JP2007002939A - Positioning structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positioning structure enabling accurate positioning while avoiding an increase in devices to which the positioning structure is applied. <P>SOLUTION: This positioning structure comprises a pair of rods 5 joined to both ends of members 2 and 3, spring receivers 6 disposed on the outer side of the rods 5, and two or more of coiled springs 7, 8 interposed in series between the both ends of the members 2 and 3 and the spring receivers 6. The spring receivers 6 are restrained to move in the direction separated from the members 2 and 3 by the rod 5 to maintain the coiled springs 7, 8 in a compressed state, and when the members 2 and 3 are moved from predetermined positions, the end part of either of the spring receivers 6 at least comes into contact with either of restraining parts 12 formed at both sides of the members 2 and 3 of a housing 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a positioning structure for positioning a member at a predetermined position.

  Conventionally, as a positioning structure for positioning a member at a predetermined position, for example, there is a structure in which a valve or the like of a shock absorber or a cylinder device is embodied, and a spool of a valve or the like is positioned at a neutral position.

More specifically, this positioning structure includes a coil spring interposed between both ends of the spool and a piston rod serving as a housing for housing the spool and a portion of the seat member facing both ends of the spool. The spool is positioned by a spring force that urges (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 7-217696 (paragraph number 0047, FIG. 1)

  Here, in the above positioning structure, the spool can be positioned at the neutral position. For example, when a seal member is provided to seal between the outer periphery of the spool and the piston rod as the housing, When a cylinder is slidably housed in the cylinder and the piston with a large sliding resistance is positioned with respect to the cylinder, the friction is large and it may be difficult to position the spool or the like at a target position. .

  In addition, when it is desired to increase the stroke length of the spool or the like, the coil spring may buckle if the aspect ratio of the coil spring increases. Therefore, the average diameter of the coil spring must be increased, such as a valve, a shock absorber, or a cylinder. This results in an increase in the size of a device that employs the positioning structure.

  Accordingly, the present invention has been devised to improve the above-described problems, and the object of the present invention is to provide a positioning structure that can perform positioning accurately while avoiding an increase in the size of equipment to which the positioning structure is applied. It is to be.

  In order to achieve the above-described object, the positioning structure of the present invention is a positioning structure for positioning a member slidably inserted in a hollow housing at a predetermined position, and a pair of rods respectively coupled to both ends of the member. Each spring receiver disposed on the outer peripheral side of each rod, and two or more coil springs interposed in series between both ends of the member and each spring receiver. The movement in the direction away from the member is restricted by the rod arranged on the side to keep the coil spring in a compressed state, and when the member moves from a predetermined position, the end of one of the spring receivers is on both sides of the member of the housing At least one of the restricting portions provided in the position is made to contact.

  Another positioning structure of the present invention is a positioning structure that positions a member slidably inserted in a hollow housing at a predetermined position, and a pair of rods that are erected from the inner surface of the housing and are opposed to both ends of the member. , Each spring receiver disposed on the outer peripheral side of each rod, and two or more coil springs interposed in series between each housing inner surface and each spring receiver, each spring receiver is on the inner peripheral side The movement of the coil spring in the direction away from the inner surface of the housing is restricted by the rod disposed in the position to keep the coil spring in a compressed state, and at least when the member moves from a predetermined position, the end of one of the spring receivers It was made to contact | abut either one of the edge parts.

  Furthermore, another positioning structure of the present invention is a positioning structure for positioning a member slidably inserted in a hollow housing at a predetermined position, a rod that is coupled to one end of the member, and a member that is erected from the inner surface of the housing A pair of rods facing the other end of each of the rods, spring receivers disposed on the outer peripheral side of each rod, two or more coil springs interposed in series between one end of the member and the spring receiver, and the inner surface of the housing Two or more coil springs interposed in series between the spring receiver and the spring receiver, and the spring receiver on one end side of the member is restricted from moving in the direction away from the member by the rod disposed on the inner peripheral side. The coil spring on one end of the member is kept in a compressed state, and the movement of the spring receiver on the other end of the member in the direction away from the inner surface of the housing is restricted by the rod disposed on the inner peripheral side. The rubber spring is kept in a compressed state, and when the member moves from a predetermined position to one end side of the member, the end of the spring receiver on one end side of the member abuts on a regulating portion provided at a position on the one end side of the member of the housing, When the member moves from a predetermined position to the other end of the member, the end of the spring receiver on the other end of the member abuts on the end of the opposing member.

