RU2360779C1 - Device to facilitate turning out-of-round parts - Google Patents

Abstract

FIELD: mechanics.

SUBSTANCE: proposed device comprises the cutting tool electric drive, cutting tool travel pickup, spindle turn angle pickup, cutting tool translation pickup, workpiece angular speed pickup and part shaping unit. The latter is connected in series, via the first adder first input, with that of the electric drive forcing the cutting tool deep into the part. The device includes also the 2^nd and 3^rd adders, the 1^st, 2^nd, 3^rd, 4^th and 5^th buffer registers and memory device. The spindle turn angle pickup output is connected to low-order digits of the part shaping unit. The cutting tool translation pickup is connected with high-bits of the part shaping unit input.

EFFECT: higher accuracy of turning standard out-of-round parts.

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Description

The proposed device relates to electromechanics and can be used to improve the accuracy of turning serial non-circular parts such as pistons of internal combustion engines.

A device in the form of a two-channel electric drive is known, intended for precise control of the position of mechanisms when practicing cyclic influences, including during turning of non-circular parts, when the cycle time is equal to the time of one revolution of the part (RF patent N2223592, 02/10/2004. Bull. No. 4). The device uses the principle of self-training, which allows turning the parts with constant non-circularity to reduce the cyclic error component (from revolution to revolution) to a minimum value.

The known device has disadvantages. If the specified non-circularity varies along the length of the part, then when using this device, the accuracy of the implementation of the given shape is impaired. The systematic, from part to part, impact on the cutting tool from the metal side at the moment of cutting during intermittent cutting, for example, when passing holes, longitudinal grooves, etc., leads to the same result.

A device is also known to improve the accuracy of turning non-circular parts, RF patent N2293010, publ. BIPM No. 4, 02/10/2007 (prototype), comprising an electric drive for moving the cutting tool in the direction of cutting depth, a sensor for moving the cutting tool in the direction of cutting depth, a sensor for the angle of rotation of the spindle, a sensor for longitudinal movement of the cutting tool, a sensor for the angular speed of rotation of the part, a shape setting unit parts connected in series through the first input of the first adder with the input of the electric drive moving the cutting tool in the direction of the depth of cut, second, third adders, first, second, tert the fourth, fifth buffer registers, a storage device. In this case, the output of the spindle angle sensor is connected to the lower bits of the input of the part shape setting block, the output of the cutting tool longitudinal movement sensor is connected to the higher bits of the input of the part shape set block, the input of the part shape setting block is connected to the input of the first buffer register and simultaneously through the first input of the third the adder - with the input of the third buffer register, the outputs of the first and third buffer registers are connected to the address input of the storage device, the data bus of which is simultaneously connected to the inputs of the second, fourth buffer registers and the output of the fifth buffer register, the input of which is connected to the output of the second adder, the output of the part shape setting unit, the output of the cutting tool moving sensor in the direction of cutting depth and the output of the fourth buffer register are connected to the first, second, third inputs the second adder, respectively, the output of the second buffer register is connected to the second input of the first adder, and the output of the angular velocity sensor of the part is connected to the second input third his adder.

This device is designed for turning non-circular parts such as pistons, cams, parts with holes, longitudinal grooves and other parts that are characterized by intermittent turning. The block diagram of the device is based on the principle of self-learning, which allows to add to the signal the task of the correction signal, determined depending on the errors when turning the previous part, to minimize systematic errors determined by the given shape of the workpiece, the location of the intermittent turning sections and repeating from part to part .

The disadvantage of this device is the limited number of identical parts, which can be processed with high accuracy during continuous operation of the system with self-training.

The reason for the limitation is the presence in the correction signal and, accordingly, in the control signal of the electric drive of the movement of the cutting tool in the direction of the depth of cut, unlimitedly increasing from part to part of high-frequency interference. These obstacles at a certain stage (details) first reduce the accuracy of the implementation of a given form, and then lead to unacceptable errors. The reason for this phenomenon is the presence in the self-learning circuit of internal positive feedback, which causes the accumulation of high-frequency effects in the storage device.

Therefore, such a device can only be used temporarily, until the start of reducing the accuracy of processing the next part. Then it is necessary, when moving on to the next parts, to work according to a strict program for processing the last part, executed with acceptable accuracy, thereby stopping the self-learning process. However, at the same time, another drawback arises - the system is insensitive to changes in parameters such as electric drive parameters for moving the cutting tool in the direction of the cutting depth, the angular speed of rotation of the part, the shape of the workpiece, the hardness of the metal, etc., which also reduces accuracy.

The technical problem solved by the invention is to remove restrictions on the number of identical workpieces, provided that the specified accuracy is maintained by eliminating the negative effect of high-frequency effects on the self-learning circuit.

