A new type of high-speed spindle broaching mechanism with self-locking and force-enhancing claws

Abstract

The present invention discloses a new type of high-speed spindle tool-pulling mechanism with self-locking and force-enhancing pull claws, including a spindle rotating shaft core, a BBT tool handle, a tool handle pull nail, a water spray push rod, a self-locking force-enhancing pull claw, a pull claw outer diameter sleeve, a one-way valve, a push spring, a disc spring front gasket, a tool-pulling rod, a disc spring assembly, a disc spring middle spacer, a spindle rear cover, and a tool-releasing pressure sleeve. Compared with the prior art, the present invention has the following advantages: this type of spindle tool-pulling mechanism adopts a BBT tool system and a self-locking force-enhancing pull claw, and can apply a new process of high-pressure water spray high-speed cutting processing of the spindle center. Combining the advantages of the three, it is applied to high-speed spindles of high-end CNC machine tools, effectively ensuring the high-speed operation of the spindle, improving processing efficiency, surface processing accuracy, and stable operation, creating excellent value.

Description

Technical Field

[0001] The invention relates to the field of machine tool parts, and in particular to a novel high-speed spindle broaching mechanism in which a broaching claw can self-lock and increase force and a spindle center can spray water and air. Background Art

[0002] In response to the country's strategic demand for high-end CNC machine tools, there is a strong demand for the development of domestic CNC machine tools and machining centers towards high-precision and high-speed machining, which requires a more compact spindle structure, higher speed requirements, more efficient and more precise machining, and the spindle's internal broaching mechanism must be more stable, more dynamically balanced, and more efficient and fast when changing tools; therefore, it is an urgent need to invent and apply a new type of spindle self-locking force-enhancing claw, and develop a new type of spindle broaching mechanism that has a self-locking force-enhancing claw that stably holds the tool handle when the spindle is in the broaching state, has good dynamic balance, and can be used for high-speed machining. Summary of the invention

[0003] The technical problem to be solved by the present invention is to develop a new type of self-locking force-enhancing pulling claw and apply it to a high-speed spindle broaching mechanism to create excellent value.

[0004] In order to solve the above technical problems, the technical solution provided by the present invention is: a new type of high-speed spindle tool pulling mechanism with self-locking and force-enhancing claws, including a spindle rotating shaft core, a BBT tool holder is installed on the front tapered hole of the spindle rotating shaft core, the tool holder has a central through hole, and a tool holder rivet is installed on the small end of the tool holder tapered shank, the tool holder rivet center through hole, the end of which is provided with a tapered hole and an oil seal groove, the tapered hole at the end of the tool holder rivet is provided with a sealing contact water spray push rod, the water spray push rod passes through the center hole of the claw pull bolt, the small diameter shaft end of the claw pull bolt and the outer side of the tool holder rivet are provided with a self-locking claw claw piece, the outer side of the self-locking claw claw piece is provided with a claw outer diameter sleeve, the claw outer diameter sleeve is lined between the claw outer diameter and the inner hole of the spindle rotating shaft core, the rotating shaft core inner diameter step is axially positioned, At the end of the water spray push rod, a one-way valve is installed at the center hole of the pull claw and the pull bolt, and a push spring is installed on the end of the one-way valve, and a disc spring front sleeve is installed at the end of the pull claw outer diameter sleeve, and a locating pin is provided between the pull claw outer diameter sleeve and the disc spring front sleeve for positioning connection, and the pull claw and the pull bolt are threadedly connected with a pull rod, and the pull rod is sequentially connected with the disc spring front sleeve, two groups of disc spring groups, and a spacer ring in the middle of the disc spring group from the center hole, and the pull rod is installed in the inner hole of the main shaft rotating axis core, and the rearward limit is adjusted by the rear end cover of the main shaft, and the rear end cover of the main shaft is threadedly connected to the main shaft rotating axis core, and a knife loosening pressure sleeve is installed on the end of the pull rod exposed from the main shaft rotating axis core, which is positioned with a tightening bolt between the pull rod, and the rear end hole of the pull rod has an inner left thread for installing a rotating connector.

