JP2009204003A - Electromagnetic spool valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve operational responsiveness in a spool 3 when starting current-carrying, in an electromagnetic spool valve for displacing the spool 3 to the other end side in the axial direction, by increasing hydraulic pressure of a hydraulic pressure camber 4 by current-carrying to an electromagnetic solenoid, by forming the hydraulic pressure chamber 4 on one end side in the axial direction of the spool 3. <P>SOLUTION: A groove 49 is arranged on the other end of a seal member 25, and a second orifice 50 is formed for communicating an inflow port 27 with the hydraulic pressure chamber 4 by the groove 49 when one end of a large diameter land part 15 abuts on the other end of the seal member 25. The first and second orifices 28 and 50 are mutually linearly communicated. Thus, since the first and second orifices 28 and 50 can be penetrated in one straight line without being arranged in a labyrinth shape, resistance to the inflow of a hydraulic fluid to the hydraulic pressure chamber 4 reduces. Thus, since the inflow of the hydraulic fluid to the hydraulic pressure chamber 4 quickens, an increase speed of hydraulic pressure increases when starting the current-carrying, and the operational responsiveness of the spool 3 is improved when starting the current-carrying. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electromagnetic spool valve that forms a hydraulic chamber at one axial end of a spool and displaces the spool in the axial direction by increasing or decreasing the hydraulic pressure in the hydraulic chamber according to the operation of an electromagnetic solenoid.

Conventionally, as shown in FIG. 6, the electromagnetic spool valve 100 includes a hydraulic chamber 102 formed on one end side in the axial direction of the spool 101, and the spool 101 is displaced via the hydraulic pressure of the hydraulic chamber 102. It is used for adjusting the hydraulic pressure in the hydraulic circuit of an automatic transmission (not shown).
The electromagnetic spool valve 100 includes a substantially cylindrical sleeve 103 and a spool 101 that is slidably supported by the sleeve 103. By increasing or decreasing the hydraulic pressure of the hydraulic chamber 102 according to the operation of the electromagnetic solenoid 104, The spool 101 is displaced in the axial direction.

  Here, one end side in the axial direction of the hydraulic chamber 102 is defined by a seal member 106 fixedly accommodated in the sleeve 103, and the other end side in the axial direction is defined by the spool 101. That is, the hydraulic chamber 102 is formed so as to be expandable / contractable by displacement of the spool 101 in the axial direction. The seal member 106 has a function of regulating the amount of displacement of the spool 101 toward one end in the axial direction. The amount of displacement of the spool 101 toward one end in the axial direction is such that one end of the spool 101 is the other end of the seal member 106. It is regulated by contacting with.

  A hydraulic oil inlet 107 to the hydraulic chamber 102 is provided in the sleeve 103, and the opening of the inlet 107 with respect to the hydraulic chamber 102 decreases as one end of the spool 101 approaches the other end of the seal member 106. The inlet 107 is provided with a first orifice 108 that regulates the flow rate of the hydraulic oil.

  A hydraulic oil outlet 109 from the hydraulic chamber 102 is provided in the seal member 106 and is opened and closed according to the operation of the electromagnetic solenoid 104. That is, the electromagnetic solenoid 104 has a shaft 111 that is displaced by being energized to the other end in the axial direction by energizing the solenoid coil 110, and a valve body that operates the opening degree of the outlet 109 at the other end of the shaft 111. 112 is provided.

  With the above configuration, in a state where the solenoid coil 110 is not energized, the shaft 111 is biased by the hydraulic pressure of the hydraulic chamber 102 and is displaced to one end side in the axial direction, and the opening degree of the outlet 109 is increased. As a result, the outflow of hydraulic oil from the hydraulic chamber 102 is promoted, and the hydraulic pressure in the hydraulic chamber 102 decreases, so that the spool 101 is urged by the restoring spring 114 and its one end abuts against the other end of the seal member 106. Displaces to one end in the axial direction until contact. Further, the shaft 111 is displaced to a position corresponding to the hydraulic pressure of the hydraulic chamber 102 when one end of the spool 101 is in contact with the other end of the seal member 106.

