solenoid

Abstract

To provide a solenoid with a configuration capable of preventing a filler ring from being broken while suppressing influences of the solenoid on a physique and thrust characteristic to the minimum.SOLUTION: In a solenoid 60, a first brazing filler metal storage groove 25 and a second brazing filler metal storage groove 19 are formed near a region welded by brazing of a base 30 and the filler ring 20, so that the first brazing filler metal ring 15 and the second brazing filler metal ring 16 can be arranged suitably for brazing. Thus, an area of the region where the base 30 and the filler ring 20 are welded is enlarged considerably, leakage of hydraulic oil can be reliably prevented, and the region welded to the filler ring 20 of the base 30 substantially shares a function as the filler ring 20.SELECTED DRAWING: Figure 3

Description

Technical Field

[0004] , , ,

[0001] The present invention relates to a solenoid, and more particularly to a solenoid having a filler ring.

Background Art

[0002] In a solenoid used in a hydraulic circuit such as a hydraulic pressure circuit, in order to prevent hydraulic oil or the like from entering the space where the coil is arranged, some solenoids are provided with a filler ring. FIG. 11 is a cross-sectional view of a solenoid according to the prior art. In FIG. 11, 80 is a proportional solenoid, 81 is a filler ring, 82 is a base, 83 is a small-diameter portion, 84 is a large-diameter portion, 85 is a large-diameter through-hole, 86 is a small-diameter through-hole, 87 is a recess, 88 is a spring receiver, 89 is a spring, 90 is a plunger and spool, 91 is an auxiliary magnetic pole portion, 92 is a case, 93 is a guide member, 94 is a flange portion, 95 is an inner protruding portion, 96 is a coil, 97 is a coil bobbin, and 98 is an auxiliary magnetic pole.

[0003] FIG. 11 shows a solenoid disclosed in Japanese Patent Application Laid-Open No. 2019-9150. The proportional solenoid 80 is for driving a spool valve provided in a hydraulic circuit and is provided integrally with the spool valve as a part of the hydraulic circuit. The plunger and spool 90 is provided so as to face the recess 87 of the base 82. Further, a spring receiver 88 is disposed inside the large-diameter through-hole 85 and the small-diameter through-hole 86 of the base 82. The spring 89 is held in a state where both ends are in contact with the spring receiver 88 and the auxiliary magnetic pole 98 fixed to the case 92. Therefore, the spring 89 biases the plunger and spool 90.

[0004] As described above, by providing the auxiliary magnetic pole portion 91 on the plunger / spool 90, even when the plunger / spool 90 and the base 82 are near the position where they are furthest apart, a sufficient amount of magnetic flux can be secured between the plunger / spool 90 and the base 82, preventing the sliding speed from becoming unintendedly low or stopping unintentionally. When the plunger / spool 90 and the base 82 are very close, the auxiliary magnetic pole portion 91 enters the small-diameter through-hole 86 of the base 82, so the component of the magnetic flux flowing between the auxiliary magnetic pole portion 91 and the base 82 that is perpendicular to the sliding direction and does not contribute to thrust increases significantly. At the same time, when the auxiliary magnetic pole portion 91 comes into contact with the spring receiver 88, the auxiliary magnetic pole portion 91 and the base 82 are very close together, so the amount of magnetic flux flowing between them increases further, and the thrust of the plunger / spool 90 also increases further.

[0005] Incidentally, in solenoids like the proportional solenoid 80, which have a configuration in which liquids such as hydraulic fluid inevitably enter the area around the base and plunger, it is necessary to shield the space where electrical components such as coils are installed to prevent the hydraulic fluid from entering. In the proportional solenoid 80, the smaller diameter portion 83 of the base 82 and the inner protrusion 95 of the guide member 93 are inserted into both ends of the filler ring 81 and further fixed with adhesive. By providing the filler ring 81, it is possible to prevent hydraulic fluid from entering the space where the coil 96 and coil bobbin 97 are installed, and furthermore, it is possible to prevent hydraulic fluid from leaking out from between the case 92 and the flange portion 94.

