JPH1167531A - Solenoid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solenoid, the cost of which can be reduced by improving a fixing means which fixes a soil ass'y to a tube ass'y and a magnetic circuit. SOLUTION: A solenoid 1 has an outer case 3, a coil ass'y 5 housed in the case 3, and a tube ass'y 9 passed through the coil ass'y 5. The coil ass'y 5 has a hollow bobbin 6 and a coil 7 wound around the bobbin 6, and the tube ass'y 9 has a fixed core 10 provided on the backside, a movable coreholding body 14 which holds a movable core 12 in a slidable state, and a pipe which integrally fixes the fixed core 10 and the movable core holding body 14 to each other. The rear section of the fixed core 10 is protruded backwards from the case 3 and has a threaded part 10d. When the coil 7 is excited after a nut 19 is engaged with the thread part 10d until the nut 19 comes into contact with the rear wall 3b of the case and the bobbin 6 is positioned until the rear coil housing wall 6b of the bobbin 6 comes into contact with the rear wall 3b of the case 3, magnetic flux is generated through the case 3, the nut 19, and the 10 and 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid having a fixed core and a movable core, the movable core being attracted and moved to the fixed core by excitation of a coil. Further, the solenoid is arranged behind the movable core. The present invention relates to a solenoid in which a movable pin is disposed on a side opposite to a suction surface of a movable core, and the movable pin pulls a spool or the like of a hydraulic valve body when the movable core is attracted to a fixed core.

[0002]

2. Description of the Related Art Generally, in a solenoid that has a fixed iron core and a movable iron core and slides so that the movable iron core approaches and separates from the fixed iron core, for example, a spool of a hydraulic valve is moved, the movable iron core is fixed. There are known a push type in which a spool connected to a movable pin of a movable core is moved when attracting the core, and a pull type in which the spool is pulled and moved. In general, a push-type solenoid is configured such that a movable iron core is arranged behind a fixed iron core, a movable pin is arranged on a suction surface side of the movable iron core, and is inserted through the fixed iron core and connected to a spool. In general, a pull-type solenoid is configured such that a fixed iron core is arranged behind a movable iron core, and a movable pin is arranged on a side of the movable iron core facing an attraction surface, and is connected to a spool.

A conventional general pull type solenoid 2
1 is an outer case 23 and an outer case 2 as shown in FIG.
Coil assembly 25 and yoke 28 arranged in 3
And a tube assembly 29 housed in the coil assembly 25. The outer case 23 is formed to have a substantially U-shaped cross section of a magnetic body, and a hole 23a through which the tube assembly 29 is inserted is formed in the rear end surface.

The coil assembly 25 is a hollow bobbin 26
And a coil 27 wound around the bobbin 26, and the tube assembly 29 is inserted into the hollow bobbin 26.

[0005] The tube assembly 29 includes a fixed iron core 30.
And a movable core holding member 3 for accommodating the movable core 32 therein.
4 and a non-magnetic pipe 36 that integrally connects the fixed core 32 and the movable core holding member 34. The fixed iron core 30 fits into the bobbin 26, and a rear portion protrudes from the outer case 23.
is formed, and the nut 37 is screwed.

The movable iron core holding member 34 has a movable iron core 32 slidably disposed therein and an outer peripheral surface fitted into the bobbin 26. The movable core holding member 34 includes the bobbin 2
6 is formed with a flange portion 34a for pressing the coil housing wall 26a formed on the front end surface from the front side. The movable iron core 32 has a movable pin 33 on the anti-adsorption side and slides inside the movable iron core holding member 34, and the movable pin 33 is connected to a spool (not shown).

A pipe 36 is fitted so as to suspend the front end of the fixed iron core 30 and the rear end of the movable iron core holding member 34, and the tube assembly 29 is integrated by welding both ends of the pipe 36. It is composed.

The thus constructed tube assembly 2
9 is inserted from the distal end side of the coil assembly 25 to a position where the flange portion 34a of the movable core holding member 34 contacts the coil storage wall 26a at the distal end of the bobbin 26. Then, the male screw portion 30a of the fixed iron core 30 protruding from the outer case 23
Then, the tube assembly 29 and the coil assembly 25 are fixed by inserting a cylindrical collar 38 made of a non-magnetic material and screwing it with a nut 37. The excitation of the coil 27 causes the outer case 23 and the yoke 2
8, since a magnetic flux is generated between the fixed core 30 and the movable core 32, the movable core 32 is attracted to the fixed core 30.

