JP2019049493A - Direct-acting system - Google Patents

Abstract

To improve detection accuracy of a displacement detector.SOLUTION: A hydraulic valve system 1 is a direct-acting system comprising a spool 51 that moves rectilinearly and a displacement detector 100 for detecting an amount of displacement of the spool 51. The displacement detector 100 comprises: a rod member 22 that is displaced following motion of the spool 51; a magnet 24, arranged in the rod member 22, which is displaced together with the rod member 22; a case 12, provided with a support hole 12d through which a shank 22a of the rod member 22 is inserted, for supporting the rod member 22 reciprocally in a direction of displacement; and a magnetism detection unit 32, arranged in the case 12, for detecting a change of a magnetic field due to the displacement of the magnet 24. The spool 51 includes a recess 55 which a contact end part 22b provided at a tip of the rod member 22 comes in contact with. As the convex-shaped contact end part 22b and the concave-shaped recess 55 come in contact with each other, the inclination of the rod member 22 with respect to a support shaft O of the support hole 12d is restricted.SELECTED DRAWING: Figure 1

Description

  BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a linear motion system provided with a linearly moving body that moves linearly and a displacement detection device that detects the amount of displacement of the linear moving body.

  In Patent Document 1, a magnet attached to a displacement member displaced following a measurement object, a magnetic sensor disposed facing the magnet, and a coil spring biasing the displacement member toward the measurement object And a displacement detection device comprising In this displacement detection device, the position of the magnet changes according to the displacement of the measurement object, and the direction and the size of the magnetic flux passing through the magnetic sensor change with the change of the position of the magnet. The displacement amount of the measurement object can be specified based on

JP, 2015-10876, A

  However, in the displacement detection device described in Patent Document 1, the displacement member to which the magnet is attached is cantilevered by the case, so when the displacement detection device detects the displacement amount of the measurement object, the displacement member is inclined. The distance between the magnetic sensor and the magnet in the direction orthogonal to the displacement direction may change. Since the output value of the magnetic sensor is likely to change under the influence of the change in the distance between the magnetic sensor and the magnet, the displacement member is inclined in the direction in which the magnetic sensor approaches the magnet, or the direction in which the magnetic sensor separates from the magnet The displacement amount detected in a state in which the displacement member is inclined has an error with respect to the actual displacement amount, and as a result, the detection accuracy of the displacement detection device may be reduced.

  The present invention has been made in view of the above problems, and an object thereof is to improve the detection accuracy of a displacement detection device that detects a displacement amount of a linear moving body.

  According to a first aspect of the present invention, the linear motion object to be subjected to displacement detection by the displacement detection device has a contact portion with which the contact end portion provided at the tip of the displacement member contacts, the contact end portion of the displacement member and the contact portion The linear motion system is characterized in that one of the protrusions is a protrusion and the other is a recess, and the protrusion and the recess are in contact with each other.

  In the first invention, since the inclination of the displacement member with respect to the axial center of the support hole is restricted by the contact of the convex portion and the concave portion, the displacement member can follow the linear movement of the linear moving body without inclination. .

  In the second invention, the concave portion is provided with an inclined surface which reduces the inclination angle of the central axis of the displacement member with respect to the axial center of the support hole as the displacement member and the linear moving body approach the convex portion. It is characterized by

  In the second aspect of the invention, the inclination angle of the displacement member becomes smaller as the displacement member and the linear motion body approach, so that the positioning accuracy of the displacement member relative to the linear motion body can be improved.

  A third invention is characterized in that the convex portion is provided with a curved surface portion which contacts the inclined surface of the concave portion.

  In the third invention, since the curved surface portion is in contact with the inclined surface of the concave portion, the convex portion can be smoothly guided and positioned by the inclined surface of the concave portion.

  A fourth invention is characterized in that the contact end portion of the displacement member does not contact the contact portion of the linear motion body if the linear motion body is less than a predetermined movement amount.

  In the fourth invention, during operation of the linear motion system, it is sufficient to detect the displacement of the linear motion body only when the linear motion body reaches a predetermined travel distance or more. Can be shortened.

  A fifth invention is characterized in that the linear moving body is a spool of the hydraulic valve device, and the contact portion is provided at an end of the spool.

  In the fifth invention, since the inclination of the displacement member with respect to the spool is restricted by the contact between the convex portion and the recess, the displacement member can follow the linear movement of the spool without inclination. As a result, it is possible to detect the displacement amount (stroke amount) of the spool of the hydraulic valve device with high detection accuracy.

  A sixth invention is characterized in that the displacement member is configured such that the convex portion contacts the concave portion even when the inclination of the support hole due to backlash in the support hole is maximum.

  According to the sixth aspect of the present invention, even when backlash occurs between the support hole and the displacement member inserted into the support hole, the projection and the recess can be brought into contact with each other.

  According to the present invention, it is possible to improve the detection accuracy of the displacement detection device that detects the displacement amount of the linear moving body.

