JP5157465B2 - Solenoid valve device for automatic transmission clutch pressure control - Google Patents

Description

  The present invention relates to an electromagnetic valve device for automatic transmission clutch pressure control in which a hydraulic characteristic is changed to a two-stage characteristic by changing a feedback force acting on a valve.

  Generally, an automatic transmission includes a plurality of friction engagement elements such as clutches and brakes that are engaged and disengaged by operating a hydraulic servo of a hydraulic circuit, and by engaging and disengaging each friction engagement element in a predetermined combination. A plurality of shift speeds are achieved.

  Generally, the clutch pressure of the clutch is controlled by a drive current control pattern as shown by a solid line in FIG. In the figure, the broken line indicates the transition of the clutch pressure with respect to the drive current. The oil pressure area ZA indicated by a broken line is an area that requires fine half-clutch control at the time of clutch shift, and is controlled so as to gradually increase the clutch pressure. A hydraulic pressure region ZB larger than the hydraulic pressure region ZA is a region where the clutch is fastened and held (directly connected) after shifting, and the clutch pressure is held at the maximum pressure.

  In this type of automatic transmission, for example, a clutch pressure is controlled to a pressure according to a drive current control pattern by an electromagnetic valve as described in Patent Document 1.

A conventional solenoid valve as described in Patent Document 1 includes a supply port for supplying hydraulic oil to a valve sleeve that houses a spool, a discharge port for discharging hydraulic oil, and a gap between the supply port and the discharge port. 9 is provided with an output port for outputting a control pressure controlled by the displacement of the spool, a feedback portion having an area difference where the control pressure acts on the spool, and a solenoid coil having a drive current control as shown in FIG. By supplying a drive current along the pattern, the clutch pressure is controlled to a desired pressure.
JP 2000-39083 A

  However, in the conventional solenoid valve used for controlling the clutch pressure of the automatic transmission, the maximum current is supplied to the solenoid coil of the solenoid valve, and the clutch is not engaged even during steady running after the clutch is engaged and held (directly coupled). It is necessary to continue supplying the maximum current to the solenoid coil of the solenoid valve so as not to slip. For this reason, the consumption of the battery power source of the vehicle is increased, which causes a reduction in vehicle fuel consumption.

  The present invention has been made in order to solve the above-described causes of a decrease in vehicle fuel consumption, and an object thereof is to provide an electromagnetic valve having a two-stage hydraulic characteristic by changing a feedback force acting on the valve. It is what.

In order to solve the above-mentioned problem, the invention according to claim 1 is characterized in that an automatic transmission for controlling a clutch pressure of an automatic transmission by displacing a spool accommodated in a valve sleeve by a solenoid unit portion having a solenoid coil. An electromagnetic valve device for controlling a clutch pressure of a machine, wherein a supply port to which hydraulic oil is supplied to the valve sleeve accommodating the spool, a discharge port from which hydraulic oil is discharged, and between the supply port and the discharge port Are provided with output ports for outputting a control pressure controlled by the displacement of the spool, respectively, and the spool is provided with two first and second feedback portions having an area difference on which the control pressure acts . and comprising first and second feedback port introducing the control pressure in the second feedback portion, the suction force of the solenoid coil Against, and a biasing member for biasing the feedback force in the same direction which acts on the feedback portion is provided, when the spool is a predetermined amount slid against the biasing force of the biasing member, the second After the feedback port is closed, the second feedback unit is configured to communicate with the drain port.

Feature of the invention according to claim 2, in claim 1, wherein the second feedback unit is provided between the two land portions having different diameters, to close the second feedback port by one land portion It is configured as an overlap valve in which the stroke required to open the second feedback portion to the drain port is increased by the other land portion, rather than the required spool stroke.

According to a third aspect of the present invention, in the first or second aspect , the solenoid unit includes a plunger for displacing the moving spool in response to a current supplied to the solenoid coil, and excitation of the solenoid coil. And a core for sucking the plunger.