[0006] However, if the hydraulic pressure of the fluid is high, cracks may form in the filler ring 81, allowing the fluid to seep into the space containing the coil 96 and coil bobbin 97. This can be prevented by significantly increasing the thickness of the filler ring 81, but this would also result in a considerably larger outer diameter for the solenoid, so it is not a desirable solution. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2019-9150 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] The present invention aims to solve the above problems by providing a solenoid having a configuration that can prevent the destruction of the filler ring while minimizing the impact on the solenoid's size and thrust characteristics. [Means for solving the problem]

[0009] The invention described in claim 1 is a solenoid comprising: a case; a coil disposed inside the case; a base which is formed in part or all in a substantially cylindrical or substantially cylindrical shape, with the portion near the base end face fixed to the case by press-fitting, the portion near the tip end face disposed inside the case, the tip end face being perpendicular to the central axis and formed in an annular shape, and the circumferential surface of the portion near the tip end face being formed as a tapered surface that decreases in diameter toward the tip end face; a plunger provided to be attracted to the base when the coil is energized and to move in a straight line in the direction of the central axis of the base; an auxiliary magnetic pole which is disposed inside part or all of the plunger, with the portion near the base end face being disposed away from the base; and a filler ring which is formed in a substantially cylindrical shape, with the portion near the tip end face of the base being inserted into the portion near the base end face and fixed to the auxiliary magnetic pole with the portion near the base end face of the auxiliary magnetic pole being inserted into the portion near the tip face. The base comprises a small diameter cylindrical portion whose circumferential surface is formed in a cylindrical shape in a portion closer to the base end surface than the tapered surface, and a large diameter cylindrical portion whose circumferential surface is formed in a cylindrical shape and has a larger diameter than the small diameter cylindrical portion in a portion closer to the base end surface than the small diameter cylindrical portion, wherein the stepped surface between the small diameter cylindrical portion and the large diameter cylindrical portion faces the base end surface, and the filler ring has a portion of its inner circumferential surface facing the tip surface of the base, and the middle of the base The solenoid is characterized in that it has an annular opposing surface perpendicular to the central axis, and a concave tapered surface opposite the tapered surface of the base that decreases in diameter toward the tip, and an annular first brazing material storage groove is formed in the region that forms the boundary between the annular opposing surface and the concave tapered surface, and the base end surface is separated from the stepped surface of the base by a predetermined distance so that the base end surface, the stepped surface of the base and the circumferential surface of the small diameter cylindrical part form an annular second brazing material storage groove.

[0010] The invention described in claim 2 is the solenoid according to claim 1, characterized in that the base and the filler ring are provided such that the tip surface and the annular opposing surface are in contact, and the tapered surface and the concave tapered surface are separated.

[0011] The invention described in claim 3 is a solenoid characterized in that, in the invention described in claim 1 or claim 2, the auxiliary magnetic pole is fixed by being press-fitted into the filler ring. [Effects of the Invention]

[0012] According to the invention described in claim 1, since the first brazing material storage groove and the second brazing material storage groove are formed by utilizing the boundary region between the base and the filler ring, two brazing material rings can be arranged. Consequently, the area of ​​the region where the base and the filler ring are joined is increased, and the region of the base fixed to the filler ring also functions as a filler ring, so that the breakage of the filler ring can be prevented without significantly increasing the outer diameter of the solenoid.

[0013] According to the invention described in claim 2, since the solder is reliably penetrated into the gap between the tapered surface and the concave tapered surface, the reliability of the joint between the base and the filler ring can be increased.