1 is a cross-sectional view showing a hydraulic valve system according to a first embodiment of the present invention. 1 is a cross-sectional view showing a displacement detection device according to a first embodiment of the present invention. It is an enlarged view of the end of the spool and the tip of the rod member in the hydraulic valve system according to the first embodiment of the present invention. It is an enlarged view of an end of a spool and a tip of a rod member in a hydraulic valve system according to a comparative example. It is a figure explaining positioning of a rod member to a spool, and shows the state where a rod member inclined. It is a figure explaining positioning of a rod member to spool, and shows the state where inclination of a rod member was controlled by a crevice. It is a sectional view showing a hydraulic valve system concerning a 2nd embodiment of the present invention. It is a figure which shows the state before the contact end part of a rod member contacts the recessed part of a spool. It is a figure which shows the state of the instant in which the contact end part of the rod member contacted the recessed part of the spool. It is a schematic diagram which shows the positional relationship of the contact end part of the rod member in the largest inclination state, the recessed part of a spool, and the end surface of a spool. It is an enlarged view of the end of the spool and the tip of a rod member in a hydraulic valve system according to a modification 1-1 of the embodiment of the present invention. It is an enlarged view of the end of the spool and the tip of a rod member in a hydraulic valve system according to Modification 1-2 of the embodiment of the present invention. It is an enlarged view of the end of the spool and the tip of a rod member in a hydraulic valve system according to a second modification of the embodiment of the present invention. It is sectional drawing which shows the linear-motion system which concerns on the modification 3 of embodiment of this invention.

First Embodiment
A linear motion system according to a first embodiment of the present invention will be described with reference to the drawings. In the first embodiment, a hydraulic valve system 1 including a hydraulic valve device 50 having a spool 51 and a displacement detection device 100 for detecting a displacement amount of the spool 51 will be described as a direct acting system. FIG. 1 is a cross-sectional view showing a hydraulic valve system 1 according to a first embodiment of the present invention.

  As shown in FIG. 1, the hydraulic valve device 50 includes a cylindrical sleeve 52 and a spool 51 disposed in the sleeve 52 and axially reciprocated. In the hydraulic valve device 50, an oil chamber 53 is defined by the inner peripheral surface of the sleeve 52, the end surface 51a of the spool 51, and the end surface of the projection 12h of the displacement detection device 100. In the hydraulic valve device 50, the hydraulic fluid is supplied to and discharged from the oil chamber 53 through the supply and discharge holes 52a provided in the sleeve 52, whereby the spool 51 is displaced in the axial direction. The displacement of the spool 51 controls the opening and closing of a port (not shown) formed in the sleeve 52. The displacement detection device 100 is attached to the end of the sleeve 52 so as to face the end face 51 a of the spool 51.

  The displacement detection device 100 is a stroke sensor that detects a displacement amount (stroke amount) of the spool (valve body) 51 of the hydraulic valve device 50.

  The displacement detection device 100 includes a rod member 22 as a displacement member which is displaced following a spool 51 which is a linear moving body, a compression coil spring 27 which biases the rod member 22 toward the spool 51, and a rod member. A magnet 24 disposed on one end side of the magnet 22 and displaced with the rod member 22, a case 12 as a support member for supporting the rod member 22 in a displaceable direction in a reciprocating manner, and a magnet 24 in a direction orthogonal to the displacement direction of the magnet 24. And a magnetic detection unit 32 disposed in the case 12 so as to face the

  The case 12 has a bottomed cylindrical case body 120, and a lid member 14 that closes the opening 12g of the case body 120. The case body 120 and the lid member 14 are each formed of a nonmagnetic material such as brass. The case body 120 is formed inside the cylindrical portion 12a, a bottom portion 12b provided on one end side of the cylindrical portion 12a, an opening 12g provided on the other end side of the cylindrical portion 12a, and the cylindrical portion 12a. And a housing portion 12c. A portion of the rod member 22 is housed in the housing portion 12 c together with the compression coil spring 27 and the magnet 24.

  In the cylindrical portion 12a, a fixing hole 12e which is opened on the outer peripheral surface of the cylindrical portion 12a and which is recessed toward the housing portion 12c is formed. The fixing hole 12 e is a non-penetrating stepped hole, and the magnetic detection unit 32 is fixed in the fixing hole 12 e.

  A support hole 12d, through which the shaft 22a of the rod member 22 is inserted, is formed through the bottom 12b of the case body 120. In the support hole 12d, bushes 18 which are bearings for slidably supporting the shaft portion 22a of the rod member 22 are provided axially at two places apart from each other. By providing the bushes 18 in two places, it is possible to suppress the inclination of the axial center of the rod member 22 supported in a cantilever manner by the case main body 120 with respect to the support axial center O which is the axial center of the support hole 12d. The bush 18 may be provided at one place, and in this case, the axial length of the case body 120 can be shortened.

  In the bottom 12 b of the case body 120, a plurality of communication holes 12 f that communicate the housing 12 c with the outside are formed around the support holes 12 d. One end of the communication hole 12f is open to the oil chamber 53 of the hydraulic valve device 50, and the hydraulic oil in the oil chamber 53 flows into the housing 12c through the communication hole 12f. That is, the accommodation portion 12c is filled with the hydraulic oil.

  The rod member 22 includes a cylindrical shaft 22a slidably supported by the case body 120 via the bush 18, a hemispherical contact end 22b provided at the tip of the shaft 22a, and a shaft 22a. And a substantially disc-like flange 22c formed at the proximal end and extending radially outward of the shaft portion 22a.

