TWI410561B - Position Sensing Pneumatic Cylinder - Google Patents

Abstract

The purpose of this invention is to provide a position sensing type pneumatic cylinder which makes use of the LVDT theory to perform position sensing of the pneumatic cylinder through the use of a coil and a magnetic core without any extra sensors. The technical means comprises: a pneumatic cylinder body consisting of a hollow main cylinder body, an insulated linear axle sleeved and fixed at the exterior of the main cylinder body, and a metal magnetic cover sleeved and fixed at the exterior of the insulated linear axle, wherein a receiving space is formed between the insulated linear axle and the metal magnetic cover; a pneumatic pole with one end movably secured in the pneumatic cylinder body and the other end protruded from and slidable in the pneumatic cylinder body; a coil group wound in the receiving space, the coil group consisting of at least one primary coil and one secondary coil; and a magnetic core sleeved at one end of the pneumatic pole out of the pneumatic cylinder body.

Description

Position sensing pneumatic cylinder

The present invention relates to a position sensing pneumatic cylinder.

A linear differential transformer (LVDT) is a type of electromechanical transducer that converts the mechanical variation of a linear motion of an object into a corresponding electronic signal.

Due to the basic physical principles of the linear differential transformer (LVDT) itself, or the materials and techniques used in its own structure, it has certain characteristics and advantages. Its characteristics and advantages are as follows:

[1] frictionless operation, [2] infinite resolution, [3] mechanical life is infinitely long, [4] will not be damaged due to exceeding the measurement range, [5] uniaxial induction, [6] separable The coil and core, [7] good environmental resistance, [8] good zero repeatability, [9] fast dynamic response, [10] absolute value output.

The pneumatic cylinder uses the pressurized gas to transfer energy to work, and uses the air pressure as the power. In short, it uses compressed air to make a power source of the pneumatic cylinder through the air pressure to generate a controlled linear motion.

Pneumatic cylinders have many advantages, and their advantages are as follows:

[1] The power source is simple and the compressed air is easy to obtain.

[2] Pneumatic components are cheap, and the use of air pressure makes it easy to achieve low-cost automation.

[3] The speed is fast, and the speed of the pneumatic cylinder can reach 1~2m/sec, which can increase the production efficiency.

[4] No explosion hazard, compressed air due to non-sparking problems, can be used for explosive or disabled power.

[5] High suitability, which is the advantage of maximum pressure. Whether the automation of the existing machine is improved or the new machine is manufactured, the cylinder can be attached to the point of application and the installation is very simple.

[6] The system is clean and clean, and there is no trouble with hydraulic leakage.

[7] The adjustment of output and speed is easy, as long as it can be adjusted via a pressure regulating valve or a throttle valve.

[8] Parts are highly reliable and easy to maintain.

[9] The stroke adjustment is simple, and the stroke adjustment of the pneumatic cylinder can be achieved by using the limit switch (Stopper).

Combining the advantages of both, and affected by the factory environment, cost and demand, the linear differential transformer (LVDT) and pneumatic cylinders are very popular with the factory, especially for pneumatic cylinders that require precise control. An excellent choice.

The aforementioned linear differential transformer (LVDT) has the following problems:

1. The general linear differential transformer (LVDT) can be used directly with the pneumatic cylinder. However, when the installation area of the pneumatic cylinder is too narrow, it cannot be used. For increasingly sophisticated mechanical devices, it cannot be applied. Measuring the amount of displacement by other means, resulting in an increase in the overall cost, will complicate the device. The most important point is that because it cannot be directly measured, it is inevitable that the overall error will increase due to external factors. In terms of precision, it is very unfavorable.

In view of this, how to make the linear differential transformer (LVDT) can be directly disposed together with the pneumatic cylinder, and does not occupy other space, and reduce the cost of the overall precision mechanical device, is one of the objects of the present invention to be improved.

