JP2005098498A - Linear drive actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a linear drive actuator, producing no backlash between a contact body and a linear shaft even when the contact body or the linear shaft wears by automatically eliminating a clearance therebetween without increasing pre-load. <P>SOLUTION: The linear drive actuator A comprises the linear shaft 2 fixed to a base 1, a linear drive body 4 to be reciprocatingly movable on a linear raceway while being guided by the linear shaft 2, the contact bodies 6, 7 for contacting the linear shaft 2, and a pre-load device 8 provided on the linear drive body 4 for thrusting the contact body 7 with required force to give pre-load to the linear shaft 2. The pre-load device 8 has a thrust part 10 movable in the direction of contacting the contact body 7 and thrusting the contact body 7 against the linear shaft 2, an energizing member 20 for energizing the thrust part 10 toward the linear shaft 2, and a lock means for locking the thrust part 10 not to be moved in the direction of separating from the linear shaft 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a linear motion body that is guided by a linear shaft so as to be reciprocally movable on a linear track, or a linear motion device that includes a linear shaft that is reciprocally movable on a linear track.

  In a linear motion apparatus having a linear motion body that is guided by a linear axis such as a rail and can reciprocate (linearly move) on a linear track, a linear motion body has been conventionally used in order to smoothly move the linear motion with little play. A preload is applied between the shaft and the linear axis.

As an example of a conventional linear motion device, as described in Patent Document 1, a ball 3 is arranged between a linear shaft (track rail 1) and a linear motion body (sliding body 2), and the ball 3 rolls. Examples include those that enable the linear motion of the linear motion body using motion (Patent Document 1, paragraphs 0002, 0019, FIGS. 1 and 2). In this type of linear motion device, a means for fitting a ball having a size slightly larger than the clearance dimension between the linear shaft and the linear motion body is used to apply the preload between the linear motion body and the linear motion shaft. (Patent Document 1, paragraph 0002).
According to the preloading method in the linear motion device described in Patent Document 1, since the ball fills the clearance between the linear shaft and the linear motion body, it is possible to suitably suppress backlash, for example, a heavy load of several hundred kilograms or more. It can also be suitably used for the purpose of linearly transporting a feed.

  However, in the preload method of the type described in Patent Document 1, since a metal ball having a size larger than the gap dimension between the metal linear shaft and the linear motion body is inserted, the ball is deformed. In addition, the rolling resistance, that is, the linear motion resistance increases, and a large amount of energy is required for driving. In addition, high wear resistance is required for linear shafts, linear motion bodies, and balls. There is a problem that the manufacturing and processing costs of the apparatus increase, the apparatus becomes heavier, and more driving energy is required as the weight increases. In addition, in order to reduce the rolling resistance of the ball and prevent damage to the linear shaft, the linear motion body, and the ball, it is necessary to supply the ball lubricant frequently and in large quantities, and there is a problem that maintenance work and costs increase.

On the other hand, for example, when a low-weight delivery object of several hundred kilograms or less is linearly transferred, it is necessary to employ a high-weight and high-cost linear motion device such as the linear motion device described in Patent Document 1. Rather, for example, as described in Patent Document 2, a contact body (lubricating element) is moved from a linear motion body (guide carriage 12) to a linear shaft (guide rail 10) by a biasing member (compression coil spring 42). A linear motion device that presses the frame 26 and the rolling race lubrication element 34) to apply a preload to the linear shaft can be employed (Patent Document 2, FIGS. 1 and 2, paragraph 0078).
According to the preload method described in Patent Document 2, the operating resistance can be reduced as compared with the linear motion device described in Patent Document 1, and the manufacturing cost can be reduced by using a lighter material. There is an advantage that labor and cost can be suppressed.
JP 2002-122136 A (paragraphs 0002, 0019, FIGS. 1 and 2) Japanese Patent Laid-Open No. 7-54843 (FIGS. 1, 2 and paragraph 0078)

  However, in the linear motion device described in Patent Document 2, when a force larger than the urging force of the urging member (compression coil spring 42) is applied to the contact body (rolling raceway lubrication element 34), There is a problem that the biasing member is deformed, and the movement of the linear motion body (guide carriage 12) is loose.

In order to solve this problem, a method of increasing the preload by adopting a biasing member having a biasing force larger than the maximum force predicted to be applied to the contact body can be considered.
However, this increases the frictional resistance generated between the contact body and the linear shaft, which increases the linear motion resistance and increases the size of the urging member, which increases the cost and weight of the device. As a result, driving energy may need to be strengthened.

  The present invention has been made to solve the above-mentioned problems, and the object of the present invention is to automatically increase the clearance between the contact body and the linear shaft without increasing the preload and even if the contact body or the linear shaft is worn. Therefore, there is a need to provide a linear motion device that does not cause backlash.

In order to solve the above problems, a linear motion device according to the present invention has the following configuration. That is, a linear shaft fixed to the base body, a linear motion body that is guided by the linear shaft and is capable of reciprocating on a linear track, a contact body that contacts the linear shaft, and a linear motion body The linear motion apparatus includes a preload device that presses the contact body with a required force to apply a preload to the linear shaft, and the preload device contacts the contact body and presses the contact body against the linear shaft. A pressing portion that is movable in a direction, a biasing member that biases the pressing portion toward the linear axis, and a lock unit that locks the pressing portion so as not to move in a direction away from the linear axis. It is characterized by having.
Further, the base, a linear shaft that is guided by a guide portion provided on the base and is capable of reciprocating on a linear track, a contact body that contacts the linear shaft, the base is provided, In a linear motion device comprising a preload device that presses a contact body with a required force and applies a preload to the linear shaft, the preload device is in contact with the contact body and presses the contact body against the linear shaft. A movable pressing part; a biasing member that biases the pressing part toward the linear axis; and a lock unit that locks the pressing part so as not to move in a direction away from the linear axis. It is characterized by.
According to this, the preload device applies the preload by pressing the contact body against the linear shaft via the pressing portion by the biasing force of the biasing member, while against the force applied from the linear shaft toward the pressing portion. The locking means restricts the movement of the pressing portion in the direction away from the linear axis, that is, in the reverse direction of the urging force of the urging member. Therefore, even if a large force is applied to the contact body and the pressing portion, There is no clearance between the shaft and no backlash. Moreover, since the force applied to the pressing portion from the linear shaft is supported by the stress of the locking means, it is not necessary to increase the preload applied by the urging member. Further, even if the linear shaft or the contact body is worn and reduced, the pressing portion and the contact body move toward the linear axis by the urging force of the urging member, and the movement is irreversible by the locking means. The clearance does not occur between the contact body and the linear shaft, and no play is generated.

Further, the lock means constitutes the pressing portion, and a piston rod that contacts the contact body directly or via a transmission member on one end side, a piston fixed to the piston rod, and the piston rod are in contact with each other A cylinder having a first sealed chamber in which the volume is reduced and a second sealed chamber in which the volume is increased by moving the piston in conjunction with the piston rod as it moves in the direction of pressing the body; An inter-chamber communication path that communicates the first sealed chamber and the second sealed chamber, a fluid filled in the first sealed chamber, the second sealed chamber, and the inter-chamber communication path, and the inter-chamber communication path And a check valve that is provided in the fluid chamber and prevents the fluid from flowing from the first sealed chamber to the second sealed chamber but from flowing from the second sealed chamber to the first sealed chamber. It is characterized by.
Further, the first sealed chamber and the second sealed chamber are formed on both sides of the piston.
According to this, since the fluid can flow into the second sealed chamber from the first sealed chamber, the pressing portion is allowed to move in the direction of pressing the contact body, while the second sealed chamber is moved to the first sealed chamber. Since the inflow of the fluid becomes impossible by the action of the check valve, the contact body cannot move in the direction away from the linear axis (the direction opposite to the direction in which the contact body is pressed), and the locking means is realized. .

The check valve is detachably provided in the inter-chamber communication path.
Normally, due to the action of the locking means, the piston rod moves only in one direction and cannot move in the reverse direction. Therefore, the piston rod once moved is returned to the original position, and the preload device is reused. I can't do it. However, if the check valve is detachably provided, the check valve can be removed from the inter-chamber communication path so that the locking means does not act. Therefore, the preload device can be reused by moving the piston rod in the reverse direction.

A first outdoor communication passage that communicates the first sealed chamber with the outside of the cylinder; a second outdoor communication passage that communicates the second sealed chamber with the outside of the cylinder; and the first and second outdoor communication passages. It has a detachable plug member that closes the passage.
According to this, by removing the plug member, the first and second sealed chambers can be communicated with the outside of the cylinder so that the locking means does not act. Therefore, the preload device can be reused by returning the piston rod in the reverse direction.

