JPH09310744A - Ball screw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve an effect to reduce the generation of vibration and noise when a ball passes through a return pipe. SOLUTION: A tube tunnel type ball screw is formed such that a return pipe 2 in a semicircular shape which is provided at two ends with an opening part to scoop up a ball and has a tongue piece formed at the tip of the opening and a nut 1 having two through-holes in which the opening parts at the two ends of the return pipe are inserted and a recessed part to support the return pipe are combined together. A sectional shape in a direction in which the two through-holes of the recessed part of the nut are interconnected has at least one of linear structures 10a, 10b, and 10c and a vibration-proof rubber or resin (a vibration absorbing member) 11 is inserted in a gap part between the nut and the return pipe.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tube tunnel type ball screw.

[0002]

2. Description of the Related Art Due to the remarkable progress of technological innovation, there is a demand for ultra-precision machining in the mechanical engineering industry. As a response to these demands, ball screws are effective for precision positioning method, machining accuracy, and productivity improvement. It has become widely used as a material. Further, the ball screw has been attracting attention as one that can provide a highly accurate feed mechanism in response to the demands of the times such as energy saving and cost reduction.

A ball screw, a so-called tube tunnel type ball screw, has a return pipe having openings at both ends for picking up a ball and a tongue piece formed at the tip of the opening, and an opening at both ends of the return pipe. It is constructed by combining two through holes and a nut that has a recess for supporting the return pipe, but the return pipe originally used was the left and right vertical parts called the deflector and the remaining part called the tunnel. Since it consisted of a horizontal part, if the number of rotations of the screw shaft is increased,
The balls in the return pipe were locked, and it was difficult to speed up the rotation speed, making mass production impossible.

In order to solve such a problem, Japanese Patent Publication No. 1-252624 discloses a tube tunnel type ball screw which has an opening for picking up a ball at both ends and a tongue at the tip of this opening. A semi-circular return pipe integrally formed with a piece, a through hole with a semi-circular vertical wall on the outer side of the nut for inserting the return pipe and a curved wall on the inner side, and the through hole. There is disclosed a ball screw which is formed between the holes and has a support portion which is formed in substantially the same shape to receive the curved surface below the return pipe.

FIG. 5 is a plan view illustrating a ball screw disclosed in Japanese Patent Publication No. 1-52624, FIG. 6 is a sectional view taken along line XX of FIG. 5, and FIG. 7 is a sectional view perpendicular to a screw axis. The running state of the ball is indicated by. In these figures, 1
Is a nut, 2 is a return pipe attached to the nut 1, 3 is a ball filled in the return pipe 2,
Reference numeral 4 denotes a return pipe retainer for fixing the return pipe 2 to the nut 1 with a screw 5, 6 denotes a thread groove, and 8 denotes a screw shaft.

[0006]

[Patent Document 1] Japanese Patent Publication No. 1-52624
The disclosed tube tunnel type ball screw uses a semi-circular pipe as the return pipe 2 and is located between two through holes of the nut 1 so that the nut 1
When the return pipe 2 is attached to the return pipe 2, the shape of the portion 7 supporting the return pipe 2 is substantially the same as the curved surface of the lower part of the return pipe 2, and the ball 3 and the inner wall of the return pipe 2 are configured by such a configuration. It is noted that the frictional resistance during the period is extremely small, the ball 3 travels smoothly, and the noise generation due to the locking phenomenon is eliminated.

The return pipe 3 has a rectangular thick plate on which a tunnel-shaped groove approximately equal to the diameter of the return pipe 3 is obliquely formed. A return pipe retainer 4 is fixed to the flat surface of the nut 1 with a screw 5. It is fixed by that.

It is an object of the present invention to improve the effect of reducing the vibration and noise generated when the balls pass through the return pipe in this type of tube tunnel type ball screw.

[0009]

Means for Solving the Problems The constitution of the present invention to solve the above problems is as follows.

(1) A semicircular return pipe having openings at both ends for picking up a ball and a tongue piece formed at the tip of the opening, and two pieces for inserting the openings at both ends of the return pipe. In a tube tunnel type ball screw formed by combining a through hole and a nut in which a recess for supporting the return pipe is formed, a linear structure having a sectional shape in a direction connecting two through holes of the recess is at least one. And a vibration absorbing member is inserted in a gap between the nut and the return pipe.

(2) In (1), the return pipe is fixed to the nut by a fixing member made of a vibration absorbing material.

(3) In (1) or (2), the outer peripheral surface of the return pipe is covered with a vibration absorbing member.

(4) In (1) or (2), the outer peripheral surface of the return pipe is sequentially covered with a thin lead layer and a vibration absorbing member.

(5) In (1) or (2) or (3) or (4), the vibration absorbing member is made of a vibration-proof rubber or resin having elasticity.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the ball screw of the present invention will be described below.

