CN106141069A - Railway vehicle truck coupler knuckle near net method for forging and molding - Google Patents

Abstract

The invention provides a near-clean forging forming method of a coupler knuckle of a railway vehicle, which solves the problems of difficulty in forging and forming of the coupler knuckle of a railway vehicle, complicated manufacturing process and the like. The method of the present invention includes the steps of material preparation, heating, prefabricated blank, pre-forging, closed forging, waste heat quenching and tempering heat treatment, finishing, flaw detection, etc., and the closed forging technology can make the knuckle realize near-net shape, save energy and materials, and The contour shape and size do not need to be machined, the material utilization rate can reach more than 92%, and the workpiece is always in a three-dimensional stress state during the entire forming process. Defects such as air holes, shrinkage, inclusions, and cracks in the cast knuckle, as well as problems such as complex manufacturing process and difficult forming of the existing forged knuckle; the invention has simple manufacturing process, high material utilization rate, and is suitable for various types of railway vehicle couplers. Mass production of tongue products.

Description

Near-clean forging forming method of coupler knuckle for railway vehicles

technical field

The invention belongs to the technical field of plastic forming of complex parts, and in particular relates to a near-clean forging forming method for coupler knuckles of railway vehicles.

Background technique

The coupler of a railway vehicle is a key part connecting the railway locomotive and the vehicle and the vehicle, and the main part of the coupler part is the knuckle, so the coupler is a key traction component of the railway vehicle, and its performance is directly related to the operation safety and quality of the railway train. reliability. With the continuous development of my country's railway transportation in the direction of high speed and heavy load, the longitudinal impact force of the train has increased sharply, the friction and wear of the coupler knuckle contact surface is serious, and the performance of the coupler knuckle has become more and more difficult to meet the requirements of modern railway transportation, seriously affecting the Safety and efficiency of rail transport.

At present, the manufacturing of the knuckle is mainly based on casting molding. The structural defects of the knuckle formed during the casting molding process, such as pores, slag inclusions, shrinkage cavities, looseness, etc., these defects form cracks under the action of alternating stress, resulting in direct fracture. The above phenomena often occur during use, causing huge losses and posing a serious threat to the operation safety of railway vehicles. Therefore, forged knuckles have become the first choice for high-speed trains and heavy-duty trucks.

Because the section of the knuckle changes greatly, the shape is complex, and forming is difficult, there are thin ribs that are not easy to forge, and its forging is difficult, so few manufacturers can achieve forging.

At present, the manufacturing method of forged knuckle is complicated, and it needs to go through multiple heating, die forging, trimming, and the shape and size of the blank after forging and the finished product are very different, so it must be processed into knuckle products by mechanical processing. The shape and size are too large, energy and materials are wasted, and the manufacturing cost is high.

Contents of the invention

The purpose of the present invention is to solve the difficult problems of forging knuckle manufacturing, complicated manufacturing process, etc., and proposes a method for near-clean forging of a railway vehicle coupler knuckle. By adopting the manufacturing method of the invention, a high-precision forged knuckle blank can be manufactured with the simplest process method, and the near-clean, rapid and precise plastic forming of the forged knuckle blank can be realized.

Technical scheme of the present invention is as follows:

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

a. Material preparation: According to the product model, use a band saw to cut the round steel of the corresponding specification to a certain length;

b. Heating: use 1500KW intermediate frequency induction heating equipment to heat the billet to 1150°C±20°C;

c. Prefabricated blank: place the heated blank on the 800-ton multi-directional forging equipment for multi-directional forging and prefabricate the blank;

d. Blank pre-forging: the pre-fabricated blank is closed forged in the pre-forging die on the 2000-ton multi-directional forging equipment, and pre-forged into a blank of a certain shape and size;

e. Near-net forging forming: place the pre-forged blank in the multi-directional forging mold dedicated to the knuckle on the 6,000-ton multi-directional forging equipment for closed forging to achieve near-net forming;

f. Heat treatment: use waste heat quenching and tempering heat treatment for the forged blank;

g. Finishing: Use CNC machining special machine to process knuckle pin holes, etc.;

h. Flaw detection: Conduct magnetic particle flaw detection on finished parts.