  The rod member 22 is formed of a nonmagnetic material as in the case 12. Since the spool 51 abuts on the contact end 22b of the rod member 22, the rod member 22 is formed of austenitic stainless steel or the like, which is harder than brass.

  In the flange 22c, a cylindrical holding shaft 22d extending on the opposite side to the shaft 22a is provided coaxially with the shaft 22a. At the tip end of the holding shaft 22d, an external thread is formed on which an internal thread of a nut 26 described later is screwed. In design, the rod member 22 is supported by the case body 120 such that the central axis of the rod member 22 and the support axis O of the support hole 12d are coaxially arranged.

  The magnet 24 is a cylindrical permanent magnet including a rare earth element such as Nd or Sm, and is disposed on the outer periphery of the holding shaft 22d so that the N pole 24a and the S pole 24b are aligned in the axial direction of the holding shaft 22d. Be placed. The magnet 24 has an insertion hole 24c through which the holding shaft 22d is inserted, and the nut 26 is attached to the tip of the holding shaft 22d protruding from the insertion hole 24c via a washer 25. Thereby, the magnet 24 is fixed to the holding shaft 22 d in a state of being held by the flange 22 c, the nut 26 and the washer 25. The nut 26 and the washer 25 are formed of a magnetic material. The nut 26 and the washer 25 are components for sandwiching the magnet 24 with the flange 22c, and are components of a displacement member which is displaced in the displacement direction following the spool 51.

  Since the magnet 24 is fixed to the rod member 22, the magnet 24 follows the spool 51 together with the rod member 22, and is displaced along the support axis O within the displacement range R1. In the present embodiment, since the rod member 22 is always in contact with the spool 51, the displacement range R2 of the spool 51 and the displacement range R1 of the magnet 24 are equal. The change in the magnetic field caused by the displacement of the magnet 24 is detected by the magnetic detection unit 32.

  The magnetic detection unit 32 is a magnetic sensor (not shown) such as a Hall element or a magnetoresistive element that outputs an output value corresponding to a change in the magnetic field caused by the displacement of the magnet 24, and an amplification circuit that processes the output value of the magnetic sensor And a processing circuit (not shown) of The magnetic detection unit 32 outputs a detection value corresponding to the displacement amount of the rod member 22 calculated based on the output value of the magnetic sensor, that is, the displacement amount (stroke amount) of the spool 51 in contact with the rod member 22.

  In the displacement detection device 100, when the rod member 22 is displaced along the support axis O, the magnet 24 is also displaced, and the direction and the magnitude of the magnetic flux passing through the magnetic detection unit 32 change. The output value of the magnetic detection unit 32 changes in accordance with the change in the direction or size of the magnetic flux passing through the magnetic detection unit 32. Therefore, the displacement detection device 100 can detect the displacement amount of the rod member 22, that is, the displacement amount of the spool 51 based on the output value of the magnetic detection unit 32.

  As shown in FIG. 1, the magnetic detection unit 32 is mounted on the substrate 34, and is assembled to the case main body 120 by fixing the substrate 34 to the stepped portion of the fixing hole 12e formed in the cylindrical portion 12a. .

  In a state where the magnetic detection unit 32 is disposed in the fixing hole 12e, the cylindrical magnetic shield 16 is assembled on the outer periphery of the cylindrical portion 12a so as to close the fixing hole 12e. The magnetic shield 16 is formed of a soft magnetic material having a small coercive force, such as an iron-based alloy capable of shielding the magnetism, and suppresses the influence of the magnetism outside the displacement detection device 100 on the magnetism detection unit 32.

  A notch (not shown) is formed in the magnetic shield 16, and a lead (not shown) for connecting a controller (not shown) for controlling the operation of the spool 51 and the magnetic detection unit 32 is wired through the notch. Ru.

  The opening 12 g of the case body 120 is closed by the lid member 14 in a state where the magnet 24 and a part of the rod member 22 to which the magnet 24 is assembled are housed in the housing portion 12 c. The opening 12g of the case main body 120 is a circular opening that communicates the housing 12c with the outside, and is provided continuously to the housing 12c.

  The lid member 14 is inserted into and fixed to the opening 12 g of the case body 120. A seal member 48 is provided between the lid member 14 and the opening 12g of the case main body 120, and the seal member 48 blocks communication between the inside and the outside of the housing portion 12c. As a method of fixing the lid member 14, a general fixing method such as press fitting or screwing is used. The lid member 14 may be configured to be pressed and fixed to the case main body 120 by assembling a member different from the lid member 14 to the case main body 120.

  The compression coil spring 27 is an elastic member formed of a nonmagnetic material such as austenitic stainless steel, and is assembled in a state of being compressed between the nut 26 and the lid member 14. Therefore, the biasing force of the compression coil spring 27 always acts in the direction of pressing the rod member 22 against the spool 51. When the contact end 22b is in contact with the spool 51, the rod member 22 is pressed toward the spool 51 by the biasing force of the compression coil spring 27, and the contact end 22b and the spool 51 are prevented from being separated from each other. Ru. That is, by providing the compression coil spring 27, the rod member 22 can be biased toward the spool 51 to be displaced following the spool 51.

