Overload protection mechanism for lifting platform

Abstract

The utility model relates to an overload protection mechanism for a lifting platform, a bearing table of the overload protection mechanism comprises a fixed plate and a movable plate, and a plurality of springs and a plurality of screw rods are arranged between the fixed plate and the movable plate. And the sensing unit comprises a plurality of sensor bodies and movable parts matched with the sensor bodies. A boss and a threaded hole are formed in the upper end face of the fixing plate. A first counter bore is formed in the end face of the boss, and side grooves are formed in the corners of the boss. A second counter bore matched with the first counter bore is formed in the lower end face of the movable plate, and the two ends of the spring are inserted into the second counter bore and the first counter bore. A convex arm matched with the side groove in the boss is formed on the periphery of the counter bore II; and the convex arm can be inserted into the side groove. The movable plate is limited on the fixed plate through the screw rod, and the spring can support the movable plate so that a gap can be formed between the movable plate and the opposite face of the boss. The sensor bodies are arranged on the four side faces of the fixing plate. The movable part is arranged on the side face of the movable plate. The problem that early warning and intervention cannot be timely and effectively achieved when the lifting platform encounters an overload operation condition is solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to scissor type hydraulic lifting device field, concretely relates to a kind of lifting platform overload protection mechanism. BACKGROUND

[0002] Scissor type hydraulic lifting platform is a kind of for wharf, workshop, freight station and the lifting device of other places for the loading and unloading and transportation of goods, and daily engineering operation.Scissor type hydraulic lifting platform has many advantages, such as stable structure, low failure rate, reliable operation, safe and efficient, simple and convenient maintenance, and is widely used in various trades.

[0003] When using in goods lifting and conveying industry, scissor type hydraulic lifting platform needs to be used safely within its designed rated load range.As existing scissor type hydraulic lifting platform does not have overload protection function, load is identified by worker calculation or estimation when using, which is prone to overload operation situation.Long-term frequent operation under overload condition, main structure (such as scissor arm, pivot, etc.) of scissor type hydraulic lifting platform is prone to heavy damage, which becomes a safety hazard. CONTENT OF UTILITY MODEL

[0004] In view of the problem that existing scissor type hydraulic lifting platform cannot realize effective intervention when encountering overload operation condition, the utility model provides a kind of lifting platform overload protection mechanism, which can early warning before goods overload and prohibit lifting platform start operation to realize overload protection purpose.

[0005] The technical scheme adopted by the utility model to solve its technical problems is: a kind of lifting platform overload protection mechanism, including scissor arm unit, hydraulic cylinder unit, support platform, sensing unit and control unit.

[0006] Control unit contains control module capable of controlling the operating state of hydraulic cylinder unit, and setting module and processing module matched with sensing unit, and setting module can set early warning interval or early warning threshold, and processing module can analyze and process sensing signal fed back by sensing unit.

[0007] Support platform includes fixed plate matched with upper pivot of scissor arm unit on left and right end side, movable plate arranged on the upper part of fixed plate, multiple springs arranged between fixed plate and movable plate, and multiple screw rods connecting fixed plate and movable plate.

[0008] Multiple bosses and threaded holes are formed on the upper end surface of fixed plate, and the bosses and threaded holes are distributed as multiple rows and multiple columns respectively.It is preferred that the bosses are evenly distributed as multiple rows and multiple columns.The threaded holes are relatively distributed between the two bosses adjacent to each other on the left and right.Sink hole one is formed on the upper end surface of boss, and side groove is formed at at least one pair of diagonal corner of boss.

[0009] A second counterbore is formed on the lower end surface of the movable plate and corresponds to the first counterbore, and the two ends of the spring are respectively inserted into the second counterbore and the first counterbore. Therefore, the first counterbore, the second counterbore and the number of springs are one-to-one corresponding. A convex arm is formed on the periphery of each second counterbore and corresponds to the plurality of side grooves on each boss, so that the convex arm is inserted into the side groove and forms a profile contact matching relationship with the side groove, which can guide the movable plate to move vertically relative to the fixed plate. The extension length of the convex arm in the vertical direction is less than the extension depth of the side groove in the vertical direction, so that after the movable plate is fixed directly above the fixed plate, there is always a vertical distance between the lower end of the convex arm and the bottom surface of the side groove, which can provide sufficient stroke space for the movable plate to move downward relative to the fixed plate.