[0009]

However, when price competition intensifies, it is necessary to reduce the cost of the solenoid, and the structure or each component must be reviewed. In particular, in the solenoid 21 described above, the coil assembly 25 and the tube assembly 29 are fixed by screwing a nut 37 to a male screw 30a formed in the fixed iron core 30,
This has been performed by interposing a collar 38 between the nut 37 and the outer case 23. The outer case 23 is made of a magnetic iron, and the collar 38 is generally a resin pipe. Since the nut 37 has a small thickness with respect to the screw diameter, it has been manufactured as a dedicated nut by machining. Therefore, it has been desired to reduce the cost by improving the means for fixing the coil assembly 25 and the tube assembly 29.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems. By improving means for fixing a coil assembly and a tube assembly, it is possible to reduce the number of collar parts and to provide a nut at a low cost. It is an object of the present invention to provide a solenoid that can reduce the number of yokes by also using a magnetic circuit, thereby reducing costs.

[0011]

Means for Solving the Problems A solenoid according to the present invention is configured as follows to solve the above-mentioned problems. That is, a magnetic outer case having a rear wall at a rear end, a hollow coil assembly housed in the outer case and having a bobbin and a coil, a fixed iron core, and a movable iron core approaching and separating from the fixed iron core. And a tube assembly that supports a front end surface of the coil assembly and is disposed so as to pass through the coil assembly, and the fixed core is disposed behind the movable iron core, A solenoid configured to have a screw portion projecting rearward from the outer case and the coil assembly, and a nut is screwed to the screw portion to fix the coil assembly and the tube assembly, and the bobbin is A coil storage wall for storing a coil is provided at both front and rear ends, and the coil storage wall behind the bobbin is arranged so as to abut against a rear wall of the outer case. Together with the nut is formed of a magnetic material so as to constitute a magnetic circuit, it is characterized in being disposed so as to abut against the rear wall of the outer casing.

Preferably, the tube assembly has a movable core holding member in which the movable core is slidably disposed, and the fixed core and the movable core holding member are integrally connected by a pipe. And a flange portion for supporting the front end surface of the bobbin.

Further, the tube assembly has a pipe in which the movable iron core is slidably disposed inside, and one end of the pipe is fixed to the fixed iron core, and the other end supports a front end face of the bobbin. It may have a flange portion.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the solenoid 1 of this embodiment has an outer case 3, a hollow coil assembly 5 housed in the outer case 3, and a tube assembly 9 inserted into the coil assembly 5. The coil assembly 5 and the tube assembly 9 are fixed by a nut 19 so as to be pressed against the rear end of the outer case 3.

The outer case 3 is formed of a magnetic material, and has a rear wall 3b having a hole 3a through which a tube assembly 9 is inserted at a rear end (upper in FIG. 1) and a rear end (upper in FIG. 1). ing.

The coil assembly 5 comprises a hollow bobbin 6 and a coil 7 wound around the bobbin 6,
The tube assembly 9 is inserted into the bobbin 6. The bobbin 6 is housed in the outer case 3, and coil housing walls 6 a and 6 b for housing the coil 7 are formed at both front and rear ends.
The rear coil housing wall 6b is disposed so as to abut the rear wall 3b of the outer case 3.

The tube assembly 9 includes a fixed iron core 10 and
A movable core holding member for movably disposing the movable core therein; and a distal end portion of the fixed core and a rear end portion of the movable core holding member are formed of a cylindrical non-magnetic material. It is fixed with a pipe 18. The fixed iron core 10 includes a fitting portion 10 a fitted into the coil assembly 5 and a screw portion 10 d projecting outward from the coil assembly 5.
a is formed in a large diameter portion 10b fitted in the bobbin 6 and a small diameter portion 10c fitted in the pipe 18, and the outer diameter of the pipe 18 fitted in the small diameter portion 10c is equal to the outer diameter of the large diameter portion 10b. The bobbin 6 is fitted into the bobbin 6 with substantially the same diameter.

