Brake pad friction block pressing device and method

Abstract

The present invention relates to the technical field of brake pad pressing, and in particular to a brake pad friction block pressing device and method. The brake pad friction block pressing device comprises: a mounting assembly; a stamping mechanism, which is mounted on the mounting assembly, and the stamping mechanism comprises a stamping die and a stamping head which are coaxially arranged; a vibration mechanism, on which a first sliding member and a second sliding member which are slidably connected are arranged, the first sliding member is fixedly mounted on the mounting assembly, and a first vibrating member is mounted on the end of the second sliding assembly away from the first sliding member along the sliding direction, and a second vibrating member is mounted on the mounting assembly, and the first vibrating member moves toward or away from the second vibrating member under the action of the second vibrating member. The brake pad friction block obtained by vibration and pressure pressing can greatly reduce internal cracks, and during the long-term operation of the train, the brake pad can work stably and effectively, avoiding the risk of the brake pad friction block breaking and falling off, and can greatly reduce the manpower maintenance and repair costs during the operation of the train.

Description

Technical Field

[0001] The invention relates to the technical field of brake pad pressing, and in particular to a brake pad friction block pressing device and method. Background Art

[0002] At present, powder metallurgy brake pads are mainly copper and iron mixed friction materials, and the main processes are mixing, pressing and sintering. Pressing is the second basic process of powder metallurgy process, which is the process of compacting metal powder into a block with a certain shape, porosity and strength.

[0003] In the pressing process of powder metallurgy brake pad friction block in the prior art, the forming process is mainly: laying - pressing - forming - demolding. Since the friction block material contains graphite powder and copper powder, the wetting angles of graphite and copper are quite different, and the surface of metallurgical powder particles is irregular, and there is friction between each other, resulting in the metallurgical powder being loosely stacked in the mold cavity, and the particles are built on each other to form an arch bridge, resulting in fine lines inside the product, which increases the porosity of the product. During the demolding process, the pressure on the product is reduced, and the fine lines will evolve into cracks. In the subsequent sintering process, the cracks on the surface of the product will close due to high temperature and high pressure, and the defects inside the product will still exist, resulting in many defects inside the produced product, which are not easy to detect directly through observation. When applied to trains, cracked friction blocks may break during braking, causing the friction blocks to fall off the steel back, posing a major safety hazard. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect in the prior art that the brake pad friction block has many internal defects after being pressed and formed, resulting in the risk of the brake pad friction block falling off the steel back when the train brakes, thereby providing a brake pad friction block pressing device and method.

[0005] In order to solve the above technical problems, the present invention provides a brake pad friction block pressing device, comprising:

[0006] Install components;

[0007] A stamping mechanism is mounted on the mounting assembly, and the stamping mechanism includes a stamping die and a stamping head which are coaxially arranged;

[0008] A vibration mechanism is provided with a first sliding member and a second sliding member which are slidably connected. The first sliding member is fixedly mounted on a mounting assembly. The first vibrating member is mounted on one end of the second sliding assembly away from the first sliding member along a sliding direction. The second vibrating member is mounted on the mounting assembly. The first vibrating member moves toward or away from the second vibrating member under the action of the second vibrating member.

[0009] Optionally, the vibration mechanism and the punching mechanism are arranged vertically.

[0010] Optionally, a pressing cavity is provided in the installation assembly, the punching mechanism is installed in the pressing cavity, and the vibration mechanism is installed on the outer side wall of the pressing cavity.

[0011] Optionally, the first vibrating member is a magnetic member, the second vibrating member is an electromagnet, and the magnetic member and the electromagnet are coaxially arranged.

[0012] Optionally, an elastic member is installed between the first vibrating member and the mounting assembly, and the axial direction of the elastic member is parallel to the sliding direction of the first sliding member and the second sliding member.

[0013] Optionally, the first sliding member is a connecting tube, the second sliding member is a connecting rod, and the connecting tube is slidably sleeve-connected to the connecting rod.

[0014] The present invention also provides a brake pad friction block pressing method, comprising the following steps:

[0015] Inject the powder material into the mold, and drive the mold to vibrate for a first predetermined time, with an amplitude range of 1 to 2 mm and a vibration frequency of 40 to 60 Hz;

[0016] The mold is closed to press the powder material, and the pressing time is not less than 3s;

[0017] The mold is driven to vibrate again for a second predetermined time, with an amplitude range of 0.5 to 1.5 mm and a vibration frequency of 40 to 60 Hz;

[0018] Demould and take out the pressed product.

