A detection tool for brush pressure

Abstract

The application belongs to the field of pressure detection, and relates to a detection tool for the pressure of an electric brush, which comprises a detection shaft, an electric brush base and a wiring board. The detection shaft is used for detecting pressure, the upper part of the detection shaft is in a conical structure, the lower part of the detection shaft is in a cylindrical structure, the electric brush base is in a stepped shaft shape, the detection shaft is installed in the middle part of the electric brush base, and the electric brush base is made of metal material. The wiring board is provided with a wiring post for connecting the electric brush to be detected. When the detection tool is used for detecting the pressure of the electric brush near the contact point of the sliding ring of any cantilever of the electric brush, the other cantilever is in a non-conduction state without changing the mechanical deformation of the electric brush. After detecting one cantilever, the detection shaft of the tool is only needed to be rotated to continue detecting the other cantilever. The upper conical part of the detection shaft is designed to make each group of electric brushes smoothly spread to the cylindrical position of the detection shaft, and the electric brush does not produce mechanical deformation greater than the use angle.

Description

Technical Field

[0001] This invention belongs to the field of pressure detection, and in particular relates to a tooling for detecting brush pressure. Background Technology

[0002] The brush is a key component of a contact potentiometer, used to transmit the changing electrical signal from the potentiometer. If the brush fails, the potentiometer will directly malfunction. Typical brush failure modes include abnormal output due to brush wear, output jumps due to insufficient brush pressure, and reduced potentiometer output accuracy due to unstable brush pressure, among others.

[0003] A slip ring (or simply slip ring) is used to transmit signals and current between two relatively rotating moving parts. A slip ring allows the moving part to rotate freely 360° while simultaneously transmitting signals and / or current. A slip ring is typically an assembly of multiple rings; the part that transmits signals instead of signal lines is called the signal ring, and the part that transmits current instead of power lines is usually called the power ring.

[0004] The brush of a precision conductive slip ring typically consists of adhesive, brush bristles, a bristle fixing plate, and a bristle pressure plate. The bristles are mainly U-shaped, and the transmission of electrical signals is achieved primarily through the overlap between the brush bristles and the conductive ring body.

[0005] The brush filaments contact the slip ring with a certain pressure. Determining the appropriate contact pressure between the brush filaments and the slip ring is crucial. The contact pressure cannot be too high or too low; higher pressure results in lower contact resistance, which is beneficial for signal or power transmission, but it also increases frictional torque, leading to increased wear on the contact area and the formation of filamentous wear particles, potentially causing short circuits between the slip rings. Lower pressure results in more flexible operation and less wear, but it increases contact resistance, causes a high temperature rise, and may even lead to the fusion of the brush filaments and slip ring, making them prone to breakage. However, existing slip ring performance testing studies have largely focused on measuring electrical quantities such as contact resistance, current carrying capacity, and electromagnetic noise. Research on contact pressure is either limited to theoretical analysis and calculations or suffers from fundamental errors due to inconsistencies between the contact point and the measurement point, significantly affecting measurement accuracy.

[0006] Existing technologies have the following drawbacks: existing testing equipment suffers from inaccurate brush pressure values, high operational risks, and cumbersome operation; the measurement of contact force at the contact point is subject to certain measurement errors. Therefore, accurate testing of brush pressure is a crucial means to ensure the performance indicators of conductive slip rings. Summary of the Invention

[0007] This invention provides a tooling for detecting brush pressure, which solves the problem of inaccurate detection of brush pressure on any single cantilever of the brush.

[0008] To achieve the above objectives, this application provides the following technical solution:

[0009] A fixture for detecting brush pressure includes: a detection shaft, a brush base, and a terminal block; the detection shaft is used to detect pressure, the upper part of the detection shaft is conical, the lower part of the detection shaft is cylindrical, and the detection shaft is also used to support the brush to be tested; the brush base is a stepped shaft, the detection shaft is installed in the middle of the brush base, and the brush base is used to support the detection shaft, and the brush base is made of metal; the terminal block is provided with terminals for connecting the brush to be tested.

