JP2022074407A - Workpiece lifting device and workpiece lifting method - Google Patents

Abstract

To provide a workpiece lifting device, etc. that does not require a liquid container to be sealed and can raise and lower a work table stably over a long period of time.SOLUTION: A workpiece lifting device 1 includes: a work table 10 on which a workpiece W is placed; a movable liquid tank 20; a fixed liquid tank 30; a pulley 40; a string body 50 one end of which is connected to the work table, the other end of which is connected to the movable liquid tank, and which is wound around the pulley; a first liquid passage 60A that connects the movable liquid tank with the fixed liquid tank; a second liquid passage 60B that connects the movable liquid tank with the fixed liquid tank; a first liquid control unit 70A to move liquid retained by the movable liquid tank to the fixed liquid tank via the first liquid passage; and a second liquid control unit 70B that moves liquid retained by the fixed liquid tank to the movable liquid tank via the second liquid passage.SELECTED DRAWING: Figure 1

Description

The present invention relates to a work elevating device and a work elevating method, and more particularly to a work elevating device and a work elevating method capable of stably elevating and lowering a work table for a long period of time without the need to seal a liquid container. ..

Two liquid containers suspended by a wire wound around a driven pulley are communicated with each other by a hose, the air in one of the sealed liquid containers is discharged to the outside, and the inside of the other liquid container is subjected to negative pressure. For example, a work elevating device for raising and lowering a work table provided in one of the liquid containers by moving the liquid between the two through the hose and changing the weight balance between the two is patented. It is described in Document 1.

Japanese Unexamined Patent Publication No. 2008-230636

However, in the work elevating device described in Patent Document 1, it is difficult to maintain the airtightness of the liquid container for a long period of time due to cracking or corrosion of the liquid tank, and the liquid held by the liquid container is outside the liquid container. There is a problem that the work table cannot be raised and lowered stably for a long period of time because it leaks to the liquid and the air in the liquid container cannot be sufficiently discharged to the outside.

The present invention has been made to solve such a problem, and is a work elevating device capable of stably raising and lowering a work table for a long period of time without the need to seal a liquid container, and a work elevating device. It provides a method for raising and lowering a work.

The work elevating device according to the present invention has a work table on which a work is placed, a movable liquid tank for holding a liquid, a fixed liquid tank for holding a liquid, a pulley, and one end connected to the work table and the other end. Is connected to the movable liquid tank, a string body wound around the pulley, a first liquid passage connecting the movable liquid tank and the fixed liquid tank, and the movable liquid tank and the fixed liquid tank. The fixed liquid tank holds the second liquid passage, the first liquid control unit that moves the liquid held by the movable liquid tank to the fixed liquid tank via the first liquid passage, and the fixed liquid tank. A second liquid control unit for moving the liquid to the movable liquid tank via the second liquid passage is provided, and the first liquid control unit holds the liquid held by the movable liquid tank. By moving the work table to the fixed liquid tank via one liquid passage, the work table is raised, and the second liquid control unit transfers the liquid held by the fixed liquid tank through the second liquid passage. By moving to the movable liquid tank, the work table is lowered.

With such a configuration, it is not necessary to seal the movable liquid tank, and the work table can be stably raised and lowered for a long period of time.

This is a first liquid control unit that moves the liquid held by the movable liquid tank to the fixed liquid tank via the first liquid passage, and a movable liquid that moves the liquid held by the fixed liquid tank through the second liquid passage. This is because it is provided with a second liquid control unit that moves the liquid to the tank. That is, the first liquid control unit raises the work table by moving the liquid held by the movable liquid tank to the fixed liquid tank via the first liquid passage, and the second liquid control unit raises the work table. This is due to lowering the work table by moving the liquid held by the fixed liquid tank to the movable liquid tank via the second liquid passage.

Here, the movable liquid tank is formed with a liquid discharge port for discharging the liquid supplied in excess of a predetermined height from the bottom surface of the movable liquid tank, and the liquid discharge port and the fixed liquid tank are formed. A third liquid passage may be further provided.

