A working method of a straightness deviation compensation device for a deep hole machining machine tool

Abstract

The application provides a straightness deviation compensation device for a deep hole processing machine tool and a working method, and belongs to the technical field of machine tool components, and comprises: a plurality of thermal actuation modules, which are arranged at the end of the side wall of a machine tool rotating part; a guide block is arranged on the side of the thermal actuation module away from the machine tool rotating part, the thermal actuation module and the guide block are connected with the machine tool rotating part through connecting fasteners, the length of the connecting fasteners is greater than the minimum length required when the connecting fasteners pass through the guide block, the thermal actuation module and complete fastening, thereby forming an axial movement space for thermal expansion and contraction; the thermal actuation module is connected with a semiconductor temperature control system; an ultrasonic sensor is further arranged outside a workpiece, the ultrasonic sensor is connected with an ultrasonic measurement system, and the ultrasonic measurement system and the semiconductor temperature control system are connected with a control system. The problems that the existing technology cannot solve the problems of limited correction hole diameter and cannot continuously regulate and control correction on line are solved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of machine tool components, and particularly relates to a straightness deviation compensation device for a deep hole machining machine tool and a working method. BACKGROUND

[0002] The statements in this section merely provide background information related to the present application and do not necessarily constitute the prior art.

[0003] Deep hole drilling is a manufacturing process specially used for machining high-precision deep holes with a length-diameter ratio greater than 10. In an internal chip removal deep hole drilling system, an asymmetric tool structure is usually adopted and self-centering positioning is achieved with the help of a guide block, and internal chip removal is performed with a high-pressure cooling and lubricating system to ensure the machining quality of the hole wall. However, in the actual drilling process, due to the combined influence of complex factors such as asymmetric tool structure, uneven distribution of cutting force, workpiece material and structural characteristics, uneven temperature field distribution, and guide block wear, the drilling axis straightness deviation is easily caused. This deviation is manifested as the radial offset of the actual hole center line relative to the theoretical axis, which directly affects the subsequent assembly quality and use performance of the workpiece.

[0004] At present, various technical means have been developed for the measurement and compensation of straightness deviation. For example, laser measurement technology can be used, or the position of the tool bit can be indirectly calculated by analyzing the bending curve of the drill rod. However, due to the poor accessibility of the measurement point, the existence of tool interference, and other problems, the application of laser and other measurement technologies is limited. Therefore, the existing technology proposes an ultrasonic wall thickness measurement method, but this method still relies on manual experience for judgment and adjustment, and it is difficult to realize automatic continuous machining, and the overall efficiency still needs to be improved. In terms of compensation technology, methods such as active guidance of hydraulic or piezoelectric elements, additional support structure of the drill rod, pulsation regulation of the cooling liquid, and pre-compensation based on mechanical finite element simulation are still relied on. However, these methods have limited hole diameter adaptation range, cannot realize online continuous regulation, and are difficult to fully meet the needs of efficient and precise machining. SUMMARY

[0005] In view of the above problems, the present application provides a straightness deviation compensation device for a deep hole machining machine tool and a working method, which solves the problems of limited correction hole diameter and inability to realize online continuous correction that cannot be solved by the prior art.

[0006] In order to achieve the above purpose, the present application is realized by the following technical scheme:

[0007] In a first aspect, the present application provides a straightness deviation compensation device for a deep hole machining machine tool, comprising: a plurality of thermal actuation modules arranged on a machine tool rotating member and arranged at the end of the side wall of the machine tool rotating member; a guide block is arranged on the side of the thermal actuation module away from the machine tool rotating member, the thermal actuation module and the guide block are connected with the machine tool rotating member through a connecting fastener, the length of the connecting fastener is greater than the minimum length required when the connecting fastener passes through the guide block and the thermal actuation module and completes fastening, forming a thermal expansion and contraction space; the thermal actuation module is composed of a semiconductor temperature control sheet close to the machine tool rotating member and a stretchable material block close to the guide block, and the semiconductor temperature control sheet is connected with a semiconductor temperature control system; an ultrasonic sensor is further arranged outside the workpiece to detect the wall thickness of the workpiece in real time, the ultrasonic sensor is connected with an ultrasonic measurement system, and the ultrasonic measurement system and the semiconductor temperature control system are connected with a control system.

