JP2013061005A - Electromagnetic spool valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a foreign matter from reaching a plunger in an electromagnetic spool valve that performs respiration on both sides of the plunger through the inside of the spool.SOLUTION: Between a drain hole 6 within a spool and a "first space A on the front side of a plunger 2", three foreign matter traps (first to third foreign matter traps X1 to X3) consisting of a "throttle portion configured to throttle a flow passage area" and a volume space surrounding the periphery of the throttle portion" are provided. Further, a second space B on the rear side of the plunger 2 is made to communicate with only the first space A. Due to this, even if foreign matter discharged into the drain hole 6 within the spool flows backward, the foreign matter is trapped by the first to third foreign matter traps X1 to X3, thereby preventing the foreign matter from reaching the plunger 2. As a result of this, wear and poor sliding at a plunger sliding part can be prevented to improve reliability.

Description

  The present invention relates to an electromagnetic spool valve that drives a spool valve by an electromagnetic actuator, and more particularly to an electromagnetic spool valve in which spaces on both sides in the axial direction of a plunger communicate with a drain space via a spool. The present invention relates to a technique suitable for use in a variable valve timing device (variable valve timing: hereinafter referred to as VVT).

In the following specification, for convenience of explanation,
・ The moving direction (axial direction) of the spool and plunger is called the front-rear direction,
-The direction in which the spool and plunger move by the driving force (axial force) of the electromagnetic actuator is forward (front: see the left side of Fig. 1),
-The direction in which the spool and plunger move due to the biasing force of the return spring is rearward (rear: see the right side of Fig. 1)
Called.
This front-rear direction is for explanation, and does not limit the actual mounting direction.

Patent Document 1 will be described as a specific example of the background art.
Patent Document 1 is a technology related to VVT that varies the advance amount of a camshaft driven by an engine (internal combustion engine).
・ Variable camshaft timing mechanism (variable camshaft timing: hereinafter referred to as VCT) that changes the amount of camshaft advance by the hydraulic pressure difference between the advance chamber and retard chamber; An oil flow control valve (hereinafter referred to as OCV: an example of an electromagnetic spool valve) that controls the hydraulic pressure difference in the chamber;
Is used.

The OCV disclosed in Patent Document 1 will be described with reference to FIG. In addition, the following code | symbol attaches | subjects the same code | symbol to the same function thing as [the form for inventing] and [Example] which are mentioned later.
The OCV 1 is a combination of a spool valve 5 adopting a four-way valve structure and an electromagnetic actuator 3 (linear solenoid) that drives the spool valve 5.

In the spool valve 5 of Patent Document 1, an in-spool drain hole 6 communicating with the drain space is formed at the center of the spool 4.
The spaces on both sides of the plunger 2 in the axial direction of the electromagnetic actuator 3 communicate with the drain space via the drain hole 6 in the spool 4 formed in the spool 4.
In the following, among the spaces on both sides in the axial direction of the plunger 2, the front space that contacts the plunger 2 (the space close to the plunger 2) is defined as the first space A, and the rear space that contacts the plunger 2. (The space on the side away from the plunger 2) will be described as a second space.

In the technique of Patent Document 1, breathing passages 101, 102, and 103 extending from the drain hole 6 in the spool to the first space A are provided so as to extend linearly (straight).
For this reason, the hydraulic oil discharged to the drain hole 6 in the spool (the hydraulic oil discharged from the advance angle chamber and the retard angle chamber) easily reaches the plunger 2.
As a result, foreign matter contained in the hydraulic oil discharged to the drain hole 6 in the spool easily reaches the plunger sliding portion. The foreign matter that has reached the plunger sliding portion causes wear of the plunger sliding portion and causes sliding failure.

JP 2003-97756 A

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a reliability that can prevent foreign matter from reaching the plunger in an electromagnetic spool valve that breathes on both sides of the plunger through the inside of the spool. High solenoid spool valve.

[Means of claim 1]
The electromagnetic spool valve has one or a plurality of foreign matter traps composed of a “throttle portion for narrowing the flow path area” and a “volume space covering the periphery of the throttling portion” between the drain hole in the spool and the first space. The first space is communicated with the drain hole in the spool via one or more foreign matter traps. For this reason, it can prevent that a foreign material reaches the front part of a plunger by one or a plurality of foreign material traps.
Further, since the second space communicates only with the first space in which the arrival of the foreign matter is prevented, the foreign matter can be prevented from reaching the rear portion of the plunger.
As described above, since the foreign matter can be prevented from reaching the plunger by the foreign matter trap, the wear of the plunger sliding portion can be suppressed, and the occurrence of the sliding failure can be prevented beforehand. The reliability of the spool valve can be increased.

