A compact closed linear displacement sensor structure

Abstract

The utility model discloses a compact closed linear displacement sensor structure, including a fixed scale, a reading head, a moving cable and a signal cable; the fixed scale includes a fixed scale base, a fixed scale pole piece, left and right end covers and a sealing strip; the fixed scale base is a straight groove structure with open ends and an upper portion, and the left and right end covers are installed at both ends of the fixed scale base; the fixed scale pole piece is fixed to the side wall of the inner cavity of the fixed scale base and is in a vertical state; the fixed scale base is symmetrical in appearance, and fixed scale mounting holes are provided on the left and right end covers. The reading head includes a reading head housing, a moving scale pole piece, a signal processing circuit and a reading head cover. The front and rear surfaces of the horizontal housing above the reading head housing are provided with reading head mounting holes for installation. The utility model has a compact structure, a small size, is easy to install and has good repeatability. At the same time, the sensor can be installed on both the front and back sides to match different outlet directions, and the overall installation is more convenient and flexible.

Description

Technical Field

[0001] The utility model relates to an improvement on the structure of a displacement sensor, in particular to a compact closed linear displacement sensor structure, belonging to the technical field of displacement detection. Background Art

[0002] At present, closed linear displacement sensors are widely used in the machine tool industry due to their good protection level. However, due to the limitations of some installation and use environments, conventional closed linear displacement sensors are thick, wide, large, and heavy, which brings great inconvenience to on-site installation. In order to facilitate the installation and use of linear displacement sensors in limited space, a compact closed linear displacement sensor with compact structure, convenient installation and good repeatability is needed. Summary of the invention

[0003] In view of the above-mentioned deficiencies in the prior art, the purpose of the utility model is to provide a compact closed linear displacement sensor structure. The linear displacement sensor of the utility model has a compact structure, a small volume, is easy to install and has good repeatability.

[0004] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0005] A compact closed linear displacement sensor structure comprises a fixed length, a reading head, a moving cable and a signal cable; the fixed length is provided with a fixed length mounting hole for fixing the fixed length to a fixed component to be measured; the fixed length comprises a fixed length base, a fixed length pole piece, a left end cover, a right end cover and a sealing strip; the fixed length base is a straight groove type structure with open ends and an upper portion, and the left end cover and the right end cover are respectively mounted on the two ends of the fixed length base to seal the open ends of the fixed length base; the sealing strip is composed of two pieces and is respectively embedded in the two side walls of the fixed length base, and the two sealing strips intersect in an eight-shaped shape to block the upper open portion of the fixed length base; the reading head comprises a reading head housing, a moving scale pole piece, a signal processing circuit and a reading head cover plate; one end of the signal cable is connected to the signal processing circuit by welding, and the other end extends from the reading head housing to be connected to a driver; it is characterized in that: the fixed length pole piece is fixed to the side wall of the inner cavity of the fixed length base and is in a vertical state; the fixed length base is symmetrical in appearance, and the fixed length mounting holes are respectively arranged on the left end cover and the right end cover.

[0006] Furthermore, the reading head housing is composed of a horizontal housing and a vertical housing integrally formed at the lower part of the horizontal housing. The horizontal housing and the vertical housing form a T-shaped whole. A movable scale mounting groove is provided on the side of the vertical housing. The movable scale pole piece is installed in the movable scale mounting groove and is in a vertical state. The horizontal housing is provided with a cavity with an upper opening. The signal processing circuit is placed in the cavity of the horizontal housing. The movable scale pole piece is connected to the signal processing circuit through a wire hidden in the reading head housing. The reading head cover is covered on the upper end of the horizontal housing to close the cavity opening. The vertical housing passes downward through the joint position of the two sealing strips into the inner cavity of the fixed-size base. The horizontal housing is located above the opening of the fixed-size base.

[0007] Furthermore, symmetrically arranged reading head mounting holes are provided on both the front and rear surfaces of the horizontal shell, and the fixed-size mounting holes on the left end cover and the right end cover are symmetrically arranged, so that the sensor can be installed on both sides to match different output directions.

