Work lift device

Abstract

To provide a work lift device that can reduce the burden of workpiece handling operations while suppressing increases in equipment costs. [Solution] The work lift device 1 includes a lift mechanism 20 that includes a tank 21 and a weight 22 that are provided to be able to move up and down in opposite directions, and a supply path 10 that supplies liquid 2 used in other equipment 5 to the tank 21 located in the raised position. The weight 22 includes a platform for the workpiece W. The weight of the liquid 2 stored in the tank 21 causes the tank 21 to descend from the raised position to the lowered position.

Description

Technical Field

[0001] The present invention relates to a work lift device.

Background Art

[0002] Patent Document 1 discloses a machine tool and a workpiece machining method of the machine tool that are intended to remove chips immediately before setting a workpiece for secondary machining without deteriorating productivity and the working environment.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When carrying out a workpiece from a processing device after processing, actuators such as a hydraulic device or a robot are usually used. However, when an actuator is introduced, the equipment cost increases. On the other hand, when an actuator is not introduced, the workpiece is carried out manually. However, when the workpiece is heavy, the burden on the operator in transportation increases.

[0005] An object of the present invention is to provide a work lift device capable of reducing the burden of work transportation while suppressing an increase in equipment cost.

Means for Solving the Problems

[0006] A work lift device according to an aspect of the present invention includes a lift mechanism including a tank and a weight that are provided so as to be able to move up and down in opposite directions to each other, and a supply path for supplying a liquid used in other equipment to the tank located at the ascending position. The weight includes a mounting table for a workpiece. Due to the self-weight of the liquid stored in the tank, the tank descends from the ascending position to the descending position. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a work lift device that can reduce the burden of workpiece transport operations while suppressing an increase in equipment costs. [Brief explanation of the drawing]

[0008] [Figure 1] This is a diagram illustrating the configuration of a work lift device according to an embodiment. [Figure 2A] This figure shows one state of the lift mechanism according to the embodiment. [Figure 2B] This figure shows one state of the lift mechanism according to the embodiment. [Figure 3A] This figure shows one state of the lift mechanism according to the embodiment. [Figure 3B] This figure shows one state of the lift mechanism according to the embodiment. [Figure 4A] This is a diagram showing one state of the opening and closing device according to the embodiment. [Figure 4B] This is a diagram showing one state of the opening and closing device according to the embodiment. [Figure 5A] This figure shows one state of the weight lock device according to the embodiment. [Figure 5B] This figure shows one state of the weight lock device according to the embodiment. [Figure 5C] This figure shows one state of the weight lock device according to the embodiment. [Figure 5D] This figure shows one state of the weight lock device according to the embodiment. [Figure 6A] This figure shows one state of the tank lock device according to the embodiment. [Figure 6B] This figure shows one state of the tank lock device according to the embodiment. [Figure 7] This is a flowchart showing the process using a work lift device. [Figure 8A] This figure shows one state of the ancillary device according to the embodiment. [Figure 8B]It is a diagram showing one state of the accessory device according to the embodiment. [Figure 8C] It is a diagram showing one state of the accessory device according to the embodiment. [Figure 9A] It is a diagram showing one state of the weight lock device according to a modification of the embodiment. [Figure 9B] It is a diagram showing one state of the weight lock device according to a modification of the embodiment. [Figure 9C] It is a diagram showing one state of the weight lock device according to a modification of the embodiment. [Figure 9D] It is a diagram showing one state of the weight lock device according to a modification of the embodiment.

Mode for Carrying Out the Invention

[0009] Hereinafter, the forklift device according to the present embodiment will be described with reference to the drawings. Elements having the same function are denoted by the same reference numerals, and redundant descriptions are omitted. For convenience of explanation, "ascending position" and "descending position" are defined. The ascending position is the position when the tank 21 or the weight 22 (see FIG. 1) has finished ascending. On the other hand, the descending position is the position when the tank 21 or the weight 22 has finished descending. As will be described later, when the tank 21 is in the ascending position, the weight 22 is in the descending position (see FIG. 1). Conversely, when the weight 22 is in the ascending position, the tank 21 is in the descending position.