[Means of claim 2]
Two or more foreign matter traps are provided.
As a result, the amount of foreign matter reaching the first space can be more reliably suppressed, and the reliability of the electromagnetic spool valve can be improved.

[Means of claim 3]
One of the foreign matter traps is a first foreign matter trap including a spool end throttle portion (a throttle portion on the rear side of the drain hole in the spool) and a cup internal volume space (internal space of the cup shaft).
The fluid that has passed through the spool end throttle portion decelerates in the cup internal volume space. Thereby, the flow of the fluid is slowed, the foreign matter can be retained in the cup volume space, and the foreign matter can be prevented from entering the plunger side.

[Means of claim 4]
One of the foreign matter traps is a second foreign matter trap composed of a cup constriction portion (a hole formed through the cup shaft in the radial direction) and a cup outer volume space (a space covering the periphery of the cup shaft).
The fluid that has passed through the cup restrictor decelerates in the cup outer volume space. As a result, the flow of the fluid is slowed, the foreign matter can be retained in the cup outer volume space, and the foreign matter can be prevented from entering the plunger side.

[Means of claim 5]
One of the foreign matter traps is a third foreign matter trap configured by a gap restricting portion (a gap between the small diameter cylindrical portion provided on the cup shaft and the collar) and the first space.
The fluid that has passed through the gap restrictor decelerates in the first space. Thereby, the flow of the fluid becomes slow, the foreign matter can be retained in the first space, and the foreign matter can be prevented from entering the second space.

The collar is a part that magnetically attracts the plunger and generates magnetic force when the coil is energized, so iron-based foreign matter that has entered inside the cup shaft is moved to the spool side of the collar (particularly inside the cup shaft). It can be fastened and iron-based foreign matter can be prevented from entering the plunger side from the collar.
Furthermore, since the iron-based foreign matter that has reached the first space is attracted to the collar, the iron-based foreign matter that has reached the first space can be prevented from reaching the plunger.

[Means of claim 6]
The first space and the in-plunger breathing hole communicate with each other only through a radial groove formed in the bottom portion of the cup shaft (a portion that directly contacts the plunger).
Thereby, since the communicating path from the first space to the in-plunger breathing hole can be complicated (bent), it becomes more difficult for foreign matter to enter the second space. As a result, foreign matter can be prevented from entering the second space.

[Means of Claim 7]
The drain hole in the spool provided in the spool has a function of a breathing passage for communicating the first and second spaces with the drain space, and also discharges the hydraulic oil discharged from the output port of the spool valve to the drain space. It has the function of a passage.
Thus, even if the drain hole in the spool has a function of the hydraulic oil discharge passage, as shown in the above [Means of Claim 1], the foreign matter can be prevented from reaching the first and second spaces. Can be removed. For this reason, while being able to suppress wear of a plunger sliding part, generation | occurrence | production of the sliding failure of a plunger can be prevented beforehand and the reliability of an electromagnetic spool valve can be improved.

[Means of Claim 8]
The electromagnetic spool valve according to claim 8 is an OCV that controls a hydraulic pressure difference between the advance port and the retard port in the VCT, and the drain hole in the spool functions as a breathing passage for communicating the first and second spaces with the drain space. In addition, it has a function of a hydraulic oil discharge passage that guides the hydraulic oil discharged through the advance port and the retard port to the drain space.
Thus, even if the drain hole in the spool has the function of the hydraulic oil discharge passage for the hydraulic oil discharged through the advance port and the retard port, the above-mentioned [Means of Claim 1] is shown. Thus, the arrival of foreign matter to the first and second spaces is prevented. For this reason, while being able to suppress wear of a plunger sliding part, generation | occurrence | production of the sliding failure of a plunger can be prevented beforehand and the reliability of OCV can be improved.

(A) Sectional view along the axial direction of the OCV, (b) View from the rear of the cup bottom of the cup shaft that contacts the plunger (Example). It is principal part sectional drawing of OCV for description of a respiratory passage (Example). It is the schematic of VVT (Example). It is sectional drawing which follows the axial direction of OCV (conventional example).

[Description of Embodiments] [Mode for carrying out the invention] will be described with reference to the drawings.
The electromagnetic spool valve 1 (OCV in the embodiment described later) has an electromagnetic actuator 3 having a plunger 2 driven in the axial direction by a magnetomotive force corresponding to the energization amount, and a spool 4 driven in the axial direction by the plunger 2. A spool valve 5 is provided, and spaces (first space A and second space B) on both sides in the axial direction of the plunger 2 communicate with the drain space via a drain hole 6 in the spool 4. Is.