 According to the positioning structure of the present invention, even when the sliding resistance between the member and the housing is large, the member can be reliably returned to a predetermined position and positioned with high accuracy.

 Since the member can be positioned at a predetermined position even if the sliding resistance is large, when the seal is disposed on the outer peripheral side of the member, the contact pressure of the seal on the inner peripheral surface of the housing is increased. This makes it possible to improve the sealing performance of the device in which the positioning structure is embodied.

  Furthermore, by arranging two or more coil springs in series, the aspect ratio of each coil spring can be set small, so that the coil spring is prevented from buckling, thereby increasing the stroke length of the member. It is possible to set, and by arranging two or more coil springs in series, it is possible to ensure an aspect ratio that does not buckle even if the coil spring diameter is set small, so the radial direction of the equipment to which the positioning structure is applied It is possible to reduce the size of the apparatus, that is, it is possible to avoid an increase in the size of the device to which the positioning structure is applied.

  The present invention will be described below based on the illustrated embodiment. FIG. 1 is a longitudinal sectional view of a cylinder device in which a positioning structure according to an embodiment is embodied. FIG. 2 is a longitudinal sectional view of a cylinder device in which a positioning structure according to a modification of the embodiment is embodied. FIG. 3 is a longitudinal sectional view of a cylinder device in which a positioning structure according to another embodiment is embodied. FIG. 4 is a longitudinal sectional view of a cylinder device in which a positioning structure according to a modification of the other embodiment is embodied.

  As shown in FIG. 1, the positioning structure in one embodiment is embodied in a cylinder device S1, and the cylinder device S1 is slidably inserted into the cylinder 1 as a housing and the cylinder 1. The piston 2 that is a part of the member, the piston rod 3 that is a part of the member that is movably inserted into the cylinder 1 via the piston 2, and the holes 33 and 34 provided at both ends of the piston rod 3 A pair of rods 5 respectively coupled to the bottom surface, each spring receiver 6 disposed on the outer peripheral side of each rod 5, and two in series between each end of the piston rod and each spring receiver 6. Coil springs 7 and 8, and restricting portions 12 provided at positions on both sides of the piston rod 3 in the cylinder 1, and is configured as a so-called double rod type cylinder device.

  The cylinder 1 will be described in detail below. The cylinder 1 is formed in a cylindrical shape, and both ends are reduced in diameter to form a reduced diameter portion 11. A restricting portion 12 that protrudes in the direction is formed. And the piston 2 is slidably inserted in the intermediate part of this cylinder 1, ie, the inner peripheral side of the site | part between the reduced diameter part 11 and the reduced diameter part 11. FIG.

  The piston 2 includes a seal member 21 slidably in contact with the inner periphery of the cylinder 1 on the outer periphery, and further, a piston rod 3 projecting from both ends of the axial core portion of the piston 2 is extended. The piston rod 3 constitutes a member.

  Further, both end sides of the piston rod 3 are slidably inserted into the reduced diameter portion 11 of the cylinder 1, and the inner periphery of the reduced diameter portion 11 and the piston rod are sealed by seal members 31 and 32 provided on the outer peripheral side of the piston rod 3. 3 is sealed to the outer periphery.

  Further, the piston rod 3 is provided with holes 33 and 34 opened from both ends thereof, and a rod 5 is projected from the bottom of each of the holes 33 and 34, and the rod 5 has a flange at the tip. 51 is provided. The rods 5 may be coupled to the bottoms of the holes 33 and 34 by screwing, or may be coupled by other methods, but a spring receiver 6 described later is provided on the outer peripheral side of the rod 5. In addition, for the convenience of the arrangement of the coil springs 7 and 8, coupling by screwing is advantageous when assembling each part constituting the positioning structure.

  Further, spring receivers 6 are arranged on the outer peripheral sides of the respective rods 5. Each spring receiver 6 is formed in a cylindrical shape, and one end thereof is bent inward to form a locking portion 61. At the same time, the other end is bent outward to form a flange 62.

