JP2007183003A - Solenoid operated type pressure regulating valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent lubricating oil from being deteriorated between sliding surfaces of a shaft and a bushing and to reduce a deposit of a product and to ensure a pressure regulation precision by preventing a sliding malfunction in a pressure regulating valve. <P>SOLUTION: The pressure regulating valve is provided with: a core 2; and a plunger 4 which loads loading on a valve body 13 via the shaft 40 being inserted through a hollow part 21 of the core. The pressure regulating valve keeps the bushing 5, of which sliding surface 5a with the shaft 40 is composed of a resin material, arranged on the hollow part 21 of the core 2 and is provided on inner periphery of the core a supply with exhaust oil path T of the lubricating oil which lubricates the sliding surfaces of the bushing 5 and the shaft 40. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pressure regulating valve, and more particularly to a solenoid valve type pressure regulating valve that applies a load to a valve body by a solenoid.

  Conventionally, a solenoid part of a pressure regulating valve of a solenoid valve type has a hollow core around which a coil is wound, a plunger that is attracted to the core against a load load by a return spring by energizing the coil, and a plunger that is attracted The shaft is fixed to the plunger, extends to the opposite side through the hollow portion of the core, and is in contact with the valve body. In the solenoid portion having such a configuration, since the shaft must accurately transmit the displacement of the plunger to the valve body, as disclosed in Patent Document 1, the shaft is supported by the core via a highly accurate bearing. Configuration is adopted. In the technique disclosed in the above publication, the bearing is made up of a bearing cage made of brass and a large number of balls that are rotatably fitted in small holes having a small diameter formed in the cage and slightly protrude to the outer periphery of the bearing cage. The linear ball bearing is configured such that a shaft disposed on the inner periphery of the bearing is supported by the core via a rolling ball and can be displaced with low resistance with respect to the core (for example, (See Patent Document 1).

  By the way, the core is generally soft so as to generate a larger plunger displacement force with as little solenoid current as possible and to make the hysteresis as small as possible in order to increase the efficiency of the pressure regulating valve. It is composed of a magnetically permeable material (for example, a soft steel material represented by SUYB1). Therefore, supporting a hard bearing ball so that it rolls directly on the inner periphery of the hollow portion of the core causes uneven deformation on the inner periphery of the core, which not only lowers the shaft and thus the centering accuracy of the plunger, but also enables smooth displacement of the shaft. Will be inhibited. Therefore, in order to prevent the occurrence of such a situation, in the above-described conventional technology, a relatively hard steel material (for example, a steel material having the same or higher hardness as a ball represented by SUJ2) is provided on the inner periphery of the hollow portion of the core. It is comprised by this and the structure which fits the sleeve which functions as an outer race of a linear ball bearing is taken.

However, in the configuration of the above prior art, not only the cost of the linear ball bearing itself is high, but also the number of parts including the linear ball bearing is large, and the number of assembling steps is accordingly large. Therefore, in order to avoid such a situation, the shaft is moved through a low-friction material for smoothly guiding the shaft without using a linear ball bearing, for example, a sliding bearing made of a resin material such as polytetrafluoroethylene, that is, a bush. The configuration supporting the core is recalled. However, when such a configuration is adopted, the clearance between the bush and the shaft must be made minute in order to prevent shakiness of the shaft. In this case, the lubricating oil is liable to stay. When the lubricating oil stays in this way, the lubricating oil is locally deteriorated by being placed in a high temperature environment due to heat generation of the coil of the pressure regulating valve through which an electric current flows and by repeated sliding of the shaft. There is concern. Further, since the lubricating oil generally contains carbon, a carbonized compound is easily generated, which may hinder smooth sliding of the shaft. In such a state, it is difficult to accurately adjust the hydraulic pressure.
Japanese Patent Laid-Open No. 3-204488

  Therefore, the present invention enables smooth sliding of the shaft while adopting a configuration in which the shaft is slidably supported in order to reduce the number of components, and the lubricating oil is supplied to and discharged from the sliding support portion with a simple configuration. A first object is to provide an electromagnetic pressure regulating valve.

