CN115415561A - Main shaft structure and digit control machine tool - Google Patents

Abstract

The application relates to the technical field of loose broach, and provides a main shaft structure and a numerical control machine tool, wherein the main shaft structure comprises a shaft core and a loose broach assembly, and the shaft core is provided with a hollow cavity extending along the axial direction; the loosening broach assembly comprises a pull rod, an elastic resetting piece and a connecting piece; the pull rod is movably arranged in the hollow cavity along the axial direction, and one end of the pull rod is connected with the knife handle, so that the pull rod drives the knife handle to extend outwards or retract inwards along the axial direction; the elastic reset piece is sleeved on the outer peripheral side of the shaft core, one end of the elastic reset piece is connected with the outer peripheral side of the shaft core, and the other end of the elastic reset piece is connected with the pull rod through the connecting piece, so that the elastic reset piece stretches along the axial direction. This application overlaps the elasticity piece that resets and establishes at axle core periphery side, has promoted pull rod intensity and assembly visibility, reduces the processing degree of difficulty and the processing cost of main shaft structure by a wide margin.

Description

Main shaft structure and digit control machine tool

Technical Field

The application relates to the technical field of loose broaches, in particular to a spindle structure and a numerical control machine tool.

Background

In order to guarantee the machining efficiency of a numerical control machine tool, a tool loosening and pulling assembly is generally arranged inside the machine tool in the industry, so that the tool changing time of the numerical control machine tool is shortened, the tool loosening and pulling assembly comprises an elastic resetting piece, a pull rod, a pull claw and the like, the tool loosening is realized through the forward movement of a piston at the rear end of a shaft core, and the tool loosening is realized through the elastic resetting piece.

In the prior art, a scheme of embedding an elastic reset piece inside a shaft core is generally adopted, and the scheme has the following defects: the inner periphery side of the shaft core and the outer periphery side of the pull rod are both required to be processed with longer deep holes along the axial direction, and the guide piece is processed between the inner periphery side of the shaft core and the outer periphery side of the pull rod and used for matching the elastic reset piece to stretch along the axial direction.

Disclosure of Invention

The main aim at of this application provides a main shaft structure and digit control machine tool, aims at reducing the processing degree of difficulty of main shaft structure, practices thrift the processing cost, improves pull rod intensity and assembles visuality.

According to a first aspect of the present application, there is provided a spindle structure including a spindle core and a loose broach assembly; the shaft core is provided with a hollow cavity extending along the axial direction; the loose broach assembly comprises a pull rod, an elastic reset piece and a connecting piece; the pull rod is movably arranged in the hollow cavity along the axial direction, and one end of the pull rod is connected with the cutter handle, so that the pull rod drives the cutter handle to extend outwards or retract inwards along the axial direction; the elastic reset piece is sleeved on the outer peripheral side of the shaft core, one end of the elastic reset piece is connected with the outer peripheral side of the shaft core, and the other end of the elastic reset piece is connected with the pull rod through the connecting piece, so that the elastic reset piece stretches along the axial direction.

In an embodiment of the present application, a through hole extending in a radial direction is formed on an outer peripheral side of the shaft core, and the connecting member penetrates through the through hole and is connected to the pull rod; the outer peripheral side of the shaft core is further provided with a first shaft shoulder which is separated from the via hole by a preset distance, and the elastic reset piece is arranged between the first shaft shoulder and the connecting piece.

In an embodiment of the present application, the via hole has a first positioning surface and a second positioning surface opposite to each other in the axial direction of the shaft core, the first positioning surface is located on one side of the second positioning surface facing the tool holder, and the connecting member moves in the axial direction between the first positioning surface and the second positioning surface; when the connecting piece is positioned on the second positioning surface, the elastic resetting piece is in a pre-compression state, the length of the elastic resetting piece is a first length, the connecting piece is at least adjacent to the first positioning surface, the elastic resetting piece is in a further compression state, the length of the elastic resetting piece is a second length, and the first length is greater than the second length.

In one embodiment of this application, first shaft shoulder orientation one side of connecting piece is equipped with first fender and fills up, the connecting piece orientation one side of first shaft shoulder is equipped with the second and keeps off the pad, the elasticity piece that resets set up in first keep off fill up with the second keeps off between the pad.

In an embodiment of the present application, an inner diameter of an inner hole of the second blocking pad is greater than or equal to an outer diameter of the shaft core at a corresponding position.

