Lead screw module and electric push rod using same

Abstract

The utility model relates to the technical field of linear driving equipment, in particular to a screw rod module and an electric push rod using the screw rod module, which comprise a screw rod nut group, a screw rod nut group and a screw rod nut group, the metal elastic sheet is connected with the nut so as to be suitable for synchronously moving along with the nut; an extending end protruding out of the nut is formed on the metal elastic sheet; the flexible circuit board at least comprises an induction board; a conductive layer is arranged on the induction plate along the stroke track of the nut; and when the metal elastic sheet reciprocates along the screw rod along with the nut, the extension end is suitable for being in contact with different contact areas of the conductive layer so as to realize switching control of on-off of a power supply circuit of the motor.

Description

Technical Field

[0001] The utility model relates to the technical field of linear drive equipment, in particular to a screw rod module and an electric push rod using the same. Background Art

[0002] Electric linear actuators are used in various fields. To meet the needs of different applications, the sizes and types of linear actuators are becoming more and more diverse. In some specific application areas, in order to adapt to the use environment, in some cases where the assembly space is limited, miniaturized linear actuators are needed to meet the use requirements. For the commonly used linear actuators, in order to facilitate the precise control of the stroke of the linear actuator, a circuit consisting of a micro switch, a diode, and a connecting wire is usually used to control the linear actuator. Under this structure, it is necessary to reserve space inside the housing of the linear actuator for assembling the micro switch, so it is difficult to achieve miniaturization of the linear actuator.

[0003] Therefore, for some application scenarios where assembly space is limited, on the basis of meeting the use requirements of accurately controlling the push rod stroke, it is also necessary to further optimize its structure to achieve miniaturization of its overall structure. Utility Model Content

[0004] The first object of the utility model is to provide a screw module to solve the technical problem of simplifying the stroke control structure of the screw module.

[0005] The second object of the utility model is to provide an electric push rod to solve the technical problems of miniaturization of the electric push rod and accurate control of the push rod stroke.

[0006] The screw rod module of the utility model is realized as follows:

[0007] A screw rod module, comprising:

[0008] A screw rod and nut assembly, comprising a screw rod and a nut adapted to reciprocate along the axial direction of the screw rod;

[0009] A metal spring sheet connected to the nut so as to be adapted to move synchronously with the nut; the metal spring sheet is formed with an extension end protruding from the nut;

[0010] The flexible circuit board at least comprises a sensing board; a conductive layer is arranged on the sensing board along the travel track of the nut;

[0011] 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 motor.

[0012] In an optional implementation of the present invention, the extension end is a hook-shaped structure, and the end surface of the extension end in contact with the conductive layer is an arc-shaped surface.

[0013] In an optional implementation of the present invention, the metal spring comprises a clamping ring body for clamping on the outer side wall of the nut and a pin bent and connected to the outer side wall of the clamping ring body;

[0014] The extension end is formed on the pin.

[0015] In an optional implementation of the present invention, the pin and the clamping ring body are bent to form a V-shaped angle; and

[0016] The tip of the included angle formed by bending the pin and the clamping ring body is in an arc shape.

[0017] In an optional implementation of the utility model, the clamping ring body includes a substrate connected to the pin, and a pair of fins connected to the substrate;

[0018] The pair of fins and the base plate together form a slot for engaging with the nut.

[0019] In an optional implementation of the present invention, a pair of fins are provided at ends away from the substrate with folding pieces bent toward the slot; and

[0020] 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.

[0021] The electric push rod of the utility model is realized as follows:

[0022] An electric push rod comprises: a housing, a motor arranged in the housing, and a screw rod module connected to the motor;

[0023] The motor is used to drive the screw of the screw module to operate.

[0024] In an optional implementation of the utility model, the flexible circuit board further includes a main board integrally connected to the induction board and used for being electrically connected to the motor;

[0025] The mainboard is electrically connected to a DC power supply; and the conductive layer is provided with exposed metal for contacting the extended end of the metal spring.

