CN109664544B

CN109664544B - Automatic pressing device for powder materials

Info

Publication number: CN109664544B
Application number: CN201811357104.2A
Authority: CN
Inventors: 燕青芝; 彭韬; 张肖璐
Original assignee: University of Science and Technology Beijing USTB
Current assignee: University of Science and Technology Beijing USTB
Priority date: 2018-11-15
Filing date: 2018-11-15
Publication date: 2020-07-10
Anticipated expiration: 2038-11-15
Also published as: CN109664544A

Abstract

The invention relates to an automatic pressing device for powder materials, which comprises a forming die frame, wherein a pressing platform, a middle template and a lower template are sequentially arranged from high to low. The middle template is fixed on the support, the lower template is connected with the pressing platform through a pull rod penetrating through the middle template, and the lower template is driven by the first pushing cylinder to be linked with the pressing platform to lift relative to the middle template. The pressing platform is provided with a die cavity, and the upper part of the middle die plate is provided with a lower punch corresponding to the die cavity. The pressing platform is provided with an upper template, and the lower part of the upper template is provided with an upper punch corresponding to the die cavity. The upper template is driven by the second pushing cylinder to lift relative to the pressing platform. The pressing platform is provided with a linear track, a sliding block is arranged on the track, and an automatic part taking device is arranged on the sliding block and comprises a clamping arm and a third pushing cylinder, wherein the third pushing cylinder drives the clamping arm to approach to the die cavity so as to clamp and demould the formed part. The slider is driven to slide reciprocally along the linear track. The automatic workpiece taking device can realize automatic workpiece taking, reduce the labor intensity of workers and improve the automation degree of production and the stability of product quality.

Description

Automatic pressing device for powder materials

Technical Field

The invention relates to a compression molding process of powder materials, in particular to an automatic compression device of powder materials.

Background

A conventional powder material pressing device mainly comprises a pressing platform (the pressing platform is provided with at least one die cavity), an upper punch, a lower punch, a hydraulic transmission mechanism, a limiting device and a timer, wherein a friction plate or friction block forming process comprises the steps of ① material injection, wherein a powder material required by a friction block is weighed firstly in a manual mode, a proper die cavity volume is calculated according to the loose packing density of the powder, the position of the lower punch is adjusted to enable the die cavity to meet the volume, then the weighed friction block powder is filled into the die cavity, a proper amount of transition layer powder is filled into the die cavity, then a friction block metal back plate is placed on the topmost layer of the powder, ② pressing is carried out, pressing pressure, pressure maintaining time and other parameters are set, ③ pressing is carried out, after pressure maintaining is finished, the upper punch automatically returns, the pressed compact is exposed out through manually lowering the pressing platform, then the pressed compact is manually taken out, and the pressing process of the friction block is realized.

The above-mentioned forming process of powder material has the following disadvantages:

① the prior art needs two times of artificial material distribution by adopting a transition layer connection mode (i.e. filling the friction material powder into the die cavity first and then filling the transition layer powder into the die cavity), which has high labor intensity and high labor cost, long auxiliary working time for weighing and filling ② materials and the like and low production efficiency, in the ③ material conveying or filling process, because each component in the powder has large specific gravity/particle size difference, the component segregation is easy to cause, the consistency of each component in a formed blank body is not favorable, and the quality and the performance of a final sintered finished product are influenced, the ④ pressed blank has low mechanical strength, and the pressed blank is easy to be damaged by adopting artificial demoulding and piece taking after the pressing is finished, and further the final performance is influenced.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides an automatic pressing device for powder materials, which is provided with an automatic part taking device and/or an automatic feeding device, and can perform mechanical automatic part taking and automatic feeding operation after one-time pressing forming is completed each time by means of the automatic part taking device and/or the automatic feeding device, so that the labor intensity and the labor cost are reduced, the automation degree of production is improved, the occupation ratio of human factors is reduced, and the large-scale production efficiency and the quality stability of products are improved.