The problem is solved in that the known device containing an electric drive for moving the cutting tool in the direction of cutting depth, a sensor for moving the cutting tool in the direction of cutting depth, a sensor for the angle of rotation of the spindle, a sensor for longitudinal movement of the cutting tool, a sensor for the angular velocity of rotation of the part, a unit for setting the shape of the part, connected in series through the first input of the first adder with the input of the electric drive moving the cutting tool in the direction of the depth of cut, the second, tr there are adders, first, second, third, fourth, fifth buffer registers, as well as a storage device, wherein the output of the spindle angle sensor is connected to the lower bits of the input of the part shape setting block, the output of the longitudinal movement sensor of the cutting tool is connected to the higher bits of the input of the shape set block parts, the input of the unit for specifying the shape of the part is connected to the input of the first buffer register and simultaneously through the first input of the third adder with the input of the third buffer register, the outputs of the first and third buffer registers are connected to the address input of the storage device, the data bus of which is simultaneously connected to the inputs of the second and fourth buffer registers and the output of the fifth buffer register, the input of which is connected to the output of the second adder, the outputs of the unit for setting the part shape, the sensor for moving the cutting tool in the direction of cutting depth are connected with the first and second inputs of the second adder, respectively, the output of the second buffer register is connected to the second input of the first adder, and the output of the angular velocity sensor This rotation of the part is connected to the second input of the third adder, additionally equipped with sixth, seventh, eighth, ninth buffer registers, as well as the fourth, fifth adders, the inputs of the sixth and seventh buffer registers connected to the data bus of the storage device, the outputs of the fourth, sixth, seventh buffer registers are connected to the third, fourth and fifth inputs of the second adder, respectively, the first inputs of the fourth and fifth adders are connected to the output of the third adder, the outputs of the fourth and fifth sums tori connected to the inputs of the eighth, ninth buffer registers respectively, the outputs of the eighth, ninth buffer registers connected to the address input of the memory and the second inputs of the fourth, fifth adders are connected to corresponding blocks of previous and subsequent assignment of addresses.

The drawing shows a structural diagram of the proposed device. The proposed device comprises an electric drive 1 of the movement of the cutting tool 2 in the direction of the depth of cutting, a sensor 3 of the movement of the cutting tool 2 in the direction of the depth of cutting, a sensor 4 of the angle of rotation of the spindle, a sensor 6 of the longitudinal movement of the cutting tool 2, the sensor 7 of the angular velocity of rotation of the workpiece 5, block 8 tasks parts 5, connected in series through the first input of the first adder 9 with the input of the electric drive 1 moving the cutting tool 2 in the direction of the depth of cut, the second 10 and third 11 adders first 12, second 13, third 14, fourth 15, fifth 16 buffer registers, as well as a storage device 17, while the output of the spindle angle sensor 4 is connected to the lower bits of the input of the part shape setting unit 8, the output of the sensor 6 for longitudinal movement of the cutting tool 2 connected to the senior bits of the input of the part shape setting unit 8, the input of the part shape setting unit 8 is connected to the input of the first buffer register 12 and simultaneously through the first input of the third adder 11 to the input of the third buffer register 14, the outputs of the first 12 and third 14 buffer registers are connected to the address input of the storage device 17, the data bus of which is simultaneously connected to the inputs of the second 13, fourth 15 buffer registers and the output of the fifth buffer register 16, the input of which is connected to the output of the second adder 10, the first input of the second adder 10 is connected to the output unit 8 for specifying the shape of the part, the second input of the second adder 10 is connected to the output of the sensor 3 for moving the cutting tool in the direction of the cutting depth, the output of the second buffer register 13 is connected to the second input of the 9 adder, the output of the sensor 7 of the angular velocity of rotation of the part is connected to the second input of the third adder 11, in addition, it is additionally equipped with a sixth 18, seventh 19, eighth 22, ninth 23 buffer registers, as well as the fourth 20, fifth 21 adders, and the inputs sixth 18 and seventh 19 buffer registers are connected to the data bus of the storage device 17, the outputs of the fourth 15, sixth 18, seventh 19 buffer registers are connected to the third, fourth and fifth inputs of the second adder 10, respectively, the first inputs of the fourth 20 and fifth 21 adders are connected to the output of the third adder 11, the outputs of the fourth 20 and fifth 21 adders are connected to the inputs of the eighth 22, ninth 23 buffer registers, respectively, the outputs of the eighth 22, ninth 23 buffer registers are connected to the address bus of the storage device 17, and the second inputs of the fourth 20 , on the fifth 21 adders are connected to the corresponding job blocks of the previous 24 and the next 25 addresses.

The device operates as follows. The signal for specifying the shape corresponding to the drawing of the outer surface of the part is generated at the output of the block for specifying the shape of the part 8 in functional dependence on the output signals of the sensor 6 for longitudinal movement of the cutting tool 2 and the sensor 4 of the spindle angle. These signals are supplied, respectively, to the higher and lower bits of the block 8 specifying the shape of the part.