  When the solenoid coil 110 is energized, the shaft 111 is displaced to the other end side in the axial direction, and the opening degree of the outlet 109 is reduced. As a result, the hydraulic pressure in the hydraulic chamber 102 rises, so that the spool 101 is detached from the seal member 106 and starts to be displaced toward the other end in the axial direction. Then, the spool 101 is displaced to the other end side in the axial direction to a position where the forces acting in the axial direction are balanced and stopped.

  By the way, in the electromagnetic spool valve 100, the operation responsiveness of the spool 101 accompanying the start of energization of the solenoid coil 110, that is, the responsiveness to the displacement of the spool 101 from the state in contact with the seal member 106 to a desired position. Securing is seen as a problem. The operation of the spool 101 at the start of energization depends on the rising speed of the hydraulic pressure in the hydraulic chamber 102 at the start of energization, and the response speed increases as the increasing speed of the oil pressure increases.

  Therefore, a groove 116 is provided at the other end of the seal member 106, and when the one end of the spool 101 is in contact with the other end of the seal member 106, the groove 116 is communicated with the inflow port 107 and the hydraulic chamber 102. A technique of functioning as an orifice 117 is considered (for example, see Patent Document 1). According to this technique, even when the spool 101 is in contact with the seal member 106, the hydraulic chamber 102 is kept inflow of hydraulic oil at a constant flow rate via the second orifice 117. For this reason, when the opening degree of the outlet 109 starts to be reduced due to the start of energization, the hydraulic pressure in the hydraulic chamber 102 can be quickly increased, so that the responsiveness at the start of energization is high.

However, the demand for improving the responsiveness at the start of energization is extremely high, and further improvement is expected particularly with respect to the responsiveness when the viscosity of the hydraulic oil is large as at low temperatures. The response at the start of energization can be improved by enlarging the hole diameter of the second orifice 117 to increase the flow rate of the hydraulic oil, but the increase in the flow rate of the hydraulic oil can be increased by a hydraulic pump (not shown). )), Resulting in a deterioration in fuel consumption. For this reason, a separate measure that does not depend on the expansion of the hole diameter of the second orifice 117 is required.
JP 2002-357281 A

  The present invention has been made to solve the above-described problems, and an object of the present invention is to form a hydraulic chamber at one end of the spool in the axial direction and raise the hydraulic pressure of the hydraulic chamber by energizing the electromagnetic solenoid. An electromagnetic spool valve that displaces the spool toward the other axial end is to improve the operation responsiveness of the spool at the start of energization.

[Means of Claim 1]
The electromagnetic spool valve according to claim 1 includes a substantially cylindrical sleeve and a spool that is slidably supported by the sleeve, forms a hydraulic chamber on one end side in the axial direction of the spool, and controls the hydraulic pressure of the hydraulic chamber. The spool is displaced in the axial direction by increasing or decreasing in accordance with the operation of the electromagnetic solenoid.
Also, one end in the axial direction of the hydraulic chamber is partitioned by a seal member that is fixedly accommodated in the sleeve, and the hydraulic chamber is provided in the inlet provided in the sleeve and the seal member in accordance with the operation of the electromagnetic solenoid. The hydraulic pressure is increased or decreased by flowing in or out of the hydraulic oil through the opening / closing outlet, and a first orifice for regulating the flow rate of the hydraulic oil is provided at the inlet.

In addition, the spool is displaced to one end in the axial direction as the opening of the outlet increases and the hydraulic pressure in the hydraulic chamber decreases, and the spool opens and the hydraulic pressure in the hydraulic chamber increases as the opening of the outlet decreases. The amount of displacement of the spool toward one end in the axial direction is regulated by one end of the spool coming into contact with the other end of the seal member. As it approaches the other end, it shrinks.
Further, at least one of the one end of the spool and the other end of the seal member is provided with a groove, and the groove communicates the inlet and the hydraulic chamber when one end of the spool is in contact with the other end of the seal member. Forming a second orifice. The first orifice and the second orifice communicate linearly.

