Polishing mechanism for heat insulating layer of engine combustion chamber

Abstract

The engine combustion chamber heat insulation layer grinding mechanism comprises a grinding head, a driving mechanism, a detection mechanism and a control module, the driving mechanism is connected with the grinding head and used for driving the grinding head to rotate and driving the grinding head to move along a to-be-ground surface, and the detection mechanism is used for detecting the distance from the grinding head to the to-be-ground surface; the control module is in communication connection with the detection mechanism and the driving mechanism and used for adjusting the feeding speed of the driving mechanism according to signals fed back by the detection mechanism. According to the engine combustion chamber heat insulation layer grinding mechanism, the technical problem that in the prior art, the quality consistency is poor in a manual heat insulation layer grinding mode is solved.

Description

Technical Field

[0001] The present application belongs to the technical field of grinding equipment, and more specifically, relates to a grinding mechanism for the insulation layer of an engine combustion chamber. Background Art

[0002] The combustion chamber of a solid rocket engine contains an insulating layer of material, located between the inner wall of the combustion chamber shell and the solid propellant. It primarily serves as a heat-insulating and corrosion-resistant layer, reducing the rate at which high-temperature combustion gas transfers heat to the shell and ensuring the thermal safety of the shell during engine ignition.

[0003] Before loading the combustion chamber shell, the insulation layer needs to be roughened to increase its roughness and improve the interfacial bonding performance, thereby enhancing the bonding strength between the insulation layer and the propellant. Existing technology generally uses manual polishing, which has poor consistency in polishing quality. Summary of the Invention

[0004] The purpose of the embodiments of the present application is to provide a mechanism for polishing the thermal insulation layer of an engine combustion chamber, so as to solve the technical problem of poor quality consistency in the manual polishing of the thermal insulation layer in the prior art.

[0005] To achieve the above-mentioned purpose, the technical solution adopted in this application is: to provide an engine combustion chamber insulation layer grinding mechanism, including: a grinding head; a driving mechanism, the driving mechanism is connected to the grinding head, used to drive the grinding head to rotate, and drive the grinding head to move along the surface to be polished; a detection mechanism, the detection mechanism is used to detect the distance from the grinding head to the surface to be polished; and a control module, the control module is communicatively connected to the detection mechanism and the driving mechanism, and the control module is used to adjust the feed speed of the driving mechanism according to the signal feedback from the detection mechanism.

[0006] In an optional embodiment, the detection mechanism includes a first laser sensor, the control module is communicatively connected to the first laser sensor, the first laser sensor is arranged on one side of the grinding head, and the first laser sensor is used to detect the distance from the grinding head to the surface to be ground.

[0007] In an optional embodiment, the detection mechanism also includes a second laser sensor, the control module is communicatively connected to the second laser sensor, the second laser sensor is arranged on the other side of the grinding head, and the second laser sensor is used to detect the grinding depth of the surface to be ground and to detect the surface type of the surface to be ground.

[0008] In an optional embodiment, the driving mechanism includes a rotating driving member and a swinging driving member, the control module is communicatively connected to the rotating driving member and the swinging driving member, the grinding head is connected to the driving end of the rotating driving member, the rotating driving member is used to drive the grinding head to rotate around its axis; the swinging driving member is connected to the grinding head, and is used to drive the grinding head to move along the surface to be polished.

[0009] In an optional embodiment, the driving mechanism also includes a first transmission assembly, one end of the first transmission assembly is connected to the driving end of the rotating driving member, and the other end of the first transmission assembly is connected to the grinding head, and the rotating driving member drives the grinding head to rotate through the first transmission assembly.

[0010] In an optional embodiment, the driving mechanism also includes a second transmission assembly, one end of the second transmission assembly is connected to the driving end of the swinging driving member, and the other end of the second transmission assembly is connected to the grinding head, and the swinging driving member drives the grinding head to move along the surface to be polished through the second transmission assembly.

[0011] In an optional embodiment, the engine combustion chamber insulation layer grinding mechanism further includes a vertical driving member, a driving end of the vertical driving member is connected to the rotary driving member and the swing driving member, and the vertical driving member is used to drive the rotary driving member and the swing driving member to move in the vertical direction.

[0012] In an optional embodiment, the engine combustion chamber insulation layer grinding mechanism further includes a horizontal driving member, the vertical driving member is connected to the driving end of the horizontal driving member, and the horizontal driving member is used to drive the vertical driving member to move in the horizontal direction.

[0013] In an optional embodiment, the engine combustion chamber insulation layer grinding mechanism further includes an extension member, one end of the extension member is connected to the driving end of the vertical driving member, and the other end of the extension member is connected to the rotating driving member and the swing driving member.

[0014] In an optional embodiment, the extension member includes an extension tube and a supporting tube, one end of the extension tube is connected to the driving end of the vertical driving member, and the other end of the extension tube is connected to one end of the supporting tube. The swing driving member is arranged in the extension tube, and the rotating driving member is arranged in the supporting tube. The other end of the supporting tube is provided with an avoidance space for avoiding the grinding head.

[0015] The beneficial effects of the engine combustion chamber insulation layer grinding mechanism provided by the present application are: compared with the existing technology, the engine combustion chamber insulation layer grinding mechanism of the embodiment of the present application can realize the automatic rotation and feed movement of the grinding head by setting a driving mechanism, and can realize continuous and uniform automatic grinding of the insulation layer of the inner wall of the combustion chamber shell; compared with manual operation, the grinding mechanism can realize 24-hour uninterrupted operation, significantly improving the grinding efficiency; at the same time, the grinding parameters can be set and repeatedly executed, ensuring the consistency of the grinding quality of different batches of products; by setting a detection mechanism, the distance between the grinding head and the surface to be polished can be monitored in real time, so that the system can adapt to the geometric deformation or installation deviation of the inner wall of the shell, ensuring that the grinding head is always at the optimal working distance, avoiding insufficient grinding due to excessive distance, or material damage due to too small distance; the control module realizes closed-loop feedback control, receives real-time distance signals from the detection mechanism, and dynamically adjusts the feed speed of the driving mechanism, realizing adaptive grinding, improving the adaptability to complex and irregular surfaces, and ensuring that the overall surface roughness is uniform and meets the standards. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0017] Figure 1 A schematic structural diagram of a grinding mechanism for an engine combustion chamber insulation layer provided in an embodiment of the present application; Figure 2 Schematic diagram of the partial structure of the engine combustion chamber insulation layer grinding mechanism provided in the embodiment of the present application Figure 1 ; Figure 3 An exploded schematic diagram of a portion of the structure of a grinding mechanism for an engine combustion chamber insulation layer provided in an embodiment of the present application; Figure 4 Schematic diagram of the internal structure of the engine combustion chamber insulation layer grinding mechanism provided in the embodiment of the present application Figure 1 ; Figure 5 Schematic diagram of the internal structure of the engine combustion chamber insulation layer grinding mechanism provided in the embodiment of the present application Figure 2 ; Figure 6 Schematic diagram of the partial structure of the engine combustion chamber insulation layer grinding mechanism provided in the embodiment of the present application Figure 2 ; Figure 7 Schematic diagram of the partial structure of the engine combustion chamber insulation layer grinding mechanism provided in the embodiment of the present application Figure 3 .

