JP2013072512A - Linear guide device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a linear guide device which can move a shaft body in the length direction with relatively small force and hardly changes a relative positional relation between an inner cylinder and the shaft body even when the vertical movement of the shaft body is repeated.SOLUTION: The linear guide device includes: an outer cylinder 51; a plurality of rolling elements 52 arranged along the inner circumferential surface of the outer cylinder; the inner cylinder 53 which retains the plurality of rolling elements movably arranged in the length direction on the inner side of the outer cylinder, rotatably while being protruded to the outer circumference side and the inner circumference side; the shaft body 54 of which the outer circumference surface is supported by the plurality of rolling elements inserted into the inner cylinder; and annular cover bodies 55 provided to each opening part of the outer cylinder, wherein a coil spring 61 formed by helically winding a wire material is provided between the inner cylinder and at least one side cover body, and the coil spring includes a first spring section 61a where the wire materials adjacent to each other are brought into contact with each other by application of a relatively small load and a second spring section 61b where the wire materials adjacent to each other are brought into contact with each other by application of a relatively large load.

Description

  The present invention relates to a linear motion guide device including a shaft that is movable in a length direction.

  The linear motion guide device includes a shaft that is movable in the length direction, and is used by being incorporated in various mechanical devices represented by an electronic component mounting device, for example. In the electronic component mounting apparatus, a plurality of linear motion guide apparatuses are incorporated in a state where the shaft bodies are arranged vertically. A suction nozzle for electronic parts is attached to the lower end of each shaft body.

  The electronic component mounting apparatus lowers the shaft body of the linear motion guide device together with the suction nozzle, lifts the shaft body after sucking the electronic components previously stored in the tray with the suction nozzle, and then moves the linear motion guide device to the printed wiring board. After moving upward, the shaft body is lowered, and the electronic component sucked by the suction nozzle is mounted (mounted) at a predetermined position of the printed wiring board. As described above, the electronic component mounting apparatus repeatedly raises and lowers (moves in the length direction) the shaft body of the linear motion guide device to mount a large number of electronic components on the surface of the printed wiring board.

  FIG. 1 is a partial cross-sectional view showing a configuration example of a conventional linear motion guide device. However, in the linear motion guide device 10, the outer cylinder 11 and the lid body 15 are cut along a plane including the central axis of the shaft body 14, and a part of the inner cylinder 13 is cut out. 2 is a cross-sectional view of the linear motion guide device 10 cut along the cutting line AA in FIG. However, the rolling element 12 is filled in without being cut.

  1 and 2 includes an outer cylinder 11 having openings at both ends, a plurality of rolling elements 12 disposed along an inner peripheral surface of the outer cylinder 11, and an inner side of the outer cylinder 11. Inserted into the inner cylinder 13 and the inner cylinder 13, which are arranged to be movable in the lengthwise direction and hold the plurality of rolling elements 12 so as to be rotatable in a state protruding from the outer peripheral side and the inner peripheral side. The shaft body 14 has an outer peripheral surface supported by the plurality of rolling elements 12 and an annular lid body 15 provided in each opening of the outer cylinder 11.

  When the outer cylinder 11 of the linear motion guide device 10 is supported and fixed and the shaft body 14 is lowered from the position shown in FIG. 1 (hereinafter referred to as “initial position”), it is sandwiched between the outer cylinder 11 and the shaft body 14. Since the rolling element 12 rolls downward, the inner cylinder 13 holding the rolling element 12 also descends from the position shown in FIG. 1 (hereinafter referred to as “initial position”). Next, when the shaft body 14 is raised and placed at the initial position, the rolling element 12 rolls upward, so that the inner cylinder 13 is also raised and placed at the initial position (original position).

  The moving speed (lifting speed) of the inner cylinder 13 that holds the rolling element 12 does not coincide with the moving speed of the shaft body 14, and theoretically becomes a half speed of the moving speed of the shaft body 14. . Therefore, the inner cylinder 13 is not normally fixed to the shaft body 14 that moves at a speed different from the moving speed of the inner cylinder 13 or the stationary outer cylinder 11.

  For this reason, if the raising / lowering of the shaft body 14 is repeated, for example, the inner cylinder 13 holding the plurality of rolling elements 12 continues to be affected by gravity (self-weight). Even if is arranged at the initial position, the inner cylinder 13 may be arranged at a position below the initial position without being arranged at the initial position.

  Further, the rolling element 12 of the linear motion guide device 10 is in a state of being pressed between the outer cylinder 11 and the shaft body 14. For example, the inner diameter of the outer cylinder 11 varies in the direction of the central axis due to slight variations in machining accuracy when the outer cylinder 11 or the shaft body 14 is manufactured, or the outer diameter of the shaft body 14 is the center. If the outer cylinder 11 and the shaft body 14 are installed with their central axes inclined due to fluctuations in the axial direction or due to the state in which the linear guide device 10 is attached to various mechanical devices, the rolling element 12 The applied pressure varies in the length direction of the outer cylinder 11. When the pressure applied to the rolling element 12 varies in the length direction of the outer cylinder 11, the rolling element 12 easily moves to a position where the pressure is small in the length direction of the outer cylinder 11. For this reason, when the shaft body 14 is repeatedly raised and lowered, the inner cylinder 13 holding the rolling element 12 is not disposed at the initial position and the initial position is maintained even if the shaft body 14 is subsequently disposed at the initial position. May be arranged at an upper or lower position (a position different from the initial position).

  As described above, in the conventional linear motion guide device 10, when the shaft body 14 is repeatedly raised and lowered, even if the shaft body 14 is subsequently placed at the initial position, the inner cylinder 13 is not placed at the initial position, and the initial position is increased. It may be arranged at a position different from the position. That is, when the shaft body 14 is repeatedly raised and lowered, the relative positional relationship between the inner cylinder 13 and the shaft body 14 may change.

  For example, in the linear motion guide device 10 shown in FIG. 1, when the shaft body 14 is raised and lowered repeatedly about 10,000 times, and then the shaft body 14 is disposed at the initial position, the inner cylinder 13 is about several mm below the initial position. It may be arranged at the position.

  Thus, when repeating the raising / lowering of the shaft body 14 of the linear guide device 10, for example, if the inner cylinder 13 continues to move downward relative to the shaft body 14, the shaft body as shown in FIG. When 14 is lowered from the initial position, the inner cylinder 13 descending together with the rolling element 12 contacts (collises) with the lid 15 provided at the opening of the outer cylinder 11 and stops. When the inner cylinder 13 is stationary, the rolling element 12 supporting the shaft body 14 is also stopped, so that the distance at which the shaft body 14 can be moved smoothly is shortened.