  FIG. 2 is a cross-sectional view showing the displacement detection device 100. As shown in FIG. As shown in FIG. 2, when the displacement detection device 100 is not assembled to the hydraulic valve device 50, the rod member 22 is pressed by the biasing force of the compression coil spring 27, and the flange 22 c of the rod member 22 is in the case body 120. It will be in the state contact | abutted to the bottom part 12b.

  The case body 120 is provided with a protrusion 12 h that protrudes from the bottom 12 b. The protrusion 12 h has a cylindrical shape, and has an outer peripheral surface on which an external thread to be engaged with an internal thread provided on the inner peripheral surface of the opening of the sleeve 52 is formed. As shown in FIG. 1, the displacement detection device 100 is attached to the hydraulic valve device 50 by screwing the male screw of the protrusion 12 h to the female screw of the opening of the sleeve 52. In a state where the displacement detection device 100 is attached to the hydraulic valve device 50, the central axis of the spool 51 and the support axial center O of the support hole 12d of the case main body 120 coincide with each other.

  FIG. 3A is an enlarged view of the end of the spool 51 and the tip of the rod member 22 in the hydraulic valve system 1. As shown in FIG. 3A, the contact end 22 b of the rod member 22 contacts a conical recess 55 recessed in the end face 51 a of the spool 51. The conical recess 55 is formed such that its central axis coincides with the central axis CL 2 of the spool 51.

  The recess 55 is formed directly on the end surface 51 a of the spool 51. Therefore, when forming the spool 51 from the rod-like member by cutting, the recess 55 can also be formed. Therefore, the operation can be simplified as compared with the case where the recess 55 is formed in the separate member connected to the spool 51.

  The contact end 22 b has a convex curved surface 23 which is in line contact with the inclined surface 55 a of the recess 55. In the present embodiment, the contact end 22b and the recess 55 are in line contact, and the line contact portion CP1 is circular.

  FIG. 3B is an enlarged view of the end of the spool 951 and the tip of the rod member 22 in the hydraulic valve system according to the comparative example. As shown in FIG. 3B, in the comparative example, no recess is provided, and the contact end 22b of the rod member 22 is in contact with the end surface 51a of the spool 951. The end surface 51 a is a flat surface orthogonal to the central axis CL 2 of the spool 95 1.

  As described above, the rod member 22 is cantilevered by the case 12. In the comparative example, since the contact end 22b of the rod member 22 is movable in the radial direction, the rod member 22 may be inclined with respect to the support axis O. When the displacement detection device detects the displacement amount of the spool 951, if the rod member 22 is inclined with respect to the support axis O, the detection accuracy of the displacement detection device is lowered.

  By repeating the reciprocation in a state where the rod member 22 is inclined, the bush 18 is worn, the inclination becomes larger, and the detection accuracy is further reduced. When the inclination of the rod member 22 is suppressed by minimizing the dimensional tolerance of the bush 18 as described above, it takes time and effort to manufacture a highly accurate displacement detection device, and the cost increases.

  On the other hand, in the present embodiment, as shown in FIG. 3A, the contact end 22b having the convex curved surface 23 is disposed inside the concave concave 55 formed on the end surface 51a of the spool 51. Ru. Since the convex curved portion 23 of the contact end 22 b is in line contact with the inclined surface 55 a of the recess 55, the radial movement of the contact end 22 b is restricted by the recess 55. That is, the inclination of the rod member 22 with respect to the support axis O of the support hole 12d is restricted by the contact of the convex curved surface portion 23 of the contact end 22b with the inclined surface 55a of the recess 55.

  4A and 4B are diagrams for explaining the positioning of the rod member 22 with respect to the spool 51. FIG. FIG. 4A shows a state in which the rod member 22 is inclined, and FIG. 4B shows a state in which the inclination of the rod member 22 is suppressed by the recess 55. The displacement detection device 100 is attached to the hydraulic valve device 50 by screwing the projection 12 h into the opening of the sleeve 52 (see FIG. 1). The rod member 22 gradually approaches the spool 51 according to the screwing amount of the protrusion 12 h. When the screwing amount of the protrusion 12 h reaches the first predetermined amount, the convex curved surface portion 23 of the contact end 22 b contacts the inclined surface 55 a of the concave portion 55 of the spool 51 as shown in FIG. 4A. At this time, when the shaft portion 22a of the rod member 22 is inclined with respect to the support axis O at an inclination angle θ (θ> 0), the contact end 22b makes point contact with the recess 55 at a point P.

  The inclined surface 55a of the recess 55 has a function of guiding the contact end 22b such that the central axis CL1 of the rod member 22 coincides with the central axis CL2 of the spool 51 as the rod member 22 approaches the spool 51. . That is, the inclined surface 55a has a function of reducing the inclination angle θ of the central axis CL1 of the rod member 22 with respect to the support axis O as the rod member 22 and the spool 51 approach each other in contact with the contact end 22b.

  Therefore, when the screwing amount of the protrusion 12h is further increased, as shown in FIG. 4B, the contact end 22b is pushed in a state of being in point contact with the inclined surface 55a. The contact end 22 b in the point contact state moves toward the bottom of the recess 55 along the inclined surface 55 a of the recess 55 as the rod member 22 moves closer to the spool 51.

