TWM576656U - Displacement measuring mechanism for automated equipment - Google Patents

Abstract

A displacement measuring mechanism for an automatic device, the automation device having at least one base, at least one load linear slide parallel to the base along a working axis, a drive unit parallel to the load linear slide and a load linear slide And a sliding table connected to the driving unit, the driving unit is connected to the sliding table by a sliding seat. The displacement measuring mechanism includes a scale disposed on the base and parallel to the working axis. A non-loading linear slide rail is disposed on the base, and the scale is disposed on the non-load linear slide. A linear slide is coupled to the slide. A read head is attached to the linear slide and corresponds to the scale. The installation method of placing the scale close to the working axis, in addition to the simple installation, is not limited by the size of the existing linear slide product, and is more advantageous for mass production to reduce the cost.

Description

Displacement measuring mechanism for automated equipment

The present invention relates to a displacement measuring device, in particular to a displacement measuring mechanism for an automatic device which is easy to assemble and disassemble, has high measurement accuracy and low cost.

The linear encoder includes a linear encoder, a magnetic encoder, a laser encoder, etc., and is generally called an optical scale. The optical scale is an optical device incorporating an electromechanical principle. It is mainly used to monitor the motion state of the operating mechanism in the automation equipment, and measure the travel distance, so that the automation equipment can complete the preset operation actions as scheduled.

Since the optical ruler can effectively reduce the positioning error caused by the thermal expansion of the ball screw in the automatic control equipment (such as the machine tool) to increase the machining accuracy and improve the quality of the workpiece, it has become one of the main position measuring devices, and the existing one. According to the installation method, the optical ruler can be mainly divided into external type and built-in type.

As shown in Fig. 6, it is an existing external optical scale which is mounted on the side of a load-bearing linear slide 2 of the machine tool, so that the ruler of the optical scale 1 and the load linear slide 2 Parallelly disposed, and a read head 4 is mounted on a load slide 3, the read head 4 is brought close to and corresponds to the optical scale 1, and the read head 4 is displaced relative to the optical scale 1 when it is driven by the load slide 3 In order to obtain displacement data.

However, the external optical ruler 1 is not only afraid of oil stain (interpretation distortion), but also easily damaged by external force impact, and more troublesome, based on the optical ruler 1 and the load-bearing linear slide 2 The requirement of maintaining parallelism, plus the 2 weeks side of the load linear slide rail, usually only leaves a narrow assembly space, which makes the optical scale 1 difficult to install, assuming that the load platform of the implement is a longer moving stroke. In the case of a gantry type milling machine, the effective range of the assembled optical scale must also be longer. As a result, the assembler is required to manually correct the optical scale 1 and load linearity in addition to the problem of narrow assembly space. The parallelism of the slide rail 2 is even more challenging, and the difficulty of manual correction is increased.

However, in order to overcome the external optical scale 1 as described above, it manually corrects difficult installation problems, as shown in Fig. 7, another built-in magnetic ruler 5, with the aid of the machine tool, the load linear slide 2 is parallel to The working axis of the machine tool is set, so that the magnetic ruler 5 is directly mounted on the chute 6 on both sides of the load-bearing linear slide rail 2, and it is easy to correct the upper optical scale. However, the general-purpose load-bearing linear slide rail 2 has its chute. 6 height is limited, about 60mm, the installation space is quite narrow, and because the resolution of the magnetic ruler 5 is lower than the resolution of the optical scale, the lower the resolution of the magnetic ruler, the lower the resolution, hindering the measurement. The need for precision, the built-in magnetic ruler 5 is not conducive to the installation of small magnetic feet (such as small size magnetic feet below 35mm), otherwise the accuracy is not high, in addition, the magnetic rule 5 is expensive, the larger the size The magnetic ruler will greatly increase the cost.

In summary, the external optical scale 1 is difficult to manually correct and is placed outside the load-bearing linear slide 2, which is not only afraid of oil pollution, but also has weak anti-vibration force and is easily damaged, while the built-in magnetic ruler 5 is less afraid of oil stains. However, the price is high and the anti-vibration resistance is also very weak. Therefore, whether it is an external optical scale 1 or a built-in magnetic ruler 5, the common problem is that the anti-vibration force is weak and is easily damaged by external impact. However, there is a problem of damage, it is difficult to disassemble, or even can not be removed at all, unless the entire machine assembly is completely disassembled, so maintenance is quite difficult.

