JP2009058013A - Solenoid valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress hydraulic hysteresis of a solenoid valve by holding a working liquid in a feedback chamber and rapidly applying a feedback force to a spool when a valve part changes a state from a first state. <P>SOLUTION: The solenoid valve controls an output pressure of an output port 54 by the communication and cutoff of respective ports of an input port 52, the output port 54, a drain port 56, and a feedback port 58. The feedback chamber 80 which introduces a working oil from the feedback port 58 is provided, and the feedback chamber 80 is constituted so that the feedback port 58 and the feedback chamber 80 are cutoff when the output pressure of the output port 54 is the greatest, and an enclosed space is formed in the feedback chamber 80. When the output pressure of the output port 54 is the greatest, the working oil in the feedback chamber 80 is retained, and therefore, when the output pressure is lowered from the state and the feedback chamber 80 is communicated with the feedback port 58, the feedback force is rapidly applied to the spool 44. As a result, the hydraulic hysteresis is suppressed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a solenoid valve.

Conventionally, as this kind of solenoid valve, a pressure regulating valve portion having a sleeve in which an input port, an output port, a drain port, and a feedback port are formed, and a spool that can be moved forward and backward in the sleeve, and thrust And a linear solenoid unit that drives the pressure regulating valve unit by generating the pressure regulator (see, for example, Patent Document 1). This solenoid valve has an outer spool and an inner spool as spools. During adjustment of the output pressure, the feedback port is opened at the inner spool so that the feedback pressure acts on the outer spool, and the output pressure is maximized. The feedback port is blocked by the inner spool so that the feedback pressure does not act on the outer spool. When the feedback port is shut off, the oil in the feedback oil passage is drained, so that the feedback force does not act.
JP 2005-155893 A

  By the way, in such a solenoid valve, if the internal oil is drained while the feedback port is shut off, the feedback force is lost, so a stable output pressure can be secured, but the output pressure is reduced from that state. When adjusting the pressure, it takes time until the feedback port is opened and the feedback pressure is applied again to the outer spool, so that hysteresis occurs in the output pressure.

  The main purpose of the solenoid valve of the present invention is to suppress the occurrence of hysteresis in the output pressure.

  The electromagnetic valve of the present invention employs the following means in order to achieve the main object described above.

The solenoid valve of the present invention is
An input port, an output port, a drain port, and a feedback port are formed, and a sleeve through which a working fluid flows in and out of each port, and a shaft-like member inserted into the sleeve, and each port as the shaft moves And a solenoid part that moves the spool in the axial direction, and the input of the input with the gradual change of the opening area of each port by driving the solenoid part A first state in which the port and the output port are communicated and the output port and the drain port are blocked; and the input port and the output port are blocked; and the output port and the drain port are communicated. A solenoid valve capable of switching between two states,
A feedback chamber is formed which is connected to the feedback port and causes a feedback force to act on the spool by the working fluid flowing in through the feedback port.
The feedback chamber communicates between the feedback port and the feedback chamber while the state of the valve portion is being switched, and when the valve portion is in the first state, the feedback port and the feedback chamber And the working fluid flowing into the feedback chamber is retained.

  In the solenoid valve of the present invention, the input port and the output port are communicated with each other by gradually changing the opening area of each of the input port, the output port, the drain port, and the feedback port by driving the solenoid unit. The first state for shutting off the port and the second state for shutting off the input port and the output port and communicating the output port and the drain port can be switched, and connected to the feedback port via the feedback port. A feedback chamber is formed in which a feedback force is applied to the spool by the inflowing working fluid, and the feedback port communicates with the feedback chamber while the state of the valve portion is being switched. In the first state, the feedback port and the feedback chamber are blocked. Working fluid that flows into the feedback chamber is formed so as to be held together with the. Therefore, when the valve unit switches the state from the first state, the working fluid is held in the feedback chamber, so that the feedback force can be quickly applied to the spool. As a result, it is possible to suppress the occurrence of hysteresis in the output pressure. Further, since the feedback port is shut off when the valve portion is in the first state, it is not necessary to use a solenoid portion that generates a large thrust, and the solenoid valve can be made compact.

  In such an electromagnetic valve of the present invention, the feedback chamber may be formed so that the outflow of the inflowing working fluid is restricted when the valve portion is in the first state. In this case, the feedback chamber may be formed so that the inflowing working fluid is not discharged when the valve portion is in the first state. In the first state, the inflowing working fluid may be formed to be discharged through an orifice.

  Further, in the solenoid valve of the present invention, the line pressure is input and regulated through the input port, and the clutch incorporated in the automatic transmission can be directly output through the output port. You can also. A solenoid valve of the type that inputs line pressure and outputs it directly to the clutch usually requires a relatively large thrust as the solenoid part, and the solenoid part tends to be enlarged. The function as a solenoid valve can be exhibited sufficiently without increasing the size. Here, the “clutch” includes not only a normal clutch that connects two rotating systems, but also one that connects one rotating system to a fixed system such as a case.

  Furthermore, in the solenoid valve according to the present invention, the spool may include a land for performing communication and blocking between the feedback port and the feedback chamber. By doing so, it is possible to communicate and block the feedback port and the feedback chamber using the land.

  In the electromagnetic valve according to the present invention, the spool performs communication and blocking between the input port, the output port, and the drain port, and performs communication and blocking between the feedback port and the feedback chamber. The spool may be a single member, and the spool includes a first spool that communicates and blocks the input port, the output port, and the drain port, and the first spool. It is also possible to include a second spool that performs communication and disconnection between the feedback port and the feedback chamber with relative movement.

  Next, the best mode for carrying out the present invention will be described using examples.

