CN210005149U

CN210005149U - Bolt for detecting outer square structure

Info

Publication number: CN210005149U
Application number: CN201921169215.0U
Authority: CN
Inventors: 李晨晖; 祝其高; 王永洁
Original assignee: SHANGHAI SHENGUANG HIGH STRENGTH BOLTS CO Ltd
Current assignee: SHANGHAI SHENGUANG HIGH STRENGTH BOLTS CO Ltd
Priority date: 2019-07-23
Filing date: 2019-07-23
Publication date: 2020-01-31
Anticipated expiration: 2029-07-23

Abstract

The utility model provides an outer four directions structure detects and uses bolt, it includes the screw rod, the cross-section of screw rod is the regular circle, the screw rod both ends are body shaping respectively and are provided with the end, two the end length inequality in the axial direction, the end periphery is provided with the screw thread, and the cross-section of end is the regular circle, longer set up cubic boss portion on the terminal surface of end, stress monitoring chip sets up in the outer terminal surface of boss portion, make the deformation that stress produced more concentrate on longer end side through set up the unequal end of axial direction length at screw rod both ends for the measurement accuracy of stress is higher, and the measuring result is also more stable.

Description

Bolt for detecting outer square structure

Technical Field

The utility model relates to a kind of outer four directions structure detects and uses bolt.

Background

At present, with the large-scale development of the wind power industry, for high-strength fasteners, a host factory pays more and more attention to exact real-time fastening axial force during bolt installation, and the intelligent high-strength bolts capable of monitoring the fastening axial force in real time have more urgent requirements.

The intelligent bolt can detect the current pretension value of bolted connection, can diagnose whether the connection structural member has faults of looseness, overload and the like, can early warn potential faults, and avoids major accidents.

According to the traditional intelligent bolt, the tension of the screw is directly detected in a mode that the strain gauge is arranged in the central hole in the bolt, the method is used for detecting the telescopic deformation of the screw by fixing the strain gauge in the hole in the bolt in a mode of bonding by using a bonding agent or filling and binding glue, and the strain of the screw cannot be directly transmitted to the strain gauge sensitive grid due to the use of the bonding agent, so that the problem of great time lag is caused. In addition, because the elastic modulus of the adhesive and the elastic modulus of the screw body are obviously different, the deformation relationship between the adhesive and the screw body has serious nonlinear relationship, the measurement range of the strain gauge is greatly limited, and the measurement precision is reduced. In addition, the strain gauge fixed by adopting the adhesive or the filling binding glue cannot be used in the occasions with higher temperature, so that the application range of the intelligent bolt is greatly limited.

In view of this, patent document 1(CN109632006A) discloses wireless intelligent bolts and an online monitoring system, which includes a bolt body, a force-measuring rod, a strain gauge, a temperature sensor, an integrated circuit board, a power supply device, a sealing cover, a local signal receiving and transmitting device and a terminal signal receiving and processing device, wherein a built-in hole with a fixed depth of is formed at the end of the non-threaded end of the bolt body, the bottom surface of the built-in hole is provided with the temperature sensor, the center of the bolt body is provided with a central hole with a fixed depth and diameter of , the bottom of the central hole is provided with a mounting thread, the end of the force-measuring rod is fixed at the bottom of the central hole of the bolt body through threaded connection, and the other end of the force-measuring rod is in close contact with the bottom surface of the built-in hole at the head of the.

However, in the field of wind power, blade bolts are used as important parts for connecting blades and hubs, bear large alternating load in the running process of a fan, and fatigue failure is more easily caused due to the fact that the blades are enlarged and lengthened, so that the quality requirement on products is higher. Because the blade bolt can bear larger alternating load in the operation process, the middle rod part can adopt a structure of a slender rod body to improve the fatigue resistance of the bolt in the common design.

In the case of a long and thin screw, the position of deformation of the screw due to stress is often not specified, or the degree of deformation is different at different screw positions, and therefore, if the technical solution of patent document 1 is adopted, the stress measurement result is difficult to maintain accurate and results.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model is to provide kinds of stress measurement accuracy is higher, the more stable outer four directions structure of measuring result detects and uses the bolt in order to overcome the defect that current stress monitoring bolt is difficult to keep precision and to send the nature when measuring the bolt of long and thin screw rod.

The utility model discloses an above-mentioned technical problem is solved through following technical scheme:

type bolts for detecting external square structures are characterized by comprising a screw rod, wherein the cross section of the screw rod is in a regular circle shape, ends are respectively body-formed at two ends of the screw rod and are provided with ends, the lengths of the two ends in the axial direction are unequal, threads are arranged on the periphery of the ends, the cross section of each end is in a regular circle shape, a cubic boss part is arranged on the end face of the longer end, and a stress monitoring chip is arranged on the outer end face of the boss part.

Preferably, the radius of the cross section of the end head is smaller than that of the cross section of the screw rod.

Preferably, the radius of the cross section of the end head is larger than that of the screw.

Preferably, the joint of the end head and the screw rod is formed into a circular truncated cone shape.

Preferably, the stress monitoring chip is provided with an ultrasonic monitoring sensor.

Preferably, the stress monitoring chip is connected to a thin film sensor, and at least parts of the thin film sensor are attached to the joints of the terminals and the screws.

The utility model has the positive improvement effect that the two ends of the screw rod are provided with the ends with different axial lengths, so that the deformation generated by the stress is more concentrated on the longer end side, the measurement precision of the stress is higher, and the measurement result is more stable.