Wherein, the shape and size of the billet in step d are realized by multi-directional forging equipment and pre-forging billet molds.

Further, in step e, the vertical direction of the multi-directional forging equipment for forging knuckles has three oil cylinders, the main oil cylinder and the upper and lower ejection cylinders; the horizontal direction has two left and right forming and locking oil cylinders and two ejection cylinders. There are four oil cylinders in total.

Further, the multi-directional forging molding die in step e is a special die for forging the knuckle; the die adopts a horizontal and vertical mixed die splitting mode, and the die is composed of four parts: an upper die, a lower die, and a left and right die; the left and right dies are embedded with The movable module is driven by the built-in oil cylinder to realize the forming of the weight-reducing groove part of the forged knuckle.

Further, in step e, the left and right molds are respectively driven by two horizontal oil cylinders in the multi-directional forging equipment to close and lock the molds.

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

Further, in step e, the forged knuckle workpiece after closed forging is ejected by four ejecting cylinders up and down, left and right.

The movement speed of the main cylinder is steplessly regulated between 50-80mm/sec; the amount of reduction is automatically controlled by the multi-directional forging equipment according to the forming state of the workpiece to ensure that the deformation rate of the workpiece remains basically unchanged during the entire forming process.

The beneficial effects of the present invention are:

(1) The forming precision is high, and the shape and size of the outer contour can achieve near-net molding without machining process, so it not only saves raw materials (saving more than 15% of raw materials), but also saves the workload of machining;

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

(3) Multi-directional occluded forging near-net forming technology, the workpiece is always in a three-dimensional stress state during the plastic deformation process, the formed workpiece has a dense structure, the distribution of metal streamlines is reasonable, and the bearing strength is greatly improved; the workpiece has zero internal defects and is safe. , reliability is guaranteed;

(4) Due to the simple forging process, less auxiliary equipment and high yield, 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%.

Description of drawings

Fig. 1 is a process flow diagram of the present invention.

Fig. 2 is the schematic diagram of prefabricated blank shape of the present invention;

Fig. 3 is the structural representation of pre-forging of the present invention;

Fig. 4 is a schematic diagram of the structure of the forged knuckle near net shape forged knuckle of the present invention;

Fig. 5 is a schematic diagram of the structure of the finished forged knuckle of the present invention;

Fig. 6 is a schematic structural diagram of a near-net shape closed forging die of the present invention.

detailed description

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

As shown in Figures 1-6, the railway vehicle coupler knuckle near net forging molding method of the present invention comprises the following steps:

Step (a), material preparation: according to the product model, the round steel of the corresponding specification is cut to a certain length with a band saw;

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

Step (c), prefabricating the blank: placing the heated blank on an 800-ton multi-directional forging device for multi-directional forging to prefabricate the blank.

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

Step (e), near-net forging forming: the pre-forged blank is placed in a multi-directional forging die dedicated to the knuckle on a 6,000-ton multi-directional forging device for closed forging to achieve near-net forming.

Step (f), heat treatment: quenching and tempering the forged blank with waste heat.

Step (g), finishing: use a CNC machining machine to process the knuckle pin hole and the like.

Step (h), flaw detection: carry out magnetic particle flaw detection on the finished product.

In the above step (c), the prefabricated blank is carried out on the multi-directional forging equipment, and the molds in the vertical direction and the horizontal direction move at different times, and the heated blank is made into a prefabricated blank with a certain height and thickness in the shortest time, and at the same time, the surface of the blank is removed Oxide.

