Grinding wheel and grinding machine provided with same

Abstract

The grinding wheel comprises a grinding layer and a base body, the grinding layer is provided with a working face, and the working face is used for making contact with a workpiece. The base body is provided with a plurality of cooling liquid flow channels penetrating through the thickness of the base body, the multiple cooling liquid flow channels are symmetrically distributed about the center of the base body, the cooling liquid is provided with a liquid inlet and a liquid outlet, the liquid inlet is far away from the working face and used for being connected with a cooling liquid supply source, and the liquid outlet is close to the working face; the sectional area of the cooling liquid flow channel is gradually reduced from the liquid inlet to the liquid outlet, so that the flow speed of the cooling liquid at the liquid outlet can be increased, the scouring effect is improved, the adverse effect on the grinding process quality caused by the fact that the cooling liquid flow channel is blocked by abrasive dust is weakened or even eliminated, and the grinding process quality is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of grinding processing, in particular to a grinding wheel and a grinding machine equipped with the same. Background Art

[0002] With the rapid development of new energy technology, solar cells have emerged. Solar cells have the advantages of being green and environmentally friendly. Among them, silicon-based cells with silicon as the matrix material have become the mainstream due to their high conversion efficiency. As an important material for silicon-based cells, the process quality of single-crystal silicon wafers affects the performance of silicon-based cells.

[0003] At present, single crystal silicon wafers are mainly prepared by cutting, squaring, grinding, slicing and other process steps of single crystal silicon rods. Among them, grinding is achieved by grinding with a grinding wheel so that the size and shape of the ground single crystal silicon rod meet the requirements. It is understandable that grinding, as the last process of machining, will directly affect the performance and quality of single crystal silicon wafers.

[0004] Therefore, how to improve the grinding quality is an urgent problem to be solved. Utility Model Content

[0005] The utility model aims to solve at least one of the technical problems existing in the prior art, and provides a grinding wheel and a grinding machine equipped with the same.

[0006] In the first aspect, the utility model provides a grinding wheel, which includes: a grinding layer and a base, the grinding layer having a working surface, the working surface being used to contact a workpiece; the base is provided with a plurality of coolant flow channels running through its thickness, the coolant flow channels having a liquid inlet and a liquid outlet, the liquid inlet being away from the working surface and being used to be connected to a coolant supply source, and the liquid outlet being close to the working surface; the cross-sectional area of ​​the coolant flow channel gradually decreases from the liquid inlet to the liquid outlet; and the plurality of coolant flow channels are symmetrically distributed about the center of the base.

[0007] In some possible embodiments, the liquid outlet includes a first inner wall, a second inner wall, a first end wall and a second end wall, the first inner wall and the second inner wall are spaced apart and opposite to each other along the radial direction of the base, and one end of the first inner wall and the second inner wall are connected by the first end wall and the other end is connected by the second end wall.

[0008] In some possible embodiments, a distance between the first inner sidewall and the second inner sidewall in the radial direction of the substrate is greater than or equal to 10 mm and less than or equal to 15 mm.

[0009] In some possible embodiments, the midpoint of a line connecting one end of the first inner wall and one end of the second inner wall along the radial direction of the base is a first reference point, and the midpoint of a line connecting the other end of the first inner wall and the other end of the second inner wall along the radial direction of the base is a second reference point; the distance between the first reference point and the second reference point along the extension direction of the coolant flow channel is greater than or equal to 50 mm and less than or equal to 70 mm.

[0010] In some possible embodiments, a plurality of weight-reducing grooves are provided on the base, and the plurality of weight-reducing grooves are symmetrically distributed about the center of the base.

[0011] In some possible embodiments, multiple weight-reducing grooves are arranged in one-to-one correspondence with multiple coolant channels, each weight-reducing groove is located between the corresponding coolant channel and the center of the substrate and close to the outlet of the corresponding coolant channel, and the outlet of the coolant channel is arranged close to the edge of the substrate.

