JP2006071074A - Linear solenoid valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem wherein hydraulic fluid supplied into a supply port passes through a part having supply port seal length and flows into a discharge port because it is impossible to take large supply port seal length when conducting no electricity and flow rate of consumption of hydraulic fluid increases. <P>SOLUTION: A tip of a yoke part 31 of a core 15 and an end fringe of a plunger 18 are set to have underlap relation when conducting no electricity to increase seal length of the supply port 50. A spring 54 for pressing the plunger against a stopper abutting position is constituted in such a way that spring constant is set to prevent set load from exceeding absorption force by the core at an initial stroke position of the plunger and set load becomes 0 or more at the stopper abutting position of the plunger. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a linear solenoid valve that displaces a spool by driving a plunger by energization of a solenoid, and more particularly to a linear solenoid valve suitable for controlling a clutch pressure of an automatic transmission.

  In general, a linear solenoid valve for clutch pressure control used in an automatic transmission performs clutch engagement and disengagement by controlling clutch hydraulic pressure corresponding to a gear position. In this type of automatic transmission, a linear solenoid valve is used as a pair with a clutch, and therefore, a plurality of linear solenoid valves are mounted depending on the number of shift stages. Then, in order to keep the clutch in an open state depending on the gear position, the solenoid is deenergized and the clutch hydraulic pressure is held in the zero state. Accordingly, since it is necessary to keep all the clutches open by the neutral control during idling, there is an opportunity to use all the linear solenoid valves in a non-energized state.

Conventionally, the core and the plunger when not energized are set to have a slightly overlapping relationship as described in Patent Document 1, for example, in order to prevent malfunction due to underlap.
Japanese Patent Laid-Open No. 11-132357 (paragraph 0013, FIG. 2)

  However, as described above, the relationship between the core and the plunger when not energized overlaps, or as shown in FIG. 6, the end edge of the core 15 and the end edge of the plunger 18 when deenergized coincide with each other in the axial direction. If the relationship of (wrap amount 0) is set, the seal length S0 of the supply port 50 portion cannot be made very long, so that the hydraulic oil supplied to the supply port 50 is connected to the spool 20 and valve of this seal length portion. It flows through the fitting gap with the sleeve 19 to the discharge port, thereby increasing the consumption flow rate of the hydraulic oil.

  In particular, in a linear solenoid valve for clutch pressure control used in an automatic transmission, all of the plurality of linear solenoid valves are held in a non-energized state by neutral control during idling, so that the total flow rate of consumed flow increases. Accordingly, since the pump capacity must be determined based on the total flow rate, a pump with a large capacity is required, which becomes a factor that hinders reduction in fuel consumption of the vehicle.

  In addition, in order to increase the seal length of the supply port when not energized, increasing the stroke of the plunger and the spool will lead to a decrease in suction force unless the solenoid is made larger than the current one, There was a problem that reliability and responsiveness of the linear solenoid valve deteriorated.

  The present invention has been made to solve the above-described conventional problems. The tip of the yoke portion and the end edge of the plunger are set so as to have an underlap relationship when not energized. It is intended to provide a linear solenoid valve with an increased length.

  In order to solve the above-mentioned problem, the invention described in claim 1 is a linear solenoid valve that displaces a spool accommodated in a valve sleeve by a solenoid unit portion, and the solenoid unit portion includes a solenoid and the solenoid. A plunger that moves in response to a supplied current; and a core that sucks the plunger when the solenoid is energized. The valve sleeve is closed by the spool when not energized and opened by displacement of the spool due to energization. A supply port connected to the output port, a discharge port that is opened when not energized and connected to the output port and is closed by the displacement of the spool due to energization, and a control pressure provided between the supply port and the discharge port. The output port has a difference in area formed in the spool with the control pressure. A feedback port that leads to the feedback portion, and a cylindrical yoke portion that opens an accommodation recess capable of accommodating one end of the plunger is provided on a surface facing the plunger of the core, and the tip of the yoke portion and the plunger The end edge is set to have an underlap relationship that is spaced apart by a predetermined amount when not energized to increase the seal length of the supply port portion, resist the suction force acting on the plunger, and to the feedback portion A spring that presses the plunger through the spool in the same direction as the feedback force that acts is provided, and the spring constant is set so that the set load does not exceed the suction force by the core at the initial stroke position of the plunger. And the set load is set to be 0 or more at the stopper contact position of the plunger. Is shall.

