JPH0726674B2 - Flexible screw - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a flexible screw capable of transmitting a feeding action by rotation of a screw or a nut member in a flexible direction, and a flexible feeding direction. The present invention relates to a flexible screw having a structure which is simple and has a simple structure as a whole, and has a structure capable of exhibiting a buckling prevention function even if the screw is flexible.

[Conventional technology]

A so-called feed screw unit utilizing the feed action of a screw or a nut member is used as one of feed mechanisms in various machines and devices including machine tools. In particular,
The ball screw unit in this feed screw unit consists of a feed screw or a lead screw in which a rolling groove of a steel ball is provided in a screw shape, and a steel ball (ball) that is loosely fitted tightly in the rolling groove of the feed screw. A nut member arranged in a thread shape on the inner surface side of the cylindrical casing to circulate this ball row in the casing is formed as a basic member.

The conventional ball screw unit rotates the feed screw to move the nut member that is prevented from rotating back and forth on the screw, or conversely, rotates the feed member to move the nut screw that rotates to prevent the rotation of the feed screw. It is used as it is.

However, in this ball screw unit, since the feed screw is a bar-shaped steel body, the forward and backward movement of the nut member can be performed only by a linear movement in which the central axis of the feed screw and the central axis of the nut member are always coaxial.

For this reason, it cannot be applied to operations in which the direction of linear motion is changed midway or curved motion is performed.

However, depending on the machine or device, it may be convenient if the direction of the feed movement by the ball screw unit can be changed and set to an arbitrary direction with respect to the direction of the unit.

For example, if the installation space for a long rigid feed screw cannot be secured because the space of the device is too small, if the feed screw can be installed in a bent state so that it can rotate, the problem of installation space can be solved and This is because a feed screw having a wide span can be realized, and an article can be moved along a winding path.

In view of the above points, the inventor of the present invention previously proposed a ball screw unit having a flexible feed screw as Japanese Patent Application No. 1-268168.

The structure of the proposed ball screw unit consists mainly of winding a linear material into a coil and combining a flexible screw shaft that uses the groove of the coil as a ball transfer groove with a load ball and nut member suitable for this. Further, regarding the screw shaft of this flexible ball screw unit, the cross section of the groove of the coil is formed into an arc shape to form a ball transfer groove, or a plurality of linear members are wound into a single coil,
It is formed so as to have a plurality of ball transfer grooves, and further, this screw shaft is used by winding it up on a suitable winding roll as needed. Each is a feature.

[Problems to be Solved by the Invention]

The flexible ball screw proposed earlier has a long length and is wound up because of its flexible property.
It is epoch-making in that the nut member can be used as a propelling means for rotating the nut member to feed the article connected to the screw in any direction such as the vertical direction or the horizontal direction. When a ball nut is used on the side, its structure must be complicated, and when lifting a loaded article in the vertical direction, it is necessary to reinforce the ball screw shaft itself to prevent buckling. .

According to the present invention, in view of such a point, the feed screw is formed to be flexible and long so that it can be wound, and the nut member is rotated to support the load on the screw so that the feed screw is particularly extended in the vertical direction. It is an object of the present invention to develop a flexible feed screw which can simplify the structure of the nut side of the flexible screw and has reinforcement to supplement buckling prevention of the screw.

[Means for Solving the Problems]

The configuration of the present invention made in order to solve the above-mentioned problems is a long coil-shaped rod that is wound by abutting each other in a coil shape on the outer surface of the linear member in the entire length of the rod. , The cross-sectional shape is a semi-circular, trapezoidal, triangular, V-shaped, U-shaped to form a flexible screw rod body, and inside the screw rod body, in the length direction,
A flexible member having a linear shape, a cord shape, a tubular shape, or a rod shape is inserted, and a nut member having a male thread structure adapted to the groove is screwed into the thread groove. To do.