According to a fourth aspect of the present invention, in any one of the first to third aspects, one of the first and second feedback sections is supplied to the solenoid coil after communicating with the drain port. The current to be reduced is reduced to a value at which the clutch can be engaged and held.

According to the first aspect of the present invention, the spool includes the first and second feedback portions having a difference in area where the control pressure acts, and the spool is biased by the biasing member by the suction force of the solenoid coil. When the second feedback port is closed when the second feedback port is closed, the second feedback unit is configured to communicate with the drain port. it can.

  Thereby, for example, it is possible to obtain an electromagnetic valve device capable of reducing the current supplied to the solenoid coil after the clutch is fastened and held at a predetermined pressure. Alternatively, by appropriately setting the feedback areas of the first and second feedback sections, it is possible to improve the override characteristics of the solenoid valve and increase the maximum pressure of the solenoid valve.

Moreover, according to the first aspect of the present invention, since the second feedback portion is configured to communicate with the drain port after the second feedback port is closed, the feedback pressure leaks and the control pressure decreases. This can be surely prevented.

According to the invention of claim 2 , it is necessary to open the second feedback portion to the drain port by the other land portion, rather than the stroke of the spool necessary to close the second feedback port by one land portion. Since it is configured as an overlap valve with a large stroke, feedback valve leakage can be easily realized by the overlap valve.

According to the third aspect of the present invention, the solenoid unit includes a plunger that displaces the moving spool in response to a current supplied to the solenoid coil, and a core that attracts the plunger as the solenoid coil is excited. Therefore, the spool can be accurately displaced together with the plunger according to the suction force of the solenoid coil.

According to the invention according to claim 4 , since one of the first and second feedback portions is communicated with the drain port, the current supplied to the solenoid coil is reduced to a value that can hold the clutch. Even if the current value is reduced, the clutch pressure can be maintained at a predetermined pressure, and the power consumption of the solenoid valve device can be reduced.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a first embodiment of the invention will be described with reference to the drawings. FIG. 1 shows an entire electromagnetic valve 10 according to the present embodiment. The electromagnetic valve 10 mainly includes a solenoid unit portion 11 and a spool valve portion 12 provided at one end of the solenoid unit portion 11. It is configured. The solenoid unit portion 11 includes a cover 14, a core 15, a yoke 16, a solenoid coil 17, a plunger 18, and the like, and the spool valve portion 12 includes a valve sleeve 19, a spool 20, and the like.

  The cover 14 is made of a magnetic material and has a bottomed cylindrical shape. On the bottom side of the cover 14, a yoke 16 made of a magnetic material having a cylindrical shape as a whole is accommodated. Further, a core 15 made of a magnetic material having a through hole is housed on the opening side of the cover 14. In the core 15, a flange portion 21 is formed on the opening end side of the cover 14, and a cylindrical portion 22 projecting from the flange portion 21 toward the bottom side of the cover 14 is formed. A flange portion 23 is formed on the bottom side of the cover 14 on the yoke 16, and a cylindrical portion 24 that projects from the flange portion 23 toward the opening end side of the cover 14 is formed.

  The cylindrical portion 22 of the core 15 and the cylindrical portion 24 of the yoke 16 are opposed to each other with a predetermined distance in the axial direction, and both ends of a stainless ring 25 made of a non-magnetic material are fitted to the outer periphery of the cylindrical portions 22 and 24. Yes. Thus, the core 15 and the yoke 16 are held concentrically with each other in a magnetically separated state. A plunger 18 made of a magnetic material is slidably fitted to the inner periphery of the yoke 16.

  The flange portion 23 of the yoke 16 is fitted to the bottom side of the cover 14, the flange portion 21 of the core 15 is fitted to the opening end side of the cover 14, and an annular space portion 26 is formed between the flange portions 21 and 23. It is formed around both cylindrical portions 22 and 24. A bobbin 27 around which a solenoid coil 17 is wound is attached to the annular space portion 26.