  A rod 5 is inserted into each spring receiver 6, and the spring receiver 6 is allowed to move in the left-right direction in the figure with respect to the rod 5, but a flange 51 is formed at the tip of the rod 5. When the spring receiver 6 is separated from the piston 2 by a predetermined distance, the locking portion 61 comes into contact with the flange 51 and the movement of the spring receiver 6 in the direction away from the piston 2 is restricted.

 The flange 51 is in sliding contact with the inner periphery of the spring receiver 6, thereby preventing the shaft of the spring receiver 6 from being shaken with respect to the rod 5.

 Further, the inner diameters of the holes 33 and 34 are such that the rod 5, the spring receiver 6 and the coil springs 7 and 8 can be inserted, and the holes 33 and 34 of the piston rod 3 and the flanges 62 of the spring receivers 6 are arranged. Two coil springs 7 and 8 arranged in series are interposed in each of them.

 The coil springs 7 and 8 have natural lengths such that the spring receiver 6 is compressed in a state where movement in the direction away from the piston 2 is restricted by the locking portion 61 and the flange 51. Thus, the coil springs 7 and 8 are always maintained in a compressed state with a predetermined initial load.

 An annular shim 200 is interposed between the left coil spring 7 and the bottom of the hole 33 in the drawing and between the right coil spring 7 and the bottom of the hole 34 in the drawing, respectively. The outer diameter of the holes 33 and 34 is set to a diameter that can prevent displacement in the radial direction due to the inner diameters of the holes 33 and 34, and the planar processing of the bottoms of the holes 33 and 34 can be omitted by the interposition of the shim 200. In addition, it is possible to facilitate the manufacture of equipment such as the cylinder device S1 in which this positioning structure is embodied, and to reduce the manufacturing cost.

 The coil springs 7 and 8 arranged in series are formed in a reverse winding, and a guide member 9 that is slidably fitted on the outer peripheral side of the spring receiver 6 is interposed between the coil springs 7 and 8. Has been.

 The guide member 9 includes an annular plate portion 91 sandwiched between the end surface of the coil spring 7 and the end surface of the coil spring 8, a fitting portion 92 that protrudes from one end side of the annular plate portion 91 and fits in the coil spring 7, and an annular shape. And a fitting portion 93 that protrudes from the other end side of the plate portion 91 and fits into the coil spring 8. As described above, the spring receiver 6 is slidably inserted into the inner circumferential side thereof. ing.

 Therefore, the coil springs 7 and 8 are positioned in the radial direction with respect to the spring receiver 6, the rod 5, and the piston rod 3 by the guide member 9, so that no axial shake occurs.

 Further, the flange 62 of each spring receiver 6 is in contact with the restricting portion 12 provided in the cylinder 1 in a state where the piston 2 is in a neutral position which is a predetermined position, that is, in a state where the piston 2 is located in the center of the cylinder 1. It is like that. In other words, the predetermined distance between the spring receiver 6 and the piston 2 described above is a distance in which the flange 62 of each spring receiver 6 just contacts the restricting portion 12 in a state where the piston 2 is in a predetermined position.

 When the predetermined position is set to a position eccentric from the neutral position, the predetermined distance may be changed as appropriate, and the predetermined position is within a certain range, for example, the left and right in the figure centering on the neutral position. In the range where the width of the piston 2 is set, the predetermined distance should be adjusted so that the flange 62 of each spring receiver 6 does not contact the restricting portion 12 within the range where the piston 2 is in the predetermined position. That's fine.

 Furthermore, the stroke length of the piston 2 is the sum of the gap lengths W between the respective restricting portions 12 on the left and right sides in the figure and the piston rod 3 in a state where the piston 2 is in the neutral position, and at least the holes 33, The length between the bottom surface of 34 and the flange 51 of each rod 5 is set to be the same as or longer than the gap length W, and the length from the tip of each rod 5 to the bottom of the holes 33 and 34. The length H is set to be shorter than the depths of the holes 33 and 34, thereby preventing the maximum stroke of the piston 2 from being shorter than the sum of the gap lengths.

