WO2018045752A1

WO2018045752A1 - Near net shape forging and moulding method for railway vehicle coupler knuckle

Info

Publication number: WO2018045752A1
Application number: PCT/CN2017/080671
Authority: WO
Inventors: 陈庆敏; 岳岩
Original assignee: 吉林大学; 青岛中天鹏锻压制造有限公司
Priority date: 2016-09-10
Filing date: 2017-04-14
Publication date: 2018-03-15
Also published as: AU2017248490A1; AU2017248490B2; CN106141069A; US20180326472A1

Abstract

A near net shape forging and moulding method for a railway vehicle coupler knuckle, comprising the following steps: (a) preparing the material; (b) heating: heating blank material to 1150 ℃ ± 20 ℃; (c) pre-fabricating blanks: placing the heated blank material on an 800 tonne multi-directional forging device to implement multi-directional forging; (d) pre-forging blanks: implementing closed die forging of the pre-fabricated blanks in a pre-forging die on a 2000 tonne multi-directional forging device; (e) near net shape forging and moulding: implementing closed die forging of the pre-forged blanks in a multi-directional forging die on a 60000 tonne multi-directional forging device to achieve near net shape moulding; (f) thermal processing: using waste heat for performing tempering thermal processing of the forged blanks; (g) precision machining: using a numerical control machining machine to machine coupler knuckle pin holes; and (h) flaw detection: implementing magnetic powder flaw detection of the finished product. The present method uses closed die forging technology and can implement near net shaping of coupler knuckles, saving energy and materials, and solving the defects of air holes, shrinkage, inclusions, and cracks in existing cast coupler knuckles and the problems of complexity and shaping difficulties in existing manufacturing processes for cast coupler knuckles.

Description

Near-net forging method for railway vehicle coupler hook

Technical field

The invention belongs to the technical field of plastic forming of complex parts, and particularly relates to a method for forming a near-net forging of a hook of a railway vehicle.

Background technique

The railway vehicle coupler is the key component between the railway locomotive and the vehicle and the vehicle. The main part of the coupler part is the knuckle. Therefore, the knuckle is the key traction component of the railway vehicle. Its performance is directly related to the safety of the railway train. reliability. As the railway transportation in China continues to develop in the direction of high speed and heavy load, the longitudinal impact force of the train increases sharply, the friction and wear of the contact surface of the hook knuckle is serious, and the performance of the knuckle tongue has become more and more difficult to meet the requirements of modern railway transportation, which seriously affects Safety and efficiency of rail transport.

At present, the manufacture of crochet tongue is mainly based on casting molding, and the structural defects such as pores, slag inclusions, shrinkage holes, and looseness formed by the knuckle during the casting process are formed, and these defects form cracks under the action of alternating stress, causing direct fracture. The above phenomenon often occurs during use, and the loss is huge, which poses a serious threat to the operational safety of railway vehicles. Therefore, the forged knuckle has become the preferred knuckle for high-speed trains and heavy-duty trucks.

Due to the large change of the cross-section of the knuckle piece, the complicated shape and the difficulty of forming, there are thin ribs which are not easy to forge, and the forging is difficult, and few manufacturers can realize the forging type.

At present, the manufacturing method of forged knuckle is complicated, and it requires multiple heating, die forging and trimming, and the shape and size of the blank and the finished product after forging are very different, and must be processed into a knuckle product by means of mechanical processing. The shape and size, waste energy and materials, and high manufacturing costs.

Summary of the invention

The object of the invention is to solve the problems of difficulty in manufacturing forged hook tongues and complicated manufacturing process, and a method for near-net forging of the hooks of railway vehicle couplers is proposed. The manufacturing method of the present invention can be minimized The convenient process produces a high-precision forged crochet blank that achieves near-net, fast, and precision plastic forming of the forged crochet blank.