  An accommodation recess 30 having an inner diameter slightly larger than the outer diameter of the plunger 18 is opened at one end of the core 15 facing the yoke 16 over a predetermined depth. As a result, one end of the core 15 is tapered. An annular protrusion 31 is formed. The end of the plunger 18 can be accommodated in the accommodating recess 30. The protruding portion 31 constitutes a magnetic delivery portion between the core 15 and the plunger 18 in a magnetic circuit including the solenoid coil 17, the core 15, the yoke 16, the plunger 18, and the cover 14.

  A valve sleeve 19 for slidably fitting the spool 20 is disposed on the end surface of the core 15 located on the opening end side of the cover 14. Then, by crimping the opening-side cylindrical end portion 14a of the cover 14 in a state where the flange portion 34 formed at the proximal end portion of the valve sleeve 19 and each end face of the flange portion 21 of the core 15 are joined together, The solenoid unit 11 is integrally coupled to the valve sleeve 19. Thereby, the core 15 and the yoke 16 accommodated in the cover 14 are fixed in the axial direction between the bottom portion of the cover 14 and the flange portion 34 of the valve sleeve 19.

  The valve sleeve 19 is formed with a first valve hole 35, a second valve hole 36, and a third valve hole 37 having different diameters, and a spring accommodating hole 38 connected to the third valve hole 37. Is formed. Each of the valve holes 35, 36, and 37 is formed such that the first valve hole 35 has the largest diameter, the third valve hole 37 has the smallest diameter, and the second valve hole 36 has the first valve hole. 35 and the third valve hole 37 is formed at an intermediate diameter. Each valve hole 35, 36, 37 and the spring accommodating hole 38 are formed so as to extend coaxially with the core 15 and the plunger 18.

  The spool 20 is slidably fitted to the first valve hole 35 and slidably fitted to the first valve hole 35 and the second valve hole 36, respectively. A third land portion 43 and a fourth land portion 44 slidably fitted in the third valve hole 37 are provided, and the fourth land portion 44 is set to have a small axial width. Yes.

  The first and second land portions 41 and 42 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 51. An annular groove 52 is formed in the valve sleeve 19 corresponding to the small diameter portion 51, and an output port 53 for outputting a control pressure is communicated with the annular groove 52. Further, the valve sleeve 19 is formed with a discharge port 54 and a supply port 55 which open corresponding to the end surfaces of the first and second land portions 41 and 42 facing each other.

  The second land portion 42 and the third land portion 43 are provided adjacent to each other, and a first feedback portion 45 including a first step portion having an area difference is disposed at the boundary portion. A first feedback port 46 formed in the valve sleeve 19 is communicated with the first feedback portion 45. The first feedback port 46 communicates with the output port 53 via an unillustrated introduction path cut out on the outer periphery of the valve sleeve 19 so that a control pressure is introduced into the first feedback port 46. Yes. The control pressure introduced to the first feedback port 46 is applied to the first step portion of the first feedback portion 45, and as shown in FIG. 2, the first feedback force f1 is applied to the spool 20 in the direction of the arrow. It is supposed to act.

  The third land portion 43 and the fourth land portion 44 are provided adjacent to each other, and a second feedback portion 47 including a second step portion having an area difference is disposed at the boundary portion. . The second feedback portion 47 communicates with a second feedback port 48 formed in the valve sleeve 19. The second feedback port 48 communicates with the output port 53 through the introduction path cut out on the outer periphery of the valve sleeve 19 so that a control pressure is introduced into the second feedback port 48. The control pressure introduced into the second feedback port 48 is applied to the second step portion of the second feedback portion 47, and as shown in FIG. 2, the spool 20 has the same direction as the first feedback force f1. The second feedback force f2 is applied.

  The first feedback force f <b> 1 is determined by the area difference (feedback area) of the first step portion of the first feedback unit 45 and the control pressure introduced into the first feedback unit 45. Similarly, the second feedback force f <b> 2 is determined by the area difference (feedback area) of the second step portion of the second feedback unit 47 and the control pressure introduced into the second feedback unit 47.

