JPH10324500A - Load balancing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a worker to move a load body by directly operating a load body so as to accurately move the load body to a target place by providing a locking mechanism for prohibiting, if a force applied between first and second supporting members is lower than a specified force, the movement of both supporting members for preventing the change of a relative positional relationship therebetween. SOLUTION: A worker applies, on a workpiece, a force of an upper direction which is smaller than a locking force. Since the force of the worker for operating the workpiece is smaller than the locking force, an engaged state between a steel ball 36 and a recessed part 37a is maintained. Since no change occurs in a relative positional relationship between first and second supporting members 32 and 30, no changes in a force applied therebetween are detected. Thus, the pressure of a driving cylinder is not changed. On the other hand, the self-weight of the workpiece and an operating force acted on the workpiece are applied to the cylinder rod of the driving cylinder. Therefore, when the worker applies an operating force of an upper direction on the workpiece, the workpiece is raised.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load balancing device, for example, when a work is moved in an assembling operation or the like, the load of the work and the pressure in a driving cylinder are equilibrated to lift the work with a small force. The present invention relates to a load balancing device capable of performing the following.

[0002]

2. Description of the Related Art Conventionally, a load balancing device as shown in FIG. 4 has been known. This load balancing device includes a load detection unit 50 that supports a load body 58 attached to a distal end of an arm 52. The other end of the arm 52 is connected to a cylinder rod of the drive cylinder 54. The pressure in the drive cylinder 54 acts on the cylinder rod by the load body 58, the load detection unit 50, and the arm 52 based on the force between the load body 58 and the load detection unit 50 detected by the load detection unit 50. It is controlled by the operation regulator 56 so as to balance the force. Accordingly, since the pressure in the drive cylinder 54 is controlled by the load body 58, the load detection unit 50, and the arm 52 so as to balance with the force acting on the cylinder rod of the drive cylinder 54, the operator can apply a small force to the load. The body 58 can be lifted. That is, if the operator exerts a slight force on the operation lever 51 attached to the arm 52, the force is transmitted to the cylinder rod of the drive cylinder 54 via the arm 52. Therefore, the balance between the pressure in the drive cylinder 54 and the force acting on the cylinder rod is lost, and the cylinder rod moves in the direction of the operator's force, and the load body 58 can move in the vertical direction.

[0003]

When such a load balancing device is used for moving a work in an assembling operation or the like, there is a demand that the work should be accurately moved to an assembling position. However, in the conventional device, since the operator moves the load body 58 by operating the operation lever 51, it is difficult to accurately move the load body 58. Therefore, when the conventional apparatus is used for moving a work in an assembling operation or the like, it is necessary to finely adjust the work after the work is removed from the apparatus.

[0004]