2. The precise control of pneumatic cylinders has been affected by its overall principle. There have been many difficulties. The measurement of displacement is very important. However, through the existing linear differential transformer (LVDT), although it can achieve certain results. However, because the linear differential transformer (LVDT) is installed in an external manner, when an error occurs in the installation, the overall device is abnormal.

In view of this, how to make the linear differential transformer (LVDT) can be directly set together with the pneumatic cylinder without installing it in an external manner to minimize the incidence of abnormal problems, which is the second object of the present invention. .

SUMMARY OF THE INVENTION The object of the present invention is to provide a position sensing type pneumatic cylinder capable of performing position sensing of a pneumatic cylinder without using an external sensor by using a LVDT principle.

In order to solve the foregoing problems and achieve the object of the present invention, the technical means of the present invention is a position sensing type pneumatic cylinder (100), characterized by comprising: a pneumatic cylinder (1), the pneumatic cylinder (1) is composed of a hollow main cylinder block (11), a set of insulated bobbins (12) fixed to the outer side of the main cylinder block (11), and a set of metal magnetic cover (13) fixed to the outer side of the insulated bobbin (12) And an accommodating space (14) is disposed between the insulating bobbin (12) and the metal magnetic cover (13); one end is disposed in the pneumatic cylinder (1), and the other end is protruded from the pneumatic cylinder a gas pressure rod body (2) outside the body (1) and capable of sliding therein; a group of coils (3) wound in the accommodating space (14) by a close parallel multi-stage winding method, The coil group (3) is composed of at least one primary coil (31) and a primary coil group (32); and a set of the pneumatic rod body (2) is located at one end of the pneumatic cylinder (1) External core (4).

According to the above position sensing type pneumatic cylinder (100), the primary coil (31) is wound around the center of the insulating bobbin (12); and the secondary coil group (32) is respectively wound around the foregoing The two ends of the primary coil (31) are composed of a first secondary coil (321) and a second secondary coil (322) wound in series in the reverse direction.

According to the above position sensing type pneumatic cylinder (100), the primary coil (31) is wound around the center of the insulating bobbin (12); and the secondary coil group (32) is respectively wound around the foregoing The two sides of the primary coil (31) are covered, and the primary coil (31) is covered to form a first secondary coil (321) and a second secondary coil (322) wound in series in the reverse direction.

According to the position sensing type pneumatic cylinder (100) described above, the secondary coil group (32) is first wound in a reverse series by being spaced apart from the insulated bobbin (12) at intervals. The primary coil (321) and the second secondary coil (322) are formed; and the primary coil (31) is arranged in two stages, and is disposed around the first secondary coil (321) away from the second secondary One side of the coil (322) and between the first secondary coil (321) and a second secondary coil (322).

According to the position sensing type pneumatic cylinder (100) described above, the insulating bobbin (12) is made of an insulating material having a small temperature coefficient.

According to the position sensing pneumatic cylinder (100) described above, the insulating bobbin (12) is made of one of the following materials: Bakelite, Steatite, and insulation containing glass frit organic resin. material.

According to the above position sensing type pneumatic cylinder (100), the coil group (3) is more electrically connected to an indicating driving device (5).

According to the above position sensing type pneumatic cylinder (100), the indicating driving device (5) further comprises a primary coil (10) capable of outputting an inductive signal (Vs) to the position sensing pneumatic cylinder (100). An AC signal generator (51); a power amplifier (52) disposed between the position sensing pneumatic cylinder (100) and the AC signal generator (51); and a position sensing pneumatic cylinder (100) a first rectifier (53) capable of receiving a first signal (Vf) generated by a secondary coil group (32) in a position sensing pneumatic cylinder (100); and a position sensing pneumatic cylinder (100) Electrically connected, a second rectifier (54) capable of receiving a second signal (Vr) generated by the secondary coil group (32) in the position sensing pneumatic cylinder (100); a first rectifier (53) and a first rectifier a rectifier (55) electrically connected to the rectifier (54); a zero adjuster (56) electrically connected to the differential amplifier (55); and a ratio of electrical connection to the zero adjuster (56) An amplifier (57); and a display (58) disposed at the output of the proportional amplifier (57).