[0014] According to the invention described in claim 3, if the auxiliary magnetic pole is press-fitted into the filler ring, the placement of the filler ring after solenoid assembly becomes more precise, making it easier to apply the present invention to hydraulic valves and the like where high precision is required. [Brief explanation of the drawing]

[0015] [Figure 1] This is a cross-sectional view of a solenoid according to an embodiment of the present invention in a non-energized state. [Figure 2] This is a cross-sectional view of a solenoid according to an embodiment of the present invention in an energized state. [Figure 3]An enlarged cross-sectional view showing the filler filling and the base in the solenoid according to an embodiment of the present invention. [Figure 4] An enlarged cross-sectional view of another cut surface of the filler filling and the base in the solenoid according to an embodiment of the present invention. [Figure 5] An enlarged cross-sectional view of the brazing target area in the solenoid according to an embodiment of the present invention. [Figure 6] An enlarged cross-sectional view showing the filler filling and the base before brazing in the solenoid according to an embodiment of the present invention. [Figure 7] An enlarged cross-sectional view of the brazing target area in the solenoid according to an embodiment of the present invention. [Figure 8] An enlarged cross-sectional view showing the state during brazing in the brazing target area in the solenoid according to an embodiment of the present invention. [Figure 9] Shows the filler filling in the solenoid according to an embodiment of the present invention, (a) is an enlarged plan view, and (b) is an enlarged cross-sectional view. [Figure 10] Shows the base in the solenoid according to an embodiment of the present invention, (a) is an enlarged front view, and (b) is an enlarged cross-sectional view. [Figure 11] A cross-sectional view of a solenoid according to the prior art.

Embodiments for Carrying Out the Invention

[0016] First, an overview of the solenoid according to an embodiment of the present invention will be described. Figure 1 is a cross-sectional view of the solenoid according to an embodiment of the present invention in an unenergized state. In Figure 1, 10 is the brazed portion, 20 is the filler ring, 21 is the thick portion, 23 is the thin portion, 30 is the base, 32 is the small diameter cylindrical portion, 33 is the large diameter cylindrical portion, 36a and 36b are the communication holes, 37 is the recessed portion, 40 is the auxiliary magnetic pole, 40a is the inner circumferential surface, 41 is the tip-side cylindrical portion, 42 is the base-side cylindrical portion, 42a is the annular groove for the O-ring, 43 is the plunger, 44 and 45 are the communication holes, 46 is the recessed portion for the spring, 47 is the coil, 48 is the coil bobbin, 49 is the shaft, 50 is the spring receiving member, 56 is the bearing, 57 is the O-ring, 58 is the spacer, and 60 is the solenoid. Figure 2 is a cross-sectional view of the solenoid according to an embodiment of the present invention in an energized state. All reference numerals used in Figure 2 indicate the same elements as in Figure 1. In the description of the solenoid 60 according to the embodiment of the present invention, "base side" refers to the side on which the base 30 is provided, i.e., the lower side of Figure 1, and "tip side" refers to the side on which the spring receiving member 50 is provided, i.e., the upper side of Figure 1. The same applies to "base side" and "tip side" in the claims. In addition, "central axis" refers to the central axis of the plunger 43. In the solenoid 60 according to this embodiment, the central axis of the plunger 43 coincides with the central axes of the filler ring 20, base 30, auxiliary magnetic pole 40, coil 47, shaft 49, and bearing 56. Therefore, when "central axis" is mentioned in the following description, it refers to the central axis common to all of these components.

[0017] The solenoid 60 according to an embodiment of the present invention is a solenoid used in a hydraulic circuit. As shown in FIG. 1, the solenoid 60 is provided with a plunger 43, a base 30, a case 52, and an auxiliary magnetic pole 40 as members that generate a magnetic field. When the coil 47 is energized, a magnetic circuit is generated around these components, and as shown in FIG. 2, the plunger 43 and the shaft 49 slide toward the proximal end side. Further, in order to adjust the pressure difference inside the solenoid 60, communication holes 36a and 36b are formed in the base 30, and communication holes 44 and 45 are formed in the plunger 43 so as to extend parallel to the central axis, thereby securing a flow path for the hydraulic oil. On the other hand, with respect to the space where the coil 47 and the coil bobbin 48 are provided, a filler ring 20 fixed to the base 30 and the auxiliary magnetic pole 40 is provided to isolate the space from which the hydraulic oil flows in and prevent the intrusion of the hydraulic oil.