SUMMARY OF THE INVENTION The above-mentioned problems are solved by a load balancing device having the following features.
That is, according to the first aspect of the present invention, a first support member for supporting a load, a second support member for movably guiding the first support member, and an intervening portion between the second support member and the immovable portion A mounted cylinder, a first working fluid supply source for supplying a working fluid to a sealed internal space formed between the first support member and the second support member, and a working fluid to the internal space Control means for controlling the inflow and outflow of the fluid so as to keep the relative positional relationship between the first support member and the second support member constant at all times, and a second working fluid supply source for supplying a working fluid to the cylinder And a second control means for controlling the inflow and outflow of the working fluid into and from the cylinder based on the pressure in the internal space, wherein the load balancer works between the first support member and the second support member. When the force is less than a predetermined force, the first support member and The relative positional relationship of the serial second support member is provided with a locking mechanism to prohibit the movement of both so as not to change it said. According to the load balancing device, when the force acting between the first support member and the second support member is equal to or less than a predetermined force, the relative positional relationship between the first support member and the second support member does not change. When the operating force of the load body supported by the first support member is not more than a predetermined force even when the operator directly operates the load body, the first support member and the second support member are provided. Does not change. Therefore, even if the load is directly operated by the operator, the pressure in the internal space does not change, and the pressure in the cylinder does not change. On the other hand, a change in load caused by the operator directly operating the load is transmitted to the cylinder. Therefore, the balance between the pressure in the cylinder and the force acting on the cylinder is lost, and the load can be moved in a target direction. As described above, the operator can move the load body by directly operating the load body, so that the load body can be accurately moved to a target place. Here, the predetermined force is appropriately determined within a range that is larger than a force required for an operator to move the load body in the vertical direction by operating the load body and smaller than the own weight of the load body to be moved. However, in order to reduce the load detection error, it is preferable that the force is set to be slightly larger than the force required for the operator to operate the load body and move the load body in the vertical direction.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a drawing showing a configuration of a load balancing device according to one embodiment of the present invention. This load balancing device comprises a first arm 16 having wheels 13 at one end.
, And can move in the factory along a rail 11 provided on a ceiling for guiding the wheels 13. A second arm 18a is connected to the other end of the first arm 16 so as to be rotatable around an axis indicated by a point B. Also, the first arm 1
At the center of 6, an operation regulator 12 and a drive cylinder 14, which will be described later, are attached via a first connection arm 15. Also, the cylinder rod 14 of the drive cylinder 14
A third arm 18b is attached to the tip of the “a” so as to be rotatable around an axis indicated by a point A. One end of the second connecting arm 17a is rotatable about an axis indicated by a point B.
a, and the other end of the second connection arm 17a is connected to the third arm 18b around the axis indicated by the point C. Further, one end of the third connecting arm 17b is connected to the second arm 18a so as to be rotatable around an axis indicated by a point D.
The other end of the connection arm 17b is connected to the third arm 18b so as to be rotatable around an axis indicated by a point E. Therefore, the second
Arm 18a, third arm 18b, second connecting arm 17
a and the third connecting arm 17b form a link mechanism,
When the cylinder rod 14a moves upward, the third connecting arm 1
7b moves down, and when the cylinder rod 14a moves down, the third connecting arm 17b moves up. Also, the first
The arm 16 is supported by a bearing 19 so as to be rotatable around the axis. Therefore, the second arm 18a, the third arm 18b, the first connecting arm 15, the second connecting arm 17
a, the third connecting arm 17 b, the drive cylinder 14, and the operation regulator 12 are integrally rotated around the axis of the first arm 16 by the rotation of the first arm 16. The third connecting arm 17b is provided with an arm receiver 18c. The fourth arm 20 is slidably attached to the arm receiver 18c. A handling section 22 is attached to the tip of the fourth arm.
2 is rotatable around the point F shown in FIG.
A load detection unit 10, which will be described later, on which the work 24 is placed, is attached to the handling unit 22. The handling unit 22 is provided with an operation lever 22a.
The operator operates the operation lever 22a to move the work 2
4 movements can be performed.