In this way, the liquid supplied to the movable liquid tank exceeding the predetermined height is discharged to the fixed liquid tank via the liquid discharge port and the third liquid passage. As a result, the weight of the movable liquid tank can be kept constant, so that the work table can be raised and lowered stably for a long period of time. For example, the weight of the movable liquid tank is kept constant even when the second liquid control unit fails and the liquid held by the fixed liquid tank is continuously moved to the movable liquid tank through the second liquid passage. Therefore, the work table can be raised and lowered stably for a long period of time. In addition, for other reasons, even when a liquid exceeding a predetermined height is supplied to the movable liquid tank, the weight of the movable liquid tank can be kept constant, so that the workbench can be stably operated for a long period of time. Can be raised and lowered.

Further, the adjusting means for adjusting the predetermined height may be further provided.

By doing so, it is possible to cope with other workpieces having different weights. That is, even if the work has different weights, the work table can be raised and lowered stably for a long period of time by adjusting the predetermined height.

Further, a brake mechanism for braking the rotation of the pulley and a brake mechanism control unit for controlling the brake mechanism may be further provided.

Further, the brake mechanism control unit may brake the rotation of the pulley when the work table rises and approaches the upper limit position, or when the work table descends and approaches the lower limit position.

For example, when the work table abuts on the stopper, the work table decelerates by operating the brake mechanism to brake the rotation of the pulley before the work table contacts the stopper that defines the upper limit position or the lower limit position. The impact is mitigated. As a result, damage to the work and displacement of the work with respect to the work table due to the impact when the work table comes into contact with the stopper are suppressed.

Further, the first liquid control unit and the second liquid control unit may be liquid pumps, respectively.

The work elevating method according to the present invention is to move the liquid held by the movable liquid tank wound around the pulley and connected to the other end of the string body to which the work base is connected to one end to the fixed liquid tank. The process of raising the work table and
The present invention comprises a step of lowering the work table by moving the liquid held by the fixed liquid tank to the movable liquid tank.

With such a configuration, it is not necessary to seal the movable liquid tank, and the work table can be stably raised and lowered for a long period of time.

This raises the work table by moving the liquid held by the movable liquid tank to the fixed liquid tank, and lowers the work table by moving the liquid held by the fixed liquid tank to the movable liquid tank. It is due to that.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a work elevating device and a work elevating method capable of stably elevating and lowering a work table for a long period of time without the need to seal the liquid container.

It is a side view of the work elevating device 1. It is sectional drawing of the movable liquid tank 20. It is a schematic block diagram of the control device 80. It is a figure for demonstrating the operation example which lowers the work table 10 located in the upper limit position P1 (see FIG. 4) of an elevating range to the lower limit position P2 (see FIG. 6) of an elevating range. It is a figure for demonstrating the operation example which lowers the work table 10 located in the upper limit position P1 (see FIG. 4) of an elevating range to the lower limit position P2 (see FIG. 6) of an elevating range. It is a figure for demonstrating the operation example which lowers the work table 10 located in the upper limit position P1 (see FIG. 4) of an elevating range to the lower limit position P2 (see FIG. 6) of an elevating range. It is a figure for demonstrating the operation example which lowers the work table 10 located in the upper limit position P1 (see FIG. 4) of an elevating range to the lower limit position P2 (see FIG. 6) of an elevating range.

Hereinafter, the work elevating device 1 according to the embodiment of the present invention will be described with reference to the attached drawings. The corresponding components in each figure are designated by the same reference numerals, and duplicate explanations are omitted.

FIG. 1 is a side view of the work elevating device 1.

The work elevating device 1 includes a work table 10 suspended by a wire 50 wound around a pulley 40 and a movable liquid tank 20, adjusts the amount of liquid held by the movable liquid tank 20, and adjusts the amount of liquid held by the work table 10 and the movable liquid. It is a device that raises and lowers the work table 10 by changing the weight balance with the tank 20.