[0018] Furthermore, the configuration of each part of the solenoid 60 will be described in detail. Figure 3 is an enlarged cross-sectional view showing the filler ring and base in a solenoid according to an embodiment of the present invention. In Figure 3, 11 is the region near the first end, 12 is the locking portion, 21a is the inner circumferential surface, 22 is the intermediate portion, 32a is the cylindrical surface, and 35b is the large diameter through hole, and the other reference numerals are the same as in Figure 1. Figure 4 is an enlarged cross-sectional view of another cross-section of the filler ring and base in a solenoid according to an embodiment of the present invention. All reference numerals used in Figure 4 are the same as in Figures 1 and 3. Furthermore, Figure 5 is an enlarged cross-sectional view of the brazing target region in a solenoid according to an embodiment of the present invention. In Figure 5, 23a is the concave tapered surface, 23b is the cylindrical surface, 23c is the guide tapered surface, 25 is the first brazing material storage groove, 31a is the tapered surface, and 31b is the tip surface, and the other reference numerals are the same as in Figures 1 and 3. In addition, Figure 9 shows a filler ring in a solenoid according to an embodiment of the present invention, where (a) is an enlarged plan view and (b) is an enlarged cross-sectional view. In Figure 9, 22a is the inner circumferential surface, 24 is the brazing region, 26 is the annular projection, 26a is the annular opposing surface, and 27 is the base end surface, with other reference numerals being the same as in Figures 1 and 3. Also, Figure 10 shows a base in a solenoid according to an embodiment of the present invention, where (a) is an enlarged front view and (b) is an enlarged cross-sectional view. In Figure 10, 16 is the second brazing ring, 31 is the frustoconical portion, 33a is the cylindrical surface, 34 is the flange portion, 35a is the small diameter through hole, 36b is the communication hole, 37a is the inner circumferential surface, 38 is the stepped surface, and 39 is the base end surface, with other reference numerals being the same as in Figures 1 and 3.

[0019] In the solenoid 60, as described above, the space containing the coil 47 and coil bobbin 48 is isolated from the space into which the hydraulic fluid flows by fixing the filler ring 20 to the base 30 and the auxiliary magnetic pole 40. Furthermore, by giving the base 30 and the auxiliary magnetic pole 40 the role of reinforcing material for the filler ring 20, this configuration can be adopted even in hydraulic circuits with relatively high pressure. As shown in Figure 10, the base 30 is formed in this order from the tip side to the base side, along the central axis, with a frustoconical portion 31, a small diameter cylindrical portion 32, a large diameter cylindrical portion 33, and a flange portion 34. The frustoconical portion 31 is formed in a substantially frustoconical shape, and a recessed portion 37 is formed so that the center of the tip surface 31b, which is formed perpendicular to the central axis, and its vicinity are recessed. The recessed portion 37 constitutes the space into which the plunger 43 enters when the coil 47 is energized. Furthermore, the circumferential surface of the frustoconical portion 31, that is, the circumferential surface in the vicinity of the tip surface 31b, is formed as a tapered surface 31a that decreases in diameter toward the tip surface 31b. The recessed portion 37 and the tapered surface 31a play a significant role in setting the thrust characteristics of the solenoid 60.