[0008] Furthermore, it also includes an adapter plate, and the fixed-size base is fixedly connected to the adapter plate through the fixed-size mounting holes on the left end cover and the right end cover.

[0009] Furthermore, the moving cable is composed of two connectors, one connector cable end is welded to the fixed-length pole piece through the end cover of the fixed-length base, and the other connector cable end is connected to the signal processing circuit in the reading head, and the two connectors are connected by plugging the connector ends.

[0010] Compared with the prior art, the utility model has the following advantages:

[0011] 1. The utility model changes the installation holes on the fixed-length base to the left and right end covers, and changes the fixed-length pole piece from being pasted on the bottom of the fixed-length base cavity to being pasted on the side wall. Through such improvements, the dimensions of the sensor in the width and height directions are greatly reduced, and the product is thinner and has a smaller cross-sectional area. Compared with the original closed linear displacement sensor, the size is reduced from the original width × height of 37mm × 85mm to the current 20mm × 50.5mm, which is only about one-third of the original.

[0012] 2. The utility model is provided with symmetrically arranged reading head mounting holes for installation on the front and rear sides of the horizontal shell, the fixed-size mounting holes on the left end cover and the right end cover are symmetrically arranged, and the fixed-size base is symmetrical in appearance, so that the sensor can be installed on both sides to match different outlet directions, making the overall installation more convenient and flexible, and more adaptable to narrow spaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall structure of the linear displacement sensor of the utility model.

[0014] Figure 2This is the exploded structure diagram of the linear displacement sensor of the utility model.

[0015] Figure 3 This is a schematic diagram of the fixed-length components of the linear displacement sensor of the utility model.

[0016] Figure 4 The utility model is a schematic diagram of the components of the reading head of the linear displacement sensor.

[0017] Figure 5 It is a schematic cross-sectional view of a fixed-length base of the utility model linear displacement sensor.

[0018] Figure 6 The utility model is a schematic diagram of the end cover structure in the sizing of the linear displacement sensor.

[0019] Figure 7 It is a schematic diagram of the overall structure of an existing linear displacement sensor. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the embodiment of the utility model clearer, the technical scheme in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. The components of the embodiment of the utility model generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiment of the utility model provided in the drawings is not intended to limit the scope of the utility model claimed for protection, but merely represents the selected embodiment of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the utility model.

[0021] See also Figure 1 and Figure 2 The utility model discloses a compact closed linear displacement sensor structure, which includes a fixed length 1, a reading head 2, a slider 3 for auxiliary installation and transportation (the slider is two pieces and will not be used during operation), a motion cable and a signal cable 5.

[0022] See also Figure 3The fixed length is mainly composed of a fixed length base 1-1, a fixed length pole piece 1-2, a left end cover 1-3, a right end cover 1-4 and a sealing strip 1-5. The fixed length base 1-1 is a straight groove structure with open ends and the top. The left end cover 1-3 and the right end cover 1-4 are respectively installed on the two ends of the fixed length base 1-1 by screw locking to close the open ends of the fixed length base; the sealing strip 1-5 is two pieces and is respectively embedded in the two side walls of the fixed length base. The two sealing strips 1-5 intersect in an eight-shaped shape to close the upper opening of the fixed length base 1-1. Compared with the conventional closed linear displacement sensor, in order to reduce the volume as much as possible, under the premise of ensuring performance, the design scheme of the fixed length pole piece is optimized, and the width of the fixed length pole piece 1-2 is narrowed by 1 / 4, from 24mm to 18mm. At the same time, the fixed length pole piece 1-2 is changed from being pasted on the bottom of the inner cavity of the fixed length base to being pasted on the side wall by glue and in a vertical state. In addition, the fixed-length base does not have mounting holes, but the mounting holes are set on the end caps on the left and right sides of the fixed-length base and are symmetrical, which greatly reduces the size of the sensor in the width and height directions. Compared with the original closed linear displacement sensor, the overall size has been improved from the original width × height of 37mm × 85mm to the current width × height of 20mm × 50.5mm. The product is thinner overall and has a smaller cross-sectional area.