  FIG. 1 is a block diagram showing an outline of the configuration of an electromagnetic valve 20 as an embodiment of the present invention, and FIG. It is a block diagram. The electromagnetic valve 20 of the first embodiment is used, for example, for hydraulic control of a clutch incorporated in an automatic transmission. As shown in the figure, hydraulic oil stored in an oil tank 12 is pumped by an oil pump 14 and a regulator. It is configured as a linear solenoid valve for direct control capable of directly controlling the clutch CL by generating an optimal clutch pressure from the hydraulic pressure (line hydraulic pressure) regulated by the valve 16, and includes a solenoid portion 30 and the solenoid portion. And a pressure regulating valve unit 40 that is driven by 30 to input the line hydraulic pressure and regulates and outputs the input line hydraulic pressure.

  The solenoid unit 30 includes a case 31 as a bottomed cylindrical member, a coil (solenoid coil) 32 in which an insulating wire is wound around an insulating bobbin 32 a disposed on the inner peripheral side of the case 31, and an opening of the case 31. A first core 34 including a flange portion 34 a having a flange outer peripheral portion fixed to the end portion, a cylindrical portion 34 b extending from the flange portion 34 a along the inner peripheral surface of the coil 32 in the axial direction, and a bottom portion of the case 31 A cylindrical second member that is in contact with the inner peripheral surface of the concave portion formed in the coil 32 and extends in the axial direction to a position spaced apart from the cylindrical portion 34b of the first core 34 along the inner peripheral surface of the coil 32. Core 35, a plunger 36 inserted into the second core 35 and slidable in the axial direction on the inner peripheral surface of the first core 34 and the inner peripheral surface of the second core 35, and Inserted into the cylindrical part 34b The inner peripheral surface of the cylindrical portion 34b abuts against the axial direction at the tip of Nja 36 and a slidable shaft 38. In addition, the solenoid unit 30 has a terminal from the coil 32 arranged in a connector unit 39 formed on the outer periphery of the case 31, and the coil 32 is energized through this terminal.

  The tip of the cylindrical portion 34b of the first core 34 is tapered on the outer surface so that the outer diameter decreases toward the tip, and the tip of the plunger 36 having an outer diameter larger than the outer diameter of the shaft 38 is formed on the inner surface. A plunger receiver 34c is formed so that the portion can be inserted. The plunger receiver 34 c is provided with an annular ring 34 d made of a nonmagnetic material so that the plunger 36 does not directly contact the first core 34.

  The case 31, the first core 34, the second core 35, and the plunger 36 are all formed of a ferromagnetic material such as high-purity iron, and the end surface of the cylindrical portion 34 b of the first core 34 and the second core 34 are formed. The space between the end surface of the core 35 is formed so as to function as a nonmagnetic material. In addition, since this space should just function as a nonmagnetic material, you may provide nonmagnetic metals, such as stainless steel and brass.

  In the solenoid unit 30, when the coil 32 is energized, a magnetic circuit is formed in which a magnetic flux flows around the coil 32 in the order of the case 31, the second core 35, the plunger 36, the first core 34, and the case 31. As a result, a suction force acts between the first core 34 and the plunger 36 to suck the plunger 36. As described above, since the shaft 38 slidable in the axial direction on the inner peripheral surface of the first core 34 is in contact with the tip of the plunger 36, the shaft 38 moves forward ( It is pushed out in the left direction in the figure.

  The pressure regulating valve portion 40 is configured to be incorporated into the valve body 100, and has a substantially cylindrical sleeve 50 having one end attached to the case 31 and the first core 34 of the solenoid portion 30, and the inside of the sleeve 50. A spool 60 inserted into the space and having one end abutted against the tip of the shaft 38 of the solenoid unit 30, an end plate 42 screwed to the other end of the sleeve 50, and between the end plate 42 and the other end of the spool 60. And a spring 44 that urges the spool 60 in the direction toward the solenoid unit 30. The end plate 42 can finely adjust the urging force of the spring 44 by adjusting the screw position.

  The sleeve 50 is formed as an opening in the inner space thereof at an approximately central position in the sleeve 50 in FIG. 1 and an input port 52 for inputting hydraulic oil from the regulator valve 16 (oil pump 14). Output port 54 for discharging hydraulic oil to the clutch CL side, a drain port 56 for draining hydraulic oil formed at the right end position in FIG. 1, and a left output position in FIG. A feedback port 58 is formed which inputs hydraulic oil from the port 54 through an oil passage 58 a formed by the inner surface of the valve body 100 and the outer surface of the sleeve 50 and feeds it back to the spool 60. Further, at both ends of the sleeve 50, there are also discharge holes 59a and 59b for discharging hydraulic oil leaking from between the inner peripheral surface of the sleeve 50 and the outer peripheral surface of the spool 60 as the spool 60 slides. Is formed.

  The spool 60 is formed as a shaft-like member inserted into the sleeve 50. As shown in FIG. 1, the spool 60 has three cylindrical lands 62, 64, 66 having an outer diameter substantially the same as the inner diameter of the sleeve 50. And the right land 62 and the central land 64 in the figure are connected to each other, the outer diameter is smaller than the outer diameter of the lands 62, 64, and the outer diameter is smaller from the lands 62, 64 toward the center. A connecting portion 68 that is formed in a tapered shape and can communicate between the input port 52, the output port 54, and the drain port 56, and a center land 64 and a left land 66 in the figure are connected to each other, and a sleeve And a connecting portion 69 that forms a feedback chamber 80 for applying a feedback force to the spool 60 together with 50 inner walls.

  A groove 64a is formed on the outer surface of the land 64 adjacent to the feedback chamber 80, and when the spool 60 (land 64) is positioned near the solenoid portion 30, the feedback port 58 and the feedback chamber are interposed via the groove 64a. When the spool 60 (land 64) is positioned near the end plate 42, the feedback port 58 is blocked from the feedback chamber 80. When the groove 64a is blocked from the feedback port 58, the feedback chamber 80 forms a sealed space by the two adjacent lands 64 and 66 and the valve body 100, and the hydraulic fluid existing inside is held. It has become so.