  Further, when the rolling element 12 supporting the shaft body 14 stops, at the same time, the shaft body 14 and the rolling element 12 rub against each other strongly (slid), and a large frictional resistance is generated between them. To do. For this reason, the accuracy of positioning by moving the shaft body 14 up and down (moving in the length direction) by the drive device is lowered, or in an extreme case, the drive device can raise and lower the shaft body 14 depending on the driving force. Sometimes it stops without being able to.

  FIG. 4 is a partial cross-sectional view showing another configuration example of a conventional linear motion guide device. 4 includes a coil spring 41 between the inner cylinder 13 and each lid body 15, and when the shaft body 14 is repeatedly raised and lowered, the inner spring 13 is moved from each coil spring 41 to the inner cylinder 13. A force to push the cylinder 13 back toward the upper and lower center position (initial position) of the outer cylinder 11 is continuously applied. For this reason, even if the raising / lowering of the shaft body 14 is repeated, the relative positional relationship between the inner cylinder 13 and the shaft body 14 is unlikely to change, and therefore the occurrence of contact between the inner cylinder 13 and the lid body 15 is suppressed. Therefore, it is difficult to shorten the distance at which the shaft body 14 can be moved smoothly.

  Moreover, since generation | occurrence | production of the contact with the inner cylinder 13 and the cover body 15 is suppressed, generation | occurrence | production of the big frictional resistance between the shaft body 14 and the rolling element 12 is also suppressed. For this reason, the fall of the positioning accuracy of the shaft body 14 is also suppressed. A linear motion guide device having the same configuration as the linear motion guide device 40 of FIG. 4 is disclosed in, for example, Patent Document 1.

Japanese Patent Laid-Open No. 11-223217 (FIG. 2)

  In the linear motion guide device 10 of FIG. 1, when the shaft body 14 is repeatedly raised and lowered, the relative positional relationship between the inner cylinder 13 and the shaft body 14 is likely to fluctuate, so that the inner cylinder 13 and the lid body 15 are in contact with each other. Since it is easy to do, the distance which can move the shaft body 14 smoothly is easy to shorten.

  In the linear motion guide device 40 of FIG. 4, a force for pushing back the inner cylinder 13 toward the upper and lower center position (initial position) of the outer cylinder 11 is continuously applied from each coil spring 41 to the inner cylinder 13. For this reason, even if the raising / lowering of the shaft body 14 is repeated, it is difficult for the relative positional relationship between the inner cylinder 13 and the shaft body 14 to fluctuate, and therefore the occurrence of contact between the inner cylinder 13 and the lid body 15 is suppressed. Therefore, it is difficult to shorten the distance at which the shaft body 14 can be moved smoothly.

  However, in the linear motion guide device 40, it is necessary to raise and lower the shaft body 14 with a large force exceeding the restoring force of the coil spring 41. Further, the restoring force of the coil spring 41 increases as the coil spring 41 shrinks. As described above, when the shaft body is moved up and down against the large and fluctuating restoring force of the coil spring, the accuracy of raising and lowering the shaft body tends to be lowered.

  The problem of the present invention is that the shaft body can be moved in the length direction with a relatively small force, and even if the shaft body is repeatedly raised and lowered, the relative positional relationship between the inner cylinder and the shaft body varies. The object is to provide a difficult linear motion guide device.

The inventor of the present invention provides a first spring section that makes contact with adjacent wires by applying a relatively small load between the inner cylinder and the lid of the linear motion guide device, and applying a relatively large load. By providing a coil spring including a second spring section that makes contact with adjacent wires, the shaft can be moved with a relatively small force for the following reason (1), and (2 For this reason, it has been found that even if the shaft body is repeatedly raised and lowered, the relative positional relationship between the inner cylinder and the shaft body hardly changes, and the present invention has been achieved.
(1) The above coil spring exhibits a relatively small spring constant before the mutually adjacent wires of the first spring section come into contact with each other, and relatively after the wires adjacent to each other in the first spring section come into contact with each other. Shows a large spring constant. For this reason, the shaft body can be moved up and down (moved in the length direction) with a relatively small force from the initial position until the adjacent wires of the first spring section come into contact with each other. When the inner cylinder approaches the lid provided at the end of the outer cylinder and the adjacent wires of the first spring section come into contact with each other, the inner cylinder is pushed back toward the initial position by the large restoring force of the coil spring. Therefore, occurrence of contact between the inner cylinder and the lid is reliably prevented.
(2) Since a force to push back the inner cylinder toward the initial position is continuously applied from the coil spring (that is, each of the first spring section and the second spring section) to the inner cylinder, the shaft body is moved up and down. Even if it repeats, it is hard to produce a fluctuation | variation in the relative positional relationship of an inner cylinder and a shaft.

  The present invention provides an outer cylinder having openings at both ends, a plurality of rolling elements disposed along an inner peripheral surface of the outer cylinder, and disposed inside the outer cylinder so as to be movable in the length direction. An inner cylinder that rotatably holds a plurality of rolling elements in a state protruding from the outer peripheral side and the inner peripheral side, and a shaft body whose outer peripheral surface is supported by the plurality of rolling elements inserted into the inner cylinder And a linear motion guide device including an annular lid provided in each opening of the outer cylinder, and formed by winding a wire rod in a spiral between the inner cylinder and at least one lid A first spring section that contacts a wire adjacent to each other by applying a relatively small load, and a wire that is adjacent to each other by applying a relatively large load. A linear motion guide device comprising: a second spring section that causes contact; .

  The linear motion guide device of the present invention can move the shaft body in the length direction with a relatively small force, and the relative position relationship between the inner cylinder and the shaft body is maintained even when the shaft body is repeatedly raised and lowered. It is difficult for fluctuations to occur.

