Miniature push rod motor and household sweeper comprising same

Abstract

The miniature push rod motor comprises a housing assembly, a driving motor, a screw rod, a nut, a flexible circuit board and a Hall plate provided with a Hall element, one end of the flexible circuit board is installed at the rear end of the driving motor, the rear end of an output shaft of the driving motor is connected with a magnetic ring, and the Hall plate is provided with a Hall element. A plurality of limiting bosses extend from one end, close to the flexible circuit board, in the shell assembly to the direction of the driving motor, and the Hall plate is clamped between the limiting bosses and the rear end face of the driving motor; a stroke limiting structure electrically connected with the circuit board is further arranged in the shell assembly. The stroke limiting structure can close the driving motor when the lead screw moves to the allowable stroke limit. The specific stroke size of the push rod is controlled by the Hall plate, and the purpose of regulating and controlling the stroke of the whole machine in real time is achieved. The stroke limiting structure closes the driving motor when the lead screw moves to the stroke limit, the push rod motor is prevented from running beyond the stroke, and therefore hybrid control over the stroke of the push rod motor is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of motors, in particular to a micro push rod motor and a household floor sweeper including the same. Background Art

[0002] In the industry of push rod motors, small push rod motors are commonly used in household floor sweepers. However, due to the complexity of the household environment, for example, when the floor sweeper works on different materials of floors or floor mats, the stroke of the micro push rod can be adjusted at any time. The common stroke control scheme is to add a Hall element and a control board behind the motor, so as to control the real-time stroke of the push rod motor. However, the Hall is easily affected by external electromagnetic interference and environmental factors such as temperature, which affects its accuracy. Only using the Hall to control the stroke may result in the situation that the operating stroke exceeds the allowable stroke. The stroke exceeding the range is likely to damage the push rod parts, there are certain safety hazards, and the existing stroke control scheme directly installs the Hall sensor on the control board, and the control board needs to be processed with Hall sensor installation holes and pre-buried corresponding wires, thus making the processing technology of the control board more complex.

[0003] In addition, the existing technology has a scheme of using a micro switch to control the movement stroke of an electric push rod. This structure needs to reserve space for assembling the micro switch inside the housing of the electric push rod. Therefore, it is difficult to miniaturize the electric push rod. If it is used in a floor sweeper, it will increase the external dimension of the floor sweeper.

[0004] In summary, how to design a micro push rod motor capable of hybrid control of the stroke is a technical problem to be solved at present. Summary of the Utility Model

[0005] In order to solve the technical problem that the micro push rod motor of the existing technology can only control the real-time stroke of the push rod and does not have a stroke limiting function, resulting in the situation that the stroke exceeds the range and is likely to damage the push rod parts, the utility model provides a micro push rod motor and a household floor sweeper including the same to solve the above problems.

[0006] The utility model provides a micro push rod motor, including a housing assembly and a driving motor, a lead screw, a nut, a flexible circuit board and a Hall board with a Hall element installed inside the housing assembly. The output shaft of the driving motor is connected to the lead screw, the lead screw is in threaded cooperation with the nut, and the nut is circumferentially limited by the housing assembly. One end of the flexible circuit board is installed at the rear end of the driving motor, a magnetic ring is connected to the rear end of the output shaft of the driving motor, and a plurality of limiting bosses extend towards the driving motor at one end of the housing assembly close to the flexible circuit board. The Hall board is clamped between the limiting bosses and the rear end face of the driving motor. A stroke limiting structure electrically connected to the circuit board is further arranged inside the housing assembly, and the stroke limiting structure can turn off the driving motor when the lead screw moves to the limit of the allowable stroke.

[0007] Further, the limiting boss includes a first boss connected to one end of the housing assembly close to the flexible circuit board and a second boss connected to the first boss. The height of the first boss is not less than the thickness of the magnetic ring. The Hall plate is clamped between the second boss and the rear end face of the drive motor. The dimension of the first boss in the thickness direction of the housing assembly is greater than that of the first boss in the thickness direction of the housing assembly.

[0008] Further, one limiting boss is respectively arranged at each of the four vertex corners at one end of the housing assembly.

