Linear actuation device with protection mechanism

Abstract

The invention relates to a linear actuating device with a protection mechanism, which comprises a motor box, a driving mechanism, a transmission mechanism and a protection structure, and is characterized in that the motor box comprises a box body, the box body is provided with a bottom plate, and the bottom plate is provided with a through hole; the driving mechanism is arranged in the box body; the transmission mechanism comprises a movement, a bearing, a placement seat and a fixing element, the movement penetrates through the through hole and is connected with the driving mechanism, the placement seat is provided with an extension plate, the extension plate is provided with a through hole, the bearing is arranged on the placement seat and sleeves the movement, the fixing element penetrates through the through hole and is fixed on the bottom plate, and the fixing element is provided with a head part; the protection structure sleeves the fixing element and is arranged between the bottom plate and the head part. Therefore, the collision damage of the object can be reduced, and the use safety can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of a linear actuator device, and in particular to a linear actuator device with a protection mechanism. Background Art

[0002] Linear actuators are used in electric beds, nursing beds, hospital beds, electric lifting tables or chairs to adjust the height or elevation angle, which is quite common. When the user encounters an obstacle during the adjustment of the aforementioned equipment, the user will contact the obstacle and generate an interaction force, which will be transmitted to the linear actuator. If the linear actuator does not stop operating immediately, the linear actuator will be damaged by the obstacle; if the obstacle is a human body, it will cause harm to the human body.

[0003] In order to solve the above problems, the industry has set up a detectable obstruction protection mechanism in the linear actuator. Among the current obstruction protection mechanisms, the ones with higher sensitivity use elements that can realize the conversion between pressure signals and electrical signals as obstruction detection elements. However, when the deformation amount at the installation position of the obstruction detection element is small, the generated deformation stress is not enough to make the obstruction detection element generate an obstruction alarm. Only after a period of time after the linear actuator and the obstacle collide, can a sufficiently large deformation stress be generated to trigger the obstruction detection element. In addition, the obstruction response speed of the existing obstruction protection mechanism is too slow, so it cannot meet the actual use requirements at this stage. Summary of the invention

[0004] One purpose of the present invention is to provide a linear actuator with a protection mechanism, which can interrupt movement after being blocked during movement, thereby reducing collision damage to objects and improving safety in use.

[0005] In order to achieve the above-mentioned purpose, the present invention provides a linear actuator with a protection mechanism, including a motor box, a driving mechanism, a transmission mechanism and a protection structure, the motor box includes a box body, the box body has a bottom plate, and a through hole is provided on the bottom plate; the driving mechanism is arranged in the box body; the transmission mechanism includes a movement, a bearing, a placement seat and a fixing element, the movement passes through the through hole and is connected to the driving mechanism, the placement seat has an extension plate, the extension plate is provided with a through hole, the bearing is arranged on the placement seat and sleeved with the movement, the fixing element passes through the through hole and is fixed to the bottom plate, and the fixing element has a head; the protection structure sleeves the fixing element and is arranged between the bottom plate and the head.

[0006] The present invention also has the following effects. Since the perforations of the extension plate are set away from the bearing sockets, it has a better amplification effect when the movement of the movement encounters resistance, so that the resistance detection function has high sensitivity and high safety and reliability. When encountering obstacles during the lifting and moving process, the movement will be subjected to an axial force and transmitted to the placement seat, so that the extension plate is stressed and compresses the protective structure, causing the elastic body to deform, thereby triggering the pressure sensor to measure the resistance. Since the pressure sensor can be set at different positions of the elastomer according to actual use requirements, and is respectively suitable for tension-type linear actuators, thrust-type linear actuators or push-pull type linear actuators, the diversity of its use is increased. When the pressure sensor fails, it only needs to remove the fixing element from the base plate to remove or replace the pressure sensor, which is more convenient to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 This is a schematic diagram of the first embodiment of the present invention applied to an electric table assembly;

[0008] Figure 2 is a perspective view of a first embodiment of the present invention;

[0009] Figure 3 It is an exploded view of the first embodiment of the present invention;

[0010] Figure 4 is a top view of the first embodiment of the present invention;

[0011] Figure 5 yes Figure 4 5-5 sectional view;

[0012] Figure 6 yes Figure 4 6-6 sectional view;

[0013] Figure 7 yes Figure 6 A magnified view of some areas;

[0014] Figure 8 is an exploded view of a second embodiment of the present invention;

[0015] Fig. 9 is a combined cross-sectional view of a second embodiment of the present invention;

[0016] Fig.10 is an exploded view of a third embodiment of the present invention;