[0026] In an optional implementation of the present invention, a current limiting resistor is provided on the mainboard; and

[0027] 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 motor to the motor; wherein

[0028] Diodes are respectively disposed on the second contact region and the third contact region.

[0029] In an optional implementation of the utility model, when the motor rotates in a first direction and the nut moves along the screw away from the 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 motor stops rotating, and the positive and negative poles of the motor are connected through the diode in the third contact area, forming a motor power-off protection circuit.

[0030] In an optional implementation of the utility model, when the motor rotates in the second direction and the nut moves along the screw toward the motor, the extended end of the metal spring slides from the third contact area to the first contact area and then to the second contact area, the motor stops rotating, and the positive and negative poles of the motor are connected through the diode in the second contact area, forming a motor power-off protection circuit.

[0031] In an optional implementation of the utility model, the housing includes a main housing for accommodating the motor and a special-shaped tube body connected to the main housing for adapting to the screw module;

[0032] The main board is arranged in the main shell, and the induction board extends from the main shell to the special-shaped tube body.

[0033] In an optional implementation of the present invention, the main housing is further provided with an insulating plate for preventing the main board from directly contacting the outer shell wall of the motor.

[0034] By adopting the above technical scheme, the utility model has the following beneficial effects: the screw module of the utility model and the electric push rod using the same, realize the switching control 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 spring connected to the nut, thereby meeting the use requirements for precise control of the stroke of the electric push rod, and at the same time, compared with the micro switch, it can reduce its occupancy rate of the assembly space, thereby reducing the overall volume of the electric push rod, thereby realizing the miniaturization of the electric push rod, so that it can be suitable for application scenarios with limited assembly space. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The figure shows the internal structure of the electric push rod of the utility model;

[0036] Figure 2 The figure shows the external structure schematic diagram of the electric push rod of the utility model;

[0037] Figure 3 The figure shows the internal structure schematic diagram of the main housing of the electric push rod of the present utility model;

[0038] Figure 4The figure shows a schematic diagram of the matching structure of the lead screw and the motor of the electric push rod of the utility model;

[0039] Figure 5 The figure shows a schematic diagram of the matching structure of the lead screw and the nut of the electric push rod of the utility model;

[0040] Figure 6 Shown is a schematic structural diagram of a nut of an electric push rod of the utility model;

[0041] Figure 7 The figure shows a schematic diagram of the structure of the metal spring of the electric push rod of the utility model;

[0042] Figure 8 The figure shows a schematic diagram of the structure of the flexible circuit board of the electric push rod of the utility model;

[0043] Fig. 9 Shown is a schematic diagram of the circuit structure of the flexible circuit board of the electric push rod of the utility model.

[0044] In the figure: main shell 11, special-shaped tube body 12, insulating plate 13, motor support block 15, screw 21, groove 211, nut 22, positioning wall 221, clamping part 222, metal spring 3, clamping ring body 31, substrate 311, fin 312, folding piece 315, pin 32, extension end 33, induction plate 41, first contact area P1, second contact area P2, third contact area P3, main board 42, welding hole 421, motor 5, connecting line 6. DETAILED DESCRIPTION

[0045] In order to make the content of the utility model more clearly understood, the utility model is further described in detail below based on specific embodiments and in conjunction with the accompanying drawings.

[0046] Embodiment 1:

[0047] See also Figures 1 to 9 As shown, this embodiment provides a screw module, including: a screw nut group, a metal spring 3 and a flexible circuit board. The screw nut group can be understood as a common means of conventional technology, that is, it includes a screw 21 and a nut 22 suitable for axial reciprocating along the screw 21. The metal spring is connected to the nut 22 so that it can move synchronously with the nut 22. In order to make the metal spring 3 cooperate with the flexible circuit board, an extension end 33 protruding from the nut 22 is formed on the metal spring 3. The extension end 33 is used to cooperate with the flexible circuit board. The reason why the extension end 33 protrudes from the nut 22 is to prevent the nut 22 and the flexible circuit board from contacting each other, and the extension end 33 of the spring metal spring 3 is in a slightly compressed state and contacts with the flexible circuit board to ensure that the contact between the two maintains a certain pressure.

