JP2011009212A - Carbon brush - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a carbon brush easy to manufacture, and, especially, for easily incorporating a process of forming a polishing element into a manufacturing method of manufacturing a brush body, as to one with a polishing mechanism integrated.SOLUTION: The polishing mechanism (25) of the carbon brush (20) has a contact structure moving relatively to the carbon brush, especially, a commutator of an electric motor in electric contact with a brush body (21) made of a carbon-content material. On a contact face (24) of the brush body (21) at a contact structure side, a polishing mechanism (25) is provided, equipped with cement (26) and abrasive grain (27) distributed. The abrasive grain (27) is arranged on the contact face by the cement (26).

Description

  The present invention relates to a carbon brush. In the carbon brush, a contact structure that moves relative to the carbon brush, in particular, a commutator of an electric motor is electrically contacted with a brush body made of a carbon-containing material. A polishing mechanism is provided on the contact surface of the brush body on the contact structure side. The present invention also relates to a method for producing such a carbon brush.

  A carbon brush of the type described at the outset, in particular an electrical contact structure that moves relative to the carbon brush, e.g. a motor commutator, is located between the contact surface of the carbon brush and the contact surface of the commutator. Carbon brushes that are electrically contacted by frictional contact are well known. It is also known about the adverse effects caused by this unique kind of electrical contact. Each of these adverse effects is due to a different cause.

  That is, matching the contact surfaces is adjusted and performed only after the initial habituation phase of the motor. As a result, initially only insufficient contact is often formed between the carbon brush and the contact structure. For this reason, the electric motor cannot be delivered immediately after the installation is completed, and firstly, after performing the “familiarity operation” in another acclimatization operation process, to an extent sufficient for the electric motor to operate without defects. It is necessary to realize surface-to-surface contact between the front surface of the carbon brush and the surface of the contact structure. Here, the insufficient contact surface is formed not only because the carbon brush contact surface is not ideally formed, but also the surface of the contact structure has blue rust, or Also, the surface of the contact structure may have irregularities.

  In order to remove such blue rust or unevenness on the surface of the contact structure, it is known to provide a polishing mechanism on the front surface of the carbon brush on which the contact surface is formed. Patent Document 1 discloses a configuration of a carbon brush including a polishing element housed in a housing groove formed on the front surface of the carbon brush. This polishing element removes the difference by grinding a point in the contact structure or corroding the surface where the difference in shape between the front surface of the carbon brush and the contact surface of the contact structure is significant. Function.

German Patent Application Publication No. 2734749

  In practice, it has been found that the production of such a carbon brush having a polishing element housed in the brush body is extremely laborious. This is because in order to dispose the polishing element in the brush body, after the brush body is manufactured, the brush body must be further cut to form a receiving groove for the polishing element.

  Accordingly, an object of the present invention is a carbon brush with an integrated polishing mechanism, which can be easily manufactured, and in particular, the process of forming a polishing element can be easily incorporated into a manufacturing method for manufacturing a brush body. It is to propose a possible carbon brush.

  In the carbon brush according to the present invention, the polishing mechanism has a bonding agent and distributed abrasive grains. The abrasive grains are disposed on the contact surface by a bonding agent.

  For this reason, the carbon brush constructed according to the present invention produces a brush body in which a contact surface having a shape suitable for contact with the contact structure is already provided at the end of the brush body by a conventional manufacturing method. Is possible. Placing the polishing mechanism on the front surface of the carbon brush is realized by a bonding agent. This bonding agent forms a mechanical bond between abrasive grains such as pumice powder and the front surface.

