JP2005067765A - Lifting device for stirrer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a screw type lifting device for a stirrer capable of eliminating chattering, removing a splash preventive cover for a lubricating oil, eliminating necessity for the maintenance work during the operation, heightening the certainty of the operation by simplifying the constitution of the whole device, and suppressing low the cost of fabrication. <P>SOLUTION: The lifting device for the stirrer is to lift and sink a receptacle seat to support an eccentric load through the drive of screw rods, wherein two guide shafts are installed upright on one side of the receptacle seat, and two screw rods set over on a machine frame and the guide shafts are put in screw engagement coaxially, and thereby the seat is made practicable to lift and sink along the guide part of the machine frame together with the guide shafts, and the screw rod is coupled with the driving source. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is agitated in a mixer such as a food production mixer, a pharmaceutical mixer, or a chemical substance mixer, or a machine for stirring and separating substances (collectively referred to as “stirrer”). The present invention relates to an elevating device used for raising and lowering a receiving seat of a stirring container where the weight of a container containing a substance (hereinafter referred to as “stirring container”) is applied as an offset load.

  Conventionally used elevating devices for stirrers are shown in FIGS. In this conventional apparatus, as shown in a side view of FIG. 6 and a plan view of FIG. A stirring vessel containing a chemical substance or the like was attached, the contents were raised to stir the contents, and when the stirring was completed, the receiving seat 28 was lowered and the stirring vessel was removed. Therefore, the weight of the stirring container and its contents is applied to the receiving seat 28 as an offset load.

  And the raising / lowering of the receiving seat 28 was performed by rotation of the screw rod 21 installed in the inside of the machine casing 51. Since the screw rods are prone to chatter as described later, it was considered to adopt a hydraulic drive mechanism, but when actually making a hydraulic prototype, the hydraulic mechanism requires periodic inspection, and parts are required during periodic inspection. Since the oil splatters around when removing, the contamination cannot be adopted for this kind of stirrer, which is the biggest contraindication problem. In addition, in the lifting device for the agitator, it is necessary to stop the stirring container at an arbitrary position during the lifting operation, and to inspect or add the contents. In the hydraulic type, unlike the screw type, the right side during the lifting operation is required. It was not easy to pause.

Therefore, the conventional screw type is preferable for the drive mechanism. However, the screw type has a problem in that minute vibration occurs and noise is generated when the receiving seat 28 is lowered. This is referred to as chatter, and there is a long-awaited expectation in the related industries for an effective solution to eliminate this chatter.
This is because when the chatter occurs, the receiving seat 28 makes a rattling sound and descends while vibrating in small increments. And various damage is given to each part of an apparatus. The most important of these is that the thread of the female screw made of gunmetal or the like is rapidly worn by this chattering and cannot be engaged with the screw rod.
In the stirrer, the offset load W is maximized when the receiving seat 28 is raised most and the contents are stirred (that is, a large force is applied downward). Sometimes, when the state where the female screw and the screw rod are not engaged with each other is reached, the screw rod is released from the locking of the female screw during the stirring operation, and the receiving seat 28 supporting the large weight suddenly descends. Cause a catastrophe.

After many years of research, the present inventor has been able to find out that the chattering is mainly caused by the following causes.
As shown in FIG. 6, the receiving seat 28 is moved up and down by being guided by the guide shaft 23 established on the machine frame 51, but there is a slight gap between the guide shaft 23 and the metal 29 forming the sliding surface 24. There is a gap. Therefore, as shown in the side view of FIG. 10, due to the presence of the offset load W, the portions A and D are separated from the guide shaft 23, and a wedge-shaped gap is formed there. It will be in a state of pressure contact. This is because a moment of L11 × W is approximately generated on the sliding surface 24 when the distance between the point of application of the offset load W and the guide shaft is L11.