According to the position sensing type pneumatic cylinder (100), the output end of the proportional amplifier (57) is further provided with at least one signal output end (59) capable of supplying power to the external device; and the signal output end (59) is one of the following: analog to digital signal output, analog signal output.

According to the above position sensing type pneumatic cylinder (100), the material of the magnetic core (4) is one of the following: ferrite, permalloy, pure iron.

According to the above position sensing type pneumatic cylinder (100), the coils of the primary coil (31) and the secondary coil group (32) have a frequency range of one of the following ranges: 1 to 10 Hz, 50 Hz, 60 Hz.

1. In the present invention, the pneumatic cylinder and the linear differential transformer are directly connected by combining the pneumatic cylinder (1), the pneumatic rod body (2), the coil group (3) and the magnetic core (4). LVDT) can be combined to eliminate the need for linear differential transformer (LVDT) installation space, and can be directly installed and used, without the need to install other measuring devices, it is very convenient to use, compared with the traditional pneumatic cylinder and linear In addition to retaining the original advantages, the differential transformer (LVDT) has the advantage of low cost and can also be applied to high-precision machines with small size.

2. Another key point of the present invention, unlike the general pneumatic cylinder, is affected by the structure of the pneumatic cylinder (1) itself, and in order for the invention to operate normally according to the principle of a linear differential transformer (LVDT), it is necessary to Through the addition of the magnetic core (4), the coil group (3) can react and output the signal for measurement, so as to measure the displacement of the pneumatic rod body (2).

The following is a detailed description of the embodiment shown in the following figure: FIG. 1 is a perspective view showing the coil group of the present invention as the first winding method, and FIG. 2 is a coil group of the present invention. FIG. 3 is a perspective view showing the three winding methods of the present invention, and FIG. 3 is a schematic view showing the third winding method of the present invention. FIG. 4, FIG. 5, and FIG. 3 is a schematic block diagram of the first winding method of the present invention, and FIG. 8 is a schematic diagram of the coil group of the present invention when the winding group is the second winding method. FIG. 9 is a block diagram showing the third winding method of the present invention. FIG. 11 is a block diagram of the circuit of the present invention.

The figure discloses a position sensing pneumatic cylinder (100), characterized by comprising: a pneumatic cylinder (1), which is composed of a hollow main cylinder (11), a set of insulated wire shafts (12) fixed to the outer side of the main cylinder block (11) and a set of metal magnetic cover (13) fixed to the outer side of the insulated wire shaft (12), and the insulated wire shaft (12) An accommodating space (14) is disposed between the metal magnetic cover (13); one end is disposed in the pneumatic cylinder (1), and the other end is protruded from the pneumatic cylinder (1) and can be a pneumatic rod body (2) which is internally slipped; a group of coils (3) wound in the accommodating space (14) by a close-coupled parallel multi-stage winding method, the coil group (3) being at least A primary coil (31) and a primary coil assembly (32); and a magnetic core (4) disposed outside the pneumatic cylinder (1) at one end of the pneumatic cylinder (1).

Wherein, by combining the pneumatic cylinder (1) and the coil group (3), the magnetic core (4) and the pneumatic rod body (2) are combined, and the pneumatic cylinder and the linearity are combined by means of the combination. The differential transformer (LVDT), combined into one, can eliminate the traditional linear differential transformer (LVDT), its installation space requirements, and can be directly installed and used, without the need to install other measuring devices, the use is very convenient, It is also suitable for use in mechanical devices with a pneumatic cylinder but not capable of installing a limit switch.

