CN215599068U

CN215599068U - Device for detecting piston

Info

Publication number: CN215599068U
Application number: CN202121595155.6U
Authority: CN
Inventors: 沈天宇
Original assignee: Wuxi Huaxing Mechanical And Electrical Manufacture Co ltd
Current assignee: Wuxi Huaxing Mechanical And Electrical Manufacture Co ltd
Priority date: 2021-07-13
Filing date: 2021-07-13
Publication date: 2022-01-21
Anticipated expiration: 2031-07-13

Abstract

The utility model relates to a device for detecting a piston, which is characterized in that: the device comprises a bracket, a driving mechanism, a detection device for piston flaw detection, a positioning device for placing a piston and a driving device for driving the piston to rotate; the driving mechanism drives the detection device to move along the surface of the piston; the positioning device is connected with the driving end of the driving device; the positioning device is rotatably arranged on the bracket. The problem of among the current scheme piston generally all not fix, lead to the detection error great is solved.

Description

Device for detecting piston

Technical Field

The utility model relates to the field of detection equipment, in particular to a device for detecting a piston.

Background

The piston is widely applied to an engine as a core part, the head of the piston and the cylinder body of the engine form a combustion chamber together, and huge explosion pressure can be generated to push the piston to do work when mixed oil gas is subjected to compression ignition. The piston is a reciprocating element in the cylinder body of the automobile engine. The basic structure of the piston can be divided into a piston top, a piston head and a piston skirt. The piston is used as one of important parts of an automobile engine mechanism, the detection precision requirement is higher and higher, and the piston detection is more and more an important component of the automobile manufacturing industry. The piston needs to be detected during production to check whether the piston meets the standard. Detection is generally carried out manually, but the existing detection is that an inspector directly holds a measuring tool to measure a piston, and the piston is not fixed generally, so that the detection error is larger. How to solve this problem becomes crucial.

Disclosure of Invention

In view of the above disadvantages of the prior art, an object of the present invention is to provide a device for detecting a piston, so as to solve the problem that the piston is not fixed generally, resulting in a large detection error.

In order to achieve the purpose, the technical scheme of the utility model is as follows:

an apparatus for piston detection;

the device comprises a bracket, a driving mechanism, a detection device for piston flaw detection, a positioning device for placing a piston and a driving device for driving the piston to rotate; the driving mechanism drives the detection device to move along the surface of the piston; the positioning device is connected with the driving end of the driving device; the positioning device is rotatably arranged on the bracket.

The further technical scheme is as follows: the driving mechanism comprises a moving module and a first power device for driving the detection device to rotate; the mobile modules are arranged in a mutually vertical and crossed manner; the first power device is arranged at the moving end of the moving module.

The further technical scheme is as follows: the moving module comprises a moving frame, a screw rod rotationally arranged in the moving frame, a moving block moving along the moving frame and a second power device driving the screw rod to rotate; the moving block is in threaded connection with the lead screw; the second power device is arranged on the movable frame.

The further technical scheme is as follows: the second power device drives the screw rod through a coupler; and the coupler is respectively connected with the screw rod and the driving end of the second power device.

The further technical scheme is as follows: the positioning device comprises a positioning cylinder, a cylinder plate arranged in the positioning cylinder, an adjusting rod arranged on the cylinder plate and a positioning piece for supporting the piston; the positioning piece is arranged on the adjusting rod; the piston is placed on the positioning cylinder.

The further technical scheme is as follows: a first adjusting mechanism for pushing the barrel plate to move along the positioning barrel is arranged in the positioning barrel; the first adjusting mechanism comprises a connecting rod, a connecting piece, a threaded rod rotating along the positioning cylinder and an adjusting piece oppositely arranged on the threaded rod; the threaded rod is relatively provided with external threads in opposite spiral directions; the adjusting piece is in threaded connection with the external thread; the connecting pieces are respectively arranged on the barrel plate and in the positioning barrel; one end of the connecting rod is connected with the connecting piece in a swinging mode; the other end of the connecting rod is connected with the adjusting piece in a swinging mode.

The further technical scheme is as follows: a supporting cylinder is arranged around the positioning cylinder; a support rod is arranged in the support cylinder in a sliding manner; the supporting rod is connected with the barrel plate; a moving hole is formed in the positioning cylinder along the moving direction of the cylinder plate; the threaded rod moves along the moving hole.