[0012] In some possible embodiments, the weight-reducing groove penetrates the thickness of the substrate, and there is a gap between the edge of the weight-reducing groove and the edge of the corresponding coolant outlet along the radial direction of the substrate; alternatively, the weight-reducing groove is formed on the side of the substrate facing the grinding layer, and the weight-reducing groove does not penetrate the thickness of the substrate, and the weight-reducing groove is connected to the corresponding coolant outlet.

[0013] In some possible embodiments, the grinding layer is annular, and a plurality of drainage grooves are opened on the working surface. The plurality of drainage grooves are evenly distributed around the center of the base body, and the inlet end of the drainage groove passes through the inner circumference of the grinding layer, and the outlet end passes through the outer circumference of the grinding layer.

[0014] In some possible embodiments, the liquid outlet of each cooling liquid flow channel is arranged opposite to one or more drain grooves.

[0015] In some possible embodiments, the outer diameter of the grinding layer is greater than 256 mm and less than or equal to 300 mm.

[0016] In a second aspect, the utility model provides a grinding machine, comprising: a driving motor, a rotating shaft and any one of the grinding wheels provided in the first aspect of the utility model, wherein the rotating shaft is fixedly connected to a base of the grinding wheel, and the driving motor is used to drive the rotating shaft to rotate.

[0017] The utility model has the following beneficial effects:

[0018] The grinding wheel provided by the utility model is designed such that the cross-sectional area of ​​the coolant flow channel gradually decreases from the liquid inlet to the liquid outlet. When the cross-sectional area of ​​the liquid inlet, the flow rate into the coolant flow channel and other parameters are consistent with the parameters in the relevant technology, the grinding wheel of this embodiment has a relatively smaller outlet of the coolant flow channel, so the flow rate of the coolant at the outlet is greater, which increases the impact force of the coolant sprayed from the outlet on the grinding chips and improves the flushing effect. This can effectively reduce the probability of the coolant flow channel being blocked by grinding chips, ensure that the coolant can play a flushing and cooling role, so as to ensure the self-sharpening of the grinding wheel, and can weaken or even eliminate the adverse effects of the grinding wheel passivation on the grinding process quality, thereby ensuring the grinding process quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A front view of a grinding wheel provided in one embodiment of the present application;

[0020] Figure 2 for Figure 1 A schematic cross-sectional view of a grinding wheel is shown;

[0021] FIG3( a ) is a front view of a modified example of the base body in the grinding wheel provided in the first embodiment of the present application;

[0022] FIG3( b ) is a front view of a modified example of the base body in the grinding wheel provided in the second embodiment of the present application;

[0023] FIG3( c ) is a front view of a modified example of the base body in the grinding wheel provided in the third embodiment of the present application;

[0024] Figure 4 A front view of a grinding wheel provided in another embodiment of the present application;

[0025] Figure 5 A partial front view of a grinding wheel provided in yet another embodiment of the present application.

[0026] Description of reference numerals:

[0027] 100-grinding wheel;

[0028] 110-base; 111-cooling liquid flow channel; 112-through hole; 113-first inner side wall; 114-second inner side wall; 115-first end wall; 116-second end wall; 117-weight reduction groove; 118-screw;

[0029] 120 - grinding layer; 121 - working surface; 122 - drainage trough. DETAILED DESCRIPTION

[0030] The grinding wheel is made of multiple abrasive grains bonded by a binder, with gaps (also called voids or pores) formed between the abrasive grains and the binder. The grinding working principle of the grinding wheel is as follows: the abrasive grains have exposed and sharp grinding edges, which squeeze and slide the workpiece, causing elastic deformation on the workpiece surface, and then the grinding edge cuts into the workpiece, causing plastic deformation on the workpiece. As the depth of the grinding edge cutting into the workpiece increases, part of the workpiece material slips and leaves the workpiece surface.

[0031] During the grinding process, the grinding edge will become blunt due to wear, resulting in an increase in the grinding force between the grinding wheel and the workpiece, weakening the grinding performance of the grinding wheel, and causing the abrasive particles to break or fall off. The fallen abrasive particles and the material leaving the workpiece surface together form grinding chips. The movement of the grinding chips will scratch the binder, thereby removing the binder and exposing new abrasive particles to continue to participate in grinding. In this way, the grinding wheel maintains good grinding performance. This characteristic is the self-sharpening property of the grinding wheel (also called self-excitation).

