Elevating assistance device

Abstract

To provide an elevating assistance device capable of suppressing generation of unintended motion.SOLUTION: This elevating assistance device comprises: an arm that holds an object; a load detection unit 31b that detects a load of the object; an input unit configured to be pressable; an elevating unit that elevates the arm; and a controller 40. The controller 40 includes a command part 44, a first processing part 42, a second processing part 43, and a stop part 45. The command part 44 outputs a command value relating to driving of the elevating unit to the elevating unit. The first processing part 42 outputs a balance driving amount to the command part 44 in accordance with the load detected by the load detection unit 31b. The second processing part 43 outputs an operation driving amount to the command part 44 in response to a pressing operation. The command part 44 drives the elevating unit on the basis of the balance driving amount and the operation driving amount. The stop part 45 stops the outputting of the operation driving amount executed by the second processing part 43 in response to the pressing operation.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a lift assist device. [Background technology]

[0002] Patent Document 1 discloses a bricklaying balancer as a lifting assist device. The bricklaying balancer has a link-type arm as an arm, a drive device as a lifting / lowering unit, and a pressure-sensitive button switch as an input unit. The lifting / lowering assist device holds a brick as an object at the tip of the link-type arm. The lifting / lowering unit moves the link-type arm in the up and down direction. The speed at which the link-type arm moves by the lifting / lowering unit is controlled according to the strength of the pressing force at the input unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-046107 Summary of the Invention [Problem to be solved by the invention]

[0004] For example, when operating the lift assist device, the worker may unintentionally apply a large amount of pressure to the input unit, which may cause the arm to move in response to the large amount of pressure, potentially resulting in an unintended operation of the lift assist device. [Means for solving the problem]

[0005] The lifting assistance device for solving the above problem comprises an arm for holding an object, a load detection unit for detecting the load of the held object, an input unit configured to enable pressing operations, a lifting unit for raising and lowering the arm, and a control device for controlling the lifting unit, wherein the control device comprises a command unit for outputting a command value related to the drive of the lifting unit to the lifting unit, a first processing unit for outputting a balance drive amount to the command unit in accordance with the load detected by the load detection unit, and a second processing unit for outputting an operation drive amount to the command unit in accordance with the pressing operation, wherein the command unit drives the lifting unit based on the balance drive amount and the operation drive amount, and the control device comprises a stop unit for stopping the output of the operation drive amount by the second processing unit in accordance with the pressing operation on the input unit.

[0006] In the above-mentioned lifting assistance device, the input unit may have a first detection unit that detects the pressing operation and a second detection unit that detects the pressing operation, and the stop unit may stop the output of the operation drive amount by the second processing unit when the pressing operation is performed on both the first detection unit and the second detection unit.

[0007] In the above-described lift assist device, the stop unit may stop the output of the operation drive amount by the second processing unit when the operation drive amount becomes equal to or greater than an upper limit value or equal to or less than a lower limit value. In the above-described lift assist device, the input unit may have the first detection unit below the second detection unit.

[0008] In the above-mentioned lifting assistance device, the second processing unit may output the operation drive amount related to raising the arm in response to the pressing operation of the first detection unit, and may also output the operation drive amount related to lowering the arm in response to the pressing operation of the second detection unit.

[0009] In the above-described lift assist device, each of the first detection unit and the second detection unit may be configured by a pressure-sensitive sensor. [Effects of the Invention]

[0010] According to the present invention, it is possible to prevent unintended actions from occurring. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view showing a lift assist device. [Figure 2] FIG. 2 is a front view showing the holding portion. [Figure 3] FIG. 3 is a block diagram showing the control device. [Figure 4] FIG. 4 is a schematic diagram showing the operation of the lift assist device. [Figure 5] FIG. 5 is a schematic diagram showing the operation of the lift assist device. DETAILED DESCRIPTION OF THE INVENTION

[0012] An embodiment of the lift assist device will be described below with reference to Figs. 1 to 5. The lift assist device is operated by a worker and assists the worker in moving an object.

[0013] <Overall view of the lift assist device> As shown in FIG. 1, the lift assist device 100 includes a base B, a lift unit 10, an arm 20, a holder 30, a control device 40, and a battery C.

[0014] <Base> The base B has a base B1, a handle B2, a support B3, an installation hole B4, and wheels B5. The base B1 is a rectangular plate with a thickness direction in the vertical direction Z. The handle B2 is provided on the upper surface of the base B1. The handle B2 is provided on one of the four edges of the base B1. The handle B2 is composed of a pair of parts extending from the base B1 in the vertical direction Z and a part connecting the upper ends of the pair of parts and extending horizontally. Wheels B5 are provided on the lower surface of the base B1. The base B1 is configured to be propelled by an operator pushing it while holding the handle B2. In other words, the base B1, the handle B2, and the wheels B5 form a cart. Hereinafter, the direction in which the cart is pushed and pulled by the operator will be referred to as the forward / backward direction X. In particular, the direction in which the cart moves when the operator pushes the handle B2 is referred to as "front," and the opposite side of "front" in the front-to-rear direction X is referred to as "rear." The direction perpendicular to each of the up-down direction Z and the front-to-rear direction X is referred to as the left-to-right direction Y.

[0015] An installation hole B4 is provided in the center of the base B1. A support pillar B3 is provided in the base B1 between the installation hole B4 and the handle portion B2 in the front-rear direction X. A battery C is provided on the base B. The battery C is placed on a rear portion of the base B1. The battery C supplies power to the control device 40 and the lifting unit 10.

[0016] <Lifting section> The lifting unit 10 includes a body 11, a cover 12, a slider 13, and a motor 14.

[0017] The body 11 is gutter-shaped and extends in the vertical direction Z. The body 11 opens forward. The body 11 is mounted on the base B. The body 11 is fixed to the front surface of the support B3. When viewed from the vertical direction Z, the body 11 is positioned so as to slightly overlap with the installation hole B4. The body 11 has a portion that extends slightly forward at each of both ends in the vertical direction Z. Each of the extended portions is plate-shaped with the thickness direction being the vertical direction Z.