[0009] Further, the second boss is in contact with the inner bottom surface of the housing assembly.

[0010] Further, the stroke limiting structure is a micro switch located inside the housing assembly, and the micro switch is triggered when the lead screw moves to the limit of the allowable stroke.

[0011] Further, the stroke limiting structure is a metal elastic piece connected to the nut and moving synchronously with the nut. An extension protruding from the nut is formed on the metal elastic piece; a conductive layer is arranged on the flexible circuit board along the stroke track of the nut; when the metal elastic piece reciprocates along the lead screw with the nut, the extension is adapted to contact different contact areas of the conductive layer to realize the switching control of the on-off of the power supply circuit of the drive motor.

[0012] Further, the metal elastic piece includes a clamping ring body for clamping on the outer side wall of the nut and pins bent and connected to the outer side wall of the clamping ring body; the extension is formed on the pins.

[0013] Further, a current limiting resistor is arranged on the flexible circuit board; and the conductive layer includes a second contact area, a first contact area and a third contact area sequentially distributed along the direction from adjacent to the drive motor to away from the drive motor; wherein, diodes are respectively arranged on the second contact area and the third contact area.

[0014] Further, when the drive motor rotates in the first direction and the nut moves along the lead screw in the direction away from the drive motor, after the extension of the metal elastic piece slides from the second contact area to the first contact area and then to the third contact area, the drive motor stops rotating, and the positive and negative electrodes of the motor are connected through the diode in the third contact area to form a power-off protection circuit for the drive motor.

[0015] Further, a V-shaped included angle is formed by bending between the pin and the clamping ring body; the tip of the included angle formed by bending the pin and the clamping ring body is arc-shaped.

[0016] Further, the clamping ring body includes a substrate connected to the pin and a pair of fins connected to the substrate; the pair of fins and the substrate together form a clamping groove for clamping with the nut.

[0017] Furthermore, at the end of a pair of the fins away from the substrate, there are folding pieces bent towards the card slot; on the outer side wall of the nut, there is a clamping portion for being embedded into the card slot; and on the clamping portion, there is a positioning wall for adapting to the folding pieces.

[0018] The present utility model also provides a household floor sweeper, including the above-mentioned micro push rod motor.

[0019] The beneficial effects of the present utility model are as follows:

[0020] (1) The specific stroke size of the push rod of the present utility model is controlled by the Hall plate. When it is detected that the push rod reaches the corresponding stroke, the push rod can be stopped at the corresponding position by controlling the on-off of the external circuit, so as to achieve the purpose of real-time regulation of the whole machine stroke. The stroke limiting structure shuts down the driving motor when the lead screw moves to the stroke limit, preventing the push rod motor from running beyond the stroke, thereby realizing the hybrid control of the push rod motor stroke.

[0021] (2) The Hall element of the present utility model is installed on the Hall plate, and there is no need to process Hall element installation holes on the original flexible circuit board. The Hall plate can be independently processed and manufactured, shortening the whole machine processing time. The Hall plate is clamped between the limiting boss in the housing assembly and the rear end face of the driving motor, and the installation is convenient.

[0022] (3) The present utility model realizes the switching control of the on-off of the power supply circuit of the motor by contacting different contact areas of the conductive layer of the flexible circuit board through the metal elastic sheet connected to the nut. In this way, it can not only meet the use requirements of precise control of the stroke of the electric push rod, but also reduce the occupancy rate of the assembly space compared with the micro switch, thereby reducing the volume of the overall electric push rod, realizing the miniaturization of the electric push rod, and making it applicable to the application scenarios with limited assembly space. Description of the Drawings

[0023] The following further describes the present utility model in conjunction with the drawings and embodiments.

[0024] Figure 1 is an exploded view of the micro push rod motor of the present utility model;

[0025] Figure 2 is an internal schematic diagram of the micro push rod motor of the present utility model;

[0026] Figure 3 is an axial sectional schematic diagram of the micro push rod motor of the present utility model;

[0027] Figure 4 is an external schematic diagram of the micro push rod motor of the present utility model;

[0028] Figure 5 It is a three-dimensional view of the metal elastic sheet in the present utility model;

[0029] Figure 6 It is an assembly schematic diagram of the nut and the lead screw in the present utility model;

[0030] Figure 7 It is a schematic diagram of the positional relationship between the metal elastic sheet and the circuit board in the present utility model;

[0031] Figure 8 It is a schematic diagram of the flexible circuit board in the present utility model;

[0032] Figure 9 It is a circuit schematic diagram of the flexible circuit board in the present utility model.

