Hot pressing furnace for sintering friction material

Abstract

The utility model discloses a hot pressing furnace for sintering friction materials, which adopts an upper pressurizing mechanism and a lower pressurizing mechanism to synchronously and bidirectionally pressurize a hearth and a bottom plate, and is matched with three-point pressure detection, so that the pressure control is more accurate, and the consistency of the thickness of a workpiece is obviously improved; by adopting the multi-station design, the vacancy time of the hearth is shortened, and the heat efficiency is improved by more than 30%; the lifting stability of the hearth is improved by combining four-stand-column guiding with a counterweight mechanism, and the risk of inclination of the hearth is eliminated; a PLC is matched with a servo system to achieve full-process precise control, the automation degree is improved, the problems that traditional equipment is low in forming precision and poor in efficiency are solved, and the device is suitable for batch production of high-performance friction materials.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of hot-pressing furnaces for sintering friction material, belong to superhard material sintering forming technical field. BACKGROUND

[0002] Hot-pressing furnace is widely used in the hot-pressing sintering of hard alloy, functional ceramics, powder metallurgy and other materials. The traditional hot-pressing furnace is mostly gantry bell-type furnace or one-way pressing hot-pressing furnace, which can only apply force in one direction (usually downward), resulting in poor uniformity of workpiece thickness, and it is difficult to accurately control due to the lack of pressure detection points. In addition, the furnace chamber has poor lifting stability and is easy to deviate. Single-station loading results in long sintering cycle and severe heat loss. SUMMARY

[0003] To solve the above problems, the utility model provides a kind of hot-pressing furnace for friction material special use with double oil cylinder synchronous pressing, high-precision pressure control and multi-station loading and unloading, to improve workpiece consistency, energy efficiency and safety.

[0004] The hot-pressing furnace of the utility model includes a rack, a furnace body, a bidirectional pressing mechanism, a multi-point pressure detection device and a controller. The rack includes a fixedly arranged upper beam and a lower beam, and a guide mechanism is arranged between the upper beam and the lower beam. The furnace body includes a furnace chamber and a bottom plate, which are driven by the bidirectional pressing mechanism to rise and fall on the guide mechanism. The bidirectional pressing mechanism includes an upper pressing mechanism and a lower pressing mechanism. The upper pressing mechanism includes an upper pressing cylinder fixedly connected to the upper beam, and its output end is fixedly connected to the furnace chamber. The lower pressing mechanism includes a lower pressing cylinder fixedly connected to the lower beam, and its output end is fixedly connected to the bottom plate. The upper pressing cylinder, the lower pressing cylinder and the pressure detection device are connected to the controller and controlled by the controller to synchronize their actions. The upper and lower pressing mechanisms apply pressure simultaneously during sintering, ensuring uniform stress on the workpiece.

[0005] Preferably, the upper pressing cylinder and the lower pressing cylinder are servo hydraulic cylinders.

[0006] Preferably, the controller is a PLC.

[0007] The multi-point pressure detection device includes a pressure sensor one for detecting the pressure of the upper pressing cylinder, a pressure sensor two for detecting the pressure of the lower pressing cylinder, and a pressure sensor three for detecting the force between the upper pressing cylinder and the furnace chamber. The pressure sensor three is a mechanical tension and compression sensor.

[0008] Preferably, a counterweight mechanism is further arranged on the upper beam, comprising a fixed pulley, a steel wire rope and a counterweight, the steel wire rope is wound around the fixed pulley, and two ends thereof are connected with the hearth and the counterweight respectively, and the weight of the counterweight is the same as that of the hearth. The dead weight of the hearth is balanced through the counterweight mechanism, the load of the upper pressing cylinder is reduced, the actual output force of the upper pressing cylinder, that is, the actual pressure received by the workpiece, is measured by the pressure sensor three, and the data of the pressure sensor one and the pressure sensor two can play a comparison and correction role, and the closed-loop control precision of the pressing system reaches ±10 kg.

[0009] Further, three in-out car mechanisms are arranged around the furnace body, each in-out car mechanism comprises a driving chain, and the driving chain is detachably clamped and matched with the trolley. Under the control of the controller, the in-out car mechanism can automatically send the trolley to the bottom plate or unload the trolley from the bottom plate. The three in-out car mechanisms are arranged in three directions on the side of the furnace body, and the intermittent time of loading and unloading the furnace is greatly shortened through rotation loading and unloading circulation, so that the working efficiency is improved and the heat loss is reduced.

[0010] Preferably, pressure heads are arranged on the hearth and the trolley respectively, and the pressure head on the trolley adopts a double-layer heat insulation pressure head, so that the heat loss during work is further reduced.