As shown in FIG. 1, the work elevating device 1 includes a work table 10, a movable liquid tank 20, a fixed liquid tank 30, a pulley 40, a brake mechanism 42, a wire 50, a first hose 60A, a second hose 60B, and a third hose. It includes 60C, a first pump 70A, a second pump 70B, and a control device 80 (see FIG. 3, omitted in FIG. 1).

The work table 10 is a table on which the work W is placed. The work W is, for example, a heavy object such as an engine component (for example, a cylinder block or a cylinder head).

The work table 10 is slidably attached to a first guide rail 91A extending in the vertical direction provided on one side of a support column 90 installed on the floor surface F. Specifically, the work table 10 is fixed to the first slide block 92A which is slidably attached to the first guide rail 91A.

The work table 10 is suspended by connecting one end of a wire 50 wound around the pulley 40. The work table 10 moves up and down along the first guide rail 91A by changing the weight balance between the work table 10 and the movable liquid tank 20. Specifically, when the weight of the movable liquid tank 20 becomes lighter than the weight of the work table 10, the work table 10 descends along the first guide rail 91A.

The work table 10 descending along the first guide rail 91A is restricted from further descending by the first slide block 92A coming into contact with the first stopper 93A provided at the lower part of the first guide rail 91A. .. At that time, the rotation of the pulley 40 is braked by the brake mechanism 42 before the first slide block 92A comes into contact with the first stopper 93A. As a result, the work table 10 (first slide block 92A) decelerates, so that the impact when the first slide block 92A comes into contact with the first stopper 93A is alleviated.

On the contrary, when the weight of the movable liquid tank 20 becomes heavier than the weight of the work table 10, the work table 10 rises along the first guide rail 91A.

The work table 10 ascending along the first guide rail 91A is restricted from further ascending by the first slide block 92A coming into contact with the second stopper 93B provided on the upper part of the first guide rail 91A. .. At that time, the rotation of the pulley 40 is braked by the brake mechanism 42 before the first slide block 92A comes into contact with the second stopper 93B. As a result, the work table 10 (first slide block 92A) decelerates, so that the impact when the first slide block 92A comes into contact with the second stopper 93B is alleviated.

The movable liquid tank 20 is a container having a space 21 for holding the liquid. Unlike the above-mentioned Patent Document 1, the space 21 for holding the liquid does not have to be sealed. The liquid is, for example, water, but may be a liquid other than water. The material of the movable liquid tank 20 is, for example, a synthetic resin.

The movable liquid tank 20 is slidably attached to a second guide rail 91B extending in the vertical direction provided on the other side of the support column 90. Specifically, the movable liquid tank 20 is fixed to the second slide block 92B which is slidably attached to the second guide rail 91B.

The movable liquid tank 20 is suspended by connecting the other end of the wire 50 wound around the pulley 40. The movable liquid tank 20 moves up and down along the second guide rail 91B by changing the weight balance between the work table 10 and the movable liquid tank 20. Specifically, when the weight of the movable liquid tank 20 becomes lighter than the weight of the work table 10, the movable liquid tank 20 rises along the second guide rail 91B. On the contrary, when the weight of the movable liquid tank 20 becomes heavier than the weight of the work table 10, the movable liquid tank 20 descends along the second guide rail 91B.

Next, an example of the adjusting means for adjusting the predetermined height H (see FIG. 2A) from the bottom surface 23 of the movable tank 20 to the liquid level of the liquid held by the movable tank 20 will be described. The adjusting means is provided so as to be able to cope with another work having a different weight.

2 (a) and 2 (b) are cross-sectional views of the movable liquid tank 20. For convenience of explanation, in FIGS. 2A and 2B, configurations other than the movable liquid tank 20, the adjusting means, and the third hose 60C are omitted.

As shown in FIG. 2A, the adjusting means includes a fixed pipe 24 and a movable pipe 25. The fixed pipe 24 and the movable pipe 25 are arranged in the movable liquid tank 20.