[0010] As shown in FIG. 1, the forklift device 1 includes a supply path 10, a lift mechanism 20, a weight lock device 30, and a tank lock device 40. The supply path 10 supplies the liquid 2 used in the other equipment 5 to the tank 21 of the lift mechanism 20. Specifically, the supply path 10 supplies the liquid 2 to the tank 21 located at the ascending position. A supply valve 13 is provided in the supply path 10.

[0011] The equipment 5 is, for example, a processing device for the workpiece W. However, as long as it is a machine that uses the liquid 2, the equipment 5 is not limited to the processing device. On the other hand, the liquid 2 is, for example, machine oil such as cutting oil used by the equipment 5, a coolant or cooling water. The liquid 2 is discharged from the equipment 5 and supplied to the tank 21 via the supply path 10. As will be described later, the liquid 2 may be temporarily stored by the tank 31 of the tank locking device 40 or another storage tank (not shown) before being supplied to the tank 21.

[0012] Next, the lift mechanism 20 will be described. As shown in FIGS. 2A and 2B, the lift mechanism 20 includes a tank 21 and a weight 22. The tank 21 and the weight 22 are connected to each other via a cable (wire) 23. The cable 23 is hung on pulleys 24, 24, and the positions of the pulleys 24, 24 are higher than the positions of the tank 21 and the weight 22. Therefore, the tank 21 and the weight 22 are suspended by the pulleys 24, 24 by gravity and are provided so as to be able to move up and down in opposite directions via the cable 23.

[0013] As shown in FIGS. 2A and 2B, the tank 21 is a container that is supported by a guide portion 25 so as to be able to move up and down and temporarily stores the liquid 2 supplied from the supply path 10. The tank 21 stores at least an amount of the liquid 2 that can lift the weight 22 and the workpiece W. An opening / closing device 70 of the supply valve 13 is provided at the upper part of the tank 21. Further, a discharge valve 14 for discharging the stored liquid 2 is provided at the bottom of the tank 21.

[0014] The weight 22 is supported by a guide portion 26 so as to be able to move up and down. The weight of the weight 22 is set such that the total weight of the weight 22 and the workpiece W is heavier than the empty tank 21 and lighter than the tank 21 when a predetermined liquid volume of the liquid 2 is stored.

[0015] As shown in Figures 3A and 3B, the weight 22 includes a mounting platform 27 for the workpiece W. The mounting platform 27 may be integrally formed with the weight 22 or it may be attached to the weight 22. In either case, the mounting platform 27 moves up and down together with the weight 22.

[0016] Here, the opening and closing device 70 for the supply valve 13 will be described. As shown in Figure 4A, the supply valve 13 comprises a valve body 13a and a cock (lever) 13b. The opening degree of the valve body 13a is adjusted according to the rotation angle of the cock 13b. For example, as shown in Figure 4A, the piping 10a of the supply path 10 is installed horizontally, and the supply valve 13 is installed in the middle of it.

[0017] In the state shown in Figure 4A, the rotation angle of the cock 13b is set to an angle parallel to the pipe 10a. In this case, the supply valve 13 is open. On the other hand, in the state shown in Figure 4B, the rotation angle of the cock 13b is set to an angle approximately perpendicular to the pipe 10a. In this case, the supply valve 13 is closed. A roller 15 is attached to the tip of the cock 13b. The roller 15 can contact either the upper plate 71 or the lower plate 72 of the opening / closing device 70.

[0018] The opening / closing device 70 comprises an upper plate 71 and a lower plate 72. The upper plate 71 and the lower plate 72 have a width longer than the roller 15 and are arranged facing each other with a gap between them in the vertical direction. The gap between the upper plate 71 and the lower plate 72 along the vertical direction is set to a value that allows the roller 15 to be inserted.

[0019] As shown in Figure 4A, the lower plate 72 extends approximately horizontally with a length greater than or equal to the width of the rotation range of the cock 13b. Viewed from above, the lower plate 72 is located in a region that includes the movement range of the roller 15. Therefore, regardless of the rotation angle of the cock 13b, the lower plate 72 is positioned to be in contact with the roller 15.