[0011] Preferably, an air pipe is arranged on the trolley and used for injecting protective gases such as nitrogen and hydrogen.

[0012] Preferably, the driving chain is driven by a servo motor.

[0013] Further, the guide mechanism comprises four vertical columns which are uniformly arranged around the furnace body.

[0014] Further, a rotary hoisting mechanism is arranged on the upper beam, comprising a hoisting arm rotatably arranged on the upper beam and a hoisting mechanism movably arranged on the hoisting arm, and the hoisting mechanism can be controlled by wireless remote control, so that the hearth is convenient to maintain.

[0015] The application is more accurate in pressure control through bidirectional pressing and three-point position pressure detection, and the deviation of the thickness of the workpiece is significantly improved (≤0.1 mm); the multi-station design reduces the idle time of the hearth, and the thermal efficiency is improved by more than 30%; the four vertical column guide cooperates with the counterweight mechanism to improve the stability of the hearth lifting, and the risk of hearth inclination is eliminated; the PLC cooperates with the servo system to realize accurate control of the whole process, and the automation degree is improved. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a structural schematic view of the utility model;

[0017] Figure 2 It is a side view of the utility model;

[0018] Figure 3 It is a top view of the utility model.

[0019] Explanation of reference numerals in the drawings:

[0020] 1 - upper beam, 2 - lower beam, 3 - column, 4 - hearth, 5 - bottom plate, 6 - upper pressing cylinder, 7 - lower pressing cylinder, 8 - pressure sensor one, 9 - pressure sensor two, 10 - pressure sensor three, 11 - fixed pulley, 12 - steel wire rope, 13 - counterweight, 14 - in-out car mechanism, 15 - trolley, 16 - rotary hoisting mechanism. DETAILED DESCRIPTION

[0021] The hot-pressing furnace of the utility model includes frame, furnace body, multi-point pressure detection device, bidirectional pressing mechanism and controller, the frame includes fixedly arranged upper beam 1 and lower beam 2, the upper beam 1 and the lower beam 2 are provided with guide mechanism 3 between, the furnace body includes hearth 4 and bottom plate 5, the hearth 4 and the bottom plate 5 are driven by bidirectional pressing mechanism and respectively ascend and descend on the guide mechanism 3, the bidirectional pressing mechanism includes upper pressing mechanism and lower pressing mechanism, the upper pressing mechanism includes upper pressing cylinder 6 fixedly connected with the upper beam 1, and the output end is fixedly connected with the hearth 4, the lower pressing mechanism includes lower pressing cylinder 7 fixedly connected with the lower beam 2, and the output end is fixedly connected with the bottom plate 5, the upper pressing cylinder 6, the lower pressing cylinder 7 and the pressure detection device are connected with the controller, and the synchronous action is controlled by the controller, and the pressure is applied simultaneously up and down when sintering, and the uniform stress of workpiece is ensured.

[0022] Preferably, the upper pressing cylinder 6 and the lower pressing cylinder 7 are both servo hydraulic cylinders.

[0023] Preferably, the controller is PLC.

[0024] The multi-point pressure detection device includes pressure sensor one 8 for detecting the pressure of the upper pressing cylinder 6, pressure sensor two 9 for detecting the pressure of the lower pressing cylinder 7 and pressure sensor three 10 for detecting the force between the upper pressing cylinder 6 and the hearth 4, and the upper oil cylinder pressure, the lower oil cylinder pressure and the pressure at the upper oil cylinder connection are monitored respectively, wherein the pressure sensor three 10 is a mechanical tension-compression sensor.

[0025] Preferably, the upper beam 1 is further provided with counterweight 13 mechanism, including fixed pulley 11, steel wire rope 12 and counterweight 13, the steel wire rope 12 passes through the fixed pulley 11, and two ends are connected with the hearth 4 and the counterweight 13 respectively, and the weight of the counterweight 13 is same with that of the hearth 4. The self weight of the hearth 4 is balanced by the counterweight 13 mechanism, the load of the upper pressing cylinder 6 is reduced, and the output force of the upper pressing cylinder 6, that is, the actual pressure of the workpiece, is measured by the pressure sensor three 10. The data of the pressure sensor one 8 and the pressure sensor two 9 can play the role of comparison and correction, and the closed-loop control precision of the pressing system reaches ±10kg.

[0026] Furthermore, three loading / unloading mechanisms 14 are arranged around the furnace body. Each loading / unloading mechanism 14 includes a drive chain, which is detachably engaged with the trolley 15. Under the control of the controller, the loading / unloading mechanism 14 can automatically deliver the trolley 15 onto the bottom plate 5 or unload it from the bottom plate 5. The three loading / unloading mechanisms 14 are arranged in three directions on the side of the furnace body. Through alternating loading and unloading cycles, the interval time between loading and unloading is greatly shortened, improving work efficiency while reducing heat loss.