  As a result, the first and second orifices can be penetrated by a single straight line without being arranged in a labyrinth, so that the resistance to the inflow of hydraulic oil into the hydraulic chamber is reduced. For this reason, the flow of the hydraulic oil into the hydraulic chamber becomes faster and the hydraulic oil rise rate in the hydraulic chamber increases, so that the operation response of the spool at the start of energization is improved.

[Means of claim 2]
According to the electromagnetic spool valve of the second aspect, the second orifice is smaller in diameter than the first orifice, and the flow axis of the first orifice and the flow axis of the second orifice are parallel to each other. It is. Assuming a cross section of the first orifice perpendicular to the flow axis of the first orifice and a cross section of the second orifice perpendicular to the flow axis of the second orifice, the cross section of the first orifice Projecting the cross section of two orifices, the cross section of the second orifice is included in the cross section of the first orifice.
As a result, the hydraulic oil that has passed through the first orifice flows into the second orifice while being prevented from spreading outward from the cross section of the first orifice. For this reason, the resistance with respect to the inflow of the hydraulic fluid into the hydraulic chamber in the first and second orifices is further reduced.

The electromagnetic spool valve of the best mode includes a substantially cylindrical sleeve and a spool that is slidably supported by the sleeve. A hydraulic chamber is formed at one end of the spool in the axial direction, and the hydraulic pressure of the hydraulic chamber is controlled by an electromagnetic solenoid. The spool is displaced in the axial direction by increasing or decreasing in accordance with the operation.
Also, one end in the axial direction of the hydraulic chamber is partitioned by a seal member that is fixedly accommodated in the sleeve, and the hydraulic chamber is provided in the inlet provided in the sleeve and the seal member in accordance with the operation of the electromagnetic solenoid. The hydraulic pressure is increased or decreased by flowing in or out of the hydraulic oil through the opening / closing outlet, and a first orifice for regulating the flow rate of the hydraulic oil is provided at the inlet.

In addition, the spool is displaced to one end in the axial direction as the opening of the outlet increases and the hydraulic pressure in the hydraulic chamber decreases, and the spool opens and the hydraulic pressure in the hydraulic chamber increases as the opening of the outlet decreases. The amount of displacement of the spool toward one end in the axial direction is regulated by one end of the spool coming into contact with the other end of the seal member. As it approaches the other end, it shrinks.
Further, at least one of the one end of the spool and the other end of the seal member is provided with a groove, and the groove communicates the inlet and the hydraulic chamber when one end of the spool is in contact with the other end of the seal member. Forming a second orifice. The first orifice and the second orifice communicate linearly.

  The second orifice is smaller in diameter than the first orifice, and the flow axis of the first orifice and the flow axis of the second orifice are parallel. Assuming a cross section of the first orifice perpendicular to the flow axis of the first orifice and a cross section of the second orifice perpendicular to the flow axis of the second orifice, the cross section of the first orifice Projecting the cross section of two orifices, the cross section of the second orifice is included in the cross section of the first orifice.

[Configuration of Example 1]
The configuration of the electromagnetic spool valve 1 according to the first embodiment will be described with reference to FIG.
The electromagnetic spool valve 1 includes a substantially cylindrical sleeve 2 and a spool 3 that is slidably supported by the sleeve 2, and a hydraulic chamber 4 is formed on one end side in the axial direction of the spool 3. Is increased or decreased according to the operation of the electromagnetic solenoid 5 to displace the spool 3 in the axial direction, and is used, for example, for adjusting the hydraulic pressure in a hydraulic circuit of an automatic transmission (not shown).

That is, in the electromagnetic spool valve 1, the portion on the other end side in the axial direction constituted by the sleeve 2 and the spool 3 is a pressure regulating valve portion 6 that regulates and outputs the input hydraulic pressure according to the position of the spool 3. In addition, the part on the one end side in the axial direction including the electromagnetic solenoid 5 and the hydraulic chamber 4 is a drive unit 7 for operating the pressure regulating valve unit 6.
First, the pressure regulation function in the pressure regulation valve unit 6 will be described.

