Solenoids and electromagnetically driven pumps

Abstract

The present invention provides a solenoid and an electromagnetic drive pump that can suppress collision noise when the electromagnetic coil is energized and when it is not energized, thereby further improving quietness. [Solution] The solenoid 100a according to the present invention comprises an electromagnetic coil 120, a fixed iron core 130 disposed inside the electromagnetic coil, a movable iron core 140 housed inside the fixed iron core, and a leaf spring 150 fitted into the movable iron core. The movable iron core has a large diameter portion 142 attracted by the electromagnetic coil, a small diameter portion 144 protruding from the large diameter portion and having a smaller diameter than the large diameter portion, and a groove 146 formed in the small diameter portion. The groove 146 in the small diameter portion is set to be shorter than the stroke length of the movable iron core, and the leaf spring 150 is fitted into the groove 146 in the small diameter portion and elastically deforms at both ends of the stroke of the movable iron core 140.

Description

Technical Field

[0001] The present invention relates to a solenoid and an electromagnetic drive pump using the same.

Background Art

[0002] Conventionally, as a pump for transferring a fluid, an electromagnetic drive pump using a solenoid as power is known. The electromagnetic drive pump transfers a fluid by reciprocating a plunger (movable iron core) inside a housing. For example, Patent Document 1 discloses an "electromagnetic pump that sucks and discharges a working fluid by reciprocating a piston".

[0003] The electromagnetic pump of Patent Document 1 includes "an electromagnetic part that applies a thrust to the base end portion of the piston to move the piston forward by attracting the plunger to the core by an electromagnetic force, a spring that applies a biasing force to the tip end portion of the piston to move the piston backward, a support member that supports the spring and has a specific portion facing the tip end portion of the piston, and an elastic member provided on at least one of the tip end portion of the piston and the specific portion of the support member".

[0004] In Patent Document 1, a leaf spring is used as the elastic member. According to Patent Document 1, when the piston moves forward with the driving of the solenoid portion of the electromagnetic pump and the leaf spring collides with the protruding end face of the valve body, the impact applied to the piston is absorbed by the elastic force of the leaf spring. Therefore, it is said that the generation of a collision sound accompanying the driving of the electromagnetic pump can be suppressed and the comfort of the occupant can be improved.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] As mentioned above, Patent Document 1 claims that it is possible to suppress the collision noise that occurs when the piston moves back and forth during the operation of an electromagnetic pump, i.e., when energized. However, with the configuration of Patent Document 1, it is not possible to suppress the collision noise between the movable core and the casing when the power is not applied (the collision noise when the movable core returns). For this reason, there is room for further improvement in the technology of Patent Document 1.

[0007] In view of these problems, the present invention aims to provide a solenoid and an electromagnetic drive pump that can suppress collision noise when the electromagnetic coil is energized and when it is not energized, thereby further improving quietness. [Means for solving the problem]

[0008] To solve the above problems, a typical configuration of the solenoid according to the present invention comprises an electromagnetic coil, a fixed iron core disposed inside the electromagnetic coil, a movable iron core housed inside the fixed iron core, and a leaf spring fitted into the movable iron core. The movable iron core has a large diameter portion attracted by the electromagnetic coil, a small diameter portion protruding from the large diameter portion and having a smaller diameter than the large diameter portion, and a groove formed in the small diameter portion. The groove in the small diameter portion is set to be shorter than the stroke length of the movable iron core, and the leaf spring is fitted into the groove in the small diameter portion and elastically deforms at both ends of the stroke of the movable iron core.

[0009] The above-described leaf spring has a notch formed in the center of the leaf spring and two relief holes formed continuously at both ends of the notch. The notch is formed to be narrower than the diameter of the small diameter section and wider than the diameter of the groove bottom, and the relief holes are formed to be larger than the diameter of the small diameter section.