FIG. 2 is a longitudinal sectional view of the operation regulator 12 and the load detector 10. First, the structure of the operation regulator 12 will be described with reference to FIG. In the operation regulator 12, an upper mold 46 is fitted to a lower mold 44,
A closed internal space is formed inside. The sealed internal space is divided into a load pilot pressure chamber 42 and a cylinder pressure chamber 43 by a partition wall 45 and a diaphragm 49 fixed to the partition wall 45. The partition wall 45 is supported so as to be vertically movable by a pressure difference between the load pilot pressure chamber 42 and the cylinder pressure chamber 43. The upper die 42 is provided with a load pilot pressure supply port 42a, and is configured so that working fluid is supplied from the load pilot pressure supply port 42a into the load pilot pressure chamber 42. The load pilot pressure supply port 42a is as shown in FIG.
The pilot pressure supply port 34a of the load detector 10 shown in FIG.
The load pilot pressure chamber 42 and an internal space 34 in the load detection unit 10 described later have the same pressure. The cylinder pressure chamber 43 communicates with a cylinder supply port 43a provided in the lower mold 44.
The cylinder supply port 43a is connected to the above-described drive cylinder 14 via a hose (not shown) so that the pressure in the cylinder pressure chamber 43 and the pressure in the drive cylinder 14 are the same. The cylinder pressure chamber 43 communicates with a supply chamber 44a via a cylinder pressure chamber supply port 43b, and the supply chamber 44a is connected to an operation section supply port 44b.
The operation section supply port 44b is connected to a working fluid supply source (not shown). Therefore, when the pressure in the load pilot pressure chamber 42 increases and the partition wall 45 and the valve body 47 are displaced downward in the drawing and the cylinder pressure chamber supply port 43b is opened, the working fluid is supplied via the supply chamber 44a. Cylinder pressure chamber 43
And is supplied into the drive cylinder 14. Also, the pressure in the cylinder pressure chamber 43 increases, and
5 is displaced upward, and the valve element 47 and the partition 45 are separated from each other.
When the exhaust port 45b provided in the valve 5 is opened, the working fluid in the cylinder pressure chamber 43 is exhausted to the outside of the operation regulator 12 through the exhaust passage 45a. Therefore, in the present embodiment, the operation regulator 1
2 functions as means for controlling the inflow and outflow of the working fluid in the drive cylinder 14 based on the pressure in the internal space 34 in the load detection unit 10. Note that the cylinder pressure chamber supply port 43b and the exhaust port 45b are closed by the valve body 47 urged upward by the elastic body 48 in a state where the load pilot pressure chamber 42 and the cylinder pressure chamber 43 are balanced. Has been adjusted.

Next, based on FIG.
Will be described. The load detection unit 10 is configured by combining a first support member 32 that places the work 24 on the second support member 30. The first support member 32 can move in the load direction (up and down) with respect to the second support member 30 while being guided by the guide rod 41. Further, the load detection unit 10 has an internal space 34 formed by the second support member 33, the first support member 32, and the seal member 35, and the internal space 34 is displaced in the vertical direction by the first support member. Its volume changes. The internal space 34 is provided with a fluid supply port 33 a for supplying a working fluid into the internal space 34 via a fluid inlet 33 b provided in the second support member 33 and a supply chamber 33.
Is in communication with The fluid supply port 33a is connected to a working fluid supply source (not shown). Further, the internal space 34
The working fluid in the internal space 34 is discharged to the outside of the load detection unit 10 by communicating with the exhaust passage 31a through the exhaust port 31b. The valve body 39 is urged in the direction of the first support member 32 by the elastic body 40, closes the exhaust port 31b in a state where the load acting on the first support member 32 and the pressure in the internal space 34 are balanced, and It is adjusted so as to close the fluid inlet 33b communicating the internal space 34 and the supply chamber 33. The force acting on the first support member 32 is
When the first support member 32 is displaced downward, the valve body 39 is also displaced downward, and the fluid inlet 33 is displaced.
b is opened, the working fluid is supplied to the internal space 34, and the first support member 32 returns to the original balanced position. Further, when the pressure in the internal space 34 becomes larger than the force acting on the first support member 32, the valve body 39 and the first support member are separated and the exhaust port 31b is opened, and the working fluid in the internal space 34 detects the load. The first support member 32 is discharged out of the portion 10
Returns to its original equilibrium position. Therefore, in the present embodiment, the valve body 39 and the elastic body 40 control the inflow and outflow of the working fluid into and out of the internal space 34 so that the relative positional relationship between the first support member 32 and the second support member 30 is always constant. It functions as a control means to keep it. A concave portion 37a is provided on the inner side surface 30s of the second support member 30, and the steel ball 36 meshing with the concave portion 37a is urged on the side surface of the first support member 32 facing the concave portion 37a. Elastic body 38
Is provided. Recess 37a
When the steel ball 36 is engaged with the first support member 3
Relative displacement between the second and second support members is prohibited. Therefore,
In the present embodiment, the concave portion 37a, the storage portion 37b, the steel ball 36
The elastic body 38 constitutes a lock mechanism. As the elastic body 38, a coil spring or the like can be used. By adjusting the initial displacement and the spring constant of the spring, the force acting between the first support member 32 and the second support member 30 exceeds a predetermined force. Then, the engagement between the concave portion 37a and the steel ball 36 can be released. Hereinafter, the force acting between the first support member 32 and the second support member 30 required to release the engagement between the recess 37a and the steel ball 36 will be referred to as a lock force. The position of the recess 37a and the steel ball 36 is determined by the first support member 32.
When the force acting on the inner space 34 and the pressure in the internal space 34 are balanced, they are adjusted to engage with each other.