[0017] Fig.11 is a combined cross-sectional view of a third embodiment of the present invention;

[0018] Fig.12 is an exploded view of a fourth embodiment of the present invention;

[0019] Fig.13 is a combined cross-sectional view of a fourth embodiment of the present invention;

[0020] Fig.14 is an exploded view of a fifth embodiment of the present invention;

[0021] Fig.15 is a combined sectional view of a fifth embodiment of the present invention;

[0022] Fig.16 is an exploded view of a sixth embodiment of the present invention;

[0023] Fig.17 is a combined cross-sectional view of a sixth embodiment of the present invention;

[0024] Fig.18 It is a combined cross-sectional view of another embodiment of the protection structure of the present invention;

[0025] Wherein, the reference numerals are:

[0026] 1: Linear actuator;

[0027] 10: Motor box;

[0028] 11: box body;

[0029] 111: Bottom plate

[0030] 112: side panel;

[0031] 113: cavity;

[0032] 114: through hole;

[0033] 115: screw hole;

[0034] 116: buckle slot;

[0035] 12: cover body;

[0036] 121: buckle hook;

[0037] 20: driving mechanism;

[0038] 21: Motor;

[0039] 22: reduction gear set;

[0040] 23: screw;

[0041] 30: transmission mechanism;

[0042] 31: Movement;

[0043] 311: lead screw;

[0044] 312: hollow tube;

[0045] 313: nut;

[0046] 32: bearing;

[0047] 33: placement seat;

[0048] 331: bearing socket;

[0049] 332: extension plate;

[0050] 333: perforation;

[0051] 34: fixing element;

[0052] 341: head;

[0053] 40, 40A: protection structure;

[0054] 41, 41A, 41B: elastomer;

[0055] 411: hole;

[0056] 412: first elastic pad;

[0057] 413: second elastic pad;

[0058] 414: groove;

[0059] 42: pressure sensor;

[0060] 421: hole;

[0061] 43: plunger;

[0062] 431: hollow column;

[0063] 432: flange;

[0064] 8: Electric table;

[0065] 81: lifting column;

[0066] 811: telescopic tube assembly;

[0067] 82: Table top. DETAILED DESCRIPTION

[0068] The detailed description and technical contents of the present invention are described as follows with reference to the accompanying drawings. However, the drawings are only provided for reference and description and are not intended to limit the present invention.

[0069] See also Figures 1 to 7As shown, the present invention provides a linear actuator with a protection mechanism, which is applied on an electric table 8. The electric table 8 includes at least one lifting column 81 and a table top 82. The lifting column 81 includes a linear actuator 1 with a protection mechanism and a telescopic tube assembly 811. The linear actuator 1 with a protection mechanism mainly includes a motor box 10, a driving mechanism 20, a transmission mechanism 30 and a protection structure 40.

[0070] Please read first Figures 2 to 5 The motor box 10 is roughly rectangular, and mainly includes a box body 11 and a cover body 12. The box body 11 has a bottom plate 111 and a plurality of side plates 112 connected to the bottom plate 111. A cavity 113 is enclosed in the bottom plate 111 and the side plates 112. A through hole 114 and a plurality of screw holes 115 are provided in the bottom plate 111. In addition, a plurality of buckle grooves 116 are provided in each side plate 112. The cover body 12 is a cover corresponding to the box body 11. A plurality of buckle hooks 121 corresponding to the buckle grooves 116 are extended around the cover body 12.

[0071] The driving mechanism 20 is accommodated in the cavity 113 of the box body 11, and it mainly includes a motor 21 and a reduction gear set 22. The motor 21 is a component that can produce forward and reverse rotation. The reduction gear set 22 is connected to one end of the motor 21, and it can be in the form of a worm gear or the like.

[0072] The transmission mechanism 30 mainly includes a movement 31, a bearing 32, a placement seat 33 and two fixing elements 34. The movement 31 mainly includes a lead screw 311, a hollow tube 312 and a nut 313. The nut 313 is fixed to one end of the hollow tube 312 and is threadedly connected with the lead screw 311 for transmission. The lead screw 311 penetrates into the box body 11 from the aforementioned through hole 114 to connect with the driving mechanism 20. The aforementioned driving mechanism 20 is locked on the top of the placement seat 33 by screws 23. The placement seat 33 has a bearing socket 331 and two extension plates 332 protruding from the bearing socket 331 in opposite directions. A through hole 333 is respectively provided at the end of each extension plate 332; the fixing element 34 of this embodiment is a screw having a head 341. The bearing 32 is disposed in the bearing socket 331 and sleeved on the lead screw 311 . The placement seat 33 is fixed by the fixing elements 34 penetrating the through holes 333 and locking the screw holes 115 , and the head 341 of the fixing element 34 is used to press the upper side of the extension plate 332 .

