Internal circulation cooling bone cutting tool based on 3D printing technology

Abstract

The invention designs an internal circulation cooling bone cutting tool based on a 3D printing technology. The internal circulation cooling bone cutting tool comprises the steps that 1, a tool internal structure capable of achieving internal circulation cooling of cooling liquid is designed and established; and 2, a three-dimensional model and a finite element model of the cutter are constructed, the effectiveness of the models is verified by analyzing stress distribution, deformation displacement and frequency sweeping operation, then the availability and rationality of a cooling liquid channel are verified by simulating the introduction of cooling liquid, and the models can be used for subsequent thermodynamic analysis. 3, the 3D printing technology is utilized, and the 45 steel material is used for printing the tool model in the step 2. And 4, carrying out mechanical analysis and experiment on the printed cutter, and analyzing the mechanical property of the cutter.

Description

Technical Field

[0001] The present invention relates to the field of thermal suppression of bone cutting in orthopedic surgery, and in particular to an internal circulation cooling bone cutting tool based on 3D printing technology. Background Art

[0002] Bone material is a material with composite material characteristics and biothermal activity. It is not resistant to high temperatures. Orthopedic surgery often uses drilling, grinding, cutting and other methods to remove bone materials, which inevitably produces heating effects. In order to avoid irreversible damage to bone materials caused by the thermal effect of accumulated cutting heat, the temperature must be controlled below 47°C. In orthopedic surgery, in most cases, doctors directly use drills or milling cutters to drill and split. For example, in craniotomy, a drill is first used to drill, and then a milling cutter is used to open the hole to complete the cutting. However, these methods will cause a lot of cutting heat. Research results show that when the cutting temperature exceeds 55°C and lasts for more than 30 seconds, bone materials will produce severe cell necrosis, causing bone cells to lose their regeneration function, and even lesions will occur, causing secondary damage to patients. In surgery, external cooling is generally performed by spraying saline, but the effect is limited and not applicable under all surgical conditions. In order to ensure that the tool is fully cooled and overcome the limitations of saline cooling, a tool with an internal circulation path is required for surgery. However, traditional machining cannot achieve an internal circulation path, and its mechanical properties are also greatly affected. Under the current circumstances, there is no mature means to optimize the cutting heat generated during bone cutting. Therefore, how to solve the thermal suppression of bone cutting becomes a very important issue. Summary of the invention

[0003] 1. Technical issues to be solved

[0004] A bone cutting tool is provided that can be filled with coolant and circulate inside. The tool is cooled by the current popular method of filling coolant. While ensuring the suppression of cutting heat, the coolant does not flow out of the tool and contaminate the bone material. The multi-hole circulation design and multi-channel design are used to ensure that the coolant can fully flow under various coolant pressures, thereby suppressing cutting heat. The problem that the complex internal channels cannot be completed by machining needs to be solved by additive manufacturing technology.

[0005] (II) Technical solution

[0006] In order to realize the above-mentioned internal circulation cooling bone cutting tool based on 3D printing technology, the present invention provides the following technical solutions:

[0007] An internal circulation cooling bone cutting tool based on 3D printing technology comprises the following steps:

[0008] Step 1: The internal cooling circulation tool of the present invention is designed by innovatively designing the internal structure of the tool and designing the cooling channel in a distributed manner. The coolant inlet channel is designed as an integral channel, which is located at the center of the tool. After receiving the coolant from the tool handle, the coolant is sent to the blade of the tool. At this time, the coolant can be diverted or continue to flow deep into the blade. There are four diverter balls in the coolant inlet channel of the blade, which are linearly distributed and can perform preliminary diversion of the coolant. These four diverter balls divide 8 coolant discharge channels for the coolant to be discharged.

[0009] Step 2: A three-dimensional model and finite element model of the tool were constructed, and the effectiveness of the model was verified by analyzing the stress distribution, deformation displacement and frequency sweep operation. Then, the coolant was simulated to verify the availability and rationality of the coolant channel. The model can be used for subsequent thermodynamic analysis.

[0010] Step 3: Use 3D printing technology to print the tool model in step 2 using 45 steel material.

[0011] Step 4: Conduct mechanical analysis and experiments on the printed tool to analyze its mechanical properties.

[0012] (III) Beneficial effects

[0013] Compared with the prior art, the present invention provides an internal circulation cooling bone cutting tool using 3D printing technology, which has the following beneficial effects: the present invention uses the finite element analysis method to analyze its stress distribution in advance before printing, and at the same time analyzes the movement of the coolant in its internal cooling channel, verifies the rationality of the structure, and realizes the internal circulation cooling of the tool, thereby achieving the suppression of cutting heat. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a geometric model view of an internal circulation cooling bone cutting tool according to an embodiment of the present invention;

[0015] Figure 2 is a schematic diagram of a tool finite element model established in an embodiment of the present invention;

[0016] Figure 3 is a schematic diagram of the flow direction of the internal coolant in an embodiment of the present invention;

[0017] Figure 4 is a full cross-sectional view of an internal circulation cooling bone cutting tool according to an embodiment of the present invention;

[0018] Figure 5 is an internal structural diagram of an internal circulation cooling bone cutting tool according to an embodiment of the present invention;

[0019] Figure 6It is a physical picture of the 3D printing verification of the embodiment of the present invention.

