Method for manufacturing a solenoid, tool for manufacturing a solenoid, and solenoid

Abstract

To provide a manufacturing method of a solenoid capable of reducing cost of manufacture, a tool for solenoid manufacture, and the solenoid.SOLUTION: The present invention relates to a manufacturing method of a solenoid comprising: a tube including a stationary magnetic pole, a rear magnetic pole and a non-magnetic pipe; a movable core which is stored in the tube and movable in an axial direction; and a case which is disposed while interposing a clearance with an outer peripheral surface of the tube. The case includes a flange at a position opposed with the stationary magnetic pole, and at least one of the stationary magnetic pole and the case includes a ring-shaped first stepped part protruding toward the other and being in contact with the other. The vicinity of a contact surface of the first stepped part with the other is pressed in the axial direction by a tip end of a cylindrical tool inserted in the clearance between the outer peripheral surface of the tube and an inner peripheral surface of the case. Thus, a part of the contact surface of the first stepped part with the other is plastically deformed toward the other, thereby forming a plastically deformed part and the plastically deformed part is engaged into a contacted surface of the other with the first stepped part, thereby joining the tube and the case.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a solenoid, a tool for manufacturing a solenoid, and a solenoid.

Background Art

[0002] Generally, an electromagnetic valve called a solenoid is used for controlling the flow rate of a fluid or the like. As a conventional solenoid, for example, the solenoid described in Patent Document 1 below can be mentioned. The solenoid described in Patent Document 1 has a structure in which a non-magnetic pipe (a cylindrical member in Patent Document 1) made of a non-magnetic material is sandwiched between a fixed magnetic pole (a stator in Patent Document 1) and a rear magnetic pole (a yoke in Patent Document 1) made of a magnetic material, a tube (an inner housing in Patent Document 1), a coil disposed on the outer peripheral side of the tube, and a movable iron core (a plunger in Patent Document 1) of a magnetic body accommodated inside the tube. The fixed magnetic pole has a flange portion for joining to a hydraulic pump or the like at an end, and the tube and the coil are covered with a case formed of a magnetic material.

[0003] In a solenoid, an electric current is passed through a coil disposed on the outer peripheral side of a tube to form a magnetic circuit in the tube and the movable iron core, and the position of the movable iron core is controlled by controlling the electric current, thereby moving a rod connected to the movable iron core and controlling a valve accordingly.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In recent years, there has also been a demand for cost reduction in solenoids. In the example of Patent Document 1, the fixed magnetic pole and the flange portion are integrally formed, and after assembling the tube using the integrally formed body, the case is finally joined. However, when the present inventors reviewed the manufacturing process, it was found that it is easier to process the tube by separating the fixed magnetic pole and the flange portion of the integrally formed body and assembling the tube from the fixed magnetic pole without the flange portion, and it can be manufactured with high precision and low cost.

[0006] Furthermore, the present inventors considered integrally forming the flange portion and the case for further cost reduction and joining the tube to the integrally formed body. However, it was found that welding or adhesion cannot be employed during joining because there is an O-ring for preventing oil supplied from a hydraulic pump from entering the coil portion around the joining portion.

[0007] An object of the present invention is to provide a method for manufacturing a solenoid, a tool for manufacturing a solenoid, and a solenoid that can reduce the manufacturing cost.

Means for Solving the Problems

[0008] The method for manufacturing a solenoid according to the present invention includes a fixed magnetic pole made of a cylindrical member composed of a magnetic material, a rear magnetic pole made of a magnetic material arranged coaxially and axially separated from the fixed magnetic pole, and a tube having a non-magnetic pipe made of a non-magnetic material arranged coaxially with the fixed magnetic pole and connecting the fixed magnetic pole and the rear magnetic pole, a movable iron core housed in the tube and axially movable coaxially with the fixed magnetic pole, a case arranged with a gap from the outer peripheral surface of the tube and covering the tube, and a solenoid coil arranged in a gap between the outer peripheral surface of the tube and the inner peripheral surface of the case. The method for manufacturing a solenoid according to the present invention is characterized in that the case has a flange at a position facing the fixed magnetic pole, At least one of the fixed magnetic pole and the case has a ring-shaped stepped portion that protrudes toward the other and contacts the other. By axially pressing the vicinity of the contact surface of the stepped portion with the other with the tip of a cylindrical tool inserted into the gap between the outer peripheral surface of the tube and the inner peripheral surface of the case, A part of the contact surface of the stepped portion with the other is plastically deformed toward the other to form a plastically deformed portion, and the plastically deformed portion is bitten into the contact surface of the other with the stepped portion, thereby joining the tube and the case.

