JP5223067B2 - Differential transformer structure - Google Patents

Description

  The present invention relates to a differential transformer structure, and particularly to a novel transformer for making an electrically neutral position variable after product completion by making a cylindrical bobbin having a transformer coil movable relative to a bobbin tube having a rod-shaped core. Regarding improvement.

  Conventionally used differential transformer structures of this type include, for example, the configurations disclosed in Patent Documents 1 and 2. In either case, the configuration is basically shown in FIG. The configuration shown was adopted.

That is, what is indicated by reference numeral 1 in FIG. 6 is a cylindrical case, and first and second end plugs 2 and 3 are provided at both ends of the case 1, and the inner wall 1a of the case 1 has A bobbin 4A having a transformer coil 4 composed of a primary coil P and a pair of secondary coils S ₁ and S ₂ is provided.

A shaft body 5 is provided between the end plugs 2 and 3 so as to freely reciprocate along the direction of the arrow A. The shaft body 5 passes through the end plugs 2 and 3 and extends outward. It protrudes.
The bobbin 4A is sealed and fixed to the end plugs 2 and 3 by a filling resin 6, and a cable 7 or a lead wire 8 connected to the transformer coil 4 is led out to the outside.

  The shaft body 5 is provided with a rod-shaped core 9 made of a magnetic material. The rod-shaped core 9 corresponds to the transformer coil 4, and the shaft body 5 is connected to a detection member (not shown). Thus, it is configured to move linearly toward the extension B and contraction C sides.

The transformer coil 4 is connected as shown in FIG. 4, and the secondary coils S ₁ and S ₂ are connected to each other via a midpoint CT so that output voltages Va and Vb are output. ing.

As shown in FIG. 6, when the rod-shaped core 9 is at the center position with respect to the longitudinal direction of the transformer coil 4, the magnetism between the primary coil P and the pair of secondary coils S ₁ and S ₂ is obtained. specifically the degree of coupling is equal, the rod-like core 9 is moved to the shrinkage C side, it intensified magnetic coupling degree between the primary coil P and a secondary coil S _2, conversely, the primary coil P and a secondary coil S ₁ The degree of magnetic coupling is weakened.

In the magnetic coupling degree, the induced electromotive force of each of the secondary coils S ₁ and S ₂ is expressed by output voltages Va and Vb. The output voltages Va and Vb are AC voltages proportional to the amount of displacement of the rod-shaped core 9. As shown in FIG. 5, the electrical neutral position D of this rod-shaped core is such a position that the output voltages Va and Vb are 0V when Va = Vb, and when the product (LVDT) is shipped, The relative position of the bobbin 4A and the rod-shaped core 9 is fixed so as to be a neutral position D.

JP 2000-74607 A Japanese Patent Laid-Open No. 10-311737

Since the conventional differential transformer structure is configured as described above, the following problems exist.
In other words, when the product is shipped, the relative relationship between the rod-shaped core and the transformer coil is mechanically fixed, and the electrical neutral point is fixed. In some cases, the combination with the device becomes difficult.

  A differential transformer structure according to the present invention includes a bobbin tube provided in a case, a shaft body that is reciprocally movable in an air conditioner of the bobbin tube and includes a probe and a rod-shaped core, and an outer periphery of the bobbin tube And a cylindrical bobbin having a transformer coil composed of a primary coil and a pair of secondary coils, and a cylindrical bobbin interposed between a stepped portion of the bobbin tube and the cylindrical bobbin. An elastic body for urging in one direction; a lid body rotatably provided in an end portion of the case; and a support recess portion for supporting the tip of the bobbin tube so as to move freely; and a protrusion of the lid body A screw portion formed on the outer periphery of the portion, and an inner peripheral screw portion formed on the inner periphery of the opening of the end portion of the case, the screw portion of the lid body being the inner peripheral screw portion of the case Screwed into the lid By being in contact with the end surface of the cylindrical bobbin, the lid body is rotatably held in the case, and the axial position of the cylindrical bobbin is variable by rotation of the lid body, Further, the elastic body is made of any one of rubber, a disc spring or a spring, and the lid body has a configuration in which one or a plurality of recesses or holes for rotating the lid body are formed. A pin is provided between the step portion of the bobbin tube and the cylindrical bobbin, and the cylindrical bobbin is allowed to move only linearly and is not rotated by the pin. A flexible material is interposed between the screw portion of the lid and the inner peripheral screw portion, and the lid is prevented from loosening by the flexible material.

