Closed-ring-driven sliding handle type linear differential transformer type displacement sensor

Abstract

The utility model discloses a closed-ring-driven sliding handle type linear differential transformer type displacement sensor, which comprises a shell, a coil framework, a coil assembly, an iron core and an elastic pull rod, wherein the coil framework, the coil assembly, the iron core and the elastic pull rod are arranged in the shell; one ends of the two elastic pull rods are connected with the two ends of the iron core respectively, the other ends of the two elastic pull rods penetrate out of the corresponding ends of the coil framework, bypass the two pulleys, are bent by 180 degrees and then are connected with the two ends of the sliding handle connecting rod, and the middle of the sliding handle connecting rod is connected with the inner end of the sliding handle. According to the utility model, the function of driving the iron core to move is realized without pushing the elastic pull rod, so that the rigidity requirement on the elastic pull rod is reduced; the application requirement can be met as long as the length is basically kept unchanged (namely, the ductility is low) in the pulling process, the pulley can be bent and wound around the pulley, and the pulley can be matched with the pull rod sliding groove to achieve limiting movement, application is more convenient, and popularization is easy.

Description

Technical Field

[0001] The utility model relates to a linear differential transformer type displacement sensor, in particular to a closed annular driven sliding handle type linear differential transformer type displacement sensor. Background Art

[0002] Linear differential transformer displacement sensor, abbreviated as LVDT, is a linear displacement sensor that uses the movement of the core to change the coil voltage to achieve displacement detection. It is widely used in complete systems such as ships, aviation, aerospace, and weapons to control and feedback linear displacement signals.

[0003] The basic structure of a traditional linear differential transformer displacement sensor includes a shell and a cylindrical coil frame placed in the shell, multiple coils wound on the coil frame, an iron core arranged in the coil frame, and a pull rod connected to the iron core. The coil generally includes a primary excitation coil and two secondary induction coils. When working, an alternating current of a certain frequency is applied to the primary excitation coil, and a certain induced voltage is generated on the two secondary induction coils. When the pull rod drives the iron core to move, the induced voltage of the two secondary induction coils will change. By measuring the voltage difference between the two secondary induction coils, the position change information of the iron core can be obtained, thereby achieving the purpose of linear displacement detection.

[0004] The defect of the above-mentioned traditional linear differential transformer displacement sensor is that the hard pull rod can only move in its axial direction (which is also the axial direction of the iron core), and its movement range is all in the axial direction of the pull rod. Therefore, sufficient space needs to be reserved at a position outside the sensor corresponding to the axial direction of the pull rod to meet normal working needs. Therefore, it cannot be used in application scenarios where sufficient space cannot be reserved in the axial direction of the pull rod (which is also the axial direction of the iron core).

[0005] In order to solve the above problems, the applicant has applied for an invention patent named "Sliding handle type linear differential transformer type displacement sensor". The application uses a bent elastic pull rod to connect the sliding handle and the iron core together, so as to realize the function of synchronous movement of the sliding handle and the iron core but not coaxial. However, there is a disadvantage in this application, that is, the elasticity and strength requirements of the elastic pull rod are relatively high in order to achieve a good push-pull transmission function. Under the condition that the elastic pull rod meets the requirements, the application is fully capable of realizing the precise angular displacement detection function, but in the case that there is no suitable material to make the elastic pull rod, the product performance will be reduced, so its application is subject to certain limitations. Utility Model Content

[0006] The utility model aims to solve the above problems and provide a closed ring driven sliding handle linear differential transformer displacement sensor which has low requirements on the performance of the elastic pull rod.

[0007] The utility model achieves the above-mentioned purpose through the following technical solutions:

[0008] A closed ring-driven sliding handle type linear differential transformer displacement sensor, comprising a shell and a cylindrical coil frame placed in the shell, a coil group wound on the coil frame, an iron core arranged in the coil frame, and an elastic pull rod, one end of the elastic pull rod is connected to the iron core, the other end of the elastic pull rod passes through the corresponding end of the coil frame and is bent 180° and connected to the inner end of the sliding handle, the outer end of the sliding handle passes through the corresponding strip through hole on the shell and is placed outside the shell, a pulley is respectively installed at the position outside the two ends of the coil frame in the shell, one end of the two elastic pull rods is respectively connected to the two ends of the iron core, the other end of the two elastic pull rods passes through the corresponding end of the coil frame and bypasses the two pulleys and is bent 180° and connected to the two ends of the sliding handle connecting rod, and the middle part of the sliding handle connecting rod is connected to the inner end of the sliding handle.

