Heavy-object-lifting structure

Abstract

[Problem] To develop a method with which it is possible, even when a nut falls due to nut wear or the like in a device for lifting and lowering a heavy object by means of a screw shaft using the nut, to supplement the nut. [Solution] Installing a main nut that moves up and down due to a rotary shaft being rotated while supporting a heavy object, and an auxiliary nut that is helically engaged with the rotary shaft on the lower side at a prescribed interval from the main nut and that follows the rotation of the main nut without supporting the heavy object, makes it possible to prevent the heavy object from falling by means of the auxiliary nut and to supplement the main nut even when the main nut falls due to wear, breakage, or the like.

Description

Heavy-duty lifting structure

[0001] The present invention relates to a device for lifting and lowering a heavy object.

[0002] Screw jacks, which raise and lower heavy objects by rotating a nut threaded onto a screw shaft, are used in a variety of fields. However, the nut may need to be raised or lowered while supporting a heavy object, or may need to maintain this support, making the nut susceptible to wear and breakage during these processes.

[0003] Here, it is conceivable that if the thread groove of the nut becomes ineffective due to wear or is damaged, the nut may fall down along with the heavy object. It would be preferable to supplement the heavy object with another nut in advance so that it can support the heavy object even in such an emergency. For example, the following prior art is disclosed as an example of an auxiliary nut.

[0004] Jikko Showa 61-1189

[0005] On the other hand, Patent Document 1 is intended to efficiently supply grease to lubricate the threaded portion, and is not intended to deal with emergencies such as the nut falling off due to wear or the like.

[0006] Therefore, the inventors of the present invention set out to develop a method for lifting and lowering a heavy object using a nut on a screw shaft, which can compensate for the nut falling off due to wear or other reasons.

[0007] As a result of intensive research by the inventors, it was discovered that by attaching an auxiliary nut that threads onto the rotating shaft at a predetermined distance below the main nut and follows the rotation of the main nut without supporting the heavy load, in addition to a main nut that moves up and down by rotating the rotating shaft while supporting the heavy load, the auxiliary nut can prevent the heavy load from falling and complement the main nut even if the main nut falls due to wear or damage, etc.

[0008] That is, the first invention of the present application is "a heavy-duty lifting device comprising: a rotating shaft having a threaded structure and arranged in a substantially vertical direction; a main nut that is threaded onto the rotating shaft and that lifts and lowers a heavy load by rotating the rotating shaft while supporting the heavy load; and an auxiliary nut that is threaded onto the rotating shaft at a predetermined distance below the main nut and that follows the rotation of the main nut without supporting the heavy load."

[0009] Next, it is preferable that the auxiliary nut can be divided into multiple pieces in the vertical direction. This divisibility allows the auxiliary nut to be attached later. In other words, the second invention of the present application is "the heavy-duty lifting device according to claim 1, wherein the auxiliary nut has a structure that allows it to be divided into multiple pieces in the vertical direction."

[0010] Next, it is preferable that the auxiliary nut can be divided into multiple parts in the vertical direction. This allows auxiliary nuts to be attached later. In other words, the third invention of the present application is "a heavy-duty lifting device according to claim 2, in which the multiple parts are divided into two parts."

[0011] Next, in order to make the auxiliary nut follow the main nut, it is preferable to use a method in which a pin provided below the main nut applies a rotational force to the auxiliary nut to make it follow the main nut. That is, the fourth invention of the present application is "a heavy-duty lifting device according to claim 1 or 2, in which a pin is provided below the main nut to make the auxiliary nut follow the main nut."

[0012] Next, the applicant also intends to use the auxiliary nut itself in the first to fourth inventions of the present application. That is, the fifth invention of the present application is "the auxiliary nut used in the heavy-duty lifting device according to any one of claims 1 to 4."