[0020] As shown in Figure 4A, the upper plate 71 includes a parallel portion 71a and an inclined portion 71b. The parallel portion 71a is positioned approximately parallel to the longitudinal direction of the cock 13b when the supply valve 13 is in the open position. The inclined portion 71b extends from the end of the parallel portion 71a closest to the valve body 13a and is inclined such that the distance from the lower plate 72 increases as it approaches the rotation center of the cock 13b (i.e., the valve body 13a).

[0021] However, the end of the inclined portion 71b is interrupted at the position where it contacts the roller 15 when the supply valve 13 is in the closed position. That is, as shown in Figure 4B, when viewed from the rotational axis of the cock 13b, the end of the inclined portion 71b remains in a region that does not interfere with the rotation of the cock 13b (roller 15) when the supply valve 13 is in the closed position.

[0022] With this configuration, when the tank 21 rises to the raised position (i.e., when transitioning from the state shown in Figure 4B to the state shown in Figure 4A), the lower plate 72 pushes the roller 15 upward, rotating the cock 13b in the direction that opens the supply valve 13. When the tank 21 reaches the raised position, the cock 13b is positioned approximately horizontally, and the supply valve 13 opens. That is, liquid 2 is supplied to the tank 21.

[0023] On the other hand, when the tank 21 descends from the raised position (i.e., when it transitions from the state shown in Figure 4A to the state shown in Figure 4B), first, the parallel portion 71a of the upper plate 71 pushes the roller 15 downward, rotating the cock 13b in the direction that closes the supply valve 13. As the tank 21 descends further, the inclined portion 71b of the upper plate 71 pushes the roller 15 further downward, closing the supply valve 13 further. When the tank 21 descends to a state where the inclined portion 71b is away from the roller 15, the cock 13b rotates to almost the closed position, and the supply valve 13 closes. In other words, the supply of liquid 2 to the tank 21 stops.

[0024] As shown by the dotted line in Figure 4A, the opening / closing device 70 may also include an auxiliary plate 73 that guides the roller 15 to the lower plate 72. The auxiliary plate 73 is provided in the vicinity of the lower plate 72 and at a position where it can contact the roller 15 when the longitudinal direction of the cock 13b is substantially perpendicular to the lower plate 72. Furthermore, the auxiliary plate 73 is inclined such that the closer it gets to the space between the lower plate 72 and the parallel portion 71a, the closer it gets to the lower plate 72. In this case, the roller 15 contacts the auxiliary plate 73 before contacting the lower plate 72, deflecting the longitudinal direction of the cock 13b so that it is parallel to the lower plate 72.

[0025] Next, the weight lock device 30 will be described. The weight lock device 30 locks the weight 22 (its movement) when the weight 22 is in the raised position. The weight lock device 30 also releases the lock when the amount of liquid 2 discharged from the tank 21 exceeds a predetermined value.

[0026] As shown in Figure 5A, the weight lock device 30 comprises a tank 31 and a hook portion 32. The tank 31 and the hook portion 32 are connected to each other via a cable 33 that is hung on a pulley 34. The pulley 34 is positioned higher than the respective positions of the release levers 32c of the tank 31 and the hook portion 32.

[0027] Tank 31 temporarily stores the liquid 2 discharged from tank 21. A switch (not shown) with a configuration similar to the switch 70 shown in Figure 4A is provided at the top of tank 31. The switch (not shown) on tank 31 opens the discharge valve 14 (see Figure 1) when tank 21 is in the lowered position, and closes the discharge valve 14 when tank 21 rises from the lowered position. Through this operation, liquid 2 is supplied to tank 31 from tank 21.

[0028] The liquid 2 stored in tank 31 is discharged from tank 31 after the lock on hook portion 32 is released. The liquid 2 discharged from tank 31 is returned to equipment 5, for example, via a recovery path 11 connected to the spring portion 31b side of tank 31.

[0029] A leg portion 31a, such as a caster, is attached to one end of the bottom of the tank 31. On the other hand, a spring portion 31b is attached to the other end of the bottom of the tank 31. The tank 21 is supported by these leg portion 31a and spring portion 31b. Due to the expansion and contraction of the spring portion 31b, the tank 31 swings around the leg portion 31a as a pivot point.

