A surface acoustic wave temperature sensor with a locking device

Abstract

The invention discloses a surface acoustic wave temperature sensor with a locking device, comprising an outer cover, a sensor antenna, a sensor temperature sensing chip, a printed circuit board, a metal base plate, a locking mechanism and a metal tie; the metal tie comprises a first metal tie and a second metal tie, one end of the first metal tie is snap-connected to one side of the metal base plate, and the other end is connected to an adjusting portion of the locking mechanism; one end of the second metal tie is snap-connected to the other side of the metal base plate, and the other end is connected to a fixing portion of the locking mechanism; the locking mechanism is configured to adjust the length of the first metal tie between the metal base plate and the locking mechanism through the adjusting portion; the printed circuit board is welded and fixed on the metal base plate, the sensor temperature sensing chip and the sensor antenna are welded on the printed circuit board, and are connected through a microstrip line on the printed circuit board; the outer cover is installed on the outside of the sensor antenna and fixed on the metal base plate.

Description

Technical Field

[0001] The present invention relates to the technical field of temperature sensors, and particularly to a surface acoustic wave temperature sensor with a locking device. Background Art

[0002] A surface acoustic wave temperature sensor is a temperature sensor based on surface acoustic wave technology, which has the advantages of being inherently passive, resistant to high voltage, large current, and strong magnetic field, and is widely used in many occasions, especially for temperature monitoring of medium and high voltage equipment.

[0003] Temperature monitoring of switch cabinets is an important application of surface acoustic wave temperature sensors. The current transmitted by the switch cabinet needs to flow through the contact surface of the moving contact and the static contact. Due to the existence of contact resistance, the contact surface of the moving and static contacts is the most concentrated part of heat generation in the switch cabinet. Therefore, for temperature monitoring of the switch cabinet, the best monitoring position is the moving contact or the static contact of the switch cabinet. To ensure the tight fit of the moving and static contacts, the outer diameter of the static contact is slightly larger than the inner diameter of the moving contact. After the static contact is inserted into the moving contact, the moving contact will expand and thicken. Due to the dimensional change before and after assembly, it is not convenient to monitor the moving contact. Relatively speaking, it is easier to monitor the static contact. Therefore, the more common way of temperature monitoring of the switch cabinet is to monitor the temperature of the static contact.

[0004] Since the front part of the static contact needs to bite with the moving contact to carry current, the temperature sensor can only be installed at the root of the static contact where it does not contact the moving contact.

[0005] The outer shape of the static contact of the switch cabinet is cylindrical, and there is a cylindrical insulating sheath for insulation on the outer layer. The gap between the inner diameter of the insulating sheath and the outer diameter of the static contact generally does not exceed 30 mm. After a person's hand is inserted, it cannot move freely and cannot perform complex operations. Therefore, conventional fixing methods such as screw fixing and buckle fixing of the sensor are not applicable.

[0006] A common way of temperature monitoring of the static contact is to add a spring to the metal base plate of the surface acoustic wave temperature sensor, fix the two ends of the spring on both sides of the metal base plate in advance, and use the elasticity of the spring to fix the sensor on the static contact.

[0007] This method has very large defects: if the spring is too loose, the sensor and the static contact will not bite tightly, and it cannot ensure the close combination of the sensor and the static contact. The vibration during the operation of the switch cabinet will cause the separation of the metal parts of the sensor and the metal parts of the static contact, resulting in a situation where the potentials of the two are not equal, and the high voltage on the static contact will damage the temperature sensor; if the spring is too tight, when installing the sensor, the sensor needs to be sleeved on the front part of the static contact first, and then pushed to the root of the static contact. During the pushing process, the spring will scratch the surface of the static contact, resulting in an increase in the contact resistance between the static contact and the moving contact, more serious heat generation of the switch cabinet, and triggering a safety accident of the switch cabinet.

[0008] The spring-loaded static contact of the sensor and the non-damage to the static contact are mutually contradictory and cannot be taken into account simultaneously. Therefore, the existing method of fixing the surface acoustic wave temperature sensor by the spring method has inherent defects.