The spool 4 is provided with a spool end restricting portion 7 having a smaller flow area than the drain hole 6 in the spool, on the rear side (closer to the plunger 2) of the drain hole 6 in the spool.
Between the plunger 2 and the spool 4, a cup shaft 8 having a bottomed cup shape and transmitting the axial force of the plunger 2 to the spool 4 is provided.

The first space A includes one or a plurality of foreign matter traps (a first to a third foreign matter trap X1 in the embodiments described later) including a throttle portion for reducing the flow path area and a volume space covering the periphery of the throttle portion. To the in-spool drain hole 6 through .about.X3).
Furthermore, the second space B communicates only with the first space A.

A specific example (example) in which the present invention is applied to the OCV 1 of the VVT will be described below with reference to the drawings. The following examples are specific examples, and it goes without saying that the present invention is not limited to the examples.
In the following embodiments, the same reference numerals as those in the above-mentioned [Mode for Carrying Out the Invention] denote the same functional objects.

(Explanation of VVT)
VVT is mounted on a vehicle running engine.
A VCT 11 that is attached to a camshaft (for example, a camshaft for an intake valve) and can continuously vary the opening / closing timing of a valve (for example, an intake valve) by continuously varying the advance amount of the camshaft. When,
A hydraulic circuit 12 using the OCV 1 that hydraulically controls the operation of the VCT 11;
An ECU 13 (an abbreviation of engine control unit) for electrically controlling the OCV 1;
It is composed of

  The VCT 11 includes a shoe housing 14 that is driven to rotate in synchronization with the crankshaft of the engine, and a vane rotor 15 that is provided so as to be rotatable relative to the shoe housing 14 and rotates integrally with the camshaft. The vane rotor 15 is rotationally driven relative to the shoe housing 14 by a hydraulic actuator configured in the shoe housing 14 to change the camshaft to the advance side or the retard side.

The shoe housing 14 is coupled to a sprocket that is rotationally driven by a crankshaft of an engine via a timing belt, a timing chain, or the like by a bolt or the like, and rotates integrally with the sprocket. As shown in FIG. 3, a plurality of substantially fan-shaped recesses 14 a (three in this embodiment) are formed in the shoe housing 14. Note that the shoe housing 14 rotates clockwise in FIG. 3, and this rotation direction is an advance angle direction.
On the other hand, the vane rotor 15 is positioned at the end of the camshaft by a positioning pin or the like and fixed to the end of the camshaft by a bolt or the like, and rotates integrally with the camshaft.

The vane rotor 15 includes a vane 15a that divides the recess 14a of the shoe housing 14 into an advance chamber α and a retard chamber β. The vane rotor 15 is provided to be rotatable within a predetermined angle with respect to the shoe housing 14. It has been.
The advance chamber α is a hydraulic chamber for driving the vane 15a to the advance side by hydraulic pressure, and is formed in the recess 14a on the counter-rotation direction side of the vane 15a. β is a hydraulic chamber for driving the vane 15a to the retard side by hydraulic pressure, and is formed in the recess 14a on the rotation direction side of the vane 15a. The liquid tightness of the advance chamber α and the retard chamber β is maintained by the seal member 16 or the like.

  The hydraulic circuit 12 supplies and discharges the oil in the advance chamber α and the retard chamber β, generates a hydraulic pressure difference between the advance chamber α and the retard chamber β, and rotates the vane rotor 15 relative to the shoe housing 14. For this purpose, the pump hydraulic pressure pumped from the oil pump 17 driven by a crankshaft or the like is metered into one of the advance chamber α or the retard chamber β, and the advance chamber α or the retard chamber β. OCV1 capable of metering and discharging the hydraulic pressure is provided.

  The OCV 1 is an electromagnetic spool valve in which a spool valve 5 having a four-way valve structure and an electromagnetic actuator 3 for driving the spool valve 5 are combined. The OCV mounted on the engine component (cylinder head or the like). The electromagnetic actuator 3 is fixed to the engine component while being inserted into a hole (a hole whose inner peripheral surface has a cylindrical shape).

The spool valve 5
A sleeve 21 to be inserted into an OCV mounting hole provided in the engine component;
A spool 4 that is slidably supported in the axial direction inside the sleeve 21 and adjusts the communication state of each port;
A return spring 22 that urges the spool 4 backward,
Is provided.

(Description of sleeve 21)
The sleeve 21 has a substantially cylindrical shape, and the outer peripheral surface is inserted and arranged with a fine clearance with respect to the OCV mounting hole.
A slide hole 23 is formed inside the sleeve 21 to support the spool 4 so as to be slidable in the axial direction. The spool 4 is supported on the inner peripheral surface of the slide hole 23 so as to be slidable in the axial direction.