[0010] A through hole is formed on the movable plate and corresponds to the screw rod, and the lower end of the rod body of the screw rod passes through the through hole and matches the threaded hole on the fixed plate, so that the fixed plate and the movable plate are connected as a whole, the vertical distance is formed between the boss and the opposite surface of the movable plate, and the spring is kept in a compressed state. That is, after the movable plate is connected above the fixed plate by the screw rod, the spring is compressed and can support the movable plate suspended directly above the fixed plate.

[0011] When the goods / heavy objects are placed on the upper end surface of the movable plate, the goods / heavy objects can press the movable plate downward, so that the spring is further compressed and the vertical distance between the lower end surface of the movable plate and the upper end surface of the boss is reduced.

[0012] The sensing unit includes a plurality of sensor bodies and a movable part corresponding to the plurality of sensor bodies.

[0013] The sensor bodies are respectively arranged on the four side surfaces of the fixed plate. When there is only one sensor body on each side surface, the sensor body is preferably arranged at the lengthwise or widthwise central position of each side surface. The movable part is fixedly arranged on the side surface of the movable plate and is directly above the corresponding sensor body. The lower end of the movable part matches the sensor body and can touch the sensor body to generate a sensing signal.

[0014] Optionally, the number of sensor bodies arranged on the lengthwise side surface of the fixed plate is more than the number of sensor bodies arranged on the widthwise side surface of the fixed plate. For example, one sensor body can be arranged on the widthwise side surface of the fixed plate, and two or three sensor bodies can be arranged on the lengthwise side surface of the fixed plate.

[0015] Optionally, at least one square (including rectangular and square) groove is formed on the upper end surface of the fixed plate at the edge, and an elastic strip is fixedly embedded in the groove.

[0016] After the movable plate is connected to the upper part of the fixed plate, the elastic strip can be pressed between the opposite surfaces of the fixed plate and the movable plate, and the opposite surfaces of the two plates can be sealed. The elastic strip protrudes in the vertical direction and the upper end of the opposite surface relative to the edge position of the fixed plate protrudes a certain height upward. When the movable plate is pressed by the gravity of the goods and moves downward relative to the fixed plate, the elastic strip can be compressed and deformed, and the deformation amount can increase with the increase of the stroke amount of the downward movement of the movable plate.

[0017] Optionally, an elastic rubber layer is fixedly arranged on the upper end surface of the movable plate. A counterbore three capable of accommodating at least the cap portion of the screw is formed at the upper end of the through hole arranged on the movable plate and matched with the screw. The elastic rubber layer can cover the counterbore three and the cap of the screw.

[0018] Optionally, the sensor body is a strain sensor body or a grating sensor body. The movable part is matched with a strain elastic body on the strain sensor body, and can elastically deform the strain elastic body by pushing downward, so that the strain sensor body generates a sensing signal; or a movable grating is fixedly arranged at the lower end of the movable part, and the movable part can extend into the grating sensor body and be matched with a fixed grating, and the movable part can cause the relative position between the movable grating and the fixed grating to change when moving downward, so that the grating sensor body generates a sensing signal.

[0019] The utility model discloses beneficial effects are: the utility model is helpful to solve the existing lifting platform, when encountering overload operating condition, can not realize effective intervention and the problem of overloading protection.

[0020] The utility model discloses beneficial effects are: the utility model is helpful to solve the existing lifting platform, when encountering overload operating condition, can not realize effective intervention and the problem of overloading protection. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is the structural schematic diagram of the utility model.

[0022] Figure 2 It is Figure 1 It is the partial close -up structure schematic diagram of I.

[0023] Figure 3 It is the overhead structure schematic diagram of fixed plate.

[0024] Figure 4 It is Figure 3 It is the section structure schematic diagram of A-A.

[0025] Figure 5 It is with Figure 4The cross-sectional view of the fixed plate corresponds to the cross-sectional structural diagram of the matching movable plate.