 The chambers R1 and R2 defined by the piston 2 of the cylinder 1 are provided with ports (not shown) that communicate with the chamber R1 and the chamber R2, respectively, on the side of the cylinder 1 so that fluid can be supplied and discharged. ing.

 Then, for example, it is possible to transmit the propulsive force generated by the cylinder device S1 to the outside by providing an output shaft at the tip of one rod 5 or the like.

 Also, a flow path that communicates the ports is provided, or a flow path that communicates the chambers R1 and R2 is provided in the piston 2 without providing the ports, and the fluid flows in the middle of the flow paths. If a diaphragm or the like that provides resistance is provided, the cylinder device S1 can also function as a shock absorber.

 In the cylinder device S1, fluid pressure is applied to each chamber formed by the reduced diameter portion 11 and the piston rod 3, that is, the space in which the rod 5, the spring receiver 6, and the coil springs 7 and 8 are accommodated. It can also be used as such a cylinder device.

  Further, when the end of the cylinder 1 may be sealed, the function as the restricting portion 12 is assigned to the end, that is, the spring receiver 6 is brought into contact with the sealed end. May be used as a regulation unit. Furthermore, since the end of the housing is normally sealed when positioning the spool of the valve, in this case as well, the restricting portion is not provided in the same way, but the sealed end is used as a restricting portion. It is enough to have a role.

 Next, the operation of positioning the piston 2 of the cylinder device S1 in which the positioning structure is embodied will be described. For example, when a force is applied to the piston 2 from the outside or the inside, and the piston 2 moves to the right in the figure, Since the rightward movement of the right spring receiver 6 is restricted by the restriction portion 12, the right coil springs 7 and 8 are compressed.

 On the other hand, the movement of the left spring receiver 6 in the direction away from the piston 2 is restricted by the flange 51 and the locking portion 61 of the left rod 5. Leave.

 Here, when the force from the outside or the inside is removed, the right coil springs 7 and 8 exert a biasing force in a direction to return the piston 2 to the neutral position, which is a predetermined position, and return the piston 2 to the neutral position.

 When the piston 2 returns to the neutral position, the locking portion 61 of the right spring receiver 6 comes into contact with the flange 51 of the right rod 5, and further extension of the coil springs 7 and 8 is restricted.

 In the above operation, the piston 2 is returned and positioned by the coil springs 7 and 8 to the neutral position. However, since the coil springs 7 and 8 are held in a compressed state in advance, the piston 2 is in the neutral position which is a predetermined position. The urging force generated by the coil springs 7 and 8 at the time of positioning is further compressed as the piston 2 moves rightward in this case from the state originally compressed by the rod 5, the spring receiver 6 and the piston rod 3. Therefore, the force for returning the piston 2 to the neutral position can be set large.

 Furthermore, in the conventional structure, the coil springs on both ends exert the urging force in the direction of the piston 2 regardless of which side the piston 2 moves to the left or right side. In this positioning structure, the coil springs 7 and 8 on the left side in the drawing move to the right together with the piston 2 and are cut off from the restricting portion 12, so that the coil springs 7 and 8 on the left side The biasing force of the right coil springs 7 and 8 for returning the piston 2 to the neutral position is not affected.

 In this positioning structure, even if the left and right coil springs 7 and 8 are both edge-cut from the restricting portion 12, the coil springs 7 and 8 on the edge-cut side are held by the rod 5 and the spring receiver 6 and fall off. Or when the piston 2 returns to the neutral position, the piston rod 3 as a member is disposed at an angle and is not compressed.

 Therefore, even when the sliding resistance between the piston 2 or the piston rod 3 and the cylinder 1 is large, the piston 2 as a member can be surely returned to the neutral position which is a predetermined position and accurately positioned. .

 Since the piston 2, which is a member, can be positioned at a predetermined position even if the sliding resistance is large, the cylinder 1 as a housing of the seal members 21, 31, 32 disposed on the outer peripheral side of the piston 2, etc. It becomes possible to increase the contact pressure to the inner peripheral surface, thereby improving the sealing performance of the device in which the positioning structure is embodied.