  Next, the operation of the electromagnetic valve 20 of the first embodiment configured as described above will be described. FIG. 3 is an explanatory view for explaining the operation of the electromagnetic valve 20 of the first embodiment. First, consider the case where the power supply to the coil 32 is turned off. In this case, since the spool 60 is moved to the solenoid unit 30 side by the urging force of the spring 44, the input port 52 is closed by the land 64, the input port 52 and the output port 54 are blocked, and the communication unit 68 is connected. Thus, the output port 54 and the drain port 56 are in communication with each other (see FIG. 3A). Accordingly, no hydraulic pressure acts on the clutch CL. Note that the feedback port 58 is in communication with the feedback chamber 80 via the groove 64 a of the land 64. Next, when energization of the coil 32 is turned on, the plunger 36 is attracted to the first core 34 with a suction force corresponding to the magnitude of the current applied to the coil 32, and the shaft 38 is pushed out accordingly. Thus, the spool 60 abutted against the tip of the shaft 38 moves to the end plate 42 side. As a result, the input port 52, the output port 54, and the drain port 56 are in communication with each other, and a part of the hydraulic fluid input from the input port 52 is output to the output port 54 and the remainder is output to the drain port 56. (See FIG. 3B). Further, the feedback port 58 is in communication with the feedback chamber 80 via the groove 64 a of the land 64, and a feedback force corresponding to the output pressure of the output port 54 acts on the spool 60. Therefore, the spool 60 stops at a position where the thrust (suction force) of the plunger 36, the spring force of the spring 44, and the feedback force of the feedback chamber 80 are just balanced. At this time, the larger the current applied to the coil 32, that is, the greater the thrust of the plunger 36, the more the spool 60 moves toward the end plate 42, thereby widening the opening area of the input port 52 and reducing the opening area of the drain port 56. Narrow. When energization to the coil 32 is maximized, the spool 60 moves closest to the end plate 42 in the movable range of the plunger 36, the input port 52 and the output port 54 are communicated with each other by the communication portion 68, and the drain port is caused by the land 62. 56 is closed and the output port 54 and the drain port 56 are shut off (see FIG. 3C). As a result, the maximum hydraulic pressure acts on the clutch CL. Further, the feedback port 58 is closed by the land 64 so that the feedback port 58 and the feedback chamber 80 are blocked, and no more hydraulic oil is introduced into the feedback chamber 80, so that a feedback force acting on the spool 60 is generated. Weaken. Thereby, since the required thrust (attraction force) of the solenoid part 30 can be made small, the pressure regulation valve part 40 can be driven appropriately, without enlarging a solenoid part. As described above, in the solenoid valve 20 of the first embodiment, the input port 52 and the output port 54 are shut off and the output port 54 and the drain port 56 are communicated with each other while the power supply to the coil 32 is turned off. It can be seen that it functions as a normally closed solenoid valve.

  Now, consider a state where the maximum hydraulic pressure is applied to the clutch CL (the state shown in FIG. 3C). In this state, the feedback port 58 is closed, and the feedback chamber 80 is in a state in which a closed space is formed by the adjacent lands 64 and 66 and the valve body 100 and hydraulic fluid is held therein. If the energization to the coil 32 is weakened from this state, the suction force of the solenoid unit 30 is weakened, so that the spool 60 moves to the solenoid unit 30 side (the state of FIG. 3B). At this time, the feedback chamber 80 communicates with the feedback port 58 via the groove portion 64 a of the land 64, and hydraulic oil corresponding to the output pressure of the output port 54 is introduced into the feedback chamber 80. Since the hydraulic oil is already held, the output pressure from the output port 54 is quickly transmitted to the feedback chamber 80 and the feedback force acts on the spool 60. FIG. 4 shows the relationship between the current I applied to the coil 32 and the output pressure Po of the output port 54. 4A shows the relationship between the current I and the output pressure Po in the embodiment, and FIG. 4B shows the relationship between the current I and the output pressure Po in the comparative example. In the comparative example, the hydraulic oil in the feedback chamber 80 is drained while the feedback port 58 is closed. As shown in the figure, in the solenoid valve 20 of the example, the hysteresis of the output pressure Po is small with respect to the current I applied to the coil 32 as compared with the comparative example. When the groove portion 64 a is blocked from the feedback port 58, the feedback chamber 80 is formed so that the two adjacent lands 64 and 66 and the valve body 100 form a sealed space to hold the hydraulic oil existing inside. It is based on these reasons.

  According to the solenoid valve 20 of the first embodiment described above, the feedback port 58 is closed and the hydraulic oil in the feedback chamber 80 is held when the output pressure of the output port 54 is at the maximum hydraulic pressure. When the pressure is reduced from the maximum hydraulic pressure, a feedback force can be quickly applied to the spool 60. As a result, it is possible to suppress the occurrence of hysteresis in the output pressure. Of course, when the thrust (suction force) of the plunger 36 is maximum (the coil 32 is energized at maximum), the output pressure of the output port 54 is output using a normally closed solenoid valve in which the output pressure of the output port 54 is the maximum hydraulic pressure. Since the feedback force acting on the spool 60 is weakened by closing the feedback port 58 when the hydraulic pressure is at the maximum hydraulic pressure, the thrust force of the plunger 36 necessary for the solenoid portion 30 can be reduced, and the solenoid portion 30 can be enlarged. As a direct solenoid linear valve for direct control, a sufficient function can be exhibited.