The technical solution of the present invention is as follows:

A method for near-net forging of a railway vehicle coupler hook, comprising the following steps:

a, material preparation: according to the product model, the corresponding specifications of the round steel with a band saw machine to intercept a certain length;

b, heating: using 1500KW medium frequency induction heating equipment to heat the billet to 1150 ° C ± 20 ° C;

c. Prefabricated blank: The heated blank is placed on a 800-ton multi-directional forging device for multi-forging, prefabricated blank;

d. Pre-forging of blank: The pre-formed blank is slid forged in a pre-forging die on a 2000-ton multi-directional forging equipment, and is pre-forged into a blank of a certain shape and size;

e, near net forging type: the pre-forged blank is placed in a 6,000-ton multi-directional forging equipment on the knuckle special multi-directional forging mold for occlusion forging, to achieve near net shape;

f, heat treatment: heat treatment of the forged blank after heat treatment;

g, finishing: using CNC machining special machine to process the grommets of the knuckles;

h. Detecting: Magnetic particle inspection of finished parts.

Among them, the shape and size of the blank in the step d are realized by the multi-directional forging equipment and the pre-forging blank mold.

Further, in step e, the vertical direction of the forged hook-and-loop multi-directional forging device has three cylinders of a main cylinder and an upper and a lower ejection cylinder; two cylinders are formed in the horizontal direction, and the left and right are formed and locked, and two cylinders are ejected. There are four cylinders in the cylinder.

Further, the multi-directional forging die in the step e is a forging crochet special mold; the mold adopts horizontal and vertical mixing and splitting mode, and the mold is composed of upper and lower molds and left and right molds; the left and right molds are embedded. The movable module is driven by the embedded cylinder to realize the forming of the forged knuckle weight reducing groove portion.

Further, in the step e, the left and right molds are respectively driven by the two cylinders in the multi-directional forging device to drive the mold clamping.

Further, in step e, the lower mold is fixed in the vertical direction, and the upper mold is driven by the main cylinder of the multi-directional forging equipment to block the extrusion blank.

Further, in the step e, the forged crochet workpiece after the clogging of the forged shape is ejected by the top, bottom, left and right ejection cylinders.

The movement speed of the master cylinder is steplessly regulated between 50 and 80 mm/sec; the amount of reduction is automatically controlled by the multi-directional forging equipment according to the molding state of the workpiece, so as to ensure that the deformation rate of the workpiece remains substantially unchanged throughout the molding process.

The beneficial effects of the invention are:

(1) The molding precision is high, the outer contour shape and size realize near net shape, no mechanical processing process is required, so the raw materials are saved (saving raw materials by more than 15%), and the machining workload is saved;

(2) Compared with the current forging method, the number of heating times and the forging process are reduced, energy is saved, and production efficiency is improved;

(3) Multi-directional occlusion forging near net forming technology, the workpiece is always in a three-direction stress state during the plastic deformation process, the formed workpiece is densely organized, the metal streamline distribution is reasonable, the bearing strength is greatly improved; the internal defect of the workpiece is zero, safety Reliability is guaranteed;

(4) Due to the simple process of forging, the auxiliary equipment is small, the yield is high, and it is easy to realize intelligent manufacturing;

(5) Compared with other forging methods, the production efficiency is increased by more than 4 times, and the production cost is reduced by about 50%.

DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic illustration of the process flow of the present invention.

Figure 2 is a schematic view showing the shape of a preform of the present invention;

Figure 3 is a schematic structural view of a pre-forging according to the present invention;

Figure 4 is a schematic view showing the structure of a near net shape forged crochet forging blank of the present invention;

Figure 5 is a schematic view showing the structure of the forged crochet of the present invention;

Figure 6 is a schematic view showing the structure of a near net shape occlusion forging die of the present invention.

detailed description

The invention will be further described below in conjunction with specific embodiments and the accompanying drawings.

As shown in FIG. 1-6, the method for forming a near-net forging of a railway vehicle coupler hook of the present invention comprises the following steps:

Step (a), material preparation: according to the product model, the corresponding specifications of the round steel with a band saw machine to intercept a certain length;

Step (b), heating: using a 1500KW medium frequency induction heating device to heat the billet to 1150 ° C ± 20 ° C;

Step (c), pre-formed blank: The heated blank is placed on an 800-ton multi-directional forging device for multi-forging, pre-formed blank.

Step (d), blank pre-forging: the pre-formed blank is slidably forged in a pre-forging die on a 2000-ton multi-directional forging equipment, and is pre-forged into a blank of a certain shape and size;

Step (e), near net forging type: The pre-forged blank is placed in a knuckle special multi-directional forging die on a 6,000-ton multi-directional forging machine for occlusion forging to achieve near-net forming.

