JP2005180646A - Spool valve with position detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spool valve with an inexpensive spool position detecting device capable of being easily handled and directly detecting a position with high accuracy without impairing the performance. <P>SOLUTION: This spool valve with the position detector is provided with a main body 1, the spool 2 having stepped parts 2a, 2b, rings 3a, 3b at both sides of an axial hole 1a, retainers capable of being kept into contact with the rings or the stepped parts, and springs 12a, 12b respectively mounted between the retainer and guide 11a, 11b. A length between the stepped parts is shorter than a length between outer side end faces of the rings, the retainers and electric terminals 20a, 20b are electrically conducted, the rings and detection electric terminals 21a, 21b are electrically conducted, the electric terminals and the detection electric terminals are electrically conducted when the rings and the retainers are kept into contact with each other, and the rings and the electric terminals are not electrically conducted when the rings and the retainers are separated from each other. The ring may be mounted only at one side to form a two-position valve. First spacers 5a, 5b, the rings, and second spacers 6a, 6b are mounted in a through hole 22 at an end part, and the spool is switched by electromagnetic coils 30a, 30b. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a spool valve with a detector that can directly detect the spool position of a spool valve (spool-type directional control valve) used in industrial machinery, construction machinery, etc., and in particular, when an electromagnetic coil of a solenoid valve is excited or not excited. The present invention relates to a spool valve with a detector that can directly detect the position of the spool.

  FIG. 4 shows the structure of a solenoid valve that is the most common spool valve. The solenoid valve 51 includes a main body 53 having an axial hole 53a having a plurality of fluid passages, a spool 52 inserted into the axial hole 53a and switched in the axial direction by the axial movement, and the spool left and right. Electromagnetic coils 30a and 30b for movement are provided, and connectors 54a and 54b for connecting the electrical terminals of the coils to the outside are connected. Steps 2a and 2b are provided on both sides of the spool 52. The rods 55a and 55b are brought into contact with the end portions 2c and 2d of the spool. The rod is integrated with a movable iron core (not shown), and the solenoid guide 11a. 11b are inserted so as to be axially movable. The solenoid guides 11 a and 11 b are fixed to the main body in a state where they are screwed into screws 53 c and 53 c provided at the end of the axial hole of the main body 53 and sealed by an O-ring 56. The rod 55a, 55b, the insertion hole of the solenoid guide 11a, 11b into which the movable iron core is inserted is sealed on the side opposite to the main body, the space between the main body 53 and the solenoid guide is sealed, and the pressure in the main body axial hole 53a is increased. This is a so-called oil-immersed solenoid valve. The electromagnetic coils 30a and 30b are fitted and inserted into the solenoid guides 11a and 11b, and the electromagnetic coils are fixed by the nuts 34. By energizing the electromagnetic coils 30a and 30b, the movable iron core is moved and the spool 52 is urged in the pressing direction by the rods 55a and 55b. Ring-shaped stoppers 57a and 57b having hollow holes provided concentrically with the spool 52 are provided at both ends of the main body.

  Either one of the contact surfaces 58a, 58b on the outer side of the stoppers 57a, 57b or the stepped portions 2a, 2b of the spool 52, or a hollow hole concentric with the spool that can be contacted simultaneously and moved in the axial direction. Ring-shaped retainers 59a and 59b are provided, and springs 12a and 12b are provided between the retainer and the solenoid guides 11a and 11b. The retainers are urged toward the axial main body by the springs. The distance between the contact surfaces 58a and 58b with which the retainers on both sides abut and the distance between the step portions 2a and 2b on both sides of the spool are substantially the same, and when the electromagnetic coils 30a and 30b are not energized, the spool 2 is spring 12a. 12b and retainers 59a and 59b are held at intermediate positions. When the interval between the step portions 2a and 2b on both sides of the spool is smaller than the interval between the contact surfaces 58a and 58b on both sides by, for example, ΔL, the retainers 59a and 59b on both sides contact the contact surfaces 58a and 58b, respectively. If the gap between the two retainers fluctuates by ΔL, and the gap between the stepped parts on both sides of the spool is larger by ΔL, for example, than the gap between the contact surfaces on both sides, the spool is maintained at a position where both spring strengths are parallel. When the forces are different, only one of the retainers comes into contact with the abutting surface, and the spool moves toward the non-abutting surface side by ΔL. For this reason, dimensions are set such that the difference ΔL between the distance between the contact surfaces on both sides and the distance between the step portions on both sides of the spool is as small as possible. As a result, when the current is not energized, the spool 52 is neutralized. When the right electromagnetic coil 30b is energized in the drawing, the rod 55b pushes the spool, and the spool pushes the left retainer 59a and the spring 12b to move to the left. Switch. At this time, the retainer 59b on the right side remains in contact with the contact surface 58b (stopper 57b). In the figure, when the left electromagnetic coil 30a is energized, the rod 55a pushes the spool 52, and the spool pushes the right retainer 59b and the spring 12b to move to the right to switch the fluid passage. At this time, the left retainer 59a remains in contact with the contact surface 58a (stopper 57a).