  Thus, since the contact surface of the brush body is configured according to the surface of the contact structure, the shape of the contact surface of the brush body is not hindered by the polishing mechanism. For this reason, the contact surface of the brush body comes into contact with the contact structure on the entire surface from the beginning, especially after the polishing mechanism that wears out by frictional contact with the contact structure is used up. Thus, already when the contact surface of the brush body and the contact structure first contact, the entire cross-section of the carbon brush can be used to pass current through the contact structure and the area of the contact surface is small Contact resistance does not occur. Further, the polishing mechanism has abrasive grains deposited and distributed on the contact surface by the bonding agent. For this reason, after the contact between the contact surface of the brush body and the contact structure for the first time, the electrical properties of the carbon-containing material used in the manufacture of the brush body are fully available. Guaranteed. After first contact with the front surface, any abrasive additive in the brush body cannot degrade the electrical properties.

  Experiments have shown that the lifetime of a carbon brush provided with a polishing mechanism according to the present invention is significantly longer than conventional carbon brushes due to the habituation movement characterized by the polishing mechanism.

  According to a preferred embodiment of the carbon brush, the bonding agent functions as a positioning structure for spatially defining the arrangement of the abrasive grains. In this case, since the abrasive grains are directly contained in the bonding agent in a distributed state, another substrate for defining the position of the abrasive grain material and arranging it in a distributed manner is provided. unnecessary.

  In another embodiment of the carbon brush, the bonding agent functions to bond the contact surface with a positioning structure that spatially defines the placement of the abrasive material. Therefore, it is possible to functionally distinguish between the bonding agent and the positioning structure. Therefore, it is possible to configure the bonding agent based only on its material characteristics, and as the bonding agent, for example, a material capable of producing an arrangement in which abrasive grains are spatially uniformly distributed, such as a suspended form. There is no need to consider making a choice. For this reason, the material for forming the positioning structure may be selected regardless of the bonding agent. For example, a substrate having a fiber structure or a substrate made of a nonwoven fabric may be selected as the positioning structure. On the substrate, abrasive grains having a predetermined particle diameter are arranged with a predetermined particle distribution.

  Depending on whether the bonding agent itself functions as a positioning structure, or the bonding agent functions only to join the positioning structure and the front surface, the bonding agent and / or positioning structure has conductivity. A configuration is preferred. By doing this, it is possible to select the abrasive grains regardless of the electrical characteristics that may occur in some cases. In particular, as the abrasive grains, non-conductors that can be selected only with respect to polishing characteristics may be used.

  In order to configure a bonding agent or positioning structure having conductivity, the bonding agent or positioning structure is preferably provided with a conductive additive. Examples of additives include carbon fibers embedded in a bonding agent or positioning structure.

  Depending on the type and degree of abrasive action of the abrasive, it may be sufficient to apply the bonding agent partially to the contact surface rather than the entire contact surface. In this case, the abrasive grains are provided only in the corresponding region, and the polishing mechanism formed on the front surface is not completely flat but structured.

  In the method for producing a carbon brush according to the present invention, a step of first preparing a brush body made of a carbon-containing material is performed. This step includes forming a contact surface. Thereafter, a process of placing a polishing mechanism having an abrasive material on the contact surface with a bonding agent applied on the contact surface continues.

  In the method according to the invention, it is possible to produce a brush body in the first method step. Depending on the carbon brush, the brush body already has a contact surface configured for steady state operation after this simple manufacturing stage. In the manufacturing method according to the present invention, the polishing mechanism does not affect or inhibit the configuration of the contact surface. In particular, the method for producing a carbon brush provided with the polishing mechanism according to the present invention can be easily configured based on a conventional method for producing a carbon brush, and there is no need to process the contact surface later.

  The polishing mechanism formed on the brush body is particularly effective when it is manufactured by supplying abrasive grains to the bonding agent before the bonding agent is applied onto the contact surface. For this reason, the polishing mechanism generates an abrasive grain distribution in the bonding agent, for example, supplying abrasive particles to the bonding agent before creating a suspension before applying the bonding agent onto the contact surface. Can be created easily. In another method, a bonding agent may be applied on the contact surface of the brush body in the first step, and the abrasive grains may be bonded to the bonding agent in the next step.