  First, the sleeve 2 communicates with the discharge side of a hydraulic pump (not shown) and is input to an input port 10 to which hydraulic pressure before pressure adjustment is input, an output port 11 to output hydraulic pressure after pressure adjustment, and a pressure regulating valve portion A discharge port 12 for discharging excess hydraulic oil in 6 to a low pressure side such as an oil pan (not shown) is sequentially provided from the other end side in the axial direction toward one end side.

  The spool 3 is provided with two large-diameter land portions 14 and 15 having a large diameter that are in sliding contact with the inner periphery of the sleeve 2. Of the two large-diameter land portions 14 and 15, the large-diameter land portion 14 on the other axial end side opens and closes the input port 10, and the large-diameter land portion 15 on one axial end side opens and closes the discharge port 12. To do. A distribution chamber 16 is formed between the large-diameter land portions 14 and 15 so that the hydraulic oil after pressure regulation always flows and communicates with the output port 11.

  That is, as will be described later, when the spool 3 is displaced to a desired position according to the hydraulic pressure of the hydraulic chamber 4, the distribution chamber 16 communicates with the input port 10 at an opening degree corresponding to the position of the spool 3. As a result, the hydraulic oil flowing into the input port 10 is adjusted in hydraulic pressure and flows into the distribution chamber 16, and the adjusted hydraulic oil flows out from the output port 11.

  Further, the spool 3 is provided with a small-diameter land portion 18 having a smaller diameter than the large-diameter land portions 14 and 15 on the other axial end side of the large-diameter land portions 14 and 15 and is in sliding contact with the inner periphery of the sleeve 2. The small-diameter land portion 18 is fed between the inner periphery of the sleeve 2 and the other end of the large-diameter land portion 14 to feed back the pressure-adjusted hydraulic pressure to the spool 3 to act. Form.

  Here, the F / B chamber 19 communicates with the distribution chamber 16 via an F / B port 20 penetrating the large-diameter land portion 14, and the hydraulic pressure after pressure adjustment from the distribution chamber 16 via the F / B port 20. Receive the supply. The hydraulic pressure in the F / B chamber 19 exerts an urging force based on the diameter difference between the large-diameter land portion 14 and the small-diameter land portion 18 on one end side in the axial direction with respect to the spool 3. That is, the adjusted hydraulic pressure is fed back to the position of the spool 3 by being supplied to the F / B chamber 19 and acting on one end side in the axial direction with respect to the spool 3.

  That is, when the hydraulic pressure after pressure adjustment is excessive, the urging force by the hydraulic pressure in the F / B chamber 19 is large, so that the spool 3 is slightly displaced toward one end in the axial direction. As a result, the opening degree of the input port 10 with respect to the distribution chamber 16 is reduced, so that the hydraulic pressure after pressure adjustment is reduced. Further, when the hydraulic pressure after pressure adjustment is excessively small, the urging force by the hydraulic pressure in the F / B chamber 19 is small, so that the spool 3 is slightly displaced toward the other end in the axial direction. As a result, the opening degree of the input port 10 with respect to the distribution chamber 16 increases, so that the hydraulic pressure after pressure adjustment increases.

  In this way, the pressure regulating valve unit 6 feeds back the pressure after the pressure regulation to the position of the spool 3 by applying the axial biasing force by the pressure after the pressure regulation to the spool 3. Minor correction to stabilize. Thereby, the pressure regulating valve unit 6 stabilizes the hydraulic pressure after pressure regulation, that is, the output hydraulic pressure.

  The F / B port 20 is provided with an orifice 21. The orifice 21 moderates the supply of hydraulic pressure from the distribution chamber 16 to the F / B chamber 19 and contributes to the stability of the position of the spool 3. Further, a restoring spring 23 is set on the other axial end side of the small-diameter land portion 18, and the restoring spring 23 biases the spool 3 toward one axial end side.

Next, the drive unit 7 will be described.
The drive unit 7 operates the pressure regulating valve unit 6 by displacing the spool 3 in the axial direction by increasing or decreasing the hydraulic pressure of the hydraulic chamber 4 according to the operation of the electromagnetic solenoid 5.