[0030] Of the two sides of the tank 31 in the horizontal direction, the portion closest to the spring portion 31b moves the most in the vertical direction due to the tilt of the tank 31. A cable 33, which connects to the hook portion 32, is connected to this portion.

[0031] The hook portion 32 locks, for example, the bottom of the weight 22 when it is in the raised position, and restricts the downward movement of the weight 22. The hook portion 32 has, for example, a claw portion 32a and a stay 32b. The claw portion 32a is formed in an L shape and is pivotably supported by the stay 32b. A release lever 32c is also provided on the claw portion 32a. A cable 33 is connected to the release lever 32c. On the other hand, the stay 32b is pivotably provided with one end as the pivot center. The other end of the stay 32b is connected to the claw portion 32a and rotatably supports the claw portion 32a.

[0032] Figure 5A shows the state where the weight 22 is in the lowered position. In this state, the tank 21 is in the raised position and liquid 2 is being supplied to the tank 21 (see Figure 1A). Meanwhile, the tank 31 is empty and maintains a nearly horizontal position.

[0033] When the amount of liquid 2 stored in tank 21 exceeds a predetermined value, the tank lock device 40, described later, releases the lock on tank 21. Consequently, as shown in Figure 5B, the weight 22 begins to rise from its lowered position and contacts the claw portion 32a of the hook portion 32. The claw portion 32a rotates (counterclockwise in Figure 5B) to be wrapped around the weight 22, while the stay 32b rotates (clockwise in Figure 5B) to move the hook portion 32 away from the weight 22. Therefore, the weight 22 can rise further without interfering with the claw portion 32a.

[0034] When the weight 22 reaches its raised position and the position of its bottom becomes higher than the position of the claw portion 32a, the posture of the claw portion 32a returns to its original position, and the tip of the claw portion 32a is positioned directly below the bottom of the weight 22. At this time, a magnet may be used to bring the claw portion 32a and the weight 22 into close contact with each other. By positioning a part of the claw portion 32a directly below the bottom of the weight 22, the downward movement of the weight 22 is restricted. In other words, the weight 22 is locked.

[0035] When the weight 22 reaches the raised position, the tank 21 has lowered to the lowered position. Consequently, the discharge valve 14 opens, and liquid 2 is supplied from tank 21 to tank 31. As liquid 2 is supplied to tank 31, the weight of the liquid 2 causes the spring section 31b to gradually contract, and the tank 31 begins to tilt towards the spring section 31b, with the leg section 31a as the pivot point. As a result, the portion of the cable 33 between the pulley 34 and the tank 31 is pulled downward. In response, the portion of the cable 33 between the pulley 34 and the release lever 32c is pulled upward, and the release lever 32c is pulled upward.

[0036] When the amount of liquid 2 stored in tank 31 exceeds a predetermined value, that is, when the cable 33 of a predetermined length is pulled downward by the tilt of tank 31, the claw portion 32a separates from the weight 22, and the lock on the weight 22 is released. At this time, most of the liquid 2 in tank 21 has been discharged. Consequently, the weight 22 descends toward the lowered position, and tank 21 rises toward the raised position. After that, tank 21 moves to the raised position, and the weight 22 returns to the state shown in Figure 5A.

[0037] Next, the tank lock device 40 will be described. The tank lock device 40 locks the tank 21 (its movement) when the tank 21 is in the raised position. The tank lock device 40 also releases the lock when the amount of liquid 2 supplied to the tank 21 exceeds a predetermined value.

[0038] As shown in Figure 6A, the tank lock device 40 comprises a tank 41, a seesaw 42, a lever 43, and a hook portion 44. One end of the seesaw 42 is connected to one end of the lever 43 via a cable 45. The other end of the lever 43 is connected to the hook portion 44 via a cable 46.

[0039] Tank 41 is located upstream of the supply valve 13 in the supply path 10 and stores the liquid 2 supplied from the supply path 10. As described above, the discharge of liquid 2 from tank 41 (i.e., the supply of liquid 2 to tank 21) is controlled by opening and closing the supply valve 13.