[0032] In order to enable the grinding wheel to maintain good self-sharpening properties, an internally cooled grinding wheel is proposed in the relevant technology. The internally cooled grinding wheel is provided with a coolant flow channel for the flow of coolant. The coolant is injected into the grinding area (i.e., the contact area between the working surface of the grinding wheel and the workpiece) through the coolant flow channel to play a role in flushing and cooling. However, in actual application, the coolant flow channel is easily blocked by grinding chips, which affects the cooling and flushing effects, and thus leads to low grinding process quality. In addition, the grinding wheel and the spindle of the grinder are prone to resonate, resulting in the formation of grinding wheel marks and knife marks on the surface of the workpiece, which seriously affects the grinding quality.

[0033] In view of this, the embodiment of the present application proposes a grinding wheel and a grinding machine equipped with the grinding wheel. The cross-sectional area of ​​the cooling liquid flow channel of the grinding wheel is gradually reduced from the liquid inlet to the liquid outlet, and the flushing effect is improved by increasing the flow rate of the liquid outlet, thereby weakening or even eliminating the adverse effect of the cooling liquid flow channel being blocked by grinding chips on the grinding process quality. In order to enable those skilled in the art to better understand the technical solution of the utility model, the grinding wheel provided by the utility model and the grinding machine equipped with the grinding wheel are described in detail below in conjunction with the accompanying drawings.

[0034] The embodiments of the present application provide a grinding machine, which is not limited to the grinding process in the field of solar cells, but can also be applied to grinding processes in other fields such as semiconductors. The following embodiments of the present application are exemplified by the grinding process of the grinding machine applied to the field of solar cells, and specifically take the fine grinding of single crystal silicon rods as an example.

[0035] The grinder comprises a grinding wheel, a rotating shaft and a driving motor. The rotating shaft is connected to the grinding wheel, the central axis of the rotating shaft coincides with the central axis of the grinding wheel, and the driving device is used to drive the rotating shaft to rotate so as to drive the grinding wheel to rotate.

[0036] In some embodiments, the grinding machine further includes a coolant supply source, which is used to provide coolant. The coolant can be an oil-based coolant (e.g., mineral oil), or a water-soluble coolant or a synthetic coolant, which is not specifically limited in this embodiment. The coolant supply source can also be provided by factory services.

[0037] In some embodiments, the grinding machine further includes a spindle box, in which a driving motor and a spindle are disposed. The driving motor drives the spindle to move, thereby driving the grinding wheel to move, so as to adjust the feed amount of the grinding wheel.

[0038] Figure 1 This is a front view of a grinding wheel provided in one embodiment of the present application. Figure 2 for Figure 1 See the schematic cross section of the grinding wheel shown in Figure 1 and Figure 2 The grinding wheel 100 proposed in the embodiment of the present application includes a base 110 and a grinding layer 120 .

[0039] The grinding layer 120 is formed by bonding a plurality of abrasive grains by a binder. The present embodiment does not impose any specific restrictions on the abrasive grains and the binder. The abrasive grains may be, for example, diamond abrasive grains, and the binder may be, for example, a resin binder. Along the thickness direction of the grinding layer 120, the grinding layer 120 has a working surface 121 and a connecting surface that are arranged opposite to each other. The working surface 121 refers to the side of the grinding layer 120 that contacts the workpiece (e.g., a single crystal silicon rod). The contact area between the working surface 121 and the workpiece is the grinding area. The grinding layer 120 is an annular structure, and accordingly, the grinding area is also annular.

[0040] A through hole 112 is provided in the middle of the base 110, and the rotating shaft extends into the through hole 112 and is fixedly connected to the base 110. Under the drive of the driving motor, the rotating shaft can drive the base 110 to rotate. Optionally, the base 110 can also be connected to a connecting member (such as a connecting plate) of the grinding machine through a screw 118. Along the extension direction of the rotation axis of the base 110, the base 110 has a first surface and a second surface that are arranged opposite to each other. The first surface is fixedly connected to the connecting surface, so that the grinding layer 120 is fixedly arranged on the base 110. The connection method of the first surface and the connecting surface can be, for example, an adhesive connection.

