Shaft core cooling structure, main shaft and machine tool

Abstract

The shaft core cooling structure comprises a pull rod and a shaft core assembly, the shaft core assembly is provided with a shaft core inner hole and a shaft core cooling channel, the pull rod is arranged in the shaft core inner hole, the pull rod is provided with a shaft core matching portion matched with the shaft core inner hole, and a cooling liquid flow channel extending to the shaft core matching portion from the tail end is arranged in the pull rod. The cooling liquid flow channel comprises a liquid inlet flow channel and a liquid return flow channel, the liquid inlet flow channel forms a liquid inlet connector on the outer wall face of the shaft core matching part, the liquid return flow channel forms a liquid return connector on the outer wall face of the shaft core matching part, the shaft core cooling channel is provided with a channel inlet and a channel outlet on the inner wall face of the shaft core inner hole, and a first ring groove is formed between the channel inlet and the liquid inlet connector. A second ring groove is formed between the channel outlet and the liquid return connector. Experiments prove that the spindle cooling structure is good in cooling effect, low in spindle core temperature rise, small in spindle thermal elongation and capable of greatly shortening spindle engine heating time and improving machine table machining efficiency and machining precision.

Description

Technical Field

[0001] The utility model is used in the field of electric spindles, in particular to a shaft core cooling structure, a spindle and a machine tool. Background Art

[0002] Electric spindles are widely used in various CNC machine tools due to their easy installation, compact structure, light weight, low vibration, high speed, high machining precision, stable machining results, and short start-up and shutdown times. However, with the upgrading of the machine tool industry, higher requirements are being placed on the functionality and stability of spindles, as well as the machining efficiency of machine tools. The problem of spindle thermal elongation is unavoidable in technical indicators such as machining stability, machining dimensional accuracy, and machining efficiency, as the thermal stability of the spindle is a key indicator of various core machine tool indicators.

[0003] Common spindle cooling structures generally use oil bath cooling and shaft core circulation cooling. Among them, oil bath cooling has disadvantages such as sealing structure design, sealing material selection, and high requirements for use conditions, while shaft core circulation cooling has a complex structure and poor cooling effect. Utility Model Content

[0004] The purpose of the utility model is to solve at least one of the technical problems existing in the prior art and to provide a shaft core cooling structure, a main shaft and a machine tool.

[0005] The technical solution adopted by the utility model to solve its technical problems is:

[0006] In the first aspect, a shaft core cooling structure includes a pull rod and a shaft core assembly, the shaft core assembly is provided with a shaft core inner hole and a shaft core cooling channel, the pull rod is arranged in the shaft core inner hole, the pull rod is provided with a shaft core matching part matching with the shaft core inner hole, a cooling liquid flow channel is provided inside the pull rod extending from the end to the shaft core matching part, the cooling liquid flow channel includes a liquid inlet flow channel and a liquid return flow channel, the liquid inlet flow channel forms a liquid inlet interface on the outer wall surface of the shaft core matching part, the liquid return flow channel forms a liquid return interface on the outer wall surface of the shaft core matching part, the shaft core cooling channel is provided with a channel inlet and a channel outlet on the inner wall surface of the shaft core inner hole, a first annular groove is provided between the channel inlet and the liquid inlet interface, and a second annular groove is provided between the channel outlet and the liquid return interface.

[0007] In combination with the first aspect, in certain implementations of the first aspect, the liquid inlet channel includes a first axial hole, which extends along the axis of the pull rod to the shaft core mating portion, and the end of the first axial hole is provided with a plurality of first radial holes extending radially to the first annular groove.

[0008] In combination with the first aspect and the above-mentioned implementation methods, in certain implementation methods of the first aspect, the return liquid channel includes a plurality of second axial holes, and the plurality of second axial holes are distributed around the first axial hole and extend to the shaft core mating portion. The end of the second axial hole is provided with a second radial hole extending radially to the second annular groove, and the first radial hole and the second radial hole are staggered axially.

[0009] In combination with the first aspect and the above-mentioned implementation methods, in some implementation methods of the first aspect, the shaft core fitting portion cooperates with the end position of the shaft core inner hole, and sealing rings are provided between the shaft core fitting portion and the shaft core assembly on both sides of the first ring groove and the second ring groove.

[0010] In combination with the first aspect and the above-mentioned implementations, in some implementations of the first aspect, the shaft core cooling channel includes a third axial hole and a fourth axial hole extending axially along the shaft core assembly, the end of the third axial hole is provided with a third radial hole extending radially to the first annular groove, the end of the fourth axial hole is provided with a fourth radial hole extending radially to the second annular groove, and the third axial hole and the fourth axial hole are connected at the front end of the shaft core assembly.