[0020] The small-diameter cylindrical portion 32 is formed in a substantially cylindrical shape and continuous with the frustoconical portion 31. The cylindrical surface 32a, which is the circumferential surface of the small-diameter cylindrical portion 32, is formed to have the same diameter as the base end of the tapered surface 31a. The large-diameter cylindrical portion 33 is formed to be continuous with the small-diameter cylindrical portion 32, but the diameter of the cylindrical surface 33a, which is the circumferential surface of the large-diameter cylindrical portion 33, is made to be slightly larger than that of the cylindrical surface 32a, and a stepped surface 38 is formed at the boundary between the cylindrical surface 33a and the cylindrical surface 32a. The stepped surface 38 is formed to face the base end surface 27 of the filler ring 20 and constitutes the space in which the second brazing ring 16, which will be the base material of the brazed portion 10 shown in Figure 1, is arranged. The flange portion 34 is formed in a substantially disc shape and is the part that is press-fitted into the base end side of the case 52. Therefore, the frustoconical portion 31, the small-diameter cylindrical portion 32, and the large-diameter cylindrical portion 33 are all located inside the case 52. Furthermore, the base 30 has a small-diameter through-hole 35a and a large-diameter through-hole 35b for inserting and supporting the shaft 49. The small-diameter through-hole 35a is for press-fitting and fixing the bearing 56 shown in Figure 1. The large-diameter through-hole 35b is open to the outside to allow the shaft 49 to protrude outside the solenoid 60. The communication holes 36a and 36b, as described above, play a role in adjusting the pressure difference inside the solenoid 60 and are formed parallel to the small-diameter through-hole 35a and the large-diameter through-hole 35b. However, as shown in Figure 4, the communication holes 36a and 36b do not appear in another cross-section. Note that, depending on the application, the shaft may not penetrate the base, and a portion of the tip may be fixed to the base by press-fitting.

[0021] As shown in Figure 9, the filler ring 20 is formed in a substantially cylindrical shape from a non-magnetic material and comprises a thick-walled portion 21 at the tip, a thin-walled portion 23 at the base, and an intermediate portion 22 between the thick-walled portion 21 and the thin-walled portion 23. The names of the thick-walled portion 21 and the thin-walled portion 23 are for convenience only, and the thickness of the thick-walled portion 21 and the thin-walled portion 23 may differ from that of the solenoid 60 according to this embodiment. The thick-walled portion 21 is the portion into which the cylindrical base portion 42 of the auxiliary magnetic pole 40 is press-fitted onto the inner circumferential surface 21a. Furthermore, as shown in Figure 1, an O-ring 57 is provided in the annular groove 42a for the O-ring of the cylindrical base portion 42, preventing hydraulic fluid from leaking from between the thick-walled portion 21 and the cylindrical base portion 42 to the coil 47. The intermediate portion 22 is positioned between the base 30 and the auxiliary magnetic pole 40, and is formed to protrude into the hollow portion of the filler ring 20. The inner circumferential surface 22a of the intermediate portion 22 is formed so that its diameter is approximately the same as the inner circumferential surface 37a of the recessed portion 37 of the base 30 and the inner circumferential surface 40a of the auxiliary magnetic pole 40, so that it does not protrude towards the plunger 43.

[0022] Incidentally, in the case of a straight shape without an intermediate section 22, as shown in Figure 11 for the filler ring 81, a relatively large space is created because there is no part corresponding to the intermediate section 22. If foreign matter accumulates in this area, it may hinder the operation of the plunger 43. In contrast, a shape like the filler ring 20 can fill most of this space. Therefore, in the solenoid 60, even if foreign matter flows into the solenoid, its accumulation can be suppressed, and the secondary effect of improving the operational reliability of the plunger 43 is also obtained.

[0023] Returning to Figure 9, the intermediate section 22 has a first brazing material storage groove 25 formed on the base end side. The first brazing material storage groove 25 is formed so that the bottom part faces the tip end and the open side faces the base end, that is, it is upside down. This is to ensure that the brazing material is securely stored in the first brazing material storage groove 25 in a predetermined position by a procedure which will be explained in detail later, and that brazing is performed properly. In addition, the annular opposing surface 26a surrounded by the first brazing material storage groove 25 is formed to face the tip surface 31b of the base 30 after the solenoid 60 is assembled and to be perpendicular to the central axis. Furthermore, in order to reduce the amount of brazing material that leaks out from the gap between the annular opposing surface 26a and the tip surface 31b when brazing is performed, the annular opposing surface 26a is provided in contact with the tip surface 31b. In addition, a concave tapered surface 23a is formed on the intermediate section 22 and the thin section 23 so as to straddle them.