[0041] A plurality of coolant channels 111 are symmetrically arranged on the substrate 110 with its center as the center. The coolant channels 111 penetrate the thickness of the substrate 110. The coolant channels 111 are used to supply coolant flow, and the coolant channels 111 have a liquid inlet and a liquid outlet. Along the flow direction of the coolant, the liquid inlet is located upstream of the liquid outlet. Among them, the liquid inlet is formed on the second surface and is used to connect with the coolant supply source, the liquid outlet is formed on the first surface, and the grinding layer 120 surrounds the outer side of the liquid outlet. In this way, the coolant provided by the coolant supply source can flow from the rear side of the substrate 110 facing away from the grinding layer 120 to the liquid inlet, then flow along the coolant channels 111 to the liquid outlet, and then flow from the middle of the grinding layer 120 to spray between the working surface 121 and the workpiece, and then the coolant can carry part of the grinding chips and heat and spray out to the outside of the grinding wheel 100 along the radial direction of the grinding layer 120, thereby achieving flushing and cooling.

[0042] Moreover, from the liquid inlet to the liquid outlet, the cross-sectional area of ​​the coolant flow channel 111 gradually decreases. That is, the cross-sectional area of ​​the coolant flow channel 111 is not equal everywhere, and the cross-sectional area of ​​the liquid inlet is larger than the cross-sectional area of ​​the liquid outlet. When the parameters such as the cross-sectional area of ​​the liquid inlet and the flow rate into the coolant flow channel 111 are consistent with the parameters in the relevant technology, the grinding wheel 100 of this embodiment has a relatively smaller outlet of the coolant flow channel 111, so the flow rate of the coolant at the outlet is greater, which increases the impact force of the coolant sprayed from the outlet on the grinding chips and improves the flushing effect. This can effectively reduce the probability of the coolant flow channel 111 being blocked by grinding chips, ensure that the coolant can play a flushing and cooling role, so as to ensure the self-sharpening of the grinding wheel 100, and can weaken or even eliminate the adverse effects of the passivation of the grinding wheel 100 on the grinding process quality. Since the grinding wheel 100 can maintain good self-sharpening, this is also conducive to avoiding an increase in the frequency of dressing of the grinding wheel 100.

[0043] Moreover, compared with the embodiment in the related art where the cross-sectional area of ​​the coolant flow channel 111 is equal everywhere, under the premise that the parameters such as the cross-sectional area of ​​the liquid inlet are consistent with the parameters in the related art, the cross-sectional area of ​​the coolant flow channel 111 of the grinding wheel 100 in this embodiment gradually decreases from the liquid inlet to the liquid outlet, and the cross-sectional area of ​​the liquid inlet of the coolant flow channel 111 is relatively larger. More material is removed from the grinding wheel 100, so that the weight of the grinding wheel 100 can be reduced, which is beneficial to reduce the possibility of resonance between the grinding wheel 100 and the spindle, so as to weaken the influence of the resonance on the grinding process quality and ensure the grinding process quality.

[0044] In summary, the grinding wheel 100 of this embodiment has a favorable effect on improving the grinding quality from the two aspects of increasing the flow rate at the liquid outlet to improve the flushing effect, reducing the probability of the coolant flow channel 111 being blocked by grinding chips, and reducing the weight of the grinding wheel 100 and reducing the resonance between the grinding wheel 100 and the spindle.

[0045] In the grinding wheel 100 disclosed herein, the base 110 can be made of metal materials such as aluminum, aluminum alloy, stainless steel, etc. When the material of the base 110 includes aluminum, aluminum has the advantage of being light in weight, which is conducive to reducing the weight of the grinding wheel 100 to reduce the risk of the grinding wheel 100 resonating with the spindle and affecting the quality of the grinding process.