[0005] The advantages of the present invention compared with the prior art are: this type of spindle broaching mechanism adopts a combination of a BBT tool system and a self-locking claw, and can apply a new high-speed cutting process of high-pressure water jetting in the spindle center. Combining the advantages of the three, it is applied to high-end CNC machine tools, effectively ensuring the high-speed operation of the spindle, improving processing efficiency, surface processing accuracy, and stable operation, which can create excellent value; the advantages are as follows:

[0006] First, the performance of the traditional BT tool system is difficult to meet the requirements of high-speed cutting. In order to solve the difficulties of high-end CNC machine tool processing and the accuracy and efficiency of deep hole processing, the axis core taper hole of this broaching mechanism adopts the BBT spindle two-sided positioning design. Compared with another high-speed tool system HSK, the taper contact surface of the tool holder base handle is larger, the taper support length is longer, and the spindle rigidity is better, which can increase the spindle speed and focus on cutting, effectively improving the processing efficiency;

[0007] Second, this type of spindle tool pulling mechanism adopts a self-locking force-enhancing claw. The claw includes a claw bolt, a claw piece, an annular spring, and a fixing screw. When the tool is pulled, the claw piece is in a self-locking wedging state, and the disc spring elastically deforms and pushes on the tool rod. The tool rod and the claw bolt, the claw bolt and the claw piece, the action force and the reaction force act in sequence. The claw bolt tightens the claw piece to move in the direction of tightening the tool, which is equivalent to a wedging effect. The same pulling force on the tool handle, but the spring tension generated by the deformation of the disc spring can be reduced, resulting in the following advantages: 1; Therefore, the same pulling force 1. Tool force. This type of claw can reduce the number of disc springs or the length of the spring, thereby reducing the total length of the spindle and making the spindle structure more compact; 2. In addition, the oil pressure of the spindle tool loosening cylinder can be reduced. The oil pressure of the tool loosening cylinder can be reduced, and the entire machine tool oil pressure system does not need to operate at high pressure, which does not waste machine tool electricity and energy and reduces losses; 3. The machine tool tool loosening process is less likely to damage the spindle precision bearings, extend the life of the spindle precision bearings, and thus extend the life of the spindle: the spindle tool loosening process is that the oil pressure of the hydraulic cylinder acts on the tool puller, compressing the disc spring, the disc spring deforms, and the tool puller acts in the direction of tool loosening to move the claw to complete the tool loosening action. The disc spring is compressed and deformed, and the fulcrum of the disc spring reaction is the front washer of the disc spring. The interaction force and reaction force are transmitted to the outer diameter sleeve of the pull claw, the axial positioning step of the inner hole of the spindle axis, the spindle axis, the inner ring of the angular contact bearing supporting the rotating axis of the spindle, the precision bearing steel balls, the outer ring of the bearing, and finally to the mounting hole support of the spindle mounting casting. The action force and reaction force will act on the precision ball steel balls between the precision bearings. The greater the actual force of the knife loosening cylinder, the greater the damage to the spindle bearings. The smaller the force, the more conducive to extending the bearing life and the spindle stability. The premise is that the spindle knife loosening is not equipped with a floating knife loosening mechanism (the floating knife loosening mechanism is when the spindle knife is loosened, the piston of the knife loosening cylinder moves a short distance, and the reaction force Connect the tool release cylinder to the rotating axis, and then push the tool pull rod to release the tool. This tool release method does not act on the spindle bearings with reaction force). Adding a floating tool-beating mechanism will make the spindle structure complicated, which will interfere with the spindle of high-end machine tools. The spindle must be integrated with the electric spindle, tool-beating cylinder, and rotating connector to introduce high-pressure cutting water. 4. When the spindle tool is pulled, the deformation of the disc spring of the tool pull mechanism is smaller than that of the ordinary type of claw, which is beneficial to extend the service life of the tool pull mechanism (small deformation of the disc spring); 5. The tool pull force of the spindle tool pull mechanism is small, the tool release cylinder releases the tool quickly, the tool release stroke is short, and the tool handle can be instantly converted from the self-locking stable state of the tool pull to the loose state, which can quickly change the tool, save processing auxiliary time, and improve the processing efficiency of the machine tool. There is experimental verification.