[0048] Based on the above situation, in order to meet the use requirements of the metal spring 3, the flexible circuit board used in this embodiment at least includes a sensing plate 41; a conductive layer is arranged on the sensing plate 41 along the travel trajectory of the nut 22. Under this structure, when the metal spring 3 reciprocates along the screw rod 21 with the nut 22, the extension end 33 is suitable for contacting with different contact areas of the conductive layer to realize the switching control of the power supply circuit of the motor 5. Specifically, regarding the different contact areas of the conductive layer here, in the process of the metal spring 3 moving along the screw rod 21 with the nut 22, the extension end 33 on the metal spring 3 will contact with different contact areas, but the control of the power supply circuit of the motor 5 generated in the contact state is different. For more detailed control of the power supply circuit on and off, see the following embodiment description.

[0049] Next, it is to be explained that, in order to ensure effective contact and cooperation between the extended end 33 of the metal spring 3 and the conductive layer and prevent the separation of the two, the design of the extended end 33 is described with reference to an optional implementation example in conjunction with the accompanying drawings:

[0050] Generally, the extension end 33 is a hook-shaped structure, and the end surface of the extension end 33 in contact with the conductive layer is an arc surface. The arc surface design here can increase the contact area between the extension end 33 and the conductive layer on the one hand, and on the other hand, can reduce the friction force generated by the extension end 33 on the conductive layer when in contact with the conductive layer, thereby reducing the probability of the flexible circuit board being scratched or damaged.

[0051] More specifically, the metal spring 3 includes a clamping ring body 31 for clamping on the outer wall of the nut 22 and a pin 32 bent and connected to the outer wall of the clamping ring body 31; the extension end 33 is formed on the pin 32. In this structure, the pin 32 itself will not contact the nut 22, and the clamping ring body 31 plays a transitional role between the pin 32 and the nut 22.

[0052] On the basis of the above structure, it is also necessary to explain that, in order to allow the extension end 33 on the pin 32 to form a certain distance with the nut 22, the pin 32 and the clamping ring body 31 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 pin 32 and the clamping ring body 31 is an arc shape. Under such a structure, when the extension end 33 is in contact with the flexible circuit board, the pressure generated by the flexible circuit board on the extension end 33 will not cause the pin 32 to deform, resulting in a break at the connection between the pin 32 and the clamping ring body 31.

[0053] Next, it is necessary to explain the assembly problem of the clamping ring and the nut 22 in this embodiment. In order to facilitate the assembly and disassembly of the metal spring 3 and the nut 22, this embodiment adopts the following design:

[0054] First, the clamping ring body 31 includes a substrate 311 connected to the pin 32, and a pair of fins 312 connected to the substrate 311; the pair of fins 312 and the substrate 311 together form a clamping groove for clamping with the nut 22. The clamping groove is generally U-shaped, so that the clamping ring body 31 and the nut 22 can be directly assembled by plugging.

[0055] Secondly, when the snap ring body 31 and the nut 22 are plugged into place, in order to prevent the snap ring body 31 from unexpectedly falling off from the nut 22, the embodiment provides a folding piece 315 bent toward the slot at the end of the pair of fins 312 away from the base sheet 311; and a snap-fitting portion 222 for embedding into the slot is provided on the outer wall of the nut 22; and a positioning wall 221 for adapting the folding piece 315 is provided on the snap-fitting portion 222. Based on this structure, when the snap ring body 31 and the nut 22 are plugged into place, the folding piece 315 is just snapped into place with the positioning wall 221, and the metal spring 3 itself has a certain elasticity, and the pair of fins 312 can be manually opened to facilitate its assembly with the nut 22, so the design of the folding piece 315 will not affect the assembly process of the metal spring 3 and the nut 22.