The further technical scheme is as follows: the adjusting rod is also provided with a second adjusting mechanism for pushing the positioning piece to move along the adjusting rod; the second adjusting mechanism comprises a linkage rod and adjusting discs sleeved at two ends of the adjusting rod; the linkage rods are connected between the adjusting discs in parallel around the adjusting rods; the linkage rods comprise rod pieces which are connected with each other in an angle; the rod piece is connected with the adjusting disc in a swinging mode.

The further technical scheme is as follows: the device also comprises a measuring mechanism for measuring the height of the positioning piece; the measuring mechanism comprises an air tightness detecting device and a spigot seat covered on the positioning device; the spigot seat is provided with a spigot; when the spigot seat covers the positioning device, the positioning piece seals the spigot; the positioning cylinder, the cylinder plate and the spigot seat form a sealed space; the sealed space is respectively communicated with the inlet and the outlet of the air tightness detection device.

The further technical scheme is as follows: the detection device is an eddy current flaw detector; the driving device is a motor.

Compared with the prior art, the utility model has the following beneficial technical effects: (1) the piston is placed on the positioning device to complete the fixation of the piston, the driving device drives the positioning device and the piston to rotate, and the driving mechanism drives the detection device to move along the surface of the piston, so that the flaw detection of the piston is completed without the need of holding the piston for measurement, and the measurement precision of the device for detecting the piston is improved; (2) the moving module arranged in the horizontal direction drives the moving module, the first power device and the detection device arranged in the vertical direction to move left and right, the moving module arranged in the vertical direction drives the first power device and the detection device to move up and down, and the first power device drives the detection device to rotate, so that the detection device moves along the surface of the piston, the flaw detection of the surface of the piston is completed, and the measurement precision of the flaw detection is improved; (3) the height of the positioning piece is adjusted, so that the upper end of the positioning piece abuts against the edge of the lower end of the seam allowance, the seam allowance is sealed by the positioning piece, the sealing space is sealed, the upper end of the positioning piece reaches the height of the edge of the lower end of the seam allowance, the adjustment and calibration of the height of the positioning piece are completed by judging the sealing performance of the sealing space, the accuracy of the height of the positioning piece is ensured by the calibration of the measuring mechanism, the positioning piece supports the piston to a certain height, and the piston is convenient to detect by the detection device; (4) the fine adjustment of the height position of the positioning piece is completed through the second adjusting mechanism, the positioning piece is supported by the adjusting disc positioned above the adjusting disc by adjusting the position of the adjusting disc on the adjusting rod, the support of the positioning piece is completed through the second adjusting mechanism, and when the piston is placed on the positioning device, the piston is outwards supported through the linkage rod and is fixed on the positioning device.

Drawings

Fig. 1 shows a schematic structural diagram of a device for piston detection according to an embodiment of the present invention.

Fig. 2 shows a schematic structural view of a drive mechanism according to an embodiment of the present invention.

Fig. 3 shows a schematic structural diagram of a positioning device according to an embodiment of the present invention.

In the drawings, the reference numbers: 1. a drive mechanism; 11. a moving module; 12. a first power unit; 13. a movable frame; 14. a screw rod; 15. a moving block; 16. a second power unit; 17. a coupling; 2. a detection device; 3. a positioning device; 31. a positioning cylinder; 32. a barrel plate; 33. adjusting a rod; 34. a positioning member; 35. moving the hole; 4. a drive device; 5. a support; 6. a first adjustment mechanism; 61. a threaded rod; 62. an adjustment member; 63. a connecting member; 64. a connecting rod; 65. a support cylinder; 66. a support bar; 7. a second adjustment mechanism; 71. adjusting the disc; 72. a linkage rod; 73. a rod member; 8. a measuring mechanism; 81. an air tightness detection device; 82. a spigot seat; 83. stopping the opening; 84. and sealing the space.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the following detailed description of the present invention is provided with reference to the accompanying drawings and the detailed description. The advantages and features of the present invention will become more apparent from the following description. It is to be noted that the drawings are in a very simplified form and are all used in a non-precise scale for the purpose of facilitating and distinctly aiding in the description of the embodiments of the present invention. To make the objects, features and advantages of the present invention comprehensible, reference is made to the accompanying drawings. It should be understood that the structures, ratios, sizes, and the like shown in the drawings and described in the specification are only used for matching with the disclosure of the specification, so as to be understood and read by those skilled in the art, and are not used to limit the implementation conditions of the present invention, so that the present invention has no technical significance, and any structural modification, ratio relationship change or size adjustment should still fall within the scope of the present invention without affecting the efficacy and the achievable purpose of the present invention.

