JP2012067875A - Detent-type 3-position electromagnetic selector valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a detent-type 3-position selector valve of an electromagnetic switching system.SOLUTION: A 3-position electromagnetic selector valve 1 includes: a spool 3 that switches flow passages T, A, B, and P to a straight state, a closed state, or a crossed state and whose position is held; right and left spindles 5, 6 continuous to both ends of the spool so as to slide the spool; right and left fixed electromagnetic coils 11, 12 for sliding the right and left spindles; a closing position control means that has stoppers 16, 17, provided on the spindles, and closing electromagnetic coils 18, 19 provided on the spool side of the fixed electromagnetic coils so as to magnetically attract the stoppers; and magnetic bodies 13, 14 provided on the side, opposite to the spool, of the spindles and attracted by electromagnetic force generated by the fixed electromagnetic coils.

Description

  The present invention relates to a detent type switching valve used in a fluid circuit or the like of a machine tool. More specifically, the present invention relates to a detent type three position electromagnetic switching valve that can be switched between straight, closed, and cross.

  A conventional detent type electromagnetic switching valve is used in the hydraulic circuit, and this switching valve holds the position by utilizing the resistance of the shaft unit integrated with the spool when holding the position of the spool. However, at the time of holding the spool, the position can be held without supplying power to the electromagnetic coil, so that there is a merit of power saving (energy saving).

  As this switching valve, a two-position switching valve and a three-position switching valve are used. The two-position switching valve includes a manual switching method and an electromagnetic switching method, but a two-position electromagnetic switching valve is used when automatic control is performed.

  However, in the detent type three-position switching valve, the manual switching method is used, but the electromagnetic switching method is not adopted. The reason is that the electromagnetic switching method has a structure in which a spool is slid by exciting a current by flowing current through either one of the left and right electromagnetic coils, so that three-position control cannot be performed.

  That is, when the right or left electromagnetic coil is fed to generate electromagnetic force, and the spindle is slid by magnetic attraction by the electromagnetic force, the position of the spool can be straight or cross. . However, when power is supplied to both the electromagnetic coils when the spool is in the closed position, the magnetic attraction force becomes stronger between the left and right iron cores closer to the electromagnetic coil, so that the left and right iron cores do not move. . For this reason, the spool cannot be returned to the closed position.

  When controlling the hydraulic circuit, it is important to control the three positions by setting the flow path to “straight”, “closed”, and “cross”. In particular, when the accumulator arranged in the hydraulic circuit is on standby, it is necessary to “close” the flow path. However, in the conventional example, since the manual switching method is adopted, unit control is automatically performed. I can't.

  In view of the above circumstances, an object of the present invention is to obtain an electromagnetic switching type detent type three-position switching valve.

  The present invention switches the flow path to straight, closed, cross, and holds the position of the spool, the left and right spindles that slide the spool continuously at both ends of the spool, and the left and right spindles that slide the left and right spindles A three-position electromagnetic switching valve having a fixed electromagnetic coil, a stopper provided on the spindle, for restricting a sliding range of the spindle, and opposed to the stopper, wherein the stopper is magnetically attracted. A closing position control means including a closing electromagnetic coil, and a magnetic body provided on the spindle and attracted by an electromagnetic force generated by the fixed electromagnetic coil.

  The spindle according to the present invention is in contact with both ends of the spool. The stopper according to the present invention is a protrusion provided on a spindle, and a magnetic adsorption member loosely fitted to the spindle and brought into and out of contact with the protrusion. And. The stopper according to the present invention is arranged on the spool side of the magnetic body or on the opposite side thereof. The magnetic adsorption member of the present invention is an electromagnetic coil or an iron core. The sliding restricting portion of the present invention is a recess having a forward restricting wall and a backward restricting wall. The magnetic body of the present invention is an iron core.

  The present invention provides a closing position control means provided on a spindle and provided with a stopper that regulates a sliding range of the spindle, and a closing electromagnetic coil that is provided opposite to the stopper and magnetically attracts the stopper. A magnetic body provided on the spindle and attracted by an electromagnetic force generated by the fixed electromagnetic coil, so that the sliding range of the spindle can be regulated by the stopper, and the closing electromagnetic coil With this control, the spool can be reliably returned to the closed position and held in position. Therefore, a detent-type three-position electromagnetic switching valve that can be automatically controlled can be obtained.