[0040] The seesaw 42 is installed inside the tank 41. A weight 47 is placed on one end of the seesaw 42, and a balancer 48 is placed on the other end of the seesaw 42. As shown in Figure 6A, the seesaw 42, together with the weight 47 and balancer 48, is completely immersed in the liquid 2. In other words, the liquid 2 is supplied to the tank 41 until the seesaw 42, weight 47, and balancer 48 are all submerged. In this state, the seesaw 42 maintains a nearly horizontal position.

[0041] On the other hand, when enough liquid 2 to lift the weight 22 is supplied from tank 41 to tank 21 via the supply valve 13, the seesaw 42 tilts towards the weight 47 (see Figure 6B). That is, the weights, dimensions, and shapes of tank 41, weight 47, and balancer 48 are adjusted and set so that this tilt of the seesaw 42 is obtained.

[0042] The configuration of the hook portion 44 is substantially the same as that of the hook portion 32. That is, the hook portion 44 has, for example, a claw portion 44a and a stay 44b, and locks the bottom of the tank 21 when it is in the raised position, restricting the lowering of the tank 21. The claw portion 44a is formed in an L shape and is supported by the stay 44b so as to be swingable. A release lever 44c is also provided on the claw portion 44a. A cable 46 is connected to the release lever 44c. On the other hand, the stay 44b is provided so as to be swingable with one end as the pivot point. The other end of the stay 44b is connected to the claw portion 44a and rotatably supports the claw portion 44a.

[0043] The operation of the hook portion 44 is substantially the same as the operation of the hook portion 32. That is, as shown in Figure 6A, the tip of the claw portion 44a is positioned directly below the bottom of the tank 21 when it is in the raised position. This restricts the descent of the tank 21, that is, the tank 21 is locked. When enough liquid 2 is stored in the tank 21 to lift the weight 22, the seesaw 42 tilts toward the weight 47, pulling the cable 45 downward. As a result, the lever 43 rotates, and the cable 46 is pulled upward. This pulls up the release lever 44c, causing the claw portion 44a to rotate and the lock on the tank 21 to be released. With the lock released, the tank 21 descends due to the weight of the liquid 2 stored inside it. In addition, the weight 22 rises in accordance with the descent of the tank 21.

[0044] As shown in Figure 7, in this embodiment, for example, the following process is performed. In the following process, equipment 5 is assumed to be a processing device. Therefore, cutting oil is used as liquid 2. Also, for the sake of explanation, the tank 41 of the tank lock device 40, the tank 21 of the lift mechanism 20, and the tank 31 of the weight lock device 30 will be referred to as the upper tank 41, the lifting tank 21, and the lower tank 31, respectively. In addition, the weight in the chart is the weight 22 of the lift mechanism 20, and the workpiece W is assumed to be placed on the mounting table 27.

[0045] First, the equipment is started (S10), and cutting fluid is supplied from the equipment to the upper tank 41 via the supply path 10 (see Figure 1) (S11). At this time, the lifting tank 21 is in the raised position, and the supply valve 13 is open (S12). Therefore, cutting fluid is supplied from the upper tank 41 to the lifting tank 21 via the supply valve 13 (S13). A predetermined amount of cutting fluid, i.e., an amount of cutting fluid sufficient to raise the weight 22 on which the workpiece W is placed, is stored in the lifting tank 21 (S14).

[0046] While cutting oil is being supplied to the lifting tank 21, the liquid level in the upper tank 41 decreases (S15). The decrease in the liquid level of cutting oil in the lifting tank 21 causes the seesaw 42 to tilt (S16). The tilting of the seesaw 42 releases the lock on the lifting tank 21 by the tank lock device 40 (S17). Meanwhile, a predetermined amount of cutting oil has been stored in the lifting tank 21 by this time. Therefore, the lifting tank 21 descends from the raised position to the lowered position, while the weight 22 rises from the lowered position to the raised position (S18). Also, as the lifting tank 21 descends from the raised position, the supply valve 13 closes (S19), and the weight 22 is locked in the raised position by the weight lock device 30 (S20).