  The invention described in claim 2 is characterized in that, in claim 1, a taper portion whose cross-sectional area decreases as it approaches the opening end of the housing recess is formed on the outer periphery of the yoke portion. is there.

  According to the invention according to claims 1 and 2 configured as described above, the wrap amount between the core and the plunger in the non-energized state of the solenoid is set to the under wrap, so that the supply port at the time of de-energization by the under wrap amount This can reduce the consumption flow rate of hydraulic oil supplied from the supply port to the discharge port side through the fitting gap between the spool land and the valve sleeve. There is an effect that can be done.

  Hereinafter, an embodiment of the present invention will be described with reference to FIG. The linear solenoid valve 10 of the present embodiment is mainly composed of a solenoid unit portion 11 and a spool valve portion 12 provided at one end of the solenoid unit portion 11. The solenoid unit portion 11 includes a cover 14, a core 15, an inner cylinder 16, a solenoid 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 made of a magnetic material has a bottomed cylindrical shape, and an inner cylinder 16 made of a magnetic material having a cylindrical shape as a whole is accommodated on the bottom side of the cover 14. A core 15 made of a magnetic material having a through hole is housed on the opening side of the cover 14. A flange portion 21 is formed on the opening end side of the cover 14 in the core 15, and a cylindrical portion 22 that protrudes 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 in the inner cylinder 16, and a cylindrical portion 24 that protrudes 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 inner cylinder 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. ing. As a result, the core 15 and the inner cylinder 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 inner cylinder 16.

  The flange portion 23 of the inner cylinder 16 is fitted to the bottom portion of the cover 14, the flange portion 21 of the core 15 is fitted to the open end 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 the solenoid 17 is wound is fitted and fixed in 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 to a predetermined depth at one end of the core 15 facing the inner cylinder 16, whereby a cylindrical shape is formed at one end of the core 15. A yoke portion 31 is formed. The receiving recess 30 can receive the end of the plunger 18, and the depth of the receiving recess 30 is set slightly smaller than the stroke amount of the plunger 18. A tapered portion 32 is formed on the outer periphery of the yoke portion 31. The tapered portion 32 decreases in cross-sectional area as it approaches the opening end of the receiving recess 30.

  The yoke portion 31 constitutes a magnetic delivery portion between the core 15 and the plunger 18 in a magnetic circuit constituted by the solenoid 17, the core 15, the inner cylinder 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, the opening-side cylindrical end portion 14a of the cover 14 is caulked in a state where the flange portion 34 formed on the valve sleeve 19 and the flange portion 21 of the core 15 are joined to each other, so that the solenoid to the valve sleeve 19 is obtained. The unit part 11 is integrally coupled. Thereby, the core 15 and the inner cylinder 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 and a second valve hole 36 having different diameters, and a spring accommodating hole 37 connected to the second valve hole 36. These valve holes 35 and 36 and the spring accommodating hole 37 are formed so as to extend coaxially with the core 15 and the plunger 18.

  The spool 20 is provided with first and second land portions 41 and 42 that fit into the first valve hole 35, respectively, and a third land portion 43 that fits into the second valve hole 36. It has been. The second land portion 42 and the third land portion 43 are provided adjacent to each other, and a step portion 44 is provided at the boundary portion. A feedback port 45 communicating with the step portion 44 is formed in the valve sleeve 19.

  The first and second land portions 41, 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 46. An annular groove 47 is formed in the valve sleeve 19 corresponding to the small diameter portion 46, and an output port 48 for outputting a control pressure is communicated with the annular groove 47. The output port 48 communicates with the feedback port 45 via a communication path (not shown). Further, the valve sleeve 19 is formed with a discharge port 49 and a supply port 50 that open corresponding to the mutually opposing end surfaces of the first and second land portions 41 and 42, respectively. Further, the valve sleeve 19 is formed with a drain port 51 that opens to the spring accommodating hole 37.

  A shaft portion 52 that projects through the through hole of the core 15 and abuts against the plunger 18 protrudes from one end of the spool 20.