It is a fragmentary sectional view which shows the structural example of the conventional linear motion guide apparatus. However, in the linear motion guide device 10, the outer cylinder 11 and the lid body 15 are cut along a plane including the central axis of the shaft body 14, and a part of the inner cylinder 13 is cut out (FIG. 5). The same applies to 4). It is sectional drawing of the linear guide apparatus 10 cut | disconnected along the cutting line AA entered in FIG. However, the rolling elements 12 are written in a state where they are not cut (the same applies to FIG. 15). It is a figure which shows the linear guide apparatus 10 of FIG. 1 in the state which the inner cylinder 13 and the cover body 15 contacted. It is a fragmentary sectional view which shows another structural example of the conventional linear motion guide apparatus. However, the coil spring 41 is written with the number of windings of the wire less than actual. It is a fragmentary cross section which shows the structural example of the linear motion guide apparatus of this invention. However, in the linear motion guide device 50, the outer cylinder 51, the lid body 55, and the coil spring 61 are cut along a plane including the central axis of the shaft body 54, and the inner cylinder 53 is partially cut out. (The same applies to FIG. 14). Note that the coil spring 61 is written with the number of windings of the wire less than the actual number (the same applies to FIGS. 6 to 14). The linear motion guide device 50 of FIG. 5 is shown in a state where the shaft body 54 is moved downward when there is no change in the relative positional relationship between the inner cylinder 53 and the shaft body 54 as shown in the figure. FIG. The linear motion guide device 50 of FIG. 5 is moved downward when the shaft body 54 is repeatedly raised and lowered and the inner cylinder 53 is disposed at a position relatively lower than the shaft body 54. FIG. It is a fragmentary sectional view which shows another structural example of the linear motion guide apparatus of this invention. However, in the linear motion guide device 80, the outer cylinder 51 and the lid 55 are cut along a plane including the central axis of the shaft body 54, and a part of the inner cylinder 53 is cut out (FIG. 5). The same applies to 9 to 13). It is a fragmentary sectional view which shows another structural example of the linear motion guide apparatus of this invention. It is a fragmentary sectional view which shows another structural example of the linear motion guide apparatus of this invention. It is a fragmentary sectional view which shows another structural example of the linear motion guide apparatus of this invention. It is a fragmentary sectional view which shows another structural example of the linear motion guide apparatus of this invention. It is a fragmentary sectional view which shows another structural example of the linear motion guide apparatus of this invention. It is a fragmentary sectional view which shows another structural example of the linear motion guide apparatus of this invention. It is sectional drawing of the linear guide apparatus 140 cut | disconnected along the cutting line BB entered in FIG.

  First, typical embodiments of the linear motion guide device of the present invention will be described with reference to the accompanying drawings.

  FIG. 5 is a partial cross-sectional view showing a configuration example of the linear motion guide device of the present invention. However, in the linear motion guide device 50, the outer cylinder 51, the lid body 55, and the coil spring 61 are cut along a plane including the central axis of the shaft body 54, and the inner cylinder 53 is partially cut out. It is. Note that the coil spring 61 is shown with the number of turns of the wire less than the actual number so that the configuration can be easily understood.

  5 includes an outer cylinder 51 having openings at both ends, a plurality of rolling elements 52 disposed along an inner peripheral surface of the outer cylinder 51, and a length direction inside the outer cylinder 51. A plurality of rolling elements 52 which are arranged so as to be movable, and are rotatably held in a state of protruding to the outer peripheral side and the inner peripheral side, and the plurality of the plurality of rolling elements 52 inserted into the inner cylinder 53. The rolling body 52 includes a shaft body 54 whose outer peripheral surface is supported, and an annular lid body 55 provided in each opening of the outer cylinder 51. About such a structure, it is the same as that of the structure of the conventional linear guide apparatus 10 shown in FIG.

  The linear motion guide device 50 includes a coil spring 61 formed by spirally winding a wire between the inner cylinder 53 and each lid body 55, and the coil spring 61 is applied with a relatively small load. It is characterized in that it includes a first spring section 61a that makes contact with adjacent wires, and a second spring section 61b that makes contact with wires adjacent to each other by applying a relatively large load.

  In the linear motion guide device 50, the load applied to the coil spring 61 increases as the inner cylinder 53 approaches the lid body 55 and the distance between the two decreases. As described above, the first spring section 61a of the coil spring 61 is brought into contact with adjacent wires by applying a relatively small load. Accordingly, when the load applied to the coil spring 61 is increased, firstly the wires adjacent to each other of the first spring section 61a are brought into contact with each other.

  Accordingly, the coil spring 61 can be reduced in its entire length direction before contacting the adjacent wires of the first spring section 61a as described above. Indicates the force required to apply unit deformation to the spring.

  On the other hand, after the coil spring 61 is brought into contact with the adjacent wires of the first spring section 61a as described above, the portion where the contact of the wire is caused is the load applied to the coil spring 61. As the load increases further, the load cannot be reduced according to the increase in load (it does not function as a spring), and therefore a relatively large spring constant is exhibited.

  Therefore, in the linear motion guide device 50, when the shaft body 54 is lowered from the initial position (position shown in FIG. 5), contact is made between adjacent wires of the first spring section 61a as shown in FIG. Until now, since the coil spring 61 exhibits a relatively small spring constant, the shaft body 54 can be moved up and down (moved in the length direction) with a relatively small force.

  On the other hand, in the linear motion guide device 50, the shaft body is repeatedly raised and lowered. For example, when the inner cylinder 53 moves to a lower position relative to the shaft body 54, the shaft body 54 is lowered from the initial position. When this is done, the load applied to the coil spring 61 increases. For this reason, when the shaft body 54 is lowered, as shown in FIG. 7, the adjacent springs of the first spring section 61a are brought into contact with each other, so that the coil spring 61 exhibits a relatively large spring constant. . Therefore, since the coil spring 61 strongly pushes back the inner cylinder 53 toward the initial position by the large restoring force, the occurrence of contact between the inner cylinder 53 and the lid 55 is reliably prevented.

  Moreover, since the force which pushes back the inner cylinder 53 toward the initial position from the coil spring 61 (that is, each of the first spring section 61a and the second spring section 61b) is continuously applied to the inner cylinder 53, Even if the shaft body 54 is raised and lowered repeatedly, the relative positional relationship between the inner cylinder 53 and the shaft body 54 hardly changes.

  In the case of the linear motion guide device 50 of FIG. 5, the cross-sectional area of the wire of the coil spring 61 is changed from one end of the coil spring 61 (end on the lid 55 side) to the other end (end on the inner cylinder 53 side). The first spring section 61a is a section on the other end side of the coil spring 61 divided into three equal parts, and the second spring section 61b is a coil spring. 61 is divided into three equal parts on the one end side. When the first spring section and the second spring section of the coil spring 61 are determined as described above, the coil spring 61 is divided into three equal parts in a state where no load is applied.