The piston rod is provided such that the other end side is exposed to the outside of the cylinder, and the piston rod is formed with a hollow portion that opens to the other end, and the first sealed chamber and the hollow portion A first hole communicating with the second sealed chamber and a second hole communicating with the hollow portion, and the other end side of the hollow portion with respect to the other end side than the first and second hole portions. A plug member having a closed portion for closing the hollow portion toward the surface and an extending portion extending from the closed portion between the first hole portion and the second hole portion of the hollow portion is detachably provided. The check valve is disposed between the outer peripheral surface of the extending portion and the inner peripheral surface of the hollow portion.
According to this, by removing the plug member, the check valve can be removed from the inter-chamber communication passage, and the first and second hole portions can be communicated to the outside through the other end of the hollow portion. Can be prevented from working. Therefore, the preload device can be reused by easily returning the piston rod in the reverse direction.

The first sealed chamber is formed on the contact body side with respect to the piston, the second sealed chamber is formed on the opposite side, and the piston is provided with an opening that opens on the second sealed chamber side, In the second sealed chamber of the cylinder, a shaft member whose tip is loosely entered into the opening is provided, a third hole communicating the first sealed chamber and the opening, the opening, and the The inter-chamber communication path is formed by a gap between the outer peripheral surface of the shaft member and the inner wall surface of the opening. The shaft member communicates with the opening and is open to the outer end surface of the cylinder. And a fourth hole portion that communicates the second sealed chamber and the hollow portion, and a plug member that closes the fourth hole portion is detachably provided in the hollow portion. It is characterized by.
According to this, by attaching and detaching the plug member, the first sealed chamber can be communicated and closed to the outside through the third hole, the opening, and the hollow portion of the shaft member, and the second sealed chamber can be It can be communicated and closed to the outside through the four holes and the hollow part. Therefore, the locking means can be easily prevented from acting, and the preload device can be reused by returning the piston rod in the reverse direction.

Further, the second sealed chamber is formed on the contact body side with respect to the piston, and the first sealed chamber is formed on the opposite side, and the piston is provided with an opening that opens on the first sealed chamber side, In the first sealed chamber of the cylinder, a shaft member whose tip is loosely entered into the opening is provided, a third hole communicating the second sealed chamber and the opening, the opening, and the The inter-chamber communication path is formed by a gap between the outer peripheral surface of the shaft member and the inner wall surface of the opening. The shaft member communicates with the opening and is open to the outer end surface of the cylinder. And a fourth hole portion that communicates the first sealed chamber and the hollow portion, and a plug member that closes the fourth hole portion is detachably provided in the hollow portion. It is characterized by.
According to this, by attaching and detaching the plug member, the second sealed chamber can be communicated and closed to the outside via the third hole, the opening, and the hollow portion of the shaft member, It can be communicated and closed to the outside through the four holes and the hollow part. Therefore, the locking means can be easily prevented from acting, and the preload device can be reused by returning the piston rod in the reverse direction.

The urging member is provided in the cylinder and urges the piston rod or the piston.
According to this, the preload device can be reduced in size.

Further, the biasing member is provided in the first or second sealed chamber.
According to this, the preload device can be further downsized.

Further, the pressing portion is configured to be movable in a direction in which the contact body is pressed and to be non-rotatable with respect to the preloading device main body, and is brought into contact with the contact body directly or via a transmission member at one end side. A first screw member having a screw part formed on the other end side and a screw part screwed with the screw part of the first screw member are formed and rotated in a predetermined rotation direction with respect to the preload device body. A second screw member that moves the first screw member in a direction of pressing the contact body by the screw portion, and the biasing member has one end on the preload device and the other end on the second screw member. A spiral spring which is fixed to the second screw member and biases the second screw member in the predetermined rotation direction, and the locking means is constituted by a screw portion into which the first and second screw members are screwed together. Features.
According to this, the second screw member is urged in the predetermined rotation direction so that the first screw member screwed with the screw portion of the second screw member can be moved in the direction of pressing the contact body. On the other hand, since the first screw member is supported by the screw portion, the first screw member does not move from the contact body toward the first screw member due to the pressing force applied in the axial direction of the screw portion, thereby realizing the locking means.

Further, the preload device is coaxial with the second screw member, and is provided to be rotatable with respect to the preload device main body, and the rotating body is allowed to rotate in the predetermined rotation direction. A ratchet device that does not rotate in the direction opposite to the predetermined rotation direction, and the spiral spring is wound when the one end is fixed to the rotation body and the rotation body is rotated in the predetermined rotation direction. Accordingly, the second screw member is biased in the predetermined rotation direction.
According to this, the spiral spring is wound by rotating the rotating body in a predetermined direction, and it becomes possible to appropriately adjust the biasing force of the spiral spring serving as a preload to the linear shaft. In addition, since no preload is generated unless the spiral spring is wound, the first screw member of the pressing portion is not irreversibly moved, and the preload device can be easily handled.

In addition, when the guide member is removed, the first screw member is provided with a removable guide member that can move in the direction in which the contact body is pressed and that cannot rotate with respect to the preload device main body. The first screw member can be rotated by the user.
Normally, due to the action of the locking means, the first screw member moves only in one direction and cannot move in the reverse direction. Therefore, the first screw member once moved is returned to the original position, and the preload device is moved. Cannot be reused. However, if the guide member is made detachable and the first screw member is rotated so that the position of the first screw member can be returned to the original position, the first screw member is returned to the original position, and the preload device is restarted. It can be used.

In addition, the contact body is a roller device.
According to this, the frictional resistance of the contact body with the linear axis can be reduced.

According to the linear motion device according to the present invention, even when the contact body or the linear shaft is worn, the clearance between the contact body and the linear shaft is automatically eliminated, and no play occurs.
Further, even if a large force is applied to the contact body from the linear shaft, the locking means prevents the clearance between the linear shaft and the contact body, so that a biasing member that applies a preload like a conventional linear motion device. There is no need to increase the size. Therefore, the linear motion device can be configured to be light and inexpensive.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of a linear motion device according to the invention will be described in detail with reference to the accompanying drawings.

1 is an explanatory perspective view of a linear motion device A according to a first embodiment of the present invention, FIG. 2 is a front view, and FIG. 3 is a side view.
The linear motion device A includes a linear shaft 2 having both ends fixed to the base body 1 and functioning as a rail, and a linear motion body 4 guided by the linear shaft 2 so as to be reciprocally movable on a linear track, Roller devices 6 and 7 as contact bodies that come into contact with the linear shaft 2 and a preload device 8 that is provided on the linear motion body 4 and presses the roller device 7 against the linear shaft 2 with a required force to apply a preload to the linear shaft 2. With.

  The linear shaft 2 as a rail is formed in a cylindrical shape having a hexagonal cross section. The material is a lightweight metal such as an aluminum alloy, which is preferably formed by extrusion.

  The linear motion body 4 is formed in a rectangular tube shape whose cross section is larger than the cross section of the linear axis 2, and is disposed so as to surround the linear axis 2.

  A roller device 6 is attached to one inner wall of the linear motion body 4. The roller device 6 includes a base portion 6 a fixed to the one inner wall of the linear motion body 4, and rollers 6 b provided so as to be rotatable with respect to the base portion 6 a and in contact with two adjacent outer surfaces of the linear shaft 2. The rollers 6b are provided so as to contact two adjacent surfaces of the linear shaft 2 two by two. The roller 6b has a ball bearing or the like inside, and can rotate smoothly.

Further, a roller device 7 and a preload device 8 are attached to a wall portion of the linear motion body 4 facing the inner wall to which the roller device 6 is attached.
The preload device 8 is fixed to the outer wall surface of the wall portion of the linear motion body 4 facing the inner wall to which the roller device 6 is attached. An opening is formed in the wall portion of the linear motion body 4 to which the preload device 8 is attached, and the pressing portion 10 (see FIG. 3) of the preload device 8 is inward of the wall portion of the linear motion body 4 through the opening portion. It protrudes.
The roller device 7 is provided with a base 7a fixed to the pressing portion 10 of the preloading device 8 and a base 7a so as to be rotatable. The roller device 7 is adjacent to the surface of the linear shaft 2 facing the roller 6b. It consists of the roller 7b which contact | abuts to an outer surface, respectively. The rollers 7b are provided so as to contact two adjacent surfaces of the linear shaft 2 two by two. The roller 7b has a ball bearing or the like inside, and can rotate smoothly.