  The second object of the present invention is to minimize the use of high-cost materials in the above-described valve.

  A third object of the present invention is to supply and discharge the lubricating oil to and from the sliding support portion with a simpler configuration.

  In order to achieve the first object, the present invention applies a load to a valve body via a hollow core at least partially disposed on the inner periphery of a coil and a shaft inserted through the hollow portion of the core. An electromagnetic pressure regulating valve that is actuated by applying an electrical signal to the coil, and is provided in a hollow portion of the core, and the shaft is movably supported with respect to the core. A bush having at least a sliding surface with a shaft made of a resin material, and a supply / discharge oil passage for lubricating oil that is formed between the core and the bush and lubricates between the sliding surfaces of the bush and the shaft. It is characterized by having.

  And in order to achieve the said 2nd objective, the sliding surface with the said shaft of the said bush is set as the structure formed with resin which coat | covers the inner periphery of a bush.

  And in order to achieve the 3rd objective, the said oil supply / discharge oil path is set as the structure formed in the inner periphery of the said core.

  In the configuration of the present invention, since a bush having a resin sliding surface is used for sliding support of the shaft, it is only necessary to arrange the bush instead of the conventional sleeve and linear ball bearing, and the number of parts and assembly man-hours are reduced. Thus, the cost of the pressure regulating valve can be reduced. In addition, since the lubricating oil that lubricates between the bush and the shaft can be supplied to and discharged from the sliding portion, the lubricating oil does not stay between the bush and the shaft, and the coil of the pressure regulating valve that allows current to flow is used. Even when operated in a high-temperature environment due to heat generation or the like, the lubricating oil does not deteriorate locally due to repeated sliding of the shaft and the lubricating performance does not deteriorate. Especially, the lubricating oil generally contains carbon because the lubricating oil contains carbon. Generation and adhesion to the sliding portion are prevented, and smooth sliding of the shaft can be maintained over a long period of time, whereby the highly accurate pressure regulation capability of the pressure regulating valve can be maintained over a long period of time.

  Moreover, in the structure of Claim 2, since the sliding surface with the shaft of a bush is formed by resin coating, the use of expensive resin can be minimized and the shaft can be smoothly slid. Possible bushings can be made cheaper.

  Further, in the configuration according to the third aspect, since the oil supply / discharge oil passage is formed on the inner periphery of the core, the oil supply / discharge oil passage is released to face the shaft, and the lubricating oil can be easily slid only by sliding the shaft. It is possible to supply and discharge parts.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  First, FIG. 1 shows in cross section the overall configuration of an embodiment of an electromagnetic pressure regulating valve to which the present invention is applied. In this example, the pressure regulating valve takes the form of a linear solenoid valve for a hydraulic control device of an automatic transmission. This valve is fitted into a valve hole formed in a valve body of an automatic transmission, and a valve portion V interposed in an oil passage formed in the valve body, and a solenoid portion positioned outside the valve body S.

  The valve part V is comprised from the sleeve 11 which comprises a valve main body, and the spool 13 which slides in the inside of the spool sliding hole 12 extended in the axial direction. The sleeve 11 has, in addition to the spool sliding hole 12, six ports P1 to P6 formed at intervals in the axial direction, and circumferential grooves G1 to G6 that connect the ports and the spool sliding hole 12. The side to which the solenoid part S is attached is enlarged in diameter, and the opposite side is thinned to have a reduced diameter. The spool 13 has two large-diameter lands R1 and R2 and one small-diameter land R3 that communicate and block the circumferential grooves G1 to G6 adjacent to each other via the spool sliding hole 12, and faces the solenoid portion S. The front end of the shaft portion is hemispherical, and is a contact portion with the shaft described in detail later. A return spring 14 is disposed on the anti-solenoid part S side of the spool sliding hole 12 of the sleeve 11, one end of the spring 14 is in contact with the small-diameter land R <b> 3 of the spool 13, and the other end is a screw plug. 15 is supported in a compressed state. The screw plug 15 is screwed into a screw hole formed in an extension of the spool sliding hole 12 and is positioned by caulking the thin portion of the sleeve 11 having a reduced diameter at a position where a predetermined return load is applied to the spool 13. It is fixed.

