CN221555304U - Bean grinding device of coffee machine - Google Patents

Abstract

The utility model discloses a bean grinding device of a coffee machine, which comprises a shell, wherein a cutter sleeve is arranged in the shell, and a cutter head is arranged in the cutter sleeve; the upper opening of the shell is provided with an upper cover, the upper cover is provided with a feed inlet, and the bottom plate of the shell is provided with a powder outlet; the turbine driven by the motor is rotatably arranged in the shell, and the cutter sleeve is concentrically fixed in the turbine; the side wall of the feed inlet of the upper cover is fixed with a vertical mounting sleeve through a connecting rib; the mounting sleeve is vertically matched with a mounting column in a sliding manner, the mounting column and the mounting sleeve are limited in the circumferential direction, the top end of the mounting column is screwed with a screwing key through threads, and the upper end of the mounting sleeve is provided with a clamping sleeve for limiting the screwing key axially; the tool bit is assembled at the lower section of the mounting column. The device can thoroughly solve the problem of unsmooth powder, avoids the residual siltation of bean flour, can effectively adjust tool bit and knife sleeve clearance width again, and then adjusts the fine and smooth degree that the bean flour ground.

Description

Bean grinding device of coffee machine

Technical Field

The utility model relates to a part of a coffee machine, in particular to a bean grinding device of the coffee machine.

Background

A bean grinding device is arranged in the coffee machine; the cutter comprises a shell, a motor, a cutter head and a cutter sleeve; the cutter head is a conical cutter head with a small upper part and a large lower part, the central hole of the cutter sleeve is a conical hole with a large upper part and a small lower part, the cutter head is positioned in the central hole of the cutter sleeve, and the cutter head and the cutter sleeve rotate relatively to enable coffee beans to be ground into powder at a gap between the cutter head and the cutter sleeve.

The early bean grinding device is generally in a structure that a cutter head is turned to a cutter sleeve, namely the cutter sleeve is fixed with a shell, the cutter head is fixed with a main shaft, and an output shaft of a motor is directly connected with the main shaft or indirectly connected with the main shaft through a belt; the main shaft and the cutter head are driven by a motor to rotate for grinding beans. Because the motor is located the main shaft lower extreme, in order to avoid being fallen the powder, can be fixed one on the main shaft of motor and belt top and get rid of the powder dish and keep off the powder, so, after the bean flour falls to getting rid of the powder dish from tool bit and knife pouch clearance, is thrown away by getting rid of the powder dish centrifugation, gets into transverse channel through the side of the casing powder outlet, finally falls to the powder funnel. However, the structure of the transverse powder outlet often has insufficient powder throwing power, and can cause residual congestion and deterioration of coffee powder in a transverse channel.

In order to overcome the defect of unsmooth transverse powder discharge of the device, an industry has proposed an improvement scheme that the cutter head 101 shown in fig. 1 does not rotate the cutter sleeve 102, namely, a turbine 103 is fixed outside the cutter sleeve, the turbine is rotatably arranged in a shell 104 through an upper bearing and a lower bearing, and a worm 106 is fixed on an output shaft of a motor 105 to drive the turbine; a mounting seat 108 is fixed in the central hole by three connecting ribs 107, and then the cutter head is fixed on the mounting seat, so that a vertical powder outlet 109 is formed in the gaps among the central hole of the bottom plate, the mounting seat and the connecting ribs; therefore, the cutter head is static, the motor drives the cutter sleeve to grind beans in a rotating way, powder is not blocked by the powder throwing disc after powder is formed, and the powder directly falls down vertically to discharge the powder, so that the problems of unsmooth transverse powder discharge and residual congestion are greatly solved.

However, after long-term use, the technical personnel find that the scheme of vertical powder discharge still has the following defects.

Firstly, three transverse connecting ribs still block the powder outlet, so that a part of coffee powder falling vertically is deposited and remained on the upper surface of each connecting rib; in order to ensure the connection strength of the mounting seat and the stable mounting of the cutter head, the three transverse connecting ribs are thicker, so that the cross section area of a channel where the bean powder falls is further occupied, and more bean powder is blocked; in other words, the vertical powder discharge scheme does not completely solve the problem of unsmooth powder discharge. Second, because this tool bit is fixed on the mount pad, its height can't be adjusted, so tool bit and knife pouch clearance are fixed, can't adjust the thickness degree of the coffee powder granule of grinding, lead to the coffee taste singleness, can't satisfy the demand of user's diversified taste.