  In this case, it is particularly effective to bond the abrasive grains to the bonding agent by taking out the abrasive grain material from the abrasive grain container. This means that, for example, a brush body whose contact surface is wetted by a bonding agent is immersed in a container of abrasive material, whereby the polishing mechanism is constituted by the abrasive material adhering to the bonding agent. Is the case.

  Alternatively, the polishing mechanism may be disposed on the contact surface of the brush body such that a substrate comprising abrasive material is placed on the bonding agent.

FIG. 1 is a view showing a carbon brush according to the first embodiment. FIG. 2 is a diagram illustrating a carbon brush according to the second embodiment. FIG. 3 is a view showing a carbon brush according to the third embodiment. FIG. 4 is a view showing a carbon brush according to the fourth embodiment. FIG. 5 is a view showing an apparatus for placing the bonding agent layer on the contact surface of the brush body. FIG. 6 is a view showing an apparatus for placing a layer composed of abrasive grains on a bonding agent layer. FIG. 7 is a view showing a polishing mechanism formed on the contact surface of the brush body after the abrasive grains are placed on the bonding agent layer. FIG. 8 is a view showing another embodiment of a carbon brush provided with a polishing mechanism. FIG. 9 is a view showing another embodiment of a carbon brush provided with a polishing mechanism. FIG. 10 is a view showing another embodiment of a carbon brush provided with a polishing mechanism.

  Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the drawings.

  FIG. 1 shows a carbon brush 20 comprising a brush body 21 composed of a carbon-containing material, in particular graphite. In the present embodiment, the brush body 21 has a contact surface 24 formed in a concave shape in this drawing on the opposite side of the connection end 23 having the litz wire 22 of the brush body 21. A polishing mechanism 25 is provided on the contact surface 24.

  The contact surface 24 of the carbon brush 20 shown in FIG. 1 is for forming conductive frictional contact with a motor commutator device having a cylindrical surface not shown in detail in this figure. . Since the contact surface 24 is formed in a concave shape, the contact between the contact surface 24 and the contact structure formed on the surface of the commutator after the polishing mechanism 25 disposed on the contact surface 24 is worn out. Contact is formed.

  The polishing mechanism 25 has a bonding agent 26. The bonding agent 26 is made of a suitable adhesive or glue, such as an epoxy resin, and accommodates a predetermined distribution of abrasive grains 27 while positioning them. The abrasive grain 27 may be composed of various materials. In this case, the polishing action of the abrasive grain 27 is given priority. For example, the abrasive grains 27 may be a kind of material called “pumice powder” in technical terms. For example, in the abrasive grain 27, every mineral particle has a prescribed particle size, and in particular, a selected particle size fraction, that is, an allowable boundary that the particle size can take according to a desired polishing action. Selected. In addition to the “pumice powder” mentioned above, materials such as silicon carbide, aluminum oxide, iron oxide, silicon dioxide, quartz, carbide, plastic particles, etc., which have sufficient polishing properties, and combinations of the materials exemplified here can also be used. It is. The particle size may be between 0.1 and 150 μm, depending on the desired polishing action.

  In particular, with respect to the embodiment of the carbon brush 20 shown in FIG. 1, an epoxy resin was selected as the bonding agent, but unlike this, it is possible to attach abrasive grains to the contact surface 24, such as pastes, lipids, Other substances such as oils, paints, and resins are also considered.

  In the embodiment shown in FIG. 1, the abrasive grains 27 are accommodated in the bonding agent 26 in a distributed state. For this reason, the bonding agent 26 not only forms a mechanical bond between the abrasive grains 27 and the contact surface 24 but also a positioning structure for positioning and positioning the abrasive grains 27 with respect to the contact surface 24. Functions to form. Here, the shear strength for holding the abrasive grains 27 on the contact surface 24 is an important factor for the selection or type of the bonding agent 26.

  FIG. 2 is a diagram illustrating a carbon brush 28 according to another embodiment. The carbon brush 28 has the same brush body 21 as the carbon brush 20. A polishing mechanism 29 is provided on the contact surface 24 of the brush body 21.