[0019] Optionally, the demoulding step includes: after the mold is separated by a predetermined distance, the mold is re-closed to perform secondary pressing on the material, and the secondary pressing is maintained for no less than 3 seconds.

[0020] Optionally, the pressing pressure applied by the mold to the material during pressing is 8 to 12 times the holding pressure applied by the mold to the material during holding pressing.

[0021] Optionally, the amplitude of the second vibration of the mold is not greater than the amplitude of the first vibration of the mold.

[0022] The technical solution of the present invention has the following advantages:

[0023] 1. The brake pad friction block pressing device provided by the present invention includes: a mounting assembly; a stamping mechanism, which is mounted on the mounting assembly, and the stamping mechanism includes a stamping die and a stamping head arranged coaxially; a vibration mechanism, on which a first sliding member and a second sliding member in sliding connection are arranged, the first sliding member is fixedly mounted on the mounting assembly, and a first vibrating member is mounted on the end of the second sliding assembly away from the first sliding member along the sliding direction, and a second vibrating member is mounted on the mounting assembly, and the first vibrating member moves toward or away from the second vibrating member under the action of the second vibrating member.

[0024] During the process of pressing and forming the brake pad friction block, the raw material powder is first loaded into the stamping die, and the vibration mechanism works. The first vibrator continuously reciprocates under the action of the second vibrator to drive the stamping mechanism to vibrate, so that the gaps between the raw material powders are eliminated by vibration, reducing the arch bridge effect of the powder in the stamping model cavity. The punch head descends to press the powder in the stamping die, so that the powder is pressed into a block. The vibration mechanism works again to drive the stamping die to vibrate, prompting the gas inside the pressed block to be discharged, further weakening the arch bridge effect. After the block is pressed again, it is demolded to obtain the pressed brake pad friction block, and the friction block is subjected to a subsequent sintering process to obtain the finished product. The density of the brake pad friction block blank obtained by vibration and pressure pressing is increased from about 80% to about 88%, and the internal cracks of the obtained product can be greatly reduced. It is used on trains with a speed of 250km / h. During the long-term operation of the train, the brake pad can work stably and effectively, avoiding the risk of the brake pad friction block breaking and falling off, and can greatly reduce the manpower maintenance and repair costs during the operation of the train.

[0025] 2. In the brake pad friction block pressing device provided by the present invention, the first vibrating member is a magnetic member, the second vibrating member is an electromagnet, and the magnetic member and the electromagnet are coaxially arranged. The use of electromagnetic vibration can control the stability of the amplitude and vibration frequency, so that the vibration mechanism produces uniform vibration, ensuring that the pre-formed block product will not be damaged in the process of eliminating the arch bridge effect.

[0026] 3. The brake pad friction block pressing method provided by the present invention comprises the following steps: injecting powder material into the mold, driving the mold to vibrate for a first predetermined time, with an amplitude range of 1 to 2 mm and a vibration frequency of 40 to 60 Hz; closing the mold to press the powder material, and the pressing time is not less than 3 seconds; driving the mold to vibrate again for a second predetermined time, with an amplitude range of 0.5 to 1.5 mm and a vibration frequency of 40 to 60 Hz; demolding, and taking out the pressed product. The density of the brake pad friction block blank obtained by vibration and pressure pressing is increased from about 80% to about 88%, and the internal cracks of the obtained product can be greatly reduced. It is used on trains with a speed of 250 km / h. During the long-term operation of the train, the brake pad can work stably and effectively, avoiding the risk of the brake pad friction block breaking and falling off, and can greatly reduce the manpower maintenance and repair costs during the operation of the train. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 It is a schematic structural diagram of a brake pad friction block pressing device provided in an embodiment of the present invention.

