A displacement switch

Abstract

The present invention discloses a displacement switch, which includes a screw sleeve, a base connected to the tail end of the screw sleeve, a sensor installed on the base, and a measuring rod passing through the screw sleeve and the base. A first positioning hole is provided in the screw sleeve, and a second positioning hole coaxial with the first positioning hole is provided in the base. A first cylindrical section matching with the first positioning hole is provided at the head end of the measuring rod, and a second cylindrical section matching with the second positioning hole is provided at the tail end thereof. The first cylindrical section is supported in the first positioning hole, and the second cylindrical section is supported in the second positioning hole. A positioning wheel is provided at the head end of the measuring rod, the rotation axis of the positioning wheel is perpendicular to the axis of the measuring rod, and at least a part of the circumferential surface of the positioning wheel is located outside the end faces of the measuring rod and the screw sleeve. The present invention has the advantages of high straightness of the telescopic movement of the measuring rod, not easy to jam the rod, and accurate measurement.

Description

Technical Field

[0001] The present invention relates to a detection device, and in particular discloses a displacement switch. Background Art

[0002] Reference Figure 1 Existing displacement switches include a screw sleeve 1, a base 2 connected to one end of the screw sleeve 1. A guide groove 2A is provided in the base 2, and a sensor 3 is installed above the guide groove 2A. A measuring rod 4 penetrates through the screw sleeve 1 and the base 2. Its head end extends out of the end face of the head end of the screw sleeve 1 for abutting against the object to be measured, and its tail end is located in the guide groove 2A of the base 2 and is connected with a slider 4A. The slider 4A cooperates with the guide groove 2A to guide the linear movement of the measuring rod 4. A touch inclined surface 4B is provided on the slider 4A, and the touch inclined surface 4B is used to press the detection contact of the sensor 3 to trigger an alarm signal. The sensor 3 is a precision device. To obtain an accurate detection signal, it is necessary to precisely control the distance between the detection contact and the slider 4. Since the driving force of the movement of the measuring rod 4 is at its head end, its telescopic movement depends only on the limit of the guide groove 21 and the slider 4A, it is difficult to ensure the linear movement of the measuring rod 4, and the slider 4A is prone to roll during the sliding process. The roll of the slider 4 will change the distance between the slider 4 and the detection contact of the sensor, resulting in the detection contact of the side sensor 3 being unable to detect the slider 4A, or the slider 4A directly damaging the detection contact of the sensor 3; serious roll of the slider 4A may also cause jamming of the rod, thereby blocking the movement of the object to be measured and causing equipment operation accidents. In addition, when the object to be measured moves radially along the measuring rod 4, the measuring rod 4 will also be worn, affecting the measurement accuracy. Summary of the Invention

[0003] Based on this, in view of the problems in the prior art, it is necessary to provide a displacement switch with high linearity of the telescopic movement of the measuring rod, not prone to rod jamming and accurate measurement.

[0004] To solve the problems of the existing technology, the present invention discloses a displacement switch, which includes a screw sleeve, a base connected to the tail end of the screw sleeve, a sensor mounted on the base, a measuring rod passing through the screw sleeve and the base, an inner hole is provided in the base, the sensing contact of the sensor faces the inner hole of the base, a first positioning hole is provided in the screw sleeve, and a second positioning hole coaxial with the first positioning hole is provided in the base. A first cylindrical section matching with the first positioning hole is provided at the head end of the measuring rod, and a second cylindrical section matching with the second positioning hole is provided at the tail end thereof. The first cylindrical section is supported in the first positioning hole, and the second cylindrical section is supported in the second positioning hole. A positioning wheel is provided at the head end of the measuring rod, the rotation axis of the positioning wheel is perpendicular to the axis of the measuring rod, and at least a part of the circumferential surface of the positioning wheel is located outside the end faces of the measuring rod and the screw sleeve. The measuring rod further includes a fifth cylindrical section, a sixth cylindrical section with a diameter smaller than that of the fifth cylindrical section and the second cylindrical section is connected to the tail end of the fifth cylindrical section, and the second cylindrical section is connected to the tail end of the sixth cylindrical section. The sensing contact of the sensor is placed between the second cylindrical section and the fifth cylindrical section. When the measuring rod is compressed, the sensing contact of the sensor can touch the tail end of the fifth cylindrical section.

