JPS624960A - Movement conversion apparatus between rotary movement and rectilinear movement - Google Patents

Abstract

PURPOSE:To obtain the compact apparatus by changing the direction and the magnitude of the thrust force applied onto a transfer body when it is revolved in trailing to a rotary shaft by a movement conversion roller by changing the direction and the degree of inclination of the axis line of the movement conversion roller for the rotary shaft by a roller holding means. CONSTITUTION:A rotary shaft 2 penetrates through a transfer body 1 so as to be relatively revolved and shifted in the direction of the relative axis line, and a movement conversion roller 3 which contacts in trailing onto the outer periphery of the rotary shaft 2 is installed onto the transfer body 1. The thrust force in the direction of the axis line 2a of the rotary shaft which the transfer body 1 varies according to the revolution angle of an edge plate 1a. Therefore, the transfer body 1 can be shifted at a desired reciprocating speed by properly selecting the revolution angle. Therefore, the apparatus can be formed within the range necessary for the arrangement of the movement conversion roller around the rotary shaft, and thus the compact apparatus can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a motion conversion device between a rotational motion and a linear motion, and more specifically, to a rotational shaft and a moving body on a rotational shaft that is combined to be movable in the axial direction of the rotational shaft. When the motion converting roller held on the moving body rolls in contact with the rotating shaft in an axially inclined position and rotates, it receives a component force in the direction of the rotating shaft axis, gives thrust to the moving body, and rotates the rotating shaft. Regarding a motion conversion device that converts motion into movement along the rotation axis of a moving object, it is used, for example, for driving reciprocating members of machine tools, reciprocating work objects, or V-feeding devices (railway type) installed in warehouses. be done.

PRIOR ART A device of this type is disclosed, for example, in US Pat. No. 2,940,322. This disclosed device holds a roller in contact with the outer periphery or inner periphery of a rotating shaft at both ends with respect to a roller holding member that is held rotatably around an axis orthogonal to the rotating shaft on a moving body that is movable along the rotating shaft. The roller is mounted in the retained state, and an externally operable thrust direction switching member is linked to this roller retaining member, and the roller retaining member is rotated by external operation of the thrust direction switching member to change the direction of inclination of the roller with respect to the rotation axis. rotates with the rotating shaft, allowing the direction of the thrust applied to the moving body to be switched between forward and reverse directions.

Problems to be Solved by the Invention A roller holding member that changes the tilt direction of the roller with respect to the rotation axis by rotating around an axis orthogonal to the rotation axis, when holding a motion converting roller that rolls in contact with the outer periphery of the rotation axis, requires more space. In particular, if you want to strongly stabilize the movement of a moving object by arranging multiple motion converting rollers around the rotation axis, space is a big problem, and roller holding members are installed individually for each roller. The structure must be operated in conjunction with each other, which complicates the structure and makes it prone to looseness and failure.

Means for Solving the Problems In order to solve the above-mentioned problems, in the present invention, in a motion conversion device between a rotational motion and a linear motion, a movable body movable along a rotation axis is connected to a cylindrical case and two ends. A motion conversion roller is formed by a plate at both ends of the movable body, and the rotary shaft and the axis line roll into contact with each other in an inclined posture, and when the rotary shaft is driven by the rotary shaft, it receives a component force in the direction of the rotary shaft axis and applies an IL force to the movable body. is provided, and at least one end plate of the movable body is provided so as to be movable relative to the cylindrical case in the circumferential direction of the rotation axis.

A plurality of motion conversion rollers may be arranged around the rotation axis, or a plurality of motion conversion rollers may be arranged in the axial direction.

When the action motion conversion roller rotates following the rotation axis, it receives a component force in the direction of the axis of the rotation axis according to the inclination of the axis with respect to the rotation axis, moves in the direction of the axis of the rotation axis together with the moving body, and changes the rotation of the rotation axis. Converts to linear movement in the direction of the axis of rotation of the moving body. This transformation can also be achieved between a rotational axis and a moving body movable along it.

The roller holding member is located next to the motion conversion roller and is moved around the rotation axis by operating the end plate, and the position of the other end around the rotation axis relative to the end held by the moving body of the motion conversion roller is The relationship is changed, the axial attitude of the interlocking conversion roller with respect to the rotational axis is changed as appropriate, and the degree and direction of the thrust applied to the moving body by the motion conversion roller when the movement conversion roller follows the rotational axis is changed.