[0026] In the figure: 10 scissor arm unit; 20 hydraulic cylinder unit; 30 supporting platform, 31 fixed plate, 311 upper end surface, 312 boss, 313 countersunk hole 1, 314 side groove, 315 threaded hole, 316 groove, 32 movable plate, 321 lower end surface, 322 countersunk hole 2, 323 boss, 324 countersunk hole 3, 33 spring, 34 elastic rubber layer, 35 screw; 40 sensor unit, 41 sensor body, 42 movable part. DETAILED DESCRIPTION

[0027] The structures, proportions, sizes, etc. illustrated in the drawings of the specification are only used to match the contents disclosed in the specification for the understanding and reading of those familiar with this technology. They are not used to limit the conditions for the implementation of the utility model and therefore have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed in the utility model without affecting the efficacy and purpose of the utility model. At the same time, terms such as "upper", "lower", "front", "back", and "middle" quoted in this specification are only for the convenience of description and are not used to limit the scope of the implementation of the utility model. Changes or adjustments in their relative relationships should also be considered as the scope of the implementation of the utility model without substantially changing the technical content.

[0028] like Figures 1 to 5 The illustrated lifting platform overload protection mechanism includes a scissor arm unit 10, a hydraulic cylinder unit 20, a supporting platform 30, a sensor unit 40 and a control unit (not shown in the figure).

[0029] The control unit contains a control module capable of controlling the operating status (start, stop, etc.) of the hydraulic cylinder unit 20, as well as a setting module and a processing module matched with the sensor unit 40. The setting module can set a warning interval (related to the load) or a warning threshold, and the processing module can analyze and process the sensor signal fed back by the sensor unit 40.

[0030] The support platform 30 includes a fixed plate 31 whose left and right ends match the upper pivot of the scissor arm unit 10, a movable plate 32 arranged on the upper part of the fixed plate 31, a plurality of springs 33 arranged between the fixed plate 31 and the movable plate 32, an elastic rubber layer 34 attached to the upper end surface of the movable plate 32, and a plurality of screws 35 connecting the fixed plate and the movable plate.

[0031] A plurality of bosses 312 and threaded holes 315 are formed on the upper end surface 311 of the fixed plate 31, and the bosses 312 and the threaded holes 315 are respectively distributed in multiple rows and multiple columns, and specifically, the bosses 312 are distributed in three rows and seven columns, and the threaded holes 315 are distributed in four rows and six columns.

[0032] Preferably, the bosses 312 are evenly distributed in multiple rows and multiple columns, so that the movable plate 32 is stably and reliably supported by the matched springs 33, and the upper end surface of the movable plate can be better ensured to be substantially horizontal and not easily inclined. The threaded holes 315 can be relatively distributed between the left and right adjacent two bosses 312, so that the threaded rods 35 matched with the threaded holes 315 can uniformly exert pressure on the movable plate 32, and the upper end surface of the movable plate 32 can be ensured to be always kept in a substantially horizontal state.

[0033] A counterbore 313 is formed on the upper end surface of the boss 312, and a side groove 314 is formed at each of the four corners of the boss 312.

[0034] A counterbore 322 corresponding to the counterbore 313 is formed on the lower end surface of the movable plate 32, and the two ends of the spring 33 are respectively inserted into the counterbores 322 and 313 on the upper and lower sides. Therefore, the number of the counterbores 313, the counterbores 322 and the springs 33 is one-to-one corresponding.

[0035] A convex arm 323 corresponding to the multiple side grooves 314 on each boss 312 is formed on the periphery of each counterbore 312, so that the convex arm 323 is inserted into the side groove 314 and forms a profile contact matching relationship with the side groove 314, and can guide the movable plate 32 to move in the vertical direction relative to the fixed plate 31.

[0036] The extension length of the convex arm 323 in the vertical direction is less than the extension depth of the side groove 314 in the vertical direction, so that after the movable plate 32 is fixed directly above the fixed plate 31, a vertical spacing can always exist / remain between the lower end surface of the convex arm 323 and the bottom surface of the side groove 314, which can provide sufficient stroke space for the movable plate 32 to move downward relative to the fixed plate 31.

