JP2005273688A - Solenoid valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stabilize pressure characteristics by preventing shortage of oil at a sliding part of a land part corresponding to a discharge port side. <P>SOLUTION: This solenoid valve is provided with a supply port 51 supplying operating fluid with corresponding to one of the two land parts 42, 43 provided on a spool 20 stored in a valve sleeve 19, and is provided with the discharge port 52 discharging operating fluid with corresponding to another of the two land parts, and has an auxiliary supply port 54 connected to the supply port 51 opened with corresponding to the land part on the discharge port 52 side. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electromagnetic valve that drives a plunger by excitation of a coil and displaces a spool along with the plunger.

  In general, an automatic transmission or the like installed in a vehicle is provided with a solenoid valve, and hydraulic fluid is controlled to a predetermined pressure by the solenoid valve. As this type of solenoid valve, conventionally, for example, a solenoid valve as disclosed in Japanese Patent Laid-Open No. 2003-314743 is known.

  That is, as shown in FIG. 3, the conventional solenoid valve includes a solenoid unit 60 and a valve unit 70 provided at one end of the solenoid unit 60.

  The valve unit 70 includes a sleeve 71 and a spool 72 accommodated in the sleeve 71 so as to be slidable. Two land portions 73 and 74 are provided on the spool 72 so as to be spaced apart from each other, and a supply port 75 is opened corresponding to an end edge of one land portion 73, and corresponding to an end edge of the other land portion 74. A discharge port 76 is opened, and an output port 77 is opened between the two land portions 73 and 74. Further, a drain port 79 is opened corresponding to a spring accommodating hole 78 provided on the side of the other land portion 74.

  When the coil 61 of the solenoid unit 60 is excited and the plunger 62 is pulled toward the core 63, the spool 72 is displaced in the sleeve 71 via the shaft 74. As a result, the flow path of the hydraulic oil provided in the sleeve 71 is appropriately switched, and the discharge of the hydraulic oil supplied from the supply port 75 to the discharge port 76 is restricted. Hydraulic oil is output.

JP 2003-314743 A (paragraph

, Paragraph

~

Fig. 1)

  As described above, in the conventional solenoid valve, hydraulic fluid having pressure is supplied to one land portion from the supply port to lubricate the sliding portion, while the other land portion is discharged. Since only the port and the drain port are supported, the sliding portion is not sufficiently lubricated, and stick slip may occur in the sliding of the spool due to running out of oil. As a result, there is a problem that the pressure characteristic at the start of the spool becomes unstable as shown in part A of FIG.

  The present invention has been made to solve the above-described conventional problems, and is intended to prevent oil shortage at the sliding portion of the land portion corresponding to the discharge port side and stabilize pressure characteristics.

  In order to solve the above-mentioned problem, the invention according to claim 1 is an electromagnetic valve that displaces a spool accommodated in a valve sleeve by a solenoid unit portion, and at least two land portions are separated from each other in the spool. A supply port for supplying hydraulic oil corresponding to one of the two land portions, a discharge port for discharging hydraulic oil corresponding to the other of the two land portions, An output port for outputting a control pressure controlled by displacement of the spool is provided between the supply port and the discharge port, and an auxiliary supply port connected to the supply port corresponding to the land portion on the discharge port side is provided. It is characterized by opening.

  The invention according to claim 2 is an electromagnetic valve for displacing a spool accommodated in the valve sleeve by a solenoid unit portion, wherein the spool is provided with first, second and third land portions. The first land portion and the second land portion are provided adjacent to each other, and the second land portion and the third land portion are provided apart from each other by a predetermined amount in the axial direction, and the first and second land portions are provided. An annular groove into which a control pressure is introduced from a feedback port is formed corresponding to the step portion formed at the boundary portion of the land portion, and the supply port and the discharge port are respectively corresponded to the second and third land portions And an annular groove communicating with the output port for outputting the control pressure correspondingly between the second and third land portions, and an annular groove communicating with the discharge port. It is characterized in that it has opened the serial supply port connected to auxiliary supply port.

  According to the first and second aspects of the invention configured as described above, the hydraulic oil supplied to the supply port is also supplied from the auxiliary supply port to the land portion corresponding to the discharge port. A part of the hydraulic oil supplied from the auxiliary supply port flows through the fitting gap between the land portion and the valve hole and is discharged from the discharge port and the drain port, respectively.

  As a result, the hydraulic oil is always held in the sliding portion of the land portion corresponding to the discharge port, so that the oil does not run out in the sliding portion of the land portion, and the sliding action of the spool is smoothly performed. And the pressure characteristics can be stabilized.

  Hereinafter, an embodiment of the present invention will be described with reference to FIG. The electromagnetic valve 10 of the present embodiment is mainly configured by a solenoid unit portion 11 and a spool valve portion 12 provided at one end of the solenoid unit portion 11. The solenoid unit portion 11 includes a cover 14, a core 15, a coil 16, a plunger 17, a shaft 18, and the like, and the spool valve portion 12 includes a valve sleeve 19, a spool 20, and the like.

