Gear demagnetizing device and gear demagnetizing method

Abstract

The invention relates to the technical field of vehicle production and manufacturing, in particular to a gear demagnetizing device and a gear demagnetizing method. The gear demagnetizing device comprises a magnetizing mechanism, a demagnetizing mechanism, a connecting cable and an electromagnetic coil; the magnetizing mechanism and the demagnetizing mechanism are connected with the electromagnetic coil through connecting cables; and the electromagnetic coil is arranged around the tooth surface of the gear. The gear demagnetization method comprises the following steps: S1, winding a cable on a gear to form an electromagnetic coil; s2, the electromagnetic coil is powered on, and the gear is magnetized; s3, the electromagnetic coil is powered on, and demagnetization treatment is conducted on the gear; s4, residual magnetism detection is conducted on the demagnetized gear, and when the residual magnetism is smaller than a set value, the operation is ended; and when the residual magnetism is greater than the set value, returning to the step S3. Magnetization and demagnetization treatment is achieved by electrifying the electromagnetic coil, overall demagnetization of the gear is achieved, the completion efficiency is high, and the speed is high; and no damage is caused to the gear, and the quality of the gear is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle production and manufacturing, and more specifically, to a gear demagnetization device and a gear demagnetization method. Background Art

[0002] During the overhaul of a certain urban rail vehicle gearbox, it was found that the residual magnetism of the gear exceeded the standard. The excessive residual magnetism will cause the gear to adsorb iron filings and magnetic powder, which is likely to cause wear during the operation of the gear, and then lead to quality problems. Therefore, it is necessary to eliminate the residual magnetism to ensure that the residual magnetism of the gear < 3 Gs.

[0003] Since the gear cannot be removed from the axle in the wheel set state, currently, only an alternating current magnetic yoke can be used to demagnetize the gear.

[0004] Under the existing technical conditions, the operator needs to connect the two poles of the alternating current magnetic yoke across both sides of the gear, then turn on the power supply, and move the electromagnetic yoke slowly along the gear. After moving more than 1 m away from the gear, the power supply is turned off to complete the demagnetization.

[0005] In practice, since the circumference of the gear is 1960 mm, this method can only demagnetize a local area of about 20 mm of the gear circumference at a time. To complete the overall demagnetization of the gear, repeated operations are required, and the demagnetization efficiency is low.

[0006] Moreover, after the alternating current magnetic yoke is powered on, the magnetic yoke itself will generate a magnetic field. The operator needs to hold the magnetic yoke tightly and overcome this magnetic field to prevent the magnetic yoke from being adsorbed to the gear under the influence of the magnetic field during demagnetization, which may cause pits and bumps on the machined surfaces such as the gear end face and tooth top, resulting in gear damage and easily causing quality problems. Summary of the Invention

[0007] The purpose of the present invention is to provide a gear demagnetization device and a gear demagnetization method, which can complete the demagnetization of the gear quickly and efficiently without causing damage to the gear.

[0008] In a first aspect, the present invention provides a gear demagnetization device, including a magnetization mechanism, a demagnetization mechanism, a connection cable, and an electromagnetic coil;

[0009] Both the magnetization mechanism and the demagnetization mechanism are connected to the electromagnetic coil through the connection cable;

[0010] The electromagnetic coil is used to be arranged around the tooth surface of the gear.

[0011] In an alternative embodiment, both the magnetization mechanism and the demagnetization mechanism are suspension piece flaw detectors.

[0012] In a second aspect, the present invention provides a gear demagnetization method using the gear demagnetization device described in the foregoing embodiment, including the following steps:

[0013] S1: Wind the cable around the gear to form an electromagnetic coil;

[0014] S2: Energize the electromagnetic coil to magnetize the gear;

[0015] S3: Energize the electromagnetic coil to demagnetize the gear;

[0016] S4: Detect the residual magnetism of the demagnetized gear. When the residual magnetism is less than the set value, end; when the residual magnetism is greater than the set value, return to step S3.

[0017] In an optional embodiment, when performing the magnetization treatment and the demagnetization treatment, the axial direction of the gear is the east-west direction.

