CN206114179U - Measure device that high strength bolt connects vice torque coefficient - Google Patents

Abstract

The utility model belongs to the technical field of mechanical measuring instruments and relates to a device for measuring the torque coefficient of high-strength bolt connection pairs. It includes a fixing device for fixed connection with the high-strength bolt connection pair to be tested, a torque wrench set at the nut that cooperates with the high-strength bolt connection pair to be tested for applying torque to the nut, the torque wrench is connected to the nut through a sleeve, and the torque wrench There is a torque sensor between the sleeve and the sleeve, the torque sensor is connected to the torque monitor, and the screw rod between the nut and the high-strength bolt connection head to be tested is provided with a one-way strain gauge to measure the axial strain of the high-strength bolt connection to be tested. , the unidirectional strain gauge is connected with the resistance strain gauge. The utility model has the advantages of simple assembly, fast operation speed and accurate and reliable measurement results, and is especially suitable for detecting the torque coefficient of small-batch high-strength bolt connections.

Description

A device for measuring the torque coefficient of high-strength bolt joints

【Technical field】

The utility model belongs to the technical field of mechanical measuring instruments and relates to a device for measuring the torque coefficient of high-strength bolt connection pairs.

【Background technique】

The high-strength large hex head bolt connection pair is a structural connection fastener composed of a bolt, a nut and two washers manufactured in the same batch. As an important way to connect steel structural members, it has the advantages of simple construction and good mechanical performance. , fatigue resistance, high connection reliability and other advantages, it has been widely used in large-scale steel structure engineering and road bridges. Among them, the torque coefficient of the high-strength bolt connection pair is an important index to evaluate the connection performance of components, and plays a key role in ensuring the safety and quality of the project.

At present, the calculation of the torque coefficient k is mainly performed through the formula k=T/(DP) stipulated in the "Code for Construction Quality Acceptance of Steel Structure Engineering" (GB50205-2001).

In the formula: k—torque coefficient;

T—applied torque, N m;

D - the nominal diameter of the bolt, mm;

P—the pretension of the bolt, KN

Since the bolt produces strain under a certain torque, the pretension P suffered by the bolt can be calculated through the linear relationship with the strain fitted by the following formula; P=EAε ₁

Where: E—modulus of elasticity of the bolt material;

A—the cross-sectional area of the screw, A=πD ² /4, and the nominal diameter of the D bolt, mm.

ε ₁ ―the strain produced by the bolt under torque

The applied torque T can be determined by a torque wrench, and the torque coefficient k can be obtained when the nominal diameter of the bolt has been determined.

When measuring the torque coefficient k of a high-strength bolt connection pair, in the prior art, during the screwing process, the operator often uses a torque wrench to manually apply torque, but because the torque wrench has a certain error, about ±3%, manual work It is difficult to control the exact precision at the time.

【Content of utility model】

In order to solve the above problems, the purpose of this utility model is to provide a device and method for measuring the torque coefficient of high-strength bolt joints. When the device is used to measure the torque coefficient k, the speed is fast, the precision is high, and it is safe and reliable.

The purpose of this utility model is achieved through the following technical solutions:

A device for measuring the torque coefficient of a high-strength bolt connection pair, including a fixing device for fixed connection with the high-strength bolt connection pair to be tested, and a torque wrench arranged at the nut matched with the high-strength bolt connection pair to be tested for applying torque to the nut , the torque wrench is connected to the nut through the sleeve, a torque sensor is set between the torque wrench and the sleeve, the torque sensor is connected to the torque display, and the screw rod between the nut and the high-strength bolt to be tested is equipped with a measuring high-strength bolt to be tested. The bolts connect the unidirectional strain gauges for the axial strain of the auxiliary screw, and the unidirectional strain gauges are connected with the resistance strain gauges.

There are multiple unidirectional strain gauges, which are arranged symmetrically in the circumferential direction of the secondary screw rod connected by the high-strength bolt to be tested.

There are two unidirectional strain gauges.

The screw rod of the high-strength bolt connection pair to be tested is provided with a groove for accommodating the wire connected to the one-way strain gauge, the upper end of the groove extends to the lower end of the one-way strain gauge, and the lower end of the groove extends downward and passes through the Measure the head of the high-strength bolt connection pair.

The fixing device includes an inner rectangular frame and an outer rectangular frame. Both the inner rectangular frame and the outer rectangular frame include a top plate at the top, a bottom plate at the bottom and baffles at both sides, and the two ends of the baffle are fixedly connected to the top plate and the bottom plate respectively. The inner rectangular frame is set inside the outer rectangular frame and the corresponding sides are parallel, the outer rectangular frame is fixed and its bottom plate is connected with the bottom plate of the inner rectangular frame, and the screw rod of the high-strength bolt connection pair to be tested runs through the inner rectangular frame and the outer rectangular frame from bottom to top In the middle of the top plate, the nuts are arranged above the top plate of the outer rectangular frame, and the head of the high-strength bolt connection pair to be tested is below the top plate of the inner rectangular frame.

