JPS6319589A - Parallel link type support mechanism - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a weight balance device for a parallel link support mechanism that supports a supported object vertically in a vertically movable manner.

(Prior Art) A parallel link mechanism is used as a mechanism for supporting a relatively lightweight supported object, such as a microscope main body of a surgical microscope, such that it can move up and down in a vertical plane.

In order to statically support an object at a predetermined spatial position, a weight balancing device is known in which a tension or compression coil spring is strung diagonally across a parallel link mechanism to balance the weight of the object. It is.

(Problems to be Solved by the Invention) However, in the conventional parallel link type support device, if there is a large change in weight due to replacement or addition of objects to be supported, there is a drawback that the weight cannot be balanced by the coil spring.

The present invention has been made by focusing on such conventional drawbacks,
The purpose is to provide a parallel link type support mechanism that can maintain weight balance even if the weight of the supported object changes.

(Means for Solving the Problems) In order to achieve this object, the present invention includes a fixed link, a main link whose one end is pivotally connected to the upper part of the fixed link by a first pivot so as to be movable up and down, A sub link is disposed below the main link in parallel with the main link and has one end pivotally connected to the lower part of the fixed link by a second pivot shaft so as to be vertically movable; The third end is attached to the end and the other end of the secondary link.
．． A parallel link mechanism is provided, which includes a support link for attaching a supported object that is pivotally connected to a fourth pivot, and a parallel link in which a compression elastic member is interposed between the fixed link side and the third pivot. a mold support mechanism, the first part on the fixed link;
．． A movable fulcrum that is movable on the fixed link side is provided on the fixed link side, and is movable on an inclined axis that intersects with the vertical axis that is inclined on the side opposite to the supported object side with respect to the vertical axis connecting the second pivot axis, and The present invention is characterized by a parallel link type support device interposed between the third pivot and the movable fulcrum.

(Function) With the above configuration, when the movable fulcrum moves on the inclined axis,
The intersection angle between the link and the compression elastic member and the length of the compression elastic member change, and an upward reaction force corresponding to the change in weight of the supported object acts on the support link of the parallel link mechanism, constantly maintaining weight balance. can be kept.

(Example) FIG. 1 shows the configuration of a parallel link type support mechanism (hereinafter simply referred to as a parallel link arm) according to the present invention, in which a parallel link arm 10 includes a fixed link 11, a main link 12, a support link 13, It is generally composed of a sub link 14, a gas spring 30, and a balance adjustment mechanism section 40.

The fixed link 11 has an arm 111, and a vertically oriented shaft 112 is fixed to the lower surface of the arm 111. Further, 100 is an arm attached to a stand (not shown), and this arm 100
A bearing 101 is formed at the tip. Moreover, axis 1
12 is rotatably held by the bearing 101, making the fixed link 111 rotatable in a horizontal plane.

At the top and bottom of the fixed link 11 are first. Second axis 21°2
2 is planted horizontally, and this pivot 21.
A main link 12 and a sub link 14 each having a U-shaped cross section are connected to the main link 22 so as to be able to pivot vertically in a vertical plane. The other ends of the main link 12 and the sub link 13 each have a third link horizontally planted in the support link 13. Fourth
is pivotally connected to pivots 23, 24 of. The fixed link 11, main link 12, sub link 14, and support link 13 constitute a parallel link mechanism with pivots 21 to 24 as intersection points.

A vertical bearing 130 is formed in the support link 13,
A supported object 1, for example, a surgical microscope main body M is attached to this bearing link 130, and its rotation around this axis is usually restricted by a tension screw 131.

A gas spring 30, which is a compression elastic member, is attached to the pivot 23.
are pivotally connected at one end. The movable piece 41 is moved up and down along its axis O1 by a feed screw 43 rotated by a handle 42.

The axis 03 of the feed screw 43 is arranged parallel to the inclined axis 02 of the shaft 31 as a movable fulcrum. Here, the tilt axis is 0
□That is, the inclination angle θ of the inclination axis with respect to the vertical axis 01 is determined by the weight of the parallel link arm, the gas pressure and spring constant of the gas spring 30, and the main link 12 and the gas spring 3.
It can be determined mechanically or experimentally based on the intersection angle α with 0 and the weight of the object to be supported.

Based on mechanical analysis and experiments, the present invention has determined that the weight of the supported object is 5.
When the weight is 5kg to 17.5kg, the inclination angle θ is 7'20' to
In the embodiment shown in FIG. 1, the inclination angle θ is set to θ=121.