Step (f), heat treatment: heat treatment is applied to the forged blank.

Step (g), finishing: using a CNC machining machine to machine the knuckle pin holes.

Step (h), flaw detection: magnetic particle inspection of the finished part.

In the above step (c), the preformed blank is carried out on a multi-directional forging device, in a vertical direction and a horizontal direction. When the mold is moved in the wrong time, the heated blank is made into a preform of a certain height and thickness in the shortest time, and the scale on the surface of the blank is removed.

In the above step (d), the pre-formed blank is placed in the pre-forging die of the multi-directional forging equipment, and the pre-forging die is divided into four parts of upper and lower, left and right, and the upper and lower parts are driven by the vertical direction cylinder of the multi-directional forging equipment, left, The right part of the mold is driven by the horizontal direction cylinder of the multi-directional forging equipment. The movement and movement distance of each part of the mold are controlled by the program. The movement of each part of the mold is terminated after the mold is closed, and the pre-formed blank is pre-forged into a certain shape and size.

In the above step (e), the near net shape of the coupler knuckle is realized by a multi-directional forging device and a multi-directional forging die. Multi-directional forging dies use horizontal and vertical mixing and splitting. After the pre-forging blank is placed in the multi-directional forging die, firstly, the two parts of the horizontal direction are driven by the horizontal direction cylinder of the multi-directional forging equipment, and the pre-forging blank is pressed, and the mold is locked after the left and right molds are closed. The upper part of the mold in the vertical direction moves rapidly downwards under the driving of the main cylinder. When the blank is coming into contact with the blank, the main cylinder turns to a slow motion, and the occlusion forging starts, the speed of the upper mold is infinitely adjustable and is programmed. Control, the whole forging process always keeps the deformation rate of the workpiece is basically the same; when the main cylinder pressure reaches the set value, the whole forging process ends, the upper mold is quickly retracted, and the cylinder is pushed up to keep the workpiece from moving upward with the upper mold, left and right molds The mold is opened and retracted, and then the lower mold is driven upward to drive out the workpiece under the driving of the lower ejection cylinder, thereby completing the near-net forging type.

In the above step (e), the hydraulic cylinder and the movable module are embedded in the horizontal direction of the multi-directional forging die. During the occlusion forging process, when the upper die moves downward to a certain position, the embedded hydraulic pressure is automatically started by the program control. The cylinder and the movable module realize partial forming of the weight reducing groove of the knuckle workpiece. At the same time as the quick return of the upper die, the embedded hydraulic cylinder starts to start the return stroke, and drives the active module to return. After the active module is returned to its original position, the left and right molds are retracted.

In the above step (f), after the workpiece is formed, heat treatment is performed using residual heat. Workpiece finish near net forging After the type is formed, the temperature is measured by the automatic temperature measurement system, and then enters the soaking furnace. The soaking furnace automatically raises or cools the workpiece according to the temperature measured by the automatic temperature measuring system and the quenching temperature. The time of the workpiece in the soaking furnace is automatically controlled by real-time monitoring with the automatic temperature measurement system of the furnace.

A specific embodiment of the method according to the invention is given below.

In this embodiment, the diameter is prepared according to the forged knuckle model.

The round bar material with a length of 405mm is heated to 1150 °C ± 20 °C. The heated billet is sent by the robot to the 800-ton multi-directional forging equipment for pre-formed blank, and the scale of the billet is removed. Figure 2 It is a schematic diagram of the shape of the preform. The manipulator then sends the preformed blank into the pre-forging die, and the multi-directional forging equipment prepares the preformed blank into a pre-forged piece of a certain shape and size. FIG. 3 is a schematic view of the structure of the pre-forging piece. Then, the pre-forged blank is transferred to the near net shape multi-directional occlusion forging die shown in FIG. 6 to realize the near net forging type of the coupler knuckle. The blank workpiece is homogenized by the residual heat of the formed blank, and then the quenching and tempering heat treatment is automatically performed. Fig. 4 is a schematic view showing the structure of a forged crochet blank after tempering and heat treatment, and Fig. 5 is a schematic view showing the finished structure of the forged crochet after machining and flaw detection.