On the other hand, some of the connectors 54a and 54b of the electromagnetic valve 51 are equipped with an indicator light assembled in parallel to the electromagnetic coils 30a and 30b. This light is turned on when a voltage is applied across the electromagnetic coil. However, this light does not indicate that the spool is surely moving with the excitation of the electromagnetic coil. For example, even if a voltage is applied to the electromagnetic coil, it is lit even when the electromagnetic coil is disconnected and the spool does not move. In the oil-immersed solenoid valve, the spool 52 is placed in a sealed pressure-resistant space, and the main body 53, the spool 52, the solenoid guides 11a and 11b, the retainers 59a and 59b, the springs 12a and 12b, and the like need strength. Therefore, the position of the spool cannot be electrically detected because metal is used and is electrically conductive. Therefore, in Patent Document 1, the position of the spool is detected from the outside of the sealed pressure resistant space using a differential transformer. In Patent Document 2, the position of the spool in the sealed pressure resistant space is detected using a magnetic sensor.
JP-A-10-177918 JP 2002-89742 A

  However, the differential transformer type as shown in Patent Document 1 has a complicated valve structure. Since a differential transformer and a dedicated electric circuit (amplifier) are required, it becomes expensive. Moreover, before use, it is necessary to adjust the position of the core which is a differential transformer or a detection body. Furthermore, there has been a problem that the detection position of the detection body changes (a phenomenon called temperature drift occurs) due to temperature changes of the differential transformer and the electric circuit (amplifier). Further, in the magnetic sensor type as shown in Patent Document 2, the valve structure is complicated. Since a magnetic sensor is required, it is expensive. Before use, it is necessary to adjust the position of the magnet which is a magnetic sensor or a detection body. There are similar problems such as a change in the detection position of the detection body (a phenomenon called temperature drift occurs) due to a temperature change of the magnetic sensor. Further, there is a problem that it is difficult to adjust the position of the magnetic sensor because there is a difference (there is hysteresis) between the position of the detection body where the magnetic sensor is turned on and the position of the detection body where the magnetic sensor is turned off. Furthermore, both of them have a problem that the sensitivity is poor because the spool in the sealed pressure resistant space is detected from the outside.

  In view of the above-mentioned problems, the subject of the present invention does not use expensive sensors and electric circuits. Simple structure and excellent durability. There is no need to adjust the position of the sensor and the detection body in the pre-use stage Unlike magnetic sensors, the detection positions at ON and OFF are the same (no hysteresis). It is an object to provide a spool valve with a spool position detecting device that can directly detect the position of a spool having a feature such that the detection position of a detection body does not change due to a change in temperature (no temperature drift), and further an electromagnetic valve. Another object is to provide a sensor structure that can directly detect the spool position even when a high back pressure is applied to the tank line, such as an oil-immersed solenoid valve. Furthermore, it is to provide a sensor structure that can be easily assembled.

  In the present invention, a main body having an axial hole provided with a plurality of fluid passages, a spool inserted into the axial hole so as to switch the fluid passage by axial movement, and having step portions on both sides, and the spool And a ring provided on both sides of the axial hole concentrically with the spool so as not to interfere with the spool, and can be brought into contact with either one of the outer end face of the ring or the stepped portion or simultaneously in the axial direction. A retainer that is concentric with the spool that is movable except for the stepped portion so as not to interfere with the spool, and a guide that is provided so as to be able to bias the retainer to the spool side via a spring. Furthermore, the length between the step portions is made smaller than the length between the outer side end faces of the ring, and the retainer on each side has conductivity and can be electrically connected to the outside. And the ring is electrically connected to a detection electrical terminal different from the electrical terminal, and the electrical terminal via the ring when the ring and the retainer are in contact with each other. By providing a spool valve with a spool position detecting device in which the detection electrical terminal is electrically conductive and at least the ring and the electrical terminal are not electrically conductive when the ring and the retainer are separated from each other. Settled.

  That is, a stopper (contact surface) provided at both ends of a conventional spool to secure a neutral position of the spool is a ring electrically insulated from the outside, and a retainer electrically connected to an electrical terminal and the ring The ring and the retainer are used as an open / close switch, for example, by making the contact surfaces of the ring and the retainer metal contact with each other so that they can conduct electricity. In addition, since the length between the step portions of the spool is made smaller than the length between the outer side end faces of the ring with which the retainer abuts, the retainer is surely brought into contact with the ring when the spool is neutral. Therefore, when the spool is neutral, the retainers on both sides come into contact with the rings by the springs, and the rings on both sides and the retainers are conducted, that is, the electrical terminals and the detection electrical terminals are conducted. Also, when the spool moves away from one ring and moves in the direction of the other ring, one ring and the retainer remain in contact (conductive), but the other retainer is caught by the moving step of the spool. It moves against the other spring, the other ring and the retainer are separated, and the other electric terminal and the detection electric terminal become non-conductive. Similarly, when the spool moves away from the other ring and moves toward one ring, one side becomes non-conductive. Thus, since the spool and the retainer are electrically conductive and non-conductive during the neutral position and operation of the spool, the spool position can be detected. Further, since the spool itself directly acts on the retainer and serves as an open / close switch, it is not necessary to detect from outside the sealed space, and the position of the spool can be directly detected in the sealed space.