[0047] When the lifting tank 21 descends to its lowered position, the discharge valve 14 opens, and cutting oil is discharged from the lifting tank 21 to the lower tank 31 (S21). Cutting oil accumulates in the lower tank 31, and its own weight causes the lower tank 31 to tilt (S22). The tilting of the lower tank 31 releases the lock on the weight 22 by the weight lock device 30 (S23). As a result, the weight 22 descends from the raised position to the lowered position, while the lifting tank 21 rises from the lowered position to the raised position (S24). Then, the lifting tank 21 is locked in the raised position by the tank lock device 40 (S25), and the supply of cutting oil from the upper tank 41 resumes. Also, due to the tilting of the lower tank 31, the cutting oil is returned to the equipment 5 via the recovery path 11 (see Figure 1) (S26).

[0048] According to this embodiment, the movement of the cable 23, tank 21, or weight 22 in the lift mechanism 20 can be used as the driving force for ancillary devices. For example, as shown in Figure 8A, the work lift device 1 may further include a work extrusion mechanism 50 and a posture changing device 60.

[0049] The workpiece extrusion mechanism 50 is a device that pushes the workpiece W, which is placed on the mounting table 27, toward the chute 8. The workpiece extrusion mechanism 50 includes a pusher 51 and a magnet 52.

[0050] The pusher 51 is formed, for example, in the shape of a rod and is positioned horizontally adjacent to the workpiece W when it is in the raised position. The pusher 51 is arranged to reciprocate horizontally toward the workpiece W by the aforementioned driving force. On the other hand, the magnet 52 is positioned to attract to the workpiece W when it is in the raised position.

[0051] The posture changing device 60 is driven by a descending tank 21 and is a device that changes the posture of a workpiece W removed from a mounting table 27. The posture changing device 60 comprises a holder 61 and a switch mechanism 62.

[0052] The holder 61 is located downstream of the chute 8 and has an opening 61a for receiving the workpiece W. The holder 61 is also supported so as to be able to swing so that the opening 61a faces upward by adjusting the center of gravity using a restoring mechanism (not shown) such as a torsion spring or weight.

[0053] The switch mechanism 62 includes a slider 63 and a pole 64 that supports the slider 63 so that it can move vertically, and is located near the tank 21. Viewed from above, a portion of the slider 63 is positioned to overlap with the bottom of the tank 21. That is, the slider 63 is shaped to be pushed by the descending tank 21. The slider 63 is also connected to the side of the holder 61 via a cable 65.

[0054] For example, as shown in Figure 8A, we can assume a situation where the workpiece W is placed on the mounting table 27 and the weight 22 is moving toward the raised position. When the weight 22 reaches the raised position, the magnet 52 attracts the workpiece W. Meanwhile, the tank 21 descends toward the lowered position, pressing the slider 63 downwards. The slider 63 moves downwards, and the cable 65 is pulled toward the slider 63. As a result, the holder 61 tilts so that its opening 61a faces the chute 8.

[0055] Subsequently, as shown in Figure 8B, the weight 22 begins to descend from its raised position, and the tank 21 begins to rise from its lowered position. In conjunction with this movement, the pusher 51 pushes the workpiece W, which was attracted to the magnet 52, toward the chute 8. The workpiece W slides along the surface of the magnet 52 and is released toward the chute 8. The released workpiece W slides along the chute 8 and is introduced into the holder 61 through the opening 61a.

[0056] As shown in Figure 8C, as the tank 21 rises further, it moves away from the slider 63. The slider 63 can then move up and down along the pole 64. Meanwhile, the tilted holder 61 returns to its original position. That is, the holder 61 returns to a position where the opening 61a faces upward. As a result, the workpiece W changes from a lying position to an almost upright position and is transported to the next device. Meanwhile, the weight 22 descends to its lowered position and waits until the next workpiece is placed on the mounting table 27.

[0057] In this way, by using the workpiece extrusion mechanism 50 and the posture changing device 60, the workpiece W can be removed from the mounting table 27 and its posture set to match the processing of the next device before the next workpiece is placed on the mounting table 27. Furthermore, these operations do not require the use of electric devices such as actuators.