[0009] Preferably, in order to better limit the elastic pull rod to achieve a more precise transmission function, a pull rod groove is provided in the outer shell at a position corresponding to the position from the pulley on the same side to the sliding handle connecting rod in the elastic pull rod, and the two elastic pull rods are respectively placed in the two pull rod grooves and can slide in a limited position.

[0010] Preferably, in order to achieve the dust-proof function, an annular dust-proof groove is provided in the outer portion of the pull rod groove, the two pulleys and the outer side of the coil group in the outer shell, and a dust-proof belt is placed in the dust-proof groove. The two ends of the dust-proof belt are respectively connected to the middle section of the sliding handle, or the sliding handle passes through the corresponding through hole on the closed annular dust-proof belt, and the dust-proof belt covers the strip through hole on the outer shell for the sliding handle to pass through and move.

[0011] Preferably, in order to facilitate reliable assembly and lead-out of leads, the iron core, the coil frame and the coil group are placed in the transformer inner cavity inside the shell, one end of the cavity wall on one side of the transformer inner cavity is provided with a lead through hole for the lead to pass through, the two pulleys are respectively placed in two pulley inner cavities in the shell, the two pulley inner cavities are respectively connected with the two ends of the transformer inner cavity and the two ends of the coil frame are respectively placed in the two connecting positions and are limited.

[0012] Preferably, in order to achieve a better shielding effect, shielding rings are respectively installed at both ends of the coil skeleton, and the two shielding rings are placed in the inner cavity of the transformer.

[0013] Preferably, in order to reliably install the pulley, a mounting shaft is provided on one side wall of the pulley inner cavity, and the pulley is sleeved on the corresponding mounting shaft through its own bearing.

[0014] Preferably, in order to facilitate processing and assembly, the shell includes a first sub-shell and a second sub-shell respectively located on both sides of the coil group and the sliding handle, the first sub-shell is provided with a countersunk groove at both ends, and the bottom of the countersunk groove is provided with a connecting screw hole, the second sub-shell is provided with a protrusion at both ends, and the protrusion is provided with a connecting through hole, the two protrusions are respectively placed in the two countersunk grooves, and a plurality of connecting screws are respectively passed through the plurality of connecting through holes and connected to the plurality of connecting screw holes.

[0015] Preferably, in order to facilitate installation of the sensor on other equipment, a mounting lug protruding outward is provided on a side of the first sub-housing and the second sub-housing away from the sliding handle, and a mounting through hole is provided on the mounting lug.

[0016] The beneficial effects of the utility model are:

[0017] The utility model connects one end of two elastic pull rods to the two ends of the iron core respectively, and connects the other ends of the two elastic pull rods to the sliding handles respectively. No matter which direction the sliding handle moves, the iron core can be driven to move by pulling the corresponding elastic pull rod. There is no need to push the elastic pull rod to achieve the function of driving the iron core to move, so the rigidity requirement of the elastic pull rod is reduced. As long as its length remains basically unchanged during the pulling process (that is, low ductility) and it can be bent to bypass the pulley and can cooperate with the pull rod slide groove to achieve limited movement, the application requirements can be met, making its application more convenient and easy to popularize. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a front view of the closed ring driven sliding handle linear differential transformer displacement sensor of the utility model;

[0019] Figure 2 It is a top view of the closed ring driven sliding handle linear differential transformer displacement sensor of the utility model;

[0020] Figure 3 It is a left view of the closed ring driven sliding handle linear differential transformer displacement sensor of the utility model;

[0021] Figure 4 yes Figure 2 AA section view in;

[0022] Figure 5 yes Figure 4 Enlarged view of "B" in the figure;

[0023] Figure 6 It is a three-dimensional diagram of the closed ring-driven sliding handle linear differential transformer displacement sensor of the utility model after removing the second sub-housing, and the lead wires are not shown in the figure;

[0024] Figure 7 This is a three-dimensional view of the first sub-housing of the closed ring-driven sliding handle linear differential transformer displacement sensor of the utility model, with a viewing angle of Figure 6 same. DETAILED DESCRIPTION

[0025] The utility model is further described below in conjunction with the accompanying drawings:

[0026] like Figure 1-Figure 7 As shown, the closed ring-driven sliding handle type linear differential transformer type displacement sensor of the utility model comprises a housing (refer to the first sub-housing 5 and the second sub-housing 3 connected to each other in the following content) and a cylindrical coil skeleton 15 placed in the housing, a coil group 14 wound on the coil skeleton 15, an iron core 13 arranged in the coil skeleton 15, and an elastic pull rod 11. The outer end of the sliding handle 4 passes through the corresponding bar-shaped through hole on the housing and is placed outside the housing. A pulley 8 is installed at the position outside the two ends of the coil skeleton 15 in the housing, one end of the two elastic pull rods 11 is respectively connected to the two ends of the iron core 13, the other ends of the two elastic pull rods 11 are respectively passed through the corresponding ends of the coil skeleton 15 and then bypass the two pulleys 8 and bend 180° to be connected to the two ends of the sliding handle connecting rod 12, and the middle part of the sliding handle connecting rod 12 is connected to the inner end of the sliding handle 4.

[0027] like Figure 1-Figure 7 As shown, the utility model also discloses the following more optimized specific structures:

[0028] In order to better limit the elastic pull rod 11 to achieve a more precise transmission function, a pull rod slot 26 is provided in the shell at a position corresponding to the position between the pulley 8 on the same side and the sliding handle connecting rod 12 in the elastic pull rod 11. The two elastic pull rods 11 are respectively placed in the two pull rod slots 26 and can slide in a limited position.

[0029] In order to achieve the dust-proof function, an annular dust-proof groove 25 is provided in the outer position of the pull rod groove 26, the two pulleys 8 and the coil group 14 in the outer shell, and the dust-proof belt 6 is placed in the dust-proof groove 25. The two ends of the dust-proof belt 6 are respectively connected to the middle section of the sliding handle 8, or the sliding handle 8 passes through the corresponding through holes on the closed annular dust-proof belt 6, and the dust-proof belt 6 covers the strip through hole on the outer shell for the sliding handle 8 to pass through and move.

[0030] In order to facilitate reliable assembly and lead-out of the lead wires, the iron core 13, the coil skeleton 15 and the coil group 14 are placed in the transformer cavity 27 in the shell, and one end of the cavity wall on one side of the transformer cavity 27 is provided with a lead through hole 24 for the lead wire (not shown in the figure) to pass through. The two pulleys 8 are respectively placed in the two pulley cavities 23 in the shell, and the two pulley cavities 23 are respectively connected to the two ends of the transformer cavity 27, and the two ends of the coil skeleton 15 are respectively placed in the two connecting positions and are limited.

[0031] In order to achieve a better shielding effect, shielding rings 16 are respectively installed at both ends of the coil skeleton 15 , and the two shielding rings 16 are both placed in the transformer inner cavity 27 .

[0032] In order to reliably install the pulley 8 , a mounting shaft 10 is provided on one side wall of the pulley inner cavity 23 , and the pulley 8 is sleeved on the corresponding mounting shaft 10 through its own bearing 9 .

[0033] To facilitate processing and assembly, the housing includes a first sub-housing 5 and a second sub-housing 3, which are respectively located on both sides of the coil group 14 and the sliding handle 4. The first sub-housing 5 has a countersunk groove 21 at both ends, and a connecting screw hole 22 is provided at the bottom of the countersunk groove 21. The second sub-housing 3 has a protrusion 7 at both ends, and a connecting through hole is provided on the protrusion 7. The two protrusions 7 are respectively placed in the two countersunk grooves 21, and a plurality of connecting screws 1 are respectively passed through the plurality of connecting through holes and connected to the plurality of connecting screw holes 22.

[0034] In order to facilitate the installation of the sensor on other equipment, a mounting lug 2 protruding outward is provided on the first sub-housing 5 and the second sub-housing 3 at a side away from the sliding handle 4, and a mounting through hole is provided on the mounting lug 2.

[0035] Figure 5 Also shown are two layers of primary excitation coils 20 (generally enameled wires) wound on the coil skeleton 15 from the inside to the outside, a first secondary induction coil 19, and a second secondary induction coil 18. Insulating tapes 17 are provided between the first secondary induction coil 19 and the second secondary induction coil 18, between the first secondary induction coil 19 and the primary excitation coil 20, and outside the second secondary induction coil 18. These structures are all conventional structures.