The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit and scope of the invention. All changes are to be covered by the patent of the present invention.

Claims

A method for near-net forging of a railway vehicle coupler hook tongue, characterized in that the method comprises the following steps:

Step (a), material preparation;

Step (b), heating: heating the billet to 1150 ° C ± 20 ° C;

Step (c), prefabricated blank: the heated blank is placed on a 800-ton multi-directional forging device for multi-forging, prefabricated blank;

Step (d), blank pre-forging: the pre-formed blank is occluded forging in a pre-forging die on a 2000-ton multi-directional forging machine;

Step (e), near net forging type: embossing the pre-forged blank into a multi-directional forging die on a 6000-ton multi-directional forging machine to achieve near-net forming;

Step (f), heat treatment: heat treatment of the forged blank is subjected to heat treatment;

Step (g), finishing: using a CNC machining machine to process the grommets of the knuckle;

Step (h), flaw detection: magnetic particle inspection of the finished part.
The method for near-net forging of a railway vehicle coupler knuckle according to claim 1, wherein the pre-formed blank in the step (c) is performed on a multi-directional forging device, and the vertical direction and the horizontal direction die are moved in a wrong time, and the heating is performed. The post blank is made into a preformed blank of a certain height and thickness while removing scale from the surface of the blank.
The method according to claim 1, wherein in the step (d), the pre-formed blank is placed in a pre-forging die of the multi-directional forging device, and the pre-forging die is divided into upper and lower portions. The left and right parts, the upper and lower parts of the mold are driven by the multi-directional forging equipment vertical direction cylinder, and the left and right parts are driven by the multi-directional forging equipment horizontal direction cylinder, and the movement and movement distance of each part of the mold are controlled by the program. After the molds are closed, the movement of the parts is terminated, and the preforms are pre-forged into a certain shape and size.
A near-net forging method for a railway vehicle coupler hook according to claim 1, characterized in that In step (e), the near net shape of the coupler knuckle is realized by a multi-directional forging device and a multi-directional forging die;

The multi-directional forging die adopts horizontal and vertical mixing and splitting mode; after the pre-forged blank is placed in the multi-directional forging die, firstly, the horizontally left and right parts are driven by the horizontal direction cylinder driving of the multi-directional forging equipment, and the pre-forging blank is started. Extrusion, the mold is locked after the left and right molds are clamped; the upper mold portion of the vertical mold is rapidly moved downward under the driving of the main cylinder, and when the blank is coming into contact with the blank, the main cylinder is turned into a slow motion and begins to be occluded. Forging, the movement speed of the upper die is infinitely adjustable and controlled by the program. The entire forging process always keeps the deformation rate of the workpiece the same; when the pressure of the main cylinder reaches the set value, the whole forging process ends, the upper die quickly retracts, and the upper cylinder is moved upwards. Keeping the workpiece does not move upward with the upper mold, the left and right molds are opened and retracted, and then the lower mold is moved upwards and driven out under the driving of the lower ejection cylinder to complete the near-net forging type.
The method for near-net forging of a railway vehicle coupler knuckle according to claim 1, wherein in the step (e), the hydraulic cylinder and the movable module are embedded in the horizontal direction mold of the multi-directional forging die, in the process of occlusion forging, When the upper mold moves downward to a certain position, the embedded hydraulic cylinder is automatically started by the program control, and the movable module is pushed to realize partial forming of the weight reducing groove of the knuckle workpiece; while the upper mold is fast returning, the embedded hydraulic cylinder starts to start. The return trip drives the active module to return; after the active module is returned to the original position, the left and right molds are retracted.
The method for near-net forging of a railway vehicle coupler hook according to claim 1, wherein in step (f), after the workpiece is formed, heat treatment is performed by using residual heat; and the workpiece is finished by near-net forging and then passed through an automatic temperature measuring system. Temperature measurement is carried out, and then enters the soaking furnace; the soaking furnace automatically compares the temperature measured by the automatic temperature measuring system with the quenching temperature, and automatically raises or cools the workpiece; the time of the workpiece in the soaking furnace is automatically measured by the furnace. Real-time monitoring for automatic control.