The movable core holding member 14 includes a fitting portion 15 fitted into the coil assembly 5 and the coil housing wall 6 of the bobbin 6.
a is formed from a flange portion 16 which presses a from the front end side and a connecting portion 17 which is connected to the valve body B at the front end portion, and a through hole 14a in which the movable iron core 12 is slidably disposed is formed therein. The fitting portion 15 is a large-diameter portion 15 fitted into the bobbin 6.
a and a small-diameter portion 15b fitted into the pipe 18, and the outer diameter of the pipe 18 fitted to the small-diameter portion 15b is fitted into the bobbin 6 with substantially the same diameter as the outer diameter of the large-diameter portion 15a. . A male screw 17a is formed on the outer peripheral surface of the connecting portion 17,
The solenoid 1 is attached to the valve body by screwing it to the valve body B.

The movable iron core 12 slides inside the movable iron core holding member 14, and the rear end face of the movable iron core 12 is formed in a planar shape as a suction surface, and is arranged to face the fixed iron core 10. A movable pin 13 having a smaller diameter than the movable core 12 is fixed to the non-adsorption side of the movable core 12, and the movable pin 13 is connected to a spool (not shown) of the valve body B.

The pipe 18 is a small-diameter portion 10 of the fixed iron core 10.
The fixed core 10 and the movable core holding member 14 are integrated by forming the tube assembly 9 by fitting the fixed core 10 and the movable core holding member 14 together with the small-diameter portion 15b of the movable core holding member 14 and fixing the respective ends by welding. ing.

A commercially available nut 19 (magnetic material) is screwed into the screw portion 10 d of the fixed iron core 10, and the nut 19 is tightened until the nut 19 is pressed against the rear surface of the rear wall 3 b of the outer case 3. The tube assembly 9 is fixed.

The solenoid 1 is configured by housing the coil assembly 5 configured as described above from the front side of the outer case 3, inserting the tube assembly 9 from the front end side of the coil assembly 5, and tightening with the nut 19. Be composed. At this time, the front end face of the outer case 3 is located at substantially the same position as the front end face of the flange portion 16 of the movable core holding member 14 and is attached to the mounting surface of the valve body B.

In the solenoid 1 configured as described above,
When the coil 7 is excited, as shown in FIG.
A magnetic flux is generated in the nut 19, the fixed core 10, and the movable core 12 to form a magnetic circuit, so that the movable core 12 slides in the movable core holding member 14 and is attracted to the fixed core 10.
Simultaneously, the movable pin 13 disposed at the front end of the movable iron core moves rearward, whereby the spool in the valve body B connected to the movable pin 13 is pulled and moved, releasing the oil flow path and releasing the hydraulic pressure. To move.

When the excitation of the coil 7 is released,
Outer case 3, nut 19, fixed core 10, movable core 19
Is demagnetized and the magnetic path disappears. Thereby, the movable iron core 12 is released from being attracted to the fixed iron core 10, and is returned by a spring (not shown). At the same time, the spool connected to the movable pin 13 also returns, and the movement of the hydraulic pressure is stopped by closing the opened flow path.

Therefore, the solenoid 1 can eliminate the collar and the yoke as compared with the conventional solenoid, so that the cost can be reduced. In addition, if the total length of the coil assembly is increased by the amount corresponding to the removal of the yoke, the suction force can be improved accordingly. Further, if the size of the solenoid is reduced by the amount of the yoke, the size of the solenoid can be reduced.

The solenoid of the present invention is not limited to the above, but may include other forms. For example, as shown in FIG. 3, a flange portion may be provided on the distal end surface of the outer case and attached to the valve body to change the configuration of the tube assembly.

The solenoid 41 has a flange portion 43c for attaching to the valve body B on the front end surface of the outer case 43.
Is formed, and the coil assembly 45 is housed inside. A rear wall 4 having a hole 43a is provided on the rear end surface of the outer case 43.
3b is formed, and the fixed core 50 of the tube assembly 49 is inserted. The coil assembly 45 includes a bobbin 46 and a coil 47 as described above.
The coil housing walls 46a and 46b for housing the coil 7 are formed.