With the above configuration, the linear motion device A is configured so that the linear motion body 4 serves as the guide portion and the contact body in a state in which a preload corresponding to the pressing force by the pressing portion 10 of the preload device 8 is applied from the linear motion body 4 to the linear shaft 2. Guided by the roller devices 6, 7, it can reciprocate linearly on a linear track along the linear axis 2.
In order to make the linear motion body 4 self-run, a drive device such as a motor is separately incorporated in the linear motion body 4 and a roller 6b or a roller 7b (or another drive roller provided separately) that contacts the linear shaft 2 is provided. What is necessary is just to provide so that it may rotate.

Next, the configuration of the preload device 8 according to the first embodiment will be described in detail.
FIG. 4 is a perspective explanatory view of the preload device 8 in a state of being removed from the linear motion device A. FIG.
The preload device 8 has a cylindrical cylinder 12, an attachment portion 14 in which a screw hole 14 a is formed when attached to the linear motion body 4, and a tip projecting from the cylinder 12 is in direct contact with the roller device 7. And a piston rod 18 constituting the pressing portion 10 that can move toward and away from the linear shaft 2 by moving in and out.

FIG. 5 shows a perspective sectional view of the preload device 8.
The cylinder 12 includes a wall portion 12a that closes an end portion on the roller device 7 (contact body) side, a wall portion 12b that closes the other end portion on the roller device 7 side, and a wall portion 12a and a wall portion 12b. A wall portion 12c that divides the space therebetween is provided.

Between the wall portion 12b and the wall portion 12c in the cylinder 12, a spring chamber 12d in which a coil spring 20 that urges the piston rod 18 toward the linear axis 2 is housed is formed.
One end of the coil spring 20 abuts on the inner surface of the wall portion 12b and the other end abuts on a projecting peripheral portion 18d protruding along the outer periphery of the piston rod 18 so that the piston rod 18 is moved in the direction of the roller device 7 (on the linear shaft 2). Energize in the direction of heading.

On the other hand, an oil chamber filled with oil as a fluid is formed between the wall 12a and the wall 12c in the cylinder 12. The internal space of the oil chamber is divided by a piston 16 provided so as to protrude from the outer periphery of the piston rod 18 and fixed to the piston rod 18, and the first sealed chamber 12e is provided on the roller device 7 side of the piston 16 on the opposite side. A second sealed chamber 12f is defined. In other words, the first sealed chamber 12e and the second sealed chamber 12f are formed on both sides of the piston 16.
Thereby, as the piston rod 18 moves in the direction in which the piston rod 18 presses the roller device 7 against the linear shaft 2 (the direction in which the piston rod 18 protrudes from the cylinder 12), the piston 16 approaches the wall portion 12a. The volume is reduced. On the other hand, as the piston rod 18 moves in the direction of pressing the roller device 7 against the linear shaft 2, the volume of the second sealed chamber 12f is increased as the piston 16 moves away from the wall portion 12c.

The piston rod 18 passes through the cylinder 12, and the other end side of the end portion on the roller device 7 side is exposed to the outside of the cylinder 12. The piston rod 18 is formed with a hollow portion 18a that opens to the other end.
Further, the piston rod 18 is formed with a first hole portion 18b that communicates the hollow portion 18a and the first sealed chamber 12e. The first sealed chamber 12e side of the first hole 18b communicates with the side of the piston 16 on the roller device 7 side.
Further, the piston rod 18 is formed with a second hole portion 18c that communicates the hollow portion 18a and the second sealed chamber 12f. The second sealed chamber 12f side of the second hole portion 18c communicates with the other side of the piston 16 on the roller device 7 side.
The first hole portion 18b, the hollow portion 18a, and the second hole portion 18c constitute an inter-chamber communication path that connects the first sealed chamber 12e and the second sealed chamber 12f.

The preloading device 8 has a plug member 22 that can be inserted into and removed from the hollow portion 18a through the opening at the other end of the hollow portion 18a.
The plug member 22 includes a closed portion 22a that closes the other end side of the first and second holes 18b and 18c of the hollow portion 18a, and the first hole 18b and the second hole of the hollow portion 18a from the closed portion 22a. An extending portion 22b extending between the hole portion 18c and having a check valve 22c is formed between the outer peripheral surface and the inner peripheral surface of the hollow portion 18a.

A screw part is formed on the outer peripheral part of the blocking part 22a, and the plug member 22 is attached to the hollow part 18a by screwing with the screw part formed on the inner peripheral part of the hollow part 18a. The other end side of the first and second holes 18b and 18c is closed. The plug member 22 can be attached to and detached from the threaded portion by inserting a flat screwdriver into a groove 22d formed at the end of the closing portion 22a and rotating it.
Further, a slight clearance through which oil can pass is formed between the outer peripheral surface of the extending portion 22b and the inner peripheral surface of the hollow portion 18a, and the clearance is filled with a check valve 22c. ing. The check valve 22c is configured by a ring-shaped elastic member having a Y-shaped cross section. The one of the check valve 22c divided into two Y-shaped branches is directed toward the first sealed chamber 12e, so that the first sealed chamber 12e, the second sealed chamber 12f, and the inter-chamber communication path are disposed inside. The filled oil flows from the first sealed chamber 12e to the second sealed chamber 12f, but does not flow from the second sealed chamber 12f to the first sealed chamber 12e.

The first sealed chamber 12e, the second sealed chamber 12f, and the inter-chamber communication path are filled with oil.
When oil is introduced into the first sealed chamber 12e, the second sealed chamber 12f, and the inter-chamber communication path, air is sucked from the opening of the hollow portion 18a of the piston rod 18 with the plug member 22 removed. The first sealed chamber 12e, the second sealed chamber 12f, and the communication path between the chambers are evacuated, and the negative pressure is used to suck oil from the opening of the hollow portion 18a. In addition, oil can be injected into the second sealed chamber 12f and the inter-chamber communication path so as not to mix air.

  In the state where the plug member 22 is removed, the first hole 18b serves as a first outdoor communication passage that communicates the first sealed chamber 12e with the outside of the cylinder 12 through the hollow portion 18a, and the second hole 18c The second sealed chamber 12f is a second outdoor communication passage that communicates with the outside of the cylinder 12 through the hollow portion 18a.

Further, a check valve 24 formed in a ring shape with a Y-shaped cross section is provided at the sliding contact portion of the walls 12a, 12c with the piston rod 18, and the oil in the first and second sealed chambers 12e, 12f is provided. Is provided so as not to leak out of the walls 12a, 12c.
In addition, a check valve 26 formed in a ring shape with a Y-shaped cross section is provided at the sliding contact portion of the piston 16 with the cylinder 12, and oil leaks from the second sealed chamber 12f to the first sealed chamber 12e. Not to be provided.

The preload device 8 of the first embodiment is in a state in which the piston rod 18 is most retracted with respect to the cylinder 12 (a state where the piston rod 18 is farthest away from the linear shaft 2) as shown in FIG. 6 before use. Set to In other words, the piston 16 is in contact with the wall 12c so that the first sealed chamber 12e has the largest volume and the second sealed chamber 12f has the smallest volume.
In this state, in order to prevent the second hole 18c from being blocked by the wall 12c and preventing the oil from flowing from the second hole 18c to the second sealed chamber 12f, A notch 12ca that escapes the opening of the second hole 18c is formed. The wall 12a also has a notch 12aa that escapes the opening of the first hole 18b so that the wall 12a does not block the first hole 18b even when the piston 16 contacts the wall 12a. Is formed.

  The preload device 8 is attached to the linear motion body 4 of the linear motion device A through the screw hole 14a of the mounting portion 14 with the piston rod 18 retracted most with respect to the cylinder 12 as shown in FIG. 18 is brought into contact with the base 7 a of the roller device 7. Then, the biasing force of the coil spring 20 is moved until it is pushed by the piston rod 18 and the roller 7 b of the roller device 7 comes into contact with the linear shaft 2. During this time, the piston 16 moves to the linear shaft 2 side (the roller device 7 side), whereby the volume of the first sealed chamber 12e is reduced and the volume of the second sealed chamber 12f is increased, and the oil passes through the inter-chamber communication path. Flow from the first sealed chamber 12e to the second sealed chamber 12f. The coil spring 20 presses the roller 7 b against the linear shaft 2 by the biasing force, so that a preload is applied from the linear motion body 4 to the linear shaft 2.

  The preload device 8 applies a preload by pressing the linear shaft 2, while the force applied to the piston rod 18 from the linear shaft 2 toward the preload device 8 is changed from the second sealed chamber 12f to the first sealed chamber 12e. Since the inflow of the oil becomes impossible by the action of the check valve 22c, the piston 16, and thus the piston rod 18 and the roller device 7 are separated from the linear shaft 2 (reverse to the direction of pressing the linear shaft 2). Direction), and the locking means is realized. In particular, since liquid oil is used as the fluid, the volume of the fluid in the first and second sealed chambers 12e and 12f does not fluctuate due to an external force, and the piston rod 18 moves in a direction away from the linear shaft 2. Are preferably locked.

