CN102818667A - Electric eddy current dynamometer - Google Patents

Abstract

The invention relates to an eddy current dynamometer, which comprises an eddy current outer ring, an eddy current inner ring and a temperature sensor which are fastened oppositely. The eddy current outer ring is provided with a blind installation hole between two adjacent annular water tanks, the eddy current outer ring is provided with a installation through hole, and the temperature sensor is mated in the installation blind hole, and the installation through hole and the installation blind hole wall A sealing structure is provided between the temperature sensor and the outer circumference of the temperature sensor respectively. When in use, since the working end of the temperature sensor is between the annular water tanks of the eddy current inner ring, and the annular water tank is at the corresponding position where the rotor of the eddy current dynamometer can generate eddy currents, the temperature sensor can directly measure the surface temperature of the eddy current inner ring , thereby solving the problem of low temperature and hysteresis detected by the temperature sensor for the eddy current inner ring of the eddy current dynamometer in the prior art.

Description

An eddy current dynamometer

technical field

The invention relates to an eddy current dynamometer in an internal combustion engine detection device, and also relates to a temperature sensor for the eddy current dynamometer. the

Background technique

The eddy current dynamometer works by electromagnetic induction. When working, the rotor of the eddy current dynamometer cuts the magnetic force line, and converts all the eddy currents generated in the eddy current ring into eddy current heat, and the eddy current heat is taken out of the dynamometer through the cooling water circulating in the annular water tank opened on the end face of the eddy current ring, The heat carried away by the water is balanced with the heat generated by electromagnetic induction, and the temperature of the eddy current ring is maintained within a certain range. Therefore, the waterway structure design of the vortex ring and the amount of cooling water can all affect the temperature of the vortex ring. For metal materials, when the temperature exceeds its Curie temperature point, the magnetic permeability and electrical conductivity of the material will undergo qualitative changes, making the eddy current dynamometer unable to work normally. At the same time, because the temperature of the eddy current ring is too high and the deformation increases, it will cause the change of the gap between the rotor and the eddy current ring, which will affect the performance of the eddy current dynamometer and reduce the service life of the eddy current dynamometer. Therefore, it is necessary to monitor the temperature detection of the eddy current ring. In general, the surface of the vortex ring corresponding to the rotor has the highest temperature. However, since the ring end surface of the eddy current ring is provided with a water groove, it is difficult to detect the temperature of the eddy current at a suitable position. A common method is to install a thermocouple temperature sensor 03 on the step surface of the eddy current outer ring 01 close to the outer circle to detect the temperature of the eddy current inner ring 02 (as shown in Figure 1 and Figure 2), but since this position does not correspond to the rotor, There is no eddy current, and the heat is conducted through the surrounding wall of the eddy current inner ring, so that the temperature detected by the detection instrument is low and lags behind. the

Contents of the invention

The invention proposes an eddy current dynamometer, aiming to solve the problem of low temperature and lag in the detection of the eddy current inner ring of the eddy current dynamometer by a temperature sensor in the prior art. the

The technical scheme of the eddy current dynamometer is as follows:

An eddy current dynamometer, comprising an eddy current outer ring and an eddy current inner ring which are relatively fastened, and a temperature sensor for measuring the temperature of the eddy current inner ring arranged on the eddy current outer ring, and the temperature sensor has a function for measuring the temperature of the eddy current inner ring At the working end of the temperature, the ring end surface of the vortex inner ring is provided with at least two annular water tanks for cooling medium circulation, and the vortex inner ring is provided with a blind installation hole on the ring end surface near the end of the vortex outer ring , the installation blind hole is between two adjacent annular water tanks; the eddy current outer ring is provided with an installation through hole communicating with the installation blind hole, and the working end of the temperature sensor is inserted through the installation through hole in the installation The blind hole is fixed on the eddy current outer ring through the thread processed on the outer circumference, and a sealing structure is provided between the installation through hole and the wall of the blind installation hole and the outer circumference of the temperature sensor.