  The cover 14 made of a magnetic body has a bottomed cylindrical outer cylindrical portion 21 and an inner cylinder that is smaller in diameter than the inner diameter of the outer cylindrical portion 21 and shorter in the axial direction than the outer cylindrical portion 21. It is comprised from the shape part 22. FIG. The outer cylindrical portion 21 and the inner cylindrical portion 22 are formed concentrically, and both the cylindrical portions 21 and 22 are integrally formed so as to be continuous at the bottom. A bottomed support hole 23 is formed in the bottom axial center of the inner cylindrical portion 22, and the coil 16 is wound in a cylindrical space formed by the inner cylindrical portion 22 and the outer cylindrical portion 21. The bobbin 24 is fitted and fixed.

  The core 15 has a flange 26, and the opening end of the outer cylindrical portion 21, that is, one end of the cover 14 is fitted to the outer periphery of the flange 26. The core 15 is made of a substantially cylindrical magnetic body, and a through hole 25 concentric with the support hole 23 is formed at the axial center thereof. The bobbin 24 is fitted on the outer peripheral surface of the core 15, and one end of the bobbin 24 is in contact with the side end of the flange 26 via a filter 27. A concave yoke portion 15 a is formed at the tip of the core 15 facing the inner cylindrical portion 22.

  A large-diameter sliding chamber 28 is formed by the inner cylindrical portion 22 and the yoke portion 15 a of the core 15. The sliding chamber 28 includes a first end surface 28a formed in the inner cylindrical portion 22 and a second end surface 28b formed in the yoke portion 15a. A plunger 17 made of a magnetic material is slidably disposed in the sliding chamber 28 with a slight gap with respect to the inner peripheral surface of the yoke portion 15a and the inner cylindrical portion 22. A shaft 18 made of a non-magnetic material is passed through and fixed to the axis of the plunger 17. One end of the shaft 18 is slidably inserted into the support hole 23 via a bush 29a. The other end of the shaft 18 is slidably inserted into the through-hole 25 of the core 15 via the bush 29b, and protrudes from the end surface of the core 15 (hereinafter referred to as a joining surface 30).

  A valve sleeve 19 for slidably fitting the spool 20 is disposed on the joint surface 30 side of the core 15. The valve sleeve 19 caulks the open end portion of the outer cylindrical portion 21 of the cover 14 in a state where the flange portion 34 formed on the side end portion is joined to the flange 26 of the core 15. 11 are integrally coupled.

  Further, the valve sleeve 19 is formed with a first valve hole 35, a second valve hole 36, and a spring accommodating hole 37, the diameter of which gradually increases from the solenoid unit 11 side. The valve holes 35 and 36 and the spring accommodating hole 37 are formed so as to extend coaxially with the cover 14, the core 15 and the plunger 17. The open end of the spring accommodating hole 37 is closed by a plug 39 that is screwed into a screw hole 38 formed on the inner peripheral surface thereof. A spring 40 is provided between the plug 39 and the spool 20, and the shaft 20 that presses the spool 20 toward the shaft 18 by the urging force of the spring 40, so that the shaft 18 that abuts the spool 20 is usually in the upper half of FIG. As shown in the figure, the plunger 17 is held at a position where it comes into contact with the first end face 28 a of the sliding chamber 28.

  The spool 20 is provided with a first land portion 41 that fits into the first valve hole 35 and second and third land portions 42 and 43 that fit into the second valve hole 36, respectively. It has been. The first land portion 41 and the second land portion 42 are provided adjacent to each other, and an annular groove 44 is formed in the valve sleeve 19 corresponding to the step portion provided at the boundary portion. A feedback port 45 is opened in the annular groove 44. The second and third land portions 42 and 43 are provided apart from each other by a predetermined amount in the axial direction, and are connected to each other by a small diameter portion 46. An annular groove 47 is formed in the valve sleeve 19 corresponding to the small diameter portion 46, and an output port 48 for outputting a control pressure is communicated with the annular groove 47. The output port 48 communicates with the feedback port 45 through a notch 19a formed on the outer periphery of the valve sleeve 19 when the valve sleeve 19 is mounted in a mounting hole of a housing (not shown). Yes. Further, annular grooves 49 and 50 are formed in the valve sleeve 19 so as to correspond to the mutually opposing end surfaces of the second and third land portions 42 and 43, respectively. A supply port 51 and a discharge port 52 communicate with the annular grooves 49 and 50, respectively. An annular groove 53 is formed in the valve sleeve 19 between the annular groove 50 and the spring accommodating hole 37, and an auxiliary supply port 54 connected to the supply port 51 is communicated with the annular groove 53. Yes. Further, a drain port 55 that opens to the spring accommodating hole 37 is formed in the plug 39.

  With the configuration described above, when the coil 16 is in a non-excited state, the spool 20 and the shaft 18 are held at a position where the plunger 17 abuts against the first end surface 28 a of the sliding chamber 28 by the biasing force of the spring 40. When hydraulic fluid is supplied to the supply port 51 in this non-excited state, the hydraulic fluid passes through the gap formed between the end face of the second land portion 42 and the supply port 51, the second valve hole 36. Output from the output port 48. At this time, the pressure of the supplied hydraulic oil is controlled and output to a control pressure corresponding to the gap.