The bottom plate of the outer rectangular frame is connected to the bottom plate of the inner rectangular frame through an adjustable screw, and the adjustable screw is coaxially arranged with the high-strength bolt connection pair to be tested. The lower end of the adjustable screw is connected to the outer rectangular frame bottom plate, and the upper end runs through the inner rectangular frame. The base plate is fitted with a first nut, and the first nut is arranged above the base plate of the inner rectangular frame.

The lower end of the adjustable screw rod is welded to the bottom plate of the outside rectangular frame.

Compared with the prior art, the utility model has the following beneficial effects:

When the device for measuring the torque coefficient of a high-strength bolted pair of the utility model measures the torque coefficient k of the bolted pair, the torque applied by the torque wrench is measured by a torque sensor and displayed by a torque display, and at the same time, the torque of the bolted pair is measured by a one-way strain gauge. The axial strain is displayed by the resistance strain gauge, and the torque coefficient k can be calculated through the measured tensile strain and the applied torque. The device of the present invention can provide accurate data for the operator's screwing process, so that when manual work Capable of controlling with exact precision.

Furthermore, by setting a plurality of unidirectional strain gauges, the influence of uneven force in each direction of the bolt rod is reduced, so that the measured axial strain value is more accurate and the measurement accuracy is guaranteed.

Further, the utility model opens a groove on the screw rod for accommodating the wire connected with the unidirectional strain gauge, embeds the wire in the groove, and the lower end of the groove extends downward and runs through the high-strength bolt connection pair to be tested. The head, thus effectively protecting the wires connected to the strain gauges from damage.

Further, the utility model connects the bottom plate of the outer rectangular frame with the bottom plate of the inner rectangular frame through an adjustable screw, and the suitable range of motion of the inner rectangular frame can be controlled by adjusting the length of the screw, so as to meet the high-strength bolt connection pairs of different lengths to be tested. Simply replace the top plate of the outer rectangular frame and the top plate of the inner rectangular frame with different apertures to meet the high-strength bolt connection pairs to be tested with different diameters.

The test device of the utility model is simple to assemble and easy to operate. It only needs to paste strain gauges on the high-strength bolt connection pairs to be tested, and apply torque to the nuts to calculate the torque coefficient, which is very suitable for the detection of small batch torque coefficients. The measurement of the data provides a reliable guarantee.

【Description of drawings】

Fig. 1 is the overall structural representation of the utility model;

Fig. 2(a) is a schematic structural diagram of the arrangement of secondary drilling holes and strain gauges connected by high-strength bolts to be tested, Fig. 2(b) is the bottom view of Fig. 2(a), and Fig. 2(c) is B-B in Fig. 2(a) cross-sectional diagram;

Fig. 3 is the structural representation of device to be tested and specimen loading device;

Among them, 1 is the outer bottom plate, 2 is the outer baffle plate, 3 is the first high-strength bolt, 4 is the inner bottom plate, 5 is the inner baffle plate, 6 is the adjustable screw rod, 6-1 is the first nut, 7 is the outer top plate, 8 is the second high-strength bolt, 9 is the torque indicator, 10 is the sleeve, 11 is the torque sensor, 12 is the torque wrench, 13 is the resistance strain gauge, 14 is the wire, 15 is the high-strength bolt connection pair to be tested, 15-1 is the Nut, 16 is the inner top plate, 17 is the third high-strength bolt, 18 is a one-way strain gauge, and 19 is a groove.

【detailed description】

Below in conjunction with accompanying drawing, the utility model is described in further detail:

As shown in Figures 1 to 3, the device for measuring the torque coefficient of the high-strength bolt connection pair of the present invention includes a device to be tested, a fixing device for a test piece, a loading device for a test piece, and a data acquisition system:

The specimen fixing device includes an outer rectangular frame, an inner rectangular frame, a first high-strength bolt 3, an adjustable screw rod 6, a second high-strength bolt 8, and a third high-strength bolt 17, wherein the outer rectangular frame includes an outer bottom plate 1 and an outer baffle 2 , the outer top plate 7, the inner rectangular frame includes the inner bottom plate 4, the inner side baffle plate 5, and the inner side top plate 16;

The device to be tested includes a one-way strain gauge 18 and a high-strength bolt connection pair 15 to be tested;

The specimen loading device includes a sleeve 10, a torque sensor 11, and a torque wrench 12;