  Unlike the polishing mechanism 25 of the carbon brush 20 shown in FIG. 1, the polishing mechanism 29 has a friction contact surface 30 formed parallel to the contact surface 24. For this reason, the friction contact surface 30 is different from the friction contact surface 31 of the carbon brush 20 configured flat, and when the commutator is configured in a cylindrical shape, the contact surface of the commutator and the entire surface from the beginning. It becomes to mesh.

  FIG. 3 is a diagram showing a carbon brush 32 as another embodiment. The carbon brush 32 of this embodiment has the same brush body 21 as the carbon brush 20 (FIG. 1) and the carbon brush 28 (FIG. 2), and a polishing mechanism 33 is provided on the contact surface 24 of the brush body 21. It has been. The polishing mechanism 33 has a configuration different from the polishing mechanism 25 or 29 in that the abrasive grains 27 are directly positioned and are not accommodated in the bonding agent 34. Since the abrasive grains 27 are positioned and not accommodated in the bonding agent 34, the positioning structure 35 configured independently of the bonding agent 34 is useful for positioning the abrasive grains 27 with respect to the contact surface 24. ing. The positioning structure 35 may be constituted by a support member in the form of a substrate, for example a support plate formed from a nonwoven fabric, in particular paper. Abrasive grains 27 are arranged on the surface of the support plate in a state of being embedded in the adhesive material 36.

  The embodiment of the carbon brush 32 shown in FIG. 3 has the advantage that the positioning structure 35 can be preassembled as a separately operable unit with the abrasive grains 27 deposited on the positioning structure 35. have. This separately operable unit also applies, for example, to so-called “abrasive paper”, which is arranged on the contact surface 24 by means of a bonding agent 34.

  FIG. 4 is a view showing the carbon brush 37. The carbon brush 37 has a different polishing mechanism 57 compared to the carbon brush 32. The polishing mechanism 57 is different in that a coupling surface 38 on which the positioning structure 35 and the bonding agent 34 are coupled is configured to be parallel to the contact surface 24 of the brush body 21. Since the coupling surface 38 is configured to be parallel to the contact surface 24 of the brush body 21, the frictional contact surface 39 formed in a concave shape corresponding to the contact surface 34 is generated.

  5-7 illustrate, by way of example, a method for creating a polishing mechanism 57 on the contact surface 24 of the brush body 21 for the embodiment of the carbon brush 37 shown in FIG. The apparatus used here includes an application roller 40 as shown in FIG. The application roller 40 rotates in a bonding agent tank not shown in detail here so that a bonding agent film 42 is formed on the roller surface 41. In order to transfer the bonding agent 34 disposed on the application roller 40 as the bonding agent film 42, a movement of feeding the brush body 21 in the direction of the feed shaft 58 is performed. Then, after the contact surface 24 comes into contact with the bonding agent film 42, the bonding agent film 42 is transferred onto the contact surface 24 correspondingly.

  As is apparent from FIG. 6, a second application roller 43 is provided to dispose the abrasive grains 27 on the bonding agent film 42 disposed on the contact surface 24. The application roller 43 rotates in a container filled with abrasive grains 27 in the form of small spheres, not shown in detail here, to obtain an adhesive layer 44. In order to transfer the abrasive grains 27 from the application roller 43 onto the bonding agent film 42 disposed on the contact surface 34, the bonding agent film 42 is moved in the direction of the feed shaft 58 shown in FIG. The contact surface 24 provided is brought into contact with the roller surface 45 of the application roller 43. As a result, the configuration of the bonding agent film 42 to which the abrasive grains 27 are attached as shown in FIG. 7 is formed.

  FIGS. 8-10 show carbon brushes 46, 47, and 48, which are other configurable embodiments. These carbon brushes have differently configured polishing mechanisms 49, 50 and 51 on the contact surface 52 of the brush body 59.

  The carbon brushes 46 to 48 shown in FIGS. 8 to 10 are configured to have a flat contact surface 52 and are particularly suitable for contact with a disk-shaped commutator device.