[0046] In some embodiments, the outer diameter of the grinding layer 120 is greater than 256 mm and less than or equal to 300 mm, preferably 300 mm. It is easy to understand that, taking the grinding wheel 100 applied to the grinding process in the field of solar cells as an example, as the size of solar cells and single crystal silicon wafers gradually increases, the size of single crystal silicon rods increases, and the outer diameter of the grinding layer 120 in this embodiment is relatively large, so that the grinding wheel 100 can be used for grinding large-sized single crystal silicon rods.

[0047] In some embodiments, please refer to Figure 1 The liquid outlet of the cooling liquid flow channel 111 includes a first inner wall 113, a second inner wall 114, a first end wall 115 and a second end wall 116. The first inner wall 113 and the second inner wall 114 are spaced apart and opposite to each other along the radial direction of the base 110. The second inner wall 114 is closer to the edge of the base 110 than the first inner wall 113. One end of the first inner wall 113 is connected to one end of the second inner wall 114 through the first end wall 115, and the other end of the first inner wall 113 is connected to the other end of the second inner wall 114 through the second end wall 116.

[0048] exist Figure 1 In the illustrated embodiment, the first inner wall 113, the second inner wall 114, the first end wall 115 and the second end wall 116 are all arc-shaped walls. In this embodiment, the coolant flow channel 111 also extends along the circumferential direction of the base 110, the first inner wall 113 and the second inner wall 114 have the same bending direction, the center of the first inner wall 113 and the center of the second inner wall 114 both coincide with the central axis of the base 110, and the orthographic projections of the first end wall 115 and the second end wall 116 on the first surface are semicircular, that is, the first end wall 115 and the second end wall 116 are tangentially connected to the first inner wall 113 and the second inner wall 114.

[0049] FIG3( a ) is a front view of a modified example of the base body in the grinding wheel provided in the first embodiment of the present application. The modified example shown in FIG3( a ) is different from FIG3( a ) in that Figure 1 The embodiment shown is similar, and the difference lies in the shape of the first end wall 115 and the second end wall 116. In the variation shown in Fig. 3(a), the first end wall 115 and the second end wall 116 are both straight walls.

[0050] FIG3( b ) is a front view of a modified example of the substrate in the grinding wheel provided in the second embodiment of the present application. The modified example shown in FIG3( b ) is different from the modified example shown in FIG3( b ). Figure 1The embodiment shown is similar, and the difference lies in the shapes of the first inner wall 113 and the second inner wall 114. In the modified example shown in FIG3(b), the first inner wall 113 and the second inner wall 114 are both straight walls, and accordingly, the extension direction of the coolant flow channel 111 is perpendicular to the radial direction of the base 110.

[0051] FIG3(c) is a front view of a modified example of the substrate in the grinding wheel provided in the third embodiment of the present application. The modified example shown in FIG3(c) is similar to the embodiment shown in FIG3(a), except that the shapes of the first inner side wall 113 and the second inner side wall 114 are different. In the modified example shown in FIG3(c), the first inner side wall 113 and the second inner side wall 114 are both straight walls, and accordingly, the extension direction of the coolant flow channel 111 is perpendicular to the radial direction of the substrate 110.

[0052] In embodiments not shown in other figures of the present application, one of the first inner side wall 113 and the second inner side wall 114 may be an arc-shaped wall and the other may be a straight wall.

[0053] By such arrangement, in this embodiment, the cross section of the coolant flow channel 111 is in the shape of an elongated strip, and the liquid inlet and the liquid outlet are also in the shape of an elongated strip. Compared with the cross section of the coolant flow channel 111 being circular, the elongated liquid outlet is more compatible with the annular grinding area, so that the portion of the area where the coolant is sprayed to the working surface 121 accounts for a larger proportion in the circumferential direction of the grinding area, so that more grinding areas can be exposed to the coolant.

[0054] Please combine Figure 1 As shown in Figure 3(b), in the embodiment where the orthographic projections of the first end wall 115 and the second end wall 116 on the first surface are semicircular, the connections between the first end wall 115 and the second end wall 116 and the first inner side wall 113 and the second inner side wall 114 are smoothly transitioned, which is not only conducive to reducing stress concentration, but also conducive to allowing the coolant to flow smoothly from the outlet of the coolant channel 111.