[0005] The beneficial effects of the present invention are as follows: Since the first cylindrical section and the second cylindrical section at both ends of the measuring rod are respectively supported by the coaxial first positioning hole and second positioning hole, the straightness of the telescopic movement of the measuring rod is high, and it is not easy to get stuck. Also, because a positioning wheel is used to contact the object to be measured, when the object to be measured moves radially along the measuring rod, the friction between the object to be measured and the positioning wheel is rolling friction. The measuring object will not cause the measuring rod to tilt sideways, nor will it wear the measuring rod, and the measurement is more accurate. Description of the Drawings

[0006] Figure 1 It is a schematic structural diagram of an existing displacement switch.

[0007] Figure 2 It is a schematic assembly structural diagram of the present invention.

[0008] Figure 3 It is a schematic full-section structural diagram of the present invention.

[0009] Figure 4 It is a schematic structural diagram of the screw sleeve of the present invention.

[0010] Figure 5 It is a schematic full-section structural diagram of the screw sleeve of the present invention.

[0011] Figure 6 It is a schematic assembly structural diagram of the positioning block and the base of the present invention.

[0012] Figure 7 It is a schematic assembly structural diagram of the measuring rod of the present invention.

[0013] Figure 8External structural schematic diagram of the present invention. Detailed implementation manners

[0014] To further understand the features, technical means, specific purposes, and functions achieved by the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners. The head end of a certain component or part mentioned below refers to the end of the component or part facing the object to be measured when the displacement switch is installed, and its tail end refers to the other end opposite to the head end. The above description of the orientation only represents the relative positional relationship in the accompanying drawings of the present invention and does not represent an absolute limitation on the protection scope of the present invention.

[0015] Reference Figure 2 、 Figure 3 and Figure 8 The present invention includes a screw sleeve 1, a base 2 connected to the tail end of the screw sleeve 1, a sensor 3 installed on the base 2, a measuring rod 4 passing through the base 1 and the base 2, and a cylindrical outer cover 5 connected to the screw sleeve 1 and covering the base 1.

[0016] Reference Figure 4 and Figure 5 The screw sleeve 1 is cylindrical, having a screw sleeve inner hole 10. Its head end face is provided with a first relief groove 11a and a second relief groove 11b that are perpendicular to each other. Its tail end is provided with a first step 12a for connecting the outer cover 5 and a second step 12b for connecting the base 2. The outer periphery of the screw sleeve 1 is provided with a mounting thread 13. A first positioning hole 11 that is coaxial with the screw sleeve inner hole 10 and has a diameter smaller than the screw sleeve inner hole 10 is provided inside the head end of the screw sleeve 1, and a card slot 15 is provided inside its tail end.

[0017] Reference Figure 3 and Figure 6 The base 2 is cylindrical, having a base inner hole 20. Its head end is connected to the tail end of the screw sleeve 1, and its tail end is provided with a mounting hole 21 that is coaxial with the inner hole 20. A positioning block 22 is provided inside the mounting hole 21, and a second positioning hole 23 that is coaxial with the first positioning hole 11 is provided inside the positioning block 22. An installation groove 24 communicating with the base inner hole 20 is provided on the base 2, and a threaded hole 25 is provided on one side of the installation groove 24. The base 1 of the present invention can also be integrally formed with the screw sleeve 2, so that the installation is simpler. However, for the convenience of processing, the present invention is preferably a split structure. The base 2 of the present invention can also not be provided with the mounting hole 21 and the positioning block 22, and the second positioning hole 23 is directly machined on the tail end face of the base 2. In this way, the process is less, but the requirement for the processing method is higher.

[0018] Reference Figure 7The measuring rod 4 is cylindrical and consists of multiple cylindrical segments with different diameters. Its first end is provided with a first cylindrical segment 41 that mates with the first positioning hole 11, and its second end is provided with a second cylindrical segment 42 that mates with the second positioning hole 23. The tail end of the first cylindrical segment 41 is connected to a third cylindrical segment 43 with a diameter larger than that of the first positioning hole 11. The tail end of the third cylindrical segment 43 is connected to a fourth cylindrical segment 44 with a diameter smaller than that of the third cylindrical segment 43. The tail end of the fourth cylindrical segment 44 is connected to a fifth cylindrical segment 45 with a diameter smaller than that of the fourth cylindrical segment 44. The tail end of the fifth cylindrical segment 45 is connected to a sixth cylindrical segment 46 with a diameter smaller than those of the fifth cylindrical segment 45 and the second cylindrical segment 42. The tail end of the sixth cylindrical segment 46 is connected to the second cylindrical segment 42. A chamfer 451 is provided at the tail end of the fifth cylindrical segment 45. An installation groove 411 is formed in the first cylindrical segment 41 and penetrates through the end face of the first end of the measuring rod 4. Shaft holes 412 are provided on both sides of the installation groove 411, and the axes of the shaft holes 412 are perpendicular to the axis of the measuring rod 4. A fixed shaft 47 is arranged in the shaft hole 412. Two clamping grooves 471 are provided on the fixed shaft 47. A positioning wheel 48 that can rotate around the fixed shaft 47 is installed between the two clamping grooves 471. Two snap rings 472 are respectively snapped into the two clamping grooves 471 to limit the positioning wheel 48 and the fixed shaft 47.

