposed. The electromagnetic coil 102 is formed by winding a wire around the bobbin 112.

[0029] As shown in FIG. 2, a suction valve 114 is disposed inside the fixed core 106. The suction valve 114 sucks a fluid from the outside of the electromagnetic drive pump 100 into the plunger 110. Also, a discharge valve 116 is disposed inside the plunger 110. The discharge valve 116 discharges the fluid inside the plunger 110. The discharge valve 116 communicates with a discharge port 120 of a discharge port body 118 shown in FIG. 1 and seals one end (the end on the discharge valve 116 side) of the cylindrical guide 108.

[0030] Also, as shown in FIG. 2, a fluid passage 122 through which the fluid passes is formed in the plunger 110. Parts such as a spring 124 and the above-described discharge valve 116 are accommodated in this fluid passage 122. Also, the spring 124 biases the plunger 110 in a direction away from the fixed core 106 as shown by an arrow A in FIG. 1.

[0031] Furthermore, the end face 126 of the plunger 110 and the end face 128 of the guide 108 shown in FIG. 2 are arranged to face the end face 130 of the fixed core 106. The electromagnetic drive pump 100 further includes a metal spacer 132 and an elastic ring 134.

[0032] The metal spacer 132 is a member made of a non-magnetic material, is arranged in contact with the end face 130 of the fixed core 106 as shown in FIG. 2, and adjusts the stroke of the plunger 110. The elastic ring 134 seals between the metal spacer 132 and the end face 128 of the guide 108, and biases the metal spacer 132 toward the end face 130 of the fixed core 106.

[0033] FIG. 3 is a diagram for explaining the operation of the electromagnetic drive pump 100 of FIG. 1. FIG. 3(a) is a diagram showing a state in which the electromagnetic coil 102 is excited in the electromagnetic drive pump 100. FIG. 3(b) is a diagram showing a state when the current to the electromagnetic coil 102 excited in the energized state of FIG. 3(a) is turned off and de-energized.

[0034] In the electromagnetic drive pump 100, when the electromagnetic coil 102 is excited, an attractive force is generated between the electromagnetic coil 102 and the plunger 110. The plunger 110 moves against the biasing force of the spring 124 toward the metal spacer 132 arranged in contact with the end face 130 (see FIG. 2) of the fixed core 106 as shown by the arrow B in FIG. 3(a). Further, as shown in FIG. 3(a), the plunger 110 stops moving when the end face 126 (see FIG. 2) of the plunger 110 comes into contact with the metal spacer 132.

[0035] That is, in the electric drive pump 100, the stroke dimension of the plunger 110 can be set by the thickness dimension of the metal spacer 132. Thereby, at the time of assembling the electromagnetic drive pump 100, by simply selecting and assembling a metal spacer 132 having an appropriate thickness dimension, the stroke dimension of the plunger 110 can be set with high precision to, for example, a specified value.

[0036] Also, in the electric drive pump 100, as shown in Fig. 3(a), when the end face 126 of the plunger 110 abuts against the metal spacer 132, the volume of the pump chamber 136 (see Fig. 1) decreases, and the pressure in the pump chamber 136 increases. As a result, in the electric drive pump 100, the discharge valve 116 opens, and the fluid in the pump chamber 136 is discharged from the discharge valve 116 as shown by the arrow C in Fig. 3(a).

[0037] Therefore, according to the electric drive pump 100, since the stroke dimension of the plunger 110 can be set with high precision with a simple structure, the discharge flow rate can be easily adjusted, and the accuracy of the discharge flow rate can be improved.

[0038] Also, the metal spacer 132 is biased toward the end face 130 of the fixed core 106 by the elastic ring 134. For this reason, in the electric drive pump 100, the metal spacer 132 can be fixed so as not to move relative to the end face 130 of the fixed core 106, and thus the assemblability can be improved.

[0039] Here, as shown in Fig. 3(a), when the electromagnetic coil 102 is excited and the end face 126 of the plunger 110 abuts against the metal spacer 132, a gap (gap) as a magnetic field is generated between the end face 130 of the fixed core 106 and the end face 126 of the plunger 110 by the thickness of the metal spacer 132 made of a non-magnetic material.

[0040] Subsequently, when the current to the electromagnetic coil 102 is turned off with the end face 126 of the plunger 110 abutting against the metal spacer 132, the plunger 110 moves away from the fixed core 106 by the biasing force of the spring 124 as shown by the arrow D in Fig. 3(b).

[0041] At this time, in the electric drive pump 100, due to the existence of a magnetic gap between the end face 130 of the fixed iron core 106 and the end face 126 of the plunger 110, the end face 126 of the plunger 110 is likely to move away from the metal spacer 132, and it becomes easier to return the plunger 110 to, for example, the initial position by the biasing force of the spring 124. Therefore, according to the electric drive pump 100, the responsiveness of the plunger 110 when the current to the electromagnetic coil 102 excited in the energized state is turned off and de-energized can be improved.

[0042] Also, in the electromagnetic drive pump 100, as shown in FIG. 3(b), when the plunger 110 moves away from the fixed iron core 106 by the biasing force of the spring 124, the volume of the pump chamber 136 (see FIG. 1) increases, and the pressure in the pump chamber 136 decreases. As a result, in the electric drive pump 100, the suction valve 114 opens, and fluid is sucked into the pump chamber 136 from the outside as shown by the arrows E and F in FIG. 3(b).