[0009] As for other methods, such as the collar installation method mentioned in the Chinese utility model patent with the publication number CN204389057U, the defects are even greater. The specific method is to design the sensor as a split type, install the temperature sensing chip on the collar, fix the collar on the static contact, and separate the sensor antenna. The temperature sensing chip and the sensor antenna are connected by a radio frequency line. The reason for this method is that the performance of the sensor chip is too poor. When installed on the static contact, due to the attenuation of the radio frequency signal by the insulation sheath outside the static contact, the sensor signal is weak and cannot work properly. Therefore, the sensor antenna has to be installed outside the insulation sheath of the static contact to solve the problem of signal attenuation by the insulation sheath. This solution has two problems. First, the space between the static contact and the insulation sheath is limited, and the collar cannot ensure close contact with the static contact after installation. In essence, it just replaces the spring with a collar, and the original problems still exist. The collar is made of metal (otherwise, the heat conduction and equipotential problems cannot be solved), and its inner diameter must be larger than that of the static contact, otherwise it cannot be installed. There must be a gap between the installed collar and the static contact. The vibration during the operation of the switchgear will inevitably cause the phenomenon that the sensor and the static contact are not equipotential and the sensor is damaged; the second problem is that the static contact is at a high potential, usually 10 kV or 35 kV. After the radio frequency line connects the split sensor chip and the sensor antenna, the sensor antenna is also at a high potential. However, the sensor antenna is far from the moving and static contacts and is in a floating state, which is a floating high potential and will inevitably cause serious partial discharge phenomena, thus bringing serious safety hazards to the switchgear. This kind of short-sighted approach has no value in actual engineering.

[0010] Therefore, the technicians in this field are committed to developing a surface acoustic wave temperature sensor with a locking device, which can well solve related problems to overcome the problems existing in the prior art. Summary of the Invention

[0011] In view of the above-mentioned defects of the prior art, the technical problems to be solved by the present invention are as follows: 1) Solve the problem that the sensor body and the static contact are separated during vibration due to the too loose spring of the spring type surface acoustic wave temperature sensor, resulting in a floating potential and being damaged by the high voltage of the static contact; 2) Solve the problem that the metal surface of the static contact is scratched during installation due to the too tight spring of the spring type surface acoustic wave temperature sensor, resulting in an increase in the contact resistance between the moving and static contacts and heat generation at the contact part of the moving and static contacts during the operation of the switch cabinet; 3) Solve the problem that the loop type surface acoustic wave temperature sensor has partial discharge due to the external placement of the sensor antenna and the floating state of the antenna; 4) Solve the problem that the installation and operation of the conventional surface acoustic wave temperature sensor are inconvenient in a narrow space.

[0012] To achieve the above object, the present invention provides a surface acoustic wave temperature sensor with a locking device, which includes an outer cover, a sensor antenna, a sensor temperature sensing chip, a printed circuit board, a metal bottom plate, a locking mechanism and a metal tie; the metal tie includes a first metal tie and a second metal tie, one end of the first metal tie is snap-connected to one side of the metal bottom plate, and the other end is connected to the adjusting part of the locking mechanism; one end of the second metal tie is snap-connected to the other side of the metal bottom plate, and the other end is connected to the fixing part of the locking mechanism; the locking mechanism is configured to adjust the length of the first metal tie between the metal bottom plate and the locking mechanism through the adjusting part; the printed circuit board is welded and fixed on the metal bottom plate, the sensor temperature sensing chip and the sensor antenna are welded on the printed circuit board and are connected through the microstrip line on the printed circuit board; the outer cover is installed outside the sensor antenna and fixed on the metal bottom plate.

[0013] Further, the outer cover is made of polyphenylene sulfide material.

[0014] Further, the metal bottom plate is made of one of copper, aluminum, copper alloy, aluminum alloy, and stainless steel.

[0015] Further, outer cover mounting holes are provided around the metal bottom plate, and the outer cover is fixed on the metal bottom plate by self-tapping screws that are screwed into the outer cover through the outer cover mounting holes from the reverse side of the metal bottom plate.

[0016] Further, tie mounting holes are provided on both sides of the metal bottom plate, the buckle includes a hollow first tie through hole and a setscrew mounting hole provided at the top, and the metal tie is connected to either side of the metal bottom plate by passing one end of the metal tie through the tie mounting hole on one side of the metal bottom plate, bending and joining them together and inserting them into the first tie through hole, and using a setscrew to screw in from the setscrew mounting hole.

[0017] Further, the tie mounting holes are serrated.