[0037] The movable plate 32 is provided with a through hole corresponding to the screw rod 35, and the lower end of the rod of the screw rod 35 passes through the through hole and matches with the threaded hole 315 on the fixed plate 31, so that the fixed plate 31 and the movable plate 32 are connected as a whole, the boss 312 and the opposite surface of the movable plate 32 form a vertical spacing, and the spring 33 is kept in a compressed state. That is, after the movable plate 32 is connected above the fixed plate 31 by the screw rod 35, the spring 33 is compressed and can support the movable plate 32 suspended above the fixed plate 31. When the goods / heavy objects are placed on the upper end surface of the movable plate 32, the goods / heavy objects can press the movable plate 32 downward, so that the spring 33 is further compressed, and the vertical spacing between the lower end surface of the movable plate 32 and the upper end surface of the boss 312 is reduced.

[0038] The sensing unit 40 includes a plurality of (six in the figure) sensor bodies 41 and movable parts 42 corresponding to the plurality of sensor bodies 41 one by one.

[0039] The sensor bodies 41 are respectively arranged on the four sides of the fixed plate 31. When there is only one sensor body 41 on each side, the sensor body 41 is preferably arranged at the lengthwise or widthwise central position of each side. The movable part 42 is fixedly arranged on the side of the movable plate 32 and is located above the corresponding matched sensor body 41. The lower end of the movable part 42 matches with the sensor body 41 and can touch the sensor body 41 to generate a sensing signal.

[0040] With the utility model, as the goods on the upper end face of the movable plate 32 increase, the compression degree of the spring 33 gradually increases, the vertical distance between the lower end face of the movable plate 32 and the upper end face of the boss 312 gradually decreases, and the movable part 42 touches the sensor body 41 to change the sensing signal. After the control unit analyzes and processes the sensing signal, the amount of downward movement of the movable plate 32 can be determined according to the sensing signal, and compared with the set early warning threshold value. If the early warning threshold value is not reached, there is no overload, and if the early warning threshold value is reached, the control unit makes the control module that controls the operating state of the hydraulic cylinder unit 20 lose power, so that the hydraulic cylinder unit 20 cannot start operating. The set early warning threshold value can be multi-level, the primary early warning threshold value indicates that the actual load is close to the rated load, and the final early warning threshold value indicates that the actual load has exceeded the rated load, and at that time the control unit should issue an instruction to make the control module that controls the operating state of the hydraulic cylinder unit lose power, so that the hydraulic cylinder unit 20 cannot start operating. It should be noted that the setting of the specific early warning threshold value, the analysis and processing of the sensing signal, and the association with the early warning threshold value are all program settings and method level content. Based on the structural features of the utility model, a variety of different schemes can be used. Since it is not the focus of the technical improvement of the utility model, it should not be considered as a limitation of the protection scope of the utility model.

[0041] The number of sensor bodies 41 arranged on the lengthwise side of the fixed plate 31 is greater than the number of sensor bodies 41 arranged on the widthwise side of the fixed plate 31. As shown in the drawings, one sensor body 41 is arranged on the widthwise side of the fixed plate 31, and two sensor bodies 41 are arranged on the lengthwise side of the fixed plate 31.

[0042] On the upper end face of the fixed plate 31, three rows of square (including rectangular and square) grooves 316 are formed at the edges, and an elastic strip is fixedly embedded in each row of grooves 316.

[0043] After the movable plate 32 is connected to the upper part of the fixed plate 31, the elastic strip can be compressed between the opposite faces of the fixed plate 31 and the movable plate 32, and can seal and elastically support the opposite faces of the two plates. The elastic strip protrudes in the vertical direction and protrudes upward by a certain height relative to the upper end face of the edge position of the fixed plate 31. When the movable plate 32 is compressed by the weight of the goods and moves downward relative to the fixed plate 31, the elastic strip can be compressed and deformed, and the deformation amount can increase with the increase of the stroke amount of the downward movement of the movable plate 32.

