RU2708488C1 - Pipe-forming machine - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: invention relates to metal forming and can be used for bending pipes according to winding pattern. Pipe bending machine comprises bed, device for billet fixation and supply to bending zone, bending device and control system. Note here that said control system comprises replaceable rod with position sensors secured at said bed. Billet securing and feeding device to the bending zone comprises an elastic element to ensure free movement of the billet.

EFFECT: enlarging technological capabilities of machine and providing additional supply of pipe at its bending.

1 cl, 3 dwg

Description

The invention relates to the field of metal forming and can be used for bending pipes according to the pattern winding scheme.

In serial production, pipe bending is usually carried out on special equipment - pipe bending machines of automatic or semi-automatic type. Typically, pipe bending machines include a bed, a device for securing and feeding the workpiece to the bending zone, a bending device and a control system. Giving the workpiece a predetermined spatial shape occurs according to the commands of the control system of coordinated responses of the device for fixing and feeding the workpiece to the bending zone and the bending device.

A device for securing and supplying the workpiece to the bending zone provides translational movement and, if necessary, the turn of the workpiece. The need to ensure the dimensions of the bent pipe within the specified tolerances requires accurate tracking of the position of the actuators at each time the operation is performed. This is usually achieved by using tracking systems on machines with linear feedback sensors, for example, in the form of coordinate optical or magnetic rulers, which have a high cost. The dependence of their dimensions and, accordingly, the cost on the overall dimensions of the workpiece also relates to the features of linear feedback sensors: the longer the workpiece is a straight pipe installed on the machine, the larger the line should be and the more expensive it becomes.

The bending device performs bending of the workpiece at a given angle. The control system operates with at least three characteristic parameters: linear displacement, angle of rotation of the plane of the bend and the angle of the bend.

Known pipe bending machines of the TBRE-MRE series manufactured by CSM, including (URL: http://www.tubebender.ru/products/item/9/7/ (Date of access: 05/15/2019)). In the process of bending, the device for securing and feeding the workpiece into the bending zone is forcibly moved forward from the initial position in the direction of the bending device. The forced translational movement of the device for securing and supplying the workpiece to the bending zone is provided by a special slider with a hydraulic drive, acting on the commands of the control system. The readjustment of the machine for manufacturing a pipe having an excellent spatial shape consists in introducing a new program into the control system through the touch screen for programming.

The disadvantages of the known pipe bending machines include the presence of a hydraulic system in the design and the complication of the control system associated with this, as well as the need to manually enter all coordinates of future bends, both linear and angular, when re-setting the machine, which implies a significant investment of time.

A known method of bending pipes and a machine for implementing the method, providing for the implementation of the device for fixing and feeding the workpiece into the bending zone in the form of a collet clamp with the possibility of axial reciprocating movement along the guides of the bed, (US Pat. RU 2422229, publ. 06/27/2011. Bull. No. 18). The bending device, according to a known solution, includes hydraulic cylinders in which the extension of the rods is determined by the commands of the control system. According to the commands of the control system, translational movement of the device for securing and supplying the workpiece to the bending zone and simultaneous operation of the bending device occur.

The disadvantages of the known method and the machine for its implementation include the unjustified complexity of the operation scheme due to linear and angular movements of the workpiece by controlled hydraulic cylinders, each of which requires a preliminary setting of the extension of the rod. The disadvantage is the presence in the design of the machine tool of the hydroelectric station necessary for the operation of hydraulic cylinders. The readjustment of the machine in a known solution takes place automatically, which also complicates the control system and, ultimately, increases the cost of manufacturing products.

A device for bending pipes is known (US Pat. RU 2434703, publ. 11/27/2011. Bull. No. 33), installed on the frame of the bending machine and including a device for securing and feeding the workpiece in the bending zone and bending device. The device for bending pipes is controlled by a CNC control system of the machine. The device for securing and supplying the workpiece to the bending zone is made in the form of a collet clamp, the bending device is equipped with a faceplate mounted on the hollow shaft with the possibility of rotation. The bending element is a roller placed on the beam, with the possibility of rotation. After installation on the machine, the workpiece is fixed in the device for fixing and feeding to exclude the possibility of its axial rotation and longitudinal movement. After that, it is fed into the bending zone along the channel inside the shaft. To reduce contact friction in the walls of the channel in the known device installed balls. Movement of the workpiece and bending are carried out using hydraulic cylinders.

The disadvantages of the known solutions include the complexity of the design, due to the use of hydraulic cylinders, which require a hydraulic station, and the presence of an extended channel through which the workpiece is fed into the bending zone. The use of balls in the design to reduce contact friction complicates the design. At the same time, the design of the faceplate does not allow to reduce the length of the shaft and determines the linear size, less than which the workpiece cannot have. This limits the overall dimensions of the future product. The linear coordinates of the bends are provided by the operation of hydraulic cylinders, which is very difficult and has limitations on accuracy. The readjustment of the machine in a known solution takes place automatically, which also complicates the control system and, ultimately, increases the cost of manufacturing products.