In order to achieve the purpose, the invention adopts the main technical scheme that:

an automatic compaction device for powdered materials comprising:

the forming die set comprises a pressing platform, a middle die plate and a lower die plate, wherein two ends of the middle die plate are fixed on a bottom support, the pressing platform and the lower die plate are respectively arranged above and below the middle die plate, the pressing platform and the lower die plate are connected through a pull rod, and the pull rod penetrates through the middle die plate but is not fixed with the middle die plate; a first pushing cylinder is arranged between the middle template and the lower template, and two ends of the first pushing cylinder are respectively connected with the middle template and the lower template; by means of extension and retraction of the first pushing cylinder, the pressing platform can be lifted up and down linearly relative to the middle template; the pressing platform is provided with at least one die cavity, the die cavity penetrates through the pressing platform, the middle die plate is provided with a lower punch corresponding to the die cavity, and the lower punch is provided with a cross section matched with the die cavity;

an upper template is arranged above the pressing platform, an upper punch is arranged on the upper template corresponding to the die cavity and provided with a section matched with the die cavity, the upper template is driven by a second pushing cylinder, and the upper template can linearly lift up and down relative to the pressing platform by virtue of the extension and retraction of the second pushing cylinder;

the pressing platform is provided with a linear track, the linear track is provided with at least one sliding block capable of sliding relative to the linear track, an automatic workpiece taking device is installed on the sliding block, the automatic workpiece taking device comprises a clamping arm and a third pushing cylinder, and the end part of the clamping arm is connected with a concave workpiece taking block; the clamping arm is driven by the third pushing cylinder to enable the clamping arm to approach or depart from the mold cavity; the sliding block is driven by a horizontal driving device, the horizontal driving device is arranged on one side of the linear track, and the sliding block is driven by the horizontal driving device to slide along the linear track.

Preferably, the horizontal driving device is a telescopic cylinder fixed at one end of the pressing platform, or the horizontal driving device comprises a combination device of a motor, a gear and a toothed belt.

Preferably, the die cavity is a cylindrical cavity, and the upper punch and the lower punch are cylindrical structures matched with the diameter of the die cavity. In other embodiments, the die cavity is any other regular or irregular cylinder cavity, and both the upper punch and the lower punch are provided with cylinder structures matched with the die cavity.

In a preferred embodiment of the present invention, the pair of linear rails is disposed on two sides of the mold cavity, and the pair of holding arms is disposed on the pair of linear rails respectively. Because the die cavity is cylindrical, the concave workpiece taking blocks are preferably designed into circular arc-shaped openings, so that a pair of concave workpiece taking blocks can be just clamped on two sides of the cylindrical pressed workpiece, and stable clamping is realized. Preferably, a layer of rubber buffer layer is arranged on the outer surface of the concave piece taking block or the concave piece taking block is made of rubber materials.

In a preferred embodiment of the invention, the slide block is further provided with an automatic feeding device, the automatic feeding device comprises a prepressing feeding barrel and a prepressing feeding barrel, the prepressing feeding barrel comprises a barrel shell with two open ends, and the inner diameter of the barrel shell is smaller than that of the die cavity; a pressing plate matched with the inner cavity of the barrel shell is arranged above the barrel shell, a central column is arranged in the center of the lower bottom surface of the pressing plate, and the pressing plate is controlled by a pre-pressing cylinder to move up and down; the bottom of the barrel shell is provided with a bottom plate, the bottom plate is opened when the bottom plate bears a pressure threshold value, so that the powder in the barrel shell is pre-extruded into a cylindrical body, leaks out of the bottom of the barrel shell and falls into the die cavity, and the pressure threshold value is 5% -10% of the pressing pressure.

The bottom plate is provided with a pressure sensor and a bottom plate driving device, and the bottom plate driving device can be a small telescopic cylinder. The bottom plates are symmetrically jointed left and right to close the lower part of the barrel shell, when the pressure of the blank in the barrel shell on the bottom plates reaches a certain preset value, the bottom plates on the left side and the right side are separated to two sides, the bottom of the barrel shell is opened, and the powder pre-pressed into a column shape leaks out from the bottom of the barrel shell. In order to adapt to the shape of the die cavity H (a through hole is formed in the center of the formed blank), a central column is arranged at the lower bottom surface of the center of the pressing plate.

In a preferred embodiment of the invention, the automatic feeding device further comprises a feeding device which quantitatively feeds materials to the automatic feeding device; the feeding device comprises a constant-volume feeding pipe, the constant-volume feeding pipe comprises a vertically arranged powder storage pipe, an opening at the upper end of the constant-volume feeding pipe is correspondingly connected with the powder bin, and an opening at the lower end of the constant-volume feeding pipe is connected with the pre-pressing feeding barrel through a spiral feeder; an upper pneumatic butterfly valve and a lower pneumatic butterfly valve are respectively arranged at openings at two ends of the powder storage pipe, and the screw pitch of the spiral feeder is 0.5 cm-5 cm. The pipe diameter of the powder storage pipe and the height between the upper pneumatic butterfly valve and the lower pneumatic butterfly valve can be adaptively changed according to powder required by a molded blank to be pressed and molded, so that constant-volume feeding is realized.