  Note that the electrical conduction between the retainer and the electric terminal is performed by connecting the conductive retainer and the electric terminal with a lead wire. Alternatively, various paths are possible, such as connecting to an electrical terminal via a conductive retainer, a conductive spring, a conductive guide, or a conductive body. In the case of a 3-position valve in which the spool moves in the neutral and left / right directions, both are conductive when neutral, when the spool is in the left position, the left side is non-conductive, the right side is conductive, the right position is conductive, and the right side is conductive. It becomes non-conductive. Also, in the case of a two-position solenoid valve type two-position valve with two positions in the left-right direction of the spool, etc. when the spool is in the left position, the left side is non-conductive, the right side is conductive, the right position is conductive, the left side is conductive, and the right side is non-conductive It can be made conductive. Note that the stepped portion is not necessarily symmetrical.

  On the other hand, even if it is a three-position valve, it is only necessary to detect the conductivity on one side. In the case of a two-position valve, for example, the spring is pushed to the left or right side to be in a neutral state (spring return state). In some cases, it may be detected. Therefore, in the invention according to claim 2, the ring is provided only on one side, and the retainer on the opposite ring side is a contact surface provided at the end of the axial hole concentric with the spool or the spool. Any one of the stepped portions on the side opposite to the ring, or a ring shape concentrically with the spool that can be contacted at the same time and movable in the axial direction, except for the stepped portion, so as not to interfere with the spool. And a spool position detecting device biased by a spring provided on the opposite ring side, wherein a length between the step portions of the spool is made smaller than a length between an outer end surface of the ring and the contact surface. With a spool valve.

  In the neutral state or the spring return state, the spool is positioned by the springs and retainers on both sides. At this time, since the length between the step portions of the spool is smaller than the length between the end surface of the ring and the contact surface, the ring and the retainer come into contact with each other and become conductive. Even if the spool is moved in the direction opposite to the ring, this state does not change. On the other hand, when the spool is moved to the ring side, the ring and the retainer are separated and become non-conductive. Therefore, in the case of the 3-position valve, it is possible to detect when the spool moves from the neutral state to the ring side. On the other hand, the same applies to the two-position valve, which is conductive in the neutral state, and when the spool is moved to the ring side, the ring and the retainer are separated and become non-conductive. Therefore, in the case of a two-position valve, the operation state can be detected by operating a rod or the like that pushes the spool on the opposite ring side, and the position of the spool in the two-position valve can be directly detected.

  The ring constituting one of the open / close switches is electrically insulated from components other than the detection electrical terminal and the retainer. More specifically, in the invention according to claim 3, a concentric through hole having a stepped portion is provided at an end portion of the axial hole of the main body, and the stepped portion is provided in the through hole. The ring-shaped first spacer in which the spool is prevented from interfering with the ring, the ring, and the cylindrical second spacer in which the retainer and the spool are prevented from interfering with each other. The tip of the guide is pushed in such a way that it is sandwiched and fixed sequentially so that it does not come into electrical contact with at least the contact portion between the first spacer and the ring and the contact portion between the ring and the second spacer. And a spool valve with a spool position detecting device insulated.

  That is, a stepped through hole is provided at the end of the axial hole of the main body, the first spacer, the ring, and the second spacer are sequentially arranged from the stepped portion of the through hole and pressed by the tip of the guide. And, for example, the first and second spacers and the ring are inlay fitted so as not to be in electrical contact with the main body. In addition, the first and second spacers are made of an electrical insulating material, or the material is a metal such as iron, steel, or aluminum, and an electrical insulating coating such as a fluorine coating or a ceramic coating is applied to the contact surface with the ring. The ring and retainer are made of iron, steel, or other conductive metal. As a result, the ring can be easily electrically insulated from the components except the retainer. Note that various types of electrical insulating materials and coatings may be appropriately selected depending on strength and electrical withstand voltage.

  Further, the connection between the ring and the detection electric terminal may be performed by brazing a lead wire or the like to a metal ring and welding it. However, when sealed in a sealed pressure resistant container, it is difficult to ensure the quality of the seal and the electrical connection part. Accordingly, in the invention according to claim 4, a communication path is opened in a direction perpendicular to the through-hole axis, a bush for sealing the communication path, a seal member provided in a through hole of the bush, and the seal member A conductive rod penetrating through the bushing through hole in a non-conductive state while being sealed with the conductive rod, and the tip of the conductive rod is provided in a direction perpendicular to the axis of the ring, so that the conductive rod is screwed in a conductive state. A spool valve with a spool position detecting device in which the other end of the conductive rod is connected to the detection electric terminal via a lead wire.