A known design of machines in which the control system provides fixed discrete predetermined movement of the working body, creating certain positions of the components of the final product in space. An example of such component parts can be threads of a certain color in the fabric, an example of a working body - a shuttle, an example of equipment - Jacquard machines, and an example of a control element - a punched card or punched tape (URL: https://ru.wikipedia.org/wiki/Jacquard_tartsky_stank (Date appeals: 05/17/2019)).

The disadvantages of the known designs include, in particular, the immutability of the punched card, it is practically impossible to change - and the discreteness of the adjustments - one punched card corresponds to one procid shuttle in a loom.

The closest set of essential features - the prototype of the claimed invention - is a machine for bending pipes (US Pat. RU No. 20267, publ. 10/27/2001. Bull. No. 30). The known design includes a device for securing and supplying the workpiece to the bending zone, called the tailstock by the authors of the solution and installed on the machine beam, a device for switching the values of the bending angle of the workpiece with adjusting stops that fix a number of set values of the angle of the bending of the workpiece, and a control system. The beam has a shaped profile, a marking scale for linear extension of the workpiece and is equipped with a set of adjustable stops-clamps of a number of linear extensions of the workpiece with locks. The drive is made in the form of a pneumatic system that provides automatic execution of a number of work operations. The fixation of a number of setpoints is provided by the shaped profile of the beam and a set of the required number of adjustable stops-clamps located along the beam and having locks controlled by the pneumatic system, and the fixation of the bending plane of the bending of the workpiece in space at given angles is ensured by clamping the pipe in the tailstock and fixing the given spatial angles by a lock stoppers on the tailstock. The clamps for the bending angles of the pipe, linear movement (extension) of the pipe and rotation of the bending plane — the three characteristic coordinates that determine the spatial shape of the pipe — are manually set before bending begins. After installing and securing the workpiece in the device for securing and feeding the workpiece into the bending zone, it is manually moved to the stop of the first bend lock and installed in the desired plane. The switch device is set to the first bend position. Subsequent operations are performed automatically by operator’s commands from the control panel.

The disadvantages of the known solutions include the use of a pneumatic system that requires a source of compressed air and the discreteness of a possible range of angles of rotation of the bending planes, due to the design of the turret switch device. The disadvantage is the large amount of work when changing the machine to a new product: it is necessary to replace the switch device of the values of the bending angle of the workpiece with adjusting stops and reinstalling the stop-clamps on the beam. It may be necessary to change the number of stops-clamps (when changing the number of bends on a new product, compared to the previous one).

The technical problem to which the invention is directed is to eliminate the disadvantages of the prototype - simplifying the design of the bending machine and reducing the duration of the readjustment when switching to the manufacture of a product that differs in the spatial form of bending.

The problem is solved due to the fact that an elastic element is introduced in the device for fixing and feeding the workpiece into the bending zone, and one of the coordinates — linear movement of the blank — is determined by the location of the position sensors on the replaceable element of the pipe bending machine, the mounting rod, and can be installed without operating time costs.

The novelty in the proposed pipe bending machine is:

- the design of the device for securing and feeding, including an elastic element, and combined with a device for turning the workpiece in the desired plane of the bend;

- the use of a replaceable rod in the control system with position sensors installed in a certain order instead of linear feedback sensors.

These signs are new, significant, non-obvious and industrially feasible and are aimed at solving the technical problem posed by the invention.

The pipe bending machine proposed as an invention is illustrated by drawings (Figs. 1, 2, 3) and includes a frame 1, a device 2 for securing and supplying a workpiece to the bending zone, a bending device 3, a control system 4. The main components of the control system 4 (Fig. 1 ) are the control panel 41, the removable rod 42 and the harnesses of the connecting wires (not shown in FIG.). The replaceable rod 42 is mounted and secured to the frame 1 in any known manner so that its linear coordinate — displacement along the longitudinal axis — is maintained with a tight tolerance. The specified requirement is ensured by any known method and is not subject to patent protection. On the interchangeable rod 42 in the brackets 421 are position sensors 422, the number and location of which corresponds to the required number and location of bends.

Guides 11 are placed on the bed 1, along which, by means of the drive 21, the device 2 is moved for securing and supplying the workpiece to the bending zone. The drive 21 can be made in any known manner, for example, with a timing belt or a ball screw pair and is not subject to patent protection. The device 2 for fixing and supplying the workpiece to the bending zone includes a servo drive 22 and the rod 23. The rod 23 is installed in the housing of the device 2 for fixing and feeding the workpiece into the bending zone parallel to the direction of movement of the device 2 for fixing and feeding the workpiece into the bending zone and protrudes from it with two sides. At the end of the rod 23 closest to the bending device 3, an external thread is made. At the opposite end of the rod 23 is installed an elastic element 24 (Fig. 2). The rod 23 is connected with the servo drive 22 in such a way that it has the possibility of axial rotation, which tells it the servo 22, and longitudinal movement.