Secondly, compared with the traditional pneumatic cylinder and linear differential transformer (LVDT), in addition to retaining the original advantages, because the conventional pneumatic cylinder and linear differential transformer (LVDT) are not purchased at the same time, as long as the invention is directly used It has the same operational effect as the above two, and has the advantage of low cost.

Secondly, unlike the general pneumatic cylinder, it is affected by the structure of the pneumatic cylinder (1) itself. In order to allow the invention to operate normally according to the principle of a linear differential transformer (LVDT), it is necessary to pass through the magnetic core (4). Adding, in order to make the coil group (3) react, output the signal for measurement, so as to achieve the effect of measuring the displacement of the pneumatic rod body (2).

Furthermore, the arrangement of the metal magnetic cover (13), in addition to mechanical protection, can produce electromagnetic and electrostatic shielding effects.

In the above, the primary coil (31) is wound around the center of the insulating bobbin (12); and the secondary coil group (32) is respectively wound around the two ends of the primary coil (31), A first secondary coil (321) and a second secondary coil (322) are wound in series in reverse.

Among them, the coil group (3) is composed of a three-stage type, which has better linearity and sensitivity, and can be used for a high-precision mechanical device.

Secondly, in this arrangement, since the linearity problem is not considered, the length of the core (4) can be larger than the coil set length of the coil group (3) [not shown].

In the above, the primary coil (31) is wound around the center of the insulating bobbin (12); and the secondary coil group (32) is respectively wound around the two ends of the primary coil (31), and The aforementioned primary coil (31) is covered, and is composed of a first secondary coil (321) and a second secondary coil (322) wound in series in the reverse direction.

Among them, the coil group (3) is composed of a three-stage type, which has linearity and sensitivity, and can be used for medium and low precision mechanical devices.

In the above, the secondary coil group (32) is a first secondary coil (321) and a second time wound in series in a reverse direction around the insulated wire shaft (12). The primary coil (322) is composed of two stages, and is disposed on a side of the first secondary coil (321) away from the second secondary coil (322), and A secondary coil (321) and a second secondary coil (322).

Among them, this setting method is a two-stage setting, because the linearity problem is considered, the length of the magnetic core (4) is preferably 70% of the coil set length of the coil group (3) [not disclosed].

In the above, the insulating bobbin (12) is made of an insulating material having a small temperature coefficient.

Among them, the insulating bobbin (12) is manufactured by using an insulating material with a small temperature coefficient, which can avoid internal temperature, affect the operation of the coil group (3), and can avoid eddy current loss, low sensitivity, poor linearity, and residual voltage. Great question.

In the above, the insulating bobbin (12) is made of one of the following materials: Bakelite, Steatite, and an insulating material containing a glass frit organic resin.

Among them, the use of different materials, suitable for pneumatic cylinders (1) of different lengths, cylinder diameters, and scope of use, can provide a more diversified choice for the industry.

In the above, the coil group (3) is more electrically connected to an indicating driving device (5).

Wherein, since there is no driving coil group (3), the displacement amount of the pneumatic rod body (2) of the present invention cannot be directly known, so that the position sensing type can be made by electrically connecting an indicating driving device (5). The pneumatic cylinder (100) operates normally.

In the above, the indicating driving device (5) further comprises an alternating current signal generator (51) capable of outputting an inductive signal (Vs) to the primary coil (31) in the position sensing pneumatic cylinder (100). AC SIGNAL GENERATOR]; a power amplifier (52) [POWER AMPLIFIER/POWER AMP] between the position sensing pneumatic cylinder (100) and the AC signal generator (51); and a position sensing pneumatic cylinder (100 a first rectifier (53) [AC TO DC RECTIFIER] capable of receiving a first signal (Vf) generated by the secondary coil group (32) in the position sensing pneumatic cylinder (100); The second pneumatic rectifier (54) is electrically connected to the sensing pneumatic cylinder (100) and can receive the second signal (Vr) generated by the secondary coil group (32) in the position sensing pneumatic cylinder (100) [AC TO DC RECTIFIER]; a differential amplifier (55) [DIFFERENTIAL AMPLIFIER] electrically connected to the first rectifier (53) and the second rectifier (54); a zero adjuster electrically connected to the differential amplifier (55) (56) [OFFSET ADJUST]; a proportional amplifier (57) [SCALE AMPLIFIER] electrically connected to the zero adjuster (56); and a display (58) provided at the output of the proportional amplifier (57) )[MONITOR].