[0018] Among them, the reference numerals in the figures are: 100-engine combustion chamber insulation layer polishing mechanism; 10-polishing head; 20-driving mechanism; 21-rotating driving member; 22-swinging driving member; 23-first transmission assembly; 231-first bevel gear; 232-second bevel gear; 233-third bevel gear; 234-transmission shaft; 235-fixing rod; 24-second transmission assembly; 241-fourth bevel gear; 242-fifth bevel gear; 243-rotating shaft; 244-belt transmission member; 30-detection mechanism; 31-first laser sensor; 32-second laser sensor; 50-vertical driving member; 61-horizontal driving member; 62-guide member; 70-extension member; 71-extension tube; 72-supporting tube; 721-avoidance space; 80-dust hood; 81-dust suction port. DETAILED DESCRIPTION

[0019] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0020] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0021] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0023] The combustion chamber of a solid rocket engine contains an insulating layer of material, located between the inner wall of the combustion chamber shell and the solid propellant. It primarily serves as a heat-insulating and corrosion-resistant layer, reducing the rate at which high-temperature combustion gas transfers heat to the shell and ensuring the thermal safety of the shell during engine ignition.

[0024] Before loading the combustion chamber casing, the insulation layer needs to be roughened to increase its roughness and improve interfacial adhesion, thereby enhancing the bond strength between the insulation layer and the propellant. However, existing technologies generally use manual polishing, which is difficult, costly, has poor quality consistency, and is inefficient, making it difficult to meet the needs of high-quality, mass-produced production.

[0025] Please also refer to Figures 1 to 7 The engine combustion chamber insulation layer grinding mechanism 100 provided in an embodiment of the present application is now described. The engine combustion chamber insulation layer grinding mechanism 100 includes: a grinding head 10; a drive mechanism 20 connected to the grinding head 10 and configured to drive the grinding head 10 to rotate and move along the surface to be ground; a detection mechanism 30 configured to detect the distance between the grinding head 10 and the surface to be ground; and a control module (not shown) communicatively connected to the detection mechanism 30 and the drive mechanism 20. The control module is configured to adjust the feed speed of the drive mechanism 20 based on a signal fed back by the detection mechanism 30.

[0026] The grinding head 10 is used to grind the surface of the thermal insulation layer, directly contacting the surface to be ground and removing material. The grinding head 10 can be implemented by a ball grinding head or a rotating grinding wheel, and the surface is covered with abrasive.

[0027] The driving mechanism 20 is used to provide power to control the movement of the grinding head 10. The driving mechanism 20 drives the grinding head 10 to complete a composite motion trajectory through a combination of rotation and linear movement. The driving mechanism 20 can be specifically implemented by a servo motor in conjunction with a screw guide or a rack and pinion mechanism. In some embodiments, the driving mechanism 20 includes a rotary motor and a feed motor. The rotary motor is connected to the grinding head 10 to drive its rotation, and the feed motor drives the grinding head 10 to move along the surface to be polished through a transmission mechanism. The driving mechanism 20 can drive the grinding head 10 to rotate automatically and move along the surface to be polished. This setting not only eliminates the limitations of manual operation, but also enables continuous operation, greatly improving work efficiency.

[0028] The detection mechanism 30 refers to a sensing device that measures the distance between the grinding head 10 and the surface to be ground in real time. It obtains dynamic distance data through non-contact measurement to feed back to the control system. Specifically, it can be implemented by using a laser distance sensor or an ultrasonic sensor. The detection mechanism 30 can be installed on the grinding head 10 or near the grinding head 10 for monitoring. In some embodiments, the detection mechanism 30 uses a laser distance sensor, which is installed near the grinding head 10 to detect the distance from the grinding head 10 to the surface to be ground. The detection mechanism 30 is used to monitor the distance from the grinding head 10 to the surface to be ground in real time, ensuring that the grinding head 10 is always at the optimal working distance, avoiding the problem of insufficient grinding due to excessive distance or material damage due to too small a distance.

[0029] In other embodiments, a three-dimensional laser scanner can be provided to reconstruct the surface morphology of the insulation layer in real time and identify defective areas such as pits, bulges, and seams; or a visual camera can be provided to identify marking points, locate the starting position of grinding, or monitor dust accumulation.

[0030] In some other embodiments, a contact force sensor may be provided, mounted on the rear end of the grinding head 10, to provide real-time feedback of the normal pressure, thereby achieving constant-force grinding. Alternatively, an infrared thermal imager may be provided to monitor local temperature rise during grinding to prevent thermal damage to the insulation layer due to overheating.

[0031] The control module is a processor that adjusts the operating state of the drive mechanism 20 based on detection data. Specifically, it can be implemented using a PLC or an embedded single-chip microcomputer combined with a PID algorithm. It dynamically adjusts the feed speed through a closed-loop feedback mechanism to maintain a constant polishing pressure, ensuring consistent polishing quality. In some embodiments, the control module utilizes an industrial control computer, connected to the detection mechanism 30 and the drive mechanism 20 via a data acquisition card. Because the entire process can be programmed and precisely controlled, polishing parameters (such as rotational speed and feed speed) can be adjusted and repeated as needed, ensuring consistent quality across batches of products.