In a preferred embodiment of the present invention, the feeding device further includes an automatic weighing apparatus, the automatic weighing apparatus includes a feeding port and a discharging port, the feeding port of the automatic weighing apparatus is correspondingly disposed at the lower end of the powder storage tube, and the discharging port of the automatic weighing apparatus is correspondingly connected to the upper end of the pre-pressing charging barrel. The automatic weighing instrument is provided with a display screen or a language counter and the like, and when the powder from the constant volume feeding pipe is obviously insufficient or excessive, the powder is sent out for the staff to make proper adjustment and calibration.

The upper end and the lower end of the constant volume feeding pipe are respectively connected with the powder bin and the automatic weighing instrument through quick connectors, and the quick connectors comprise flexible connections such as rubber sleeve connections.

In a preferred embodiment of the invention, a release agent spraying device is further arranged on the slide block, and the automatic part taking device is positioned between the automatic feeding device and the release agent spraying device; the release agent spraying device comprises a spray head and a hose, wherein the spray head sprays release agent downwards, the spray head is fixedly connected to the sliding block through a connecting arm, one end of the hose is connected with the spray head, and the other end of the hose is connected with a release agent storage tank.

In a preferred embodiment of the present invention, a demolding protection device is disposed between the second pushing cylinder and the upper mold plate, the demolding protection device is a middle cylinder, a cylinder body of the middle cylinder is connected to a piston rod of the second pushing cylinder, and a piston rod of the middle cylinder is connected to the upper mold plate.

In a preferred embodiment of the present invention, an upper limiting device is disposed between the upper mold plate and the pressing platform, the upper limiting device includes a buffering limiting cylinder disposed on the edge of the upper mold plate, the buffering limiting cylinder includes a cylinder body, a piston rod and an adjusting bolt, the cylinder body is mounted on the upper mold plate, and the lower end of the piston rod is connected to the adjusting bolt through a thread. According to the specific requirement of the distance between the upper template and the pressing platform, the distance from the lower end of the adjusting bolt to the upper template is adjusted to achieve the purpose of limiting.

In a preferred embodiment of the present invention, a lower limiting device is disposed between the pressing platform and the middle mold plate, and includes a lateral limiting cylinder horizontally mounted on the middle mold plate, a cylinder body of the lateral limiting cylinder is fixed on the middle mold plate, a piston rod end of the lateral limiting cylinder is connected to a limiting slider, and a limiting block corresponding to the limiting slider is mounted on a lower bottom surface of the pressing platform.

In a preferred embodiment of the present invention, the pressing platform is fixed with guide posts, the upper mold plate is provided with guide cylinders engaged with the guide posts, and the guide cylinders are slidably engaged with the guide posts to guide the upper mold plate to move vertically and vertically relative to the pressing platform, so as to prevent the upper punch from deviating from the mold cavity and causing damage to the upper punch or the mold cavity.

The invention has the beneficial effects that:

the automatic pressing device for the powder materials comprises an automatic part taking device, so that the pressed products are taken away automatically, and the powder pressing products are prevented from being broken and damaged due to improper operation when the parts are taken manually by a person.

The automatic pressing device for the powder materials further comprises an automatic feeding device and a feeding device, so that the powder materials can be automatically and quantitatively added into the die cavity, the requirement of batch injection of multiple layers of powder materials is met, the labor cost is reduced, the accurate control of the adding amount of the powder materials is improved, the production automation degree and the production efficiency are improved, the proportion of manual participation is reduced, the problems of inaccurate feeding, part taking damage and the like caused by human factors are avoided, the yield is improved, and the quality stability of products is effectively ensured.

The invention can pre-press the powder before the powder is added into the die cavity H in the pre-pressing feeding barrel, and the components are relatively fixed by pre-pressing, so that the component segregation caused by large specific gravity/particle size difference of the components in the powder is prevented, the consistency of the components of each part in the press-formed blank is facilitated, and the quality and the performance of the final sintered product are improved.