  The cross-sectional area of the wire of the coil spring 61 is such that the one end of the coil spring 61 (that is, the end on the second spring section 61b side) to the other end (that is, the end on the first spring section 61a side). ) Continuously decreased. Accordingly, the spring constant of the first spring section 61a of the coil spring 61 is smaller than the spring constant of the second spring section 61b. For this reason, when a load is applied to the coil spring 61 (that is, when the same load is applied to each spring section), the first spring section 61a is elastically deformed (reduced) relatively large. This makes it easier to make contact between adjacent wires. Thus, the first spring section 61a of the coil spring 61 is brought into contact with adjacent wires by applying a relatively small load, and the second spring section 61b is applied with a relatively large load. Thus, contact is made between adjacent wires.

  The coil spring 61 can be manufactured as follows, for example. First, a coil spring is produced by spirally winding a wire having a circular cross section. However, the outer diameter of the coil spring is adjusted so as to gradually increase (or decrease) along the central axis direction of the coil spring. Thus, a coil spring having a truncated cone shape is produced. For example, a part of the outer peripheral surface of the produced conical cone-shaped coil spring is removed by polishing so that the outer diameter of the coil spring has a uniform outer diameter along the central axis direction, as shown in FIG. The coil spring 61 in which the cross-sectional area is continuously reduced from one end to the other end can be produced.

  FIG. 8 is a partial sectional view showing another configuration example of the linear motion guide device of the present invention. However, in the linear motion guide device 80, the outer cylinder 51 and the lid body 55 are cut along a plane including the central axis of the shaft body 54, and a part of the inner cylinder 53 is cut out.

  The configuration of the linear motion guide device 80 in FIG. 8 is such that the cross-sectional area of the wire rod of the coil spring 81 is maintained from the one end (the end on the lid 55 side) to the other while the cross-sectional shape of the wire is kept circular. 5 is the same as the configuration of the linear motion guide device 50 of FIG. 5 except that it continuously decreases toward the end (the end on the inner cylinder 53 side).

  FIG. 9 is a partial cross-sectional view showing still another configuration example of the linear motion guide device of the present invention. The configuration of the linear motion guide device 90 in FIG. 9 is the same as the configuration of the linear motion guide device 50 in FIG. 5 except that the configuration of the coil spring 91 is different.

  That is, in the case of the linear motion guide device 90 of FIG. 9, the interval (pitch) between the adjacent wire rods of the coil spring 91 is changed from one end portion (end portion on the lid 55 side) of the coil spring 91 to the other end portion (end portion). The first spring section 91a is a section on the one end section side that divides the coil spring 91 into three equal parts, and is continuously increased. The spring section 91b is a section on the other end side of the coil spring 91 divided into three equal parts. As described above, when the first spring section 91a and the second spring section 91b of the coil spring 91 are determined, the coil spring 91 is divided into three equal parts in a state where no load is applied.

  The interval (pitch) between the wire rods adjacent to each other in the coil spring 91 is such that the one end of the coil spring 91 (that is, the end on the first spring section 91a side) to the other end (the second spring section 91b). (The end of the side) increases continuously. For this reason, the number of turns of the wire of the first spring section 91a of the coil spring 91 is larger than the number of turns of the wire of the second spring section 91b. Accordingly, the spring constant of the first spring section 91a of the coil spring 91 is smaller than the spring constant of the second spring section 91b. For this reason, when a load is applied to the coil spring 91, the first spring section 91a is relatively elastically deformed (reduced), and the adjacent wires are likely to contact each other. As a result, the first spring section 91a of the coil spring 91 is brought into contact with adjacent wires by applying a relatively small load, and the second spring section 91b is applied with a relatively large load. Thus, contact is made between adjacent wires.

  FIG. 10 is a partial cross-sectional view showing still another configuration example of the linear motion guide device of the present invention. The configuration of the linear motion guide device 100 in FIG. 10 is the same as the configuration of the linear motion guide device 50 in FIG. 5 except that the configuration of the coil spring 101 is different.

  That is, in the case of the linear motion guide device 100 of FIG. 10, the coil spring 101 has a configuration in which two coil spring pieces 102a and 102b having a uniform cross-sectional area of the wire and different cross-sectional areas are arranged in a line. The first spring section 101a is composed of a coil spring piece 102a having the smallest cross-sectional area of the wire, and the second spring section 101b is composed of a coil spring piece 102b having the largest cross-sectional area of the wire.

  The cross-sectional area of the wire rod of the coil spring piece 102a constituting the first spring section 101a of the coil spring 101 is smaller than the cross-sectional area of the wire rod of the coil spring piece 102b constituting the second spring section 101b. Accordingly, the spring constant of the first spring section 101a of the coil spring 101 is smaller than the spring constant of the second spring section 101b. For this reason, when a load is applied to the coil spring 101, the first spring section 101 a is relatively greatly elastically deformed (reduced), and the adjacent wires are likely to come into contact with each other. Thus, the first spring section 101a of the coil spring 101 is brought into contact with adjacent wires by applying a relatively small load, and the second spring section 101b is applied with a relatively large load. Thus, the wires adjacent to each other are brought into contact with each other.

  FIG. 11 is a partial cross-sectional view showing still another configuration example of the linear motion guide device of the present invention. The configuration of the linear motion guide device 110 in FIG. 11 is the same as the configuration of the linear motion guide device 50 in FIG. 5 except that the configuration of the coil spring 111 is different.

  That is, in the case of the linear motion guide device 110 of FIG. 11, the coil spring 111 has a configuration in which two coil spring pieces 112a and 112b in which the intervals (pitch) between adjacent wires are uniform and different from each other are arranged in a line. The first spring section 111a is composed of a coil spring piece 112a having the smallest wire spacing, and the second spring section 111b is composed of a coil spring piece 112b having the largest wire spacing.

  The interval between the wire rods of the coil spring pieces 112a constituting the first spring section 111a of the coil spring 111 is smaller than the interval between the wire rods of the coil spring pieces 112b constituting the second spring section 111b. That is, the number of turns of the wire of the first spring section 111a of the coil spring 111 is larger than the number of turns of the wire of the second spring section. Accordingly, the spring constant of the first spring section 111a of the coil spring 111 is smaller than the spring constant of the second spring section 111b. For this reason, when a load is applied to the coil spring 111, the first spring section 111a is relatively elastically deformed (reduced), and the adjacent wires are likely to contact each other. Accordingly, the first spring section 111a of the coil spring 111 is brought into contact with adjacent wires by applying a relatively small load, and the second spring section 111b is applied with a relatively large load. Thus, contact is made between adjacent wires.

  FIG. 12 is a partial cross-sectional view showing still another configuration example of the linear motion guide device of the present invention. The configuration of the linear motion guide device 120 of FIG. 12 is the same as that of FIG. 12 except that the first spring section 121a of the coil spring 121 is on the lid 55 side and the second spring section 121b is on the inner cylinder 53 side. The configuration of the ten linear motion guide devices 100 is the same.