  The contact end 22 b is guided by the inclined surface 55 a so as to be directed to the bottom of the recess 55, whereby the inclination angle θ of the shaft 22 a approaches zero. When the contact state with the inclined surface 55a shifts from a point contact state to a line contact state, the contact end 22b positions the rod member 22 at that position.

  According to the first embodiment described above, the following effects can be obtained.

  (1) The spool 51 has a recess 55 in contact with the contact end 22 b provided at the tip of the rod member 22. The contact end 22 b of the rod member 22 is formed in a convex shape, and the concave portion 55 of the spool 51 is formed in a concave shape. The contact end 22b which is a convex portion and the recess 55 contact each other, thereby restricting the radial movement of the contact end 22b of the rod member 22, and the inclination of the rod member 22 with respect to the support axis O of the support hole 12d It is regulated.

  The contact between the contact end 22 b and the recess 55 restricts the inclination and positional deviation (eccentricity) of the central axis CL 1 of the rod member 22 with respect to the support axial center O. It can follow without tilting to movement. Thus, the detection accuracy of the displacement detection device 100 that detects the displacement amount of the spool 51 can be improved.

  (2) Since the radial movement of the contact end 22b can be restricted inside the recess 55 and the inclination of the rod member 22 with respect to the support axis O can be suppressed, the progress of the wear of the bush 18 accompanying the reciprocation of the rod member 22 Can be suppressed. As a result, high detection accuracy can be maintained over a long period of time.

  (3) Since the dimensional tolerance of the bush 18 can be increased, the manufacturing cost can be reduced.

  (4) The inclined surface 55a reduces the inclination angle θ of the central axis CL1 of the rod member 22 with respect to the support axial center O as the rod member 22 and the spool 51 approach the concave portion 55 in contact with the contact end 22b. Is provided. By attaching the displacement detection device 100 to the hydraulic valve device 50, the contact end 22b is guided by the inclined surface 55a, and the inclination angle θ of the rod member 22 is automatically reduced. Can be improved.

  (5) The convex curved surface portion 23 in contact with the inclined surface 55 a of the concave portion 55 is provided at the contact end portion 22 b. Thereby, the contact end 22 b can be smoothly guided and positioned by the inclined surface 55 a of the recess 55.

Second Embodiment
A hydraulic valve system 201 according to a second embodiment of the present invention will be described. FIG. 5 is a cross-sectional view showing a hydraulic valve system 201 according to a second embodiment of the present invention. In the following description, differences from the first embodiment are mainly described, and in the figure, the same reference numerals are given to the same or corresponding components as the components described in the first embodiment, and the description is omitted. .

  In the displacement detection device 100 according to the first embodiment, the contact end 22b of the rod member 22 has a hemispherical shape (see FIG. 1), while in the displacement detection device 200 according to the second embodiment, FIG. As shown, the contact end 222b of the rod member 222 is cylindrically shaped.

  In the first embodiment, the hydraulic valve system 1 has been described in which the displacement range R1 of the rod member 22 during operation is equal to the displacement range R2 of the spool 51 and the rod member 22 always contacts the spool 51 (see FIG. 1) . On the other hand, in the hydraulic valve system 201 according to the second embodiment, as shown in FIG. 5, the displacement range R1 of the rod member 222 during operation is smaller than the displacement range R2 of the spool 51.

  In the second embodiment, the contact end 222 b of the rod member 222 does not contact the recess 55 of the spool 51 when the spool 51 is less than the predetermined movement amount X. When the spool 51 moves by the predetermined movement amount X or more, the contact end 222b of the rod member 222 contacts the recess 55 of the spool 51, and the rod member 222 is displaced together with the spool 51. Therefore, the total movement amount (displacement range R2) of the spool 51 is a value obtained by combining the predetermined movement amount X and the total movement amount (displacement range R1) of the rod member 222.

  6A shows a state before the contact end 222b of the rod member 222 comes in contact with the recess 55 of the spool 51, and FIG. 6B shows that the contact end 222b of the rod member 222 contacts the recess 55 of the spool 51. Showing the state of the moment of

  In FIGS. 6A and 6B, the inclination angle θ of the rod member 222 with respect to the support axis O is the maximum angle θmax, and the amount of protrusion of the shaft portion 22a from the case main body 120 is maximum (hereinafter referred to as the maximum inclination state It is indicated that).

  In the present embodiment, in the state where the displacement detection device 200 is attached to the hydraulic valve device 50, the spool 51 and the rod member 222 repeat the contact state and the non-contact state. For this reason, the outer diameter W of the recess 55 is set so that the contact end 22 b contacts the inclined surface 55 a of the recess 55 even when the rod member 222 is in the maximum inclination state. That is, the rod member 222 of the present embodiment is configured such that the contact end 222b contacts the recess 55 even if the inclination with respect to the support axis O due to the radial direction rattle in the support hole 12d is maximum.

  At the contact end 222b of the rod member 222 in the maximum inclination state, a perpendicular drawn from the corner E1 located most outward from the support axis O toward the support axis O (center axis CL2) and the support axis O And the point of intersection with the point I1. The outer diameter W of the recess 55 of the spool 51 is set to a dimension larger than twice the distance Y from the intersection point I1 to the corner E1 (W> 2 × Y).

