JP3089626B2 - Solenoid control valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic control valve for controlling a flow rate of a fluid.

[0002]

2. Description of the Related Art Conventionally, in a solenoid control valve of this type, when a moving core is driven by a magnetic attraction force generated in a solenoid portion, a spool housed in a sleeve is driven together with the moving core, and the magnetic attraction force is reduced. The resultant force of the spring and the spring that urges the spool in the opposite direction of the magnetic attraction force reciprocates the spool to adjust the fluid flow rate. At this time, ideally, as shown in FIG. 7C, it is desirable that the stroke of the moving core, that is, the axial position, is determined substantially in proportion to the current value.
To this end, as shown in FIG. 7A, the current input to the solenoid unit and the magnetic flux generated in the solenoid unit are substantially proportional to the magnetic attraction for driving the moving core. As shown, this magnetic attraction force needs to be constant irrespective of the stroke of the moving core. In particular, since the moving core moves in the axial direction by the magnetic attraction force, it is necessary to devise to keep the magnetic attraction force constant regardless of the stroke of the moving core. An electromagnetic control valve described below is known so that the suction force is constant regardless of the stroke of the spool.

This electromagnetic control valve has a non-magnetic shaft formed separately from the spool, and the shaft is press-fitted so that both ends protrude from the center of a moving core of a magnetic material which receives a magnetic attraction force. doing. Both ends of the protruding part of the shaft are supported by ball bearings to reduce frictional resistance received by the shaft and move extremely smoothly in the axial direction, and one end of the shaft receiving the magnetic attraction of the moving core abuts the spool. Let me.

In another electromagnetic control valve, the radial attraction force increases as the moving core attracts and moves and the amount of wrap between the side surface of the moving core and the opposing magnetic body increases, thereby increasing the axial attraction force. The moving core is formed in a tapered shape in which the outer diameter becomes narrower toward the tip in order to prevent the moving core from decreasing. Still another electromagnetic control valve has a magnetic attraction force between the suction side end surface of the moving core and the magnetic material opposing surface by providing a magnetic material opposing surface facing and approaching the suction side end surface of the moving core. This further prevents a decrease in the axial suction force. However, in this electromagnetic control valve, when the suction-side end surface of the moving core and the opposing surface of the magnetic material come into contact with each other, the suction-side end surface of the moving core and the opposing surface of the magnetic material are attracted by a strong suction force, and the solenoid portion There is a problem that even if the current is cut off, it is not immediately separated. As a countermeasure, a non-magnetic member may be interposed between the suction-side end surface of the moving core and the facing surface. As a method of interposing a non-magnetic member, a method of press-fitting a non-magnetic member into a spool-integrated moving core, a method of disposing a non-magnetic member as a separate component between the moving core and a ball bearing, and the like. There is a way. At this time, when the moving core moves to the suction side most, the gap between the moving core and the facing surface of the magnetic material, that is, the axially interposed member of the magnetic material member greatly affects the magnetic attraction characteristics.

[0005]

In such a conventional electromagnetic control valve, if the moving core has a tapered shape in which the outer diameter decreases as the suction-side end of the moving core moves toward the tip, the tapered portion of the moving core and the diameter of the moving core become smaller. As the amount of wrap with the magnetic material facing in the direction increases, the reduction in the axial suction force is prevented to some extent, but is still insufficient. Further, in an electromagnetic control valve that interposes a non-magnetic material member to prevent a suction side end face of a moving core and a magnetic body opposed to the suction side end face from being attracted to each other, an electromagnetic control valve is provided between the suction side end face of the moving core and the opposed magnetic body. The thickness of the non-magnetic material needs to be thin to some extent in order to increase the magnetic attraction generated with the approach,
If it is too thin, there is a problem that the assemblability and durability deteriorate.

The present invention has been made to solve such a problem, and provides an electromagnetic control valve which enables highly accurate control of a fluid flow rate with a simple structure.