[0013] Next, the heavy-duty lifting device of the present invention is particularly suitable for use in the configurations described in the specific examples of cases in which the heavy-duty lifting device is used in the specification of this application. That is, the sixth invention of this application is "the heavy-duty lifting device according to claim 1 or 2, used as a mechanism for lifting a specific area in a conveyor system comprising: a pair of drive sprockets and driven sprockets rotatably arranged at a predetermined interval relative to a support body; a mechanism for moving the position of the driven sprocket relative to the support body; a pair of endless conveyor chains wound around the drive sprocket and driven sprockets, the upper sides of which form a conveying surface for articles; formwork frames attached at equal intervals between the pair of conveyor chains; and a mechanism for lifting a specific area on the conveying surface side of the pair of conveyor chains."

[0014] By using the heavy-duty lifting device of the present invention, even in an emergency such as when the main nut is worn or damaged, the auxiliary nut can complement the main nut, preventing the heavy object from falling.

[0015] FIG. 1 is a schematic overall front view of a first embodiment of the heavy object lifting device of the present invention, and a schematic overall front view showing changes when the device is lifted. FIG. 2 is a schematic perspective view showing the vicinity of the auxiliary nut of the first embodiment of the present invention. FIG. 3 is a schematic overall front view of the first embodiment of the present invention, and a schematic overall front view showing changes when the main nut shows wear, etc. FIG. 4 is a schematic overall front view showing the function of the confirmation pin of the first embodiment of the present invention, and a schematic overall front view showing changes. FIG. 5 is a schematic perspective view showing the divided state of the auxiliary nut of the first embodiment of the present invention. FIG. 6 is a schematic perspective view showing the divided direction of the auxiliary nut of the present invention. FIG. 7 is a schematic perspective view showing a mounting method for mounting the auxiliary nut of the present invention to a screw shaft. FIG. 8 is a schematic perspective view showing a pin fixing member (pin fixing plate) of the first embodiment of the present invention. FIG. 9 is a schematic perspective view showing another embodiment of the auxiliary nut of the present invention (when there are two pins). FIG. 10 is a schematic side view of a frying processing apparatus as an example equipped with a heavy object lifting device of the present invention. FIG. 11 is a schematic side view of a frying processing apparatus as an example equipped with a heavy object lifting device of the present invention, including a side plate.

[0032] Figure 14 is a schematic side view showing an enlarged view of the vicinity of a driven sprocket of a conveyor device in a frying processing apparatus equipped with a heavy load lifting device of the present invention. Figure 15 is a schematic perspective view of a frame connected to a conveyor chain of a conveyor device in a frying processing apparatus equipped with a heavy load lifting device of the present invention. Figure 16 is a schematic side view of a frame before lifting, showing the process of lifting the frame including a specific area of ​​the conveyor chain of the conveyor device, a track regulating rod, and a lid conveyor device for a lid in a frying processing apparatus equipped with a heavy load lifting device of the present invention. Figure 17 is a schematic side view showing the frame in the middle of lifting from Figure 14. Figure 18 is a schematic side view showing the frame having completed lifting from Figure 15.

[0016] REFERENCE SIGNS LIST 1 Rotating shaft (screw shaft) having a screw structure 3 Sprocket 5 Main nut 7 Auxiliary nut 9 Pin 11 Pin fixing member (pin fixing plate) 13 Recess 15 Support bar 17 Connecting bar 19 Confirmation pin 21 Connecting screw 23 Connecting bolt 31 Side plate 33 Heavy load lifting device 35 Support 37 Driving sprocket 39 Driven sprocket 41 Sinker 43 Wire 45 Conveyor chain 47 Formwork 49 Feeder 51 Frying tank 53 Lid 55 Track regulation rod 57 Another transport conveyor 59 Lid conveyor device 61 Frame (including lid conveyor device, etc.)

[0017] The present invention will be described below with reference to the embodiments. However, the present invention is not limited to the following embodiments. The first invention of this application is "a heavy-duty lifting device comprising: a rotating shaft having a threaded structure and arranged in a substantially vertical direction; a main nut that is threaded onto the rotating shaft and that lifts and lowers a heavy load by rotating the rotating shaft while supporting the heavy load; and an auxiliary nut that is threaded onto the rotating shaft at a predetermined distance below the main nut and that follows the rotation of the main nut without supporting the heavy load."