[0055] When the cooling liquid channel 111 is in the shape of an elongated strip, in some embodiments, the distance between the first inner side wall 113 and the second inner side wall 114 in the radial direction of the substrate 110 is W, and W satisfies: 10 mm ≤ W ≤ 15 mm. That is, the width of the liquid outlet in the radial direction of the substrate 110 ranges from 10 mm to 15 mm. It can be understood that, taking the substrate 110 as Figure 1 Taking the structure shown as an example, accordingly, the arc radius R1 of the first inner wall 113 is less than the arc radius R2 of the second inner wall 114, and R2-R1=W; and the radius R3 of the first end wall 115 and the radius R4 of the second end wall 116 are both equal to W*1 / 2.

[0056] When the coolant flow channel 111 is in an elongated shape, in some embodiments, the midpoint of a line connecting one end of the first inner sidewall 113 and one end of the second inner sidewall 114 along the radial direction of the base 110 is the first reference point, and the midpoint of a line connecting the other end of the first inner sidewall 113 and the other end of the second inner sidewall 114 along the radial direction of the base 110 is the second reference point. For ease of understanding, in the various drawings of the embodiments of the present application, A and B represent the first reference point and the second reference point, respectively.

[0057] The distance between the first reference point A and the second reference point B along the extension direction of the coolant channel 111 is greater than or equal to 50 mm and less than or equal to 70 mm. Figure 1 Taking the structure shown in FIG. 3 as an example, the arc length of arc AB is 50 mm ≤ 70 mm; taking the structure of the substrate 110 as shown in FIG. 3( c ) as an example, the length of the liquid outlet along its extension direction is L, and 50 mm ≤ L ≤ 70 mm.

[0058] It is easy to understand that this technical solution is particularly suitable for embodiments in which the outer diameter of the grinding layer 120 is greater than 256 mm and less than or equal to 300 mm. Since the outlet of the coolant flow channel in the related art is usually circular and the aperture of the outlet is 5 mm, compared with the related art, this embodiment designs the coolant flow channel 111 to be long and the width and extension length of the outlet are large to ensure that enough material is removed from the substrate 110 to ensure that weight reduction has an effect on weakening the influence of resonance on the quality of the grinding process. In other words, due to the large width and extension length of the outlet, the coolant flow channel 111 in this embodiment can also be equivalent to a weight reduction hole. At the same time, it is also beneficial to ensure that the flow rate of coolant available for passing through the coolant flow channel 111 is sufficient to ensure flushing and cooling effects.

[0059] It should also be pointed out that since the width and extension length of the liquid outlet of the coolant flow channel 111 in this embodiment are relatively large, the liquid inlet is correspondingly larger. This is conducive to ensuring that the liquid inlet can be aligned with the outlet of the fixed coolant supply source to ensure that the coolant sprayed from the outlet of the coolant supply source can enter the coolant flow channel 111.

[0060] Of course, the size of the liquid outlet is not limited thereto, and can be designed according to demand and actual working conditions.

[0061] Figure 4 This is a front view of a grinding wheel provided in another embodiment of the present application. As another optional example, please refer to Figure 4The base 110 may also be provided with a plurality of weight-reducing grooves 117, which are symmetrically distributed about the center of the base 110. By designing the weight-reducing grooves 117, the weight of the grinding wheel 100 is reduced, which is conducive to reducing the possibility of resonance between the grinding wheel 100 and the spindle during the grinding process, thereby reducing or even eliminating the adverse effects of the resonance on the grinding, and ensuring the grinding quality.

[0062] It is particularly important to note that in this embodiment, the base 110 is provided with both a coolant channel 111 and a weight-reducing groove 117. Even if the outlet of the coolant channel 111 is relatively small, the weight-reducing groove 117 can still be used to reduce weight and ensure grinding quality.