[0018] The body 11 has a guide (not shown) inside. The guide extends in the vertical direction Z. The cover 12 is plate-shaped with its longitudinal direction in the vertical direction Z. The thickness direction of the cover 12 is in the front-rear direction X. The cover 12 is provided on the front side of the body 11. In other words, the cover 12 is provided on one of the surfaces of the body 11 in the front-rear direction X that does not face the support B3. The cover 12 is attached to the body 11 while being spaced apart from the body 11 in the front-rear direction X. Specifically, the cover 12 is sandwiched between extended portions at both upper and lower ends of the body 11 in the vertical direction Z. The cover 12 is fixed to the body 11.

[0019] A gap 10a is formed between the cover 12 and the body 11. The gap 10a extends in the vertical direction Z. The gap 10a communicates with the outside of the lifting unit 10 in the horizontal direction Y.

[0020] The slider 13 is provided in the gap 10a. The slider 13 has a thickness direction in the front-rear direction X and is plate-shaped extending in the up-down direction Z. The slider 13 has a pair of connecting portions 13a. Each connecting portion 13a is an end portion of the slider 13 in the left-right direction Y. The slider 13 is bent forward at the pair of connecting portions 13a. In other words, the slider 13 is trough-shaped, extending in the up-down direction Z and opening forward. The slider 13 is provided between the cover 12 and the body 11. The slider 13 is provided in the gap 10a so that the pair of connecting portions 13a protrude from the gap 10a. The slider 13 is reciprocable in the up-down direction Z along the body 11. As will be described later, an arm 20 is connected to the slider 13 via an attachment member 24.

[0021] The motor 14 is provided at the lower end of the body 11. The motor 14 has a rotating shaft (not shown) extending in the vertical direction Z. The rotating shaft of the motor 14 is housed in the gap 10a. The motor 14 is fixed to the body 11 and inserted into the installation hole B4. The motor 14 is fixed to the body 11 so that the rotating shaft can rotate inside the gap 10a. In this embodiment, the motor 14 is a servo motor.

[0022] The motor 14 has, for example, a ball screw (not shown) on its rotation shaft, and is connected to the slider 13 via the ball screw. The ball screw is arranged parallel to the guide inside the body 11. In other words, the ball screw extends in the vertical direction Z. The motor 14 rotates the rotation shaft, thereby moving the slider 13 in the vertical direction Z via the ball screw. The rotation of the rotation shaft by the motor 14 and the reciprocating movement of the slider 13 in the vertical direction Z are linked. In other words, the body 11, the cover 12, the slider 13, and the motor 14 constitute a linear actuator. In this embodiment, the lifting unit 10 is a linear actuator. Therefore, the lifting assistance device 100 has a linear actuator.

[0023] <Arm> The arm 20 is supported by the lifting unit 10. The arm 20 is attached to the front side of the lifting unit 10. The arm 20 extends horizontally from the base end to the tip. The base end of the arm 20 is attached to the lifting unit 10. The tip of the arm 20 can swing relative to the base end. In other words, the arm 20 can swing in a horizontal plane relative to the lifting unit 10.

[0024] The arm 20 has a first arm member 21 and a second arm member 22. The first arm member 21 constitutes a portion of the arm 20 closer to the base end. The second arm member 22 constitutes a portion of the arm 20 closer to the tip end. The first arm member 21 and the second arm member 22 are connected to each other.

[0025] The first arm member 21 has a columnar shape extending horizontally from a first end to a second end. The first arm member 21 has a first support shaft 20a at the first end. The first support shaft 20a has a cylindrical shape with a central axis in the vertical direction Z. The first support shaft 20a is fixed to the first arm member 21.

[0026] The first arm member 21 is connected at a first end to a pair of mounting members 24 via a first support shaft 20a. The first end of the first arm member 21 is sandwiched between the pair of mounting members 24 in the vertical direction Z. A through hole (not shown) that penetrates the mounting members 24 in the vertical direction Z is formed in the mounting members 24. The first arm member 21 is connected to each mounting member 24 by inserting the first support shaft 20a into the through hole of each mounting member 24. The first support shaft 20a is inserted into the through hole so as to be rotatable relative to the pair of mounting members 24. In other words, the first arm member 21 is swingable relative to the mounting members 24, with the central axis of the first support shaft 20a serving as the swing axis.

[0027] The first arm member 21 has a second support shaft 20b at a second end. The second support shaft 20b is cylindrical with a central axis in the vertical direction Z. The second support shaft 20b is fixed to the first arm member 21.

[0028] The second arm member 22 has a columnar shape extending horizontally from a first end to a second end. The second arm member 22 is connected at its first end to the second end of the first arm member 21. A through-hole (not shown) that penetrates in the vertical direction Z is provided at the first end of the second arm member 22, and a second support shaft 20b is inserted into the through-hole. The second support shaft 20b is inserted into the through-hole so as to be rotatable relative to the second arm member 22. In other words, the first arm member 21 can swing relative to the second arm member 22, with the central axis of the second support shaft 20b serving as a swing axis. In other words, the second arm member 22 is connected to the first arm member 21 with the central axis of the second support shaft 20b serving as a swing axis.

[0029] A through hole (not shown) that penetrates in the vertical direction Z is provided at the second end of the second arm member 22. The arm 20 is connected to the lifting unit 10 by attaching the mounting member 24 to the slider 13. The arm 20 moves in the vertical direction Z along the body 11 as the slider 13 moves in the vertical direction Z. In other words, the arm 20 moves in conjunction with the slider 13. More specifically, as the slider 13 moves in the vertical direction Z, the first arm member 21 and the second arm member 22 move in the vertical direction Z. The first arm member 21 moves in conjunction with the slider 13 in the vertical direction Z, and swings in the horizontal direction independently of the slider 13, with the central axis of the first support shaft 20a serving as the swing axis. Furthermore, the second arm member 22 moves in conjunction with the slider 13 in the vertical direction Z, and swings in the horizontal direction independently of the slider 13, with the second support shaft 20b as the swing axis.

[0030] <Holding part> The holding unit 30 is provided at the tip of the arm 20. More specifically, the holding unit 30 is provided at the second end of the second arm member 22. The holding unit 30 is supported by the arm 20. The holding unit 30 is configured to be able to hold an object W. In this embodiment, the holding unit 30 has a fork 31a, and holds the object W with the fork 31a.