[0010] Furthermore, in the aforementioned testing fixture, each brush has two cantilever arms, each cantilever arm abutting against the testing shaft; the testing shaft includes a first insert made of conductive material and a second insert made of insulating material; the first insert and the second insert correspond to each other; the upper part of the first insert is a semi-cone and the lower part is a semi-cylinder, and correspondingly, the upper part of the second insert is also a semi-cone and the lower part is also a semi-cylinder; the first insert and the second insert are combined together to realize that the upper part of the testing shaft is a conical structure and the lower part is a cylindrical structure.

[0011] Furthermore, in the testing fixture described above, the first insert is made of brass, and the second insert is made of polyimide rod; the first insert contacts the cantilever of the brush to be tested for measuring the pressure of the cantilever; the first insert and the second insert are fixedly connected by pins or keys.

[0012] Furthermore, in the testing fixture described above, the wiring board is provided with a first hole, the central axis of the testing shaft coincides with the central axis of the first hole, the first hole is used to provide space for accommodating the testing shaft, and the testing shaft passes through the first hole in the wiring board.

[0013] Furthermore, in the testing fixture described above, the terminal block is arranged circumferentially along the first hole; the terminal block has a cylindrical structure; the terminal block is fixedly connected to the brush; the terminal block is made of metal material; the brushes are arranged at equal intervals along the axial direction of the first hole; in the radial projection plane, the angle between the projections of every two adjacent brushes along the circumferential direction of the first hole is the same.

[0014] Furthermore, in the testing fixture described above, a pressure plate is provided on the upper end face of the brush base. The pressure plate rotates and presses against the terminal block to fix the terminal block. Screws are provided on the pressure plate to fix the pressure plate, the terminal block, and the brush base. The screws are made of metal.

[0015] Furthermore, the testing fixture described above also includes: a testing circuit, which is used to measure the pressure of the brush. One end of the testing circuit is connected to the corresponding terminal of the brush to be tested, and the other end is connected to the brush base. The testing circuit includes a pressure instrument, and the force measuring point of the pressure instrument is set within a range of no more than 1 mm from the contact point between the brush to be tested and the first insert.

[0016] Furthermore, in the testing fixture described above, the upper part of the brush base is provided with a notch to provide a path for connecting the testing circuit when the terminal block is inverted; the brush base is made of brass material.

[0017] Furthermore, in the aforementioned testing fixture, the testing shaft also includes the sleeve, which covers the lower part of the two inserts and fixes the two inserts together. The sleeve is made of metal.

[0018] Furthermore, in the testing fixture described above, the terminal block has a cylindrical structure; the terminal block is fixedly connected to the brush.

[0019] The terminal block is made of metal; each brush has two cantilever arms, each cantilever arm abutting against the detection shaft; the insulating and conductive segments of the terminal block are spaced apart along the axial direction of the first hole, each conductive segment connects to one brush, and all brushes on the terminal block coincide on the radial projection plane.

[0020] The technical solution of the present invention has the following beneficial effects:

[0021] 1. When the brush pressure near the slip ring contact point of any cantilever of the brush is detected, the other cantilever is in a non-conductive state without changing the mechanical deformation of the brush.

[0022] 2. After inspecting one cantilever, simply rotate the inspection shaft of the fixture to continue inspecting the other cantilever;

[0023] 3. Two brushes are tested in one clamping.

[0024] 4. The upper conical design of the detection shaft allows each set of brushes to smoothly unfold to the cylindrical position of the detection shaft, and prevents the brushes from producing mechanical deformation greater than the operating angle. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the wiring board structure of a brush pressure detection fixture according to the present invention.

[0026] Figure 2 This is a schematic diagram of the brush and slip ring of a brush pressure detection fixture according to the present invention.

[0027] Figure 3 This is a schematic diagram of the detection circuit connection of a brush pressure detection fixture according to the present invention.

[0028] Figure 4 This is a cross-sectional view of the detection axis of a brush pressure detection fixture according to the present invention.

[0029] Figure 5 This is a top view of the detection axis of a brush pressure detection fixture according to the present invention;

[0030] Figure 6 This is a front view of the brush base of a brush pressure detection fixture according to the present invention.

[0031] Figure 7 This is a top view of the brush base of a brush pressure detection fixture according to the present invention.

[0032] Figure 8 This is a cross-sectional schematic diagram of a brush pressure detection fixture according to the present invention.