In an embodiment of the application, the inner periphery side of axle core is equipped with spacing step on the axial direction of axle core, spacing step is located first shoulder with between the via hole, the periphery side of pull rod is equipped with the second shoulder, the second shoulder spacing in spacing step department.

In an embodiment of the present application, the minimum distance between the first positioning surface and the limiting step is greater than the minimum distance between the connecting piece and the second shoulder, or the minimum distance between the first positioning surface and the limiting step is less than the minimum distance between the connecting piece and the second shoulder.

In an embodiment of the present application, an inner diameter of the limiting step is greater than or equal to an outer diameter of the second shoulder.

In an embodiment of the application, pull rod periphery side sets up first sealing washer and second sealing washer, first sealing washer with the second sealing washer is used for sealing the pull rod with the axle core, the via hole is located first sealing washer with between the second sealing washer.

In an embodiment of the application, the number of the connecting pieces includes at least two, the at least two connecting pieces are circumferentially arrayed on the outer circumference side of the shaft core, and at least two through holes are correspondingly arranged on the outer circumference side of the shaft core.

In one embodiment of the application, the loosening and broaching tool assembly further comprises a driving mechanism, and the driving mechanism is arranged at one end, deviating from the handle, of the pull rod and is used for driving the pull rod to move along the axial direction.

In an embodiment of the application, the pine broach subassembly is still including locating draw claw and the cover that rises in the cavity, draw the claw to be located the cover periphery side rises, draw the claw with the handle of a knife is connected, the cover that rises connect in the pull rod deviates from actuating mechanism's one end.

According to a second aspect of the present application, there is provided a numerically controlled machine tool including the spindle structure according to any one of the first aspects.

The spindle structure provided by the embodiment of the application comprises a spindle core and a loose broach assembly; the shaft core is provided with a hollow cavity extending along the axial direction; the loose broach assembly comprises a pull rod, an elastic reset piece and a connecting piece; the pull rod is movably arranged in the hollow cavity along the axial direction, and one end of the pull rod is connected with the cutter handle, so that the pull rod drives the cutter handle to extend outwards or retract inwards along the axial direction; the elastic reset piece is sleeved on the outer peripheral side of the shaft core, one end of the elastic reset piece is connected with the outer peripheral side of the shaft core, and the other end of the elastic reset piece is connected with the pull rod through the connecting piece, so that the elastic reset piece stretches along the axial direction. According to the embodiment of the application, the elastic reset piece is sleeved on the outer peripheral side of the shaft core, one end of the elastic reset piece is connected with the outer peripheral side of the shaft core, the other end of the elastic reset piece is connected with the outer peripheral side of the pull rod through the connecting piece, the elastic reset piece can stretch along the axial direction, and the cutter feeding or the cutter pulling is realized through the axial movement of the pull rod; secondly, deep holes do not need to be machined in the pull rod, so that the length-diameter ratio of the pull rod is larger, the strength of the pull rod is improved, the pull rod is not easy to deform during machining, and the product yield is improved; finally, the assembly state of the loose broach assembly can be visually seen, and the assembly effect of the loose broach assembly is ensured.

The utility model provides a digit control machine tool, at the inside above-mentioned main shaft structure of being equipped with of digit control machine tool, the loose broach subassembly through main shaft structure can shorten digit control machine tool changing time to guarantee the machining efficiency of digit control machine tool.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive exercise.

Fig. 1 shows a cross-sectional view of a spindle structure provided in a first embodiment of the present application;

FIG. 2 illustrates a cross-sectional view of another spindle configuration provided in a first embodiment of the present application;

fig. 3 is a sectional view showing a shaft core of a spindle structure provided in a first embodiment of the present application;

fig. 4 shows a cross-sectional view of a drawbar of a spindle structure provided in a first embodiment of the present application.