[0009] According to this configuration, since a flange is provided on the case and the case and the tube are joined, the manufacturing cost of the solenoid can be reduced. Further, since the case and the tube are joined by pressing, even if there is an O-ring around the joined portion, the adverse effect on the O-ring is small.

[0010] In the solenoid of the present invention, the fixed magnetic pole has the stepped portion, The stepped portion may be configured to be formed over the entire circumference on the contact surface with the case and include a circumferential groove into which an O-ring is fitted.

[0011] According to this configuration, a circumferential groove is formed on the outer peripheral surface of the stepped portion that protrudes radially outward from the fixed magnetic pole, and the circumferential groove can be easily formed by cutting.

[0012] In the solenoid of the present invention, the fixed magnetic pole may have the stepped portion, and the case may have a stepped portion facing the stepped portion.

[0013] According to this configuration, since the fixed magnetic pole and the case each have a stepped portion, the strength of both can be increased.

[0014] Further, the tool for manufacturing a solenoid of the present invention is a tool used in the above-described method for manufacturing a solenoid, The tip has a plurality of caulking blades arranged in the circumferential direction.

[0015] According to this configuration, since a plurality of plastic deformation portions are formed in the circumferential direction, the joining strength in the circumferential direction between the fixed magnet and the case can be increased.

[0016] In the solenoid manufacturing tool of the present invention, the cutting edge of the caulking blade may be configured to extend along the circumferential direction.

[0017] According to this configuration, since the plastic deformation portion occurs in the radial direction, the joining strength between the fixed magnet and the case in contact in the radial direction can be increased.

[0018] Further, the solenoid of the present invention includes a fixed magnet made of a cylindrical member made of a magnetic material, a rear magnet made of a magnetic material arranged coaxially with the fixed magnet and axially separated therefrom, and a non-magnetic pipe made of a non-magnetic material arranged coaxially with the fixed magnet and connecting the fixed magnet and the rear magnet, a movable iron core housed in the tube and axially movable coaxially with the fixed magnet, a case arranged with a gap from the outer peripheral surface of the tube and covering the tube, and a solenoid coil arranged in a gap between the outer peripheral surface of the tube and the inner peripheral surface of the case. The case has a flange at a position facing the fixed magnet. At least one of the fixed magnet and the case has a ring-shaped stepped portion that protrudes toward the other and contacts the other. The stepped portion has a plastic deformation portion formed by plastically deforming a part of the contact surface with the other toward the other. The tube and the case are joined by the plastic deformation portion biting into the contact surface with the stepped portion of the other.

[0019] According to this configuration, a flange is provided on the case, and since this case and the tube are joined, the manufacturing cost of the solenoid can be reduced. Further, since the case and the tube are joined by pressing, even if there is an O-ring around the joined portion, it will not adversely affect the O-ring.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Figure 3A

Figure 3B

Figure 3C

Figure 3D

Figure 3E

Figure 4

Figure 5

Figure 6A

Figure 6B

Figure 6C

Figure 7A

Figure 7B

Figure 7C

Figure 7D

Modes for Carrying Out the Invention

[0021] [Configuration of Solenoid] Hereinafter, an example of an embodiment of the solenoid of the present invention will be described with reference to the drawings.