In addition, due to the limited measurement accuracy of the built-in magnetic ruler, as shown in Fig. 8, a manufacturer also installs a magnetic ruler 5, 7 on each side of the chute 6 of the load-bearing linear slide 2. One is an incremental magnetic ruler 5, and the other is an absolute magnetic ruler 7. As a result, the cost of use is increased, and the measurement error is limited. A magnetic ruler 5, 7 is mounted on each of the left and right chutes 6, which is difficult to install and disassemble.

The displacement measuring mechanism of the automated device of the present invention will be equipped with a scale near the working axis, which is not only easy to assemble, but also facilitates the convenience of disassembly.

In the displacement measuring mechanism of the automatic device of the present invention, since the scale is installed close to the working axis, the scale is not limited by the size, which is advantageous for the mass production of the scale to reduce the manufacturing and use cost.

The displacement measuring mechanism of the automatic equipment of the present invention, because the installation position of the scale is located on the working axis (machining point) of the automation equipment, the two coincide with each other and lie on the same straight line, the working error is extremely small, and the highest machining precision can be obtained. degree.

Therefore, the displacement measuring mechanism of the automatic device proposed by the present invention has at least one base, at least one load linear slide rail disposed parallel to the base along a working axis, and a load linearity a driving unit parallel to the sliding rail, and a sliding table coupled to the load linear sliding rail and the driving unit, the driving unit rod is connected to the sliding table by a sliding seat, and the displacement measuring mechanism comprises: a scale , placed on the base and parallel to the working axis. A non-loaded linear slide rail is disposed on the base, and the scale is disposed on the non-load linear slide rail. A linear slide is coupled to the slide. A read head is coupled to the linear slide and corresponds to the scale.

The displacement measuring mechanism of the above-mentioned automatic device according to the present invention further includes a fixing frame, the linear sliding seat is fixed on the sliding seat, and the fixing frame is disposed on the linear sliding seat and adjacent to the driving unit. The read head is disposed on the fixing frame, and the sliding carriage drives the linear sliding seat to synchronously drive the displacement of the fixing frame to interlock the reading head, so that the reading head is displaced relative to the scale, thereby obtaining displacement data. .

The displacement measuring mechanism of the above-described automatic device according to the present invention, wherein the scale is adjacent to the driving unit and adjacent to the working axis.

According to the creation of the displacement measuring mechanism of the above-mentioned automatic device, the mounting position of the scale is the working axis of the shaft for the automation device.

The displacement measuring mechanism of the above-mentioned automatic device according to the present invention, wherein the base further comprises a reference platform parallel to the load linear slide, the non-load linear slide resting on the reference platform, so that The non-loaded linear slide is disposed in parallel with the load linear slide.

According to the present invention, the displacement measuring mechanism of the above-mentioned automatic device, wherein the scale and the read head constitute a linear encoder, which is any one of a magnetic encoder, an optical encoder, and a laser encoder.

According to the creation of the displacement measuring mechanism of the above-mentioned automatic device, the driving unit is any one of a ball screw, a ruler and a gear, and a linear motor.

Another displacement measuring mechanism of the automated device of the present invention, the automation device having at least one base, at least one load linear slide rail disposed parallel to the base along a working axis, and a load parallel to the load linear slide a driving unit, and a sliding table coupled to the load linear sliding rail and the driving unit, wherein the driving unit is connected to the sliding table by a sliding seat, the displacement measuring mechanism comprises: a scale disposed thereon On the slide table, parallel to the working axis. A non-loaded linear slide rail is disposed on the slide table, and the scale is disposed on the non-load linear slide rail. A linear slide is attached to the base. A read head is coupled to the linear slide and corresponds to the scale.

The displacement measuring mechanism of the above-mentioned automatic device according to the present invention further includes a fixing frame disposed on the linear sliding seat and adjacent to the driving unit, the reading head is disposed on the fixing frame, close to And corresponds to the scale.

According to the creation of the above-mentioned displacement measuring mechanism of the automatic device, wherein, at the moment A ruler is adjacent to the drive unit and adjacent to the working axis.

According to the present invention, the displacement measuring mechanism of the above-mentioned automatic device, wherein the scale and the read head constitute a linear encoder, which is any one of a magnetic encoder, an optical encoder, and a laser encoder.