[0032] Moreover, the control module can dynamically adjust the feed speed of the driving mechanism 20 according to the real-time signal provided by the detection mechanism 30, thereby realizing adaptive polishing, enabling the system to efficiently process complex and irregular surfaces, ensuring that the surface roughness of the entire insulation layer is uniform and meets the standards, thereby effectively enhancing the bonding strength between the insulation layer and the propellant.

[0033] The present application realizes automatic rotation and feeding motion of the grinding head 10 through the driving mechanism 20, and combines the detection mechanism 30 to monitor the distance in real time and feed back to the control module to form a closed-loop control system, thereby improving the grinding efficiency while ensuring the uniformity of the grinding depth and adapting to the geometric deformation or installation deviation of the inner wall of the shell.

[0034] The polishing mechanism uses a drive mechanism 20 to automatically rotate and advance the polishing head 10, providing continuous and uniform automated polishing of the insulation layer on the inner wall of the combustion chamber housing. A detection mechanism 30 monitors the distance between the polishing head 10 and the surface being polished in real time, enabling the system to adapt to geometric deformations or installation deviations of the housing's inner wall, ensuring the polishing head 10 is always at the optimal working distance. The control module receives real-time distance signals from the detection mechanism 30 and dynamically adjusts the feed speed of the drive mechanism 20, achieving adaptive polishing and improving adaptability to complex, irregular surfaces.

[0035] Furthermore, the grinding head 10 can be connected via a quick-change interface, facilitating the replacement of different types of ball mills or grinding wheels to accommodate varying materials and roughness requirements. The grinding head 10 can also be connected via a ball joint or universal joint, allowing for free swing within a certain angle range. This allows the grinding head 10 to automatically adapt to local curvature variations in the housing's inner wall, maintaining a good fit in areas like tapered sections and seams, and minimizing edge leakage.

[0036] During operation, the drive mechanism 20 drives the grinding head 10 to rotate at high speed and move it along a preset trajectory. A laser rangefinder measures the distance between the grinding head 10 and the surface being polished in real time and transmits this data to the control module. Based on this distance signal, the control module calculates the optimal feed speed using a preset algorithm and outputs control commands to adjust the feed motor speed, thereby maintaining a constant distance between the grinding head 10 and the surface being polished, ensuring uniform polishing.

[0037] The automatic rotation and feeding movement of the grinding head 10 are realized by the driving mechanism 20, and the distance is monitored in real time by the detection mechanism 30 and the feeding speed is dynamically adjusted by the control module, thereby solving the problems of low efficiency and uneven quality of manual grinding. It has the advantages of improving grinding efficiency, ensuring the consistency of grinding quality of different batches of products, adapting to the geometric deformation of the inner wall of the shell, and ensuring that the surface roughness is uniform and meets the standards.

[0038] Automated equipment reduces dependence on skilled workers, reduces labor intensity, eliminates the need for workers to enter confined spaces for operation, and reduces safety hazards. Through precise control and real-time monitoring, closed-loop feedback control improves adaptability to complex and irregular surfaces, ensuring that the entire surface roughness is uniform and meets standards, ensuring polishing quality and consistency, and improving product reliability and durability.

[0039] This solution enables automated grinding of the insulation layer on the inner wall of the combustion chamber housing. Real-time distance detection and adaptive control overcome the difficulty of manually controlling the position of the grinding head 10, ensuring uniform grinding. Automated operation allows for 24-hour uninterrupted operation, significantly improving production efficiency.

[0040] The engine combustion chamber insulation layer grinding mechanism 100 provided in the embodiment of the present application, compared with the prior art, can realize automatic rotation and feed movement of the grinding head 10 by setting a driving mechanism 20, and can realize continuous and uniform automatic grinding of the insulation layer on the inner wall of the combustion chamber shell; compared with manual operation, the grinding mechanism can realize 24-hour uninterrupted operation, significantly improving the grinding efficiency; at the same time, the grinding parameters can be set and repeatedly executed, ensuring the consistency of the grinding quality of different batches of products; by setting a detection mechanism 30, the distance between the grinding head 10 and the surface to be ground can be monitored in real time, so that the system can adapt to the geometric deformation or installation deviation of the inner wall of the shell, ensuring that the grinding head 10 is always at the optimal working distance, avoiding insufficient grinding due to excessive distance, or material damage due to too small distance; the control module implements closed-loop feedback control, receives the real-time distance signal of the detection mechanism 30, and dynamically adjusts the feed speed of the driving mechanism 20, realizing adaptive grinding, improving the adaptability to complex and irregular surfaces, and ensuring that the overall surface roughness is uniform and meets the standards.

[0041] In some embodiments of this application, please refer to Figures 4 to 7 The detection mechanism 30 includes a first laser sensor 31. The control module is in communication with the first laser sensor 31. The first laser sensor 31 is disposed on one side of the grinding head 10. The first laser sensor 31 is used to detect the distance from the grinding head 10 to the surface to be ground.

[0042] like Figure 4 and Figure 5 The first laser sensor 31 is mounted non-contactly to the side of the grinding head 10, with its detection axis forming a preset angle with the axis of the grinding head 10. The first laser sensor 31 calculates the real-time distance between the grinding head 10 and the surface being ground by emitting a laser beam and receiving the reflected signal. The first laser sensor 31 is mounted away from the rotational path of the grinding head 10 to avoid mechanical interference.

[0043] The first laser sensor 31, mounted laterally, enables multi-angle detection. As the grinding head 10 moves along a curved surface, it continuously acquires surface profile data at different locations. After receiving the distance signal, the control module determines the current operating status based on a preset threshold range: the feed speed is increased when the detection distance exceeds the upper limit, and reduced when it falls below the lower limit. Therefore, high-frequency, high-precision data acquisition effectively overcomes measurement errors caused by variations in surface reflectivity or local geometric changes, ensuring that the control module accurately maintains a constant working distance between the grinding head 10 and the surface.

