JP2007212177A - Torque fluctuation measuring device for ball screw - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a torque fluctuation measuring device for a ball screw capable of accurately measuring the torque fluctuation of the ball screw. <P>SOLUTION: This torque fluctuation measuring device 10 for the ball screw has a constitution, equipped with a torque detector 11 for detecting a rotating torque generated in a nut 2, when a screw shaft 1 is rotated, and a detector support mechanism 12 for supporting the torque detector 11. The torque detector 11 is constituted of a torque detection plate 19 having a screw shaft insertion hole for inserting the screw shaft 1, and at least two pin type load cells 21, provided on the torque detection plate 19 that is to be fitted respectively to each one of a plurality of bolt insertion holes 8 formed of a flange 7 for fixing a nut of the ball screw. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a ball screw torque fluctuation measuring device used when measuring a torque fluctuation of a ball screw.

In various industrial machines such as machine tools, for example, a ball screw as shown in FIG. 5 is often used as a mechanical element that converts rotational motion into linear motion. This ball screw includes a screw shaft 1 and a nut 2, and a ball screw groove 3 is formed on the outer peripheral surface of the screw shaft 1. The ball screw groove 3 faces a ball screw groove 4 formed on the inner peripheral surface of the nut 2, and the ball 5 provided between the ball screw groove 3 and the ball screw groove 4 is, for example, a screw shaft 1. When the ball rotates about the axis, it rolls on the ball rolling path formed between the ball screw grooves 3 and 4 and then rolls in the ball circulation tube 6 assembled to the nut 2 for infinite circulation. It has become.
By the way, when measuring such a torque fluctuation of a ball screw, conventionally, a ball stopper is attached to a nut of the ball screw, and the torque of the nut is detected by a torque detector via the rotation stopper bar. The torque fluctuation of the screw is measured.

However, in such a method, since the torque detector detects the rotational torque of the nut via the non-rotating bar, it is difficult to accurately measure even a small torque fluctuation of the ball screw.
The present invention has been made paying attention to such a problem, and an object of the present invention is to provide a ball screw torque fluctuation measuring device capable of accurately measuring the torque fluctuation of a ball screw. .

  In order to achieve the above object, the invention of claim 1 is directed to a torque detector for detecting a rotational torque generated in the nut when a screw shaft of a ball screw is rotated, and a detection for supporting the torque detector. A torque variation measuring device for a ball screw comprising a device support mechanism, wherein the torque detector includes a torque detection plate having a screw shaft insertion hole for allowing the screw shaft to pass therethrough, and a nut fixing of the ball screw. It comprises at least two load cells provided on the torque detection plate so as to be fitted to any one bolt insertion hole among a plurality of bolt insertion holes formed in the flange.

The invention according to claim 2 is the ball screw torque fluctuation measuring apparatus according to claim 1, wherein the detector support mechanism is a base and a slider provided on the upper surface of the base so as to be slidable via a linear guide rail. And a detector support member protruding upward from the upper surface of the slider.
The invention according to claim 3 is the ball screw torque fluctuation measuring device according to claim 1, wherein the detector support mechanism has a donut-shaped detector mounting surface facing the flange side end surface of the nut. And a detector pressing mechanism for pressing the torque detector mounted on the detector mounting surface of the detector support member against the flange side end surface of the nut.
According to a fourth aspect of the present invention, in the ball screw torque fluctuation measuring device according to the third aspect, the detector pressing mechanism extends from the detector mounting surface of the detector support member toward the flange side end surface of the nut. It is comprised from the several L-shaped arm to take out.

  According to the present invention, when measuring the torque fluctuation of the ball screw, the torque torque of the ball screw can be accurately measured because the torque detector can detect the rotational torque of the nut without using a detent bar. it can.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a ball screw torque fluctuation measuring apparatus according to a first embodiment of the present invention. As shown in the figure, the ball screw torque fluctuation measuring apparatus 10 according to the first embodiment of the present invention detects torque that is generated in the nut 2 when the screw shaft 1 of the ball screw is rotated. A detector 11 and a detector support mechanism 12 that supports the torque detector 11 so as to be movable in the axial direction of the screw shaft 1 are provided. Here, the detector support mechanism 12 has a base 13 and a slider 15 slidably provided on the base 13 via a linear guide rail 14. The torque detector 11 is an upper surface portion of the slider 15. It is attached to the upper end part of the detector support member 16 which makes the shape of a rod projecting upward from the top.

The detector support mechanism 12 has a guide ring 17 for guiding the screw shaft 1, and the guide ring 17 is an upper end of a bar-shaped guide ring support member 18 projecting upward from the upper surface of the slider 15. It is fixed to the part.
On the other hand, the torque detector 11 has a torque detection plate 19 formed in a circular shape with a diameter substantially the same as the nut fixing flange 7 of the ball screw, and a screw shaft is provided at the center of the torque detection plate 19. 1 is provided with a screw shaft insertion hole 20 (see FIG. 2).

  The torque detection plate 19 has a donut-shaped load cell mounting surface 19a (see FIG. 3) facing the flange-side end surface 2a of the nut 2, and the load cell mounting surface 19a has three types as shown in FIG. A pin type load cell 21 is fixed. These pin type load cells 21 are fixed on the load cell mounting surface 19 a at equal intervals in the circumferential direction of the nut fixing flange 7, and each load cell 21 has a plurality of bolt insertion holes provided in the nut fixing flange 7. 8 is configured to be fitted to any one of the bolt insertion holes 8.