As shown in FIG. 11, the above-described state is a state in a vertical plane (hereinafter referred to as “first surface”) orthogonal to the plane including the two guide shafts 23a and 23b. The same kind of state occurs in a vertical plane (hereinafter referred to as “second plane”) parallel to the plane including the guide shafts 23a and 23b. This is because the offset load W is not always distributed equally to the arms 35a and 35b of the seat 28, and the load applied to one arm, for example 35a, is greater than the load applied to the other arm 35b. This is because it is quite natural in actual operations.
At that time, a slight gap is generated between the guide shaft 23 and the metal 29 in the second surface, and the same state as described above is obtained. That is, assuming that the distance between the point of application of the offset load W ′ applied to one arm and the guide shaft is L33, a moment of L33 × W ′ is approximately generated on the sliding surface 24.

The force generated with respect to the guide shaft 23 can be typified by the moment in the first surface and the second surface described above, but actually, the moment in the first surface and the second surface orthogonal to the moment in the first surface. It is thought that the resultant force with the moment is constantly changing. In particular, the force that is most involved in chattering is the force in the first plane where the moment due to the offset load W is maximized. Therefore, the phenomenon occurring in the first surface will be described in detail below, and the phenomenon occurring in the other surface is the same as that described above, and the description thereof is omitted.

In the conventional stirrer lifting device, since the above moment is always generated with respect to the guide shaft 23, as shown in FIG. As shown, it is always in pressure contact with the guide shaft 23. Therefore, the slip resistance at the points U and B is large, and the downward movement of the receiving seat 28 is locked at the points U and B.
In this state, if the screw rod 21 rotates and a downward screw thrust F is newly applied,
The force is a moment of L22 × F (L22 is a distance in the first surface between the guide shaft 23 and the screw rod 21) and acts on the sliding surface 24, eliminating the gap on the wedge. For this reason (in other words, the downward thrust of the screw rod works so as to eliminate the gap on the wedge on the sliding surface), the sliding resistance between c and i disappears and the locked state is released. Then, the receiving seat 28 falls rapidly.

  However, the speed at which the receiving seat 28 is dropped is higher than the speed at which the screw rod 21 rotates and the female screw 22 is lowered, so that a gap on the wedge is formed again and a locked state appears. This is repeated to generate minute vibrations and generate noise. It has been found that chatter occurs mainly in this way. And once chattering occurs, it continues until the seat 28 reaches the lowest position.

  Conventionally, various attempts have been made to eliminate this chatter and prevent the above-mentioned catastrophe. For example, as shown in FIG. 6, the drive system including the screw rod 21 is lubricated by the grease cups 32a and 32b, and the sliding surface 24 is lubricated by the grease cup 32c to reduce the sliding resistance. For this reason, refueling with grease was indispensable. Alternatively, if the processing accuracy is increased, the wedge-shaped gap described above can be reduced, so that it has been considered to increase the processing accuracy. However, the general normal processing accuracy cannot suppress the occurrence of chatter, and more precise. If processing is attempted, the manufacturing cost will rise, so this was not a realistic measure.

Therefore, the metal push bolt 34a shown in FIG. 7 (a) or the brass screw 34b shown in FIG. 7 (b) is used to keep the receiving seat 28 as horizontal as possible so as not to generate a wedge-shaped gap. However, although the effect of reducing the chatter was increased, the effect on the right was also temporary, and the metal and screws with a small contact area were quickly worn out. It took a lot of work to readjust. In addition, adjustment of the metal push bolt 34a and the brass screw 34b, or supply of grease makes the maintenance work during operation indispensable.

  A more important problem than the above is that the handling of the stirrer using this apparatus is very disliked to be mixed with food, chemicals and contaminants. In the above-described chatter mitigation means, excessive oil supply is often performed. Then, excessively lubricated grease or the like leaks to the outside from the guide shaft 23, the screw rod 21, the female screw 22 and the like, and is likely to be mixed into food, chemical substances, etc. in the processing container. Therefore, the operator has spent a lot of time and labor on wiping off excess grease and refueling grease during operation.

Therefore, in order to prevent this contamination, conventionally, a lubricant prevention cover has been provided. That is. As shown in FIG. 6, in order to block the spread of grease from the guide shaft 23, the guide shaft cover 31 is provided integrally with the receiving seat 28, and in order to block the spread of grease from the screw rod 21 and the female screw 22, Similarly, the front cover 30 was integrally provided on the receiving seat 28. Therefore, the structure is complicated, the production cost is further increased, and the cleaning work is extremely troublesome.
Further, the front cover 30 hangs down to the lower side of the machine casing 51 as shown by a two-dot chain line in FIG. 8 when the receiving seat 28 is lowered. It was a big thing.

