JPS5933520B2 - machine hand - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION When producing a wide variety of products in small quantities, it may be desirable to hold products with different diameters so that their centers are in the same position.

An example of this is when a shaft material is grasped with a machine hand and mounted on a chuck of a lathe. The present invention
The present invention relates to a machine hand suitable for use in such applications. Conventionally, as a device suitable for such uses, a device in which a pair of fingers always open and close while remaining parallel has been proposed (hereinafter referred to as a parallel movement type machine hand), as shown in Japanese Utility Model Application Publication No. 49-100368. .

However, since this type of device moves the fingers in a straight line, the structure becomes complicated. Furthermore, it is desirable that the distance between the tips of the pair of fingers is wide before holding the workpiece.
This is because the positioning accuracy of the fin car with respect to the workpiece can be reduced. However, parallel moving machines...
In this case, wide spacing between the tips of the fingers increases the time required to open and close the fingers, which is undesirable. The pair of fingers each has a fulcrum, and the fingers rotate in opposite directions around this fulcrum to open and close (hereinafter referred to as a rotating machine hand), compared to a parallel moving machine hand. The structure is simple, and even if the distance between the tips of the pair of fingers in the open state is considerably wide, the opening/closing operation can be made faster.

However, in the case of this rotating machine hand, if the diameter of the work to be gripped differs, the center position of the work with respect to the position of the holder that supports the fingers will differ.

The present invention has been made in view of the above, and its purpose is to easily adjust the workpiece relative to the holder even if the diameter of the workpiece to be gripped is different by simply adding a few parts to the rotary machine hand. To construct a machine hand that can always keep the center position at a constant position.

Another object of the present invention is to construct a machine which can speed up the opening and closing operations even though the distance between the tips of the pair of fingers in the open state is considerably wide.

The principle of the present invention will be described as follows.

As shown in Fig. 1, the radius of the workpiece is D, ,D2,
Consider different workpieces from D3, and assume that the centers of these workpieces are supported at the same point 0. Further, the center of rotation of one finger (only one finger will be described here) is assumed to be 02. Draw tangents Ll, L2, L3 from 02 to each workpiece o Each tangent L1? The distances from the intersection points PlP2 and P3 of L2 and L3 with the workpiece to point 02 are different.

Therefore, if the length of the finger is set to 02P1 when supporting a workpiece with radius D, 02P2 when supporting a workpiece with radius D2, and 02P3 when supporting a workpiece with radius D3, the workpiece with radius D1 will also be D2.
Both the workpiece and the workpiece D3 can be supported with their centers at the same position 01 relative to point 02. Therefore, in the present invention, in a rotating machine hand, the finger is divided into a rotating finger and a sliding finger.

The sliding finger 1 is slidable relative to the rotating finger 1. A guide means is provided so that the contact points of the slide finger 1 with the workpiece are Pl, P2, and P3, thereby regulating the sliding amount of the slide finger 1 with respect to the rotating finger 1. The guide path of the guide means is not calculated mathematically, but if a certain point Pa of the slide finger is on L, and it is at the position shown in the figure, then on L2 it will shift to Pb, and on L3 it will move to Pb. All you have to do is move to PC. Here 02Pb=02Pa+L
2-L, and 02PC=02Pa+L3-L1. The guide means guides a part Pa of the slide finger 1 along a smooth line 1n connecting PaPbPc. In addition, in this figure, when a workpiece with radii Dl and D2 is held, the workpiece escapes downward in the figure, but this is just a diagram of the principle, and in reality, for example, one finger has two claws each. Ori, husband Pl, P2, P
Think of it as holding the workpiece with the claws provided between the two. At this time, it is preferable that the pawl is pivotally attached to the finger by a pin so that it can rotate to some extent. By doing this, even if the diameter of the workpiece differs with the rotary machine hand, the center of the workpiece relative to the holder can be held at a constant position.