[0033] Figure 9 This invention relates to a tooling for detecting brush pressure. Figure 1 AA section view in the middle;

[0034] Figure 10 This is a schematic diagram of the terminal structure of a brush pressure detection fixture according to the present invention.

[0035] Figure 11 This is a top view of the terminals of a brush pressure detection fixture according to the present invention.

[0036] The reference numerals in the attached diagram are as follows: Detection shaft 1, first insert 11, second insert 12, sleeve 13, terminal block 2, brush 21, brush base 3, pressure plate 31, notch 32, detection circuit 4, pressure detection direction F. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the embodiments of this invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0038] In the description of this invention, it should be noted that the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0039] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0040] See attached document Figure 1-11 This invention provides a detailed description of a brush pressure detection fixture, wherein... Figure 1 This is a schematic diagram of the wiring board structure of a brush pressure detection fixture according to the present invention. Figure 2 This is a schematic diagram of the brush and slip ring of a brush pressure detection fixture according to the present invention. Figure 3 This is a schematic diagram of the detection circuit connection of a brush pressure detection fixture according to the present invention. Figure 4 This is a cross-sectional view of the detection axis of a brush pressure detection fixture according to the present invention. Figure 5 This is a top view of the detection axis of a brush pressure detection fixture according to the present invention; Figure 6 This is a front view of the brush base of a brush pressure detection fixture according to the present invention. Figure 7 This is a top view of the brush base of a brush pressure detection fixture according to the present invention. Figure 8 This is a cross-sectional schematic diagram of a brush pressure detection fixture according to the present invention. Figure 9 This invention relates to a tooling for detecting brush pressure. Figure 1 AA section view in the middle; Figure 10 This is a schematic diagram of the terminal structure of a brush pressure detection fixture according to the present invention. Figure 11 This is a top view of the terminals of a brush pressure detection fixture according to the present invention.

[0041] The purpose of this invention is to design a testing fixture that can perform non-destructive testing of the brush pressure on any cantilever of each brush 21: when the brush pressure near the slip ring contact point of any cantilever of brush 21 is tested, the other cantilever is in a non-conductive state without changing its mechanical deformation; after testing one cantilever, the testing shaft 1 of the fixture can be rotated to continue testing the other cantilever; it can meet the requirements of non-destructive testing of brush pressure in products (i.e., terminal block 2) with one to four brushes and slip rings axially integrated, realizing the testing of two brushes in one clamping, thus improving testing efficiency.

[0042] In short, the basic technical solution of this invention is briefly described as follows:

[0043] This application provides a tooling for detecting brush pressure, comprising: a detection shaft 1, a brush base 3, and a detection circuit 4; the upper part of the detection shaft 1 has a conical structure, and the lower part of the detection shaft 1 has a cylindrical structure, and the detection shaft 1 is used to detect pressure.

[0044] The brush base 3 is in the shape of a stepped shaft, and the detection shaft 1 is installed in the middle of the brush base 3. The brush base 3 is used to support the detection shaft 1 and the terminal block 2.

[0045] The detection shaft 1 includes a first insert 11 that has a conductive function and a second insert 12 that has an insulating function, with the first insert 11 and the second insert 12 corresponding to each other; the upper part of the first insert 11 is a semi-cone and the lower part is a semi-cylinder, and correspondingly, the upper part of the second insert 12 is also a semi-cone and the lower part is also a semi-cylinder; the first insert 11 and the second insert 12 are combined together to realize that the upper part of the detection shaft 1 is a conical structure and the lower part is a cylindrical structure;

[0046] The first insert 11 is made of brass, and the second insert 12 is made of polyimide rod;

[0047] The first insert 11 and the second insert 12 are fixedly connected by a pin or a key.

[0048] The testing fixture includes a terminal block 2 for supporting the terminal block and the brush 21; the terminal block 2 has a first hole, and the central axis of the testing shaft 1 coincides with the central axis of the first hole; the first hole is used to provide space for accommodating the testing shaft 1, and the testing shaft 1 passes through the first hole in the terminal block 2.