The sealing structure is an O-shaped sealing ring or a sealant layer arranged between the wall of the installation through hole and the installation blind hole and the outer periphery of the temperature sensor. the

The outer periphery of the temperature sensor is provided with an annular installation groove matched with the O-ring. the

The temperature sensor is a thermocouple temperature sensor or a PT100 platinum thermal resistance temperature sensor. the

The thermocouple temperature sensor includes a cylindrical sensor body, one end of the sensor body is provided with a blocking plate for sealing its opening, and the thread processed on the outer periphery of the temperature sensor is on the outer periphery of the other end of the sensor body , the blocking plate is provided with a round hole for a bolt whose axis coincides with the extension line of the axis of the sensor body, and a mounting bolt and a mounting nut used in conjunction are arranged in the hole for the bolt, and the mounting nut is located on the blocking plate Close to one end of the sensor body, the outer circumference of the mounting bolt is provided with an annular thermocouple sheet between the mounting nut and the blocking plate, and the thermocouple sheet is connected with an inner hole for passing through the sensor body to connect with the control system the leads. the

The outer periphery of the end of the sensor main body away from the blocking plate is provided with an everted annular edge. the

In the present invention, the eddy current dynamometer is provided with an installation blind hole for inserting a temperature sensor between two adjacent annular water tanks of the eddy current inner ring, and is provided with a blind hole connected to the installation blind hole on the ring end surface of the eddy current outer ring. Install the through hole, and the working end of the temperature sensor is inserted into the blind installation hole through the installation through hole, and is fixed on the eddy current outer ring through the thread processed on its circumference. At the same time, the outer circumference of the temperature sensor and the installation through hole There is a sealing structure between the hole wall and the hole wall where the blind hole is installed. When in use, since the working end of the temperature sensor is between the annular water tank of the eddy current inner ring, and the annular water tank is on the eddy current inner ring and the eddy current dynamometer The position corresponding to the rotor of the dynamometer, that is, at the setting of the annular water tank, the rotor of the eddy current dynamometer can generate eddy currents, so the temperature sensor can directly measure the surface temperature of the inner ring of the eddy current, thereby solving the problem of using the temperature sensor in the prior art. The problem of low temperature and hysteresis in the detection of the eddy current inner ring of the eddy current dynamometer. the

Description of drawings

Fig. 1 is the structural representation of existing eddy current dynamometer;

Fig. 2 is a partial enlarged view of place A in Fig. 1;

Fig. 3 is the structural representation of eddy current testing machine of the present invention;

Fig. 4 is a schematic structural view at B in Fig. 3;

Fig. 5 is a schematic structural view of the temperature sensor in Fig. 3;

FIG. 6 is a structural schematic diagram of the installation blind hole and the installation through hole in FIG. 3 . the

Detailed ways

Embodiment of the eddy current dynamometer of the present invention: as shown in Fig. 3 to Fig. 5, the eddy current dynamometer comprises the eddy current outer ring 1 and the eddy current inner ring 2 interlocked with each other, and the eddy current outer ring 1 is provided with A temperature sensor 3 for measuring the temperature of the eddy current inner ring 2, wherein a plurality of annular water grooves 4 for the circulation of the cooling medium are provided on the ring end surface of the eddy current inner ring 2, and the ring end faces of the vortex inner ring 2 are adjacent to two There are installation blind holes 5 between the annular water tanks 4; the ring end surface of the vortex outer ring 1 is provided with an installation through hole 6 communicating with the installation blind hole 5, and the installation through hole 6 is located on the hole wall at the end far away from the installation blind hole 5 Processed with threads; the temperature sensor 3 is a thermocouple temperature sensor, the cylindrical working end of the temperature sensor 3 passes through the installation through hole 6 and is inserted into the installation blind hole 5, and passes through the installation through hole 6 processed on its outer periphery The screw threads on the screw thread are fixed on the vortex outer ring 1. the

Wherein, the temperature sensor 3 mainly consists of a cylindrical sensor body 7, a blocking plate 8, an annular thermocouple strip 9, mounting bolts 10 and mounting nuts 11, the blocking plate 8 is at the end of the sensor body 7 and the sensor body The end opening of 7 is sealed, and the outer circumference of the other end of the sensor main body 7 is processed with the threads processed on the outer circumference of the above-mentioned temperature sensor 3, and the extension line of the axis of the sensor main body 7 coincides with the axis of the sensor main body 7 on the blocking plate 8. Bolts are provided with round holes, and the bolts are provided with mounting bolts 10 and mounting nuts 11 for use in cooperation. The mounting nuts 11 are located at the end of the blocking plate 8 close to the sensor body 7. The ring-shaped thermocouple piece 9 between the nut 11 and the blocking plate 8 is installed, and the thermocouple piece 9 is connected with a lead wire 12 for passing through the inner hole of the sensor body 7 and connected to the control system. the