  In this way, the first spring section and the second spring section can be arranged at arbitrary positions in the length direction of the coil spring.

  FIG. 13 is a partial sectional view showing still another configuration example of the linear motion guide device of the present invention. The configuration of the linear motion guide device 130 of FIG. 13 is the same as the configuration of the linear motion guide device 100 of FIG. 10 except that the configuration of the coil spring 131 is different.

  That is, in the case of the linear motion guide device 130 of FIG. 13, the coil spring 131 has a configuration in which three coil spring pieces 132a, 132b, and 132c having the same cross-sectional area and different cross-sectional areas are arranged in a line. The first spring section 131a is composed of a coil spring piece 132b having the smallest cross-sectional area of the wire, and the second spring section 131b is composed of a coil spring piece 132a having the largest cross-sectional area of the wire.

  The cross-sectional area of the wire rod of the coil spring piece 132b constituting the first spring section 131a of the coil spring 131 is smaller than the cross-sectional area of the wire rod of the coil spring piece 132a constituting the second spring section 131b. Therefore, the spring constant of the first spring section 131a of the coil spring 131 is smaller than the spring constant of the second spring section 131b. For this reason, when a load is applied to the coil spring 131, the first spring section 131a is relatively greatly elastically deformed (reduced), and the adjacent wires are easily contacted. Accordingly, the first spring section 131a of the coil spring 131 is brought into contact with adjacent wires by applying a relatively small load, and the second spring section 131b is applied with a relatively large load. Thus, contact is made between adjacent wires.

  When there are two or more coil spring pieces having the smallest cross-sectional area of the wire, any of the coil spring pieces may be a coil spring constituting the first spring section. Similarly, when there are two or more coil spring pieces having the largest cross-sectional area of the wire, any of the coil spring pieces may be a coil spring piece constituting the second spring section.

  FIG. 14 is a partial cross-sectional view showing still another configuration example of the linear motion guide device of the present invention. However, the shaft body 144 is entered with a part thereof cut away. FIG. 15 is a cross-sectional view of the linear motion guide device 140 cut along the cutting line BB entered in FIG.

  In the configuration of the linear motion guide device 140 of FIG. 14, a plurality of (for example, four) linear grooves 141 a are formed on the inner peripheral surface of the outer cylinder 141 to accommodate the rolling elements 142 protruding to the outer peripheral side of the inner cylinder 53. Other than the fact that a plurality of linear grooves 144a are formed on the outer peripheral surface of the shaft body 144 to accommodate the rolling elements 142 protruding toward the inner periphery of the inner cylinder 53, and the sizes of the rolling elements 142 are different. These are the same as the structure of the linear motion guide apparatus 50 of FIG.

  In the linear motion guide device 140 of FIG. 14, the outer cylinder 141 and the shaft body 144 are engaged with each other via a plurality of rolling elements 142, so that the rotational movement of the shaft body 144 relative to the outer cylinder 141 is prevented. . Therefore, for example, by supporting and fixing the article to be moved to the end of the shaft body 144 of the linear motion guide device 140, the length of the shaft body 144 can be increased without rotating the article in the circumferential direction of the shaft body 144. It is possible to move smoothly in the vertical direction. Further, by rotating the outer cylinder 141 of the linear guide device 140, the outer cylinder 141 can be rotated together with the shaft body 144 on which the article is supported and fixed.

  It is preferable that 2 to 10 (particularly 3 to 6) linear grooves are formed on the inner peripheral surface of the outer cylinder. Similarly, it is preferable that 2 to 10 (particularly 3 to 6) linear grooves are formed on the outer peripheral surface of the shaft body.

  In order to prevent rotational movement of the shaft body 144 with respect to the outer cylinder 141, it is only necessary to include at least one of the linear groove 141a of the outer cylinder 141 and the linear groove 144a of the shaft body 144. FIG. It is particularly preferable that both straight grooves 141a and 144a are provided as shown in FIG.

  In addition, for example, when the linear motion guide device includes only the linear groove of the shaft body that accommodates the rolling element, a linear groove in which a protrusion is provided on the inner cylinder holding the rolling element and the protrusion is formed on the outer cylinder. By engaging with the shaft, the rotational movement of the shaft relative to the outer cylinder can be prevented.

  Next, the configuration and preferred embodiments of the present invention will be described in detail.

  As described above, the linear motion guide device of the present invention includes an outer cylinder having openings at both ends, a plurality of rolling elements disposed along the inner peripheral surface of the outer cylinder, and a length direction inside the outer cylinder. An inner cylinder that is rotatably disposed in a state in which the plurality of rolling elements protrude in the outer peripheral side and the inner peripheral side, and the plurality of rolling elements that are inserted into the inner cylinder. A shaft body whose outer peripheral surface is supported, and an annular lid body provided in each opening of the outer cylinder, and the wire rod is spiraled between the inner cylinder and at least one lid body. A coil spring formed by winding in a shape, and the coil springs are connected to each other by a relatively small load and contact each other with adjacent wires, and a relatively large load is applied to each other. And a second spring section that makes contact with adjacent wires. .

  The outer cylinder, the rolling element, and the shaft are usually formed from a metal material typified by steel. In addition, a resin material can be used to reduce the weight of the linear motion guide device, and a ceramic material can be used to improve heat resistance and corrosion resistance.

  As the rolling elements, balls (spheres) are usually used. Rollers can also be used as the rolling elements.

  There is no particular limitation on the number of rolling elements, but in order to stably support the shaft body, the plurality of rolling elements of the linear motion guide device are arranged at intervals along the length direction of the shaft body. Within a range of 2 to 10 (preferably 3 to 6) sets of rolling elements within the range of -50 (preferably 3 to 30) spaced apart from each other along the circumferential direction of the shaft It is preferable to include in the number of groups.

  The inner cylinder is set to an outer diameter smaller than the inner diameter of the outer cylinder, an inner diameter larger than the outer diameter of the shaft body, and a thickness smaller than the diameter of the rolling element.