  Further, the valve sleeve 19 is formed with a drain port 56 that opens into the spring accommodation hole 38. Normally, the drain port 56 and the second feedback portion 47 communicate with each other in the fourth axial direction with a small axial width. Is blocked by the land portion 44. However, when the fourth land portion 44 is slid together with the spool 20 by a predetermined amount by the attractive force of the solenoid coil 17, the second feedback port 48 is closed by the third land portion 43. A port 56 is opened to the second feedback unit 47. As a result, the second feedback unit 47 and the drain port 56 communicate with each other, and a drain pressure is applied to the second feedback unit 47. As described above, the second valve hole 36 that fits the third land portion 43 straddles the second feedback port 48 so that the second feedback port 48 can be closed by the third land portion 43. Is formed.

  That is, the second feedback section 47 of the spool 20 is configured as an overlap valve so that the second feedback port 48 does not open to the drain port 56 and the feedback pressure leaks and the control pressure does not decrease. ing. In other words, as shown in FIG. 2, the second land 47 has the second feedback portion 47 by the fourth land portion 44 rather than the stroke S <b> 1 of the spool 20 required to close the second feedback port 48 by the third land portion 43. The stroke S2 required to open the drain port 56 is configured to be large.

  A shaft portion 57 that protrudes through the through hole of the core 15 and contacts the plunger 18 protrudes from one end of the spool 20.

  The open end of the spring accommodating hole 38 is closed by a plug 58 that is screwed into a screw hole formed in the inner peripheral surface thereof, and a spring 59 as an urging member is provided between the plug 58 and the spool 20. . The spool 20 is pressed toward the plunger 18 by the urging force of the spring 59, whereby the plunger 18 is held at the initial position where it abuts against the bottom surface of the normal cover 14 via the shaft portion 57 of the spool 20. At the initial position of the plunger 18, as shown in FIG. 1, the end edge of the protruding portion 31 of the core 15 and the end edge of the plunger 18 are aligned in the axial direction.

  A current is supplied to the solenoid coil 17 from the current control device 80. In accordance with the current value supplied to the solenoid coil 17, as shown in FIG. 18 is held at a position where the following equation is established that balances the resultant force of the first and second feedback forces f1 and f2 and the urging force k of the spring 59.

(Equation 1)
F = f1 + f2 + k

  The solenoid valve 10 having the above-described configuration has the valve sleeve 19 fitted and fixed to the housing 70. The supply port 55 is connected to a pressure oil supply source via a supply passage formed in the housing 70, and hydraulic oil controlled to a constant pressure by a regulator valve (not shown) is supplied from the pressure oil supply source. Yes. On the other hand, the output port 53 is connected to the oil chamber 62 of the clutch 60 of the automatic transmission shown in FIG. 3 via a control pressure supply passage 61 formed in the housing 70. The clutch 60 includes a piston 63 that slides with hydraulic oil supplied to the oil chamber 62 and a multi-plate clutch plate 64 that frictionally engages with the sliding of the piston 63. The piston 63 is urged by a spring 65 in a direction away from the clutch plate 64. When the pressure of the hydraulic oil supplied to the oil chamber 62 of the clutch 60 overcomes the urging force of the spring 65, the piston 63 slides against the urging force of the spring, and the clutch plate 64 is supplied to the oil chamber 62. The clutch 60 is fastened by frictional engagement according to the oil pressure.

  Next, the operation of the above-described configuration in the present embodiment will be described. When the solenoid coil 17 is in a non-excited state, the spool 20 presses the plunger 18 in the left direction in FIG. 1 by the urging force of the spring 59, and the initial position where the plunger 18 abuts against the bottom surface of the cover 14 (FIG. 1). Held in the upper half). In this state, the spool 20 is held in the state shown in the upper half of FIG. 1, and the output port 53 is blocked from communicating with the supply port 55 and communicated with the discharge port 54, whereby the output port 53 53 is maintained at a low pressure.