  While securing the conductive rod in the sealed pressure-resistant space with the conductive rod penetrating the through hole while being sealed by the seal member provided in the through hole of the bush that seals the communication path opened in the direction perpendicular to the through hole axis A part (the other end) of the conductive rod can be exposed to the outside, and is connected to the detection electric terminal with a lead wire. Further, the tip of the conductive rod is screwed to the ring, and conductivity with the ring is ensured. Further, even if the pressure in the sealed pressure-resistant space is high, the conductive rod is supported by the ring through the female screw, so that it does not jump out of the bush through hole. Also, when assembling the conductive rod, first fix the ring in place so that the female threaded portion of the ring faces the communication path side of the main body, and insert the conductive rod from the communication path side of the main body and screw it in. In addition, a seal member and a bush may be assembled. The same applies to the decomposition. The connector provided with the electrical terminal and the detection electrical terminal is preferably provided in the vicinity of the communication path or on the communication path.

  The means for driving the spool can be an electromagnetic coil, manual operation, hydraulic pilot system, or the like. In particular, those using electromagnetic coils are easy to operate and remote control is easy. Therefore, in the invention according to claim 5, a rod is provided that can be brought into contact with an end of the spool, the rod is connected to a movable iron core, and the movable iron core is driven by an electromagnetic coil. A spool valve with a spool position detector, which is an electromagnetic valve, was used. As a result, the electromagnetic coil is excited, the movable iron core is moved, the spool is pushed by the rod and moved, and the movement of the spool can be detected by the ring and the retainer.

  In the present invention, an open / close switch is constituted by the ring and the retainer so that the neutral position of the spool and the ring and the retainer are electrically conductive and non-conductive at the time of operation, and the position of the spool can be directly detected in the sealed space. Therefore, the detection accuracy is good, expensive sensors and electric circuits are unnecessary, the structure is simple, the durability is excellent, the position adjustment of the sensor and the detection body is not required before use, and there is no hysteresis or drift. Furthermore, the present invention provides a spool valve with a spool position detector that is easy to handle and easy to use. In addition, the conventional parts can be configured without significantly changing. Further, the present invention can be applied to a three-position valve and a two-position valve by providing detectors on both sides and one side.

  In addition, the first spacer, ring, and second spacer are sequentially arranged from the stepped portion of the through hole provided at the end of the axial hole, and the ring is clamped and fixed by pressing at the tip of the guide, and the ring The main body and the main body are not touched electrically, so the structure is simple and durable. Further, since it can be configured in a sealed pressure-resistant space, it is suitable for an oil-immersed solenoid valve or the like (claim 3). Furthermore, the conductive rod that passes through the through hole while being sealed by the seal member provided in the through hole of the bush is secured in the sealed pressure-resistant space and connected to the external detection electric terminal, and the tip of the conductive rod is screwed to the ring. Since it is fixed, it can be applied even when the pressure in the sealed pressure-resistant space is high, and the spool position can be detected directly even when a high back pressure is applied to the tank line like an oil-immersed solenoid valve. Furthermore, since a conductive rod, seal, and bush can be assembled to the female thread of the ring from the side of the communication passage perpendicular to the through-hole of the main body, a spool valve with a spool position detector that can be easily assembled and disassembled is provided. (Claim 4).

  The spool of a spool valve with a spool position detector with such a structure can be moved by pushing it with a rod of a movable iron core, and the solenoid of the solenoid valve can be easily detected by making the movable iron core an electromagnetic valve that can be driven by an electromagnetic coil. (Claim 5).

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a partial cross-sectional view of a spool valve with a spool position detector showing an embodiment of the present invention when neutral. The spool valve 31 with a spool position detector of the present invention is an oil-immersed three-position solenoid valve having electromagnetic coils 30a and 30b on the left and right sides. FIG. 1 shows a case where the solenoid valve is de-energized and the spool 2 is in a neutral state. Is shown. As shown in FIG. 1, the main body 1 includes a body 10 ′ having an axial hole having a plurality of fluid passages, an axial hole fixed on both sides of the body 10 ′, and a case 10a having a stepped through hole. 10b. The main body 1 may be integrally formed, but has a complicated fluid path, and in order to facilitate processing, handling, and assembly, the conventional casting main body 53 is diverted to the body 10 '. The body 1 is provided with metal cases 10a and 10b on both sides thereof. A spool 2 inserted into the axial hole 1a of the main body 1 and adapted to switch the fluid passage by axial movement is inserted. Stepped through holes 22a and 22b are provided at the ends of the axial holes 1a of the cases 10a and 10b. The axial hole and the through hole are concentric. The end screws of solenoid guides 11a and 11b, which are guides, are screwed onto the screws 22c and 22d at the end of the through holes, and the guides are fixed to the cases 10a and 10b. A male screw (not shown) is cut on the opposite screw side of the guides 11a and 11b, and a nut 34 is screwed. The electromagnetic coils 30a and 30b in which the guides are inserted are sandwiched between the cases 10a and 10b of the main body 1 and the nuts 34 and 34, whereby the main body (body and case), the guides, and the electromagnetic coils are integrated. The electromagnetic coils 30a and 30b are provided with connectors 54a and 54b for connecting coil terminals to an external power source. Connectors 19 a and 19 b that can be electrically connected to the outside are attached to the cases 10 a and 10 b of the main body 1. The connectors 19a and 19b are provided with terminals and electrically insulated detection electrical terminals 21a and 21b, and electrical terminals 20a and 20b electrically connected (grounded) to the cases 10a and 10b and the body 10 'of the main body 1. And are provided.