Disclosure of utility model

The utility model aims to solve the technical problem of providing the bean grinding device of the coffee machine, which can thoroughly solve the problem of unsmooth powder production, avoid residual sedimentation of bean powder, and effectively adjust the gap width between the cutter head and the cutter sleeve so as to adjust the fineness of bean powder grinding.

The technical proposal of the utility model is to provide a bean grinding device of a coffee machine, which comprises a shell, wherein a knife sleeve is arranged in the shell, and a knife head is arranged in the knife sleeve; the upper opening of the shell is provided with an upper cover, the upper cover is provided with a feed inlet, and the bottom plate of the shell is provided with a powder outlet; the turbine driven by the motor is rotatably arranged in the shell, and the cutter sleeve is concentrically fixed in the turbine; the side wall of the feed inlet of the upper cover is fixed with a vertical mounting sleeve through a connecting rib; the mounting sleeve is vertically matched with a mounting column in a sliding manner, the mounting column and the mounting sleeve are limited in the circumferential direction, the top end of the mounting column is screwed with a screwing key through threads, and the upper end of the mounting sleeve is provided with a clamping sleeve for limiting the screwing key axially; the tool bit is assembled at the lower section of the mounting column.

During bean grinding, coffee beans are poured into the shell from the feeding port, the motor drives the cutter sleeve to rotate relative to the cutter head through the turbine, the beans are ground into powder, and then the powder falls vertically from the powder outlet.

Compared with the prior art, the bean grinding device of the coffee machine with the structure has the following advantages.

The connecting ribs are required for installing the cutter head, and the essence of the application is that the connecting ribs are moved up from the powder outlet to the feeding port, so that the ground coffee powder is free from any shielding on the section of the powder outlet, can completely and smoothly fall down vertically, and does not remain silt on the upper surface of the connecting ribs like the prior art; of course, although the connecting rib moves upwards to the feeding port, as the coffee beans are large in volume and vibration of grinding beans is transmitted to the connecting rib, even if a small amount of coffee beans fall on the connecting rib, the coffee beans can be rapidly shaken off into the shell by the connecting rib, namely, the upward movement of the connecting rib has almost no influence on the bean feeding process; the screw key can freely rotate along the circumferential direction but cannot move up and down due to the restriction of the clamping sleeve in the axial direction, and the mounting column can move up and down relative to the mounting sleeve and cannot rotate, so that the top end of the screw key can be rotated to drive the cutter head to move up and down by rotating the screw key, thereby adjusting the gap width between the cutter head and the cutter sleeve and adjusting the grinding fineness of the bean powder. In conclusion, the structure thoroughly solves the problem of unsmooth powder discharge, and can effectively adjust the gap width between the cutter head and the cutter sleeve.

Preferably, the upper cover is fixed with a funnel, and the lower opening of the funnel is communicated with the feeding opening of the upper cover; the funnel is provided with a frustum with a small upper part and a large lower part, the top end of the screwing key extends out of a central hole of the frustum, and the top end of the screwing key is fixed with a turntable; the lower part of the turntable is convexly provided with a limiting pin, the frustum is provided with concentric fan-shaped annular convex ribs, and the limiting pin is clamped between two straight side ribs of the fan-shaped annular convex ribs; the rotary table is held by hand to rotate the screwing key more easily, so that the operation is convenient; the two straight side ribs of the fan-shaped convex rib clamp the limiting pin, the maximum screwing amplitude of the turntable and the screwing key is limited, and the adjusting amplitude of the clearance between the cutter head and the cutter sleeve is limited, so that a conventional adjusting interval is formed, the granularity of grinding the bean powder is controlled in a reasonable range in the interval, and the conventional adjusting requirement of a user in daily use can be met; and the excessive regulation of the user can be avoided, because the regulating amplitude and the regulating range are summarized by technicians according to experience and are regulated before delivery, and if the user exceeds the range, the coffee powder is too coarse or too fine.