According to the present preloading device 8, since the movement of the piston rod 18 in the direction away from the linear shaft 2, that is, the reverse direction of the urging force of the coil spring 20, is restricted by the locking means, the roller device 7 and the piston rod 18 are controlled. Even if a large force is applied to the roller device, there is no clearance between the roller device 7 and the linear shaft 2, and therefore no play is generated.
Further, since the force applied from the linear shaft 2 to the roller device 7 and the piston rod 18 is supported by the stress of the locking means, it is not necessary to increase the preload applied by the coil spring 20.
Further, even if the linear shaft 2 or the rollers 6b and 7b are worn down, the piston rod 18 and the roller device 7 are moved toward the linear shaft 2 by the urging force of the coil spring 20, and the movement is Since the movement is irreversible by the locking means, there is no clearance between the rollers 6b and 7b and the linear shaft 2, and no play occurs.

Incidentally, in the linear motion device A, for example, when performing maintenance work or repair work, it may be necessary to remove the linear motion body 4 from the linear shaft 2 or to remove the preload device 8 from the linear motion body 4. In such a case, the piston rod 18 is urged toward the roller device 7 side (side protruding with respect to the cylinder 12) by the coil spring 20, and thus operates and protrudes until the piston 16 contacts the wall portion 12a. However, due to the locking means, it cannot be returned to the original position (FIG. 6) by external force.
Therefore, when it is desired to return the piston rod 18 to the original position, the stopper member 22 is removed to remove the check valve 22c attached to the stopper member 22 from the inter-chamber communication path, so that the locking means does not act. What should I do? If it does so, the piston rod 18 can be moved to the reverse direction to the roller apparatus 7 side, and can be returned to the original position.
In addition, in a state where the plug member 22 is removed, it can be said that the first outdoor communication path and the second outdoor communication path are communicated with the outside of the cylinder 12, thereby preventing the locking means from acting.

  After the position of the piston rod 18 is restored, air is sucked from the opening of the hollow portion 18a of the piston rod 18 with the plug member 22 removed, and the first sealed chamber 12e, the second sealed chamber 12f, and the inter-chamber link. The inside of the passage is evacuated, and the negative pressure is used to suck oil from the opening of the hollow portion 18a, whereby air is introduced into the first sealed chamber 12e, the second sealed chamber 12f, and the inter-chamber communication passage. By injecting oil so as not to be mixed and attaching the plug member 22 again, the preload device 8 can function as it was.

The preload device 8 used in the linear motion device A of the first embodiment is not limited to the above configuration, and can be replaced with a preload device having another configuration.
Next, a second embodiment in which a preload device 30 is used instead of the preload device 8 as the linear motion device A will be described.
FIG. 7 is a perspective view of the preload device 30 according to the second embodiment.
The preload device 30 includes a cylindrical cylinder 32, a screw portion 34 formed on the outer periphery of the cylinder 32 as an attachment portion when attached to the linear motion body 4, and a tip directly contacting the roller device 7. It has a piston rod 38 constituting the pressing portion 10 that can move toward and away from the linear shaft 2 by moving in and out.

FIG. 8 shows a perspective sectional view of the preload device 30.
The cylinder 32 is provided with a wall portion 32a that closes an end portion on the roller device 7 side, and a cylinder member 32b that forms a wall portion that closes the other end portion of the end portion on the roller device 7 side.

Between the wall part 32a in the cylinder 32 and the cylinder member 32b, an oil chamber filled with oil as a fluid is formed. The internal space of the oil chamber is divided by a piston 36 that is provided so as to protrude from the outer periphery of the piston rod 38 and is fixed to the piston rod 38, and a first sealed chamber 32 e is provided on the roller device 7 side of the piston 36, and on the opposite side. A second sealed chamber 32f is defined. In other words, the first sealed chamber 32e and the second sealed chamber 32f are formed on both sides of the piston 36.
Thereby, as the piston rod 38 moves in the direction in which the piston rod 38 presses the roller device 7 against the linear shaft 2 (the direction in which the piston rod 38 protrudes from the cylinder 32), the piston 36 approaches the wall portion 32a. The volume is reduced. On the other hand, as the piston rod 38 moves in the direction of pressing the roller device 7 against the linear shaft 2, the volume of the second sealed chamber 32f increases as the piston 36 moves away from the cylinder member 32b.

A coil spring 40 that urges the piston 36 (piston rod 38) toward the linear axis 2 is accommodated in the second sealed chamber 32 f in the cylinder 32.
The coil spring 40 has one end abutting against a projecting peripheral portion 32ba projecting from a peripheral wall of a shaft member 44 (described later) of the cylinder member 32b and the other end abutting against the piston 36, thereby causing the piston 36 to move toward the roller device 7 (linear shaft 2). In the direction toward the).

  The piston 36 is fixed to the other end of the end of the piston rod 38 on the roller device 7 side, and an opening 36a that opens to the second sealed chamber 32f side is formed on the end surface so as to surround the other end. The The piston 36 is formed with a third hole 36b that communicates the opening 36a and the first sealed chamber 32e.

Further, a shaft member 44 extending in the direction of the piston 36 and loosely entering the opening 36a is provided integrally with the cylinder member 32b at the center of the cylinder member 32b. The shaft member 44 is provided substantially coaxially with the cylinder member 32b.
The inter-chamber communication path is formed by the third hole 36b, the opening 36a, and a gap between the outer peripheral surface of the shaft member 44 and the inner wall surface of the opening 36a. Further, the shaft member 44 has a check valve 44a between the outer peripheral surface and the inner peripheral surface of the opening 36a.
A slight clearance through which oil can pass is formed between the outer peripheral surface of the shaft member 44 and the inner peripheral surface of the opening 36a. The clearance is filled with a check valve 44a. The check valve 44a is configured by a ring-shaped elastic member having a Y-shaped cross section. The one of the check valve 44a divided into two Y-shaped branches is disposed toward the first sealed chamber 32e, so that the first sealed chamber 32e, the second sealed chamber 32f, and the inter-chamber communication path are disposed inside. The filled oil flows from the first sealed chamber 32e to the second sealed chamber 32f, but does not flow from the second sealed chamber 32f to the first sealed chamber 32e.

The shaft member 44 has a small-diameter hollow portion 44c that communicates with the opening 36a along the axis, and a small-diameter hollow portion 44c that communicates with the small-diameter hollow portion 44c and has a larger diameter than the small-diameter hollow portion 44c. An open large-diameter hollow portion 44d is formed.
The third hole portion 36b, the opening portion 36a, the small-diameter hollow portion 44c, and the large-diameter hollow portion 44d constitute a first outdoor communication path that communicates the first sealed chamber 32e with the outside of the cylinder 32.
Further, the shaft member 44 has a fourth hole portion 44b that communicates the second sealed chamber 32f and the large-diameter hollow portion 44d of the shaft member 44, and the second chamber outside that communicates the second sealed chamber 32f to the outside of the cylinder 32. It is formed as a communication path.

Furthermore, a plug member 42 that closes the small-diameter hollow portion 44c and the fourth hole portion 44b is detachably provided in the large-diameter hollow portion 44d.
The plug member 42 is in contact with a step portion on the inner periphery of the large-diameter hollow portion 44d and the small-diameter hollow portion 44c from the large-diameter hollow portion 44d side, and between the large-diameter hollow portion 44d and the small-diameter hollow portion 44c. A packing 42b for sealing and closing, and a packing 42c for sealing and closing between the fourth hole portion 44d (second outdoor communication path) and the opening of the large-diameter hollow portion 44d are provided. By attaching the plug member 42, the first and second outdoor communication paths are closed from the outside. A screw portion is formed on the outer peripheral portion of the plug member 42, and a screw formed on the inner peripheral portion of the large-diameter hollow portion 44d by rotating a slotted screwdriver in a groove portion (not shown) formed on the end portion 42a. And is detachably attached in the large-diameter hollow portion 44d.

The first sealed chamber 32e, the second sealed chamber 32f, and the inter-chamber communication path are filled with oil.
When oil is introduced into the first sealed chamber 32e, the second sealed chamber 32f, and the inter-chamber communication path, the opening of the shaft member 44 (opening of the large-diameter hollow portion 44d) with the plug member 42 removed. The air is sucked in from the first sealed chamber 32e, the second sealed chamber 32f, and the communication path between the chambers, and the negative pressure is used to suck oil from the opening of the shaft member 44. Oil can be injected into the first sealed chamber 32e, the second sealed chamber 32f, and the inter-chamber communication path so that air is not mixed.