  The spool 2 is a neutral all-port block type, and step portions 2a and 2b are provided on both sides of the spool. Further, rods 55a and 55b are provided concentrically with the spool 2 and capable of contacting the spool end portions 2c and 2d. The rod is connected to a movable iron core (not shown) and is inserted into the guide holes 11c and 11d. The movable iron core and the electromagnetic coils 30a and 30b constitute biasing means for biasing the rods 55a and 55b in the spool 2 direction. Yes. By energizing the electromagnetic coils 30a and 30b, the rods 55a and 55b are pressed against the spool 2 through the movable iron core and moved in the axial direction. Retainers 4a and 4b, which have hollow holes larger than the small diameter portions 2e and 2f forming the step portions 2a and 2b of the spool 2 and smaller than the outer diameter of the step portion, can slide on the small diameter portions. Is fitted. The retainers 4a and 4b are configured so that the retainers push the spool by springs 12a and 12b provided between the ends of the guides 11a and 11b and the retainers.

  The end of the spool 2 protrudes into the case through holes 22a and 22b. The first spacers 5a and 5b, the rings 3a and 3b, and the second spacers 6a and 6b having hollow holes concentric with the shaft of the spool 2 are sequentially arranged from the stepped portions 23a and 23b of the through holes, and the guides 11a, It is pushed and clamped at the tip of 11b. Recessed inlay portions 5c, 5d, 6c, 6d are formed on the ring side surfaces of the first and second spacers. Convex portions 3c, 3d, 3e, and 3f are formed on both end faces of the ring so as to be fitted into the concave inlay portions. As a result, the rings 3a and 3b are sandwiched between the first and second spacers 5a, 5b, 6a and 6b in the direction perpendicular to the axis, and the ring and the main body 1 (cases 10a and 10b, body 10 ') are brought into contact with each other. It is preventing. The first and second spacers are electrically insulating materials so that the ring and the case are not electrically connected. In the embodiment of the present invention, the electrical insulating material is a glass fiber reinforced polyamide 66 resin in view of mechanical strength, heat resistance, oil resistance, and the like. Accordingly, the rings 3a, 3b are electrically insulated from the main body 1 (cases 10a, 10b, body 10 ') and the first and second spacers 5a, 5b, 6a, 6b. Naturally, the diameters of the hollow holes of the first spacer and the ring are set so as not to interfere with the moving spool 2. The second spacers 6a and 6b have a cylindrical shape so as not to interfere with the retainers 4a and 4b and the springs 12a and 12b.

  The retainers 4a and 4b are configured to press the spool 2 with springs 12a and 12b. The outer circumferences of the retainers 4a and 4b are made smaller than the inner diameter of the second spacer, and are in contact with the outer side end faces (contact surfaces between the retainer and the rings) 13a and 13b of the rings 3a and 3b. When the spool step portions 2a and 2b are located on the inner side of the positions of the outer end faces 13a and 13b of the ring, the retainers 4a and 4b are brought into contact with the outer end face of the ring. When it is outside the position, the retainer comes into contact with the step portion of the spool. The length between the step portions 2a and 2b of the spool is smaller than the length between the outer end faces 13a and 13b of the ring. When the spool 2 is neutral, the rings 3a and 3b on both sides and the retainer 4a are always provided. , 4b are in contact with each other. The contact surfaces (outer side end surfaces) 13a and 13b of the ring with the retainer have no insulating coating, and the metal surface is exposed, so that the ring and the retainer are electrically conductive by contact. The retainers 4a and 4b, which are conductors, are always in conduction with the cases 10a and 10b and the body 10 ', which are also conductors, via springs 12a and 12b, which are also conductors, and solenoid guides 11a and 11b. Since the case is connected to the electric terminals 20a and 20b, the retainers 4a and 4b and the electric terminals are always in conduction.