[0024] The concave tapered surface 23a is positioned opposite the tapered surface 31a of the base 30 and is formed to decrease in diameter towards the tip. Furthermore, as shown in Figure 5, a predetermined gap is maintained between the concave tapered surface 23a and the tapered surface 31a so that the brazing material melted by heating during brazing covers the entire tapered surface 31a. In addition, the cylindrical surface 23b, which is continuous from the concave tapered surface 23a towards the base end, is the region where the small diameter cylindrical portion 32 of the base 30 is lightly press-fitted, and a small gap exists between it and the cylindrical surface 32a of the small diameter cylindrical portion 32. This gap between the cylindrical surface 23b and the cylindrical surface 32a is maintained so that the brazing material, which becomes liquid during brazing, covers the entire cylindrical surface 32a. The guided tapered surface 23c is a concave tapered surface formed to guide the small-diameter cylindrical portion 32 when lightly press-fitting it into the cylindrical surface 23b. The guided tapered surface 23c is also an area that will be covered by brazing material during brazing.

[0025] Furthermore, the base end surface 27, together with the stepped surface 38 and cylindrical surface 32a of the base 30 shown in Figure 10, constitutes a second brazing material storage groove 19, as shown in Figure 5. As mentioned above, the filler ring 20 has a first brazing material storage groove 25, so the solenoid 60 is configured to house two brazing materials. By using two brazing materials, during brazing, the brazing material is distributed throughout the brazing region 24, which consists of a concave tapered surface 23a, a cylindrical surface 23b, and a guide tapered surface 23c. In other words, by configuring the filler ring 20 and the base 30 as described above, as shown in Figure 4, the first brazing region 11 of the brazing section 10 is brazed mainly by the brazing material stored in the first brazing material storage groove 25, and the second brazing region 12 is brazed mainly by the brazing material stored in the second brazing material storage groove 19. Note that the shape of the brazing section 10 may vary slightly depending on the type of brazing material.

[0026] Returning to Figure 1, let's describe the other components. The auxiliary magnetic pole 40 is one of the components that make up the magnetic circuit. It is formed in a roughly cylindrical shape, and a plunger 43 is positioned inside it. The tip-side cylindrical portion 41 of the auxiliary magnetic pole 40 is inserted into the spring receiving member 50 and case 52, but is not press-fitted, because it can be difficult to assemble accurately due to the effects of heating during brazing. On the other hand, the base-side cylindrical portion 42 is press-fitted into the thick-walled portion 21 of the filler ring 20. Furthermore, since the auxiliary magnetic pole 40 is machined with high precision like a sleeve, the central axis of the filler ring 20 can be accurately set when assembling the solenoid 60. In addition, the inner diameter of the inner circumferential surface 40a of the auxiliary magnetic pole 40 is larger than the outer diameter of the plunger 43, and as mentioned above, it is approximately the same as the inner diameter of the inner circumferential surface 22a of the filler ring 20. Moreover, an annular groove 42a for positioning the O-ring 57 is provided on the circumferential surface of the base-side cylindrical portion 42.

[0027] The plunger 43 has a through hole formed along its central axis, and a shaft 49 is fixed to this through hole by press-fitting. The shaft 49 is supported by a bearing 56 fixed to a small diameter through hole 35a in the base 30 by press-fitting, and the plunger 43 is also supported via the shaft 49. A spring recess 46 for housing a spring 55 is formed on the tip side of the plunger 43. The shaft 49 is biased toward the tip by a component of a hydraulic circuit (not shown), and at the same time, the plunger 43 is biased toward the base end by the spring 55. When current is supplied to the coil 47, the plunger 43 immediately slides toward the base end, resulting in the state shown in Figure 2. In order to prevent the plunger 43 from sticking to the base 30 due to the pressure difference around the plunger 43, a spacer 58 shown in Figure 1 is provided. The spacer 58 is positioned in the recess 37 of the base 30 and is inserted through the shaft 49. The coil 47 is formed by winding coil wire around a coil bobbin 48 and is located inside the case 52. The spring receiving member 50 is fixed to the case 52, and the tip portion of the plunger 43 and the spring 55 are housed in the recessed portion 51. The case 52 is one of the components that make up the magnetic circuit and also serves as a base for accurately positioning other components relative to the central axis. The flange portion 34 of the base 30 is fixed to the base fitting portion 53 on the proximal end of the case 52 by press-fitting, and the tip cylindrical portion 41 is fixed to the auxiliary magnetic pole fitting portion 54 on the tip end by press-fitting.