[0031] The holder 30 may hold the object W using a configuration different from the fork 31a. For example, the holder 30 may have a configuration capable of sucking the object W, instead of the fork 31a. The holder 30 may also have a hook, instead of the fork 31a, on which the object W can be hung. The method by which the holder 30 holds the object W may be changed depending on the shape of the object W.

[0032] 1 and 2, the holding unit 30 has a main body 31 and a handle 32. An operator (not shown) holds the handle 32 and moves the handle 32 in the horizontal direction to position the main body 31 in the horizontal direction.

[0033] The main body 31 has a fork 31a and a load detection unit 31b. The main body 31 is configured such that the fork 31a and the load detection unit 31b are aligned in the vertical direction Z. The fork 31a is provided below the load detection unit 31b.

[0034] The forks 31a support the object W from below to hold it. That is, the holding unit 30 holds the object W while supporting it with the forks 31a. The load detection unit 31b is provided at the tip of the arm 20. The load detection unit 31b is attached to the second end of the second arm member 22. The holder 30 is connected to the tip of the arm 20 by the load detection unit 31b. The fork 31a is provided on the arm 20 via the load detection unit 31b. The load detection unit 31b is configured to be able to detect the load of the object W held by the fork 31a. In other words, the holder 30 holds the object W and detects the load of the object W. For example, the load detection unit 31b has a load cell and detects the load applied to the fork 31a using the load cell. In other words, the load detection unit 31b detects the load of the held object W.

[0035] In a situation where an operator operates the arm 20 via the holding unit 30 using the handle 32, the load detection unit 31b detects a load caused by the operation by the operator in addition to the load of the object W. The load caused by the operation by the operator is generated by, for example, the inertia of each of the object W and the holding unit 30.

[0036] A third support shaft 30a extending upward is provided on the top surface of the main body 31. The main body 31 is attached to the second arm member 22 by inserting the third support shaft 30a into a through-hole (not shown) at the second end of the second arm member 22. The third support shaft 30a is rotatable in the through-hole at the second end of the second arm member 22. In other words, the holding unit 30 is provided at the second end of the second arm member 22 so as to be rotatable about the third support shaft 30a as the rotation axis.

[0037] The handle 32 has a cylindrical shape extending horizontally. The handle 32 is provided in the main body 31 at a position above the fork 31a and below the third support shaft 30a. The handle 32 is provided on the main body 31 on the base end side of the fork 31a. The direction in which the axis of the handle 32 extends is perpendicular to the direction in which the fork 31a extends.

[0038] The handle 32 has an input unit 33. That is, the lifting assistance device 100 has the input unit 33. The input unit 33 is provided on the surface of the handle 32. The input unit 33 is located in a position where it is grasped together with the handle 32 when the worker grasps the handle 32.

[0039] The input unit 33 has a first detection unit 331 and a second detection unit 332. The first detection unit 331 is provided on a portion of the circumferential surface of the handle 32 that faces downward in the vertical direction Z. The second detection unit 332 is provided on a portion of the circumferential surface of the handle 32 that faces upward in the vertical direction Z. In other words, the input unit 33 has the first detection unit 331 below the second detection unit 332.

[0040] The first detection unit 331 is configured with a pressure sensor. The first detection unit 331 protrudes downward from the circumferential surface of the handle 32, and is configured to be displaceable upward relative to the handle 32 when pressed upward by the operator. When pressed, the first detection unit 331 is displaced toward the inside in the radial direction of the handle 32. The first detection unit 331 detects the amount of displacement associated with the pressing as a pressure value. Hereinafter, the pressure value detected by the first detection unit 331 will be referred to as the first pressure value.

[0041] The second detection unit 332 is composed of a pressure sensor. The second detection unit 332 protrudes upward from the circumferential surface of the handle 32, and is configured to be displaceable downward relative to the handle 32 when pressed downward by the operator. When pressed, the second detection unit 332 is displaced radially inward of the handle 32. The second detection unit 332 detects the amount of displacement associated with the pressing as a pressure value. Hereinafter, the pressure value detected by the second detection unit 332 will be referred to as the second pressure value.

[0042] Each of the first pressure value and the second pressure value is a positive value equal to or greater than zero. The greater the amount of displacement of the first detection unit 331 due to the pressing, the greater the first pressure value. The greater the amount of displacement of the second detection unit 332 due to the pressing, the greater the second pressure value.

[0043] The input unit 33 is configured to be capable of being pressed. Consider a state in which the input unit 33 is not being held by an operator. Hereinafter, the state in which the input unit 33 is not being held by an operator will be referred to as a reference state S1. In the reference state S1, the first detection unit 331 and the second detection unit 332 each protrude from the circumferential surface of the handle 32. When the operator holds the portion of the handle 32 where the input unit 33 is provided, the first detection unit 331 and the second detection unit 332 are each pressed radially inward of the handle 32. Hereinafter, a state in which the first detection unit 331 or the second detection unit 332 of the input unit 33 is pressed by the operator will be referred to as an operation state S2.

[0044] <Control device> As shown in FIG. 1 , the control device 40 is provided outside the lifting unit 10. The control device 40 is fixed to the support B3. The control device 40 is electrically connected to the lifting unit 10 and the holding unit 30. More specifically, the control device 40 is electrically connected to each of the motor 14, the load detection unit 31b, the first detection unit 331, and the second detection unit 332. The control device 40 controls the lifting and lowering of the arm 20 by the lifting unit 10. Specifically, the control device 40 controls the lifting and lowering of the arm 20 by the lifting unit 10 by controlling the rotation of the motor 14 based on a signal output from the holding unit 30.

[0045] 3, the control device 40 has a conversion unit 41, a first processing unit 42, a second processing unit 43, a command unit 44, and a stop unit 45. In the control device 40, the conversion unit 41 is connected to each of the first processing unit 42 and the second processing unit 43. The first processing unit 42 and the second processing unit 43 are each connected to the command unit 44. The stop unit 45 refers to a value input to the second processing unit 43. The stop unit 45 is configured to be able to control the second processing unit 43 based on the value.