[0049] The terminal block 2 includes terminals for connecting brushes 21, and can also connect wires to provide an external connection path. It can also connect to the stator in the signal motor, providing input and / or output paths for the stator; in other words, the terminal block 2 provides an external connection path through the terminals. The terminals are cylindrical in shape; the terminals are fixedly connected to the brushes 21; the terminals are made of metal; each brush has two cantilever arms, each cantilever arm abutting against the detection shaft 1.

[0050] The upper part of the brush base 3 is provided with a notch 32 to provide a path for connecting the detection circuit 4 when the terminal block 2 is inverted. The number of notches 32 can be one or more, such as 1, 2 or 3, depending on the requirements of the circuit.

[0051] The detection circuit 4 is used to measure the pressure of the brush. The brush 21 is semi-circular, but it can also be U-shaped, π-shaped, or C-shaped; the following description uses a U-shaped brush as an example.

[0052] The brush base 3 is made of brass and has good conductivity. One end of the detection circuit 4 is connected to the corresponding terminal of the brush to be tested; the other end is connected to the brush base 3, which is connected to the first insert 11.

[0053] The detection shaft 1 also includes a sleeve 13, which covers the lower part of the two inserts and secures the two inserts together tightly.

[0054] A pressure plate 31 is provided on the upper end surface of the brush base 3 for fixing the terminal block 2. The pressure plate 31 can rotate and press on the terminal block 2 to fix the terminal block 2. Screws are provided on the pressure plate 31 to fix the pressure plate 31, the terminal block 2 and the brush base 3. The screws are also used to provide circuit connection points for the detection circuit 4. That is, one end of the detection circuit 4 is connected to the corresponding terminal of the brush to be tested; the other end is connected to the screw of the brush base 3 connected to the first insert 11.

[0055] The following is a detailed description of the brush pressure detection fixture provided by the present invention. This brush pressure detection fixture includes the detection shaft 1, brush base 3, detection circuit 4, and pressure plate 31 mentioned in the above embodiments.

[0056] The detection shaft 1 plays a crucial role; its upper part is a conical structure, and its lower part is a cylindrical structure, with the bottom surfaces and central axes of the cone and cylinder being identical. The detection shaft 1 is used to detect pressure. During detection, the detection shaft 1 gradually expands the brush 21 along with the conical structure without damaging it, until the cylindrical structure contacts the brush 21. The diameter of the bottom surface of the cylinder is in the range of 3-5 mm, for example, 3, 4, or 5 mm; preferably, the diameter of the bottom surface of the cylinder is 4 mm. The device includes two corresponding (symmetrical) inserts. The first insert 11 is conductive; specifically, it is made of metal, preferably brass, and has an upper semi-conical shape and a lower semi-cylinder shape. The second insert 12 is insulating; specifically, it is made of insulating material, preferably polyimide rod, and has an upper semi-conical shape and a lower semi-cylinder shape. In one embodiment, the first insert 11 and the second insert 12 are fixedly connected by a pin or key.

[0057] In one specific embodiment, the detection shaft 1 further includes a sleeve 13, which is made of metal, preferably brass. The sleeve 13 is used to fix two inserts; specifically, the sleeve 13 covers the lower part of the two inserts, tightly fixing the two inserts together. The two inserts are combined to form an upper conical structure and a lower cylindrical structure and are installed in the sleeve 13. That is, as... Figure 3 As shown, the detection shaft 1 is assembled from a first insert 11 made of brass for conductive purposes, a second insert 12 made of polyimide rod for insulating purposes, and a sleeve 13 made of brass, and then fixed together with structural adhesive.

[0058] The testing fixture measures the brush pressure near each contact point. Since the brushes 21 are made of metal, both cantilevers of each brush 21 are simultaneously conductive with the slip ring during operation. To test the brush pressure near the slip ring contact point of any cantilever of brush 21, the other cantilever needs to be in a non-conductive state without altering its mechanical deformation. Therefore, the testing shaft 1 in this application adopts a structure combining a semi-conical and semi-cylindrical conductive body (first insert 11) and a semi-conical and semi-cylindrical insulating body (second insert 12). The brushes 21 and slip rings, as a group, transmit one electrical signal. Generally, to transmit two or more electrical signals, two or more brushes and slip rings can be axially integrated and arranged.

[0059] The brush 21 can be U-shaped, π-shaped, or C-shaped. The brush 21 contacts the detection shaft 1 through two cantilever arms. Preferably, each cantilever arm is used to abut against the detection shaft 1.