  The inner cylinder is formed with a plurality of through holes that rotatably accommodate and hold the rolling elements. If the rolling elements that are rolling contact each other (collision) and stop, the smooth movement of the shaft supported by the rolling elements may be hindered. Therefore, there is no particular limitation on the number of rolling elements accommodated in each of the above-mentioned through holes, but it is preferable to reduce the number of rolling elements accommodated in each of the through holes as much as possible. The number of rolling elements accommodated in each through hole is preferably in the range of 1 to 5, more preferably in the range of 1 to 3, and particularly preferably 1. When the number of rolling elements accommodated in each through hole is one, it is preferable to use a circular hole or a long hole extending in the length direction of the inner cylinder as the through hole, and it is particularly preferable to use a circular hole. preferable. When the number of rolling elements accommodated in each through hole is plural, it is preferable to use a long hole extending in the length direction of the inner cylinder as the through hole.

  The inner cylinder is formed from, for example, a metal material or a resin material. As the metal material, it is preferable to use brass or stainless steel because machining at the time of forming each through hole of the inner cylinder (for example, the through hole 53a of the inner cylinder 53 shown in FIG. 5) is facilitated. As the resin material, for example, polyacetal resin, polyphenylene sulfide (PPS) resin, or polyether ether ketone (PEEK) resin is preferably used because the mechanical strength of the inner cylinder is increased.

  The inner diameter of the annular lid is smaller than the outer diameter of the coil spring and larger than the outer diameter of the shaft body (usually larger than the outer diameter of the shaft body) in order to prevent the coil spring from jumping out from the opening of the outer cylinder. ) Set to the inner diameter.

  However, in the linear motion guide device of the present invention, a coil spring may be installed only between the inner cylinder and one lid as will be described later. In this case, the inner diameter of the annular lid provided in the opening on the side where the coil spring of the outer cylinder is not installed is larger than the outer diameter of the inner cylinder in order to prevent the inner cylinder from protruding from the opening of the outer cylinder. Is set to an inner diameter smaller than the outer diameter of the shaft body (usually larger than the outer diameter of the shaft body).

  The lid is made of a metal material (typical example, iron) or a resin material. A rubber coating may be provided on the inner peripheral surface of the lid. In this case, the inner diameter of the lid body is made equal to the outer diameter of the shaft body (the rubber coating on the inner circumferential surface of the lid body is brought into contact with the outer circumferential surface of the shaft body), so that Intrusion can be suppressed.

  The lid may be formed integrally with the outer cylinder, or may be formed as a separate body from the outer cylinder. If the coil spring (or inner cylinder) can be prevented from protruding from the opening of the outer cylinder as described above, the annular lid body may be divided into a plurality of parts, or a part in the circumferential direction may be It may be removed (it may be set to a C shape).

  For example, in the case of the linear motion guide device 50 of FIG. 5, an annular lid body that is partly removed in the circumferential direction and set in a C shape (sometimes called a “retaining ring” or “slip ring”). 55 is used, and an inner peripheral surface of the opening of the outer cylinder 51 is formed with a peripheral groove 51a in which a part of the outer peripheral side of the lid 55 is accommodated. The lid body 55 is inserted into the inside from the opening of the outer cylinder 51 in a state in which a force is applied from the outer peripheral edge side and is elastically deformed so that the outer diameter is reduced. When the lid 55 reaches the circumferential groove 51a of the outer cylinder 51, the lid 55 returns to its original shape, and a part of the outer peripheral side thereof is accommodated in the circumferential groove 51a. When the lid has a continuous annular shape, a part of the outer peripheral side can be accommodated in the circumferential groove of the outer cylinder by press-fitting the lid into the inside from the opening of the outer cylinder. .

  As described above, the linear guide device of the present invention includes a coil spring formed by winding a wire rod in a spiral shape between the inner cylinder and at least one lid, and the coil spring is relatively And a first spring section that makes contact with adjacent wires by application of a small load and a second spring section that makes contact with wires adjacent to each other by application of a relatively large load. is there.

  The coil spring can be provided only between the inner cylinder and one lid body, or can be provided between the inner cylinder and each lid body. A compression coil spring is usually used as the coil spring.

  For example, when the linear motion guide device is used in a state where the shaft body is vertically arranged, if the shaft body is repeatedly raised and lowered, the inner cylinder holding the plurality of rolling bodies will continue to be affected by gravity (self-weight). Therefore, when the shaft body is subsequently placed at the initial position, the inner cylinder is often placed at a position below the initial position. In such a case, if a coil spring is provided only between the inner cylinder and the lower lid, the number of coil springs used is only one, which simplifies the configuration of the linear motion guide device and increases the manufacturing cost. Lower. In this case, a normal coil spring (hereinafter simply referred to as “normal coil spring”) having no first spring section and second spring section as described above is provided between the inner cylinder and the upper lid. It can also be provided.

  The coil spring is preferably provided between the inner cylinder and each lid. As a result, when the shaft body is repeatedly raised and lowered, the force to push back the inner cylinder toward the upper and lower center position (initial position) of the outer cylinder is continuously and well-balanced from each coil spring to the inner cylinder. Therefore, the relative positional relationship between the inner cylinder and the shaft body is extremely difficult to change.

  One end of the coil spring can be fixed to the lid. Similarly, the other end of the coil spring can be fixed to the inner cylinder. The coil spring may be integrally formed, or may be formed separately for each spring section. In the latter case, adjacent spring sections can also be fixed together.

  The coil spring may be formed by winding a wire in a right-handed manner, or may be formed by winding a wire in a left-handed manner. As described above, when the coil spring is provided between the inner cylinder and each lid, the wire material of one coil spring may be wound in a right-handed manner, and the wire material of the other coil spring may be wound in a left-handed manner.

  The coil spring can be formed from a metal material typified by steel, brass, phosphor bronze, for example, as in the case of a normal coil spring.

  Note that the shaft rod of the linear motion guide device may be moved either up or down (in the length direction). Therefore, the initial position of the inner cylinder is usually set at the center position in the length direction of the outer cylinder (the initial position of the shaft body means the position of the shaft body when the inner cylinder is arranged at the initial position). To do). Of course, the initial position of the inner cylinder can be set to a position different from the center position in the length direction of the outer cylinder.

  The coil spring includes a first spring section that makes contact with adjacent wires by applying a relatively small load, and a second spring section that makes contact with adjacent wires by applying a relatively large load. In the simplest case, when the load applied to the coil spring is gradually increased, the wires adjacent to each other in a part in the length direction of the coil spring are brought into contact with each other and the wires adjacent to each other in the remaining part. It can be confirmed whether or not a state in which no contact has occurred occurs. That is, when the above-described state occurs in the coil spring when the load applied to the coil spring is gradually increased, the coil spring comes into contact with adjacent wires by applying a relatively small load. It can be said that it includes a spring section and a second spring section that makes contact with adjacent wires by applying a relatively large load.