[0033] In the figure, 1 is the housing assembly, 101 is the housing, 102 is the housing cover, 2 is the drive motor, 3 is the lead screw, 4 is the nut, 5 is the flexible circuit board, 6 is the Hall plate, 7 is the push rod, 701 is the round tube, 702 is the connector, 8 is the outer tube, 9 is the plug, 10 is the magnetic ring, 11 is the limit boss, 1101 is the first boss, 1102 is the second boss, 12 is the metal elastic sheet, 1201 is the clamping ring body, 1202 is the pin, 1203 is the extension end, 13 is the substrate, 14 is the fin, 15 is the connecting wire, 16 is the welding hole, P1 is the first contact area, P2 is the second contact area, P3 is the third contact area, 17 is the folding piece, 18 is the clamping part, 19 is the positioning wall, 20 is the insulating board. Specific embodiments

[0034] The following details the embodiments of the present utility model. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present utility model and should not be construed as a limitation of the present utility model.

[0035] Embodiment 1

[0036] A micro push rod motor includes a housing assembly 1 and a drive motor 2, a lead screw 3, a nut 4, a flexible circuit board 5 and a Hall plate 6 installed with Hall elements inside the housing assembly 1. The output shaft of the drive motor 2 is connected to the lead screw 3. The lead screw 3 is in threaded cooperation with the nut 4. The nut 4 is circumferentially limited by the housing assembly 1. When the drive motor 2 operates, the output shaft of the drive motor 2 drives the lead screw 3 to rotate, and the nut 4 moves back and forth along with the rotation of the lead screw 3. The push rod 7 is fixed to the nut 4 and reciprocates synchronously with the nut 4.

[0037] As Figure 1As shown in the figure, the push rod 7 includes a round tube 701 and a connector 702 located at the end of the round tube 701. The nut 4 has internal and external threads. The internal thread of the nut 4 is sleeved on the lead screw 3 and is screwed with the lead screw 3, and the external thread of the nut 4 is screwed with the left end of the round tube 701; the right end of the round tube 701 is screwed with the connector 702, and the connector 702 is connected to the client, driving the client to perform telescopic movement. An outer tube 8 and a plug 9 fixed to the housing assembly 1 are provided outside the push rod 7 to provide a moving channel for the nut 4. The internal rectangular cross-section inside the outer tube 8 cooperates with the outer surface of the nut 4 to limit the circumferential rotation of the nut 4.

[0038] In the present utility model, taking the direction in which the lead screw 3 extends as the front, the push rod 7 is located in front of the driving motor 2, and the Hall plate 6 is located behind the driving motor 2.

[0039] As Figure 2 and Figure 3 As shown in the figure, one end of the flexible circuit board 5 is installed at the rear end of the driving motor 2. A magnetic ring 10 is connected to the rear end of the output shaft of the driving motor 2. A plurality of limiting bosses 11 extend towards the driving motor 2 at one end of the housing assembly 1 close to the flexible circuit board 5. The limiting bosses 11 can limit the front and rear directions of the Hall plate 6, so that the Hall plate 6 is clamped between the limiting bosses 11 and the rear end face of the driving motor 2, and the assembly can be successfully completed without installation tools; a stroke limiting structure electrically connected to the circuit board is further provided in the housing assembly 1, and the stroke limiting structure can turn off the driving motor 2 when the lead screw 3 moves to the allowable stroke limit. The allowable stroke limit includes the stroke limit when the lead screw 3 extends and the stroke limit when the lead screw 3 retracts.