[0056] In summary, for the screw module of the present embodiment, the metal spring sheet 3 connected to the nut 22 is used to contact different contact areas of the conductive layer of the flexible circuit board to realize the switching control of the on and off of the power supply circuit of the motor 5. Therefore, when it is used in the electric push rod, it can not only meet the use requirements for precise control of the stroke of the electric push rod, but also reduce its occupancy rate of the assembly space compared to the micro switch, thereby reducing the volume of the overall electric push rod, thereby realizing the miniaturization of the electric push rod, so that it can be suitable for application scenarios with limited assembly space.

[0057] Embodiment 2:

[0058] See also Figures 1 to 9 As shown, based on the screw module of Example 1, this embodiment provides an electric push rod, including: a housing, a motor 5 arranged in the housing and the screw module of Example 1 connected to the motor 5; wherein the motor 5 is used to drive the screw 21 of the screw module to operate.

[0059] In order to facilitate the direct matching of the screw rod 21 with the motor 5, a groove 211 is provided at the head of the screw rod 21 for matching the motor 5. During assembly, the output shaft of the motor 5 is directly inserted into the groove 211 at the head of the screw rod 21, so that when the motor 5 rotates, the screw rod 21 is driven to rotate, thereby transmitting the torque of the motor 5. This matching method has the advantages of simple assembly and low cost.

[0060] Furthermore, the flexible circuit board used in this embodiment also includes a main board 42 integrally connected to the induction board 41 for electrically connecting to the motor 5, wherein the main board 42 is electrically connected to the DC power supply, and a connection line 6 for connecting to the DC power supply is welded on the main board 42. The main board 42 is also provided with a circuit consisting of a current limiting resistor R1, a welding hole 421 and copper foil, and is covered with an insulating layer, wherein the welding hole 421 is used for welding and connecting to the motor 5; the main board 42 and the induction board 41 are preferably an integrally processed structure.

[0061] The conductive layer is provided with bare metal such as but not limited to copper foil for contacting the extension end 33 of the metal spring sheet 3. 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 33 of the metal spring sheet to drive the motor 5 to 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 33 of the metal spring sheet to drive the motor 5 to rotate reversely.

[0062] What will be described in detail next is that the conductive layer includes a second contact area P2, a first contact area P1 and a third contact area P3 which are sequentially distributed along a direction adjacent to the motor 5 and away from the motor 5; wherein diodes are respectively provided on the second contact area P2 and the third contact area P3.

[0063] Based on the above, please refer to Fig. 9 As shown, when the motor 5 rotates in the first direction (forward rotation), the nut 22 moves along the screw 21 in the direction away from the motor 5, and the extension end 33 of the metal spring 3 slides from the second contact area P2 to the first contact area P1 and then to the third contact area P3, the motor 5 stops rotating, and the positive and negative poles of the motor 5 are connected through the diode D2 of the third contact area P3, forming a power-off protection circuit for the motor 5, which plays the role of continuous current in the coil of the motor 5, consumes the energy stored in the coil, and prevents the retained electric energy from affecting the operation of the motor 5. When the motor 5 rotates in the second direction (reverse rotation), the nut 22 moves along the screw 21 in the direction close to the motor 5, and the extension end 33 of the metal spring 3 slides from the third contact area P3 to the first contact area P1 and then to the second contact area P2, the motor 5 stops rotating, and the positive and negative poles of the motor 5 are connected through the diode D1 of the second contact area P2, forming a power-off protection circuit for the motor 5, which plays the role of continuous current in the coil of the motor 5, consumes the energy stored in the coil, and prevents the retained electric energy from affecting the operation of the motor 5.

[0064] In addition, it is necessary to explain that the housing used in this embodiment includes a main housing 11 for accommodating the motor 5 and a special-shaped tube body 12 connected to the main housing 11 for adapting to the screw module; the main board 42 is arranged in the main housing 11, and the induction plate 41 extends from the main housing 11 to the special-shaped tube body 12. Here, the inner hole size of the special-shaped tube body 12 is larger than the size of the nut 22, so that the nut 22 can slide back and forth along the inner hole of the special-shaped tube body 12. There is a motor 5 support block 15 in the main housing 11. When the motor 5 is installed with the main housing 11, the motor 5 support block 15 contacts the outer shell of the motor 5 to fix the motor 5; the support block uses soft rubber material, which can effectively reduce the noise generated when the motor 5 vibrates.