  In the solenoid valve 20 of the first embodiment, the normally closed electromagnetic system that shuts off the input port 52 and the output port 54 and communicates the output port 54 and the drain port 56 with the power to the coil 32 cut off. Although configured as a valve, the input port 152 and the output port 154 are communicated with each other and the output port 154 is in a state in which the power supply to the coil 32 is cut off, as shown in the electromagnetic valve 120 of the modified example of FIG. It may be configured as a normally open solenoid valve that shuts off the drain port 156. In addition, since the solenoid valve 120 of this modification uses the same thing as the solenoid part 30 of the solenoid valve 20 of an Example, description about the solenoid part 30 is abbreviate | omitted. In the electromagnetic valve 120 of the modified example, the pressure regulating valve unit 140 is configured to be incorporated in the valve body 200, and similarly to the electromagnetic valve 20 of the first embodiment, the sleeve 150, the spool 160, the end plate 142, A spring 144. The sleeve 150 is formed at an approximately central position in the sleeve 150 in FIG. 5 as an opening portion of the inner space, and an input port 152 for inputting hydraulic oil, and is formed on the left side in FIG. 5 and operates on the clutch CL side. An output port 154 that discharges oil, a drain port 156 that is formed at the left end position in FIG. 5 and that drains hydraulic oil, and a hydraulic oil from the output port 154 that is formed at a right position in FIG. A feedback port 158 is formed through an oil passage 158 a formed by the inner surface of the sleeve 150 and the outer surface of the sleeve 150 and fed back to the spool 160. Discharge holes 159a and 159b for discharging hydraulic oil leaking from between the inner peripheral surface of the sleeve 150 and the outer peripheral surface of the spool 160 as the spool 160 slides are also provided at both ends of the sleeve 150. Is formed. The spool 160 connects the three land lands 162, 164, 166 having an outer diameter substantially the same as the inner diameter of the sleeve 150, and the left land 166 and the center land 164 in the figure to connect the lands 164, 166. The outer diameter of each of the input port 152, the output port 154, and the drain port 156 communicates with each other in a taper shape so that the outer diameter is smaller than the outer diameter of each of the lands 164 and 166. A possible communication portion 168, and a connecting portion 169 that connects between the center land 164 and the right land 162 in the figure and forms a feedback chamber 180 for applying a feedback force to the spool 160 together with the inner wall of the sleeve 150; Is provided. A groove 164a is formed on the outer surface of the land 164 adjacent to the feedback chamber 180. When the spool 160 (land 164) is located closer to the solenoid portion 30, the land 164 causes the feedback port 158 and the feedback chamber 180 to be connected. When the spool 160 (land 164) is located closer to the spring 144, the feedback port 158 and the feedback chamber 180 are communicated with each other through the groove 164a. When the groove portion 164a is blocked from the feedback port 158, the feedback chamber 180 forms a sealed space by the two adjacent lands 162, 164 and the valve body 200, and the hydraulic oil flowing into the inside of the feedback chamber 180 It is supposed to be retained.

  Next, the operation of the electromagnetic valve 120 of the modified example configured as described above will be described. FIG. 6 is an explanatory diagram for explaining the operation of the electromagnetic valve 120 according to the modification. First, consider the case where the power supply to the coil 32 is turned off. In this case, since the spool 160 is moved to the solenoid unit 30 side by the urging force of the spring 144, the input port 152 and the output port 154 communicate with each other through the communication unit 168 and the drain port 156 is blocked by the land 166. Thus, the output port 154 and the drain port 156 are blocked (see FIG. 6A). As a result, the maximum hydraulic pressure acts on the clutch CL. Further, the feedback port 158 is closed by the land 164 so that the feedback port 158 and the feedback chamber 180 are blocked, and no more hydraulic oil is introduced into the feedback chamber 180, so that a feedback force acting on the spool 160 is generated. Weaken. The feedback chamber 180 is formed with a sealed space as it is disconnected from the feedback port 158, and the internal hydraulic fluid is held without flowing out. Next, when energization of the coil 32 is turned on, the plunger 36 is attracted to the first core 34 with a suction force corresponding to the magnitude of the current applied to the coil 32, and the shaft 38 is pushed out accordingly. Then, the spool 160 that is in contact with the tip of the shaft 38 moves to the end plate 142 side. As a result, the input port 152, the output port 154, and the drain port 156 are in communication with each other, and part of the hydraulic fluid input from the input port 152 is output to the output port 154 and the remainder is output to the drain port 156. (See FIG. 6B). Further, the feedback port 158 communicates with the feedback chamber 180 via the groove 164 a of the land 164, and a feedback force corresponding to the output pressure of the output port 154 acts on the spool 160. Accordingly, the spool 160 stops at a position where the thrust (suction force) of the plunger 36, the spring force of the spring 144, and the feedback force of the feedback chamber 180 are just balanced. At this time, the larger the current applied to the coil 32, that is, the greater the thrust of the plunger 36, the more the spool 160 moves toward the end plate 142, thereby narrowing the opening area of the input port 152 and reducing the opening area of the drain port 156. spread. When energization to the coil 32 is maximized, the spool 160 moves closest to the end plate 142 in the movable range of the plunger 36, the land 164 closes the input port 152, and the input port 152 and the output port 154 are blocked. At the same time, the output port 154 and the drain port 156 are in communication with each other via the communication portion 168 (see FIG. 6C). Accordingly, no hydraulic pressure acts on the clutch CL. The feedback port 158 communicates with the feedback chamber 180 through the groove 164a of the land 164. As described above, in the solenoid valve 120 according to the modified example, the input port 152 and the output port 154 are communicated with each other while the coil 32 is energized, and the output port 154 and the drain port 156 are blocked. It can be seen that it functions as an open type solenoid valve.

  The electromagnetic valve 120 of this modified example also closes the feedback port 158 and holds the hydraulic oil in the feedback chamber 180 when the output pressure of the output port 154 is at the maximum hydraulic pressure. The same effect as 20 can be achieved. In addition, when the thrust (suction force) of the plunger 36 is zero (the energization to the coil 32 is off), the output pressure of the output port 154 is obtained by using a normally open type solenoid valve in which the output pressure of the output port 154 becomes the maximum hydraulic pressure. Since the feedback force acting on the spool 160 is weakened by closing the feedback port 158 when is the maximum hydraulic pressure, it is not necessary to use a spring 144 having a strong spring force. Therefore, since the thrust force of the plunger 36 required by the solenoid unit 30 can be reduced, a sufficient function as a linear solenoid valve for direct control can be exhibited without increasing the size of the solenoid unit 30.