  The communication passage 14 is opened in the direction perpendicular to the through holes 22a and 22b at the lower positions of the connectors 19a and 19b of the cases 10a and 10b of the main body 1. The communication path is located at the same position as the side surfaces of the rings 3a and 3b provided in the through holes. Further, the rotational direction positions of the rings 3a and 3b are provided on the side surfaces of the ring when viewed from the communication path 14, so that the screw 15 is substantially in front. A stepped bush 8 is inserted at the end of the communication path, and an O-ring 16 is attached to the stepped portions 8c and 8d. Further, a through hole 18 is formed in the bush 8 and an O-ring 17 as a seal member is mounted in the through hole, and a seal plate 9 for stopping the O-ring is provided, and both the bush and the seal plate are glass which is an electrical insulating material. The fiber reinforced polyamide 66 resin is used. The conductive rods 7a and 7b pass through the through hole 18 and the through hole O-ring 17, and the outer periphery of the conductive rod is sealed with an O-ring of the through hole. Since the tips of the conductive rods 7a and 7b are provided on the side surfaces of the ring, they are screwed and fixed to the screw 15 in an electrically conductive state. The other ends of the conductive rods 7a and 7b are connected to the detection electrical terminals 21a and 21b and lead wires. 24 are connected to each other. Thereby, the rings 3a and 3b, the conductive rods 7a and 7b, and the detection electrical terminals 21a and 21b are always electrically connected, while the main body 1 (cases 10a and 10b, body 10 ') and the guides 11a and 11b. Etc. are insulated.

  Next, the operation of the spool valve 31 with a spool position detector will be described. FIG. 2 is a partial cross-sectional view showing a state in which the electromagnetic coil 30b on the right side of the spool valve with a spool position detector in FIG. 1 is energized. Note that the same components as those in FIG. 1 are denoted by the same reference numerals. In the neutral state shown in FIG. 1 when both the electromagnetic coils 30a and 30b are not excited, the rings 3a and 3b and the retainers 4a and 4b on both sides are in contact with each other at the contact surfaces 13a and 13b, and the electric terminals 20a and 20b. The detection electrical terminals 21a and 21b are electrically connected to each other. As shown in FIG. 2, when the right electromagnetic coil 30b is excited as seen in the figure, the spool 2 moves to the left. Then, the right retainer 4b and the ring 3b remain in contact with each other at the contact surface 13b, but the left retainer 4a moves to the left as the spool moves, so the left retainer and the ring 3a are not in contact with each other. It becomes. That is, the right electrical terminal 20b and the detection electrical terminal 21b are electrically connected, but the left electrical terminal 20a and the detection electrical terminal 21a are not electrically connected. When the left electromagnetic coil 30a is excited by the same principle, the left electrical terminal 20a and the detection electrical terminal 21a are electrically connected, but the right electrical terminal 20b and the detection electrical terminal 21b are not electrically connected. As described above, the contact states of the left and right retainers 4a and the ring 3a are all different in the non-excitation state, the excitation state of the right electromagnetic coil 30a, and the excitation state of the left electromagnetic coil 30b. The contact state between the retainer and the ring varies depending on each state, which means that the conduction state between the electrical terminals connected to each retainer and the ring also changes, and this is used to determine the position of the spool 2. Can be detected directly.

  The difference ΔL in the distance between the spool step portions 2a and 2b and the outer side end surfaces (contact surfaces) 13a and 13b is that the spool 2 is moved when the electromagnetic coils 30a and 30b are excited, and the retainers 4b and 4a are moved. The distance (the gap between the retainer and the spool) is the maximum value. Therefore, for example, in the neutral state (all port block type) shown in FIG. 1, the supply port 41 and the load ports 42a and 42b, and the load port and the tank ports 43a and 43b are shut off so that the ports do not communicate with each other. The length of each land 44a, 44b, 45a, 45b is preferably longer than ΔL. Further, the first and second spacers 5a, 5b, 6a, 6b for fixing the rings 3a, 3b and the bush 8 for supporting the conductive rods 7a, 7b and the seal plate 9 need to be insulated. It may be manufactured from an insulator, or after being manufactured from a conductor, an insulating treatment such as an insulating coating may be applied. The retainers 4a and 4b are electrically connected to the guides 11a and 11b and the cases 10a and 10b through contact conductor parts such as springs 12a and 12b, and are connected to the electrical terminals 20a and 20b. May be connected to an external terminal. Although the main body 1 has been described as being separated into the cases 10a and 10b and the body 10 ', it may be integrated.

  Another embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a partial cross-sectional view of a two-position type spool valve with a spool position detector showing another embodiment of the present invention when neutral (when the electromagnetic coil is de-energized and when the spring is returned). Components similar to those in FIG. 1 are denoted by the same reference numerals and a part of the description is omitted. The spool valve 31 'with a spool position detector according to another embodiment is an oil-immersed two-position solenoid valve having an electromagnetic coil 30a on the left side as viewed in FIG. In the case of FIG. 1, the opening / closing switch of the case 10b, the ring 3b and the retainer 4b is provided only on one side with respect to the body 10 ', and the electromagnetic coil 30a including the rod 55a and the movable iron core for operating the spool 2' is anti-ringed. It differs in that it is provided only on one side. Furthermore, the retainer 4 'on the side opposite to the ring is not a ring but abuts on a contact surface 58a similar to the conventional one (provided directly on the body without providing a stopper). The counter-ring side retainer 4 'is concentric with either the contact surface 58a or the step 2'a on the counter-ring side of the spool 2' or a spool that can be contacted simultaneously and moved in the axial direction. It has a ring shape with a hollow hole and is biased by a spring 12a provided on the side opposite to the ring. Further, the spool step portions 2'a and 2b are asymmetrical, and the length between the spool step portions having different shapes is smaller than the length between the end surface (contact surface) 13b of the ring 3b and the contact surface 58a. This is different from the three-position valve shown in FIG. The left side step 2'a of the spool 2 'is formed by providing a flange on the small diameter portion at the end of the spool.