[Work]

The flexible screw unit of the present invention is formed by winding a linear material in a coil shape to form a thread groove on the outer peripheral surface thereof and using this thread groove as a thread groove to be screwed with the nut member side, thereby providing a flexible thread unit. Formed for use as a lead screw, the lead screw can be disposed along a curved section. Further, since this feed screw is flexible, it can be wound appropriately in a roll shape.

Moreover, the above-mentioned screw is formed by inserting an appropriate flexible material inside the entire length of the screw to prevent buckling.

Therefore, this flexible screw is wound in a roll shape, and the nut member screwed on the screw is rotated to
For example, even if the screw is extended in the vertical direction, since the flexible material is inserted thereinto, it does not buckle or is extremely difficult to buckle, and it is lifted up and down while maintaining a straight posture. As a result, this feed screw can exert its power by being used as an expansion and contraction drive mechanism of the telescopic structure in the telescopic structure of the telescopic structure in which a plurality of cylindrical bodies having different diameters are housed in each other. .

〔Example〕

 Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an example of a feed screw unit using the flexible screw rod of the present invention. FIG. 1 is a front sectional view of an essential part of the feed screw unit, and FIG. 2 is a front sectional view of an example of a flexible screw rod in the unit of the present invention. , FIG. 3 is also a side sectional view, FIG.
FIG. 4A is a plan view showing an example of a feed screw mechanism using the flexible screw rod of the present invention, FIG. 4B is a plan view of another example, and FIG. 5 is a plan view showing a structural example of the support member 8. A sectional view, FIG. 6 is a front sectional view of an example in which a feed screw unit having a flexible screw of the present invention is used for an extendable column.
FIG. 7 is a cross-sectional view of an essential part showing another example of the thread groove of the flexible screw rod, and FIG. 8 is a partially cutaway oblique view of the flexible screw of the present invention using a spiral string.

In these figures, 1 is a steel wire 2 wound in a coil shape with each wire closely contacting each other, and a substantially semicircular shape for ball transfer is formed on the outer circumference along the joining line of each line. It is a hollow flexible screw rod formed by screwing the forming groove 3. In the illustrated embodiment, the linear member having a circular cross section is used, but the linear member may have a rectangular cross section such as a rectangle or a trapezoid.

Here, the ball transfer groove is formed by processing the cross section of the linear material forming the coil into a concave arc shape, or by winding the linear material in a coil shape, the joining line portion of each filament is formed. Any one may be used, which is formed by previously processing the cross section of the linear material so that the cross section has an arc shape.

Thus, the screw rod 1 has a so-called ball screw-like appearance, but since the linear member 2 is wound around the screw rod 1 and formed on the screw rod 1, it has flexibility in the axial direction. .

Reference numeral 3 denotes a thread groove which is provided on the outer peripheral surface of the threaded rod 1 along the joining line of the linear members 2 and is formed so that balls, which will be described later, come into rolling contact therewith.

FIG. 7 shows that when the outer surface of the filament material itself is wound into a coil,
This is an example in which the cross-sectional shape of the linear material is processed in advance so that the thread groove 3'is formed.

Reference numeral 4 is an example of the flexible member of the present invention which is inserted in close contact with the inner surface side of the screw rod 1 in which the screw groove 3 is formed, and is formed into a tubular shape by winding a wire rod in a coil shape. It is a core. In the example of FIG. 2, the core body 4 is formed by winding the wire rod 4 in the opposite direction to the threaded rod body 1. However, it is optional to set the winding direction to the right or to the left. is there.

Further, the core body 4 formed in a coil shape can be inserted into the screw rod body 1 in a threaded manner.

That is, the flexible screw rod 1 of the present invention is integrated with the core body 4 and is formed as a coaxial double-coil type screw rod.

In place of the core body 4, a flexible tube body (not shown) having an external surface formed with a screw-shaped convex thread to be screwed into a screw formed by a joining line of the linear threads formed on the inner surface of the screw rod 1 is inserted. You may do it.

In addition, a twisted wire may be inserted inside the screw rod 1, the core body 4 inserted therein, or the inside of the flexible pipe to enhance the buckling strength.