  Next, the electromagnetic valve 220 of the second embodiment will be described. FIG. 7 is a configuration diagram showing an outline of the configuration of the electromagnetic valve 220 of the second embodiment. The electromagnetic valve 220 according to the second embodiment is different from the electromagnetic valve 20 according to the first embodiment in which only one spool 60 is provided in that two spools 260 and 270 are provided as spools of the pressure regulating valve portion 240. In addition, since the solenoid valve 220 of the second embodiment is the same as the solenoid portion 30 of the solenoid valve 20 of the embodiment, the description of the solenoid portion 30 is omitted.

  The pressure regulating valve portion 240 is configured to be incorporated in the valve body 300, and includes a sleeve 250, an outer spool 260, an inner spool 270 incorporated in the outer spool 260, an end plate 242, and an outer spool. And a spring 244 for urging 260 to the solenoid unit 30 side.

  In the sleeve 250, as an opening of the inner space, an input port 252 that is formed at a substantially central position in the sleeve 250 in FIG. 7 and inputs hydraulic oil, and is formed at a position on the right side in FIG. An output port 254 that discharges hydraulic oil, a drain port 256 that is formed at the right end position in FIG. 7 and drains the hydraulic oil, and a hydraulic oil from the output port 254 that is formed at a left position in FIG. A feedback port 258 is formed through an oil passage 258 a formed by the inner surface of 300 and the outer surface of the sleeve 250 and fed back to the outer spool 260. Further, at both ends of the sleeve 250, discharge holes 259a for discharging hydraulic oil leaking from between the inner peripheral surface of the sleeve 250 and the outer peripheral surface of the outer spool 260 as the outer spool 260 slides, 259b is also formed.

  The outer spool 260 connects two lands 262 and 264 having a columnar outer diameter substantially the same as the inner diameter of the sleeve 250, and the two lands 262 and 264, and has an outer diameter smaller than the outer diameter of the lands 262 and 264. In addition, the input port 252, the output port 254, and the communication port 268 that can communicate with each port of the drain port 256 are provided so as to have a smaller outer diameter toward the center from the lands 262 and 264. A spring receiver 266 is provided at the end of the land 264 on the end plate 242 side, and the spring 244 is disposed between the end plate 242 and the spring receiver 266. The land 264 is configured as a hollow member that houses the inner spool 270, and three through holes 264a to 264c are formed.

  The inner spool 270 is housed in the internal space of the land 264 of the outer spool 260, and has two cylindrical lands 272 and 274 having an outer diameter substantially the same as the inner diameter of the land 264, and two lands 272 and 274. The two lands 272 and 274 are connected with a small outer diameter, and a communication portion 276 that connects the through hole 264b and the through hole 264c of the land 264 of the outer spool 260 is provided. A spring 278 is disposed between the land 274 of the inner spool 270 and the spring receiver 266 of the outer spool 260, and the inner spool 270 is urged toward the solenoid part 30 of the outer spool 260 by the spring 278. .

  The through hole 264 a of the outer spool 260 is formed so that the output pressure of the output port 254 acts on the inner spool 270 in the direction opposite to the urging force of the spring 278. When the hydraulic pressure overcoming the urging force of the spring 278 is not acting on the inner spool 270 via the through hole 264a, the inner spool 270 moves relative to the outer spool 260 toward the solenoid portion 30 by the spring 278, and the communication portion 276 Thus, the through holes 264b and 264c communicate with each other, and the feedback port 258 communicates with the feedback chamber 280 through the through hole 264b of the land 264, the communication portion 276 of the inner spool 270, and the through hole 264c of the land 264. On the other hand, when a hydraulic pressure that overcomes the urging force of the spring 278 is applied to the inner spool 270 via the through hole 264 a, the inner spool 270 moves relative to the outer spool 260 toward the end plate 242, and the land 272 of the inner spool 270 The through hole 264b of the land 264 of the outer spool 260 is closed to block the feedback port 258 and the feedback chamber 280 from each other. At this time, the feedback chamber 280 forms a sealed space by the land 264 of the outer spool 260, the lands 272, 274 of the inner spool 270, and the valve body 300, and the hydraulic fluid flowing into the inside is held. ing.