  As shown in FIG. 8, the preload device 30 is attached to the linear motion body 4 of the linear motion device A by being screwed by the screw portion 34 with the piston rod 38 being most retracted with respect to the cylinder 32. Is brought into contact with the base 7 a of the roller device 7.

  The preload device 30 according to the second embodiment, like the preload device 8 according to the first embodiment, applies a preload by pressing the linear shaft 2 by the biasing force of the coil spring 40, while the force applied from the linear shaft 2 toward the preload device 8. On the other hand, since the inflow of oil from the second sealed chamber 32f to the first sealed chamber 32e is disabled by the action of the check valve 44a, the piston 36, and hence the piston rod 38 and the roller device 7, It cannot move in the direction away from the linear shaft 2 (the direction opposite to the direction in which the linear shaft 2 is pressed), and the locking means is realized.

In the preload device 30, when it is desired to return the piston rod 38 to the original position, the plug member 42 is removed to remove the first outdoor communication path (the third hole portion 36 b, the opening portion 36 a, the small-diameter hollow portion 44 c and the large-diameter hollow portion 44 c). The diameter hollow portion 44d) and the second outdoor communication path (fourth hole portion 44b) may be communicated with the outside of the cylinder 32. Then, oil and outside air can freely enter and leave the first and second sealed chambers 32e and 32f, and the locking means by the check valve 44a does not act, so that the piston rod 38 is connected to the roller device 7. It can be moved in the opposite direction to the side and returned to its original position.
After returning, the air is sucked from the opening of the shaft member 44 with the plug member 42 removed, and the first sealed chamber 32e, the second sealed chamber 32f, and the inside of the inter-chamber communication path are evacuated, and the negative pressure Using this, oil may be sucked from the opening of the shaft member 44.

Next, a description will be given of a third embodiment in which a preload device 50 is adopted as the linear motion device A in place of the preload device 8 described above.
FIG. 9 is a perspective view of the preload device 50 according to the third embodiment.
The preloading device 50 includes a cylindrical main body (housing) 52, an attachment portion 54 formed with a screw hole 54a when attached to the linear motion body 4, and a tip protruding from the main body 52 directly contacting the roller device 7. And a first screw member 58 constituting a pressing portion that can move toward and away from the linear shaft 2 by moving in and out of the main body 52.

FIG. 10 is an assembly view of the preload device 50, and FIG. 11 is a perspective sectional view of the preload device 50.
The first screw member 58 is movable in the direction in which the roller device 7 is pressed and is not rotatable with respect to the preload device main body 52. One end is in contact with the roller device 7 and a female screw portion 58a is formed at the other end. Has been. The first screw member 58 is formed so that the cross-sectional shape of the distal end portion is formed by cutting out a part of an arc, and an opening 64 a that matches the shape is formed, and is passed through a guide member 64 fixed to the main body 52. Thus, the main body 52 is held so as to be able to advance and retreat and not to rotate. The guide member 64 is detachably attached to the female screw portion 54b of the attachment portion 54 of the main body 52 by a screw through the screw hole 64b.

  As shown in FIG. 11, a ball bush 68 (not shown in FIG. 10) that smoothly guides the advancing and retreating operation of the first screw member 58 is provided in a portion around the first screw member 58 in the main body 52. ) Is provided. In FIG. 11, a ball that is provided in the ball bush 68 and contacts the outer peripheral surface of the first screw member 58 is not shown.

  Further, the preload device 50 is formed with a male screw portion 56a that is screwed with the female screw portion 58a of the first screw member 58, and is rotatable with respect to the preload device main body 52 and cannot be advanced or retracted in the direction of the roller device 7. A second screw member 56 is provided that moves in the direction of pressing the roller device 7 by the male screw portion 56a by rotating in a predetermined rotation direction.

  The second screw member 56 is formed with two disk-like portions 56b and 56b that are coaxial with the screw portion 56a. A spiral spring 60 as an urging member is held between the two disk-like portions 56b and 56b. The end portion on the inner peripheral side of the spiral spring 60 is attached and fixed to a shaft portion 56c that connects between the centers of the disk-like portions 56b and 56b.

  The preload device 50 is disposed coaxially with the second screw member 56 so as to surround the two disk-like portions 56 b and 56 b and the spiral spring 60, and is provided so as to be rotatable with respect to the preload device main body 52. A body 62 is provided. The other end of the one end of the spiral spring 60 is fixed to the inner peripheral portion of the rotating body 62. The rotating body 62 is formed in a cylindrical shape having one end opened and the other end closed. On the outer surface of the wall portion that closes the other end side of the rotating body 62, a surface that faces in one rotational direction is formed along the circumferential direction so that the surface that faces in the other rotational direction is almost vertical. A number of protrusions 62a, 62a,... Are formed. Further, a claw member 66 fixed to the main body 52 is in sliding contact with the outer surface of the wall portion of the rotating body 62, and the ratchet that allows the rotating body 62 to rotate only in the predetermined direction together with the protrusions 62a, 62a,. A device (ratchet mechanism) is configured.

As shown in FIG. 11, the preload device 50 according to the third embodiment has the female screw portion 58a of the first screw member 58 and the male screw portion 56a of the second screw member 56 screwed in most deeply as shown in FIG. The first screw member 58 is set in the most retracted state with respect to the main body 52 (the most separated state with respect to the linear shaft 2).
The preload device 50 is attached to the linear motion body 4 of the linear motion device A through the screw hole 54a of the mounting portion 54 in a state where the first screw member 58 is most retracted with respect to the main body 52 as shown in FIG. The tip of the first screw member 58 is brought into contact with the base portion 7 a of the roller device 7.

  In the preload device 50 according to the third embodiment, the second screw member 56 is urged to rotate by the urging force of the spiral spring 60, but the user rotates the rotating body 62 in the predetermined direction to cause the spiral spring 60 to rotate. Since the urging force of the spiral spring 60 does not work until winding, there is no inconvenience that the first screw member 58 comes out of the main body 52 and cannot be returned when the preload device 50 is attached. Compared with the preload devices 8 and 30 of the second embodiment, it is easier for the user to handle.

When the preload device 50 is attached to the linear moving body 4, the rotating body 62 is rotated to wind the spiral spring 60 in the predetermined direction. Then, the second screw member 56 is urged and rotated in the predetermined direction by the urging force of the spiral spring 60, and the first screw member 58 is pushed out toward the roller device 7 by the screw portions 56a and 58a. When the roller 7b and the linear shaft 2 come into contact with each other, the movement of the first screw member 58 is stopped, so that the rotation of the second screw member 56 is stopped, and the spiral spring 60 remains biased by the second screw member 56. Stop at. In this state, the first screw member 58 is continuously pushed toward the linear shaft 2 by the urging force of the spiral spring 60, and preload is applied from the linear motion body 4 to the linear shaft 2.
Further, since the degree of winding of the spiral spring 60 changes and the urging force changes depending on the number of rotations that rotate the rotating body 62, the preload can be appropriately adjusted according to the convenience of the user.

The preload device 50 applies the preload by pressing the linear shaft 2, while the first screw member 58 is not moved to the preload device 50 side by the force applied from the linear shaft 2 toward the preload device 8. This is because the first screw member 58 and the second screw member 56 are screwed together by the screw portions 56 a and 58 a, so that the linear force applied in the axial direction of the first screw member 58 and the second screw member 56 is This is because no torque is generated to rotate the second screw member 56 via the screw portions 56a and 58a.
That is, the locking means for locking the first screw member 58 (pressing portion 10) so as not to move in the direction away from the linear shaft 2 by the screw portions 58a and 56a to which the first and second screw members 58 and 56 are screwed. Is configured.

According to the preload device 50 of the third embodiment, the locking means (screw portions 58a, 56a) causes the first screw member 58 (pressing portion 10) to move away from the linear axis 2, that is, the biasing force of the spiral spring 60. Since movement in the reverse direction is restricted, there is no clearance between the roller device 7 and the linear shaft 2 even if a large force is applied to the roller device 7 and the first screw member 58, and thus play is generated. There is no.
Moreover, since the force applied to the roller device 7 and the first screw member 58 from the linear shaft 2 is supported by the stress of the locking means (first and second screw members 58 and 56 and screw portions 58a and 56a), the spiral spring 60 Therefore, it is not necessary to increase the preload applied.
Further, even if the linear shaft 2 or the rollers 6b and 7b are worn and reduced, the second screw member 56 is rotated by the urging force of the spiral spring 60, and the first screw member 58 (pressing portion 10) and the roller device 7 are moved. Since it moves toward the linear shaft 2 by the amount of wear, and the movement is irreversible by the locking means, there is no clearance between the rollers 6b, 7b and the linear shaft 2, and play occurs. There is nothing.