[0060] The terminal block 2 is provided with a first hole. Specifically, the terminal block 2 is provided with a first hole in the middle, and the central axis of the detection shaft 1 coincides with the central axis of the first hole. The first hole is used to provide space for accommodating the detection shaft 1, and the detection shaft 1 passes through the first hole in the terminal block 2.

[0061] The terminal block 2 includes terminals for connecting the brush 21, facilitating connection between the brush 21 and an external circuit. The terminals are cylindrical and made of metal, preferably copper. They are arranged circumferentially around the first hole. The terminal block 2 has positioning holes, preferably two holes evenly spaced around the circumference of the first hole. The terminals are symmetrically arranged with respect to the line connecting the centers of the two positioning holes. The number of terminals can be one or more, for example, 1, 2, 3, 4, 5, 6, 7, or 8. Each terminal has a connecting end located at its end for connecting to the detection circuit 4.

[0062] like Figure 10As shown, each terminal has a slot, and the brush 21 is fixedly connected to the terminal through the slot; specifically, the slot is fixed to the terminal by snapping or welding; preferably, the brush 21 is fixed to the terminal by welding through the slot. The number of slots can be one or more, and the number of slots can be specifically set according to the required height of the brush 21 in the axial direction of the terminal.

[0063] The terminal block includes a rotor terminal block for connecting the rotor, and each rotor terminal block is provided with a brush 21; one side of the brush 21 is fixedly connected to the slot, and the other side of the brush 21 opens towards the detection shaft 1. The brush 21 includes a connecting section located between two cantilever arms, so that the brush 21 is U-shaped, Π-shaped, or C-shaped. The cantilever arms are located outside the slot, and the connecting section is welded to the slot. The opening formed by the two cantilever arms faces the detection shaft 1. Preferably, all brushes 21 are arranged on one side of the line connecting the centers of the two positioning holes. Along the axial direction of the first hole, the brushes 21 provided on each pair of adjacent terminal blocks are spaced at a predetermined interval. Preferably, along the axial direction of the first hole, the brushes 21 are arranged at equal intervals. Figure 10 As shown, taking four brushes 21 as an example, the brush 21 set at the top is the first brush, and the brushes arranged from top to bottom along the axial direction of the first hole are the first brush, the second brush, the third brush, and the fourth brush.

[0064] In one specific embodiment, a set angle is rotated between each pair of adjacent brushes along the circumferential direction of the first hole. Preferably, in the radial projection plane, the angle between the projections of each pair of adjacent brushes along the circumferential direction of the first hole is the same.

[0065] In another specific embodiment, the brushes 21 are arranged on the same terminal along the axial direction of the first hole. Specifically, the insulating and conductive segments of the terminal are distributed at intervals along the axial direction of the first hole, and all the brushes 21 on the terminal coincide on the radial projection plane. Each conductive segment can be connected to a brush, and the connection can be by snap-fit ​​or welding. Preferably, each conductive segment and brush are welded and fixed. Preferably, the brushes are arranged at equal intervals along the axial direction of the first hole. The detection circuit 4 includes a pressure instrument, and the force measuring point of the pressure instrument is set at or near the contact point between the brush to be tested and the first insert 11. Specifically, the force measuring point of the pressure instrument is set within a range of no more than 1 mm from the contact point between the brush to be tested and the first insert 11. In this connection method, the upper and lower brushes do not cross each other, so the upper and lower brushes will not interfere with each other when the pressure instrument measures the pressure of the brush at the force measuring point. Therefore, the number of brushes can be set to more, such as 1-12, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12. Compared with the previous implementation method, the insulation requirements of this terminal are higher.

[0066] like Figure 4-7As shown, the brush base 3 is a stepped shaft shape used to support the detection shaft 1 and the terminal block 2. The central axis of the brush base 3 coincides with the central axis of the detection shaft 1. The brush base 3 is made of metal, preferably brass. The conical part of the detection shaft 1 is mounted upward along its central axis in the middle of the brush base 3. Since the brush 21 of the terminal block 2 is hollow, the detection shaft 1 passes through the brush 21 of the terminal block 2, and the terminal block 2 is located on the outer ring of the detection shaft 1. The brush base 3 and the detection shaft 1 slide vertically together, and the bottom surfaces of the brush base 3 and the detection shaft 1 are flush on an insulating mat on a table for easy disassembly.