[0043] Then, the fluid discharged from the discharge valve 116 shown by the arrow C in FIG. 3(a) is transferred to the outside of the electromagnetic drive pump 100 through the discharge port 120 as shown by the arrow G in FIG. 3(b) along with the movement of the plunger 110. In this way, the electromagnetic drive pump 100 can reciprocally drive the plunger 110 inside the electromagnetic coil 102 by alternately operating the ON / OFF of the current to the electromagnetic coil 102, thereby transferring the fluid.

[0044] Furthermore, in the electromagnetic drive pump 100, since the space between the metal spacer 132 and the end face 128 of the guide 108 is sealed by the elastic ring 134, it is also possible to seal between the metal spacer 132, the guide 108, and the bobbin 112. Therefore, it is possible to prevent the fluid from leaking to the bobbin 112 side.

[0045] Also, by sealing between the metal spacer 132, the guide 108, and the bobbin 112 with the elastic ring 134, for example, it is possible to block the air remaining around the guide 108 from the pump chamber 136. According to the electromagnetic drive pump 100, this prevents the formation of an air pocket in the pump chamber 136 and enables maintaining a proper discharge flow rate corresponding to the stroke of the plunger 110 with high precision.

[0046] FIG. 4 is a diagram showing a modified example of the electromagnetic drive pump 100 of FIG. 1. In the figure, the main parts of the electromagnetic drive pumps 100A and 100B, which are modified examples, are shown corresponding to a part of FIG. 2.

[0047] The electromagnetic drive pump 100A is different from the above-described electromagnetic drive pump 100 in that, as shown in FIG. 4(a), it includes a plunger 110A instead of the above-described plunger 110. The plunger 110A has a groove 138. The groove 138 is formed on the end face 126A of the plunger 110A and extends in the radial direction of the plunger 110A. Further, the groove 138 communicates from the fluid passage 122 of the plunger 110A to the gap 140 between the plunger 110A and the guide 108.

[0048] Therefore, the air is dispersed through the groove 138 to the fluid passage 122 without staying in this gap 140. Thus, in the electromagnetic drive pump 100A, it is possible to avoid the air staying in the gap 140.

[0049] The electromagnetic drive pump 100B is different from the above-described electromagnetic drive pump 100 in that, as shown in FIG. 4(b), it includes a plunger 110B instead of the above-described plunger 110. The plunger 110B has a hole 142. The hole 142 is formed in the plunger 110B and extends in the radial direction of the plunger 110B. Further, the hole 142 communicates from the fluid passage 122 of the plunger 110B to the gap 144 between the plunger 110B and the guide 108.

[0050] Therefore, the air is not retained in this gap 144 and is dispersed through the hole 142 to the fluid passage 122. Thus, in the electromagnetic drive pump 100B, it is possible to avoid the air being retained in the gap 144.

[0051] As described above, the preferred embodiments of the present invention have been described with reference to the accompanying drawings. Needless to say, the present invention is not limited to such examples. It is obvious that those skilled in the art can conceive of various modifications or corrections within the scope described in the claims, and it is naturally understood that they also belong to the technical scope of the present invention.

Industrial Applicability

[0052] The present invention can be used as an electromagnetic drive pump that uses an electromagnetic coil as power.

Explanation of Reference Numerals

[0053] 100, 100A, 100B... electromagnetic drive pumps, 102... electromagnetic coil, 104... housing, 106... fixed core, 108... guide, 110, 110A, 110B... plungers, 112... bobbin, 114... suction valve, 116... discharge valve, 118... discharge port body, 120... discharge port, 122... fluid passage, 124... spring, 126, 126A... end faces of the plunger, 128... end face of the guide, 130... end face of the fixed core, 132... metal spacer, 134... elastic ring, 136... pump chamber, 138... groove of the plunger, 140, 144... gaps, 142... hole of the plunger

Claims

1. An electromagnetic drive pump having an electromagnetic coil, comprising: a fixed iron core disposed inside the electromagnetic coil; a plunger that moves inside the electromagnetic coil; a cylindrical guide that guides the movement of the plunger inside the electromagnetic coil, wherein an end face of the plunger and an end face of the guide are disposed opposite to an end face of the fixed iron core, and the electromagnetic drive pump further comprises: a metal spacer disposed in contact with the end face of the fixed iron core to adjust the stroke of the plunger; an elastic ring that seals between the metal spacer and the end face of the guide and biases the metal spacer toward the end face of the fixed iron core. The electromagnetic drive pump is characterized by comprising the above.

2. The electromagnetic drive pump according to claim 1, wherein the metal spacer is made of a non-magnetic material.

3. A fluid passage through which a predetermined fluid passes is formed inside the plunger, and a groove communicating from the fluid passage to a gap between the plunger and the guide is formed in an end face of the plunger. The electromagnetic drive pump according to claim 1 or 2 is characterized by this.

4. A fluid passage through which a predetermined fluid passes is formed inside the plunger, and a hole communicating from the fluid passage to a gap between the plunger and the guide is formed in the plunger. The electromagnetic drive pump according to claim 1 or 2 is characterized by this.

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