  The technical problem of the present invention is to eliminate the above-mentioned problems in the conventional screw-type lifting device that lifts and lowers the receiving seat of the stirring vessel, where the weight is applied as an offset load. This eliminates the cause of the occurrence of problems, increases the accuracy of operation by ensuring the transmission of driving force, makes the overall configuration simple, eliminates maintenance work during operation, and keeps production costs low. An object of the present invention is to provide a lifting device for a stirrer.

The present invention employs the following means, mainly for removing the cause of chatter that cannot be avoided in a lifting device with an offset load.
In a device that lifts and lowers a receiving seat that supports the offset load by driving a screw rod, two guide shafts are erected on one side of the receiving seat and mounted on a female screw and a machine frame that are connected to the guide shaft. The screw rod is placed in a plane including two guide shafts, and the screw rod and the female screw are screwed together so that the receiving seat can move up and down along the guide portion of the machine frame together with the guide shaft. The screw rod was connected to the drive source.
As a result, since the screw rod and the female screw are arranged in the plane including the two guide shafts, the distance between the surface including the screw rod and the female screw and the surface including the two guide shafts is zero. Thus, the downward thrust of the screw rod does not work so as to eliminate the wedge-shaped gap on the sliding surface. Therefore, the occurrence of the lock state is not repeated, and the cause of chattering is eliminated.

In the present invention, the following means are adopted mainly for the purpose of preventing the occurrence of chattering and preventing contamination of the substance to be stirred.
There are two screw rods, the two guide shafts that receive the screw rods are hollowed, grease is enclosed therein, and female screws are provided on the inner surfaces of the upper ends of the two guide shafts. And screwed together.
Since the two screw rods and the two female screws have the same axial center, the downward thrust of the screw rods acts to eliminate the wedge-shaped gap on the sliding surface in the first surface and the second surface. As a result, the chatter due to the offset load is almost completely eliminated, and the screw rod and female screw are lubricated with grease in the guide shaft, so they are not dissipated to the outside, causing contamination. Was effectively prevented.

The following means is adopted in the present invention with the main aim of removing the cause of chattering by a simplified mechanism.
One screw rod was used, and one female screw was provided in the middle of the two guide shafts, and the female screw was screwed into the screw rod.
As a result, the moment in the first surface, which is most involved in the occurrence of chatter, can be reduced to zero, and the chatter in the first surface can be eliminated.

The present invention adopts the following means mainly for ensuring the transmission of the driving force to increase the accuracy of the operation and to facilitate maintenance and inspection.
The lifting pulley provided at the upper end of the screw rod was positioned on the upper surface of the machine frame, and the pulley and the motor pulley positioned on the upper surface of the machine frame were wound with a toothed belt.
As a result, accurate power transmission is ensured by the toothed belt, and the drive system can be checked on the upper surface of the machine frame.

The present invention employs the following means mainly aiming at simplifying the configuration of the entire apparatus and making maintenance work during operation unnecessary.
The machine frame is formed into a box shape with the upper part protruding forward and a space below the box shape, and a guide is provided on the bottom of the box shape. It was configured to be entirely covered by the front wall of the part.
As a result, the screw rod that is the largest source of contamination is accommodated in the box-shaped portion, and the conventionally used anti-scattering cover for the lubricating oil becomes unnecessary, and cleaning work and the like are extremely simplified.
The production cost can be kept low by the above means.

  The occurrence of chatter is synonymous with the generation of sound and vibration, which not only increases discomfort in the work environment, but also breaks or breaks down the guide shaft, screw rod, female screw, etc., which are important parts of the screw type lifting device. Sometimes it is a cause of catastrophe. As described above, the present invention has succeeded in finding the root cause of this chatter and preventing it from occurring in the screw type lifting device.