[0073] Please continue reading Figure 6 and Figure 7The protective structure 40 of this embodiment is sleeved with the aforementioned fixing element 34 and is between the bottom plate 111 and the extension plate 332, and mainly includes an elastic body 41 and a pressure sensor (pressure-sensitive sensor) 42. The elastic body 41 can be a rubber cushion, which has a hole 411. The pressure sensor 42 also has a hole 421 (i.e., another hole), which is pasted on the lower surface of the elastic body 41. The elastic body 41 and the pressure sensor 42 are sleeved with the aforementioned fixing element 34 through their holes 411 and 421, and are clamped between the extension plate 332 and the bottom plate 111. In this way, when the elastic body 41 is compressed, a pre-pressure is generated in the pressure sensor 42. The aforementioned configuration structure is suitable for a thrust type linear actuator.

[0074] In one embodiment, the pressure sensor 42 may be a resistance strain gauge pressure sensor. When a force is applied to the elastic body 41, the pressure sensor 42 will be deformed, thereby causing a change in resistance value. The change in resistance value is processed by a control device (not shown) and output in the form of an electrical signal. The common types are metal resistance strain gauges and semiconductor strain gauges.

[0075] When in use, when the lifting column 81 encounters an obstacle during the upward movement, the pressure sensor 42 will feel the pre-pressure of the elastic body 41 being compressed. When the lifting column 81 increases the load, the extension plate 332 of the placement seat 33 will further compress the elastic body 41, the pressure on the pressure sensor 42 increases, and its resistance value decreases. When the lifting column 81 reduces the load, the compression of the elastic body 41 by the extension plate 332 of the placement seat 33 decreases, the pressure on the pressure sensor 42 decreases, and its resistance value increases.

[0076] When the lifting column 81 is subjected to a load change, the amount of compression of the elastic body 41 by the extension plate 332 of the placement seat 33 also changes, thereby causing the pressure of the elastic body 41 on the pressure sensor 42 to change. When the pressure of the pressure sensor 42 changes, the resistance value changes accordingly; the lifting column 81 is protected by controlling the device to cut off the power or to make the motor 21 rotate in the opposite direction.

[0077] See also Figure 8 and Fig. 9As shown, the linear actuator with a protection mechanism of this embodiment is substantially the same in structure as the first embodiment described above, with the difference being that: there are two protection structures 40, which are respectively disposed between the two extension plates 332 of the placement seat 33 and the bottom plate 111, and each pressure sensor 42 is respectively adhered to the upper surface of each elastomer 41, and each elastomer 41 and each pressure sensor 42 is sleeved on each fixing element 34 through its holes 411 and 421, and is clamped between each extension plate 332 and the bottom plate 111. The aforementioned configuration structure is applicable to a tension type linear actuator.

[0078] See also Fig.10 and Fig.11 As shown, the difference between the linear actuator with protection mechanism of this embodiment and the above-mentioned embodiments is that the protection structure 40 mainly includes an elastic body 41A and a pressure sensor 42. The elastic body 41A includes a first elastic pad 412 and a second elastic pad 413. The first elastic pad 412 is arranged between the extension plate 332 of the placement seat 33 and the bottom plate 111 of the box body 11, and the second elastic pad 413 is arranged between the head 341 of the fixing element 34 and the extension plate 332 of the placement seat 33. The pressure sensor 42 is arranged between the head 341 of the fixing element 34 and the second elastic pad 413.

[0079] See also Fig.12 and Fig.13 As shown, the difference between the linear actuator with a protection mechanism of this embodiment and the aforementioned embodiments is that: the protection structure 40 mainly includes an elastic body 41B and a pressure sensor 42, the elastic body 41B has an embedding groove 414, and the through hole 333 of the extension plate 332 is embedded through the embedding groove 414, so that part of the elastic body is formed on the upper and lower sides of the extension plate 332 respectively, and the pressure sensor 42 is arranged between the head 341 of the fixing element 34 and the upper surface of the elastic body 41B.

[0080] See also Fig.14 and Fig.15 As shown, the difference between the linear actuator with a protection mechanism of this embodiment and the aforementioned fourth embodiment is that: the protection structure 40 also includes a plunger 43, which has a hollow column 431 and a flange 432 radially extending from one end of the hollow column 431, wherein the hollow column 431 passes through the hole 411 of the aforementioned elastomer 41B, and the elastomer 41B is positioned between the flange 432 and the bottom plate 111 of the box body 11, and the pressure sensor 42 is arranged between the flange 432 of the plunger 43 and the upper surface of the elastomer 41B.