[0007]

According to a first aspect of the present invention , there is provided an electromagnetic fluid control valve having a sleeve formed in a cylindrical shape and having an opening serving as a fluid passage; A spool having a large-diameter portion and a small-diameter portion slidably supported on the inner wall of the sleeve, and a magnetic body formed in a cylindrical shape, fixed to the axial end of the sleeve, and wound around a coil. A magnetic drive unit and a cylinder made of a magnetic material
Moving core formed in a shape, and said moving core
Mounted slightly protruding from the magnetic suction side end face of
A non-magnetic member, said fixed through the moving core in the axial direction, a shaft made of a nonmagnetic material which can contact the axial end of the spool, the axial both ends of the shaft
Fixed to the magnetic drive so as to slidably support the
A support member, and magnetically attracted at both ends of the shaft.
The supporting member for supporting a pulling side, wherein the moving
The surface facing the magnetic attraction side that faces the core in the axial direction is a magnetic material.
And a supporting member to be formed . Book
In the invention according to claim 2 of the present invention, the moving core
An annular groove is formed on the magnetic suction side end surface of the
A ring made of non-magnetic material fits into the groove so that
It is characterized by being fitted. Claim 3 of the present invention
In the described invention, the moving core has a magnetic suction side end.
Has a tapered shape whose outer diameter decreases as it goes to the magnetic attraction side.
It is characterized by being formed. Claim 4 of the present invention
In the described invention, both ends of the shaft are
Is supported so that it can slide smoothly in the axial direction.
And

[0008]

According to the electromagnetic control valve of the first aspect of the present invention.
And the support member that supports the magnetic attraction side of the shaft.
To form a facing surface facing the moving core with a magnetic material.
This reduces the decrease in the magnetic attraction in the axial direction.
At this time, a non-magnetic member is attached to the suction side end face of the moving core.
By mounting so that it protrudes, the moving core and
Prevents the support member from adsorbing
The gap between the cocoa and the support member can be reduced. In addition,
The non-magnetic member attached to the suction core end face of the moving core is
As described in claim 2, the suction side end of the moving core.
To fit a ring made of non-magnetic material into the groove provided on the surface
Thus, it is possible to mount the device. Claim 3 of the present invention
According to the described electromagnetic control valve, the magnetic field generated in the solenoid
When the moving core is sucked by the bundle, the shaft
The shaft is supported by a support member so that it can slide in
Friction resistance when the shaft reciprocates in the axial direction is reduced
You. According to the electromagnetic control valve of the fourth aspect, the mu
The suction side end of the bing core is tapered.
Magnetic attraction force regardless of the axial position of the moving core
It is difficult to change.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. One embodiment in which the electromagnetic control valve of the present invention is applied to a hydraulic control valve of a valve timing adjusting device for an internal combustion engine is shown in FIGS. FIG. 1 shows a state in which no magnetic attraction force is generated without flowing a current to the solenoid unit 1, and FIG. 2 shows a state in which a magnetic core is generated by supplying a current to the solenoid unit 1 to operate the moving core. Show.

The hydraulic control valve includes a solenoid unit 1 for generating a magnetic attraction force by supplying a current, a solenoid unit 1
The spool control valve 2 is driven by the magnetic attraction force generated in the control valve and adjusts the flow rate of oil supplied to the control chambers 21 and 22 and the flow rate of oil discharged from the control chambers 21 and 22.
Consists of The yoke 3 and the stator 4, which are cylindrical magnetic bodies, are fixed by caulking and fixed to each other to form a magnetic circuit. The solenoid portion 1 has an inner diameter portion 3 a of the yoke 3, a center portion 4 a of the stator 4, and a yoke 3. A hollow cylindrical coil 5 is built in between the outer diameter portion 3b. The coil 5 has a winding end connected to the terminal 7 and is integrally formed with the resin portion 6.

The inner diameter portion 3a of the yoke 3 and the center portion 4a of the stator 4 are opposed to each other via a space gap 9 in the axial direction. Ball bearings 8 are press-fitted and fixed to the inner wall of the inner diameter portion 3a of the yoke 3 and the inner wall of the central portion 4a of the stator 4, respectively. Ball bearing 8 is ball 8a
And an outer ring 8b for holding the ball 8a.
The outer ring 8b on the arrow B side in FIG. 1 is formed of a magnetic material.