FIG. 1 is a plan view of a ball screw according to an embodiment of the present invention, FIG. 2 is a perspective view of a return pipe, and FIG. 3 is FIG.
4 is a cross-sectional view taken along line XX of FIG. 4, and FIG. 4 is a cross-sectional view perpendicular to the screw axis. The same parts as those in FIGS.
Reference numeral 9 denotes a vibration-proof rubber applied to the entire outer peripheral portion of the semicircular return pipe 2 having openings at both ends of the nut 1 for scooping up the balls 3 and tongues 2a and 2b formed at the tips of the openings. Alternatively, the resins 10a, 10b, 10c are provided in the recess of the nut 1 in which two through holes for inserting the openings at both ends of the return pipe 2 into the thread groove 6 and a recess for supporting the return pipe 2 are formed. 3 shows three linear parts, 11 is a vibration-proof rubber or resin inserted in the space formed by the inner peripheral surface of the return pipe 2 and the linear parts 10a, 10b, 10c of the concave portion of the nut 1,
Reference numeral 12 denotes a fixing member made of vibration-proof resin for fixing the return pipe, which is filled after the return pipe 2 is mounted in the recess for mounting the return pipe 2 provided in the nut 1. The balls 3 in the return pipe 2 in FIG. 1 are schematically shown in relation to the return pipe 2.

As described above, in this tunnel type ball screw, the cross-sectional shape in the direction connecting the two through holes of the recess has a linear structure of at least one, and in the space between the nut 1 and the return pipe 2. Since the vibration absorbing member is inserted, it is possible to avoid a metal-metal contact in which the return pipe 2 support portion of the nut 1 and the inner peripheral surface of the return pipe 2 directly contact each other, so that the gap is closely attached. It becomes possible to improve the degree, and the return pipe 2 and the nut 1
It is possible to prevent the occurrence of resonance sound due to the gap between the mating portion with the main body and the occurrence of vibration.

In the above ball screw, the case where the outer peripheral surface of the return pipe 2 is covered with the vibration absorbing member has been described. However, in the case where the outer peripheral surface is sequentially covered with the thin lead layer and the vibration absorbing member, , Small vibration can be absorbed by the lead thin film, and large vibration can be absorbed by the vibration absorbing member.
It is effective in terms of vibration and noise prevention. When used for relatively low speeds, the vibration absorbing member may be used without being covered.

For the vibration absorbing member, for example, elastic vibration-proof rubber or resin such as urethane rubber is used.

Further, as a method of fixing the return pipe 2 to the nut 1, a return pipe retainer as shown in FIGS. 5 and 7 can be used. The use of the fixing member made of material is superior in work efficiency.

[0021]

INDUSTRIAL APPLICABILITY The present invention makes it possible to improve the effect of reducing the vibration and noise generated when a ball passes through the return pipe in the tube tunnel type ball screw of this type. Is a great thing.

[Brief description of drawings]

FIG. 1 is a plan view of a main part of an embodiment of a ball screw of the present invention.

FIG. 2 is a perspective view of another main part of the same.

FIG. 3 is a sectional view taken along line XX of FIG.

4 is a sectional view of the same in a direction perpendicular to the screw axis of FIG. 1. FIG.

FIG. 5 is a plan view illustrating a conventional ball screw.

6 is a sectional view taken along line XX of FIG.

FIG. 7 is a sectional view taken along a direction perpendicular to the screw axis of the sectional view of FIG.

[Explanation of symbols]

1 ... nut, 2 ... return pipe, 3 ... ball, 6 ... thread groove, 8 ... screw shaft, 9 ... vibration resistant rubber or resin, 10a,
10b, 10c ... (provided in the concave portion of the nut 1)
Straight part, 11 ... (Inner peripheral surface of return pipe 2 and nut 1
Vibration-proof rubber or resin, which is inserted in the space formed by the linear portions 10a, 10b, 10c of the concave portion of
2. Fixing member (made of vibration-proof resin).

Claims (5)

[Claims] 1. A semicircular return pipe having an opening at both ends for picking up a ball and a tongue piece formed at the tip of the opening, and two insert pipes for inserting the openings at both ends of the return pipe. In a tube tunnel type ball screw formed by combining a through hole and a nut in which a recess for supporting the return pipe is formed, a linear structure having a cross-sectional shape of at least one through hole of the recess is a linear structure. A ball screw, characterized in that a vibration absorbing member is inserted into a gap between the nut and the return pipe. 2. The ball screw according to claim 1, wherein the return pipe is fixed to the nut by a fixing member made of a vibration absorbing material. 3. The ball screw according to claim 1, wherein an outer peripheral surface of the return pipe is covered with a vibration absorbing member. 4. The ball screw according to claim 1, wherein the return pipe has an outer peripheral surface sequentially coated with a thin lead layer and a vibration absorbing member. 5. The ball screw according to claim 1, 2 or 3 or 4, wherein the vibration absorbing member is made of vibration-proof rubber or resin having elasticity.