The data acquisition system includes a torque display 9 and a resistance strain gauge 13;

The outer bottom plate 1 is fixed at the fixed installation position by the first high-strength bolt 3;

The bottom of the outer baffle 2 is symmetrically welded to both ends of the outer bottom plate 1, and the top of the outer baffle 2 is fixedly connected to the outer top plate 7 by second high-strength bolts 8 to form an outer rectangular frame;

The inner base plate 4 has a hole with the same diameter as the adjustable screw rod 6 at the center position, the adjustable screw rod 6 is provided with threads on the surface, the bottom is welded on the center position of the outer base plate 1, the top passes through the hole of the inner base plate 4 and connects with the first The nut 6-1 is fixedly connected; the bottom of the inner baffle 5 is symmetrically welded to the two ends of the inner bottom plate 4, and the top of the inner baffle 5 is fixedly connected with the inner top plate 16 by the third high-strength bolt 17 to form an inner rectangular frame;

The inside top plate 16 and the outside top plate 7 are provided with a hole matching the diameter of the high-strength bolt connection pair 15 to be tested in the center, and the screw rod of the high-strength bolt connection pair 15 to be tested passes through the inside top plate 16 and the outside top plate 7 from bottom to top for the screw rod. Holes that pass through and are in intimate contact with the corresponding roof surface;

The high-strength bolt connection pair 15 to be tested has a groove 19 on the screw near its head, the lower end of the groove 19 runs through the head of the high-strength bolt connection pair 15 to be tested, and the one-way strain gauge 18 is arranged at the end of the upper end of the groove 19 The surface of the screw, and arranged symmetrically in the circumferential direction, two one-way strain gauges 18 are arranged, and the average strain of the two can be taken as the tensile strain of the screw rod during measurement; the lead 14 connected on the one-way strain gauge 18 is embedded In the groove 19, the lead 14 is drawn out from the head of the high-strength bolt connection pair 15 to be tested, and finally the lead 14 is fixedly connected to the head;

One end of the sleeve 10 is provided with an accommodating groove matching the external dimensions of the nut 15, the nut 15 is a hexagonal head nut, and the other end is provided with a cylindrical protrusion, and the protrusion is provided with threads; one end of the torque sensor 11 is provided with a cylindrical A groove matching the shape and size of the protrusion, and a hexagonal protrusion at the other end; the lower end of the torque wrench 12 is provided with a groove matching the shape and size of the hexagonal protrusion;

The nut 15-1 matched on the high-strength bolt connection pair 15 to be tested is connected to the sleeve 10, the sleeve 10 is connected to the torque sensor 11, the torque sensor 11 is connected to the torque wrench 12, and the torque sensor 11 is connected to the torque display 9;

The resistance strain gauge 13 is composed of a measuring bridge, an amplifier, a display instrument and a reading mechanism, etc., and is attached to the high-strength bolt connection to be tested, and the one-way strain gauge 18 on the high-strength bolt connection pair 15 to be tested is connected to the measuring bridge through a wire 14 , and connect it in series to form a path, record the deformation of the screw caused by the torque, and send a signal to the resistance strain gauge, so that the measuring bridge has a voltage output, and after being amplified by the amplifier, the corresponding strain value is read from the display on the resistance strain gauge .

The utility model patent is divided into the following four steps when testing the torque coefficient k:

In the first step, the outer bottom plate 1 is fixed on the ground by the first high-strength bolt 3, the outer baffle 2 is welded to the outer bottom plate 1, and then the outer top plate 7 and the outer baffle 2 are connected by the second high-strength bolt 8, so that the outer The bottom plate 1, the outer top plate 7 and the two outer baffles 2 form an outer rectangular frame; the inner top plate 16 is connected with the inner baffle 5 through the third high-strength bolt 17, and forms an inner rectangular frame together with the inner bottom plate 4; the inner bottom plate 4 passes through The adjustable screw rod 6 welded on the outer bottom plate 1 and the first nut 6-1 matched and connected on the adjustable screw rod 6 are connected with the outer bottom plate 1, so that the inner rectangular frame and the outer rectangular frame form a whole, and can be used according to the Measure the length of the high-strength bolt connection pair 15, and adjust the adjustable screw rod 6 to a suitable position;

In the second step, two unidirectional strain gauges 18 are symmetrically pasted on the screw rods of the 19 high-strength bolt connection pairs 15 to be tested that have been opened through the groove, and the wires are buried in the groove, and the wires are connected from the high-strength bolt to be tested. Lead out from the end of the pair 15, fix the head end of the high-strength bolt connection pair 15 to be tested on the top plate of the inner rectangular frame, fix the nut end on the top plate of the outer rectangular frame, and lead the wire out from the nut to measure the resistance strain instrument phase connection;