  The operation of the thus configured solenoid valve 220 of the second embodiment will be described. FIG. 8 is an explanatory diagram for explaining the operation of the electromagnetic valve 220 of the second embodiment. First, consider the case where the power supply to the coil 32 is turned off. In this case, since the outer spool 260 is moved to the solenoid part 30 side by the urging force of the spring 244, the input port 252 is closed by the land 264, the input port 252 and the output port 254 are blocked, and the connecting part 268. As a result, the output port 254 and the drain port 256 are in communication with each other (see FIG. 8A). Accordingly, no hydraulic pressure acts on the clutch CL. The feedback port 258 is in communication with the feedback chamber 280 through the through hole 264b of the land 264, the communication portion 276 of the inner spool 270, and the through hole 264c of the land 264. Next, when energization of the coil 32 is turned on, the plunger 36 is attracted to the first core 34 with a suction force corresponding to the magnitude of the current applied to the coil 32, and the shaft 38 is pushed out accordingly. Thus, the outer spool 260 abutted against the tip of the shaft 38 moves to the end plate 242 side. As a result, the input port 252, the output port 254, and the drain port 256 are in communication with each other, and part of the hydraulic fluid input from the input port 252 is output to the output port 254 and the remainder is output to the drain port 256. (See FIG. 8B). The feedback port 258 is in communication with the feedback chamber 280 via the through hole 264b, the communication portion 276, and the through hole 264c of the land 264, and a feedback force corresponding to the output pressure of the output port 254 acts on the outer spool 260. To do. Therefore, the spool 260 stops at a position where the thrust (suction force) of the plunger 36, the spring force of the spring 244, and the feedback force of the feedback chamber 280 are just balanced. At this time, the larger the current applied to the coil 32, that is, the greater the thrust of the plunger 36, the more the spool 260 moves toward the end plate 242, thereby widening the opening area of the input port 252 and increasing the opening area of the drain port 256. Narrow. When energization of the coil 32 is maximized, the spool 260 moves closest to the end plate 242 in the movable range of the plunger 36, and the input port 252 and the output port 254 are communicated with each other by the communication portion 268 and at the same time the drain port by the land 262. 256 is closed and the output port 254 and the drain port 256 are shut off (see FIG. 8C). As a result, the maximum hydraulic pressure acts on the clutch CL. At this time, a hydraulic pressure exceeding the urging force of the spring 278 is applied to the inner spool 270 via the through hole 264 a, so that the inner spool 270 moves relative to the outer spool 260 toward the end plate 242, and is moved by the land 272 of the inner spool 270. The through hole 264b of the outer spool 260 is closed and the feedback port 258 and the feedback chamber 280 are blocked. Accordingly, since no more hydraulic oil is introduced into the feedback chamber 280, the feedback force acting on the outer spool 260 is weakened. Thereby, since the required thrust (attraction force) of the solenoid part 30 can be made small, the pressure regulation valve part 240 can be driven appropriately, without enlarging a solenoid part. As described above, in the electromagnetic valve 220 of the second embodiment, the input port 252 and the output port 254 are shut off and the output port 254 and the drain port 256 are communicated with each other when the power supply to the coil 32 is turned off. It can be seen that it functions as a normally closed solenoid valve.

  Now, consider a state where the maximum hydraulic pressure is applied to the clutch CL (the state shown in FIG. 8C). In this state, the feedback port 258 is closed, and the feedback chamber 280 is in a state where a sealed space is formed by the land 264, the land 272, 274, and the valve body 300, and hydraulic fluid is held inside. If the energization to the coil 32 is weakened from this state, the suction force of the solenoid unit 30 is weakened, so the outer spool 260 moves to the solenoid unit 30 side (the state of FIG. 8B). At this time, the feedback chamber 280 communicates with the feedback port 258 via the through hole 264b, the communication portion 276, and the through hole 264c, and hydraulic oil corresponding to the output pressure of the output port 254 is introduced into the feedback chamber 280. Since the hydraulic oil is already held in the feedback chamber 280, the output pressure from the output port 254 is quickly transmitted to the feedback chamber 280, and the feedback force acts on the outer spool 260. Therefore, the hysteresis of the output pressure is reduced.

  According to the solenoid valve 220 of the second embodiment described above, the feedback port 258 is closed and the hydraulic oil in the feedback chamber 280 is held when the output pressure of the output port 254 is at the maximum hydraulic pressure. The same effects as those of the electromagnetic valve 20 of the embodiment can be obtained.

  In the solenoid valve 220 of the second embodiment, the normally closed electromagnetic system that shuts off the input port 252 and the output port 254 and communicates the output port 254 and the drain port 256 while the power to the coil 32 is cut off. Although configured as a valve, the input port 352 and the output port 354 are communicated with each other and the output port 354 is in a state where the power supply to the coil 32 is cut off, as shown in the electromagnetic valve 320 of the modified example of FIG. It may be configured as a normally open type electromagnetic valve that shuts off the drain port 356. In the electromagnetic valve 320 of the modified example, the pressure regulating valve portion 340 is configured to be incorporated in the valve body 400. Similar to the electromagnetic valve 220 of the second embodiment, the sleeve 350, the outer spool 360, and the inner spool 370 are configured. And an end plate 342 and a spring 344. In the sleeve 350, as an opening portion of the inner space, an input port 352 that is formed at a substantially central position in the sleeve 350 in FIG. 9 and inputs hydraulic oil, and is formed at a position on the left side in FIG. An output port 354 that discharges the hydraulic oil, a drain port 356 that is formed at the left end position in FIG. 9 and drains the hydraulic oil, and a hydraulic oil from the output port 354 that is formed at the right position in FIG. A feedback port 358 is formed through an oil passage 358 a formed by the inner surface of 400 and the outer surface of the sleeve 350 and fed back to the outer spool 360. Further, at both ends of the sleeve 350, discharge holes 359a for discharging hydraulic oil leaking from between the inner peripheral surface of the sleeve 350 and the outer peripheral surface of the outer spool 360 as the outer spool 360 slides, 359b is also formed. The outer spool 360 has two cylindrical lands 362 and 364 having an outer diameter substantially the same as the inner diameter of the sleeve 350, and the two lands 362 and 364, and has an outer diameter smaller than the outer diameter of the lands 362 and 364. The input port 352, the output port 354, and a communication portion 368 capable of communicating between the respective ports of the drain port 356 are provided so as to have a smaller outer diameter toward the center portion from the lands 362, 364. A spring receiver 366 is provided at the end of the land 364 on the solenoid unit 30 side. The land 364 is configured as a hollow member that accommodates the inner spool 370, and three through holes 364a to 364c are formed. The inner spool 370 connects two lands 372 and 374 having a cylindrical outer diameter substantially the same as the inner diameter of the land 364 and the two lands 372 and 374 with an outer diameter smaller than the two lands 372 and 374. A communication portion 376 that connects the through hole 364b and the through hole 364c of the land 364 of 360 is provided. A spring 378 is disposed between the land 374 of the inner spool 370 and the spring receiver 366 of the outer spool 360, and the inner spool 370 is biased toward the end plate 342 of the outer spool 360 by the spring 378. The through hole 364a of the outer spool 360 is formed so that the output pressure of the output port 354 acts on the inner spool 370 in the direction opposite to the urging force of the spring 378. When the hydraulic pressure overcoming the urging force of the spring 378 is not acting on the inner spool 370 via the through hole 364a, the inner spool 370 is moved relative to the outer spool 360 toward the end plate 342 by the spring 378, and the communication portion 376 Thus, the through holes 364b and 364c communicate with each other, and the feedback port 358 communicates with the feedback chamber 380 through the through hole 364b of the land 364, the communication portion 376 of the inner spool 370, and the through hole 364c of the land 364. On the other hand, when a hydraulic pressure that overcomes the urging force of the spring 378 is applied to the inner spool 370 via the through hole 364 a, the inner spool 370 moves relative to the outer spool 360 toward the solenoid portion 30, and the land 372 of the inner spool 370 The through hole 364b of the land 364 of the outer spool 360 is closed to block the feedback port 358 and the feedback chamber 380 from each other. At this time, the feedback chamber 380 forms a sealed space by the land 364 of the outer spool 360, the lands 372 and 374 of the inner spool 370, and the valve body 400, so that the hydraulic oil flowing into the inside is held. ing.