  FIG. 7 is a schematic view showing the positional relationship between the contact end 222 b of the rod member 222 in the maximum inclination state, the recess 55 of the spool 51, and the end surface 51 a of the spool 51. FIG. 7 is a diagram obtained by orthographically projecting the outer shapes of the end surface of the contact end 222b, the recess 55, and the end surface 51a of the spool 51 on a plane orthogonal to the support axis O. As shown in FIG.

  As shown in FIG. 7, the size and shape of the recess 55 are set such that all of the end surfaces of the contact end 222 b fit within the projection plane of the recess 55. In other words, the size and shape of the recess 55 are set such that the corner E1 contacting the inclined surface 55a of the recess 55 is disposed in the projection plane of the recess 55.

  According to such a second embodiment, in addition to the same function and effect as (1) to (3) described in the first embodiment, the following function and effect can be obtained.

  (6) The contact end 222b of the rod member 222 does not contact the recess 55 of the spool 51 when the spool 51 is less than the predetermined movement amount X, and the contact end 222b of the spool 51 when the spool 51 has the predetermined movement amount X or more. Contact with During the operation of the hydraulic valve system 201, the length of the rod member 222 and the length of the compression coil spring 27 should be short because it is sufficient to detect the displacement of the spool 51 only when the spool 51 reaches the predetermined movement amount X or more. it can.

  (7) The rod member 222 is configured such that the contact end 222 b contacts the recess 55 even if the inclination with respect to the support axial center O due to backlash in the support hole 12 d is maximum. For this reason, even when backlash occurs between the support hole 12d and the rod member 222 inserted into the support hole 12d, the contact end 222b can be in contact with the recess 55.

  (8) In the same manner as in the first embodiment, the inclination of the central axis CL1 of the rod member 222 with respect to the support axis O as the rod member 222 and the spool 51 approach the contact end 222b in the recess 55 and approaches. An inclined surface 55a is provided to reduce the angle θ. For this reason, even when the rod member 222 is inclined, when the recess 55 of the spool 51 contacts the contact end 222b of the rod member 222, the inclination angle θ of the rod member 222 is reduced by the inclined surface 55a. The contact end 222b is guided. As a result, at an initial stage in the process of moving the rod member 222 by the spool 51 coming into contact with the rod member 222, the rod member 222 can be automatically positioned properly.

  The following modifications are also within the scope of the present invention, and the configuration shown in the modification and the configuration described in the above embodiment may be combined, the configurations described in the different embodiments above may be combined, or the following differences It is also possible to combine the configurations described in the modification.

(Modification 1)
In the above embodiment, the concave portion 55 has a conical shape, the contact end 22b has a hemispherical shape, and the contact end 222b has a cylindrical shape, but the present invention is limited to this. I will not. For example, as in the following modification 1-1, modification 1-2, and modification 1-3, the contact portion of the spool and the contact end portion of the rod member can have various shapes.

(Modification 1-1)
As shown in FIG. 8A, in the modification 1-1, the bottom of the recess 355 provided in the spool 351 is formed in a planar shape parallel to the end face 51 a of the spool 51. Further, in the modification 1-1, the top of the contact end 322 b provided on the rod member 322 is formed in a planar shape orthogonal to the central axis CL 1 of the rod member 322.

(Modification 1-2)
As shown to FIG. 8B, in this modification 1-2, the recessed part 455 provided in the spool 451 is formed in hemispherical shape. The center of the hemispherical recess 455 is located on the support axis O. The inner peripheral surface of the recess 455 is a concave surface, and guides the contact end 22 b so that the inclination angle θ of the rod member 22 with respect to the support axis O decreases as the rod member 22 and the spool 451 approach. Is an inclined surface.

(Modification 1-3)
The recess 55 may be formed in a polygonal pyramid shape. For example, when the recess 55 is formed in a quadrangular pyramid shape, the contact end 22 b comes into point contact with the four side surfaces of the recess 55 in a state where the displacement detection device 100 is assembled to the hydraulic valve device 50.

(Modification 2)
In the embodiment described above, the example has been described in which the spool 51 is provided with the concave portion 55 and the rod members 22 and 222 are provided with the contact end portions 22b and 222b inserted inside the concave portion 55. It is not limited to this. The relationship between the recess and the protrusion may be reversed. For example, as shown in FIG. 9, the rod member 522 may be provided with a concave contact end 522 b, and the spool 551 may be provided with a convex projection 555. The contact end 522b is provided with an inclined surface 523 for decreasing the inclination angle θ of the central axis CL1 of the rod member 522 with respect to the support axial center O as the rod member 522 and the spool 551 come into contact with the convex portion 555. Be

(Modification 3)
In the above embodiment, the direct acting system has been described by taking the hydraulic valve system 1, 201 having the hydraulic valve device 50 and the displacement detecting devices 100, 200 as an example, but the present invention is not limited to this. The present invention can be applied to various linear motion systems provided with a linear motion body that moves linearly and a displacement detection device that detects a displacement amount of the linear motion body.

  For example, as shown in FIG. 10, the present invention may be applied to a hydraulic cylinder system 601 which is a linear motion system including a hydraulic cylinder 650 and a displacement detection device 600. The hydraulic cylinder 650 has a piston 651 that moves linearly and a cylinder tube 652 that accommodates the piston 651. The displacement detection device 600 detects the displacement amount (stroke amount) of the piston 651.