[0008] As a further implementation manner, the stretchable material block and the semiconductor temperature control sheet are both in sheet structure.

[0009] As a further implementation manner, the stretchable material block and the semiconductor temperature control sheet are both provided with a sensor mounting hole, and a temperature sensor is mounted in the sensor mounting hole; the temperature sensor is connected with the semiconductor temperature control system.

[0010] As a further implementation manner, the ultrasonic sensor is mounted on the workpiece through a ring-shaped support, a plurality of ultrasonic sensors are uniformly arranged on the ring-shaped support, and adjacent ultrasonic sensors are arranged at a set angle.

[0011] As a further implementation manner, the ultrasonic measurement system further comprises a signal processing unit and a calculation unit, both of which are connected with the control system.

[0012] As a further implementation manner, the thermal actuation module and the guide block are mounted on the machine tool rotating member through a connecting fastener; a bolt counterbore is arranged on the guide block.

[0013] As a further implementation manner, the end of the machine tool rotating member is embedded with a first blade, a second blade and a third blade.

[0014] As a further implementation manner, the stretchable material block adopts a thermal expansion and contraction material with high responsiveness and stable mechanical properties.

[0015] In a second aspect, the present application further provides a working method of a straightness deviation compensation device for a deep hole machining machine tool, comprising:

[0016] In the machining state, the machine tool rotating member and the workpiece rotate in opposite directions;

[0017] In the rectification state, the machine tool rotating part stops rotating while the workpiece keeps rotating;

[0018] In the machining state and the rectification state, the signal processing unit calculates the wall thickness value of the workpiece at each sensor measuring point according to the real-time ultrasonic echo signal; the calculation unit calculates the current center position of the hole, the straightness deviation value and the deviation direction of the hole relative to the ideal axis in real time based on the plurality of wall thickness values, the known outer diameter of the workpiece and the inner diameter of the hole through a geometric fitting algorithm, and the machining state is changed to the rectification state if the straightness deviation exceeds the set threshold.

[0019] As a further implementation manner, when the state is changed to the rectification state, the semiconductor temperature control system starts the compensation program immediately; the control system determines the target temperature control area according to the deviation direction provided by the ultrasonic measurement system, and sends an instruction to the semiconductor temperature control piece; the semiconductor temperature control piece starts to work, rapidly adjusts the temperature of the expansion and contraction material block to make it produce controllable expansion and contraction deformation, and the guiding block contacts the inner wall of the workpiece through the guiding block, thereby compensating the straightness deviation.

[0020] Compared with the prior art, the application has the advantages and positive effects that:

[0021] The application can drive the corresponding guiding block by the temperature control volume change thermal actuator module, the guiding block contacts the inner wall of the hole of the workpiece, the compression degree of the corresponding guiding block and the inner wall of the hole can be independently adjusted by accurately controlling the expansion and contraction of the thermal expansion and contraction material in the thermal actuator module, thereby actively changing the radial force of the machine tool rotating part in the hole to guide the tool bit to deflect in the target direction; the wall thickness of the workpiece is detected by the ultrasonic measurement system to judge the machining deviation, and the temperature is monitored and controlled by the semiconductor temperature control system to compensate the straightness deviation, thereby fundamentally avoiding the problems of wear, vibration and complex structure of the traditional mechanical compensation device, the number of system moving parts is greatly reduced, the structure is simple and compact, and the long-term operation reliability and service life of the equipment in harsh machining environment are significantly improved.

[0022] The application converts the traditional dynamic compensation into static control by only rotating the workpiece through the semiconductor temperature control system, rapid response and accurate control, and the process of static regulation of the tool bit and dynamic guidance of the workpiece. Through real-time temperature feedback and closed-loop control algorithm, micron-level accurate adjustment of the pressure of the guiding block can be realized, the accumulation of straightness deviation is effectively suppressed, and the accuracy of the drilling trajectory is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0023] The drawings accompanying the specification of the application form a part of the application and serve to further understand the application. The schematic embodiments of the application and the description thereof are used to explain the application and do not constitute an improper limitation on the application.