  The open end of the spring accommodating hole 37 is closed by a plug 53 that is screwed into a screw hole formed on the inner peripheral surface thereof, and a spring 54 is provided between the plug 53 and the spool 20. The spool 20 is pressed toward the plunger 18 by the urging force of the spring 54, so that the plunger 18 normally contacts the bottom surface of the cover 14 (when the solenoid 17 is not energized) via the shaft portion 52 of the spool 20. It is held in the contact position.

  At the stopper contact position of the plunger 18, as shown in detail in FIG. 2, the end edge of the yoke portion 31 of the core 15 and the end edge of the plunger 18 are in an underlap relationship separated by ΔS amount. The seal length S1 of the supply port 50 is increased by the underlap amount ΔS.

  That is, the conventional edge of the yoke portion 31 and the end of the plunger 18 are set to have a relationship that coincides with the axial direction or slightly overlaps as shown in FIG. On the other hand, in the present embodiment, the stopper contact position of the plunger 18 is shifted to the right in the figure by the above-described underlap amount ΔS. Therefore, the spool 20 that moves together with the plunger 18 is also held at a position shifted by ΔS in the right direction compared to FIG. Therefore, S1 (S1 = S0 + ΔS), in which the seal length between the valve sleeve 19 of the supply port 50 portion and the first land portion 41, which conventionally has a seal length S0 as shown in FIG. Become.

  In this way, the end edge of the yoke portion 31 of the core 15 and the end edge of the plunger 18 are set in an underlap relationship, so that the suction force with respect to the stroke of the plunger 18 is increased as shown in FIG. In the underlap region ΔS until the end edge of the arm portion 31 coincides with the end edge of the yoke portion 31, the suction force characteristic FI decreases to the right. However, when the stroke of the plunger 18 increases beyond the underlap region ΔS, the suction force hardly changes with respect to the stroke of the plunger 18 due to the influence of the tapered portion 32 formed in the yoke portion 31. It becomes a characteristic of attractive attraction.

  Further, in order to ensure the seal length S1 at the supply port 50 portion even when the solenoid 17 is not energized, the set load F0 of the spring 54 when the solenoid 17 is not energized is 0 as shown in FIG. It is set to be the above. Thus, the plunger 18 is reliably held at the stopper contact position SA that contacts the bottom surface of the cover 14 when the power is not energized, even though the stroke amount of the spool 20 is increased due to the underlap. .

  Further, as shown in FIG. 3, the spring constant of the spring 54 is such that the set load FX of the spring 54 at the initial stroke position (between the stopper contact position SA and the hydraulic pressure rising stroke position SB) of the plunger 18 is It is set so as not to exceed the suction force FI. As a result, even at the initial stroke position of the plunger 18, the spool 20 can stably stroke due to the balance between the suction force and the spring 54, and malfunction does not occur.

  Although not shown, the supply port 50 is supplied with hydraulic oil controlled to a low pressure by a regulator valve (not shown) from a pressure oil supply source, and output from the output port 48. The hydraulic fluid is supplied to each clutch of an automatic transmission (not shown).

  Next, the operation of the above-described configuration in the present embodiment will be described.

  When the solenoid 17 is not energized, the spool 20 presses the plunger 18 in the right direction in FIG. 1 by the biasing force of the spring 54 and holds the plunger 18 in the stopper contact position where the plunger 18 contacts the bottom surface of the cover 14. Yes. In this non-energized state, the output port 48 is disconnected from the supply port 50 and is also connected to the discharge port 49, whereby the output port 48 is maintained at a low pressure.

  When the solenoid 17 is energized, the spool 18 is displaced against the urging force of the spring 54 by pulling the plunger 18 toward the core 15. As a result, the second land portion 42 starts to open the supply port 50 and the first land portion 41 starts to limit the opening area of the discharge port 49, so that the control pressure of the output port 48 is gradually increased. The clutch hydraulic pressure is controlled by the control pressure.

  The control pressure is also introduced into the feedback port 45 and acts on the stepped portion 44 provided at the boundary between the second land portion 42 and the third land portion 43. For this reason, the feedback force obtained by the product of the area difference between the second land portion 42 and the third land portion 43 and the control pressure acts in the same direction as the biasing direction of the spring 54.

  That is, in such a linear solenoid valve 10, the core 15 attracts the plunger 18 according to the current value energized to the solenoid 17, and the position where the urging force of the spring 54 and the resultant force of the feedback force balance. The spool 20 is held, whereby the control pressure is controlled to a pressure corresponding to the current value supplied to the solenoid 17.