[0008] 3. When the spindle is cutting at high speed, a rotating connector can be installed from the rear end of the broaching rod to introduce high-pressure water spray to the center of the tool holder, and then to the tool edge for high-pressure spray. This is a new type of high-speed cutting technology. The operating principle of high-pressure water spray in the center of high-speed cutting tools: When the tool cuts the workpiece at high speed, it will produce high-temperature water vapor, and the water vapor on the surface of the workpiece will isolate the cutting fluid from adhering, resulting in a cooling effect of less than 20% on the workpiece or tool. Only when the cutting fluid is pressurized to more than 1000PSI (70BAR) can the cutting fluid directly contact the workpiece and the tool to achieve the most efficient cooling effect. When the tool is not easy to overheat, the linear speed and feed rate can be greatly increased; the main high-pressure water spray at the center of the spindle produces no iron chips entangled, and the chips are directly broken and discharged; it takes away the high-temperature heat of friction during cutting and extends the service life of the tool. The direct advantages are: 1. Directly and significantly improve the processing efficiency by 50%; 2. Significantly improve the service life of the tool and save production costs; 3. Reduce tool marks and obtain good processing surface quality.

[0009] Conclusion: This type of spindle broaching mechanism effectively assists in improving the development and application of high-speed spindles for domestic high-end CNC machine tools, greatly improves machine tool processing efficiency and surface processing accuracy, and saves energy costs.

[0010] As an improvement, a threaded connection is provided between the spindle rear cover and the rear inner hole of the spindle rotating shaft core of the spindle broaching mechanism, which can control the amount of rearward movement of the broaching rod after the broaching tool is tightened; the screw hole on the rear end cover of the spindle is used to install a tightening bolt, which is pressed against the rear end face of the rotating shaft core to lock the spindle rear cover from displacement, and there is a tightening screw hole on the rear cover of the rear spindle, through which screws can be added or subtracted for balancing purposes when the spindle is subjected to a dynamic balancing experiment.

[0011] As an improvement, the novel self-locking force-enhancing claw is designed with two contact surfaces of the inclined wedge self-locking force-enhancing principle: one is a small wedge-angle self-locking conical surface provided at the joint between the claw bolt and the claw piece; the other is a contact conical surface with a wedge angle greater than 35 degrees between the claw piece and the inner hole step of the claw outer diameter sleeve;

[0012] As an improvement, a high-pressure water and ventilation one-way channel is designed in the center of the broaching mechanism. O-ring seals are provided between the knife handle and the knife handle pull pin, between the knife handle pull pin and the water spray push rod, between the water spray push rod and the pull claw pull bolt, and between the water spray push rod and the one-way valve. A spring push is designed to ensure continuous sealing contact between the water spray push rod and the knife handle knife pin. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The schematic diagram of the structure is a new type of high-speed spindle broaching mechanism in which the claws can self-lock and increase force.

[0014] Figure 2 The present invention is a schematic diagram of the structure of the spindle rear end cover of a new type of high-speed spindle broaching mechanism in which the pull claws can self-lock and increase force.

[0015] Figure 3It is a new type of claw structure that can self-lock and increase force.

[0016] Figure 4 This is a diagram of the BBT tool system.

[0017] Figure 5 The schematic diagram of the water injection mechanism of a new type of high-speed spindle broach mechanism in which the claws can self-lock and increase force.

[0018] Figure 6 The diagram shows the distribution position of the O-ring seal in the center channel of a new type of high-speed spindle broach mechanism in which the claws can self-lock and increase force.

[0019] Figure 7 The present invention is a distribution diagram of the pressure F of the hydraulic cylinder on the pressure sleeve of the tool loosening mechanism of a new high-speed spindle tool broaching mechanism in which the claws can self-lock and increase force.

[0020] Figure 8 The diagram is a new type of high-speed spindle tool pulling mechanism in which the pulling claw can self-lock and increase force, and the tool tightening state diagram of the pulling claw.

[0021] Fig. 9 The present invention is a state diagram of the tool loosening process 1 of a new type of high-speed spindle tool pulling mechanism in which the pulling claw can self-lock and increase force.

[0022] Fig.10 The present invention is a state diagram of the tool loosening process of a new type of high-speed spindle tool pulling mechanism in which the pulling claw can self-lock and increase force.