[0022] FIG. 1 is a longitudinal sectional view showing an example of a solenoid. The solenoid 1 is arranged along the axis L. In the following description, the direction parallel to the axis L is referred to as the axial direction D1, the radial direction of the circle centered on the axis L is referred to as the radial direction D2, and the direction along the circle centered on the axis L is referred to as the circumferential direction D3. Also, the axial direction D1 may be defined with reference to the solenoid 1. For example, the direction in which the rod 51 moves away from the solenoid 1 is also referred to as the forward direction, and the direction in which the rod 51 approaches the solenoid 1 is also referred to as the rearward direction. That is, in each figure, among the axial directions D1, the arrow direction is also referred to as the forward direction, and among the axial directions D1, the direction opposite to the arrow direction is also referred to as the rearward direction.

[0023] The solenoid 1 includes a substantially cylindrical tube 2 centered on the axis L, a solenoid coil 3 arranged so as to surround the tube 2, and a case 4 arranged so as to surround the solenoid coil 3. A movable iron core 5 is accommodated inside the tube 2. The solenoid 1 is configured such that when an electric current is passed through the solenoid coil 3, the movable iron core 5 moves in the axial direction D1 while being guided by the inner peripheral surface of the tube 2.

[0024] The tube 2 has a fixed magnetic pole 21 made of a magnetic material, a rear magnetic pole 22 made of a magnetic material, and a non-magnetic pipe 23 made of a non-magnetic material. The fixed magnetic pole 21, the rear magnetic pole 22, and the non-magnetic pipe 23 are arranged coaxially with each other.

[0025] As the material of the fixed magnetic pole 21, carbon steel with a small carbon content is preferred, and generally, iron materials such as S10C can be used. The fixed magnetic pole 21 includes a fixed iron core 21a, a ring-shaped stepped portion 21b that protrudes radially outward in the radial direction D2 from the outer peripheral surface of the fixed iron core 21a, and a ring-shaped locking portion 21c that protrudes radially outward in the radial direction D2 from the outer peripheral surface of the stepped portion 21b. The fixed magnetic pole 21 is provided with a through hole 21d that penetrates the fixed iron core 21a along the axis L, and is a substantially cylindrical member as a whole. The stepped portion 21b is provided over the entire circumference at the front end of the fixed iron core 21a. The locking portion 21c is provided over the entire circumference at the front end of the stepped portion 21b.

[0026] The stepped portion 21b contacts the second stepped portion 4c (described later) of the case 4. Here, the contact between the stepped portion 21b and the second stepped portion 4c means that, in addition to the case where the gap between the outer peripheral surface of the stepped portion 21b and the inner peripheral surface of the second stepped portion 4c becomes completely zero, it includes the case where the gap between the outer peripheral surface of the stepped portion 21b and the inner peripheral surface of the second stepped portion 4c is sufficiently small, for example, the case where the gap between the two is 0.5 mm or less.

[0027] The stepped portion 21b has a plastic deformation portion 21e formed by plastic deformation toward the outside in the radial direction D2. The plastic deformation portion 21e bites into the inner peripheral surface of the second stepped portion 4c. Note that the reference numeral 21p (see FIG. 2) is a claw mark generated when forming the plastic deformation portion 21e by the manufacturing method described later.

[0028] In addition, the stepped portion 21b is provided with a circumferential groove 21f formed over the entire circumference on the outer peripheral surface. An O-ring 24 is fitted into the circumferential groove 21f. The O-ring 24 is for preventing oil supplied from a hydraulic pump (not shown) from entering the space where the solenoid coil 3 is disposed. The distance h21 from the rear end of the stepped portion 21b to the circumferential groove 21f is preferably equal to or greater than the axial movement amount of the cylindrical tool 9 in the axial direction D1 in the state shown in FIG. 3C described later. Specifically, it is preferably 1 mm or more, and more preferably 1.5 mm or more. If the distance h21 is less than 1.5 mm, there is a risk of adversely affecting the O-ring 24 when forming the plastic deformation portion 21e.

[0029] Further, the fixed magnetic pole 21 includes an annular portion 21g that projects rearward from the peripheral edge of the rear end of the fixed iron core 21a. The front portion of the movable iron core 5 is disposed inside the annular portion 21g.