[0018] Further, the fixing part of the locking device includes a U-shaped seat. The bottom of the U-shaped seat is provided with an inner through hole and an outer through hole for fixing the metal tie strap. The adjusting part of the locking device includes a locking pin and two rotating gears. The locking pin vertically passes through the two side walls of the U-shaped seat. The two rotating gears respectively abut against the outer sides of the respective side walls of the U-shaped seat. The locking pin drives the rotating gears to be rotatable relative to the center line of the locking pin. The part of the locking pin located between the two side walls of the U-shaped seat has a second tie strap through hole. At least one anti-loosening protrusion is provided on the outer sides of the two side walls of the U-shaped seat. The anti-loosening protrusion cooperates with at least one of the two rotating gears to prevent the locking pin and the rotating gears from rotating in the reverse direction of the set rotating direction.

[0019] Further, the second metal tie strap is fixed to the U-shaped seat of the locking mechanism by passing the other end of the second metal tie strap from top to bottom through the inner through hole, folding it back, and then passing it from bottom to top through the outer through hole, so that the second metal tie strap hooks the metal sheet between the inner through hole and the outer through hole.

[0020] Further, one end of the locking pin has a bent part, and the bent part abuts one of the two rotating gears against one of the two side walls of the U-shaped seat.

[0021] Further, the other end of the locking pin has a blocking part. The blocking part abuts the other of the two rotating gears against the other of the two side walls of the U-shaped seat. The blocking part has a hollow locking through hole for assisting in locking the sensor.

[0022] Compared with the prior art, the advantages of the present invention are as follows:

[0023] 1. By adopting the locking device, after installation, the surface acoustic wave temperature sensor and the static contact can be in close contact without loosening, solving the problem that due to unreasonable installation in the conventional method, there is looseness between the temperature sensor and the static contact, resulting in the potential suspension state of the temperature sensor and being damaged by the high voltage of the static contact.

[0024] 2. The metal tie strap and the locking device cooperate. When the metal tie strap is sleeved on the static contact, the metal tie strap does not need to touch the front part of the static contact, will not cause damage to the surface of the static contact, and will not increase the contact resistance between the moving and static contacts due to the installation of the surface acoustic wave temperature sensor.

[0025] 3. With an integrated design, the sensor antenna does not need to be external, and there is no partial discharge situation.

[0026] 4. The installation is simple. Only an L-shaped metal rod is needed to install the sensor, and there is no need for manual operation in a narrow space.

[0027] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, features and effects of the present invention. Description of the Drawings

[0028] Figure 1 is an exploded view of a surface acoustic wave temperature sensor with a locking device according to a preferred embodiment of the present invention;

[0029] Figure 2 is a schematic structural diagram of an assembled surface acoustic wave temperature sensor with a locking device according to a preferred embodiment of the present invention;

[0030] Figure 3 is a schematic structural diagram of a metal base plate according to a preferred embodiment of the present invention;

[0031] Figure 4 is a schematic structural diagram of a through-hole type buckle according to a preferred embodiment of the present invention;

[0032] Figure 5 is a schematic structural diagram of a locking head according to a preferred embodiment of the present invention;

[0033] Figure 6 is a schematic structural diagram of the locking head from another angle according to a preferred embodiment of the present invention.

[0034] Among them, 1 - outer cover, 2 - sensor antenna, 3 - sensor temperature sensing chip, 4 - printed circuit board, 5 - metal base plate, 6 - first set screw, 7 - first through-hole type buckle, 8 - locking head, 9 - second set screw, 10 - second through-hole type buckle, 11 - first metal tie strap, 12 - second metal tie strap, 51 - outer cover mounting hole, 52 - tie strap mounting hole, 71 - set screw mounting hole, 72 - first tie strap through-hole, 81 - U-shaped seat, 82 - outer side through-hole, 83 - inner side through-hole, 84 - second tie strap through-hole, 85 - locking through-hole, 86 - locking pin, 87 - anti-loosening protrusion, 88 - rotating gear. Detailed Embodiments

[0035] The following introduces multiple preferred embodiments of the present invention with reference to the accompanying drawings of the specification to make its technical content clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, and the protection scope of the present invention is not limited to the embodiments mentioned in the text.

[0036] In the drawings, components with the same structure are denoted by the same reference numerals, and components with similar structures or functions are denoted by similar reference numerals. The size and thickness of each component shown in the drawings are arbitrarily shown, and the present invention does not limit the size and thickness of each component. In order to make the illustration clearer, the thickness of some parts in the drawings is appropriately exaggerated.

[0037] Embodiment

[0038] As Figure 1 As shown in Fig. -2, the present invention provides a surface acoustic wave temperature sensor with a locking device, which includes an outer cover 1, a sensor antenna 2, a sensor temperature sensing chip 3, a printed circuit board 4, a metal base plate 5, a first set screw 6, a first through-hole type buckle 7, a locking head 8, a second set screw 9, a second through-hole type buckle 10, a first metal tie-rod 11 and a second metal tie-rod 12.