Wherein, since the first secondary coil (321) and the second secondary coil (322) output alternating current, it is necessary to use the first rectifier (53) and the second rectifier (54) to generate both of them. The first signal (Vf) and the second signal (Vr) are converted into DC signals that the differential amplifier (55) can use for calculation.

Secondly, the differential amplifier (55) can be used to input the DC signal converted by the first signal (Vf) and the second signal (Vr) to be input into the proportional amplifier (57).

In addition, the use of the zero adjuster (56) allows the user to arbitrarily set the origin for ease of use.

Furthermore, the proportional amplifier (57) is used because the signals generated by the first rectifier (53) and the second rectifier (54) are too small, so a proportional amplifier (57) is needed to amplify it for subsequent use. Judgment.

In addition, through the display (58), the user can directly know the signal data.

In the above, at the output end of the proportional amplifier (57), at least one signal output terminal (59) [OUTPUT] capable of supplying power to the external device is further provided; and the signal output terminal (59) is as follows One: analog to digital signal output, analog signal output.

Among them, through the addition of the signal output terminal (59), it is convenient to electrically connect with other external devices to facilitate subsequent control.

Secondly, by means of different signal outputs (59), the selection of external devices to which the invention can be connected can be increased to meet the needs of the modern industry.

In the above, the material of the magnetic core (4) is one of the following: ferrite, high magnetic nickel (permalloy), pure iron.

Among them, through the use of different magnetic core (4) materials, the pneumatic cylinders (1) suitable for different lengths, cylinder diameters, and applications can provide a more diversified choice for the industry.

Next, the material of the magnetic core (4) In the above, the coils of the primary coil (31) and the secondary coil group (32) have a frequency range of one of the following ranges: 1 to 10 Hz, 50 Hz, 60 Hz.

Among them, the coil frequency range generally used commercially is mostly 50 Hz or 60 Hz, and when there are different requirements, 1 to 10 Hz can also be applied, no matter which kind of coil frequency, it can be directly extended to reduce the cost. .

FIG. 10 is a schematic circuit diagram of the present invention, and FIG. 12 is a schematic diagram showing the implementation of a circuit block in the operation of the present invention.

The drawing discloses that the operational flow of the present invention, when indicating the AC signal generator (51) in the driving device (5), passes through the power amplifier (52) to the primary coil of the position sensing pneumatic cylinder (100) ( 31) After inputting a sensing signal (Vs) of the alternating voltage, the generated magnetic field causes the secondary coil group (32) to induce an alternating voltage.

The first secondary coil (321) is connected to one side of the second secondary coil (322), and the other side is outputted, that is, reversely connected in series.

Since the first secondary coil (321) and the second secondary coil (322) are connected in reverse series, the induced voltages of the first secondary coil (321) and the second secondary coil (322) are 180 degrees out of phase with each other, and the output is The voltage is the induced voltage of the first secondary coil (321) and the second secondary coil (322), that is, the first signal (Vf) is subtracted from the second signal (Vr).

When the magnetic core (4) is in the middle, the first signal (Vf) and the second signal (Vr) of the two first secondary coils (321) and the second secondary coil (322) are the same size, and the output voltage is zero.