[0030] Further, a first recess 21h is formed at the rear end of the outer peripheral surface of the fixed magnetic pole 21. The first recess 21h is formed over the entire circumference of the fixed magnetic pole 21, and the non-magnetic pipe 23 is fitted therein.

[0031] The rear magnetic pole 22 is disposed axially away from the fixed magnetic pole 21 in the axial direction D1. As the material of the rear magnetic pole 22, carbon steel with a small carbon content is preferable, and generally, iron materials such as S10C (carbon steel) can be used. The rear magnetic pole 22 includes a rear portion 22a that constitutes the rear portion of the tube 2, and a long cylindrical portion 22b that extends forward from the rear portion 22a. The outer peripheral surface of the long cylindrical portion 22b is flush with the outer peripheral surface of the rear portion 22a. The inner peripheral surface of the long cylindrical portion 22b contacts the outer peripheral surface of the movable iron core 5 and guides the movable iron core 5 in the axial direction D1.

[0032] The rear magnetic pole 22 includes a second recess 22c formed at the front end of the outer peripheral surface of the long cylindrical portion 22b. The second recess 22c is formed over the entire circumference of the rear magnetic pole 22, and the non-magnetic pipe 23 is fitted therein.

[0033] The rear magnetic pole 22 includes a screw hole 22d that penetrates the rear portion 22a. A screw 25 is inserted into the screw hole 22d. A spring (not shown) is inserted between the screw 25 and the movable iron core 5 such that both ends thereof contact the rear end of the movable iron core 5 and the tip of the screw 25, and the force for pressing the movable iron core 5 can be adjusted by the rotation of the spring and the screw 25. Thereby, the attracting force of the solenoid 1 can be adjusted. Note that the screw 25 is not necessarily provided, and if the screw 25 is not provided, the screw hole 22d does not necessarily need to be provided. Also, the aforementioned spring (not shown) is not necessarily provided.

[0034] As the material of the non-magnetic pipe 23, non-magnetic stainless steel such as SUS304 can be used. The non-magnetic pipe 23 is a cylindrical member, and both ends in the axial direction D1 are respectively fitted into the first concave portion 21h of the fixed magnetic pole 21 and the second concave portion 22c of the rear magnetic pole 22. The outer peripheral surface of the non-magnetic pipe 23 is flush with the outer peripheral surface of the fixed iron core 21a and the outer peripheral surface of the long cylindrical portion 22b.

[0035] The solenoid coil 3 includes a bobbin 31, a coil wire 32, and an exterior mold 33. The bobbin 31 has a main body portion formed in a substantially cylindrical shape and flanges formed at both ends in the axial direction D1 of the main body portion. The coil wire 32 is wound around the main body portion between the two flanges of the bobbin 31. A control device (not shown) is connected to the coil wire 32, and a controlled current flows through it. The exterior mold 33 houses the coil wire 32 together with the bobbin 31. A lid member 34 is provided at the rear end of the solenoid coil 3.

[0036] The case 4 includes a cylindrical case body 4a, a flange 4b formed at the front end of the case body 4a, a stepped portion 4c formed at the front end of the case body 4a and protruding radially inward in the direction D2 from the inner peripheral surface of the case body 4a, and a bent portion 4d protruding rearward from the peripheral edge portion at the rear end of the case body 4a. As the material of the case 4, carbon steel with a small carbon content is preferable, and generally, iron materials such as S10C (carbon steel) can be used.

[0037] The case body 4a covers the tube 2 via the solenoid coil 3. The flange 4b is integrally formed with the case body 4a, for example, by forging.

[0038] The stepped portion 4c is disposed to face the stepped portion 21b of the fixed magnetic pole 21. The rear end surface of the stepped portion 4c is substantially flush with the rear end surface of the stepped portion 21b. A locked portion 4e that is notched over the entire circumference is formed at the front end of the inner peripheral surface of the stepped portion 4c. The locked portion 4e is locked to the locking portion 21c of the fixed magnetic pole 21.