[0063] Furthermore, if Figure 4 As shown, a plurality of weight-reducing grooves 117 are arranged in one-to-one correspondence with a plurality of coolant channels 111, each weight-reducing groove 117 is located between the corresponding coolant channel 111 and the center of the base 110, and each weight-reducing groove 117 is arranged close to the liquid outlet of the corresponding coolant channel 111, and the liquid outlet of the coolant channel 111 is also arranged close to the edge of the base 110. In this way, the coolant channel 111 and the weight-reducing groove 117 are close to the edge of the base 110, and the weight of the edge of the grinding wheel 100 is reduced, which can effectively reduce the possibility of resonance between the grinding wheel 100 and the spindle, so as to reduce or even eliminate the adverse effects of resonance on the grinding quality.

[0064] For example, in Figure 4 In the example shown, the weight-reducing groove 117 may penetrate the thickness of the substrate 110, and there is a gap between the edge of the weight-reducing groove 117 and the edge of the corresponding liquid outlet of the coolant flow channel 111 along the radial direction of the substrate 110. In other words, the weight-reducing groove 117 is a through-hole structure, and the weight-reducing groove 117 is not connected to the corresponding coolant flow channel 111.

[0065] Figure 5 A partial front view of a grinding wheel provided in another embodiment of the present application. As an alternative embodiment, Figure 5As shown, the weight-reducing groove 117 can be formed on the side of the substrate 110 facing the grinding layer 120, and the weight-reducing groove 117 does not penetrate the thickness of the substrate 110, and the weight-reducing groove 117 is also connected to the outlet of the corresponding coolant channel 111. In other words, the weight-reducing groove 117 is a blind hole structure. With this design, under the premise of ensuring that the weight of the grinding wheel 100 can be achieved so that the grinding process quality is not affected by resonance, because the weight-reducing groove 117 is a blind hole structure, the weight-reducing groove 117 can also play a role in storing water. During the grinding process, part of the coolant flowing through the coolant channel 111 flows into the corresponding connected weight-reducing groove 117, and the grinding wheel 100 rotates at a high speed. The coolant accumulated in the weight-reducing groove 117 rushes to the grinding area under the action of centrifugal force, which is conducive to improving the flushing effect of the coolant, so that as much grinding chips as possible are discharged from the grinding area in the outer diameter direction of the grinding wheel 100, reducing the risk of the coolant channel 111 being blocked by grinding chips, so as to ensure the quality of the grinding process.

[0066] In any of the above examples, please continue to see Figure 1 , a plurality of drainage grooves 122 may be formed on the working surface 121 of the grinding layer 120, and the plurality of drainage grooves 122 are evenly distributed around the center of the base 110, the inflow end of the drainage groove 122 penetrates the inner peripheral surface of the grinding layer 120, and the outflow end of the drainage groove 122 penetrates the outer peripheral surface of the grinding layer 120. During the grinding process of the grinding wheel 100 of this embodiment, part of the coolant flowing out of the liquid outlet is mixed with the grinding chips to form a mixed fluid, and the mixed fluid is sprayed into the drainage groove 122, and then discharged from the outflow end of the drainage groove 122 to the outside of the grinding wheel 100. The provision of the drainage groove 122 helps to discharge the mixed fluid, so as to prevent the coolant carrying the grinding chips from flowing back and affecting the quality of the coolant, so as to reduce or eliminate the adverse effects on the grinding process quality caused by the reduction of the coolant quality.

[0067] The extension direction of the drain trough 122 is not limited. Figure 1 As shown, the drainage groove 122 may extend along the radial direction of the grinding layer 120 ; or, as shown, an angle may be formed between the extension direction of the drainage groove 122 and the radial direction of the grinding layer 120 .

[0068] Optionally, the cross-sectional area of ​​the drain trough 122 is equal everywhere from the inflow end to the outflow end of the drain trough 122. As an alternative embodiment, Figure 1 As shown, the cross-sectional area of ​​the drain groove 122 gradually decreases from the inflow end to the outflow end of the drain groove 122 , so that the coolant entrained with the grinding chips can more easily flow into the drain groove 122 .

[0069] like Figure 1As shown, 20 drain grooves 122 can be evenly and spaced apart on the grinding layer 120 along its circumferential direction. Thus, the number of drain grooves 122 is large, which improves the sewage discharge effect. The number of drain grooves 122 can also be 8, 10, etc., which is not specifically limited in this embodiment.