Fig. 1 shows a schematic structural diagram of a device for piston detection according to an embodiment of the present invention. Fig. 2 shows a schematic structural view of a drive mechanism according to an embodiment of the present invention. Fig. 3 shows a schematic structural diagram of a positioning device according to an embodiment of the present invention. Referring to fig. 1, 2 and 3, the present invention discloses a device for piston detection. The direction of X in the figure is the upper end of the structural schematic diagram of the utility model, and the direction of Y in the figure is the right end of the structural schematic diagram of the utility model.

The device for piston detection comprises a bracket 5, a driving mechanism 1, a detection device 2 for piston flaw detection, a positioning device 3 for placing a piston and a driving device 4 for driving the piston to rotate. The drive mechanism 1 drives the detection device 2 along the piston surface. The positioning device 3 is connected with the driving end of the driving device 4. The positioning device 3 is rotatably arranged on the bracket 5.

Preferably, the driving means 4 is a motor. The driving device 4 is arranged on the bracket 5 in the vertical direction. The upper end of the driving device 4 is the driving end of the driving device 4. The upper end of the driving device 4 is connected with the positioning device 3. The piston is placed on the positioning device 3 and the driving device 4 drives the positioning device 3 and the piston to rotate.

The piston is placed on the positioning device 3, the piston is fixed, the positioning device 3 and the piston are driven to rotate through the driving device 4, the detection device 2 is driven to move along the surface of the piston through the driving mechanism 1, the flaw detection of the piston is completed, the piston does not need to be held by hand for measurement, and the measurement precision of the device for detecting the piston is improved.

The drive means 4 is a motor, the choice of motor type being common knowledge. Those skilled in the art can select the motor according to the working condition of the device, for example, the motor with the model number of PL22-750W-10S can be selected.

The driving mechanism 1 comprises a moving module 11 and a first power device 12 for driving the detection device 2 to rotate. The moving modules 11 are arranged to cross each other perpendicularly. The first power device 12 is arranged at the moving end of the moving module 11.

Preferably, the inspection apparatus 2 is an eddy current flaw detector. Preferably, the first power device 12 is an electric motor. Preferably, the moving modules 11 are two sets. The moving modules 11 are horizontally disposed. The other set of moving modules 11 is vertically disposed. The horizontally arranged moving module 11 is arranged on the support 5. The moving module 11 arranged in the vertical direction is arranged at the moving end of the moving module 11 arranged in the horizontal direction. The first power device 12 is arranged at the moving end of the moving module 11 arranged in the vertical direction.

The detection device 2 is an eddy current flaw detector, and the selection of the type of the eddy current flaw detector belongs to the common knowledge. Those skilled in the art can select the device according to the working condition of the device, for example, an eddy current flaw detector with the model number being DMD-85RFT can be selected.

The first power means 12 is an electric motor, and the selection of the type of the electric motor is common knowledge. Those skilled in the art can select the motor according to the working condition of the device, for example, the motor with the model number of PL22-750W-10S can be selected.

The moving module 11 includes a moving frame 13, a lead screw 14 rotatably provided in the moving frame 13, a moving block 15 moving along the moving frame 13, and a second power unit 16 driving the lead screw 14 to rotate. The moving block 15 is screwed to the lead screw 14. The second power device 16 is arranged on the moving frame 13.

The second power device 16 drives the screw 14 through a coupling 17. The coupling 17 is respectively connected with the screw rod 14 and the driving end of the second power device 16.

Preferably, the second power device 16 is an electric motor. The second power device 16 drives the coupler 17 to rotate, the coupler 17 drives the lead screw 14 to rotate, and the lead screw 14 pushes the moving block 15 to move.

