JP2006038190A - Rack and pinion device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rack and pinion device superior in durability, by preventing the situation of not meshing when a rack runs on a pinion, when meshing the rack moving in the longitudinal direction with the pinion. <P>SOLUTION: This rack and pinion device meshes the rack 1 moving in the longitudinal direction with the pinion 2, and is formed into a structure for pushing a first tooth r1 against the pinion 2 by rocking a separate member 1B, by arranging a support shaft 3 in the rear of the first tooth r1, by rockably supporting this separate member 1B by the support shaft 3 parallel to a rotary shaft of the pinion 2, by forming a front end part including the first tooth r1 of the rack 1 into the separate member 1B. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rack and pinion device that converts rotational motion into linear motion, and a transport device that uses this device.

  When the rack that moves in the longitudinal direction is meshed with the pinion, the top of the first tooth of the rack may abut the top of the tooth of the pinion, the rack may ride on the pinion, and the rack and the pinion may not mesh. In order to prevent this climbing, a rack and pinion device has been proposed in which a pin that can be advanced and retracted in the tooth height direction is provided in front of the first tooth of the rack, and this pin is urged by an elastic member in its axial direction (patent) Reference 1).

  In this device, a pin provided in front of the first tooth of the rack presses the tooth surface of the pinion to rotate the pinion, and by this rotation, the subsequent tooth of the pinion is engaged with the first tooth of the rack. Move. Also, when the top of the pin abuts the top of the pinion tooth, the associated pin retracts in the axial direction to allow the pinion to rotate, and the subsequent tooth of the pinion meshes with the first tooth of the rack Move to position.

  However, this device is inferior in the reliability of preventing the rack from climbing up. That is, when the top part of the pin abuts against the top part of the pinion tooth, the pin may be inclined with respect to the axial direction due to the frictional force generated at the abutment part, and may not smoothly advance and retreat.

Moreover, this apparatus is inferior in durability. That is, the pin provided in front of the first tooth of the rack receives a force in a direction orthogonal to the axial direction. However, the advancing and retracting mechanism that supports the pin so as to advance and retract is structurally weak against a force in a direction orthogonal to the pin. Therefore, this device has a problem of poor durability.

Japanese Patent Laid-Open No. 2-150536

  The problem to be solved by the present invention is to provide a rack and pinion device that reliably prevents a situation where the rack rides on the pinion and does not mesh when the rack that moves in the longitudinal direction is meshed with the pinion, and that is excellent in durability. It is.

  In order to solve the above problems, in a rack and pinion device in which a rack moving in the longitudinal direction is meshed with a pinion and this pinion is driven by a rotary drive mechanism and fed to the rack, the rack first of the rack is connected to the pinion. The front end portion including the first tooth meshing with the first pinion is formed as a separate member, and the separate member is supported by a support shaft parallel to the rotation shaft of the pinion so as to be swingable, and the support shaft is disposed rearward of the first tooth. The separate member is swung to press the first teeth against the pinion.

Such a rack and pinion device is more preferable when the following configuration is added.
1) The distance from the first tooth of the rack to the next tooth is a distance corresponding to twice the inter-tooth pitch of the pinion.
2) The rack is disposed above the pinion, the support shaft is disposed behind the center of gravity of the separate member, and the separate member swings by its own weight to press the first tooth against the pinion. With structure.
3) A slow speed means for delaying the peripheral speed of the pinion immediately before the first teeth of the rack mesh with the teeth of the pinion is slower than the moving speed of the rack.

This slow speed means is preferably configured as shown below.
1) Release means for releasing the drive of the pinion is provided, and the drive of the pinion is released by the release means until the first tooth of the rack is engaged with the tooth of the pinion, and the first tooth of the rack The peripheral speed of the pinion immediately before meshing with the teeth of the pinion is made slower than the moving speed of the rack.
2) A braking means for applying a braking force to the rotation of the pinion is provided, and the braking force is applied to the rotation of the pinion by the braking means, and the circumference of the pinion immediately before the first teeth of the rack mesh with the teeth of the pinion. The speed is made slower than the moving speed of the rack.

  Further, when the rack and pinion device described above is used, for example, the rack of the rack and pinion device is provided on the carriage, and a plurality of pinions of the rack and pinion device are provided along the traveling direction of the carriage on the traveling path of the carriage, Before the carriage advances and the rack is removed from the pinion, the rack can be engaged with the next pinion, and the conveying device that drives the engaged pinion to advance the carriage can be configured. In this invention, the conveyance apparatus is also provided.