[0044] The first laser sensor 31 can be a laser displacement sensor based on the triangulation ranging principle, including a laser transmitter and a photoelectric receiver. The laser beam emitted by the laser transmitter is irradiated onto the surface to be polished and then reflected back to the photoelectric receiver. By measuring the emission angle and reflection angle of the laser beam, the precise distance from the polishing head 10 to the surface to be polished can be calculated.

[0045] The first laser sensor 31 is mounted on the side of the grinding head 10. Its measurement range covers the normal range of distance variation during operation. This allows the first laser sensor 31 to monitor the distance between the grinding head 10 and the surface being ground in real time, providing accurate distance data to the control module. Based on this data, the control module adjusts the feed speed of the drive mechanism 20, achieving precise control of the grinding process.

[0046] Therefore, the provision of the first laser sensor 31 enables real-time and precise monitoring of the distance between the grinding head 10 and the surface being ground, enabling the mechanism to adapt to geometric deformations or installation deviations of the housing inner wall, ensuring that the grinding head 10 always maintains the optimal working distance. This avoids problems such as insufficient grinding due to excessive distance, or material damage due to insufficient distance. This improves the consistency and reliability of grinding quality and enhances the grinding mechanism's adaptability to complex and irregular surfaces.

[0047] In some embodiments of this application, please refer to Figures 4 to 7 The detection mechanism 30 also includes a second laser sensor 32. The control module is communicatively connected to the second laser sensor 32. The second laser sensor 32 is arranged on the other side of the grinding head 10. The second laser sensor 32 is used to detect the grinding depth of the surface to be ground and to detect the surface type of the surface to be ground.

[0048] The second laser sensor 32 and the first laser sensor 31 are located on both sides of the grinding head 10 and can be arranged symmetrically. Figure 6 The laser beam emitted by the second laser sensor 32 is arranged at an angle to the detection direction of the first laser sensor 31, and can be at a complementary angle. The second laser sensor 32 performs detection and generates a detection signal. The control module can calculate the material removal thickness in real time by comparing the difference in the signals from the first laser sensor 31 and the second laser sensor 32. At the same time, the control module can determine whether the target roughness or texturing depth has been achieved based on this result. If it is not achieved, the control module will automatically increase the number of grinding times or adjust the parameters.

[0049] A second laser sensor 32 scans the surface profile and, combined with an algorithm, determines the surface type of the area, such as a flat surface, a large arc of curvature, a small radius chamfer, or an insulation seam. Different surface types require different grinding parameters. For curved surfaces, the feed rate is reduced to maintain stable contact; for seams, the grinding path is increased to enhance edge adhesion; for flat surfaces, efficiency is increased and the pass rate is fast. This allows for process adjustments and improves overall grinding quality consistency.

[0050] The laser beam emitted by the second laser sensor 32 is projected onto the polished area at an inclined angle. The intensity of the reflected light received increases with the increase of the polishing depth. When the insulation layer material is removed to the set threshold, the reflection intensity corresponds to the preset roughness standard value.

[0051] The coordinated detection of the second laser sensor 32 and the first laser sensor 31 avoids the blind spots of single-point detection and improves the system's adaptability to complex surfaces. When a high-reflectivity surface is detected, the grinding head 10's rotational speed is automatically reduced to prevent overheating. When a low-reflectivity area is detected, the feed speed is increased to compensate for machining efficiency. If a sensor experiences an abnormal signal due to dust obstruction, reflectivity changes, or other factors, the other sensor can serve as a redundant reference to assist in determining the true state. Dual-sided measurement can also compensate for errors caused by mechanical vibration or posture deviation, enhancing the system's stability and reliability in harsh industrial environments.

[0052] The first laser sensor 31 and the second laser sensor 32 can be laser displacement sensors based on the triangulation principle. The first laser sensor 31 emits a laser beam to illuminate the surface to be polished, receives the reflected light and calculates the distance from the polishing head 10 to the surface. The second laser sensor 32 also emits a laser beam and receives the reflected light, and determines the polishing depth and surface type of the surface by analyzing the intensity and scattering characteristics of the reflected light. The measurement data of the two laser sensors are transmitted to the control module via a data line for processing. The control module adjusts the feed speed of the drive mechanism 20 according to the distance data of the first laser sensor 31 to maintain the optimal working distance between the polishing head 10 and the surface. At the same time, based on the polishing depth data fed back by the second laser sensor 32, the control module can dynamically adjust the polishing parameters, such as the rotation speed and pressure of the polishing head 10, to ensure polishing uniformity.

[0053] In addition, the surface type information detected by the second laser sensor 32 can be used to identify the insulation layer materials in different areas, thereby optimizing the grinding strategy. For example, different grinding parameters can be used for insulation layer areas with different hardness or thickness.

[0054] In some embodiments, a third laser sensor can also be provided and installed directly in front of the grinding head 10, which cooperates with the industrial camera to form a 3D contour scanning system to reconstruct the three-dimensional morphology point cloud data of the area to be polished in real time; identify defects such as pits, bulges, and seam dislocations in advance, predict the grinding allowance, and assist in path planning; compared with single-point laser, line laser can obtain surface information and significantly improve surface recognition capabilities.

[0055] By setting up a first laser sensor 31 and a second laser sensor 32, precise control and adaptive adjustment of the polishing process are achieved. The first laser sensor 31 monitors the distance between the polishing head 10 and the surface to be polished in real time to ensure that the polishing head 10 always remains in the optimal working position, avoiding uneven polishing or material damage caused by distance deviation. The intelligence level of the polishing process is further enhanced by setting up a second laser sensor 32. By detecting the polishing depth, the polishing effect can be evaluated in real time to ensure that the entire surface meets the expected roughness requirements. At the same time, the surface type recognition function enables the polishing mechanism to automatically adjust the polishing parameters according to the material characteristics of different areas, thereby improving the consistency and adaptability of the polishing quality. The dual detection mechanism greatly improves the accuracy and controllability of the polishing process, effectively solves the problem of difficulty in ensuring uniformity and consistency in traditional manual polishing, and significantly improves the polishing quality of the insulation layer of the combustion chamber shell.