[0039] The first set screw 6 and the second set screw 9 have the same structure but different installation positions. The first through-hole type buckle 7 and the second through-hole type buckle 10 have the same structure but different installation positions. The first metal tie-rod 11 and the second metal tie-rod 12 have the same structure but different installation positions.

[0040] The sensor temperature sensing chip 3 is a surface acoustic wave (SAW) temperature sensing chip.

[0041] The outer cover 1 is made of an insulating and high-temperature resistant material. Preferably, it is made of polyphenylene sulfide (PPS) material.

[0042] The sensor antenna 2, the sensor temperature sensing chip 3 and the printed circuit board 4 are arranged inside the outer cover 1.

[0043] The outer cover 1 can be fixed on the metal base plate 5 by screws.

[0044] The sensor temperature sensing chip 3 is soldered on the printed circuit board 4.

[0045] The sensor antenna 2 is soldered on the printed circuit board 4.

[0046] In some embodiments, the sensor antenna 2 can adopt a spiral antenna.

[0047] The sensor temperature sensing chip 3 and the sensor antenna 2 are connected by a microstrip line on the printed circuit board 4.

[0048] The printed circuit board 4 is fixed on the metal base plate 5 by screws.

[0049] The material of the metal base plate 5 is preferably copper, and it can also be other non-magnetic metal materials, such as aluminum, copper alloy, aluminum alloy, stainless steel, etc.

[0050] As Figure 3 As shown, four outer cover mounting holes 51 are provided around the metal base plate 5. Self-tapping screws pass through the outer cover mounting holes 51 from the reverse side of the metal base plate 5 and are screwed into the outer cover 1. Zebra mounting holes 52 are provided on both sides of the metal base plate 5. The zebra mounting holes 52 are serrated to prevent the metal tie-rod from sliding.

[0051] As Figure 4 shown, both the first through-hole buckle 7 and the second through-hole buckle 10 have a first cable tie through-hole 71, and a set screw mounting hole 71 is provided at the top thereof.

[0052] Refer to Figure 1 and Figure 2 , one end of the first metal cable tie 11 passes through the cable tie mounting hole 52 on one side of the metal base plate 5, and after being bent, they are inserted into the first cable tie through-hole 71 of the first through-hole buckle 7 together.

[0053] The first set screw 6 is screwed into the set screw mounting hole 71 at the top of the first through-hole buckle 7 to press the first metal cable tie 11.

[0054] As Figure 5 and Figure 6 shown, the locking head 8 includes a U-shaped seat 81, and an inner through-hole 83 and an outer through-hole 82 are provided at the bottom of the U-shaped seat 81 for fixing the metal cable tie.

[0055] Refer to Figure 1 , Figure 5 and Figure 6 , the other end of the first metal cable tie 11 passes through the second cable tie through-hole 84 of the rotary pin 86 of the locking head 8.

[0056] One end of the second metal cable tie 12 passes through the cable tie mounting hole 52 on the other side of the metal base plate 5, and after being bent, they are inserted into the first cable tie through-hole 71 of the second through-hole buckle 10 together.

[0057] The second set screw 9 is screwed into the set screw mounting hole 71 at the top of the second through-hole buckle 10 to press the second metal cable tie 12.

[0058] The other end of the second metal cable tie 12 passes through the inner through-hole 83 of the locking head 8 from top to bottom, folds back and then passes through the outer through-hole 82 of the locking head 8 from bottom to top, and extends more than 10 mm out of the U-shaped base, and the second metal cable tie 12 hooks the metal piece between the inner through-hole 82 and the outer through-hole 83 at the bottom of the U-shaped seat 81 of the locking head 8 to fix the second metal cable tie 12 on the locking head 8.

[0059] When in use, rotate the locking pin 86 of the locking head 8 counterclockwise, and the locking pin 86 will rotate together with the second metal cable tie 12, and finally tighten the second metal cable tie 12 on the object to be installed.

[0060] On the locking pin 86 of the locking head 8, a locking through-hole 85 is provided. Use a suitable metal rod (such as an L-shaped metal rod) to hook the locking through-hole 85 and rotate the metal rod to achieve the purpose of locking the sensor and realize the installation of the sensor in a narrow space.