The sleeve 21 has a plurality of input / output ports.
Specifically, in the radial direction of the sleeve 21, an input port 24 that communicates with the oil discharge port of the oil pump 17, an advance port 25 that communicates with the advance chamber α, and a retard port 26 that communicates with the retard chamber β are provided. ing.
These radial ports are arranged in the order of an advance port 25, an input port 24, and a retard port 26 from the front side to the rear side of the sleeve 21.
On the other hand, a drain port 27 that communicates with a drain space (a space that communicates with a drain pan) is provided at the front end of the sleeve 21.

(Description of spool 4)
The spool 4 has a substantially cylindrical shape, and the outer peripheral surface thereof is inserted and arranged with a fine clearance with respect to the inner peripheral surface of the sleeve 21.
Then, when the spool 4 slides from the rear to the front, the switching state of each port changes, and the retarded state (the state in which the camshaft is driven toward the retarded side) and the holding state (the advance amount of the camshaft). ) And an advance angle state (a state in which the camshaft is driven to the advance side) are achieved.

  On the outer periphery of the spool 4, a first land 31 (a large diameter portion for closing the advance port) that closes the advance port 25 in a state where the spool 4 is driven to an intermediate position in the axial direction with respect to the sleeve 21. A second land 32 (a large diameter portion for closing the retarding port) for closing the retarding port 26 is provided.

A circumferential groove 33 (small diameter portion) is provided between the first land 31 and the second land 32 on the outer periphery of the spool 4.
The circumferential groove 33 always communicates with the input port 24.
(I) When the spool 4 moves forward, the input port 24 and the advance port 25 are communicated to increase the hydraulic pressure in the advance chamber α.
(Ii) When the spool 4 moves rearward, the input port 24 and the retard port 26 communicate with each other to perform the function of a distribution chamber that increases the hydraulic pressure of the retard chamber β.

  As described above, the spool 4 has a substantially cylindrical shape, and an in-spool drain hole 6 extending in the axial direction and always communicating with the drain port 27 in the front is formed in the spool 4.

  An advance angle discharge port 34 penetrating in the radial direction is provided in front of the first land 31 in the spool 4. The advance discharge port 34 is used for lowering the hydraulic pressure in the advance chamber α by connecting the advance port 25 and the drain hole 6 in the spool when the spool 4 moves rearward.

  A retard discharge port 35 penetrating in the radial direction is provided behind the second land 32 in the spool 4. The retard discharge port 35 is for communicating the retard port 26 with the drain hole 6 in the spool when the spool 4 moves forward, and lowering the hydraulic pressure in the retard chamber β.

  At the rear end of the spool 4, the hydraulic oil discharged from the advance angle discharge port 34 or the retard angle discharge port 35 to the inside of the drain hole 6 in the spool is positively flowed forward (to the drain port 27 side), and rearward. As a means for preventing the flow to the (electromagnetic actuator 3 side), a spool end restricting portion 7 having a flow path area smaller than the drain hole 6 in the spool is provided.

  The flow path area of the spool end throttle portion 7 is smaller than the flow path area of the drain hole 6 in the spool, the flow path area of the advance discharge port 34, and the flow path area of the retard discharge port 35. . Specifically, the flow area of the drain hole 6 in the spool> the flow area of the advance discharge port 34 (or the flow area of the advance port 25) ≈the flow area of the retard discharge port 35 (or a delay). The flow path area of the corner port 26)> the flow path area of the spool end throttle portion 7 is provided.

(Description of return spring 22)
The return spring 22 is a compression coil spring that urges the spool 4 rearward.
Here, the sleeve 21 is provided with an annular wall 36 perpendicular to the axial direction around the drain port 27, and a spring receiving step 37 (spool drain hole 6 in the spool 4) provided on the spool 4. Are assembled in a state of being compressed in the axial direction between the steps of the portion that expands forward on the front side.
Note that a spring chamber (a volume variation chamber provided at the front portion of the spool 4) in which the return spring 22 is disposed communicates with the drain space via the drain port 27.

(Description of electromagnetic actuator 3)
The electromagnetic actuator 3 includes a coil 41, a plunger 2, a cup guide 43, a magnetic suction stator 44, a collar 45, a magnetic delivery stator 46, a yoke 47, a stay 48 and a connector 49.
The coil 41 is a magnetic force generating means for generating a magnetic force for magnetically attracting the plunger 2 when energized, and is obtained by winding a large number of conductive wires (such as enamel wires) covered with insulation around a resin coil bobbin. is there.

  The plunger 2 is a cylindrical body formed of a magnetic metal (for example, iron: a ferromagnetic material constituting a magnetic circuit) that drives the spool 4 forward by overcoming the urging force of the return spring 22 by the magnetic force generated by the coil 41. And supported on the inner peripheral surface of the cup guide 43 so as to be slidable in the axial direction.