  When the top of the first tooth of the rack abuts the top of the tooth of the pinion, another member at the front end of the rack including the first tooth of the rack swings around the support shaft, and the top of the first tooth of the rack is pinion. The top of the teeth of the rack is overcome, so that the rack does not rise. Even if a force in a direction perpendicular to the tooth height direction acts on the first tooth of the rack, the support shaft of the swing mechanism is received by dispersing the force on the cylindrical surface, so that it is not easily damaged and is durable. Excellent.

  FIG. 1 shows an embodiment of a rack and pinion device of the present invention. The rack and pinion device includes a rack 1 that moves in the longitudinal direction and a pinion 2 that meshes with the moved rack 1 and feeds it.

  In the rack 1, the front end portion 1B including the first teeth r1 is a separate member independent of the main body 1A. The separate member 1B is supported by a support shaft 3 parallel to the rotation axis of the pinion 2, and can swing around the support shaft 3. The support shaft 3 is disposed behind the first tooth r1.

  The rack 1 and the pinion 2 are arranged so that the rack 1 is on the upper side of the pinion 2. Further, the support shaft 3 that supports the separate member 1B at the front end of the rack is disposed behind the center of gravity of the separate member 1B. Therefore, a rotational moment about the support shaft 3 acts on the separate member 1B due to its own weight, and the direction of the rotational moment is a direction in which the front end of the separate member 1B is lowered. Accordingly, the separate member 1B swings around the support shaft 3 by its own weight, and the first teeth r1 positioned in front of the support shaft 3 are pressed against the pinion 2 below.

  A stopper 6 is provided at the front end of the main body 1A. The stopper 6 receives the front end of the swinging separate member 1B from below, and prevents the first teeth r1 of the separate member 1B from interfering with the tooth bottom of the pinion 2.

  The rack 1 has a structure in which the original second tooth is removed, and the distance 4 from the first tooth r1 to the next tooth r2 is a distance corresponding to twice the inter-tooth pitch 5 of the pinion 2. . The distance from the tooth r2 to the next tooth r3 is the same as the interdental pitch 5, and the distance between the subsequent teeth is also the same as the interdental pitch 5.

  The pinion 2 is driven by a hydraulic motor (not shown) and rotates. The pinion 2 and the hydraulic motor are connected via a clutch (not shown). When the clutch is connected, the pinion 2 can be driven, and when the clutch is disconnected, the drive of the pinion 2 can be released. The pinion 2 is connected to a brake (not shown) that applies a braking force to its rotation.

  Hereinafter, usage examples of the rack and pinion device will be described.

  The pinion 7 behind the rack 1 feeds the rack 1 and moves the rack 1 in the longitudinal direction. The rack 1 approaches the pinion 2 at the front thereof, and the first tooth r1 comes into contact with the tooth p1 of the pinion 2.

  Until the tooth r1 is engaged with the tooth p1, the clutch is disengaged to release the drive of the pinion 2 by the hydraulic motor. The pinion 2 released from driving is coasting or stopped, and the moving speed of the tooth tip of the pinion 2 at this time, that is, the peripheral speed is slower than the moving speed of the rack 1.

  Thereafter, the rack 1 and the pinion 2 mesh with each other without the rack 1 riding on the pinion 2. When the tooth r1 of the rack 1 is abutted with the tooth p1 of the pinion 2 (FIG. 2), and when the tooth r1 of the rack 1 is meshed with the tooth p1 of the pinion 2 without being abutted (FIG. 3). The meshing operation will be described below.

  As shown in FIG. 2A, when the tooth r <b> 1 of the rack 1 abuts the tooth p <b> 1 of the pinion 2, the separate member 1 </ b> B at the front end of the rack swings about the support shaft 3. At this time, since the moving speed of the tooth p1 is slower than the moving speed of the tooth r1, the top of the tooth r1 gets over the top of the tooth p1, and as shown in FIG. 2B, the tooth gap adjacent to the tooth p1. Depressed. The tooth r1 that has fallen into the tooth gap meshes with the tooth p0 that is one tooth ahead of the tooth p1.

  When the tops of the teeth face each other, the tooth r1 smoothly climbs over the tooth p1, so that the rack 1 is unlikely to rise. That is, a frictional force is generated at the tooth butting portion. If the frictional force is large, the tops of the teeth that are butted are not easily displaced, so that the rack 1 is likely to run up. However, in the case of this device, since the separate member 1B including the tooth r1 is swung, the frictional force generated at the abutting portion is small, and therefore the apex portions of the abutted teeth are easily displaced from each other, and the tooth r1 smoothly moves the tooth p1. It is difficult to get over the rack 1 and ride on the rack 1.