[0056] In some embodiments of this application, please refer to Figures 4 and 5 The driving mechanism 20 includes a rotating driving member 21 and a swinging driving member 22. The control module is communicatively connected with the rotating driving member 21 and the swinging driving member 22. The grinding head 10 is connected to the driving end of the rotating driving member 21. The rotating driving member 21 is used to drive the grinding head 10 to rotate around its axis; the swinging driving member 22 is connected to the grinding head 10 and is used to drive the grinding head 10 to move along the surface to be polished.

[0057] The rotary drive 21 is connected to the grinding head 10, ensuring that the rotational torque is directly transmitted to the grinding head 10. The swing drive 22 can drive the grinding head 10 by directly driving the grinding head 10 or by tilting the grinding head 10 to approach the surface to be polished. The swing drive 22 can be configured as a servo motor or a screw mechanism, and its travel range covers the maximum length of the surface to be polished.

[0058] When powered, the rotary drive 21 drives the output shaft at a set speed, driving the grinding head 10 to rotate synchronously, creating a circumferential cutting motion. The oscillating drive 22 propels the rotating grinding head 10 along an arc or linear path across the surface being polished. The timing of the rotary and oscillating drives 21 and 22 is coordinated by the control module. When the detection mechanism 30 reports a distance change, the oscillating drive 22 immediately adjusts its speed while the rotary drive 21 maintains a constant speed, ensuring a stable cutting force.

[0059] By independently controlling the rotational and traversing speeds of the grinding head 10, optimal grinding parameters can be adjusted based on material properties, resulting in a more uniform surface roughness. For workpieces of varying shapes and sizes, such as complex curved surfaces or large components, the operating parameters of the two drive components can be flexibly adjusted, allowing the grinding process to better meet actual needs.

[0060] Both the rotary drive 21 and the swing drive 22 are controlled by a control module. Based on signals fed back by the detection mechanism 30, the control module adjusts the rotational speed of the rotary drive 21 and the feed rate of the swing drive 22, achieving adaptive grinding. When the control module detects an increase in the distance between the grinding head 10 and the surface being ground, it reduces the feed rate of the swing drive 22, allowing the grinding head 10 more time to dwell and grind in that area. Conversely, when the distance decreases, the feed rate can be appropriately increased.

[0061] The automatic rotation and feed motion of the grinding head 10, achieved through the rotary drive 21 and the swing drive 22, enables continuous and uniform automated grinding of the insulation layer on the inner wall of the combustion chamber housing. This improves grinding efficiency and reduces the labor intensity of manual operation. Furthermore, the control module's precise control of the drive mechanism 20 ensures consistent and uniform grinding quality, enhancing its adaptability to complex and irregular surfaces.

[0062] In some embodiments of this application, please refer to Figure 4 The driving mechanism 20 also includes a first transmission assembly 23, one end of the first transmission assembly 23 is connected to the driving end of the rotating driving member 21, and the other end of the first transmission assembly 23 is connected to the grinding head 10, and the rotating driving member 21 drives the grinding head 10 to rotate through the first transmission assembly 23.

[0063] The first transmission assembly 23 efficiently and stably transmits the power of the rotary drive member 21 to the grinding head 10. The first transmission assembly 23 can be implemented as a coupling, a gear set, or a synchronous pulley. By providing the first transmission assembly 23, power transmission can be optimized, ensuring that the output of the rotary drive member 21 better meets the actual needs of the grinding head 10. For example, for applications requiring high torque, using a transmission assembly such as a speed reducer can significantly increase torque output.

[0064] In some embodiments, as Figures 4 to 7 The first transmission assembly 23 includes a first bevel gear 231, a second bevel gear 232, a third bevel gear 233 and a transmission shaft 234. The first bevel gear 231 is fixedly connected to the driving end of the rotating driving member 21, the second bevel gear 232 is rotatably sleeved on the outside of the transmission shaft 234, and is engaged with the first bevel gear 231. The third bevel gear 233 is fixedly connected to the connecting end of the grinding head 10 and is engaged with the second bevel gear 232.

[0065] The meshing of the first bevel gear 231 and the second bevel gear 232 transmits the rotational power of the rotary drive member 21 to the transmission shaft 234 , and the meshing of the third bevel gear 233 and the second bevel gear 232 converts the rotational power of the transmission shaft 234 into circumferential rotation of the grinding head 10 .

[0066] The first bevel gear 231 can be made of precision-machined alloy steel for high strength and wear resistance. The second bevel gear 232 and the third bevel gear 233 can be made of the same material to ensure meshing accuracy. The transmission shaft 234 can be made of high-strength alloy steel with a hardened surface for improved wear resistance.

[0067] The first transmission assembly 23 is provided to realize the rotational motion control of the grinding head 10, and the grinding head 10 can realize self-rotation, thereby improving the grinding efficiency. The bevel gear transmission structure is compact, the transmission is stable, and the reliability is high.

[0068] In some embodiments of this application, please refer to Figures 5 and 6 The driving mechanism 20 also includes a second transmission assembly 24, one end of the second transmission assembly 24 is connected to the driving end of the swing driving member 22, and the other end of the second transmission assembly 24 is connected to the grinding head 10. The swing driving member 22 drives the grinding head 10 to move along the surface to be polished through the second transmission assembly 24.

[0069] By providing a second transmission assembly 24, the position of the grinding head 10 on the surface to be polished can be precisely controlled, ensuring a uniform and consistent polishing effect. The second transmission assembly 24 can be configured as a combination of a ball screw and a slide, with the ball screw connected to a slide via a nut seat, and the slide mounted with the grinding head 10 and the second transmission assembly 24. Alternatively, it can be configured as a rack and pinion transmission, with the swing drive 22 driving a slide via a rack and pinion mechanism, and the slide mounted with the grinding head 10 and the second transmission assembly 24.

[0070] In some embodiments, as Figures 4 to 7 The second transmission assembly 24 includes a fourth bevel gear 241, a fifth bevel gear 242, a rotating shaft 243, a belt transmission member 244 and a fixed rod 235. The fourth bevel gear 241 is fixedly connected to the driving end of the swing driving member 22. The fifth bevel gear 242 is sleeved on the outside of the rotating shaft 243 and meshes with the fourth bevel gear 241. One end of the belt transmission member 244 is sleeved on the outside of the rotating shaft 243, and the other end of the belt transmission member 244 is sleeved on the outside of the transmission shaft 234. One end of the fixed rod 235 is fixedly connected to the transmission shaft 234, and the other end of the fixed rod 235 is rotatably connected to the connecting end of the grinding head 10.