[0046] <Conversion section> The conversion unit 41 is connected to the load detection unit 31b. A load obtained by adding a load related to the weight of the arm 20 and the holding unit 30 to the load detected by the load detection unit 31b is input to the conversion unit 41. Furthermore, in a situation where the holding unit 30 is being operated by an operator, the load detected by the load detection unit 31b includes a load caused by the operator's operation. The conversion unit 41 converts the input load into a digital signal. Hereinafter, the digital signal related to the input load will be referred to as a digital load. The conversion unit 41 outputs the digital load to the first processing unit 42.

[0047] The conversion unit 41 is connected to each of the first detection unit 331 and the second detection unit 332. The conversion unit 41 receives an input of a first pressure value detected by the first detection unit 331. The conversion unit 41 also receives an input of a second pressure value detected by the second detection unit 332. The conversion unit 41 converts each of the first pressure value and the second pressure value into a digital signal. Hereinafter, a digital signal related to the first pressure value will be referred to as a first digital pressure value. Also, a digital signal related to the second pressure value will be referred to as a second digital pressure value. The conversion unit 41 outputs the first digital pressure value and the second digital pressure value to the second processing unit 43. Each of the first digital pressure value and the second digital pressure value changes in response to the operator's pressing operation on the input unit 33.

[0048] <First processing section> The first processing unit 42 receives the digital load from the conversion unit 41. The first processing unit 42 calculates the drive amount of the motor 14 required to balance the arm 20 in the vertical direction Z with respect to the load associated with the digital load. Hereinafter, the drive amount calculated by the first processing unit 42 will be referred to as the balance drive amount. The load associated with the weight of the arm 20 and the holding unit 30 does not change. In other words, the balance drive amount changes depending on the weight of the object W held by the arm 20. The heavier the object W, the greater the balance drive amount.

[0049] Here, in a situation where the worker is operating the holding unit 30, the digital load input to the first processing unit 42 takes into account the load resulting from the worker's operation of the holding unit 30. In other words, in this situation, the first processing unit 42 calculates the drive amount according to the load of the object W, the load related to the weight of the arm 20 and the holding unit 30, and the load resulting from the worker's operation of the holding unit 30. In other words, the balance drive amount of the first processing unit 42 includes the drive amount for moving the holding unit 30 that holds the object W.

[0050] A correspondence relationship between the input load and the balance drive amount to be output is set in advance in the first processing unit 42. The first processing unit 42 outputs the balance drive amount based on the correspondence relationship.

[0051] The first processing unit 42 outputs the calculated balance drive amount to the command unit 44. That is, the first processing unit 42 outputs to the command unit 44 a balance drive amount corresponding to the load detected by the load detection unit 31b.

[0052] <Second processing section> The second processing unit 43 receives the first digital pressure value and the second digital pressure value from the conversion unit 41. The second processing unit 43 calculates a drive amount of the motor 14 corresponding to the magnitude of each of the first digital pressure value and the second digital pressure value. Hereinafter, the drive amount calculated by the second processing unit 43 will be referred to as the operation drive amount. That is, the motor 14 is driven in accordance with the operation drive amount, and the slider 13 moves in the vertical direction Z along the body 11 due to this drive. In other words, the drive of the motor 14 in accordance with the operation drive amount moves the arm 20 in the vertical direction Z via the slider 13. The operation drive amount changes in accordance with each of the first pressure value and the second pressure value.

[0053] A correspondence relationship between the input first digital pressure value and the input second digital pressure value and the operation drive amount to be output is set in advance in the second processing unit 43. The second processing unit 43 outputs the operation drive amount based on the correspondence relationship.

[0054] In this embodiment, the operation drive amount can be a positive value or a negative value. A positive operation drive amount causes the motor 14 to drive the slider 13 in a direction to raise the slider 13. A negative operation drive amount causes the motor 14 to drive the slider 13 in a direction to lower the slider 13. Note that the operation drive amount does not have to be a positive or negative value. For example, a predetermined reference value may be set, and the operation drive amount may be determined by the difference from the reference value.

[0055] The second processing unit 43 calculates a positive operation drive amount in accordance with the first digital pressure value. In other words, the second processing unit 43 calculates a operation drive amount in a direction in which the arm 20 and the holding unit 30 rise in accordance with the first digital pressure value. The second processing unit 43 also calculates a negative operation drive amount in accordance with the second digital pressure value. In other words, the second processing unit 43 calculates a operation drive amount in a direction in which the arm 20 and the holding unit 30 fall in accordance with the second digital pressure value. In other words, the second processing unit 43 outputs an operation drive amount related to the rise of the arm 20 in accordance with the pressing operation of the first detection unit 331. The second processing unit 43 also outputs an operation drive amount related to the descent of the arm 20 in accordance with the pressing operation of the second detection unit 332.

[0056] The second processing unit 43 outputs the calculated operation drive amount to the command unit 44. That is, the second processing unit 43 outputs to the command unit 44 an operation drive amount corresponding to the pressing operation. <Command Department> The command unit 44 receives the balanced drive amount as input from the first processing unit 42 and the operation drive amount as input from the second processing unit 43. The command unit 44 refers to the balanced drive amount and the operation drive amount, and derives a command value related to the drive of the motor 14 according to the balanced drive amount and the operation drive amount. That is, the command unit 44 derives a command value related to the drive of the lifting unit 10. In this embodiment, the command value is the rotation speed or torque value of the motor 14. The command unit 44 can appropriately switch between the rotation speed and the torque value as the derived command value. In this embodiment, the command unit 44 sets the command value derived from the balanced drive amount as the torque value, and sets the command value derived from the operation drive amount as the rotation speed.

[0057] The command unit 44 is connected to the motor 14. The command unit 44 and the motor 14 are connected by wiring (not shown). The command unit 44 and the motor 14 may be configured to be able to communicate wirelessly. The command unit 44 outputs the derived command value to the motor 14. The motor 14 rotates based on the input command value.