It is a longitudinal cross-sectional view which shows 1st Embodiment of this invention, and is a figure which shows the state of a straight. It is a longitudinal cross-sectional view which shows 1st Embodiment of this invention, and is a figure which shows the state of a closed state. It is a longitudinal cross-sectional view which shows 1st Embodiment of this invention, and is a figure which shows the state of a cross. 2 is an enlarged view of the main part of FIGS. 1 to 3, FIG. 2A is the position of the spindle when the spool is held in the straight position, FIG. 2B is the position of the spindle when the spool is held in the closed position, and FIG. Indicates the position of the spindle when the spool is held in the cross position. It is a front view of a spring (snap ring) fitted on a spindle.

  A first embodiment of the present invention will be described with reference to FIGS. The three-position electromagnetic switching valve 1 includes a flow path portion 1a and a drive portion 1b. The flow path portion 1a is provided with four flow paths (ports) T, B, P, A and a spool 3 for opening and closing the flow paths T to A.

  The drive unit 1b is a cylindrical body disposed on the left and right sides of the flow path unit 1a, and spindles 5 and 6 are slidably disposed in the hollow portion. The spindles 5 and 6 are provided with projecting portions 5s and 6s. As the projecting portions 5s and 6s, for example, a disc body is used. One end portions 5a and 6a of the spindles 5 and 6 pass through the fixed support plate 2 and are connected to the spool 3, and the spindles 5 and 6 and the spool 3 have three axial centers. It is located on the center line C of the electromagnetic switching valve 1.

  A small-diameter portion a, a medium-diameter portion b larger in diameter than the small-diameter portion a, and a large-diameter portion c larger in diameter than the medium-diameter portion b are continuously formed at one end portions 5a and 6a of the spindle. (See FIG. 4). A spring 7 and a spring 8 are provided at the one end portions 5a and 6a. The spring 7 is a position holding spring, and is a snap ring that tightens the spindles 5 and 6 to provide resistance (see FIG. 3). ).

  Stoppers 16 and 17 are slidably inserted (free fitting) on the spindles 5 and 6, and magnetic bodies 13 and 14 are mounted on the opposite side. Magnetic stoppers such as iron cores and electromagnetic coils are used as the stoppers 16 and 17, but the stoppers 16 and 17 are provided outside the protrusions 5s and 6s (on the side opposite to the spool 3) and are slidable. It is inserted in the movement restricting portions 21 and 22. The sliding restricting portions 21 and 22 include forward restricting walls 21a and 22a and backward restricting walls 21b and 22b. Further, iron cores are used as the magnetic bodies 13 and 14. Fixed electromagnetic coils 11 and 12 and closing electromagnetic coils 18 and 19 are concentrically arranged on the outer peripheral side of the iron cores 13, 14, 16 and 17. The electromagnetic coils 18 and 19 for closing are arranged to face the stoppers 16 and 17, and are arranged to face the iron cores 13 and 14.

  The iron cores 13 and 14 are formed to have a diameter larger than the diameter of the spindles 5 and 6 and slide while being magnetically attracted by the electromagnetic force generated by the electromagnetic coils 11 and 12. The stoppers 16 and 17 slide while being magnetically attracted by the electromagnetic force generated by the closing electromagnetic coils 18 and 19. The stoppers 16 and 17 and the closing electromagnetic coils 18 and 19 are closing position control means for bringing the spool 3 into a closing position.

  Next, the operation of this embodiment will be described. When the left electromagnetic coil 11 is fed and excited, the iron core 13 is electromagnetically attracted and slides in the direction of arrow A13. Therefore, since the spool 3 slides in the same direction, it becomes a straight position, and the port PA and the port TB are opened and communicated (see FIG. 4A).

At this time, the protrusion 6s of the spindle 6 pushes the stopper 17 and slides it in the direction of the arrow A13, but the stopper 17 comes into contact with the retreat restriction wall 22b of the slide restriction part 22 and stops. Therefore, the spool 3 accurately stops at the designed stop position (see FIG. 1).
At this time, the stopper 16 does not move because it is not pressed by the protrusion 5s.