[0036] like Figure 1-Figure 7As shown, when working, an alternating current of a certain frequency is applied to the primary excitation coil 20, a certain induced voltage is generated on the first secondary induction coil 19 and the second secondary induction coil 18, the sliding handle 4 is connected to the moving part of the device to be detected, the moving part drives the sliding handle 4 to move linearly, the sliding handle 4 drives the elastic pull rod 11 to move synchronously, the elastic pull rod 11 bypasses the pulley 8 to achieve bending movement and pulls the iron core 15 to move synchronously, the induced voltage of the first secondary induction coil 19 and the second secondary induction coil 18 will change, by measuring the voltage difference between the first secondary induction coil 19 and the second secondary induction coil 18, the position change information of the iron core 15 can be obtained, thereby achieving the purpose of linear displacement detection of the moving part.

[0037] The above embodiments are only preferred embodiments of the present utility model and are not limitations on the technical solutions of the present utility model. Any technical solution that can be implemented on the basis of the above embodiments without creative work should be deemed to fall within the scope of protection of the patent of the present utility model.

Claims

1. A closed ring-driven sliding handle linear differential transformer displacement sensor, comprising a housing and a cylindrical coil frame placed in the housing, a coil group wound on the coil frame, an iron core arranged in the coil frame, and an elastic pull rod, one end of the elastic pull rod is connected to the iron core, the other end of the elastic pull rod passes through the corresponding end of the coil frame and then bends 180° and is connected to the inner end of the sliding handle, the outer end of the sliding handle passes through the corresponding bar-shaped through hole on the housing and is placed outside the housing, characterized in that: A pulley is installed in the outer shell at the outer sides of the two ends of the coil frame, one end of the two elastic pull rods is connected to the two ends of the iron core, the other ends of the two elastic pull rods pass through the corresponding ends of the coil frame, bypass the two pulleys and bend 180° before being connected to the two ends of the sliding handle connecting rod, and the middle part of the sliding handle connecting rod is connected to the inner end of the sliding handle.

2. The closed loop driven sliding handle linear differential transformer displacement sensor according to claim 1, characterized in that: A pull rod sliding groove is provided in the shell at a position corresponding to the position between the pulley on the same side and the sliding handle connecting rod in the elastic pull rod, and the two elastic pull rods are respectively placed in the two pull rod sliding grooves and can slide within a limited position.

3. The closed loop driven sliding handle linear differential transformer displacement sensor according to claim 2, characterized in that: An annular dustproof slide groove is provided in the outer part of the outer shell at the position of the pull rod slide groove, the two pulleys and the outer side of the coil group. A dustproof belt is placed in the dustproof slide groove. The two ends of the dustproof belt are respectively connected to the middle section of the sliding handle. Alternatively, the sliding handle passes through the corresponding through hole on the closed annular dustproof belt, and the dustproof belt covers the strip through hole on the outer shell for the sliding handle to pass through and move.

4. The closed loop driven sliding handle linear differential transformer displacement sensor according to claim 1, 2 or 3, characterized in that: The iron core, the coil frame and the coil group are placed in the transformer inner cavity in the shell, one end of the cavity wall on one side of the transformer inner cavity is provided with a lead through hole for the lead wire to pass through, the two pulleys are respectively placed in the two pulley inner cavities in the shell, the two pulley inner cavities are respectively connected with the two ends of the transformer inner cavity and the two ends of the coil frame are respectively placed in the two connecting positions and are limited.

5. The closed loop driven sliding handle linear differential transformer displacement sensor according to claim 4, characterized in that: Shielding rings are respectively installed at both ends of the coil frame, and the two shielding rings are placed in the inner cavity of the transformer.

6. The closed loop driven sliding handle linear differential transformer displacement sensor according to claim 4, characterized in that: A mounting shaft is provided on one side wall of the inner cavity of the pulley, and the pulley is sleeved on the corresponding mounting shaft through its own bearing.

7. The closed loop driven sliding handle linear differential transformer displacement sensor according to claim 1, 2 or 3, characterized in that: The housing includes a first sub-housing and a second sub-housing respectively located on both sides of the coil group and the sliding handle, the first sub-housing is provided with a recessed groove at both ends, the bottom of the recessed groove is provided with a connecting screw hole, the second sub-housing is provided with a convex piece at both ends, the convex piece is provided with a connecting through hole, the two convex pieces are respectively placed in the two recessed grooves, and a plurality of connecting screws are respectively passed through the plurality of connecting through holes and connected to the plurality of connecting screw holes.

8. The closed loop driven sliding handle linear differential transformer displacement sensor according to claim 7, characterized in that: A mounting lug protruding outward is provided on one side of the first sub-housing and the second sub-housing away from the sliding handle, and a mounting through hole is provided on the mounting lug.

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