[0071] The meshing of fourth bevel gear 241 and fifth bevel gear 242 transmits the rotational motion of swing drive member 22 to rotating shaft 243. Belt drive member 244 connects rotating shaft 243 to drive shaft 234 via a belt, achieving secondary power transmission. By altering the direction of power transmission through bevel gear meshing, belt drive member 244 further cushions vibrations and accommodates varying speed requirements. Belt drive member 244 forms a flexible connection between rotating shaft 243 and drive shaft 234, mitigating the impact of rigid transmission. The bevel gear meshing structure ensures that the power transmission direction is perpendicular to the axis of drive shaft 234, optimizing spatial layout and enabling drive mechanism 20 to achieve multi-stage transmission within a limited space.

[0072] When the swing drive member 22 drives the transmission shaft 234 to rotate via the transmission structure, the second bevel gear 232 is rotatably mounted on the transmission shaft 234. The movement of the second bevel gear 232 is not affected, and the transmission shaft 234 can drive the fixed rod 235 to rotate about its axis, thereby driving the grinding head 10 to move along the surface to be polished. In other words, the rotational connection structure at the other end of the fixed rod 235 allows the grinding head 10 to maintain its own rotation while maintaining a power transmission relationship with the transmission shaft 234. Therefore, the swing drive member 22 can drive the grinding head 10 to move along the surface to be polished via the second transmission assembly 24.

[0073] Thus, the transmission paths of the rotational power and the movement power are integrated into the same transmission shaft 234, avoiding the problem of mechanism interference caused by multi-axis transmission. The fixing rod 235 can be made of a lightweight and high-strength aluminum alloy material to reduce the overall weight.

[0074] The length of the belt drive 244 can be adjusted according to the actual installation requirements to meet the grinding requirements of combustion chamber shells of different sizes. Figure 4 The rotary drive member 21 is positioned near the grinding head 10 to directly drive the grinding head 10 in rotation. The swing drive member 22 is spaced apart from the rotary drive member 21, and the belt drive member 244 is located on the side of the rotary drive member 21. Through the combination of bevel gears and belt drive, the power transmission path is broken down into two stages, which not only ensures transmission efficiency but also reduces the impact of vibration on the motion trajectory of the grinding head 10, thereby improving the smooth movement of the grinding head 10.

[0075] In addition, if Figure 5 There are two belt transmission parts 244, which are located on both sides of the rotating shaft 243, so that the rotating shaft 243 and the two ends of the transmission shaft 234 are connected through the two belt transmission parts 244, the power transmission is smoother, and the grinding head 10 can be driven to move more stably, thereby improving the grinding accuracy.

[0076] The fourth bevel gear 241 can be made of a cemented carbide material with high wear resistance and strength. The fifth bevel gear 242 can be made of a stainless steel material with good corrosion resistance. The rotating shaft 243 can be made of a high-strength alloy steel material to withstand greater torque and stress. The belt transmission member 244 can be a synchronous belt made of a wear-resistant rubber material, and a toothed structure can be provided on the inside to ensure the accuracy and stability of the transmission; in addition, a positioning member can be provided to abut against the synchronous belt to maintain the accuracy and stability of the power transmitted by the synchronous belt. The belt transmission member 244 is respectively mounted on the outside of the rotating shaft 243 and the transmission shaft 234, and the tension of the belt is adjusted by the tensioning pulley to ensure the reliability of the transmission.

[0077] The bevel gear transmission structure in the second transmission assembly 24 can change the power transmission direction by 90 degrees to adapt to the space layout requirements. In addition, the use of a belt drive also facilitates the adjustment of the transmission ratio. By replacing pulleys of different sizes, the feed speed of the grinding head 10 can be flexibly adjusted to meet different grinding requirements.

[0078] The rotary drive member 21 rotates the first bevel gear 231, which in turn meshes with the second bevel gear 232, causing the second bevel gear 232 to rotate. The meshing of the third bevel gear 233 with the second bevel gear 232 then drives the grinding head 10 to rotate. The swing drive member 22 rotates the transmission shaft 234, which in turn moves the grinding head 10 via the fixed rod 235. This transmission method achieves a combined rotation and feed motion of the grinding head 10, improving grinding efficiency and uniformity.

[0079] The overall transmission structure is simple, takes up little space, and facilitates the insertion of the grinding mechanism into the combustion chamber housing for insulation grinding. It is also easy to maintain and suitable for long-term continuous operation. This transmission method can flexibly adjust the motion trajectory of the grinding head 10 to adapt to different shapes of surfaces to be ground, thereby improving the adaptability and uniformity of the grinding process.

[0080] In some embodiments of this application, please refer to Figure 1 and Figure 2 The engine combustion chamber insulation layer grinding mechanism 100 also includes a vertical driving member 50, the driving end of the vertical driving member 50 is connected to the rotating driving member 21 and the swing driving member 22, and the vertical driving member 50 is used to drive the rotating driving member 21 and the swing driving member 22 to move in the vertical direction.

[0081] The vertical drive 50 utilizes a linear motion mechanism, with its drive end secured to the mounting bases of the rotary drive 21 and the swing drive 22 via rigid connectors. The vertical drive 50 moves perpendicular to the axis of the grinding head 10. The vertical drive 50 can be a combination of a motor and guide rails, or a hydraulic cylinder.

[0082] The vertical direction refers to the height direction of the grinding mechanism during normal use. The vertical drive member 50 drives the rotary drive member 21 and the swing drive member 22 to move as a whole in the vertical direction, so that the grinding head 10 can approach or move away from the surface to be ground. By adjusting the position in the vertical direction, the axial deviation caused by the shell installation error or the deformation of the inner wall can be eliminated. Before grinding, the initial distance between the grinding head 10 and the inner wall of the combustion chamber shell can be adjusted by the vertical drive member 50 so that the distance between the grinding head 10 and the inner wall falls within the driving distance range of the swing drive member 22, so that the swing drive member 22 drives the grinding head 10 to press against the inner wall of the shell for grinding.