Next, the operation of this load balancing device will be described.
A description will be given based on FIG. 1 and FIG. (1) Load Detection First, in order to transfer the work 24 placed on the table 26 to the upper surface of the first support member 32, the operation lever 22a
Is operated so that the load detector 10 comes under the work 24. In this state, the load lever 10 is moved upward by operating the operation lever 22a, and the work 24 is transferred to the upper surface of the first support member 32. The operation of the load detector 10 when the work 24 is transferred to the upper surface of the first support member 32 will be described. The first support member 32 overcomes the lock force of the lock mechanism due to its own weight of the work 24, and is displaced downward by being guided by the guide rod 41. When the first support member 32 is displaced downward, the first support member 32
9 is displaced downward. When the valve body 39 is displaced downward, the fluid inlet 33b is opened, and the internal space 3
4 and the supply chamber 33 are in communication. Therefore, the working fluid is supplied into the internal space 34 from the working fluid supply source via the fluid supply port 33a. Then, the pressure in the internal space 34 increases, and the first support member 32 moves upward. When the first support member 32 moves to a position where the steel ball 36 and the concave portion 37 mesh with each other, the force acting on the first support member 32 and the pressure in the internal space 34 are in a balanced state, and the fluid inlet 33
b is closed by the valve body 39, and the supply of the fluid into the internal space 34 ends. Next, the operation in the operation regulator 12 will be described. When the working fluid is supplied to the internal space 34 of the load detector 10 and the pressure increases, the pressure in the load pilot chamber 42 also increases at the same time. Therefore, the pressure balance between the load pilot chamber 42 and the cylinder pressure chamber 43 is lost,
The partition wall 45 and the diaphragm 49 are displaced downward. When the partition wall 45 is displaced downward, the valve body 47 is displaced downward at the same time, and the cylinder pressure chamber inlet 43b is opened. Therefore, the operation unit supply port 4
The working fluid is supplied to the cylinder pressure chamber 43 via 4b. Therefore, the pressure in the cylinder pressure chamber 43 increases, and the valve body 4
7 and the partition 45 are displaced upward. When the pressures in the load pilot chamber 42 and the cylinder pressure chamber 43 become the same, the cylinder pressure chamber inlet 43b is closed. At this time, as the pressure in the cylinder pressure chamber 43 increases, the cylinder supply port 43a
, The working fluid flows into the drive cylinder 14 and the pressure in the drive cylinder 14 increases. Therefore, the drive cylinder 14
The internal pressure increases by the weight of the work 24,
It is in a new balance state.

(2) Work lifting operation The operation of the load balancing device when the worker directly operates the work 24 to perform the lifting operation of the work 24 will be described. First, an operator applies an upward force smaller than the lock force to the work 24. Since the force by which the worker operates the work 24 is smaller than the locking force, the steel ball 36 and the recess 37a are used.
Will maintain the meshed state. Therefore, since the relative position between the first support member 32 and the second support member 30 does not change, a change in the force acting between the first support member 32 and the second support member is not detected. Therefore, the pressure in the drive cylinder 14 does not change. On the other hand, drive cylinder 1
The weight of the work 24 and the operating force applied to the work 24 are acting on the fourth cylinder rod 14a. Therefore, when an operator exerts an upward operation force on the work 24, a large downward force acts on the cylinder rod 14a by an amount corresponding to the operator's operation force. Accordingly, the cylinder rod 14a of the drive cylinder 14 moves downward, and the work 24 rises. Next, the operation in the operation regulator 12 will be described.
When the cylinder rod 14a of the drive cylinder 14 moves downward, the pressure in the cylinder decreases. Therefore, the pressure in the cylinder pressure chamber 43 in the operation regulator 12 becomes lower than the pressure in the load pilot pressure chamber 42. When the pressure in the cylinder pressure chamber 43 decreases, the partition wall 45 is displaced downward,
The valve body 47 is pushed down. When the valve element 47 is pushed down, the cylinder pressure chamber inflow port 43b is opened, and the working fluid is supplied from the working fluid supply source into the cylinder pressure chamber 43 and the drive cylinder 14 via the operation section supply port 44b. . Therefore, the pressure in the cylinder pressure chamber 43 is balanced with the pressure in the load pilot pressure chamber 42 again, and the pressure in the internal space 34 of the load detector 10 and the pressure in the drive cylinder 14 are reduced by the operating force of the operator. Returns to the same equilibrium as before.