[0011] In combination with the first aspect and the above-mentioned implementation methods, in some implementation methods of the first aspect, the front end of the shaft core assembly is embedded with a shaft core sealing block in the inner hole of the shaft core, and a third annular groove is provided between the shaft core sealing block and the shaft core assembly, and the third axial hole and the fourth axial hole are both provided with a fifth radial hole connected to the third annular groove.

[0012] In combination with the first aspect and the above-mentioned implementations, in certain implementations of the first aspect, the shaft core assembly is provided with a plurality of third axial holes and a plurality of fourth axial holes along the circumferential direction, and the third axial holes and the fourth axial holes are distributed alternately.

[0013] In combination with the first aspect and the above-mentioned implementation manner, in some implementation manners of the first aspect, it also includes an axis core cooling assembly, which is arranged at the end of the pull rod, and the axis core cooling assembly includes a body component and a pull rod connecting component, and the pull rod connecting component is supported on the body component by a bearing, and the pull rod connecting component extends axially from the first end to the second end, and the second end of the pull rod connecting component forms a floating plug hole for connecting to the pull rod, and the pull rod connecting component is provided with a transition cooling channel extending to the inner wall surface of the floating plug hole, and the body component is provided with a cooling interface connected to the transition cooling channel, and the transition cooling channel includes a liquid inlet cooling channel and a liquid return cooling channel, and the cooling interface includes a liquid inlet cooling interface connected to the liquid inlet cooling channel and a liquid return cooling interface connected to the liquid return cooling channel.

[0014] In a second aspect, a main shaft comprises the shaft core cooling structure described in any implementation of the first aspect.

[0015] In a third aspect, a machine tool comprises the spindle described in any implementation of the second aspect.

[0016] One of the above technical solutions has at least one of the following advantages or beneficial effects: In the technical solution of the present invention, the coolant can enter the liquid inlet channel from the end of the pull rod and flow to the shaft core fitting part, and enter the shaft core assembly through the liquid inlet interface, the first annular groove, and the channel inlet at the shaft core fitting part. The coolant flows in the shaft core cooling channel of the shaft core assembly, takes away the temperature of the shaft core assembly, and then flows back to the liquid return channel of the pull rod through the channel outlet, the second annular groove, and the liquid return interface. This structure introduces the coolant into the shaft core assembly through the pull rod to achieve cooling of the shaft core assembly, and has the characteristics of simple structure, high stability, and easy installation and disassembly. The present invention can be applied to all types of spindles that require a shaft core cooling structure. After experimental verification, this structure has a good cooling effect, low shaft core temperature rise, and small thermal elongation of the spindle. It can greatly shorten the spindle warm-up time and improve the machine processing efficiency and processing accuracy.

[0017] Additional aspects and advantages of the present invention will be given in part in the following description and will become apparent from the following description or learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0019] Figure 1 This is a schematic diagram of the structure and coolant flow of an embodiment of the shaft core cooling structure of the utility model;

[0020] Figure 2 yes Figure 1 A schematic structural diagram of the shaft-core matching portion of a pull rod according to an embodiment is shown;

[0021] Figure 3 yes Figure 2 The cross-section diagram is shown in the middle AA;

[0022] Figure 4 yes Figure 2 The cross-section diagram of the middle BB;

[0023] Figure 5 yes Figure 1 A schematic structural diagram of a shaft core assembly according to an embodiment is shown;

[0024] Figure 6 yes Figure 5 The cross-section diagram is shown in the middle CC;

[0025] Figure 7 yes Figure 5 DD shows the cross-section. DETAILED DESCRIPTION

[0026] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0027] In the present invention, if there is a description of directions (up, down, left, right, front and back), it is only for the convenience of describing the technical solution of the present invention, and does not indicate or imply that the technical features referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0028] In this utility model, "several" means one or more, "multiple" means more than two, "greater than," "less than," "exceeds," etc. are understood to exclude the number itself; "above," "below," "within," etc. are understood to include the number itself. In the description of this utility model, the use of "first" or "second" is solely for the purpose of distinguishing technical features and is not to be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0029] In this utility model, unless otherwise expressly defined, terms such as "disposed," "installed," and "connected" should be interpreted broadly. For example, they may refer to direct connection or indirect connection through an intermediate medium; fixed connection or detachable connection or integral molding; mechanical connection or electrical connection or mutual communication; and internal connection between two components or interaction between two components. Those skilled in the art can reasonably determine the specific meanings of these terms in this utility model based on the specific content of the technical solution.