As further preferable, the tool bit is vertically matched with the mounting column in a sliding way and is limited with the mounting column in the circumferential direction; the bottom surface of the cutter head is fixed with an adjusting seat, and the bottom surface of the adjusting seat is provided with a circle of lower limit pits; the lower section of the mounting column is screwed with an adjusting sleeve through threads, the adjusting sleeve is sleeved in a central hole of the adjusting seat in a clearance mode, the adjusting sleeve and the adjusting seat are limited in the axial direction, a knob is fixed at the lower end of the adjusting sleeve, and a lower wave bead screw used for being clamped into a lower limiting pit is arranged in a mounting hole on the top surface of the knob.

The adjusting sleeve is sleeved in the center hole of the adjusting seat in a clearance mode, the adjusting sleeve and the adjusting seat are limited in the axial direction, so that the adjusting sleeve can rotate freely in the circumferential direction, the adjusting seat can only be driven to move up and down by the limiting of the adjusting seat in the axial direction, and the cutter head and the adjusting seat are fixed, so that the rotating knob can drive the adjusting sleeve to lift spirally along the mounting column, and further the adjusting seat and the cutter head are driven to lift synchronously, so that the height of the cutter head is adjusted. The tool bit and the tool sleeve can be greatly screwed down or even removed when the tool bit and the tool sleeve clamp powder, so that the clamped powder is cleaned, and the tool bit and the tool sleeve are convenient to overhaul; secondly, if the taste of the client is different from that of an abnormal person, the client likes thicker or finer bean powder, and when the conventional regulation interval set by the factory cannot meet the special taste requirement, the lower knob is utilized to carry out secondary regulation and correction on the conventional interval set by the factory, so that the personal customization of the fineness of the bean powder is realized. If the fineness of the bean powder is set at 5-10 stages when leaving the factory, a normal user can adjust the bean powder along a conventional adjusting interval by using the rotary table, but a buyer likes finer taste, the rotary table is rotated to lift the cutter head, and the adjusting interval is changed into 3-8 stages which are finer. In addition, the design of the clamping connection of the lower limit pit and the lower wave bead screw also has two functions, namely, the specific amplitude of the adjustment of the knob and the adjusting sleeve is quantized, so that the gear is shifted, and the accuracy and the standardization of the user operation in the secondary adjusting process are improved; secondly, as the adjusting sleeve is positioned at the lowest end of the mounting column, the overhanging distance is large, vibration generated by grinding beans can be amplified, so that the adjusting sleeve is vibrated and even loosened with the threads of the mounting column, and once the adjusting sleeve is loosened, the gap width between the cutter head and the cutter sleeve is changed, so that the fineness of the bean powder is changed; but the spring in the wave bead screw can effectively absorb, dissolve vibration, plays locking antidetonation effect, avoids adjusting sleeve and erection column to be shaken loose, ensures that the cutter head and the knife sleeve clearance are invariable in the bean grinding process, promotes grinding quality and stability.

As still further preferable, the side surface of the mounting column is provided with a first concave vertical groove, the side wall of the mounting sleeve is penetrated with a threaded hole, a limit screw is screwed in the threaded hole, the rod part of the limit screw extends into the first vertical groove, and the width of the first vertical groove is larger than the diameter of the rod part of the limit screw; the wall of the central hole of the cutter head is provided with a second vertical groove, the head of the limit screw extends into the second vertical groove, and the width of the second vertical groove is larger than the diameter of the head of the limit screw; because the mounting sleeve is fixed on the shell and is not movable, the mounting column and the cutter head can slide up and down but cannot rotate; in other words, only one group of limiting screws are used, and the circumferential limiting of the two groups of parts, namely the mounting post and the mounting sleeve, the cutter head and the mounting post, is realized, and the assembly is convenient and fast.

As still further preferable, the bottom surface of the turntable is provided with a convex ring, and the convex ring is provided with a circle of limiting pits; the frustum is provided with a base, and an upper wave bead screw for being clamped into the upper limit pit is arranged in the base mounting hole; therefore, the specific amplitude of adjustment of the turntable and the screwing key is quantized, the gear is shifted, and the accuracy and standardization of user operation in the conventional adjustment process are improved.