Drawings

Fig. 1 is an overall schematic view of an automatic compacting apparatus for powder materials according to an embodiment of the present invention.

Fig. 2 is a schematic top view of an apparatus for automatically compacting powder material according to an embodiment of the present invention, including an upper die plate and a compacting platform.

Fig. 3 is a schematic view of an automatic feeding device in an automatic pressing device for powder material according to an embodiment of the present invention.

Fig. 4 is a schematic view of a release agent spraying apparatus in the automatic compacting apparatus for powder materials according to the embodiment of the present invention.

Fig. 5 is a schematic view of a feeding device of an automatic pressing device for powder material according to an embodiment of the present invention.

Detailed Description

For the purpose of better explaining the present invention and to facilitate understanding, the present invention will be described in detail by way of specific embodiments with reference to the accompanying drawings.

Referring to fig. 1, the overall schematic diagram of the automatic powder material pressing apparatus according to the embodiment of the present invention includes a forming mold frame 20, wherein the forming mold frame 20 includes a pressing platform 21, an intermediate mold plate 22 and a lower mold plate 23, two ends of the intermediate mold plate 22 are fixed to a bottom bracket 40 (the bottom bracket 40 may be fixed to the ground or other work base surface), the pressing platform 21 and the lower mold plate 23 are respectively disposed above and below the intermediate mold plate 22 and are fixedly connected to each other by a pull rod L1, the pull rod L1 penetrates through a through hole of the intermediate mold plate 22 and is not fixedly connected to the intermediate mold plate 22, a first pushing cylinder 24 is disposed between the intermediate mold plate 22 and the lower mold plate 23, two ends of the first pushing cylinder 24 are respectively connected to the intermediate mold plate 22 and the lower mold plate 23, so that the pressing platform 21 can linearly move up and down by the extension and retraction of the first pushing cylinder 24 and cooperate with the guiding function of the pull rod L1, at least one mold cavity H is disposed on the pressing platform 21, the mold cavity H is a hole penetrating through the cylindrical through hole, and the middle mold plate 3922 is disposed corresponding to the lower mold cavity 221, and the stamping section of the lower mold plate 221 is matched.

An upper die plate 30 is provided above the press platform 21. The upper die plate 30 may be in an assembled relationship with the molding frame 20 or the upper die plate 30 may be a separate independent component from the molding frame 20. The upper die plate 30 has an upper punch 31 corresponding to the cavity H on the lower bottom surface thereof, and the upper punch 31 has a cross section (the same as the cross section of the lower punch 221) matching the cavity H. The upper die plate 30 is provided with a second pushing cylinder 34 for driving, and the upper die plate 30 can be linearly lifted up and down relative to the pressing platform 21 by virtue of the linear motion of extension and retraction of the second pushing cylinder 34. Preferably, in this embodiment, the guide posts 211 are fixed on the pressing platform 21, the upper die plate 30 is provided with the guide cylinders 301 which are matched with the guide posts 211, and the upper die plate 30 is further guided to vertically move up and down relative to the pressing platform 21 through the sliding matching action of the guide cylinders 301 and the guide posts 211, so as to prevent the upper punch 31 from deviating from the die cavity H, and the adverse result that the upper punch 31 is broken and the die cavity H is damaged is avoided.

Referring to fig. 1 to 2, the pressing platform 21 is provided with linear rails R1 and R2, and the linear rails R1 and R2 are disposed on two sides of the mold cavity H in parallel and symmetrically. At least one slide block is arranged on the linear track R1 and/or the linear track R2, as shown in FIG. 2, the number of the slide blocks in the embodiment is 4, 2 first slide blocks 51, 1 second slide block 52 and 1 third slide block 53. In other embodiments, the number of the sliding blocks is 2 or more, and the sliding blocks are respectively arranged corresponding to the number of the automatic part taking devices, the automatic feeding devices and the release agent spraying devices. The first slider 51 of the R1 and the first slider 51 of the R2 are connected to one holding arm 61, respectively, and the end of each holding arm 61 is connected to the concave pick-up block 611. Wherein each clamping arm 61 is driven by a third pushing cylinder 64; specifically, the clamping arm 61 is configured as a piston rod of the third pushing cylinder 64 or is linearly connected with the piston rod. The third pushing cylinder 64, the clamping arm 61 and the concave part taking block 611 at the end part of the clamping arm form an automatic part taking device 60. After the powder press forming part in the die cavity H is pressed, the pressing platform 21 moves downwards to expose the forming part, the first sliding blocks 51 on the left and right linear rails R1 and R2 move to the positions opposite to the die cavity H, the third pushing cylinder 61 extends, the two clamping arms 61 approach to the forming part from two sides and clamp the forming part, and the powder press forming part is moved away along with the movement of the first sliding blocks 51, so that the purpose of automatically taking the forming part is achieved.