[0018] The details of this will be explained below. Fig. 1 is a front view showing the entire heavy-duty lifting device of the present invention. Fig. 2 is a schematic perspective view showing the vicinity of the auxiliary nut.

[0019] Rotating Shaft with Threaded Structure The heavy-duty lifting device 33 of the present invention includes a rotating shaft (screw shaft) 1 with a threaded structure. As shown in the first embodiment of FIG. 1 , the rotating shaft 1 is placed vertically and is a threaded shaft. The threaded shaft 1 has a threaded portion extending from the top to the bottom, and a cylindrical portion without thread grooves that is continuous with the threaded portion. A sprocket 3 is attached to the cylindrical portion so as to be positioned horizontally. A separate chain is attached to the sprocket 3, allowing it to rotate in conjunction with a power unit (not shown). Furthermore, bearings, gears, supports, etc. are appropriately provided to hold the threaded shaft 1 vertically and enable it to rotate.

[0020] Next, a main nut 5 that threads onto the screw shaft 1 is first attached to the screw shaft 1. A pin fixing member 11 equipped with a pin 9 that facilitates the following movement of an auxiliary nut 7, which will be described later, is attached to the lower part of the screw shaft 1. Furthermore, an auxiliary nut 7 that threads onto the screw shaft 1 is provided at a predetermined interval, and the auxiliary nut 7 is attached so that the tip of the pin 9 engages with a recess provided in the auxiliary nut 7. For convenience, in Figure 1, the main nut and pin fixing member are shown in cross section, and the pin 9 and auxiliary nut 7 are shown in front view.

[0021] Next, a cylindrical support bar 15 is attached to the main nut 5 by inserting it into the side of the main nut 5 from above, and is fixed integrally with the main nut 5 with a screw. A connecting bar 17 for connecting to a predetermined load is provided on the upper part of the cylindrical support bar 15. The load is applied to the main nut 5 via the support bar 15. On the other hand, no load is applied to the auxiliary nut 7.

[0022] --Lifting and Lowering Heavy Objects-- In a first embodiment of the present invention, a sprocket 3 attached to a screw shaft 1 is rotated to lift a heavy object upward (jack up) as shown in Figure 1. Meanwhile, the main nut 5 threaded onto the screw shaft 1 cannot rotate because the load of the heavy object is applied to it via a support bar. Therefore, when the screw shaft 1 rotates, the main nut threaded onto the screw shaft rises as shown in Figure 1. In this way, the load (heavy object) can be raised by the rise of the main nut 5.

[0023] Of course, the screw shaft can be rotated by connecting it to a predetermined motor or manually. In the first embodiment of the present invention, a chain is wound around the sprocket 3 and connected to a predetermined power unit to apply rotational force. Next, the auxiliary nut 7 is threaded onto the screw shaft 1 at a predetermined distance from the main nut 5 and the pin fixing member 11. Furthermore, the auxiliary nut 7, which engages with the main nut 5 via the pin 9, is driven by the main nut 5, so that the auxiliary nut 7 also rises as the main nut 5 rises.

[0024] In addition, under normal conditions, the auxiliary nut 7 simply follows the main nut 5 and is not subjected to any load from above. Conversely, when lowering a load (heavy object), the main nut 5 can be lowered by rotating the screw shaft in the opposite direction, and the heavy object will also be lowered.

[0025] --In the event of wear or damage to the main nut-- The heavy load lifting device 33 of the present invention employs a configuration in which, even if the above-mentioned main nut 5 is damaged or falls downward, the auxiliary nut 7 complements the main nut 5 as an emergency measure. In the configuration of the present invention, the main nut 5 is subjected to a load, making it more susceptible to wear or damage during the process of lifting or lowering the main nut. Here, as shown in Figure 3, it is conceivable that the main nut 5 may fall downward if the thread groove on the main nut side becomes non-functional due to wear or if damage occurs.