Embodiment In FIGS. 1 and 2, a rotary shaft 2 is passed through a movable body 1 so as to be movable in relative rotation and relative axial directions. The rotating shaft 2 is usually installed in a fixed position and driven to rotate, and the movable body 1 is connected to a reciprocating member (not shown) of a machine tool, or a guide bar (not shown) parallel to the rotating shaft 2. Rotation around the rotational axis 2 is blocked by fitting with the rotational axis 2, and movement only along the rotational axis 2 is allowed.

The movable body 1 is provided with a motion converting roller 3 that rolls into contact with the outer periphery of the rotating shaft 2 so as to be rotatable. In this embodiment, four motion converting rollers 3 are arranged evenly around the rotating shaft 2 and in only one row in the direction of the axis 2a of the rotating shaft 2. It is also possible to provide one to several sets of motion converting rollers 3 or several sets of motion converting rollers 3 having similar mechanisms in the direction of the axis 2a. The moving body 1 includes a cylindrical case 1b large enough to surround these three groups of rollers, and end plates 1 at both ends of the cylindrical case 1b.
Each end plate 1a of the movable body 1 has a bearing 4 on each end shaft 3a of the roller 3 facing the end plate 1a so as to be able to align with each other.

As shown in FIG. 3, the bearing 4 is made up of a spherical bushing 4a that is slidably and rotatably attached to each end shaft 3a and held so as to be rotatable in any direction by a housing 4b that is attached to the end plate 1a. .

At least one of the end plates 1a, 1a is connected to the moving body 1.
It is not only rotatable in the circumferential direction with respect to the cylindrical case 1b that forms the cylindrical case 1b, but also rotatable in the circumferential direction by a screw (not shown) or a gear mechanism provided between the end plate 1a and the cylindrical case 1b. Rotation in the direction can be finely adjusted.

As shown in FIG. 4, when each end plate 1a is rotated by an arbitrary angle in opposite directions as shown by arrows a and b, each end shaft 3a of the roller 3 bearing 4 on each end plate 1a is rotated. are also moved in the directions of arrows a and b, respectively, and the axis 3b of each roller 3 is inclined by an angle α with respect to the axis 2a of the rotating shaft 2.

In this state, when the rotating shaft 2 is rotated in the direction of arrow C, each motion conversion roller 3 is rotated by the rotating shaft 2, uniformly receives a component force in the direction of arrow d, and is applied to the moving body 1. A thrust in the direction of arrow d along the axis of rotation 2a is applied to move the movable body 1 in the direction of arrow d along the rotation axis 2.

When the movable body 1 is moved in the direction of arrow d and reaches the forward movement end point, when each end plate 1a is rotated around the rotation axis 2 in the opposite direction to the directions a and b, each roller 3 The axis 3b is the rotation axis 2
It is inclined in the opposite direction to the above-mentioned direction with respect to the axis 2a of. Therefore, the direction of rotation of each roller 3 is reversed with respect to the rotating shaft 2 which continues to rotate in the same direction as shown by the arrow C, and the component force in the direction of the axis 2a of the rotating shaft 2 received by the following rotation is also indicated by the arrow C. The direction is opposite to the direction d, and a backward ill force is applied to the moving body 1.

In the direction of the rotating shaft axis 2a that the moving body 1 receives? Since the Ii force changes depending on the rotation angle of the end plate 1a, by appropriately selecting this rotation angle, the movable body 1 can be moved at a desired reciprocating speed.

A dimensional change in the axis 2a direction between the roller end shafts 3a due to a change in the degree of inclination or direction of the motion converting roller 3 with respect to the rotating shaft axis 2a is absorbed by relative movement in the axial direction between the end shaft 3a and the bushing 4a.

When the degree of inclination or direction is changed, the distance from the center of the rotating shaft 2 at which the roller 3 is held by the moving body 1 around the rotating shaft also changes somewhat. However, it is very small and has no practical effect.