Since the differential transformer structure according to the present invention is configured as described above, the following effects can be obtained.
That is, a bobbin tube provided in the case, a shaft body that is reciprocally moved in the air conditioner of the bobbin tube, and includes a probe and a rod-shaped core, and is provided on the outer periphery of the bobbin tube so as to be directly movable. A cylindrical bobbin having a transformer coil composed of a primary coil and a pair of secondary coils, and interposed between the stepped portion of the bobbin tube and the cylindrical bobbin to constantly urge the cylindrical bobbin in one direction. Formed on the outer periphery of the projecting portion of the lid body, and a lid body that is rotatably provided in the end portion of the case and has a support recess for supporting the tip of the bobbin tube so as to move freely. A screw portion and an inner peripheral screw portion formed on an inner periphery of the opening of the end portion of the case, and the screw portion of the lid body is screwed to the inner peripheral screw portion of the case, and the lid The body is the end face of the cylindrical bobbin Due to the contact, the lid body is rotatably held in the case, and the position of the cylindrical bobbin in the axial direction is made variable by the rotation of the lid body, thereby freely changing the electrical neutral position. It can be changed according to the specifications of the device to be incorporated on the user side, and the usability can be greatly improved.
The elastic body is made of rubber, a disc spring, or a spring, and the lid body is formed with one or a plurality of recesses or holes for rotating the lid body. A lid can be easily rotated by inserting a jig into the hole.
Further, a pin is provided between the step portion of the bobbin tube and the cylindrical bobbin, and the cylindrical bobbin is allowed to move only linearly and is not rotated by the pin. The rotation of the cylindrical bobbin is stopped, and the cylindrical bobbin can be moved directly.
In addition, a flexible material is interposed between the screw portion of the lid and the inner peripheral screw portion, and the lid is prevented from being loosened by the flexible material, so that after setting the neutral position, There is no looseness of the lid, and high reliability can be obtained.

  The present invention provides a differential transformer structure in which a cylindrical bobbin having a transformer coil is movable with respect to a bobbin tube having a rod-like core so that the electrical neutral position can be changed after the product is completed. Objective.

Hereinafter, preferred embodiments of a differential transformer structure according to the present invention will be described with reference to the drawings.
Note that the same or equivalent parts as in the conventional example will be described using the same reference numerals.
In FIG. 1, a reference numeral 1 denotes a case whose overall shape is a cylindrical shape. In this case 1, a cup-shaped bobbin tube 11 having a closure-type cavity 10 is provided with a tenth ring 12. Is fixed through.

In the cavity 10, the shaft body 5 connected to the member 13 to be detected is provided in a non-contact state with the bobbin tube 11 so as to freely reciprocate along the direction of the arrow A. A cylindrical bobbin 4A having a primary coil P and a pair of secondary coils S ₁ and S ₂ for constituting the transformer coil 4 is provided at the outer peripheral position of the cavity 10 so as to be movable relative to the bobbin tube 11. ing.

  The shaft body 5 is formed of a probe 5a and a rod-shaped core 9, and rubber, a disc spring, and an outer peripheral position of the bobbin tube 11 between the stepped portion 14 of the bobbin tube 11 and the cylindrical bobbin 4A. An elastic body 15 made of any one of a spring or the like is disposed, and the cylindrical bobbin 4A is always urged only in the direction of the arrow B by the spring force of the elastic body 15.

  A lid 16 having a convex cross section is rotatably provided at the outer peripheral position of the tip 11a of the bobbin tube 11. The tip 11a is positioned and supported in the support recess 22 of the lid 16, and is provided on the outer periphery thereof. The provided second O-ring 17 is in sliding contact with the inner wall 1 a of the case 1, and an outer thread portion 21 of the protrusion 20 of the lid 16 is an inner thread of an opening 23 formed in the end portion 1 b of the case 1. Screwed into the portion 24.

  As shown in FIGS. 1 and 3, one or a plurality of recesses 30 or holes (not shown) are formed on the end surface of the lid body 16, and a jig (not shown) is provided in the recess 30. The lid 16 is inserted and rotated, and the lid 16 is in contact with the end face 4B of the cylindrical bobbin 4A directly or via a washer or the like. In addition, it can also be rotated with a suction cup etc., without using the recessed part 30 grade | etc.,.