When the magnetic core (4) moves toward the first secondary coil (321), the inductance of the first secondary coil (321) increases, the induced voltage increases, and the first signal (Vf) increases; the other direction The second secondary coil (322) is removed by the magnetic core (4), the inductance of the second secondary coil (322) is reduced, the induced voltage is decreased, the second signal (Vr) is decreased, and the first signal is on both sides. (Vf) The voltage subtracted from the second signal (Vr) is the output voltage of the present invention, which is transmitted through the first rectifier (53), the second rectifier (54), the differential amplifier (55), and the zero adjuster ( 56) After the use of the proportional amplifier (57), the position change of the pneumatic rod body (2) can be measured, and the displacement change is directly known to the display (58).

Finally, it should be noted that although the above and the figure, there are only two winding groups (3) winding method, this is because the winding group (3) has a large number of winding methods, so it will not be described in detail here. The part of the coil group (3) in the figure is easy to understand for the reader, and the coil group (3) in each of the above figures is represented by a block, a hatching line, and actually a coil group ( 3) is a coil that is wound around.

As can be seen from the above, in the present invention, the cooperation between the pneumatic cylinder and the linear differential transformer (LVDT) is directly integrated directly by the above-described arrangement, and the repetition is eliminated. It can reduce the use of space, reduce the failure rate and reduce the overall cost. Compared with the current pneumatic cylinder and linear differential transformer (LVDT), it is more practical, efficient and industrially usable.

In the above, the structure, features and effects of the present invention are described in detail according to the embodiments shown in the drawings. Since the novel and progressive requirements are met, the invention patent application is filed according to the law; however, the above description is only preferred of the present invention. The present invention is not limited by the scope of the invention, and the modifications of the present invention are intended to be within the scope of the present invention as long as they are within the scope of the present invention.

1. . . Pneumatic cylinder

11. . . Master cylinder

12. . . Insulated bobbin

13. . . Metal magnetic cover

14. . . Housing space

2. . . Pneumatic rod body

3. . . Coil group

31. . . Primary coil

32. . . Secondary coil set

321. . . First secondary coil

322. . . Second secondary coil

4. . . Magnetic core

5. . . Indicating drive

51. . . AC signal generator

52. . . Power amplifier

53. . . First rectifier

54. . . Second rectifier

55. . . Differential amplifier

56. . . Zero adjuster

57. . . Proportional amplifier

58. . . monitor

59. . . Signal output

100. . . Position sensing pneumatic cylinder

Vf. . . First signal

Vr. . . Second signal

Vs. . . Inductive signal

Figure 1 is a perspective view showing the coil group of the present invention in the first winding method.

Fig. 2 is a perspective view showing the coil group of the present invention in the second winding method.

Fig. 3 is a perspective view showing the coil group of the present invention in a third winding method.

Figure 4 is a full cross-sectional view of Figure 1.

Figure 5 is a full cross-sectional view of Figure 2.

Figure 6 is a full cross-sectional view of Figure 3.

Fig. 7 is a block diagram showing the coil group of the present invention in the first winding method.

Figure 8 is a block diagram showing the coil group of the present invention in the second winding method.

Fig. 9 is a block diagram showing the third winding method of the coil group of the present invention.

Figure 10 is a schematic diagram of the circuit of the present invention.

Figure 11 is a block diagram of the circuit of the present invention.

Figure 12 is a block diagram showing the implementation of the circuit block in the operation of the present invention.

1. . . Pneumatic cylinder

11. . . Master cylinder

12. . . Insulated bobbin

13. . . Metal magnetic cover

14. . . Housing space

2. . . Pneumatic rod body

3. . . Coil group

31. . . Primary coil

32. . . Secondary coil set

321. . . First secondary coil

322. . . Second secondary coil

4. . . Magnetic core

5. . . Indicating drive

100. . . Position sensing pneumatic cylinder

Claims (10)