The fixed pipe 24 includes a first pipe 24a and a second pipe 24b. The first pipe 24a is a pipeline extending in the vertical direction. The first pipe 24a is formed with an external screw (male screw) into which the movable pipe 25 (internal screw) is screwed.

The second pipe 24b is a pipeline extending in the horizontal direction. A first pipe 24a (lower part) is connected to one end of the second pipe 24b. A third hose 60C is connected to the other end (liquid discharge port 24b1) of the second pipe 24b via an opening formed in the side surface 22 of the movable liquid tank 20.

The movable pipe 25 is a pipeline extending in the vertical direction. The movable pipe 25 is formed with an internal screw (female screw) into which the fixed pipe 24 (external screw) is screwed. The lower portion (internal screw) of the movable pipe 25 is screwed into the upper portion (external screw) of the first pipe 24a of the fixed pipe 24.

According to the adjusting means having the above configuration, the predetermined height H (water level) up to the liquid level of the liquid held by the movable tank 20 can be adjusted by rotating the movable pipe 25. For example, the predetermined height H can be adjusted to the height shown in FIG. 2 (a) or the height shown in FIG. 2 (b). The liquid supplied to the movable liquid tank 20 (space 21) exceeding the predetermined height H is connected to the movable pipe 25, the fixed pipe 24, the liquid discharge port 24b1 of the fixed pipe 24, and the liquid discharge port 24b1. It is discharged to the fixed liquid tank 30 via the third hose 60C.

As a result, the height from the bottom surface 23 of the movable tank 20 to the liquid level of the liquid held by the movable tank 20 is maintained at a predetermined height H (see FIG. 2A). In other words, the weight of the liquid held by the movable tank 20 is kept constant. The predetermined height H is considered so that the weight of the movable liquid tank 20 holding the liquid supplied up to the predetermined height H is heavier than the total weight of the work table 10 and the work W placed on the work table 10. It is the height.

By adjusting the predetermined height H as described above and increasing or decreasing the liquid (amount of water when full) held by the movable liquid tank 20 (space 21), the weight of the work placed on the work table 10 is increased or decreased. The weight of the movable liquid tank 20 can be adjusted. This makes it possible to handle different workpieces having different weights.

The fixed liquid tank 30 is a container having a space 31 for holding the liquid. Unlike the above-mentioned Patent Document 1, the space 31 for holding the liquid does not have to be sealed. The material of the fixed liquid tank 30 is, for example, a synthetic resin. The fixed liquid tank 30 is installed on the floor surface F, for example. The capacity of the fixed liquid tank 30 is larger than the capacity of the movable liquid tank 20, and the fixed liquid tank 30 holds more liquid than the movable liquid tank 20.

The pulley 40 is a driven pulley that rotates about a rotating shaft 41, and is provided at the upper end of the support column 90.

A wire 50 having one end connected to the work table 10 and the other end connected to the movable liquid tank 20 is wound around the pulley 40. The wire 50 is an example of the string body of the present invention.

The brake mechanism 42 is a mechanism for braking the rotation of the pulley 40. Since various known brake mechanisms can be used as the brake mechanism 42, detailed description of the brake mechanism 42 will be omitted.

The first hose 60A communicates the movable liquid tank 20 and the fixed liquid tank 30. Specifically, one end of the first hose 60A is connected to the first pump 70A arranged in the movable liquid tank 20. On the other hand, the other end of the first hose 60A is inserted into the fixed liquid tank 30. The first hose 60A is an example of the first liquid passage of the present invention.

The second hose 60B communicates the movable liquid tank 20 and the fixed liquid tank 30. Specifically, one end of the second hose 60B is inserted into the movable liquid tank 20. On the other hand, the other end of the second hose 60B is connected to the second pump 70B arranged in the fixed liquid tank 30. The second hose 60B is an example of the second liquid passage of the present invention.