A fixed iron core 50 similar to that described above is disposed on the rear end side of the tube assembly 49, and one end of a pipe 58 is fitted and fixed to a small diameter portion 50c of a fitting portion 50a of the fixed iron core inserted into the bobbin 46. The other end of the pipe 58 extends to the distal end surface of the bobbin 46, and a flange portion 58a for pressing the distal end surface of the coil housing wall 46a rearward is formed outward. The movable iron core 52 is slidably disposed in the pipe 58, the suction surface is formed in a flat shape so as to face the fixed iron core 50, and the movable pin 53 is disposed on the non-adsorption side, and the distal end thereof is mounted on a spool (not shown). It is connected.

The rear end of the fixed core 50 protrudes outward from the rear wall 43b of the outer case 43 to form a screw portion 50d, and a nut 57 is screwed to the screw portion 50d. Nut 57
Is screwed into the screw portion 50d to form a rear wall 43b of the outer case 43.
It is arranged so that it may contact. Therefore, when the coil 47 is excited, the outer case 43, the nut 57, the fixed core 5
0. Magnetic flux is generated in the movable core 52, and the movable core 52 is attracted to the fixed core 50. Therefore, in this embodiment, not only the movable core holding member can be omitted and the cost can be further reduced, but also the suction surface of the movable core can be formed wider, so that the suction force can be improved.

[0031]

According to the present invention, a solenoid comprises a magnetic outer case having a rear wall at a rear end, a hollow coil assembly housed in the outer case having a bobbin and a coil, and a fixed iron core. And a movable core that approaches and separates from the fixed core, and a tube assembly that supports a front end surface of the coil assembly and is arranged to pass through the coil assembly. The fixed iron core is disposed behind the movable iron core, and has a screw portion protruding rearward from the outer case and the coil assembly. A nut is screwed to the screw portion, and the coil assembly and the tube are mounted. It is configured to fix the assembly. Further, the bobbin has a coil housing wall for housing a coil at both front and rear ends, and a coil housing wall behind the bobbin is arranged so as to abut against a rear wall of the outer case, and the nut forms a magnetic circuit. And is arranged so as to abut the rear wall of the outer case. Therefore, the conventional collar can be omitted, and a magnetic circuit is formed in the outer case, the nut, the fixed iron core, and the movable iron core. Therefore, the conventional yoke can be omitted, and the cost can be reduced.

Further, in this solenoid, if the movable core is housed through a movable core holder, the movable core holder can be attached to a valve body, and the inside of a pipe connecting the movable core to the fixed core is provided. , The outer case can be provided with a flange portion and attached to the valve body.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a solenoid according to one embodiment of the present invention.

FIG. 2 is a diagram showing a magnetic circuit of FIG. 1;

FIG. 3 is a cross-sectional view showing a solenoid according to another embodiment of the present invention.

FIG. 4 is a sectional view showing a conventional solenoid.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Solenoid 3 ... Outer case 3b ... Rear wall 5 ... Coil assembly 6 ... Bobbin 6a / 6b ... Coil storage wall 7 ... Coil 9 ... Tube assembly 10 ... Fixed iron core 10d ... Screw part 12 ... Movable iron core 13 ... Movable pin 14 ... Movable iron core holding member 16 ... Flange part 18 ... Pipe 19 ... Nut B ... Valve

Claims (3)

[Claims] An outer case made of a magnetic material having a rear wall at a rear end; a hollow coil assembly housed in the outer case having a bobbin and a coil; a fixed core and a distance from and away from the fixed core; And a tube assembly that supports the front end face of the coil assembly and is disposed so as to pass through the coil assembly.The fixed core is disposed behind the movable core. A solenoid configured to have a screw portion projecting rearward from the outer case and the coil assembly, and a nut is screwed to the screw portion to fix the coil assembly and the tube assembly, The bobbin has a coil storage wall for storing a coil at both front and rear ends, such that a coil storage wall behind the bobbin abuts on a rear wall of the outer case. Is location, solenoid the nut while being formed of a magnetic material so as to constitute a magnetic circuit, characterized in that it is arranged so as to abut against the rear wall of the outer casing. 2. The tube assembly has a movable core holder for slidably arranging the movable core therein, and connects the fixed core and the movable core holder integrally by a pipe. 2. The solenoid according to claim 1, further comprising a flange portion for supporting a front end surface of the bobbin. 3. The tube assembly has a pipe in which the movable core is slidably disposed inside, and one end of the pipe is fixed to the fixed core, and the other end supports a front end face of the bobbin. The solenoid according to claim 1, further comprising a flange portion.