The reference numerals are illustrated below:

1. a shaft core; 11. a hollow cavity; 12. a via hole; 121. a first positioning surface; 122. a second positioning surface; 13. a first shoulder; 14. a limiting step; 151. a first bearing mounting location; 152. a second bearing mounting location; 16. fixing the rotor; 21. a pull rod; 211. a second shoulder; 212. a gasket; 213. a first seal ring; 214. a second seal ring; 215. a third seal ring; 216. a gas-liquid hole; 217. a swivel joint linkage; 218. a threaded hole; 219. a counter bore; 22. an elastic restoring member; 221. a first stopper pad; 222. a second stopper pad; 23. a drive mechanism; 231. an oil cylinder; 232. a piston; 233. a positioning sleeve; 24. a connecting member; 3. a shaft sleeve; 41. a first bearing set; 411. a first bearing cap; 42. a second bearing set; 421. a second bearing housing; 51. a stator; 52. a rotor; 6. a swivel joint.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In order to guarantee the machining efficiency of a numerical control machine tool, a loosening broach assembly is generally arranged inside the machine tool in the industry, so that the tool changing time of the numerical control machine tool is shortened, the loosening broach assembly comprises an elastic reset piece, a pull rod, a pull claw and the like, the tool loosening is realized through forward movement of a piston at the rear end of a shaft core, and the tool broaching is realized through the elastic reset piece. The prior art often adopts the scheme of placing the elastic reset piece in the shaft core, the long deep holes need to be processed along the axial direction at the inner peripheral side of the shaft core and the outer peripheral side of the pull rod, and a guide piece is processed between the inner peripheral side of the shaft core and the outer peripheral side of the pull rod and used for matching the elastic reset piece to stretch along the axial direction.

In order to solve the above problem, please refer to fig. 1-2, an embodiment of the present application provides a numerical control machine tool including a spindle structure, the spindle structure includes a shaft sleeve 3, a first bearing set 41, a second bearing set 42, a shaft core 1, and a loose broach assembly. The outer periphery of the shaft core 1 is provided with a first bearing installation position 151 and a second bearing installation position 152 along the axial direction, the first bearing installation position 151 is located on one side, facing the tool holder, of the second bearing installation position 152, a first bearing group 41 is arranged at the first bearing installation position 151, a second bearing group 42 is arranged at the second bearing installation position 152, and the shaft core 1 is installed inside the shaft sleeve 3 through the first bearing group 41 and the second bearing group 42.

The shaft core 1 is provided with a hollow cavity 11 extending along the axial direction, the loose broach assembly comprises a pull rod 21, an elastic reset piece 22 and a connecting piece 24, the pull rod 21 is movably arranged in the hollow cavity 11 along the axial direction, one end of the pull rod 21 is connected with a hilt, and then the hilt is connected with a cutter or a workpiece through the hilt, so that the pull rod 21 drives the hilt to extend outwards or retract inwards along the axial direction; the elastic reset piece 22 is sleeved on the outer peripheral side of the shaft core 1, one end of the elastic reset piece 22 is connected with the outer peripheral side of the shaft core 1, and the other end of the elastic reset piece 22 is connected with the pull rod 21 through the connecting piece 24, so that the elastic reset piece 22 stretches along the axial direction.

According to the embodiment of the application, the elastic reset piece 22 is sleeved on the outer peripheral side of the shaft core 1, one end of the elastic reset piece 22 is connected with the outer peripheral side of the shaft core 1, the other end of the elastic reset piece 22 is connected with the outer peripheral side of the pull rod 21 through the connecting piece 24, the elastic reset piece 22 can stretch along the axial direction, and the cutter feeding or the cutter pulling can be realized through the axial movement of the pull rod 21; secondly, deep holes do not need to be machined in the pull rod 21, so that the length-diameter ratio of the pull rod 21 is larger, the strength of the pull rod 21 is improved, the pull rod is not easy to deform during machining, and the yield of products is improved; finally, the assembly state of the loose broach assembly can be visually seen, and the assembly effect of the loose broach assembly is ensured. It should be noted that, in the present embodiment, the axial direction refers to the axial direction along the shaft core 1, and the radial direction refers to the radial direction along the shaft core 1.

The spindle structure of the present embodiment can be applied to a case where a motor is built in, and can also be applied to a case where a motor is not built in. The condition of the built-in motor is as shown in fig. 1, specifically, an annular rotor fixing position 16 is further arranged on the outer peripheral side of the shaft core 1, the rotor fixing position 16 is located between a first bearing mounting position 151 and a second bearing mounting position 152, a motor is sleeved on the outer peripheral side of the rotor fixing position 16, the motor includes a stator 51 and a rotor 52 sleeved on the inner peripheral side of the stator 51, the rotor fixing position 16 is sleeved on the inner peripheral side of the rotor 52, and the shaft core 1 is driven to rotate through the rotor 52. In addition, as shown in fig. 2, when the motor is not built in, specifically, one end of the shaft core 1 far away from the tool holder drives the shaft coupling to drive the shaft core 1 to rotate through the chain wheel.