[0058] As shown in Figures 9A to 9D, the weight 22 may be provided with a guide portion 28. The guide portion 28 is provided on the side of the weight 22 that can face the hook portion 32. The hook portion 32 may also have a roller 35. The roller 35 is rotatably mounted about a rotation axis parallel to the pivot axis of the hook portion 32. The roller 35 is positioned so as to be able to contact the inclined surface 28a of the guide portion 28. Therefore, the roller 35 is attached, for example, to the tip of the claw portion 32a facing the weight 22.

[0059] The guide portion 28 has an inclined surface 28a. The inclined surface 28a extends, for example, from the upper corner to the lower corner of the weight 22. The uppermost part of the inclined surface 28a, when viewed from above, is located on the side opposite to the side where the hook portion 32 is located, with respect to the rotation center of the roller 35. The inclined surface 28a is inclined in the vertical direction such that as the weight 22 rises and approaches the claw portion 32a, the distance between the weight 22 and the claw portion 32a in the horizontal direction decreases. This distance decreases as the weight 22 rises and becomes zero at some point along the inclined surface 28a in the vertical direction. That is, the inclined surface 28a is formed so that the weight 22 comes into contact with the roller 35 during its rise.

[0060] As the weight 22 rises, the roller 35 first makes contact with the inclined surface 28a. As the weight 22 rises further, the roller 35 rotates while in contact with the inclined surface 28a and is pushed away from the weight 22 (to the left in Figure 9B). At this time, the claw portion 32a rotates so as to be wrapped around the weight 22 (counterclockwise in Figure 9B), and the stay 32b rotates so as to move the hook portion 32 away from the weight 22 (clockwise in Figure 9B). In this way, by the roller 35 making contact with the inclined surface 28a and moving smoothly along the inclined surface 28a, the reverse rotation of the claw portion 32a and the stay 32b is avoided, and smooth operation of the hook portion 32 can be reliably achieved.

[0061] The operation of the hook portion 32 when the weight 22 reaches the raised position is the same as when the inclined surface 28a and roller 35 are not provided. That is, when the position of the bottom of the weight 22 becomes higher than the position of the claw portion 32a, the posture of the claw portion 32a returns to its original position, and the tip of the claw portion 32a is positioned directly below the bottom of the weight 22. The downward movement of the weight 22 is restricted by a part of the claw portion 32a being positioned directly below the bottom of the weight 22. In other words, the weight 22 is locked (see Figure 9C).

[0062] Furthermore, when the amount of liquid 2 stored in the tank 31 exceeds a predetermined value while the weight 22 is locked in the raised position, the tank 31 tilts counterclockwise. This causes the cable 33 to pull the release lever 32c upward, releasing the weight 22 from the weight locking device 30 (see Figure 9D).

[0063] As shown in Figures 9A to 9D, legs 31c may be provided at the bottom of the tank 31. In this case, a stopper 36 is provided on one side of the tank 21 in the horizontal direction, on the side opposite to the side to which the cable 33 is connected. The legs 31c support the tank 31 so that it can swing. The position of the legs 31c is set such that an empty tank 31 tilts towards the stopper 36, and a tank 31 containing a predetermined amount of liquid 2 tilts away from the stopper 36. The stopper 36 also supports the tank 31 tilted towards the stopper 36 from below.

[0064] When the amount of liquid 2 stored in tank 31 exceeds a predetermined value due to the supply of liquid 2 from tank 21 to tank 31, the center of gravity of tank 31 moves from the stopper 36 side to the opposite side, relative to the position of the leg portion 31c. As a result, tank 31 tilts counterclockwise with the leg portion 31c as the pivot point (see Figure 9D). This tilt causes tank 31 to pull the cable 33, and the release lever 32c is pulled upward. As a result, the claw portion 32a separates from the weight 22, and the lock on the weight 22 is released. At this point, most of the liquid 2 in tank 21 has been discharged. Therefore, the weight 22 descends toward the lowered position, and tank 21 rises toward the raised position. After that, tank 21 moves to the raised position, and the weight 22 returns to the state shown in Figure 9A.