[0024] Figure 1The structural schematic diagram of the straightness deviation compensation device of the present application;

[0025] Figure 2 The installation position schematic diagram of the telescopic material block, the semiconductor temperature control sheet and the guide block of the present application;

[0026] Figure 3 The working position schematic diagram of the ultrasonic measuring device of the present application;

[0027] Figure 4 The bolt counterbore schematic diagram of the guide block of the present application;

[0028] Figure 5 The temperature sensor installation position schematic diagram of the present application.

[0029] In the figure: 1, guide block; 2, telescopic material block; 3, semiconductor temperature control sheet; 4, connecting fastener; 5, machine tool rotating part; 6, guide groove; 7, first blade; 8, second blade; 9, third blade; 10, ultrasonic sensor; 11, workpiece; 12, annular support; 13, bolt counterbore; 14, temperature sensor. DETAILED DESCRIPTION

[0030] It should be noted that the following detailed description is illustrative only, and is intended to provide further description in order to provide a further understanding of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0031] It should be noted that the terms used herein are only for the purpose of describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless otherwise explicitly stated in the present application, the singular form is also intended to include the plural form, and in addition, it should be understood that when the terms "comprise" and / or "include" are used in the present specification, it means that there is a feature, step, operation, device, component and / or combination thereof;

[0032] Example 1

[0033] The present embodiment provides a straightness deviation compensation device for a deep hole machining machine tool, as shown in Figure 1 - Figure 5As shown, it comprises: a machine tool rotating part 5, and a plurality of thermal actuation modules arranged on the machine tool rotating part 5, and arranged at the end of the side wall of the machine tool rotating part 5; the thermal actuation module is provided with a guide block 1 away from one side of the machine tool rotating part 5, which is used to realize the active adjustment of the direction of the tool head, the thermal actuation module and the guide block 1 are connected with the machine tool rotating part 5 through a connecting fastener 4, the length of the connecting fastener 4 is greater than the minimum length required when it passes through the guide block 1 and the thermal actuation module and completes the fastening, forming a thermal expansion and contraction active space; the thermal actuation module is composed of a semiconductor temperature control sheet 3 close to the machine tool rotating part 5 and a stretchable material block 2 close to the guide block 1, and the semiconductor temperature control sheet 3 is connected with a semiconductor temperature control system; an ultrasonic sensor 10 is further arranged outside the workpiece 11, which can detect the wall thickness of the workpiece in real time, and the ultrasonic sensor 10 is connected with an ultrasonic measurement system, and the ultrasonic measurement system and the semiconductor temperature control system are connected with a control system; specifically, the corresponding guide block 1 is pushed by the thermal actuation module which can change the volume by temperature control, the guide block 1 contacts with the inner wall of the hole of the workpiece 11, and the compression degree of the corresponding guide block 1 and the inner wall of the hole can be independently adjusted by accurately controlling the expansion and contraction of the thermal expansion and contraction material in the thermal actuation module, so as to actively change the radial force of the machine tool rotating part 5 in the hole, so as to guide the tool head to deflect to the target direction; the wall thickness of the workpiece 11 is detected by the ultrasonic measurement system, the processing deviation is judged, the temperature is monitored and controlled by the semiconductor temperature control system, and then the compensation of straightness deviation is realized, so as to fundamentally avoid the problems of wear, vibration and complex structure of the traditional mechanical compensation device, the system moving parts are greatly reduced, the structure is simple and compact, and the long-term operation reliability and service life of the equipment in harsh machining environment are significantly improved.