[0058] <Stop part> The stop unit 45 has preset upper and lower limit values ​​for the operation drive amount. The upper limit value is an absolute value of the operation drive amount for each of the maximum first and second pressure values ​​that the operator is allowed to input. In this embodiment, the maximum first and second pressure values ​​that the operator is allowed to input are set to the same value. In other words, the upper limit value in this embodiment is a single value. For example, the upper limit value is the absolute value of the operation drive amount calculated by the second processing unit 43 when the first or second pressure value is about 8 [N]. Note that the maximum first and second pressure values ​​that the operator is allowed to input may be changed as appropriate.

[0059] The lower limit value is the absolute value of the operation drive amount related to the minimum value of each of the first pressure value and the second pressure value that is permitted to be input by the operator. In this embodiment, the minimum value of the first pressure value and the minimum value of the second pressure value that is permitted to be input by the operator are set to the same value. In other words, the lower limit value in this embodiment is a single value. For example, the lower limit value is the absolute value of the operation drive amount calculated by the second processing unit 43 when the first pressure value or the second pressure value is about 2 [N]. Note that the minimum value of the first pressure value and the minimum value of the second pressure value that is permitted to be input by the operator may be changed as appropriate.

[0060] When the absolute value of the operation drive amount derived by the second processing unit 43 becomes equal to or greater than the upper limit, the stop unit 45 stops the output of the operation drive amount from the second processing unit 43 to the command unit 44. That is, when a first pressure value corresponding to an operation drive amount whose absolute value is equal to or greater than the upper limit is input from the first detection unit 331 to the second processing unit 43, the stop unit 45 stops the output of the operation drive amount by the second processing unit 43. Furthermore, when a second pressure value corresponding to an operation drive amount whose absolute value is equal to or greater than the upper limit is input from the second detection unit 332 to the second processing unit 43, the stop unit 45 stops the output of the operation drive amount by the second processing unit 43.

[0061] When the absolute value of the operation drive amount derived by the second processing unit 43 becomes equal to or less than a lower limit value, the stop unit 45 stops output of the operation drive amount from the second processing unit 43 to the command unit 44. That is, when a first pressure value corresponding to an operation drive amount whose absolute value is equal to or less than a lower limit value is input from the first detection unit 331 to the second processing unit 43, the stop unit 45 stops output of the operation drive amount by the second processing unit 43. Furthermore, when a second pressure value corresponding to an operation drive amount whose absolute value is equal to or less than a lower limit value is input from the second detection unit 332 to the second processing unit 43, the stop unit 45 stops output of the operation drive amount by the second processing unit 43.

[0062] The first pressure value is a value that changes in response to the pressing operation of the first detection unit 331 by the worker. The second pressure value is a value that changes in response to the pressing operation of the second detection unit 332 by the worker. In other words, the stopping unit 45 stops the output of the operation drive amount by the second processing unit 43 in response to the pressing operation. More specifically, the stopping unit 45 stops the output of the operation drive amount by the second processing unit 43 when the absolute value of the operation drive amount is equal to or greater than an upper limit value or equal to or less than a lower limit value.

[0063] The stop unit 45 stops the output of the operation drive amount by the second processing unit 43 even when the first pressure value and the second pressure value are simultaneously input to the second processing unit 43. In other words, the stop unit 45 stops the output of the operation drive amount by the second processing unit 43 when a pressing operation is performed on both the first detection unit 331 and the second detection unit 332.

[0064] When the stop unit 45 stops the output of the operation drive amount from the second processing unit 43, the command unit 44 issues a command to stop the operation of the lifting unit 10. The command to stop the operation of the lifting unit 10 is, for example, a command to set the rotation speed of the motor 14 to zero.

[0065] <Operation of the lift assist device> 4 and 5, the operation of the lift-down assistance device 100 will be described. The lift-down assistance device 100 is operated by a worker (not shown). Here, the operation of the worker using the lift-down assistance device 100 to move the object W in the horizontal direction will be described.

[0066] Consider a situation where the object W is not being held by the holder 30. In this situation, the fork 31a is located above the object W. At this time, the worker performs an operation to lower the holder 30 in order to hold the object W with the fork 31a. The operation to lower the holder 30 is performed by the control device 40 in response to the worker pressing the input unit 33. More specifically, in order to lower the holder 30, the worker grips the handle 32 and presses the second detection unit 332.

[0067] When the operator presses the second detection unit 332, the second detection unit 332 changes from the reference state S1 to the operation state S2. In the operation state S2, the second detection unit 332 detects a second pressure value corresponding to the pressing and outputs the second pressure value to the conversion unit 41. The conversion unit 41 outputs a second digital pressure value related to the input second pressure value to the second processing unit 43. The second processing unit 43 derives the operation drive amount according to the input second digital pressure value.

[0068] Here, it is assumed that the pressure applied by the worker to the second detection unit 332 is gradually increased. Immediately after the worker starts to press the second detection unit 332, the second pressure value detected by the second detection unit 332 is small. In other words, the absolute value of the second digital pressure value is also small, and therefore the operation drive amount derived by the second processing unit 43 is also small. The stopping unit 45 does not cause the second processing unit 43 to output the operation drive amount until the absolute value of the operation drive amount exceeds a lower limit value. When the absolute value of the operation drive amount exceeds the lower limit value due to an increase in the pressure applied by the worker, the stopping unit 45 causes the second processing unit 43 to output the operation drive amount to the command unit 44.

[0069] In this situation, the operation drive amount input to the command unit 44 is derived based on the second digital pressure value, and is therefore an operation drive amount related to the lowering of the holding unit 30. That is, the command unit 44 rotates the motor 14 in a direction that lowers the arm 20 and the holding unit 30 according to the input operation drive amount. As described above, the lifting unit 10 lowers the arm 20 and the holding unit 30 when the operator presses the second detection unit 332.

[0070] After the operator lowers the holder 30 to a position where the fork 31a can support the object W, the operator stops pressing the second detector 332. That is, the second detector 332 changes from the operating state S2 to the reference state S1. As a result, the second detector 332 no longer detects the second pressure value, and the motor 14 stops, and the arm 20 and holder 30 stop descending.