Further, when the core body inserted inside the threaded rod 1 is a flexible pipe body, it may be desirable to allow fluid to be freely supplied and drained inside the pipe body. This is because it is useful when the entire flexible screw is wound on a reel or the like, or when it is unwound to have a straight posture and buckling strength is exhibited in this posture.

Furthermore, a shape memory alloy is used for the core body, and for example, a portion where the flexible screw rod 1 being wound straight extends forms a temperature environment in which the memory alloy returns to a straight line under a certain temperature condition. You may do it.

Reference numeral 5 shown in FIG. 1 is an example of a nut member screwed to the screw rod 1, and here, in the inner peripheral surface of a short cylindrical main body having an opening diameter that is loosely inserted loosely into the outer diameter of the screw rod 1. It is formed of a large number of balls 6 which are arranged spirally along the groove of the screw rod 1 and circulate inside the nut member.

In FIG. 1, reference numeral 51 denotes a flange portion provided on the outer circumference of the nut body, in which the outer circumference is formed with external teeth 51a so that the rotational force is input from the outside.

In the above example, the ball nut using the ball 6 as the nut member 5 has been described. However, in the flexible screw of the present invention, as the nut member 5, a male screw screwed into the thread groove 3 of the screw rod 1 on the inner surface of the nut block. Screwed to the inner surface of the nut block 5B, instead of the ball 6 or the male screw, as an example, as shown in FIG. 8, a helical string 61 formed in a male screw shape with a suitable material such as synthetic resin is formed. What was done can be used. As the material of the string 61, metal, ceramics, or a composite material thereof may be used in addition to the above columns.

Next, an example of a ball screw unit using an example of the flexible screw of the present invention is formed by the members 1 to 6 shown in FIGS.
An example of the usage mechanism will be described.

A nut member 5 screwed via a ball 6 to a flexible screw rod body 1 in which linear members 2 are wound in a coil shape in close contact with each other, and a groove 3 for ball transfer is spirally formed on the outer surface, As shown in FIG. 4 (a), by rotating the nut member 5 forward or backward at a fixed position, the screw rod 1 which has been prevented from rotating can be moved in either the front or rear direction. You can

On the other hand, as shown in FIG. 4 (b), contrary to the above, a rotation stopping mechanism 51b is added to the nut member 5 between the nut member 5 and the forward / backward movement path W thereof to rotate the screw rod 1 in the forward and reverse directions. Is given, the nut member 5 is moved back and forth along the axial direction of the screw rod 1. Here, 7 is a motor, 7b is its output shaft, and 1c is a coupling.

The feed screw unit using the screw of the present invention which operates as described above can be used as a feed mechanism as shown in FIG. 4 (a) as an example. Therefore, this point will be described below.

In FIG. 4 (a), the main body of the nut member 5 is rotatably arranged at a fixed position via a bearing 5a or a bearing. Since the outer teeth 51a are formed on the flange portion 51 of the nut member 5, the motor 7 is attached to the outer teeth 51a.
The motor 7 is arranged by meshing the output pinion 7a. On the other hand, the flexible screw rod 1 according to the present invention is screwed and inserted into the nut member 5 which is rotated at a fixed position.

Since the flexible screw rod 1 of the present invention screwed and inserted into the nut member 5 is flexible, as an example, as shown in FIG. 4 (a), the flexible screw rod 1 is arranged with its axial direction turned by 90 degrees. Even so, the nut member 5 is rotated to move forward and backward.

In FIG. 4 (a), 8 is a supporting member for the flexible screw rod 1 arranged at the turn portion of the screw rod 1, and the supporting member 8 is a flexible screw of the present invention as shown in FIG. The rod 1 is in close contact with the rod 1 so that the rod 1 can slide.

That is, in FIG. 5, 81 is a bearing member that is densely mounted on the screw rod 1, and 82 is a support member that is fitted to the outer periphery of the bearing member 81 via balls 82a so as to form a bearing shape. The support ring member 82 is a ring member and is fixed to the advancing / retreating path W by a wall surface or the like, and the flexible screw rod 1 that advances and retracts
The bearing member 81 is slidably supported by rotating the bearing member 81 in the ring member 82 as needed.