[0034] The control system is a closed-loop control system based on an industrial computer or a programmable logic controller, and is electrically connected with the ultrasonic measurement system and the semiconductor temperature control system respectively. The control system receives real-time straightness deviation data sent by the ultrasonic measurement system; compares the real-time straightness deviation with a preset deviation threshold. The control system has a built-in or connected compensation parameter database, which stores preset parameters related to straightness deviation compensation; the preset parameters include the temperature-deformation relationship curve of the stretchable material block, the correspondence between the straightness deviation direction and the target thermal actuation module, and the temperature control power and duration parameters required to achieve a certain compensation amount, which are used to provide accurate compensation decision basis for the control system during the correction process. The stretchable material block 2 and the semiconductor temperature control sheet 3 are both sheet structures, the temperature control and heating are realized by the semiconductor temperature control sheet, and then the stretchable material block changes the volume to push the guide block to move, realizing the deviation compensation.

[0035] As a further implementation manner, the telescopic material block 2 and the semiconductor temperature control sheet 3 are both provided with a sensor mounting hole, and a temperature sensor 14 is mounted in the sensor mounting hole; the temperature sensor 14 is connected with the semiconductor temperature control system.

[0036] As a further implementation manner, the ultrasonic sensor 10 is mounted on the workpiece 11 through a ring-shaped support 12, a plurality of ultrasonic sensors 10 are uniformly arranged on the ring-shaped support 12, and adjacent ultrasonic sensors 10 are arranged at an included angle of 45°.

[0037] As a further implementation manner, the ultrasonic measurement system further comprises a signal processing unit and a calculation unit, both of which are connected with the control system, for measuring the straightness deviation of the hole in parallel during the machining process. The signal processing unit is used to calculate the wall thickness value of the workpiece 11 at each sensor measuring point according to the ultrasonic echo signal; the calculation unit is used to calculate the current center position of the hole in real time based on a plurality of wall thickness values, a known outer diameter of the workpiece 11 and an inner diameter of the drilled hole, and to obtain the straightness deviation value and deviation direction of the hole relative to the ideal axis through a geometric fitting algorithm.

[0038] As a further implementation manner, the thermal actuator module and the guide block 1 are mounted on the machine tool rotating part 5 through the connecting fastener 4; the guide block 1 is provided with a bolt counterbore 13. A counterbore is arranged on the upper part of the guide block 1 for accommodating the head of the connecting fastener, so that the connecting fastener 4 does not exceed the working surface of the guide block 1; the connecting fastener 4 is sequentially threaded through the guide block 1, the telescopic material block 2 and the semiconductor temperature control sheet 3 and finally screwed into the threaded hole at the bottom of the guide groove 6 at the end of the side wall of the machine tool rotating part 5, and the rod part of the connecting fastener 4 is in clearance fit with the through holes on the semiconductor temperature control sheet 3 and the telescopic material block 2 respectively, so as to ensure that the bolt does not constrain the telescopic deformation of the telescopic material block 2 due to temperature change.

[0039] As a further implementation manner, the end of the machine tool rotating part 5 is embedded with a first blade 7, a second blade 8 and a third blade 9.

[0040] As a further implementation manner, the telescopic material block 2 adopts a thermal expansion and cold shrink material with high responsiveness and stable mechanical properties. The telescopic material block 2 adopts a thermal expansion and cold shrink material with high responsiveness, stable mechanical properties and excellent environmental resistance as the core telescopic element, which can produce significant and controllable deformation under active temperature control; at the same time, it has good mechanical strength and cycle stability, which can adapt to harsh working conditions such as high pressure, vibration and corrosion of cutting fluid in the process of deep hole drilling, and ensure long-term reliability and maintain compensation accuracy.

[0041] Example 2

[0042] The embodiment provides a working method of a straightness deviation compensation device of a deep hole machining machine tool, and the compensation device comprises two working states: a machining state and a deviation rectifying state.

[0043] In the machining state, the machine tool rotating part 5 and the workpiece 11 rotate in opposite directions, and the relative rotation design helps balance the cutting force, improves chip removal and enhances the cooling and lubrication effect, so that the wall surface quality, machining efficiency and overall straightness stability of drilling are improved.