[0023] Fig.11 A new type of high-speed spindle broaching mechanism with self-locking and force-enhancing claws. The claw release state diagram

[0024] As shown in the figure: 1. Spindle rotating shaft core, 2. BBT tool handle, 3. Tool handle pull pin, 4. Pull claw outer diameter sleeve, 5. Pull claw claw piece, 6. Water spray push rod, 7. One-way valve, 8. Push spring, 9. Disc spring front sleeve, 10. Pull tool rod, 11. Disc spring assembly, 12. Disc spring middle spacer, 13. Spindle rear end cover, 14. Tool loosening pressure sleeve, 15. Pull claw pull bolt. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0026] In the specific implementation of the present invention, the cone surface and the end surface of the spindle and the tool must be constrained on both sides, and the end surface clearance must be reset to zero, which is almost impossible. Therefore, the BBT system uses elastic deformation to achieve the purpose of two-sided constraint, such as Figure 4As shown in the figure, before tightening the tool, the spindle and the tool only have the conical surface in contact, leaving a certain gap between the spindle and the end face of the tool; after tightening the tool, the tool holder is subjected to the axial pulling force of the pulling claw, and the inner hole of the spindle is forced to expand and produce elastic deformation, so that the end face gap between the spindle and the tool is eliminated and then fits together, achieving the purpose of two-sided constraint. The elastic deformation of the inner hole of the spindle is closely related to the axial displacement of the tool, so it is very important to control the axial displacement of the tool. The rear end cover of the spindle of the spindle broaching mechanism component is shown in the figure. Figure 2 As shown, it controls the backward movement of the tool puller after tightening the tool. There are screw holes on the rear cover of the spindle for installing the tightening bolts, which are pressed against the rear end face of the rotating shaft core to lock the rear cover of the spindle from moving. It is also used for balancing the spindle when doing dynamic balancing experiments.

[0027] To ensure stable contact between the tool holder and the spindle taper, the tool holder and the spindle taper must be kept clean. During the tool change process, the broaching mechanism is designed to clean the taper from the spindle center: Figure 5 As shown in the figure, the rear end hole of the spindle tool puller is threadedly connected to install a rotating connector, and the external high-pressure air source is blown out from the rotating connector, the center hole of the tool puller, the one-way valve, and the air blowing ejector rod. The air blowing is continued during the tool changing process.

[0028] Spindle center water jet: Figure 5 , Figure 6 As shown, the air source channel is also the high-pressure water source channel, and both share the central channel of the spindle broaching mechanism (rotating connector, to the central through hole of the broaching rod, to the one-way valve, water spraying push rod, when spraying water, the water spraying push rod reaches the central conical hole of the tool handle broaching pin, and the push spring keeps the water spraying push rod in contact with the tool handle broaching pin, and sprays out at the center of the blade). During cutting, high-pressure water is sprayed from the center of the spindle, and air is blown from the center of the spindle during tool change. Both are introduced from the rotating connector installed at the rear end of the broaching rod. High-pressure filtered cutting water or air source is provided outside the machine tool, and the switching is controlled by an external solenoid valve. Before the water source and air source enter the shared pipeline, they must pass through the one-way valve to prevent backflow.

[0029] Working principle of the present invention: When the new broaching mechanism loosens the knife: Figure 7 , the piston of the spindle tool release cylinder moves forward and contacts the tool release pressure ring at the rear end of the spindle; Figures 8 to 11 From top to bottom, this is the new type of claw loosening process. The machine tool spindle loosening oil hydraulic cylinder compresses the loosening pressure sleeve and moves it to the front end of the spindle; the pressure sleeve pushes the large end of the pull rod to compress the disc spring group, and the pull rod pushes the claw and bolt part to move toward the tool handle. Figure 8 to Figure 9During the process, the claw and bolt move forward relative to the claw piece to release the wedged state, and the claw piece is still in the state of holding the tool handle. In Figure 9, the large diameter step of the claw and bolt begins to push the claw piece forward, and the rear part of the tool claw piece begins to radially converge toward the center and is guided along the conical surface of the claw outer diameter sleeve by the annular spring. In Figure 10, the rear part of the tool claw piece begins to shrink into the small diameter part of the claw outer diameter sleeve hole; in Figure 11, the front part of the claw piece has been opened, and the front end of the claw and bolt pushes the tool handle pull pin to complete the tool loosening process.

[0030] The process of tightening the tool with the pulling claw is that the pulling claw is in the open state, that is, the tool release cylinder has been pressing the tool release pressure sleeve at the rear end of the pulling rod to compress the disc spring. During the automatic tool changing process of the machining center, the tool handle is inserted into the spindle hole by the robot. After the signal is sensed in place, the solenoid valve of the spindle tool release cylinder is reversed, and the tool release cylinder retreats. The pulling rod is pushed during the process of the disc spring recovering its deformation, and the rear end of the spindle retreats. The pulling rod connects the pulling claw and the pulling bolt to move toward the rear end of the spindle. The process is the opposite of the tool release process. Fig.11 Status to Figure 8 In this state, the broaching tool claw is squeezed into the large hole of the outer diameter sleeve of the broaching tool by the cone surface of the broaching bolt. Figure 9 to Figure 8 During the process, after the pulling claw is connected to the tool holder, it enters the wedging self-locking state, and the tool loosening cylinder piston continues to retreat, disengaging the pressure sleeve at the rear end of the tool pulling rod, completing the tool locking process; during the entire tool loosening and pulling process, the spindle remains in the blowing state to clean the tool holder taper shank and the spindle taper hole.