[0018] In an optional embodiment, when performing the demagnetization treatment, alternating current is used.

[0019] In an optional embodiment, when performing the demagnetization treatment, the current of the alternating current gradually decays.

[0020] In an optional embodiment, when performing the demagnetization treatment, the magnetic field strength is greater than or equal to the residual magnetic field strength of the gear.

[0021] In an optional embodiment, when performing step S2, the current range is 940 - 1300A.

[0022] In an optional embodiment, when performing step S2, the magnetization is performed at least twice, and each magnetization is for a first set time.

[0023] In an optional embodiment, when performing step S3, the demagnetization is performed at least twice, and each demagnetization is for a second set time.

[0024] The beneficial effects of the embodiments of the present invention are as follows:

[0025] Wind the cable around the tooth surface of the gear to form an electromagnetic coil. By energizing the electromagnetic coil, magnetization and demagnetization treatments are realized, achieving overall demagnetization of the gear, with high efficiency and fast speed. At the same time, since the outer packaging of the cable is soft packaging and does not move during the magnetization and demagnetization processes, it will not cause any damage to the gear, ensuring the quality of the gear. Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0027] Figure 1Schematic diagram of the gear demagnetization device provided by the embodiment of the present invention;

[0028] Figure 2 Flowchart of the gear demagnetization method provided by the embodiment of the present invention;

[0029] Figure 3 Principle diagram of gear demagnetization provided by the embodiment of the present invention.

[0030] Icon: 1 - Gear; 2 - Electromagnetic coil; 3 - Connecting cable; 4 - Suspension part flaw detector. Detailed implementation manners

[0031] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0033] It should be noted that: Similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0034] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present invention is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive distinction and cannot be construed as indicating or implying relative importance.

[0035] In addition, the terms "horizontal", "vertical", "hanging", etc. do not mean that the components are required to be absolutely horizontal or hanging, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0036] In the description of the present invention, it should also be noted that unless otherwise clearly specified and defined, the terms "arrangement", "installation", "connection", and "coupling" should be understood in a broad sense. For example, it 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, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] The following will describe in detail some embodiments of the present invention with reference to the accompanying drawings of the specification. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0038] In a first aspect, the present invention provides a demagnetizing device for a gear 1, as Figure 1 shown, which includes a magnetization mechanism, a demagnetization mechanism, a connecting cable 3, and an electromagnetic coil 2; both the magnetization mechanism and the demagnetization mechanism are connected to the electromagnetic coil 2 through the connecting cable 3; the electromagnetic coil 2 is arranged around the tooth surface of the gear 1.

[0039] In this embodiment, the electromagnetic coil 2 is a part of the connecting cable 3, that is, the electromagnetic coil 2 is formed by winding the connecting cable 3.

[0040] In this embodiment, after the connecting cable 3 is wound around the gear 1, both ends are connected to the demagnetization mechanism and the magnetization mechanism. The magnetization mechanism supplies power to the connecting cable 3, and the electromagnetic field formed by the electromagnetic coil 2 disturbs the residual magnetism on the gear 1, overcomes the coercive force, and facilitates demagnetization; the demagnetization mechanism supplies power to the cable, and the electromagnetic field formed by the electromagnetic coil 2 demagnetizes the gear 1, achieving the final purpose of demagnetizing the gear 1.

[0041] In this embodiment, the magnetization mechanism and the demagnetization mechanism can be connected in series or in parallel.

[0042] In a preferred embodiment, the magnetization mechanism and the demagnetization mechanism are the same mechanism.

[0043] Specifically, in this embodiment, both the magnetization mechanism and the demagnetization mechanism are suspension part flaw detectors 4.

[0044] The suspension part flaw detector 4 can both perform magnetization treatment and demagnetization treatment.

[0045] Specifically, the gear 1 to be detected can be magnetized by an electric current or a permanent magnet.

[0046] When using the suspension part flaw detector 4 for demagnetization, it is mainly based on the magnetic hysteresis loop and the characteristics of sinusoidal alternating current, and is realized through specific current and magnetic field control.