When turning the next part, the correction signal from the output of the second buffer register 13, formed in the storage device 17 when turning the previous part, is added to the output signal of the unit 8 for setting the part shape in the first adder 9. This correction signal is aimed at reducing shaping errors caused by the limited speed of the electric drive 1 moving the cutting tool in the direction of the depth of cut.

When turning the first part, the correction signal is zero.

Reading the current value of the correction signal from the storage device 17 and transmitting it from the data bus of the latter to the output of the second buffer register 13 occurs simultaneously with the transfer from the input of the first buffer register 12 to its output of the current value of the address of the address space generated by the output signals of the spindle angle sensor 4 and sensor 6 longitudinal movement of the cutting tool.

In the next three points in time at the corresponding addresses through the third 14th, eighth 22th, ninth 23 buffer registers, the data stored in the memory of the memory device 17 are read and transferred from the data bus to the outputs of the fourth 15th, sixth 18th, seventh 19 buffer registers, respectively. Moreover, the address at the output of the eighth buffer register 22 is the previous one, and at the output of the ninth buffer register 23 the next with respect to the output address of the third buffer register 14, which is ensured by the inclusion of the corresponding task units 24, 25 and fourth 20, fifth 21 adders in the device. The address transmitted through the third buffer register 14 is formed at the output of the third adder 11 by subtracting from the current address the value determined by the output signal of the component angular speed sensor 7.

And, finally, at the last time interval, at the address transmitted through the third buffer register 14, the value of the correction signal for the next part is written to the memory 17 from the output of the second adder 10 through the fifth buffer register 16. The signals from the outputs of the sixth 18, seventh 19 buffer registers are summed in the second adder 10 with the output signal of the fourth buffer register 15 with the same weights.

The above procedure in the form of five consecutive time intervals for controlling the elements of the structural diagram shown in the drawing is repeated at each address of the address space that describes the surface of the part in block 8 of the form.

As a result, at the end of turning the next part in the storage device 17, the values of the correction signal are written to all addresses of the address space, which will be used when turning the next part. In this case, the actual values of the correction signal at each address are determined depending on the current values of the shape errors identified in the process of turning the previous part.

Adding a correction signal to the first adder 9 reduces the formation errors when turning the next part, and since the magnitude of this signal is determined taking into account the formation errors of the previous part, the systematic component of the shape errors gradually, from part to part, tends to its minimum value. Moreover, due to the presence in the device of additional buffer registers 18, 19, 22, 23, as well as adders 20, 21, blocks for setting the previous and subsequent addresses 24, 25, included according to the structural diagram of the figure, a stable process of self-learning from part to part is ensured with minimal systematic error.

Claims (1)

A device for improving the accuracy of turning non-circular parts, containing an electric drive for moving the cutting tool in the direction of cutting depth, a sensor for moving the cutting tool in the direction of cutting depth, a sensor for the angle of rotation of the spindle, a sensor for longitudinal movement of the cutting tool, a sensor for angular speed of rotation of the part, a part shape setting unit, connected in series through the first input of the first adder with the input of the electric drive moving the cutting tool in the depth direction second, third adders, first, second, third, fourth, fifth buffer registers, a storage device, the output of the spindle angle sensor is connected to the lower bits of the input of the part shape setting unit, the output of the longitudinal movement sensor of the cutting tool is connected to the higher bits of the block input specifying the shape of the part, the input of the specifying block of the form of the part is connected to the input of the first buffer register and simultaneously through the first input of the third adder to the input of the third buffer register, the outputs of the first and third of buffer registers are connected to the address input of a memory device configured to record the values of the correction signal at the addresses, the data bus of the memory device is simultaneously connected to the inputs of the second and fourth buffer registers and the output of the fifth buffer register, the input of which is connected to the output of the second adder, the first input of the second the adder is connected to the output of the unit for setting the part shape, the second input of the second adder is connected to the output of the sensor for moving the cutting tool in the direction depth of cut, the output of the second buffer register is connected to the second input of the first adder, the output of the component angular speed sensor is connected to the second input of the third adder, while it is equipped with the sixth, seventh, eighth, ninth buffer registers, as well as the fourth, fifth adders, and the inputs the sixth and seventh buffer registers are connected to the data bus of the storage device, the third input of the second adder is connected to the output of the fourth buffer register, the outputs of the sixth, seventh buffer registers are connected to the fourth and fifth inputs of the second adder, respectively, the first inputs of the fourth and fifth adders are connected to the output of the third adder, the outputs of the fourth and fifth adders are connected to the inputs of the eighth, ninth buffer registers, respectively, the outputs of the eighth, ninth buffer registers are connected to the address input of the storage device, the second inputs of the fourth, fifth adders are connected to the corresponding blocks of the previous and subsequent addresses in relation to the output address of the third buffer histra.