[0071] In this situation, the worker swings the arm 20 to move the fork 31a from the side of the object W toward the object W, and then lifts the handle 32 to have the fork 31a support the object W, as shown by the solid line in FIG. 4 . While the fork 31a supports the object W, the load detection unit 31b detects the load of the object W. The detected load is output to the conversion unit 41 and converted into a digital load. The digital load is output to the first processing unit 42. The first processing unit 42 calculates a balance drive amount for the load related to the digital load and outputs the balance drive amount to the command unit 44. The command unit 44 outputs a command value corresponding to the input balance drive amount to the motor 14. As a result, the motor 14 is driven to achieve the torque value required to balance the arm 20 and the holding unit 30 in the vertical direction Z against the load of the object W.

[0072] The operator presses the first detection unit 331 when the arm 20 and the holding unit 30 are balanced with respect to the object W. The first detection unit 331 detects a first pressure value related to the pressing. The detected first pressure value is converted into an operation drive amount by the second processing unit 43 via the conversion unit 41.

[0073] Here, it is assumed that the pressure applied by the worker to the first detection unit 331 is gradually increased. Immediately after the worker starts to press the first detection unit 331, the first pressure value detected by the first detection unit 331 is small. In other words, the absolute value of the first digital pressure value is also small, and therefore the operation drive amount derived by the second processing unit 43 is also small. The stopping unit 45 does not cause the second processing unit 43 to output the operation drive amount until the operation drive amount exceeds a lower limit value. When the pressure applied by the worker increases and the operation drive amount exceeds the lower limit value, the stopping unit 45 causes the second processing unit 43 to output the operation drive amount to the command unit 44.

[0074] The operation drive amount is an operation drive amount related to the lifting of the arm 20 and the holding unit 30. That is, the command unit 44 rotates the motor 14 in a direction in which the arm 20 and the holding unit 30 lift, according to the operation drive amount. In this situation, the command unit 44 outputs the number of rotations of the motor 14 required to lift the arm 20 and the holding unit 30 together with the object W from a state in which the arm 20 and the holding unit 30 and the object W are balanced. As a result, in accordance with the pressing of the first detection unit 331 by the operator, the lifting unit 10 lifts the arm 20 and the holding unit 30 together with the object W while maintaining a balanced state with the object W.

[0075] The worker continues to press the first detection unit 331 until the object W reaches the desired height. The desired height is, for example, the height of a platform on which the object W is placed. As indicated by the two-dot chain line in FIG. 4, the worker stops pressing the first detection unit 331 after the object W exceeds the desired height. This ends the lifting of the arm 20, the holder 30, and the object W.

[0076] When moving the object W in the horizontal direction, the worker grasps the handle 32 and moves the holding unit 30 holding the object W in the horizontal direction. Here, we consider a case where the object W is moved from the position shown by the solid line in FIG. 5 to the position shown by the two-dot chain line in FIG. 5, and then the object W is moved forward of the base B. At this time, the worker moves the holding unit 30 forward together with the object W. As the worker moves the holding unit 30, the first arm member 21 swings relative to the mounting member 24 around the first support shaft 20a as a swing axis. Furthermore, the second arm member 22 swings relative to the first arm member 21 around the second support shaft 20b as a swing axis. This increases the angle between the first arm member 21 and the second arm member 22. With the base end fixed to the base B, the angle between the first arm member 21 and the second arm member 22 increases, and therefore the distance between the base end and the tip end of the arm 20 in the horizontal direction increases. As a result, the holder 30 and the object W move toward the front of the base B together with the tip of the arm 20.

[0077] As indicated by the two-dot chain line in FIG. 5 , the worker stops moving the holding unit 30 in the horizontal direction when the object W reaches a desired position in the horizontal direction. The desired position is, for example, a position where the object W will be placed. The worker presses the second detection unit 332 to place the object W at the desired position. The second detection unit 332 detects a second pressure value related to the pressing. The detected second pressure value is output to the command unit 44 via the conversion unit 41 and the second processing unit 43. The command unit 44 outputs a command value to the motor 14 that takes into account a balance drive amount related to the load of the object W to an operation drive amount related to the second pressure value. As a result, the lifting unit 10 lowers the holding unit 30 and the arm 20 together with the object W while maintaining a balanced state with the object W in response to the worker's pressing of the second detection unit 332. In this manner, the worker uses the lifting assistance device 100 to move the object W to a desired position.

[0078] [Operation of this embodiment] The operation of this embodiment will be described. In the process in which the worker moves the object W using the lift assist device 100, the first detection unit 331 and the second detection unit 332 may detect the first pressure value and the second pressure value that are not intended by the worker. The first pressure value and the second pressure value that are not intended are detected, for example, when the worker grips the input unit 33 with a large force due to an erroneous operation.

[0079] The stop unit 45 refers to the value input to the second processing unit 43, and when a large value is input to the second processing unit 43, stops the output of the operation drive amount by the second processing unit 43 to the command unit 44. In other words, the lifting assistance device 100 does not raise or lower the arm 20 in response to a pressing operation of a magnitude unintended by the worker.

[0080] [Effects of this embodiment] The effects of this embodiment will be described. (1) The operation drive amount related to the pressing operation of the input unit 33 is calculated by the second processing unit 43 and output to the command unit 44. The stop unit 45 refers to the operation drive amount calculated by the second processing unit 43 and can stop the output of the operation drive amount by the second processing unit 43. As a result, even if an unintended pressing operation is performed on the input unit 33, the control device 40 can stop the lifting and lowering of the arm 20 by the lifting unit 10 using the stop unit 45. As described above, the lifting assistance device 100 can suppress the occurrence of unintended operations.

[0081] (2) Since the input unit 33 has the first detection unit 331 and the second detection unit 332, the worker can press both or either one of the first detection unit 331 and the second detection unit 332. When both the first detection unit 331 and the second detection unit 332 are pressed, the control device 40 can stop the output of the operation drive amount by the second processing unit 43 using the stop unit 45. In other words, the worker can stop the operation of the lifting assistance device 100 by gripping the handle 32 so as to press both the first detection unit 331 and the second detection unit 332. As a result, even if the lifting unit 10 starts an unintended operation, the worker can stop the lifting or lowering of the arm 20 with an operation that is simpler than, for example, turning off the power to the lifting assistance device 100.