[0067] A pressure plate 31 is provided on the upper end surface of the brush base 3 for fixing the terminal block 2. One end of the pressure plate 31 is fixed on the brush base 3, and the other end can rotate and press on the terminal block 2 to fix the terminal block 2. The pressure plate 31 is made of stainless steel. Screws are provided on the pressure plate 31 to fix the pressure plate 31, the terminal block 2 and the brush base 3.

[0068] In one specific embodiment, the screw can also be used to connect the detection circuit 4, facilitating the clamping of the meter for detecting DC resistance; the screw is made of metal; the screw, brush base 3 and first insert 11 are conductive.

[0069] like Figure 6 , Figure 7 As shown, the upper part of the brush base 3 is provided with a notch 32 to provide a path for connecting the detection circuit 4 when the terminal block 2 is inverted; the number of notches 32 can be one or more, such as 1, 2 or 3, and the number of notches 32 is set according to the needs of the circuit.

[0070] During the testing process, due to the interference between the positions of the four brushes, the top two brushes were tested first, that is, the first and second brushes were tested first. Then the terminal block 2 was inverted, and the third and fourth brushes were tested.

[0071] The specific steps are as follows:

[0072] like Figure 3 , Figure 6 , Figure 7 , Figure 8 , Figure 10As shown, in one specific embodiment (first embodiment), the detection shaft 1 is first installed in the brush base 3 from the lower part along the central axis upwards. Specifically, the detection shaft 1 is installed into the brush base 3 from the lower part along the central axis upwards. Then, the terminal block 2 is installed into the brush base 3 from the upper part along the central axis downwards, and fixed by the pressure plate 31 and screws. After the terminal block 2 is installed, the first brush is tested first. One end of the detection circuit 4 is connected to the terminal of the corresponding terminal of the first brush, and the other end is connected to the screw of the brush base 3 to start testing the brush pressure of the cantilever contacted by the first insert 11. After the cantilever is tested, the detection shaft is rotated 180° to test the brush pressure of the other cantilever. The testing steps for the second brush are the same as those for the first brush. The above operation steps are repeated to test the pressure of the two cantilever arms of the second brush. Of course, the second brush can also be tested first, and then the first brush can be tested. The order of testing can be adjusted.

[0073] Replace one end of the detection circuit 4 with the corresponding terminal of the second brush, and repeat the above steps to detect the pressure on the two cantilever arms of the second brush. Alternatively, the second brush can be detected first, followed by the first brush; the order of detection can be adjusted.

[0074] To eliminate interference between the first and second brushes, the terminal block 2 needs to be inverted before testing the fourth and third brushes. The wires from the terminals are connected to the detection circuit 4 through the notch 32 in the brush base 3. Specifically, the terminal block 2 is inverted and inserted into the brush base 3 from the top along the central axis, and fixed by the pressure plate 31 and screws. The fourth brush is then tested. One end of the detection circuit 4 is connected to the terminal corresponding to the fourth brush, and the other end is connected to the screw in the brush base 3. The brush pressure of the cantilever contacted by the first insert 11 is then tested. After the cantilever is tested, the detection shaft 1 is rotated to test the brush pressure of the other cantilever. The testing steps for the third and fourth brushes are the same; the above steps are repeated to test the pressure of the two cantilever arms of the third brush. Alternatively, the third brush can be tested first, followed by the fourth brush; the order of testing can be adjusted.

[0075] In another specific embodiment (second embodiment), the terminal block 2 is first installed into the brush base 3 from the upper part along the central axis downwards, and fixed by the pressure plate 31 and screws; then the detection shaft 1 is installed into the brush base 3 from the lower part along the central axis upwards; then the detection circuit 4 is connected, and the connection method and detection steps are the same as the above operation steps.

[0076] In the two specific embodiments described above, preferably, the detection shaft 1 is first installed into the brush base 3, and then the terminal block is installed into the brush base 3. That is, the first embodiment is preferred.