The third hose 60C communicates the movable liquid tank 20 (liquid discharge port 24b1) with the fixed liquid tank 30. Specifically, one end of the third hose 60C is connected to the liquid discharge port 24b1 formed in the movable liquid tank 20 (side surface 22). On the other hand, the other end of the third hose 60C is inserted into the fixed liquid tank 30. The third hose 60C is an example of the third liquid passage of the present invention.

The first pump 70A is, for example, a liquid pump. It is desirable that the first pump 70A be arranged as close to the bottom surface 23 in the movable liquid tank 20 as possible so as not to suck in air. One end of the first hose 60A is connected to the first pump 70A. The first pump 70A moves the liquid held by the movable liquid tank 20 to the fixed liquid tank 30 via the first hose 60A. The first pump 70A is an example of the first liquid control unit of the present invention.

The second pump 70B is, for example, a liquid pump. It is desirable that the second pump 70B be arranged as close to the bottom surface 32 in the fixed liquid tank 30 as possible so as not to suck in air. The other end of the second hose 60B is connected to the second pump 70B. The second pump 70B moves the liquid held by the fixed liquid tank 30 to the movable liquid tank 20 via the second hose 60B. The second pump 70B is an example of the second liquid control unit of the present invention.

Next, the control device 80 will be described.

FIG. 3 is a schematic configuration diagram of the control device 80.

As shown in FIG. 3, the control device 80 includes a storage unit 81, a control unit 82, a memory 83, and the like.

The storage unit 81 is, for example, a non-volatile storage unit such as a hard disk device or a ROM. For example, the program 81a is stored in the storage unit 81.

Although not shown, the control unit 82 includes a processor. A first sensor 84, a second sensor 85, a third sensor 86, a fourth sensor 87, a first pump 70A, a second pump 70B, and a brake mechanism 42 are electrically connected to the control unit 82 (processor). .. The processor is, for example, a CPU. There may be one processor or multiple processors. For example, the processor executes the program 81a read from the storage unit 81 into the memory 83 such as the RAM to control the first pump control unit 82a that controls the first pump 70A and the second pump that controls the second pump 70B. It functions as a brake mechanism control unit 82c that controls the control unit 82b and the brake mechanism 42.

The first sensor 84 is a sensor that detects whether or not the work W is placed on the work table 10, and is, for example, a proximity sensor or a passing sensor. The first sensor 84 is attached to, for example, a work table 10 (for example, a work mounting surface).

The second sensor 85 is a sensor that detects the water level (for example, full or empty) of the liquid held by the movable liquid tank 20, and is attached to the movable liquid tank 20.

The third sensor 86 is a sensor that detects whether or not the descending work table 10 has approached the first stopper 93A, and is, for example, a proximity sensor or a passing sensor. The third sensor 86 is attached, for example, in front of the first stopper 93A (above the first stopper 93A in FIG. 1).

The fourth sensor 87 is a sensor that detects whether or not the rising work table 10 has approached the second stopper 93B, and is, for example, a proximity sensor or a passing sensor. The fourth sensor 87 is attached, for example, in front of the second stopper 93B (below the first stopper 93A in FIG. 1).

Next, an example of the operation of the work elevating device 1 having the above configuration will be described.

Hereinafter, an operation example in which the work table 10 located at the upper limit position P1 (see FIG. 4) of the elevating range is lowered to the lower limit position P2 (see FIG. 6) of the elevating range will be described with reference to FIGS. 4 to 7.

4 to 7 are diagrams for explaining an operation example in which the work table 10 located at the upper limit position P1 (see FIG. 4) of the elevating range is lowered to the lower limit position P2 (see FIG. 6) of the elevating range. .. For convenience of explanation, in FIGS. 4 to 7, configurations other than the work table 10, the movable liquid tank 20, the fixed liquid tank 30, the wire 50, and the support column 90 are omitted.