[0065] On the basis of the above structure, it is also necessary to explain that since the outer shell wall of the motor 5 is made of metal and is prone to short circuit, in order to prevent the outer shell wall of the motor 5 from directly contacting the flexible circuit board and causing a short circuit, an insulating plate 13 is also provided in the main housing to prevent the main board 42 from directly contacting the outer shell wall of the motor 5. That is to say, although the motor 5 needs to be welded to the main board 42 of the flexible circuit board, the outer shell of the motor 5 other than the part welded to the main board 42 will not be in direct contact with the main board 42.

[0066] In summary, the electric push rod of this embodiment not only has a miniaturized structure size, but also has a simple structure, a low failure rate in use, and is easy and efficient to assemble.

[0067] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0068] In the description of the present invention, it is necessary to understand that the terms indicating orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention 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 therefore cannot be understood as a limitation on the present invention.

[0069] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like 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 a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0070] In the present utility model, unless otherwise clearly specified and limited, the first feature being above or below the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through another feature between them. Moreover, the first feature being above, above, and above the second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being below, below, and below the second feature includes the first feature being directly below and obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

Claims

1. A screw module, characterized in that: include: A screw rod and nut assembly, comprising a screw rod and a nut adapted to reciprocate along the axial direction of the screw rod; A metal spring sheet connected to the nut so as to be adapted to move synchronously with the nut; the metal spring sheet is formed with an extension end protruding from the nut; The flexible circuit board at least comprises a sensing board; a conductive layer is arranged on the sensing 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 motor.

2. The screw rod module according to claim 1, characterized in that: The extension end is a hook-shaped structure, and the end surface of the extension end contacting the conductive layer is an arc surface.

3. The screw rod module according to claim 1 or 2, 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 bent and connected to the outer side wall of the clamping ring body; The extension end is formed on the pin.

4. The screw rod module according to claim 3, 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.

5. The screw rod module according to claim 3, 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.

6. The screw rod module according to claim 5, 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 piece is provided on the clamping portion.

7. An electric push rod, characterized in that: include: A housing, a motor disposed in the housing, and a screw module as claimed in any one of claims 1 to 6 connected to the motor; The motor is used to drive the screw of the screw module to operate.

8. The electric linear actuator according to claim 7, characterized in that: The flexible circuit board also includes a main board integrally connected to the induction board and used for being electrically connected to the motor; The mainboard is electrically connected to a direct current power supply; and the conductive layer is provided with exposed metal for contacting the extended end of the metal spring.

9. The electric linear actuator according to claim 8, characterized in that: The mainboard 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 motor to the motor; wherein Diodes are respectively disposed on the second contact region and the third contact region.

10. The electric linear actuator according to claim 9, characterized in that: When the motor rotates in the first direction and the nut moves along the screw away from the 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 motor stops rotating and the positive and negative poles of the motor are connected through the diode in the third contact area to form a motor power-off protection circuit.

11. The electric linear actuator according to claim 9, characterized in that: When the motor rotates in the second direction and the nut moves along the screw toward the motor, the extended end of the metal spring slides from the third contact area to the first contact area and then to the second contact area. The motor stops rotating and the positive and negative poles of the motor are connected through the diode in the second contact area to form a motor power-off protection circuit.

12. The electric linear actuator according to claim 8, characterized in that: The housing comprises a main housing for accommodating the motor and a special-shaped tube body connected to the main housing for adapting to the screw module; The main board is arranged in the main shell, and the induction board extends from the main shell to the special-shaped tube body.

13. The electric linear actuator according to claim 12, characterized in that: The main housing is also provided with an insulating plate for preventing the main board from directly contacting the housing wall of the motor.

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