  The solenoid portion S has a diameter-enlarged portion abutted on the diameter-enlarged portion at one end in the axial direction of the sleeve 11, and is fitted to the core 2 fixed to the sleeve 11 by caulking of the inner end portion of the solenoid case 10 and the outer periphery of the core 2. The coil 3 is attached to the case 10 so as to be insertable, the plunger 4 is disposed on the outer end of the core 2 so as to face the core 2, and the shaft 40 is fixed to the plunger 4 by caulking. . In the figure, reference numeral 16 denotes a filter that also serves as a buffer material for preventing the coil from floating, 41 denotes a spacer made of a nonmagnetic material such as brass that maintains the minimum gap between the core 2 and the plunger 4, and 17 denotes an opening of the case 10. A covering plate 31 is a connector plug socket for connecting the coil 3 to an electronic control device (not shown).

  In accordance with the present invention, the hollow portion 21 of the core 2 is provided with a bush 5 that slidably supports the shaft 40 on the core 2. The sliding surface 5a that supports at least the shaft 40 of the bush 5 is made of polytetrafluoroethylene resin as a low friction synthetic resin material in this example. Specifically, the bush 5 is made of steel, and the resin material is lined on the inner peripheral surface of the bush 5 to form a coating with resin. The bush 5 is fitted and disposed at both ends of the inner periphery of the hollow portion 21 of the core 2.

  This valve is provided with a lubricating oil supply / discharge passage T for lubricating between the bush 5 and the shaft 40. The oil passage T communicates the space Cs surrounded by the core 2, the bush 5, and the shaft 40 with the other valve inner spaces Vs and Ss where the lubricating oil exists, and the oil passage whose formation position will be described in detail later. Has been.

  As shown in detail in FIG. 2 by disassembling the core and the bush, in this embodiment, the oil passage T is formed of a stepped hole whose diameter is increased at both ends in order to position the bush 5 in the axial direction. Are formed as a pair of “V” -shaped grooves that extend in parallel to each other in the axial direction over the entire length of the core 2 and face each other in the radial direction.

  In the linear solenoid valve of this embodiment having such a configuration, when the solenoid current is not loaded, the spool 13 is in the uppermost position shown in FIG. 1 with the load of the return spring 14, and in this position, the output port P3 is a drain. The base pressure that is communicated with port P2 and is supplied from port P4 (the modulator pressure that has been reduced so that the line pressure can be regulated with high precision within the stroke range of the spool of the linear solenoid valve using the modulator valve) is shut off by land R2. Has been.

  When a current with a duty ratio corresponding to the control state is supplied to the coil 3 from an electronic control device (not shown) with respect to the linear solenoid valve in such a state, the plunger 4 moves toward the end of the core 2 by electromagnetic attraction force. The shaft 40 is attracted and the displacement of the shaft 40 is transmitted to the spool 13.

  Then, the spool 13 is displaced downward from the illustrated position, and the base pressure supplied from the port P4 is reduced to a predetermined pressure by the land R2, and is output to the port P3. The output pressure at this time is fed back as a secondary pressure to the step surface of the land R2 via the oil passage in the spool, and the output pressure is kept at a predetermined pressure by a balance of solenoid load load, spring load load, and feedback pressure load.