The connecting member 24 of the present embodiment may adopt any one of a rigid pin, a baffle plate, and a connecting rod, and may adopt other forms of connecting members 24 as long as rigid connection is achieved.

The elastic restoring member 22 of the present embodiment may be any one of a disc spring, a coil spring and a rectangular spring as long as it has a restoring function.

The spindle structure and the numerical control machine tool including the spindle structure will be described in detail below by taking an example in which the spindle structure incorporates a motor, the connecting member 24 is a rigid pin, and the elastic restoring member 22 is a disc spring.

As for the arrangement mode of the rigid pin, please refer to fig. 1-4, a through hole 12 extending in the radial direction is opened on the outer circumferential side of the shaft core 1, and the rigid pin penetrates through the through hole 12 and is connected to the pull rod 21; the outer periphery side of the shaft core 1 is further provided with a first shaft shoulder 13 arranged at an interval with the via hole 12, and the elastic reset piece 22 is arranged between the first shaft shoulder 13 and the rigid pin.

Therefore, one end of the rigid pin penetrates through the through hole 12 on the shaft core 1 and is in threaded connection with the threaded hole 218 formed in the radial direction on the outer periphery of the pull rod 21, the elastic reset piece 22 sleeved on the outer periphery of the shaft core 1 can move in the axial direction through the arrangement of the rigid pin, the relative rotation between the pull rod 21 and the shaft core 1 can be limited, a pull rod 21 anti-rotation component of a traditional main shaft structure can be omitted, and the main shaft structure is simplified.

In order to achieve stable matching between the rigid pin and the pull rod 21, please refer to fig. 4, firstly, a counter bore 219 is machined on the outer periphery of the pull rod 21, i.e. a sunken plane is machined on the outer periphery of the pull rod 21 in the radial direction, and then a threaded hole 218 is machined on the plane in the radial direction, so that the rigid pin is in threaded connection with the threaded hole 218, compared with the method of directly machining the threaded hole 218 on the outer periphery of the pull rod 21, the machining mode of machining the counter bore 219 in the radial direction and machining the threaded hole 218 in the radial direction on the counter bore 219 increases the contact area between the rigid pin and the pull rod 21, thereby ensuring the connection reliability. The rigid pin and the tie rod 21 may be fixed by interference fit or the like, and will not be described here. Further, please refer to fig. 3, the through hole 12 has a first positioning surface 121 and a second positioning surface 122 opposite to each other along the axial direction of the shaft core 1, and the first positioning surface 121 and the second positioning surface 122 may be arc surfaces or planes; the first positioning surface 121 is located on one side of the second positioning surface 122 facing the tool shank, and the connecting piece 24 moves axially between the first positioning surface 121 and the second positioning surface 122; when the connecting member 24 is located on the second positioning surface 122, the elastic restoring member 22 is in a pre-compression state, the length of the elastic restoring member 22 is a first length, when the connecting member 24 is at least adjacent to the first positioning surface 121, the elastic restoring member 22 is in a further compression state, the length of the elastic restoring member 22 is a second length, and the first length is greater than the second length. Since the spindle 1 of the spindle structure is rotated at a high speed during operation, in order to stably mount the elastic restoring member 22 in the spindle structure, the elastic restoring member 22 has a pre-compression amount at the beginning of mounting, the elastic restoring member 22 has a minimum compression amount of 20% -30% of its natural extension length after being mounted on the outer periphery side of the spindle 1, when the rigid pin is located on the second positioning surface 122, the elastic restoring member 22 is in a pre-compression state, the first length of which is 70% -80% of its natural extension length, and when the rigid pin is at least adjacent to the first positioning surface 121, the elastic restoring member 22 is in a further compression state, the second length of which is 50% -60% of its natural extension length.

In order to enable the elastic restoring member 22 to stably extend and retract, please refer to fig. 3, a first blocking pad 221 is disposed on one side of the first shaft shoulder 13 facing the rigid pin, a second blocking pad 222 is disposed on one side of the rigid pin facing the first shaft shoulder 13, and the elastic restoring member 22 is disposed between the first blocking pad 221 and the second blocking pad 222, and since the outer peripheral side of the rigid pin is an arc-shaped surface, the other end of the elastic restoring member 22 is connected through a plane of the second blocking pad 222, so that the problem that the elastic restoring member 22 slips with the arc surface of the rigid pin in the extending and retracting process is prevented, and the elastic restoring member 22 can stably extend and retract between the first blocking pad 221 and the second blocking pad 222.