As shown in fig. 2, the first slider 51, the second slider 52, the third slider 53, and the like are driven by a horizontal driving device 50 (the horizontal driving device 50 on the side of the rail R1 is not shown) provided on one side of the linear rail R1 or R2 to drive the first, second, and

third sliders

51, 52, 53 to slide back and forth along the linear rail R1 or R2. The horizontal driving means 50 may be a telescopic cylinder fixed at one end of the pressing platform 21, or a combination device including a motor, a gear and a toothed belt. In the present embodiment, the latter mode is implemented, and each of the first, second, and

third sliders

51, 52, and 53 is provided with a rack that engages with a rack belt. The concave pick-up block 611 has an arc-shaped opening to match the cross-sectional shape of the press-formed part, so as to stably clamp the pick-up block and prevent the loss of the press-formed part. Preferably, the outer surface of the concave pick-up block 611 is provided with a layer of rubber buffer layer or is made of rubber as a whole, so as to further ensure that the pressed product is not damaged when picking up the piece. Wherein, automatic get a device 60 and can also the metal backplate of a suppression clutch blocks of centre gripping, put it into die cavity H, consequently automatic get a device 60 and still have reinforced function. In addition, a group of automatic picking devices 60 can be additionally arranged, or a manipulator which slides along the linear track R1 or R2 can be independently arranged for grabbing the metal back plate and the like, so as to replace the operation of manually adding the metal back plate.

Referring to fig. 1, a demolding protection device 35 is disposed between the second pushing cylinder 34 and the upper mold plate 30, and is a middle cylinder, a cylinder body of the middle cylinder is connected to a piston rod of the second pushing cylinder 34, and the piston rod of the middle cylinder is connected to the upper mold plate 30. The middle cylinder plays a role in demoulding and pressure maintaining.

Further, an upper limiting device is arranged between the upper die plate 30 and the pressing platform 21, the upper limiting device comprises a buffering limiting cylinder 321 arranged on the edge of the upper die plate, the buffering limiting cylinder 321 comprises a cylinder body 3211, a piston rod 3212 and an adjusting bolt 3213, the cylinder body 3211 is mounted on the upper die plate 30, and the lower end of the piston rod 3212 is in threaded connection with the adjusting bolt 3213. According to the specific requirement of the distance between the upper template and the pressing platform, the distance between the lower end of the adjusting bolt 3213 and the upper template 30 is adjusted to achieve the purpose of limiting the distance.

Furthermore, a lower limiting device is arranged between the pressing platform 21 and the middle template 22, and comprises a lateral limiting cylinder horizontally mounted on the middle template 22, a cylinder body 2231 of the lateral limiting cylinder is fixed on the middle template 22, the end of a piston rod 2232 of the lateral limiting cylinder is connected with a limiting slide block A, and a limiting block B corresponding to the limiting slide block A is mounted on the lower bottom surface of the pressing platform 21 so as to achieve the purpose of limiting the distance. The limiting slide block A can be replaced according to actual needs.

In addition, a position detecting device or a distance sensor, such as an infrared distance measuring sensor (not shown), may be disposed between the upper die plate 30 and the pressing platform 21, between the pressing platform 21 and the middle die plate 22 to help the worker to grasp the relative positions of the upper punch 31, the lower punch 221 and the die cavity H, so as to adjust the actual pressing volume of the die cavity H to the die cavity volume calculated according to the requirement of the pressed product and the loose density of the powder.