[0039] The bent portion 4d is bent inward in the radial direction D2 to fix the lid member 34. As a result, the solenoid coil 3 is sealed between the case 4 and the tube 2.

[0040] The movable iron core 5 is made of a magnetic material. As the material of the movable iron core 5, carbon steel with a small carbon content is preferable, and generally, iron materials such as S10C (carbon steel) can be used. Further, the outer peripheral surface of the movable iron core 5 may be coated with resin.

[0041] The movable iron core 5 is provided with a pin hole 5a extending rearward from the front end. The rear portion of the rod 51 is inserted into the pin hole 5a, and the movable iron core 5 and the rod 51 are integrated. As the movable iron core 5 moves in the axial direction D1, the rod 51 also moves in the axial direction D1, and the rod 51 presses a spool (not shown).

[0042] A spacer 52 is disposed on the front end surface of the movable iron core 5. The spacer 52 is sandwiched between the movable iron core 5 and the rod 51.

[0043] [Manufacturing Method of Solenoid] Next, the manufacturing method of the solenoid 1 will be described. FIGS. 3A to 3E are diagrams schematically showing the manufacturing process of the solenoid 1.

[0044] First, as shown in FIG. 3A, the tube 2 (including the movable iron core 5) and the case 4 are arranged on a press table (not shown) such that the first-stage portion 21b of the fixed magnetic pole 21 and the second-stage portion 4c of the case 4 are in contact with each other. As described above, the gap between the outer peripheral surface of the first-stage portion 21b and the inner peripheral surface of the second-stage portion 4c is set to 0.5 mm or less. The O-ring 24 is previously fitted in the circumferential groove 21f of the tube 2.

[0045] The position of the case 4 in the axial direction D1 with respect to the tube 2 is determined by the engagement of the engaged portion 4e of the case 4 with the engaging portion 21c of the fixed magnetic pole 21. The rear end surfaces of the first-stage portion 21b and the second-stage portion 4c are substantially flush.

[0046] There is a gap between the outer peripheral surface of the tube 2 and the inner peripheral surface of the case 4 into which the solenoid coil 3 is inserted in a subsequent process. Note that at the stage of FIG. 3A, the plastic deformation portion 21e is not formed on the first stepped portion 21b of the tube 2. Also, at the stage of FIG. 3A, the bent portion 4d of the case 4 is not bent inward in the radial direction D2.

[0047] Next, as shown in FIG. 3B, a cylindrical tool 9 (see FIG. 4, details of which will be described later) is inserted in the axial direction D1 into the gap between the outer peripheral surface of the tube 2 and the inner peripheral surface of the case 4 until the caulking blade 91 provided at the tip contacts the rear end surface of the first stepped portion 21b. The position where the cutting edge 91a of the caulking blade 91 contacts the first stepped portion 21b is in the vicinity of the outer peripheral surface (contact surface with the second stepped portion 4c) of the first stepped portion 21b, and specifically, it is preferably at a position 0.1 to 0.5 mm radially inward of the outer peripheral surface of the first stepped portion 21b, and more preferably at a position 0.2 to 0.4 mm.

[0048] Next, the cylindrical tool 9 is moved in the axial direction D1 and pressed in the axial direction D1 to the position shown in FIG. 3C. Note that the process from FIG. 3A to FIG. 3B and the process from FIG. 3B to FIG. 3C may be executed continuously. The press depth, that is, the amount of movement of the cylindrical tool 9 in the axial direction D1 from the state shown in FIG. 3B to the state shown in FIG. 3C, depends on the size of the solenoid 1, but is preferably about 1 to 1.5 mm.

[0049] FIG. 3D shows a state in which the cylindrical tool 9 has been retracted after the pressing process shown in FIG. 3C. By performing the pressing process, as shown in FIG. 3D, a plastic deformation portion 21e that is plastically deformed outward in the radial direction D2 is formed on the outer peripheral surface of the first stepped portion 21b, and this plastic deformation portion 21e bites into the inner peripheral surface of the second stepped portion 4c. Thereby, the tube 2 and the case 4 are joined. Also, a claw mark 21p by the caulking blade 91 remains on the rear end surface of the first stepped portion 21b.