  First, one axial end side of the hydraulic chamber 4 is defined by a seal member 25 that is fixedly accommodated in the sleeve 2, and the other axial end side is defined by a large-diameter land portion 15 of the spool 3. That is, the hydraulic chamber 4 is formed so as to be expandable / contractable by displacement of the spool 3 in the axial direction. The seal member 25 has a function of regulating the amount of displacement of the spool 3 toward the one end side in the axial direction. The amount of displacement of the spool 3 toward the one end side in the axial direction depends on one end of the spool 3 (the large-diameter land portion 15). One end) is regulated by contacting the other end of the seal member 25.

  The inlet of the hydraulic oil to the hydraulic chamber 4 is an inflow port 27 provided on the sleeve 2 at one end side in the axial direction from the discharge port 12. The inflow port 27 communicates with the discharge side of the hydraulic pump. The opening degree of the inflow port 27 with respect to the hydraulic chamber 4 decreases as one end of the large-diameter land portion 15 approaches the other end of the seal member 25. The inflow port 27 is provided with a first orifice 28 that regulates the flow rate of hydraulic oil flowing into the hydraulic chamber 4.

  The outlet of the hydraulic oil from the hydraulic chamber 4 is an outflow port 29 provided in the seal member 25, and the outflow port 29 is opened and closed according to the operation of the electromagnetic solenoid 5. Here, the inner peripheral surface of the seal member 25 includes a tapered surface 30 that is tapered toward one end side in the axial direction to form the hydraulic chamber 4, and the outflow port 29 is connected to one end of the tapered surface 30. It is provided to do. Further, the other axial end of the taper surface 30 is opened to the other end of the seal member 25 with a large diameter, and the other end of the seal member 25 is annular. The other end of the seal member 25 abuts against one end of the large-diameter land portion 15 in an annular shape.

  Further, an outflow chamber 32 into which hydraulic oil flowing out from the outflow port 29 flows is formed on one end side in the axial direction of the seal member 25, and the hydraulic oil flowing into the outflow chamber 32 is more axial than the inflow port 27 in the sleeve 2. The gas is discharged to the low pressure side by the second discharge port 33 provided on one end side in the direction. The opening degree of the outflow port 29 with respect to the outflow chamber 32 is operated by a valve body 35 provided at the other end of the shaft 34 of the electromagnetic solenoid 5.

  One end side in the axial direction of the outflow chamber 32 is partitioned by a pressure-proof shielding plate 38 disposed on the front surface on the other end side in the axial direction of the diaphragm 37 that seals the inside of the electromagnetic solenoid 5. The pressure-proof shielding plate 38 prevents the hydraulic pressure in the outflow chamber 32 from directly acting on the diaphragm 37. The diaphragm 37 has an outer peripheral portion sandwiched between the sleeve 2 and the stator core 39, and an inner peripheral portion fitted in a groove provided on the outer periphery of the shaft 34. To prevent intrusion.

The electromagnetic solenoid 5 is slidably disposed on a solenoid coil 41 that is energized, a stator core 39 that is disposed on the inner peripheral side and the other axial end side of the solenoid coil 41 to form a magnetic circuit, and an inner peripheral side of the stator core 39. A moving core 42 that is excited by being energized to the solenoid coil 41 and displaced toward the other end in the axial direction, a shaft 34 that is press-fitted into the moving core 42 and displaced together with the moving core 42, an outer peripheral side of the solenoid coil 41, and one axial end side. It has a yoke 43 which is arranged and forms a magnetic circuit, a connector terminal 44 which forms an input end of power from a power source (not shown), and the like.
Further, as described above, the valve body 35 for operating the opening degree of the outflow port 29 with respect to the outflow chamber 32 is provided at the other end of the shaft 34.