  Specifically, FIG. 3 shows a case where the solenoid valve 30a is deenergized and the spool 2 'is in a neutral (spring return) state. The main body 1 'includes a body 10' having an axial hole 1a having a plurality of fluid passages, an axial hole provided on the right side of the body and a case 10b having a stepped through hole, and an axial direction on the left side of the body. And a cover 10 having a hole. A spool 2 'inserted into the axial hole 1a of the main body 1' and adapted to switch the fluid passage by axial movement is inserted. As in FIG. 1, the case 10b is provided with a stepped through hole 22b, and a guide 11 '(in this case, a cap nut shape) 11' is screwed onto the screw 22d at the end of the through hole, and the guide 11 'is attached to the case 10b. 10b is fixed. A connector 19b that can be electrically connected to the outside is attached to the case 10b. The connector 19b is provided with a detection electrical terminal 21b provided with terminals and being electrically insulated, and an electrical terminal 20b electrically connected (grounded) to the case.

  Retainers 4 'and 4b, which have hollow holes larger than the inner diameter of the small diameter portion forming the step portions 2'a and 2b of the spool and smaller than the outer diameter of the step portion, are slidable on the small diameter portion. It is possible to fit. The retainers 4 'and 4b are provided with springs 12a and 12b between the ends of the guides 11a and 11' and the retainers, respectively, so that the retainers are urged toward the spool by the springs.

  The end of the spool 2 'projects into the through hole 22b of the case 10b. A first spacer 5b, a ring 3b, and a second spacer 6b are sequentially arranged from the stepped portion 23b of the through hole on the case 10b side. The details of the ring, the first, and the second spacer are the same as described above, and thus the description thereof is omitted. A retainer 4b on the case 10b side pushes the spool 2 'by a spring 12b. The outer periphery of the retainer 4b is smaller than the inner diameter of the second spacer 6b and is in contact with the outer side end surface (contact surface) 13b of the ring 3b. When the right side step portion 2b of the spool is located on the inner side (body side) from the outer end surface 13b of the ring, the retainer 4b is brought into contact with the outer side end surface of the ring, and the spool step portion 2b is moved from the outer end surface of the ring. When in the outer side (guide side), the retainer 4b comes into contact with the step portion 2b of the spool. The length between the step portions 2'a and 2b of the spool 2 'is smaller than the length between the outer side end surface (contact surface) 13b of the ring 3b and the contact surface 58a, and when the spool is neutral The right ring 3b and the retainer 4b are always in contact with each other. The contact surface 13b between the right ring and the retainer is electrically conductive, and the retainer is electrically connected to the electrical terminal 20b via the spring 12b, the guide 11 ', and the case 10b, and the right retainer and the electrical terminal are connected to each other. Always conducting. Since the seal and wiring to the connector 19b of the case 10b and the ring 3b in the case are the same as described above, description thereof is omitted.

  The cover 10 on the side opposite to the ring is provided with a through hole 22 concentric with the axial hole of the spool 2 ', and a tip screw of a guide (solenoid guide) 11a is screwed onto a screw 22c at the end of the through hole, and the guide is fixed to the cover. ing. A male thread (not shown) is cut on the opposite thread side of the guide 11a, and a nut 34 is screwed. The electromagnetic coil 30a in which the guide 11a is inserted is sandwiched between the case and the nut 34, whereby the electromagnetic coil 30a, the solenoid guide 11a, the main body 1 '(cover 10, body 10', case 10b), and the right guide 11 'are integrated. It is said that. The electromagnetic coil 30a is provided with a connector 54a for connecting the coil terminal to an external power source. An end portion of the spool 2 ′ protrudes into the cover through hole 22, and a rod 55 a is provided that is concentric with the spool and can come into contact with the end portion. The rod 55a is connected to a movable iron core (not shown) and is inserted into the solenoid guide hole 11c, and the movable iron core and the electromagnetic coil 30a constitute an urging means for urging the rod. By energizing the electromagnetic coil 30a, the rod 55a is pressed against the spool 2 'via the movable iron core and biased in the right direction. Further, the through hole 22 is provided with a ring-shaped cover side retainer 4 'that comes into contact with a contact surface 58a provided at the end of the axial hole of the body 10'. The retainer 4 'abuts against the step 2'a and presses the spool 2' with the spring 12a against the anti-electromagnetic coil 30a side (body 10 'side). The position is regulated. Note that the structure of the left retainer 4 'may be the same as that shown in FIG. In this case, the retainer 59a is brought into contact with the contact surface 58a as the retainer contact surface of the metal annular stopper 57a shown in FIG.