[0050] Note that after the pressing process shown in Fig. 3C, the cylindrical tool 9 may be retracted once and then rotated by a predetermined angle (22.5° in the case of the cylindrical tool 9 shown in Fig. 4) around the axis L, and the pressing process may be performed again. As will be described later, a plurality of caulking blades 91 are arranged along the circumferential direction D3 at the tip of the cylindrical tool 9. By rotating the cylindrical tool 9 and pressing it multiple times, many locations can be caulked, increasing the joint strength. Also, since it is possible to press at a lower pressure than pressing many locations at once, the adverse effect of pressing on the O-ring 24 is small.

[0051] Finally, the solenoid coil 3 (including the lid member 34) is inserted into the gap between the outer peripheral surface of the tube 2 and the inner peripheral surface of the case 4, and the bent portion 4d of the case 4 is bent radially inward in the direction D2 to seal the solenoid coil 3 as shown in Fig. 3E.

[0052] [Configuration of the cylindrical tool] Fig. 4 is a front view and a side view of the cylindrical tool 9. The material of the cylindrical tool 9 is preferably a hard and tough material, for example, SKD11 (quenched steel) is used. The cylindrical tool 9 has a cylindrical tool body 90 and a plurality of caulking blades 91 provided at the tip 90a of the tool body 90. The caulking blade 91 of the present embodiment has a substantially triangular prism shape.

[0053] Preferably, 4 to 16 caulking blades 91 are provided along the circumferential direction D3. Also, the plurality of caulking blades 91 are preferably arranged at equal intervals along the circumferential direction D3. In the example shown in Fig. 4, 8 caulking blades 91 are provided at equal intervals along the circumferential direction D3. The cutting edge 91a of the caulking blade 91 extends along the circumferential direction D3.

[0054] The caulking blade 91 is provided within a range of an angle θ1 around the axis L. The angle θ1 is preferably 10 to 15°. If the angle θ1 is less than 10°, the width of the caulking blade 91 in the circumferential direction D3 becomes small, and it is difficult to obtain sufficient joint strength. Also, if the angle θ1 is greater than 15°, it becomes difficult to provide a plurality of caulking blades 91 along the circumferential direction D3.

[0055] FIG. 5 is an enlarged cross-sectional view of a main part taken along line V-V of the cylindrical tool 9 shown in FIG. 4. The caulking blade 91 has an inner surface 91b on the inner side in the radial direction D2 and an outer surface 91c on the outer side in the radial direction D2. The line where the inner surface 91b and the outer surface 91c intersect is the cutting edge 91a. The inner surface 91b is inclined at an angle θ2 with respect to the axial direction D1. The angle θ2 is preferably 10 to 30°. On the other hand, the outer surface 91c is inclined at an angle θ3 with respect to the axial direction D1. The angle θ3 is preferably 30 to 40°.

[0056] Note that the solenoid 1, the manufacturing method of the solenoid 1, and the cylindrical tool 9 are not limited to the configurations of the above-described embodiments, nor are they limited to the above-described operational effects. Also, the solenoid 1, the manufacturing method of the solenoid 1, and the cylindrical tool 9 can of course be variously modified without departing from the gist of the present invention. For example, each configuration and each method of the above-described plurality of embodiments may be arbitrarily adopted and combined, and further, one or more of the configurations and methods according to the following various modification examples may be arbitrarily selected and adopted in the configurations and methods according to the above-described embodiments.