  The operation of the modified electromagnetic valve 320 configured as described above will be described. FIG. 10 is an explanatory view for explaining the operation of the electromagnetic valve 320 according to a modification. First, consider the case where the power supply to the coil 32 is turned off. In this case, since the outer spool 360 is moved to the solenoid unit 30 side by the biasing force of the spring 344, the input port 352 and the output port 354 are communicated with each other via the communication unit 368 and the drain port 356 is connected with the land 362. The output port 354 and the drain port 356 are blocked by being blocked (see FIG. 10A). Therefore, the maximum hydraulic pressure acts on the clutch CL. Further, the through hole 364b is closed by the land 372 of the inner spool 370, and the feedback port 358 and the feedback chamber 380 are blocked, and no more hydraulic oil is introduced into the feedback chamber 380. The acting feedback force is weakened. In the feedback chamber 380, a sealed space is formed when the feedback port 358 is disconnected from the feedback port 358, and the internal hydraulic fluid is held without flowing out. Next, when energization of the coil 32 is turned on, the plunger 36 is attracted to the first core 34 with a suction force corresponding to the magnitude of the current applied to the coil 32, and the shaft 38 is pushed out accordingly. Thus, the outer spool 360 abutted against the tip of the shaft 38 moves to the end plate 342 side. As a result, the input port 352, the output port 354, and the drain port 356 are in communication with each other, and a part of the hydraulic fluid input from the input port 352 is output to the output port 354 and the remainder is output to the drain port 356. (See FIG. 10B). Further, the feedback port 358 is in communication with the feedback chamber 380 through the through hole 364b, the communication portion 376, and the through hole 364c, and a feedback force according to the output pressure of the output port 354 acts on the outer spool 360. Therefore, the outer spool 360 stops at a position where the thrust (suction force) of the plunger 36, the spring force of the spring 344, and the feedback force of the feedback chamber 380 are just balanced. At this time, as the current applied to the coil 32 increases, that is, as the thrust of the plunger 36 increases, the outer spool 360 moves to the spring side 344, narrowing the opening area of the input port 352 and reducing the opening area of the drain port 356. spread. When energization of the coil 32 is maximized, the outer spool 360 moves closest to the end plate 342 in the movable range of the plunger 36, the land 364 closes the input port 352, and the input port 352 and the output port 354 are blocked. In addition, the output port 354 and the drain port 356 are in communication with each other via the communication portion 368 (see FIG. 10C). Accordingly, no hydraulic pressure acts on the clutch CL. The feedback port 358 is in communication with the feedback chamber 180 via the through hole 364b, the communication portion 376, and the through hole 364c. As described above, in the solenoid valve 320 according to the modified example, the input port 352 and the output port 354 are communicated with each other while the coil 32 is energized, and the output port 354 and the drain port 356 are blocked. It can be seen that it functions as an open type solenoid valve.

  The electromagnetic valve 320 of the modified example also closes the feedback port 358 and retains the hydraulic oil in the feedback chamber 380 when the output pressure of the output port 354 is at the maximum hydraulic pressure. The same effect as 220 can be achieved. In addition, when the thrust (suction force) of the plunger 36 is zero (the energization to the coil 32 is off), the output pressure of the output port 354 is output using a normally open type solenoid valve in which the output pressure of the output port 354 becomes the maximum hydraulic pressure. Since the feedback force acting on the spool 360 is weakened by closing the feedback port 358 when the hydraulic pressure is at the maximum hydraulic pressure, it is not necessary to use a spring having a strong spring force. Therefore, since the thrust force of the plunger 36 required by the solenoid unit 30 can be reduced, a sufficient function as a linear solenoid valve for direct control can be exhibited without increasing the size of the solenoid unit 30.

  In the solenoid valve 20 of the first embodiment and the solenoid valve 220 of the second embodiment, and modifications thereof, the discharge holes 59a, 159a, 259a, 359a are provided adjacent to the feedback chambers 80, 180, 280, 380. However, if the feedback chambers 80, 180, 280, 380 are completely sealed with respect to the discharge holes 59a, 159a, 259a, 359a, the discharge holes 59a, 159a, 259a, 359a may not be provided. .