[0047] Specifically, an alternating magnetic field generated by alternating current is used to continuously change the direction of the magnetic field while gradually decreasing the magnitude of the current, making the trajectory of the hysteresis loop smaller and smaller. First, the magnetic field strength used for demagnetization needs to be greater than the original residual magnetic field strength on the workpiece to overcome the coercive force and be sufficient to reverse the direction of the original residual magnetic field on the workpiece. Subsequently, as the magnitude of the current gradually decreases, the magnetic field strength also decreases. When the current gradually decays to 0, the magnetic field also gradually decays to 0, and the residual magnetism remaining in the workpiece is also close to 0, achieving demagnetization.

[0048] More specifically, in this embodiment, the model of the suspension piece flaw detector 4 is CJW-4000.

[0049] In a second aspect, the present invention provides a method for demagnetizing the gear 1 using the gear 1 demagnetization device described in the foregoing embodiment, as Figure 2 shown, including the following steps:

[0050] S1: Wind a cable around the gear 1 to form an electromagnetic coil 2;

[0051] S2: Energize the electromagnetic coil 2 to magnetize the gear 1;

[0052] S3: Energize the electromagnetic coil 2 to demagnetize the gear 1;

[0053] S4: Detect the residual magnetism of the demagnetized gear 1. When the residual magnetism is less than the set value, end; when the residual magnetism is greater than the set value, return to step S3.

[0054] Before performing the demagnetization treatment on the gear 1, first detect the residual magnetism of the gear 1.

[0055] In the following embodiments, a JCZ-50 type pocket magnetometer is used to measure the residual magnetism of the gear 1. Calculated based on the measurement result of 20 Gs, 1 Gs ≈ 80 A / m. Therefore, the residual magnetic field strength of the gear 1 is 1600 A / m.

[0056] After determining the residual magnetism of the gear 1, wind a cable around the gear 1 so that the cable forms an electromagnetic coil 2 on the gear 1, and both ends of the cable are connected to the magnetization and demagnetization equipment.

[0057] Since the direction of the magnetic field of the residual magnetism cannot be determined, first magnetize the gear 1 to disrupt the original residual magnetic field on the gear 1.

[0058] After that, demagnetize the gear 1 again.

[0059] Finally, the residual magnetism of the demagnetized gear 1 is detected. When the residual magnetism is less than the set value, such as the detection result < 3 Gs, it meets the residual magnetism requirement of the gear 1, and the demagnetization operation ends; when the residual magnetism is greater than the set value, that is, > 3 Gs, the residual magnetism does not meet the requirement, and demagnetization treatment needs to be carried out again. At this time, demagnetization treatment is carried out again until the finally detected residual magnetism reaches the set requirement.

[0060] In an alternative embodiment, when performing magnetization treatment and demagnetization treatment, the axial direction of the gear 1 is in the east-west direction.

[0061] For effective demagnetization, the gear 1 is arranged in the east-west direction, and the axis of the cable is perpendicular to the geomagnetic field, reducing the influence of the geomagnetism on the detection result and the demagnetization effect.

[0062] In an alternative embodiment, when performing demagnetization treatment, alternating current is used.

[0063] Since the magnitude and direction of the alternating current change with the time period and can generate an alternating magnetic field, in this embodiment, the demagnetization current is selected as alternating current.

[0064] In an alternative embodiment, when performing demagnetization treatment, the current of the alternating current gradually decays.

[0065] By gradually decaying, the weakening of the magnetic field is achieved, and finally the demagnetization effect is achieved.

[0066] The specific demagnetization principle is as Figure 3 shown. Demagnetization is to place the workpiece in an alternating magnetic field, make the amplitude of the alternating magnetic field gradually decrease, and the trajectory of the hysteresis loop also becomes smaller and smaller. When the magnetic field gradually decays to zero, the residual magnetism remaining in the workpiece is also close to zero. The demagnetization principle is as Figure 3 shown. There are many demagnetization methods, but no matter which method is used, the magnetic field direction is constantly changed, and at the same time, the magnitude of the demagnetization current is decreased to zero, so that the residual magnetism is close to zero. It can be seen from this that during demagnetization, the changes in the direction and magnitude of the current and the magnetic field must be "commutation and attenuation are carried out simultaneously". Generally, the demagnetization principle is that the magnetic field strength used for demagnetization should be at least equal to or greater than the magnetic field strength used for magnetization to overcome the coercive force and be sufficient to reverse the direction of the original residual magnetic field on the workpiece; in addition, the decreasing amount of the magnetic field strength should be as small as possible to achieve the desired demagnetization effect.