As will be apparent from the above description, an appropriate member, for example, shown in FIG. 4 (a), which is desired to be moved forward and backward, is provided at the tip or the middle of the flexible screw rod 1 of the mechanism shown in FIG. As shown in the figure, when the target member 9 to be transferred is attached to the tip end side of the flexible screw rod 1, the member 9 is moved forward and backward together with the advance and retraction of the flexible screw rod 1.

Since the amount of advance / retreat of the member 9 is determined by the total length of the screw rod 1, the flexible screw rod 1 of the present invention is formed in a long size, and the rear end side 1b thereof is wound up and fed out on a suitable winding wheel or the like (not shown). By freely winding the member 9, the member 9 can be arbitrarily moved forward and backward (elevated) at a considerable distance (height) and can be positioned at an arbitrary position therebetween.

Here, when a large amount of advance / retreat of the screw rod 1 is taken in the up-and-down direction of the screw rod 1, the intermediate portion of the screw rod 1 is supported, so that two or more intermediate members that perform the same function as the bearing member 8 described above. It is desirable that a flexible cord member such as a piano wire P having a predetermined length be hung and provided below the support member 91 and the target member 9. That is, the intermediate bearing member 91 has a through hole 9a for the screw rod 1 in the center, and the outer peripheral side is slidably held in the advancing / retreating path W of the screw rod 1 formed by a wall surface or the like, a plurality of which are predetermined. By suspending and supporting the target member 9 with a piano wire having a span, even if the flexible screw rod 1 is vertically lifted by a considerable amount, the screw rod 1 does not substantially buckle.

As described above, the flexible screw of the present invention, which is incorporated in the feed screw unit to be freely wound and unwound, allows the tip end side of the screw rod 1 to be freely advanced and retracted. It can be used as a telescopic drive mechanism in a telescopic support having a structure as shown in FIG. Next, an example of this retractable support column and its moving mechanism will be described with reference to FIG.

In FIG. 6, 11 to 16 are cylindrical bodies having different diameters, respectively, as examples of cylindrical bodies having different diameters.
It is a plurality of cylindrical bodies with different diameters, which are loosely inserted into the cylindrical body.

The cylindrical bodies 11 to 16 are respectively composed of bottom plates 11a to 16a and an intermediate partition plate.
12d to 16d (However, in the illustrated example, the intermediate partition plate 11d
Is not provided because it is unnecessary) and
In addition, the outer diameter of the lower ends 11b to 15b of the small-diameter cylinder is made larger than the inner diameter of the upper ends 12c to 16c of the large-diameter cylinder to prevent the small-diameter cylinder from coming out of the large-diameter cylinder. I have to.

Incidentally, 11e is a canopy member attached to the upper end 11c of the smallest diameter cylindrical body 11, and 17 is a mechanism chamber integrally formed with the bottom portion 16a side of the largest diameter cylindrical body 16, and the lower part is omitted in FIG. ing. Further, each intermediate partition plate 12d ~ 16d, as an example, when each cylinder 11 ~ 15 is extended, a thin cord so that each partition plate is located approximately in the middle of each cylindrical body,
For example, it is assumed that the piano wire P is supported from above and below and is suspended in the inside of each cylindrical body.

With the above configuration, each of the cylindrical bodies 11 to 16 is such that the small-diameter side cylindrical body is sequentially loosely inserted into the large-diameter side cylindrical body, and when the small-diameter cylindrical body 11 is pulled up in this state, At its lower end, the upper end of the large-diameter cylindrical body 12 is hooked, and the small-diameter cylindrical bodies 12 ... Are successively pulled up with the large-diameter cylindrical bodies 13 ...