At the same time, an O-ring 13 is arranged between the wall of the installation through hole 6 and the installation blind hole 5 and the outer periphery of the sensor body 7 of the temperature sensor 3, and the O-ring 13 is installed on the outer periphery of the temperature sensor 3 In the annular groove 14 opened. Wherein, the O-ring 13 between the hole wall of the installation through hole 6 and the outer periphery of the sensor body 7 of the temperature sensor 3 can prevent the cooling medium in the annular water tank 4 of the eddy current inner ring 2 from flowing from the sensor body 7 of the temperature sensor 3 The O-ring 13 between the installation blind hole 5 and the outer circumference of the sensor body 7 of the temperature sensor 3 can prevent cooling in the annular water tank 4 of the vortex inner ring 2 The medium flows from between the sensor body 7 of the temperature sensor 3 and the wall of the blind hole 5 to the working end of the temperature sensor 3 , thereby affecting the normal operation of the temperature sensor 3 . the

In addition, on the outer periphery of the threaded end of the sensor body 7, an everted annular edge 7-1 is provided. This annular edge 7-1 can not only ensure the convenient installation of the temperature sensor 3, but also can connect the temperature sensor 3 through its end surface. The extrusion fit between the outer surfaces of the eddy current outer ring 1 acts as a limiter, thereby avoiding the situation that the vibration generated during the working process of the eddy current dynamometer causes the measurement position of the temperature sensor 3 to change. the

In the above embodiments, the temperature sensor is a thermocouple temperature sensor, in other embodiments, the temperature sensor can also be a PT100 platinum thermal resistance temperature sensor, wherein the cylindrical working end of the PT100 platinum thermal resistance temperature sensor passes through the eddy current outer ring The installation through hole opened on the top is mated in the installation blind hole opened on the vortex inner ring, and the outer circumference of the working end is processed with a thread matched with the thread processed on the hole wall of the installation through hole. the

In the above-mentioned embodiments, an O-ring is provided between the wall of the installation through hole and the installation blind hole and the outer periphery of the sensor body of the temperature sensor. In other embodiments, the O-ring can also be sealed with a sealant. Layer replacement, that is, the sealing structure set between the installation through hole and the wall of the blind hole and the outer periphery of the sensor body of the temperature sensor is a sealant layer. After the sealant is cured, it should be able to ensure the convenient disassembly of the temperature sensor, so as to facilitate Overhaul of the temperature sensor. the

In the above embodiments, threads are processed on the outer circumference of the sensor body at the end far away from the blocking plate. In other embodiments, the outer circumference of the sensor body can also be all processed with the above-mentioned threads. the

Claims (6)

1. An eddy current dynamometer, comprising a relatively fastened eddy current outer ring and an eddy current inner ring, and a temperature sensor for measuring the temperature of the eddy current inner ring arranged on the eddy current outer ring, the temperature sensor has a function for measuring the eddy current The working end of the inner ring temperature, the ring end surface of the vortex inner ring is provided with at least two annular water grooves for the circulation of the cooling medium. There is an installation blind hole on the top, and the installation blind hole is between two adjacent annular water tanks; an installation through hole communicating with the installation blind hole is opened on the vortex outer ring, and the working end of the temperature sensor passes through the installation The through hole is mated in the installation blind hole, and is fixed on the eddy current outer ring through the thread processed on the outer circumference. A sealing structure is provided between the installation through hole and the wall of the installation blind hole and the outer circumference of the temperature sensor respectively. 2. The eddy current dynamometer according to claim 1, characterized in that: the sealing structure is an O-ring or a sealing ring arranged between the wall of the installation through hole and the installation blind hole and the outer periphery of the temperature sensor. glue layer. 3. The eddy current dynamometer according to claim 2, characterized in that: an annular mounting groove for matching with the O-ring is opened on the outer periphery of the temperature sensor. 4. The eddy current dynamometer according to claim 1, wherein the temperature sensor is a thermocouple temperature sensor or a PT100 platinum thermal resistance temperature sensor. 5. The eddy current dynamometer according to claim 4, characterized in that: the thermocouple temperature sensor comprises a cylindrical sensor body, and one end of the sensor body is provided with a blocking plate for sealing its opening , the thread processed on the outer circumference of the temperature sensor is on the outer circumference of the other end of the sensor main body, and a round hole for a bolt whose axis coincides with the extension line of the axis of the sensor main body is opened on the blocking plate, and the round hole for the bolt is There are mounting bolts and mounting nuts used in conjunction inside, and the mounting nut is at the end of the blocking plate close to the sensor body, and the outer circumference of the mounting bolts is provided with an annular thermocouple sheet between the mounting nut and the blocking plate, Lead wires for passing through the inner hole of the sensor body and connecting with the control system are connected to the thermocouple sheet. 6 . The eddy current dynamometer according to claim 5 , characterized in that: the outer circumference of the end of the sensor body away from the blocking plate is provided with an everted ring-shaped edge. 7 .

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