[0023] See also Figure 4 The reading head 2 is mainly composed of a reading head housing 2-1, a moving scale pole piece 2-2, a signal processing circuit 2-3, a reading head cover 2-4 and a clamping ring 2-5. The reading head housing 2-1 is composed of a horizontal housing and a vertical housing integrally formed at the lower part of the horizontal housing. The reading head housing 2-1 composed of the horizontal housing and the vertical housing is in a T-shape as a whole. A moving scale mounting groove is provided on the side of the vertical housing, and the moving scale pole piece 2-2 is pasted and installed in the moving scale mounting groove and is in a vertical state. The horizontal housing is provided with a cavity with an upper opening, and the signal processing circuit 2-3 is placed in the cavity of the horizontal housing. The moving scale pole piece 2-2 is connected to the signal processing circuit 2-3 by welding a wire, and the wire is hidden in the reading head housing. The reading head cover 2-4 covers the top of the horizontal housing and is screwed to close the cavity opening. The signal processing circuit 2-3 is hidden inside the reading head housing and is protected in all directions. The wire clamping ring 2-5 is installed on the reading head housing 2-1, and is mainly used to fix the cable coming out of the signal processing circuit 2-3 to avoid signal instability caused by sliding.

[0024] During assembly, the reading head 2 is first assembled with the slider 3, and then inserted from one end of the fixed-length base 1-1. The vertical shell of the reading head penetrates the inner cavity of the fixed-length base 1-1, and the horizontal shell is exposed above the opening of the fixed-length base. The entire moving scale part is contained in the inner cavity of the fixed-length base and is protected. Based on the cooperation between the slider 3 and the fixed-length base 1-1, the reading head is positioned during installation and transportation to ensure the installation gap between the moving scale and the fixed scale.

[0025] The fixed-length base of the utility model is made of aluminum alloy material and is integrally formed through a mold extrusion process. It has a square shape, a hollow interior, a flat cross section, and is shaped like a rectangular long straight slot. The length is adapted according to different measuring strokes. The left and right end caps are respectively located on the left and right sides of the fixed-length base, and together with the fixed-length base, form a rectangular parallelepiped with five closed sides, front, back, left, right, and bottom, and only a notch on the top. Figure 5 The opening of the fixed-length base is located in the middle of the upper part, and two symmetrical grooves are arranged on the two side walls of the opening. The larger groove at the bottom is the embedding groove of the sealing strip, and the smaller groove at the top is the guide groove of the moving part reading head and is in the shape of a dovetail groove. The bottom of the slider is made into a dovetail tenon shape that matches the shape of the guide groove. The slider is connected to the reading head by screws, located at the left and right ends of the lower part of the reading head. The reading head relies on the slider to embed in the dovetail groove and maintains a relative position relationship with the fixed-length base. Based on the initial positioning of the reading head by the slider, it can be ensured that when the fixed-length base and the reading head are respectively installed on the fixed part and the moving part of the moving object to be measured, the reading head can make linear reciprocating motion without contacting the fixed length, thereby converting the linear displacement of the moving part to be measured relative to the fixed part into the linear displacement of the reading head relative to the fixed-length base for displacement measurement.

[0026] During installation and use, take the surface at the bottom of the fixed-length base as a reference, adjust its position to maintain good parallelism with the moving direction of the measured moving part, fasten the fixed-length base to the fixed part through the end covers on its left and right sides, and install the reading head on the measured moving part. In particular, when the required stroke is longer, an adapter plate can be added, and the fixed-length base is fixedly connected to the adapter plate through the fixed-length mounting holes on the left and right end covers, and then the adapter plate is connected to the fixed part. This can better ensure that the reference surface of the fixed-length base has good parallelism with the measured moving part. Even if it is transferred through an adapter plate, the fixed-length base is first installed on the adapter plate, and then the installation of the adapter plate relative to the moving part is adjusted, and the space it occupies is still relatively small.