The connection structure of the screwing key and the turntable is preferably that the top end of the screwing key is provided with an internal thread blind hole, the turntable is communicated with a T hole, the screwing key is connected with the turntable through a bolt, the head of the bolt is clamped in the T hole, and the rod part is screwed into the internal thread blind hole; the upper part of the outer wall of the screwing key is externally protruded with a limit tooth, the bottom surface of the rotary table is fixedly provided with a limit sleeve, the top end of the screwing key is sleeved by the limit sleeve, and a limit groove of the inner wall of the limit sleeve is used for clamping the limit tooth of the outer wall of the screwing key; therefore, the screw-on key and the turntable are firmly connected in the axial direction, the circumferential torque transmission of the screw-on key and the turntable is stable, and the installation is convenient and quick.

The structure of axial limit of the clamping sleeve on the screwing key is preferable that a limit step is outwards protruded from the side wall of the screwing key, a clamping ring is inwards protruded from the side wall of the clamping sleeve, and the clamping ring presses the limit step of the screwing key downwards to enable the lower part of the screwing key to be abutted against the top ring surface of the mounting sleeve; the structure enables the screwing key to rotate freely, but is limited by the axial direction of the clamping sleeve and cannot slide up and down; and the assembly process of the structure is quick and convenient.

The connecting structure of the upper end of the mounting sleeve and the clamping sleeve is preferably that the upper end of the mounting sleeve is provided with external threads, the lower opening of the clamping sleeve is provided with internal threads, and the external threads of the upper end of the mounting sleeve are screwed with the internal threads of the lower opening of the clamping sleeve; therefore, when the clamping sleeve and the mounting sleeve are screwed, the axial limit of the screwing key can be completed, so that the assembly process is quicker and more convenient.

Drawings

Fig. 1 is an exploded view of a bean grinding device of a prior art coffee maker.

Fig. 2 is a schematic structural view of a bean grinding device of the coffee maker of the present utility model.

Fig. 3 is a schematic view of the structure of fig. 2 after being deflected by a certain angle.

Fig. 4 is a schematic cross-sectional view of a bean grinding device of the coffee maker of the present utility model.

Fig. 5 is a schematic sectional exploded view of a bean grinding device of the coffee maker of the present utility model.

Fig. 6 is a schematic view of the structure of fig. 5 after being deflected by a certain angle.

Fig. 7 is an exploded view of the bean grinding device of the coffee maker of the present utility model.

Fig. 8 is a schematic view of the structure of the upper cover and the mounting sleeve of the bean grinding device of the coffee maker of the present utility model.

Fig. 9 is a schematic view of the structure of a cutter head of a bean grinding device of the coffee maker of the present utility model.

Fig. 10 is a schematic view of the structure of the adjusting sleeve and the cutter head of the bean grinding device of the coffee maker of the present utility model.

Shown in the figure

101. The device comprises a cutter head, 102, a cutter sleeve, 103, a turbine, 104, a shell, 105, a motor, 106, a worm, 107, connecting ribs, 108, a mounting seat, 109 and a powder outlet;

1. The device comprises a shell, 2, an upper cover, 3, a feed inlet, 4, a powder outlet, 5, a motor, 6, a turbine, 7, an upper bearing, 8, a lower bearing, 9, a cutter sleeve, 10, a cutter head, 10.1, a second vertical groove, 11, a connecting rib, 12, a mounting sleeve, 13, a mounting column, 13.1, a first vertical groove, 14, a funnel, 15, a limit screw, 16, a screwing key, 16.1, a limit step, 16.2, limit teeth, 17, a clamping sleeve, 17.1, a clamping ring, 18, a frustum, 19, an oblique rib, 20, a turntable, 20.1, a limit sleeve, 20.2, an upper limit pit, 21, a bolt, 22, a limit pin, 23, a straight side rib, 24, a base, 25, an upper bead screw, 26, an adjusting seat, 26.1, a lower limit pit, 26.2, a center pit, 27, an adjusting sleeve, 27.1, an annular raised line, 28, a knob, 29 and a lower bead screw.

Detailed Description

The utility model will be further described with reference to the drawings and the specific examples.