[0083] The vertical drive member 50 can also be electrically connected to a control module. The control module can control the movement of the vertical drive member 50 based on a preset program or signals fed back by the detection mechanism 30, thereby adjusting the vertical position of the grinding head 10. For example, upon detecting a change in the height of the surface to be polished, the control module can drive the vertical drive member 50 to adjust the height of the grinding head 10 accordingly to maintain a certain distance between the grinding head 10 and the surface to be polished, allowing the swing drive member 22 to further control the grinding head 10 to approach the inner wall of the housing.

[0084] The vertical drive member 50 allows for vertical adjustment of the grinding head 10, improving the grinding mechanism's adaptability to combustion chamber housing inner walls of varying heights and shapes. Automated height adjustment improves grinding efficiency and reduces manual error.

[0085] In some embodiments of this application, please refer to Figure 1 The engine combustion chamber insulation layer grinding mechanism 100 further includes a horizontal driving member 61, and the vertical driving member 50 is connected to the driving end of the horizontal driving member 61. The horizontal driving member 61 is used to drive the vertical driving member 50 to move in the horizontal direction.

[0086] The horizontal direction refers to the direction in which the mechanism is used. Figure 1 The horizontal drive member 61 can drive the vertical drive member 50 and the grinding head 10 to move horizontally, allowing them to enter the combustion chamber housing for grinding. The horizontal drive member 61 can be a linear motor or a ball screw structure, with its drive end rigidly connected to the fixed base of the vertical drive member 50. The horizontal movement direction is orthogonal to the movement direction of the vertical drive member 50. The horizontal travel can cover the entire length of the combustion chamber housing or be set to be longer to accommodate combustion chamber housings of different lengths.

[0087] The horizontal drive member 61 drives the vertical drive member 50 and the connected grinding head 10 to move axially along the housing, expanding the operating range of the grinding head 10. For example, when grinding the inner wall of a cylindrical housing, the coordinated movement of the horizontal drive member 61 and the vertical drive member 50 allows the grinding head 10 to move in both vertical and horizontal directions, ensuring that the working surface of the housing inner wall is covered.

[0088] The provision of a horizontal drive member 61 overcomes the difficulty of precisely controlling horizontal displacement during manual grinding, enabling precise positioning of the grinding head 10 throughout the entire axial range of the housing. The coordinated movement of the horizontal drive member 61 and the vertical drive member 50 enables the grinding mechanism to adapt to combustion chamber housings of varying lengths. By controlling the horizontal movement path, uniform grinding pressure is ensured across all areas of the annular insulation surface, avoiding the uneven grinding caused by positioning deviations in traditional manual operations and significantly improving the consistency of the grinding quality of the inner wall of the long cylindrical housing.

[0089] When the control module determines that a grinding zone needs to be switched based on a signal from the detection mechanism 30, the horizontal drive member 61 is activated, driving the vertical drive member 50 and the grinding head 10 to move along the housing axis. During this movement, the detection mechanism 30 continuously monitors the distance between the grinding head 10 and the inner wall, ensuring that the distance between the grinding head 10 and the inner wall remains stable during movement.

[0090] The vertical drive member 50 cooperates with the horizontal drive member 61 to enable the grinding head 10 to move flexibly in three-dimensional space, ensuring comprehensive coverage and grinding of complex curved surfaces. Figure 1 A guide member 62 is also provided to cooperate with the guide rail of the horizontal driving member 61 to guide the horizontal movement of the vertical driving member 50 to make the movement more stable.

[0091] In some embodiments of this application, please refer to Figures 1 to 3 The engine combustion chamber insulation layer grinding mechanism 100 also includes an extension member 70, one end of the extension member 70 is connected to the driving end of the vertical driving member 50, and the other end of the extension member 70 is connected to the rotating driving member 21 and the swing driving member 22.

[0092] By providing the extension piece 70 , the extension piece 70 can effectively extend the reachable distance of the grinding head 10 , so that the grinding device can penetrate deep into the combustion chamber housing, especially a longer housing.

[0093] Due to the presence of the extension member 70 , the grinding head 10 can operate under more stable conditions, reducing vibration or deviation caused by excessive extension of the robotic arm, thereby ensuring stability and consistency during the grinding process.

[0094] The extension member 70 can be a hollow steel pipe structure with light weight, high strength, low cost, and the inner diameter can be set to be large enough for wiring, etc.; it can also be a multi-section telescopic structure with adjustable length for easy storage and transportation.

[0095] For components with long internal cavities, such as large rocket engines, the use of extension piece 70 ensures that the grinding head 10 can reach and process all areas of the casing's inner wall without requiring a major redesign of the equipment. Because the extension piece 70 allows the grinding head 10 to penetrate deep into the combustion chamber casing, it reduces the risk of personnel entering confined spaces and greatly improves operational safety.

[0096] In some embodiments of this application, please refer to Figures 1 to 3 The extension member 70 includes an extension tube 71 and a supporting tube 72. One end of the extension tube 71 is connected to the driving end of the vertical driving member 50, and the other end of the extension tube 71 is connected to one end of the supporting tube 72. The swing driving member 22 is arranged in the extension tube 71, and the rotating driving member 21 is arranged in the supporting tube 72. The other end of the supporting tube 72 is provided with an avoidance space 721 for avoiding the grinding head 10.

[0097] The extension tube 71 is connected to the driving end of the vertical drive member 50, and the supporting tube 72 is welded to the end of the extension tube 71, forming an overall extended structure. The motor of the swing drive member 22 is installed inside the extension tube 71, and the output shaft is connected to the drive shaft 234 via a belt drive member 244. The drive shaft 234 is located in the supporting tube 72 and drives the rotating parts of the rotary drive member 21. A support frame can be provided inside the supporting tube 72, and the motor of the rotary drive member 21 is fixed to the support frame. The output shaft is connected to the grinding head 10 via a gear set. An escape space 721 is provided at the end of the supporting tube 72, and the grinding head 10 is located in the escape space 721, that is, it is exposed to the outside. A gap is maintained between the edge of the escape space 721 and the grinding head 10 to prevent movement interference. When it is necessary to adapt to a longer housing, the total length of the extension tube 71 and the supporting tube 72 can be customized according to the length of the housing, and quick adjustment can be achieved by replacing extension tubes 71 of different lengths. The extension tube 71 and the supporting tube 72 both adopt a hollow tubular structure. The extension tube 71 and the supporting tube 72 can be made of lightweight aluminum alloy material, and reinforcing ribs are provided inside to improve the structural rigidity and avoid deformation during long-distance transmission.