[0031] This new spindle broaching mechanism is designed for high-end CNC machine tool spindles with high speed and high efficiency for heavy cutting. It adopts the BBT spindle two-sided positioning system (the tool holder conical surface and the flange end face contact the spindle conical hole and the spindle front end face at the same time), and combines the stability of the broach with new self-locking claws and the new processing technology of high-pressure cutting water spraying, so that the spindle has good rigidity and is suitable for processing with long tool holder overhang, such as large molds, boxes, shells, and parts with more heavy cutting, and requires a long tool holder overhang, which can ensure high efficiency and stability.

[0032] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features, and in the description of the present invention, "plurality" means two or more, unless otherwise clearly and specifically defined.

[0033] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0035] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0036] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention.

Claims

1. A new type of high-speed spindle broaching mechanism with self-locking and force-enhancing claws, characterized in that: A BBT tool holder (2) is mounted on the front tapered hole of the main spindle rotating shaft core (1), the tool holder (2) having a central through hole, a tool holder rivet (3) being mounted on the small end of the tool holder tapered shank, the tool holder rivet (3) having a central through hole and a tapered hole and an oil seal groove at the end, the tapered hole at the end of the tool holder rivet (3) having a sealing contact water spraying ejector rod (6), the water spraying ejector rod (6) passing through the central hole of the pull claw pull bolt (15), the small diameter shaft end of the pull claw pull bolt (15) and the outer side of the tool holder rivet (3) being provided with a self-locking pull claw claw piece (5), the self-locking pull claw claw piece (5) A claw outer diameter sleeve (4) is provided on the outside, the claw outer diameter sleeve is inserted between the claw outer diameter and the inner hole of the main shaft rotating shaft core, and the rotating shaft core inner diameter step is axially positioned. A one-way valve (7) is installed at the end of the water spray push rod (6) and the center hole of the claw pull bolt (15). A push spring (8) is installed on the end of the one-way valve (7). A disc spring front sleeve (9) is installed at the end of the claw outer diameter sleeve (4). A positioning pin is provided between the claw outer diameter sleeve and the disc spring front sleeve for positioning connection. The claw pull bolt (15) is threadedly connected with the tool rod (10 ), the broaching rod (10) is connected in sequence from the center hole with a disc spring front bushing (9), two disc spring groups (11), and a disc spring group intermediate ring (12). The broaching rod (10) is installed in the inner hole of the spindle rotating shaft core (1) and is limited by the spindle rear cover (13). The spindle rear cover and the spindle shaft core are threadedly connected. A loosening pressure sleeve (14) is installed on the end of the broaching rod (10) exposed from the spindle rotating shaft core (1). The spindle rear cover of the spindle broaching mechanism component is threadedly connected to the rear inner hole of the spindle rotating shaft core, which can control the broaching. The amount of rearward movement of the tool bar after the tool is tightened; the screw hole on the rear end cover of the spindle is used to install the clamping bolt, which is pressed against the rear end face of the rotating shaft core to lock the rear cover of the spindle from displacement, and there is a clamping screw hole on the rear cover of the rear spindle, which can be used to add or subtract screws for balancing the spindle during dynamic balancing experiments. The claw is designed with two contact surfaces based on the principle of inclined wedge self-locking force enhancement: one is a small wedge angle self-locking conical surface provided at the matching position of the claw pull bolt (15) and the claw piece (5); the other is a contact conical surface with a wedge angle greater than 35 degrees between the claw piece and the inner hole step of the claw outer diameter sleeve.

2. According to claim 1, a new type of high-speed spindle broaching mechanism with self-locking and force-enhancing claws, characterized in that: This broaching mechanism has a one-way sealing channel in the center, which is designed with a spring push to ensure continuous sealing contact between the water spray ejector rod and the tool handle pull pin, ensuring the sealing performance of the spindle center water spray or air jet channel, and is used for spindle high-pressure water spray or air jet.

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