[0026] On the other hand, under normal conditions, the auxiliary nut 7 simply follows the rotation of the main nut 5 and is not subjected to any load from above, so the auxiliary nut 7 is much less likely to wear or break than the main nut 5. For this reason, if the main nut 5 falls due to wear or breakage of the thread groove of the main nut 5, it will fall the distance between it and the auxiliary nut 7, but in such an emergency, the auxiliary nut 7 can absorb this, so the fall of the load can be limited, preventing the fall of heavy objects and preventing serious damage.

[0027] If the main nut falls, the support bar 15 will also fall, so in order to detect such an abnormality, a confirmation pin 19 mechanism is provided that, under normal circumstances, penetrates horizontally through the side of the support bar 15 and directly above the upper end of the screw shaft 1, as shown in Figure 4. In the event of an abnormality, the main nut 5 and support bar 15 will fall and the confirmation pin 19 will no longer be able to be inserted, making it possible to detect an abnormality. In particular, the confirmation pin 19 mechanism is an effective confirmation method when the main nut 5 and auxiliary nut 7 cannot be seen from the outside due to a cover or the like.

[0028] --The auxiliary nut has a structure that allows it to be divided into multiple parts in the vertical direction-- In the present invention, it is preferable that the auxiliary nut 7 has a structure that allows it to be divided into multiple parts in the vertical direction. That is, for example, in the first embodiment of the present invention shown in the drawings, the auxiliary nut 7 can be divided into two parts in the vertical direction as shown in Fig. 8, and can be formed as an integral unit by attaching two connecting screws 21, one at the front and one at the back, which are inserted horizontally as shown in Fig. 5.

[0029] It should be noted that the division method is not limited to two divisions, and it may of course be three, four, or more divisions. Furthermore, "vertical divisibility" in this application means that the auxiliary nut 7 can be divided in the direction of the spiral progression of the thread groove (vertical direction), and the direction of division need not necessarily be parallel to the spiral progression of the thread groove, as shown in Figure 6, but may also be oblique or curved. Furthermore, the method of reintegrating the divided auxiliary nut 7 is not limited, and various means such as using a bolt and nut, welding, etc. are possible.

[0030] In this way, by making it possible to form the auxiliary nut 7 separable, there is an advantage in that the auxiliary nut 7 can be retrofitted to a heavy-duty lifting device that is already equipped with only the screw shaft 1 and the main nut 5. In other words, if an attempt is made to retrofit the auxiliary nut 7 to a heavy-duty lifting device for lifting or lowering a heavy load that does not have the auxiliary nut 7, that is, a state in which only the screw shaft 1 and the main nut 5 are equipped to support the heavy load, if the auxiliary nut 7 cannot be separated, it will be necessary to go through the process of removing the main nut 5 from the screw shaft 1, re-attaching the auxiliary nut 7, and then attaching the main nut 5.

[0031] Completely separating the screw shaft 1 and the main nut 5 in this way often requires moving a heavy object, making it a complicated and difficult task. On the other hand, if the auxiliary nut 7 can be separated into multiple parts, the auxiliary nut 7 can be attached after the load is already being supported by the main nut 5, as shown in Figure 7, which has the advantage of making the work easier and allowing for quick response. Furthermore, in the first embodiment of the present invention, a structure is required in which the pin 9 is inserted later. In such a case, if the auxiliary nut 7 is not separable, there is a risk of restrictions on the assembly procedure and structure. In other words, a separable structure has the advantage of allowing the auxiliary nut 7 to be attached in accordance with the position (phase) of the pin 9 to be fixed.

[0032] --Mechanism for Following the Rotation of the Main Nut-- The present invention requires a mechanism for following the auxiliary nut 7 with the main nut 5 described above. Various methods can be selected for this follower mechanism. For example, the first embodiment of the present invention discloses a method using a pin fixing member (pin fixing plate) 11 attached below the main nut. The first embodiment of the present invention shown in Figures 1 and 2 employs a two-piece pin fixing plate 11 without a thread groove 1, as shown in Figure 8, in which a connecting bolt 23 is inserted from the lower part of the plate and then inserted and fixed to the lower part of the main nut 5. Furthermore, by making it separable, it can be installed later, similar to the auxiliary nut 7 described above.