[0082] (3) The stop unit 45 raises and lowers the arm 20 when the absolute value of the operation drive force of the second processing unit 43 is greater than the lower limit and less than the upper limit. In other words, the lifting assistance device 100 can raise and lower the arm 20 by the lifting unit 10 within a predetermined range of the magnitude of the pressing operation. Furthermore, by causing the stop unit 45 to stop the output of the second processing unit 43 when the absolute value of the operation drive force is equal to or less than the lower limit, operation of the lifting unit 10 can be suppressed even if the worker accidentally touches the input unit 33.

[0083] (4) In the handle 32, the first detection unit 331 and the second detection unit 332 are aligned in the vertical direction Z. That is, the direction in which the first detection unit 331 and the second detection unit 332 are aligned coincides with the direction in which the arm 20 moves up and down. Furthermore, the direction in which the first detection unit 331 and the second detection unit 332 are aligned coincides with the direction in which the operator presses the input unit 33. That is, the operator can align the direction of the operator's own movement related to the pressing operation with the direction in which the arm 20 moves up and down. As a result, the operator can operate the arm 20 more easily than, for example, when the first detection unit 331 and the second detection unit 332 are provided on the same plane.

[0084] (5) When the worker wants to raise the arm 20, he or she applies an upward pressure to the first detection unit 331. This causes the motor 14 to drive in the direction of raising the arm 20 via the conversion unit 41 and the second processing unit 43. When the worker wants to lower the arm 20, he or she applies a downward pressure to the second detection unit 332. This causes the motor 14 to drive in the direction of lowering the arm 20 via the conversion unit 41 and the second processing unit 43. Therefore, the direction of the pressing operation related to raising and lowering the arm 20 matches the direction in which the arm 20 rises and falls due to the pressing operation. This allows the worker to operate the arm 20 more easily than, for example, when the direction of the pressing operation and the direction in which the arm 20 rises and falls do not match.

[0085] (6) Since each of the first detection unit 331 and the second detection unit 332 is configured by a pressure sensor, it is possible to continuously change the rotation speed of the motor 14 in conjunction with continuous changes in the pressure applied by the worker. In other words, the worker can adjust the speed at which the arm 20 moves up and down by adjusting the magnitude of the pressure applied to the input unit 33.

[0086] (7) The lifting assistance device 100 lifts and lowers the object W using the lifting unit 10, and positions the object W in the horizontal direction using the arm 20. In other words, the lifting assistance device 100 can move the object W independently in the horizontal direction and the up-down direction Z. As a result, the object W can be positioned more easily than with an assistance device that includes, for example, a link-type arm.

[0087] (8) In the lifting assistance device 100, the arm 20 operates when positioning the object W in the horizontal direction. For example, unlike an assistance device equipped with a link-type arm, when moving the object W in the vertical direction Z, there is no need to consider horizontal movement of the object W caused by the swinging of the arm 20. In other words, the lifting assistance device 100 can be made smaller in the horizontal direction than an assistance device equipped with a link-type arm.

[0088] (9) The command unit 44 drives the motor 14 in accordance with the drive amounts input from the first processing unit 42 and the second processing unit 43. In other words, the control device 40 can control the motor 14 in accordance with the load detected by the load detection unit 31b even when the worker does not control it via the input unit 33. For example, the control by the worker via the input unit 33 is referred to as speed control, and the control in accordance with the load detected by the load detection unit 31b is referred to as torque control. In this case, the control device 40 of this embodiment is configured to be able to switch between speed control and torque control. In other words, the lifting assistance device 100 is able to switch between speed control and torque control. As a result, the lifting assistance device 100 can reduce the burden on the worker involved in moving the object W compared to when the control device 40 only controls speed. Furthermore, since the lifting assistance device 100 can switch between speed control and torque control, even if the load detection unit 31b detects a sudden change in load due to the object W lifting off the ground, for example, unintended movement of the arm 20 can be suppressed.

[0089] (10) The lifting unit 10 is provided on the base B that constitutes the carriage, and is therefore movable together with the base B. In other words, the lifting assistance device 100 is movable. [Example of change] The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

[0090] Each of the first detection unit 331 and the second detection unit 332 does not have to be configured as a pressure sensor. In this case, each of the first detection unit 331 and the second detection unit 332 is preferably configured to be able to detect continuous changes in the pressure applied by the operator as continuous pressure values. As an example, each of the first detection unit 331 and the second detection unit 332 may be configured as a pair of operating levers, and detect the depression of the pair of operating levers as a pressure value.

[0091] The second processing unit 43 may output an operation drive amount related to lowering the arm 20 in response to a pressing operation of the first detection unit 331. In this case, the second processing unit 43 may output an operation drive amount related to raising the arm 20 in response to a pressing operation of the second detection unit 332.

[0092] The input unit 33 may have the first detection unit 331 above the second detection unit 332. The input unit 33 may have the first detection unit 331 and the second detection unit 332 on the same plane.

[0093] The stop portion 45 may be set with only one of the upper limit and the lower limit. The lower limit value and the upper limit value for the operation drive amount do not have to be set in the stop unit 45. In this case, for example, the stop unit 45 may measure the time during which the pressure value is input to the second processing unit 43, and may stop the output by the second processing unit 43 when the input to the second processing unit 43 continues for a certain period of time or more.

[0094] The input unit 33 does not have to include the first detection unit 331 and the second detection unit 332. For example, the input unit 33 may be configured with a single detection unit. The stop unit 45 does not have to stop the output of the operation drive amount by the second processing unit 43 when both the first detection unit 331 and the second detection unit 332 are pressed. That is, the second processing unit 43 may receive both the first digital pressure value and the second digital pressure value. In this case, for example, when the first digital pressure value is greater than the second digital pressure value, the second processing unit 43 rotates the motor 14 in a direction that raises the arm 20. At this time, the greater the difference between the first digital pressure value and the second digital pressure value, the greater the absolute value of the rotation speed of the motor 14. On the other hand, when the second digital pressure value is greater than the first digital pressure value, the second processing unit 43 rotates the motor 14 in a direction that lowers the arm 20. At this time, the greater the difference between the second digital pressure value and the first digital pressure value, the greater the absolute value of the rotation speed of the motor 14.