The magnetic attraction stator 44 magnetically attracts the plunger 2 forward. The disk portion 44a disposed between the sleeve 21 and the coil 41 and the magnetic flux of the disk portion 44a to the vicinity of the plunger 2. A magnetic metal (for example, iron: a ferromagnetic material constituting a magnetic circuit) composed of a guiding cylindrical portion 44b, and a magnetic attraction gap (main gap) is provided between the plunger 2 and the cylindrical portion 44b in the axial direction. It is formed.
The cylindrical portion 44b is provided so as to be able to intersect in the axial direction when the plunger 2 moves forward. Further, a taper is formed at the end of the cylindrical portion 44b, and this taper is provided so that the magnetic attractive force does not change with respect to the stroke amount of the plunger 2.

The collar 45 is an annular magnetic part that is inserted into the cylindrical portion 44 b of the magnetic attraction stator 44 and increases the magnetic attraction force of the plunger 2 so as to face the front end of the plunger 2.
The collar 45 is formed by, for example, pressing a magnetic metal plate (for example, iron: a ferromagnetic material constituting a magnetic circuit) into an annular shape, and a step formed on the rear end of the sleeve 21 and the cup guide 43. It is sandwiched between and fixed.

  The magnetic delivery stator 46 delivers the circumference of the plunger 2 in the radial direction through the cup guide 43, covers the outer periphery of the plunger 2 through the cup guide 43, and is inserted into the inner circumference of the coil bobbin. A magnetic part metal (for example, iron: a strong magnetic force that constitutes a magnetic circuit). Magnetic material), and a magnetic flux delivery gap (side gap) is formed between the cylindrical portion 46a and the plunger 2 in the radial direction.

  The yoke 47 is a magnetic metal having a cylindrical shape that covers the periphery of the coil 41 (for example, iron: a ferromagnetic material constituting a magnetic circuit). The yoke 47 and the sleeve 21 are caulked with a claw formed at the front end. Combined.

The cup guide 43 is a means for defining a range in which the oil is guided inside the electromagnetic actuator 3 so that the oil inside the electromagnetic actuator 3 does not leak to the outside, and is a non-magnetic material having a cylindrical cup shape (for example, , Stainless steel, etc.).
The front end of the cup guide 43 is provided with an enlarged flange portion that extends in the radial direction. This enlarged flange portion is connected to the sleeve 21 (specifically, an O-ring 51 disposed at the rear end of the sleeve 21). By being sandwiched between the magnetic suction stator 44, the inside and outside of the cup guide 43 is sealed.
The O-ring 52 disposed on the outer periphery of the rear portion of the sleeve 21 is for preventing oil from leaking from the OCV mounting hole.

The stay 48 is means for coupling the OCV 1 to the engine component, and is fixed between the step portion formed at the front end of the yoke 47 and the magnetic attraction stator 44. The stay 48 may be connected to the electromagnetic actuator 3 by other techniques, such as being welded to the yoke 47.
Then, as described above, the spool valve 5 is inserted into the OCV mounting hole, and the stay 48 of the electromagnetic actuator 3 is fastened to the engine component, whereby the OCV 1 is assembled to the engine.

  The connector 49 is a coupling means formed by a part of secondary molding resin for resin-molding the coil 41 and the like, and terminal terminals 49a respectively connected to the conductive wire end portions of the coil 41 are arranged therein. Yes. The terminal terminal 49a is resin-molded in a secondary molding resin with one end inserted into the coil bobbin, and the other end of the terminal terminal 49a is exposed in the connector 49.

(Description of ECU 13)
The ECU 13 has a function of calculating a “target phase angle” corresponding to the engine operating state, and also includes means for detecting the “actual phase angle” of the vane rotor 15 with respect to the shoe housing 14, and the “actual phase angle” is The energization control of the coil 41 is performed so that the “target phase angle” is obtained.
As a specific example, the ECU 13 controls the amount of current supplied to the coil 41 by duty ratio control. By controlling the amount of current supplied to the coil 41, the position of the spool 4 in the axial direction is linearly slid. And the hydraulic pressure according to the engine operating state is generated in the advance chamber α and the retard chamber β to variably control the advance amount of the camshaft.

(Description of means for preventing foreign matter from reaching plunger 2)
As described above, the plunger 2 slides in the axial direction inside the cup guide 43. In order for the plunger 2 to move in the axial direction, the volume of the second space B formed between the rear end of the plunger 2 and the bottom of the cup guide 43 needs to be provided so as to be variable.
The second space B communicates with the space between the spool 4 and the plunger 2 through a plunger in-hole breathing hole 53 formed in the central portion of the plunger 2 in the axial direction.
The space between the spool 4 and the plunger 2 communicates with the drain port 27 via the spool end throttle 7 and the spool drain hole 6 described above.