According to the creation of the displacement measuring mechanism of the above-mentioned automatic device, the driving unit is any one of a ball screw, a ruler and a gear, and a linear motor.

According to the above, compared with the parallelism of the existing optical scale, the installation is not easy, and the existing built-in magnetic ruler is not conducive to the overall manufacturing design of the machine tool, and the problems that both are difficult to disassemble and repair. In the displacement measuring mechanism of the automatic device of the present invention, the installation method of placing the scale close to the working axis is not limited by the size, and is also advantageous for the mass production of the scale. To reduce costs. In addition, through the setting of the non-loading linear slide rail, the scale is more convenient to install and parallel with the working axis (machining path) to ensure the accuracy of the displacement measurement and more effectively reduce the working error.

The case:

10‧‧‧ machine base

11‧‧‧ benchmark platform

20‧‧‧Linear slides

21‧‧‧Slide

30‧‧‧Drive unit

31‧‧‧Slide

40‧‧‧ slide table

50‧‧‧ Displacement measuring mechanism

51‧‧‧ scale

52‧‧‧Reading

53‧‧‧ Non-load linear slides

531‧‧‧ Track

54‧‧‧linear slide

541‧‧‧ lock points

55‧‧‧Retaining frame

60‧‧‧Processing tools

61‧‧‧Workpiece

70‧‧‧ fixed frame

80‧‧‧Rotary bearings

81‧‧‧ inner circle

82‧‧‧Outer ring

90‧‧‧Processing tools

100‧‧‧Automation equipment

L‧‧‧Working axis

A‧‧‧Processing point

S‧‧‧ distance

Prior art:

1‧‧‧Load linear slide

2‧‧‧Slide rails

3‧‧‧ optical ruler

4‧‧‧Load slide

5‧‧‧Reading

6‧‧‧Magnetic ruler

7‧‧‧Chute

8‧‧‧Magnetic ruler

1 is a combination diagram of a first preferred embodiment of a displacement measuring mechanism of an authoring automation device.

Figure 2 is a schematic view of the read head mounted on the linear slide by the holder.

Figure 3 is a view similar to Figure 1 illustrating the displacement measuring mechanism mounted slightly off the working axis.

Figure 4 is a combination diagram of a second preferred embodiment of the displacement measuring mechanism of the authoring automation device.

Figure 5 is a schematic view of the displacement measuring mechanism applied to a rotating bearing.

Figure 6 is a schematic view of a conventional optical scale mounted on a load-bearing linear slide.

Figure 7 is a plan view of a conventional magnetic ruler and load linear slide.

Figure 8 is a schematic view showing the mounting of two magnetic feet on both sides of the load linear slide.

Referring to Figures 1 and 2, in a first preferred embodiment of the displacement measuring mechanism of the present invention, the automation device 100 has at least one base 10, at least one of which is placed in parallel along a working axis L. a load linear slide 20 on the seat 10, a drive unit 30 disposed parallel to the load linear slide 20, and a slide 40 coupled to the load linear slide 20 and the drive unit 30, the load linear slide 20, the driving unit 30 and the sliding table 40 are respectively connected to a sliding seat 31 by a sliding seat 21, so that the sliding table 40 is linearly loaded by the sliding seat 21 and the sliding seat 31. The slide rail 20 and the driving unit 30 slide to perform a linear motion of moving left or right. The driving unit 30 is any one of a ball screw (Ballscrew), a ruler and a gear (Rack and Pinion), and a linear motor. In the embodiment, the driving unit 30 is a ball screw.

The present invention is characterized in that the displacement measuring mechanism 50 includes a scale (Graduation, commonly known as Scale) 51, a read head 52, a non-load linear slide 53 and a linear slide 54.

The scale 51 is disposed on the base 10 in parallel and adjacent to the working axis L and adjacent to the drive unit 30. In this embodiment, the scale 51 and the read head 52 form a linear encoder, which includes a magnetic encoder (also known as a magnetic scale) and an optical encoder (a linear encoder). ), laser encoder (Laser Encoder, also known as laser optical ruler). In addition, since the magnetic ruler has the advantage of being resistant to oil and stain, the scale 51 is preferably optimized to use a magnetic ruler.

The non-loading linear slide rail 53 is disposed on the base 10, and the scale 51 is disposed on the non-loading linear slide rail 53.