[0067] In an alternative embodiment, when performing demagnetization treatment, the magnetic field strength is greater than or equal to the residual magnetic field strength of the gear 1.

[0068] The JCZ-50 type pocket magnetometer is used to measure the residual magnetism of the gear 1, and the measurement result is 20 Gs. 1 Gs ≈ 80 A / m, so the residual magnetic field strength of the gear 1 is 1600 A / m.

[0069] In order to reverse the original residual magnetic field direction on Gear 1 and overcome the coercive force, the magnetic field strength used during demagnetization should be greater than (at least equal to) the residual magnetic field strength of Gear 1.

[0070] Therefore, the magnetic field strength used during demagnetization is selected to be 2400 - 3200 A / m.

[0071] In an alternative embodiment, when performing step S2, the current range is 940 - 1300 A.

[0072] In this embodiment, the common width of Gear 1 is 87.7 mm, the diameter of the cable is 17.4 mm, the number of turns of the wire = width of Gear 1 / diameter of the cable = 5. The circumference of Gear 1 is 1960 mm, the shortest length of the cable = 1960 x 5 = 9800 mm, and adding the distance connected to the power supply, the final length of the cable is determined to be 15 m.

[0073] Combining the magnetic field strength, the number of turns of the coil, and the circumference of Gear 1, according to the magnetization formula, the demagnetization current is finally determined to be 940 - 1300 A.

[0074]

[0075] Where: H - magnetic field strength (A / m)

[0076] N - number of turns of the wire

[0077] I - current (A)

[0078] L - circumference of Gear 1 (m)

[0079] In an alternative embodiment, when performing step S2, the number of magnetizations is at least two times, and each magnetization is for a first set time.

[0080] In this embodiment, the number of magnetizations can be selected according to the initial residual magnetic field detection result. When the residual magnetic field is relatively high, multiple magnetizations can be used to enhance the magnetization effect.

[0081] In this embodiment, the first set time is 2 s.

[0082] It should be noted that in this embodiment, both the number of magnetizations and the first set time can be adjusted accordingly according to actual needs, not limited to the setting of 2 magnetizations and a magnetization time of 2 s. As long as it can disrupt the original magnetic field of Gear 1 through magnetization and achieve the effect of reducing the coercive force.

[0083] In an alternative embodiment, when performing step S3, the number of demagnetizations is at least two times, and each demagnetization is for a second set time.

[0084] Similarly, in this embodiment, performing multiple demagnetization operations can better achieve the demagnetization effect.

[0085] In this embodiment, the second set time is 3 s, that is, each demagnetization operation lasts for 3 s, and two demagnetization processes can achieve a better demagnetization effect.

[0086] It can be understood that both the number of demagnetization times and the second set time can be adjusted according to the actual residual magnetism result to achieve the best demagnetization effect.

[0087] Specifically, the specific operation process of the above method is as follows:

[0088] The first step: Wind the cable around Gear 1 for a total of 5 turns to form a coil. According to the law of electromagnetic induction, when an electric current is passed through the coil, a longitudinal magnetic field parallel to the coil axis is generated inside the coil. Subsequently, connect the cable to the magnetization circuit of the CJW-4000 type suspension part flaw detector 4.

[0089] The second step: Adjust the current to 940 - 1300 A, and press the magnetization button on the device to magnetize Gear 1 as a whole twice, with each magnetization time being 2 s, aiming to disrupt the direction of the original residual magnetic field on Gear 1.

[0090] The third step: Press the demagnetization button on the device to demagnetize Gear 1 twice, with each demagnetization time being 3 s, which can demagnetize Gear 1 as a whole.

[0091] The fourth step: Use a JCZ-10 type pocket magnetometer to measure the residual magnetism of Gear 1, and the measurement result is < 3 Gs, meeting the requirements.