Here, between the plunger 2 and the spool 4, a cup shaft 8 having a bottomed cup shape and transmitting the axial force of the plunger 2 to the spool 4 is provided.
The cup shaft 8 is a press-work product provided by a non-magnetic material (for example, stainless steel) having a two-stage cylindrical shape in which a large-diameter cylindrical portion is provided on the front side and a small-diameter cylindrical portion is provided on the rear side. is there. Then, the cup opening (the front side of the large-diameter cylindrical portion) is fitted around the small-diameter portion formed at the rear end of the spool 4, and the cup bottom abuts against the front end of the plunger 2, and the axial force of the plunger 2 is increased. While being transmitted to the spool 4, the urging force of the return spring 22 is provided to the plunger 2.

In order to employ such a configuration, the space between the spool 4 and the plunger 2 is
A volume space C in the cup in the cup shaft 8;
A volume space D outside the cup covering the periphery of the cup shaft 8 on the front side of the collar 45;
A first space A in contact with the plunger 2 on the rear side of the collar 45;
It is divided into.

In the OCV 1 of this embodiment, the hydraulic oil discharged into the spool drain hole 6 (the hydraulic oil discharged into the spool drain hole 6 from the advance port 25 and the retard port 26) is discharged into the first space A and As a means to prevent reaching the second space B,
(A) The first space A is formed through a foreign substance trap (in this embodiment, the first to third foreign substance traps X1 to X3) including a throttle part that restricts the flow path area and a volume space that covers the periphery of the throttle part. It is provided so as to communicate with the drain hole 6 in the spool,
(B) The second space B is provided so as to communicate only with the first space A.

The above (a) will be specifically described.
The OCV 1 of this embodiment is provided with three foreign matter traps (first to third foreign matter traps X1 to X3) between the drain hole 6 in the spool and the first space A.
The first foreign matter trap X1 is
A spool end throttle 7 at the rear end of the spool 4;
A volume space C in the cup in the cup shaft 8;
Consists of.

  The spool end restricting portion 7 has a function of the restricting portion of the foreign substance trap in addition to the function of preventing the hydraulic oil discharged from the advance chamber α and the retard chamber β from flowing into the drain hole 6 in the spool to the electromagnetic actuator 3 side. It also serves. The spool end throttle portion 7 opens at the center of the large diameter cylindrical portion of the cup shaft 8, and the inner diameter dimension of the large diameter cylindrical portion of the cup shaft 8 is sufficiently larger than the inner diameter dimension of the spool end throttle portion 7. Largely provided.

The hydraulic fluid that has passed through the spool end restricting portion 7 and entered the cup volume space C diffuses in the cup volume space C and decelerates. Thereby, the flow of hydraulic fluid can be slowed in the cup internal volume space C, and the foreign matter contained in the hydraulic oil can be retained in the cup internal volume space C.
Thus, the amount of foreign matter entering the plunger 2 from the cup shaft 8 can be reduced by the first foreign matter trap X1.

The second foreign matter trap X2 is
A cup throttle portion 54 formed through the large diameter cylindrical portion of the cup shaft 8 in a radial direction;
A cup outer volume space D covering the periphery of the cup shaft 8;
Consists of.

The cup throttle portion 54 opens on the inner diameter side of the large-diameter cylindrical portion (portion sandwiched between the spool 4 and the cup guide 43) in the collar 45 and passes through the cup throttle portion 54 and enters the external volume space D of the cup. The hydraulic fluid thus diffused in the cup outer volume space D is provided so as to decelerate. Thereby, the flow of hydraulic oil can be slowed in the cup outer volume space D, and the foreign matter contained in the hydraulic oil can be retained in the cup outer volume space D.
In particular, in this embodiment, since the large-diameter cylindrical portion in the collar 45 is provided larger than the inner diameter dimension of the sliding hole 23 provided in the sleeve 21, foreign matter contained in the hydraulic oil is removed from the large-diameter cylindrical portion in the collar 45. Can be stopped.
Thus, the amount of foreign matter entering the plunger 2 side from the cup shaft 8 can be reduced by the second foreign matter trap X2.

The third foreign matter trap X3 is
A small-diameter cylindrical portion provided on the cup shaft 8 (portion inserted into the cylindrical portion 44b) and a gap throttle portion 55 formed by a radial gap between the collar 45;
・ First space A,
Consists of.