[0040] The output shaft of the driving motor 2 extends from the rear end, and the magnetic ring 10 is installed and fixed on the output shaft and can rotate with the output shaft. The Hall plate 6 is located between the magnetic ring 10 and the driving motor 2. The Hall elements on the Hall plate 6 are aligned with the magnetic ring 10 in the forward direction. Whenever a magnetic pole of the magnetic ring 10 rotates past a Hall element, the change in the magnetic field will cause a change in the internal voltage of the Hall, so that the Hall plate 6 outputs a pulse signal. If the number of magnetic poles of the magnetic ring 10 is n, then for each rotation of the driving motor 2, each Hall element outputs n pulse signals. By monitoring the number of output pulse signals, the number of rotations of the driving motor 2 can be monitored in real time, and the stroke of the push rod motor is in a fixed proportional relationship with the number of rotations of the driving motor 2, so the real-time stroke size of the push rod 7 pushed out can be detected at the same time. When it is detected that the push rod 7 reaches the corresponding stroke, the push rod 7 can be stopped at the corresponding position by controlling the on-off of the external circuit, so as to achieve the purpose of real-time regulation of the whole machine stroke.

[0041] During the operation of the push rod 7, the present utility model can control the push rod motor by switching the power supply on and off and reversing rotation according to the signal feedback by the Hall plate 6, so that the push rod 7 stops at a specified position. At the same time, the push rod 7 can also be controlled to stop at the limit state of extension or retraction by the stroke limiting structure, avoiding damage to the internal parts of the push rod motor.

[0042] As Figure 1 and Figure 2 shown, the limit boss 11 includes a first boss 1101 connected to one end of the housing assembly 1 close to the flexible circuit board 5 and a second boss 1102 connected to the first boss 1101. The height of the first boss 1101 is not less than the thickness of the magnetic ring 10. The Hall plate 6 is clamped between the second boss 1102 and the rear end face of the drive motor 2. The dimension of the first boss 1101 in the thickness direction of the housing assembly 1 is greater than that of the first boss 1101 in the thickness direction of the housing assembly 1. The height of the first boss 1101 refers to the outer dimension of the first boss 1101 in the front-rear direction of the push rod motor. The first boss 1101 is located outside the magnetic ring 10. During installation, the Hall plate 6 can only be inserted from the front of the first boss 1101, thus avoiding collision and friction between the Hall plate 6 and the magnetic ring 10 during installation and causing damage to the electrical components on the Hall plate 6. The cross-sectional dimension of the first boss 1101 is larger, and the cross-sectional dimension of the second boss 1102 is smaller. The second boss 1102 mainly presses on the corners of the Hall plate 6.

[0043] Preferably, a limit boss 11 is respectively provided at each of the four top corners at one end of the housing assembly 1, pressing on the four top corners of the Hall plate 6. The second boss 1102 can be provided in the middle of the end face of the first boss 1101. To reduce the friction between the second boss 1102 and the Hall plate 6, the second boss 1102 preferably contacts the inner bottom surface of the housing assembly 1, where the inner bottom surface of the housing assembly 1 includes the upper and lower inner bottom surfaces. As Figure 1 shown, the housing assembly 1 is composed of a housing 101 and a housing cover 102. A limit boss 11 is provided at each of the two top corners at the rear end of the housing 101 and the housing cover 102. The second boss 1102 on the housing 101 is connected to the inner bottom surface of the housing 101, and the second boss 1102 on the housing cover 102 is connected to the inner bottom surface of the housing cover 102.

[0044] The stroke limiting structure can be a microswitch located inside the housing assembly 1, and the microswitch is triggered when the lead screw 3 moves to the allowable stroke limit.

[0045] Embodiment 2

[0046] Since the microswitch in Embodiment 1 needs to occupy additional assembly space, which is not conducive to the miniaturization design of the push rod motor. For this reason, the following stroke limiting structure is adopted in this embodiment:

[0047] The stroke limit structure is a metal elastic piece 12 connected to the nut 4 and moving synchronously with the nut 4. An extension end 1203 protruding from the nut 4 is formed on the metal elastic piece 12; a conductive layer is arranged on the flexible circuit board 5 along the stroke track of the nut 4; when the metal elastic piece 12 reciprocates along the lead screw 3 with the nut 4, the extension end 1203 is adapted to contact different contact areas of the conductive layer to realize the switching control of the on-off of the power supply circuit of the driving motor 2.