  When the coil 16 is excited, the spool 17 is displaced against the biasing force of the spring 40 by pulling the plunger 17 toward the core 15. As a result, the gap between the end face of the second land portion 42 and the supply port 51 is gradually reduced. Conversely, a gap is formed between the end face of the third land portion 43 and the discharge port 50 that was initially closed by the third land portion 43, and the gap gradually increases. For this reason, the control pressure of the output port 48 gradually decreases.

  Further, the control pressure of the output port 48 is introduced into the annular groove 44 via the feedback flow path 45. This control pressure acts on the step portion provided at the boundary between the first land portion 41 and the second land portion 42. For this reason, the thrust of the area difference between the first land portion 41 and the second land portion 42 acts against the spring 40.

  That is, in this electromagnetic valve 10, it is based on a force that attracts the plunger 17 that acts in accordance with the current value supplied to the coil 16 (an electromagnetic attracting force that acts on the core), an urging force by the spring 40, and a feedback control pressure. The control pressure is controlled to be a pressure corresponding to the current value supplied to the coil 16 by the balance with the force.

  Incidentally, the hydraulic oil supplied to the supply port 52 is also supplied to the annular groove 53 from the auxiliary supply port 54. A part of the hydraulic oil supplied to the annular groove 53 from the auxiliary supply port 54 flows through the fitting gap between the third land portion 43 and the second valve hole 36 located on both sides of the annular groove 53, The gas is discharged from the discharge port 52 and the drain port 55 through the annular groove 50 and the spring accommodating hole 37, respectively.

  As a result, hydraulic oil is always held in the sliding portion of the third land portion 43 of the spool 20, so that no oil runs out in the sliding portion of the third land portion 48, and the sliding of the spool 20 does not occur. The operation can be performed smoothly.

  Therefore, the stick slip of the spool 20 due to running out of oil as in the prior art can be prevented, and the pressure characteristics can be stabilized as shown in FIG.

  In the solenoid valve 10 having the above-described configuration, the space C1 where the spool 20 and the shaft 18 abut and the sliding chamber 28 containing the plunger 17 are notched grooves formed in the inner periphery of the through hole 25 fitted into the bush 29b. Further, the sliding chamber 28 and the bottom of the support hole 23 are in communication with each other via a notch groove formed in the inner periphery of the support hole 23 fitted into the bush 29b. Accordingly, when the plunger 17 slides, the hydraulic oil flows through these notched grooves, and a damping action is imparted to the operation of the plunger 17 and the shaft 18.

  In addition, this invention is not limited to said embodiment, It can change suitably in the range which does not deviate from the summary. For example, in the above-described embodiment, the example applied to the electromagnetic valve 10 having the pressure characteristic in which the control pressure is decreased in accordance with the increase in the current value to be supplied to the coil 16 is described. It is also possible to apply to the solenoid valve 10 having a pressure characteristic that increases the control pressure in accordance with an increase in the current value to be performed.

  In the above embodiment, the drain port 57 that opens to the spring accommodation hole 37 is described as being formed in the plug 39. However, the drain port 57 can be formed in the valve sleeve 19 in the same manner as in the prior art. In this case, it may be provided adjacent to the auxiliary supply port 54.

It is sectional drawing of the solenoid valve which shows embodiment of this invention. It is a figure which shows the pressure characteristic in embodiment of this invention. It is sectional drawing of the conventional solenoid valve. It is a figure which shows the pressure characteristic in the conventional solenoid valve.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Solenoid valve 11 Solenoid unit part 12 Spool valve part 14 Cover 15 Core 16 Coil 17 Plunger 19 Valve sleeve 20 Spool 35, 36 Valve hole 37 Spring accommodation hole 41, 42, 43 Land part 45 Feedback port 48 Output port 51 Supply port 52 Discharge port 54 Auxiliary supply port

Claims (2)

An electromagnetic valve that displaces a spool accommodated in a valve sleeve by a solenoid unit,
The spool is provided with at least two land portions spaced apart from each other, a supply port for supplying hydraulic oil is provided corresponding to one of the two land portions, and the spool corresponds to the other of the two land portions. A discharge port for discharging hydraulic oil is provided, and an output port for outputting a control pressure controlled by displacement of the spool is provided between the supply port and the discharge port, and corresponds to the land portion on the discharge port side. An auxiliary supply port connected to the supply port is opened. An electromagnetic valve that displaces a spool accommodated in a valve sleeve by a solenoid unit,
The spool is provided with first, second and third land portions, and the first land portion and the second land portion are provided adjacent to each other, and the second land portion and the third land portion are provided. The part is provided with a predetermined amount apart in the axial direction, and forms an annular groove into which control pressure is introduced from the feedback port corresponding to the stepped part formed at the boundary part of the first and second land parts, An annular groove communicating with the supply port and the discharge port is formed corresponding to each of the second and third land portions, and the control pressure is output between the second and third land portions. An electromagnetic valve, wherein an annular groove communicating with a port is formed, and an auxiliary supply port connected to the supply port is opened in the annular groove communicating with the discharge port.

Images