A moving core 10 made of a magnetic material is disposed in a space surrounded by an inner wall of a central portion 4a of the stator 4 and a pair of ball bearings 8. Moving core 1
The tapered portion 10a is formed at the end on the magnetic attraction side indicated by an arrow B in FIG. 1 of FIG. 1 so that the outer diameter decreases toward the magnetic attraction side, and an annular counterbore 10b is formed at the tip end surface of the tapered portion 10a.
Are formed. A non-magnetic shaft 11 is press-fitted and fixed to the center of the moving core 10 through the moving core 10 in the axial direction. The protruding portions 11a and 11b of the shaft 11 are supported by the ball bearings 8, respectively, so that the moving core 10 can move smoothly and axially integrally with the shaft 11. Non-magnetic rings 12 and 13 are press-fitted and fixed to the shaft 11, respectively, and are in contact with both ends of the moving core 10.
The ring 12 is further embedded in the counterbore 10b and slightly protrudes from the moving core 10. Ring 1
2 and 13 are ideally 2 to maintain the press fit weight.
mm, and the amount of protrusion of the ring 12 from the counterbore 10b is set to 1 mm or less.

One end of a sleeve 14 of the spool control valve 2 is caulked and fixed to the yoke 3, and an adjustment nut 16 is screwed into the other end. The sleeve 14 has a plurality of openings 14 a, 14 b, 14 c, 14 d, and 14 e communicating with a plurality of passages through which oil passes to predetermined wall surfaces. The hydraulic release passage 31 is provided between the opening 14 a and the oil tank 1.
9 and the hydraulic passage 32 is connected to the opening 14 b and the control chamber 2.
1, the hydraulic supply path 33 connects the opening 14c and the oil pump 18, the hydraulic path 34 connects the opening 14d and the control chamber 22, and the hydraulic release path 35 connects the opening 14e.
And the oil tank 19.

A spool 15 is supported on the inner wall of the sleeve 14 so as to be slidable in the axial direction. The spool 15 is
It comprises large-diameter portions 15a, 15b, 15c, and 15d, which are lands having substantially the same diameter as the inner diameter of the sleeve 14, and small-diameter portions connecting these large-diameter portions. A spring 17 is interposed between one end of the spool 15 and the adjustment nut 16.
The other end of 5 is in contact with the shaft 11, and the ring 13 is pressed against the outer ring 8b of the ball bearing 8 on the arrow A side shown in FIG. Further, the urging force of the compression coil spring 17 can be adjusted by adjusting the tightening degree of the adjustment nut 16.

FIG. 1 shows a state in which no current is supplied to the coil 5, no magnetic attraction is applied to the moving core 10, and the spool 15 and the moving core 10 are compressed by a compression coil spring 17 as shown by arrows in FIG. It is urged in the A direction. At this time, the opening 14 of the spool control valve 2
c and the opening 14d communicate with each other, and the opening 14b and the opening 1
4c and between the opening 14a and the opening 14b are shut off, whereby oil from the pump 18 is pumped into the control chamber 22. At the same time, communication between the opening 14a and the opening 14b is established .
Then, the oil in the control chamber 21 is discharged to the tank 19.

FIG. 2 shows a state in which a current is supplied to the coil 5 from the state shown in FIG. 1 and the moving core 10 moves. Magnetic attraction is generated between the inner diameter portion 3a of the yoke 3 and the moving core 10, and the moving core 10 and the spool 1
5 moves from the state shown in FIG. 1 to the magnetic attraction side in the direction of arrow B in FIG. 1 and moves to the position shown in FIG. 2 against the urging force of the spring 17. The moving core 10 includes the ring 1
2 is stationary when the outer ring 8b of the ball bearing 8 on the magnetic attraction side abuts. At this time, the spool control valve 2
The opening 14b and the opening 14c communicate with each other,
Oil is pressure-fed to the control pressure chamber 21 by blocking between c and the opening 14d and between the opening 14a and the opening 14b . At the same time, the opening 14d communicates with the opening 14e ,
The oil in the control pressure chamber 22 is discharged to the tank 19.