  In the third modification, a conical recess 55 is provided on the end face of the piston 651. The central axis of the conical recess 55 is parallel to the central axis CL 2 of the piston 651. The displacement detection device 600 is attached to the hydraulic cylinder 650 such that the central axis of the recess 55 of the piston 651 coincides with the support axis O. When the piston 651 moves more than a predetermined amount of movement, the recess 55 of the piston 651 contacts the contact end 22b of the rod member 22, and the rod member 22 is displaced together with the piston 651.

(Modification 4)
In the second embodiment, even if the inclination of the central axis CL1 of the rod member 22 with respect to the support axial center O due to backlash in the support hole 12d is maximum, the rod member 222 is in contact with the recess 55. Although the example which is configured is described, the same configuration can be adopted for the rod member 22 of the first embodiment. Even when backlash occurs between the support hole 12d and the rod member 22 inserted into the support hole 12d, when the contact end 22b of the rod member 22 is brought into contact with the spool 51, the contact end 22b and the recess 55 can be brought into contact. Thereby, positioning of the rod member 22 with respect to the spool 51 can be performed easily.

  The configuration, operation, and effects of the embodiment of the present invention configured as described above will be collectively described.

  The linear motion system (hydraulic valve system 1, 201, hydraulic cylinder system 601) includes a linear motion body (spools 51, 351, 451, 551, piston 651) and a linear motion body (spools 51, 351, 451, 551, 551). A linear motion system including a displacement detection device 100, 200, 600 for detecting a displacement amount of a piston 651), wherein the displacement detection device 100, 200, 600 is a linear motion body (spools 51, 351, 451, 551). Displacement member (rod member 22, 222, 322, 522) which is biased toward the piston 651 and displaced following the linear moving body (spool 51, 351, 451, 551, piston 651), and displacement member Rod members 22, 222, 322, 522), and displacement members (rod members 22, 222, 322, 522) and The magnet 24 is also displaced, and a support hole 12d through which the displacement member (rod member 22, 222, 322, 522) is inserted is provided, and the displacement member (rod member 22, 222, 322, 522) is reciprocated in the displacement direction A linearly moving body (spools 51, 351) comprising: a support member (case 12) to be freely supported; and a magnetic detection unit 32 disposed on the support member (case 12) and detecting a change in the magnetic field accompanying displacement of the magnet 24. , 451, 551 and pistons 651) are contact portions (recesses 55, 355, 455) with which contact end portions 22b, 222b, 322b, 522b provided at the tip of the displacement member (rod members 22, 222, 322, 522) contact. Contact portion 22b, 222b, 322b, 522b and linear motion of the displacement member (rod member 22, 222, 322, 522). One of the contact portions (recesses 55, 355, 455, and the convex portion 555) of the (spools 51, 351, 451, and 551, and the piston 651) is a convex portion (contact end portions 22b, 222b and 322b, and the convex portion 555). The other is a recess (recess 55, 355, 455, contact end 522b), and the protrusion (contact end 22b, 222b, 322b, protrusion 555) and recess (recess 55, 355, 455, contact end) Contact with 522b).

  In this configuration, displacement of the support hole 12d with respect to the axial center of the support hole 12d is caused by contact between the projection (contact end 22b, 222b, 322b, projection 555) and the recess (recess 55, 355, 455, contact end 522b) Since the inclination of the member (rod member 22, 222, 322, 522) is regulated, the displacement member (rod member 22, 222, 322, 522) is a linear moving body (spool 51, 351, 451, 551, piston 651) It can follow without tilting to the linear movement of As a result, it is possible to improve the detection accuracy of the displacement detection device 100, 200, 600 that detects the displacement amount of the linear moving body (spools 51, 351, 451, 551, the piston 651).

  The linear motion system (hydraulic valve system 1, 201, hydraulic cylinder system 601) has convex portions (contact end portions 22b, 222b, 322b, convex portion 555) in the concave portions (recess portions 55, 355, 455, contact end 522b). As the displacement member (rod members 22, 222, 322, 522) and the linear moving bodies (spools 51, 351, 451, 551, piston 651) come close to contact with each other, Inclined surfaces 55a, 523 are provided to reduce the inclination angle θ of the central axis CL1 of the rod member 22, 222, 322, 522).

  In this configuration, as the displacement member (rod member 22, 222, 322, 522) and the linear moving body (spools 51, 351, 451, 551, piston 651) approach, the displacement member (rod member 22, 222, 322, Since the inclination angle θ of 522) is reduced, the positioning accuracy of the displacement member (rod member 22, 222, 322, 522) with respect to the linear moving body (spools 51, 351, 451, 551, piston 651) can be improved.

  In the linear motion system (hydraulic valve system 1, hydraulic cylinder system 601), a curved surface portion (convex curved surface portion 23) in contact with the inclined surface 55a of the concave portions 55, 355, 455 is in the convex portion (contact end 22b, 322b). Provided.

  In this configuration, since the curved surface portion (convex curved surface portion 23) contacts the inclined surface 55a of the concave portions 55, 355, 455, the convex portion (contact end 22b, 322b) is inclined to the concave portions 55, 355, 455 The surface 55a can be smoothly guided and positioned.