Drawings

Fig. 1 is a schematic structural diagram of a bolt for detecting an outer square structure according to the preferred embodiment of the present invention 1.

Fig. 2 is a schematic structural diagram of a bolt for detecting an outer square structure according to the preferred embodiment of the present invention 2.

Detailed Description

The present invention will be more clearly and completely described below by way of examples and with reference to the accompanying drawings.

Example 1

Fig. 1 is a schematic structural view of a bolt for detecting an outer square structure according to the present embodiment, and as shown in fig. 1, a bolt 100 for detecting an outer square structure according to embodiment 1 includes a screw 10, the cross section of the screw 10 is a perfect circle,

ends

11 and 12 are respectively formed by at both ends of the screw 10, the outer peripheries of the

ends

11 and 12 are respectively provided with a thread 112 and a thread 122, and the cross sections of the

ends

11 and 12 are perfect circles.

The end 11 is provided with a cubic boss 13 with a square section on the outer end face, the stress monitoring chip 20 is attached to the outer end face of the cubic boss 13, the length of the end 11 in the axial direction is larger than that of the end 12, that is, an end of the cubic boss 13 is connected to the end 11 in a body molding manner, and the stress monitoring chip 20 is arranged on the square end face of another end.

The end 11 is provided with the square cubic boss 13, the cubic boss 13 is used for bearing the torque force of a wrench, so that the stress borne by the end 11 is larger, the length of the end 11 in the axial direction is larger than that of the end 12, most of the shearing force of the bolt 100 for detecting the outer tetragonal structure is concentrated on the side of the end 11 , therefore, deformation mainly occurs on the side of the end 11 , and the stress monitoring chip 20 is located on the outer end face of the cubic boss 13 and is close to a deformation occurrence region, so that the monitoring precision and the stability of a monitoring result are improved.

Furthermore, the cross-sectional radius of the

end heads

11, 12 is larger than the cross-sectional radius of the screw 10. The joints of the

ends

11 and 12 and the screw 10 are respectively formed into circular

truncated cone shapes

111 and 121. The stress monitoring chip 20 has an ultrasonic monitoring sensor (not shown in the figure).

Here, the joints of the

ends

11 and 12 and the screw 10 are both formed into a circular truncated cone shape, so that the end 12 can also share part of shearing force , and the screw 10 and the end 11 are less prone to fracture, and in addition, the circular truncated cone shape can better feed back ultrasonic signals for a stress monitoring chip using an ultrasonic monitoring sensor, so that the monitoring precision is further improved .

The performance index of the bolt 100 for detecting the outer square structure in the embodiment 1 can reach the following standard through practical monitoring: the hardness is 32-39 HRC, the tensile strength is not less than 1040MPa, the yield strength is not less than 940MPa, the elongation is not less than 9%, and the reduction of area is not less than 48%. The flatness of the end face of the cubic boss 13 is less than or equal to 0.02mm, the roughness is less than or equal to Ra0.8, and the area is 2-3 mm larger than the diameter of the strain gauge. The protruding length of the cubic boss 13 is less than or equal to 10mm, and the use of the square socket wrench is not influenced after the stress monitoring chip is pasted with the sheet.

Example 2

Fig. 2 is a schematic structural view of an outer square structure detection bolt according to embodiment 2. Embodiment 2 differs from embodiment 1 in that the cross-sectional radius of the screw 10 is slightly larger than the cross-sectional radius of the

heads

11, 12. The outer circumference of the screw 10 is slightly flush with the

threads

112, 122.

The stress monitoring chip 20 may be connected to a film sensor, at least of which is attached to the film sensor is attached to the outer surface of the screw thread 112 in fig. 2 to cover the connection between the tip 11 and the screw 10. the film sensor may be arranged to be attached to the outer periphery of the connection between the tip 11 and the screw 10 in a ring shape.

Although particular embodiments of the present invention have been described above, it will be appreciated by those skilled in the art that these are examples only and that the scope of the present invention is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the spirit and the principles of the present invention, and these changes and modifications are all within the scope of the present invention.

Claims

1, kind of outer four directions structure detects uses bolt, its characterized in that, it includes:

the section of the screw rod is in a perfect circle shape;

ends are respectively arranged at the two ends of the screw rod in a -shaped manner;

the lengths of the two end heads are not equal in the axial direction, threads are arranged on the peripheries of the end heads, and the cross sections of the end heads are in a regular circle shape;

a cubic boss part is arranged on the end face of the longer end head;

and the stress monitoring chip is arranged on the outer end face of the boss part.

2. The stud for detecting tetragonal structure as in claim 1,

the radius of the cross section of the end head is smaller than that of the cross section of the screw.

3. The stud for detecting tetragonal structure as in claim 2,

the radius of the cross section of the end head is larger than that of the cross section of the screw.

4. The detecting bolt of any of claims 2-3, wherein the bolt is a square-shaped bolt,

the joint of the end head and the screw rod is in a circular truncated cone shape.

5. The stud for detecting tetragonal structure as in claim 4,

the stress monitoring chip is provided with an ultrasonic monitoring sensor.

6. The stud for detecting tetragonal structure as in claim 5,

the stress monitoring chip is connected to a film sensor, and at least parts of the film sensor are attached to the joints of the terminals and the screws.