Next, the operation and effects of the embodiment of the present invention will be described in comparison with a comparative example. 5 and 6 show comparative examples. In the comparative example shown in FIG. 5, a ring 120 having a thickness of 2 mm capable of holding a sufficient press-fitting force is interposed on the end surface of the moving core 100 on the magnetic attraction side. When a current is supplied to the coil 5 from a state in which no current is supplied to the coil 5 of the solenoid unit 1 shown in FIG. 5A, the magnetic attraction force depends on the magnitude of the current supplied to the coil 5 as shown in FIG. Is different. The magnetic attraction force once rises with respect to the axial movement of the moving core 100, and the ring 120 shown in FIG.
Shows a tendency to decrease as it moves to a position where the ball bearing 8 contacts the outer ring 8b. This is because the ring 120 is in contact with the ball bearing 8 in FIG.
Since the gap between the outer ring 8b of the ball bearing 8 and the suction side end face of the moving core 100 does not become less than the thickness of the ring 120 in the state shown in FIG.
0 and the outer ring 8b of the ball bearing 8 do not generate a sufficient magnetic attraction force, and the magnetic attraction force in the radial direction increases with an increase in the wrap amount a between the moving core 100 and the yoke 3 facing in the radial direction. Because you do.

On the other hand, in this embodiment, as shown in FIG.
A ring 12 having a thickness of 2 mm is embedded and interposed in the counterbore 10b of the moving core 10, and the ring 12 protrudes 1 mm or less from the foremost surface of the moving core 10 on the magnetic attraction side. When a current is supplied to the coil 5 from a state in which no current is supplied to the coil 5 of the solenoid unit 1 shown in FIG. 3A, the magnetic attraction force depends on the magnitude of the current supplied to the coil 5 as shown in FIG. Is different. When the moving core 10 moves in the axial direction and the ring 12 abuts on the outer ring 8b of the ball bearing 8 as shown in FIG. 3B, the suction side end surface of the moving core 10 and the opposing surface of the outer ring 8b of the ball bearing 8 Is 1 mm or less. For this reason, the yoke 3 radially opposed to the moving core 10
Even if the lap amount a increases, the flow of magnetic flux in the axial direction increases as compared with the comparative example, so that a sufficient magnetic attraction force is generated between the moving core 10 and the outer ring 8b made of the magnetic material of the ball bearing 8. However, as shown in FIG. 4, the magnetic attraction force does not decrease, and a constant magnetic attraction force characteristic can be obtained regardless of the axial position of the moving core 10. In the comparative example, if the thickness of the ring 120 is reduced, it is possible to obtain the same magnetic attraction characteristics as in the present embodiment, but it is not practical because there is a problem that the strength at the time of assembling and at the time of use is reduced. .

In this embodiment, the magnetic attraction force can be kept constant irrespective of the axial position of the moving core 10.
The axial position of the moving core 10 is determined substantially in proportion to the current value supplied to the coil 5. Therefore, the position of the spool 15 is determined by the magnitude of the current value.
The flow rate of the discharged oil can be controlled with high precision.

In this embodiment, the moving core 10 is supported by ball bearings 8 at both ends and smoothly moves in the axial direction. The axial movement range is restricted by the outer ring 8b of the ball bearing 8. Thereby, the moving core 10 between the inner diameter portion 3a of the sleeve 3 and the center portion 4a of the stator 4 is formed.
The space in which the sleeve 3 and the ball bearing 8 are built is one section having substantially the same diameter, so that the sleeve 3 and the stator 4 can each be easily formed as a single object with a simple shape.

Further, in this embodiment, the ring 12 made of a non-magnetic material is interposed between the suction side end face of the moving core 10 made of a magnetic material and the outer ring 8b of the ball bearing 8. For this reason, the end surface of the moving core 10 on the magnetic attraction side and the outer ring 8 b of the ball bearing 8 come into contact with each other and are attracted by a strong magnetic attraction force. 17
Can be prevented from being separated by the urging force. Further, since the ring 12 is press-fitted and fixed to the shaft 11, assembly is very easy.