[0010] To solve the above problems, a typical configuration of the electromagnetically driven pump according to the present invention is characterized by comprising the solenoid described above and a pump that sucks in and discharges fluid by a piston that moves back and forth pushed by a movable iron core. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a solenoid and an electromagnetic drive pump that can suppress collision noise when the electromagnetic coil is energized and when it is not energized, thereby further improving quietness. [Brief explanation of the drawing]

[0012] [Figure 1] This diagram illustrates an electromagnetically driven pump using a solenoid according to this embodiment. [Figure 2] This is a diagram illustrating the details of the valve body. [Figure 3] This is a diagram illustrating the movable iron core and leaf spring. [Figure 4] This is a schematic diagram illustrating the operation of the electromagnetically driven pump of this embodiment. [Modes for carrying out the invention]

[0013] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. The dimensions, materials, and other specific numerical values ​​shown in these embodiments are merely examples to facilitate understanding of the invention and do not limit the present invention unless otherwise specified. In this specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals to avoid redundant explanations, and elements not directly related to the present invention are omitted from the illustrations.

[0014] Figure 1 is a diagram illustrating an electromagnetically driven pump 100 using a solenoid 100a according to this embodiment. As shown in Figure 1, the electromagnetically driven pump 100 of this embodiment consists of a solenoid 100a and a pump 100b.

[0015] The solenoid 100a has a housing 110, in which an electromagnetic coil 120 is housed. A fixed core 130 is positioned inside the electromagnetic coil 120, and a movable core 140 (also called a plunger) is housed inside the fixed core 130. A leaf spring 150, described later, is fitted into the movable core 140.

[0016] The pump 100b sucks and discharges fluid by means of a piston 170 that is pushed by a movable iron core 140 and reciprocates. The pump 100b has a sleeve 160. The sleeve 160 houses a piston 170 that is pushed by the movable iron core 140 and moves, and a return spring 180 that biases the piston 170 toward the solenoid 100a.

[0017] Inside the housing 110 of the solenoid 100a, a moving space 110a, which is a space for the movable iron core 140 to move, is formed. Also, inside the sleeve 160 of the pump 100b, a pump chamber 110b, which is a space for the piston 170 to move, is formed.

[0018] Valve bodies 200 for suction and discharge are arranged in the pump 100b. In the sleeve 160 of the electromagnetic drive pump 一百, a discharge port 162 and a suction port 164 that communicate with the valve body 200 are formed.

[0019] FIG. 2 is a diagram for explaining the details of the valve body. FIG. 2(a) is an enlarged view of the main part of FIG. 1. FIG. 2(b) is a diagram for explaining the valve body 200 and the seat 210. As shown in FIGS. 1 and 2(a), the electromagnetic drive pump 100 of the first embodiment has a single valve body 二百 arranged in the pump chamber 110b and a seat 210 arranged between the valve body 200 and the return spring 180. For the sake of convenience of explanation, a slight gap is provided between the valve body 200 and the seat 210 and between the valve body 200 and the sleeve 160 in the drawing, but in reality, these are attached in close contact.

[0020] ? The valve body 200 is formed of an elastic material (for example, spring steel). A plurality of spiral slits 202 are formed in the valve body 200. Although spiral slits 202 are illustrated in FIG. 2, the present invention is not limited thereto, and the slits 202 may have other shapes such as a C shape.

[0021] With the above configuration, the area inside the slit 202 is partitioned from other areas, and on the valve plate, an intake-side valve body 204 (intake-side valve body) and a discharge-side valve body 206 (discharge-side valve body), which are two valve bodies, are formed. When pressure is applied, the valve bodies 204 and 206 elastically deform and protrude.

[0022] As shown in FIG. 2(b), the sheet 210 has a large-diameter hole 212 with a diameter larger than that of the intake-side valve body 204 and a small-diameter hole 214 with a diameter smaller than that of the discharge-side valve body 206. The large-diameter hole 212 functions as a space for allowing the stroke of the intake-side valve body 204. The small-diameter hole 214 functions as a valve seat for restricting the stroke of the discharge-side valve body 206.

[0023] The sheet 210 also has a bottom surface 216 formed on the return spring 180 side of the large-diameter hole 212. Thereby, when the intake-side valve body 204 strokes, it is possible to restrict excessive deformation of the intake-side valve body 204 that would cause plastic deformation. A communication hole 218 communicating with the pump chamber 110b is formed in the bottom surface 216 of the large-diameter hole 212. Thereby, even when the large-diameter hole 212 has the bottom surface 216, it is possible to suitably allow the fluid to flow into the pump chamber 110b.