  Further, due to the frictional force generated at the abutting portion, a force oblique to the swinging direction acts on the separate member 1B. However, since the swing mechanism operates smoothly against such a force in an oblique direction, this apparatus reliably prevents the rack from being ridden.

  Further, if the braking force is applied to the pinion 2 with a brake until the tooth r1 meshes with the tooth p0, the rack 1 is more unlikely to ride. That is, the braking force acts in a direction to hold the pinion 2 that tries to follow the rack 1, so that the tops of the teeth are easily displaced. Therefore, the tooth r1 gets over the tooth p1 more reliably, and the rack 1 is more unlikely to ride up. This braking force is released after the tooth r1 meshes with the tooth p0.

  On the other hand, as shown in FIG. 3A, when the tooth r1 of the rack 1 meshes with the tooth p1 of the pinion 2 without the teeth colliding, the rack 1 meshes with the pinion 2 as it is.

  When the tooth r1 meshes with the tooth p1, a force in a direction perpendicular to the tooth height direction acts on the tooth r1, but the support shaft 3 of the swing mechanism disperses and receives the force on the cylindrical surface. Because it is hard to break. Therefore, this device is excellent in durability.

  Further, even if the tooth r1 meshes with the tooth p1 shallowly, the rack 1 is unlikely to ride up. That is, when the tooth r1 and the tooth p1 mesh shallowly, the tooth r1 is pushed up while meshing with the tooth p1. At this time, if there is a tooth corresponding to the original second tooth between the tooth r1 and the tooth r2, the tooth is displaced from the tooth p1, as shown in FIG. However, there is a case where the rack 1 rides on the pinion 2 by colliding with the tooth p2 behind one tooth. However, in the case of this device, since there is no tooth between the tooth r1 and the tooth r2, such tooth matching does not occur. Further, since the positional deviation of the tooth r2 due to the pushing up of the tooth r1 is relatively small, the tooth r2 is less likely to collide with the tooth p3 that is one tooth behind the tooth p2.

  As described above, the rack 1 meshes with the pinion 2 without riding on the pinion 2 (FIGS. 2 (c) and 3 (b)). After engaging, the clutch is connected and the pinion 2 is driven.

  In the present embodiment, the separate member 1B at the front end of the rack swings by its own weight and presses the teeth r1 against the pinion 2, so that the structure is simple and the durability is high. On the other hand, as shown in FIG. 5A, a spring 8 is provided between the separate member 1B at the front end of the rack and the main body 1A, and the separate member 1B is swung by the restoring force of the spring 8 so that the tooth r1 is pinned 2 It is good also as a structure pressed against. When the spring 8 is used, the strength of the force pressing the tooth r1 can be controlled, and the rack 1 can be more reliably prevented from climbing.

  Further, the separate member 1B at the front end of the rack may be provided with only the first teeth r1, as shown in FIG. 5B, for example.

  Further, the hydraulic motor may be replaced with another mechanism that drives and rotates the pinion 2, such as an electric motor or an air motor.

  The drive of the pinion 2 may be released by stopping the supply of hydraulic pressure to the hydraulic motor, and the braking force is applied to the pinion 2 by a method of controlling the hydraulic pressure of the hydraulic motor to reduce its rotational speed. You may do it.

  In addition, it is preferable to chamfer the tooth tip of the tooth | gear which the separate member 1B of a rack front end has a round shape as shown in a figure. In this way, when the tooth r1 and the tooth p1 face each other, the top of the tooth r1 passes over the top of the tooth p1 more smoothly, and the rack 1 is more unlikely to run.

  Further, as shown in FIG. 1, it is preferable that the rear end portion of the rack 1 is formed as a separate member 1C and has the same structure as the rack front end. In this way, even when the rack 1 is retracted and meshed with the rear pinion, the rack 1 does not ride up.

  FIG. 6 shows an embodiment of the transport apparatus of the present invention. The transport device includes a carriage D on which a conveyed product H is mounted and a traveling path S through which the carriage D travels.

  On the carriage D, the rack 1 having the above-described structure is arranged along the traveling direction (lateral direction in the drawing) of the carriage D. In the traveling path S, pinions 20, 21, and 22 similar to the above-described pinion are arranged in order along the traveling direction of the carriage D with a certain interval.