That is, by arranging the screw rod for transmitting the driving force in the plane including the two guide shafts, the distance between the screw rod and the guide shaft in the plane perpendicular to the plane can be made zero. While the seat is lowered, the downward thrust of the screw rod does not work so as to eliminate the wedge-shaped gap on the sliding surface of the guide shaft, and chatter due to the downward thrust of the screw rod does not occur. While the seat rises, the thrust of the screw rod works upward, so that it does not become a force to eliminate the wedge-shaped gap, but the distance between the screw rod and the guide shaft becomes zero, so the sliding surface The pressure contact force against the guide shaft (the pressure contact force at points a and c in FIG. 10) is also reduced, and the resistance at the time of ascent that has occurred in the conventional apparatus can be almost eliminated.

  In the present invention that requires two screw rods, the configuration is such that the two screw rods and the guide shaft are aligned with each other and screwed together, so chattering can be almost completely suppressed. In addition, the guide shaft is made hollow so that grease is enclosed in it, so that it is necessary to re-adjust grease and push bolts and brass screws to reduce chatter, which was required in the past. This eliminates the need for maintenance work such as cleaning, and simplifies the cleaning work.

In the present invention, which requires a single screw rod, it is possible to eliminate the main cause of chatter by configuring the single screw rod and the guide shaft to be aligned with each other and screwing together. For this reason, the main effects of the present invention can be achieved with a further reduction in production costs. In addition, it is no longer necessary to consider driving the two screw rods synchronously.
In this case, if necessary, a conventionally used metal push bolt (see FIG. 7 (a)) or brass screw (see FIG. 7 (a)) is used. The cause of chattering on the second surface can be easily removed.

In the present invention, a female screw is connected to a guide shaft, and two or one lifting pulley and a motor pulley are connected by a single toothed belt to simplify the overall structure. With its simple structure, the operation was reliable and stable. As a result, the cleaning work, which has been a burden on the operation, has become extremely simple, the hygiene has been improved, and the entire apparatus has become compact.

In this type of stirrer, foreign matter is most disliked in the food or chemical substance to be mixed. Therefore, conventionally, a cover for preventing the diffusion of lubricating oil has been provided, but in the present invention, it is also unnecessary.
Further, in the conventional apparatus, since the contents scatter and adhere to the guide shaft established on the machine frame during the agitation work, wiping of the guide shaft and the like has been an indispensable work. Since the upper part of the box is a box-shaped part protruding forward and the lower part of the box-shaped part is a void, the scattered contents fall into the void and the wiping work such as the guide shaft may be omitted. did it.
The various configurations described above have greatly reduced production costs and significantly improved the performance of the agitator.

Furthermore, in the present invention, since the two screw rods are screwed to the two guide shafts, even if the female screw of one guide shaft is worn and does not mesh with the screw rod, the other guide shaft Since the internal thread of the shaft is still engaged, there is no fear of a major accident such as suddenly dropping a heavy stirring container during a stirring operation.
In conventional devices, if lubrication is insufficient, not only chattering but also sliding parts wear out, so oiling during operation is indispensable. Since the lubrication of the rod and female screw is not interrupted without refueling, stable operation is possible, and there are significant advantages in terms of improving safety.

1 shows the best mode of the present invention.
In a device that lifts and lowers a receiving seat that supports the offset load by driving a screw rod, two hollow guide shafts are erected on one side of the receiving seat, and a female screw is formed on the inner surface of the upper ends of the two guide shafts. The hollow part is filled with grease, and the two screw rods mounted on the machine frame and the female screw are screwed together with the shaft center aligned, so that the receiving seat is attached to the guide part of the machine frame along with the guide shaft. The machine frame is formed in a box shape with its upper part protruding into the box and the lower part of the box as a space. A guide part is provided on the bottom surface of the part, and the entire length of the screw rod is entirely covered by the front wall of the box-shaped part.

An embodiment of the present invention is shown in FIGS. 1 is a front view showing a cross section of a part of Example 2 with two screw rods, FIG. 2 is a side view showing a part of Example 2, and FIG. 3 is a plan view of Example 2. 4A is a plan view showing the AA cross section of FIG. 1, FIG. 4B is a plan view showing the main part of FIG. 2, and FIG. 5A is an embodiment in which one screw rod is used. 3 is a front view showing a part of section 3 in section, and FIG. 5B is a side view showing a section of example 3 in section.
In addition, the outline | summary of the raising / lowering apparatus for stirrers conventionally used normally is shown by FIGS.