The hydraulic oil that has passed through the gap restrictor 55 decelerates in the first space A. As a result, the flow of the hydraulic oil becomes slow, foreign matter can be retained in the first space A, and foreign matter can be prevented from entering the second space B.
Further, since the collar 45 is a component that generates a magnetic force when the coil 41 is energized, the iron-based foreign matter that has entered the inside of the cup shaft 8 is kept on the spool 4 side of the collar 45 (particularly, inside the cup shaft 8). It is possible to prevent the iron-based foreign matter from entering the plunger 2 side from the collar 45.
Furthermore, even if the iron-based foreign matter reaches the first space A, the iron-based foreign matter is attracted to the collar 45, thereby preventing the iron-based foreign matter reaching the first space A from reaching the plunger 2. it can.

  The breathing passage from the drain hole 6 in the spool to the first space A is “the drain hole 6 in the spool → the spool end throttle 7 → the volume in the cup C → the cup throttle 54 → the volume outside the cup D → the gap throttle 55”. → First space A (see arrow in FIG. 2) ”.

The above (b) will be specifically described.
As described above, the OCV 1 of this embodiment is provided such that the second space B communicates only with the first space A via the plunger breathing hole 53.
The cup bottom portion of the cup shaft 8 directly contacts the plunger 2, and the first space A and the in-plunger breathing hole 53 communicate with each other only through a radial groove 56 formed in the cup bottom portion of the cup shaft 8 and extending in the radial direction. To do.

Specifically, the cup bottom of the cup shaft 8 and the plunger breathing hole 53 are both coaxially arranged on the axis of the plunger 2, and the cup bottom of the cup shaft 8 (the portion that comes into contact with the plunger 2). The diameter dimension is larger than the inner diameter dimension of the breathing hole 53 in the plunger.
For this reason, in order to reach the in-plunger breathing hole 53 from the first space A, it is necessary to pass through the radial groove 56 extending in the radial direction, and the communication path from the first space A to the in-plunger breathing hole 53 is complicated ( Can be bent).

  The breathing passage from the drain hole 6 in the spool to the second space B is “the drain hole 6 in the spool → the spool end throttle 7 → the volume in the cup C → the cup throttle 54 → the volume outside the cup D → the gap throttle 55”. → the first space A → the radial groove 56 → the in-plunger breathing hole 53 → the second space B (see the arrow in FIG. 2) ”.

(Effect 1 of an Example)
As described above, the OCV 1 of this embodiment includes a “throttle portion for narrowing the flow path area” and a “volume space covering the periphery of the throttling portion” between the drain hole 6 in the spool and the first space A. Three foreign matter traps (first to third foreign matter traps X1 to X3) are provided. Further, the second space B is communicated only with the first space A.
Thereby, even if the foreign matter (foreign matter mixed in the hydraulic oil) discharged into the drain hole 6 in the spool flows backward together with the hydraulic oil, the foreign matter is trapped by the first to third foreign matter traps X1 to X3. Foreign matter can be prevented from reaching the plunger 2.
For this reason, wear of the plunger sliding portion can be suppressed, and occurrence of poor sliding of the plunger 2 can be prevented in advance. As a result, the reliability of OCV1 can be increased and the reliability of VVT can be increased.

(Effect 2 of Example)
In the OCV 1 of this embodiment, as described above, the first space A and the in-plunger breathing hole 53 communicate with each other only through the radial groove 56 provided in the cup bottom of the cup shaft 8. The communication passage from A to the plunger breathing hole 53 is complicated (bent).
Thereby, since it is difficult for foreign matter to enter the second space B, it is possible to avoid a problem that foreign matter enters the second space B.

  In the above embodiment, an example in which the sleeve 21 (cylindrical member) is used as an example of the valve housing has been described. However, the valve housing is not limited to the sleeve 21 but a member in which an oil passage is formed inside. It may be a valve housing (without using the sleeve 21) in which the sliding hole 23 for inserting the spool 4 is directly formed.

In the above embodiment, the example in which the present invention is applied to the OCV 1 used in the VVT has been shown, but the application of the electromagnetic spool valve is not limited.
Moreover, although the example which uses the spool valve 5 of a four-way valve structure was shown in said Example, the spool valve 5 is not limited to a four-way valve structure, The switching number more than a three-way valve structure or a five-way valve is shown. The spool valve 5 may be used.
As a specific example, the present invention may be applied to, for example, an electromagnetic spool valve having a three-way valve structure for an automatic transmission.