As shown in FIG. 4, when the work table 10 is located at the upper limit position P1, the work table 10 (first slide block 92A) is in contact with the second stopper 93B. On the other hand, when the work table 10 is located at the lower limit position P2 (see FIG. 6), the work table 10 (first slide block 92A) is in contact with the first stopper 93A.

In the following description, since the liquid L ₂₀ is initially supplied to the movable liquid tank 20 up to a predetermined height H (full state) and the weight of the movable liquid tank 20 is heavier than the weight of the work table 10, the work table Reference numeral 10 is assumed to have risen to the upper limit position P1 (see FIG. 4).

As shown in FIG. 5, on the work table 10 located at the upper limit position P1, the work W transported on the first transport path R1 arranged in the upper stage is placed (moved) by a predetermined mechanism (not shown). Will be listed). The first transport path R1 may be, for example, a chute arranged at an angle with respect to the horizontal, or may be a belt conveyor.

When the first sensor 84 detects that the work W is placed on the work table 10 (when the transfer completion signal is received from the first sensor 84), the first pump control unit 82a uses the first pump 70A. Is operated to move the liquid L ₂₀ held by the movable liquid tank 20 to the fixed liquid tank 30 via the first hose 60A (see the arrow Ar1 in FIG. 5). Then, when the second sensor 85 detects that the movable liquid tank 20 is empty, the first pump control unit 82a stops the first pump 70A.

As a result, when the weight of the movable liquid tank 20 becomes lighter than the total weight of the work table 10 and the work W mounted on the work table 10, the work table 10 on which the work W is placed descends along the first guide rail 91A. (See arrow Ar2 in FIG. 5).

The work table 10 on which the work W is placed descends until the first slide block 92A abuts on the first stopper 93A, that is, to the lower limit position P2 (see FIG. 6). At that time, when the third sensor 86 detects that the descending work table 10 (first slide block 92A) has approached the first stopper 93A, the brake mechanism control unit 82c has the first slide block 92A as the first. The brake mechanism 42 is operated to brake the rotation of the pulley 40 before it comes into contact with the stopper 93A. As a result, the work table 10 (first slide block 92A) decelerates, so that the impact when the first slide block 92A comes into contact with the first stopper 93A is alleviated. As a result, damage to the work W and misalignment of the work W with respect to the work table 10 due to the impact when the first slide block 92A abuts on the first stopper 93A are suppressed.

As shown in FIG. 6, in the second transport path R2 arranged in the lower stage, the work W placed on the work table 10 located at the lower limit position P2 is placed (transferred) by a predetermined mechanism (not shown). ). The second transport path R2 may be, for example, a chute arranged at an angle with respect to the horizontal, or may be a belt conveyor.

When the first sensor 84 detects that the work W is placed on the second transport path R2 arranged in the lower stage (when the transfer completion signal is received from the first sensor 84), the second pump control unit. 82b operates the second pump 70B to move the liquid L ₃₀ held by the fixed liquid tank 30 to the movable liquid tank 20 via the second hose 60B (see arrow Ar3 in FIG. 7). Then, when the second sensor 85 detects that the movable liquid tank 20 is full, the second pump control unit 82b stops the second pump 70B.

As a result, when the weight of the movable liquid tank 20 becomes heavier than the weight of the work table 10, the work table 10 rises along the first guide rail 91A (see arrow Ar4 in FIG. 7). At that time, the liquid L ₂₀ supplied to the movable liquid tank 20 (space 21) exceeding the predetermined height H includes the movable pipe 25, the fixed pipe 24, the liquid discharge port 24b1 of the fixed pipe 24, and the liquid discharge port. It is discharged to the fixed liquid tank 30 via the third hose 60C connected to 24b1.

The work table 10 continues to rise until the first slide block 92A abuts on the second stopper 93B, that is, to the upper limit position P1. That is, it keeps rising until it returns to the state (initial state) of FIG. At that time, when the fourth sensor 87 detects that the rising work table 10 (first slide block 92A) has approached the second stopper 93B, the brake mechanism control unit 82c has the first slide block 92A second. The brake mechanism 42 is operated to brake the rotation of the pulley 40 before it comes into contact with the stopper 93B. As a result, the impact when the first slide block 92A comes into contact with the second stopper 93B is alleviated.