[0029] Explanation of the accompanying drawings: 1. Installation assembly; 2. Stamping die; 3. Stamping head; 4. First sliding member; 5. Second sliding member; 6. First vibrating member; 7. Second vibrating member; 8. Elastic member. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are 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 understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0032] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0034] Example 1

[0035] like Figure 1 The present embodiment shows a brake pad friction block pressing device, which includes: a supporting cavity structure as a mounting assembly 1, a stamping mechanism for pressing and forming, and a vibration mechanism for driving the stamping mechanism to vibrate. A pressing cavity is provided in the mounting assembly 1, the stamping mechanism is installed in the pressing cavity, and the vibration mechanism is installed on the outer wall of the pressing cavity.

[0036] The punching mechanism is installed on the mounting assembly 1, and the punching mechanism includes a coaxially arranged punching die 2 and a punching head 3. The punching die 2 is fixedly installed at the bottom of the pressing cavity, and the punching head 3 is installed at the top of the pressing cavity through a cylinder. The cylinder drives the punching head 3 to move up and down to press or demold the material in the punching die 2.

[0037] The vibration mechanism is arranged vertically with the punching mechanism. The vibration mechanism is provided with a first sliding member 4 and a second sliding member 5 which are slidably connected. The first sliding member 4 is fixedly mounted on the mounting assembly 1. A first vibrating member 6 is mounted on one end of the second sliding assembly away from the first sliding member 4 along the sliding direction. A second vibrating member 7 is mounted on the mounting assembly 1. The first vibrating member 6 moves toward or away from the second vibrating member 7 under the action of the second vibrating member 7.

[0038] In this embodiment, the first vibrating member 6 is a permanent magnet as a magnetic member, and the second vibrating member 7 is an electromagnet, and the magnetic member and the electromagnet are coaxially arranged. A spring as an elastic member 8 is installed between the first vibrating member 6 and the mounting assembly 1, and the axial direction of the spring is parallel to the sliding direction of the first sliding member 4 and the second sliding member 5. The first sliding member 4 is a connecting tube, and the second sliding member 5 is a connecting rod, and the connecting tube is connected to the connecting rod by a sliding sleeve. By passing alternating current into the electromagnet, the magnetic pole of the electromagnet is constantly changed, thereby repelling or attracting the permanent magnet. The maximum distance between the permanent magnet and the electromagnet can be limited by the spring, and at the same time, an elastic force is applied to the permanent magnet to move toward the electromagnet to avoid the two being too far apart, resulting in the permanent magnet being unable to move close to the electromagnet. The vibration generated by the vibration mechanism is transmitted to the stamping die 2 in the pressing cavity through the side wall of the pressing cavity, thereby causing the material in the stamping die 2 to vibrate.

[0039] During the press-forming process of the brake pad friction block, the raw material powder is first loaded into the stamping die 2, and the vibration mechanism works. The first vibrator 6 continuously reciprocates under the action of the second vibrator 7 to drive the stamping mechanism to vibrate, so that the gaps between the raw material powders are eliminated by vibration, reducing the arch bridge effect of the powder in the cavity of the stamping die 2. The punch head 3 descends to press the powder in the stamping die 2, so that the powder is pressed into a block. The vibration mechanism works again to drive the stamping die 2 to vibrate, causing the gas inside the pressed block to be discharged, further weakening the arch bridge effect. After the block is pressed again, it is demolded to obtain the pressed brake pad friction block, and the finished product can be obtained after the friction block is subjected to a subsequent sintering process. The density of the brake pad friction block blank obtained by vibration and pressure pressing is increased from the original 80% to about 88%, and the internal cracks of the product can be greatly reduced. It is used on trains with a speed of 250km / h. During the long-term operation of the train, the brake pad can work stably and effectively, avoiding the risk of breakage and falling off of the brake pad friction block, and can greatly reduce the manpower maintenance and repair costs during train operation.

[0040] Example 2

[0041] This embodiment provides a brake pad friction block pressing method, using the brake pad friction block pressing device provided in Embodiment 1, comprising the following steps:

[0042] First, the powder material is injected into the punching die of the punching mechanism, and the punching die is driven to vibrate for 30 seconds by the vibration mechanism, with an amplitude range of 1 to 2 mm and a vibration frequency of 40 to 60 Hz; the vibration time, amplitude range and vibration frequency can be adjusted according to the ratio of the metal copper powder and the graphite powder in the powder. In this embodiment, the vibration frequency is 50 Hz and the amplitude is 2 mm.