  In this transport device, the rack 1 of the carriage D is successively engaged with the pinions 20, 21, and 22 of the traveling path S as shown in FIG. 7, and the carriage D is advanced along the traveling path S.

  That is, the pinion 20 feeds the rack 1 of the carriage D to advance the carriage D (FIG. 7A), and before the rack 1 is removed from the pinion 20 as the carriage D advances, the next pinion 21 is racked. 1 (FIG. 7B). After meshing, the pinion 21 feeds the rack 1 and advances the carriage D (FIG. 7 (c)). Before the rack 1 is removed from the pinion 21 as the carriage D proceeds, the next pinion 22 meshes with the rack 1. After meshing, the pinion 22 feeds the rack 1 and advances the carriage D (FIG. 7 (d)). In addition, if the pinion of the traveling path S is increased, the moving distance of the carriage D can be arbitrarily extended.

At this time, the horizontal posture of the carriage D is maintained by wheels and rails (not shown) provided on the carriage D and the traveling path S, respectively.

  Since the rack 1 of the carriage D meshes smoothly without climbing on the front pinion, the conveyed product H mounted on the carriage D can be smoothly conveyed. Further, since the swinging mechanism of the rack 1 is not easily damaged, this transport device is excellent in durability. In particular, when the transported object H is a heavy object of 5 tons or more, such as a die of an ultra-high pressure press, the difference in the reliability of preventing the climbing and the durability of the transporting apparatus compared with the transport apparatus using the conventional rack and pinion. Becomes prominent.

The figure which shows embodiment of the rack and pinion apparatus of this invention The figure which shows the meshing | engagement process of an apparatus same as the above in the state in which the tooth | gear of the rack was attached to the tooth | gear of the pinion The figure which shows the meshing process of the apparatus same as the above in the state in which the tooth | gear of the rack did not mate with the tooth | gear of a pinion The figure which shows the state where the rack rides on the pinion (A) is a figure which shows the 1st modification of the rack and pinion device of this invention, (b) is a figure which shows a 2nd modification. The figure which shows embodiment of the conveying apparatus of this invention The figure which shows the process in which the trolley | bogie of a conveyance apparatus same as the above advances

Explanation of symbols

1 rack 1A main body 1B separate member 2 pinion 3 support shaft 4 distance from first tooth to second tooth 5 inter-tooth pitch r1 first tooth r2 tooth next to first tooth D carriage S traveling path 20, 21, 22 pinion

Claims (7)

In a rack and pinion device that engages a rack that moves in a longitudinal direction with a pinion, and drives the pinion with a rotation drive mechanism to feed the rack, a front end portion of the rack that includes first teeth that first mesh with the pinion The separate member is supported by a support shaft parallel to the rotation axis of the pinion so as to be swingable, and the support shaft is disposed behind the first tooth to swing the separate member. The rack and pinion device is configured to press the first teeth against the pinion.   The rack and pinion device according to claim 1, wherein a distance from the first tooth of the rack to the next tooth is a distance corresponding to twice the inter-tooth pitch of the pinion.   The rack is disposed above the pinion, the support shaft is disposed behind the center of gravity of the separate member, and the separate member swings by its own weight so as to press the first teeth against the pinion. The rack and pinion device according to claim 1 or 2, wherein the device is a rack and pinion device.   4. The speed reducing device according to claim 1, further comprising: a speed reducing means for delaying a peripheral speed of the pinion immediately before the first teeth of the rack are engaged with the teeth of the pinion from a moving speed of the rack. Rack and pinion equipment.   Release means for releasing the drive of the pinion is provided, the release means constitutes the slow speed means, and the drive of the pinion is released by the release means until the first teeth of the rack are engaged with the teeth of the pinion. The rack and pinion device according to claim 4, wherein the peripheral speed of the pinion immediately before the first teeth of the rack mesh with the teeth of the pinion is delayed from the moving speed of the rack.   A braking means for applying a braking force to the rotation of the pinion is provided, the slowing means is configured by the braking means, the braking force is applied to the rotation of the pinion by the braking means, and the first tooth of the rack is moved to the pinion of the pinion. The rack and pinion device according to claim 4, wherein a peripheral speed of the pinion immediately before meshing with teeth is delayed from a moving speed of the rack.   A rack of the rack and pinion device according to any one of claims 1 to 6 is provided on a carriage, and a plurality of pinions of the rack and pinion device are provided along a traveling direction of the carriage on a traveling path of the carriage, so that the carriage advances. Then, before the rack is detached from the pinion, the rack is engaged with the next pinion, and the engaged pinion is driven to advance the carriage.

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