[0028] Next, the brazing procedure in the solenoid 60 according to an embodiment of the present invention will be described. Figure 6 is an enlarged cross-sectional view showing the filler ring and base of the solenoid according to an embodiment of the present invention before brazing. In Figure 6, 15 is the first brazing ring, 16 is the second brazing ring, and the other reference numerals are the same as those in Figure 2. Figure 7 is an enlarged cross-sectional view showing the brazing target region of the solenoid according to an embodiment of the present invention. All reference numerals used in Figure 7 are the same as those in Figures 2 and 6. Furthermore, Figure 8 is an enlarged cross-sectional view showing the state during brazing in the brazing target region of the solenoid according to an embodiment of the present invention. In Figure 8, 13 is the first brazing material, 14 is the second brazing material, and the other reference numerals are the same as those in Figure 7.

[0029] When brazing is performed in the solenoid 60, as shown in Figure 7, the first brazing ring 15 is placed in the first brazing groove and the second brazing ring 16 is placed in the second brazing groove 19 in advance. The first brazing ring 15 and the second brazing ring 16 are often made of copper or a copper alloy, but may also contain other metals. Next, as shown in Figure 6, the base 30 is placed on top and the filler ring 20 is placed on the bottom, that is, the top and bottom are reversed compared to the state shown in Figure 1. When the base 30 and the filler ring 20 are heated in this state, the first brazing ring 15 and the second brazing ring 16 melt and penetrate and spread into the narrow gap between the base 30 and the filler ring 20, as shown in Figure 8 with the first brazing material 13 and the second brazing material 14.

[0030] As described above, in the solenoid 60 according to the embodiment of the present invention, a first brazing material storage groove 25 and a second brazing material storage groove 19 are formed near the area where the base 30 and the filler ring 20 are welded together, so that the first brazing ring 15 and the second brazing ring 16 can be arranged in a manner suitable for brazing. Consequently, the area of ​​the welded region between the base 30 and the filler ring 20 is greatly increased, ensuring reliable prevention of hydraulic fluid leakage, and the area of ​​the base 30 welded to the filler ring 20 substantially acquires the function of the filler ring 20. Similarly, the cylindrical portion 42 on the base end side of the auxiliary magnetic pole 40 is press-fitted into the thick portion 21 of the filler ring 20, and an O-ring 57 is provided between them, ensuring reliable prevention of hydraulic fluid leakage, and the area of ​​the auxiliary magnetic pole 40 press-fitted into the filler ring 20 acquires the function of the filler ring 20 to some extent. Consequently, the breakage of the filler ring 20 can be prevented without significantly increasing the outer diameter of the solenoid 60. In addition, since the solder reliably penetrates the gap between the tapered surface 31a and the concave tapered surface 23a, the reliability of the joint between the base 30 and the filler ring 20 can be improved. Furthermore, since the cylindrical tip portion 41 of the auxiliary magnetic pole 40 is press-fitted into the filler ring 20, the placement of the filler ring 20 after assembly of the solenoid 60 becomes even more precise, making it easier to apply the present invention to hydraulic valves and other applications requiring high precision.