  Next, when the power supply to the electromagnetic coil 11 is stopped and then the right electromagnetic coil 12 is supplied with power and excited, the iron core 14 is electromagnetically attracted and slides in the direction of arrow A14. Therefore, the spool 3 slides in the same direction and becomes a cross position, and the port P-B and the port AT are opened and communicated (see FIG. 4C)).

At this time, the protrusion 5s of the spindle 5 pushes the stopper 16 and slides it in the direction of the arrow A14, but the stopper 16 comes into contact with the retreat restriction wall 21b of the slide restriction part 21 and stops. Therefore, the spool 3 accurately stops at the designed stop position (see FIG. 3).
At this time, the stopper 17 does not move because it is not pressed by the protrusion 6s.

  When power is supplied to the closing electromagnetic coils 18 and 19 in a state where the power supply to both the electromagnetic coils 11 and 12 is stopped, the stoppers 16 and 17 are attracted by the electromagnetic force of the electromagnetic coils 18 and 19 and approach each other. That is, it slides in the direction of arrow A13 and arrow A14. Therefore, the spool 3 is pushed from both sides and moves to the center in a balanced manner, so that the spool 3 is in the closed position (see FIG. 4B).

  At this time, the stoppers 16 and 17 abut against the forward restricting walls 21a and 22a of the sliding restricting portions 21 and 22 while pressing the stoppers 16 and 17, so that the spool 3 accurately stops at the designed position ( (See FIG. 2).

The embodiment of the present invention is not limited to the above, and may be as follows, for example.
(1) Instead of connecting the spindle and the spool integrally, they are brought into contact with each other so as to be separable.
(2) Instead of using an electromagnetic coil (electromagnet) as a stopper, use a magnetic material or a permanent magnet.

(3) Instead of disposing the stopper on the inner side (spool side) of the magnetic body, the stopper is provided on the outer side (opposite side of the spool), or one stopper is on the inner side and the other spool is on the outer side. It can also be arranged.
(4) As a detent structure, the end of the spindle is made into three stages, and instead of tightening and holding the position of the spindle with a spring (snap ring), the thickness of the spindle is made constant, and the groove where the spring is caught is formed. Three may be provided. In this case, a method of pressing with a ball point can be employed instead of the spring.

DESCRIPTION OF SYMBOLS 1 Detent type 3 position electromagnetic switching valve 3 Spool 5 Spindle 6 Spindle 11 Fixed electromagnetic coil 12 Fixed electromagnetic coil 13 Iron core 14 Iron core 16 Stopper 17 Stopper 18 Closing electromagnetic coil 19 Closing electromagnetic coil C Center line

Claims (7)

The flow path is switched between straight, closed, and cross, the position is maintained, the left and right spindles that are continuous with both ends of the spool, and the left and right spindles that slide the left and right spindles. A three-position electromagnetic switching valve comprising:
A stopper provided on the spindle for regulating a sliding range of the spindle;
A closing position control means provided with a closing electromagnetic coil provided opposite to the stopper and magnetically attracting the stopper;
A magnetic body provided on the spindle and attracted by electromagnetic force generated by the fixed electromagnetic coil;
A detent-type three-position electromagnetic switching valve characterized by comprising:   The detent type 3-position electromagnetic switching valve according to claim 1, wherein the spindle is in contact with both ends of the spool.   The stopper includes a protrusion provided on a spindle, and a magnetic adsorption member that is loosely fitted to the spindle and contacts and separates from the protrusion, and is an air-gas adsorption member accommodated in the sliding restriction portion. The detent type three-position electromagnetic switching valve according to claim 1 or 2, further comprising:   3. The detent type three-position electromagnetic switching valve according to claim 1, wherein the stopper is disposed on the spool side of the magnetic body or on the opposite side thereof.   The detent type three-position electromagnetic switching valve according to claim 1, wherein the magnetic adsorption member is an electromagnetic coil or an iron core.   The detent-type three-position electromagnetic switching valve according to claim 3, wherein the sliding restricting portion is a recess having a forward restricting wall and a backward restricting wall. The detent type three-position electromagnetic switching valve according to claim 1, wherein the magnetic body is an iron core.

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