  When the solenoid coil 17 is excited by the current control device 80 according to the drive current control pattern shown in FIG. 4, the plunger 18 is pulled toward the core 15 according to the drive current, so that the spool 20 resists the biasing force of the spring 59. Is displaced in the right direction of FIG. As a result, the second land portion 42 starts to open the supply port 55 and the first land portion 41 starts to limit the opening area of the discharge port 54, so that the control pressure output from the output port 53 is increased. The control pressure is supplied to the oil chamber 62 of the clutch 60 through the control pressure supply passage 61. As a result, the clutch pressure is increased according to the drive current.

  That is, as shown in FIG. 4, in order to end the idle stroke of the clutch 60 rapidly, the precharge current Ap is first supplied to the solenoid coil 17, and then the clutch pressure of the clutch 60 is changed to the linearity in the hydraulic pressure region ZA. So that the drive current supplied to the solenoid coil 17 is gradually increased, and finally, in the hydraulic pressure region ZB, the solenoid coil 17 has a clutch pressure necessary for fastening and holding the clutch 60. Is increased to the maximum current A3.

  The clutch 60 quickly absorbs the idle stroke by the precharge current Ap supplied to the solenoid coil 17, and gradually increases the pressure as shown by the broken line in FIG. When the clutch plate 64 of the clutch 60 is tightly joined, the clutch pressure rapidly increases and reaches the maximum pressure, and the clutch plate 64 is held in the engaged state (direct connection).

  On the other hand, in the spool valve portion 12, when the current is supplied to the solenoid coil 17, the plunger 18 is sucked by the core 15 with the suction force F corresponding to the current value supplied to the solenoid coil 17, and the plunger 18 is spring 59. It is displaced in the direction against the urging force k.

  At this time, the control pressure is introduced from the output port 53 to the first and second feedback portions 45 and 47 via the first and second feedback ports 46 and 48, and each of the first and second step portions is provided. Each affects the area difference. Therefore, the spool 20 includes a first feedback force f1 obtained by the product of the area difference (feedback area) of the first step portion and the control pressure, and the area difference (feedback area) of the second step portion. A second feedback force f2 determined by the product of the control pressure acts in the same direction as the biasing force k of the spring 59.

  As a result, the attraction force F by which the core 15 attracts the plunger 18 according to the current value supplied to the solenoid coil 17 and the resultant force of the urging force k of the spring 59 and the first and second feedback forces f1 and f2 are obtained. The spool 20 is held so as to be balanced (F = f1 + f2 + k).

  By the way, in the present embodiment, when the spool 20 is moved by a predetermined amount, the second feedback port 48 is closed by the third land portion 43 and then the drain port 56 is opened in the second feedback portion 47. Then, the drain pressure is applied to the second feedback unit 47 (the state of the lower half of FIGS. 1 and 2). As a result, the second feedback force f2 disappears, and the spool 20 is balanced by the following equation.

(Equation 2)
F = f1 + k

  FIG. 5 is a hydraulic characteristic diagram showing the relationship between the current supplied to the solenoid coil 17 and the clutch pressure of the clutch 60. The diagram X shows when the spool 20 is balanced at “F = f1 + k”. The diagram Y shows the hydraulic pressure characteristic when the spool 20 is balanced at “F = f1 + f2 + k”.

  In the diagram X, since the feedback area of the electromagnetic valve 10 is small, the clutch pressure rises at the current A1 and reaches the maximum pressure P1 at the current A2. On the other hand, in the diagram Y, because the feedback area of the solenoid valve 10 is large, the clutch pressure rises in the same way at the current A1, but the current A2 does not reach the maximum pressure P1, but at a current A3 larger than the current A2. Maximum pressure. That is, the diagram Y is such that the clutch pressure rises with a small gradient with respect to the diagram X, and rises to the maximum pressure P1 necessary for engaging and holding the clutch 60 at a current value A3 larger than the current value A2. Become.