The linear slider 54 is coupled to the slide table 40.

The read head 52 is coupled to the linear slider 54 and corresponds to the scale 51. In this embodiment, the read head 52 is a decoder (Decoder) for interpreting the position data of the scale 51, and then being controlled by a control center (not shown) to control the execution of the slide 40. The movement of right shift or right shift, because the control center is not the main appeal of this case, it will not be explained here.

The displacement measuring mechanism 50 further includes a fixing bracket 55. The linear sliding seat 54 is coupled to the sliding seat 31. The fixing bracket 55 is disposed on the linear sliding seat 54 and coupled to the driving unit 30. The reading head 52 is disposed on the fixing frame 55. In practice, the non-loading linear slide rail 53 can be disposed on the base 10 when the base 10 is manufactured. Thus, the scale 51 is disposed on the track 531 on the side of the non-load-loaded linear slide 53. The read head 52 is mounted on the fixing frame 55, and the linear slider 54 is driven by the sliding seat 31, and the displacement of the fixing frame 55 is synchronously driven to interlock the reading head 52 to make the reading head. 52 is displaced relative to the scale 51 to obtain displacement data.

In addition, as shown in FIG. 2, in practice, the base 10 of the automation device further has a reference platform 11 which is disposed in parallel with the load-bearing linear slide 20 in FIG. 1, so that when installed When the displacement measuring mechanism 50 is positioned, the non-loading linear slide rail 53 is directly abutted on the reference platform 11 so that the non-loading linear slide rail 53 and the load linear slide rail 20 are arranged in parallel, thereby eliminating the need for correction. The scale 51 placed thereon is aligned parallel to the machining point A of the machining tool 60 (see Fig. 1), and the assembly is fast and accurate, so as to save the inconvenience of recalibration.

In the present embodiment, the displacement measuring mechanism 50 is included on each working axis of the automatic equipment machine 100, for example, mounted on the side of the driving unit (ball screw) close to the X-axis, the Y-axis, and the Z-axis.

Therefore, the displacement measuring mechanism of the authoring automation device, the scale 51 Close to the mounting manner of the driving unit 30, since the space around the driving unit 30 is relatively spacious, in addition to facilitating disassembly and assembly, more than a limited size of the scale 51 can be installed, so the scale 51 is In the case of no size limitation, it can be mass-produced to reduce manufacturing costs and is suitable for various types of automation equipment (tool machines). Secondly, based on the mounting position of the scale 51, the machining point A for machining a workpiece 61 by the automation device 100 is coincident with the working axis L and is in the same straight line, the angular deviation is equal to zero or close to Zero, the Abbe error is quite small, so that the read head 52 is placed on the side of the slider 31 to correspond to the scale 51, and can be read through the read head 52 as the slide 40 is displaced. Taking the position data of the scale 51, the linear movement of the slide 40 to perform right shift or right shift is controlled correctly and without error to facilitate the cutting work of the workpiece 61 and obtain the highest machining accuracy.

Further, as shown in FIG. 3, the displacement measuring mechanism 50 is mounted on one side of the carriage 31 such that the read head 52 corresponds to the scale 51, and the scale 51 is mounted on the circumferential side of the drive unit 30. And adjacent to the working axis L, since the distance S between the scale 51 and the driving unit 30 is relatively short, the distance S value is very small, almost approaching zero, and the Abbe error is also relatively small, so When the workpiece 61 performs cutting work, a high degree of machining accuracy can also be obtained.

Referring to FIG. 4, in a second preferred embodiment of the displacement measuring mechanism of the present invention, the automation device 100 has at least one base 10 and at least one parallelly disposed along a working axis L (machining point A). a load linear slide rail 20 on the base 10, a drive unit 30 disposed in parallel with the load linear slide rail 20, and a slide table 40 coupled to the load linear slide rail 20 and the drive unit 30, the load The linear slide rail 20, the driving unit 30 and the sliding table 40 are respectively connected to a sliding seat 31 by a sliding seat 21, so that the sliding table 40 is located by the sliding seat 21 and the sliding seat 31. The load linear slide 20 is slid on the driving unit 30 for linear movement of left shift or right shift. The driving unit 30 is any one of a ball screw, a ruler and a gear, and a linear motor. In the embodiment, the driving unit 30 is a ball screw.