[0024] On the other hand, as shown in FIGS. 1 and 2(a), a discharge port 162 with a diameter larger than that of the discharge-side valve body 206 and a suction port 164 with a diameter smaller than that of the intake-side valve body 204 are formed in the sleeve 160 of the electromagnetic drive pump 100 of the first embodiment. The discharge port 162 functions as a space for allowing the stroke of the discharge-side valve body 206. The suction port 164 functions as a valve seat for the intake-side valve body 204.

[0025] FIG. 3 is a diagram for explaining the movable iron core 140 and the leaf spring 150. FIG. 3(a) is a front view of the leaf spring 150. FIG. 3(b) is a diagram showing a state before fitting the leaf spring 150 to the movable iron core 140. FIG. 3(c) is a diagram showing a state during fitting the leaf spring 150 to the movable iron core 140. FIG. 3(d) is a diagram showing a state after fitting the leaf spring 150 to the movable iron core 140.

[0026] As shown in Figure 3(b), the movable core 140 consists of a large-diameter section 142 and a small-diameter section 144. The large-diameter section 142 is the part that is attracted by the electromagnetic coil 120 (see Figure 1). The small-diameter section 144 is the part that protrudes from the large-diameter section 142 toward the piston 170 (see Figure 1). The diameter D2 of the small-diameter section is set to be smaller than the diameter D1 of the large-diameter section 142.

[0027] Furthermore, a groove 146 is formed in the circumferential direction in the small-diameter section 144. The diameter D3 at the bottom of the groove 146 is naturally smaller than the diameter D2 of the small-diameter section. Also, the length L of the groove 146 is set to be shorter than the stroke length of the movable core 140.

[0028] As shown in Figure 3(a), the leaf spring 150 is a disc-shaped member having a notch 152 and two relief holes 154 in the center. The notch 152 is formed in the center of the leaf spring 150. The width W of the notch 152 is set to be narrower than the diameter D2 of the small diameter portion 144 and wider than the diameter D3 of the groove bottom of the groove 146.

[0029] The two relief holes 154 are formed continuously at both ends of the notch 152. The diameter D4 of the relief holes 154 is set to be larger than the diameter D2 of the small diameter section 144.

[0030] When fitting the leaf spring 150 onto the movable core 140, as shown in Figure 3(b), the small-diameter portion 144 of the movable core 140 is inserted into the relief hole 154 of the leaf spring 150. This positions the leaf spring 150 in the groove 146 of the small-diameter portion 144, as shown in Figure 3(c). Then, as shown in Figure 3(d), the leaf spring 150 is slid horizontally. This positions the groove 146 in the notch 152, and the leaf spring 150 is fitted into the groove 146 of the small-diameter portion 144, thus fitting onto the movable core 140.

[0031] In other words, the notch 152 is a "claw" for fitting the leaf spring 150 into the groove 146. Furthermore, weight-reducing cutouts 156 are provided on both sides of the notch 152 of the leaf spring 150. This reduces the rigidity of the notch 152, making it more susceptible to elastic deformation.

[0032] Figure 4 is a schematic diagram illustrating the operation of the electromagnetically driven pump 100 of this embodiment. When the electromagnetic coil 120 is not energized, as shown in Figure 4(a), the movable core 140 is pushed by the piston 170 (see Figure 1) and comes into contact with the housing 110. Here, the length L of the groove 146 of the small diameter portion 144 (see Figure 3(b)) is set to be shorter than the stroke length of the movable core 140. As a result, the leaf spring 150 is biased by the movable core 140 and undergoes elastic deformation, becoming bent. Therefore, the leaf spring 150 generates a biasing force in the direction of pushing out the movable core 140.

[0033] When the electromagnetic coil 120 is energized (transitional period of energization), the movable iron core 140 begins to move toward the piston 170, as shown in Figure 4(b). At the start of movement, the biasing force (restoring force) of the leaf spring 150 assists the movement of the piston 170. As a result, the movable iron core 140 can start moving quickly and responsively.