The bending device 3 is located on the bed 1 with the possibility of axial rotation and is connected by a shaft 32 through a gearbox 34 with the motor 33. The bending device 3 includes a mandrel 35, rigidly connected to the shaft 32, and a movable stop 36, mounted with the possibility of its movement by the drive 31 in the guide 37 for pressing the workpiece 5 to the mandrel 35.

Pipe bending machine operates as follows.

Previously, on the interchangeable rod 42, brackets 421 with position sensors 422 are installed, placing them in accordance with the number and location of bends on a future product. The wires from the sensors are formed into a common bundle of connecting wires. The assembled replaceable rod 42 is mounted and secured to the bed 1. The connecting wire harness (not shown in FIG.) Is connected to the control panel 41 in a known manner, for example, through a connector (not shown in FIG.). From the control panel 41 enter the angular coordinates of rotation of the shaft 32.

The workpiece 5 (Fig. 1), having the connecting heads and union nuts formed at the ends, is mounted on the rod 23 from the side facing the bending device 3. The union nut of the workpiece 5 is tightened on the threaded part of the end of the rod 23.

After the operator starts the bending process from the control panel 41, all transitions are performed automatically. The device 2 for fixing and supplying the workpiece to the bending zone is moved by the servo drive 21 to the first position sensor 422, which corresponds to the position of the first bend, and stops. Drives 26 and 31 move the stops 24 and 36 in the guides 25 and 37, respectively, pressing the workpiece 5 to the mandrel 35. After pressing the workpiece 5 to the mandrel 35, the motor 33 is turned on, which through the gearbox 34 and the shaft 32 rotates the mandrel 35 with the workpiece pressed against it 5 at a given angle.

The billet 5 is bent according to the winding scheme on the mandrel 35. Therefore, when bending the billet 5, its additional feed is required by an amount depending on the bending angle and determined by the well-known formula taking into account the spring of the workpiece 5. This feed occurs when the rod 23 is axially moved relative to the fixed device 2 for fixing and feeding the workpiece into the bending zone while deforming the elastic element 24. The maximum possible deformation of the elastic element 24 is pre-selected so as to have a guaranteed th margin blank feed 5 at a given radius and maximum angle of bend.

The engine 33 stops when it reaches the specified angle of rotation of the mandrel 35 with the workpiece 5 pressed against it. The movable stops 24 and 36 are retracted by the drives 26 and 31, freeing the workpiece 5 for subsequent movement. The device 2 for fixing and feeding the workpiece into the bending zone moves to the next position sensor 422 and stops. When moving the device 2 for fixing and supplying the workpiece to the bending zone, the elastic element 24 returns the bar 23 to its original position relative to the device 2 for fixing and feeding the workpiece to the bending zone.

The linear coordinate — the position of the position sensor 422 on the removable rod 42 — is preliminarily calculated so that by the time the device 2 for fixing and feeding near the position sensor 42 stops, the rod 23 returns to its original position, and the deformation of the elastic element 24 accumulated during the previous movement of the device 2 for fixing and filing, reset. Servo 22 rotates the workpiece 5 around the axis by the desired angle, changing the position of the plane of the bend. After this, the bending will continue in automatic mode until all the 422 position sensors have passed on the replaceable rod 42.

The use of the elastic element 24 allows you to simplify the control system of the pipe bending machine and reduce the cost of its design by eliminating coordinate optical or other rulers. As the elastic element 24 can be applied a cylindrical compression spring, and, taking into account the specifics of the work, the requirements for the accuracy of its manufacture will be low.

If it is necessary to manufacture on the proposed pipe bending machine an item (pipe) that differs in spatial shape and dimensions, it is necessary to replace the interchangeable rod 42 with installed position sensors 422 and enter new coordinates on the control panel 41.

The technical result of the invention is: simplification and cheapening of the design of the pipe bending machine by replacing linear feedback sensors with position sensors installed on the replaceable rod in accordance with the number and location of bends in the final product, as well as reducing the auxiliary time - time for readjustment of the pipe bending machine in preparation to the manufacture of a new product. Reduction of auxiliary time occurs due to the redistribution of adjustment work: advance preparation of the replacement rod with installed position sensors in such a way that when changing the machine, a simple replacement of replacement rods is required, which can be done without involving a highly qualified installer.

The proposed design of a pipe bending machine has been tested and introduced into serial production at the Altai precision products plant.

Claims (2)

1. A pipe bending machine comprising a bed, a device for securing and supplying a workpiece to a bending zone, a bending device and a control system, characterized in that the device for securing and feeding contains a resilient element configured to allow free movement of the workpiece when forming a curved section on it and the control system contains a removable rod with position sensors pre-installed in accordance with the number and location of bends in the final product. 2. The pipe bending machine according to claim 1, characterized in that the said elastic element is made in the form of a cylindrical compression spring.

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