The receiving seat 10 has rigidity capable of supporting the offset load W shown in FIGS. 2 and 4B. If the receiving seat 10 is formed of two arms 13a and 13b whose arms are widened and one side is opened as shown in FIGS. 3 and 4 (a), the stirring container can be inserted and removed from the open side. However, it is not limited to this form.
Two guide shafts 3 a and 3 b are erected on one side of the receiving seat 10. In the figure, the receiving seat 10 is provided at the lower end of the guide shafts 3a and 3b.
The screw rods 1a and 1b are connected to various drive sources capable of normal rotation, reverse rotation, or temporary stop.

A second embodiment of the present invention with two screw rods will be described.
The shafts of the threaded rods 1a, 1b mounted on the machine frame 12 and the guide shafts 3a, 3b erected on the receiving seat 10 are made to coincide with each other so that they are screwed together so that the receiving seat 10 is guided by the guide shaft. Along with the guide portions 11a and 11b of the machine casing 12 together with 3a and 3b, it can be moved up and down.
The guide portions 11a and 11b can be made of a guide metal that forms the sliding surfaces 4a and 4b. However, the guide portions 11a and 11b are not limited to metal as long as they are materials that do not easily wear.
If oilless metal is used for the guide portions 11a and 11b and the guide shafts 3a and 3b are made of stainless steel, the sliding surfaces become dry, and contaminants do not adhere to the guide shafts 3a and 3b.

If the guide shafts 3a and 3b are made hollow, as shown in FIGS. 1 and 2, grease can be enclosed therein. Then, female screws 2a and 2b are provided on the inner surface of the upper end, and these are screwed with the male screws of the screw rods 1a and 1b, so that the receiving seat 10 is guided by the guide shaft 3a, It can be lifted and lowered along the guide portions 11a and 11b of the machine casing 12 together with 3b. It should be noted here that the screw rods 1a and 1b are always immersed once in the grease enclosed in the guide shafts 3a and 3b while the screw rods 1a and 1b are rotated forward and backward. is there.

The two guide portions 11 a and 11 b are provided inside the lower end of the front surface of the machine frame 12. According to the illustrated example, when the receiving seat 10 is in the raised position, the lower half of the screw rods 1a and 1b is immersed in the grease sealed in the guide shafts 3a and 3b (see FIG. 2). However, when the receiving seat 10 starts to descend, the screw rods 1a, 1b wetted with grease start to appear above the female screws 2a, 2b, and when the receiving seat 10 is fully lowered, the screw rod 1a, wet with grease, The substantially entire length of 1b will be exposed. When there is a concern that the grease adhering to the upper portions of the female screws 2a and 2b of the screw rods 1a and 1b may diffuse forward and contaminate the inside of the stirring vessel, the machine frame 12 provided with two guide portions 11a and 11b at the lower end It is desirable that the front surface of the cover be configured so as to cover the front of the screw rods 1a and 1b wetted with the grease and prevent the grease from being diffused.

A third embodiment with a single screw rod will be described.
For Example 3, reference is made in particular to FIG.
A female screw 15 is fixed in the middle of the two guide shafts 13a and 13b erected on the receiving seat 10. The shaft 10 of the female screw and the screw rod 14 mounted on the machine frame 12 are made to coincide with each other so that they are screwed together, so that the receiving seat 10 and the guide shafts 13a and 13b have the guide portions 4a, It is configured to be able to move up and down along 4b.
The screw rod 14 is connected to various driving sources capable of normal rotation, reverse rotation, or temporary stop via an elevating pulley 16.