  In the spool valve 31 'with a two-position type spool position detector, the right ring 3b and the retainer 4b are in contact with each other when the electromagnetic coil 30a is in a neutral state (when the spring is returned), and the electric terminal 20b and the detection electrical terminal 21b are electrically connected to each other. When the electromagnetic coil 30a is excited, the spool 2 'moves in the right direction. Then, since the retainer 4b moves to the right along with the movement of the spool, the retainer 4b and the ring 3b are not in contact with each other. In this way, the electrical connection state of each electrical terminal connected to the retainer and the ring changes according to the energization state of the electromagnetic coil 30a, and this is used to directly detect the position of the spool 2 '. can do. The main body 1 'is composed of the cover 10, the body 10', and the case 10b, but it goes without saying that it may be integrated.

It is a fragmentary sectional view at the time of neutral of the spool valve with a spool position detector which shows embodiment of this invention. It is a fragmentary sectional view which shows the state which supplied with electricity to the electromagnetic coil of the right side of the spool valve with a spool position detector shown in FIG. It is a fragmentary sectional view at the time of neutral of the spool valve with a two-position type spool position detector showing another embodiment of the present invention (when the electromagnetic coil is de-energized and at the time of spring return). It is a fragmentary sectional view of the conventional 3 position solenoid valve.

Explanation of symbols

1, 1 'body 1a axial hole 2, 2' spool 2a, 2b, 2'a step 3a, 3b ring 4a, 4b, 4 'retainer 5a, 5b first spacer 5c, 5d spigot 6a, 6b first Second spacer 7a, 7b Conductive rod 8 Bush 11a, 11b, 11 'Guide (solenoid guide)
12a, 12b Spring 13a, 13b Outer end face (contact surface)
14 Communication path 15 Female thread 16, 17 Seal member (O-ring)
18 Through hole 20a, 20b Electrical terminal (ground)
21a, 21b Detection electrical terminal 22, 22a, 22b Through hole 23, 23a, 23b (Through hole) Stepped portion 24 Lead wire 30a, 30b Electromagnetic coil 31, 31 'Spool valve with spool position detector 55a, 55b Rod 58a, 58b Contact surface (contact surface provided at the end of the axial hole)

Claims (5)

  A main body having an axial hole with a plurality of fluid passages, a spool inserted into the axial hole so as to switch the fluid passage by axial movement and having stepped portions on both sides, and the shaft concentric with the spool A ring provided on both sides of the directional hole so as not to interfere with the spool, and either the outer side end surface of the ring or the stepped portion can be contacted at the same time, or can be moved in the axial direction. A retainer concentrically with the spool except for the stepped portion so as not to interfere with the spool, and a guide provided so that the retainer can be biased to the spool side via a spring, and The length between the step portions is smaller than the length between the outer side end faces of the ring, and the retainer on each side is electrically connected with an electric terminal that is electrically conductive and can be electrically connected to the outside. The ring is electrically connected to a detection electrical terminal different from the electrical terminal, and when the ring and the retainer abut, the electrical terminal and the detection electrical terminal are conducted through the ring. A spool valve with a spool position detecting device, wherein at least the ring and the electrical terminal are prevented from conducting when the ring and the retainer are separated from each other.   The ring is provided only on one side, and the retainer on the side opposite to the ring is either a contact surface provided at the end of the axial hole concentric with the spool or the step on the side opposite to the ring of the spool, or A ring shape that is concentric with the spool that can be simultaneously contacted and movable in the axial direction except for the stepped portion so as not to interfere with the spool, and is attached by a spring provided on the side opposite to the ring. The spool position detecting device according to claim 1, wherein the length between the step portions of the spool is smaller than the length between the outer end surface of the ring and the contact surface. Spool valve.   A concentric through hole having a stepped portion is provided at the end of the axial hole of the main body, and the first ring-shaped first member is formed in the through hole so that the spool does not interfere in order from the stepped portion. The spacer, the ring, and the cylindrical second spacer in which the retainer and the spool are prevented from interfering are sequentially clamped and fixed so that the ring does not electrically contact the main body. The tip of the guide is pushed in, and at least the contact portion between the first spacer and the ring and the contact portion between the ring and the second spacer are electrically insulated. The spool valve with a spool position detecting device as described.   A communication path is opened in a direction perpendicular to the through-hole axis, a bush for sealing the communication path, a seal member provided in a through hole of the bush, and the bush through hole in a non-conductive state while being sealed by the seal member A conductive rod penetrating therethrough, and the tip of the conductive rod is provided in a direction perpendicular to the axis of the ring, so that the conductive rod is screwed in a conductive state, and the other end of the conductive rod is connected to the detection electrical terminal and the lead The spool valve with a spool position detecting device according to claim 3, wherein the spool valve is connected via a wire. 2. A rod provided to be abuttable with an end of the spool, the rod being connected to a movable iron core, and the movable iron core being an electromagnetic valve capable of being driven by an electromagnetic coil. The spool valve with a spool position detector as described in any one of thru | or 4.

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