[0027] In the utility model, the moving cable is composed of two connectors, the cable end of one connector 4-1 is connected to the fixed-length pole piece by welding through the end cover of the fixed-length base, and the cable end of the other connector 4-2 is connected to the signal processing circuit in the reading head, and the two connectors are connected by the matching plug-in of the connector ends. One end of the signal cable 5 is connected to the signal processing circuit 2-3 by welding, and the other end extends from the reading head housing and is connected to the driver. The clamping ring 2-5 is used to fix the wire coming out of the signal processing circuit to avoid signal instability caused by sliding and ensure the reliability of grounding. After the fixed-length base and the reading head are installed respectively, the slider is removed, and under the control of the driver, the measured moving part drives the reading head to move to measure the displacement. First, the circuit generates an excitation signal and transmits it to the fixed-length pole piece through the moving cable. Based on the time-grid measurement principle, the moving scale pole piece and the fixed-length pole piece will generate an induction signal due to the coupling effect of the electric field. The signal sensed by the moving scale pole piece is transmitted to the signal processing circuit through the wire transmission, and then the induction signal is converted into a linear displacement feedback to the driver end after being processed by the signal processing circuit.

[0028] For the entire measurement module, the reading head components and the one-piece fixed-length base have become simpler, which reduces the manufacturing difficulty and makes the volume thinner. Similarly, the reading head is suspended relative to the fixed-length base, and will not produce friction with the fixed-length base, with low wear and tear. The repeatability accuracy is guaranteed on the basis of miniaturization, and the closed structure also protects the fixed-length pole piece, moving-length pole piece and signal processing circuit of the sensor well.

[0029] Main features and functions of fixed-length parts:

[0030] 1. The fixed-length base is based on one-piece molding, with a simple overall shape, easy processing, and relatively lower manufacturing cost. The appearance is symmetrical front and back, with good flatness, and the bottom surface has good verticality with the front and rear mounting surfaces. The fixed-length pole piece is installed on the inner side of one of the front and rear surfaces, which can better ensure the straightness of the edge of the fixed-length pole piece relative to the base mounting surface.

[0031] 2. Compatibility of front and back side installation and double-sided wiring: The combination of the fixed-length base and the left and right end covers not only provides installation holes while reducing the volume, but more importantly, since the left and right end covers are provided with fixed-length installation holes (countersunk holes in the embodiment) on the front and back sides and the fixed-length base is symmetrical in appearance, the wiring direction can be swapped in the left and right directions through the front and back side installation.

[0032] 3. Waterproof and sealing: The sealing strips on both sides intersect in an inverted "figure eight" shape and are centered on the opening of the fixed-length base (the opposite direction to the previous description, with the reading head at the bottom and the fixed length at the top), which can provide better sealing and waterproofing. Under normal working conditions, its protection level is equivalent to that of conventional closed linear displacement sensors, that is, the IP level can reach IP53 under normal circumstances, especially if it is inflated, it can reach IP64. For this purpose, an inflation hole is left on the end cover, and the air hole can be blocked with the air hole plug 1-3-1 when not in use, see Figure 6 .

[0033] 4. To guide the slider: The dovetail groove structure on the top of the fixed-length base body matches the shape of the slider, so that the slider can move along the dovetail groove of the fixed-length base body.

[0034] Features of the reading head housing: The overall structure is T-shaped, the overall shape is simple, easy to process and manufacture, and the cost is relatively low. Its main features are used to constrain the position of the moving scale pole piece and provide mounting holes for the reading head. Constrain the position of the moving scale pole piece: There is an inner cavity on the side wall of the lower end of the T-shaped housing (i.e., the vertical housing), which has good flatness and is used to stick and fix the moving scale pole piece, which can better ensure the flatness requirements of the moving scale pole piece. In order to better adapt to the customer's requirements for the cable outlet direction at the site, two reading head mounting holes (countersunk holes in the embodiment) are provided on both sides of the T-shaped upper end (i.e., the horizontal housing), which facilitates the installation of both sides of the reading head, so that the sensor can be installed on both sides to match different outlet directions.