Further, the broach force is adjusted by adjusting the thicknesses of the first stop pad 221 and the second stop pad 222, that is, if the broach force is too large, the thickness of any one of the first stop pad 221 and the second stop pad 222 can be at least reduced, the compression amount of the elastic restoring member 22 is reduced, and the broach force is reduced; if the broaching force is too small, the thickness of at least one of the first stopper 221 and the second stopper 222 may be increased to further compress the elastic restoring member 22, thereby increasing the broaching force. By adjusting the thickness of the first and second stop pads 221 and 222, the adjustment of the broach force can be achieved, thereby determining different unclamping positions and broach positions.

Preferably, since the elastic restoring member 22 has a pre-compression amount, two ends of the elastic restoring member 22 are respectively abutted against the first blocking pad 221 and the second blocking pad 222, so that the elastic restoring member 22 can be fixed, and the main shaft structure is more convenient to disassemble and assemble by means of abutment.

And, the inner diameter of the inner hole of the second retaining pad 222 is greater than or equal to the outer diameter of the corresponding axle core 1, that is, the first retaining pad 221 is in at least clearance fit with the outer periphery of the axle core 1, and the second retaining pad 222 is in clearance fit or contact with the outer periphery of the axle core 1, because the position of the first retaining pad 221 remains unchanged, the first retaining pad 221 can be in clearance fit or interference fit with the outer periphery of the axle core 1, and the second retaining pad 222 needs to move in the axial direction, in order to prevent the second retaining pad 222 from generating larger friction with the outer periphery of the axle core 1 and affecting the axial movement of the second retaining pad 222, the second retaining pad 222 is in clearance fit or contact with the outer periphery of the axle core 1, so that the second retaining pad 222 can move smoothly.

As shown in fig. 3 to fig. 4, a limiting step 14 is disposed on an inner peripheral side of the shaft core 1, in an axial direction of the shaft core 1, the limiting step 14 is located between the first shoulder 13 and the through hole 12, a second shoulder 211 is disposed on an outer peripheral side of the pull rod 21, the limiting step 14 is used for limiting the second shoulder 211, in order to prevent the pull rod 21 and the inner peripheral side of the shaft core 1 from generating large friction and limit the movement of the pull rod 21, an inner diameter of the limiting step 14 is greater than or equal to an outer diameter of the second shoulder 211, that is, the second shoulder 211 is in clearance fit or contact with an inner wall of the limiting step 14, so that the pull rod 21 moves smoothly.

In order to prevent the pull rod 21 from pushing the tool shank to move excessively, so that the pull rod 21 falls off, the following three ways may be adopted in the embodiment: firstly, the position is limited only by the via hole 12; secondly, the tool loosening position of the pull rod 21 is limited preferentially through a through hole 12 on the shaft core 1, then the tool loosening position of the pull rod 21 is further limited in a mode that a limiting step 14 is arranged on the inner periphery side of the shaft core 1, and a second shoulder 211 is arranged on the outer periphery side of the pull rod 21, so that the problem that the first limiting mode fails due to deflection of the rigid pin is solved, and the limiting position of the rigid pin is a position which is moved to be attached to a first locating surface; thirdly, the tool loosening position of the pull rod 21 is limited by preferentially arranging the limiting step 14 on the inner periphery side of the shaft core 1 and arranging the second shoulder 211 on the outer periphery side of the pull rod 21, and then the tool loosening position of the pull rod 21 is further limited through the through hole 12 on the shaft core 1, so that the problem that the first limiting mode fails due to the failure of the limiting step 14 or the second shoulder 211 is solved, and at the moment, the limiting position of the rigid pin can move to a position adjacent to the first locating surface 121.

In the second limiting manner, the rigid pin can move between the first locating surface 121 and the second locating surface 122, so that the first locating surface 121 and the second locating surface 122 function as a first limiting, and the minimum distance between the first locating surface 121 and the limiting step 14 is greater than the minimum distance between the rigid pin and the second shoulder 211, so that when the rigid pin is located on the first locating surface 121, a certain distance should be kept between the limiting step 14 and the second shoulder 211, and when the rigid pin is inclined, the pull rod 21 continues to move towards the handle direction until the second shoulder 211 contacts the limiting step 14, and functions as a second limiting, thereby further preventing the pull rod 21 from moving excessively.