 Further, by arranging two or more coil springs in series, the aspect ratio of each coil spring can be set small, so that the coil spring is prevented from buckling, and thereby the piston 2 as a member is prevented from buckling. Positioning structure is applied because it is possible to set a long stroke length and to secure an aspect ratio that does not buckle even if the coil spring diameter is set small by arranging two or more coil springs in series. It is possible to make the size of the cylinder device S1 in the radial direction compact, that is, it is possible to avoid an increase in the size of the cylinder device S1.

 Further, since the piston rod 3 which is a member is provided with holes 33 and 34 into which the rod 5, the spring receiver 6 and the coil springs 7 and 8 can be inserted, a corresponding figure of the cylinder device S1 to which this positioning structure is applied. The overall length in the middle / left / right direction can be set short. In this positioning structure, the holes 33 and 34 can be omitted when it is not necessary to set the overall length of the cylinder device S1 to be short.

 Furthermore, in this embodiment, the adjacent coil springs 7 and 8 are reversely wound coil springs. The coil spring has a property that one end of the filament rotates in the circumferential direction with respect to the other end during compression and extension, but as described above, the adjacent coil springs 7 and 8 are reversely wound. If the specifications are the same except that the coil springs 7 and 8 are reversely wound, the guide members 9 can rotate in synchronization with the ends of the coil springs 7 and 8 when the coil springs 7 and 8 are compressed and extended. The annular plate 91 and the end of the piston rod 3 as a member and the flange 62 of the spring receiver 6 are not damaged.

 Since the annular plate 91 and the end of the piston rod 3 as a member and the flange 62 of the spring receiver 6 are not damaged, no contamination occurs when the positioning structure is embodied in a hydraulic device or the like.

  Further, the thread in the screw portion 5 a of the rod 5 is set in the direction opposite to the winding direction of the coil spring 7. That is, when the coil spring 7 is compressed and rotated in the circumferential direction, a torque in a direction to be screwed into the piston rod 3 acts on the rod 5, whereby the rod 5 and the piston rod 3 are fastened. As a result, the rod 5 can be reliably prevented from falling off from the piston rod 3. In this proposal, the coil springs 7 and 8 are set in the reverse direction. However, when the coil springs 7 and 8 are set so as to be wound in the same direction, the thread of the screw portion 5a is opposite to the winding direction of both the coil springs. Set it to. Since the torque acting on the rod 5 by the coil spring 7 is reduced when the coil spring is extended, the rod 5 is always screwed with a large torque during compression even if it is repeatedly expanded and contracted. There is no fear of it.

 Next, a positioning structure in a modification of the embodiment will be described. This positioning structure is also embodied in the cylinder device S2.

 In the description of the cylinder device S2, the same parts as those of the cylinder device S1 are simply denoted by the same reference numerals, and detailed description thereof will be omitted, and different parts will be described in detail. This also applies to the description after the modification.

 In the cylinder device S2, as shown in FIG. 2, the piston rod 3 is not provided with a hole, and the rod 5 is directly coupled to the end, and the rod 5 is an annular plate spring receiver 100. Further, the spring receiver 100 is regulated by the flange 51 of the rod 5 from being separated from the piston rod 3 as a member by a predetermined distance or more.

 Coil springs 7 and 8 are interposed between the spring receiver 100 and the end of the piston rod 3, and a guide member 9 is provided between the coil springs 7 and 8.

 The guide member 9 is set so that the inner diameter is in sliding contact with the outer periphery of the rod 5, thereby preventing the shaft springs of the coil springs 7 and 8 from being shaken.

 Only the right end side of the cylinder device S2 is shown in the drawing, and the left end and the central portion are omitted, but the piston 2 is provided at the center portion of the cylinder device S2, and the left end is the same as the right end side shown in the figure. It has a configuration.

 The cylinder 1 includes a restricting portion 12, and the predetermined distance is set so that the spring receiver 100 contacts the restricting portion 12 in a state where the piston 2 is in a neutral position at a predetermined position.

 Even in the positioning structure embodied in the cylinder device S2, the coil springs 7, 8 can be kept in a compressed state as in the embodiment, and the coil springs 7, 8 return the piston 2 to the neutral position. The coil springs 7 and 8 on the opposite side do not affect the urging force.