[0048] The flexible circuit board 5 is made of a flexible material and can be bent. As Figure 2 and Figure 7 shown, the flexible circuit board 5 is bent into an L shape. One end of the flexible circuit board 5 extends along the axial direction of the push rod motor, and the other end is attached to the rear end of the driving motor 2. Since the outer shell wall of the driving motor 2 is made of metal and is likely to cause a short circuit, an insulating plate 20 is also provided in the housing 101 to prevent the flexible circuit board 5 from directly contacting the outer shell wall of the driving motor 2. That is to say, for the driving motor 2, although it needs to be welded to the flexible circuit board 5, the outer shell of the driving motor 2 except for the part welded to the flexible circuit board 5 will not directly contact the flexible circuit board 5.

[0049] The extension end 1203 of the metal elastic piece 12 is used to cooperate with the flexible circuit board 5. The reason why the extension end 1203 protrudes from the nut 4 is to prevent the nut 4 from contacting the flexible circuit board 5. The extension end 1203 of the metal elastic piece 12 is in a slightly compressed state when contacting the flexible circuit board 5 to ensure the contact between the two and maintain a certain pressure.

[0050] Regarding the different contact areas of the conductive layer, during the process of the metal elastic piece 12 moving along the lead screw 3 with the nut 4, the extension end 1203 on the metal elastic piece 12 will contact different contact areas, but the control situation of the power supply circuit of the driving motor 2 in the contact state is different. For a more detailed description of the control of the on-off of the power supply circuit, see the following embodiment description.

[0051] As Figure 4 and Figure 8 shown, a connecting wire 15 for connecting to a DC power supply is welded on the flexible circuit board 5. And a circuit composed of a current-limiting resistor R1, a welding hole 16 and a copper foil is also provided on the flexible circuit board 5, and an insulating layer is covered above it. The welding hole 16 is used for welding to the driving motor 2.

[0052] On the conductive layer, there is exposed metal such as, but not limited to, copper foil for contacting the extension end 1203 of the metal shrapnel 12. When the DC power supply is connected to the forward power supply, the current passes through the current-limiting resistor R1 and the extension end 1203 of the metal shrapnel 12 to make the drive motor 2 rotate forward; when the DC power supply is connected to the reverse power supply, the current passes through the current-limiting resistor R1 and the extension end 1203 of the metal shrapnel 12 to make the drive motor 2 rotate in reverse.

[0053] Next, what will be described in detail is that for the conductive layer, as Figure 8 shown, it includes a second contact area P2, a first contact area P1, and a third contact area P3 that are sequentially distributed along the direction from adjacent to the drive motor 2 to away from the drive motor 2; diodes are respectively provided on the second contact area P2 and the third contact area P3.

[0054] Based on the above situation, please refer to Figure 9 shown. When the drive motor 2 rotates in the first direction (forward rotation) and the nut 4 moves along the lead screw 3 away from the drive motor 2, after the extension end 1203 of the metal shrapnel 12 slides from the second contact area P2 to the first contact area P1 and then slides to the third contact area P3, the drive motor 2 stops rotating, and the positive and negative electrodes of the drive motor 2 are connected through the diode D2 in the third contact area P3 to form a power-off protection circuit for the drive motor 2, which plays a role in continuous current of the coil in the drive motor 2, consumes the stored energy in the coil, and prevents the remaining electric energy from affecting the operation of the drive motor 2. When the drive motor 2 rotates in the second direction (reverse rotation) and the nut 4 moves along the lead screw 3 towards the drive motor 2, after the extension end 1203 of the metal shrapnel 12 slides from the third contact area P3 to the first contact area P1 and then slides to the second contact area P2, the drive motor 2 stops rotating, and the positive and negative electrodes of the drive motor 2 are connected through the diode D1 in the second contact area P2 to form a power-off protection circuit for the drive motor 2, which plays a role in continuous current of the coil in the drive motor 2, consumes the stored energy in the coil, and prevents the remaining electric energy from affecting the operation of the drive motor 2.