Next, a fourth embodiment of the present invention will be described.
12 is a front view of a linear motion device B according to Embodiment 4 of the present invention, FIG. 13 is a side view, and FIG. 14 is a perspective sectional explanatory view.
The linear motion device B is formed on a rail member 70 fixed to a base body 69, and a linear shaft 72 having a function as a rail and a linear shaft 72 guided by the linear shaft 72 so as to be reciprocally movable on a linear track. The moving body 74 and roller devices 76 and 77 as contact bodies that come into contact with the linear shaft 72 and the linear motion body 74 are provided. The roller device 77 is pressed against the linear shaft 72 with a required force, and the linear shaft 72 is preloaded. And a preload device 78 for applying.

  The linear shaft 72 as a rail is formed in a C-shaped cross section. The material is a lightweight metal such as an aluminum alloy, and it is preferable that the material is formed integrally with the rail member 70 by extrusion molding.

  The linear motion body 74 is formed in the shape of a long plate having a trapezoidal cross section, and the short side of the trapezoid (in the cross section) faces the C-shaped opening of the linear shaft 72, and the longitudinal direction is arranged along the linear axis 72 Is done.

  A roller device 76 is attached to the wall forming the oblique side of the cross section of the linear motion body 74. The roller device 76 is provided so as to abut on each outer edge portion of the C-shaped opening in the cross section of the linear shaft 72 in a line in the longitudinal direction of the linear motion body 74. The roller device 76 has a ball bearing or the like inside, and can rotate smoothly.

A preload device 78 is attached (fixed) to the long side surface of the linear motion body 74 opposite to the short side of the cross section. The preload device 78 is disposed at an intermediate portion of the roller device 76 that is disposed side by side in the longitudinal direction of the linear motion body 74.
The linear moving body 74 is formed with an opening penetrating from the long side surface to the short side surface, and the pressing portion 80 of the preload device 78 includes the opening of the linear moving body 74 and the linear shaft 72. The linear shaft 72 extends inwardly through the C-shaped opening.
The roller device 77 is provided at the distal end portion of the pressing portion 80 with a base 77a fixed with screws or the like, and is rotatable with respect to the base portion 77a. It comprises two rollers 77b provided so as to be in contact with each other. The roller 77b has a ball bearing or the like inside and can rotate smoothly.

  The preload device 78 urges the pressing portion 80 toward the main body of the preload device 78, thereby pressing the roller device 77 against the linear shaft 72 with a required force to apply preload.

With the above configuration, the linear motion device B is applied with a preload corresponding to the pressing force (the force that pulls the pressing portion 80 by the biasing member) from the linear motion body 74 to the linear shaft 72 by the pressing portion 80 of the preloading device 78. The linear motion body 74 is guided by the roller devices 76 and 77 as the guide portion and the contact body, and can reciprocate linearly on the linear track along the linear axis 72.
In order to make the linear motion body 74 self-run, a drive device such as a motor is separately incorporated in the linear motion body 74, and a roller device 76 or a roller device 77 that abuts on the linear shaft 72 (or another drive roller provided separately). The roller of the apparatus may be provided so as to be rotationally driven.

FIG. 15 is a perspective sectional view of the preload device 78 of the fourth embodiment.
In the preloading device 78 of the fourth embodiment, the piston rod 88 as the pressing portion 80 is urged in the direction opposite to the preloading device 8 of the first embodiment (the direction in which the piston rod 88 is pulled into the cylinder 82), and the roller as the contact body As a positional relationship with respect to the device 7, the first sealed chamber 82 f and the second sealed chamber 82 e are provided so as to be opposite to the preload device 8 of the first embodiment. As a result, the preload device 78 according to the fourth embodiment is biased in the direction in which the piston rod 88 is retracted with respect to the cylinder 82, and the movement in the protruding direction is locked.

Hereinafter, the configuration of the preload device 78 of the fourth embodiment will be described in detail.
The preload device 78 includes a cylindrical cylinder 82, a mounting portion 84 in which a screw hole 84 a is formed when mounted on the linear motion body 74, and a roller device 77 fixed to the tip protruding from the cylinder 82. And a piston rod 88 that constitutes a pressing portion 80 that can move the roller device 77 toward and away from the linear shaft 72 (moving in the direction in which the linear shaft 72 is pressed).

  The cylinder 82 includes a wall portion 82a that closes an end portion on the roller device 77 (contact body) side, a wall portion 82b that closes the other end portion on the roller device 77 side, and a wall portion 82a and a wall portion 82b. A wall portion 82c is provided for partitioning the space therebetween.

Between the wall part 82b and the wall part 82c in the cylinder 82, there is a coil spring 90 that urges the piston rod 88 in a direction (upward in the drawing) in which the roller device 77 presses the linear shaft 72. A spring chamber 82d to be housed is formed.
One end of the coil spring 90 is in contact with the inner surface of the wall portion 82c and the other end is in contact with a projecting peripheral portion 88d that protrudes along the outer periphery of the piston rod 88. The shaft 72 is biased in the pressing direction.

On the other hand, an oil chamber filled with oil as a fluid is formed between the wall 82a and the wall 82c in the cylinder 82. The internal space of the oil chamber is divided by a piston 86 provided so as to protrude from the outer periphery of the piston rod 88 and fixed to the piston rod 88, and a second sealed chamber 82e is provided on the roller device 77 side of the piston 86 on the opposite side. A first sealed chamber 82f is defined. In other words, the second sealed chamber 82e and the first sealed chamber 82f are formed on both sides of the piston 86.
Thereby, as the piston rod 88 moves in the direction in which the piston rod 88 presses the roller device 77 against the linear shaft 72 (direction in which the piston rod 88 is pulled into the cylinder 82), the piston 86 approaches the wall portion 82c. The volume is reduced. On the other hand, as the piston rod 88 moves in the direction of pressing the roller device 77 against the linear shaft 72, the volume of the second sealed chamber 82e is increased as the piston 86 moves away from the wall portion 82a.

The piston rod 88 passes through the cylinder 82, and the other end side of the end portion on the roller device 77 side is exposed outside the cylinder 82. The piston rod 88 is formed with a hollow portion 88a that opens to the other end.
Further, the piston rod 88 is formed with a first hole 88b that communicates the hollow portion 88a and the first sealed chamber 82f. The second sealed chamber 82e side of the first hole 88b communicates with the other surface side of the piston 86 on the roller device 77 side.
Further, the piston rod 88 is formed with a second hole 88c that communicates the hollow portion 88a and the second sealed chamber 82e. The second sealed chamber 82e side of the second hole 88c communicates with the side of the piston 86 on the roller device 77 side.
The first hole portion 88b, the hollow portion 88a, and the second hole portion 88c constitute an inter-chamber communication path that communicates the second sealed chamber 82e and the first sealed chamber 82f.

Further, the preload device 78 has a plug member 92 that can be inserted into and removed from the hollow portion 88a through the opening at the other end of the hollow portion 88a.
The plug member 92 includes a closed portion 92a for closing the other end side of the first and second hole portions 88b and 88c of the hollow portion 88a, and a first hole portion 88b and a second portion of the hollow portion 88a from the closed portion 92a. An extending portion 92b having a check valve 92c is formed between the outer peripheral surface and the inner peripheral surface of the hollow portion 88a.

A screw portion is formed on the outer peripheral portion of the closing portion 92a, and the plug member 92 is attached to the hollow portion 88a by screwing with a screw portion formed on the inner peripheral portion of the hollow portion 88a. The other end side is closed from the first and second hole portions 88b and 88c. The plug member 92 can be attached to and detached from the screw portion by inserting a flathead screwdriver into a groove 92d formed at the end of the closing portion 92a and rotating it.
Further, a slight clearance through which oil can pass is formed between the outer peripheral surface of the extension portion 92b and the inner peripheral surface of the hollow portion 88a. The clearance is filled with a check valve 92c. ing. The check valve 92c is configured by a ring-shaped elastic member having a Y-shaped cross section. The one of the check valve 92c that is divided into two Y-shaped branches is directed toward the second sealed chamber 82e, so that the second sealed chamber 82e, the first sealed chamber 82f, and the communication path between the chambers are disposed. The filled oil flows from the second sealed chamber 82e to the first sealed chamber 82f, but does not flow from the first sealed chamber 82f to the second sealed chamber 82e.