In the second embodiment, the displacement measuring mechanism 50 includes a scale 51, a read head 52, a non-loading linear slide 53 disposed on the slide 40, and a linear slide 54 coupled to the base 10, the scale 51 being disposed on the non-load linear slide 53 and The sliding table 40 is coupled to be parallel and adjacent to the working axis L. The reading head 52 is fixed to the linear sliding seat 54 and coupled to the base 10, and corresponds to the scale 51. In this embodiment, a fixed portion is further included. The holder 70 is disposed on the base 10 and adjacent to the driving unit 30, and the reading head 52 is disposed on the fixing frame 70, adjacent to and corresponding to the scale 51. Thereby, the scale 51 is mounted on the slide table 40 in parallel with the working axis L, and the read head 52 is coupled to the base 10 through the support erection of the fixing frame 70, and is close to the scale. The ruler 51 can drive the scale 51 to be displaced relative to the read head 52 through the slide table 40, and can also obtain the displacement data, and achieve the same use effect as the above embodiment, which will not be further explained.

In summary, since the displacement measuring mechanism 50 of the present invention discards the original method of arranging the optical ruler (magnetic ruler) on the load linear slide rail, it is installed on the machine platform in an independent small slide rail mode. The non-loading linear slide 53 does not bear the function of the support slide 40, but is simply used as a function of a displacement sensor. Therefore, the scale 51 is no longer subjected to the existing load linear slide. The limitation of the cross-sectional shape and size, on the one hand, facilitates the assembler to visually assemble the space to install the displacement measuring mechanism 50, and therefore, the creation is not limited by the original slide rail size except for the advantages of disassembly and assembly and maintenance. However, the displacement measuring mechanism 50 of the present invention can also adopt the existing small slide rails and mass production advantages to reduce the cost. In addition, through the non-loading linear slide 53 setting, the scale 51 is more convenient to install and parallel with the working axis L (machining path) to ensure the accuracy of the displacement measurement, and more effectively reduce the work. error.

Incidentally, based on the scale 51 being mounted close to the driving unit 30, the head 52 is assembled at the bottom of the slider 31 and the interval corresponds to the scale 51. Therefore, in actual installation, The scale 51 is mounted on the circumferential side of the driving unit 30, and the closer to the working axis L, the better, and it is optimal to fall on the working axis L (as in the mounting mode of FIG. 1). If there is no deviation or imitation (as shown in Fig. 3 or Fig. 4), as long as the position of the read head 52 is adjusted so that the two correspond to each other, the intended use effect and purpose can be achieved. Secondly, referring to FIG. 2, since the general automation device is provided with a plurality of locking points 551 for providing locking on the sliding seat 31, in practice, the existing locking point 551 can be used together with the fixing frame. The connection of the head 52 is such that the read head 52 is placed thereon so that the read head 52 corresponds to the scale 51, so that the assembly convenience is increased, and the assembly is ensured to improve the overall assembly. The accuracy.

Finally, there is a problem that the existing optical scale or the magnetic ruler has difficulty in installation. However, the displacement measuring mechanism 50 of the present invention is installed close to the driving unit 30, which is convenient for wiring, and is also relatively easy to assemble and disassemble. It is easy and simple, and is placed on the side of the drive unit 30 or below, and can avoid dust and oil pollution, and is not directly affected by the high-load linear slide and its unit vibration.

It is worth mentioning that, from the point of view of the error factors of precision mechanical design, in addition to the manufacturing problems of optical tapes or magnetic scales (sensors), we still need to consider the existence of Abbe error. According to the calculation formula of Abbe error: Abbe error=S*Sinθ (where S represents the distance between the linear motion axis and the sensing axis, and θ represents the angular difference between the cutting axis and the sensing axis), therefore, S The larger the value, the larger the error.

Similarly, since the installation position of the creation scale 51 is placed on the working axis L (Fig. 1) or adjacent to the working axis L (such as Fig. 3 or Fig. 4), the installation position is close to work. The axis L, the angular deviation is equal to zero or close to zero, according to Abbe error=S*Sinθ, therefore, the machining point A at which the machining tool 60 of the automation device 100 processes the workpiece 61 coincides with the working axis L and is in the same straight line, and The distance S between the scale 51 and the driving unit 30 is relatively short, and the optimum distance S value is equal to zero (Fig. 1) or almost close to zero (such as Fig. 3 or Fig. 4), so the creation displacement The measurement mechanism 50 has a relatively small Abbe error. Therefore, compared with the existing optical scale and the magnetic scale installed on the load linear slide, the Abbe error of the creation is extremely small, so that the automation equipment can be improved. Precision.