[0044] A third countersunk hole 324 capable of accommodating the nut portion of the screw 35 can be formed at the upper end of the through hole provided on the movable plate 32 and matching the screw 35. The elastic rubber layer can cover the third countersunk hole 324 and the nut of the screw 35.

[0045] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. The present invention is susceptible to numerous improvements without departing from the overall concept. Those skilled in the art will appreciate the potential for modification or alteration of the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations accomplished by those skilled in the art without departing from the spirit and technical principles disclosed herein shall be encompassed by the claims of the present invention.

Claims

1. An overload protection mechanism for an elevating platform, comprising a scissor arm unit, a hydraulic cylinder unit, a supporting platform and a control unit; the supporting platform comprises a fixed plate matched with the pivot of the scissor arm unit; the control unit comprises a control module capable of controlling the operating state of the hydraulic cylinder unit; characterized in that: The sensor unit comprises a plurality of sensor bodies and a movable part corresponding to the sensor bodies; The control unit further comprises a setting module and a processing module corresponding to the sensor unit, the setting module is capable of setting a pre-warning threshold, and the processing module is capable of analyzing and processing the sensing signals fed back by the sensor unit; The supporting table further comprises a movable plate arranged on the upper portion of the fixed plate, a plurality of springs arranged between the fixed plate and the movable plate, and a plurality of screw rods connecting the fixed plate and the movable plate; A plurality of bosses and threaded holes are formed on the upper end surface of the fixed plate, and the bosses and the threaded holes are distributed in multiple rows and multiple columns respectively; a counterbore one is formed on the upper end surface of the boss, and a side groove is formed at at least one pair of opposite corner edges of the boss; A counterbore two corresponding to the counterbore one is formed on the lower end surface of the movable plate, and the two ends of the spring are respectively inserted into the counterbores two and one opposite to each other; a protruding arm corresponding to the plurality of side grooves on the boss is formed on the periphery of the counterbore two, so that the protruding arm can be inserted into the side groove and form a profile contact matching relationship with the side groove; the length of the protruding arm is less than the depth of the side groove; A through hole corresponding to the screw rod is formed on the movable plate, and the screw rod passes through the through hole and matches the threaded hole on the fixed plate, so that the spring can be compressed and a vertical spacing is formed between the opposite surfaces of the boss and the movable plate; The sensor bodies are arranged on the four side surfaces of the fixed plate; the movable part is fixedly arranged on the side surface of the movable plate and is located above the sensor bodies; the lower end of the movable part matches the sensor body.

2. An overload protection mechanism for a lift platform as claimed in claim 1, wherein: The number of sensor bodies arranged on the lengthwise side surface of the fixed plate is greater than the number of sensor bodies arranged on the widthwise side surface of the fixed plate.

3. An overload protection mechanism for a lifting platform according to claim 1 or 2, characterized in that: On the upper end surface of the fixed plate, at least one circle of square frame-shaped grooves is formed at the edge, and a resilient strip is fixedly embedded in the groove; the resilient strip can be squeezed between the opposite surfaces of the fixed plate and the movable plate.

4. An overload protection mechanism for a lifting platform according to claim 1 or 2, characterized in that: An elastic rubber layer is fixedly arranged on the upper end surface of the movable plate.

5. An overload protection mechanism for a lift platform as claimed in claim 4, wherein: A counterbore three capable of accommodating at least the cap portion of the screw rod is formed at the upper end port of the through hole corresponding to the screw rod arranged on the movable plate; the elastic rubber layer can cover the counterbore three and the cap of the screw rod.

6. An overload protection mechanism for a lifting platform according to claim 1 or 2, characterized in that: The sensor body is a strain sensor body; the movable part matches the strain elastic body on the strain sensor body, and can push and press the strain elastic body downward to cause elastic deformation, so that the strain sensor body generates a sensing signal.

7. An overload protection mechanism for a lifting platform according to claim 1 or 2, characterized in that: The sensor body is a grating sensor body; a movable grating is fixedly arranged at the lower end of the movable part, and the movable part can carry the movable grating to extend into the grating sensor body and match a fixed grating; when the movable part moves downward, the relative position between the movable grating and the fixed grating changes, so that the grating sensor body generates a sensing signal.

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