  Therefore, in the electromagnetic valve 10 of the present embodiment, for example, if the second feedback unit 47 is set to communicate with the drain port 56 with the current A2 supplied to the solenoid coil 17, the FIG. As indicated by the bold line, the clutch pressure changes along the line Y while the current is between A1 and A2. When the current exceeds A2, the second feedback unit 47 is communicated with the drain port 56, and the feedback area is reduced only to the feedback area of the first feedback unit 45. The hydraulic characteristic has a two-stage characteristic that rapidly increases so as to match the characteristic.

  Thus, according to the electromagnetic valve 10 of the present embodiment, even if the attractive force F of the solenoid coil 17 is small by the attractive force ΔF corresponding to the second feedback force f2, the balanced state of the electromagnetic valve 10 is maintained. Therefore, the current supplied to the solenoid coil 17 can be reduced by a current corresponding to the attractive force ΔF. In other words, if the current required to obtain the suction force (F−ΔF) obtained by subtracting the suction force ΔF from the suction force F is supplied to the solenoid coil 17, the clutch 60 can be engaged and held.

  Therefore, in the present embodiment, as shown in the drive current control pattern of FIG. 4, the maximum current (A3) is supplied to the solenoid coil 17, the clutch 60 is engaged and held (directly coupled), and then the clutch 60 is engaged. The clutch pressure can be maintained at the maximum pressure P1 even if the current value is reduced to a value slightly larger than the solenoid coil drive current (A2) necessary for holding.

  As a result, the solenoid coil drive current required to engage and hold the clutch 60 can be reduced by ΔA1 in FIG. 4, and the power-saving solenoid valve 10 can be obtained. Accordingly, the maximum pressure can be obtained with a smaller current than before without increasing the sensitivity (inclination) of the hydraulic characteristics in the hydraulic pressure region in which the clutch 60 is half-clutch controlled, thereby reducing the power consumption of the solenoid valve 10. Vehicle fuel efficiency can be improved.

  In the embodiment described above, an example in which the solenoid coil driving current required for fastening and holding the clutch 60 is reduced by using the two-stage hydraulic characteristic to obtain the power-saving solenoid valve 10 can be obtained. As described above, the solenoid valve 10 having the above-described configuration can be used for another purpose described below in addition to reducing the solenoid coil drive current.

  In the example shown in FIG. 6, the override characteristic of the solenoid valve is improved by utilizing the above-described two-stage characteristic of the hydraulic characteristic. The override characteristic indicates a pressure drop amount ΔP of the clutch pressure when oil is supplied to the clutch 60. In other words, the override characteristic is the ability to supply oil to the clutch 60. The smaller the pressure drop amount ΔP when the oil is supplied to the clutch 60, the faster the clutch 60 can be engaged, and the response of the clutch 60 is improved. Can be increased.

  The pressure drop amount ΔP is expressed by the following formula.

(Equation 3)
ΔP = −kΔx / A

  Here, k is a spring constant of the spring 59, Δx is a stroke change amount of the spring 59, and A is a feedback area. From the above equation, it can be seen that the pressure drop amount ΔP can be reduced by increasing the feedback area A.

  Therefore, the feedback area of the first feedback unit 45 and the feedback area of the second feedback unit 47 are made equal to the feedback area of the conventional solenoid valve having one feedback unit. The sum with the feedback area can be made larger than the feedback area in the conventional solenoid valve having one feedback section, and the override characteristics can be improved.

  According to this, as shown by a thick line in FIG. 6, the clutch 60 is controlled half-clutch compared to the conventional hydraulic characteristic X1 (the clutch pressure becomes the maximum pressure P1 by supplying the current A3 to the solenoid coil 17). Since the solenoid valve 10 can be controlled with the hydraulic characteristic Y1 that can reduce the sensitivity (inclination) of the hydraulic characteristic in the hydraulic region Z1 to be performed, it is possible to improve the pressure adjustment accuracy of the hydraulic pressure during half-clutch control. Furthermore, by reducing the sensitivity (slope) of the hydraulic characteristics, the feedback area can be increased with the same suction force as before, so the override characteristics of the solenoid valve 10 are improved and the clutch 60 operates with high response. Can be made.