A position sensing pneumatic cylinder (100), comprising: a pneumatic cylinder (1), the pneumatic cylinder (1) is fixed to the main by a hollow main cylinder (11) An insulating bobbin (12) outside the cylinder block (11) and a set of metal magnetic shields (13) fixed to the outside of the insulating bobbin (12), and the insulating bobbin (12) and the metal magnetic shield (13) Between the two, there is a accommodating space (14); a pneumatic rod body which is located at one end of the pneumatic cylinder (1) and protrudes outside the pneumatic cylinder (1) at the other end and can slide therein (2) a group of coils (3) wound in the accommodating space (14) in a close-coupled parallel multi-stage winding method, the coil group (3) being composed of at least one primary coil (31) And a primary coil set (32); and a magnetic core (4) disposed outside the pneumatic cylinder (1) at one end of the pneumatic cylinder (1). The position sensing pneumatic cylinder (100) according to claim 1, wherein the primary coil (31) is wound around a center of the insulated bobbin (12); and the secondary coil group (32) It is composed of a first secondary coil (321) and a second secondary coil (322) which are respectively wound around the two sides of the primary coil (31) and wound in series in the reverse direction. The position sensing pneumatic cylinder (100) according to claim 1, wherein the primary coil (31) is wound around a center of the insulated bobbin (12); and the secondary coil group (32) Is a first secondary coil (321) and a second secondary coil which are respectively wound around the two sides of the primary coil (31) and covered by the primary coil (31) to be wound in series in the reverse direction. (322) is composed. The position sensing pneumatic cylinder (100) according to claim 1, wherein the secondary coil group (32) is reversed from the insulated wire shaft (12) at an interval, respectively. a first secondary coil (321) and a second secondary coil (322) wound in series; and the primary coil (31) is arranged in two stages, and is wound around the first secondary coil (321) being away from a side of the second secondary coil (322) and between the first secondary coil (321) and a second secondary coil (322). The position sensing type pneumatic cylinder (100) according to claim 1, wherein the insulating bobbin (12) is made of an insulating material having a small temperature coefficient. The position sensing type pneumatic cylinder (100) according to claim 1, wherein the insulating bobbin (12) is made of one of the following materials: bakelite, block talc, and organic resin containing glass frit. Insulation material. The position sensing pneumatic cylinder (100) according to claim 1, characterized in that the coil group (3) is further electrically connected to an indicating driving device (5). The position sensing type pneumatic cylinder (100) according to claim 7, characterized in that: the indicating driving device (5) further comprises a position sensing type pneumatic cylinder (Vs) capable of outputting an induction signal (Vs) ( 100) an alternating current signal generator (51) at the inner primary coil (31); a power amplifier (52) disposed between the position sensing pneumatic cylinder (100) and the alternating current signal generator (51); The first pneumatic device (53) electrically connected to the measuring pneumatic cylinder (100) and capable of receiving the first signal (Vf) generated by the secondary coil group (32) in the position sensing pneumatic cylinder (100); The sensing pneumatic cylinder (100) is electrically connected to receive a second rectifier (54) of the second signal (Vr) generated by the secondary coil group (32) in the position sensing pneumatic cylinder (100); a differential amplifier (55) electrically connected to the first rectifier (53) and the second rectifier (54); a zero adjuster (56) electrically connected to the differential amplifier (55); and a zero adjuster (56) an electrically connected proportional amplifier (57); and a display (58) disposed at the output of the proportional amplifier (57). The position sensing pneumatic cylinder (100) according to claim 8, characterized in that: at the output end of the proportional amplifier (57), at least one signal output terminal capable of supplying power to the external device is provided (59) The signal output terminal (59) is one of the following: analog to digital signal output, analog signal output. The position sensing type pneumatic cylinder (100) according to claim 1, wherein the material of the magnetic core (4) is one of the following: an oxyiron body, a high magnetic nickel steel, and pure iron; The coils of the primary coil (31) and the secondary coil group (32) have a frequency range of one of the following ranges: 1 to 10 Hz, 50 Hz, 60 Hz.