Therefore, in the present invention, the tip 1a of the screw rod 1 in the feed screw unit of the flexible screw and the ball nut member of the present invention is fixed to the back surface of the bottom plate 11a of the cylindrical body 11 having the smallest diameter, and the other cylindrical bodies 12 to A support member in which the screw rod 1 closely penetrates the 16 bottom plates 12a to 16a and the intermediate partition plates 12d to 16d.
12f to 16f are provided so that the threaded rod 1 is inserted while being supported at the center position of the cylindrical body, while the latter half side of the flexible threaded rod 1 is wound around the winding roll 18 in the mechanism chamber 17.

As the supporting members 12f to 16f, those having the same function as the structure of the supporting member 8 in the previous embodiment (see FIG. 5) are used, or there is a hole through which the screw rod 1 tightly penetrates. A simple structure may be used or optional.

On the other hand, the nut member 5 is rotatably held at that position inside the mechanism chamber 17. The outer periphery of the flange portion 51 of the nut member 5 is formed with teeth 51c of the worm wheel here, and the worm wheel has a motor 7
The worm 7c attached to the output shaft 7b of is engaged with. As a power transmission system for rotating the nut member 5, it is of course possible to use a system other than the worm and the worm wheel. In FIG. 6, 19 is a pair of support rolls supporting the rising portion of the flexible screw shaft, and two or more sets of these rolls may be provided at appropriate positions.

In the above configuration, when the cylindrical bodies 11 to 16 are in the states shown in FIGS. 6A and 6B, when the motor 7 is rotated in the normal direction and the worm 7c and the worm wheel 51c are radiated to transmit the rotation to the nut member 5, The upper end 1a of the flexible screw rod 1 is raised by the rotation of the nut member 5.

This rise causes the cylindrical body 11 having the smallest diameter to rise inside the next large-diameter cylindrical body 12, and the lower end of the small-diameter cylindrical body 11 is the large-diameter cylindrical body 12.
When it reaches the upper end of the cylinder, it rises from this position along with the cylinder 12, and thereafter, the cylinders 11, 14 ... of the large diameter side are sequentially lifted by the cylinder 11 which is continuously lifted to extend and stand as a pillar. Is done.

Here, the screw rod 1 is raised in a vertical posture, and
Support members 12 respectively provided on the bottom plates 12a to 16b of the cylindrical bodies 12 to 16 and the intermediate partition members 12d to 16d at a plurality of intermediate locations.
e to 16e, and since the buckling prevention core body 4 is inserted inside the screw rod body 1, it is of course sufficient strength against vertical load. Together with the cylinders 11 to 16, it exhibits sufficient strength against lateral loads.

Moreover, even if a vertical load is applied, the screw rod 1 is held in a so-called self-locking state by the engagement of the worm wheel 51b of the nut member 5 and the worm 7b, so that the flexible screw rod 1 moves to the descending side of the column by itself. There is no such thing.

For shortening and storing the strut by the elongated cylinders 11 to 16, the nut member 5 is rotated in a direction opposite to the upward direction, and the tip 1a of the screw rod 1 is lowered so that the flexible screw is lowered. By winding the rod 1 on a roll 18,
This is performed by pulling back and housing the small-diameter cylindrical bodies 11 to 15 inside the large-diameter cylindrical bodies 12 to 16.

As described above, the feed screw unit using the flexible screw rod 1 of the present invention is for expanding and contracting the expansion / contraction column of the type in which a plurality of different-diameter cylindrical bodies are accommodated in the large-diameter cylindrical body in order of the small-diameter side. It is useful as a drive mechanism.

When the cylindrical body is a cylindrical body, it is desirable to prevent the inner and outer surfaces of each cylindrical body from rotating due to the relationship between the key and the key groove, but in the case of a prism, this is not necessary. Also, when each cylinder is extended and erected on the support pillar, due to the tightness of coupling between the cylinders,
The outer surface of the lower end and the inner surface of the upper end of each cylinder may be tapered.

〔The invention's effect〕

As described above, the flexible screw of the present invention has the following unique effect because the screw rod in the feed screw unit is made flexible by incorporating the flexible core body therein.