[0043] After the vibration is completed, the mold is closed to press the powder material. The cylinder drives the punch head to descend and extend into the punch die. When the punch head contacts the material alone, it continues to descend 5mm, and then maintains the pressing state for 3s. The rear cylinder drives the punch head to lift. Then the vibration mechanism is used again to drive the punch die of the punch mechanism to vibrate for 15s, with an amplitude range of 0.5-1.5mm and a vibration frequency of 40-60Hz; the vibration time, amplitude range and vibration frequency can be adjusted according to the proportion of metal copper powder and graphite powder in the powder. The amplitude of the second mold vibration is not greater than the amplitude of the first mold vibration. In this embodiment, the vibration frequency of the second vibration is 50Hz and the amplitude is 1mm.

[0044] After completing the secondary vibration to eliminate the gas in the preformed product block, the cylinder drives the punch head to press down again and apply molding pressure to the product, and maintains the pressing for 3 seconds. The pressing pressure applied to the material by the mold during pressing is 8 to 12 times the holding pressure applied by the mold to the material during pressing and holding. In this embodiment, the holding pressure is one tenth of the pressing pressure. After the pressing is completed, the cylinder drives the punch head to lift and open the mold, take out the pressed product, and after the subsequent sintering process, the final brake pad friction block product can be obtained.

[0045] The density of the brake pad friction block blank obtained through the electromagnetic vibration secondary pressurization process can be increased from the original 80% to 88%, and the internal cracks of the product can be greatly reduced. When used on trains with a speed of 250km / h, the brake pad can work stably and effectively during the long-term operation of the train, avoiding the risk of breakage and falling off of the brake pad friction block, and can greatly reduce the manpower maintenance and repair costs during train operation.

[0046] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A method for pressing a brake pad friction block, characterized in that: The following steps are involved: Inject the powder material into the mold, and drive the mold to vibrate for a first predetermined time, with an amplitude range of 1-2 mm and a vibration frequency of 40-60 Hz; The mold is closed to press the powder material, and the pressing time is not less than 3s; The mold is driven to vibrate again for a second predetermined time, with an amplitude range of 0.5-1.5 mm and a vibration frequency of 40-60 Hz; After the mold is separated by a predetermined distance, the mold is re-closed to perform secondary pressing on the material. The secondary pressing is maintained for no less than 3s, and the pressed product is taken out.

2. The brake pad friction block pressing method according to claim 1, characterized in that: The pressing pressure applied by the mold to the material during pressing is 8 to 12 times the holding pressure applied by the mold to the material during holding pressing.

3. The brake pad friction block pressing method according to claim 1, characterized in that: The amplitude of the second mold vibration is not greater than the amplitude of the first mold vibration.

4. A brake pad friction block pressing device, characterized in that: The method for pressing a brake pad friction block according to any one of claims 1 to 3 comprises: Install component (1); A punching mechanism, mounted on the mounting assembly (1), the punching mechanism comprising a punching die (2) and a punching head (3) which are coaxially arranged; A vibration mechanism, on which a first sliding member (4) and a second sliding member (5) are provided which are slidably connected, the first sliding member (4) being fixedly mounted on the mounting assembly (1), a first vibrating member (6) being mounted on one end of the second sliding member which is away from the first sliding member (4) in a sliding direction, a second vibrating member (7) being mounted on the mounting assembly (1), the first vibrating member (6) moving towards or away from the second vibrating member (7) under the action of the second vibrating member (7), the first sliding member (4) being a connecting tube, the second sliding member (5) being a connecting rod, the connecting tube being slidably sleeve-connected to the connecting rod; The vibration mechanism is arranged perpendicularly to the stamping mechanism, the first vibration member (6) is a magnetic member, the second vibration member (7) is an electromagnet, the magnetic member and the electromagnet are arranged coaxially, an elastic member (8) is installed between the first vibration member (6) and the mounting assembly (1), and the axial direction of the elastic member (8) is parallel to the sliding direction of the first sliding member (4) and the second sliding member (5).

5. The brake pad friction block pressing device according to claim 4, characterized in that: A pressing cavity is provided in the installation assembly (1), the punching mechanism is installed in the pressing cavity, and the vibration mechanism is installed on the outer side wall of the pressing cavity.

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