[0081] See also Fig.16 and Fig.17As shown, the difference between the linear actuator with a protection mechanism of this embodiment and the aforementioned third embodiment is that: the protection structure 40 mainly includes an elastomer 41A and a pressure sensor 42, the elastomer 41A includes a first elastic pad 412 and a second elastic pad 413, the first elastic pad 412 is arranged between the extension plate 332 of the placement seat 33 and the bottom plate 111 of the box body 11, and the second elastic pad 413 is arranged between the head 341 of the fixing element 34 and the extension plate 332 of the placement seat 33; wherein the pressure sensor 42 is configured between the second elastic pad 413 and the extension plate 332 of the placement seat 33.

[0082] See also Fig.18 As shown, the difference between the protection structure 40A of this embodiment and the aforementioned embodiments is that the protection structure 40A mainly includes an elastomer 41 and a pressure sensor 42. The pressure sensor 42 is embedded in the elastomer 41, and the hole 421 of the pressure sensor 42 is configured corresponding to the hole 411 of the elastomer 41. The aforementioned configuration structure is applicable to a push-pull type linear actuator.

[0083] The above description is only a preferred embodiment of the present invention and is not intended to limit the patent scope of the present invention. Other equivalent changes that apply the patent spirit of the present invention should all fall within the patent scope of the present invention.

Claims

1. A linear actuator with a protection mechanism, It is characterized in that include: A motor box, comprising a box body, the box body having a bottom plate, and a through hole is provided in the bottom plate; A driving mechanism, disposed in the box body; A transmission mechanism, comprising a movement, a bearing, a placement seat and a fixing element, wherein the movement passes through the through hole and is connected to the driving mechanism, the placement seat has an extension plate, the extension plate has a through hole, the bearing is arranged on the placement seat and sleeved with the movement, the fixing element passes through the through hole and is fixed to the bottom plate, and the fixing element has a head; and A protection structure is provided to cover the fixing element and is arranged between the bottom plate and the head.

2. The linear actuator with protection mechanism according to claim 1, It is characterized in that The placement seat also has a bearing socket, the extension plate extends out from the bearing socket, and the bearing is arranged in the bearing socket.

3. The linear actuator with protection mechanism according to claim 2, It is characterized in that The protection structure includes an elastic body and a pressure sensor. The elastic body and the pressure sensor are located between the bottom plate and the extension plate and are stacked on each other.

4. The linear actuator with protection mechanism according to claim 3, It is characterized in that The pressure sensor is located between the base plate and the elastic body.

5. The linear actuator with protection mechanism according to claim 3, It is characterized in that The pressure sensor is located between the elastic body and the extension plate.

6. The linear actuator with protection mechanism according to claim 2, It is characterized in that The extension plate and the protection structure are both in plurality.

7. The linear actuator with a protection mechanism according to claim 2, It is characterized in that The protection structure includes a first elastic pad and a second elastic pad, wherein the first elastic pad is located between the extension plate and the bottom plate, and the second elastic pad is arranged between the head and the extension plate.

8. The linear actuator with protection mechanism according to claim 7, It is characterized in that The protection structure further includes a pressure sensor, which is located between the head and the second elastic pad.

9. The linear actuator with protection mechanism according to claim 7, It is characterized in that The protection structure further includes a pressure sensor, and the pressure sensor is located between the second elastic pad and the extension plate.

10. The linear actuator with a protection mechanism according to claim 2, It is characterized in that The protection structure includes an elastic body and a pressure sensor. The elastic body has an embedding groove, and the extension plate is embedded in the embedding groove through the through hole.

11. The linear actuator with a protection mechanism according to claim 10, It is characterized in that The pressure sensor is located between the head and the elastic body.

12. The linear actuator with a protection mechanism according to claim 10, It is characterized in that The protection structure also includes a plunger having a hollow column and a flange radially extending from one end of the hollow column. The hollow column passes through the elastomer and is positioned between the flange and the base plate. The pressure sensor is arranged between the flange and the elastomer.

13. The linear actuator with a protection mechanism according to claim 1, It is characterized in that The protection structure includes an elastic body and a pressure sensor, and the pressure sensor is embedded in the elastic body.

14. The linear actuator with protection mechanism according to claim 13, It is characterized in that The elastic body has a hole, and the pressure sensor has another hole, and the other hole of the pressure sensor is configured corresponding to the hole of the elastic body.

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