A fourth embodiment having a lifting pulley, a motor pulley, and a toothed belt will be described.
In Example 2 with two screw rods, as shown in FIGS. 1 and 2, lifting pulleys 6 a and 6 b are attached to the upper ends of the screw rods 1 a and 1 b, and are positioned on the upper surface of the machine frame 12. In Example 3 with one screw rod, as shown in FIG. 5, a lifting pulley 16 is attached to the upper end of the screw rod 14, and it is positioned on the upper surface of the machine frame 12. The motor pulley 7 is attached to the drive shaft of the motor 5 installed in the machine frame 12, and the motor pulley 7 is positioned on the upper surface of the machine frame 12. As shown in FIG. 3 or FIG. 5, a toothed belt 8 is wound around the lifting pulley 6a, 6b or 16 and the motor pulley 7.

In the case of Example 2 with two screw rods, if the motor pulley 7 can be moved on the upper surface of the machine frame 12, the tension of the toothed belt 8 can be easily adjusted.
It should be noted that the screw rod 1a and the screw rod 1b having the same pitch must be completely synchronized with each other. Although the rotational speeds of the two are different, this structure is indispensable because the receiving seat 10 may cause an unexpected disaster when it rises and falls.
With this configuration, the configuration of the entire apparatus is simplified, and the manufacturing cost can be kept low.

A fifth embodiment having a feature in the configuration of the machine casing 12 will be described.
For Example 5, reference is made in particular to FIG. 2 and FIG.
The upper part of the machine casing 12 is box-shaped and protrudes forward. Then, the screw rod 1a, 1b or 14 is set behind the front wall. The guide portions 11a and 11b are provided on the bottom surface of the box-shaped portion, and the space below the box-shaped portion is a space that can be used for raising and lowering the two guide shafts 3a, 3b or 13a, 13b together with the receiving seat 10. To do.

It is the front view which carried out the cross section and showed a part of Example 2 which used two screw rods. It is the side view which carried out a cross section and showed a part of Example 2. 6 is a plan view of Example 2. FIG. In Example 2, (a) is a plan view showing the AA cross section of FIG. 1, and (b) is a side view showing the main part of FIG. About Example 3 which used one screw rod, (a) is the front view which showed a section in part, and (b) is the side view which showed a section in part. It is the side view which cut and showed a part of conventional screw type lifting device. About two examples of the chatter mitigation means used in the conventional screw type lifting device, (a) shows the push bolt of the metal push, and (b) shows the brass screw. It is a front view of the conventional screw type lifting device. It is the top view which cut and showed a part of conventional screw type raising and lowering device. It is the side view which cut and showed a part of principal part of the conventional screw type raising / lowering apparatus. The moment in the conventional screw type lifting device is illustrated, (a) is a top view, (b) is a side view.

Explanation of symbols

1a, 1b, 14 Screw rod 2a. 2b, 15 Female thread 3a, 3b, 13a, 13b Guide shaft 6a, 6b, 16 Lifting pulley 7 Motor pulley 8 Toothed belt 10 Receiving seat 11a, 11b Guide portion 12 Machine frame

Claims (5)

  In a device that lifts and lowers a receiving seat that supports the offset load by driving a screw rod, two guide shafts are erected on one side of the receiving seat and mounted on a female screw and a machine frame that are connected to the guide shaft. The screw rod is placed in a plane including two guide shafts, and the screw rod and the female screw are screwed together so that the receiving seat can move up and down along the guide portion of the machine frame together with the guide shaft. A lifting load lifting device characterized in that a screw rod is connected to a drive source. There are two screw rods, the two guide shafts that receive the screw rods are hollowed, grease is enclosed therein, and female screws are provided on the inner surfaces of the upper ends of the two guide shafts. The elevating device for a stirrer according to claim 1, wherein the elevating device is a screw.   The elevating device for a stirrer according to claim 1, wherein one screw rod is provided, one female screw is continuously provided between two guide shafts, and the female screw is screwed to the screw rod.   The lifting pulley provided at the upper end of the screw rod is positioned on the upper surface of the machine frame, and the pulley and the motor pulley positioned on the upper surface of the machine frame are wound by a toothed belt. Or the raising / lowering apparatus for a stirrer of Claim 3. The machine frame is formed into a box shape with the upper part protruding forward and a space below the box shape, and a guide is provided on the bottom of the box shape. The lifting device for a stirrer according to claim 1, wherein the lifting device for the stirrer is configured to be entirely covered with a front wall of the portion.

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