  In the electromagnetic valve 20 of the first embodiment, the hydraulic oil in the feedback chamber 80 is configured not to be discharged to the outside when the feedback port 58 is closed, but the pressure regulating valve portion of the modified example of FIG. As shown in 40B, the feedback chamber 80 and the discharge hole 59a may be connected to the sleeve 50 by an orifice 90. Even in this case, since the outflow of the working oil in the feedback chamber 80 is limited, the working oil can be held in the feedback chamber 80 to some extent when the feedback port 58 and the feedback chamber 80 are shut off. Therefore, next, when the feedback port 58 is opened, the feedback force can be applied to the spool 60 relatively quickly by the hydraulic oil from the feedback port 58, and hydraulic pressure hysteresis can be suppressed. The orifice 90 is not limited to the one provided in the sleeve 50, and may be formed in the land 66 of the spool 60 or may be formed in the valve body 100. The same applies to the electromagnetic valve 120 of the modified example, the electromagnetic valve 220 of the second embodiment, and the electromagnetic valve 320 of the modified example.

  The solenoid valve 20 of the first embodiment and the solenoid valve 220 of the second embodiment, and in these modifications, the pressure regulation is made up of sleeves 50, 150, 250, 350, spools 60, 160, 260, 270, 360, 370, etc. Although the valve portions 40, 140, 240, and 340 are incorporated in the valve body 100, 200, 300, and 400, a sleeve portion is formed integrally with the valve body, and a solenoid is inserted into the sleeve portion by inserting a spool or the like. It is good also as what comprises a valve.

  In the electromagnetic valve 20 of the first embodiment, the electromagnetic valve 220 of the second embodiment, and the modifications thereof, they are used for hydraulic control of the clutch CL incorporated in the automatic transmission. It may be used for controlling the fluid pressure.

  The best mode for carrying out the present invention has been described with reference to the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the gist of the present invention. Of course, it can be implemented in the form.

  The present invention can be used in the electromagnetic valve manufacturing industry, the automobile industry, and the like.

It is a block diagram which shows the outline of a structure of the solenoid valve 20 as one Example of this invention. It is a partial block diagram which shows partially the hydraulic circuit 10 provided with the solenoid valve 20 of 1st Example. It is explanatory drawing explaining operation | movement of the solenoid valve 20 of 1st Example. It is explanatory drawing which shows the relationship between the electric current I and the output pressure Po. It is a block diagram which shows the outline of a structure of the solenoid valve 120 of a modification. It is explanatory drawing explaining operation | movement of the solenoid valve 120 of a modification. It is a block diagram which shows the outline of a structure of the solenoid valve 220 of 2nd Example. It is explanatory drawing explaining operation | movement of the solenoid valve 220 of 2nd Example. It is a block diagram which shows the outline of a structure of the solenoid valve 320 of a modification. It is explanatory drawing explaining operation | movement of the solenoid valve 320 of a modification. It is a block diagram which shows the outline of a structure of the pressure regulation valve part 40B of a modification.

Explanation of symbols

  20, 120, 220, 320, 420 Solenoid valve, 30 solenoid part, 31 case, 32 coil, 32a bobbin, 34 first core, 34a flange part, 34b cylindrical part, 34c plunger receiver, 34d ring, 35 second Core, 36 Plunger, 38 Shaft, 39 Connector part, 40, 140, 240, 340, Pressure regulating valve part, 42, 142, 242, 342 End plate, 44, 144, 244, 344 Spring, 50, 150, 250, 350 Sleeve, 52, 152, 252, 352 Input port, 54, 154, 254, 354 Output port, 56, 156, 256, 356 Drain port, 58, 158, 258, 358 Feedback port, 58a, 158a, 258a, 358a Oil passage, 59a, 5 b, 159a, 159b, 259a, 259b, 359a, 359b Discharge hole, 60, 160 Spool, 62, 64, 66, 162, 164, 166, 262, 264, 362, 364 Land, 64a, 164a Groove, 68, 168 , 268, 368 Communication portion, 69, 169 Connection portion, 100, 200, 300, 400 Valve body, 260, 360 Outer spool, 264a-264c, 364a-364c Through hole, 266, 366 Spring receiver, 270, 370 Inner spool 272, 274, 372, 374 Land, 276, 376 Communicating part, 278, 378 Spring.

Claims (8)

An input port, an output port, a drain port, and a feedback port are formed, and a sleeve through which a working fluid flows in and out of each port, and a shaft-like member inserted into the sleeve, and each port as the shaft moves And a solenoid part that moves the spool in the axial direction, and the input of the input with the gradual change of the opening area of each port by driving the solenoid part A first state in which the port and the output port are communicated and the output port and the drain port are blocked; and the input port and the output port are blocked; and the output port and the drain port are communicated. A solenoid valve capable of switching between two states,
A feedback chamber is formed which is connected to the feedback port and causes a feedback force to act on the spool by the working fluid flowing in through the feedback port.
The feedback chamber communicates between the feedback port and the feedback chamber while the state of the valve portion is switched, and when the valve portion is in the first state, the feedback port and the feedback chamber A solenoid valve formed so that the working fluid flowing into the feedback chamber is held while being shut off.   The electromagnetic valve according to claim 1, wherein the feedback chamber is formed so that outflow of the inflowing working fluid is restricted when the valve portion is in the first state.   The electromagnetic valve according to claim 2, wherein the feedback chamber is formed so that the inflowing working fluid is not discharged when the valve portion is in the first state.   3. The electromagnetic valve according to claim 2, wherein the feedback chamber is formed so that the inflowing working fluid is discharged through an orifice when the valve portion is in the first state.   The line pressure is input through the input port to adjust the pressure, and the clutch incorporated in the automatic transmission is configured to be output directly through the output port. solenoid valve.   The solenoid valve according to any one of claims 1 to 5, wherein the spool includes a land that communicates and blocks the feedback port and the feedback chamber.   2. The spool is a single member that performs communication and blocking between the input port, the output port, and the drain port, and performs communication and blocking between the feedback port and the feedback chamber. 7. Solenoid valve in any one of 6.   The spool includes a first spool that performs communication and blocking between the input port, the output port, and the drain port, and the feedback port and the relative movement with relative movement of the first spool. The solenoid valve according to any one of claims 1 to 6, further comprising a second spool that communicates with and interrupts the feedback chamber.