  Then, when the current value supplied to the solenoid coil 17 becomes, for example, A3, the clutch required to hold the clutch 60 at the clutch pressure by connecting the second feedback portion 47 to the drain port 56. The pressure can be rapidly increased to P1.

  In this case, the sum of the feedback area of the first feedback unit 45 and the feedback area of the second feedback unit 47 is made approximately the same as the feedback area in a conventional solenoid valve having one feedback unit. If the override characteristic of the solenoid valve 10 is made similar to the conventional characteristic, even if the solenoid coil 17 is reduced in size, the current supplied to the solenoid coil 17 is similar to the hydraulic characteristic shown in FIG. For example, when A3 is reached, the clutch pressure can be increased to the clutch pressure P1 necessary for fastening and holding the clutch 60 by communicating the second feedback portion 47 with the drain port 56. It is possible to reduce the size.

  The example shown in FIG. 7 shows an example in which the maximum pressure of the clutch 60 can be increased using the above-described two-stage characteristics. In this case, the first feedback area and the second feedback By making the sum of the feedback area approximately the same as the feedback area in the conventional solenoid valve having one feedback unit, the inclination in the hydraulic region Z1 in which the clutch 60 is half-clutch controlled is changed to the hydraulic characteristic X1 of the conventional solenoid valve. Can be almost the same. As a result, the spool 20 is moved by a predetermined amount and the second feedback port 48 communicates with the drain port 56, whereby the clutch pressure can be increased. The maximum pressure P1 shown in FIG. 6 can be increased to a larger pressure P2.

  According to this, the pressure adjustment accuracy of the hydraulic pressure at the time of half-clutch control, the override characteristic (feedback area) of the solenoid valve 10 and the operation response of the clutch 60 are kept at the same level as before, and the clutch pressure is increased. Therefore, the clutch 60 can be downsized.

  FIG. 8 shows a second embodiment of the present invention, in which an aluminum material is used as the magnet wire of the solenoid coil 117. That is, in the past, a copper material was used as the magnet wire of the solenoid coil 17. However, since the copper magnet wire is expensive and has a high density, it increases the cost and weight of the solenoid coil. Therefore, the magnet wire is changed from a copper material to an aluminum material, and the cost and weight of the solenoid coil 117 can be reduced. Since other configurations are the same as those of the first embodiment, the same reference numerals are given to the main components, and description thereof will be omitted.

  However, when the magnet wire is made of an aluminum material, the resistance value of the aluminum material is larger than that of the copper material, so that the coil resistance increases. Therefore, if the maximum current is continuously supplied to the solenoid coil 117 to keep the clutch 60 engaged, the amount of heat generated by the solenoid coil 117 increases. On the contrary, if the coil resistance is made the same as that of the copper material, the wire diameter of the aluminum material has to be increased, the volume of the solenoid coil 117 is increased, and the solenoid valve 10 is enlarged.

  Therefore, in the second embodiment, as described in the first embodiment, the spool 20 is provided with the first and second feedback portions 45 and 47, and the spool 20 is slid by a predetermined amount. In this case, the second feedback unit 47 is communicated with the drain port 56. As described above, the feedback force acting on the spool 20 is changed, and the hydraulic characteristic is set to a two-stage characteristic and controlled by the solenoid coil drive current control pattern shown in FIG. If reduced, heat generation of the solenoid coil 117 can be suppressed.

  Therefore, according to the second embodiment shown in FIG. 8, an inexpensive magnet wire can be used, and the cost of the solenoid coil 117 can be reduced. Further, the weight of the solenoid coil 117 can be reduced by using a light magnet wire, and the electromagnetic valve 10 can be reduced in size, so that the fuel efficiency of the vehicle can be improved.

