JP2001124227A - Solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solenoid valve with reduced overall length by integratedly fixing a pilot spool housing to a solenoid by an easy and reliable assembling method. SOLUTION: In the solenoid valve for control the hydraulic pressure generating the electromagnetic force in a moving core when a coil is energized to move a pilot spool in the pilot spool housing by a shaft to change the hydraulic pressure, a recessed part is provided in a solenoid case, a circumferential groove is provided in an inner wall of the recessed part to fix the solenoid case to the pilot spool housing, an O-ring is disposed in the circumferential groove, and the pilot spool housing is tightened to the solenoid case in the recessed part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for mounting a pilot spool of a hydraulic solenoid and a reduction in size.

[0002]

2. Description of the Related Art When a pilot spool is mounted on a solenoid, as shown in FIG.
A screw groove 10 was provided inside 9, and a screw thread 11 was formed in the housing 7 of the pilot spool and tightened. However, in this method, it takes time and effort to cut the screw groove 10,
Due to high costs, manufacturing itself was not easy.

Further, since the screwing portion 9 is provided so as to protrude outside the solenoid case 1, the total length of the solenoid valve after assembly has been long. In order to shorten the overall length, there is a method of shortening the overall length of the solenoid body.However, since the overall length of the coil 3 is shortened, the number of turns of the coil has to be reduced, and the drawback that the suction force characteristic is reduced accordingly. Had.

Therefore, an improved example 1 is shown in FIG. Improvement example 1
The solenoid case 1 has a built-in solenoid magnetic circuit, and a recess 14 is provided near the mouth in such a manner that the inside of the solenoid case 1 is dug down. As a mounting method, the pilot spool housing 7 was pressed into the recess 14. The structure shown in FIG. 4 has a relatively short overall length because the recess 14 is provided inside the solenoid case. Therefore, the problem of shortening the overall length without lowering the suction force characteristics was solved. However, at the time of mounting, the inner wall of the concave portion 14 is cut off due to friction, and contaminants (shavings) are generated. If the contaminants enter the fluid passage of the solenoid, the flow of the fluid is obstructed, and the operation of the solenoid is stopped. Was adversely affected.

[Problems to be solved by the invention]

An object of the present invention is to provide a solenoid valve in which a pilot spool can be easily mounted without increasing the size of the solenoid, and which has high reliability.

[0006]

As shown in the embodiment of the present invention shown in FIG. 1, the invention according to claim 1 has a shape in which the inside of the solenoid case 1 is dug in the vicinity of the mouth, and the recess 14 and the inner wall of the recess 14 have a circular shape. The pilot spool housing 7 was fitted into the solenoid case 1 after the groove 17 was provided and the O-ring 15 was arranged in the circumferential groove 17.

As shown in FIG. 2, the pilot spool housing 7 is provided with a hook-shaped projection 16 at the tip thereof, and the hook-shaped projection 16 is hooked on the O-ring 15 to thereby provide a pilot spool. housing
The pilot spool housing 7 was prevented from falling off the solenoid case 1 after the solenoid case 7 was fastened to the solenoid case 1.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the present invention, in which a solenoid case 1 has a built-in solenoidal magnetic circuit, and has a concave portion 14 and a circumferential groove formed in the inner wall of the concave portion 14 in the shape of digging the inside of the solenoid case 1 near the mouth. 17 were provided.
FIG. 2 is an enlarged view of the tip of the pilot spool housing 7. A hook-shaped projection 16 is provided at the tip of the pilot spool housing 7. When attaching the pilot spool housing 7 to the solenoid case 1, an O-ring 15 is arranged in the circumferential groove 17, and the pilot spool housing 7 is fitted to the solenoid case 1. The hook-shaped projection 16 has a slanted tip so that it can be easily fitted. Further, since the hook-shaped projection 16 has a key-shaped tip, the O-ring 1
Once in 5, it is designed so that it does not come off when pulled. In this way, a firm fixation can be obtained reliably. Further, since the fixing position using the O-ring 15 is provided as a concave portion so as to enter the inside of the solenoid case 1, the total length of the solenoid valve can be shortened. Further, since an O-ring is used for the fastening, the inner wall of the concave portion 14 is not shaved and no contamination occurs.

Next, the operation of the solenoid valve of the present invention will be described.
Explanation will be made based on 1. The movable iron core 4 is fastened to the shaft 6 by caulking or the like. A current is supplied to the lead wire 12 from an electronic control unit (not shown), and the current is sent to the coil 3 so that the coil 3 generates an electromagnetic force. With this electromagnetic force, the solenoid case 1 forms an electromagnetic circuit, a force is generated in the movable iron core 4 through the end cap 2 and the fixed iron core 5, and the movable iron core 4 and the shaft integrally fixed to the movable iron core 4
6, and pilot spool 8 pressed by shaft 6
Is sucked against the urging force of the spring 13, and the movable iron core
4 is adsorbed on the fixed iron core 5. The movable iron core 4, the shaft 6, and the pilot spool 8 pressed by the shaft 6 stagnate at this suction position due to the electromagnetic force of the coil 3.

When the supply of electric current to the coil 3 is stopped by turning off the energization and the electromagnetic force stops acting, the shaft 6 returns to the position before the energization by the urging force of the spring 13, and the end cap 2 is connected to the end cap 2. Abut At this time, the pilot spool 8 also returns to the position before energization. During this series of operations, the fluid passes through the hole 18 and is jetted to a manifold (not shown) until the movable iron core 4 is adsorbed by the fixed iron core 5 and returns to the original position before energization.

[0011]

As described above, according to the present invention, there is provided a solenoid valve which does not increase the total length of the solenoid, has high reliability free from occurrence of defects due to contamination, and is easy to mount. Yes, with great industrial applicability.

[Brief description of the drawings]

FIG. 1 is a sectional view of a solenoid valve of the present invention.

FIG. 2 is a front view of the pilot spool of the present invention.

FIG. 3 is a sectional view of a conventional solenoid valve.

FIG. 4 is a sectional view of a solenoid valve according to a first modification.

[Brief description of reference numerals]

 1. 1. Solenoid case End cap 3. Coil 4. Movable iron core 5. Fixed iron core 6. Shaft 7. 7. Pilot spool housing Pilot spool 9. Screw fixing part 10. Thread groove 11. Thread 12. Lead wire 13. Spring 14. Recess 15. O-ring 16. Hook-shaped projection 17. Circumferential groove 18. Hole

Claims (2)

[Claims] When a coil is energized, an electromagnetic force is generated in a movable iron core and a shaft moves a pilot spool in a pilot spool housing to change a hydraulic pressure. In a solenoid valve for hydraulic control, a solenoid case and the pilot spool are provided. A solenoid valve fixed to the housing by providing a concave portion at the end of the solenoid case and a circumferential groove in the inner wall of the concave portion, and arranging an O-ring in the circumferential groove to fasten the pilot spool housing and the solenoid case. 2. The solenoid valve according to claim 1, wherein the front end of the pilot spool housing has a hook shape so that the pilot spool housing can be smoothly mounted, and the pilot spool housing does not fall off after mounting.