The second power means 16 is an electric motor, the choice of the type of motor being common knowledge. Those skilled in the art can select the motor according to the working condition of the device, for example, the motor with the model number of PL22-750W-10S can be selected.

The horizontal direction sets up remove the module 11, first power device 12 and the detection device 2 and remove about the removal module 11 of the vertical direction setting of removal module 11 drive, and the first power device 12 of the removal module 11 drive and the detection device 2 that vertical direction set up reciprocate, and first power device 12 drive detection device 2 is rotatory for detection device 2 moves along the piston surface, accomplishes the detection of detecting a flaw on piston surface, has improved the measurement accuracy who detects a flaw.

The positioning device 3 includes a positioning cylinder 31, a cylinder plate 32 provided in the positioning cylinder 31, an adjustment rod 33 provided on the cylinder plate 32, and a positioning member 34 supporting the piston. The positioning member 34 is provided on the adjustment lever 33. The piston is placed on the positioning cylinder 31.

The positioning cylinder 31 is vertically rotatably provided on the holder 5. The cylinder plate 32 is horizontally disposed in the positioning cylinder 31. The adjustment lever 33 is vertically provided on the cylinder plate 32. The lower end of the adjustment lever 33 is connected to the upper surface of the cylinder plate 32. The positioning member 34 is provided at the upper end of the adjustment lever 33.

The positioning cylinder 31 is provided with a first adjusting mechanism 6 for pushing the cylinder plate 32 to move along the positioning cylinder 31. The first adjusting mechanism 6 comprises a connecting rod 64, a connecting piece 63, a threaded rod 61 rotating along the positioning cylinder 31 and an adjusting piece 62 oppositely arranged on the threaded rod 61. The threaded rod 61 is provided with external threads with opposite spiral directions. The adjustment member 62 is threaded onto the external threads. The connecting members 63 are provided on the barrel plate 32 and in the positioning barrel 31, respectively. One end of the connecting rod 64 is connected with the connecting piece 63 in a swinging way. The other end of the connecting rod 64 is pivotally connected to the adjustment member 62.

Preferably, there are two connecting members 63. The threaded rod 61 is disposed in the left-right direction. External threads are opened around the left and right sides of the threaded rod 61. The adjustment member 62 is screwed to the left and right sides of the threaded rod 61. The connecting members 63 are provided on the lower surface of the barrel plate 32 and the lower end inside the positioning barrel 31, respectively. The connecting member 63 is connected to the adjusting member 62 by a connecting rod 64.

A support cylinder 65 is provided around the positioning cylinder 31. A support rod 66 is slidably arranged in the support cylinder 65. The support rod 66 is connected to the barrel plate 32. The positioning cylinder 31 is provided with a moving hole 35 along the moving direction of the cylinder plate 32. The threaded rod 61 moves along the moving hole 35.

The support cylinder 65 is vertically disposed in the positioning cylinder 31. The support rod 66 is slidably disposed in the support cylinder 65 in the vertical direction. The upper end of the support rod 66 is connected to the lower surface of the cylinder plate 32. The lower end of the support rod 66 slides along the support cylinder 65. The moving hole 35 is opened on the right side of the outer surface of the positioning cylinder 31. The threaded rod 61 is inserted into the moving hole 35 in the left-right direction. The threaded rod 61 moves up and down along the inside of the moving hole 35.

The adjusting lever 33 is further provided with a second adjusting mechanism 7 for pushing the positioning member 34 to move along the adjusting lever 33. The second adjusting mechanism 7 includes a linkage rod 72 and an adjusting plate 71 sleeved on both ends of the adjusting rod 33. The lever 72 is connected in parallel between the adjustment disks 71 around the adjustment lever 33. The linkage 72 includes links 73 that are connected to each other at an angle. The lever 73 is connected to the dial 71 by swinging.

Preferably, there are two adjustment discs 71. The adjusting plate 71 is sleeved on the upper and lower ends of the adjusting rod 33. The upper end of the linkage 72 is connected with the adjusting disk 71 positioned above in a swinging mode. The lower end of the linkage 72 is connected with the adjusting disc 71 positioned below in a swinging mode. The upper end of the lower rod 73 is connected at an angle to the lower end of the upper rod 73. The lower end of the lower rod 73 is connected with the lower adjusting disk 71 in a swinging mode. The upper end of the upper rod 73 is connected with the upper adjusting disk 71 in a swinging way.