[0030] in, Figure 1 The reference direction coordinate system of the embodiment of the present utility model is given below. Figure 1 The embodiment of the present invention is described with reference to the direction shown.

[0031] See also Figure 1 、 Figure 2An embodiment of the present invention provides a shaft core cooling structure, including a pull rod 100 and a shaft core assembly 200. The shaft core assembly 200 is provided with a shaft core inner hole 201 and a shaft core cooling channel 202. The pull rod 100 is arranged in the shaft core inner hole 201. The pull rod 100 can cooperate with the oil cylinder 300 at the end of the shaft core assembly 200 to move axially during operation to realize the tool changing function. The pull rod 100 is provided with a shaft core fitting portion 101 that fits with the shaft core inner hole 201. The outer wall surface of the shaft core fitting portion 101 fits with the shaft core inner hole 201. A coolant flow channel is provided inside the pull rod 100, extending from the end to the shaft core fitting portion 101. The coolant flow channel extends inside the shaft core assembly 200 and is used for the coolant to flow therein to take away the temperature of the shaft core assembly 200. The coolant flow channel includes a liquid inlet channel 102 and a liquid return channel 103. The liquid inlet channel 102 forms a liquid inlet interface 104 on the outer wall surface of the shaft core fitting portion 101, and the liquid return channel 103 forms a liquid return interface 105 on the outer wall surface of the shaft core fitting portion 101. The shaft core cooling channel 202 is formed on the inner wall of the shaft core inner hole 201. A channel inlet 203 and a channel outlet 204 are provided on the surface, and a first annular groove 106 is provided between the channel inlet 203 and the liquid inlet interface 104. The first annular groove 106 can be provided on the outer peripheral surface of the pull rod 100 and / or the inner wall surface of the shaft core inner hole 201. The first annular groove 106 is used for the communication between the channel inlet 203 and the liquid inlet interface 104, and collects and evenly flows out the cooling liquid. A second annular groove 107 is provided between the channel outlet 204 and the return liquid interface 105. The second annular groove 107 can be provided on the outer peripheral surface of the pull rod 100 and / or the inner wall surface of the shaft core inner hole 201. The second annular groove 107 is used for the communication between the channel outlet 204 and the return liquid interface 105, and collects and evenly flows out the cooling liquid.

[0032] Combine Figure 1 In the technical solution of the present invention, the coolant can enter the liquid inlet channel 102 from the end of the pull rod 100 and flow to the shaft core fitting part 101. At the shaft core fitting part 101, it enters the shaft core assembly 200 through the liquid inlet interface 104, the first annular groove 106, and the channel inlet 203. The coolant flows in the shaft core cooling channel 202 of the shaft core assembly 200, taking away the temperature of the shaft core assembly 200, and then flows back to the return liquid channel 103 of the pull rod 100 through the channel outlet 204, the second annular groove 107, and the return liquid interface 105. This structure introduces the coolant into the shaft core assembly 200 through the pull rod 100 to achieve cooling of the shaft core assembly 200. It has the characteristics of simple structure, high stability, and easy installation and disassembly. The present invention can be applied to all kinds of spindles that require a shaft core cooling structure. Experimental verification shows that this structure has a good cooling effect, low shaft core temperature rise, and small spindle thermal elongation. It can greatly shorten the spindle warm-up time and improve the machine processing efficiency and processing accuracy.

[0033] The embodiments of the present utility model can effectively reduce the shaft core problem, have high reliability, and can be applied to various types of high-precision spindles. After actual spindle testing, the present structure can reduce 90% of the temperature rise, reduce the thermal elongation of the spindle by more than 80%, and shorten the thermal stabilization time from the original 20 minutes to 3 minutes, which can greatly improve the use effect of the machine and has excellent application and promotion value.

[0034] The liquid inlet channel 102 is opened inside the tie rod 100. In some embodiments, see Figure 1 、 Figure 2 、 Figure 3 The liquid inlet channel 102 includes a first axial hole 108, which extends along the axis of the tie rod 100 to the shaft core mating portion 101. The first axial hole 108 is located at the end of the shaft core mating portion 101 and is provided with a plurality of first radial holes 109 extending radially to the first annular groove 106. The coolant is introduced into the tie rod 100 through the first axial hole 108 and then into the first annular groove 106 through the plurality of first radial holes 109. After being collected in the first annular groove 106, the coolant flows into the channel inlet 203 of the coolant channel of the shaft core assembly 200. The liquid inlet channel 102 in this embodiment has a simpler structure, smoother coolant inflow and flow, and better cooling effect.