  With such a configuration, when the solenoid coil 41 is not energized, the shaft 34 is urged by the hydraulic pressure of the hydraulic chamber 4 to be displaced to one end side in the axial direction, and the opening degree of the outflow port 29 relative to the outflow chamber 32. Expands. Accordingly, the hydraulic oil in the hydraulic chamber 4 is urged to flow out from the hydraulic chamber 4 and the hydraulic pressure in the hydraulic chamber 4 is lowered. Therefore, the spool 3 is urged by the restoring spring 23 and one end of the large-diameter land portion 15 is connected to the seal member 25. Displacement toward one end in the axial direction until it comes into contact with the other end. Further, the shaft 34 is displaced to a position corresponding to the hydraulic pressure of the hydraulic chamber 4 when one end of the large-diameter land portion 15 is in contact with the other end of the seal member 25.

  When the solenoid coil 41 is energized, the shaft 34 together with the moving core 42 is displaced to the other end side in the axial direction, and the opening degree of the outflow port 29 with respect to the outflow chamber 32 is reduced. As a result, the hydraulic pressure in the hydraulic chamber 4 rises, so that the large-diameter land portion 15 is detached from the seal member 25, and the spool 3 starts to be displaced toward the other end side in the axial direction. Then, the spool 3 has the other axial end to a position where the force acting in the axial direction, that is, the biasing force due to the hydraulic pressure of the hydraulic chamber 4, the biasing force due to the restoring spring 23, and the biasing force due to the hydraulic pressure of the F / B chamber 19 are balanced. Displace to the side and stop.

  Here, the hydraulic pressure in the hydraulic chamber 4 is determined according to the opening degree of the outflow port 29, and the opening degree of the outflow port 29 is determined according to the displacement amount of the shaft 34, that is, the energization amount to the solenoid coil 41. The stop position is determined according to the energization amount to the solenoid coil 41 as a result.

  An adjuster 46 that restricts displacement of the shaft 34 toward one end in the axial direction of the shaft 34 is screwed into the yoke 43 at one end in the axial direction of the shaft 34. A coil spring 47 is mounted between the adjuster 46 and the shaft 34 to exert an urging force on the other end side in the axial direction with respect to the shaft 34, and the shaft 34 can be gently displaced by the coil spring 47.

[Features of Example 1]
According to the electromagnetic spool valve 1 of Example 1, one groove 49 is provided at the other end of the seal member 25 as shown in FIGS. The groove 49 forms a second orifice 50 that communicates the inflow port 27 and the hydraulic chamber 4 when one end of the large-diameter land portion 15 is in contact with the other end of the seal member 25. The first orifice 28 and the second orifice 50 communicate linearly.

  The second orifice 50 is smaller in diameter than the first orifice 28, and the flow path axis of the first orifice 28 (referred to as the first flow path axis 52) and the flow path of the second orifice 50. The axis (referred to as the second flow path axis 53) is coaxial. A cross section 54 of the first orifice 28 perpendicular to the first flow path axis 52 and a cross section 55 of the second orifice 50 perpendicular to the second flow path axis 53 are assumed. When projected, the cross section 55 is included in the cross section 54.

[Effect of Example 1]
In the electromagnetic spool valve 1 of the first embodiment, a groove 49 is provided at the other end of the seal member 25, and the groove 49 flows in when one end of the large-diameter land portion 15 is in contact with the other end of the seal member 25. A second orifice 50 that communicates the port 27 and the hydraulic chamber 4 is formed. The first orifice 28 and the second orifice 50 communicate linearly.
As a result, the first and second orifices 28 and 50 can be penetrated by one straight line without being arranged in a labyrinth, so that the resistance to the inflow of hydraulic oil into the hydraulic chamber 4 is reduced. For this reason, since the inflow of the hydraulic oil into the hydraulic chamber 4 becomes faster, the increase rate of the hydraulic pressure increases with respect to the increase of the hydraulic pressure in the hydraulic chamber 4 due to the start of energization. As a result, the operation responsiveness of the spool 3 at the start of energization is improved.

Further, assuming a cross section 54 of the first orifice 28 perpendicular to the first flow path axis 52 and a cross section 55 of the second orifice 50 perpendicular to the second flow path axis 53, the cross section 55 is represented by the cross section 55. When projected, the cross section 55 is included in the cross section 54.
As a result, the hydraulic oil that has passed through the first orifice 28 flows into the second orifice 50 while being prevented from spreading outward from the cross section 54. For this reason, the resistance to the inflow of the hydraulic oil into the hydraulic chamber 4 at the first and second orifices 28 and 50 is further reduced.