As shown in fig. 2 and 3, an automatic feeding device 70 is further mounted on the second slide block 52, and is fixedly connected to the second slide block 52 through a bracket 71. The automatic feeding device 70 comprises a pre-pressing feeding barrel 72, wherein the pre-pressing feeding barrel 72 comprises a barrel shell with two open ends, and the inner diameter of the barrel shell is smaller than that of the die cavity H. A pressure plate 721 matched with the inner cavity of the barrel shell is arranged above the barrel shell, a central column 722 is arranged in the center of the lower bottom surface of the pressure plate, and the pressure plate is controlled by a pre-pressing air cylinder 723 to move up and down. The bottom of the barrel shell is provided with a bottom plate 724 which is opened when the bottom plate bears a pressure exceeding a certain threshold value, so that the powder in the barrel shell is pre-extruded into a cylindrical body, leaks out of the bottom of the barrel shell and falls into the die cavity H. When the mold cavity H is charged for the next molding after the molding of one powder compact is completed and the molding is removed, the second slide 52 is moved by the horizontal driving device 50 to a position aligned with the mold H, and the bottom of the preliminary pressing charging barrel 72 is aligned with the mold cavity H and is charged. By pre-extruding the powder material into a dough in the pre-pressing feeding barrel 72, the serious consequences that the ingredients in the pressed green body are segregated and the performance of the final sintered finished product is poor due to the fact that the ingredients in the powder material are obviously layered due to large specific gravity and grain size differences in the process of falling into the die cavity H is avoided.

Preferably, a pressure sensor (not shown) and a base plate driving device 725 are disposed on the base plate 724. The floor drive 725 may be a small telescopic cylinder. The bottom plates are symmetrically jointed left and right to close the lower part of the barrel shell, when the pressure of the blank in the barrel shell on the bottom plate 724 reaches a certain preset value, the bottom plates on the left side and the right side are separated to two sides, the bottom of the barrel shell is opened, and the powder pre-pressed into a column shape leaks out from the bottom of the barrel shell. In order to adapt to the structure of the mold cavity H (because the final product has through holes, the mold cavity H or the lower punch 221 needs to be provided with corresponding structures), a central column 722 is arranged on the central lower bottom surface of the pressing plate 721, and the outer diameter of the central column 722 is larger than that of the mold columns in the mold cavity H, so that the powder formed by prepressing can accurately fall into the proper position in the mold cavity H.

As shown in fig. 5, the present invention further includes a feeding device for quantitatively feeding the material to the automatic feeding device 70 for further accurate quantitative feeding. The feeding device comprises a constant volume feeding pipe 81 and an automatic weighing instrument 82. The constant volume feeding pipe 81 includes a vertically disposed powder storage pipe 811, an upper opening of which is correspondingly connected to the large-capacity powder bin 83, and a lower opening of which is correspondingly connected to the automatic weighing apparatus 82. The opening parts at the two ends of the powder storage pipe 811 are respectively provided with an upper pneumatic butterfly valve 811A and a lower pneumatic butterfly valve 811B, and the two pneumatic butterfly valves are turned and opened alternately at intervals and for a while when the powder is supplied with constant volume. In actual production, the pipe diameter of the powder storage pipe 811, the height between the upper pneumatic butterfly valve and the lower pneumatic butterfly valve and the turning time interval of the two pneumatic butterfly valves are adaptively replaced and controlled according to powder required by a molded blank to be pressed and molded, so that constant-volume feeding is realized. The upper pneumatic butterfly valve 811A and the lower pneumatic butterfly valve 811B are driven by a micro cylinder to realize overturning respectively, and the micro cylinder is connected with a gas station, which is the prior art and is not described herein.

Wherein, the feed inlet of automatic weighing instrument 82 is correspondingly arranged at the lower end of powder storage pipe 811, and the discharge outlet of automatic weighing instrument 82 is correspondingly connected with one end of pre-pressing charging barrel 72 opposite to discharge outlet 721. The automatic weighing instrument 82 is provided with a display screen for displaying a weighing result or a device for reporting a number in language and the like, and is used for checking whether the weight conveyed by the constant volume feeding pipe 81 is accurate or not, and sending a corresponding prompt when the powder amount is found to be obviously insufficient or excessive so as to make proper adjustment and control. The automated weighing apparatus 82 has an electronic scale with a weight sensor at the bottom and a controllably closable valve at the bottom of its container holding the material. Wherein, the upper and lower both ends of constant volume feed pipe 81 pass through quick-operation joint with powder storehouse 83 and automatic weighing appearance 82 respectively and are connected.