1 OCV (Electromagnetic spool valve)
2 Plunger 3 Electromagnetic actuator 4 Spool 5 Spool valve 6 Drain hole in the spool 7 Spool end throttle part (throttle part in the first foreign matter trap)
8 Cup shaft 11 VCT (Variable camshaft timing mechanism)
25 Lead angle port (Output port that can discharge hydraulic oil to drain hole in spool)
26 Retarded port (Output port that can discharge hydraulic oil to the drain hole in the spool)
45 Collar 53 Breathing hole 54 in plunger Cup throttling part (throttling part in second foreign matter trap)
55 Gap throttling part (throttling part in the third foreign matter trap)
56 radial groove α advance chamber β retard chamber A 1st space (volume space in the 3rd foreign substance trap)
B 2nd space C Volume space in the cup (volume space in the 1st foreign material trap)
D Volume space outside the cup (volume space in the second foreign substance trap)
X1 First foreign matter trap X2 Second foreign matter trap X3 Third foreign matter trap

Claims (8)

An electromagnetic actuator (3) having a plunger (2) driven in the axial direction by a magnetomotive force according to the amount of energization, and a spool valve (5) having a spool (4) driven in the axial direction by the plunger (2) And
In the electromagnetic spool valve (1), the spaces on both sides in the axial direction of the plunger (2) communicate with the drain space via the drain hole (6) in the spool formed in the spool (4).
The spool (4) is provided with a spool end throttle (7) having a smaller flow area than the drain hole (6) in the spool on the side close to the plunger (2) of the drain hole (6) in the spool. ,
Between the plunger (2) and the spool (4), a cup shaft (8) is provided which has a bottomed cup shape and transmits the axial force of the plunger (2) to the spool (4).
Of the spaces on both sides in the axial direction of the plunger (2), the space in contact with the plunger (2) on the side close to the spool (4) is defined as a first space (A) and is separated from the spool (4). When the space in contact with the plunger (2) on the other side is defined as the second space (B),
The first space (A) communicates with the drain hole (6) in the spool via one or a plurality of foreign matter traps each including a throttle portion for reducing the flow path area and a volume space covering the periphery of the throttle portion. And
The electromagnetic spool valve, wherein the second space (B) communicates only with the first space (A). Electromagnetic spool valve (1) according to claim 1,
Two or more foreign matter traps are provided between the drain hole (6) in the spool and the first space (A). In the electromagnetic spool valve (1) according to claim 1 or 2,
One of the foreign traps is
The spool end throttle (7);
A cup internal volume space (C) in the cup shaft (8);
An electromagnetic spool valve characterized by being a first foreign matter trap (X1) comprising: In the electromagnetic spool valve (1) according to any one of claims 1 to 3,
One of the foreign traps is
A cup squeeze portion (54) formed to penetrate in the radial direction of the cup shaft (8);
A cup outer volume space (D) covering the periphery of the cup shaft (8);
An electromagnetic spool valve characterized by being a second foreign matter trap (X2) comprising: In the electromagnetic spool valve (1) according to any one of claims 1 to 4,
Between the plunger (2) and the spool (4), an annular collar (45) for increasing the magnetic attractive force of the plunger (2) is provided,
One of the foreign traps is
A narrowing portion (55) formed by a gap between the small diameter cylindrical portion provided on the cup shaft (8) and the collar (45);
The first space (A);
An electromagnetic spool valve characterized by being a third foreign matter trap (X3). In the electromagnetic spool valve (1) according to any one of claims 1 to 5,
Inside the plunger (2), there is provided an in-plunger breathing hole (53) communicating the first space (A) and the second space (B),
The bottom of the cup shaft (8) directly contacts the plunger (2),
The first space (A) and the in-plunger breathing hole (53) communicate with each other only through a radially extending groove (56) formed in the bottom of the cup shaft (8). Solenoid spool valve to do. In the electromagnetic spool valve (1) according to any one of claims 1 to 6,
The drain hole (6) in the spool is discharged from the output port of the spool valve (5) in addition to the function of a breathing passage for communicating the first and second spaces (A, B) with the drain space. An electromagnetic spool valve having a function of a hydraulic oil discharge passage that guides hydraulic oil to the drain space. Electromagnetic spool valve (1) according to claim 7,
The electromagnetic spool valve (1) includes an advance port (25) communicating with an advance chamber (α) in the variable camshaft timing mechanism (11), and a retard chamber (β) in the variable camshaft timing mechanism (11). A retarding port (26) communicating with the valve, and controlling a hydraulic pressure difference between the advance chamber (α) and the retard chamber (β), and the drain hole (6) in the spool includes the first, In addition to the function of a breathing passage for communicating the second space (A, B) with the drain space, the advance port (25) leading to the advance chamber (α) and the retard chamber (β) An electromagnetic spool valve comprising a function of a hydraulic oil discharge passage that guides hydraulic oil discharged through the retard port (26) to the drain space.

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