[0098] One end of the extension tube 71 can be connected to the output end of the vertical drive member 50 via welding or threading, while the other end is secured to one end of the support tube 72 via a flange or welding. The swing drive member 22 is positioned within the interior of the extension tube 71, its output shaft connected to the transmission shaft 234 via a coupling. The rotational drive member 21 is mounted on a bracket within the interior of the support tube 72, its output end connected to the rotating shaft 243 of the grinding head 10 via a keyway. The other end of the support tube 72 is machined with a U-shaped groove, creating a clearance space 721 to facilitate installation of the grinding head 10.

[0099] By providing an extension tube 71 and a supporting tube 72, the technical limitation of the traditional grinding mechanism that it cannot adapt to the extra-long combustion chamber shell is effectively solved. The composite structure composed of the extension tube 71 and the supporting tube 72 realizes the linear expansion of the working length of the grinding head 10 while maintaining the integrity of the drive mechanism 20. The swing drive component 22 is integrated inside the extension tube 71, which not only ensures the continuity of power transmission but also avoids the occupation of external space; the rotating drive component 21 is encapsulated inside the supporting tube 72 to ensure the stable output of the rotating drive force. This structure maintains the rigidity of the mechanism while expanding the grinding range, prevents vibration problems caused by excessive cantilever length, and ensures uniform and stable grinding pressure. The extended assembly composed of the extension tube 71 and the supporting tube 72 realizes the separate layout of the drive system and the actuator, keeps the drive components away from the high-temperature grinding area, and effectively extends the service life of the equipment. The avoidance space 721 avoids interference between the tube body and the workpiece surface while ensuring the free rotation of the grinding head 10.

[0100] In addition, if Figure 7 A dust hood 80 is attached to the outside of the grinding head 10 and connected to a dust removal system. A dust inlet 81 moves synchronously with the grinding head 10 to remove combustible dust generated during grinding, ensuring immediate dust removal and ensuring safety during the grinding process. A dust concentration sensor can also be added to automatically shut down and alarm when dust concentration exceeds the standard. Alternatively, a combustible gas detector can be installed to prevent explosion risks.

[0101] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A grinding mechanism for the thermal insulation layer of an engine combustion chamber, characterized in that: include: grinding head; a driving mechanism connected to the grinding head, for driving the grinding head to rotate and move the grinding head along the surface to be ground; A detection mechanism, the detection mechanism is used to detect the distance between the grinding head and the surface to be ground; as well as A control module is communicatively connected with the detection mechanism and the drive mechanism, and is used to adjust the feed speed of the drive mechanism according to a signal fed back by the detection mechanism.

2. The engine combustion chamber insulation layer grinding mechanism according to claim 1, characterized in that: The detection mechanism includes a first laser sensor, the control module is in communication with the first laser sensor, the first laser sensor is arranged on one side of the grinding head, and the first laser sensor is used to detect the distance from the grinding head to the surface to be ground.

3. The engine combustion chamber insulation layer polishing mechanism according to claim 2, characterized in that: The detection mechanism also includes a second laser sensor. The control module is communicatively connected to the second laser sensor. The second laser sensor is arranged on the other side of the grinding head. The second laser sensor is used to detect the grinding depth of the surface to be ground and to detect the surface type of the surface to be ground.

4. The engine combustion chamber insulation layer grinding mechanism according to any one of claims 1 to 3, characterized in that: The driving mechanism includes a rotating driving member and a swinging driving member, the control module is in communication with the rotating driving member and the swinging driving member, the grinding head is connected to a driving end of the rotating driving member, and the rotating driving member is used to drive the grinding head to rotate around its axis; The swing driving member is connected to the grinding head and is used to drive the grinding head to move along the surface to be ground.

5. The engine combustion chamber insulation layer grinding mechanism according to claim 4, characterized in that: The driving mechanism also includes a first transmission assembly, one end of which is connected to the driving end of the rotating drive member, and the other end of the first transmission assembly is connected to the grinding head. The rotating drive member drives the grinding head to rotate through the first transmission assembly.

6. The engine combustion chamber insulation layer grinding mechanism according to claim 5, characterized in that: The driving mechanism also includes a second transmission assembly, one end of the second transmission assembly is connected to the driving end of the swing driving member, and the other end of the second transmission assembly is connected to the grinding head. The swing driving member drives the grinding head to move along the surface to be polished through the second transmission assembly.

7. The engine combustion chamber insulation layer grinding mechanism according to claim 4, characterized in that: The engine combustion chamber insulation layer grinding mechanism also includes a vertical driving member, a driving end of which is connected to the rotating driving member and the swinging driving member, and the vertical driving member is used to drive the rotating driving member and the swinging driving member to move in the vertical direction.

8. The engine combustion chamber insulation layer grinding mechanism according to claim 7, characterized in that: The engine combustion chamber insulation layer polishing mechanism further includes a horizontal driving member, the vertical driving member is connected to the driving end of the horizontal driving member, and the horizontal driving member is used to drive the vertical driving member to move in the horizontal direction.

9. The engine combustion chamber insulation layer grinding mechanism according to claim 7, characterized in that: The engine combustion chamber insulation layer grinding mechanism also includes an extension piece, one end of the extension piece is connected to the driving end of the vertical driving piece, and the other end of the extension piece is connected to the rotating driving piece and the swing driving piece.

10. The engine combustion chamber insulation layer grinding mechanism according to claim 9, characterized in that: The extension member includes an extension tube and a supporting tube, one end of the extension tube is connected to the driving end of the vertical driving member, and the other end of the extension tube is connected to one end of the supporting tube. The swing driving member is arranged in the extension tube, and the rotating driving member is arranged in the supporting tube. The other end of the supporting tube is provided with an avoidance space for avoiding the grinding head.

Images