In order to reduce the lifting load of the pressing platform 21, the feeding device may be disposed on a bracket 84 on one side of the pressing platform 21, the bracket 84 may be disposed independently of the pressing platform 21, for example, may be disposed on the ground beside the forming mold frame 20, and the bottom of the automatic weighing device 82 may be connected to the pre-pressing material feeding barrel 72 through a screw feeder. In order to reduce the component segregation caused by the large specific gravity and particle size difference of different components in the powder when the powder is delivered from the automatic weighing instrument 82 to the pre-pressing feed barrel 72, the invention preferably adopts a screw feeder for delivery, the screw pitch of the screw feeder is preferably 0.5 cm-5 cm, and the denser screw pitch can reduce the component segregation of the powder. The powder which is measured well and needs to be conveyed into the pre-pressing feeding barrel 72 is conveyed in a differentiated mode in a multi-section cutting mode through the screw feeder, bubbles or air sections inside the powder in the conveying pipe are reduced, the component segregation phenomenon of the powder is relieved, and the improvement of the uniformity of powder components of each part of the press-formed blank is facilitated.

In some embodiments, the powder bin 83 is suspended by a truss in a reciprocating manner, the constant-volume feeding pipe 81 and the automatic weighing apparatus 82 are sequentially connected below the powder bin 83 from top to bottom, and the bottom of the automatic weighing apparatus 82 is connected to the pre-pressing feeding barrel 72 through a connecting pipe with a very smooth inner wall and a large inclination angle. Preferably, the hopper 83 is reciprocally moved in synchronization with the second slider 52.

Referring to fig. 2 and 4, a release agent spraying device 90 is mounted on the third slide block 53, and as shown in fig. 2, the automatic feeding device 70, the automatic pickup device 60 and the release agent spraying device 90 are arranged in sequence from front to back. The release agent spraying device 90 includes a nozzle 91 for spraying the release agent downward, the nozzle 91 being fixedly connected to the second slider 52 by a connecting arm 911, and a hose 92 having one end connected to the nozzle 91 and the other end connected to a release agent tank. The spray head 91 may spray the release agent onto the surface of the pressed powder compact. The release agent serves to promote smooth separation of the cured article from the mold cavity H, resulting in a smooth, flat article.

It should be noted that the connecting arm 911 connected to the third slider 53 and the bracket 71 connected to the second slider 52 can be both configured to be connected to the telescopic cylinder, and the connecting arm 911 can be used for supporting and routing the hose 92.

The production process for performing powder compression molding by using the automatic pressing device for the powder material comprises the following process steps:

(1) adjusting the mold cavity: and calculating the actual working volume of the die cavity H according to the specification of the friction block to be pressed and the powder bulk density, so that the first pushing cylinder 24 can adjust the relative position of the lower punch 221 on the middle template 22 relative to the die cavity H in a lifting manner and move to a preset position.

(2) Injecting materials: in packing into the large capacity powder storehouse 83 respectively with a large amount of clutch blocks powder and transition layer powder, weigh quantitative clutch blocks powder and transition layer powder respectively by automatic weighing instrument 82 and get into two pre-compaction charging barrels 72, move to die cavity H top in proper order through two pre-compaction charging barrels 72 of horizontal drive device 50 drive, stripper 722 is opened to the cylinder 723 of unloading, make clutch blocks powder and transition layer powder pour into die cavity H in proper order in, get a metal backplate of device 60 centre gripping again by the automation, place the powder top layer in the die cavity H, accomplish and annotate the material.

(3) Pressing: after the material injection action is completed, the relative positions of the upper and

lower punches

31 and 221 and the die cavity H are detected through a position detection device or a distance sensor and an upper and lower limiting device, a proper relative position is reached under the second pushing cylinder 34, the second pushing cylinder 34 drives the upper die plate 30, the powder material in the die cavity H is molded and pressurized by the upper punch 31, and automatic demolding is started after the set pressure maintaining pressure and pressure maintaining time are reached.

(4) Demolding: after the pressure maintaining is finished, the demolding protection device 35 continues to press the upper mold plate 30, then the pressed piece is exposed out of the mold cavity H under the action of the first pushing cylinder 24, the upper mold punch 31 automatically returns, and the pressed piece is clamped and moved out by the clamping arm 61 of the automatic piece taking device 60.

(5) Spraying a release agent: after the workpiece is taken out, the mold release agent is sprayed into the mold cavity H through the nozzle 91 of the mold release agent spraying device 90.

The automatic pressing device for the powder materials is used for pressing and forming the powder materials, can be used for manufacturing friction blocks, and has the technical effects of greatly reducing the labor cost, improving the product yield, improving the product quality stability and improving the production efficiency.