[0044] In the deviation rectifying state, the machine tool rotating part 5 stops rotating while the workpiece 11 keeps rotating, when the radial pressure of the specific guide block 1 decreases or increases, the tool bit can produce controllable and accurate deflection under the friction, and necessary mechanical conditions are created for dynamic compensation of straightness deviation.

[0045] In the machining state and the deviation rectifying state, the signal processing unit calculates the wall thickness values of the workpiece 11 at the measuring points of the ultrasonic wave sensors 10 according to real-time ultrasonic echo signals; the calculation unit calculates the current center position of the hole in real time based on the plurality of wall thickness values, the known outer diameter of the workpiece and the inner diameter of the hole through a geometric fitting algorithm, and obtains the straightness deviation value and the deviation direction of the hole relative to the ideal axis, and if the straightness deviation exceeds the set threshold value, the machining state is changed to the deviation rectifying state.

[0046] As a further implementation manner, when the state is changed to the deviation rectifying state, the semiconductor temperature control system immediately starts the compensation program; the control system determines the target temperature control area according to the deviation direction provided by the ultrasonic measurement system, and sends an instruction to the corresponding semiconductor temperature control sheet 3; the semiconductor temperature control sheet 3 immediately starts to work, rapidly adjusts the temperature of the expansion material block 2 in the area, so that controllable expansion deformation is generated, the mechanical structure directly transmits the controllable expansion deformation to the corresponding guide block 1, the support pressure of the guide block 1 on the hole wall is changed, and the machine tool rotating part 5 is deflected.

[0047] It can be understood that the working method is as follows: when the workpiece starts to be machined, the machine tool rotating part 5 and the workpiece 11 simultaneously rotate in opposite directions. During the deep hole drilling process, the ultrasonic measurement system starts to work; the ultrasonic wave sensors 10 arranged on the outer wall of the workpiece 11 continuously measure the wall thickness of each point of the workpiece; the signal processing unit calculates the wall thickness values according to the echo signals, and the calculation unit calculates the current center position of the hole in real time according to the wall thickness values, the known outer diameter of the workpiece 11 and the inner diameter of the hole through a geometric fitting algorithm, and compares the current center position of the hole with the ideal axis to obtain the real-time straightness deviation value and the deviation direction.

[0048] The control system continuously receives the straightness deviation data from the ultrasonic measurement system and compares it with the preset deviation threshold. When the system determines that the real-time deviation exceeds the allowable range, the control system immediately sends a command to the machine tool spindle to stop the rotation of the machine tool rotating part 5 and keep it at the current axial position.

[0049] After the machine tool rotating part 5 completely stops, the system enters the high-precision static compensation phase. The ultrasonic measurement system makes multiple measurements and filtering to obtain more accurate hole center position and deviation direction. The control system calculates the target area of the expansion material block that needs to be activated, as well as the required power, target temperature and duration, etc. from the pre-stored compensation parameter database according to the accurate deviation direction; the control system sends a command to the semiconductor temperature control system, which starts working according to the command of the control system; the control system sends a control signal to the semiconductor temperature control sheet 3 corresponding to the target guide block; the semiconductor temperature control sheet 3 starts immediately and uses the Peltier effect to accurately regulate the temperature of the expansion material block 2 in close contact with it; the expansion material block 2 produces controllable thermal expansion deformation under the action of temperature control, which is directly transmitted to the corresponding guide block 1 through the mechanical structure, thereby accurately adjusting the radial support pressure of the guide block 1 on the hole wall to accurately regulate the direction of the tool head.

[0050] When the machine tool rotating part 5 stops rotating but the workpiece 11 is still rotating, by changing the pressure of the target side guide block, the machine tool rotating part 5 will produce a small and accurate deflection in the direction of reduced pressure under the guidance of the workpiece friction force after the force balance is broken, thereby realizing the compensation of the straightness deviation of the hole.

[0051] After the compensation action is completed, the control system confirms that the parameters are normal, and then restarts the machine tool spindle, and the drilling process continues; the ultrasonic measurement system enters the real-time monitoring state again until the deep hole machining is completed, thereby dynamically maintaining the straightness of the hole during the entire machining process.