 Therefore, even when the sliding resistance between the piston 2 or the piston rod 3 and the cylinder 1 is large, the piston 2 as a member can be surely returned to the neutral position which is a predetermined position and accurately positioned. .

 Further, by arranging two or more coil springs in series, the aspect ratio of each coil spring can be set small, so that the coil spring is prevented from buckling, and thereby the piston 2 as a member is prevented from buckling. Positioning structure is applied because it is possible to set a long stroke length and to secure an aspect ratio that does not buckle even if the coil spring diameter is set small by arranging two or more coil springs in series. It is possible to make the size of the cylinder device S2 in the radial direction compact, that is, it is possible to avoid an increase in the size of the cylinder device S2.

 In this modification as well, the guide member 9 can rotate in synchronism with the end portions of the coil springs 7 and 8 when the coil springs 7 and 8 are compressed and extended, and the piston rod which is the annular plate portion 91 and the member. The three ends and the flange 62 of the spring receiver 6 are not damaged, and no contamination occurs when the positioning structure is embodied in a hydraulic device or the like.

 Next, positioning structures in other embodiments will be described. The positioning structure in the other embodiment is also embodied in the cylinder device S3.

 In the cylinder device S3, as shown in FIG. 3, the rod 5 is provided not on the piston rod 3 side but on the cylinder 1 side.

 That is, the rod 5 is coupled to the end 13 of the cylinder 1 which is the inner surface of the housing on the right side in the figure, and this rod 5 faces the end of the piston rod 3 which is a member. It is inserted into a spring receiver 6 having the same configuration as in FIG.

 The coil springs 7 and 8 have the same configuration as that of the embodiment, and the coil springs 7 and 8 are interposed between the flange 62 of the spring receiver 6 and the end 13 of the cylinder 1 in series.

 Further, a hole 34 is provided at the end of the piston rod 3, and the rod 5, the spring receiver 6, and the coil springs 7, 8 can all enter the hole 34.

 In other words, in the positioning structure in one embodiment, the rod 5, the spring receiver 6, and the coil springs 7 and 8 are held on the piston rod 3 side. In other embodiments, the cylinder 1 serving as the inner surface of the housing is provided. It is held by the end portion 13, and the spring receiver 6 is restricted from being separated from the end portion 13 by a predetermined distance or more by the abutment of the flange 51 and the locking portion 61, whereby the coil springs 7 and 8 are in a compressed state. Has been.

 Only the right end side of the cylinder device S3 is shown in the drawing, and the left end and the central portion are omitted, but the piston 2 is provided at the center portion of the cylinder device S3, and the left end is the same as the right end side shown in the figure. It has a configuration.

 In the positioning structure according to the other embodiment, the end 13 and the spring receiver 6 are arranged such that the left end of the spring receiver 6 is in contact with the bottom of the hole 34 with the piston 2 in the neutral position. The predetermined distance is set. Therefore, the end of the member in this case is the bottom of the hole 34.

 And, in the positioning structure in this other embodiment, since the attachment site of the positioning structure in one embodiment is only reversed, the operation effect thereof is the same as that in the positioning structure in one embodiment. It is the same.

 Even in the positioning structure in the other embodiments, the hole 34 can be omitted when it is not necessary to set the entire length of the cylinder device S3 to be short.

 Finally, a positioning structure in a modification of another embodiment will be described. As shown in FIG. 4, this positioning structure is embodied in a cylinder device S4. Basically, the mounting portion of the positioning structure in one embodiment is arranged on the inner surface of the housing in the same manner as the positioning structure in the other embodiments. The cylinder 1 is held at the end 13.

 In the cylinder device S4, as shown in FIG. 4, the rod 5 is directly coupled to the end 13 of the cylinder 1 serving as the inner surface of the housing, and the rod 5 is placed in the annular plate-shaped spring receiver 100. Further, the spring receiver 100 is regulated to be separated from the end portion 13 of the cylinder 1 by a predetermined distance or more by the flange 51 of the rod 5.

 Further, as the rod 5 is coupled to the end 13 of the cylinder 1, a hole 35 is provided in the piston rod 3 so that the rod 5 can be inserted.

 Coil springs 7 and 8 are interposed between the spring receiver 100 and the end 13 of the cylinder 1, and a guide member 9 is provided between the coil springs 7 and 8.