[0095] The stopping unit 45 may stop the operation of the lifting / lowering unit 10 when the pressure values ​​of the first detection unit 331 and the second detection unit 332 exceed a preset threshold. In other words, even when the first pressure value and the second pressure value are input to the second processing unit 43 simultaneously, the stopping unit 45 may continue the operation of the lifting / lowering unit 10 when the first pressure value or the second pressure value is equal to or less than the threshold.

[0096] The lifting assistance device 100 may be provided with a brake device that stops the operation of the lifting unit 10. In this case, the command unit 44 and the brake device may be connected, and the stop unit 45 may stop the lifting unit 10 by the brake device via the command unit 44.

[0097] The input unit 33 may detect the pressing operation by the operator as something other than a pressure value. For example, the input unit 33 may be configured to be rotatable relative to the handle 32. In this case, the second processing unit 43 may calculate the operation drive amount based on the amount of rotation of the input unit 33 associated with the pressing. Furthermore, for example, the input unit 33 may be configured to be tiltable relative to the handle 32. In this case, the second processing unit 43 may calculate the operation drive amount based on the tilt angle of the input unit 33 associated with the pressing. Furthermore, when the input unit 33 is provided above and below the handle 32, the input unit 33 may have a temperature sensor and detect the amount of change in temperature transmitted from the operator's hand associated with the pressing. In this case, the second processing unit 43 calculates the operation drive amount based on the detected temperature.

[0098] The input unit 33 does not have to be provided on the handle 32. For example, the input unit 33 may be provided on the main body 31. Alternatively, the input unit 33 may be provided on the lifting unit 10.

[0099] The lifting unit 10 does not have to be provided on the base B. In other words, the lifting assistance device 100 does not have to be movable. The lifting unit 10 does not have to be driven by the motor 14. In this case, the command value from the command unit 44 is not limited to the rotation speed of the motor 14. The key point is that the lifting unit 10 only needs to be configured to be able to reciprocate the arm 20 in the vertical direction Z and to be driven by the command unit 44.

[0100] The lifting unit 10 does not have to have the motor 14 at the lower end of the body 11. For example, the lifting unit 10 may have the motor 14 at the upper end of the body 11. In this case, a rotation shaft (not shown) extends downward from the motor 14.

[0101] The base B does not necessarily have to be provided with the installation hole B4. In this case, the motor 14 is disposed above the base B1. The configuration of the base B is not limited to that described in the embodiment. The point is that the base B may have any configuration that allows the lifting unit 10 to be installed thereon.

[0102] The lifting assistance device 100 does not have to have the battery C. In other words, the driving source of the lifting assistance device 100 is not limited to the battery C. For example, the lifting assistance device 100 may be connected to an external power source. In other words, the lifting assistance device 100 may be driven by an external power source.

[0103] Each of the first support shaft 20a, the second support shaft 20b, and the third support shaft 30a may have a through-hole that passes through in the axial direction. In other words, each of the first support shaft 20a, the second support shaft 20b, and the third support shaft 30a may be cylindrical. In this case, the wiring connecting the motor 14 and the command unit 44 may pass through the through-hole of each of the first support shaft 20a, the second support shaft 20b, and the third support shaft 30a.

[0104] The handle 32 does not have to be cylindrical. Furthermore, the handle 32 does not have to extend horizontally. For example, the handle 32 may be made of a square pipe that extends in a direction other than the horizontal. In short, the handle 32 only needs to be configured so that it can be gripped by an operator.

[0105] The first detection unit 331 and the second detection unit 332 do not have to protrude from the circumferential surface of the handle 32. For example, the first detection unit 331 and the second detection unit 332 may be embedded in the circumferential surface of the handle 32. The point is that the first detection unit 331 and the second detection unit 332 only need to be capable of being pressed by an operator.

[0106] The control device 40 does not have to be fixed to the support B3. The control device 40 may be provided in a position where it can communicate with the lifting unit 10. For example, the control device 40 may be provided on a wall or the like near the location where the lifting unit 10 is operated.

[0107] The control device 40 may perform control by the operator via the input unit 33 based on a torque value, and may perform control according to the load detected by the load detection unit 31b based on the rotation speed.

[0108] The load detection unit 31b does not need to detect the load caused by the operation by the operator. [Explanation of symbols]

[0109] 10...lifting section, 20...arm, 31b...load detection section, 33...input section, 40...control device, 42...first processing section, 43...second processing section, 44...command section, 45...stopping section, 100...lifting assistance device, W...object, 331...first detection section, 332...second detection section.

Claims

1. an arm for holding an object; a load detection unit that detects the load of the held object; an input unit configured to enable a pressing operation; a lifting unit that lifts and lowers the arm; a control device for controlling the lifting unit, The control device a command unit that outputs a command value related to driving the lift unit to the lift unit; a first processing unit that outputs a balance drive amount to the command unit in accordance with the load detected by the load detection unit; a second processing unit that outputs an operation drive amount to the command unit in response to the pressing operation, The command unit is an elevation assist device that drives the elevation unit based on the balance drive amount and the operation drive amount, The control device has a stop unit that stops the output of the operation drive amount by the second processing unit in response to the pressing operation on the input unit.

2. the input unit includes a first detection unit that detects the pressing operation and a second detection unit that detects the pressing operation, The lift assist device according to claim 1 , wherein the stop unit stops the output of the operation drive amount by the second processing unit when the pressing operation is performed on both the first detection unit and the second detection unit.

3. The lift assist device according to claim 1 or 2, wherein the stop unit stops the output of the operation drive amount by the second processing unit when the operation drive amount is equal to or greater than an upper limit value or equal to or less than a lower limit value.

4. The lift assist device according to claim 2 , wherein the input unit has the first detection unit below the second detection unit.

5. The lifting assistance device described in claim 2, wherein the second processing unit outputs the operation drive amount related to raising the arm in response to the pressing operation of the first detection unit, and outputs the operation drive amount related to lowering the arm in response to the pressing operation of the second detection unit.

6. 3. The lift assist device according to claim 2, wherein each of the first detection unit and the second detection unit is configured by a pressure sensor.

Images