In the third limiting mode, the limiting step 14 and the second shoulder 211 play a role of first limiting, and the minimum distance between the first locating surface 121 and the limiting step 14 is smaller than the minimum distance between the rigid pin and the second shoulder 211, so that when the second shoulder 211 abuts against the limiting step 14, the rigid pin keeps a certain distance from the first locating surface 121, and when any one of the second shoulder 211 and the limiting step 14 fails to cause the rigid pin to be unable to abut against the rigid pin, the pull rod 21 continues to move towards the direction of the tool holder until the rigid pin contacts the first locating surface 121, and plays a role of second limiting, thereby further preventing the pull rod 21 from moving excessively.

Wherein, the minimum distance between the first positioning surface 121 and the limiting step 14 means: the surface of the limiting step 14 closest to the first positioning surface 121 is a first plane (the first plane is a plane extending along the radial direction), and the perpendicular distance between the first plane and the first positioning surface 121 is the minimum distance. The minimum distance between the rigid pin and the second shoulder 211 is: two tangent planes parallel to the first plane in the tangent planes on the outer peripheral side of the rigid pin are selected, one tangent plane closer to the tool shank is selected, and the perpendicular distance between the tangent plane and a second plane extending along the radial direction of the second shoulder 211 is the minimum distance.

Through the various limiting methods, the pull rod 21 can be prevented from falling off the shaft core 1 due to excessive movement.

In some embodiments, with continued reference to fig. 1-2, the unclamp assembly includes a driving mechanism 23, and the driving mechanism 23 is disposed at an end of the pull rod 21 away from the tool shank, and is used for driving the pull rod 21 to move in the axial direction. The driving mechanism 23 comprises an oil cylinder 231 (pneumatic or hydraulic) and a piston 232, the piston 232 is fixed on one side of the oil cylinder 231, which is far away from the pull rod 21, through a positioning sleeve 233, and when the tool is in a tool releasing state, the piston 232 moves axially under the driving of the oil cylinder 231 (pneumatic or hydraulic) to push the pull rod 21 to move away from the gasket 212 at one end of the tool holder, so that the pull rod 21 moves towards the tool holder, and the elastic resetting piece 22 is compressed; in the broaching state, in the direction away from the tool shank, the piston 232 is driven by the oil cylinder 231 (pneumatic or hydraulic) to move axially, so that the piston 232 leaves the gasket 212, that is, the gasket 212 has an axial moving space, and at this time, the elastic resetting piece 22 extends to push the pull rod 21 to move towards the direction away from the tool shank.

Further, in order to realize cutter loosening and cutter pulling, the cutter loosening and cutter pulling assembly further comprises a pulling claw and an expansion sleeve which are arranged in the hollow cavity 11, the pulling claw is positioned on the outer peripheral side of the expansion sleeve, the pulling claw is connected with the cutter handle, and the expansion sleeve is connected to one end, deviating from the driving mechanism 23, of the pull rod 21. Specifically, the knife handle is limited between the pull claw and the inner peripheral side of the shaft core 1, the pull claw can move in the hollow cavity 11 along the radial direction, when the pull rod 21 pushes the expansion sleeve to move towards the knife handle, the expansion sleeve is separated from the inner periphery of the pull claw, the pull claw contracts along the radial direction, the knife handle is separated from the pull claw, and therefore knife loosening is achieved, otherwise, when the pull rod 21 drives the expansion sleeve to move away from the knife handle, the expansion sleeve pushes the pull claw to enable the pull claw to expand along the radial direction, the knife handle is abutted to the inner peripheral side of the shaft core 1, and therefore knife pulling is achieved.

In addition, the spindle structure of the present embodiment further includes a rotary joint 6 and a rotary joint connecting rod 217, the rotary joint 6 is located on one side of the positioning sleeve 233 away from the pull rod 21, and the rotary joint 6 is communicated with a gas-liquid hole 216 built in the pull rod 21 through the rotary joint connecting rod 217 so as to introduce a gas-liquid mixture into the gas-liquid hole 216. Alternatively, separate gas and liquid ports are built into the tie rod 21 to allow separate delivery of gas and liquid. However, both of the above manners may cause at least one of gas and liquid to leak into the cavity between the shaft core 1 and the shaft sleeve 3 through the gap between the rigid pin and the through hole 12 when the rigid pin moves in the axial direction, thereby causing contamination of the motor, the first bearing group 41, and the second bearing group 42.