As described above, according to the present embodiment, it is not necessary to keep the movable liquid tank 20 in a sealed state, and the work table 10 can be stably moved up and down for a long period of time.

This is a first pump 70A that moves the liquid held by the movable liquid tank 20 to the fixed liquid tank 30 via the first hose 60A, and a liquid held by the fixed liquid tank 30 via the second hose 60B. This is because the second pump 70B for moving to the movable liquid tank 20 is provided. That is, the first pump 70A raises the work table 10 by moving the liquid held by the movable liquid tank 20 to the fixed liquid tank 30 via the first hose 60A, and the second pump 70B raises the work table 10. This is because the work table 10 is lowered by moving the liquid held by the fixed liquid tank 30 to the movable liquid tank 20 via the second hose 60B.

Further, according to the present embodiment, the liquid supplied to the movable liquid tank 20 exceeding the predetermined height H is the movable pipe 25, the fixed pipe 24, the liquid discharge port 24b1 of the fixed pipe 24, and the liquid discharge port. It is discharged to the fixed liquid tank 30 via the third hose 60C connected to 24b1.

As a result, the weight of the movable liquid tank 20 can be kept constant without the liquid overflowing from the movable liquid tank 20, so that the work table 10 can be raised and lowered stably for a long period of time. For example, even when the second pump 70B fails and the liquid held by the fixed liquid tank 30 continues to be moved to the movable liquid tank 20 via the second hose 60B, the weight of the movable liquid tank 20 is constant. Therefore, the work table 10 can be raised and lowered stably for a long period of time. Further, for other reasons, even when a liquid exceeding a predetermined height H is supplied to the movable liquid tank 20, the weight of the movable liquid tank 20 can be kept constant, so that it is stable for a long period of time. The work table 10 can be raised and lowered. Further, since the weight of the movable liquid tank 20 can be kept constant, the ascending / descending speed of the work table 10 can be controlled.

Further, according to the present embodiment, since the adjustment means (see FIG. 2) for adjusting the predetermined height H from the bottom surface 23 of the movable tank 20 to the liquid level of the liquid held by the movable tank 20 is provided, the weight is provided. Can be used for different workpieces. That is, even if the work is different in weight, the work is stable for a long period of time by adjusting the predetermined height H from the bottom surface 23 of the movable tank 20 to the liquid level of the liquid held by the movable tank 20. The table 10 can be raised and lowered. Further, by adjusting the predetermined height H according to the weight of the work, the ascending / descending speed of the work table 10 can be controlled.

Further, according to the present embodiment, the brake mechanism 42 for braking the rotation of the pulley 40 and the brake mechanism control unit 82c for controlling the brake mechanism 42 are provided, and the work table 10 is raised in the brake mechanism control unit 82c. When the upper limit position P1 is approached, or when the work table 10 is lowered and approaches the lower limit position P2, the brake mechanism 42 is controlled to brake the rotation of the pulley 40.

For example, the brake mechanism 42 is operated to brake the rotation of the pulley 40 before the work table 10 (first slide block 92A) comes into contact with the stoppers 93A and 93B defining the upper limit position P1 or the lower limit position P2. As a result, the work table 10 (first slide block 92A) decelerates, so that the impact when the first slide block 92A comes into contact with the stoppers 93A and 93B is alleviated. As a result, damage to the work and displacement of the work with respect to the work table 10 due to the impact when the first slide block 92A abuts on the stoppers 93A and 93B are suppressed.