[0019] Reference Figure 2 and Figure 3。The assembly method of the present invention is as follows: 1) Insert the head end of the measuring rod 4 into the tail end of the screw sleeve 1 until the third cylindrical section 43 thereof abuts against the inner side of the first positioning hole 11; 2) Insert the backlash spring 6 into the measuring rod 4 from the tail end of the screw sleeve 1 and abut it against the tail end of the third cylindrical section 43 of the measuring rod 4. Then, snap the snap ring 16 into the slot 15 of the screw sleeve 1 to fix the backlash spring 6. The inner diameter of the snap ring 15 is smaller than the outer diameter of the fourth cylindrical section 44; 3) Fix the positioning block 22 in the mounting hole 21 of the base 2. Then, insert the inner hole 20 of the base into the tail end of the measuring rod 4 until the head end of the base 2 abuts against the second step 12b of the screw sleeve 1. Insert the second cylindrical section 42 of the measuring rod 4 into the second positioning hole 23 of the positioning block 22 and weld the base 2 and the screw sleeve 1; 4) Place the positioning wheel 48 into the mounting groove 411 of the measuring rod 4. Then, pass the fixing shaft 47 through the positioning wheel 48 and the two shaft holes 412 of the measuring rod 4. Then, snap the two circlips 472 into the two slots 471 respectively to limit the positioning wheel 48 and the fixing shaft 47. The positioning wheel 48 is located in the first relief groove 11a of the screw sleeve 1, and a part of its circumferential surface is outside the head end faces of the measuring rod 4 and the screw sleeve 1. The two ends of its fixing shaft 47 are located in the second relief groove 11b; 5) Fix the sensor 3 in the mounting groove 24 on the base 2 with screws passing through the threaded holes 25. The sensing contact 31 of the sensor faces the inner hole 20 of the base and is placed at a suitable position between the second cylindrical section 42 and the fifth cylindrical section 45 of the measuring rod 4. The wiring terminal 32 of the sensor 3 faces outside the base 2, and a lead wire (not shown in the figure) is connected to the wiring terminal 32; 6) Insert the outer cover 5 from the tail end of the base 2 until its opening abuts against the first step 12a of the screw sleeve 1 and weld the outer cover 5 and the screw sleeve 1.

[0020] Reference Figure 3 。The installation method of the present invention is as follows: First, screw the rear nut M2 into the external thread 13 of the screw sleeve. Then, pass the screw sleeve 1 through the chassis B. Next, screw the front nut M1 onto the external thread 13 of the screw sleeve outside the chassis B. The front and rear nuts M1 and M2 clamp the screw sleeve 1 on the chassis B. During the installation process, it is necessary to adjust the distance and perpendicularity between the positioning wheel 48 and the measured object A so that the positioning wheel 48 abuts against the measured object A, the backlash spring 6 is appropriately compressed, and the positioning wheel 48 has a suitable pre-tightening force on the measured object A. When the measured object A moves radially along the measuring rod 4, make the tangent of the contact point between the positioning wheel 48 and the measured object parallel to the direction of this radial movement. In this way, when the measured object A moves radially along the measuring rod 4, it drives the positioning wheel 48 to roll, and the friction between the measured object A and the positioning wheel 48 is rolling friction. The backlash spring 6 is used to provide a pre-tightening force for the measuring rod 4 to eliminate the gap between the measuring rod 4 and the measured object A. The head end of the third cylindrical section 43 of the measuring rod 4 cooperates with the inner side of the first positioning hole 11 of the base to limit the maximum extension amount of the measuring rod 4, and the tail end of its fourth cylindrical section 44 cooperates with the snap ring 16 to limit the maximum compression amount of the measuring rod 4.