[0031] The present invention is not limited to what has been described above, and can be applied to various solenoids having filler rings that are used under relatively high hydraulic pressure, without departing from the scope of each claim. [Explanation of Symbols]

[0032] 10 Brazed section 11 First brazing area 12 Second brazing area 13 First brazing material 14. Second brazing material 15. First brazing ring 16. Second brazing ring 19. Second brazing material storage groove 20 Filler Rings 21 Thick part 21a Inner surface 22 Middle section 22a Inner surface 23 Thin-walled section 23a Concave tapered surface 23b Cylindrical surface 23c Tapered surface for guiding 24 Brazing area 25 First brazing material storage groove 26 Annular projection 26a Annular opposing surface 27 Proximal surface 30 base 31. Truncated cone section 31a Tapered surface 31b Tip surface 32 Small diameter cylindrical part 32a Cylindrical surface 33 Large diameter cylindrical part 33a Cylindrical surface 34 Flange section 35a Small diameter through hole 35b Large diameter through hole 36a Communication hole 36b Communication hole 37 Recessed area 37a Inner surface 38 Step surface 39 Proximal surface 40 Auxiliary magnetic pole 40a Inner surface 41 Cylindrical part at the tip 42 Cylindrical portion on the base end side 42a Annular groove for O-ring 43 Plungers 44 Communication hole 45 Communication hole 46 Recessed section for spring 47 coils 48 Coil Bobbins 49 shaft 50 Spring support member 51 Recessed area 52 cases 53 Base fitting section 54 Auxiliary magnetic pole fitting section 55 Spring 56 Bearings 57 O-rings 58 Spacers 60 Solenoid 80 Proportional Solenoid 81 Fillering 82 Bass 83 Small diameter section 84 Diameter Large Part 85mm diameter large through hole 86 Small diameter through hole 87 Recessed area 88 Spring receiver 89 Spring 90 Plunger and Spool 91 Auxiliary magnetic pole part 92 cases 93 Guide Member 94 Flange section 95 Inner protrusion 96 coils 97 Coil Bobbin 98 Auxiliary magnetic pole

Claims

1. The case and, A coil arranged inside the aforementioned case, A base which is formed in part or entirely in a substantially cylindrical or substantially cylindrical shape, the portion near the base end face is fixed by press-fitting into the case, the portion near the tip face is positioned inside the case, the tip face is perpendicular to the central axis and formed in an annular shape, and the circumferential surface of the portion near the tip face is formed as a tapered surface that decreases in diameter toward the tip face, A plunger is provided which, when the coil is energized, is attracted to the base and moves in a straight line in the direction of the central axis of the base, An auxiliary magnetic pole is provided, in which part or all of the plunger is arranged inside, and the portion near the base end face is arranged to be separated from the base. A solenoid having a filler ring formed in a substantially cylindrical shape, wherein the portion near the tip surface of the base is fixed to the base with the portion near the base surface inserted into the portion near the base surface, and the portion near the base surface of the auxiliary magnetic pole is fixed to the auxiliary magnetic pole with the portion near the tip surface inserted into the portion near the base surface, The base comprises a small-diameter cylindrical portion whose circumferential surface is formed in a cylindrical shape, located closer to the base end surface than the tapered surface, and a large-diameter cylindrical portion whose circumferential surface is formed in a cylindrical shape and whose diameter is larger than that of the small-diameter cylindrical portion, wherein the stepped surface between the small-diameter cylindrical portion and the large-diameter cylindrical portion faces the base end surface of the filler ring. The filler ring is characterized in that a portion of its inner circumferential surface faces the front end surface of the base and is formed of an annular opposing surface perpendicular to the central axis of the base, and a concave tapered surface that faces the tapered surface of the base and decreases in diameter toward the front end, and an annular first brazing material storage groove is formed in the region that forms the boundary between the annular opposing surface and the concave tapered surface, and the base end surface is spaced a predetermined distance from the stepped surface of the base so that the base end surface, the stepped surface of the base and the circumferential surface of the small diameter cylindrical portion form an annular second brazing material storage groove.

2. The solenoid according to claim 1, characterized in that the base and the filler ring are provided such that the tip surface and the annular opposing surface are in contact, and the tapered surface and the concave tapered surface are separated.

3. The solenoid according to claim 1 or 2, characterized in that the auxiliary magnetic pole is fixed by being press-fitted into the filler ring.

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