[0035] Further, see Figure 1 、 Figure 2 、 Figure 4 The return channel 103 includes a plurality of second axial holes 110 distributed around the first axial hole 108 and extending to the shaft-core mating portion 101. The ends of the second axial holes 110 are provided with second radial holes 111 extending radially to the second annular groove 107. The first radial holes 109 and the second radial holes 111 are axially staggered, forming a multi-stage radial hole distribution along the axial direction. The liquid inlet channel 102 in this embodiment has a simpler structure, smoother return flow of the coolant, and better cooling effect.

[0036] In some embodiments, see Figure 1 The shaft core fitting portion 101 cooperates with the end position of the shaft core inner hole 201, so that the coolant can enter from the end of the shaft core assembly 200, and after the shaft core assembly 200 is circulated and cooled, it flows out from the end position of the shaft core assembly 200, thereby realizing overall cooling of the shaft core assembly 200.

[0037] See also Figure 1 、 Figure 2A sealing ring 112 is provided on both sides of the first annular groove 106 and the second annular groove 107 between the shaft core fitting part 101 and the shaft core assembly 200. The sealing ring 112 effectively ensures the sealing between the pull rod 100 and the shaft core inner hole 201, avoids the leakage of coolant at the connection position between the pull rod 100 and the shaft core assembly 200, and avoids affecting the tool unloading function of the pull rod 100.

[0038] In some embodiments, see Figure 1 、 Figure 5-Figure 7 The shaft core cooling channel 202 includes a third axial hole 205 and a fourth axial hole 206 extending axially along the shaft core assembly 200. The end of the third axial hole 205 is provided with a third radial hole 207 extending radially to the first annular groove 106. The end of the fourth axial hole 206 is provided with a fourth radial hole 208 extending radially to the second annular groove 107. The third axial hole 205 and the fourth axial hole 206 are connected at the front end of the shaft core assembly 200. The coolant entering the shaft core assembly 200 from the pull rod 100 first flows from the end to the front through the third axial hole 205, and then flows back from the front to the end through the fourth axial hole 206, thus realizing a cooling cycle for the entire axis.

[0039] Further, in some embodiments, see Figure 1 、 Figure 5 At the front end of the shaft core assembly 200, a shaft core sealing block 209 is embedded in the shaft core inner bore 201. A third annular groove 210 is provided between the shaft core sealing block 209 and the shaft core assembly 200. A passage is formed through the third annular groove 210. The third axial hole 205 and the fourth axial hole 206 are both provided with a fifth radial hole connected to the third annular groove 210. The shaft core sealing block 209 collects the coolant to the front end of the shaft core assembly 200. After passing through the third annular groove 210, the coolant flows along the fourth axial hole 206 of the shaft core assembly 200 to the rear end.

[0040] It is understandable that the shaft core assembly 200 can also be a split shaft core, that is, the reversing and reflux function of the third axial hole 205 and the fourth axial hole 206 is realized through the split shaft core, thereby satisfying the conversion of the coolant through the shaft core structure.

[0041] In some embodiments, see Figure 6 、 Figure 7 The spindle assembly 200 is provided with a plurality of third axial holes 205 and a plurality of fourth axial holes 206 along the circumferential direction, and the third axial holes 205 and the fourth axial holes 206 are alternately distributed. The plurality of third axial holes 205 and the plurality of fourth axial holes 206 alternately distributed along the circumferential direction enable the coolant to cool the spindle assembly 200 more evenly and fully, effectively reducing the thermal expansion of the spindle.

[0042] In some embodiments, see Figure 1The core cooling structure also includes a core cooling assembly 400, which is arranged at the end of the pull rod 100. The core cooling assembly 400 includes a body part 401 and a pull rod connecting part 402. The pull rod connecting part 402 is supported on the body part 401 through a bearing 403. The pull rod connecting part 402 extends axially from the first end to the second end. The second end of the pull rod connecting part 402 forms a floating socket for connecting to the pull rod 100. The pull rod connecting part 402 is provided with a transition cooling channel extending to the inner wall surface of the floating socket. The body part 401 is provided with a cooling interface connected to the transition cooling channel. The transition cooling channel includes a liquid inlet cooling channel 404 and a liquid return cooling channel 405. The cooling interface includes a liquid inlet cooling interface 406 connected to the liquid inlet cooling channel 404 and a liquid return cooling interface 407 connected to the liquid return cooling channel 405. During use, the pull rod connecting component 402 is floatingly plugged into the end of the pull rod 100, and the shaft core coolant flows from the liquid cooling interface 406 through the body component 401 into the transition cooling channel of the pull rod connecting component 402. The coolant advances axially along the transition cooling channel and further flows through the pull rod 100 and the shaft core to achieve shaft core cooling, which can effectively take away heat, reduce the thermal elongation of the spindle, greatly shorten the spindle warm-up time, and improve the machine processing efficiency and accuracy.