 The guide member 9 is set so that the inner diameter is in sliding contact with the outer periphery of the rod 5, thereby preventing the shaft springs of the coil springs 7 and 8 from being shaken.

 Note that only the right end side of the cylinder device S4 in the drawing is shown, and the left end and the center portion are omitted, but the piston 2 is provided at the center portion of the cylinder device S4, and the left end is the same as the right end side shown in the figure. Of course, it has a configuration.

 Further, the predetermined distance is set so that the spring receiver 100 contacts the end portion 36 of the piston rod 3 in a state where the piston 2 is in a neutral position at a predetermined position.

 Therefore, the end portion of the member is the end portion 36 of the piston rod in the modification of the other embodiment.

 Even in the positioning structure embodied in this cylinder device S4, the coil springs 7, 8 can be kept in a compressed state as in the embodiment, and the coil springs 7, 8 return the piston 2 to the neutral position. The coil springs 7 and 8 on the opposite side do not affect the urging force.

 Therefore, even when the sliding resistance between the piston 2 or the piston rod 3 and the cylinder 1 is large, the piston 2 as a member can be surely returned to the neutral position which is a predetermined position and accurately positioned. .

 Further, by arranging two or more coil springs in series, the aspect ratio of each coil spring can be set small, so that the coil spring is prevented from buckling, and thereby the piston 2 as a member is prevented from buckling. Positioning structure is applied because it is possible to set a long stroke length and to secure an aspect ratio that does not buckle even if the coil spring diameter is set small by arranging two or more coil springs in series. It is possible to make the size of the cylinder device S4 in the radial direction compact, that is, it is possible to avoid an increase in the size of the cylinder device S4.

 In this modification as well, the guide member 9 can rotate in synchronism with the end portions of the coil springs 7 and 8 when the coil springs 7 and 8 are compressed and extended, and the piston rod which is the annular plate portion 91 and the member. The three ends and the flange 62 of the spring receiver 6 are not damaged, and no contamination occurs when the positioning structure is embodied in a hydraulic device or the like.

 This is the end of the description of the positioning structure in each embodiment. The left end side of the member is the configuration of the positioning structure of one embodiment, and the right end side of the member is the configuration of the positioning structure of the other embodiments. It is also possible to replace the rod, spring support, member configuration, and rod holding location in the positioning structure in each embodiment with those of the positioning structure of different embodiments at the left end or the right end of the member.

 Although not shown, in the modification of the embodiment, between the coil spring 7 and the end of the piston rod 3, the coil spring 8 and By interposing an annular shim that is positioned in the radial direction by inserting the rod 5 between the end portion 13 of the cylinder 1, planar processing of each end portion can be omitted. Similar to the positioning structure of the embodiment, the presence of the shim facilitates the manufacture of equipment such as a cylinder device and can reduce the manufacturing cost.

 Furthermore, in one embodiment, the thread in the threaded portion of the rod 5 is set in the direction opposite to the winding direction of the coil spring 7, and in another embodiment and its modification, the coil spring 8 If the coil spring 7 or the coil spring 8 is compressed and rotated in the circumferential direction as in the embodiment, the rod 5 has the piston rod 3 or the cylinder 1 in the same direction as the winding direction. As a result, torque in the direction of screwing is applied to the end 13 of the cylinder, so that the rod 5 and the piston rod 3 or the end 13 of the cylinder 1 can be fastened by screwing as in the embodiment. Further, it is possible to reliably prevent the rod 5 from dropping from the piston rod 3 or the end portion 13 of the cylinder 1.

 In the above description, the case where the positioning structure is embodied in the cylinder device has been described. However, the positioning structure may be embodied in a valve for positioning the spool, and the other members may be mounted on the housing. Of course, it can be embodied in a positioning device.

  This is the end of the description of the embodiment of the present invention, but the scope of the present invention is of course not limited to the details shown or described.