  In the linear motion system (hydraulic valve system 201, hydraulic cylinder system 601), the contact ends 222b, 322b, 522b of the displacement members (rod members 222, 322, 522) are linear bodies (spools 51, 351, 451, 551, If the piston 651) is less than the predetermined movement amount X, it does not contact the contact portions (recesses 55, 355, 455, and the convex portion 555) of the linear moving bodies (spools 51, 351, 451, 551, and piston 651).

  In this configuration, when the linear moving body (spools 51, 351, 451, 551, the piston 651) reaches a predetermined movement amount X or more during operation of the linear movement system (the hydraulic valve system 201, the hydraulic cylinder system 601). Since it is only necessary to detect the displacement of the linear moving body (spools 51, 351, 451, 551, piston 651), the length of the displacement member (rod members 222, 322, 522) and the length of the compression coil spring 27 can be shortened.

  In the linear motion system (hydraulic valve system 1, 201), the linear motion bodies are the spools 51, 351, 451, 551 of the hydraulic valve device 50, and the contact portions (recesses 55, 355, 455, convex portion 555) are It is provided at the end (end face 51 a) of the spools 51, 351, 451, 551.

  In this configuration, the spools 51, 351, 451, 551 are brought into contact with each other by bringing the projections (contact ends 22b, 222b, 322b, projections 555) into contact with the recesses (recesses 55, 355, 455, contact end 522b). Since the inclination of the displacement member (rod member 22, 222, 322, 522) with respect to the axis is restricted, the displacement member (rod member 22, 222, 322, 522) moves against linear movement of the spools 51, 351, 451, 551. Can follow without tilting. As a result, displacement amounts (stroke amounts) of the spools 51, 351, 451, and 551 of the hydraulic valve device 50 can be detected with high detection accuracy.

  In the linear motion system (hydraulic valve system 1, 201, hydraulic cylinder system 601), the displacement member (rod members 22, 222, 322, 522) has a maximum inclination with respect to the support axis O due to backlash in the support hole 12d. Even if there is a projection (contact end 22b, 222b, 322b, projection 555), it is configured to contact the recess (concave 55, 355, 455, contact end 522b).

  In this configuration, even if backlash occurs between the support hole 12d and the displacement member (rod members 22, 222, 322, 522) inserted through the support hole 12d, the convex portion (contact end 22b, The recesses 222 b and 322 b and the protrusion 555 can be in contact with the recesses (recesses 55 355 and 455 and the contact end 522 b).

  As mentioned above, although the embodiment of the present invention was described, the above-mentioned embodiment showed only a part of application example of the present invention, and in the meaning of limiting the technical scope of the present invention to the concrete composition of the above-mentioned embodiment. Absent.

  1, 201: hydraulic valve system (linear motion system), 601: hydraulic cylinder system (linear motion system), 12: case (support member), 12d: support hole, 22, 222, 322 , 522: rod member (displacement member), 22b, 222b, 322b: contact end, 23: convex curved surface (curved surface), 24: magnet, 32: magnetic detector, 50 ・ ・ ・ hydraulic valve device, 51, 351, 451, 551 ... Spool (linear moving body), 651 ... piston (linear moving body), 51a ... end face (end), 55, 355, 455 · recesses (contact portion), 555 ... protrusions (contact portions) 55a, 523 ... inclined surface, 100,200,600 ... displacement detector, O ... support axis (shaft center ), Θ ... inclination angle

Claims (6)

A linear motion system comprising: a linear moving body that moves linearly; and a displacement detection device that detects a displacement amount of the linear moving body,
The displacement detection device is
A displacement member which is urged toward the linear moving body and is displaced following the linear moving body;
A magnet disposed on the displacement member and displaced together with the displacement member;
A support member which is provided with a support hole through which the displacement member is inserted, and which reciprocably supports the displacement member in a displacement direction;
And a magnetic detection unit disposed on the support member and detecting a change in a magnetic field caused by the displacement of the magnet.
The linear moving body has a contact portion with which a contact end portion provided at the tip of the displacement member contacts.
A linear motion system characterized in that one of the contact end portion of the displacement member and the contact portion of the linear motion body is a convex portion and the other is a concave portion, and the convex portion and the concave portion are in contact with each other. . In the linear motion system according to claim 1,
The concave portion is provided with an inclined surface which reduces the inclination angle of the central axis of the displacement member with respect to the axial center of the support hole as the displacement member and the linear moving body approach the contact with the convex portion. A linear motion system characterized by In the linear motion system according to claim 2,
The linear motion system characterized in that the convex portion is provided with a curved surface portion that contacts the inclined surface of the concave portion. The linear motion system according to any one of claims 1 to 3
The contact end of the displacement member is
A linear motion system characterized in that the linear motion body does not contact the contact portion of the linear motion body if the linear motion body is less than a predetermined movement amount. The linear motion system according to any one of claims 1 to 4.
The linear moving body is a spool of a hydraulic valve device, and
The linear motion system, wherein the contact portion is provided at an end of the spool. The linear motion system according to any one of claims 1 to 5,
The linear motion system according to claim 1, wherein the displacement member is configured such that the convex portion contacts the concave portion even if the inclination of the support hole with respect to the axial center due to backlash in the support hole is maximum.

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