An index 44 is attached to the movable piece 41 as shown in FIG.
13, and by rotating the handle 42, the movable piece 41 and the shaft 31 are moved by adjusting the index to the corresponding weight scale of the weight scale 114 according to the weight W of the supported object M, Balance the weight.

In the present invention, the tilt axis 02 is not tilted rightward in the figure with respect to the vertical axis O□, but is tilted leftward by θ.

As a result, in the present invention, the tilt axis 0□ is changed from the vertical axis 0
Compared to the case where it is tilted by θ to the right in the figure with respect to □,
It has excellent support capacity. This point will be explained based on the following table. In the zero-order table, the left and right inclination angles of the inclination axis 01 with respect to the vertical axis 0□ are the same, and the link 1
It shows the length, angle, component force, spring force, etc. of the gas spring 30 when the shaft 31 is moved up and down with 2.14 held horizontally.

As can be seen from this table, when the tilt axis 02 is tilted to the right, if the spring force of the gas spring 30 increases or decreases as the axis 31 moves up or down, the spring force of the gas spring 30 increases or decreases as the spring force increases or decreases. Since the upward component of the force decreases or increases, the increase or decrease in the spring force of the gas spring 30 cannot be used effectively. In contrast, in the present invention, even if the spring force of the gas spring 30 increases or decreases as the shaft 31 moves downward or upward, the upward component force exerted by the gas spring 30 also increases or decreases with this increase or decrease. Therefore, the increase and decrease of the gas spring 30 can be effectively utilized.

Therefore, if the amount of vertical movement of the shaft 31 is the same, the amount of change in the upward component of the spring force is greater in the case of the present invention than in the case of the inclined axis 02.
is larger than when the tilt axis 0□ is tilted to the right, so the weight range that can be supported by the support link 13 of the present invention can be made larger than when the tilt axis 0□ is tilted to the right. In other words, when the weight range that can be supported by the support link 13 is the same, the amount of movement of the shaft 31 can be smaller in the present invention than when the tilt axis 0□ is tilted to the right.

(Effect) As described above, according to the present invention, the first
．． A movable fulcrum movable on the fixed link side is provided on the fixed link side and is movable on an inclined axis that intersects with the vertical axis that is inclined on the side opposite to the supported object side with respect to the vertical axis connecting the second pivot axis. Since the structure is such that it is interposed between the third pivot and the movable fulcrum, even if the weight of the supported object changes, the balance adjustment mechanism can be operated to connect the main link between the gas spring, which is a compressive elastic member, etc. By changing the intersection angle with the compression elastic member and the length of the compression elastic member, weight balance can be maintained at all times.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a support mechanism according to the present invention, and FIG. 2 is a diagram showing the configuration of an index portion thereof. 10... Parallel link arm, 11... Fixed link, 12... Main link, 13...
Sub link, 14...Support link, 21...
・First axis. 22...Second axis, 23...Third axis. 24... Fourth pivot, 30... Gas spring (compression resilient member), 31...
- Axis (movable fulcrum), 40...balance adjustment mechanism. 0□... Vertical axis, 02... Inclined axis.

Claims (4)

[Claims] (1) a fixed link, a main link whose one end is pivotally connected to the upper part of the fixed link by a first pivot shaft so as to be able to move vertically; and a main link which is disposed below the main link in parallel with the main link and which a sub link whose one end is movably pivoted to the lower part of the fixed link by a second pivot, and whose upper and lower parts are connected to the other end of the main link and the other end of the sub link with third and fourth pivots. A parallel link type support mechanism is provided, which includes a support link for attaching a supported object, which is pivotally connected to the support link, and a compression resilient member is interposed between the fixed link side and the third pivot shaft. and a movable fulcrum movable on the fixed link side on an inclined axis that intersects the vertical axis connecting the first and second pivots on the fixed link with an inclination toward the side opposite to the supported object side. A parallel link type support mechanism, characterized in that the compressive resilient member is interposed between the third pivot shaft and the movable fulcrum. (2) The parallel link type support mechanism according to claim 1, wherein the movable fulcrum is moved by a feed screw whose rotation axis is an axis parallel to the tilt axis. (3) The parallel link type support mechanism according to claim 2, wherein the compression resilient member is a gas spring. (4) The parallel link type support mechanism according to any one of claims 1 to 4, wherein the angle of intersection of the inclined axis with the vertical axis is in the range of 7° to 16°. .