  During the above operation, the displacement of the shaft 40 increases the volume of the internal space Ss of the case 10 in which the plunger 4 is accommodated by a volume corresponding to the amount of pushing of the shaft 40 into the internal valve space Vs. . As a result, the pressure in the internal space Ss of the case 10 decreases, so that the oil in the internal valve space Vs passes through the hollow portion 21 of the core 2, specifically the groove T, and is sucked into the space Ss. As the oil flows, the oil in the space Cs sandwiched between the bushes 5 and 5 is entangled and flows. On the contrary, when the shaft 40 is displaced upward in the figure, the volume of the space Ss decreases by the volume of the shaft 40 to be pushed. As a result, the pressure in the space Ss rises, and the oil in the space Ss passes through the groove T of the core 2 and is pushed out into the space Vs. Thus, not only the duty ratio is changed by the electronic control unit, but also the oil in the space Cs always flows into the space Vs and the space Ss by the displacement operation of the shaft 40 by the spool operation of the linear solenoid valve that regulates the output pressure to a predetermined pressure. .

  Thus, according to the valve of this embodiment, the lubricating oil that always lubricates the shaft support portion is supplied and discharged by the displacement of the shaft 40, and the lubricating oil interposed between the sliding surfaces is always replaced. Therefore, the lubricating oil stays between the bush 5 and the shaft 40, and the lubricating oil locally deteriorates due to repeated sliding of the shaft 40 in a high temperature environment. In particular, carbonization due to the lubricating oil generally containing carbon. Formation of the compound is prevented, and the shaft 40 can be smoothly slid. Moreover, since the inner periphery of the bush 5 is coated with resin, the use of expensive polytetrafluoroethylene resin can be minimized and the bush 5 can be formed at low cost. Further, since the bush 5 is disposed at both ends of the inner periphery of the core 2, the sliding contact area between the bush 5 and the shaft 40 is small, the sliding resistance of the shaft 40 can be reduced, and the shaft 40 is smoother. Sliding is possible. Furthermore, since the shaft 40 is supported in the vicinity of both ends thereof, rattling does not occur. Moreover, the material for forming the bush 5 is reduced, and the cost is reduced.

  As described in detail above, in the case of the above-described embodiment, even if the electromagnetic pressure regulating valve is used in a high temperature environment for a long period of time, the lubricating oil flow around the sliding portion between the bush 5 and the shaft 40 is formed by the groove T. Is ensured, the lubricating oil stays and degrades locally, the lubrication performance is lowered, the product adheres to the surface of the bush 5 and the shaft 40 is reduced, and the sliding failure of the shaft 40 in the bush 5 is reduced. Hydraulic pressure adjustment accuracy is ensured without occurring. As described above, since the lubricating oil can be supplied to and discharged from the sliding portion by the reciprocating motion of the shaft 40, there is no need for special pressurization or the like for causing the lubricating oil to flow. Also, if the oil flow capacity of the groove T is sufficient, the resistance of the plunger 4 to move in the oil through the groove T between the inside and outside of the solenoid case 10 is reduced as compared with the conventional one. The responsiveness can be further improved.

  In addition, this invention is not limited to the said embodiment, It can change variously based on the meaning of this invention, and does not exclude them from the scope of the present invention.

It is sectional drawing which shows embodiment of the electromagnetic pressure regulating valve to which this invention was applied. It is a disassembled perspective view which shows the core part of the said pressure regulation valve in a partial cross section.

Explanation of symbols

2 Core 4 Plunger 5 Bush 5a Sliding surface 13 Spool (Valve)
21 Hollow part 40 Shaft T Groove (oil passage)

Claims (3)

A hollow core at least partially disposed on the inner periphery of the coil, and a plunger for applying a load to the valve body through a shaft inserted through the hollow portion of the core, and an electrical signal is transmitted to the coil In an electromagnetic pressure regulating valve that operates when applied,
A bush disposed in the hollow portion of the core, supporting the shaft movably with respect to the core, and at least a sliding surface of the shaft made of a resin material;
An electromagnetic pressure regulating valve formed between the core and the bush, and having an oil supply / discharge oil passage for lubricating between the sliding surfaces of the bush and the shaft.   The electromagnetic pressure regulating valve according to claim 1, wherein a sliding surface of the bush with the shaft is formed of a resin that covers an inner periphery of the bush.   The electromagnetic pressure regulating valve according to claim 1, wherein the oil supply / discharge oil passage is formed on an inner periphery of the core.

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