In view of this, a first sealing ring 213 and a second sealing ring 214 are disposed on the outer circumferential side of the pull rod 21, the first sealing ring 213 and the second sealing ring 214 are respectively disposed on two sides of the rigid pin along the radial direction of the shaft core 1, the through hole 12 is located between the first sealing ring 213 and the second sealing ring 214, that is, no matter how the rigid pin moves in the through hole 12, the through hole 12 is always located in the first sealing ring 213 and the second sealing ring 214, and any one of gas and liquid does not enter the cavity between the shaft core 1 and the shaft sleeve 3 through the through hole 12, so as to isolate the motor and the first bearing group 41 and the second bearing group 42 from being polluted, and meanwhile, the first sealing ring 213 and the second sealing ring 214 can also play a guiding role in the axial movement process of the pull rod 21. Further, a third seal ring 215 may be provided at another position on the outer peripheral side of the tie rod 21, thereby performing a better sealing and guiding function.

In this embodiment, the number of the connecting members 24 includes at least two, the at least two connecting members 24 are circumferentially distributed on the outer periphery of the shaft core 1 in an array, and at least two of the vias 12 are correspondingly disposed on the outer periphery of the shaft core 1. Specifically, referring to fig. 1 or fig. 2, the number of the connecting members 24 includes two, the two connecting members 24 are respectively disposed on two axial sides of the shaft core 1, the two axial sides of the shaft core 1 are correspondingly provided with two through holes 12, further, two through holes 12 are disposed on the outer circumferential side of the shaft core 1 along the same radial direction, and a rigid pin moving along the axial direction of the shaft core 1 is disposed in the through holes 12, so that synchronous limiting on the two axial sides of the shaft core 1 is achieved, and the stability of the axial movement of the pull rod 21 in the hollow cavity 11 is ensured.

The action process of the embodiment is as follows:

and (3) loosening the cutter to operate: piston 232 moves axially towards the handle direction under the drive of hydro-cylinder 231 (pneumatic or hydraulic), pushes away gasket 212 and pull rod 21 and fixes the rigid pin synchronous motion on pull rod 21, makes second stop pad 222 compress elasticity reset 22, along with elasticity reset 22 compression to certain distance, the rigid pin contacts with first locating surface 121 first, or, second shoulder 211 contacts with spacing step 14 first, the claw that draws of pull rod 21 one end loosens, realizes the pine sword. The moving distance of the pull rod 21 towards the direction of the tool holder needs to be calculated, so that the pull rod 21 is ensured to move in a reasonable range, and the first bearing set 41 is prevented from being damaged by excessive movement of the pull rod 21.

The broach operation process: the piston 232 moves axially in the direction away from the tool holder under the driving of the oil cylinder 231 (pneumatic or hydraulic), at this time, the piston 232 is separated from the gasket 212, the gasket 212 has a moving space, the pull rod 21 has no driving force, the elastic reset piece 22 lengthens, the gasket 212, the pull rod 21 and the rigid pin fixed on the pull rod 21 are pushed to move axially in the direction away from the tool holder, and the pull claw at one end of the pull rod 21 contracts to realize the broaching. The distance of the pull rod 21 moving away from the tool holder needs to be calculated, and the rigid pin is matched with the second positioning surface 122 for limiting, so as to ensure the tool pulling force, and prevent the pull rod 21 from excessively moving and damaging the second bearing set 42.

It is noted that, in this document, relational terms such as "first" and "second," and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrases "comprising a," "8230," "8230," or "comprising" does not exclude the presence of additional like elements in a process, method, article, or apparatus that comprises the element.