Since the entire threaded rod is flexible, even if the threaded rod is laid out with an appropriate radius and bending angle, it can be screwed with the nut member in the straight portion, and in this state, from the outside. The flexible screw rod can be freely moved back and forth in response to the rotation of the rotated nut member, or the nut member can be freely moved back and forth by rotating the screw rod from the outside. With the screw shaft, the feed screw unit can be applied even in a curved space or a narrow space where it cannot be installed, which is extremely convenient in designing and manufacturing various mechanisms.

Further, the feed screw unit incorporating the flexible screw rod of the present invention is flexible as a whole including the core body inserted to prevent buckling of the screw rod. By using it as a drive mechanism for the expansion and contraction operation of a retractable support column of a type housed in a large diameter one after another, an expansion support column with smooth expansion and contraction and large lateral and vertical load resistance is constructed. be able to.

[Brief description of drawings]

FIG. 1 shows an example of a feed screw unit using the flexible screw rod of the present invention. FIG. 1 is a front sectional view of an essential part of the feed screw unit, and FIG. 2 is a front sectional view of an example of a flexible screw rod in the unit of the present invention. , FIG. 3 is also a side sectional view, FIG.
FIG. 4A is a plan view showing an example of a feed screw mechanism using the flexible screw rod of the present invention, FIG. 4B is a plan view of another example, and FIG. 5 is a plan view showing a structural example of the support member 8. A sectional view, FIG. 6 is a front sectional view of an example in which a feed screw unit having a flexible screw of the present invention is used for an extendable column, and FIG. 7 is a sectional view of a main part showing another example of a thread groove of a flexible screw rod, FIG. 8 is a partially cutaway perspective view of the flexible screw of the present invention using a spiral string. 1 ... Screw shaft, 2 ... Linear material, 3 ... Ball transfer groove, 4
…… Core body, 5 …… Nut member, 6 …… Ball, 7 …… Motor, 8 …… Supporting member, 11 to 16 …… Cylindrical body with different diameters,
11a to 16a ... bottom plate of each cylinder, 11b to 16b ... lower end of each cylinder, 11c to 16c ... upper end of each cylinder, 12d to 16d ... intermediate partition plate, 12e to 16e ... support member, 17: Mechanism room,

Claims (9)

[Claims] 1. A long coil-shaped rod, which is formed by abutting and winding a linear member in a coil shape, has a semicircular cross section, a trapezoidal cross section, on the outer surface of the linear member over the entire length of the rod. Triangle, V
A flexible screw rod is formed by forming either a U-shaped or U-shaped screw groove, and the inside of the screw rod may be linear, cord-shaped, tubular, or rod-shaped along its length. A flexible screw, wherein a flexible member is inserted and a nut member having a male thread structure adapted to the groove is screwed into the thread groove. 2. The flexible screw according to claim 1, wherein the male thread structure formed on the nut member is any one of a ridge formed in a spiral shape on the nut member, balls arranged in a spiral shape, and a spiral string. . 3. The spiral string is made of metal, synthetic resin, ceramics or composite material.
Flexible screw. 4. The flexible screw according to claim 1, wherein the cord-shaped flexible member is formed by twisting a single wire or a twisted wire. 5. The flexible screw according to any one of claims 1 to 3, wherein the tubular flexible member is a coiled rod formed by winding a linear material into a coil like the flexible screw rod. 6. The flexible screw according to claim 5, wherein the tubular flexible member has a flexible core member appropriately inserted therein. 7. The flexible screw according to claim 5, wherein the flexible member having a tubular shape is filled with a fluid such that the fluid can be supplied and discharged therein. 8. The flexible screw according to claim 5, wherein the tubular flexible member has a bellows shape. 9. A plurality of plate-shaped intermediate partition plates, each having a hole through which the coiled rod is densely inserted, are arranged in the forward / backward path of a long coiled rod that is moved forward / backward by rotation of a nut member. The flexible screw according to claim 1.