  In addition, when it is necessary to specify the first spring section and the second spring section of the coil spring (for example, as will be described later, the magnitude of the load that causes contact between adjacent wires of the first spring section, and In the case where it is necessary to compare the magnitude of the load that causes contact between the adjacent wires of the second spring section, for example, each section can be determined as follows.

  First, the coil spring is divided every time the wire turns twice (every two turns of wire). And a coil spring is divided | segmented for every division and a micro spring piece is produced. Next, a load is applied to each spring piece, and the load is gradually increased to obtain a load that causes contact between adjacent wires. Among the above-mentioned spring pieces, a section composed of spring pieces that come into contact with adjacent wires by applying the smallest load is defined as a first spring section, and contact with adjacent wires by applying the largest load. A section made up of spring pieces that generates the second spring section is defined.

  In the case where there are two or more spring pieces that come into contact with the adjacent wires by applying the smallest load, a section made of any of the spring pieces may be defined as the first spring section. Similarly, in the case where there are two or more spring pieces that come into contact with the adjacent wires by applying the largest load, a section made of any of the spring pieces may be defined as the second spring section.

  In addition, since the first spring section and the second spring section are determined by the magnitude relationship of the load as described above (relative relationship of the magnitude of the load), the spring pieces are brought into contact with adjacent wires. If the load measuring method is unified, a measuring method different from the above can be adopted.

  Further, if the shape of the spring piece constituting each section of the coil spring and the material of the wire are clear, it is possible to obtain the load causing contact between the wire pieces adjacent to each other for each spring piece by calculation. Therefore, the first spring section and the second spring section can be determined based on the magnitude relationship of the loads obtained by calculation. This method has the advantage that it is not necessary to cut the coil spring.

  In addition, as described in the following (A) to (D), when the coil spring has a specific configuration, the first spring section and the second spring section are determined by a simple method suitable for each. be able to.

  (A) When the cross-sectional area of the coil spring wire continuously decreases from one end of the coil spring to the other end (for example, in the case of the coil spring 61 shown in FIG. 5 or the coil spring 81 shown in FIG. 8) ): The first spring section is defined as a section on the other end side in which the coil spring is divided into three equal parts, and the second spring section is the one of the one in which the coil spring is divided into three equal parts. It is defined as a division on the end side.

  (B) When the space | interval of the wire rod which mutually adjoins a coil spring is increasing continuously from one edge part of the coil spring to the other edge part (for example, the case of the coil spring 91 shown in FIG. 9): 1st spring The section is defined as a section on the one end side obtained by dividing the coil spring into three equal parts, and the second spring section is a section on the other end side obtained by dividing the coil spring into three equal parts. It is determined.

  In addition, when using the coil spring of the structure described in the above (A) and (B), the contact between the adjacent wire rods in each section means that all the pairs of adjacent wire rods included in the same section are simultaneously wire rods. Is not meant to cause contact, but rather means at least one set of adjacent wires.

  (C) When the coil spring has a configuration in which two or more coil spring pieces each having a uniform cross-sectional area of the wire and different from each other are arranged in a line (for example, the coil spring 101 shown in FIG. 10 and the coil spring shown in FIG. (In the case of the coil spring 121 or the coil spring 131 shown in FIG. 13): The first spring section is defined as a section composed of coil spring pieces having the smallest cross-sectional area of the wire, and the second spring section has the cross-sectional area of the wire most. It is defined as a section consisting of large coil spring pieces.

  In addition, when there are two or more coil spring pieces having the smallest cross-sectional area of the wire, a section made of any of the coil spring pieces may be defined as the first spring section. Similarly, when there are two or more coil spring pieces having the largest cross-sectional area of the wire, a section made of any of the coil spring pieces may be defined as the second spring section.

  (D) When the coil spring has a configuration in which two or more coil spring pieces each having a uniform interval between adjacent wires and different from each other are arranged in a row (for example, in the case of the coil spring 111 shown in FIG. 11): The first spring section is defined as a section composed of coil spring pieces having the smallest wire spacing, and the second spring section is defined as a section comprising coil spring pieces having the largest wire spacing.

  In addition, when there are two or more coil spring pieces with the smallest interval between the wire rods, any of the coil spring pieces may be defined as the first spring section. Similarly, when there are two or more coil spring pieces having the largest interval between the wire rods, any one of the coil spring pieces may be defined as the second spring section.

  The magnitude of the load that causes contact between adjacent wires of the first spring section may be within a range of 20 to 80% of the magnitude of the load that causes contact between adjacent wires of the second spring section. preferable.

  When the magnitude of the load causing contact with the adjacent wires in the first spring section is set to a value of 20% or more of the magnitude of the load causing contact with the adjacent wires in the second spring section The distance that the shaft body can be moved with a relatively small force can be made sufficiently long. On the other hand, the magnitude of the load causing contact with the adjacent wires in the first spring section is set to a value of 80% or less of the magnitude of load causing contact with the adjacent wires in the second spring section. In this case, since the second spring section can support the inner cylinder while being sufficiently reduced even after contact with the wire of the first spring section, the inner cylinder and the inner cylinder The rolling elements that are held are difficult to stop.

  The value of the spring constant of the second spring section is preferably in the range of 1.2 to 10 times the spring constant of the coil spring, and more preferably in the range of 1.5 to 5 times. When such a condition is satisfied, the coil spring exhibits a sufficiently large spring constant after contact with the wire of the first spring section. Accordingly, since the coil spring strongly pushes back the inner cylinder toward the initial position by the large repulsive force, it is possible to more reliably prevent the contact between the inner cylinder and the lid.

  The value of the spring constant of the first spring section is preferably smaller than the value of the spring constant of the second spring section.

For example, when the coil spring (spring constant: k) is composed of a first spring section (spring constant: k ₁ ) and a second spring section (spring constant: k ₂ ), each spring constant is as follows: The relationship of Formula (1) is satisfied. Therefore, the value of the spring constant of the coil spring is smaller than the value of the spring constant of any spring section (the same applies when the coil spring includes another spring section).
Formula (1) 1 / k = 1 / k ₁ + 1 / k ₂

However, when the value of the spring constant of the first spring section is smaller than the value of the spring constant of the second spring section as described above, that is, when the relationship of k ₁ <k ₂ is satisfied, k ₁ > k Compared with the case where the relationship of ₂ is satisfied, the coil spring exhibits a large spring constant value after contact is made between the adjacent wires of the first spring section. Therefore, the inner cylinder can be strongly pushed back toward the initial position by the large repulsive force of the coil spring.