[0033] Next, the pin fixing plate 11 to which the pin 9 is fixed is fixedly attached below the main nut 5 described above, and rises and falls integrally with the main nut 5. In the first embodiment of the present invention, a recess 13 into which the pin 9 is inserted is formed in the auxiliary nut 7, and the auxiliary nut 7 is configured to rise and fall via the pin 9 as the main nut 5 rises and falls. Although the first embodiment of the present invention shows an example in which the pin fixing plate 11 is used, other methods may also be used in which the pin 9 is attached directly below the main nut 5. Of course, the number of pins 9 may be two or more, for example, as shown in FIG.

[0034] Furthermore, it goes without saying that various other methods are possible for attaching the pin 9. Furthermore, various other methods are possible for the mechanism for causing the auxiliary nut 7 to follow the up and down movement of the main nut 5, in addition to the method using the pin 9 described above.

[0035] --Specific Example of Use of the Auxiliary Nut of the Present Invention--A specific example of use of the heavy object lifting device 33 of the present invention will be described below. The present invention can be used as a device for lifting various heavy objects. For example, Figure 10 shows an example of application to a conveyor device in a frying device used in the production of instant noodles. Note that Figure 10 shows a cross-sectional view of the frying device.

[0036] In reality, the dotted line portion is covered with a side panel, and as shown in FIG. 11, the heavy-duty lifting device of the present invention is connected to the side panel.

[0037] --Overall Configuration of Frying Processing Apparatus Including Conveyor Device-- As shown in Figures 10 and 11, the conveyor device of the frying processing apparatus has a pair of drive sprockets 37 and driven sprockets 39 mounted parallel to a predetermined support 35. Of these, the pair of drive sprockets 37 are fixed to the support 35 and connected to a predetermined power unit such as a motor. The driven sprocket 39 is mounted so that it can slide horizontally. Figure 12 is an enlarged view of the heavy load lifting device of the present invention and the vicinity of the driven sprocket 39 with the side panel 31 omitted.

[0038] A hanging weight 41 is connected to the driven sprocket 39 via a wire 43, and tension acting outward relative to the conveyor device is applied. The tension of the conveyor chain 45 opposes this tension, and the driven sprocket 39 is located at the point where the two are balanced.

[0039] A pair of conveyor chains 45 are endlessly wound around the driven sprocket 39 and the driving sprocket 37, and the driving force of the driving sprocket 37 is transmitted to the driven sprocket 39. In addition to the driving sprocket 37 and the driven sprocket 39, a number of guides and sprockets are installed to regulate the direction of conveyance of the conveyor chain. Between the pair of conveyor chains 45, the upper surface serves as the conveying surface for articles, and a form (retainer) 47 is connected as shown in Figure 13, and articles to be conveyed are stored in the form and conveyed.

[0040] After the objects have been transported, the inverted form 47 is transported along the lower side of the conveyor chain 45, and this process is repeated in a circular fashion. Next, a feeder 49 for feeding objects is installed near the driven sprocket 39, and objects supplied from above are sequentially fed into the form. In particular, when producing noodle blocks for instant noodles, a noodle feeder 49 is installed, and groups of noodle strands hanging down from the upper conveyor are often cut sequentially by a rotary blade, and the cut groups of noodle strands are fed into the form near the driven sprocket 39, and this conveyor device can be suitably used for producing such noodle blocks.

[0041] On the conveyor transport surface, after the items to be fried are supplied from the feeder and transported, a lid 53 is placed over the form 47 before it enters the frying tank 51, and the form 47 enters the frying tank 51 while still holding down the top of it with the lid 53, so that the fried items do not fall out of the form 47 while being fried. Note that track-regulating bars 55 are appropriately provided inside the frying tank to regulate the track of the conveyor chain 45 in the frying tank 51. The conveyor chain 45 is configured to pass over these track-regulating bars 55, thereby fixing the transport track of the conveyor chain 45.

[0042] Furthermore, when the product is removed from the frying tank 51, the upper lid 53 is removed and the form 47 is transported alone. With the lid 53 removed, the form 47 is inverted and faces upside down at the end of the transport surface, and as shown in Figures 10 and 11, another transport conveyor 57 receives the fried products from the inverted form 47 and transfers them separately to the next process.