[0057] (1) In the solenoid 1 according to the above-described embodiment, the fixed magnetic pole 21 has a stepped portion 21b, and the case 4 has a stepped portion 4c facing the stepped portion 21b. However, the solenoid 1 is not limited to such a configuration. The case 4 may have a stepped portion, and the fixed magnetic pole 21 may have a stepped portion. At this time, as shown in FIG. 6A, by pressing the vicinity of the contact surface of the stepped portion of the case 4 (the stepped portion 4c in the above-described embodiment) with the fixed magnetic pole 21 in the axial direction D1 with the tip of the cylindrical tool 9, a part of the contact surface between the stepped portion (the stepped portion 4c in the above-described embodiment) and the stepped portion (the stepped portion 21b in the above-described embodiment) is plastically deformed toward the fixed magnetic pole 21 to form a plastically deformed portion 4f, and the plastically deformed portion 4f is made to bite into the contact surface of the fixed magnetic pole 21 with the stepped portion (the stepped portion 4c in the present embodiment), which may also be the configuration.

[0058] (2) In the solenoid 1 according to the above embodiment, the fixed magnetic pole 21 has the stepped portion 21b, and the case 4 has the stepped portion 4c facing the stepped portion 21b. However, the solenoid 1 is not limited to such a configuration. For example, as shown in FIG. 6B, the case 4 may not have the stepped portion. At this time, the plastic deformation portion 21e bites into the case body 4a of the case 4.

[0059] Also, as shown in FIG. 6C, the fixed magnetic pole 21 may not have the stepped portion 21b. At this time, the stepped portion 4c is plastically deformed toward the fixed magnetic pole 21 to form the plastic deformation portion 4f, and the plastic deformation portion 4f bites into the fixed iron core 21a of the fixed magnetic pole 21.

[0060] (3) In the solenoid 1 according to the above embodiment, the fixed magnetic pole 21 has the stepped portion 21b, and the stepped portion 21b is formed over the entire circumference on the contact surface with the case 4 (the outer peripheral surface of the stepped portion 21b) and includes the circumferential groove 21f into which the O-ring 24 is fitted. However, the solenoid 1 is not limited to such a configuration. A configuration in which the stepped portion 4c of the case 4 is formed over the entire circumference on the contact surface with the fixed magnetic pole 21 and includes the circumferential groove into which the O-ring 24 is fitted may also be used. However, considering the ease of processing, it is preferable to form the circumferential groove 21f on the contact surface of the stepped portion 21b with the case 4 (the outer peripheral surface of the stepped portion 21b).

[0061] (4) In the cylindrical tool 9 according to the above-described embodiment, eight caulking blades 91 having a substantially triangular prism shape are provided at equal intervals along the circumferential direction D3. However, the cylindrical tool 9 is not limited to such a configuration. FIGS. 7A to 7D are front views and side views of a cylindrical tool 9 according to another embodiment. In the example shown in FIG. 7A, the caulking blade 91 has a cylindrical shape with a rounded tip. In the example shown in FIG. 7B, the caulking blade 91 has a substantially quadrangular pyramid shape. In the example shown in FIG. 7C, the caulking blade 91 has a substantially triangular prism shape, but the cutting edge 91a extends along the radial direction D2. However, when the cutting edge 91a extends along the radial direction D2, since the plastic deformation portion mainly occurs in the circumferential direction D3, the strength of joining the tube 2 and the case 4 in contact with the radial direction D2 tends to be weakened. In the example shown in FIG. 7D, sixteen caulking blades 91 having a substantially triangular prism shape are provided at equal intervals along the circumferential direction D3.

[0062] (5) In the cylindrical tool 9 according to the above-described embodiment, the configuration is such that the tip 90a has a plurality of caulking blades 91 arranged in the circumferential direction D3. However, the cylindrical tool 9 is not limited to such a configuration. The cylindrical tool 9 may have a configuration in which the tip 90a has a caulking blade 91 that is continuous over the entire circumference. In this case, the joining strength in the axial direction D1 of the tube 2 and the case 4 can be obtained, but the joining strength in the circumferential direction D3 is difficult to obtain. Therefore, preferably, the cylindrical tool 9 has a plurality of caulking blades 91 arranged in the circumferential direction D3 at the tip 90a.