The third step is to select a suitable sleeve 10 according to the size of the high-strength bolt connection pair 15 to be tested and put it on the nut 15-1, and select a torque sensor 11 of a suitable size on the upper end of the sleeve 10 according to the cylindrical protrusion and screw it into it , connect the torque indicator 9 in the torque sensor 11, so as to display the indication when the torque is applied, the groove of the torque wrench 12 is closely connected with the hexagonal protrusion of the torque sensor 11, so that the specimen loading device forms a whole ;

In the fourth step, when the test is required, apply the planned torque to the torque wrench 12 in a smooth and balanced manner, and read the planned indication on the torque display 9. Due to the axial force generated at the screw rod under the action of a certain torque, a Deformation, elongation are measured by unidirectional strain gauge 18 and the measurement signal is delivered to resistance strain gauge 13, read out the strain indicator on the display of resistance strain gauge 13, get the average strain of two strain gauges as the tensile strain of screw rod ;

Then calculate the pre-tension force P by P= _EAε1 , and then obtain the torque coefficient according to the formula k=T/(DP) stipulated in the "Code for Construction Quality Acceptance of Steel Structure Engineering" (GB50205-2001), and calculate the arithmetic mean of the torque coefficient value and standard deviation.

Claims (7)

1. A device for measuring the torque coefficient of a high-strength bolted pair, characterized in that it comprises a fixture for fixed connection with the high-strength bolted pair (15) to be measured, and is arranged to cooperate with the high-strength bolted pair (15) to be measured A torque wrench (12) for applying torque to the nut (15-1) at the nut (15-1), the torque wrench (12) is connected with the nut (15-1) through a sleeve (10), and the torque wrench (12 ) and the sleeve (10) are provided with a torque sensor (11), the torque sensor (11) is connected to the torque display (9), and the nut (15-1) is connected to the head of the high-strength bolt connection pair (15) to be tested The screw rod is provided with a one-way strain gauge (18) for measuring the axial strain of the screw rod of the high-strength bolt connection pair (15) to be tested, and the one-way strain gauge (18) is connected with the resistance strain gauge (13). 2. A device for measuring the torque coefficient of a high-strength bolted pair according to claim 1, characterized in that, the one-way strain gauge (18) is provided with a plurality, and the screw of the high-strength bolted pair (15) to be measured set symmetrically in the circumferential direction. 3. A device for measuring the torque coefficient of high-strength bolted joints according to claim 2, characterized in that two unidirectional strain gauges (18) are provided. 4. A device for measuring the torque coefficient of a high-strength bolt connection pair according to claim 1, wherein the screw rod of the high-strength bolt connection pair (15) to be measured is provided with a unidirectional strain gauge (18) for accommodating ) to the groove (19) of the wire (14) connected, the upper end of the groove (19) extends to the lower end of the one-way strain gauge (18), and the lower end of the groove (19) extends downward and runs through the high-strength bolt connection to be tested The head of the vice (15). 5. A device for measuring the torque coefficient of high-strength bolted joints according to claim 1, wherein the fixing device includes an inner rectangular frame and an outer rectangular frame, and both the inner rectangular frame and the outer rectangular frame include a top plate above, The lower bottom plate and the baffles on both sides, the two ends of the baffle are fixedly connected to the top plate and the bottom plate respectively, the inner rectangular frame is set inside the outer rectangular frame and the corresponding sides are parallel, the outer rectangular frame is fixed and its bottom plate is connected to the inner rectangular frame The bottom plate of the frame is connected, the screw rod of the high-strength bolt connection pair (15) to be tested runs through the middle of the top plate of the inner rectangular frame and the outer rectangular frame from bottom to top, and the nut (15-1) is arranged above the top plate of the outer rectangular frame. The head of the high-strength bolt connection pair (15) is below the top plate of the inner rectangular frame. 6. A device for measuring the torque coefficient of high-strength bolted joints according to claim 5, wherein the bottom plate of the outer rectangular frame is connected with the bottom plate of the inner rectangular frame by an adjustable screw (6), and the adjustable screw (6) Set coaxially with the high-strength bolt connection pair (15) to be tested, the lower end of the adjustable screw rod (6) is connected with the bottom plate of the outer rectangular frame, the upper end runs through the bottom plate of the inner rectangular frame, and is matched with the first nut (6) -1), the first nut (6-1) is arranged above the bottom plate of the inner rectangular frame. 7. A device for measuring the torque coefficient of high-strength bolted joints according to claim 6, characterized in that the lower end of the adjustable screw (6) is welded to the bottom plate of the outer rectangular frame.