(3) Work lowering operation The operation of the load balancing device when the operator directly operates the work 24 to perform the work lowering operation will be described. First, a worker applies a downward force to the work 24 with an operation force smaller than the lock force. As in the case of the lifting operation of the work 24 described above, the first support member 32 is not displaced, and the first support member 32 and the second support member 30 are not displaced.
No change in the force acting during is detected. On the other hand, the operation force applied to the work 24 is transmitted to the cylinder rod 14a of the drive cylinder 14 via the arm. Since the change in the force acting between the first support member 32 and the second support member 30 is not detected and the pressure in the drive cylinder 14 does not change,
A large upward force acts on the cylinder rod 14a by the amount of the operator's operation force. Accordingly, the cylinder rod 14a of the drive cylinder 14 moves upward, and the work 24 descends. Next, the operation in the operation regulator 12 will be described.
When the cylinder rod 14a of the drive cylinder 14 rises, the pressure inside the drive cylinder 14 rises. for that reason,
The pressure of the cylinder pressure chamber 43 in the operation regulator 12 is
It becomes higher than the pressure of the load pilot pressure chamber 42,
5 is displaced upward, and the valve body 47 and the partition wall 45 are separated from each other. As a result, the exhaust port 45b is in an open state, and the cylinder pressure chamber 43 and the drive cylinder 1
The working fluid in 4 is discharged out of the operation regulator 12. For this reason, the pressure in the cylinder pressure chamber 43 decreases, and is again balanced with the pressure in the load pilot pressure chamber 42,
In addition, the pressure in the internal space 34 of the load detection unit 10 and the pressure in the drive cylinder 14 are in the same balanced state as before the operation force by the operator is applied.

(4) Movement of Work to Table The operation of the load balancing device when the work 24 is transferred to the table 26 will be described. First, the work 24 is moved to the table 26 (installation place). Thereafter, the operator operates the operation lever 22a of the load detection unit 10 to transfer the work 24 to the table 26. That is, the operator moves the operation lever 22a downward with a force greater than the lock force described above. The operation of the load detector 10 at this time will be described. First, since the force acting between the first support member 32 and the second support member 30 is larger than the locking force, the engagement between the steel ball 36 and the concave portion 37a is released, and the first support member 32 moves upward. Become. When the first support member 32 is displaced upward, the valve body 33b and the exhaust port 31b are separated from each other.
Therefore, the working fluid in the internal space 34 is
It is discharged outside. Therefore, the working fluid is discharged until the force acting between the first support member 32 and the second support member 30 and the pressure in the internal space 34 are balanced. Next, the operation in the operation regulator 12 will be described. Since the internal space 34 of the load detection unit 10 and the load pilot pressure chamber 42 in the operation regulator 12 are connected to each other by a hose or the like to have the same pressure, the pressure of the load pilot pressure chamber 42 is lower than the pressure of the cylinder pressure chamber 43. Become. For this reason, the partition 4
5 is displaced upward, and the working fluid in the cylinder pressure chamber 43 and the drive cylinder 14 is discharged from the operation regulator 12 through the exhaust passage 45a. Therefore, the load pilot pressure chamber 42 and the cylinder pressure chamber 43 become the same pressure again to be in a balanced state, and the pressure in the internal space 34 of the load detector 10 and the pressure in the drive cylinder 14 are also in a balanced state.