  FIG. 4 shows the pressure characteristics of the linear solenoid valve 10 in the present embodiment. In a region where the current value supplied to the solenoid 17 is small, the spool 20 does not close the discharge port 49, and the pressure is Does not rise. In this state, the spool 20 is controlled by the balance between the biasing force of the spring 54 and the suction force. As the current value energized to the solenoid 17 increases, the suction force increases accordingly, so the spool 20 closes the discharge port 49 and the pressure rises. Therefore, as described above, since the spool 20 is controlled based on the suction force, the urging force of the spring 54, and the feedback force as described above, the current value supplied to the solenoid 17 is increased as shown in FIG. The control pressure output from the output port 48 is increased in proportion.

  By the way, in the present embodiment, the wrap amount between the core 15 and the plunger 18 in the non-energized state of the solenoid 17 is set to an under wrap, so that the seal length of the supply port 50 portion when the energization is not performed by this under wrap amount ΔS. Since the height S1 is increased, the consumption flow rate of the hydraulic oil supplied from the supply port 50 to the discharge port 49 through the fitting gap between the land portion 42 of the spool 20 and the valve sleeve 19 in the seal length S1 portion is reduced. Can be reduced.

  FIG. 5 shows a flow rate characteristic A of the linear solenoid valve 10 according to the present embodiment as a solid line, and a conventional flow rate characteristic B as a broken line for comparison. From the figure, it can be seen that the consumption flow rate at the time of non-energization in the flow rate characteristic A is reduced by the flow rate ΔL as compared with the consumption flow rate at the time of non-energization in the flow rate characteristic B.

  Therefore, when the linear solenoid valve in the present embodiment is used in an automatic transmission that controls the clutch pressure corresponding to the gear position, the total flow rate of the flow rate when each of the plurality of linear solenoid valves is not energized is greatly increased. As a result, the pump can be used with a small capacity, and it can contribute to improving the fuel efficiency of the vehicle by reducing the size and weight.

It is sectional drawing of the linear solenoid valve which shows embodiment of this invention. It is the figure which expanded the principal part of FIG. It is a figure which shows the relationship between the attraction | suction force and spring load in embodiment of this invention. It is a figure which shows the pressure characteristic in embodiment of this invention. It is a figure which shows the flow volume characteristic in embodiment of this invention. FIG. 3 is a conventional view corresponding to FIG. 2.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Linear solenoid valve, 11 ... Solenoid unit part, 12 ... Spool valve part, 14 ... Cover, 15 ... Core, 17 ... Solenoid, 18 ... Plunger, 19 ... Valve sleeve, 20 ... Spool, 30 ... Housing recessed part, 31 ... Yoke part, 32 ... taper part, 35, 36 ... valve hole, 41, 42, 43 ... land part, 45 ... feedback port, 48 ... output port, 49 ... discharge port, 50 ... supply port, 54 ... spring.

Claims (2)

A linear solenoid valve that displaces a spool accommodated in a valve sleeve by a solenoid unit;
The solenoid unit includes a solenoid, a plunger that moves according to a current supplied to the solenoid, and a core that attracts the plunger as the solenoid is energized.
The valve sleeve is closed by the spool when not energized and opened by displacement of the spool due to energization and connected to the output port. When not energized, the supply port is opened and connected to the output port and connected to the output port. A discharge port that is closed by displacement; an output port that is provided between the supply port and the discharge port and outputs a control pressure; and a feedback port that guides the control pressure to a feedback portion having an area difference formed in the spool. Provided,
A cylindrical yoke portion having an opening for accommodating one end of the plunger is provided on the surface of the core facing the plunger, and the tip of the yoke portion and the end edge of the plunger are separated by a predetermined amount when no power is supplied. Increased the seal length of the supply port part by setting to be the relationship of the underlap
A spring that presses the plunger through the spool in the same direction as the feedback force that acts on the feedback portion and that resists the suction force that acts on the plunger is provided. The linear solenoid valve is characterized in that the spring constant is set so as not to exceed the suction force by the core at, and the set load is set to 0 or more at the stopper contact position of the plunger. 2. The linear solenoid valve according to claim 1, wherein a taper portion whose cross-sectional area decreases as it approaches the opening end of the housing recess is formed on the outer periphery of the yoke portion.

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