As shown in fig. 2 to 10, the bean grinding device of the coffee machine comprises a shell 1, wherein the shell 1 is opened upwards, an upper cover 2 is connected with an upper opening of the shell 1 in a screw mode, and a feeding opening 3 for allowing coffee beans to enter is formed in the center of the upper cover 2; the center of the bottom plate of the shell 1 is penetrated with a powder outlet 4 for coffee powder to vertically fall. A turbine 6 driven by a motor 5 is rotatably arranged in the shell 1, the upper part of the turbine 6 is connected with the side wall of the shell 1 through an upper bearing 7, and the lower part of the turbine 6 is connected with the bottom plate of the shell 1 through a lower bearing 8; the motor 5 is fixed to the side of the housing 1, and a worm is fixed to the output shaft of the motor 5, and the worm is meshed with the worm wheel 6. A cutter sleeve 9 and a cutter head 10 are arranged in the shell 1, the cutter sleeve 9 is concentric with the turbine 6, and the cutter sleeve 9 is fixed in the turbine 6. The cutter head 10 is positioned in the central hole of the cutter sleeve 9. The above structure is the mature prior art.

The side wall of the feed inlet 3 of the upper cover 2 is fixed with a vertical installation sleeve 12 through two connecting ribs 11. Of course, to ensure smoother bean feeding and prevent clogging, the upper portion of the cross section of each connecting rib 11 is provided with a pointed cone shape. The mounting sleeve 12 is vertically and slidably matched with a mounting column 13, the mounting column 13 and the mounting sleeve 12 are circumferentially limited, namely, the side surface of the mounting column 13 is provided with a first concave vertical groove 13.1, the side wall of the mounting sleeve 12 is penetrated with a threaded hole, a limit screw 15 is screwed in the threaded hole, the rod part of the limit screw 15 extends into the first vertical groove 13.1, and the width of the first vertical groove 13.1 is larger than the diameter of the rod part of the limit screw 15; thus, the mounting post 13 can slide up and down along the mounting sleeve 12 but cannot rotate. Of course, a limiting protrusion may be provided on the inner surface of the side wall of the mounting sleeve 12 to circumferentially clamp the mounting post 13, or a vertical spline groove may be provided on the outer spline surface of the mounting post 13 and the inner surface of the side wall of the mounting sleeve 12 to mutually clamp to circumferentially limit.

The top end of the mounting column 13 is screwed with a screwing key 16 through threads, namely, the top end of the mounting column 13 extends out of an upper opening of the mounting sleeve 12 and is provided with external threads, the lower opening of the screwing key 16 is provided with internal threads, and the external threads at the top end of the mounting column 13 are screwed with the internal threads at the lower opening of the screwing sleeve. Of course, the structure that the top surface of the mounting column 13 is provided with an internal thread blind hole, the bottom end of the screwing key 16 is provided with a screw rod, and the screw rod of the screwing key 16 is screwed into the internal thread blind hole at the top end of the mounting column 13 can be used for realizing the screw connection of the two.

The upper end of the mounting sleeve 12 is provided with a clamping sleeve 17 for axially limiting the screwing key 16, namely, the side wall of the screwing key 16 is externally protruded with a limiting step 16.1, the side wall of the clamping sleeve 17 is internally protruded with a clamping ring 17.1, the clamping ring 17.1 presses down the limiting step 16.1 of the screwing key 16 to enable the lower part of the screwing key 16 to abut against the annular surface of the top of the mounting sleeve 12, so that the screwing key 16 can freely rotate circumferentially but cannot move up and down axially limited by the clamping sleeve 17. Of course, an annular groove can be formed in the side wall of the screwing key 16, a threaded hole is formed in the side wall of the clamping sleeve 17 and is screwed into the bolt, and the bolt rod portion is inserted into the annular groove, so that the effects that the screwing key 16 rotates freely and is limited by the clamping sleeve 17 in the axial direction can be achieved.

The upper end of the mounting sleeve 12 is preferably connected with the clamping sleeve 17, wherein the upper end of the mounting sleeve 12 is provided with external threads, the lower opening of the clamping sleeve 17 is provided with internal threads, and the external threads at the upper end of the mounting sleeve 12 are screwed with the internal threads at the lower opening of the clamping sleeve 17. Of course, the sleeve 17 and the mounting sleeve 12 can be connected in an elastic interference fit manner, or an elastic convex ring is arranged at the upper end of the mounting sleeve 12, an inner-coiled elastic flanging is arranged at the lower opening of the sleeve 17, and the flange can be clamped by hard extrusion to fix the sleeve 17 at the upper end of the mounting sleeve 12.