It is a longitudinal cross-sectional view of the cylinder apparatus with which the positioning structure in one Embodiment was actualized. It is a longitudinal cross-sectional view of the cylinder apparatus with which the positioning structure in the modification of one Embodiment was embodied. It is a longitudinal cross-sectional view of the cylinder apparatus with which the positioning structure in other embodiment was embodied. It is a longitudinal cross-sectional view of the cylinder apparatus with which the positioning structure in the modification of other embodiment was embodied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylinder 12 which is housing Restriction part 13 End part which is inner surface of housing 2 Piston 3 which is a part of member 3 Piston rod 33 and 34 which is a part of member 5 Rod 51 Flange 6, 100 Spring receiver 61 Locking part 62鍔 7, 8 Coil spring 9 Guide members S1, S2, S3, S4 Cylinder device

Claims (11)

In a positioning structure for positioning a member slidably inserted in a hollow housing at a predetermined position, a pair of rods respectively coupled to both ends of the member, and each spring receiver disposed on the outer peripheral side of each rod Two or more coil springs interposed in series between each end of the member and each spring receiver, and each spring receiver is restricted from moving away from the member by a rod disposed on the inner peripheral side. The coil spring is kept in a compressed state, and when the member moves from a predetermined position, the end of one of the spring receivers abuts at least one of the restricting portions provided at positions on both sides of the housing member. A positioning structure characterized by that. The positioning structure according to claim 1, wherein at least one end of the member is provided with a hole through which a spring receiver and a coil spring can enter, and the rod is coupled to the bottom of the hole. The spring receiver is formed in a cylindrical shape and has a flange at the end. The spring receiver is inserted into each of the coil springs arranged in series, and each coil spring is supported by the flange and the end of the member. The positioning structure according to claim 1 or 2, characterized in that: The positioning structure according to claim 3, wherein a guide member that is in sliding contact with the outer periphery of the cylinder is provided between the coil springs arranged in series, and the adjacent coil springs are formed in a reverse winding. In a positioning structure for positioning a member slidably inserted into a hollow housing at a predetermined position, a pair of rods standing from the inner surface of the housing and opposed to both ends of the member are disposed on the outer peripheral side of each rod. Each spring receiver is provided with two or more coil springs interposed in series between each housing inner surface and each spring receiver, and each spring receiver is separated from the housing inner surface by a rod disposed on the inner peripheral side. The coil spring is kept in a compressed state, and at least when the member moves from a predetermined position, the end of one of the spring receivers abuts one of the opposite ends of the member. Characteristic positioning structure. 6. The positioning structure according to claim 5, wherein at least one of the members is provided with a hole into which one of the rod, the rod, the coil spring, and the spring receiver can enter all at one end. The spring receiver is formed in a cylindrical shape and has a flange at the end. The spring receiver is inserted into each coil spring arranged in series, and each coil spring is supported by the flange and the inner surface of the housing. The positioning structure according to claim 5 or 6. The positioning structure according to claim 7, wherein a guide member that is in sliding contact with the outer periphery of the cylinder is provided between the coil springs arranged in series, and the adjacent coil springs are formed in a reverse winding. In a positioning structure for positioning a member slidably inserted into a hollow housing at a predetermined position, a rod coupled to one end of the member, a pair of rods standing from the inner surface of the housing and facing the other end of the member, Each spring receiver arranged on the outer peripheral side of each rod, two or more coil springs interposed in series between one end of the member and the spring receiver, and two or more in series between the inner surface of the housing and the spring receiver And a spring receiver on one end side of the member is restricted from moving in a direction away from the member by a rod disposed on the inner peripheral side to keep the coil spring on the one end side of the member in a compressed state. The movement of the spring receiver on the other end side of the member in the direction away from the inner surface of the housing is restricted by the rod arranged on the inner peripheral side, the coil spring on the other end side of the member is kept in a compressed state, and the member is When moving from one position to the other end of the member, the end of the spring receiver on one end of the member abuts on a restricting portion provided at a position on one end of the member of the housing, so that the member is at a predetermined position or the other end of the member A positioning structure in which the end of the spring receiver on the other end side of the member abuts on the end of the opposing member when moving to the position. 10. The positioning structure according to claim 9, wherein a hole for allowing the spring receiver and the coil spring to enter is provided at one end of the member, and the rod is coupled to the bottom of the hole. 11. The positioning structure according to claim 9, wherein the member is provided with a hole at the other end through which the rod, the rod, the coil spring, and the spring support can all enter.

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