[0043] --Mechanism for Raising and Lowering a Predetermined Region on the Conveyor Surface of the Pair of Conveyor Chains-- The frying processing apparatus has a mechanism for raising and lowering a predetermined region of the conveyor chain 45 on the upper conveyor surface of the conveyor device. In the first embodiment of the present invention shown in Figure 1, the conveyor path of the conveyor device is provided in the frying tank 51. In food production, the frying tank must be cleaned at the end of production or when changing varieties. In this case, it is necessary to remove the conveyor chain 45 and the mold 47 connected to the conveyor chain from the conveyor path.

[0044] In this way, a mechanism is provided for raising and lowering the area of ​​the conveyor chain 45's transport surface that passes through the frying tank 51 when the conveyor chain 45 is moved. In this embodiment of the present invention, for a specific area of ​​the conveyor chain 45 located within the frying tank of the conveyor device and in its vicinity, the entire frame 61 including the track regulating rod 55 that regulates the track of the conveyor chain within the frying tank and the lid conveyor device 59 of the lid 53 is lifted upward (jacked up) by the heavy load lifting device 33 of the present invention.

[0045] The total length of the frying processing apparatus is not particularly limited, but may be, for example, approximately 10 to 30 meters, and the weight of the entire frame, including the area through which the conveyor chain passes through the frying tank and the lid conveyor device, which is lifted upward, may be approximately 2,000 to 10,000 kg. The heavy-duty lifting device 33 of the present invention can be suitably used for such heavy objects. Figures 14 to 16 show the state in which the entire frame 61, including the lid conveyor device of the frying processing apparatus, is lifted and lowered using the heavy-duty lifting device 33 of the present invention.

[0046] Three heavy-duty lifting devices 33 of the present invention are installed on each of the left and right sides of the frying processing device, for a total of six on both sides. A chain is wound around the lower sprocket 3 to rotate the screw shaft 1, and the power of a separately installed motor is transmitted to rotate the screw shaft.

[0047] Rotating the screw shaft 1 changes the position from Figure 14 to Figure 15 to Figure 16, completing the jack-up. In the state shown in Figure 16, the frying tank 51 is exposed, allowing workers to clean the inside of the frying tank. The frame is configured so that the position of the driven sprocket 39 changes during the process of raising the entire frame, allowing the entire frame to be raised smoothly. An auxiliary nut 7 is attached to the lower part of the main nut 5, and this serves to compensate for the main nut falling off due to wear or the like.

[0048] This application is based on Japanese application No. 2023-168933, filed on September 29, 2023, the contents of which are incorporated herein by reference.

Claims

1. A heavy load lifting device comprising: a rotating shaft having a screw structure and arranged in a substantially vertical direction; a main nut that screws onto the rotating shaft and lifts and lowers a heavy load by rotating the rotating shaft while supporting the heavy load; and an auxiliary nut that screws onto the rotating shaft at a specified distance below the main nut and follows the rotation of the main nut without supporting the heavy load.

2. A heavy-duty lifting device as described in claim 1, wherein the auxiliary nut has a structure that allows it to be divided into several parts vertically.

3. The heavy-duty lifting device according to claim 2, wherein the multiple sections are two sections.

4. A heavy-duty lifting device as claimed in claim 1 or 2, wherein a pin is provided at the lower part of the main nut for causing the auxiliary nut to follow the main nut.

5. The auxiliary nut used in the heavy load lifting device according to any one of claims 1 to 4.

6. A heavy load lifting device as claimed in claim 1 or 2, which is used as a mechanism for lifting and lowering a specific area in a conveyor system comprising: a pair of drive sprockets and driven sprockets rotatably arranged at a predetermined interval relative to a support body; a mechanism for moving the position of the driven sprocket relative to the support body; a pair of endless conveyor chains wound around the drive sprocket and driven sprocket and having an upper side that forms a transport surface for goods; formwork attached at equal intervals between the pair of conveyor chains; and a mechanism for lifting and lowering a specific area on the transport surface side of the pair of conveyor chains.

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