The second sealed chamber 82e, the first sealed chamber 82f, and the inter-chamber communication path are filled with oil.
When oil is introduced into the second sealed chamber 82e, the first sealed chamber 82f, and the inter-chamber communication path, air is sucked from the opening of the hollow portion 88a of the piston rod 88 with the plug member 92 removed. The second sealed chamber 82e, the first sealed chamber 82f, and the communication path between the chambers are put in a vacuum state, and the negative pressure is used to suck oil from the opening of the hollow portion 88a, whereby the second sealed chamber 82e. The oil can be injected into the first sealed chamber 82f and the inter-chamber communication path so that air is not mixed.

  When the plug member 92 is removed, the first hole 88b serves as a first outdoor communication path that communicates the first sealed chamber 82f to the outside of the cylinder 82 through the hollow portion 88a, and the second hole 88c The second closed chamber 82e serves as a second outdoor communication passage that communicates with the outside of the cylinder 82 through the hollow portion 88a.

In addition, a check valve 94 formed in a ring shape with a Y-shaped cross section is provided at a sliding contact portion between the wall portions 82a and 82c and the piston rod 88, and oil in the second and first sealed chambers 82e and 82f is provided. Is provided so as not to leak out of the walls 82a and 82c.
Further, a check valve 96 formed in a ring shape with a Y-shaped cross section is provided at the sliding contact portion of the piston 86 with the cylinder 82, and oil leaks from the second sealed chamber 82e to the first sealed chamber 82f. Not to be provided.

The preload device 78 according to the fourth embodiment is set to a state in which the piston rod 88 protrudes most from the cylinder 82 (a state in which the roller device 77 is farthest from the linear shaft 72) before use. In other words, the piston 86 is set in contact with the wall 82a so that the first sealed chamber 82f has the largest volume and the second sealed chamber 82e has the smallest volume.
In this state, in order to prevent the second hole 88c from being blocked by the wall 82a and preventing the oil from flowing from the second hole 88c into the second sealed chamber 82e, A notch 82aa that escapes the opening of the second hole 88c is formed. In addition, when the piston 86 contacts the wall portion 82c, the wall portion 82c also has a notch portion 82ca that escapes the opening of the first hole portion 88b so that the wall portion 82c does not block the first hole portion 88b. Is formed.

  The preload device 78 is attached to the linear motion body 74 of the linear motion device B through the screw hole 84a of the mounting portion 84 with the piston rod 88 protruding most with respect to the cylinder 82, and the base portion 77a of the roller device 77. Attached to. Then, the biasing force of the coil spring 90 is pulled by the piston rod 88 and moved until the roller 77 b of the roller device 77 contacts the linear shaft 72. During this time, the piston 86 moves to the linear shaft 72 side (the roller device 77 side), thereby reducing the volume of the first sealed chamber 82f and increasing the volume of the second sealed chamber 82e, and the oil passes through the inter-chamber communication path. Then flows from the first sealed chamber 82f to the second sealed chamber 82e. The coil spring 90 presses the roller 77 b against the linear shaft 72 by the biasing force, so that a preload is applied from the linear motion body 74 to the linear shaft 72.

  The preload device 78 applies a preload by pressing the linear shaft 72, while the force applied to the piston rod 88 from the linear shaft 72 toward the preload device 78 is changed from the second sealed chamber 82e to the first sealed chamber 82f. Since the inflow of the oil becomes impossible by the action of the check valve 92c, the roller device 77 becomes immovable in the direction away from the linear shaft 72 (the direction opposite to the direction in which the linear shaft 72 is pressed). Is realized. In particular, since liquid oil is used as the fluid, the volume of the fluid in the first and second sealed chambers 82f and 82e is not changed by an external force, and the piston rod 88 moves in a direction away from the linear shaft 72. Are preferably locked.

  Therefore, the present preload device 78 can provide the same operational effects as the preload device of the first embodiment.

Next, a third embodiment in which the preload device 100 is used instead of the preload device 78 as the linear motion device B will be described.
FIG. 16 is a perspective sectional view of the preload device 100 according to the fifth embodiment.
In addition, since the preload device 100 of the fifth embodiment has substantially the same structure as the preload device 30 of the second embodiment, the same configuration as the preload device 30 of the second embodiment is denoted by the same reference numerals and described. Is omitted.

The configuration of the preload device 100 according to the fifth embodiment is different from the configuration of the preload device 30 according to the second embodiment in the arrangement of the coil spring 140 and the direction of the check valve 144a.
The coil spring 100 is disposed in the sealed chamber 32e on the contact body (roller device 77) side (the projecting side of the piston rod 38) of the two sealed chambers 32e and 32f divided by the piston 36, and one end is in contact with the coil spring 100. The body abuts against the body-side wall portion 32a, the other end abuts against the piston 36, and urges the piston 36 in the opposite direction to the contact body side.
The check valve 144a, contrary to the preload device 30 of the second embodiment, allows oil to flow from the sealed chamber 32f to the sealed chamber 32e, but does not allow oil to flow from the sealed chamber 32e to the sealed chamber 32f. It is arranged so that there is no.

According to the linear motion device B of the fifth embodiment in which the preload device 78 of the fourth embodiment is replaced with the preload device 100, the piston rod 38 as the pressing portion 80 is urged in the direction of being pulled into the cylinder 32. Thus, the roller device 77 can be pressed against the linear shaft 72 to give a preload. According to the configuration of the preload device 100, contrary to the preload device 30 of the second embodiment, the sealed chamber 32 f functions as a first sealed chamber and the sealed chamber 32 e functions as a second sealed chamber, and the piston rod 38 is The movement in the direction protruding from the cylinder 32 (the direction in which the roller device 77 is separated from the linear shaft 72) is locked. Therefore, the present preload device 100 can obtain the same operational effects as the preload device 78 of the fourth embodiment.
Note that claim 9 of the present application corresponds to the preload device 78 of the fifth embodiment (the preload device of claim 9 is the reverse of the first sealed chamber and the second sealed chamber in claim 8 corresponding to the second embodiment). It is the composition that became).

Next, a description will be given of a sixth embodiment in which a preload device having another configuration is adopted as the linear motion device B in place of the preload device 78 described above.
The preload device according to the sixth embodiment is the same as the preload device 50 according to the third embodiment shown in FIGS. 9 to 11 except that the screw portions 58a and 56a of the first and second screw members 58 and 56 are the preload device 50 according to the third embodiment. Is a reverse screw.

  According to the preload device of the sixth embodiment, when the second screw member 56 is rotated in the predetermined rotation direction by the biasing force of the spiral spring 60, the screw portions 58a, 56a of the first and second screw members 58, 56 are used. As a result, the first screw member 58 is pulled into the preloading device main body, contrary to the preloading device 50 of the third embodiment.

Therefore, according to the linear motion device B of the sixth embodiment in which the preload device 78 of the fourth embodiment is replaced with a preload device in which the screw directions of the screw portions 58a and 56a are reversed, the first screw member as the pressing portion 80 is used. 58 is biased in the direction of being pulled into the preloading device body, and the roller device 77 can be pressed against the linear shaft 72 to apply preloading.
At the same time, the screw portions 58 a and 56 a that are screwed together constitute a lock means that locks the roller device 77 as a contact body so as not to move in a direction away from the linear shaft 72.

The present embodiment (Examples 1 to 6) is linear motion devices A and B in which linear motion bodies 4 and 74 are linearly moved along linear axes 2 and 72 fixed to bases 1 and 69. Further, a guide portion such as a roller device or a preload device may be provided on the base, and the linear shaft may be guided by the guide portion so as to move linearly. Even in this case, the preload devices of Examples 1 to 6 described in the above embodiment can be used as a preload device that applies preload from the base to the linear shaft.
For example, as shown in FIG. 17, roller devices 6, 7 and a preload device 8 are provided on the base 11 as guide portions and contact bodies, and the linear shaft 13 is guided by the roller devices 6, 7 so as to move linearly. You may do it.

Further, in the present embodiment, the piston rods 18, 38, 88 and the first screw member 58 constituting the pressing portions 10, 80 of the preload device are in direct contact with the roller device 7 as a contact body. The present invention is not limited to this configuration.
For example, another transmission member is provided between the piston rod 18, 38, 88 or the first screw member 58 and the contact body (roller device 7, 77), and the contact body is indirectly pressed through the transmission member. You may comprise so that it may carry out.

According to the linear motion device according to the present invention, even when the contact body or the linear shaft is worn, the clearance between the contact body and the linear shaft is automatically eliminated, and no play occurs.
Further, even if a large force is applied to the contact body from the linear shaft, the locking means prevents the clearance between the linear shaft and the contact body, so that a biasing member that applies a preload like a conventional linear motion device. There is no need to increase the size. Therefore, the linear motion device can be configured to be light and inexpensive.