In the above step (d), the prefabricated blank is placed in the pre-forging die of the multi-directional forging equipment. The pre-forging die is divided into four parts: upper and lower, left and right. The upper and lower parts are driven by the vertical oil cylinder of the multi-directional forging device. The two parts on the right are driven by the horizontal oil 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 prefabricated blank is pre-forged into a certain shape and size.

In the above step (e), the near-net shape of the coupler knuckle is achieved by means of multi-directional forging equipment and multi-directional forging dies. The multi-directional forging die adopts the horizontal and vertical mixed mode of parting. After the pre-forging blank is placed in the multi-directional forging mold, firstly, the left and right parts of the mold in the horizontal direction are driven by the horizontal direction oil cylinder of the multi-directional forging equipment to start to move, and the pre-forging blank is extruded, and the left and right molds are closed to realize mold locking. ;The upper mold part of the mold in the vertical direction moves down quickly under the drive of the main oil cylinder. When it is about to contact the blank, the main oil cylinder turns to slow motion and starts to forge. The movement speed of the upper mold is infinitely adjustable and controlled by the program. Control, the deformation rate of the workpiece is kept basically the same throughout the forging process; when the pressure of the main cylinder reaches the set value, the entire forging process ends, the upper die quickly retreats, and at the same time, the push cylinder moves to keep the workpiece from moving upward with the upper die, and the left and right dies The mold is opened and retracted, and then the lower mold moves upward to eject the workpiece under the drive of the lower ejector cylinder, and the near-net forging is completed.

In the above step (e), the horizontal mold of the multi-directional forging mold is embedded with hydraulic cylinders and movable modules. During the closed forging process, when the upper mold moves downward to a certain position, the embedded hydraulic cylinder is automatically activated by program control. Cylinder, and push the movable module to realize partial forming of the weight-reducing groove of the knuckle workpiece. While the upper die returns quickly, the embedded hydraulic cylinder starts to return, driving the movable module back. After the movable module returns to its original position, the left and right molds are opened and returned.

In the above step (f), quenching and tempering heat treatment is performed with waste heat after the workpiece is formed. After the near-net forging and forming of the workpiece, the temperature is measured by the automatic temperature measurement system, and then enters the soaking furnace. The soaking furnace automatically heats up or cools down the workpiece according to the temperature measured by the automatic temperature measurement system and the quenching temperature. The time of the workpiece in the soaking furnace is automatically controlled by the real-time monitoring of the automatic temperature measurement system with the furnace.

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

In this example, according to the forged knuckle model, the prepared diameter is For a round bar with a length of 405mm, the round bar blank is heated to 1150°C±20°C, and the heated billet is sent by the robot to the 800-ton multi-directional forging equipment for prefabrication of the blank, and the oxide skin on the surface of the billet is removed at the same time, as shown in Figure 2 Schematic diagram of the shape of the prefabricated blank. The manipulator then sends the prefabricated blank to the pre-forging die, and the multi-directional forging equipment makes the prefabricated blank into a pre-forging of a certain shape and size. Figure 3 is a schematic diagram of the pre-forging structure. Then transfer the pre-forged blank to the near-net-shaping multi-directional closed forging die shown in Figure 6 to realize the near-net forging of the coupler knuckle. Using the residual heat of the blank after forming, the blank workpiece is subjected to soaking treatment, and then the quenching and tempering heat treatment is automatically performed. Fig. 4 is a schematic diagram of the structure of a forged knuckle blank after quenching and tempering heat treatment, and Fig. 5 is a schematic diagram of the structure of a forged knuckle finished product after machining and flaw detection.

The embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Within the scope of knowledge of those of ordinary skill in the art, various modifications made on the premise of not departing from the gist of the present invention All these changes should belong to the scope covered by the patent of the present invention.