The adjustment plate 71 is screwed with a screw, which is inserted into the adjustment rod 33, and the position of the adjustment plate 71 can be adjusted by screwing the screw.

A measuring mechanism 8 for measuring the height of the positioning element 34 is also included. The measuring mechanism 8 comprises a tightness detection device 81 and a spigot seat 82 covering the positioning device 3. The spigot seat 82 is provided with a spigot 83. When the spigot seat 82 is covered on the positioning device 3, the positioning piece 34 seals the spigot 83. The positioning cylinder 31, the cylinder plate 32 and the spigot seat 82 form a sealed space 84. The sealed spaces 84 are respectively communicated with the inlet and the outlet of the air tightness detecting device 81.

Preferably, the air tightness detecting device 81 is an air tightness detector. When the spigot seat 82 is covered on the positioning device 3, the lower surface of the spigot seat 82 is attached to the upper surface of the positioning cylinder 31, the upper end of the positioning piece 34 abuts against the edge of the lower end of the spigot 83, and the positioning piece 34 seals the spigot 83, so that the positioning cylinder 31, the cylinder plate 32 and the spigot seat 82 form a sealed space 84. The spigot 83 opens at the upper end of the spigot seat 82. An inlet hole and an outlet hole are formed in the positioning cylinder 31, and the sealing space 84 is communicated with the inlet hole and the outlet hole respectively. The inlet is communicated with the inlet of the air tightness detection device 81 through an air pipe. The outlet is communicated with the outlet of the air tightness detection device 81 through an air pipe.

The air tightness detection device 81 is an air tightness detector, and the selection of the type of the air tightness detector belongs to the common knowledge. The person skilled in the art can choose the type of airtightness detector, SLA-M-1501-D, for example, according to the working conditions of the apparatus.

The measuring device 8 serves for calibrating the height of the positioning element 34. The spigot seat 82 covers the positioning device 3, the air tightness detection device 81 conveys air into the sealed space 84, the upper end of the positioning piece 34 does not abut against the edge of the lower end of the spigot 83, the positioning piece 34 cannot seal the spigot 83, and the sealing performance of the sealed space 84 is poor at the moment, which indicates that the upper end of the positioning piece 34 does not reach the height of the edge of the lower end of the spigot 83. The height of the retainer 34 is adjusted so that the upper end of the retainer 34 abuts the edge of the lower end of the seam allowance 83, and the retainer 34 seals the seam allowance 83 and seals the sealed space 84, indicating that the upper end of the retainer 34 reaches the height of the edge of the lower end of the seam allowance 83. By judging the tightness of the sealed space 84, the height adjustment calibration of the positioning member 34 is completed. Through the calibration of measuring mechanism 8, the accuracy of setting element 34 height has been guaranteed for setting element 34 supports the piston to a take the altitude, makes things convenient for detection device 2 to detect the piston. After the measuring device 8 has been calibrated, the stop socket 82 is removed from the positioning device 3 and the piston is placed on the positioning device 3.

When the height of the positioning member 34 needs to be lowered, the threaded rod 6 is screwed, the threaded rod 6 pushes the adjusting members 62 away from each other, the lower connecting member 63 supports the adjusting members 62 through the connecting rod 64, the upper connecting member 63 moves downward, and the adjusting members 62 support the upper connecting member 63 through the connecting rod 64. When the connecting piece 63 located above moves downwards, the barrel plate 32 moves downwards along the positioning barrel 31, the threaded rod 6 moves downwards along the moving hole 35, and at this time, the barrel plate 32 drives the second adjusting mechanism 7, the adjusting rod 33 and the positioning piece 34 to move downwards.

When the height of the positioning member 34 needs to be adjusted upward, the threaded rod 6 is reversely screwed, the threaded rod 6 pushes the adjusting members 62 to approach each other, the connecting member 63 located at the lower side supports the adjusting members 62 through the connecting rod 64, the connecting member 63 located at the upper side moves upward, and the adjusting members 62 support the connecting member 63 located at the upper side through the connecting rod 64. When the connecting member 63 located above moves upward, the barrel plate 32 moves upward along the positioning barrel 31, the threaded rod 6 moves upward along the moving hole 35, and at this time, the barrel plate 32 drives the second adjusting mechanism 7, the adjusting rod 33 and the positioning member 34 to move upward.