Claims

1. An automatic pressing device for powder materials, comprising:

the pressing platform is provided with a linear track, the linear track is provided with at least one sliding block capable of sliding relative to the linear track, an automatic workpiece taking device is installed on the sliding block, the automatic workpiece taking device comprises a clamping arm and a third pushing cylinder, and the end part of the clamping arm is connected with a concave workpiece taking block; the clamping arm is driven by the third pushing cylinder to enable the clamping arm to approach or depart from the mold cavity; the sliding block is driven by a horizontal driving device, the horizontal driving device is arranged on one side of the linear track, and the horizontal driving device drives the sliding block to slide along the linear track;

an automatic feeding device is further mounted on the sliding block and comprises a prepressing feeding barrel, the prepressing feeding barrel comprises a barrel shell with two open ends, and the inner diameter of the barrel shell is smaller than that of the die cavity; a pressing plate matched with the inner cavity of the barrel shell is arranged above the barrel shell, a central column is arranged in the center of the lower bottom surface of the pressing plate, and the pressing plate is controlled by a pre-pressing cylinder to move up and down; the bottom of the barrel shell is provided with a bottom plate, the bottom plate is opened when the bottom plate bears a pressure threshold value, so that the powder in the barrel shell is pre-extruded into a cylindrical body and leaks out of the bottom of the barrel shell and falls into the die cavity, and the pressure threshold value is 5% -10% of the pressing pressure.

2. An apparatus for automatically compacting powder material according to claim 1, wherein said pair of linear rails are provided on both sides of said die cavity, and said pair of holding arms are provided on said pair of linear rails, respectively.

3. An apparatus for automatically compacting powder material according to claim 2, wherein said concave pick-up blocks are preferably formed with a circular arc shaped opening, so that a pair of concave pick-up blocks can be clamped exactly on both sides of a cylindrical compact for a stable clamping.

4. The automatic compaction device for powder materials according to claim 1 further comprising a feeding device that feeds the automatic feeding device quantitatively; the feeding device comprises a constant-volume feeding pipe, the constant-volume feeding pipe comprises a vertically arranged powder storage pipe, an opening at the upper end of the constant-volume feeding pipe is correspondingly connected with the powder bin, and an opening at the lower end of the constant-volume feeding pipe is connected with the pre-pressing feeding barrel through a spiral feeder; an upper pneumatic butterfly valve and a lower pneumatic butterfly valve are respectively arranged at openings at two ends of the powder storage pipe, and the screw pitch of the spiral feeder is 0.5 cm-5 cm.

5. The apparatus according to claim 4, wherein the feeding device further comprises an automatic weighing device, the automatic weighing device comprises a feeding port and a discharging port, the feeding port of the automatic weighing device is correspondingly disposed at the lower end of the powder storage tube, and the discharging port of the automatic weighing device is correspondingly connected to the upper end of the pre-pressing charging barrel.

6. The automatic press for powder materials according to claim 1, wherein a release agent spraying device is further installed on the slide block, and the automatic picking device is located between the automatic feeding device and the release agent spraying device; the release agent spraying device comprises a spray head for spraying the release agent downwards, and the spray head is fixedly connected to the sliding block through a connecting arm.

7. The apparatus for automatically compacting powder material as claimed in claim 1, wherein a de-molding protection device is disposed between the second pushing cylinder and the upper mold plate, the de-molding protection device is a middle cylinder, a cylinder body of the middle cylinder is connected to a piston rod of the second pushing cylinder, and a piston rod of the middle cylinder is connected to the upper mold plate.

8. The automatic powder material pressing device according to claim 1, wherein an upper limiting device is disposed between the upper die plate and the pressing platform, the upper limiting device comprises a buffering limiting cylinder disposed on the edge of the upper die plate, the buffering limiting cylinder comprises a cylinder body, a piston rod and an adjusting bolt, the cylinder body is mounted on the upper die plate, and the lower end of the piston rod is in threaded connection with the adjusting bolt.

9. The apparatus for automatically compacting powder material according to claim 1, wherein the compacting platform has guide posts fixed thereon, and the upper mold plate has guide cylinders engaged with the guide posts, and the guide cylinders are slidably engaged with the guide posts to guide the upper mold plate to vertically move up and down with respect to the compacting platform.