[0052] The above describes the specific embodiments of the present application in conjunction with the drawings, but is not a limitation on the scope of protection of the present application. Those skilled in the art should understand that various modifications or variations made by those skilled in the art on the basis of the technical solutions of the present application without creative labor are still within the scope of protection of the present application.

Claims

1. A method for operating a straightness deviation compensation device for a deep hole machining machine, characterized in that, include: A rotating part of a machine tool, and a plurality of thermally actuated modules disposed on the rotating part of the machine tool, all disposed at the end of the side wall of the rotating part of the machine tool; A guide block is provided on the side of the thermal actuation module away from the rotating part of the machine tool. The thermal actuation module and the guide block are connected to the rotating part of the machine tool by connecting fasteners. The length of the connecting fasteners is greater than the minimum length required for them to pass through the guide block and the thermal actuation module to complete the fastening, forming a thermotropic expansion space. The thermal actuation module consists of a semiconductor temperature control chip near the rotating part of the machine tool and a telescopic material block near the guide block. The semiconductor temperature control chip is connected to a semiconductor temperature control system. An ultrasonic sensor is also provided on the outside of the workpiece to detect the wall thickness of the workpiece in real time. The ultrasonic sensor is connected to an ultrasonic measurement system. Both the ultrasonic measurement system and the semiconductor temperature control system are connected to the control system. The ultrasonic measurement system includes a signal processing unit and a computing unit, both of which are connected to the control system. The working methods include: During machining, the rotating parts of the machine tool and the workpiece rotate in opposite directions. In the corrective state, the rotating parts of the machine tool stop rotating while the workpiece continues to rotate; In both the machining and correction states, the signal processing unit calculates the wall thickness of the workpiece at each ultrasonic sensor measuring point based on the real-time ultrasonic echo signal. The calculation unit calculates the current center position of the hole in real time using a geometric fitting algorithm based on multiple wall thickness values, the known outer diameter of the workpiece, and the inner diameter of the drill hole, and obtains the straightness deviation value and direction relative to the ideal axis. If the straightness deviation exceeds the set threshold, the machining state is switched to the correction state. Once the state transitions to the correction state, the semiconductor temperature control system immediately initiates the compensation program. The control system determines the target temperature control zone based on the deviation direction provided by the ultrasonic measurement system and sends a command to the semiconductor temperature control chip. The semiconductor temperature control chip starts working and quickly adjusts the temperature of the telescopic material block to produce controllable telescopic deformation. Through the guide block, it contacts the inner wall of the workpiece, thereby compensating for the deviation in straightness.

2. The working method of the straightness deviation compensation device for a deep hole machining machine tool as described in claim 1, characterized in that, Both the telescopic material block and the semiconductor temperature control sheet are sheet-like structures.

3. The working method of the straightness deviation compensation device for a deep hole machining machine tool as described in claim 2, characterized in that, Both the telescopic material block and the semiconductor temperature control plate are provided with sensor mounting holes, and temperature sensors are installed in the sensor mounting holes; the temperature sensors are connected to the semiconductor temperature control system.

4. The working method of the straightness deviation compensation device for a deep hole machining machine tool as described in claim 1, characterized in that, The ultrasonic sensor is mounted on the workpiece via a ring bracket. Multiple ultrasonic sensors are evenly arranged on the ring bracket, with adjacent ultrasonic sensors forming a predetermined angle.

5. The working method of the straightness deviation compensation device for a deep hole machining machine tool as described in claim 1, characterized in that, The thermal actuation module and the guide block are mounted on the rotating part of the machine tool via connecting fasteners; the guide block is provided with bolt countersunk holes.

6. The working method of the straightness deviation compensation device for a deep hole machining machine tool as described in claim 1, characterized in that, The end of the rotating part of the machine tool is fitted with a first blade, a second blade, and a third blade.

7. The working method of the straightness deviation compensation device for a deep hole machining machine tool as described in claim 1, characterized in that, The expansion and contraction material block is made of a thermally expanding and contraction-reducing material with high responsiveness and stable mechanical properties.

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