[0077] The function of detection circuit 4 is to accurately read the pressure of brush 21 by controlling the circuit's on / off state. Detection circuit 4 includes an external micro-ohmmeter for detecting DC resistance. When brush 21 contacts detection shaft 1, detection circuit 4 is in a conductive state. Detection circuit 4 includes a pressure instrument. The pressure measuring point of the pressure instrument is set at or near the contact point between the brush to be tested and the first insert 11. Specifically, the pressure measuring point is set within a range of no more than 1 mm from the contact point between the brush to be tested and the first insert 11. Preferably, the pressure instrument is a force meter, meaning the force measuring point of the force meter is set at or near the contact point between the brush to be tested and the first insert 11. The smaller this distance, the more accurate the measurement. At the measuring point, the force meter applies a force perpendicular to the cantilever of brush 21 outwards. Figure 3 As shown, the pressure detection direction F is required to be perpendicular to the cantilever outwards, and the error in the direction of the force shall not exceed 10 degrees. As the force applied by the force meter increases, at the instant the circuit is disconnected, the value of the force meter at this moment is read, which is the brush pressure of the brush 21 on the cantilever side.

[0078] After the test is completed, first remove the test circuit 4 and the pressure instrument, then remove the test shaft 1, remove the screws and pressure plate 31, and remove the terminal block 2 from the brush base 3. The above test will not cause damage to the brush 21 beyond its elastic capacity.

[0079] The purpose of the test is to monitor the brush pressure and ensure it is controlled within a certain range; it must not exceed the maximum limit to minimize brush filament wear and extend service life; and it must not fall below the minimum limit to ensure reliable contact between the brush and slip ring under vibration and impact conditions, smooth electrical signal transmission, and no open circuits or poor contact.

[0080] The testing fixture provided by this invention can meet the non-destructive testing of brush pressure in products with two to four brushes and slip rings axially integrated, and improve testing efficiency.

[0081] For those skilled in the art, the present invention can be implemented through other embodiments that do not depart from its spirit or essential characteristics. It is obvious that the present invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments are merely illustrative and not exhaustive, and should be considered exemplary and non-limiting. The scope of the invention is defined by the appended claims rather than the foregoing description, and therefore all changes falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims. All changes within the scope of the present invention or equivalent to the scope of the present invention are included in the present invention.

Claims

1. A fixture for detecting brush pressure, characterized in that, include: Detection shaft, brush base, terminal block; The detection shaft is used to detect pressure. The upper part of the detection shaft has a conical structure, and the lower part of the detection shaft has a cylindrical structure. The detection shaft is also used to support the brush to be tested. The brush base is in the shape of a stepped shaft, the detection shaft is installed in the middle of the brush base, the brush base is used to support the detection shaft, and the brush base is made of metal material; The terminal block is provided with terminals for connecting the brush to be tested; Each of the terminals is provided with a slot; the brush is fixedly connected to the terminal through the slot; The terminal block is provided with a first hole, the central axis of the detection shaft coincides with the central axis of the first hole, the first hole is used to provide space to accommodate the detection shaft, and the detection shaft passes through the first hole in the terminal block; The terminal block is arranged circumferentially along the first hole; Along the axial direction of the first hole, the brushes are arranged at equal intervals; in the radial projection plane, the angle between the projections of every two adjacent brushes along the circumference of the first hole is the same.

2. The testing fixture according to claim 1, characterized in that, Each of the brushes has two cantilever arms, and each of the cantilever arms abuts against the detection shaft; The detection shaft includes a first insert made of conductive material and a second insert made of insulating material; The first insert and the second insert correspond to each other; The upper part of the first insert is a semi-cone and the lower part is a semi-cylinder. Correspondingly, the upper part of the second insert is also a semi-cone and the lower part is also a semi-cylinder. The first insert and the second insert are combined to realize that the upper part of the detection shaft is a conical structure and the lower part is a cylindrical structure.

3. The testing fixture according to claim 2, characterized in that, The first insert is made of brass, and the second insert is made of polyimide rod; The first insert contacts the cantilever of the brush to be tested for measuring the pressure on the cantilever. The first insert and the second insert are fixedly connected by a pin or a key.

4. The testing fixture according to claim 3, characterized in that, The terminal block has a cylindrical structure; The terminal block is fixedly connected to the brush; The terminals are made of metal.