Fine adjustment of the height position of the positioning member 34 is accomplished by the second adjustment mechanism 7. By adjusting the position of the adjustment plate 71 on the adjustment lever 33, the positioning element 34 is supported by the adjustment plate 71 located above. The support of the positioning element 34 is accomplished by the second adjustment mechanism 7. When the piston is placed on the positioning device 3, the piston is supported outwards through the linkage rod 72, and the piston is fixed on the positioning device 3.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the utility model. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. An apparatus for piston testing, characterized by: the device comprises a bracket, a driving mechanism, a detection device for piston flaw detection, a positioning device for placing a piston and a driving device for driving the piston to rotate; the driving mechanism drives the detection device to move along the surface of the piston; the positioning device is connected with the driving end of the driving device; the positioning device is rotatably arranged on the bracket.

2. The apparatus for piston sensing of claim 1, wherein: the driving mechanism comprises a moving module and a first power device for driving the detection device to rotate; the mobile modules are arranged in a mutually vertical and crossed manner; the first power device is arranged at the moving end of the moving module.

3. The apparatus for piston sensing of claim 2, wherein: the moving module comprises a moving frame, a screw rod rotationally arranged in the moving frame, a moving block moving along the moving frame and a second power device driving the screw rod to rotate; the moving block is in threaded connection with the lead screw; the second power device is arranged on the movable frame.

4. The apparatus for piston sensing of claim 3, wherein: the second power device drives the screw rod through a coupler; and the coupler is respectively connected with the screw rod and the driving end of the second power device.

5. The apparatus for piston sensing of claim 1, wherein: the positioning device comprises a positioning cylinder, a cylinder plate arranged in the positioning cylinder, an adjusting rod arranged on the cylinder plate and a positioning piece for supporting the piston; the positioning piece is arranged on the adjusting rod; the piston is placed on the positioning cylinder.

6. The apparatus for piston sensing of claim 5, wherein: a first adjusting mechanism for pushing the barrel plate to move along the positioning barrel is arranged in the positioning barrel; the first adjusting mechanism comprises a connecting rod, a connecting piece, a threaded rod rotating along the positioning cylinder and an adjusting piece oppositely arranged on the threaded rod; the threaded rod is relatively provided with external threads in opposite spiral directions; the adjusting piece is in threaded connection with the external thread; the connecting pieces are respectively arranged on the barrel plate and in the positioning barrel; one end of the connecting rod is connected with the connecting piece in a swinging mode; the other end of the connecting rod is connected with the adjusting piece in a swinging mode.

7. The apparatus for piston sensing of claim 6, wherein: a supporting cylinder is arranged around the positioning cylinder; a support rod is arranged in the support cylinder in a sliding manner; the supporting rod is connected with the barrel plate; a moving hole is formed in the positioning cylinder along the moving direction of the cylinder plate; the threaded rod moves along the moving hole.

8. The apparatus for piston sensing of claim 7, wherein: the adjusting rod is also provided with a second adjusting mechanism for pushing the positioning piece to move along the adjusting rod; the second adjusting mechanism comprises a linkage rod and adjusting discs sleeved at two ends of the adjusting rod; the linkage rods are connected between the adjusting discs in parallel around the adjusting rods; the linkage rods comprise rod pieces which are connected with each other in an angle; the rod piece is connected with the adjusting disc in a swinging mode.

9. The apparatus for piston sensing of claim 5, wherein: the device also comprises a measuring mechanism for measuring the height of the positioning piece; the measuring mechanism comprises an air tightness detecting device and a spigot seat covered on the positioning device; the spigot seat is provided with a spigot; when the spigot seat covers the positioning device, the positioning piece seals the spigot; the positioning cylinder, the cylinder plate and the spigot seat form a sealed space; the sealed space is respectively communicated with the inlet and the outlet of the air tightness detection device.

10. The apparatus for piston sensing of claim 1, wherein: the detection device is an eddy current flaw detector; the driving device is a motor.