[0061] The U-shaped seat 81 of the locking head 8 is provided with a loosening prevention protrusion 87. The loosening prevention protrusion 87 can be a wedge-shaped block. The rotating gear 88 can only rotate in one direction (the direction facing the slope of the wedge-shaped block). When rotating in the reverse direction, it will be blocked by the loosening prevention protrusion 87 and cannot rotate, so as to prevent the metal cable tie from loosening after installation.

[0062] In some other embodiments, the locking direction can also be clockwise, which is determined by the direction of the loosening prevention protrusion 87.

[0063] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations according to the concept of the present invention without creative labor. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field based on the concept of the present invention through logical analysis, reasoning or limited experiments on the basis of the prior art should be within the protection scope determined by the claims.

Claims

1. A surface acoustic wave temperature sensor with a locking device, characterized in that: It includes an outer cover, a sensor antenna, a sensor temperature sensing chip, a printed circuit board, a metal base plate, a locking mechanism and a metal tie; the metal tie includes a first metal tie and a second metal tie, one end of the first metal tie is connected to one side of the metal base plate by a buckle, and the other end is connected to the adjusting part of the locking mechanism; one end of the second metal tie is connected to the other side of the metal base plate by a buckle, and the other end is connected to the fixing part of the locking mechanism; the locking mechanism is configured to adjust the length of the first metal tie between the metal base plate and the locking mechanism through the adjusting part; the printed circuit board is welded and fixed to the metal base plate, the sensor temperature sensing chip and the sensor antenna are welded to the printed circuit board, and are connected through the microstrip line on the printed circuit board; the outer cover is installed on the outside of the sensor antenna and fixed to the metal base plate; both sides of the metal base plate are provided with tie mounting holes, the buckle includes a hollow first tie through hole and a top screw mounting hole opened on the top, The metal strap is connected to any side of the metal base plate by passing one end of the metal strap through the strap mounting hole on one side of the metal base plate, bending and inserting the ends of the metal strap into the first strap through hole, and screwing a top screw into the top screw mounting hole; the fixing part of the locking device includes a U-shaped seat, and the bottom of the U-shaped seat is provided with an inner through hole and an outer through hole for fixing the metal strap; the adjusting part of the locking device includes a locking pin and two rotating gears, the locking pin vertically passes through the two side walls of the U-shaped seat, the two rotating gears respectively abut against the outer sides of the side walls of the U-shaped seat, the locking pin drives the rotating gear to rotate relative to the center line of the locking pin, the part of the locking pin located between the two side walls of the U-shaped seat has a second strap through hole, and at least one anti-loosening protrusion is provided on the outer sides of the two side walls of the U-shaped seat, and the anti-loosening protrusion cooperates with at least one of the two rotating gears to prevent the locking pin and the rotating gear from rotating in the opposite direction of the set rotation direction.

2. The surface acoustic wave temperature sensor with a locking device according to claim 1, characterized in that: The outer cover is made of polyphenylene sulfide material.

3. The surface acoustic wave temperature sensor with a locking device as claimed in claim 1, characterized in that: The metal bottom plate is made of one of copper, aluminum, copper alloy, aluminum alloy and stainless steel.

4. The surface acoustic wave temperature sensor with a locking device as claimed in claim 1, characterized in that: Cover mounting holes are provided around the metal bottom plate, and the cover is fixed to the metal bottom plate by self-tapping screws that penetrate through the cover mounting holes on the reverse side of the metal bottom plate and are screwed into the cover.

5. The surface acoustic wave temperature sensor with a locking device as claimed in claim 1, characterized in that: The cable tie mounting hole is in a sawtooth shape.

6. The surface acoustic wave temperature sensor with a locking device as claimed in claim 1, characterized in that: The second metal cable tie is fixed to the U-shaped seat of the locking mechanism by passing the other end of the second metal cable tie through the inner through hole from top to bottom, folding back and then passing through the outer through hole from bottom to top, so that the second metal cable tie hooks the metal sheet between the inner through hole and the outer through hole.

7. The surface acoustic wave temperature sensor with a locking device as claimed in claim 1, characterized in that: One end of the locking pin has a bent portion, and the bent portion presses one of the two rotating gears against one of the two side walls of the U-shaped seat.

8. The surface acoustic wave temperature sensor with a locking device as claimed in claim 7, characterized in that: The other end of the locking pin has a blocking portion, which presses the other of the two rotating gears against the other of the two side walls of the U-shaped seat. The blocking portion has a hollow locking through hole for assisting in locking the sensor.

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