Further, in Patent Document 1, since the two tanks (liquid containers) move up and down, it is necessary to control the amount of liquid. That is, in Patent Document 1, the work table 10 is moved up and down by the weight difference between the two tanks (liquid containers), and when the weight difference changes, the raising and lowering speed also changes, so that it is important to control the total amount of liquid. .. Further, in Patent Document 1, since the liquid amount changes after repair of the tank (liquid container) and hose or when used in a constant temperature environment (evaporation, etc.), it is necessary to confirm or adjust the liquid amount. On the other hand, according to the present embodiment, there is an advantage that it is not necessary to control the liquid amount.

All the numerical values shown in the above embodiments are examples, and it goes without saying that appropriate numerical values different from these can be used.

The above embodiments are merely exemplary in all respects. The present invention is not limitedly construed by the description of the above embodiment. The present invention can be practiced in various other forms without departing from its spirit or key features.

1 ... Work lifting device 10 ... Work table 20 ... Movable liquid tank 21 ... Space 22 ... Side surface 23 ... Bottom surface 24 ... Fixed pipe 24a ... First pipe 24b ... Second pipe 24b1 ... Liquid discharge port 25 ... Movable pipe 30 ... Fixed liquid Tank 31 ... Space 32 ... Bottom surface 40 ... Pulley 41 ... Rotating shaft 42 ... Brake mechanism 50 ... Wire 60A ... First hose 60B ... Second hose 60C ... Third hose 70A ... First pump 70B ... Second pump 80 ... Control device 81 ... Storage unit 81a ... Program 82 ... Control unit 82a ... First pump control unit 82b ... Second pump control unit 82c ... Brake mechanism control unit 83 ... Memory 84 ... First sensor 85 ... Second sensor 86 ... Third sensor 87 ... 4th sensor 90 ... Support 91A ... 1st guide rail 91B ... 2nd guide rail 92A ... 1st slide block 92B ... 2nd slide block 93A ... 1st stopper 93B ... 2nd stopper F ... Floor surface H ... Predetermined height L ₂₀ , L ₃₀ ... Liquid P1 ... Upper limit position P2 ... Lower limit position R1 ... First transport path R2 ... Second transport path W ... Work

Claims (7)

A work table on which the work is placed and
A movable liquid tank that holds liquid, and
A fixed liquid tank that holds the liquid, and
With the pulley,
One end is connected to the work table, the other end is connected to the movable liquid tank, and a string body wound around the pulley.
A first liquid passage communicating the movable liquid tank and the fixed liquid tank,
A second liquid passage that communicates the movable liquid tank and the fixed liquid tank,
A first liquid control unit that moves the liquid held by the movable liquid tank to the fixed liquid tank via the first liquid passage.
A second liquid control unit for moving the liquid held by the fixed liquid tank to the movable liquid tank via the second liquid passage is provided.
The first liquid control unit raises the work table by moving the liquid held by the movable liquid tank to the fixed liquid tank through the first liquid passage.
A work elevating device in which the second liquid control unit lowers the work table by moving the liquid held by the fixed liquid tank to the movable liquid tank via the second liquid passage. The movable liquid tank is formed with a liquid discharge port for discharging the liquid supplied from the bottom surface of the movable liquid tank in excess of a predetermined height.
The work elevating device according to claim 1, further comprising a third liquid passage that connects the liquid discharge port and the fixed liquid tank. The work elevating device according to claim 2, further comprising an adjusting means for adjusting the predetermined height. A brake mechanism that brakes the rotation of the pulley and
The work elevating device according to any one of claims 1 to 3, further comprising a brake mechanism control unit for controlling the brake mechanism. The work according to claim 4, wherein the brake mechanism control unit brakes the rotation of the pulley when the work table rises and approaches the upper limit position, or when the work table descends and approaches the lower limit position. lift device. The work elevating device according to any one of claims 1 to 5, wherein the first liquid control unit and the second liquid control unit are liquid pumps, respectively. The process of raising the work table by moving the liquid held by the movable liquid tank wound around the pulley and connected to the other end of the string body to which the work table is connected to the fixed liquid tank to the fixed liquid tank.
A work elevating method comprising a step of lowering the work table by moving the liquid held by the fixed liquid tank to the movable liquid tank.

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