[0070] It should be noted that if Figure 1 As shown, each liquid outlet may be opposite to two drain grooves 122 in the plurality of drain grooves 122. Alternatively, as shown in FIG. Figure 4 As shown, each liquid outlet is opposite to one of the plurality of drain grooves 122. Alternatively, each liquid outlet can be opposite to more than three of the plurality of drain grooves 122.

[0071] In this way, the coolant flowing out from the outlet of the coolant flow channel 111 can easily flow into the corresponding drain groove 122, thereby ensuring the sewage discharge effect.

[0072] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A grinding wheel, characterized in that: include: A grinding layer having a working surface, wherein the working surface is used for contacting with a workpiece; as well as A substrate, wherein the substrate is provided with a plurality of coolant flow channels penetrating the thickness thereof, the coolant flow channels having a liquid inlet and a liquid outlet, the liquid inlet being away from the working surface and used for connecting to a coolant supply source, and the liquid outlet being close to the working surface; the cross-sectional area of ​​the coolant flow channel gradually decreases from the liquid inlet to the liquid outlet; and the plurality of coolant flow channels are symmetrically distributed about the center of the substrate.

2. The grinding wheel according to claim 1, characterized in that The liquid outlet includes a first inner wall, a second inner wall, a first end wall and a second end wall. The first inner wall and the second inner wall are spaced apart and opposite to each other along the radial direction of the base body. One end of the first inner wall and the second inner wall are connected through the first end wall, and the other end is connected through the second end wall.

3. The grinding wheel according to claim 2, characterized in that: The distance between the first inner side wall and the second inner side wall in the radial direction of the base body is greater than or equal to 10 mm and less than or equal to 15 mm; and / or, The midpoint of a line connecting one end of the first inner side wall and one end of the second inner side wall along the radial direction of the base is a first reference point, and the midpoint of a line connecting the other end of the first inner side wall and the other end of the second inner side wall along the radial direction of the base is a second reference point; a distance between the first reference point and the second reference point along the extension direction of the coolant flow channel is greater than or equal to 50 mm and less than or equal to 70 mm.

4. The grinding wheel according to claim 1, characterized in that The base is provided with a plurality of weight-reducing grooves, and the plurality of weight-reducing grooves are symmetrically distributed about the center of the base.

5. The grinding wheel according to claim 4, characterized in that: The multiple weight-reducing grooves are arranged in one-to-one correspondence with the multiple coolant channels, and each of the weight-reducing grooves is located between the corresponding coolant channel and the center of the substrate and close to the corresponding liquid outlet of the coolant channel, and the liquid outlet of the coolant channel is arranged close to the edge of the substrate.

6. The grinding wheel according to claim 4, characterized in that The weight-reducing groove penetrates the thickness of the substrate, and along the radial direction of the substrate, there is a gap between the edge of the weight-reducing groove and the edge of the corresponding coolant outlet of the coolant channel; alternatively, the weight-reducing groove is formed on a side of the substrate facing the grinding layer, and the weight-reducing groove does not penetrate the thickness of the substrate, and the weight-reducing groove is connected to the corresponding coolant outlet of the coolant channel.

7. The grinding wheel according to any one of claims 1 to 6, characterized in that The grinding layer is annular, and a plurality of drainage grooves are provided on the working surface. The plurality of drainage grooves are evenly distributed around the center of the base body, and the inflow end of the drainage groove passes through the inner circumference of the grinding layer, and the outflow end passes through the outer circumference of the grinding layer.

8. The grinding wheel according to claim 7, characterized in that The liquid outlet of each cooling liquid flow channel is arranged opposite to one or more drain grooves.

9. The grinding wheel according to any one of claims 1 to 6, characterized in that The outer diameter of the grinding layer is greater than 256 mm and less than or equal to 300 mm.

10. A grinding machine, characterized in that: include: The grinding wheel according to any one of claims 1 to 9; A rotating shaft, fixedly connected to the base of the grinding wheel; as well as The driving motor is used to drive the rotating shaft to rotate.

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