Claims (6)

1. railway vehicle truck coupler knuckle near net method for forging and molding, it is characterised in that comprise the following steps:

Step (a), material prepare；

Step (b), heating: by blank heating to 1150 DEG C ± 20 DEG C；

Step (c), precut blanks: be placed in the blank after heating on 800 tons of multiway forging equipment and carry out forging to prefabricated hair more Base；

Step (d), blank blocking: precut blanks carries out block forging in the Preform Die on 2000 tons of multiway forging equipment；

Step (e), near net forging molding: the multiway forging mould being placed in the blank after blocking on 6000 tons of multiway forging equipment Inside carry out block forging, it is achieved near-net-shape；

Step (f), heat treatment: waste heat hardening and tempering heat treatment is used to the blank after forging；

Step (g), finishing: use numerical control machine to be processed hook bolt pin-and-hole；

Step (h), flaw detection: magnetic powder inspection is carried out to finished parts.

2. railway vehicle truck coupler knuckle near net method for forging and molding according to claim 1, it is characterised in that step (c) In precut blanks be to carry out on multiway forging equipment, vertical direction and horizontal direction mould are staggered the time motion, base after heating The precut blanks of certain altitude and thickness made by material, removes the oxide skin of blank surface simultaneously.

3. railway vehicle truck coupler knuckle near net method for forging and molding according to claim 1, it is characterised in that step (d) In, precut blanks is positioned in the Preform Die of multiway forging equipment, and Preform Die is divided into upper and lower, left and right four part, upper and lower Two parts mould is by multiway forging equipment vertical direction hydraulic oil cylinder driving, and left and right two parts mould is by multiway forging equipment level side To hydraulic oil cylinder driving, the motion of each several part mould and move distance are by programme-control, and motion after each several part mould matched moulds terminates, will be pre- Roughcast is swaged into definite shape and size in advance.

4. railway vehicle truck coupler knuckle near net method for forging and molding according to claim 1, it is characterised in that step (e) The near-net-shape of middle coupler knuckle for car coupler relies on multiway forging equipment and multiway forging mould to realize；

Multiway forging mould uses level to mix mould-dividing mode with vertical；After blocking blank is placed in multiway forging mould, first It is horizontally oriented left and right two parts mould by the horizontal direction hydraulic oil cylinder driving setting in motion of multiway forging equipment, blocking blank is entered Row extruding, realizes mold-locked after the mould matched moulds of left and right；The part of the upper die of vertical direction mould is quick under the driving of master cylinder Moving downward, when contacting with blank, master cylinder transfers microinching to, proceeds by block forging, upper mold movement velocity Electrodeless adjustable and be controlled by program, whole forging process remains that workpiece rate of deformation is identical；When master cylinder pressure reaches After setting value, whole forging process terminates, and upper mold is quickly return, go up simultaneously charging cylinder action with keep workpiece not with upper mold to Upper motion, left and right mould die sinking simultaneously returns, then lower mold under the driving of lower liftout tank upwards motion eject workpiece, complete near Net forging molding.

5. railway vehicle truck coupler knuckle near net method for forging and molding according to claim 1, it is characterised in that step (e) The embedded hydraulic cylinder of horizontal direction mould inside of middle multiway forging mould and active module, during block forging, work as upper mold When being moved downwardly to certain position, automatically started this embedded hydraulic cylinder by programme-control, and promote active module to realize hook bolt work Part lightening grooves part is locally-shaped；While upper mold quick return, embedded hydraulic cylinder starts and starts backhaul, drives active module to move back Return；After active module is return in situ, left and right mould die sinking is return.

6. railway vehicle truck coupler knuckle near net method for forging and molding according to claim 1, it is characterised in that step (f) In, utilize waste heat to carry out Tempering and Quenching after Workpiece shaping；Workpiece is entered by automatic temperature measurement system after completing near net forging molding Trip temperature is measured, subsequently into soaking pit；Soaking pit compares with hardening heat according to automatic temperature measurement system measured temperature, to workpiece Automatically carry out heating up or cooling process；Time in soaking pit for the workpiece is monitored in real time by stove automatic temperature measurement system and carries out automatically Control.