5. The testing fixture according to claim 1, characterized in that, A pressure plate is provided on the upper end surface of the brush base. The pressure plate rotates and presses against the terminal block to fix the terminal block. The pressure plate is provided with screws, which are used to fix the pressure plate, the terminal block and the brush base. The screws are made of metal.

6. The testing fixture according to claim 2, characterized in that, Also includes: A detection circuit is used to measure the pressure of the brush. One end of the detection circuit is connected to the corresponding terminal of the brush to be tested, and the other end is connected to the brush base. The detection circuit includes a pressure instrument, and the pressure measuring point of the pressure instrument is set within a range of no more than 1 mm from the contact point between the brush to be tested and the first insert.

7. The testing fixture according to claim 6, characterized in that, The upper part of the brush base is provided with a notch to provide a path for connecting the detection circuit when the terminal block is inverted; The brush base is made of brass.

8. The testing fixture according to claim 2, characterized in that, The detection shaft also includes a sleeve that covers the lower part of the two inserts and fixes the two inserts together. The sleeve is made of metal.

9. A fixture for detecting brush pressure, characterized in that, include: Detection shaft, brush base, terminal block; The detection shaft is used to detect pressure. The upper part of the detection shaft has a conical structure, and the lower part of the detection shaft has a cylindrical structure. The detection shaft is also used to support the brush to be tested. The brush base is in the shape of a stepped shaft, the detection shaft is installed in the middle of the brush base, the brush base is used to support the detection shaft, and the brush base is made of metal material; The terminal block is provided with terminals for connecting the brush to be tested; Each of the terminals is provided with a slot; the brush is fixedly connected to the terminal through the slot; The terminal block has a first hole, the central axis of the detection shaft coincides with the central axis of the first hole, the first hole is used to provide space to accommodate the detection shaft, the detection shaft passes through the first hole and is installed in the terminal block; each brush has two cantilever arms, each cantilever arm abutting against the detection shaft; The insulating and conductive segments of the terminal are distributed at intervals along the axial direction of the first hole. Each conductive segment is connected to one brush, and all the brushes on the terminal coincide on the radial projection plane.

10. The testing fixture according to claim 9, characterized in that, Each of the brushes has two cantilever arms, and each of the cantilever arms abuts against the detection shaft; The detection shaft includes a first insert made of conductive material and a second insert made of insulating material; The first insert and the second insert correspond to each other; The upper part of the first insert is a semi-cone and the lower part is a semi-cylinder. Correspondingly, the upper part of the second insert is also a semi-cone and the lower part is also a semi-cylinder. The first insert and the second insert are combined to realize that the upper part of the detection shaft is a conical structure and the lower part is a cylindrical structure.

11. The testing fixture according to claim 10, characterized in that, The first insert is made of brass, and the second insert is made of polyimide rod; The first insert contacts the cantilever of the brush to be tested for measuring the pressure on the cantilever. The first insert and the second insert are fixedly connected by a pin or a key.

12. The testing fixture according to claim 11, characterized in that, The terminal block has a cylindrical structure; The terminal block is fixedly connected to the brush; The terminals are made of metal.

13. The testing fixture according to claim 9, characterized in that, A pressure plate is provided on the upper end surface of the brush base. The pressure plate rotates and presses against the terminal block to fix the terminal block. The pressure plate is provided with screws, which are used to fix the pressure plate, the terminal block and the brush base. The screws are made of metal.

14. The testing fixture according to claim 10, characterized in that, Also includes: A detection circuit is used to measure the pressure of the brush. One end of the detection circuit is connected to the corresponding terminal of the brush to be tested, and the other end is connected to the brush base. The detection circuit includes a pressure instrument, and the pressure measuring point of the pressure instrument is set within a range of no more than 1 mm from the contact point between the brush to be tested and the first insert.

15. The testing fixture according to claim 14, characterized in that, The upper part of the brush base is provided with a notch to provide a path for connecting the detection circuit when the terminal block is inverted; The brush base is made of brass.

16. The testing fixture according to claim 10, characterized in that, The detection shaft also includes a sleeve that covers the lower part of the two inserts and fixes the two inserts together. The sleeve is made of metal.

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