[0055] Next, what needs to be explained is that in order to ensure the effective contact and cooperation between the extension end 1203 of the metal shrapnel 12 and the conductive layer and prevent separation between the two, for the design of the extension end 1203, an optional implementation case will be given by combining the attached drawings:

[0056] As Figure 5 shown, generally, the extension end 1203 is a hook-shaped structure, and the end face of the extension end 1203 in contact with the conductive layer is an arc surface. The design of the arc surface here can increase the contact area between the extension end 1203 and the conductive layer on the one hand, and can reduce the friction force generated on the conductive layer in the contact state between the extension end 1203 and the conductive layer on the other hand, reducing the probability of damage to the flexible printed circuit board 5 being scratched or damaged.

[0057] More specifically, asFigure 5 and Figure 7 As shown, the metal spring 12 includes a clamping ring body 1201 for clamping on the outer wall of the nut 4 and a pin 1202 bent and connected to the outer wall of the clamping ring body 1201; the extension end 1203 is formed on the pin 1202. In this structure, the pin 1202 itself will not contact the nut 4, and the clamping ring body 1201 plays a transitional role between the pin 1202 and the nut 4.

[0058] On the basis of the above structure, it is also necessary to explain that, in order to allow the extension end 1203 on the pin 1202 to form a certain distance with the nut 4, the pin 1202 and the clamping ring body 1201 are bent to form a V-shaped angle, and the V-shaped angle here is preferably an acute angle. In addition, in an optional implementation, the tip of the angle formed by the bending of the pin 1202 and the clamping ring body 1201 is in an arc shape. Under such a structure, when the extension end 1203 is in contact with the flexible circuit board 5, the pressure generated by the flexible circuit board 5 on the extension end 1203 will not cause the pin 1202 to deform, resulting in a break at the connection between the pin 1202 and the clamping ring body 1201.

[0059] Next, it is necessary to explain the assembly problem of the clamping ring body 1201 and the nut 4 in this embodiment. In order to facilitate the assembly and disassembly of the metal spring 12 and the nut 4, this embodiment adopts the following design:

[0060] First, the clamping ring body 1201 includes a substrate 13 connected to the pin 1202, and a pair of fins 14 connected to the substrate 13; the pair of fins 14 and the substrate 13 together form a clamping groove for clamping with the nut 4. The clamping groove is generally U-shaped, so that the clamping ring body 1201 and the nut 4 can be directly assembled by plugging.

[0061] Secondly, after the clamping ring body 1201 and the nut 4 are plugged into place, in order to prevent the clamping ring body 1201 from unexpectedly falling off from the nut 4, Figures 5 - 7 As shown, in this embodiment, a pair of fins 14 are provided with a folding piece 17 bent toward the slot at the end away from the base sheet 13; and a clamping portion 18 for embedding into the slot is provided on the outer wall of the nut 4; and a positioning wall 19 for fitting the folding piece 17 is provided on the clamping portion 18. Based on this structure, when the clamping ring body 1201 and the nut 4 are plugged into place, the folding piece 17 is just clamped into place with the positioning wall 19, and the metal spring sheet 12 itself has a certain elasticity, and the pair of fins 14 can be manually opened to facilitate its assembly with the nut 4, so the design of the folding piece 17 will not affect the assembly process of the metal spring sheet 12 and the nut 4.

[0062] For the push rod motor of this embodiment, not only can its structural dimensions be miniaturized, but also its structure is simple, the failure rate during use is low, and the assembly is convenient and efficient.

[0063] Embodiment 3

[0064] A household floor sweeper includes the above-mentioned micro push rod motor. The household floor sweeper has a small structural size, can accurately control the extension length of the push rod 7 according to the height of the ground, and when the ground height is too large, the present utility model can control the push rod 7 to move within the structural allowable range of the push rod motor, avoiding damage to the internal parts of the push rod motor caused by excessive extension of the push rod 7, ensuring the safe operation of the household floor sweeper and increasing its service life.

[0065] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by terms such as "center", "thickness", "upper", "lower", "front", "rear", "left", "right", "inner", "outer", "axial", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation on the present utility model.