The foregoing are merely exemplary embodiments of the present invention, which enable those skilled in the art to understand or practice the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (13)

1. A spindle structure, comprising:

the shaft core (1), the shaft core (1) is provided with a hollow cavity (11) extending along the axial direction; and

the loose broach assembly comprises a pull rod (21), an elastic resetting piece (22) and a connecting piece (24); the pull rod (21) is movably arranged in the hollow cavity (11) along the axial direction, one end of the pull rod (21) is connected with the cutter handle, so that the pull rod (21) drives the cutter handle to extend outwards or retract inwards along the axial direction; elasticity resets piece (22) cover and locates the periphery side of axle core (1), elasticity resets piece (22) one end with axle core (1) periphery side is connected, elasticity resets piece (22) other end through connecting piece (24) with pull rod (21) are connected, so that elasticity resets piece (22) along the axial flexible.

2. The spindle structure according to claim 1, characterized in that a through hole (12) extending in a radial direction is opened at an outer peripheral side of the spindle core (1), and the connecting piece (24) penetrates through the through hole (12) and is connected to the tie rod (21);

the outer peripheral side of the shaft core (1) is further provided with a first shaft shoulder (13) which is arranged at an interval with the via hole (12), and the elastic reset piece (22) is arranged between the first shaft shoulder (13) and the connecting piece (24).

3. The spindle structure according to claim 2, wherein the through hole (12) has a first locating surface (121) and a second locating surface (122) which are opposite to each other in the axial direction of the spindle core (1), the first locating surface (121) is located on one side of the second locating surface (122) facing the tool shank, and the connecting member (24) moves in the axial direction between the first locating surface (121) and the second locating surface (122);

when the connecting piece (24) is located on the second positioning surface (122), the elastic resetting piece (22) is in a pre-compression state, the length of the elastic resetting piece (22) is a first length, when the connecting piece (24) is at least adjacent to the first positioning surface (121), the elastic resetting piece (22) is in a further compression state, the length of the elastic resetting piece (22) is a second length, and the first length is larger than the second length.

4. A spindle arrangement according to claim 3, characterised in that the first shoulder (13) is provided with a first stop pad (221) on the side facing the connecting piece (24), that the connecting piece (24) is provided with a second stop pad (222) on the side facing the first shoulder (13), and that the elastic return member (22) is arranged between the first stop pad (221) and the second stop pad (222).

5. The spindle structure according to claim 4, wherein an inner diameter of an inner hole of the second stop pad (222) is greater than or equal to an outer diameter of the spindle core (1) at a corresponding position.

6. The spindle structure according to claim 2 or 3, wherein a limiting step (14) is provided on an inner peripheral side of the spindle core (1), the limiting step (14) is located between the first shoulder (13) and the through hole (12) in an axial direction of the spindle core (1), a second shoulder (211) is provided on an outer peripheral side of the pull rod (21), and the second shoulder (211) is limited at the limiting step (14).

7. The spindle arrangement according to claim 6, characterized in that the minimum distance between the first positioning surface (121) of the through hole (12) and the stop step (14) is greater than the minimum distance between the connecting piece (24) and the second shoulder (211), or the minimum distance between the first positioning surface (121) of the through hole (12) and the stop step (14) is smaller than the minimum distance between the connecting piece (24) and the second shoulder (211).

8. The spindle arrangement according to claim 6, characterized in that the inner diameter of the limit step (14) is greater than or equal to the outer diameter of the second shoulder (211).

9. The spindle structure according to claim 2, wherein a first sealing ring (213) and a second sealing ring (214) are disposed on an outer peripheral side of the pull rod (21), the first sealing ring (213) and the second sealing ring (214) are used for sealing the pull rod (21) and the spindle core (1), and the through hole (12) is located between the first sealing ring (213) and the second sealing ring (214).

10. The spindle structure according to claim 2, wherein the number of the connecting members (24) comprises at least two, the at least two connecting members (24) are circumferentially arrayed on the outer circumference side of the spindle core (1), and at least two through holes (12) are correspondingly arranged on the outer circumference side of the spindle core (1).

11. The spindle structure according to claim 1, characterized in that the loose broach assembly further includes a driving mechanism (23), and the driving mechanism (23) is disposed at an end of the pull rod (21) away from the shank, and is used for driving the pull rod (21) to move axially.

12. The spindle structure of claim 11, wherein the loose broach assembly further includes a pulling claw and an expanding sleeve which are arranged in the hollow cavity (11), the pulling claw is located on the outer peripheral side of the expanding sleeve, the pulling claw is connected with the tool holder, and the expanding sleeve is connected to one end of the pull rod (21) which is far away from the driving mechanism (23).

13. A numerically controlled machine tool comprising a spindle structure according to any one of claims 1 to 12.

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