  The polishing mechanism 49 shown in FIG. 8 has a band-like structure 53 of a bonding agent 54 that extends perpendicularly to the plane in the drawing. Here, the band-shaped structure 53 has a band 55 of bonding agent arranged at an equal distance. Unlike the belt-like structure 53 of the bonding agent 54, the abrasive grains 27 are arranged above the contact surface 52 in a state of being distributed over the entire surface. As is apparent from FIG. 8, as the polishing mechanism 49 wears, this initially causes frictional contact across the entire surface, and then contacts the contact surface 52 and is formed by the polishing gap 56 between the strips 55 of adhesive. A belt-like frictional contact is generated.

  FIG. 9 shows the polishing mechanism 50. In the polishing mechanism 50, as in FIG. 8, the bonding agent 54 is arranged in the form of a band 55 of bonding agent. A difference from the embodiment shown in FIG. 8 is that the abrasive grains 27 are disposed only on the bonding material band 55 and are not disposed between the bonding material bands 55. For this reason, as soon as the frictional contact between the polishing mechanism 50 and the commutator starts, a belt-like frictional contact is made.

  Finally, FIG. 10 shows the polishing mechanism 51. In the polishing mechanism 51, the bonding agent 54 functions simultaneously to form a positioning structure for spatially defining and arranging the abrasive grains 27.

20, 28, 32, 37, 46, 47, 48 Carbon brush 21 Brush body 24, 52 Contact surface 25, 29, 33, 49, 50, 51, 57 Polishing mechanism 26, 34, 42, 54 Bonding agent 27 Abrasive grain 35 Positioning structure

Claims (11)

A carbon brush (20, 28, 32, 37, 46, 47, 48), wherein the carbon brush has a contact structure that moves relative to the carbon brush, in particular, the commutator of the electric motor is a carbon-containing material. The brush body (21) configured from the above is electrically contacted, and the contact surface (24, 52) of the brush body on the contact structure side is provided with a polishing mechanism (25, 29, 33). , 49, 50, 51, 57),
The polishing mechanism has a bonding agent (26, 34, 42, 54) and distributed abrasive grains (27), and the abrasive grains are formed on the contact surface by the bonding agent. A carbon brush characterized by being arranged.   The carbon brush according to claim 1, wherein the bonding agent (26, 42) functions as a positioning structure for spatially defining the arrangement of the abrasive grains (27).   The bonding agent (34) functions to bond the positioning structure (35) that spatially defines the arrangement of the abrasive grains and the contact surface (24, 52). Item 10. A carbon brush according to Item 1.   The carbon brush according to any one of claims 1 to 3, wherein at least the bonding agent or the positioning structure is configured to have conductivity.   The carbon brush according to claim 1, wherein at least the bonding agent or the positioning structure is provided with a conductive additive.   The carbon brush according to any one of claims 1 to 5, wherein the bonding agent (54) is applied only to a part of the contact surface (52). Preparing a brush body (21) composed of a carbon-containing material;
A polishing mechanism (25, 25) having abrasive grains (27) distributed on the contact surface (24, 52) of the brush body by the bonding agent (26, 34, 42, 54) applied on the contact surface. 29, 33, 49, 50, 51, 57). The method for producing a carbon brush according to any one of claims 1 to 6, characterized in that:   The abrasive (27) is supplied to the bonding agent (26) before applying the bonding agent (26) onto the contact surface (24, 52). the method of.   In the first step, the bonding agent (42) is applied onto the contact surface (24) of the brush body (21), and in the next step, the abrasive grains (27) are applied to the bonding agent (42). 8. A method according to claim 7, characterized in that they are combined.   10. A method according to claim 9, characterized in that the step of bonding the abrasive grains (27) to the bonding agent (42) is carried out by removing the abrasive grains from an abrasive container.   In order to bond the abrasive grains (27) to the bonding agent (34), a positioning structure (35) having the abrasive grains in a spatially defined arrangement is placed on the bonding agent. The method according to claim 9.

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