[Modification]
The first and second orifices 28 and 50 of the first embodiment are provided so that the first and second flow path shafts 52 and 53 are on the same axis. However, the setting ranges shown in FIGS. The setting position of the second orifice 50 may be changed so that the first and second flow path axes 52 and 53 are parallel to each other at 57 and 58. That is, the setting position of the second orifice 50 can be changed as long as it can be penetrated by the first orifice 28 and one straight line.

Further, although the single groove 49 of the first embodiment is provided at the other end of the seal member 25, the groove 49 may be provided at one end of the spool 3, or the number of the grooves 49 may be plural.
Furthermore, although the electromagnetic spool valve 1 of the first embodiment is used for adjusting the hydraulic pressure in the hydraulic circuit of the automatic transmission, the electromagnetic spool valve 1 is used for adjusting the hydraulic pressure in the hydraulic circuit other than the automatic transmission. You can also.

It is sectional drawing which shows the structure of an electromagnetic spool valve (Example 1). It is a partial expanded sectional view which shows the principal part of an electromagnetic spool valve (Example 1). (A) is AA sectional drawing of FIG. 2, (b) is BB sectional drawing of FIG. 2 (Example 1). It is a partial expanded sectional view which shows the setting range of a 2nd orifice (modification example). It is CC sectional drawing of FIG. 4 which shows the setting range of a 2nd orifice (modification). (A) is sectional drawing which shows the structure of an electromagnetic spool valve, (b) is the elements on larger scale which show the principal part of an electromagnetic spool valve (conventional example).

Explanation of symbols

1 Electromagnetic Spool Valve 2 Sleeve 3 Spool 4 Hydraulic Chamber 5 Electromagnetic Solenoid 25 Seal Member 27 Inflow Port (Inlet)
28 First orifice 29 Outflow port (outlet)
49 Groove 50 Second orifice 52 First flow path axis (first orifice flow path axis)
53 Second channel axis (channel axis of the second orifice)
54 cross section (cross section of the first orifice)
55 cross section (second orifice cross section)

Claims (2)

A substantially cylindrical sleeve and a spool that is slidably supported by the sleeve are provided. A hydraulic chamber is formed at one axial end of the spool, and the hydraulic pressure in the hydraulic chamber is increased or decreased according to the operation of the electromagnetic solenoid. In the electromagnetic spool valve that displaces the spool in the axial direction,
One end side in the axial direction of the hydraulic chamber is partitioned by a seal member that is fixedly accommodated in the sleeve,
In the hydraulic chamber, the hydraulic oil flows in and out through an inlet provided in the sleeve and an outlet provided in the seal member and opened and closed according to the operation of the electromagnetic solenoid.
The inlet is provided with a first orifice for regulating the flow rate of hydraulic oil,
The spool is displaced toward one end in the axial direction as the opening of the outlet increases and the hydraulic pressure of the hydraulic chamber decreases, and the opening of the outlet decreases and the hydraulic pressure of the hydraulic chamber increases. Is displaced to the other axial end side,
The amount of displacement of the spool toward one end in the axial direction is regulated by one end of the spool coming into contact with the other end of the seal member. As it approaches the edge, it shrinks,
At least one of one end of the spool and the other end of the seal member is provided with a groove,
The groove forms a second orifice that communicates the inlet and the hydraulic chamber when one end of the spool is in contact with the other end of the seal member;
The electromagnetic spool valve, wherein the first orifice and the second orifice communicate linearly. The electromagnetic spool valve according to claim 1, wherein
The second orifice is smaller in diameter than the first orifice;
The flow axis of the first orifice and the flow axis of the second orifice are parallel;
Assuming a cross section of the first orifice perpendicular to the flow axis of the first orifice and a cross section of the second orifice perpendicular to the flow axis of the second orifice,
An electromagnetic spool valve characterized in that when the cross section of the second orifice is projected onto the cross section of the first orifice, the cross section of the second orifice is included in the cross section of the first orifice.

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