[0027] Preferably, pressure heads are provided on the furnace 4 and the trolley 15 respectively. The pressure heads on the trolley 15 are double-layered heat-insulated pressure heads, which further reduces heat loss during operation.

[0028] Preferably, the trolley 15 is equipped with a ventilation pipe for injecting protective gases such as nitrogen and hydrogen.

[0029] Preferably, the drive chain is driven by a servo motor.

[0030] Furthermore, the guide mechanism 3 consists of four columns, evenly arranged around the furnace body.

[0031] Furthermore, a rotating hoisting mechanism 16 is provided on the upper beam 1, including a boom that is rotatably installed on the upper beam 1 and a hoisting mechanism that is movably installed on the boom. The hoisting mechanism can be controlled by wireless remote control, which is convenient for the maintenance of the furnace 4.

[0032] The working process for this application is as follows:

[0033] Loading stage: The workpiece is placed in the trolley, and the PLC controls the chain to push the trolley into the furnace working position, and the bottom plate rises to close the furnace.

[0034] Sintering stage: The upper and lower pressure cylinders are pressurized synchronously, three pressure sensors provide real-time feedback, and the servo hydraulic system dynamically adjusts the pressure and speed;

[0035] Unloading stage: After sintering, the bottom plate is lowered, and the PLC controls the chain to pull the trolley to move out automatically. The trolley on the other side enters simultaneously to achieve continuous production.

Claims

1. A hot-pressing furnace for sintering friction materials, comprising a frame, a furnace chamber, a bottom plate, a bidirectional pressing mechanism, a multi-point pressure detection device and a controller, the frame comprising a fixedly arranged upper beam and a fixedly arranged lower beam, a guide mechanism being arranged between the upper beam and the lower beam, characterized in that, The hearth and the bottom plate are driven by a bidirectional pressing mechanism to ascend and descend on a guide mechanism; the bidirectional pressing mechanism comprises an upper pressing mechanism and a lower pressing mechanism, the upper pressing mechanism comprises an upper pressing cylinder fixedly connected with an upper beam, and an output end of the upper pressing cylinder is fixedly connected with the hearth; the lower pressing mechanism comprises a lower pressing cylinder fixedly connected with a lower beam, and an output end of the lower pressing cylinder is fixedly connected with the bottom plate; the multi-point pressure detection device comprises a pressure sensor one for detecting the pressure of the upper pressing cylinder, a pressure sensor two for detecting the pressure of the lower pressing cylinder, and a pressure sensor three for detecting the acting force between the upper pressing cylinder and the hearth; the upper pressing cylinder, the lower pressing cylinder, the pressure sensor one, the pressure sensor two and the pressure sensor three are connected with a controller, and the controller controls the upper pressing cylinder and the lower pressing cylinder to synchronously act.

2. The hot press furnace of claim 1, wherein, The upper pressing cylinder and the lower pressing cylinder are both servo hydraulic cylinders.

3. The hot press furnace of claim 1, wherein, The pressure sensor three is a mechanical tension and compression sensor.

4. The hot press furnace of claim 1, wherein, The guide mechanism is four vertical columns, and a counterweight mechanism is further arranged on the upper beam, the counterweight mechanism comprises a fixed pulley, a steel wire rope and a counterweight, the steel wire rope is wound around the fixed pulley, and two ends of the steel wire rope are respectively connected with the hearth and the counterweight, and the weight of the counterweight is the same as the weight of the hearth.

5. The hot press furnace according to any one of claims 1, 3, 4, wherein An in-out trolley mechanism is arranged around the furnace body, the in-out trolley mechanism comprises a driving chain, and the driving chain is detachably clamped with the trolley.

6. The hot press furnace of claim 5, wherein, The in-out trolley mechanism is provided with three trolleys, which are arranged in three directions on the side of the furnace body.

7. The hot press furnace of claim 6, wherein, A pressure head is arranged on the hearth and the trolley respectively, and the pressure head on the trolley is a double-layer heat insulation pressure head.

8. The hot press furnace of claim 6, wherein, An air pipe for injecting protective gas is arranged on the trolley.

9. The hot press furnace of claim 6, wherein, The driving chain is driven by a servo motor, and the servo motor is connected with the controller.

10. The hot press furnace of claim 1 or 3, wherein A rotary hoisting mechanism is arranged on the upper beam, the rotary hoisting mechanism comprises a hoisting arm rotatably mounted on the upper beam and a hoisting mechanism movably arranged on the hoisting arm.

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