  In the above-described embodiment, by changing the feedback force acting on the valve, it is possible to reduce the power consumption of the solenoid valve 10 by using the solenoid valve 10 having a two-stage hydraulic characteristic, Although an example in which the override characteristic of the valve 10 is improved or the maximum pressure of the solenoid valve 10 can be increased has been described, the present invention includes two feedback units 45 and 47, and changes the feedback force. The purpose of use is not particularly limited as long as the hydraulic characteristic can be changed to a two-stage characteristic.

  In the above-described embodiment, the example in which the first and second feedback portions 45 and 47 are provided adjacent to the spool 20 has been described. However, the first and second feedback portions 45 and 47 are disposed in the spool. It can also be provided separately at both ends of 20. Further, the first feedback portion 45 may be communicated with the drain port by sliding the spool 20.

  Thus, the present invention is not limited to the configurations described in the embodiments, and various forms can be adopted without departing from the gist of the present invention described in the claims. is there.

It is sectional drawing of the solenoid valve which shows the 1st Embodiment of this invention. It is the figure which expanded the principal part of FIG. It is a figure which shows the clutch of an automatic transmission. It is a figure which shows the drive current control pattern which controls a solenoid valve. It is a figure which shows the hydraulic characteristic of a clutch. It is a figure which shows the modification of the hydraulic characteristic of a clutch. It is a figure which shows another modification of the hydraulic characteristic of a clutch. It is sectional drawing of the solenoid valve which shows the 2nd Embodiment of this invention. It is a figure which shows the drive current control pattern which controls the conventional solenoid valve.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Solenoid valve, 11 ... Solenoid unit part, 12 ... Spool valve part, 15 ... Core, 17 ... Solenoid coil, 18 ... Plunger, 19 ... Valve sleeve, 20 ... Spool, 35, 36, 37 ... Valve hole, 41, 42, 43, 44 ... Land part, 45 ... First feedback part, 46 ... First feedback port, 47 ... Second feedback part, ... Second feedback port, 53 ... Output port, 54 ... Discharge port, 55 ... Supply port, 56 ... Drain port, 59 ... Biasing member (spring), 60 ... Clutch, 80 ... Current control device.

Claims (4)

An electromagnetic valve device for controlling an automatic transmission clutch pressure for displacing a spool housed in a valve sleeve by a solenoid unit having a solenoid coil and controlling a pressure of a clutch of the automatic transmission,
A supply port for supplying hydraulic oil, a discharge port for discharging hydraulic oil, and a control pressure controlled by displacement of the spool between the supply port and the discharge port to the valve sleeve that houses the spool. Each output port is provided,
The spool is provided with first and second feedback portions having an area difference on which the control pressure acts,
The first and second feedback ports for introducing control pressure into the first and second feedback units,
Providing a biasing member that resists the suction force of the solenoid coil and biases in the same direction as the feedback force acting on the feedback unit;
When the spool is slid by a predetermined amount against the urging force of the urging member, the second feedback port is closed and then the second feedback portion is communicated with the drain port. An electromagnetic valve device for controlling the clutch pressure of an automatic transmission. The second feedback portion according to claim 1 , wherein the second feedback portion is provided between two land portions having different diameters, and a stroke of a spool necessary for closing the second feedback port by one land portion is set to the other. An electromagnetic valve device for automatic transmission clutch pressure control, characterized in that the land portion is configured as an overlap valve that increases a stroke required to open the second feedback portion to the drain port. 3. The solenoid unit according to claim 1 , wherein the solenoid unit portion is a plunger that moves according to an electric current supplied to the solenoid coil to displace the spool, and a core that attracts the plunger as the solenoid coil is excited. An electromagnetic valve device for automatic transmission clutch pressure control. In claims 1 any one of claims 3, wherein one of the first and second feedback portion, said after communicating with the drain port, the value of the current supplied to the solenoid coil can be concluded hold the clutch A solenoid valve device for automatic transmission clutch pressure control, characterized in that the pressure is reduced to a minimum.

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