[0020] Figure 7 It is a schematic diagram of mechanical simulation displacement deformation of an embodiment of the present invention.

[0021] Figure 8 It is a schematic diagram of equivalent stress in mechanical simulation according to an embodiment of the present invention. DETAILED DESCRIPTION

[0022] The following is a detailed description of the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] The present invention provides an internal circulation cooling bone cutting tool based on 3D printing technology, comprising the following steps:

[0024] Step 1: The internal cooling circulation tool of the present invention is designed by innovatively designing the internal structure of the tool and designing the cooling channel in a distributed manner. The coolant inlet channel is designed as an integral channel, which is located at the center of the tool. After receiving the coolant from the tool handle, the coolant is sent to the blade of the tool. At this time, the coolant can be diverted at the diverter ball, or continue to flow deep into the blade. There are four diverter balls in the coolant inlet channel of the blade, which are linearly distributed and can divert the coolant in turn. These four diverter balls divide 8 coolant discharge channels for the coolant to be discharged. If the coolant flow rate is too high, the coolant will be discharged from the coolant discharge channels of the four diverter balls. If the coolant flow rate is low, only a small part of the coolant will directly enter the diverter channel, and most of the coolant will directly enter each diverter area and the entire channel in turn along the coolant inlet channel, and then fully flow into the coolant diversion channel, and finally converge in the liquid collecting chamber of the coolant discharge channel. The coolant in the 8 coolant outflow channels converges in the liquid collecting chamber and then is divided into two channels to enter the final coolant discharge channel for discharge, completing the coolant circulation.

[0025] Step 2: Construct a finite element model of the tool, and verify the validity of the model by analyzing stress distribution, deformation displacement and frequency sweeping operations. Then, simulate the introduction of coolant to verify the availability and rationality of the coolant channel. The model can be used for subsequent thermodynamic analysis. Empower the material properties of the tool, and its basic material parameters are the same as those of the structural steel. In the finite element analysis, the speed is given as 3000rpm, and the cutting force is 20N in the XY direction, while considering the influence of gravity. Then calculate the characteristic frequency to obtain the modal response and deformation of each order. This verifies that the tool can proceed to the next test. Figure 1 The figure below shows the geometric model of the tool created using SolidWorks. Figure 2 The following is a schematic diagram of the finite element model of the tool, and a schematic diagram of the internal coolant direction is shown in Figure 3 As shown. Figure 4 is a full cross-sectional view of an internal circulation cooling bone cutting tool, such as Figure 5 The figure shows the internal structure of a bone cutting tool with internal circulation cooling. Figure 7 Shown is a schematic diagram of the mechanical simulation displacement deformation of the bone cutting tool with internal circulation cooling. Figure 8 It is a schematic diagram of equivalent stress in mechanical simulation according to an embodiment of the present invention.

[0026] Step 3: Use 3D printing technology to perform initial printing verification using PLA material. The verification prototype is as follows: Figure 7 As shown. Verification is completed and the tool model of step 2 is printed using 45 steel material.

[0027] Step 4: Perform mechanical analysis and experiments on the printed tool to analyze its mechanical properties. First, use a pump to verify the integrity of the tool's cooling channel. After the coolant is pumped into the coolant inlet channel, the coolant is discharged from the coolant discharge channel, successfully proving its applicability, and then further mechanical analysis is performed.

Claims

1. The present invention relates to a new type of bone cutting tool with internal circulation cooling based on 3D printing, which has an internal trunk shunt coolant channel, aiming to effectively realize the circulation of coolant inside the tool, thereby ensuring that the tool is fully cooled during operation. The structural design of the tool significantly improves the adaptability to different coolant flow rates, and further optimizes the service life and performance of the tool. Specifically, the diameter design of the cooling channel of the present invention is shown in Table 1 and Table 2. The selection of these sizes has been accurately calculated to ensure that the coolant can effectively cover the key parts of the tool and effectively take away the heat generated during the processing, thereby maintaining the stability and performance of the tool. Table 1 Characterization of the structural parameters of the coolant channel at the tool edge Table 2 Characterization of the coolant channel structure parameters in the tool handle 2. The present invention relates to a bone cutting tool that realizes internal cooling circulation by 3D printing. Its finite element model is analyzed by finite element method, and frequency sweeping processing is performed to verify its reliability under high-speed operation. At the same time, the internal structure of the tool is verified in detail by fluid simulation to ensure its design rationality and usability. After a series of analyses, the present invention realizes the circulating coolant cooling of the bone cutting tool, providing a reliable guarantee for its efficient and stable operation.

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