Description of Reference Numerals

[0063] 1... solenoid, 2... tube, 3... solenoid coil, 4... case, 4a... case body, 4b... flange, 4c... stepped portion, 4d... bent portion, 4e... engaged portion, 4f... plastically deformed portion, 5... movable iron core, 5a... pin hole, 9... cylindrical tool, 21... fixed pole, 21a... fixed iron core, 21b... stepped portion, 21c... locking portion, 21d... through hole, 21e... plastically deformed portion, 21f... circumferential groove, 21g... annular portion, 21h... first recess, 21p... claw mark, 22... rear pole, 22a... rear portion, 22b... long cylindrical portion, 22c... second recess, 22d... screw hole, 23... non-magnetic pipe, 24... O-ring, 25... screw, 31... bobbin, 32... coil wire, 33... exterior mold, 34... lid member, 51... rod, 52... spacer, 90... tool body, 90a... tip, 91... caulking blade, 91a... cutting edge, 91b... inner surface, 91c... outer surface, D1... axial direction, D2... radial direction, D3... circumferential direction, L... axis

Claims

1. A fixed magnetic pole composed of a cylindrical member made of a magnetic material, a rear magnetic pole composed of a magnetic material arranged coaxially with and axially separated from the fixed magnetic pole, and a non-magnetic pipe made of a non-magnetic material arranged coaxially with the fixed magnetic pole and connecting the fixed magnetic pole and the rear magnetic pole, a tube having the non-magnetic pipe, a movable iron core housed in the tube and axially movable coaxially with the fixed magnetic pole, a case arranged with a gap from the outer peripheral surface of the tube and covering the tube, and a solenoid coil arranged in a gap between the outer peripheral surface of the tube and the inner peripheral surface of the case, and a method for manufacturing a solenoid, wherein the case has a flange at a position facing the fixed magnetic pole, at least one of the fixed magnetic pole and the case has a ring-shaped stepped portion protruding toward the other and contacting the other, by axially pressing the vicinity of the contact surface with the other of the stepped portion with the tip of a cylindrical tool inserted into the gap between the outer peripheral surface of the tube and the inner peripheral surface of the case, a part of the contact surface of the stepped portion with the other is plastically deformed toward the other to form a plastically deformed portion, and the plastically deformed portion is bitten into the contact surface of the other with the stepped portion, thereby joining the tube and the case, a method for manufacturing a solenoid.

2. the fixed magnetic pole has the stepped portion, the stepped portion is formed over the entire circumference on the contact surface with the case and has a circumferential groove into which an O-ring is fitted, the method for manufacturing a solenoid according to Claim 1.

3. the fixed magnetic pole has the stepped portion, and the case has a stepped portion facing the stepped portion, the method for manufacturing a solenoid according to Claim 1 or 2.

4. A tool used in the method for manufacturing a solenoid according to any one of Claims 1 to 3, a tool for manufacturing a solenoid having a plurality of caulking blades arranged in the circumferential direction at the tip.

5. the cutting edge of the caulking blade extends along the circumferential direction, the tool for manufacturing a solenoid according to Claim 4.

6. A fixed magnet pole composed of a cylindrical member made of a magnetic material, a rear magnet pole composed of a magnetic material arranged coaxially with and axially separated from the fixed magnet pole, and a tube having a non-magnetic pipe made of a non-magnetic material arranged coaxially with the fixed magnet pole and connecting the fixed magnet pole and the rear magnet pole, A movable iron core housed in the tube and axially movable coaxially with the fixed magnet pole, A case arranged with a gap from the outer peripheral surface of the tube and covering the tube, A solenoid coil arranged in a gap between the outer peripheral surface of the tube and the inner peripheral surface of the case, and comprising, The case has a flange at a position facing the fixed magnet pole, At least one of the fixed magnet pole and the case has a ring-shaped stepped portion that projects toward the other and contacts the other, The stepped portion has a plastic deformation portion formed by plastically deforming a part of the contact surface with the other toward the other, A solenoid in which the tube and the case are joined by the plastic deformation portion biting into the contact surface with the stepped portion of the other.

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