[0034] When the electromagnetic coil 120 is energized and moves to the front end of the moving space 110a, the movement of the movable core 140 is completed. Here, the length L of the groove 146 of the small diameter portion 144 is set to be shorter than the stroke length of the movable core 140. As a result, as shown in Figure 4(c), the leaf spring 150 is pressed by the movable core 140 and undergoes elastic deformation, which dampens the movement speed of the movable core 140. This suppresses the collision sound caused by the piston 170 hitting the seat 210. In addition, the elastic force of the leaf spring 150 generates a biasing force in the direction that returns the movable core 140 to its original position.

[0035] When the electromagnetic coil 120 is de-energized again, the movable iron core 140 moves in the direction of returning to the housing 110, pushed by the piston 170, as shown in Figure 4(d). At this time, the biasing force (restoring force) of the elastically deformed leaf spring 150 assists the movement of the piston 170. In order to effectively obtain the assisting effect of the leaf spring 150 when the power is de-energized, it is preferable to make the biasing force of the leaf spring 150 stronger than the attractive force of the residual magnetic force.

[0036] Then, when the movable core 140 returns and contacts the housing 110 as shown in Figure 4(a), the leaf spring 150 undergoes elastic deformation. This reduces the movement speed of the movable core 140, thereby suppressing the collision noise caused by the movable core 140 hitting the housing 110.

[0037] As described above, with the electromagnetically driven pump 100 of this embodiment, the leaf spring 150 undergoes elastic deformation at both ends of the stroke of the movable iron core 140, thereby suppressing collision noise when the electromagnetic coil 120 is energized and when it is not energized. Therefore, it is possible to improve the quietness of the electromagnetically driven pump 100.

[0038] In this embodiment, an electromagnetically driven pump 100 to which the solenoid 100a of the present invention is applied has been described, but the invention is not limited to this. The solenoid 100a of the present invention can be applied to other devices as long as they use the solenoid 100a as a drive source.

[0039] Preferred embodiments of the present invention have been described above with reference to the attached drawings, but it goes without saying that the present invention is not limited to these examples. It will be obvious to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally also fall within the technical scope of the present invention. [Industrial applicability]

[0040] The present invention can be used as a solenoid and an electromagnetically driven pump using the same. [Explanation of symbols]

[0041] D1…Diameter, D2…Diameter, D3…Diameter, D4…Diameter, 100…Electromagnetically driven pump, 100a…Solenoid, 100b…Pump, 110…Housing, 110a…Movement space, 110b…Pump chamber, 120…Electromagnetic coil, 130…Fixed core, 140…Movable core, 142…Large diameter section, 144…Small diameter section, 146…Groove, 150…Leaf spring, 152…Notch, 154…Relief hole, 156…Weight reduction, 162…Discharge port, 164…Intake port, 170…Piston, 180…Return spring, 200…Valve body, 202…Slit, 204…Intake side valve body, 206…Discharge side valve body, 210…Seat, 212…Large diameter hole, 214…Small diameter hole, 216…Bottom surface, 218…Communication hole

Claims

1. Electromagnetic coil and, A fixed iron core is placed inside the electromagnetic coil, A movable core housed inside the fixed core, A leaf spring fitted into the gap of the aforementioned movable iron core, Equipped with, The aforementioned movable iron core is The large-diameter portion that is attracted by the electromagnetic coil, A smaller diameter portion protrudes from the larger diameter portion and has a smaller diameter than the larger diameter portion, The groove formed in the small diameter portion, It has, The groove in the small diameter portion is set to a length shorter than the stroke length of the movable core. The leaf spring is fitted into the groove of the small-diameter portion and is elastically deformed at both ends of the stroke of the movable iron core, characterized in the solenoid.

2. The leaf spring has a notch formed in the center of the leaf spring and two relief holes formed continuously at both ends of the notch. The notch is formed to be narrower in width than the diameter of the small diameter portion and wider in width than the diameter of the groove bottom. The solenoid according to claim 1, characterized in that the relief hole is formed to be larger than the diameter of the small diameter portion.

3. A solenoid according to claim 1 or 2, A pump that draws in and discharges fluid by a piston that moves back and forth, pushed by the movable iron core, An electromagnetically driven pump characterized by having the following features.

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