The upper cover 2 is fixed with a funnel 14, and the lower opening of the funnel 14 is communicated with the feed inlet 3 of the upper cover 2; the funnel 14 is provided with a frustum 18 with a small upper part and a large lower part, the frustum 18 is fixed with the funnel 14 through three oblique ribs 19, and the frustum 18 is covered above the feed inlet 3; of course, the length of the ribs 19 is much greater than the size of the beans to ensure that the gap between the frustum 18 and the funnel 14 is wide enough not to jam the beans.

After the top end of the screwing key 16 extends out of the upper opening of the clamping sleeve 17, the screwing key continues to extend upwards out of the center hole of the frustum 18, and a turntable 20 is fixed at the top end of the screwing key 16. The top end of the screwing key 16 is provided with an internal thread blind hole, the turntable 20 is penetrated with a T hole, the screwing key 16 is connected with the turntable 20 through a bolt 21, the head of the bolt 21 is clamped in the T hole, and the rod part is screwed into the internal thread blind hole; the upper part of the outer wall of the screwing key 16 is externally protruded with a limit tooth 16.2, the bottom surface of the rotary table 20 is fixed with a limit sleeve 20.1, the limit sleeve 20.1 is sleeved on the top end of the screwing key 16, and a limit groove in the inner wall of the limit sleeve 20.1 is used for clamping the limit tooth 16.2 on the outer wall of the screwing key 16.

The rotary table 20 is provided with a limiting pin 22 in a protruding mode, the frustum 18 is provided with concentric fan-shaped protruding ribs, and the limiting pin 22 is clamped between two straight side ribs 23 of the fan-shaped protruding ribs. The bottom surface of the turntable 20 is provided with a convex ring which is provided with a circle of limiting pits 20.2; the frustum 18 is provided with a base 24, and an upper wave bead screw 25 for being clamped into the upper limit pit 20.2 is arranged in a mounting hole of the base 24.

The cutter head 10 is assembled at the lower section of the mounting column 13, namely, the cutter head 10 is vertically matched with the mounting column 13 in a sliding way, and the cutter head 10 and the mounting column 13 are limited in the circumferential direction; specifically, the wall of the central hole of the cutter head 10 is provided with a second vertical groove 10.1, the head of the limit screw 15 extends into the second vertical groove 10.1, and the width of the second vertical groove 10.1 is larger than the diameter of the head of the limit screw 15. Thus, the tool bit 10 cannot rotate but can move up and down relative to the mounting sleeve 12.

The bottom surface of the cutter head 10 is fixed with an adjusting seat 26 through a screw, a circle of lower limit pits 26.1 are arranged on the bottom surface of the adjusting seat 26, and a central pit 26.2 is arranged on the top surface of the adjusting seat 26; the lower section of the mounting column 13 is screwed with an adjusting sleeve 27, the adjusting sleeve 27 is sleeved with a central hole of the adjusting seat 26 in a clearance way, and the adjusting sleeve 27 and the adjusting seat 26 are limited in the axial direction. In other words, the adjusting sleeve 27 can freely rotate circumferentially but is limited by the adjusting seat 26 to move up and down only along with the cutter head 10, that is, the upper end of the adjusting sleeve 27 is provided with a U-shaped clamping plate 28, the middle section of the adjusting sleeve 27 is provided with an annular convex strip 27.1, the gap of the adjusting sleeve 27 passes through the central hole of the adjusting seat 26, the U-shaped clamping plate 28 clamps the pit bottom of the central pit 26.2 of the adjusting seat 26, and the annular convex strip 27.1 clamps the bottom surface of the adjusting seat 26. The lower end of the adjusting sleeve 27 is fixed with a knob 28, and a lower wave bead screw 29 used for being clamped into the lower limit pit 26.1 is arranged in a mounting hole on the top surface of the knob 28.