It is a perspective view of the linear motion apparatus A which concerns on embodiment of this invention. It is a front view of the linear motion apparatus A which concerns on embodiment of this invention. It is a side view of the linear motion apparatus A which concerns on embodiment of this invention. 1 is a perspective view of a preload device 8 of Example 1. FIG. 1 is a perspective sectional view of a preload device 8 of Example 1. FIG. It is a perspective sectional view showing the initial state of preload device 8 of Example 1. FIG. It is a perspective view of the preload apparatus 30 of Example 2. FIG. It is a perspective sectional view of the preload device 30 of the second embodiment. It is a perspective view of the preload apparatus 50 of Example 3. FIG. FIG. 5 is an assembly diagram of a preload device 50 according to a third embodiment. It is a perspective sectional view of preload device 50 of Example 3. It is a front view of the linear motion apparatus B which concerns on embodiment of this invention. It is a side view of the linear motion apparatus B which concerns on embodiment of this invention. It is a perspective sectional view of linear motion apparatus B concerning an embodiment of the invention. It is a perspective sectional view of preload device 78 of Example 4. It is a perspective sectional view of preloader 100 of Example 5. It is a perspective view which shows the linear motion apparatus comprised so that it may guide to the guide part provided in the base | substrate and a linear axis may linearly move.

Explanation of symbols

A, B Linear motion device 1, 11, 69 Base body 2, 13, 72 Linear shaft 4, 74 Linear motion body 6, 76 Roller device (guide part)
7,77 Roller device (guide section, contact body)
8, 30, 50, 78, 100 Preload device 10, 80 Pressing portion 12, 32, 82 Cylinder 12e, 82f First sealed chamber 12f, 82e Second sealed chamber 14, 34, 54, 84 Mounting portion 16, 36, 86 Piston 18, 38, 88 Piston rod (pressing part)
18a, 88a Hollow portion 18b, 88b First hole portion 18c, 88c Second hole portion 20, 40, 90, 140 Coil spring (biasing member)
22, 42, 92 Plug member 22a, 92a Blocking portion 22b, 92b Extension portion 22c, 44a, 92c, 144a Check valve 32e First sealed chamber (second sealed chamber in the fourth embodiment)
32f Second sealed chamber (first sealed chamber in Example 4)
36a Opening 36b 3rd hole 44 Shaft member 44b 4th hole 52 Preloader main body 54b Female screw part (For attachment of guide member)
56 Second screw member 56a Male screw part (thread part)
58 First screw member (pressing part)
58a Female thread (thread)
60 Spiral spring (biasing member)
62 Rotating body 64 Guide member 64a Opening 64b Screw hole 66 Claw member

Claims (15)

A linear axis fixed to the substrate;
A linear motion body guided by the linear shaft and provided so as to be able to reciprocate on a linear track;
A contact body in contact with the linear axis;
A linear motion device comprising: a preload device that is provided on the linear motion body, presses the contact body with a required force, and applies a preload to the linear shaft;
The preload device is
A pressing portion that contacts the contact body and is movable in a direction of pressing the contact body against the linear axis;
A biasing member that biases the pressing portion toward the linear axis;
A linear motion device comprising: locking means for locking the pressing portion so as not to move in a direction away from the linear shaft. A substrate;
A linear shaft that is guided by a guide portion provided on the base body and is reciprocally movable on a linear track;
A contact body in contact with the linear axis;
In a linear motion device provided with the preload device provided on the base body and pressing the contact body with a required force to preload the linear shaft,
The preload device is
A pressing portion that contacts the contact body and is movable in a direction of pressing the contact body against the linear axis;
A biasing member that biases the pressing portion toward the linear axis;
A linear motion device comprising: locking means for locking the pressing portion so as not to move in a direction away from the linear shaft. The locking means is
A piston rod that constitutes the pressing portion and abuts the contact body directly or via a transmission member on one end side;
A piston fixed to the piston rod;
As the piston rod moves in the direction of pressing the contact body, the piston moves in conjunction with the piston rod, so that the first sealed chamber in which the volume is reduced and the second sealed chamber in which the volume is increased. A cylinder having
A communication path between the chambers communicating the first sealed chamber and the second sealed chamber;
Fluid filled in the first sealed chamber, the second sealed chamber, and the inter-chamber communication path;
A check provided in the communication path between the chambers, wherein the fluid flows from the first sealed chamber to the second sealed chamber but does not flow from the second sealed chamber to the first sealed chamber. The linear motion device according to claim 1, further comprising a valve.   The linear motion device according to claim 3, wherein the first sealed chamber and the second sealed chamber are formed on both sides of the piston.   The linear motion device according to claim 3 or 4, wherein the check valve is detachably provided in the inter-chamber communication path. A first outdoor communication path communicating the first sealed chamber with the outside of the cylinder;
A second outdoor communication passage communicating the second sealed chamber to the outside of the cylinder;
The linear motion device according to claim 3, further comprising a detachable plug member that closes the first and second outdoor communication paths. The piston rod is provided such that the other end side is exposed outside the cylinder,
The piston rod has a hollow portion that opens to the other end, communicates the first sealed chamber and the hollow portion, and communicates the second sealed chamber and the hollow portion. A second hole to be formed,
In the hollow portion, a closed portion for closing the hollow portion toward the other end side from the first and second hole portions, and from the closed portion, the first hole portion and the second hole portion of the hollow portion. A plug member having an extending portion extending between and detachable,
The linear motion device according to claim 3 or 4, wherein the check valve is disposed between an outer peripheral surface of the extension portion and an inner peripheral surface of the hollow portion. The first sealed chamber is formed on the contact body side with respect to the piston, and the second sealed chamber is formed on the opposite side, respectively.
The piston is provided with an opening that opens to the second sealed chamber side,
A shaft member is provided in the second sealed chamber of the cylinder, the tip of which loosely enters the opening,
The inter-chamber communication path is formed by a third hole communicating the first sealed chamber and the opening, the opening, and a gap between the outer peripheral surface of the shaft member and the inner wall surface of the opening. And
The shaft member is formed with a hollow portion that communicates with the opening portion and opens at an outer end surface of the cylinder, and a fourth hole portion that communicates the second sealed chamber and the hollow portion,
The linear motion device according to claim 4, wherein a plug member that closes the fourth hole portion is detachably provided in the hollow portion. The second sealed chamber is formed on the contact body side with respect to the piston, and the first sealed chamber is formed on the opposite side, respectively.
The piston is provided with an opening that opens to the first sealed chamber side,
A shaft member is provided in the first sealed chamber of the cylinder, the tip of which loosely enters the opening,
The inter-chamber communication path is formed by a third hole communicating the second sealed chamber and the opening, the opening, and a gap between the outer peripheral surface of the shaft member and the inner wall surface of the opening. And
The shaft member is formed with a hollow portion that communicates with the opening portion and opens at an outer end surface of the cylinder, and a fourth hole portion that communicates the first sealed chamber and the hollow portion,
The linear motion device according to claim 4, wherein a plug member that closes the fourth hole portion is detachably provided in the hollow portion.   The linear motion device according to claim 3, wherein the biasing member is provided in the cylinder and biases the piston rod or the piston.   The linear motion device according to claim 10, wherein the biasing member is provided in the first or second sealed chamber. The pressing portion is configured to be movable in a direction of pressing the contact body and to be non-rotatable with respect to the preloading device main body, and is in contact with the contact body directly or via a transmission member at one end side, and the other end A first screw member having a thread portion formed on the side;
A threaded portion that is screwed with the threaded portion of the first threaded member is formed, and rotates in a predetermined rotation direction with respect to the preloading device main body, thereby pressing the contact body against the first threaded member by the threaded portion. A second screw member that is moved in a direction to
The biasing member is a spiral spring having one end fixed to the preload device and the other end fixed to the second screw member, and biasing the second screw member in the predetermined rotation direction,
The linear motion device according to claim 1, wherein the locking means is constituted by a threaded portion in which the first and second screw members are screwed together. The preload device is
A rotating body provided coaxially with the second screw member and rotatably with respect to the preloading device main body;
A ratchet device that allows the rotating body to rotate in the predetermined rotation direction, but does not rotate in a direction opposite to the predetermined rotation direction;
The one end of the spiral spring is fixed to the rotating body, and the rotating body is wound when the rotating body is rotated in the predetermined rotation direction, and biases the second screw member in the predetermined rotation direction. The linear motion device according to claim 12. A detachable guide member that guides the first screw member to be movable in a direction of pressing the contact body and to be non-rotatable with respect to the preload device main body,
The linear motion device according to claim 12 or 13, wherein when the guide member is detached, a user can rotate the first screw member.   The linear motion device according to claim 1, wherein the contact body is a roller device.

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