[0022]

The electromagnetic control valve of the present invention described above has a simple structure that linearly approximates the characteristics of the axial position of the moving core and the current supplied to the solenoid, and corresponds to the value of the current supplied to the solenoid. The accurate axial position of the moving core can be ascertained, so that the flow rate of the fluid can be controlled with high accuracy, and the assemblability is improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment in which an electromagnetic control valve of the present invention is applied to a hydraulic control valve of a valve timing adjusting device at the most retarded angle.

FIG. 2 is a cross-sectional view showing an embodiment in which the electromagnetic control valve of the present invention is applied to a hydraulic control valve of a valve timing adjusting device at the most advanced angle.

FIG. 3 is a sectional view showing a main part of the electromagnetic control valve of the present invention. (A) shows the time of the most retarded angle, and (B) shows the time of the most advanced angle.

FIG. 4 is a characteristic diagram showing a relationship between a moving core axial position and a magnetic attraction force according to a position embodiment of the present invention.

FIG. 5 is a sectional view showing a main part of an electromagnetic control valve of a comparative example. (A) shows the time of the most retarded angle, and (B) shows the time of the most advanced angle.

FIG. 6 is a characteristic diagram illustrating a relationship between a moving core axial direction position and a magnetic attraction force of a comparative example.

FIG. 7A is a characteristic diagram showing an ideal relationship between a current supplied to a solenoid unit and a magnetic attraction force generated in the solenoid unit by the supplied current. (B) is a characteristic diagram showing an ideal relationship between the magnetic attraction generated in the solenoid portion and the axial position of the moving core. (C) is a characteristic diagram showing an ideal relationship between a current supplied to the solenoid unit and an axial position of the moving core.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Solenoid part 2 Spool control valve 3 Yoke (magnetic drive part) 4 Stator (magnetic drive part) 5 Coil (magnetic drive part) 8 Ball bearing (support member) 10 Moving core 10a Tapered part 10b Counterbore (groove) 11 Shaft 12 Ring 13 Ring 14 Sleeve 14a Opening 14b Opening 14c Opening 14d Opening 14e Opening 15 Spool 15a Large Diameter (Land) 15b Large Diameter (Land) 15c Large Diameter (Land) 15d Large Diameter Department (land part)

Continuation of the front page (56) References JP-A-1-316682 (JP, A) JP-A-3-61775 (JP, A) JP-A-2-129483 (JP, A) JP-A-5-61578 (JP) , U) Japanese Utility Model 63-184274 (JP, U) Japanese Utility Model Application Hei 3-86264 (JP, U) Japanese Utility Model Application Utility Model 4-42974 (JP, U) (58) Fields surveyed (Int. Cl. ⁷ , DB Name) F16K 31/06-31/11

Claims (4)

(57) [Claims] A sleeve formed in a cylindrical shape and having an opening serving as a fluid passage; a spool slidably supported by an inner wall of the sleeve and having a large diameter portion and a small diameter portion; is formed, is fixed to the axial end of the sleeve, and a magnetic driving portion composed of a magnetic material by winding a coil around, made of a magnetic material, and a moving core formed in a tubular shape, the magnetic of the moving core Slightly project from the suction side end face.
A shaft made of a non-magnetic member mounted and extended , a non-magnetic member fixedly penetrating the moving core in the axial direction, and capable of contacting an end of the spool in the axial direction ; So that it can slide in the direction
A support member fixed to the magnetic drive unit, wherein the
The support portion that supports the magnetic attraction side of both ends of the shaft
In the material, a magnetic material axially opposed to the moving core.
An electromagnetic control valve , comprising: a support member whose opposite surface on the air suction side is formed of a magnetic material . 2. A magnetic suction side end face of the moving core.
Has an annular groove, A ring made of a non-magnetic material is protruded from the groove.
2. The device according to claim 1, wherein the groove is fitted into the groove.
On-board electromagnetic control valve. 3. An end portion of the moving core on a magnetic attraction side.
Has a tapered shape whose outer diameter decreases as it goes to the magnetic attraction side.
2. The method according to claim 1, wherein the first member is formed.
3. The electromagnetic control valve according to 2. 4. The support member has opposite ends of the shaft.
It is supported so that it can slide smoothly in the axial direction.
The electromagnetic device according to any one of claims 1 to 3,
Control valve.