As described above, the load balancing device according to the present embodiment allows the operator to directly operate and move the work, so that the work is easier to perform than the conventional operation lever. Since the work can be moved with a sense, the work can be moved to an accurate position.
When the work is moved to the table, the operating fluid can be discharged from the load detector and the drive cylinder only by operating the operation lever. Therefore, the operation of opening and closing the valve becomes unnecessary, and a malfunction of opening and closing the valve by the operator does not occur. Further, even if the lock mechanism as in the present embodiment is provided in the load detection unit, a load detection error hardly occurs. This is because the locking force acts only when the steel ball 36 and the recess 37a are engaged, but the steel ball 36 and the recess 37a
This is because when the gears are not meshed, the locking force does not act and the load detection of the load body is not affected. Load balancing device according to the present embodiment (diameter of cross section of internal space: 50 mm,
Set lock force: 2 kgf, recess: width 1.5 mm; depth 2
(mm, steel ball diameter: 5/32 inch, load: 20 kgf), and as a result of measuring the automatic load detection value, the variation was 0.3 kgf or less, which was within a range in which there was no practical problem.

The above-described operation of the load balancing device has been described in the case where the operator directly moves the work 24 to move the work up and down. However, while the work is moved in the factory and the installation location is accurate. In the case where it is not necessary, the work 24 may be moved by the operation lever 22a. The operation of the load balancing device in this case is the same as the above-described (2) work lifting operation and (3) work lowering operation. In addition, the lateral movement of the work is performed by moving along a rail 11 provided on the ceiling.
Further, the second arm 18a and the third arm 18b
It can also be performed by rotating around the axis of the arm 16. In this case, the load detector 10 and the operation regulator 12 maintain a balanced state. Further, in the above-described embodiment, the load balancing device including the load detection unit 10 of the type in which the work 24 is placed on the first support member 32 has been described. However, the present invention is not limited to this. The present invention can be applied to a load balancing device having a type load detecting unit. For example, as shown in FIG.
4 can also be applied to a type in which the hook 4 is connected to the first support member of the load detection unit 10 by the hook 27. Also, the load detection unit 10
The working fluid supply source that supplies the working fluid to the internal space 34 and the working fluid supply source that supplies the working fluid to the drive cylinder 14 may be the same supply source or separate supply sources.

[0014]

According to the load balancing device of the first aspect, the operator can move the load by directly operating the load.

[Brief description of the drawings]

FIG. 1 is a drawing showing a configuration of a load balancing device according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a load detector and an operation regulator of the load balancing device shown in FIG.

FIG. 3 is a drawing showing a configuration of a load balancing device according to another embodiment of the present invention.

FIG. 4 is a drawing for explaining a conventional load balancing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Load detection part 12 ... Operation regulator 14 ... Driving cylinder 30 ... 2nd support member 32 ... 1st support member 34 ... Internal space 36 ... Steel ball 37a ... Recess 38: Elastic body

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuhiro Mizutani 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Automobile Co., Ltd. Within Giken (72) Inventor Yukiya Abe Kochi City, Aichi Prefecture

Claims (1)

[Claims] A first support member for supporting the load, a second support member for movably guiding the first support member, and a cylinder interposed between the second support member and a stationary part. A first working fluid supply source for supplying working fluid to a sealed internal space formed between the first support member and the second support member, and controlling the flow of the working fluid into and out of the internal space. A first control means for keeping the relative positional relationship between the first support member and the second support member constant at all times; a second working fluid supply source for supplying working fluid to the cylinder;
In a load balancing device having a second control unit that controls inflow and outflow of a working fluid into and from the cylinder based on the pressure of the internal space, a force acting between the first support member and the second support member is A load balancing device, comprising: a lock mechanism for inhibiting movement of the first support member and the second support member so that the relative positional relationship between the first support member and the second support member does not change when the force is not more than a predetermined force.