  In the above-described configuration, for example, when the lid body 16 is rotated in a state where the probe 5a of the shaft body 5 is connected to the detected member 13, the lid body 16 itself can move along the direction of the arrow A, The cylindrical bobbin 4A in contact with the lid body 16 moves in the direction opposite to the arrow B direction, and the lid body 16 is rotated in a state where it reaches the electrical neutral position where the output voltages Va and Vb are 0V. Stop.

  In the above-described state, a flexible material 40 such as a resin is attached to the outer periphery of the screw portion 21 of the lid body 16, and the flexible material 40 is positioned between the screw portion 21 and the inner peripheral screw portion 24. Therefore, the flexible member 40 serves as a brake, and the lid body 16 is held at the position where the rotation of the lid body 16 is stopped, and the cylindrical bobbin 4A is maintained at the electrically neutral position.

  Therefore, according to the differential transformer structure of the present invention, the axial position of the cylindrical bobbin 4A can be freely adjusted, and the electrical detection is performed regardless of the type and length of the detected member 13 connected on the user side. The neutral position can be adjusted freely. The pin 50 planted in the axial direction on the bobbin tube 11 is engaged with the recess 4Ab of the flange 4Aa of the cylindrical bobbin 4A, so that the cylindrical bobbin 4A is allowed to move only in the axial direction. The rotation is stopped.

1 is a cross-sectional view showing a differential transformer structure according to the present invention. It is a side view which shows the cover body of FIG. FIG. 3 is a right side view of FIG. 2. FIG. 7 is a connection diagram of the transformer coil of FIGS. 1 and 6. It is a characteristic view which shows the output voltage of the transformer coil of FIG.1 and FIG.6. It is sectional drawing which shows a conventional structure.

Explanation of symbols

1 case 1a inner wall 1b end 4 transformer coil P primary coil _S 1, _{S 2} secondary coil 5 shaft 5a probe 10 cavity 11 bobbin tube 11a tip 12 second 1O ring 13 detected member 14 stepped portion 15 elastic member 16 lid 17 2nd O-ring 20 Protruding part 21 Screw part 22 Supporting recessed part 23 Opening 24 Inner peripheral threaded part 30 Recessed part 40 Flexible material 50 Pin

Claims (4)

A bobbin tube (11) provided in the case (1), and a probe (5a) and a rod-shaped core (9) disposed in the cavity (10) of the bobbin tube (11) so as to be reciprocally movable. A cylinder having a shaft body (5) and a transformer coil (4) which is provided on the outer periphery of the bobbin tube (11) so as to be linearly movable and includes a primary coil (P) and a pair of secondary coils (S ₁ , S ₂ ). The cylindrical bobbin (4A) is interposed between the step portion (14) of the bobbin tube (11) and the cylindrical bobbin (4A) so as to constantly urge the cylindrical bobbin (4A) in one direction. An elastic body (15) and a support recess (22) for rotatably supporting the tip (11a) of the bobbin tube (11) provided rotatably in the end (1b) of the case (1). ) Having a lid (16), a screw portion (21) formed on the outer periphery of the protrusion (20) of the lid (16), and an opening (1b) of the end (1b) of the case (1) ( 23) an inner peripheral thread portion (24) formed on the inner periphery of
The screw portion (21) of the lid (16) is screwed into the inner peripheral screw portion (24) of the case (1), and the lid (16) is the end surface (4B) of the cylindrical bobbin (4A). ), The lid (16) is rotatably held in the case (1), and the axial position of the cylindrical bobbin (4A) is adjusted by the rotation of the lid (16). A differential transformer structure characterized by being variable.   The elastic body (15) is made of rubber, a disc spring, or a spring, and the lid (16) has one or a plurality of recesses (30) or holes for rotating the lid (16). The differential transformer structure according to claim 1, wherein the differential transformer structure is formed.   A pin (50) is provided between the step (14) of the bobbin tube (11) and the cylindrical bobbin (4A), and the cylindrical bobbin (4A) is linearly moved by the pin (50). 3. The differential transformer structure according to claim 1, wherein only the rotation is allowed and the rotation is stopped.   A flexible material (40) is interposed between the screw portion (21) of the lid (16) and the inner peripheral screw portion (24), and the lid (16) is provided by the flexible material (40). The differential transformer structure according to any one of claims 1 to 3, wherein the loosening is prevented.

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