[0043] An embodiment of the present invention further provides a main shaft, comprising the shaft core cooling structure in any of the above embodiments.

[0044] An embodiment of the present utility model further provides a machine tool, comprising the spindle in any one of the above embodiments.

[0045] Throughout this specification, references to terms such as "example," "embodiment," or "some embodiments" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0046] Of course, the invention is not limited to the above-mentioned embodiments. Those skilled in the art may make equivalent modifications or substitutions without violating the spirit of the invention. These equivalent modifications or substitutions are all within the scope defined by the claims of this application.

Claims

1. A shaft core cooling structure, characterized in that: It includes a pull rod and an axis core assembly, the axis core assembly is provided with an axis core inner hole and an axis core cooling channel, the pull rod is arranged in the axis core inner hole, the pull rod is provided with an axis core matching part matching with the axis core inner hole, and a cooling liquid flow channel is provided inside the pull rod extending from the end to the axis core matching part, the cooling liquid flow channel includes an inlet flow channel and a return flow channel, the inlet flow channel forms a liquid inlet interface on the outer wall surface of the axis core matching part, the return flow channel forms a return liquid interface on the outer wall surface of the axis core matching part, the axis core cooling channel is provided with a channel inlet and a channel outlet on the inner wall surface of the axis core inner hole, a first annular groove is provided between the channel inlet and the liquid inlet interface, and a second annular groove is provided between the channel outlet and the return liquid interface.

2. The shaft core cooling structure according to claim 1, characterized in that: The liquid inlet channel includes a first axial hole extending along the axis of the pull rod to the shaft core fitting portion, and an end portion of the first axial hole is provided with a plurality of first radial holes extending radially to the first annular groove.

3. The shaft core cooling structure according to claim 2, characterized in that: The return liquid channel includes a plurality of second axial holes, which are distributed around the first axial hole and extend to the shaft core mating portion. The end of the second axial hole is provided with a second radial hole extending radially to the second annular groove, and the first radial hole and the second radial hole are staggered along the axial direction.

4. The shaft core cooling structure according to claim 1, characterized in that: The shaft core fitting portion is fitted with the end position of the shaft core inner hole, and sealing rings are provided between the shaft core fitting portion and the shaft core assembly on both sides of the first annular groove and the second annular groove.

5. The shaft core cooling structure according to claim 4, characterized in that: The shaft core cooling channel includes a third axial hole and a fourth axial hole extending axially along the shaft core assembly, the end of the third axial hole is provided with a third radial hole extending radially to the first annular groove, the end of the fourth axial hole is provided with a fourth radial hole extending radially to the second annular groove, and the third axial hole and the fourth axial hole are connected at the front end of the shaft core assembly.

6. The shaft core cooling structure according to claim 5, characterized in that: A shaft core sealing block is embedded in the shaft core inner hole at the front end of the shaft core assembly, a third annular groove is provided between the shaft core sealing block and the shaft core assembly, and the third axial hole and the fourth axial hole are both provided with a fifth radial hole connected to the third annular groove.

7. The shaft core cooling structure according to claim 5, characterized in that: The shaft core assembly is provided with a plurality of third axial holes and a plurality of fourth axial holes along the circumferential direction, and the third axial holes and the fourth axial holes are distributed alternately.

8. The shaft core cooling structure according to claim 1, characterized in that: It also includes an axis core cooling assembly, which is arranged at the end of the pull rod. The axis core cooling assembly includes a body component and a pull rod connecting component. The pull rod connecting component is supported on the body component by a bearing. The pull rod connecting component extends axially from the first end to the second end. The second end of the pull rod connecting component forms a floating plug hole for connecting to the pull rod. The pull rod connecting component is provided with a transition cooling channel extending to the inner wall surface of the floating plug hole. The body component is provided with a cooling interface connected to the transition cooling channel. The transition cooling channel includes a liquid inlet cooling channel and a liquid return cooling channel. The cooling interface includes a liquid inlet cooling interface connected to the liquid inlet cooling channel and a liquid return cooling interface connected to the liquid return cooling channel.

9. A spindle, characterized in that: The invention comprises the shaft core cooling structure according to any one of claims 1 to 8.

10. A machine tool, characterized in that: Including the main shaft according to claim 9.

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