[0065] (1) The work lift device 1 according to this embodiment includes a lift mechanism 20 including a tank 21 and a weight 22 that are provided to be able to move up and down in opposite directions, and a supply path 10 that supplies liquid 2 used in other equipment 5 to the tank 21 located in the raised position. The weight 22 includes a platform 27 for placing the workpiece W. The tank 21 is lowered from the raised position to the lowered position by the weight of the liquid 2 stored in the tank 21. In this device, the liquid 2 is used as the power source and does not require electricity. That is, there is no need to introduce electric devices such as actuators. Therefore, it is possible to reduce the burden on workers in transporting workpieces while suppressing an increase in equipment costs.

[0066] (2) The liquid 2 stored in the tank 21 may be discharged when the tank 21 moves to the lowered position. This allows the raising and lowering of the tank 21 and the weight 22 to continue.

[0067] (3) The work lift device 1 may further include a recovery path 11 that returns the liquid 2 discharged from the tank back to the equipment from which the liquid 2 was discharged. This makes it possible to reuse the liquid 2 in the equipment and reduces excessive consumption of the liquid 2.

[0068] (4) The work lift device 1 may further include a weight lock device 30 that locks the weight 22 when the weight 22 is in the raised position and releases the lock on the weight 22 when the amount of liquid 2 discharged from the tank 21 exceeds a predetermined value. This makes it possible to stably stop the position of the weight 22 (i.e., the position of the work W) for a certain period of time without using an electric device such as an actuator, and to perform the lifting and lowering operation of the tank 21.

[0069] (5) The work lift device 1 may further include a tank lock device 40 that locks the tank 21 when the tank 21 is in the raised position and releases the lock on the tank 21 when the amount of liquid supplied to the tank 21 exceeds a predetermined value. This ensures that the amount of liquid 2 necessary to lower the tank 21 is reliably supplied into the tank 21. Furthermore, a flow sensor for measuring the amount of liquid 2 supplied and an actuator for releasing the lock are not required.

[0070] (6) The work lift device 1 may further include a posture changing device 60 driven by a descending tank 21 to change the posture of the workpiece W removed from the mounting table 27. The posture of the workpiece W can be changed using the weight of the liquid 2 stored in the tank 21. That is, the posture of the workpiece W can be changed without using electricity. The posture of the workpiece W is changed after it has been removed from the mounting table 27 of the weight 22 and during the stage when the mounting table 27 is preparing to place the next workpiece (i.e., when the weight 22 is descending). That is, this period can be used to change the posture of the workpiece W without wasting any time.

[0071] The embodiments described above are merely illustrative examples provided to facilitate understanding of the invention. The technical scope of the invention is not limited to the specific technical matters disclosed in the embodiments described above, but also includes various modifications, changes, and alternative technologies that can be easily derived therefrom. [Explanation of Symbols]

[0072] 1. Work lift device 2 Liquid (cutting oil) 5 Equipment 10. Supply routes 11. Recovery Route 20 Lift mechanism 21 Tank (Lifting Tank) 22 weights 27 Mounting platform 30 Weight locking device 40 Tank Lock Device 50 Workpiece extrusion mechanism 60. Posture changing device Double job

Claims

1. A lift mechanism including a tank and a weight, which are provided to be able to move up and down in opposite directions, The system includes a supply path for supplying liquid used in other equipment to the tank located at an elevated position, The aforementioned weight includes a workpiece mounting base. The weight of the liquid stored in the tank causes the tank to descend from the raised position to the lowered position. Work lifting device.

2. The liquid stored in the tank is discharged when the tank moves to the lowered position. The work lift device according to claim 1.

3. The system further includes a recovery path for returning the liquid discharged from the tank back to the other equipment. The work lift device according to claim 2.

4. The system further includes a weight locking device that locks the weight when it is in the raised position and releases the lock when the amount of liquid discharged from the tank exceeds a predetermined value. The work lift device according to claim 2 or 3.

5. The tank lock device further includes a tank locking mechanism that locks the tank when it is in the raised position and releases the lock when the amount of liquid supplied to the tank exceeds a predetermined value. The work lift device according to claim 2 or 3.

6. The device further comprises a posture changing device, which is driven by the descending tank and changes the posture of the workpiece removed from the aforementioned stand, The work lift device according to claim 1.

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