Figure 6 (al, [bl, (C1) shows other different embodiments of the motion conversion rollers, where the roller 3A has a shape in which two rollers with an arcuate outer peripheral surface are connected, and the roller 3B has a shape in which two rollers are connected. 1-13c, which has a shape in which the small diameter parts of two truncated cones having thin disc parts at both ends are connected, is a shape in which the side surface of the cylindrical body is concave and curved toward the central axis.

When the interlocking conversion rollers 3A, 3B, and 3G are configured as described above, when the roller 3 with a constant diameter is tilted with respect to the rotating shaft axis 2a, it contacts only one point on the rotating shaft 2 (Fig. 7, black circle). However, it is now possible to make contact with two points on the rotating shaft 2 (white circles in Figure 7), which stabilizes the contact with the rotating shaft 2 and allows the movable body 1 to move more reliably along the rotating shaft 2. can be set.

When the end plate 1a is rotated at an arbitrary angle in the circumferential direction of the moving body 1 using the motion conversion rollers 3A, 3B, and 3C that contact at two points, the rotation rate is greater than when the motion conversion roller 3 that contacts at one point is used. ,
The radial play of the rotating shaft 2 increases, and the axial play also occurs between the end plate 1a and the bearing 4. However, as shown in FIGS. 8 and 9, this play is caused by the biasing means 5 acting on at least one of the end plate 1a and the bearing 4 in the radial direction and the axial direction. It can be absorbed by The biasing means 5 is not limited to a spring.

In the case of the embodiments shown in FIGS. 1 and 2, the biasing means may also be applied in the axial and radial directions of the rollers 3.

Effects of the Invention According to this invention, the roller holding means moves around the rotation axis by operating the end plate located beside the motion conversion roller and forms a moving body, thereby reducing the inclination of the axis of the motion conversion roller with respect to the rotation axis. The degree and direction of the motion conversion rollers are changed to change the degree and direction of the thrust given to the moving body when the motion conversion rollers follow the rotation axis, so the device can be used within the bulk range required for the installation of the motion conversion rollers around the rotation axis. It can be configured and the whole thing is compact.

In addition, since both ends of the motion converting roller are held by the end plates of the movable body and only moved by one or both of the end plates, the roller support structure and moving structure are simple, and the overall structure is simple and trouble-free. It will be difficult.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional side view of a half part of a moving body according to an embodiment of the present invention, FIG. 2 is a front view with a part of the end plate of the moving body cut away, and FIG. 3 is a motion conversion roller. FIG. 4 is an enlarged sectional view showing details of the holding part; FIG. 4 is a side view showing a half of the movable body in cross section when the axis of the motion conversion roller is inclined with respect to the axis of the rotating shaft;
Fig. 5 is a partially cutaway front view of the end plate of the movable body shown in Fig. 4, and Fig. 6 (al, (bl, (C1) shows different implementations of interlocking conversion rollers in two-point contact with the rotating shaft. FIG. 7 is a side view showing one-point contact and two-point contact with the rotating shaft. FIG. 8 is a side view showing a cross section of a half of the moving body of another embodiment. FIG. 9 is a side view showing an example. is a partially cutaway front view of the end plate of the eighth and first moving body. 1... Moving body, 1a... End plate, 1b... Cylindrical case, 2... Rotating shaft, 2a...Rotating shaft axis, 3.3A
, 3B, 3C...Motion conversion roller, 3b...Axis of roller, 4...Bearing,

Claims (3)

[Claims] (1) A cylindrical case and two movable bodies that can move along the rotation axis.
A movement is formed by two end plates of the moving body, and the rotating shaft and the axis line are rolled into contact with each other in an inclined posture, and when the rotating shaft is driven by the rotating shaft, the moving body receives a component force in the direction of the rotating shaft axis, and gives a thrust to the moving body. A conversion roller is provided, and at least one end plate of the movable body is
A motion conversion device between rotational motion and linear motion, characterized in that the device is provided so as to be movable relative to the cylindrical case in the circumferential direction of the rotating shaft. (2) A motion conversion device between rotational motion and linear motion according to claim 1, wherein the motion conversion roller is formed so as to make two-point contact with the rotating shaft. (3) The motion converting roller has a rotational motion and a linear motion according to claim 1 or 2, in which the bearing part receives a biasing force in the radial direction or the axial direction between the end plate of the moving body. Movement and movement conversion device