It is worth mentioning that, in the first to fourth figures of the present invention, the displacement sensing mechanism 50 discloses a manner of installation and use of a linear motion. Of course, the displacement sensing mechanism 50 can also be applied to an automatic device for rotating motion. As shown in FIG. 5, for example, the read head 52 is mounted on an inner ring 81 of a rotary bearing 80, and the scale 51 is mounted on an outer ring 82, or the positions of the two are interchanged, whereby When a machining tool 90 performs a rotational motion along the machining point A, the rotational displacement data can be obtained with respect to the scale 51 through the read head 52.

The above description is only a preferred embodiment of the present invention, and the scope of the present invention cannot be limited by this, that is, the simple equivalent changes and modifications made by the applicant according to the scope of the patent application and the new description of the creation are all It should remain within the scope of this creation patent.

Claims (12)

A displacement measuring mechanism for an automatic device, the automation device having at least one base, at least one load linear slide rail disposed parallel to the base along a working axis, and a driving unit disposed in parallel with the load linear slide rail And a sliding table coupled to the load linear sliding rail and the driving unit, the driving unit rod is connected to the sliding table by a sliding seat, and the displacement measuring mechanism comprises: a scale disposed on the base Parallel to the working axis; a non-loaded linear slide rail is disposed on the base, the scale is disposed on the non-load linear slide rail; a linear slide is coupled to the slide table; and a read head , attached to the linear slide, and corresponding to the scale. The displacement measuring mechanism of the automatic device of claim 1, further comprising a fixing frame, wherein the linear sliding seat is fixed on the sliding seat, the fixing frame is disposed on the linear sliding seat, and is close to The driving unit is disposed on the fixing frame, and the slider drives the linear sliding seat to synchronously drive the displacement of the fixing frame to interlock the reading head, so that the reading head is displaced relative to the scale. Further, displacement data is obtained. The displacement measuring mechanism of the automated device of claim 1, wherein the scale is adjacent to the driving unit and adjacent to the working axis. The displacement measuring mechanism of the automatic device of claim 1, wherein the mounting position of the scale is an axis of operation of the axis with respect to the automation device. The displacement measuring mechanism of the automatic device of claim 1, wherein the base further comprises a reference platform parallel to the load linear slide, the non-load linear slide leaning against the reference platform Upper, so that the non-loaded linear slide is disposed in parallel with the load linear slide. The displacement measuring mechanism of the automatic device according to claim 1, wherein the scale and the read head comprise a linear encoder, the linear encoder is a magnetic encoder, an optical encoder, and a lightning Shoot any of the encoders. The displacement measuring mechanism of the automatic device according to claim 1, wherein the driving unit is any one of a ball screw, a ruler and a gear, and a linear motor. A displacement measuring mechanism for an automatic device, the automation device having at least one base, at least one load linear slide rail disposed parallel to the base along a working axis, and a driving unit disposed in parallel with the load linear slide rail And a sliding table coupled to the load-bearing linear slide rail and the driving unit, the driving unit is connected to the sliding table by a sliding seat, the displacement measuring mechanism comprises: a scale disposed on the sliding table, Parallel to the working axis; a non-loaded linear slide rail disposed on the slide table, the scale is disposed on the non-load linear slide rail; a linear slide joint coupled to the base; and a read head , attached to the linear slide, and corresponding to the scale. The displacement measuring mechanism of the automatic device of claim 8, further comprising a fixing frame disposed on the linear sliding seat and adjacent to the driving unit, the reading head being disposed at the fixing On the shelf, close to and corresponding to the scale. The displacement measuring mechanism of the automated device of claim 8, wherein the scale is adjacent to the driving unit and adjacent to the working axis. The displacement measuring mechanism of the automatic device according to claim 8, wherein the scale and the read head comprise a linear encoder, the linear encoder is a magnetic encoder, an optical encoder, and a laser encoder. Any one. The displacement measuring mechanism of the automatic device according to claim 8, wherein the driving unit is any one of a ball screw, a ruler and a gear, and a linear motor.