Claims (8)

1. A bean grinding device of a coffee machine comprises a shell, wherein a cutter sleeve is arranged in the shell, and a cutter head is arranged in the cutter sleeve; the upper opening of the shell is provided with an upper cover, the upper cover is provided with a feed inlet, and the bottom plate of the shell is provided with a powder outlet; the turbine driven by the motor is rotatably arranged in the shell, and the cutter sleeve is concentrically fixed in the turbine; the method is characterized in that: the side wall of the feed inlet of the upper cover is fixed with a vertical mounting sleeve through a connecting rib; the mounting sleeve is vertically matched with a mounting column in a sliding manner, the mounting column and the mounting sleeve are limited in the circumferential direction, the top end of the mounting column is screwed with a screwing key through threads, and the upper end of the mounting sleeve is provided with a clamping sleeve for limiting the screwing key axially; the tool bit is assembled at the lower section of the mounting column.

2. A bean grinding device of a coffee machine according to claim 1, characterized in that: the upper cover is fixed with a funnel, and the lower opening of the funnel is communicated with the feeding opening of the upper cover; the funnel is provided with a frustum with a small upper part and a large lower part, the top end of the screwing key extends out of a central hole of the frustum, and the top end of the screwing key is fixed with a turntable; the rotary table is provided with a limiting pin in a protruding mode, the frustum is provided with a concentric fan-shaped annular protruding rib, and the limiting pin is clamped between two straight side ribs of the fan-shaped annular protruding rib.

3. A bean grinding device of a coffee machine according to claim 2, characterized in that: the tool bit is vertically matched with the mounting column in a sliding way, and the tool bit is circumferentially limited with the mounting column; the bottom surface of the cutter head is fixed with an adjusting seat, and the bottom surface of the adjusting seat is provided with a circle of lower limit pits; the lower section of the mounting column is screwed with an adjusting sleeve through threads, the adjusting sleeve is sleeved in a central hole of the adjusting seat in a clearance mode, the adjusting sleeve and the adjusting seat are limited in the axial direction, a knob is fixed at the lower end of the adjusting sleeve, and a lower wave bead screw used for being clamped into a lower limiting pit is arranged in a mounting hole on the top surface of the knob.

4. A bean grinding device of a coffee machine as claimed in claim 3, characterized in that: the side surface of the mounting column is provided with a first concave vertical groove, the side wall of the mounting sleeve is penetrated with a threaded hole, a limit screw is screwed in the threaded hole, the rod part of the limit screw extends into the first vertical groove, and the width of the first vertical groove is larger than the diameter of the rod part of the limit screw; the wall of the central hole of the cutter head is provided with a second vertical groove, the head of the limit screw extends into the second vertical groove, and the width of the second vertical groove is larger than the diameter of the head of the limit screw.

5. A bean grinding device of a coffee machine according to claim 2, characterized in that: the bottom surface of the turntable is provided with a convex ring which is provided with a circle of limiting pits; the frustum is provided with a base, and an upper wave bead screw used for being clamped into the upper limit pit is arranged in the base mounting hole.

6. A bean grinding device of a coffee machine according to claim 2, characterized in that: the top end of the screwing key is provided with an internal thread blind hole, the turntable is penetrated with a T hole, the screwing key is connected with the turntable through a bolt, the head of the bolt is clamped in the T hole, and the rod part is screwed into the internal thread blind hole; the upper part of the outer wall of the screwing key is externally protruded with a limit tooth, the bottom surface of the rotary table is fixed with a limit sleeve, the top end of the screwing key is sleeved by the limit sleeve, and the limit groove of the inner wall of the limit sleeve is used for clamping the limit tooth of the outer wall of the screwing key.

7. A bean grinding device of a coffee machine according to claim 1, characterized in that: the side wall of the screwing key is externally protruded with a limit step, the side wall of the clamping sleeve is internally protruded with a clamping ring, and the clamping ring presses down the limit step of the screwing key to enable the lower part of the screwing key to be abutted against the top ring surface of the mounting sleeve.

8. The coffee grinder of claim 7, wherein: the upper end of the mounting sleeve is provided with an external thread, the lower opening of the clamping sleeve is provided with an internal thread, and the external thread at the upper end of the mounting sleeve is screwed with the internal thread of the lower opening of the clamping sleeve.