[0092] It can be seen from the above embodiments that the technical solution of this application, compared with the existing AC yoke demagnetization direction, has the following results:

[0093] For the existing AC yoke demagnetization technology, it can only perform local demagnetization on a place about 20 mm in the circumference of Gear 1 each time. At the same time, in order to avoid confusing the demagnetization area, marks need to be made on Gear 1 before and after each demagnetization. The demagnetization time for each time is 1 minute. And the circumference of a Gear 1 is 1960 mm. To complete the demagnetization of the entire Gear 1, it is necessary to repeat the demagnetization 98 times, consuming 98 minutes.

[0094] The gear 1 demagnetization device and the gear 1 demagnetization method provided by the present invention can demagnetize the entire Gear 1 at one time. The demagnetization time only needs 30 minutes (including the cable winding and overhead crane lifting time), and the demagnetization duration is reduced by 68 minutes compared with the existing technology, and the production efficiency is greatly improved.

[0095] In the existing AC yoke demagnetization technology, when the AC yoke is powered on, a magnetic field will be generated by the yoke itself. The operator needs to hold the yoke tightly and overcome this magnetic field to prevent the yoke from being adsorbed to Gear 1 under the influence of the magnetic field during demagnetization, which may cause pits and bumps on the machined surfaces such as the end face and tooth tip of Gear 1, resulting in damage to Gear 1 and making it extremely prone to quality problems.

[0096] The gear 1 demagnetization device and gear 1 demagnetization method provided by the present invention rely on the law of electromagnetic induction during the entire demagnetization process. The magnetic field generated by the cable will not damage Gear 1, and the demagnetization effect is stable, effectively reducing the operation difficulty of the operator and ensuring the product quality.

[0097] The beneficial effects of the embodiments of the present invention are as follows:

[0098] The cable is wound around the tooth surface of Gear 1 to form an electromagnetic coil 2. Magnetization and demagnetization treatments are achieved by energizing the electromagnetic coil 2, realizing the overall demagnetization of Gear 1 with high efficiency and fast speed. At the same time, since the outer packaging of the cable is a soft package and does not move during magnetization and demagnetization, it will not cause any damage to Gear 1, ensuring the quality of Gear 1.

[0099] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A gear demagnetization device, characterized in that: It includes a magnetizing mechanism, a demagnetizing mechanism, a connecting cable and an electromagnetic coil; The magnetizing mechanism and the demagnetizing mechanism are both connected to the electromagnetic coil via the connecting cable; The electromagnetic coil is used to be arranged around the tooth surface of the gear.

2. The gear demagnetization device according to claim 1, characterized in that: The magnetizing mechanism and the demagnetizing mechanism are both suspended parts flaw detectors.

3. A method for gear demagnetization using the gear demagnetization device according to claim 1 or 2, characterized in that: The steps include: S1: Wind the cable around the gear to form an electromagnetic coil; S2: The electromagnetic coil is energized to magnetize the gear; S3: The electromagnetic coil is energized to demagnetize the gear; S4: Perform residual magnetism detection on the demagnetized gear. When the residual magnetism is less than the set value, the process ends; when the residual magnetism is greater than the set value, the process returns to step S3.

4. The gear demagnetization method according to claim 3, characterized in that: During the magnetization and demagnetization processes, the axial direction of the gear is the east-west direction.

5. The gear demagnetization method according to claim 3, characterized in that: When demagnetizing, alternating current is used.

6. The gear demagnetization method according to claim 5, characterized in that: During the demagnetization process, the current of the alternating current gradually decays.

7. The gear demagnetization method according to claim 3, characterized in that: During the demagnetization process, the magnetic field strength is greater than or equal to the residual magnetic field strength of the gear.

8. The gear demagnetization method according to claim 3, characterized in that: When performing step S3, the current range is 940-1300A.

9. The gear demagnetization method according to claim 3, characterized in that: When performing step S2, the magnetization is performed at least twice, and each magnetization is performed for a first set time.

10. The gear demagnetization method according to claim 3, characterized in that: When performing step S3, the demagnetization is performed at least twice, and each demagnetization lasts for a second set time.

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