[0035] Since the fixed-length pole pieces are installed on the front and back surfaces of the fixed-length base body, the fixed-length base body can also be installed left-right swapped. Therefore, the utility model can realize the left-right swapped installation of a separate fixed-length, the left-right swapped installation of a separate reading head, and the left-right swapped installation of the reading head and the fixed-length together. The installation form is flexible and convenient to adjust according to the actual installation site.

[0036] Figure 7 It is a schematic diagram of the overall structure of the existing linear displacement sensor. Figure 1 and Figure 7 By comparison, it can be seen that the utility model greatly reduces the size of the sensor in the width and height directions, the product is thinner, and the cross-sectional area is smaller, which is only about one third of the size before the improvement.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described by referring to the preferred embodiments of the utility model, those skilled in the art should understand that various changes can be made in form and details without departing from the spirit and scope of the utility model as defined in the appended claims.

Claims

1. A compact closed linear displacement sensor structure, comprising a fixed length, a reading head, a moving cable and a signal cable; the fixed length is provided with a fixed length mounting hole for fixing the fixed length to a fixed component to be measured; the fixed length comprises a fixed length base, a fixed length pole piece, a left end cover, a right end cover and a sealing strip; the fixed length base is a straight groove structure with open ends and an upper portion, and the left end cover and the right end cover are respectively mounted at the two ends of the fixed length base to seal the openings at both ends of the fixed length base; the sealing strip is composed of two pieces and is respectively embedded in the two side walls of the fixed length base, and the two sealing strips intersect in an eight-shaped shape to block the upper opening of the fixed length base; the reading head comprises a reading head housing, a moving ruler pole piece, a signal processing circuit and a reading head cover plate; one end of the signal cable is connected to the signal processing circuit by welding, and the other end extends from the reading head housing to be connected to the driver; the characteristics are: The fixed-size pole piece is fixed on the side wall of the inner cavity of the fixed-size base and is in a vertical state; the fixed-size base is symmetrical in appearance, and the fixed-size mounting holes are respectively arranged on the left end cover and the right end cover.

2. A compact closed linear displacement sensor structure according to claim 1, characterized in that: The reading head housing is composed of a horizontal housing and a vertical housing integrally formed at the lower part of the horizontal housing. The horizontal housing and the vertical housing form a T-shaped whole. A movable scale installation groove is provided on the side of the vertical housing. The movable scale pole piece is installed in the movable scale installation groove and is in a vertical state. The horizontal housing is provided with a cavity with an upper opening. The signal processing circuit is placed in the cavity of the horizontal housing. The movable scale pole piece is connected to the signal processing circuit through a wire hidden in the reading head housing. The reading head cover plate is covered on the upper end of the horizontal housing to close the cavity opening. The vertical housing passes downward through the joint position of the two sealing strips into the inner cavity of the fixed-size base. The horizontal housing is located above the opening of the fixed-size base.

3. A compact closed linear displacement sensor structure according to claim 1, characterized in that: Both the front and rear surfaces of the horizontal shell are provided with symmetrically arranged reading head mounting holes for installation, and the fixed-size mounting holes on the left end cover and the right end cover are symmetrically arranged, so that the sensor can be installed on both the front and back sides to match different outlet directions.

4. A compact closed linear displacement sensor structure according to claim 1, characterized in that: It also includes an adapter plate, and the fixed-length base is fixedly connected to the adapter plate through fixed-length mounting holes on the left end cover and the right end cover.

5. The compact closed linear displacement sensor structure according to claim 1, characterized in that: The moving cable is composed of two connectors, one connector cable end is welded to the fixed-length pole piece through the end cover of the fixed-length base, and the other connector cable end is connected to the signal processing circuit in the reading head. The two connectors are connected by plugging and matching the connector ends.

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