  In such a configuration, when measuring the torque fluctuation of the ball screw, after passing the screw shaft 1 of the ball screw through the screw shaft insertion hole 20 of the torque detection plate 19, the load cell 21 attached to the torque detection plate 19 is attached. The nut fixing flange 7 is fitted into the bolt insertion hole 8. If the screw shaft 1 of the ball screw is rotated in this state, the torque fluctuation of the ball screw can be measured by the load cell 21 fitted in the bolt insertion hole 8 of the nut fixing flange 7.

  In the above-described first embodiment of the present invention, the torque detector 11 that detects the rotational torque of the nut 2 includes the torque detection plate 19 having the screw shaft insertion hole 20 and the plurality of nut fixing flanges 7. By comprising three pin type load cells 21 fixed to the torque detection plate 19 so as to be fitted to any one of the bolt insertion holes 8, as in the prior art described above, Since the torque detector 11 can detect the rotational torque of the nut 2 without using a detent bar when measuring the torque fluctuation of the ball screw, the torque fluctuation of the ball screw can be accurately measured.

Next, a second embodiment of the present invention will be described with reference to FIG.
In FIG. 4, a torque fluctuation measuring device for a ball screw according to a second embodiment of the present invention includes a torque detector 11 for detecting rotational torque generated in a nut 2 when the screw shaft 1 of the ball screw is rotated. The torque detector 11 is provided with a detector support mechanism 23 that rotatably supports the ball screw. Here, the torque detector 11 has a torque detection plate 19 formed in a circular shape with a diameter substantially equal to that of the nut fixing flange 7, and the screw shaft 1 is provided at the center of the torque detection plate 19. A screw shaft insertion hole 20 is provided for passing through.

The torque detector 11 has three pin type load cells 21 that fit into one of a plurality of bolt insertion holes 8 provided in the nut fixing flange 7. These load cells 21 are nut fixing flanges. 7 is provided on the torque detection plate 19 so as to protrude toward the position 7.
On the other hand, the detector support mechanism 23 has a detector support member 24 that supports the torque detector 11. The detector support member 24 is formed in a block shape, and when measuring the torque fluctuation of the ball screw, the torque fluctuation is measured through the screw shaft 1 through the screw shaft insertion hole 25 formed in the detector support member 24. It has a configuration.

  The detector support mechanism 23 has a detector pressing mechanism 26 that presses the torque detector 11 attached to the detector attachment surface 24 a of the detector support member 24 against the flange-side end surface 2 a of the nut 2. . The detector pressing mechanism 26 includes a plurality of L-shaped arms 27 extending from the detector mounting surface 24 a of the detector support member 24 toward the flange-side end surface 2 a of the nut 2. The torque detector 11 is pressed against the flange-side end surface 2 a of the nut 2 by engaging the tip end portion with the nut fixing flange 7 via the ball bearing 28.

In the second embodiment of the present invention configured as described above, similarly to the first embodiment, the torque of the nut 2 is torqued without using a detent bar when measuring the torque fluctuation of the ball screw. Since it can detect with the detector 11, the torque fluctuation of a ball screw can be measured accurately.
In the first and second embodiments described above, the three load cells 21 are attached to the torque detection plate 19, but the same effect can be obtained even if the number of load cells 21 attached to the torque detection plate 19 is two. Can do.

It is a schematic block diagram of the torque variation measuring apparatus for ball screws which concerns on the 1st Embodiment of this invention. It is a front view of the torque detector shown in FIG. It is a side view of the torque detector shown in FIG. It is a schematic block diagram of the torque variation measuring apparatus for ball screws which concerns on the 2nd Embodiment of this invention. It is a schematic block diagram of a ball screw.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Screw shaft 2 Nut 3, 4 Ball screw groove 5 Ball 6 Ball circulation tube 7 Nut fixing flange 8 Bolt insertion hole 11 Torque detector 12 Detector support mechanism 13 Base 14 Linear guide rail 15 Slider 16 Detector support member 17 Guide Ring 18 Guide ring support member 19 Torque detection plate 20 Screw shaft insertion hole 21 Load cell 23 Detector support mechanism 24 Detector support member 25 Screw shaft insertion hole 26 Detector pushing mechanism 27 L-shaped arm 28 Ball bearing

Claims (4)

  A torque variation measuring apparatus for a ball screw, comprising: a torque detector that detects rotational torque generated in the nut when the screw shaft of the ball screw is rotated; and a detector support mechanism that supports the torque detector. The torque detector includes a torque detection plate having a screw shaft insertion hole for passing the screw shaft, and a plurality of bolt insertion holes formed in a nut fixing flange of the ball screw. A torque fluctuation measuring device for a ball screw, comprising: at least two load cells provided on the torque detection plate so as to be respectively fitted to bolt insertion holes.   The detector support mechanism includes a base, a slider slidably provided on the upper surface of the base via a linear guide rail, and a detector support member projecting upward from the upper surface of the slider. The ball screw torque fluctuation measuring device according to claim 1, wherein:   The detector support mechanism includes a detector support member having a donut-shaped detector mounting surface facing the flange end surface of the nut, and the torque detector mounted on the detector mounting surface of the detector support member. The ball screw torque fluctuation measuring device according to claim 1, further comprising a detector pressing mechanism that presses the nut against a flange side end surface of the nut.   The said detector pressing mechanism is comprised from the several L-shaped arm extended toward the flange side end surface of the said nut from the detector mounting surface of the said detector support member. Torque fluctuation measuring device for ball screws.

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