[0066] In addition, terms such as "first", "second", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the term "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances. In addition, in the description of the present utility model, unless otherwise stated, the meaning of "a plurality" is two or more.

[0067] In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments.

[0068] Taking the above-mentioned ideal embodiment of the present utility model as an inspiration, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of this utility model. The technical scope of this utility model is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A micro push rod motor, characterized in that: It comprises a housing component, a driving motor, a lead screw, a nut, a flexible circuit board and a Hall plate with a Hall element installed inside the housing component, wherein the output shaft of the driving motor is connected to the lead screw, the lead screw is threadedly matched with the nut, and the nut is circumferentially limited by the housing component; one end of the flexible circuit board is installed at the rear end of the driving motor, the rear end of the output shaft of the driving motor is connected to a magnetic ring, a plurality of limiting bosses are extended toward the driving motor at one end of the housing component close to the flexible circuit board, and the Hall plate is sandwiched between the limiting boss and the rear end face of the driving motor; A travel limit structure electrically connected to the circuit board is also provided in the housing component, and the travel limit structure can shut down the drive motor when the lead screw moves to the allowable travel limit.

2. The micro push rod motor according to claim 1, characterized in that: The limiting boss includes a first boss connected to one end of the shell component close to the flexible circuit board and a second boss connected to the first boss, the height of the first boss is not less than the thickness of the magnetic ring, the Hall plate is clamped between the second boss and the rear end face of the drive motor, and the size of the first boss along the thickness direction of the shell component is greater than the size of the first boss along the thickness direction of the shell component.

3. The micro push rod motor according to claim 1, characterized in that: The limiting boss is respectively arranged at four vertex corners of one end of the housing component.

4. The micro push rod motor according to claim 2, characterized in that: The second boss contacts the inner bottom surface of the housing assembly.

5. The micro push rod motor according to claim 1, characterized in that: The stroke limit structure is a micro switch located inside the housing assembly, and the micro switch is triggered when the lead screw moves to the allowable stroke limit.

6. The micro push rod motor according to claim 1, characterized in that: The travel limit structure is a metal spring connected to the nut and moves synchronously with the nut, and an extension end protruding from the nut is formed on the metal spring; A conductive layer is arranged on the flexible circuit board along the travel track of the nut; When the metal spring moves back and forth along the lead screw along with the nut, the extension end is suitable for contacting different contact areas of the conductive layer to realize the switching control of the power supply circuit of the drive motor.

7. The micro push rod motor according to claim 6, characterized in that: The metal spring sheet comprises a clamping ring body for clamping on the outer side wall of the nut and a pin connected to the outer side wall of the clamping ring body by bending; the extending end is formed on the pin.

8. The micro push rod motor according to claim 6, characterized in that: The flexible circuit board is provided with a current limiting resistor; and The conductive layer includes a second contact area, a first contact area and a third contact area which are sequentially distributed in a direction from the vicinity of the drive motor to the direction away from the drive motor; wherein Diodes are respectively disposed on the second contact region and the third contact region.

9. The micro push rod motor according to claim 8, characterized in that: When the drive motor rotates in the first direction and the nut moves along the screw rod away from the drive motor, the extended end of the metal spring slides from the second contact area to the first contact area and then to the third contact area. The drive motor stops rotating and the positive and negative poles of the motor are connected through the diode in the third contact area, forming a power-off protection circuit for the drive motor.

10. The micro push rod motor according to claim 7, characterized in that: The pin and the clamping ring body are bent to form a V-shaped angle; and The tip of the included angle formed by bending the pin and the clamping ring body is in an arc shape.

11. The micro push rod motor according to claim 7, characterized in that: The clamping ring body includes a substrate connected to the pin, and a pair of fins connected to the substrate; The pair of fins and the base plate together form a slot for engaging with the nut.

12. The micro push rod motor according to claim 11, characterized in that: A pair of fins are provided with folding pieces bent toward the slot at the ends away from the base; and A clamping portion for embedding into the clamping slot is provided on the outer side wall of the nut; and a positioning wall for adapting to the folding sheet is provided on the clamping portion.

13. A household sweeping machine, characterized in that: The micro push rod motor comprises any one of claims 1-12.

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