  More preferably, the value of the spring constant of the first spring section is in the range of 20 to 80% of the value of the spring constant of the second spring section.

  For example, in the case of the linear motion guide device 100 of FIG. 10, if the first spring section 101a and the second spring section 101b are respectively taken out from the coil spring 101, the spring constant of each spring section is the same as in the case of a normal coil spring. The relationship of the following formula (2) is satisfied.

Expression (2) k ₀ = (G × d ⁴ ) / (8 × Na × D ³ )
[In formula (2), k ₀ is a spring constant (N / mm), G is a transverse elastic modulus (kgf / mm ² ) (a constant determined by the type of the material of the wire), and d is the wire constant Is the diameter (mm), Na is the effective number of turns of the coil spring, and D is the average diameter (mm) of the coil. ]

  Accordingly, the magnitude of the spring constant of each spring section of the coil spring can be easily adjusted by setting the transverse elastic coefficient G, the wire diameter d, the effective number of turns Na of the coil spring, and the average diameter D of the coil.

  The magnitude of the spring constant of each spring section can be confirmed according to a test method defined in Japanese Industrial Standard (JIS B 2704).

  However, when confirming whether each spring category satisfies the above-mentioned relationship between the spring constants (relative relationship between the magnitudes of the spring constants), the spring constant test method for each spring category is unified. If so, a test method different from the above can be adopted.

  If the transverse elastic modulus G of each spring section, the wire diameter d, the effective number of turns Na of the coil spring, and the average diameter D of the coil are clear, the spring constant of each spring section can be calculated using the above equation (2). The value can also be obtained by calculation. Therefore, based on the spring constant obtained by calculation, it can also be confirmed whether each spring section satisfies the above-described magnitude relation of the spring constant. This method has the advantage that it is not necessary to cut the coil spring.

DESCRIPTION OF SYMBOLS 10 Linear motion guide apparatus 11 Outer cylinder 12 Rolling body 13 Inner cylinder 14 Shaft body 15 Cover body 40 Direct motion guide apparatus 41 Coil spring 50 Direct motion guide apparatus 51 Outer cylinder 51a Circumferential groove 52 Rolling body 53 Inner cylinder 53a Through-hole 54 Shaft body 55 Lid 61 Coil spring 61a First spring section 61b Second spring section 71a, 71b Coil spring piece 80, 90 Linear motion guide device 81, 91 Coil spring 81a, 91a First spring section 81b, 91b Second spring section 100 , 110 Linear motion guide device 101, 111 Coil spring 101a, 111a First spring segment 101b, 111b Second spring segment 102a, 102b Coil spring piece 112a, 112b Coil spring piece 120, 130 Linear motion guide device 121, 131 Coil spring 121a, 131a 1st spring section 121b, 131b 2nd Spring section 132a, 132b, 132c coil spring piece 140 linear motion guide device 141 outer cylinder 141a linear groove 142 rolling element 144 shaft body 144a linear groove

Claims (14)

An outer cylinder having openings at both ends, a plurality of rolling elements disposed along the inner peripheral surface of the outer cylinder, and the plurality of rolling elements disposed inside the outer cylinder so as to be movable in the length direction. An inner cylinder that rotatably holds the moving body in a state of protruding from the outer peripheral side and the inner peripheral side, a shaft body whose outer peripheral surface is supported by the plurality of rolling elements inserted into the inner cylinder, and the outer cylinder A linear motion guide device including an annular lid provided in each of the openings,
A coil spring formed by spirally winding a wire rod is provided between the inner cylinder and at least one lid, and the coil spring contacts the adjacent wire rods by applying a relatively small load. A linear motion guide device comprising: a first spring section that is generated; and a second spring section that is brought into contact with adjacent wires by applying a relatively large load.   The cross-sectional area of the coil spring wire continuously decreases from one end of the coil spring to the other end, and the first spring section is divided into three equal parts of the coil spring. 2. The linear motion guide device according to claim 1, wherein the second spring section is a section on the one end side of the coil spring divided into three equal parts.   The interval between the wire rods adjacent to each other in the coil spring is continuously increased from one end of the coil spring to the other end, and the first spring section is divided into three equal parts. 2. The linear motion guide device according to claim 1, wherein the second spring section is a section on the other end side of the coil spring divided into three equal parts.   The magnitude of the load that causes contact between adjacent wires of the first spring section is in the range of 20 to 80% of the magnitude of the load that causes contact between adjacent wires of the second spring section. The linear motion guide device according to 2 or 3.   The linear motion guide device according to any one of claims 2 to 4, wherein a value of a spring constant of the second spring section is in a range of 1.5 to 5 times a spring constant of the coil spring.   The linear motion guide device according to any one of claims 2 to 5, wherein a value of a spring constant of the first spring section is smaller than a value of a spring constant of the second spring section.   The coil spring has a configuration in which two or more coil spring pieces each having a uniform cross-sectional area of the wire rod and different cross-sectional areas are arranged in a line, and the first spring section is a coil spring piece having the smallest cross-sectional area of the wire rod. The linear guide device according to claim 1, wherein the second spring section comprises a coil spring piece having the largest cross-sectional area of the wire.   The coil spring has a configuration in which two or more coil spring pieces each having a uniform interval between adjacent wire rods and different from each other are arranged in a line, and the first spring section is a coil spring piece having the smallest wire rod interval. The linear guide device according to claim 1, wherein the second spring section is composed of a coil spring piece having the largest wire spacing.   The magnitude of the load that causes contact between adjacent wires of the first spring section is in the range of 20 to 80% of the magnitude of the load that causes contact between adjacent wires of the second spring section. The linear motion guide device according to 7 or 8.   The linear motion guide device according to any one of claims 7 to 9, wherein a value of a spring constant of the second spring section is in a range of 1.5 to 5 times a spring constant of the coil spring.   The linear motion guide device according to any one of claims 7 to 10, wherein a value of a spring constant of the first spring section is smaller than a value of a spring constant of the second spring section.   The linear motion guide device according to any one of claims 1 to 11, wherein a coil spring is provided between the inner cylinder and each lid.   The linear motion guide device according to any one of claims 1 to 12, wherein a plurality of linear grooves are formed on the inner peripheral surface of the outer cylinder to accommodate the rolling elements protruding toward the outer peripheral side of the inner cylinder.   The linear motion guide device according to any one of claims 1 to 13, wherein a plurality of linear grooves are formed on the outer peripheral surface of the shaft body to accommodate the rolling elements protruding toward the inner peripheral side of the inner cylinder.

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