Furthermore, since the fingers rotate about their respective pivot points, a machine hand that can open and close quickly can be configured even if the distance between the tips of the fingers in the open state is considerably wide. I can do it. 2 to 5 are diagrams showing embodiments of the machine hand of the present invention. This example will be explained below. A holder 2 is fixed to the end of the arm 1. The holder 2 is composed of two plates 3 and 4 arranged in parallel, and a connecting plate 5 that connects these two plates. Then, the connecting plate 5 is fixed to the end of the arm 1. A pair of fingers 6 and 7 are provided. These fingers 6, 7 are rotating fingers 6a, 7a and slide fingers 6b, 7, respectively.
It consists of b. The rotating fingers 6a, 7a are bent at their midpoints, and the midpoints are pivotally connected to the holder 2 by pins 6c, 7c, respectively, as pivoting means. Rotating fingers 6a, 7a
Elongated holes 6e and 7e are provided at the ends of sides 6d and 7d, and a rod 8 of a cylinder that reciprocates linearly as a driving means is engaged with these elongated holes. Sides 6f, 7 of rotating fingers 6a, 7a
Grooves 6g and 7g are provided in f. The widths of the grooves 6g and 7g are made wider as they get closer to the bottom. The slide fingers 6b and 7b have a wedge-shaped cross section and fit into the grooves 6g and 7g, respectively. The slide fingers 6b, 7b are slidable relative to the rotary fingers 6a, 7a in the direction in which the grooves 6g, 7g extend. Slide finger 6
Engagement pieces 6h and 7h are provided on b and 7b, respectively. plate 3
, 4, respectively, a guide means 61 that engages with the engagement pieces 6h, 7h,
A hole is provided as 71. This hole engages with the engaging pieces 6h, 7h to regulate the position of the slide fingers 6b, 7b with respect to the rotating fingers 6a, 7a, and has a circular cross section supported by both the slide fingers 6b, 7b. Center 0 of work 9
1 is provided so as to guide slide fingers 6b and 7b so that they are at the same point with respect to the holder 2 even if the diameter of the workpiece changes. Note that claws 10 and 11 6j and 7j are side plates of the holder 2. When opening the fingers 6 and 7 in the structure as described above, the rod 8 is moved to the second
There is no diagram, and if you look at Figure 4, move it farthest to the bottom of the diagram.

Then, the rotating fingers 6a, 7a are connected to the pins 6c, 7c.
The rotating finger 6a rotates in a left rotation direction, and the rotation finger 7a rotates in a right rotation direction, with the rotation finger 6a being a fulcrum. Due to this, the slide fingers 6b, 7b
are guided by the guide means 61, 71, and the pins 6c, 7
The distance from c to the claws 6j, 7j becomes shorter. Work 9
When the rod 8 is between the claws 6j and 7j, pull the rod 8 toward the arm 1 side.

Then, the rotating finger 6a rotates to the right, and the rotating finger 7a
rotates to the left. Accordingly, the slide fingers 6b, 7b are guided by the guide means 61, 71, and the claws 61, 71 move so as to restrict the center of the work 9 to a constant position 01 with respect to the holder 2. And work 9
grasp.

[Brief explanation of drawings]

FIG. 1 is a diagram used to explain the principle of the machine hand of the present invention, FIG. 2 is a partially cutaway front view showing an embodiment of the machine hand of the present invention, and FIG. 3 is a cutaway front view showing the operating state. Figure 4 is a diagram showing Figure 2 cut along line 4-4;
The figure is a diagram showing FIG. 2 cut along line 5--5. 2 is a holder; 6a and 7a are rotating fingers; 6b and 7b are sliding fingers; 6c and 7c are pins that are an example of a pivoting means; 61 and 71 are holes that serve as guide means; and 8 is an example of a driving means. Showing cylinder rod.

Claims (1)

[Claims] 1. A holder, a pair of rotating fins, means for pivotally connecting each of these rotating fingers so as to be rotatable with respect to the holder, and a means for pivoting the pair of rotating fins around the pivoting means. drive means capable of driving in different directions respectively; a slide finger provided so as to be able to slide on the rotary finger; and a drive means provided on the holder to engage with the slide finger and drive the rotary finger in different directions; A machine hand comprising a guide means for regulating the position of the slide finger and guiding the workpiece having a circular cross section supported by both the slide fingers so that the center of the workpiece is always at the same point with respect to the holder.