[0021] ReferenceFigure 3 . The working mode of the present invention is as follows: during the operation of the object A to be measured, the measuring rod 4 is continuously compressed. When the chamfer 451 at the end of the fifth cylindrical section 45 of the measuring rod 4 contacts the sensing contact 31 of the sensor 3, the chamfer 451 slowly compresses the sensing contact 31 until the sensor 3 emits an alarm signal, indicating that the object A to be measured has reached the alarm position. By providing the chamfer 451 at the end of the fifth cylindrical section 45, the impact on the sensing contact 31 can be mitigated, and the direct impact of the end of the fifth cylindrical section 45 on the sensor sensing contact 31 can be avoided.

[0022] In the present invention, since the first cylindrical section and the second cylindrical section at both ends of the measuring rod are respectively supported by the coaxial first positioning hole and the second positioning hole, the linearity of the telescopic movement of the measuring rod is high and it is not easy to get stuck. Also, since the positioning wheel is used to contact the object to be measured, when the object to be measured moves radially along the measuring rod, the friction between the object to be measured and the positioning wheel is rolling friction, the measuring object will not drive the measuring rod to tilt laterally, nor will it wear the measuring rod, and the measurement is more accurate.

[0023] The above-described embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the present invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A displacement switch, comprising a screw sleeve, a base connected to the tail end of the screw sleeve, a sensor mounted on the base, a measuring rod passing through the screw sleeve and the base, an inner hole is provided in the base, and the sensing contact of the sensor faces the inner hole of the base, and is characterized in that: A first positioning hole is provided in the screw sleeve, a second positioning hole coaxial with the first positioning hole is provided in the base, a first cylindrical section mating with the first positioning hole is provided at the head end of the measuring rod, a second cylindrical section mating with the second positioning hole is provided at the tail end thereof, the first cylindrical section is supported in the first positioning hole, the second cylindrical section is supported in the second positioning hole, a positioning wheel is provided at the head end of the measuring rod, the rotation axis of the positioning wheel is perpendicular to the axis of the measuring rod, at least a partial circumferential surface of the positioning wheel is located outside the end faces of the measuring rod and the screw sleeve, the measuring rod further includes a fifth cylindrical section, a sixth cylindrical section with a diameter smaller than that of the fifth cylindrical section and the second cylindrical section is connected to the tail end of the fifth cylindrical section, the second cylindrical section is connected to the tail end of the sixth cylindrical section, the sensor sensing contact is placed between the second cylindrical section and the fifth cylindrical section, and when the measuring rod is compressed, the sensor sensing contact can touch the tail end of the fifth cylindrical section.

2. The displacement switch according to claim 1, wherein: A third cylindrical section with a diameter larger than that of the first positioning hole is connected to the tail end of the first cylindrical section on the measuring rod, a clamping groove is provided in the screw sleeve, a snap ring is provided in the clamping groove, a backlash eliminating spring is sleeved on the measuring rod, one end of the backlash eliminating spring abuts against the tail end of the third cylindrical section, and the other end abuts against the snap ring. The head end of the third cylindrical section mates with the inner side of the first positioning hole of the base to limit the maximum extension amount of the measuring rod.

3. The displacement switch according to claim 2, wherein: A fourth cylindrical section with a diameter smaller than that of the third cylindrical section and larger than the inner diameter of the snap ring is connected to the tail end of the third cylindrical section, and the tail end of the fourth cylindrical section mates with the snap ring to limit the maximum compression amount of the measuring rod.

4. The displacement switch according to claim 3, wherein: The fifth cylindrical section is provided at the tail end of the fourth cylindrical section and has a diameter smaller than that of the fourth cylindrical section.

5. The displacement switch according to claim 1, wherein: A chamfer is provided at the tail end of the fifth cylindrical section.

6. The displacement switch according to claim 1, wherein: The head end of the base is connected to the tail end of the screw sleeve, an installation hole is provided at the tail end of the base, a positioning block is provided in the installation hole, and the second positioning hole is provided in the positioning block.

7. The displacement switch according to claim 1, wherein: An installation groove penetrating through the head end face of the measuring rod is provided on the first cylindrical section of the measuring rod, fixing shafts perpendicular to the axis of the measuring rod are provided on both sides of the installation groove, and the positioning wheel is installed on the fixing shafts.

8. The displacement switch according to claim 7, wherein: A first relief groove and a second relief groove perpendicular to each other are provided at the head end of the screw sleeve, the positioning wheel is located in the first relief groove, and both ends of the fixing shaft are located in the second relief groove.

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